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Theoretical and Experimental Stress Analysis of Cam With Simple Harmonic Motion
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Cams are considered as one of the most important mechanical components that depends the contact action to do its job and suffer a lot of with drawbacks to be predicted and overcame in the design process. this work aims to investigate the induced cam contact and the maximum shear stress energy or (von misses) stresses during the course of action analytically using Hertz contact stress equation and the principal stress formulations to find the maximum stress value and its position beneath the contacting surfaces. The experimental investigation adopted two dimensions photoelastic technique to analyze cam stresses under a plane polarized light. The problem has been numerically simulated using Ansys software version 15 as FE solver and depending on Lagrange and Penalty contact algorithm. The effect of cam geometry, characterized by some parameters such as follower radius, face width, rise and return angles, and modulus of elasticity on the contact stress is investigated aiming  to minimize the induced stresses.

 

 

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Publication Date
Thu Aug 03 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Variation of Charging Parameters on A dust Grain in Laboratory Plasma by Using Orbital-Motion Limited Theory
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       Using orbit- motion limited theory, as the exact theory in calculating the ion and electron current in dusty plasma, the variations of charge number on a dust grain in Ar-plasma are studied by changing various charging parameters. Most of dependences of charge number on plasma parameters in this paper take into account the close packed effect.

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Publication Date
Wed Jan 01 2020
Journal Name
Archives Of Clinical Infectious Diseases
Toxoplasmosis and Risk of Endothelial Dysfunction: Role of Oxidative Stress and Pro-Inflammatory Mediators
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Background: Infection with Toxoplasma gondii (T. gondii) leads to activation of T-helper cells (Th-1 and Th-2) which are involved in the synthesis and release of different cytokines which may lead to endothelial dysfunction. Objectives: To evaluate the endothelial function in patients with acute toxoplasmosis. Methods: This case-control study involved 31 patients with toxoplasmosis aged 19 - 47 years matched with 20 healthy subjects. Anti-T. gondii antibody (IgG, IgM, IgA) was determined by direct antigen-antibody reaction. Interleukin-6(IL-6), endothelin-1 (ET-1) and human malondialdehyde (MDA) serum levels were measured. Results: IgM, IgG and IgA levels were high in the infected patients compared with controls (P < 0.01). Furthermore, IL-

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Publication Date
Mon Jan 02 2017
Journal Name
Journal Of Educational And Psychological Researches
Toward a theoretical model of the terrorist personality and differentiation from psychopathic personality
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The current theoretical research targeted to construct a model of terrorist personality and its differentiation from psychopathic personality . Several assumptions or theories of perspectives of psychopathic personality have been compared with the terrorist personality studies that concerned . The suggested theoretical  model is interrupting the terrorist personality . The conclusions , discussions are mentioned. Finally, recommendation is suggested .

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Publication Date
Sun Apr 16 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Theoretical Design of Electrostatic Lens Accelerating and Decelerating Operated Under Different Magnification Conditions
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  In this paper,  design computationl investigation in the field of charged-particle optics with the aid of numerical analysis methods  under the absence of space charge effects. The work has been concentrated on the design of three-electrode  einzel electrostatic  lens accelerating and decelerating operated under different magnification conditions.     The potential field distribution of  lens has been represented by exponential function.  The paraxial-ray equation has been solved for the proposed field to determine the trajectory of charged-particles traversing in the lens.  From The axial  potential distribution and its first and second derivatives, the optical propertie

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Publication Date
Fri Feb 02 2024
Journal Name
Iraqi Journal Of Science
Using Sensitivity Analysis in Linear Programming with Practical Physical Applications
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Linear programming currently occupies a prominent position in various fields and has wide applications, as its importance lies in being a means of studying the behavior of a large number of systems as well. It is also the simplest and easiest type of models that can be created to address industrial, commercial, military and other dilemmas. Through which to obtain the optimal quantitative value. In this research, we dealt with the post optimality solution, or what is known as sensitivity analysis, using the principle of shadow prices. The scientific solution to any problem is not a complete solution once the optimal solution is reached. Any change in the values of the model constants or what is known as the inputs of the model that will chan

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Publication Date
Thu Aug 01 2024
Journal Name
Fuel
Experimental influence assessments of water drive and gas breakthrough through the CO2-assisted gravity drainage process in reservoirs with strong aquifers
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Mature oil reservoirs surrounded with strong edge and bottom water drive aquifers experience pressure depletion and water coning/cresting. This laboratory research investigated the effects of bottom water drive and gas breakthrough on immiscible CO2-Assisted Gravity Drainage (CO2-AGD), focusing on substantial bottom water drive. The CO2-AGD method vertically separates the injected CO2 to formulate a gas cap and Oil. Visual experimental evaluation of CO2-AGD process performance was performed using a Hele-Shaw model. Water-wet sand was used for the experiments. The gas used for injection was pure CO2, and the “oleic” phase was n-decane with a negative spreading coefficient. The aqueous phase was deionized water. To evaluate the feasibilit

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Publication Date
Mon Dec 20 2021
Journal Name
Baghdad Science Journal
Temperature Stress on Physiological and Morphological Traits in Rhizophora apiculata
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Global warming has had considerable effects on vital ecosystems, which has also been caused by increased temperatures and CO2 that follow changes in different abiotic factors, which poses threats to mangrove forests environment. This research was conducted to examine the physiological and morphological characteristics of the Rhizophora apiculata mangrove regarding higher air temperature for the variety of tree species that respond to climate change. Seedlings were cultivated for three months in regulated growth chambers with three varying temperatures of 38°C, 21°C under CO2 at 450 ppm, and ambient CO2 concentration i.e., 450 ± 20 ppm under average temperature at 28°C as the control condition

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Publication Date
Mon Mar 28 2022
Journal Name
The Open Dentistry Journal
Depression, Anxiety and Stress Among Dentists During COVID-19 Lockdown
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Introduction:

The objective of this study was to investigate the levels of depression, anxiety, and stress among dentists during covid-19 lockdown and to investigate the relationship between stress and each mental health state.

Methods:

A cross-sectional survey on 269 dentists was conducted using DASS-21 and PHQ-9 questionnaires. Bivariate and multivariate models were constructed and the odds ratio (OR) was calculated to assess the strength of the association between an independent categorical variable and the outcome.

Results and Discussion:

Being unsatisfied with the job was as

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Publication Date
Wed Sep 15 2021
Journal Name
Journal Of Baghdad College Of Dentistry
Salivary Cortisol as a Stress Biomarker and Total Viable Count of Salivary Bacterial Microbiome among COVID-19 Patients
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Background: The COVID-19 virus outbreak had a massive effect on many parts of people's lives, as they were advised to quarantine and lockdown to prevent the virus from spreading, which had a big impact on people's mental health, anxiety, and stress. Many internal and external factors lead to stress. This negatively influences the body's homeostasis. As a result, stress may affect the body's capacity to use energy to defend against pathogens. Many recent investigations have found substantial links between human mental stress and the production of hormones, prohormones, and/or immunological chemicals. some of these researches have verified the link between stress and salivary cortisol levels. The aim of this study is to measure salivary corti

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Publication Date
Sat Dec 02 2023
Journal Name
Journal Of Engineering
Simulation and Experimental Investigation of Performance and Flow Behavior for Steam Ejector Refrigeration System
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The ejector refrigeration system is a desirable choice to reduce energy consumption. A Computational Fluid Dynamics CFD simulation using the ANSYS package was performed to investigate the flow inside the ejector and determine the performance of a small-scale steam ejector. The experimental results showed that at the nozzle throat diameter of 2.6 mm and the evaporator temperature of 10oC, increasing boiler temperature from 110oC to 140oC decreases the entrainment ratio by 66.25%. At the boiler temperature of 120oC, increasing the evaporator temperature from 7.5 to 15 oC increases the entrainment ratio by 65.57%. While at the boiler temperature of 120oC and

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