New terpolymers from n-butyl acrylate,glycidyl methacrylate and tetrahydrofurfuryl acrylate: Synthesis,characterisation and estimation of reactivity ratios

Development and practical application of multicomponent copolymerisation systems, such as terpolymerisation, is an on-going process because even a small addition of a particular comonomer may have a significant impact on the desired property. Commonly, three separate pairs of binary polymerisation experiments are carried out to obtain monomer reactivity ratios (MRR) values that relates to the ternary polymerisation reactions. However, the reaction conditions in each binary system may not be representative of the whole ternary system. The error-in-variables model (EVM) method is a relatively recent statistical approach to solving multi-response parameter estimation problems, with the advantage that all MRR parameters can be directly estimated from terpolymerisation data. New ternary copolymers derived from n-butyl acrylate (nBA), glycidyl methacrylate (GMA) and tetrahydrofurfuryl acrylate (THFA) were synthesised in solution at 70±1 °C in the presence of benzoyl peroxide (BPO) as a free radical initiator. The terpolymers were characterised by ¹H NMR, ¹³C NMR and FTIR spectroscopic techniques. The terpolymer compositions were determined using ¹H NMR analysis. The polydispersities of the terpolymers with values between 1.66 and 1.85 suggest a strong tendency for chain termination by disproportionation. The glass transition temperatures of the terpolymers are found to be between those of the corresponding homopolymers and relative to their content. Increase in the nBA or THFA contents and decrease in the GMA content in terpolymers results in a decrease in the glass transition temperatures. The determination of MRR for the ternary system was obtained by employing the EVM model. Experimental terpolymerisation data agree well with calculations based on the Alfrey-Goldfinger equation and the unitary and binary azeotropes were calculated.     

Immobilised Sarawak Malaysia yeast cells for production of bioethanol

Bioethanol production using yeast has become a popular topic due to worrying depleting worldwide fuel reserve. The aim of the study was to investigate the capability of Malaysia yeast strains isolated from starter culture used in traditional fermented food and alcoholic beverages in producing Bioethanol using alginate beads entrapment method. The starter yeast consists of groups of microbes, thus the yeasts were grown in Sabouraud agar to obtain single colony called ST1 (tuak) and ST3 (tapai). The growth in Yeast Potatoes Dextrose (YPD) resulted in specific growth of ST1 at micro = 0.396 h-1 and ST3 at micro = 0.38 h-1, with maximum ethanol production of 7.36 g L-1 observed using ST1 strain. The two strains were then immobilized using calcium alginate entrapment method producing average alginate beads size of 0.51 cm and were grown in different substrates; YPD medium and Local Brown Sugar (LBS) for 8 h in flask. The maximum ethanol concentration measured after 7 h were at 6.63 and 6.59 g L-1 in YPD media and 1.54 and 1.39 g L-1in LBS media for ST1 and ST3, respectively. The use of LBS as carbon source showed higher yield of product (Yp/s), 0.59 g g-1 compared to YPD, 0.25 g g-1 in ST1 and (Yp/s), 0.54 g g-1 compared to YPD, 0.24 g g-1 in ST3 . This study indicated the possibility of using local strains (STI and ST3) to produce bioethanol via immobilization technique with local materials as substrate.     

Changes in chemical and selected biochemical components,protein quality,and digestibility of mung bean (Vigna radiata) during gemination and cooking

The effect of germination on the nutritive value of mung beans (Vigna radiata) was studied in raw and cooked samples after 0, 2 and 4 days of germination. Water content increased, but crude protein, lipids, crude fiber, ash and carbohydrates decreased with germination. Trypsin inhibitor activity did not change significantly while hemagglutinins were absent. Essential amino acids (methionine, tyrptophan and lysine) decreased with germination.Net protein ratio (NPR) and protein efficiency ratio (PER) in rats decreased with germination especially in cooked sprouts. True digestibility did not change consistently due to germination or cooking. In conclusion, loss of protein quality in mung beans occurs upon germination and cooking.Publication INCAP/UNU-4.     

Efficiency of fertilizer formulation,stock solution volume and media on chili (Capsicum annum kulai F1)

The growth of the greenhouse chili industry is rapidly increasing in the world including Malaysia. Currently, compost is the most popular growing media. Four fertilizer formulations commonly used by farmers (Local), including the recommended Cooper, Bennoit and Cooper Modified formulation, were evaluated in combination with two volumes (400 and 750 L) for enhancement fruit yield of chili in soilless culture. The results indicate that, the day of blooming and fruiting was reduced by 91% and 50% in media containing coconut dust (CD) + empty fruit bunch (EFB) compared with CD alone. Yield with CD+EFB was increased 36% compared with CD while volume of water shows insignificant difference. Interestingly, Cooper, Local and Cooper Modified formulation enhanced 32, 28 and 19% of yield, respectively. As conclusion, combination of CD+EFB with Cooper, Local and Cooper Modified were more efficient in yield production compared with CD alone for future research.     

Sulfur dioxide resistance of Indian trees I. Experimental evaluation of visible symptoms and SO 2 sorption

Saplings of 12 species of common Indian trees were exposed to varying concentration of SO₂ to determine the level of SO₂ causing no injury, mild injury and severe injury in plants. The following order of sensitivity was emerged, T. indica > P. dulce > M. indica > F. rumphii > H. integrifolia > B. ceiba > F. bengalensis > A. indica > F. religiosa > S. cuminii > P. guajava > F. racemosa. SO₂ sorption was extremely low in T. indica and M. indica while F. religiosa and F. racemosa exhibited best efficiency of SO₂ Aorption. A correlation was found between the efficiency of SO₂ sorption and alkalinity of cytoplasmic pH. Similarly plants rich in sulfite oxidase, in general, exhibited a better resistance. No single intrinsic factor could be held responsible for the manifested response of a tree towards SO₂.     

Trait phenotyping and SSR markers characterization of wheat (Triticum aestivum L.) germplasm for breeding early maturing wheat’s for Western-Himalayas

Genetic Resources and Crop Evolution - The study involved evaluation of 96 wheat genotypes for early maturity and related traits and molecular characterization of trait specific candidate genotypes...     

Correction to: Neopestalotiopsis clavispora and Pseudopestalotiopsis camelliae-sinensis causing grey blight disease of tea (Camellia sinensis) in Malaysia

European Journal of Plant Pathology -     

Effect of four different vegetable oils (red palm olein, palm olein, corn oil, coconut oil) on antioxidant enzymes activity of rat liver

The objective of the study was to evaluate the effect of four different vegetable oils [red palm olein (RPO), palm olein (PO), corn oil (CO), coconut oil (COC)] on antioxidant enzymes activity of rat liver. Sixty six Sprague Dawley male rats which were randomly divided into eleven groups of 6 rats per group and were treated with 15% of RPO, PO, CO and COC for 4 and 8 weeks. Rats in the control group were given normal rat pellet only while in treated groups, 15% of additional different vegetable oils were given. After 4 weeks of treatment the catalase (CAT) activity results showed that there was no significance difference (p > or = 0.05) between the control group and treated groups while after 8 weeks of treatment showed that there was no significant different (p > or = 0.05) between control group and RPO group but the treated rat liver with PO, CO and COC groups were the lowest and it were significantly lower (> or = 0.05) than control group. For superoxide dismutase (SOD) there was no significance difference (p > or = 0.05) between the control group and treated groups of vegetable oils after 4 and 8 weeks of treatment. Thus the study indicated that there was no significant (p > or = 0.05) effect on antioxidant enzyme (superoxide dismutase) but there was significant effect (p > or = 0.05) on catalase in rat liver.     

Competitive ability of some cover crop species against Asystasia gangetica and Pennisetum polystachion

Abstract

Asystasia gangetica and Pennisetum polystachion are the most troublesome weeds in oil palm plantations in Malaysia and establishment of cover crops under oil palms is an integral part of sustainable weed management in plantations. Replacement-series experiments were conducted to evaluate the mode and strength of competitiveness of four legume cover crop species, Calopogonium caeruleum, Centrosema pubescens, Mucuna bracteata and Pueraria javanica, and one soft grass species, Axonopus compressus, against Asystasia gangetica and Pennisetum polystachion. Relative yield, relative yield total and relative crowding coefficient were calculated with reference to shoot biomass. Asystasia gangetica was a consistently weaker competitor than Pennisetum polystachion. The legume cover crop species had higher relative yield when grown in mixtures, whereas the yield of Asystasia gangetica was lower in mixtures with legumes than in monoculture. The higher competitiveness of legumes was due to greater canopy height and leaf area index. Centrosema pubescens was a slightly weaker competitor than the other legumes. Although leaf area per plant of Centrosema pubescens did not differ from that of other three legumes, canopy height and blocking photosynthetically active radiation to the soil surface were lower. When grown with a cover crop for 12 weeks, dry weight per plant, leaf area and shoot number of Pennisetum polystachion increased as its proportion decreased in mixtures. Relative yield data indicated that Pennisetum polystachion is a strong competitor. Axonopus compressus was less susceptible to Pennisetum polystachion interference than the legumes. All cover crop species studied proved highly competitive against Asystasia gangetica, but none could compete against Pennisetum polystachion. The study confirms the feasibility of using a cover crop for management of Asystasia gangetica.     

Changes of Physical and Chemical Characteristics during Microbial Composting of Rice Straw at Various pH Levels

ABSTRACT

The physical and chemical parameters were monitored for seven weeks during Trichoderma/Aspergillus inoculated rice straw composting at various pH levels. Three treatments (A, B, and C) were inoculated with lignocellulolytic microbial consortium (Aspergillus niger, F44 and Trichoderma viride, F26) and three were un-inoculated (D, E, and F). pH of the starting materials was amended to 5.75 (A and D), 6.75 (B and E), and 7.75 (C and F) with either acetic acid or sodium hydroxide. Three typical phases of temperature were observed both in inoculated and un-inoculated treatments during composting: mesophilic phase, thermophilic phase, and followed by cooling and maturation phase. The bioconversion were maximum in Trichoderma/Aspergillus inoculated treatments within 14–21 days as indicated by the profiles of electrical conductivity, bulk density, total carbon and nitrogen, and germination index. After day 21, the germination index of Trichoderma/Aspergillus inoculated treatment (B) without any pH amendment was increased to 74.5 indicating the maturity of compost and suitability for field application.