Search

There are few methods available to arrest crack propagation or fatigue life of a structure. One of the crack arresting methods is by using kerf fabrication parallel to the edge crack. Recent study has proved that the introduction of the kerf parallel to an edge crack for a case of tension loading has reduced the stress intensity factor of the crack tip and thus will be able to arrest crack propagation or as long as the applied load is not significantly increased. However the study of kerf for the case of bending loading is still not available. Therefore this study aims to extend the study of kerf fabrication for a case of bending loading to conclude whether the kerf also can be applied as a crack arrestor for a structure under bending loading. This research focuses on total fatigue life cycle of a specimen that contains an edge crack and an edge kerf under fatigue three-point bending loading. The total fatigue cycles to failure using fatigue test for various specimens with different crack and kerf geometries were observed and compared with specimen without any kerf fabrication. Result shows the fatigue cycles can be further extended with maximum 39% extension. This can be achieved when kerf length to crack length ratio, k/a = 0.8 and distance to width ratio, d/w = 0.25. It can be concluded that the highest fatigue cycles’ extension can be achieved when the kerf and distance between kerf and crack are the longest. [ABSTRACT FROM AUTHOR]

Review papers on the basic principles and applications of plasma discharge in liquid have been reported. However, the development of plasma discharge in liquid is not widely reviewed. The aim of this paper is to review on the elements involved in developing plasma discharge in liquid. An overview will be given of the various types of existing power source, working gas, dielectric barrier, electrode material used to produce plasma, and reactive species production inside plasma discharge. [ABSTRACT FROM AUTHOR]

An atmospheric plasma system using Helium gas was developed. The effect of helium plasma treatment on skin scaffold surface was studied by scanning electron microscopy (SEM). The changes of skin scaffold surfaces before and after helium plasma treatment was recorded. The surface of skin scaffold changed with the prolonged of helium plasma treatment time. The depth of helium plasma penetration was studied using methylene blue dye staining method. The methylene blue will detect the presence or absence of an oxygen that was induced from plasma excitation. The presence of the oxygen indicated on the depth of helium plasma penetration. Results showed plasma are able to penetrate 4mm of skin scaffold after 1200 seconds of exposure. [ABSTRACT FROM AUTHOR]

Many researches had been conducted to enhance the properties of contact lens. Most of the research conducted discussed on the factors that affect the adhesion process to contact lenses, rate of contact lens contamination, and type of microbe that adhere on the contact lens surface and contact lens casing. Studies on the proposed strategies or technology that can be used to slower down the formation of bacteria on contact lens are being explored. New technologies or strategies to prevent or slow down the adhesion of bacteria on contact lens have become a priority in this area. This review paper covers two main aspects, namely factor that affect the bacteria adhesion on contact lens and also the introduction of plasma treatment as a potential method for contact lens treatment. [ABSTRACT FROM AUTHOR]