Universiti Malaysia Sabah or UMS is the ninth Malaysian public university located in Kota Kinabalu, Sabah, Malaysia and was established on November 24, 1994. His Majesty the Yang di-Pertuan Agong proclaimed the establishment of UMS under Section 6 of the Universities and University Colleges Act 1971. Wikipedia.
Djamila H.,Universiti Malaysia Sabah
Renewable and Sustainable Energy Reviews | Year: 2017
Thermal comfort is a complex topic and the methods studied so far are only approximate. Many investigators are likely to face some of the issues addressed in this article. The focus of the review is on selected issues and trends relevant to thermal comfort. Meta-analysis was performed using the ASHRAE RPA-884 database. The aim is to address some of the methodological issues of preliminary data analysis and predictions of comfort temperatures. An examination of how to assess the age factor for thermal comfort consideration in the ASHRAE database was also conducted by using an explicit transparent methodology. A new procedure was developed for predicting and analysing comfort temperature. The suggested procedure goes beyond the obvious need for more research studies to underscore deficiencies in data collection, which will lead to better data analysis. Editors might use the results and recommendations from this investigation before publishing original research on thermal comfort. © 2017 Elsevier Ltd
News Article | December 19, 2016
Scientists at the University of York have found that oil palm plantations, which produce oil for commercial use in cooking, food products, and cosmetics, may act as a barrier to the movement of butterflies across tropical landscapes. The study, conducted in Borneo, Southeast Asia, highlights the importance of maintaining connected networks of rainforest to support and conserve biodiversity. To make way for oil palm plantations, large areas of lowland rainforests are cut down, which is thought to have an impact on the movement of rainforest species across these landscapes. Until now, however, there was little known about insect movement behaviour at rainforest-plantation boundaries. The team, in collaboration with the Universiti Malaysia Sabah, examined the ability of butterflies to cross rainforest boundaries in relation to particular characteristics, such as wing size; the number of food plants their caterpillars can feed on; where in the world populations can be found; and the presence or absence of food plants within oil palm plantations. Sarah Scriven, PhD student and lead author of the research paper, said: "It is essential that rainforest species, such as fruit-feeding butterflies, move through the forest freely in order to search for food sources, suitable areas for breeding, and mates. By breeding with individuals in neighbouring habitats, genetic diversity and stable populations can be maintained. "In order to understand whether oil palm plantations have any impact on butterfly movement, we carefully numbered the wings of large butterflies, and colour coded smaller butterflies with small dots." Using a grid system spanning several boundaries of the Borneo rainforest and oil palm plantations, Sarah set up a number of butterfly-friendly banana food traps to see how many of the numbered and colour-coded species moved from the forest into the plantation. The study showed that small butterflies were more likely to cross from rainforest into oil palm plantations compared to larger butterflies. This was because the plants that caterpillars from small butterflies feed on are often grass, which grows in the plantation habitat. These smaller species can potentially breed in oil palm plantations. Professor Jane Hill, project supervisor at the University of York, said: "Larger butterflies were over two times less likely than small butterflies to move into oil palm plantations. This is because their larval food sources, largely rainforest herbs, shrubs and trees, do not grow in the plantations. "Our results, therefore, suggest that oil palm plantations may act as barriers to the movement of forest-dependent butterflies, which highlights the importance of conserving existing forest areas that form corridors linking forest reserves." The researchers also point out that movement across boundaries will become more important in the context of future climate change. If forests become warmer, certain species will need to move across plantations in search of cooler locations at higher elevations. Co-author, Dr Colin Beale, also from the Department of Biology at York, said: "Oil palm provides a valuable crop to many farmers in the tropics, but conversion of rainforest to oil palm plantations results in a dramatic change in habitat structure, making plantation habitats unsuitable for many rainforest species. "Our study adds to the growing understanding that leaving a connected network of forest is the best way to allow forest species to move around the landscape." The research paper, 'Barriers to dispersal of rain forest butterflies in tropical agricultural landscapes', is published in Biotropica and is available online at: http://onlinelibrary.
Agency: GTR | Branch: NERC | Program: | Phase: Research Grant | Award Amount: 1.30M | Year: 2013
Anthropogenic disturbance and land-use change in the tropics is leading to irrevocable changes in biodiversity and substantial shifts in ecosystem biogeochemistry. Yet, we still have a poor understanding of how human-driven changes in biodiversity feed back to alter biogeochemical processes. This knowledge gap substantially restricts our ability to model and predict the response of tropical ecosystems to current and future environmental change. There are a number of critical challenges to our understanding of how changes in biodiversity may alter ecosystem processes in the tropics; namely: (i) how the high taxonomic diversity of the tropics is linked to ecosystem functioning, (ii) how changes in the interactions among trophic levels and taxonomic groups following disturbance impacts upon functional diversity and biogeochemistry, and (iii) how plot-level measurements can be used to scale to whole landscapes. We have formed a consortium to address these critical challenges to launch a large-scale, replicated, and fully integrated study that brings together a multi-disciplinary team with the skills and expertise to study the necessary taxonomic and trophic groups, different biogeochemical processes, and the complex interactions amongst them. To understand and quantify the effects of land-use change on the activity of focal biodiversity groups and how this impacts biogeochemistry, we will: (i) analyse pre-existing data on distributions of focal biodiversity groups; (ii) sample the landscape-scale treatments at the Stability of Altered Forest Ecosystems (SAFE) Project site (treatments include forest degradation, fragmentation, oil palm conversion) and key auxiliary sites (Maliau Basin - old growth on infertile soils, Lambir Hills - old growth on fertile soils, Sabah Biodiversity Experiment - rehabilitated forest, INFAPRO-FACE - rehabilitated forest); and (iii) implement new experiments that manipulate key components of biodiversity and pathways of belowground carbon flux. The manipulations will focus on trees and lianas, mycorrhizal fungi, termites and ants, because these organisms are the likely agents of change for biogeochemical cycling in human-modified tropical forests. We will use a combination of cutting-edge techniques to test how these target groups of organisms interact each other to affect biogeochemical cycling. We will additionally collate and analyse archived data on other taxa, including vertebrates of conservation concern. The key unifying concept is the recognition that so-called functional traits play a key role in linking taxonomic diversity to ecosystem function. We will focus on identifying key functional traits associated with plants, and how they vary in abundance along the disturbance gradient at SAFE. In particular, we propose that leaf functional traits (e.g. physical and chemical recalcitrance, nitrogen content, etc.) play a pivotal role in determining key ecosystem processes and also strongly influence atmospheric composition. Critically, cutting-edge airborne remote sensing techniques suggest it is possible to map leaf functional traits, chemistry and physiology at landscape-scales, and so we will use these novel airborne methods to quantify landscape-scale patterns of forest degradation, canopy structure, biogeochemical cycling and tree distributions. Process-based mathematical models will then be linked to the remote sensing imagery and ground-based measurements of functional diversity and biogeochemical cycling to upscale our findings over disturbance gradients.
News Article | November 15, 2016
TAINAN, Taiwan--(BUSINESS WIRE)--In response to Taiwan government’s New Southbound Policy, National Cheng Kung University (NCKU) is committed to serving as the major international education hub in Asia, initiating a joint master degree program to facilitate international student mobility. University of Malaya (UM), Indian Institute of Technology Bombay (IIT Bombay), Institut Teknologi Bandung (ITB), Universiti Malaysia Sabah (UMS), and NCKU signed a Memorandum of Understanding (MoU) November 11
Wahidin S.,University of Kuala Lumpur |
Idris A.,University of Technology Malaysia |
Shaleh S.R.M.,Universiti Malaysia Sabah
Bioresource Technology | Year: 2013
Illumination factors such as length of photoperiod and intensity can affect growth of microalgae and lipid content. In order to optimize microalgal growth in mass culture system and lipid content, the effects of light intensity and photoperiod cycle on the growth of the marine microalgae, Nannochloropsis sp. were studied in batch culture. Nannochloropsis sp. was grown aseptically for 9days at three different light intensities (50, 100 and 200μmolm-2s-1) and three different photoperiod cycles (24:0, 18:06 and 12:12h light:dark) at 23°C cultivation temperature. Under the light intensity of 100μmolm-2s-1 and photoperiod of 18h light: 6h dark cycle, Nannochloropsis sp. was found to grow favorably with a maximum cell concentration of 6.5×107cellsmL-1, which corresponds to the growth rate of 0.339d-1 after 8day cultivation and the lipid content was found to be 31.3%. © 2012 Elsevier Ltd.
Hossain M.A.,Universiti Malaysia Sabah |
Rahman S.M.M.,University of Dhaka
Food Research International | Year: 2011
Pineapple has several beneficial properties including antioxidant activity. The fruit of pineapple was extracted with ethyl acetate, methanol and water. The phenolic content of the extracts was determined by Folin-Ciocalteu method and antioxidant activity was assayed through some in vitro models such as antioxidant capacity by phosphomolybdenum, β-carotene-linoleate, and radical scavenging activity using α,α-diphenyl-β-picrylhydrazyl (DPPH) method. The phenolic contents of the extracts as caffeic acid equivalents were found to be highest in methanol (51.1%) followed by ethyl acetate (13.8%) and water extract (2.6%). Antioxidant capacity of the extracts as equivalent to ascorbic acid (μmol/g of the extract) was in the order of methanol extract. > ethyl acetate extract. > water extract. In comparison with butylated hydroxyanisole (BHA), at 100. ppm of concentration, the antioxidant and free radical scavenging activities of the extracts assayed through β-carotene-linoleate and DPPH method were also found to be highest with methanol extract followed by ethyl acetate and water extracts. The results indicated that the extent of antioxidant activity of the extract is in accordance with the amount of phenolics present in that extract and the pineapple fruit being rich in phenolics may provide a good source of antioxidant. © 2010 Elsevier Ltd.
Suali E.,Universiti Malaysia Sabah |
Sarbatly R.,Universiti Malaysia Sabah
Renewable and Sustainable Energy Reviews | Year: 2012
This paper primarily presents an overall review of the use of microalgae as a biofuel feedstock. Among the microalgae that have potential as biofuel feedstock, Chlorella, specifically, was thoroughly discussed because of its ability to adapt both to heterotrophic and phototrophic culture conditions. The lipid content and biomass productivity of microalgae can be up to 80% and 7.3 g/l/d based on the dried weight of biomass, respectively, making microalgae an ideal candidate as a biofuel feedstock. The set-up of the system and the biomass productivity of microalgae cultivated in an open pond and a photobioreactor were also compared in this work. The effect of the culture condition is discussed based on the two-stage culture period. The issues that were discussed include the light condition and the CO 2, DO and N supply. The microalgal productivities under heterotrophic and phototrophic culture conditions were also compared and highlighted in this work. The harvesting process and type of flocculants used to aid the harvesting were highlighted by considering the final yield of biomass. A new idea regarding how to harvest microalgae based on positive and negative charges was also proposed in this work. The extraction methods and solvents discussed were primarily for the conventional and newly invented techniques. Conversion processes such as transesterification and thermochemical processes were discussed, sketched in figures and summarized in tables. The cost-benefit analysis of heterotrophic culture and the cultivation system was highlighted at the end of this work. Other benefits of microalgae are also mentioned in this work to give further support for the use of microalgae as a feedstock for biofuel production. © 2012 Elsevier Ltd. All right reserved.
Liew W.Y.H.,Universiti Malaysia Sabah
Wear | Year: 2010
This paper evaluates the performance of TiAlN/AlCrN nano-multilayer coated, TiAlN single-layer coated and uncoated carbide tools in low-speed milling of STAVAX (modified 420 stainless steel) under flood and mist lubrication. Scanning electron microscope, energy dispersive X-ray analysis system and Raman spectroscopy were used to examine the tool wear and determine the type of oxide formed on the tool surface during machining. In machining STAVAX with a hardness of 40 HRC, the coated tools were subjected to delamination, attrition and abrasive wear throughout the duration of testing. During machining STAVAX with a hardness of 55 HRC, three distinct stages of tool wear occurred, (i) initial wear by delamination, attrition and abrasion, followed by (ii) cracking at the substrate and (iii) the formation of individual surface fracture at the cracks which would then enlarge and coalesce to form a large fracture surface. The TiAlN/AlCrN coated tool exhibited higher resistance against delamination and abrasive wear than the TiAlN coated tool. The cracking resistance and hardness of the coating, and oxidation of the coating during machining appeared to have significant influences on the resistance of the tool against these wear mechanisms. A longer cutting distance was required to cause TiAlN/AlCrN coated tool to crack and fracture. This was due to the substrate receiving greater protection against cracking and fracture as a result of the coating being removed at a slower pace by abrasion and delamination. The likeliness of the uncoated tool to chip, crack and fracture, and the severity of abrasion increased with an increase in the hardness of the workpiece. Small quantity of mineral oil sprayed in mist form was effective in reducing the severity of delamination and abrasive wear, and delaying the occurrence of cracking, fracture and chipping. The influence of the ductility of the workpiece, tool wear and the lubricants on the surface finish are also discussed. © 2010 Elsevier B.V.
Sarbatly R.,Universiti Malaysia Sabah |
Chiam C.-K.,Universiti Malaysia Sabah
Applied Energy | Year: 2013
This paper presents the energy evaluation of the cross-flow vacuum membrane distillation (VMD) for three types of lab-fabricated polyvinylidene fluoride (PVDF) membranes and the commercial Westran S PVDF membrane. Membranes with the effective area 23.5cm2 are tested with distilled water and geothermal water as the feed solutions. Results show that the membrane porosity controlled the flux through the fabricated membranes and the commercial membrane. The commercial membrane with porosity of approximately 76.5%, which was the most porous among the tested membranes, gave the highest flux at 9.28kg/m2 h under the optimum conditions of 33.2L/h feed flow rate and 30kPa downstream pressure. The corresponding specific energy consumption was 66.03kW/kgh-1 when distilled water was examined. Heating energy of 87-89kW/kgh-1, which is approximately 95% of the total energy consumption, could be saved when the warm geothermal water is fed directly into the VMD system. The water produced meets the drinking water quality with the TDS varying between 102 and 119ppm, thus the geothermal water desalination using the VMD system to produce the drinking water is satisfactory. An economic analysis for a 20,000m3/d VMD desalination plant finds that the water production costs are $0.50/m3 and $1.22/m3 respectively for the plant operated with and without geothermal energy (GE). Compare to the plant without GE utilisation, the water production costs of the plant operated with GE are less than $0.50/m3 that is at least $0.72/m3 or approximately 59% in cost saving when the water fluxes are larger than 6.6kg/m2h. The specific membrane cost reduced from $0.058/m3 to $0.035/m3 when the membrane life extended from 3 to 5years. © 2012 Elsevier Ltd.
Mukai Y.,Universiti Malaysia Sabah
Fisheries Science | Year: 2011
The sutchi catfish Pangasianodon hypophthalmus is an important species for aquaculture in Southeast Asia. However, larvae typically have low survival rates due to their predilection for cannibalism during rearing. This study investigated larval feeding behavior and rearing conditions. The former experiments were performed to elucidate the role of sensory organs in feeding, and the latter experiments examined the effect of dim light on larval rearing and survival rates. Neither lighting conditions (light and dark) nor blocking of free neuromasts by streptomycin had significant effects on feeding behavior. Therefore, the feeding behavior of sutchi catfish larvae most likely depends on chemosensing rather than visual sensing. In the later experiments, larval rearing at 0.1l× yielded significantly higher survival rates than other lighting conditions (0.00, 1, 10, 100l×). Survival in the 0.1l× group was almost three times higher than in the 100 l× group. Moreover, larvae reared under 0.1l× showed steady growth. Therefore, it is concluded that 0.1l× is the optimum light intensity for sutchi catfish larval rearing. © 2010 The Japanese Society of Fisheries Science.