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Enhancing the Performance of Piezoelectric Energy Harvesters Using Permanent Magnets
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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.

 

 

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Publication Date
Mon Dec 25 2017
Journal Name
Al-khwarizmi Engineering Journal
Prediction of Oxygen Mass Transfer Coefficients in Stirred Bioreactor with Rushton Turbine Impeller for Simulated (Non-Microbial) Medias
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 Abstract

The study of oxygen mass transfer was conducted in a laboratory scale 5 liter stirred bioreactor equipped with one Rushton turbine impeller. The effects of superficial gas velocity, impeller speed, power input and liquid viscosity on the oxygen mass transfer were considered. Air/ water and air/CMC systems were used as a liquid media for this study. The concentration of CMC was ranging from 0.5 to 3 w/v. The experimental results show that volumetric oxygen mass transfer coefficient increases with the increase in the superficial gas velocity and impeller speed and decreases with increasing liquid viscosity. The experimental results of kla were correlated with a mathematical correlation des

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Publication Date
Wed Dec 13 2017
Journal Name
Al-khwarizmi Engineering Journal
Design of a Kinematic Neural Controller for Mobile Robots based on Enhanced Hybrid Firefly-Artificial Bee Colony Algorithm
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The paper present design of a control structure that enables integration of a Kinematic neural controller for trajectory tracking of a nonholonomic differential two wheeled mobile robot, then  proposes a Kinematic neural controller to direct a National Instrument mobile robot (NI Mobile Robot). The controller is to make the actual velocity of the wheeled mobile robot close the required velocity by guarantees that the trajectory tracking mean squire error converges at minimum tracking error. The proposed tracking control system consists of two layers; The first layer is a multi-layer perceptron neural network system that controls the mobile robot to track the required path , The second layer is an optimization layer ,which is impleme

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Publication Date
Fri Jul 01 2016
Journal Name
Journal Of Economics And Administrative Sciences
Some Organizational Factors Role in Limited Talent Management Strategies Field Research in Number of Talent Schools in Iraq)
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Abstract:

 The purpose of this research is measuring relationship level and impact between Organizational Factors and their Dimensions (Leadership, Organizational Structure, Organizational Culture), and Talent Management Strategies (Talent Recruitment,Talent performance management, Talent Development, Talent Retention ). it was relied on the Questionnaire form as a basic instrument in collecting the Data by using (Likert) instrument ,which was distributed on the research Sample which number was (100) individual included (Managers of schools, assistants  (scientific and Administration ) and teachers in Four schools of Talents in Iraq (Baghdad , AL-Nagaf , AL-Basra, Mesan). All fo

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Publication Date
Sun Jun 05 2016
Journal Name
Baghdad Science Journal
Preparation, Characterization and Biological Evaluation of some Lanthanide (ΙΙΙ) ions Complexes with 3-(1-methyl-2-benzimidazolylazo)-Tyrosine
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A series of lanthanide metal (???) complexes have been prepared from the new azo ligand, 3-(1-methyl-2-benzimidazolylazo)-Tyrosine (MBT). The structural feature were confirmed on the basis of their elemental analysis, metal content, molar conductance, magnetic measurement, FTIR, 1 HNMR and UV-Vis spectra studies. The isolated complexes were found to have a mole ratio (1:2) (metal:ligand) stoichiometry with the general formula [Ln(MBT)2]Cl (Ln(???) = La, Ce, Pr, Nd, Sm, Eu and Gd). The chelates were found to have octahedral structures. The FTIR spectra shows that the ligand (MBT) is coordinated to lanthanide ions as a N, N, O-tridentate anion via benzimidazole nitrogen, azo nitrogen and oxygen of hydroxyl after deprotonation. Com

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Publication Date
Mon Aug 30 2021
Journal Name
Al-kindy College Medical Journal
Clinical Course and Disease`s Outcome Aspects of COVID-19 Pediatric Patients in Ibn Al-Khateeb Isolation Hospital
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Background: Corona virus disease 2019 (COVID-19) is a communicable disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). It was first identified in December 2019 in Wuhan, China, and has since spread globally, leading to an ongoing pandemic.

Aim of study: to review the clinical, lab investigation and imaging techniques, in pediatric age group affected COVID-19 to help medical experts better understand and supply timely diagnosis and treatment.

Subjects and methods: this study is a retrospective descriptive clinical study. The medical records of patients were analyzed. Information’s recorded include demographic data, exposure history, symptoms, signs, laboratory findin

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Publication Date
Tue Jun 01 2021
Journal Name
Journal Of Petroleum Exploration And Production Technology
Incremental and acceleration production estimation and their effect on optimization of well infill locations in tight gas reservoirs
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Abstract<p>The main role of infill drilling is either adding incremental reserves to the already existing one by intersecting newly undrained (virgin) regions or accelerating the production from currently depleted areas. Accelerating reserves from increasing drainage in tight formations can be beneficial considering the time value of money and the cost of additional wells. However, the maximum benefit can be realized when infill wells produce mostly incremental recoveries (recoveries from virgin formations). Therefore, the prediction of incremental and accelerated recovery is crucial in field development planning as it helps in the optimization of infill wells with the assurance of long-term economic sustainabi</p> ... Show More
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Publication Date
Thu Nov 03 2022
Journal Name
Journal Of Materials Engineering And Performance
Influence of Scanning Velocity on a CoCrMoW Alloy Built via Selective Laser Melting: Microstructure, Mechanical, and Tribological Properties
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Publication Date
Sat May 01 2021
Journal Name
European Journal Of General Dentistry
Assessment of Serum Interleukin-1β and Interleukin-6 Levels in Patients with Chronic Periodontitis and Coronary Heart Disease
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Abstract<p> Objective The aim of this study was to assess whether serum cytokine levels correlate with clinical periodontal parameters in health or disease.</p><p> Materials and Methods Male subjects (40–60 years) with CP (n = 30), CP + CHD (n = 30), and healthy controls (n = 20) had plaque index (PLI), gingival index (GI), bleeding on probing, probing pocket depth (PPD), and clinical attachment level (CAL) evaluated. Serum IL-1β and IL-6 levels were quantified using enzyme-linked immunosorbent assay.</p><p> Results PLI, GI, PPD, and CAL were significantly higher in patients with CP + CHD compared to those with CP. Serum levels of IL-1β and IL-6 were also si</p> ... Show More
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Publication Date
Thu Apr 18 2019
Journal Name
Al-kindy College Medical Journal
Maternal knowledge related to anemia during pregnancy among a sample of mothers attending Primary Health Care centers. Baghdad.
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Background: Anaemia is a major public health concern and is one of the most prevalent health issue in women within reproductive age group.

Objective: to assess maternal knowledge related to anaemia during pregnancy.

Type of the study: A cross –sectional study.

Method: The study including 200 mothers who attended selected primary health care centres, Baghdad during November and December 2015, they completed a previously prepared questionnaire coveringsocio-demographic characteristics and knowledge regarding anaemia in 4 main domains. The responses were analysed by using frequency, percentage and percent score for each statement a

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Publication Date
Wed Nov 01 2023
Journal Name
Iraqi Journal Of Pharmaceutical Sciences ( P-issn 1683 - 3597 E-issn 2521 - 3512)
Protective Effect of Daidzein on Ifosfamide-Induced Neurotoxicity Via Improving Some Selected Oxidative Stress Parameters in Male Rats
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  In this study, the possible protective effects of daidzein on ifosfamide-induced neurotoxicity in male rats were examined by the determination of changes in selected oxidant–antioxidant markers of male rats’ brain tissue.

Twenty-eight (28) apparently-healthy Wistar male rats weighing (120-150gm) allocated into 4 groups (n=7) were used in this study. Rats orally-administered 1% tween 20 dissolved in distilled water/Control (Group I); rats were orally-administered daidzein suspension (100mg/kg) for 7 days (Group II); rats intraperitoneally-injected with a single dose of ifosfamide (500 mg/kg) (Group III); rats orally-administered for 7 days with the daidzein (100mg/

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