This work aimed to study the effect of laser surface treatment on the mechanical characteristics and corrosion behaviour of grey cast iron type A159. Many technical applications used conventional surface treatment, but laser surface hardening has recently been used to enhance the surface properties of many alloys. The mechanical characteristics, including microstructure, microhardness, and wear resistance of A159 grey cast iron, were studied, in addition to corrosion behaviour. The experimental laser parameters in this work were 0.9, 1.2, and 1.5 KW power with continuous wave carbon dioxide lasers with scanning speeds of 10 and 12 mm/s were used. The results found that phase-transitional alterations in microstructure were influenced by laser therapy. Also, the microhardness increased with increasing power, with the maximum reaching approximately 950 HV while the base metal has an average of approximately 260 HV. Also, we found the power laser increased corrosion resistance by lowering the corrosion rate (CR) from 21.10 for the untreated sample to 1.02 (m.p.y.), additionally, corrosion protection efficiency (CPE) increased to 95.27 percent.
This study introduced the effect of using magnetic abrasive finishing method (MAF) for finishing flat surfaces. The results of experiment allow considering the MAF method as a perspective for finishing flat surfaces, forming optimum physical mechanical properties of surfaces layer, removing the defective layers and decreasing the height of micro irregularities. Study the characteristics which permit judgment parameters of surface quality after MAF method then comparative with grinding
In this work an approach has been developed to investigate the influence of surface roughness on thermohydrodynamic performance in aligned and misaligned journal bearings by considering an average flow model and deriving the shear flow factor for various roughness configurations, similar to the pressure flow factor. An average Reynolds equation for rough surfaces is defined in term of pressure and shear flow factors, which can be obtained by numerical flow simulation, though the use of measured or numerically generated rough surfaces. Reynolds, heat conduction and energy equations are solved simultaneously by using a suitable numerical technique (Finite Difference Method) to obtain the pressure and temperature di
... Show MoreBackground: To investigate the effect of different types of storage media on enamel surface microstructure of avulsed teeth by using atomic force microscope.Materials and methods : Twelve teeth blocks from freshly extracted premolars for orthodontic treatment were selected . The study samples were divided into three groups according to type of storage media :A-egg white , B- probiotic yogurt , and C-bovine milk . All the samples were examined for changes in surface roughness and surface granularity distribution using atomic force microscope, at two periods: baseline, and after 8 hours of immersing in the three types of storage media. Results: Milk group had showed a significant increase in the mean of the roughness values at
... Show MoreABSTRACTBackground : Acne vulgaris is a
common skin disease, affecting more than 85% of
adolescents and often continuing into adulthood.
People between 11 and 30 years of age and up to
5% of older adults. For most patients acne remains
a nuisance with occasional flares of unsightly
comedones, pustules and nodules. For other less
fortunate persons, the sever inflammatory response
to Propionibacterium acnes (P.acnes) results in
permanent
Methods: Disfiguring scars. (1, 2) Stigmata of sever
acne cane lead to social ostracism, withdrawal
from society and severe psychologic
depression (1-4).
Result Pathogenesis of acne Traditionally, acne
has been thought of as a multifactorial disease of
the fo
has experienced a step-change since the inception of ambient mass spectrometry removed the requirement for samples to be investigated under vacuum conditions. Approaches based on surface– plasma interactions are especially promising, including PADI. Whilst the mechanisms involved in generating PADI spectra still need to be unravelled, PADI shows significant promise to become a valuable and versatile tool in the instrumental arsenal available to the surface analyst
Background: Nanotechnology has emerged as a pivotal domain in material science research with extensive applications across various sectors including biotechnology and medicine. Nanoparticles offer unique properties facilitating advancements in nanobiotechnology, particularly in nanomedicine, to combat bacterial infections and antibiotic resistance. This study aimed to determine the application of nanoparticles, specifically nano-TiO2, in treating plasmid-mediated antibiotic resistance in both Gram-negative and Gram-positive bacteria. Method: We evaluated antibiotic and nanomaterial sensitivity through disc diffusion and broth microdilution assays. Plasmid curing experiments were conducted using varying concentrations of nano-TiO2 an
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