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Fulltext Wear Mechanism of Multilayer Coated Carbide Cutting Tool in the Milling Process of AISI 4340 under Cryogenic Environment

Muhamad SS, Ghani JA, Che Haron CH, Yazid H

Materials (Basel), 2022 Jan 11;15(2).
PMID: 35057242 DOI: 10.3390/ma15020524

Cryogenic technique is the use of a cryogenic medium as a coolant in machining operations. Commonly used cryogens are liquid nitrogen (LN2) and carbon dioxide (CO2) because of their low cost and non-harmful environmental impact. In this study, the effects of machining conditions and parameters on the wear mechanism were analysed in the milling process of AISI 4340 steel (32 HRC) under cryogenic conditions using a multilayer coated carbide cutting tool (TiAlN/AlCrN). A field emission scanning electron microscope with energy-dispersive X-ray analysis was used to examine the wear mechanisms comprehensively. At low machining parameters, abrasion and adhesion were the major wear mechanisms which occurred on the rake face. Machining at high machining parameters caused the removal of the coating material on the rake face due to the high temperature and cutting force generated during the cutting process. In addition, it was found that continuously adhered material on the rake face would lead to crater wear. Furthermore, the phenomenon of oxidation was also observed when machining at high cutting speed, which resulted in diffusion wear and increase in the crater wear. Based on the relationship between the cutting force and cutting temperature, it can be concluded that these machining outputs are significant in affecting the progression of tool wear rate, and tool wear mechanism in the machining of AISI 4340 alloy steel.
Fulltext Combining ability for germination traits in Jatropha curcas L

Islam AK, Anuar N, Yaakob Z, Ghani JA, Osman M

ScientificWorldJournal, 2013;2013:935981.
PMID: 24222756 DOI: 10.1155/2013/935981

Six parents of Jatropha curcas were crossed in half diallel fashion, and the F 1s were evaluated to determine the combining ability for nine germination parameters. The ratio between general combining ability (GCA) and specific combining ability (SCA) variances indicated preponderance of additive gene action for all the characters except germination percentage, time of 50% germination, seedling length, and seedling vigor index. The parents P 1 and P 2 were the best general combiner for most of the characters studied. The cross P 1 × P 5 was the best specific combiner for speed of emergence, germination percentage, germination energy, germination index, and seedling vigor index, the cross P 2 × P 5 for mean germination time, time of 50% germination, and seedling length, and the cross P 4 × P 5 for number of days to first germination. The germination percentage varied from 58.06 to 92.76% among the parents and 53.43 to 98.96% among the hybrids. The highest germination (98.96%) was observed in hybrid P 2 × P 4, and none of the hybrids or parents showed 100% germination. The highest germination index (GI) and seedling vigor index (SVI) were found in hybrid P 1 × P 5 and P 2 × P 5, respectively. The results of this study provide clue for the improvement of Jatropha variety through breeding program.
Production of methanol from biomass waste via pyrolysis

Kamarudin SK, Shamsul NS, Ghani JA, Chia SK, Liew HS, Samsudin AS

Bioresour Technol, 2013 Feb;129:463-8.
PMID: 23266847 DOI: 10.1016/j.biortech.2012.11.016

The production of methanol from agricultural, forestry, livestock, poultry, and fishery waste via pyrolysis was investigated. Pyrolysis was conducted in a tube furnace at 450-500 °C. Sugarcane bagasse showed the methanol production (5.93 wt.%), followed by roots and sawdust with 4.36 and 4.22 wt.%, respectively. Animal waste offered the lowest content of methanol, as only 0.46, 0.80, and 0.61 wt.% were obtained from fishery, goat, and cow waste, respectively. It was also observed that the percentage of methanol increased with an increase in volatile compounds while the percentage of ethanol increased with the percentage of ash and fix carbon. The data indicate that, pyrolysis is a means for production of methanol and ethanol after further optimization of the process and sample treatment.
Postural assessment in pen-and-paper-based observational methods and their associated health effects: a review

Sukadarin EH, Deros BM, Ghani JA, Mohd Nawi NS, Ismail AR

Int J Occup Saf Ergon, 2016 Sep;22(3):389-98.
PMID: 27173135 DOI: 10.1080/10803548.2016.1156924

INTRODUCTION: This review describes standardized ergonomics assessment based on pen-and-paper observational methods for assessing ergonomics risk factors.
OBJECTIVE: The three main objectives are to analyze published pen-and-paper observational methods, to extract and understand the risk levels of each method and to identify their associated health effects.
METHODOLOGY: The authors searched scientific databases and the Internet for materials from 1970 to 2013 using the following keywords: ergo, posture, method, observational, postural angle, health effects, pain and diseases. Postural assessments of upper arms, lower arms, wrists, neck, back and legs in six pen-and-paper-based observational methods are highlighted, extracted in groups and linked with associated adverse health effects.
RESULTS: The literature reviewed showed strengths and limitations of published pen-and-paper-based observational methods in determining the work activities, risk levels and related postural angles to adverse health effects. This provided a better understanding of unsafe work postures and how to improve these postures.
CONCLUSION: Many pen-and-paper-based observational methods have been developed. However, there are still many limitations of these methods. There is, therefore, a need to develop a new pen-and-paper-based observational method for assessing postural problems.
Fulltext How relevant is environmental quality to per capita health expenditures? Empirical evidence from panel of developing countries

Yahaya A, Nor NM, Habibullah MS, Ghani JA, Noor ZM

Springerplus, 2016;5(1):925.
PMID: 27386369 DOI: 10.1186/s40064-016-2505-x

Developing countries have witnessed economic growth as their GDP keeps increasing steadily over the years. The growth led to higher energy consumption which eventually leads to increase in air pollutions that pose a danger to human health. People's healthcare demand, in turn, increase due to the changes in the socioeconomic life and improvement in the health technology. This study is an attempt to investigate the impact of environmental quality on per capital health expenditure in 125 developing countries within a panel cointegration framework from 1995 to 2012.
Fulltext Reliability Study of Solder Paste Alloy for the Improvement of Solder Joint at Surface Mount Fine-Pitch Components

Rahman MNA, Zubir NSM, Leuveano RAC, Ghani JA, Mahmood WMFW

Materials (Basel), 2014 Dec 02;7(12):7706-7721.
PMID: 28788270 DOI: 10.3390/ma7127706

The significant increase in metal costs has forced the electronics industry to provide new materials and methods to reduce costs, while maintaining customers' high-quality expectations. This paper considers the problem of most electronic industries in reducing costly materials, by introducing a solder paste with alloy composition tin 98.3%, silver 0.3%, and copper 0.7%, used for the construction of the surface mount fine-pitch component on a Printing Wiring Board (PWB). The reliability of the solder joint between electronic components and PWB is evaluated through the dynamic characteristic test, thermal shock test, and Taguchi method after the printing process. After experimenting with the dynamic characteristic test and thermal shock test with 20 boards, the solder paste was still able to provide a high-quality solder joint. In particular, the Taguchi method is used to determine the optimal control parameters and noise factors of the Solder Printer (SP) machine, that affects solder volume and solder height. The control parameters include table separation distance, squeegee speed, squeegee pressure, and table speed of the SP machine. The result shows that the most significant parameter for the solder volume is squeegee pressure (2.0 mm), and the solder height is the table speed of the SP machine (2.5 mm/s).
Development and validation of the knowledge, attitude and practice questionnaire (LAUNDERKAP) regarding white coat use among medical students during clinical practice

Chan CK, Lam TY, Mohanavel L, Ghani JA, Anuar ASK, Lee CJ, et al.

Am J Infect Control, 2022 Dec;50(12):1374-1380.
PMID: 35292298 DOI: 10.1016/j.ajic.2022.02.033

BACKGROUND: Medical students' white coats were found to harbor harmful organisms. This could be due to non-compliance to white coat hygiene measures. Therefore, we aim to develop and validate a questionnaire to assess the of knowledge, attitude, and practice (LAUNDERKAP) of white coat use among medical students in Malaysia.
METHODS: This study was conducted in 4 local medical schools. LAUNDERKAP was developed via literature review and had 3 domains: attitude, knowledge, practice. An expert panel assessed the content validity and clarity of wording. LAUNDERKAP was then piloted among 32 medical students. To test construct validity and internal consistency, 362 medical students were approached. Construct validity was assessed using exploratory factor analysis. Internal consistency was evaluated using Cronbach alpha for attitude and practice, while Kuder-Richardson 20 (KR-20) was used for knowledge.
RESULTS: A total of 319 of 362 students responded. Exploratory factor analysis extracted 1 factor each for attitude and knowledge respectively, and 3 factors for practice. Cronbach alpha for attitude was 0.843 while KR-20 for knowledge was 0.457. Cronbach alpha for practice ranged from 0.375 to 0.689. The final LAUNDERKAP contained 32-items (13 attitude, 9 knowledge, 10 practice).
CONCLUSIONS: LAUNDERKAP had adequate psychometric properties and can be used to assess KAP of medical students towards white coat use.
Knowledge, attitude, and practice of white coat use among medical students during clinical practice (LAUNDERKAP): A cross-sectional study

Chan CK, Lam TY, Mohanavel L, Ghani JA, Anuar ASK, Lee CJ, et al.

Am J Infect Control, 2024 Jan;52(1):35-40.
PMID: 37423404 DOI: 10.1016/j.ajic.2023.06.022

BACKGROUND: Recent studies found white coats to be reservoirs for bacteria and medical students did not conform to proper hygiene measures when using these white coats. We investigated the knowledge, attitude, and practice (KAP) of medical students toward white coat use in clinical settings (LAUNDERKAP).
METHODS: A validated, online-based survey was disseminated to 670 students from four Malaysian medical schools via random sampling. Scores were classified into good, moderate, or poor knowledge and practice, and positive, neutral, or negative attitude. Mann-Whitney U and Kruskal-Wallis tests were used to analyze the relationship between demographic variables and knowledge, attitude, and practice scores.
RESULTS: A total of 492/670 students responded (response rate: 73.4%). A majority showed negative attitudes (n = 246, 50%), poor knowledge (n = 294, 59.8%), and moderate practice (n = 239, 48.6%). Senior and clinical year students had more negative attitudes. Male students had higher knowledge, while students from private medical schools and preclinical years had better practice. There was a significant relationship between attitude and practice (r = 0.224, P