Preferred Language
Articles
/
alkej-251
Studying and Modeling the Effect of Graphite Powder Mixing Electrical Discharge Machining on the Main Process Characteristics
...Show More Authors

Abstract

This paper concerned with study the effect of a graphite micro powder mixed in the kerosene dielectric fluid during powder mixing electric discharge machining (PMEDM) of high carbon high chromium AISI D2 steel. The type of electrode (copper and graphite), the pulse current and the pulse-on time and mixing powder in kerosene dielectric fluid are taken as the process main input parameters. The material removal rate MRR, the tool wear ratio TWR and the work piece surface roughness (SR) are taken as output parameters to measure the process performance. The experiments are planned using response surface methodology (RSM) design procedure. Empirical models are developed for MRR, TWR and SR, using the analysis of variance (ANOVA).The best results for the productivity of the process (MRR) obtained when using the graphite electrodes, the pulse current (22 A), the pulse on duration (120 µs) and using the graphite powder mixing in kerosene dielectric reaches (82.84mm³/min). The result gives an improvement in material removal rate of (274%) with respect to the corresponding value obtained when copper electrodes with kerosene dielectric alone. The best results for the tool wear ratio (TWR) of the process obtained when using the copper electrodes, the pulse current (8 A), the pulse on duration (120 µs) and using the kerosene dielectric alone reaches (0.31 %). The use of graphite electrodes, the kerosene dielectric with 5g/l graphite powder mixing, the pulse current (8 A), the pulse on duration (40 µs) give the best surface roughness of a value (2.77 µm).This result yields an improvement in SR by (141%) with respect to the corresponding value obtained when using copper electrodes and the kerosene dielectric alone with the same other parameters and machining conditions.

Keywords: EDM, RSM, MRR, TWR, SR, AISI D2die steel, graphite powder mixing.

View Publication Preview PDF
Quick Preview PDF
Publication Date
Mon Aug 02 2021
Journal Name
International Journal Of Dental Hygiene
Efficacy of erythritol powder air‐polishing in active and supportive periodontal therapy: A systematic review and meta‐analysis
...Show More Authors
Abstract<sec><title>Objective

This systematic review aimed to analyse available evidence to answer two focused questions about the efficacy of erythritol powder air‐polishing (EPAP) (i) as an adjunctive during active periodontal therapy (APT) and (ii) as an alternative to hand/ultrasonic instrumentation during supportive periodontal therapy (SPT). Additionally, microbiological outcomes and patient's comfort/perceptions were assessed as secondary outcomes.

Methods

PubMed, Cochrane and Medline were searched for relevant articles published before February 2021 following PRISMA guidelines. The search was conducted by three indep

... Show More
View Publication
Scopus (18)
Crossref (18)
Scopus Clarivate Crossref
Publication Date
Thu Feb 06 2020
Journal Name
Political Sciences Journal
The effect of the media in forming knowledge and political awareness
...Show More Authors

Abstract The dissemination of knowledge is no longer confined to schools and universities, not even books. For nearly two centuries, the media have become prominent in disseminating knowledge and culture, in its public and particularly political aspects. After the development of the media from newspapers and magazines to the visual media, their role has increased from the dissemination of abstract information and abstract knowledge towards the process of forming new knowledge through what it publishes and broadcasts from different programs such as drama, news and talk shows. The impact of the media has changed the overall community awareness. Half a century ago the media was not so powerful and widespread. The evolution of the 1990s made

... Show More
View Publication Preview PDF
Crossref (1)
Crossref
Publication Date
Sun Mar 06 2011
Journal Name
Baghdad Science Journal
Electrical and dielectric properties of kevlar - carbon hybrid fiber / epoxy laminated composites
...Show More Authors

This paper reports a.c., d.c. conductivity and dielectric behavior of Ep-hybrid composite with12 Vol.% Kevlar-Carbon hybrid . D.C. conductivity measurements are conducted on the graded composites by using an electrometer over the temperature range from (293-413) K. It was shown then that conductivity increases by increasing number of Kevlar –Carbon fiber layers (Ep1, Ep2, Ep3), due to the high electrical conductivity of Carbon fiber. To identify the mechanism governing the conduction, the activation energies at low temperature region (LTR) and at high temperature region (HTR) have been calculated. The activation energy values for hybrid composite decrease with increasing number of fiber layers. The a.c. conductivity was measured over fr

... Show More
View Publication Preview PDF
Crossref
Publication Date
Wed Jan 01 2020
Journal Name
Advanced Composites Letters
Enhanced thermal and electrical properties of epoxy/carbon fiber–silicon carbide composites
...Show More Authors

The silicon carbide/carbon fiber (SiC/CF) hybrid fillers were introduced to improve the electrical and thermal conductivities of the epoxy resin composites. Results of Fourier transform infrared spectroscopy revealed that the peaks at 3532 and 2850 cm−1 relate to carboxylic acid O–H stretching and aldehyde C–H stretching appearing deeper with an increased volume fraction of SiC. Scanning electron microscopic image shows a better interface bonding between the fiber and the matrix when the volume fraction of SiC particles are increased. As frequency increases from 102 Hz to 106 Hz, dielectric constants decrease slightly. Dissipation factor (tan δ) values keep low a

... Show More
View Publication
Scopus (30)
Crossref (38)
Scopus Clarivate Crossref
Publication Date
Sun Feb 10 2019
Journal Name
Iraqi Journal Of Physics
Electrical and morphological study of thermally evaporated (Sb2S3)1-xSnx thin films
...Show More Authors

(Sb2S3)1-xSnx thin films with different concentrations (0, 0.05 and
0.15) and thicknesses (300,500 and 700nm) have been deposited by
single source vacuum thermal evaporation onto glass substrates at
ambient temperature to study the effect of tin content, thickness and
on its structural morphology, and electrical properties. AFM study
revealed that microstructure parameters such as crystallite size, and
roughness found to depend upon deposition conditions. The DC
conductivity of the vacuum evaporated (Sb2S3)1-x Snx thin films was
measured in the temperature range (293-473)K and was found to
increase on order of magnitude with

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sun Feb 01 2009
Journal Name
Materials Science And Engineering: B
Microstructure, electrical properties and Hall coefficient of europium-doped Li–Ni ferrites
...Show More Authors

View Publication
Scopus (43)
Crossref (42)
Scopus Clarivate Crossref
Publication Date
Fri Dec 30 2022
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Mathematical Modeling and Kinetics of Removing Metal Ions from Industrial Wastewater
...Show More Authors

The study's objective is to produce Nano Graphene Oxide (GO) before using it for batch adsorption to remove heavy metals (Cadmium Cd+2, Nickel Ni+2, and Vanadium V+5) ions from industrial wastewater. The temperature effect (20-50) °C and initial concentration effect (100-800) mg L-1 on the adsorption process were studied. A simulation aqueous solution of the ions was used to identify the adsorption isotherms, and after the experimental data was collected, the sorption process was studied kinetically and thermodynamically. The Langmuir, Freundlich, and Temkin isotherm models were used to fit the data. The results showed that Cd, Ni, and V ions on the GO adsorbing surface matched the Langmuir mo

... Show More
View Publication Preview PDF
Crossref (6)
Crossref
Publication Date
Sun Jan 01 2023
Journal Name
Journal Of The Mechanical Behavior Of Materials
Groundwater flow modeling and hydraulic assessment of Al-Ruhbah region, Iraq
...Show More Authors
Abstract<p>Al-Ruhbah region is located in the southwest of Najaf Governorate. A numerical model was created to simulate groundwater flow and analyze the water quality of the groundwater, by developing a conceptual model within the groundwater modeling system software. Nineteen wells were used, 15 for pumping and four for observation. A three-dimensional model was built based on the cross-sections indicating the geologic layers of the study area, which were composed of five layers. When a distance of 1,000 m between the wells was adopted, 135 wells can be operated simultaneously. These wells were hypothetically operated at 6, 12, and 18 h intervals, with a discharge of 200, 430, and 650 m<j></j></p> ... Show More
Scopus (5)
Crossref (4)
Scopus Clarivate Crossref
Publication Date
Thu Dec 05 2013
Journal Name
Robotica
Modeling, stability and walking pattern generators of biped robots: a review
...Show More Authors
SUMMARY<p>Biped robots have gained much attention for decades. A variety of researches have been conducted to make them able to assist or even substitute for humans in performing special tasks. In addition, studying biped robots is important in order to understand human locomotion and to develop and improve control strategies for prosthetic and orthotic limbs. This paper discusses the main challenges encountered in the design of biped robots, such as modeling, stability and their walking patterns. The subject is difficult to deal with because the biped mechanism intervenes with mechanics, control, electronics and artificial intelligence. In this paper, we collect and introduce a systematic discussion of modelin</p> ... Show More
View Publication
Scopus (39)
Crossref (33)
Scopus Clarivate Crossref
Publication Date
Wed Oct 20 2010
Journal Name
The International Journal Of Advanced Manufacturing Technology
Finite element modeling and simulation of proposed design magneto-rheological valve
...Show More Authors

Magneto-rheological (MR) valve is one of the devices generally used to control the speed of Hydraulic actuator of MR fluid. The performance of valve depends on the magnetic circuit design. Present study deals with a new design of MR valve. A mathematical model for the MR valve is developed and the simulation is carried out to evaluate the newly developed MR valve. The design of the magnetic circuit is accomplished by magnetic finite element software such as Finite Element Method Magnetic (FEMMR). The model dimensions of MR valve, material properties are taken into account. The results of analysis are presented in terms of magnetic strength H and magnetic flux density B. The simulation results based on the proposed model indicate that the ef

... Show More
View Publication
Scopus (37)
Crossref (30)
Scopus Clarivate Crossref