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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
Wed Jan 01 2025
Journal Name
Modern Sport
Vertical Resistance and Its Relationship with Speed-Strength and Biomechanical Variables During the Takeoff Phase and the Performance of Selected Activities in Individual and Team Sports
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Jumping ability is a fundamental variable in many sports, as its execution requires an integration of muscular strength Q1 and certain biomechanical variables. This is particularly evident in gymnastics jumping events and jump shots in ball games, both of which rely on a high level of vertical resistance. Vertical resistance serves as an indicator of an athlete’s ability to overcome their body weight while counteracting gravitational force to achieve optimal performance. As such, it is considered one of the key factors in movements that demand explosive power and speed. The researchers believe that despite the significant relationship between vertical resistance, speed-strength of the arms and legs, and certain biomechanical varia

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Publication Date
Mon Feb 19 2018
Journal Name
Al-academy
Balanced performance and structural mechanisms in industrial product design systems
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The research focused on (balanced performance and structural mechanisms in industrial product design systems) by focusing on product development in a manner that is able to meet the human requirements through the effect of smart technology on the systems of product designs and its effectiveness in achieving the design and functional variables that have an effective effect in User and industrial products, correspond to the requirements of the user life at the level of daily interaction. The first chapter ensures the problem of research is the following question: What are the mechanisms to achieve balanced performance in some systems design to fit with the variables B N User and industrial products? The objective of the research was to ide

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Publication Date
Tue Dec 01 2015
Journal Name
Journal Of Economics And Administrative Sciences
Electronic Trading Useand its Impacton Iraqi Stock Exchange Performance Improvement
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The Research examines the transmission advantage from Floor Trading (FT) to the Electronic Trading (ET) in the Iraqi Stock Exchange (ISE). Testing three hypothesis, first, test the significant different of market depth before and after period of ET used, second, test the significant different of market liquidity also before and after period of ET used. And third test the impact of market depth and liquidity on the performance of ISE. AnEvent Study is depended with 74 observing distributed equality on research period which is extent among 2006 to 2012, Note that the event window is 5-7-2009.The Result of hypothesis testing explore that the all three null main hypothesis is refusing and accept the alternative of it's because the ET

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Publication Date
Sun Dec 30 2001
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Analyzing and Optimizing Bits Performance in Three Iraqi Oil-Fields
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Publication Date
Wed Sep 30 2020
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Performance Comparison between Recycled Single Stage and Double Stage Hydrocyclones
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   This research presents a comparison of performance between recycled single stage and double stage hydrocyclones in separating water from water/kerosene emulsion. The comparison included several factors such as: inlet flow rate (3,5,7,9, and 11 L/min), water feed concentration (5% and 15% by volume), and split ratio (0.1 and 0.9). The comparison extended to include the recycle operation; once and twice recycles. The results showed that increasing flow rate as well as the split ratio enhancing the separation efficiency for the two modes of operation. On the contrary, reducing the feed concentration gave high efficiencies for the modes. The operation with two cycles was more efficient than one cycle. The maximum obtained effici

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Publication Date
Wed Jan 01 2020
Journal Name
Communications In Computer And Information Science
Performance Evaluation for Four Supervised Classifiers in Internet Traffic Classification
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Publication Date
Mon Aug 01 2011
Journal Name
Journal Of Engineering
LDPC CODED MULTIUSER MC-CDMA PERFORMANCE OVERMULTIPATH RAYLEIGH FADING CHANNEL
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This work presents the simulation of a Low density Parity Check (LDPC) coding scheme with
multiuserMulti-Carrier Code Division Multiple Access (MC-CDMA) system over Additive White
Gaussian Noise (AWGN) channel and multipath fading channels. The decoding technique used in
the simulation was iterative decoding since it gives maximum efficiency with ten iterations.
Modulation schemes that used are Phase Shift Keying (BPSK, QPSK and 16 PSK), along with the
Orthogonal Frequency Division Multiplexing (OFDM). A 12 pilot carrier were used in the estimator
to compensate channel effect. The channel model used is Long Term Evolution (LTE) channel with
Technical Specification TS 25.101v2.10 and 5 MHz bandwidth including the chan

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Publication Date
Tue Dec 01 2020
Journal Name
Journal Of Economics And Administrative Sciences
Strategic Entrepreneur ship and its role in a marketing performance
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The current research aims through its chapters to verify the relationship and impact of strategic leadership as an independent variable in the marketing performance as a respondent variable, in a leap cement plant, and try to come up with a set of recommendations that contribute to enhancing the practice and adoption of the two variables in the organization under discussion. And based on the importance of the research topic to the community, and to the researched organization and its members, the analytical and analytical approach was adopted in the completion of this research, and the research community included a leap cement plant in Anbar Governorate, while the research sample was represented by (department heads, and people o

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Publication Date
Thu Sep 01 2022
Journal Name
Iraqi Journal Of Physics
Calculation of the Magnetic Dipole and Electric Quadrupole Moments of some Sodium Isotopes using Shell Model with Skyrme Interaction
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         In the present work, the magnetic dipole and electric quadrupole moments for some sodium isotopes have been calculated using the shell model, considering the effect of the two-body effective interactions and the single-particle potentials. These isotopes are; 21Na (3/2+), 23Na (3/2+), 25Na (5/2+), 26Na (3+), 27Na (5/2+), 28Na (1+) and, 29Na (3/2+). The one-body transition density matrix elements (OBDM) have been calculated using the (USDA, USDB, HBUMSD and W) two-body effective interactions carried out in the sd-shell model space. The sd shell model space consists of the active 2s1/2, 1d5/2,

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Publication Date
Tue Jun 30 2015
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Using the Artificial Gas Lift to Increase the Productivity of Noor Oil Field / Mishrif Formation
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Noor Oil Field is one of Iraqi oil fields located in Missan province / Amarah city. This field is not subjected to licensing rounds, but depends on the national effort of  Missan Oil Company. The first two wells in the field were drilled in seventies and were  not opened to production until 2009. The aim of this study is to study the possibility of using the method of gas lift to increase the productivity of this field . PROSPER software was used to design the continuous  gas lift by using maximum production rate in the design.

   The design was made after comparing  the measured pressure with the calculated pressure, this comparison  show  that the method of Beggs-Brill and Petroleum Exper

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