Browse publications by year: 2015

  1. Ghosh S, Choudhury D, Roy T, Bin Mamat A, Masjuki HH, Pingguan-Murphy B
    Sci Technol Adv Mater, 2015 Jun;16(3):035002.
    PMID: 27877803
    Osteoarthritis-oriented synovial fluid (OASF), i.e., that typical of a patient with osteoarthritis, has different physical and biological characteristics than bovine serum (BS), a lubricant widely used in biotribological investigations. Micro-dimpled and diamond-like carbon- (DLC) coated surfaces are key emerging interfaces for orthopedic implants. In this study, tribological performances of dimpled surfaces, with and without DLC coating, have been investigated under both BS and OASF. The friction tests were performed utilizing a pin on a disk tribometer, whereas contact pressure, speed, and temperature were simulated to a 'medium walking gait' of hip joint conditions. The mechanical properties of the specimen and the physical properties of the lubricant were characterized before the friction test. Raman analysis was conducted to identify the coating condition both before and after the test. The DLC-coated dimpled surface showed maximum hardness and residual stress. A DLC-coated dimpled surface under an OASF lubricated condition yielded a lower friction coefficient and wear compared to those of plain and dimpled specimens. The higher graphitization of coated materials with increasing load was confirmed by Raman spectroscopy.
  2. Vellayappan MV, Balaji A, Subramanian AP, John AA, Jaganathan SK, Murugesan S, et al.
    Sci Technol Adv Mater, 2015 Jun;16(3):033504.
    PMID: 27877785
    Cardiovascular disease claims millions of lives every year throughout the world. Biomaterials are used widely for the treatment of this fatal disease. With the advent of nanotechnology, the use of nanocomposites has become almost inevitable in the field of biomaterials. The versatile properties of nanocomposites, such as improved durability and biocompatibility, make them an ideal choice for various biomedical applications. Among the various nanocomposites, polyhedral oligomeric silsesquioxane-poly(carbonate-urea)urethane, bacterial cellulose with polyvinyl alcohol, carbon nanotubes, graphene oxide and nano-hydroxyapatite nanocomposites have gained popularity as putative choices for biomaterials in cardiovascular applications owing to their superior properties. In this review, various studies performed utilizing these nanocomposites for improving the mechanical strength, anti-calcification potential and hemocompatibility of heart valves are reviewed and summarized. The primary motive of this work is to shed light on the emerging nanocomposites for heart valve applications. Furthermore, we aim to promote the prospects of these nanocomposites in the campaign against cardiovascular diseases.
  3. Ting Tan A, Wen Tan A, Yusof F
    Sci Technol Adv Mater, 2015 Jun;16(3):033505.
    PMID: 27877786
    Nanocomposite lead-free solders are gaining prominence as replacements for conventional lead-free solders such as Sn-Ag-Cu solder in the electronic packaging industry. They are fabricated by adding nanoparticles such as metallic and ceramic particles into conventional lead-free solder. It is reported that the addition of such nanoparticles could strengthen the solder matrix, refine the intermetallic compounds (IMCs) formed and suppress the growth of IMCs when the joint is subjected to different thermal conditions such as thermal aging and thermal cycling. In this paper, we first review the fundamental studies on the formation and growth of IMCs in lead-free solder joints. Subsequently, we discuss the effect of the addition of nanoparticles on IMC formation and their growth under several thermal conditions. Finally, an outlook on the future growth of research in the fabrication of nanocomposite solder is provided.
  4. Liza S, Ohtake N, Akasaka H, Munoz-Guijosa JM
    Sci Technol Adv Mater, 2015 Jun;16(3):035007.
    PMID: 27877808
    In this work, the thermal stability and the oxidation and tribological behavior of nanoporous a-BC:H films are studied and compared with those in conventional diamond-like carbon (DLC) films. a-BC:H films were deposited by pulsed plasma chemical vapor deposition using B(CH3)3 gas as the boron source. A DLC interlayer was used to prevent the a-BC:H film delamination produced by oxidation. Thermal stability of a-BC:H films, with no delamination signs after annealing at 500 °C for 1 h, is better than that of the DLC films, which completely disappeared under the same conditions. Tribological test results indicate that the a-BC:H films, even with lower nanoindentation hardness than the DLC films, show an excellent boundary oil lubricated behavior, with lower friction coefficient and reduce the wear rate of counter materials than those on the DLC film. The good materials properties such as low modulus of elasticity and the formation of micropores from the original nanopores during boundary regimes explain this better performance. Results show that porous a-BC:H films may be an alternative for segmented DLC films in applications where severe tribological conditions and complex shapes exist, so surface patterning is unfeasible.
  5. Ghosh S, Choudhury D, Roy T, Moradi A, Masjuki HH, Pingguan-Murphy B
    Sci Technol Adv Mater, 2015 Aug;16(4):045002.
    PMID: 27877822
    The concentration of biological components of synovial fluid (such as albumin, globulin, hyaluronic acid, and lubricin) varies between healthy persons and osteoarthritis (OA) patients. The aim of the present study is to compare the effects of such variation on tribological performance in a simulated hip joint model. The study was carried out experimentally by utilizing a pin-on-disk simulator on ceramic-on-ceramic (CoC) and ceramic-on-polyethylene (CoP) hip joint implants. The experimental results show that both friction and wear of artificial joints fluctuate with the concentration level of biological components. Moreover, the performance also varies between material combinations. Wear debris sizes and shapes produced by ceramic and polyethylene were diverse. We conclude that the biological components of synovial fluid and their concentrations should be considered in order to select an artificial hip joint to best suit that patient.
  6. Hong LF, Cheng LH, Lee CY, Peh KK
    Food Technol Biotechnol, 2015 Sep;53(3):278-285.
    PMID: 27904359
    A series of propionylated starches with different degrees of substitution (DS) was synthesised and their physicochemical properties and application as a stabiliser were investigated. Starch propionates with moderate DS were prepared by esterification of native corn starch with propionic anhydride. By varying the reaction times of the esterification process, twelve starch propionates with DS of 0.47 to 0.94 were prepared. FTIR and NMR confirmed the introduction of propionyl groups to the starch. X-ray diffraction pattern showed reduced crystallinity in the starch propionates. The contact angle was found to increase proportionately with the increase in DS. Swelling power results showed that starch propionates were able to swell more than native corn starch at low temperature (40 °C). Oil-in- -water (O/W) emulsions prepared using starch propionates (DS of 0.64 to 0.86) showed exceptional stability when challenged by centrifugation stress test. These stable O/W emulsions had viscosities in the range of 1236.7-3330.0 mPa·s. In conclusion, moderately substituted short-chain (propionylated) starches could be a promising cold swelling starch, thickener and O/W emulsion stabiliser in food, pharmaceutical and cosmetic industries.
  7. Hardwick SR, Toumi R, Pfeifer M, Turner EC, Nilus R, Ewers RM
    Agric For Meteorol, 2015 Feb 15;201:187-195.
    PMID: 28148995 DOI: 10.1016/j.agrformet.2014.11.010
    Land use change is a major threat to biodiversity. One mechanism by which land use change influences biodiversity and ecological processes is through changes in the local climate. Here, the relationships between leaf area index and five climate variables - air temperature, relative humidity, vapour pressure deficit, specific humidity and soil temperature - are investigated across a range of land use types in Borneo, including primary tropical forest, logged forest and oil palm plantation. Strong correlations with the leaf area index are found for the mean daily maximum air and soil temperatures, the mean daily maximum vapour pressure deficit and the mean daily minimum relative humidity. Air beneath canopies with high leaf area index is cooler and has higher relative humidity during the day. Forest microclimate is also found to be less variable for sites with higher leaf area indices. Primary forest is found to be up to 2.5 °C cooler than logged forest and up to 6.5 °C cooler than oil palm plantations. Our results indicate that leaf area index is a useful parameter for predicting the effects of vegetation upon microclimate, which could be used to make small scale climate predictions based on remotely sensed data.
  8. Almurshedi A, Ismail AK
    Transl Neurosci, 2015;6(1):187-197.
    PMID: 28123804 DOI: 10.1515/tnsci-2015-0020
    Perceptual decision making depends on the choices available for the presented task. Most event-related potential (ERP) experiments are designed with two options, such as YES or NO. In some cases, however, subjects may become confused about the presented task in such a way that they cannot provide a behavioral response. This study aims to put subjects into such a puzzled state in order to address the following questions: How does the brain respond during puzzling moments? And what is the brain's response to a non-answerable task? To address these questions, ERP were acquired from the brain during a scintillation grid illusion task. The subjects were required to count the number of illusory dots, a task that was impossible to perform. The results showed the presence of N130 over the parietal area during the puzzling task. Coherency among the brain hemispheres was enhanced with the complexity of the task. The neural generators' source localizations were projected to a multimodal complex covering the left postcentral gyrus, supramarginal gyrus, and angular gyrus. This study concludes that the brain component N130 is strongly related to perception in a puzzling task network but not the visual processing network.
  9. Aktar-Uz-Zamana, Md., Tuhina-Khatun, Mst., Mohamed Hanafi Musa, Sahebi, Mahbod
    MyJurnal
    A resistant variety with high yielding potential is key for increasing crop production to
    fulfill the food requirement of the ever increasing world populations. Consequently, the aim of plant
    breeders is to develop high yielding varieties or cultivars that are resistant or tolerant to specific
    diseases or insects. For developing a resistant variety, it is enormously indispensable to incorporate or
    introgress the specific resistant genes of that particular disease into the recipient. Suppression
    subtractive hybridization (SSH) is a powerful technique for the identification of disease specific
    differentially expressed genes that are expressed in a resistant or susceptible variety. This paper
    presents a brief review on the SSH technique with examples focusing on the identification of the
    wheat disease specific differentially expressed genes and their defense mechanisms against fungal
    pathogens in global wheat cultivars. This review is helpful for wheat researchers for the updated
    information on the SSH technique for the identification of differentially expressed genes in the global
    wheat cultivars and varieties. Eventually, the identified genes could be used to develop the disease
    resistance variety through marker-assisted backcrossing programme or conventional breeding.
    MeSH terms: Crop Production; Animals; Breeding; Fungi; Inbreeding; Insects; Research Personnel; Triticum; Subtractive Hybridization Techniques
  10. Wardatun Nadrah Mohd Amin, Zainal Abidin Talib, Zulkarnain Zainal, Hong Ngee, Lim, Sook Keng, Chang
    MyJurnal
    Quantum dots-sensitized solar cell (QDSSC) is one of the third generation solar cell that is
    the most promising low cost, easy to manufacture and highly efficient solar cell. Compared to Dyesensitized
    solar cell (DSSC), quantum dots (QDs) of QDSSC has a narrow bandgap and possess
    excellent properties such as tunable band gaps, strong light absorption and high multiple electron
    generation. Titanium dioxide or titania (TiO2) is an oxides semiconductor material that is frequently
    used as a photoanode in this photovoltaic system due to high stability under visible light illumination.
    TiO2 is also known as a good photocatalyst and an excellent choice in environmental purification. The
    efficiencies of electron injection and light harvesting in QDSSC are affected by the nature, size
    morphology, and quantity of this nanomaterial. In this review, the concept and principles of the
    QDSSCs are reviewed. The preparation and fabrication method ofTiO2 electrode in QDSSC are also
    discussed. It is worthwhile to know the architecture of TiO2 in order to enhance the efficiency of
    QDSSC.
  11. Nurul Najihah Mohd Nasir, Noor Baity Saidi
    MyJurnal
    Nitric oxide (NO) is a signaling molecule involved in numerous physiological processes in
    both animals and plants. The bioactivity of NO is mainly transduced via post-translational modification
    of cysteine residues of proteins termed S-nitrosylation. Interestingly, a number of key regulatory
    components in plant defense responses have been found to be regulated by S-nitrosylation making this
    type of protein modification an important modulator of plant immunity. As a signaling molecule, NO
    intimately interact with other important molecules such as reactive oxygen species. Since the
    identification of NO in plants, increasing number of papers isbeing published in the area of NO biology
    each year. Here, a collection of papers describing the role of NO in plant immunity has been brought
    together to provide a bird's-eye view on the focus area.
  12. Malek, M. A., Heyrani, M., Juneng, Liew
    ASM Science Journal, 2015;9(1):8-19.
    MyJurnal
    In this study, the implementation of the Regional Climate Model into the hydrodynamic model has been applied for streamflow projection on a river located at the south of Peninsular Malaysia within the years 2070 till 2099. The data has been obtained from a Regional Climate Model (RCM), named Précis, on a daily basis. It begins by comparing historical rainfall data generated from Précis versus the actual gauged recorded rainfall data from Department of Irrigation and Drainage Malaysia (DID). The bias of the generated rainfall data has been reduced by statistical techniques. The same has been applied to the future generated rainfall data from 2070 to 2099. Using the generated precipitation data as input to the hydrological model, results in the daily output of river discharge identified as the main contributor of flood occurrences. Based on the results of the hydrological model utilised, e.g. HEC-HMS, comparison was made between the future and historical generated discharge data using Précis between the years 1960 till 1998. Dividing a year into three segments, e.g. January-April, May-August, SeptemberDecember, the results show that there would be a significant drop of peak discharge in the third segment and an increase in discharge during the second segment. The first part remains almost with no changes. As an addition, the drop of the peak shows reduction in the probability of flood occurrences. It also indicates the reduction in water storage capacity which coherently affects the water supply scheme
    MeSH terms: Climate; Drainage; Malaysia; Probability; Water; Water Supply; Rivers; Floods; Hydrodynamics; Hydrology
  13. Ng, W. L., Tan. S.G.
    ASM Science Journal, 2015;9(1):30-39.
    MyJurnal
    Inter-simple sequence repeats (ISSRs) are regions in the genome flanked by microsatellite sequences.
    PCR amplification of these regions using a single primer yields multiple amplification products that can
    be used as a dominant multilocus marker system for the study of genetic variation in various organisms.
    ISSR markers are easy to use, low-cost, and methodologically less demanding compared to other
    dominant markers, making it an ideal genetic marker for beginners and for organisms whose genetic
    information is lacking. Here, we comment upon some of the intricacies often overlooked in designing an
    ISSR experiment, clarify some misconceptions, and provide recommendations on using ISSR markers
    in genetic variation studies.
  14. Ibrahim, Ahmad1
    ASM Science Journal, 2015;9(1):28-29.
    MyJurnal
    The first time I visited Kuching, Sarawak, was in the 1980s. I then worked for the Rubber Research Institute of
    Malaysia. In the 1980s, Kuching was a small town. I remember that then, the route going to the airport was lined with
    shops selling the famous Sarawak vases. They were a big hit among visitors. A visit to Sarawak was not complete
    without taking back a set of the black-and-white vases. They came in many shapes and sizes(Copied from article).
  15. Tan, S.L.
    ASM Science Journal, 2015;9(1):21-27.
    MyJurnal
    Public awareness and understanding of the technology behind the creation of Genetically Modified Organisms
    (GMOs) varies greatly from country to country, and indeed within the different sectors of any one country. Perhaps,
    it is “the fear of the unknown” at work, or it is just a pure rejection of the idea that “Man is playing God”. For whatever
    reason, and for whatever vested interest, there is often widespread clamor for stringent studies to be carried out
    when conducting a risk assessment of GMOs.
    For example, in Indonesia, regulation on the release of GMOs requires studies on any impact on non-target
    organisms (NTOs) as well as on soil microorganisms (Machmud Thohari 2014). Similarly, in Vietnam, it is mandatory
    to determine if there is any impact to the soil environment or ecosystem (Truong 2014), while in Cambodia, there is
    worry over high levels of damage to NTOs and the environment from GMOs, because of the lack of capacity to cope
    with such damage if it occurs (Pisey 2014).
    All too often, opponents of modern biotechnology (a term used to define technologies resulting in GMOs), and,
    indeed, the regulators themselves forget that there is already a procedure in place to provide a check and balance;
    the risk assessment (RA) protocol. Most times, RA is far more stringent when conducted on GMOs compared with
    when exotic species which are non-GMOs are involved (Tan 2013). It is also overlooked that modern biotechnology
    can after all be considered a sophisticated new tool in plant breeding, an activity which has been practiced both by
    farmers and scientists for millennia, and a technology accepted by all and sundry.
    While GMOs are currently used in biological and medical research, for the production of pharmaceutical drugs,
    in experimental medicine (e.g. gene therapy) and in agriculture, this paper is confined to discussions on GMOs in
    agriculture.
  16. Devendra, C.
    ASM Science Journal, 2015;9(1):1-20.
    MyJurnal
    The natural environment embraces agriculture and all its components-crops, animals, land, water,
    forestry and fisheries. It is the most important user of environmental resources, made more complex
    by the interactions of the various systems, biophysical elements and their implications. Increased food
    production, especially of animal protein supplies are unable to meet current and projected future needs
    for humans, including about 15 %of the world population being malnourished. Agriculture is currently
    waning, and a coordinated and concerted technologically-driven transformation is necessary. Poorly
    managed agriculture for example, can lead to serious environmental degradation and exacerbate
    poverty. Land and water are considered to be the most limiting factors in the future. Non- irrigated
    rainfed areas can be divided into high potential and low potential areas; the former offers considerable
    promise to expand food production. This paper argues for increased Research and Development (R&D)
    focus that can maximise improved natural resource management(NRM), and whether agricultural
    development can maximise productivity yields .Other opportunities include expanding crop–animal
    production systems in less favoured areas (LFAs), intensifying land use for silvopastoral systems in
    rainfed areas , and enhance carbon sequestration. Ruminants can be used as an entry point for the
    development of LFAs, and the presence of about 41.5% of the goat population found in the semi-arid/
    arid AEZs X provides good opportunities for expanding food security and human well-being. Communitybased
    interdisciplinary and systems approaches are essential to provide the solutions. The legacy of
    continuing malnutrition and food insecurity must be overcome by effective development policy, multidonor
    resource allocation, governance and political will that target food insecurity and poverty. The R&D
    agendas and resource allocations are compelling, but dedicated vision can lead the way for sciencedriven
    sustainable environment, efficiency in NRM, and self-reliance to the extent possible , in harmony
    with nature and the environment.
    MeSH terms: Natural Resources; Acrodermatitis; Agriculture; Animals; Environment; Fisheries; Food Supply; Goats; Humans; Poverty; Water; Zinc; Forestry; Crops, Agricultural; Resource Allocation; Malnutrition; Carbon Sequestration
  17. Zuan, A. M. S., Anuar, M. K. Z., Syahrullail, S., Musa, M. N., Rahim, E. A.
    MyJurnal
    Ocean wave energy is a renewable energy that is abundant on Earth. It is a concentrated
    form of solar energy where differential heating on Earth generate wind which transfer their energy into
    open water in form of waves. In relation to atmospheric emission, wave power is less environmentallydegrading
    than most other form of power generation. The fluctuating wave contains potential and
    mechanical energy which can be converted into electrical energy. A special device needs to be
    developed to harness the energy which is called Float Wave Energy Converter (FWEC). The purpose
    of this project is to design, fabricate and test the experimental model of FWEC. The efficiency of the
    model will be analysed based on wave power and power generated. The model are capable to generate
    power for small devices with low power consumption. The power generated from designated FWEC
    will be depends on several parameters which is wave amplitude, diameter ratio and shape of the model.
    This parameter would be used to determine the best design for FWEC. Copyright © 2015 Penerbit
    Akademia Baru - All rights reserved.
  18. Ya, N. A., Singh, H. R., Samat, A., Mohd Rashid, H. N., Ramli, N. H., Makhtar, N., et al.
    MyJurnal
    Length-weight relationship (LWR) of six fish species from the Sepang Besar River estuary,
    Peninsular Malaysia were analyzes. A total of 594 individuals belonging to six species namely Arius
    sagor, Photopectoralis bindus, Plotosus lineatus, Toxotes chatareus, Toxotes jaculatrix, and Thryssa
    dussumieri collected from April 2014 to February 2015 were measured and weighed. Among them, four
    species showed positive allometric growth and the other two species showed negative allometric
    growth. The exponent b value of LWR ranged between 2.94 (Toxotes chatareus) and 3.50
    (Photopectoralis bindus). This outcome of the present study has contributed to the knowledge of basic
    information on the length–weight relationship of six most abundant species in Sepang Besar River
    estuary which is important for future ecological studies and assist in fishery management. Copyright
    © 2015 Penerbit Akademia Baru - All rights reserved.
  19. Kadir, Z. A., Mohammad, R., Othman, N.
    MyJurnal
    Purpose of this study to be conducted is to identify the risk factor of low back pain amongst port crane operator and to improve the health management program in the company. The objectives of this study are to evaluate the major group of port crane operator that having low back pain problem, to analyse the risk factors that associated to low back pain problem (WBV, Awkward prolonged sitting and shift work-psychological) , individual characteristics (sport activity or hobby), to analyse the associated rate operator’s absence from work (medical leave) and low back pain problem and to propose the basic ergonomic assessment checklist for management to investigate health incident cases and fit-to-work (ergonomics) screening checklist for new recruitment. A survey research design through the distribution of the questionnaire and interview & field observation will
    be used for research methodology. The population of this study consists of port crane operatorsRubber Tyred Gantry Operator (RTG). Questionnaire method used to collect all relevant information from correspondence. Interview also will be conducted to gain further details information. Data were analyzed with the usage of Statistical Package for the Social Sciences (SPSS) to make the process of analysis easier. As result, firstly, the study shown that there are association of risk factor for working posture and years of exposure with Low back Pain. The null hypothesis was rejected and there is probability that these risk factors have influence the low back pain. It was also concluded that the null hypothesis was accepted which means there are no correlation of risk factors for heavy physical works, previous job experience, previous accident with low back pain problem. Thirdly, the study
    shown there are no correlation of rate operator’s absence from work (medical leave) with low back pain problem as the null hypothesis was accepted with p value <0.05
    Keywords: Port, Low Back Pain, Ergonomics, Occupational Safety & Health, Rubber tyre gantry, Back Pain
    MeSH terms: Adult; Humans; Malaysia; Prevalence; Low Back Pain*; Sick Leave
  20. Mohammad, R., Amin, Z., Abdul Aziz, S., Othman, N.
    MyJurnal
    The aim of this paper is to measure the safety awareness level of workers by means of
    hand related injury accident recorded in Production Department of Metal Fabrication Process
    Company located in southern peninsular Malaysia. Base on the accident data obtained from year
    2008 until 2012, it showed an increasing numbers of accidents involving hand. In year 2008 the rate
    is 36.3%, year 2009 is 30%, year 2010 is 37.5%, year 2011 is 33.3% and year 2012 is 37.5%. Site
    observation has been conducted to assess the hazards involve (safety and ergonomic) to the metal
    fabrication activities being carried out. Survey Questionnaires have been distributed to 80
    respondents from different job trade. The Respondent data was analysed to obtain the safety
    awareness level for each worker’s trade. Copyright © 2015 Penerbit Akademia Baru - All rights
    reserved.
External Links