Sago Starch and its Acrylamide Modified Products as Coating Material in Recycled Paper

Starches are usually used in recycled paper to improve the paper strength properties. Apart from the common starches available in the market, sago starch offers another alternative since it is cheaper. This study was carried out to determine the suitability of sago starch as paper additive. The basic properties i.e., pH, viscosity and solid content, of the unmodified (4%, 5% and 6% w/v basis) and modified sago starch [sago starch blended with acrylamide (38.5% grafting efficiency), sago starch grafted with acrylamide in an acidic condition and sago starch grafted with acrylamide in an alkaline condition] were determined. The starches were then used to coat laboratory made recycled papers. Various effects were studied, namely, starch concentrations, methods of sago starch modification, addition of different types of initiator and further curing at different temperatures. Increasing the concentration of the unmodified sago starch solutions from 4% to 6% caused significant reduction in their pH values and increased both the viscosity and solid content of the solutions. The unmodified sago starch solution was very viscous (>447 mPa.s) and were susceptible to biological attack after two days at ambient. The incorporation of acrylamide into sago starch through blending or grafting significantly reduced the viscosity of the solutions. All the modified starches remained biologically resistant even after 14 days of exposure to ambient

The role of palaeofloras and Bornean aroids in the investigation of phytochores

It was Edred J.H. Corner who first drew attention to the partial commonality of the tree floras of the E and NW coast of Peninsular Malaysia and that of N Borneo, and postulated this to be a result of these areas sharing remnants of a once extensive expanse of lowland humid forest and river deltas centred on what is now the South China Sea (Corner, 1960). Corner coined the name the „Riau Pocket‟ for this, now fragmented, phytochore. Remarkably, for more than 40 years no-one picked up on Corner‟s landmark but much-overlooked paper. The intimation that interest was reviving in the exciting prospect of being able to study extant fragments of a “lost” biosphere joining the archipelagic and mainland elements of the Indomalaya Ecozone was a paper by Wong Khoon Meng (Wong, 1998) dealing with patterns plant endemism and rarity in Malaysia. Somewhat later still Peter Shaw Ashton (Ashton, 2005) mapped the known extent of the extant Riau Pocket fragments, and linked them to the known phytochores for Borneo. Between these papers, and subsequently, there have been a number of general and not a few specific studies drawing further reference to the importance of palaeobiogeography and modern distributions of taxa in SE Asia (van Welzen et al. 2003, Roos, 2004, van Welzen & Slik 2009, Raes et al. 2009), although none except Atkins et al. (2001), attempted phylogeographical analysis, and none has specifically analysed the veracity of the putative Riau Pocket phytochore fragments

Studies on Schismatoglottideae of Borneo XV - A Second Species of Bakoa

Bakoa brevipedunculata is newly combined as a second species of the Bornean endemic genus Bakoa (Araceae: Schismatoglottideae), based on Hottarum brevipedunculatum. A new generic delimitation to Bakoa and a key to the species of Bakoa are presented

Ten New Endemic Genera of Araceae on Borneo

Phylogenetic relationships within Araceae tribe Schismatoglottideae are elucidated based on nuclear ITS and plastid matK. Thirty genera are recognised, composed of 13 pre-existing genera (Apoballis, Aridarum, Bakoa, Bucephalandra, Fenestratarum, Galantharum, Ooia, Phymatarum, Pichinia, Piptospatha, Schismatoglottis, Schottariella and Schottarum), five resurrected genera (Colobogynium, Gamogyne, Heteroaridarum, Hottarum and Rhynchopyle) and 11 new genera: Bakoaella, Bidayuha, Burttianthus, Gosong, Hera, Kiewia, Nabalu, Pursegloveia, Naiadia, Tawaia and Toga. Except for Kiewia, all newly described genera are endemic to Borneo. Schismatoglottis remains imperfectly delineated despite resolution of a well-supported corpus defined by hapaxanthic stems and containing the nomenclature type. The research continues to show that Borneo supports extraordinarily rich and diverse aroid flora

Untangling the oil-nuts-genomics of engkabang

Shorea macrophylla (engkabang jantong) in its typical expression with glossy glabrous maroon or green caducous stipules and thinly chartaceous leaf blades is largely confined to NW Borneo west of the Lupar, occurring gregariously along riverbanks and adjacent flood plains in the lowlands. In the westerly part of its range S. macrophylla is often admixed with S. splendida. Both species, together with podzol-restricted S. stenoptera, are important sources of the fat-rich engkabang nuts that provide valuable periodic income to local people, and which potentially are a significant element of sustainable indigenous agroforestr