Optimization Process for Esterification of Rubber Seed Oil (RSO) With Trimethylolpropane (TMP)

Trimethylolpropane (TMP) ester has the potential to serve as a basic material in the biolubricant production due to its biodegradability, environmental friendly and good thermal properties. Thus, an investigation on the optimization of esterification of TMP with rubber seed oil (RSO) fatty acid was carried out with sulphuric acid acting as the catalyst. In seeking optimised reaction, various temperature levels, durations and catalyst concentrations were applied. The results show that RSO has successfully being converted to TMP ester with 78% of TE at the temperature of 150oC using 2% (w/w) of sulphuric acid at 5 hours reaction time. Purification of TMP ester resulted in percentage yield of 66.8% of TMP ester with a mixture of DE and TE at 0.9% and 99.1%, respectively. TMP ester was analysed using high temperature gas chromatography (GC-FID) to determine the percentage composition of ester formed and fourier transform infrared spectroscopy (FTIR) to confirm the structure

Pengalaman pembelajaran informal dalam kalangan sukarelawan Mycorps, Kuala Lumpur

Kajian ini bertujuan untuk mengetahui pengalaman pembelajaran informal dalam kalangan sukarelawan MYCORPS dengan menggunakan kaedah kualitatif melalui temubual separa berstruktur dan menggunakan kaedah persampelan snowball. Tiga objektif kajian iaitu (i) meneroka pengalaman pembelajaran informal yang dialami oleh para sukarelawan MYCORPS, (ii) mengkaji faktor penyebab pengalaman pembelajaran informal yang dialami oleh para sukarelawan MYCORPS dan (iii) menyelidiki kesan pengalaman pembelajaran informal yang dialami oleh para sukarelawan MYCORPS. Data yang diperoleh dianalisis menggunakan kaedah analisis tematik. Pengalaman pembelajaran informal terbahagi kepada dua iaitu kemahiran insaniah dan kemahiran nyata. Faktor penyebab pengalaman pembelajaran informalterjadi adalah strategi pembelajaran, orang luar dan ahli kumpulan yang mengesankan pengetahuan, kemahiran dan sikap sukarelawan. Pendekatan fenomenologi yang dipilih bertujuan untuk memahami sesuatu fenomena. Hasil kajian mendapati pembelajaran informal dialami disebabkan faktor berkenaan dan memberi kesan kepada pengetahuan, kemahiran dan sikap. Kajian ini memberi implikasi kepada pengamal pembelajaran dewasa, teori yang digunakan dan juga sukarelawan

Effects of Honey-Spices Marination on Polycyclic Aromatic Hydrocarbons and Heterocyclic Amines Formation in Gas-Grilled Beef Satay

The effects of honey-spices marination on simultaneous formation of polycyclic aromatic hydrocarbons (PAHs) and heterocyclic amines (HCAs) in gas-grilled beef satay were investigated at different grilling temperatures (150 °C, 250 °C, and 350 °C). Beef satay samples used in this study were prepared using two types of honey-spices marination (Apis mellifera-spices and Trigona sp.-spices). Quantifications of fifteen PAHs using high performance liquid chromatography with fluorescence detection (HPLC-FLD) and nine HCAs using liquid chromatography tandem-mass spectrometry (LC–MS/MS) were performed with gradient programme. Results on PAHs and HCAs in marinated samples were compared with control. Highest concentrations (p < 0.05) of PAHs (marinated beef satay) and HCAs (control) were detected at 350 °C. The most prominent PAH and HCA were phenanthrene (24.61–84.36 ng/g) and 9H-pyrido-[4,3-b]indole (Norharman) (2.67–393.89 ng/g). Marination significantly (p < 0.05) reduced naphthalene, fluorene, pyrene, 2-amino-9H-pyrido[2,3-b]indole (AαC), 1-methyl-9H-pyrido-[4,3-b]indole (Harman), and Norharman in gas-grilled beef satay across all temperatures. Overall, inverse quantitative profiles of PAHs and HCAs formation were observed in marinated gas-grilled beef satay

Optimization Process for Esterification of Rubber Seed Oil (RSO) with Trimethylolpropane (TMP)

Trimethylolpropane (TMP) ester has the potential to serve as a basic material in the biolubricant production due to its biodegradability, environmental friendly and good thermal properties. Thus, an investigation on the optimization of esterification of TMP with rubber seed oil fatty acid was carried out with sulphuric acid acting as the catalyst. In seeking optimised reaction, various temperature levels, durations and catalyst concentrations were applied. The results show that RSO has successfully being converted to TMP ester with 78% of TE at the temperature of 150oC using 2% (w/w) of sulphuric acid at 5 hours reaction time. Purification of TMP ester resulted in percentage yield of 66.8% of TMP ester with a mixture of DE and TE at 0.9% and 99.1%, respectively. TMP ester was analysed using high temperature gas chromatography (GC-FID) to determine the percentage composition of ester formed and fourier transform infrared spectroscopy (FTIR) to confirm the structure

Effect of Different Amino Acids and Heating Conditions on the Formation of 2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) and Its Kinetics Formation Using Chemical Model System

The formation of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) was investigated using a kinetic study approach as described by first-order, Arrhenius, and Eyring equations. Chemical model systems with different amino acid precursors (proline, phenylalanine, and glycine) were examined at different times (4, 8, 12, and 16 min) and temperatures (150, 180, 210, 240, and 270 &deg;C). PhIP was detected using high-performance liquid chromatography equipped with fluorescence detector (HPLC-FLD). The good fit in first-order suggested that PhIP formation was influenced by the types of amino acids and PhIP concentration significantly increased with time and temperature (up to 240 &deg;C). PhIP was detected in proline and phenylalanine model systems but not in the glycine model system. The phenylalanine model system demonstrated low activation energy (Ea) of 95.36 kJ/mol that resulted in a high rate of PhIP formation (great amount of PhIP formed). Based on the ∆S&Dagger; values both proline and phenylalanine demonstrated bimolecular rate-limiting steps for PhIP formation. Altogether these kinetic results could provide valuable information in predicting the PhIP formation pathway

Effect of different amino acids and heating conditions on the formation of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) and its kinetics formation using chemical model system

The formation of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) was investigated using a kinetic study approach as described by first-order, Arrhenius, and Eyring equations. Chemical model systems with different amino acid precursors (proline, phenylalanine, and glycine) were examined at different times (4, 8, 12, and 16 min) and temperatures (150, 180, 210, 240, and 270 °C). PhIP was detected using high-performance liquid chromatography equipped with fluorescence detector (HPLC-FLD). The good fit in first-order suggested that PhIP formation was influenced by the types of amino acids and PhIP concentration significantly increased with time and temperature (up to 240 °C). PhIP was detected in proline and phenylalanine model systems but not in the glycine model system. The phenylalanine model system demonstrated low activation energy (Ea) of 95.36 kJ/mol that resulted in a high rate of PhIP formation (great amount of PhIP formed). Based on the ∆S‡ values both proline and phenylalanine demonstrated bimolecular rate-limiting steps for PhIP formation. Altogether these kinetic results could provide valuable information in predicting the PhIP formation pathway