In this work, results of a mathematical analysis of the role of workpiece preheating in laser keyhole welding were presented. This analysis considered the steady-state welding as well as certain range of boundary conditions over which preheating effect would be indicated. This work is an attempt to interpret the role of preheating to increase welding depth and perform keyhole welding with high quality using physical and thermal properties of steel alloys.

The long healing time of bone after tooth extraction in order to construct artificial teeth is uncomfortable to the patient because of aesthetic or masticatory problems in addition to the daily visit to dental clinic. The objective of this study was to evaluate the effect of 805 nm diode laser with long time intervals on repair of bone and skin incisions in rabbits through biochemical, radiological and histological findings. Eighteen New-Zealand rabbits were undergone surgical operations to make a cavity in the bone of the lower jaw, the rabbits were divided into two groups:- Group A (control group) containing nine rabbits. Group B (lased group) containing nine rabbits in which two cavities were done, one on the right side and the other

Photobiomodulation (PBM) is a form of the use of visible red and Near-infrared (NIR) light at low power, where a laser light photon is absorbed at the electronic level, without heat production. PBM can be applied in wide range of treatment to help the wound, inflammation, edema, and pain reduction. However, there is a lack of scientific documentation regarding its actual effects. Objectives: This study assesses the impact of PBM on the release of M1-related cytokine in monocyte cells with particular emphasis on interleukin-1β (IL-1β) and Tumour Necrosis Factor α (TNF-α). Methods: Tamm-Horsfall Protein 1 (THP-1) macrophages M1 cells have been exposed to the light from the diode laser of 850nmat different doses (0, 0.6, 1.2 and 3.

The effect of 410nm with 100 mW output power and one centimetre spot size (0.128 W/cm2 power density) Diode laser irradiation at different exposure times on the growth of Gram-negative Pseudomonas aeruginosa and Gram-positive Staphylococcus aureus was evaluated. Seventy swap samples were collected from burn and infected wounds of 35 patients admitted to the burn-wound unit in Al-Yarmouk Teaching Hospital in Baghdad during the period from December 2014 to February 2015. These bacteria were isolated and identified depending on their growth on selective media, cultural characteristics, Gram stain morphology and biochemical tests and finally were confirmed by Vitek 2 compact system test .Susceptibility of bacterial isolates to 15antibiotics

A field experiment was conducted during winter, 2015-16 with the objective to investigate the effect of bread wheat cultivars (Abu-Ghraib3, Ibaa99, and Alfeteh) and seed priming 100, 100, 150 mg L-1 of benzyl adenine, salicylic acid, gibberellic acid (GA3), respectively, ethanolic extract of Salix Sp., water extract of Glycyrrhiza glabra and distilled water (control) on grain growth rate (GGR), effective filling period (EFP) and accelerating of physiological maturity. Randomized complete block design with three replicates was applied. GA3×Ibaa99 surpassed others in grain yield (7.432 tonne ha-1) when gave the highest grain weight (45.13 mg grain-1) and GGR (1.5 mg grain-1 day-1) with the fastest time to start and end EFP (5 and 34 days), w

This work studies with produce of light fuel fractions of gasoline, kerosene and gas oil from treatment of residual matter that will be obtained from the solvent extraction process as by product from refined lubricate to improve oil viscosity index in any petroleum refinery. The percentage of this byproduct is approximately 10% according to all feed (crude oil) in the petroleum refinery process. The objective of this research is to study the effect of the residence time parameter on the thermal cracking process of the byproduct feed at a constant temperature, (400 °C). The first step of this treatment is the thermal cracking of this byproduct material by a constructed batch reactor occupied with control device at a selective range of re

  Benzene is a hydrocarbon chemical consisting of six atoms arranged in a ring structure. At normal ambient temperatures; it is a liquid, which evaporates rapidly at room temperature and is highly flammable. It has a characteristic of aromatic odor and is slightly soluble in water (1.5 g/liter at 20ºC) but miscible with most other organic solvents [1].           Long-term inhalation of benzene causes blood disorders. It specifically affects bone marrow [2]. And it may cause anemia, excessive bleeding, damage to the immune system and DNA [3, 4]. Increased incidence of leukemia (cancer of the tissues that form white blood cells) has been observed in people occupationally exposed to