Preferred Language
Articles
/
alkej-163
Drilling of FR-4 Composite Materials Using Single Pulse of Nd:YAG Laser
...Show More Authors

Laser drilling is capable of producing small, precisely positioned holes with high degree of reproductively. In this paper , IR millisecond Nd:YAG single pulsed laser was used to determine the effect of laser parameters on the drilled hole of the glass - fiber reinforced epoxy composite FR-4 sample of 2 mm in thickness . The type of laser source was GSI lumonics JK760TR Series laser 1.064μm system in a CNC cabin. The JK760TR series has a 0.3-50ms pulse length and a maximum repetition rate 500Hz with an average power of 600W. The investigation of single pulse laser drilling in this paper was based on theoretical and experimental solutions. In single pulse technique, the investigation included focal plane position fpp, pulse shape, laser peak power, and pulse duration. It was found that (-1) was the best fpp due to less taper for the drilled holes made by this level (Entrance hole =0.68, Exit hole = 0.27). To predict pulse shape effects; three types were : rectangular , rump-up and cool down, it were  examined found that rectangular pulse was efficient  more than the other types due to its ability to produce holes with less tapering as compared with others types. Also its found that all pulse shapes had the same effect on the materials microstructure . Laser peak power and pulse duration had the predominant affects on the hole dimensions and edge quality without any defect except hole tapering.  

View Publication Preview PDF
Quick Preview PDF
Publication Date
Sat Aug 31 2019
Journal Name
Iraqi Journal Of Physics
The Effect of Laser And Thermal Treatment on the Hardness and Adhesion Force on the Cermet Coating By Thermal Spray Technique
...Show More Authors

Ceramic coating compose from a ceramic mixture (MgO, Al2O3) and metall (Al-Ni) were produced by Thermal Spray Technique. The mixed ratio of used materials Al:Ni (50%) and 40% of Al2O3 and 10% MgO. This mixture was spray on a stainless steel substrate of type (316 L) by using thermal spray with flame method and at spraying distances (8, 12, 16 and 20) cm, then the prepared films were treated by laser and thermal treatment. After that performing a hardness and adhesion tests were eximined. The present study shows that the best value of the thermal treatment is 1000 ℃ for 30 mint; the optimum spray distance is 12 cm and most suitable laser is 500 mJ where the microscopic and mechanical character

... Show More
View Publication Preview PDF
Crossref (1)
Crossref
Publication Date
Fri Jun 30 2023
Journal Name
Journal Of The College Of Education For Women
Developing Tenth Grade Female Students' Attitudes in Critical Reading Skills Using the Reflective Thinking Method in the Sultanate of Oman
...Show More Authors

        This study aimed to developing the skills of critical reading for the tenth basic school female students through a training program using the reflective thinking method. The study sample consisted of (64) students. To achieve the objective of the study, the researcher uses the quasi-experiment approach consisting of a control group (32 students) and an experimental group (32 students). The researcher used three research inventories as follows: 1) A list of critical reading skills included (30) skills within three aspects (Recognition – Deduction – Evaluation and Judgment). 2) An executive program using reflective thinking for developing critical reading skills. 3) Achievement test to measure

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sun Feb 28 2021
Journal Name
Journal Of Economics And Administrative Sciences
Effects of Macroeconomic Variables on Gross Domestic Product in Saudi Arabia using ARDL model for the period 1993-2019
...Show More Authors

 

This paper analyses the relationship between selected macroeconomic variables and gross domestic product (GDP) in Saudi Arabia for the period 1993-2019. Specifically, it measures the effects of interest rate, oil price, inflation rate, budget deficit and money supply on the GDP of Saudi Arabia. The method employs in this paper is based on a descriptive analysis approach and ARDL model through the Bounds testing approach to cointegration. The results of the research reveal that the budget deficit, oil price and money supply have positive significant effects on GDP, while other variables have no effects on GDP and turned out to be insignificant. The findings suggest that both fiscal and monetary policies should be fo

... Show More
View Publication Preview PDF
Crossref
Publication Date
Mon Jun 12 2006
Journal Name
Iraqi Journal Of Laser
Laser-Induced Low-Resistance Ohmic Contacts on n-Si
...Show More Authors

In the present work, the feasibility of formation near-ideal ohmic behavior of In/n-Si contact efficiently by 300 s duration Nd:YAG pulsed laser processing has been recognized. Several laser pulses energy densities have been used, and the optimal energy density that gives best results is obtained. Topography of the irradiated region was extensively discussed and supported with micrographic illustrations to determine the surface condition that can play the important role in the ohmic contact quality. I-V characteristics in the forward and reverse bias and barrier height measurements have been studied for different irradiated samples to determine the laser energy density that gives best ohmic behavior. Comparing the current results with

... Show More
View Publication Preview PDF
Publication Date
Wed Jun 10 2009
Journal Name
Iraqi Journal Of Laser
A new achromatic glass for near infrared laser instruments
...Show More Authors

This research investigates new glasses which are best suitable for design of optical systems
working in the infrared region between 1.01 to 2.3μm. This work is extended to Oliva & Gennari
(1995,1998) research in which they found that the best known achromatic pairs are (BAF2-IRG2; SRF2-
IRG3; BAF2-IRG7; CAF2-IRGN6; BAF2-SF56A and BAF2-SF6). Schott will most probably stop the
production of these very little used and commercially uninteresting IRG glasses. In this work equally
good performances can be obtained by coupling BAF2, SRF2&CAF2 with standard glasses from Schott
or Ohara Company. The best new achromatic pairs found are (SRF2-S-TIH10; CAF2-S-LAL9; CAF2-SLAL13
and CAF2-S-BAH27). These new achromatic pai

... Show More
View Publication Preview PDF
Publication Date
Tue Dec 01 2020
Journal Name
Minar International Journal Of Applied Sciences And Technology
Electron density spectroscopic measurement in Al laser induced plasma
...Show More Authors

Plasma generated by a 1064 nm pulsed Nd: YAG laser with pulse duration of 10 ns concentrated onto an Al solid target under vacuum pressure was examined spectroscopically. The temperature and electron density specifying the plasma were measured by time-resolved spectroscopy of neutral atom and ion line emissions in the time period range of 300–2000 ns. An echelle spectrograph is utilized to appear the plasma emission lines. The temperature was obtained using the spectral line comparison method and the electron density was calculated using the Stark Broadening (SB) method. The electron density was characterized as a function of laser pulse energy. The time range where the plasma is optically thin and is also in local thermodynamic equilibri

... Show More
Publication Date
Tue Jul 22 2025
Journal Name
Journal Of Baghdad College Of Dentistry
The effect of the addition of silanized Nano titania fillers on some physical and mechanical properties of heat cured acrylic denture base materials
...Show More Authors

Background: Polymethyl methacrylate (PMMA) is the most commonly used material in denture fabrication. The material is far from ideal in fulfilling the mechanical requirement. The purpose of this study was to evaluate the effect of addition of 3% wt of treated (silanized) Titanium oxide Nano filler on some physical and mechanical properties of heat cured acrylic denture base material. Materials and methods: 100 specimens were constructed, 50 specimens were prepared from heat cure PMMA without additives (control) and 50 specimens were prepared from heat cure PMMA with the addition of TiO2 Nano fillers. Each group was divided into 5 sub groups according to the test performed which was mixed by probe ultra-sonication machine. Results: A highly

... Show More
View Publication Preview PDF
Publication Date
Sat Apr 01 2023
Journal Name
Baghdad Science Journal
Synthesis, Spectroscopy of New Lanthanide Complexes with Schiff Base Derived From (4-Antipyrinecarboxaldehyde with Ethylene Di-Amine) and Study the Bioactivity
...Show More Authors

The study involved preparing a new compound by combining Schiff bases generated from compounds for antipyrine, including lanthanide ions (lanthanum, neodymium, erbium, gadolinium, and dysprosium). The preparation of the ligand from condensation reactions (4-antipyrinecarboxaldehyde with ethylene di-amine) at room temperature, and was characterization using spectroscopic and analytical studies ( FT-IR, UV-visible spectra, 1H-NMR, mass spectrometry, (C.H.N.O), thermogravimetric analysis (TGA), in addition to the magnetic susceptibility and conductivity measurement of the synthesis complexes, among the results we obtained from the tests, we showed that the ligand behaves with the (triple Valence) lanthanide ions, the multidentate

... Show More
View Publication Preview PDF
Scopus (14)
Crossref (2)
Scopus Crossref
Publication Date
Mon May 25 2015
Journal Name
International Journal Of Current Research
Synthesis, Spectral and Antimicrobial Activity of Mixed Ligand Complexes of Co(II),Ni(II),Cu(II) and Zn(II) with 4-aminoantipyrine and Tributylphosphine
...Show More Authors

Complexes of Co(II),Ni(II),Cu(II)and Zn(II) with mixed ligand of 4- aminoantipyrine (4-AAP) and tributylphosphine (PBu3) were prepared in aqueous ethanol with (1:2:2) (M:L:PBu3). The prepared complexes were characterized using flame atomic absorption, FT.IR and UV-Vis spectroscopic methods as well as magnetic susceptibility and conductivity measurements. In addition biological activity of the two ligands and their complexes against three selected type of bacteria were also examined. The general compositions of the complexes are found to be [M(4-AAP)2(PBu3)2] Cl2 . Where M= Co(II),Ni(II),Cu(II)and Zn(II). Some of the complexes exhibit good bacterial activities. From the obtained data the octahedral structures have suggested for all prepare

... Show More
Publication Date
Tue Jul 22 2025
Journal Name
Journal Of Baghdad College Of Dentistry
The Effect of Zirconium Silicate Nanopowder Reinforcement on Some Mechanical and Physical Properties of Heat Cured Poly (Methyl Methacrylate) Denture Base Materials
...Show More Authors

Background: Polymethylmethacrylate (PMMA) has relatively unsatisfactory mechanical properties such as low flexural strength and impact strength also dimensional instability. Material and method: Zirconium silicate nanoparticles were coated with a layer of trimethoxysilylpropylmethacrylate (TMSPM) before sonication in monomer (MMA) with the percentages 1% and 1.5% by weight then mixed with powder using conventional procedure, (150) samples were prepared and divided into three groups, each group consisted of (50) samples, the first group prepared from PMMA without addition (control), another group with the addition of 1% wt Zrsio4 nanoparticles (experimental) and the third one with 1.5% wt Zrsio4 nanoparticles (experimental). Each group

... Show More
View Publication Preview PDF