The laser micro-cutting process is the most widely commonly applied machining process which can be applied to practically all metallic and non-metallic materials. While this had challenges in cutting quality criteria such as geometrical precision, surface quality and numerous others. This article investigates the laser micro-cutting of PEEK composite material using nano-fiber laser, due to their significant importunity and efficiency of laser in various manufacturing processes. Design of experiential tool based on Response Surface Methodology (RSM)-Central Composite Design (CCD) used to generate the statistical model. This method was employed to analysis the influence of parameters including laser speed, laser power, laser frequency and number of passes on the cutting characteristics -and geometrical. Cutting-geometry requirements are significant quality features since they are one of the metrics for the geometrical precision of micro-cutting proses it was concluded that higher laser power, slower speed, and more pass number result in a low kerf taper, these parameters have a significant impact on the other cutting characteristics, and geometrical. Whereas the frequency has the lowers impact on the cutting geometrical. Finally, the experiments show Maximum depth was 2000, width minimum top kerf width was 305.56 µm and the minimum angle of 2.8906.
Background: Bone is essentially a highly vascular, living, constantly changing mineralized connective tissue. It is remarkable for its hardness, resilience and regenerative capacity, as well as its characteristic growth mechanisms. This study aimed to: 1. To evaluate the effect of bone morphogenetic protein7 (BMP7) on bone healing in artificially created intrabony defect in rabbits upper diastema, histologically. 2. To study the immunohistochemical expression of TGF-β3 and IGF-1R as bone formation markers in experimental and control groups during bone healing. Material and method: Forty male rabbits, was used in this study, 8 rabbits for each healing interval (3 days, 1,2 ,4 and 6 weeks). In each rabbit two bone holes were created on th
... Show MoreABSTRACT Background: Generally, the facial esthetics depends on the esthetic appearance of the maxillary anterior teeth. The purposes of this study were to analyse the macro-aesthetic appearance of the face and the micro-aesthetic appearance of the maxillary anterior teeth to establish the normative values for class I normal occlusion and to detect possible gender differences. Materials and methods: The sample consisted of 120 Iraqi adults (60 males and 60 females) aged (18-23) years. Each individual was clinically examined, then with cephalostat based head position, extraoral and intraoral photographs were taken for each subject. The facial and dental measurements were measured using AutoCad program 2014. Descriptive statistics was obtaine
... Show MoreThe efficiency of Nd:YAG laser radiation in removing debris and smear layer from prepared root
canal walls was studied. Fifty-seven human extracted single rooted anterior teeth were divided into three
groups. A group that was not lased is considered as a control group. The remaining teeth were exposed to
different laser parameters regarding laser energy, repetition rate and exposure time. For the case of the set of
parameters of 7 mJ laser energy, the cleaning was maximum at 3 p.p.s. repetition rate for 3 seconds exposure
time for, the coronal, middle and apical thirds. Above and below this energy level, there was an overdose
(melting) or under dose (no effect). Nevertheless for 10mJ laser energy case, the cleaning effi
This search aim to measure Hardness for Epoxy resin and for unsaturated Polyester resin as base materials for composite Hybrid and the materials used is Hybrid fiber Carbon-Kevlar. The Hand Lay-up method was used to manufacture plates of Epoxy resin (EP) and unsaturated Polyester EP,UPE backed by Hybrid fiber (Carbon-Kevlar) and with small volume fraction 5,10 and 15 for every there are Layer of fibers (1,2 and 3). The hardness test was count for material EP, UPE resin and there composites and that we notice that the Hardness (HB) decreased with increase of temperatures.
This study aimed to investigate the ability of clove and cinnamon extracts to make pathogenic multidrug-resistant (MDR) Klebsiella pneumoniae more sensitive to the host’s immune system and thereby interrupt the bacterial infection process in the rat model. Therefore, 60 Wistar male rats were used in this study. The phytochemical constituents of the plant extract were analysed using the gas chromatography-mass spectrometry (GC-MS) technique. Then, the capability of the plant extracts, as prophylactic and treatment, against K. pneumoniae in rats was studied by estimating the complete blood counts (CBCs) and the serum concentrations of interleukin-4 (IL-4) and interferon-gamma (IFN-γ) before and after the treatment. The results showed that
... Show MoreBackground: Vibration decreases the viscosity of composite, making it flow and readily fit the walls of the cavity. This study is initiated to see how this improved adaptation of the composite resin to the cavity walls will affect microleakage using different curing modes
Materials and methods: Standard Class V cavities were prepared on the buccal surface of sixty extracted premolars. Teeth were randomly assigned into two groups (n=30) according to the composite condensation (vibration and conventional) technique, then subdivided into three subgroups (n=10) according to light curing modes (LED-Ramp, LED-Fast and Halogen Continuous modes). Cavities were etched and bonded with Single Bond Universal
... Show MoreThis study has been conducted to examin the effect of sodium propionate at different level of 0.03,0.06,0.10% on the number of bacteria and mold and to extend the storage life of laboratory processed biscuit. The results indicated that the use of 0.10% sodium propionate prolonged the storage peroid until the third month, while the use of 0.20% sodium propionate showed no growth of bacteria up to six month of storage, three types of bacteria has been isolated from processed biscuit, namely, Staphylococcus aureus, Bacillus cereus, Esherichia coli. using 0.10% sodium propionate showed no growth of mold up to three month of storage ,while using of 0.15 % and 0.20% sodium propionate prevent the growth
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