Preferred Language
Articles
/
alkej-129
The Stability Conditions of the Pump Structure Vibration
...Show More Authors

 The general approach of this research is to assume that the small nonlinearity can be separated from the linear part of the equation of motion. The effect of the dynamic fluid force on the pump structure system is considered vibrates at its natural frequency but the amplitude is determined by the initial conditions. If the motion of the system tends to increase the energy of the pump structure system, the vibration amplitude will increase and the pump structure system is considered to be unstable. A suitable MATLAB program was used to predict the stability conditions of the pump structure vibration. The present research focuses on fluid pump problems, namely, the role played by damping coefficient C, damping factor D and angular speed ω (termed the ratio () and the determining stability of a centrifugal pump structure. The data demonstrate substantial rotor dynamic effects, a destabilizing chart appears to be inversely proportional to the D, C, and ω, and resonance changes significantly with flow rate.

View Publication Preview PDF
Quick Preview PDF
Publication Date
Thu Feb 24 2022
Journal Name
Journal Of Educational And Psychological Researches
Question Asking Skills: Levels, Conditions, Classification, and Types
...Show More Authors

The research aims to know the question asking skills in terms of levels, conditions, classification, and types. The research limited to the literature that dealt with the importance of questioning for students and teachers. The most important term used in the research is the skill (Ryan defined it as "the ability to perform with great efficiency, accuracy, and ease). The results of the research are as follows: 1. the questions asked by the schoolteacher within the assessment of students' learning. 2. Teachers should focus on the lower levels of learning (remembering, understanding and comprehension) and then evaluating students at the higher levels (synthesis and evaluation). 3. Teacher with good knowledge can skillfully use the question

... Show More
View Publication Preview PDF
Publication Date
Fri Feb 01 2019
Journal Name
Journal Of Economics And Administrative Sciences
Impact of quantitative (indirect) instruments of monetary policy on some indicators of financial stability in Iraq for the period (2003-2016)
...Show More Authors

The indirect monetary policy tools led to financial stability for the period being studied through the use of indicators of financial stability (aggregate) to show the effect of the foreign reserves of the Central Bank of Iraq and its indirect instruments in achieving financial and economic stability, especially after the significant decline in oil prices and dependence of the Iraqi economy on Oil (rent) and lower reserves of the Central Bank of Iraq after 2014 and now compared to previous years, the goal of this research is to achieve financial stability according to selected indicators and achieve an optimal monetary policy to achieve the development goals of The economic policy in the country. Standard models were used to test

... Show More
View Publication Preview PDF
Crossref (1)
Crossref
Publication Date
Tue Feb 05 2019
Journal Name
Journal Of The College Of Education For Women
The Concept of Value in De Saussair Linguistics and their Extension in the Book (Arabic Language, Its Meaning and Structure) by Tammam Hassan
...Show More Authors

This research was distributed into two sections, the first section was concerned with the concept of value for De Saussair and its methodological impact on his linguistic structural conceptions with respect of the distinction between synchronism and diachronism, the value role of linking function between the sounds and the though, the basing of his theoretical conception on the language being a form and not a material according to this principle and the value impact on the demonstration that the linguistic element acquires its functional importance from the relations inside the language system. It also stopped at the methodological impact of value on defining the analytical linguistic unit and the value role in semantics through the prin

... Show More
View Publication Preview PDF
Publication Date
Wed Jun 30 2004
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Formulation of Multi-Purpose Grease for Use under Severe Conditions
...Show More Authors

View Publication Preview PDF
Publication Date
Sun Jul 09 2023
Journal Name
Journal Of Engineering
Effect of Operating Conditions on Reverse Osmosis (RO) Membrane Performance
...Show More Authors

The aim of this research is to study the effect of high concentrations of salts, pressure and temperature on the performance of the RO membrane with time. Four different (Na2CO3) concentrations (5000, 15000, 25000 and 35000) ppm and various pressures such as (1, 3 and 5) bars at different temperatures of the feed solution (i.e., 25, 35 and 45) ◦C were used in this work. It was found that, as the concentration of salt and feed temperatures increase, the rejection of the salt decrease. While the salt rejection of the membranes increases with increase of transmembrane pressure.

View Publication Preview PDF
Crossref (12)
Crossref
Publication Date
Tue Mar 20 2018
Journal Name
Offshore Technology Conference Asia
Prediction of Hydrate Phase Equilibrium Conditions for Different Gas Mixtures
...Show More Authors
Abstract<p>Gas hydrate formation poses a significant threat to the production, processing, and transportation of natural gas. Accurate predictions of gas hydrate equilibrium conditions are essential for designing the gas production systems at safe operating conditions and mitigating the problems caused by hydrates formation. A new hydrate correlation for predicting gas hydrate equilibrium conditions was obtained for different gas mixtures containing methane, nitrogen and carbon dioxide. The new correlation is proposed for a pressure range of 1.7-330 MPa, a temperature range of 273-320 K, and for gas mixtures with specific gravity range of 0.553 to 1. The nonlinear regression technique was applie</p> ... Show More
Scopus (6)
Scopus Crossref
Publication Date
Mon Jan 01 2018
Journal Name
Fuel
Wettability of nanofluid-modified oil-wet calcite at reservoir conditions
...Show More Authors

Nanofluids, liquid suspensions of nanoparticles (Np), are an effective agent to alter the wettability of oil-wet reservoirs to water-wet thus promoting hydrocarbon recovery. It can also have an application to more efficient carbon storage. We present a series of contact angle (θ) investigations on initially oil-wet calcite surfaces to quantify the performance of hydrophilic silica nanoparticles for wettability alteration. These tests are conducted at typical in-situ high pressure (CO2), temperature and salinity conditions. A high pressure–temperature (P/T) optical cell with a regulated tilted surface was used to measure the advancing and receding contact angles at the desired conditions. The results showed that silica nanofluids can alte

... Show More
Scopus (150)
Crossref (140)
Scopus Clarivate Crossref
Publication Date
Tue Jul 06 2021
Journal Name
Animals
Comparison of the Genetic Structure of Invasive Bigheaded Carp (Hypophthalmichthys spp.) Populations in Central-European Lacustrine and Riverine Habitats
...Show More Authors

Bigheaded carps (bighead carp, Hypophthalmichthys molitrix, and silver carp, Hypophthalmichthys nobilis) and their hybrids play an important ecological and economic role in their original habitat, while their introduced stocks may pose serious ecological risks. To address questions about the persistence and invasiveness of these fish, we need to better understand their population structures. The genetic structures of bigheaded carp populations inhabiting Lake Balaton and the Tisza River were examined with ten microsatellite markers and a mitochondrial DNA marker (COI). The Lake Balaton stock showed higher genetic diversity compared with the Tisza River stock. Based on hierarchical clustering, the Tisza population was characterized o

... Show More
View Publication
Crossref (9)
Crossref
Publication Date
Tue May 30 2023
Journal Name
Iraqi Journal Of Science
Ground State Structure of Helium and Phosphorus Isotopes using the Radial Wave Functions of Harmonic-Oscillator and Hulthen Potentials
...Show More Authors

     The ground state density distributions and electron scattering Coulomb form factors of Helium (4,6,8He) and Phosphorate (27,31P) isotopes are investigated in the framework of nuclear shell model. For stable (4He) and (31P) nuclei, the core and valence parts are studied through Harmonic-oscillator (HO) and Hulthen potentials. Correspondingly, for exotic (6,8He) and (27P) nuclei, the HO potential is applied to the core parts only, while the Hulthen potential is applied to valence parts. The parameters for HO and Hulthen are chosen to reproduce the available experimental size radii for all nuclei under study. Finally, the CO component of electron scattering charge form factors are also investigated. Unfortunately, there is no

... Show More
View Publication
Scopus (2)
Scopus Crossref
Publication Date
Wed Sep 01 2010
Journal Name
Materials &amp; Design
Influence of glass addition and sintering temperature on the structure, mechanical properties and dielectric strength of high-voltage insulators
...Show More Authors

View Publication
Scopus (13)
Crossref (10)
Scopus Clarivate Crossref