Characterization of surface roughness of laser deposited Titanium alloy and copper using AFM

Abstract: Laser Metal Deposition (LMD) is the process of using the laser beam of a nozzle to produce a melt pool on a metal surface usually the substrate and metal powder is been deposited into it thereby creating a fusion bond with the substrate to form a new material layer against the force gravity. A good metal laminate is formed when the wettability between the dropping metal powder and the substrate adheres. This paper reports the surface roughness of laser deposited titanium alloy and copper (Ti6Al4V + Cu) using the Atomic Force Microscopy (AFM). This AFM is employed in order to sense the surface and produce different manipulated images using the micro-fabricated mechanical tip under a probe cartridge of high resolution. The process parameters employed during the deposition routine determines the output of the deposit. A careful attention is given to the laser deposited Ti6Al4V + Cu samples under the AFM probe because of their single tracked layers with semi-circular pattern of deposition

Non-proportionality of strain and coupling effects on dislocation distribution and ductility in ferritic steel polycrystals

Non-proportionality of straining, initial texture and hardening have been investigated in a ferritic steel polycrystal within a crystal plasticity finite element framework. Two extreme forms of hardening are investigated; namely, isotropic latent-hardening and anisotropic self-hardening. Dislocation density evolutions on all independent slip systems have been calculated in order to investigate the establishment of dislocation distributions and evaluate their dependence on non-proportionality, hardening, texture and predicted ductility. The results show that non-proportionality effects are more pronounced under isotropic latenthardening as opposed to anisotropic self-hardening especially under non-proportional uniaxial strains

Knowledge and attitudes towards cervical cancer and human papillomavirus: A Nigerian pilot study

This study aimed to ascertain the knowledge and attitudes of urban and rural dwellers to cervical cancer and HPV in Gwagwalada Area Council of Nigeria. 400 participants aged 15-45 years were selected from Gwagwalada town and the adjourning Giri village to respond to a multi-choice–free response questionnaire designed to obtain informationon respondents’ biodata, knowledge of STIs, human papilloma virus and cervical cancer, health and communication resources in their communities. This was supplemented by focus group discussions among religious and tribal groups within the urban and rural communities. We found a low level of awareness about HPV and cervical cancer which majority felt could not be prevented. Although awareness of STDs was high in both urban and rural dwellers, condom use was low. The study underscores the need for a well planned and implemented health communication and education program on STIs, HPV and cervical cancer in Nigeri.(Afr J Reprod Health 2010; 14[1]:95-108)