Preferred Language
Articles
/
joe-389
Enhancing the Performance of Piezoelectric Energy Harvesters Using Permanent Magnets
...Show More Authors

A cantilevered piezoelectric beam with a tip mass at its free end is a common energy harvester configuration. This paper introduces a new principle of designing such a harvester which increases the generated voltage without changing the natural frequency of the harvester: The attraction force between two permanent magnets is used to add stiffness to the system. This magnetic stiffening counters the effect of the tip mass on the natural frequency. Three setups incorporating piezoelectric bimorph cantilevers of the same type in different mechanical configurations are compared theoretically and experimentally to investigate the feasibility of this principle. Theoretical and experimental results show that magnetically stiffened harvesters have important advantages over conventional setups. They generate more voltage and they can be tuned across a wide range of excitation frequencies.

 

 

View Publication Preview PDF
Quick Preview PDF
Publication Date
Sun Jan 13 2019
Journal Name
Iraqi Journal Of Physics
Energy transfer process between two laser compounds coumarin 334 & rhodamine 590
...Show More Authors

In the current research the absorption and fluorescence spectrum
of Coumarin (334) and Rhodamine (590) in ethanol solvent at
different concentration (10-3, 10-4, 10-5) M had been studied. The
absorption intensity of these dyes increases as the Concentration
increase in addition to that the spectrum was shifted towards the
longer wavelength (red shift). The energy transfer process has been
investigated after achievement this condition. The fluorescence peak
intensity of donor molecule was decrease and its bandwidth will
increases on the contrary of the acceptor molecule its intensity
increase gradually and its bandwidth decreases as the acceptor
concentration increase.

View Publication Preview PDF
Crossref (1)
Crossref
Publication Date
Mon Jul 15 2019
Journal Name
Iet Microwaves, Antennas & Propagation
Hilbert metamaterial printed antenna based on organic substrates for energy harvesting
...Show More Authors

Abstract In this study, an investigation is conducted to realise the possibility of organic materials use in radio frequency (RF) electronics for RF-energy harvesting. Iraqi palm tree remnants mixed with nickel oxide nanoparticles hosted in polyethylene, INP substrates, is proposed for this study. Moreover, a metamaterial (MTM) antenna is printed on the created INP substrate of 0.8 mm thickness using silver nanoparticles conductive ink. The fabricated antenna performances are instigated numerically than validated experimentally in terms of S11 spectra and radiation patterns. It is found that the proposed antenna shows an ultra-wide band matching bandwidth to cover the frequencies from 2.4 to 10 GHz with bore-sight gain variation from 2.2 to

... Show More
View Publication
Scopus (55)
Crossref (35)
Scopus Clarivate Crossref
Publication Date
Tue Jan 30 2024
Journal Name
Mathematical Modelling Of Engineering Problems
A Novel Design for Enhancing Speed and Reducing Vibration in Railway Wheel-Track Profiles
...Show More Authors

View Publication
Scopus Crossref
Publication Date
Tue Feb 14 2023
Journal Name
Journal Of Educational And Psychological Researches
Mental Health and Its Role in Enhancing Self-Confidence Positive Behavior among University Students
...Show More Authors

Abstract
The current research aims to identify mental health and its role in promoting self-confidence and positive behavior of female university students. The researcher adopted the descriptive analytical approach in this research. The researcher depended on the availability of sources and references, literature, and previous field studies to analyze and study all aspects related to mental health and its role in promoting self-confidence and positive behavior of university students and then expand its importance and identify the areas of mental health, self-confidence, positive behavior, and university. The second chapter included the concept of mental health, the importance of the study, the most important factors of health and psyc

... Show More
View Publication Preview PDF
Publication Date
Fri Apr 12 2019
Journal Name
Journal Of Economics And Administrative Sciences
Core competencies and Their Role in Enhancing Organizational flexibility: An Analytical Study of the Views of a Sample of Employees in Presidency University of Mosul
...Show More Authors

Abstract

The study aims to identify the levels of core competencies dimensions and types of organizational flexibility in the investigated organization, as well as to determine the nature of the relationship and the impact of core competencies dimensions with the process of organizational flexibility. Thus, a number of research questions were presented to express the research problem as follows:

  • What is the level of the investigated individuals' awareness to core competencies and organizational flexibility across their dimensions and types in the investigated organization?
  • To what extent are core competencies and organizational flexibility available in the Organiz

... Show More
View Publication Preview PDF
Crossref (1)
Crossref
Publication Date
Thu Apr 30 2020
Journal Name
Journal Of Economics And Administrative Sciences
The Role of E-Learning in enhancing Total Quality Management in Educational Institutions: an exploratory study of the opinions of a sample of the staff of the Directorate of Education in the province of Nineveh
...Show More Authors

Purpose: The research aims to determine the relationship between E-Learning and Total Quality Management (TQM) in Educational institutions in Nineveh Governorates.

Methodology / Design: The researchers distributed (30) questionnaires to employees (teachers and administrators) of Nineveh Governorate education who represent the community of the research sample, as they were analyzed using the SPSS V.20

The importance of research: The importance of the research in the fact that it focuses on one of the educational methods represented in integrating the traditional method and relying on modern technologies using computers and the Internet in the field of education to improve the reali

... Show More
View Publication Preview PDF
Crossref
Publication Date
Thu Sep 08 2022
Journal Name
Al-khwarizmi Engineering Journal
Performance Prediction in EDM Process for Al 6061 Alloy Using Response Surface Methodology and Genetic Algorithm
...Show More Authors

The Electric Discharge (EDM) method is a novel thermoelectric manufacturing technique in which materials are removed by a controlled spark erosion process between two electrodes immersed in a dielectric medium. Because of the difficulties of EDM, determining the optimum cutting parameters to improve cutting performance is extremely tough. As a result, optimizing operating parameters is a critical processing step, particularly for non-traditional machining process like EDM. Adequate selection of processing parameters for the EDM process does not provide ideal conditions, due to the unpredictable processing time required for a given function. Models of Multiple Regression and Genetic Algorithm are considered as effective methods for determ

... Show More
View Publication Preview PDF
Scopus (2)
Crossref (1)
Scopus Crossref
Publication Date
Sat Sep 01 2018
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
The impact of the organizational commitmentIn the job performance of employees of the Iraqi Insurance company
...Show More Authors

The research aims at shedding light on the impact of the organizational commitment on the performance of the Iraqi insurance company as a service company that provides many services to customers both internal (individuals working) or external, Whenever the company was able to adopt new concepts to increase the understanding and knowledge of how their attention to individuals working and to provide an appropriate working environment, and to clarify the objectives and strategies for them, and create a sense of their importance, as reflected on job performance in attracting new customers, and build long-term relationships with them . In order to achieve this, the research relied on the questionnaire as a main tool for collecting data and in

... Show More
View Publication Preview PDF
Crossref
Publication Date
Wed Feb 01 2017
Journal Name
Journal Of Economics And Administrative Sciences
Local policy and its impact on the performance of the province of Baghdad.
...Show More Authors

Abstract

The current research aims to clarify the role of local policies on the performance of the province of Baghdad, after studies proved practical experience what those policies of the major role and effect on the lives of citizens, as well as alleviate the burden on central government, which make a lot of states give local governments broad powers and her specialty funds for the exercise of its vital role and actor in various joints of local development, research has indentified a problem in a number of questions such as: do you have the policy of the provincial council of local qualified and able to influence the performance of the province? What are the main forces of powerful and implementation of policies at all

... Show More
View Publication Preview PDF
Crossref
Publication Date
Wed Apr 01 2015
Journal Name
Journal Of Educational And Psychological Researches
The Effect of Enrichment Programs on the Performance of Gifted Students in KSA
...Show More Authors

       The current study aimed at identifying the impact of each of the full and part time summer enrichment programs on the performance of gifted students. Moreover, it aimed to study the difference between the full and part time programs on the performance of gifted students. The study sample consisted of (115) students from the full time programs and (137) students from the part time programs, they have been randomly selected from the gifted students participating in the full and part time summer enrichment programs. The researcher used the scale of student performance. The results indicated that there were statistically significant differences between the averages of the pre and post applications of the

... Show More
View Publication Preview PDF