This paper presents the theoretical and experimental results of drilling high density
polyethylene sheet with thickness of 1 mm using millisecond Nd:YAG pulsed laser. Effects of laser
parameters including laser energy, pulse duration and peak power were investigated. To describe and
understand the mechanism of the drilling process Comsol multiphysics package version 4.3b was used to
simulate the process. Both of the computational and experimental results indicated that the drilling
process has been carried out successfully and there are two phases introduced in the drilling process,
vaporization and melting. Each portion of these phases depend on the laser parameters used in the
drilling process
The nuclear charge density distributions, form factors andcorresponding proton, charge, neutron, and matter root mean squareradii for stable 4He, 12C, and 16O nuclei have been calculated usingsingle-particle radial wave functions of Woods-Saxon potential andharmonic-oscillator potential for comparison. The calculations for theground charge density distributions using the Woods-Saxon potentialshow good agreement with experimental data for 4He nucleus whilethe results for 12C and 16O nuclei are better in harmonic-oscillatorpotential. The calculated elastic charge form factors in Woods-Saxonpotential are better than the results of harmonic-oscillator potential.Finally, the calculated root mean square radii usingWoods-Saxonpotentials ho
... Show MoreBackground: This study was conducted to evaluate the hard palate bone density and thickness during 3rd and 4th decades and their relationships with body mass index (BMI) and compositions, to allow more accurate mini-implant placement. Materials and method: Computed tomographic (CT) images were obtained for 60 patients (30 males and 30 females) with age range 20-39 years. The hard palate bone density and thickness were measured at 20 sites at the intersection of five anterioposterior and four mediolateral reference lines with 6 and 3 mm intervals from incisive foramen and mid-palatal suture respectively. Diagnostic scale operates according to the bioelectric impedance analysis principle was used to measure body weight; percentages of body fa
... Show MoreDifferent methods can be used to remove tissue during gingivectomy and produce a good gingival margin, the most common is the conventional gingivectomy which is done by the use of scalpel, now a day’s Laser is widely spread and can be used to perform surgeries. Materials and methods: 50 patients divided into two equal groups, Group 1 gingivectomy was done by Diode Laser, Group 2 gingivectomy was done by scalpel, plaque and gingival index were measured at 1st, 2nd and 3rd visit, swab were taken and sent foe detecting bacterial growth and biopsy were taken for histopathological examination. Group 1 show no significant differences in plaque and gingival means between the visits, the bacteriological examination showed no growth of bact
... Show MoreBackground: different methods can be used to remove tissue during gingivectomy and produce a good gingival margin, the most common is the conventional gingivectomy which is done by the use of scalpel, now a day’s Laser is widely spread and can be used to perform surgeries. Materials and methods: 50 patients divided into two equal groups, Group 1 gingivectomy was done by Diode Laser, Group 2 gingivectomy was done by scalpel, plaque and gingival index were measured at 1st, 2nd and 3rd visit, swab were taken and sent foe detecting bacterial growth and biopsy were taken for histopathological examination. Group 1 show no significant differences in plaque and gingival means between the visits, the bacteriological examination showed no growth of
... Show MoreCompaction of triticale grain with three moisture contents (8%, 12%, and 16% wet basis) was measured at five applied pressures (0, 7, 14, 34, and 55 kPa). Bulk density increased with increasing pressure for all moisture contents and was significantly (p < 0.0001) dependent on both moisture content and applied pressure. A Verhulst logistic equation was found to model the changes in bulk density of triticale grain with R2 of 0.986. The model showed similar beha
Land Use / Land Cover (LULC) classification is considered one of the basic tasks that decision makers and map makers rely on to evaluate the infrastructure, using different types of satellite data, despite the large spectral difference or overlap in the spectra in the same land cover in addition to the problem of aberration and the degree of inclination of the images that may be negatively affect rating performance. The main objective of this study is to develop a working method for classifying the land cover using high-resolution satellite images using object based method. Maximum likelihood pixel based supervised as well as object approaches were examined on QuickBird satellite image in Karbala, Iraq. This study illustrated that
... Show MoreSingle Point Incremental Forming (SPIF) is a forming technique of sheet material based on layered manufacturing principles. The sheet part is locally deformed through horizontal slices. The moving locus of forming tool (called as toolpath) in these slices constructed to the finished part was performed by the CNC technology. The toolpath was created directly from CAD model of final product. The forming tool is a Ball-end forming tool, which was moved along the toolpath while the edges of sheet material were clamped rigidly on fixture.
This paper presented an investigation study of thinning distribution of a conical shapes carried out by incremental forming and the validation of finite element method to evaluate the limits of the p
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