Preferred Language
Articles
/
alkej-544
Semi-Active Damping of Mechanical Vibrating Systems Using Variable Stiffness Actuator
...Show More Authors

      In this research, a variable stiffness actuator is proposed to enhance the damping of the mechanical vibrating system. The frequency response analysis of the vibrating system is dependant in order to analyze and synthesis this semi-active damping, where the suggested process is using active filter to estimate the present frequency of the vibration system, and this will limit the value of the stiffness of the vibrated system. Two active filter s are needed, low-pass-filter (LPF) to choose the higher stiffness of the actuator at small frequencies as well as more damping and high-pass-filter (HPF) to choose the lower stiffness of the actuator at high frequencies as well as more damping, and so the result will be good damping as a wholre.

      These smart systems and others will increase the importance of the mechatronics systems. This job has a case study to explain the semi-active damping system proposed.

View Publication Preview PDF
Quick Preview PDF
Publication Date
Fri Jul 21 2023
Journal Name
Journal Of Engineering
DESIGN OF A VARIABLE GAIN NONLINEAR FUZZY CONTROLLER AND PERFORMANCE ENHANCEMENT DUE TO GAIN VARIATION
...Show More Authors

In this paper, variable gain nonlinear PD and PI fuzzy logic controllers are designed and the effect of the variable gain characteristic of these controllers is analyzed to show its contribution in enhancing the performance of the closed loop system over a conventional linear PID controller. Simulation results and time domain performance characteristics show how these fuzzy controllers outperform the conventional PID controller when used to control a nonlinear plant and a plant that has time delay.

View Publication Preview PDF
Crossref
Publication Date
Sun Jan 01 2012
Journal Name
Journal Of Engineering
DESIGN OF A VARIABLE GAIN NONLINEAR FUZZY CONTROLLER AND PERFORMANCE ENHANCEMENT DUE TO GAIN VARIATION
...Show More Authors

In this paper, variable gain nonlinear PD and PI fuzzy logic controllers are designed and the effect of the variable gain characteristic of these controllers is analyzed to show its contribution in enhancing the performance of the closed loop system over a conventional linear PID controller. Simulation results and time domain performance characteristics show how these fuzzy controllers outperform the conventional PID controller when used to control a nonlinear plant and a plant that has time delay.

Publication Date
Mon Mar 07 2022
Journal Name
Journal Of Educational And Psychological Researches
The Mental Disorder of mothers as a Mediating Variable Between Marital adjustment and Kindergarteners Development
...Show More Authors

This current study aimed to explore the mediation effects of mother's mental health symptoms between marital adjustment and child development aspects. (666) participants of mothers and their children were the sample of the study. The researchers used the marital adjustment scale prepared by Manson, Morse, Lerner, Arthur, as well as, a package of tests for some aspects of growth Kindergarten children prepared by Kenawi and Mohamed (1999). In addition, theyemployed a list of modified symptoms (Symptom Checklist-90- Revised (SCL) -90-, prepared by Derogatis, Lipman and Lipogun & Cov (1976), The results of the current study showed there is a statistically significant relationship between marital adjustment and the symptoms of mental diso

... Show More
View Publication Preview PDF
Publication Date
Mon Oct 01 2012
Journal Name
Computers & Mathematics With Applications
Boundary element formulations for the numerical solution of two-dimensional diffusion problems with variable coefficients
...Show More Authors

View Publication
Crossref (25)
Crossref
Publication Date
Sun Mar 01 2026
Journal Name
Civil Engineering Journal
Flexural Response of RC Beams with Variable-Width Prestressed and Non-Prestressed CFRP Plate Strengthening
...Show More Authors

This experimental research was conducted to quantify the combined effect of the external bonded Carbon Fiber Reinforced Polymer (CFRP) plate width and prestressing on the flexural performance of reinforced concrete (RC) beams in terms of strength improvement. Seven beams (one control and six strengthened) were subjected to two-point loading tests. The experimental methodology consisted of the testing of three different widths of the CFRP plates (25, 40, and 60 mm) in non-prestressed and prestressed conditions. Prestressing was accomplished by tensioning the plates to 23% of the CFRP tensile strength using a novel, locally developed mechanical anchorage system, which is one of the key experimental contributions that distinguishes thi

... Show More
View Publication
Crossref
Publication Date
Sun Jul 03 2011
Journal Name
Journal Of Educational And Psychological Researches
Effect of using the active learning in the achievement of third grade intermediate students in mathematics and them tendency towards the study of its
...Show More Authors

Current research aims to find out:

  1. Effect of using the active learning in the achievement of third grade intermediate students in mathematics.
  2. Effect of using of active learning in the tendency towards the study of mathematics for students of third grade intermediate.

In order to achieve the goals of the research, the researcher formulated the following two hypotheses null:

  1. There is no difference statistically significant at the level of significance (0.05) between two average of degrees to achievement

... Show More
View Publication Preview PDF
Publication Date
Wed Dec 01 2010
Journal Name
Al-khwarizmi Engineering Journal
Evaluation of Mechanical Properties of Particulate Composites
...Show More Authors

A series of experiments have been taken out to test the validity of the effect of Aluminum hydrate on its interaction with Aluminum during sintering of aluminum metal matrix. The approach has been shown to be valid and several compositions have been fabricated. The alumina hydrate particle size and the amount of alumina hydrate in the composites are also shown to have an influence on the extent of densification.

The densities for all sintered specimens were measured. It was found that density increases as compaction pressure increases, the density decreases as particles size increases. At 400 MPa there is an optimum particles size which is (90-125) µm to reach maximum density and the density decreases as volume fraction increase

... Show More
View Publication Preview PDF
Publication Date
Fri May 08 2020
Journal Name
Electronic Theses And Dissertations
Improving Nitrogen Management in Potatoes with Active Optical Sensors
...Show More Authors

Nitrogen (N) fertilizer rate is important for high yield and good quality of potato tubers. In this dissertation, I seek to study the response of different potato cultivars under different N fertilizer rates and how that can impact tuber quality, examine the performance of active optical sensors in improving a potato yield prediction algorithm, and evaluate the ability of active optical sensors (GreenSeeker (GS) and Crop Circle (CC)) to optimize a N recommendation algorithm that can be used by potato growers in Maine. This research was conducted at 11 sites over a period of two years (2018–2019) in Aroostook County, Maine; all sites depended on a rainfed system. Three potato cultivars, Russet Burbank, Superior, and Shepody, were planted u

... Show More
View Publication
Publication Date
Wed Mar 15 2023
Journal Name
Al-academy
Active design and its principles in industrial product design
...Show More Authors

 The problem of the research came through the following question (what is the effectiveness of active design in contemporary industrial products), and it emphasized the importance of research to make society with its members in a positive state of activity, and what can help the industrial product design to achieve this, but the goal of the study is (determining the characteristics and principles of design Active and its effectiveness in the industrial product), and the study was determined by industrial products related to daily, recreational and sports activity, The researcher relied on a form to determine the axes of analysis for the sample models, in order to reach the results of the research, the most important of which are: Realiz

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sun Mar 30 2003
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Active Alumina Extraction from Iraqi Bauxite for Catalyst's Support
...Show More Authors

View Publication Preview PDF