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
Tue Feb 11 2025
Journal Name
Journal Of Baghdad College Of Dentistry
The influence of cavity design for cusp coverage on fracture strength of weakened maxillary first premolars using two esthetic restorative systems (CAD/CAM hybrid ceramic and nanohybrid composite) (An in vitro study)
...Show More Authors

Background: Maxillary first premolar with wide MOD cavity more susceptible to fracture. The aim of this study was to assess the influence of cavity design for cusp coverage on the fracture resistance of weakened maxillary first premolar restored with CAD/CAM hybrid ceramic versus nanohybide composite. Materials and Methods: Fifty six intact maxillary first premolars of approximately comparable sizes were divided into seven groups eight for each: Group A: Intact teeth (control group); Group B: teeth prepared for MOD inlay; Group C: teeth prepared for MOD onlay covering the lingual cusp; Group D: teeth prepared for MOD covering buccal and lingual cusps ,the previous three groups indirectly restored with nanohybrid composite (3M ESPE Z 250 X

... Show More
View Publication Preview PDF
Publication Date
Wed Aug 01 2018
Journal Name
Journal Of Economics And Administrative Sciences
Prepare a plan for the Total Productive Maintenance in the light of the concurrent engineering A Field Study in AL-Askandria General Company Machanical Industries and AL-Musaib Electric Power Station
...Show More Authors

           Strives Total Productive Maintenance  to increase the overall effectiveness of the equipment through the early involvement in the design and manufacture of equipment productivity. It also operates in an environment of simultaneous engineering work on the synchronization of activities to take advantage of early information by maintenance engineers, design, operation, and that helps to reduce the faults and facilitate future maintenance tasks.

    Has adopted a search in the theoretical concept of the total maintenance productivity and concurrent engineering activities carried out during which the conjunction a

... Show More
View Publication Preview PDF
Crossref (1)
Crossref
Publication Date
Wed Aug 29 2018
Journal Name
Biomedical And Pharmacology Journal
Comparison of Some Mechanical and Physical Properties of three Types of Impression Materials with Different Dental Implant Angulations
...Show More Authors

Choosing an appropriate impression material is a challenge for many dentists, yet an essential component to provide an excellent clinical outcome and improve productivity and profit. The purpose of present study was to compare wettability, tear strength and dimensional accuracy of three elastomeric impression materials, with the same consistencies (light-body). Three commercially available light body consistency and regular set 3M ESPE Express polyvinylsiloxane (PVS), 3M ESPE Permadyne polyether (PE), and Identium (ID), impression materials were comparedTear strength test, contact angle test and linear dimensional accuracy were evaluated for three elastic impression material. Among the three experimental groups PE impression materia

... Show More
View Publication
Crossref (2)
Crossref
Publication Date
Mon Oct 01 2018
Journal Name
The Saudi Dental Journal
Evaluation of some mechanical properties of a new silicone elastomer for maxillofacial prostheses after addition of intrinsic pigments
...Show More Authors

Objective: The approximate life span of a silicone maxillofacial prosthesis is as short as1.5–2 years of clinical service, then a new prosthesis should be fabricated. The most common reasonfor re-making the prosthesis is silicone mechanical properties degradation. The aim of this studywas to assess some mechanical properties of VST-30 silicone for maxillofacial prostheses after addi-tion of intrinsic pigments.Methods: Two types of intrinsic pigments (rayon flocking and burnt sienna); each of them wasincorporated into silicone. One hundred and twenty samples were prepared and split into 4 groupsaccording to the conducted tests (tear strength, hardness, surface roughness, and tensile strengthand elongation percentage) with 30 samples for ea

... Show More
View Publication
Scopus (19)
Crossref (18)
Scopus Clarivate Crossref
Publication Date
Sun Nov 01 2015
Journal Name
Engineering And Technology Journal
Synthesized Cu (In, Ga) Se2 (CIGS) thin films and implementation as the active light absorbing material in photovoltaic devices (PVs)
...Show More Authors

This review article summarizes our research focused on Cu(In, Ga)Se2 (CIGS) nanocrystals, including their synthesis and implementation as the active light absorbing material in photovoltaic devices (PVs). CIGS thin films were prepared by arrested precipitation from molecular precursors consisting of CuCl, InCl3, GaCl3 and Se metal onto Mo/soda-lime glass (SLG) substrates. We have sought to use CIGS nanocrystals synthesized with the desired stoichiometry to deposit PV device layers without high temperature processing. This approach, using spray deposition of the CIGS light absorber layers, without high temperature selenization, has enabled up to 1.5 % power conversion efficiency under AM 1.5 solar illumination. The composition and morphology

... Show More
View Publication Preview PDF
Publication Date
Tue Feb 11 2025
Journal Name
Iraqi Journal Of Agricultural Sciences
PURIFICATION OF PHYTASE PRODUCED FROM A LOCAL FUNGAL ISOLATE AND ITS APPLICATIONS IN FOOD SYSTEMS
...Show More Authors

View Publication
Publication Date
Fri Apr 01 2016
Journal Name
Journal Of Engineering
The Use of the Artificial Damped Outrigger Systems in Tall R.C Buildings Under Seismic Loading
...Show More Authors

This paper studies the combination of fluid viscous dampers in the outrigger system to add supplementary damping into the structure, which purpose to remove the dependability of the structure to lower variable intrinsic damping. This optimizes the accuracy of the dynamic response and by providing higher level of damping, basically minimizes the wanted stiffness of the structure while at the same time optimizing the achievement.

     The modal considered is a 36 storey square high rise reinforced concrete building. By constructing a discrete lumped mass model and using frequency-based response function, two systems of dampers, parallel and series systems are studied. The maximu

... Show More
View Publication Preview PDF
Publication Date
Fri Dec 15 2023
Journal Name
Iraqi Journal Of Laser
Numerical Simulation of Metasurface Grating to Function as Polarization Modulator in Quantum Key Distribution Systems
...Show More Authors

larization modulation plays an important role in polarization encoding in quantum key distribution. By using polarization modulation, quantum key distribution systems become more compact and more vulnerable as one laser source is used instead of using multiple laser sources that may cause side-channel attacks. Metasurfaces with their exceptional optical properties have led to the development of versatile ultrathin optical devices. They are made up of planar arrays of resonant or nearly resonant subwavelength pieces and provide complete control over reflected and transmitted electromagnetic waves opening several possibilities for the development of innovative optical components. In this work, the Si nanowire metasurface

... Show More
Preview PDF
Crossref
Publication Date
Sat Jan 30 2021
Journal Name
Iraqi Journal Of Science
Solving Systems of Non-Linear Volterra Integral Equations by Combined Sumudu Transform-Adomian Decomposition Method
...Show More Authors

     This paper is used for solving component Volterra nonlinear systems by means of the combined Sumudu transform with Adomian decomposition process. We equate the numerical results with the exact solutions to demonstrate the high accuracy of the solution results. The results show that the approach is very straightforward and effective.

View Publication Preview PDF
Scopus (6)
Crossref (1)
Scopus Crossref
Publication Date
Thu May 18 2023
Journal Name
Journal Of Engineering
Experimental Study of Power Increase Transient in Heat Generation Systems Simulated By Immersed Heat Source
...Show More Authors

Theoretical and experimental investigations of the transient heat transfer parameters of constant heat flux source subjected to water flowing in the downward direction in closed channel are conducted. The power increase transient is ensured by step change increase in the heat source power. The theoretical investigation involved a mathematical modeling for axially symmetric, simultaneously developing laminar water flow in a vertical annulus. The mathematical model is based on one dimensional downward flow. The boundary conditions of the studied case are based on adiabatic outer wall, while the inner wall is subjected to a constant heat flux. The heat & mass balance equation derived for specified element of bulk water within the annulu

... Show More
View Publication Preview PDF
Crossref