MyMedR

Physicochemical property enhancement of biodiesel synthesis from hybrid feedstocks of waste cooking vegetable oil and Beauty leaf oil through optimized alkaline-catalysed transesterification

Milano J, Ong HC, Masjuki HH, Silitonga AS, Kusumo F, Dharma S, et al.

Waste Manag, 2018 Oct;80:435-449.

PMID: 30455026 DOI: 10.1016/j.wasman.2018.09.005

Recycling waste cooking vegetable oils by reclaiming and using these oils as biodiesel feedstocks is one of the promising solutions to address global energy demands. However, producing these biodiesels poses a significant challenge because of their poor physicochemical properties due the high free fatty acid content and impurities present in the feedstock, which will reduce the biodiesel yields. Hence, this study implemented the following strategy in order to address this issue: (1) 70 vol% of waste cooking vegetable oil blended with 30 vol% of Calophyllum inophyllum oil named as WC70CI30 used to alter its properties, (2) a three-stage process (degumming, esterification, and transesterification) was conducted which reduces the free fatty acid content and presence of impurities, and (3) the transesterification process parameters (methanol/oil ratio, reaction temperature, reaction time, and catalyst concentration) were optimized using response surface methodology in order to increase the biodiesel conversion yield. The results show that the WC70CI30 biodiesel has favourable physicochemical properties, good cold flow properties, and high oxidation stability (22.4 h), which fulfil the fuel specifications stated in the ASTM D6751 and EN 14214 standards. It found that the WC70CI30 biodiesel has great potential as a diesel substitute without the need for antioxidants and pour point depressants.

Synthesis, characteristics and sonocatalytic activities of calcined γ-Fe2O3 and TiO2 nanotubes/γ-Fe2O3 magnetic catalysts in the degradation of Orange G

Pang YL, Lim S, Ong HC, Chong WT

Ultrason Sonochem, 2016 Mar;29:317-27.

PMID: 26585012 DOI: 10.1016/j.ultsonch.2015.10.003

In this work, γ-Fe2O3 and TiO2 NTs/γ-Fe2O3 composites with good magnetism and sonocatalytic activity were prepared by a facile polyol method and utilize the principle of isoelectric point method, respectively. The structural and magnetic features of the prepared calcined γ-Fe2O3 and composite catalysts were investigated by transmission electron microscopy (TEM), powder X-ray diffraction (XRD), surface analysis, UV-Vis diffuse reflectance spectra (UV-Vis DRS), vibrating sample magnetometry (VSM) and zeta potential analysis. The effects of calcination temperature on γ-Fe2O3 phase variation, physical properties and sonocatalytic properties were investigated. The porosity, specific surface area, band gap energy and sonocatalytic activity of γ-Fe2O3 were gradually decreased with calcination temperature increased. TiO2 NTs/γ-Fe2O3 with appropriate composition and specific structural features possess synergetic effects such as efficient separation of charge carriers and hydroxyl radicals produced by heterogeneous fenton and fenton-like reactions. This enhanced the sonocatalytic activity for the degradation of Orange G under ultrasonic irradiation. The sonocatalytic reactions obeyed pseudo first-order kinetics. All these information provide insight into the design and development of high-efficiency catalyst for wastewater treatment.

Obstetrical data in Malaysian aborigine women

Ong HC

Trop Geogr Med, 1974 Dec;26(4):384-8.

PMID: 4456697

Fulltext Cost-benefit analysis and emission reduction of energy efficient lighting at the Universiti Tenaga Nasional

Ganandran GS, Mahlia TM, Ong HC, Rismanchi B, Chong WT

ScientificWorldJournal, 2014;2014:745894.

PMID: 25133258 DOI: 10.1155/2014/745894

This paper reports the result of an investigation on the potential energy saving of the lighting systems at selected buildings of the Universiti Tenaga Nasional. The scope of this project includes evaluation of the lighting system in the Library, Admin Building, College of Engineering, College of Information Technology, Apartments, and COE Food court of the university. The main objectives of this project are to design the proper retrofit scenario and to calculate the potential electricity saving, the payback period, and the potential environmental benefits. In this survey the policy for retrofitting the old lighting system with the new energy saving LEDs starts with 10% for the first year and continues constantly for 10 years until all the lighting systems have been replaced. The result of the life cycle analysis reveals that after four years, the selected buildings will bring profit for the investment.

Migration in Malaysian aborigines: clinical observations in pregnancy

Ong HC

Southeast Asian J. Trop. Med. Public Health, 1975 Sep;6(3):407-412.

PMID: 1221499

This study presents clinical observations in pregnancy made on aborigines of the deep jungle and "outside" populations. Migration out of the jungle results in lowered nutritional status as a result of low socio-economic status in the "outside" aborigine. This, together with food habits, increased family size and higher incidence of helminthic infestations, results in lower mean values of Hb, PVC and MCHC and a higher prevalence of anaemia in pregnancy in the migrant aborigine. A higher population density in the "outside" population resulting in frequent intermingling and increased chances of cross-contamination probably explains the increased vaginal bacterial growth in the "outside" Aborigine women. A higher prevalence of vaginal candidiasis in the "outside" aborigine woman is probably related to exposure to oral contraceptives and broad-spectrum antibiotics. On the other hand, better medical and obstetrical services become more readily available to the "outside" aborigine and this results in a favourable influence on perinatal health.

State-of-the-art of the pyrolysis and co-pyrolysis of food waste: Progress and challenges

Su G, Ong HC, Fattah IMR, Ok YS, Jang JH, Wang CT

Sci Total Environ, 2022 Feb 25;809:151170.

PMID: 34699825 DOI: 10.1016/j.scitotenv.2021.151170

The continuous growth of population and the steady improvement of people's living standards have accelerated the generation of massive food waste. Untreated food waste has great potential to harm the environment and human health due to bad odor release, bacterial leaching, and virus transmission. However, the application of traditional disposal techniques like composting, landfilling, animal feeding, and anaerobic digestion are difficult to ease the environmental burdens because of problems such as large land occupation, virus transmission, hazardous gas emissions, and poor efficiency. Pyrolysis is a practical and promising route to reduce the environmental burden by converting food waste into bioenergy. This paper aims to analyze the characteristics of food waste, introduce the production of biofuels from conventional and advanced pyrolysis of food waste, and provide a basis for scientific disposal and sustainable management of food waste. The review shows that co-pyrolysis and catalytic pyrolysis significantly impact the pyrolysis process and product characteristics. The addition of tire waste promotes the synthesis of hydrocarbons and inhibits the formation of oxygenated compounds efficiently. The application of calcium oxide (CaO) exhibits good performance in the increment of bio-oil yield and hydrocarbon content. Based on this literature review, pyrolysis can be considered as the optimal technique for dealing with food waste and producing valuable products.

Fulltext Backcalculation of HIV infection rates in Malaysia

Ong HC, Soo KL

Med J Malaysia, 2006 Dec;61(5):616-20.

PMID: 17623964 MyJurnal

It has been almost two decades ago since the first AIDS case was reported in Malaysia. It has also been approximately eight years ago when the method of backcalculation was used to estimate the past HIV infection rate from the AIDS incidence data and an estimate of the incubation period distribution. This method is used because it makes use of the Malaysian AIDS incidence which is fairly reliable and reflects the trend of the epidemic as compared to the HIV infection rate recorded. The latest results generated show a slowdown in the increase of the number of estimated infected HIV+ cases in the late 1990s and this trend is supported by a slowdown in the increase of the number of AIDS cases recorded.

Fulltext An application of the backcalculation method to estimate past HIV infection rates in Malaysia

Ong HC, Quah SH, Low HC

Med J Malaysia, 1998 Dec;53(4):385-91.

PMID: 10971982

The method of backcalculation estimates past HIV infection rates from available AIDS incidence data and an estimate of the incubation period. The method is used on the Malaysian data to model the AIDS epidemic because it makes use of the Malaysian AIDS incidence data which is fairly reliable and is more reflective of the trend of the epidemic as compared to the HIV infection rate recorded. An application is made on the monthly AIDS incidence data in Malaysia from January 1995 until August 1996 released by the Ministry of Health, Malaysia using the backcalculation program from Bacchetti et al and the incubation period distribution from Brookmeyer to generate the current HIV infection rate for Malaysia (until August 1996).

Fulltext Towards better perinatal health

Ong HC

Med J Malaysia, 1983 Sep;38(3):176-7.

PMID: 6672555

A case of primary adenocarcinoma of the fallopian tube

Ong HC, Chan WF, Sinnathuray TA

Med J Malaysia, 1978 Mar;32(3):217-9.

PMID: 683046

Anencephalic pregnancies in a Malaysian hospital

Ong HC, Singh H, Ng TK, Chong CH

Med J Malaysia, 1978 Mar;32(3):212-4.

PMID: 683044

Human placental lactogen physiological role in pregnancy

Ong HC

Med J Malaysia, 1976 Mar;30(3):165-7.

PMID: 958050

Brow presentation

Ong HC, Chelvam P

Med J Malaysia, 1975 Jun;29(4):299-301.

PMID: 1196178

Partial exchange transfusion in the treatment of severe anaemia in late pregnancy

Ong HC, Chan WF, Hussein N

Med J Malaysia, 1975 Sep;30(1):63-65.

PMID: 1207535

Face presentation

Ong HC, Teo SP

Med J Malaysia, 1976 Sep;31(1):42-5.

PMID: 1023012

Onset of labour

Chong HL, Ong HC, Ang LT

Med J Malaysia, 1974 Sep;29(1):44-53.

PMID: 4282630

Hematological values in pregnancy in Orang Asli (aboriginal) women

Ong HC

Med J Malaysia, 1973 Jun;27(4):240-2.

PMID: 4270778

The ovaries at abdominal hysterectomy-conservation or removal?

Ong HC

Med J Malaysia, 1975 Sep;30(1):48-51.

PMID: 1207532

Fulltext Development and Validation of a Coping Scale for Caregivers in Malaysia

Ibrahim N, Ong HC, Wahab S

Malays J Med Sci, 2017 May;24(3):83-91.

PMID: 28814936 MyJurnal DOI: 10.21315/mjms2017.24.3.10

INTRODUCTION: Caregivers often experience stressful situations while in the midst of the caregiving process. Thus, various methods of coping have been widely applied and studied in previous researches. The aim of this study was to develop a novel questionnaire to assess the coping strategies employed by those who provide care to patients, and to further validate it among caregivers of schizophrenia patients in Malaysia.

METHODS: This study, which involved the caregivers of schizophrenia patients from a hospital in Kuala Lumpur, Malaysia, was comprised of three parts, namely in-depth interviews, a pilot study, and the validation of the developed questionnaire, known as Caregiver Cope (CgCopeTM).

RESULTS: Part A originally consisted of eight themes, and it was later modified to seven themes with four items each after discussions with some experts. Part B initially had 28 items derived from the seven themes in Part A, which were then reduced to six components after a factor analysis. Part C of the questionnaire consisted of 19 items, with six components (Distraction, Caring for patient, Venting, Religion, Recreation, and Social support) having a moderate to high reliability ranging from a Cronbach's alpha coefficient of 0.54 to 0.82. A factor analysis showed that the six factors of coping accounted for 62.36% of the total variance.

CONCLUSION: The CgCOPETM questionnaire is suitable for use among caregivers of schizophrenia patients. There is a need to further validate the instrument among caregivers of other patient populations.

Fulltext Pattern of heart disease and pregnancy seen in a Malaysian hospital

Ong HC, Puraviappan AP, Sinnathuray TA, Chong CH, Sen DK

Singapore Med J, 1978 Jun;19(2):93-7.

PMID: 751193

Pregnancy was associated with cardiac disease in 0.94% of pregnancies. 0.66% with rheumatic lesions and 0.25'\'0 with congenital lesions. The Malays had a higher incidence than the Chinese and Indians. Most of the cardiac pregnancies were in patients between 20-30 years of age and gravida 1 to 4. Nevertheless. still about 30% of cardiac pregnancies were in patients 30 years and over in age and 20% in patient gravida 5 and above. Rheumatic lesions predominated. involving mainly the mitral valve. of which the major lesion was mitral stenosis. PDA. ASD and VSD were the major congenital lesions. Major antepartum matemal complications included arrhythmias. heart failure, anemia and pre-eclampsia. Of the arrhythmias. atrial fibrillation and sinus tachycardia occurred most commonly. A high incidence of prophylactic forceps and vacuum deliveries
was evident. There was one matemal death. The majority of infants were bom alive and well.

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