Displaying publications 81 - 100 of 811 in total

  1. Prasad, Arun, Kazemian, Sina, Kalantari, Behzad, Bujang B.K. Huat
    In the literature, several methods of ground improvement have been presented including compacted stone columns. The bearing capacity of the granular column is governed mainly by the lateral confining pressure mobilized in the soft soil to restrain or prevent bulging of the granular column. Therefore, the technique becomes unfeasible in peat that does not provide sufficient lateral confinement. This condition can be overcome by encasing the stone column with geogrid. This paper investigates the performance of the geogrid encased vibrocompacted stone column in peat. This study was carried out using PLAXIS software equipped with unit cell concept. The peat was modelled using soft soil model and the stone column using Mohr-Coulomb soil model, respectively. The geogrid was modelled using the geogrid option and could take only tensile force. The results indicate that the geogrid encased stone column can take much higher load in comparison to ordinary stone columns as the stiffness of the column increases. Meanwhile, the length of encasement also varied and it was observed that it was very effective up to about two times the diameter of the column. It also increased the column stiffness, and therefore led to a significant strain reduction. It was also observed that the columns at a spacing of three times the diameter are very effective. The results presented here can be used by the geotechnical engineers to design the geogrid reinforced stone column based on the strength of the soil, diameter of the column, spacing of the columns and stiffness of the geogrid.
  2. Usubamatov, R., Qasim, A.Y., Zain, Z.M.
    Wind energy has often been touted as one of the most reliable sources of renewable energy that should be used for people. Today, wind energy (mainly by propeller type wind turbines) produces less than one percent of the total energy used worldwide. Practically, a standard three-blade propellers efficiency of use of the wind energy is around twenty percents and this is due to its design and shape that use the wind lift force and a rotating turbine. In addition, these turbines are quite expensive due to the complex aerodynamic shape of the propellers which are made of composite materials. The new world boom for wind turbines obliges inventors to create new wind turbine designs that have high efficiency and are better than any known design. This paper proposes the new patented invention of the vane-type wind turbine which uses wind energy more efficiently and is only dependent on the acting area of the vanes. The vane wind turbine was designed to increase the output of a wind turbine that uses kinetic energy of the wind. Due to its high efficiency, simple construction and technology, the vane wind turbine can be used universally, apart from the fact that it is made from cheap materials. The new design of the vane-type wind turbine has quite small sizes than the propeller type one of same output power.
  3. Dasmawati Mohamad, Wan Suzaini Wan Hamzah, Wan Rosli Wan Daud, Zainul Ahmad Rajion, Wan Zaripah Wan Bakar, Mazlan Ibrahim
    The aims of this study were to fabricate cellulose acetate (CA) film from oil palm empty fruit bunch (OP-EPB), as well as to characterize and evaluate their biocompatibility. Several processes were carried out, and these included prehydrolysis-soda method, chlorine free bleaching method, including oxygen, ozone and peroxide, to produce the cellulose pulp. Then, a liquid phase acetylation method was applied through acetic acid-acetic anhydride-sulphuric acid. Triethyl citrate (TEC) ester was used as additive at different percentages of 10, 20, 30 and 40 wt%. The film produced was characterized by FTIR to identify the functional group of the CA film and their tensile properties were further characterized. Biocompatibility of the film was evaluated using cytotoxicity test. Stem cell derived from human deciduous teeth (SHED) was used with MTS assay. The results showed at 30% of TEC, the tensile strength and elongation of CA (OP-EFB) film was at the optimum and is therefore suitable to be used in dental application. The cytotoxicity evaluated showed that the fabricated CA (OP-EFB) films were non-toxic up to the concentration tested, and are thus compatible with SHED.
  4. Ng, K.M., Adam, N.M., Azmi, B.Z.
    A numerical simulation of UPM Solar Bowl is presented in this paper. The numerical analysis considereda general model of solar bowl, which was divided into three modules: (a) reflection characterisation ofthe bowl, (b) solar flux density along the receiver, and (c) radiation contour mapping of the receiver.The governing equations are resolved in a segregated manner using Matlab programming environment.The influence of the tropical clear sky irradiance on the collector was numerically studied, whereas thecollector performance in time domain was also quantified. Single reflection is a major element in thermalconcentration. It was observed that solar flux density of collector substantially deteriorated during offsolar noon hour, in which during 08:00 and 16:00 under clear sky of tropics, the percentage reductionof flux density is over 82% at all points of the receiver. The simulated radiation contour mapping of thereceiver supports the finding. Other results of the UPM Solar Bowl simulation model are also shownand discussed.
  5. Farzanmanesh, Raheleh, Ahmad Makmom Abdullah, Shakiba, Alireza, Jamil Amanollahi
    Iran is situated in a very diverse environmental area. The climate of the region is varied and influencedby different patterns. In order to best describe the expected climate change impacts for the region,climate change scenarios and climate variables must be developed on a regional, or even site-specific,scale. The weather generator is one of the valid downscaling methods. In the current study, LARSWG(a weather generator) and the outputs from ECHO-G for present climate, as well as future timeslice of 2010-2039 based on A1 scenario, were used to evaluate LARS-WG as a tool at 13 synopticstations located in the north and northeast parts of Iran. The results obtained in this study illustratethat LARS-WG has a reasonable capability of simulating the minimum and maximum temperaturesand precipitation. In addition, the results showed that the mean precipitation decreased in Semnan, thesouth of Khorasan and Golestan. Meanwhile, the mean temperature during 2010-2039 would increaseby 0.5°C, especially in the cold season.
  6. Bader Ahmad Aljawadi, Mohd Rizam Abu Bakar, Noor Akma
    This study deals with the analysis of the cure rate estimation based on the Bounded Cumulative Hazard (BCH) model using interval censored data, given that the exact distribution of the data set is unknown. Thus, the non-parametric estimation methods are employed by means of the EM algorithm. The Turnbull and Kaplan Meier estimators were proposed to estimate the survival function, even though the Kaplan Meier estimator faces some restrictions in term of interval survival data. A comparison of the cure rate estimation based on the two estimators was done through a simulation study.
  7. Khan, Z.A., Siddiquee, A.N., Kamaruddin, S.
    This paper presents an effective approach for the optimization of an in-feed centreless cylindrical grindingof EN52 austenitic grade steel (DIN: X45CrSi93) with multiple performance characteristics based on thegrey relational analysis. To study the effect of the entire space of the input variables, nine experimentalruns, based on the Taguchi method of L9 orthogonal arrays, were performed to determine the best factorlevel condition. The response table and response graph for each level of the machining parameters wereobtained from the grey relational grade. In this study, the in-feed centreless cylindrical grinding processparameters, such as dressing feed, grinding feed, dwell time and cycle time, were optimized by takinginto consideration the multiple-performance characteristics like surface roughness and out of cylindricity.By analyzing the grey relational grade, it was observed that dressing feed, grinding feed and cycle timehad significant effect on the responses. The optimal multiple performance characteristics were achievedwith dressing feed at level 1 (5 mm/min), grinding feed at level 2 (6 mm/min), dwell time at level 2(2.5 s), and cycle time at level 2 (11 s). It is clearly shown that the above performance characteristics inthe in-feed Centreless cylindrical grinding process can be improved effectively through this approach.
  8. Siew, Ching Ngai, Ramasamy, Rajesh, Syahril Abdullah
    Many diseases are potential targets for gene therapy using either non-viral or viral vectors. Unlike nonviralmethods, viral vectors, such as lentiviruses, have the ability to integrate into the host chromosome,which can lead to long-term transgene expression. Lentiviruses have advantages over other types ofviruses due to their capacity to transduce non-dividing cells. An optimized generation of lentivirusescarrying green fluorescent protein (GFP) reporter gene driven by either UbC (LV/UbC/GFP) orCMV (LV/CMV/GFP) promoter is described in this paper. The lentiviruses were produced by cotransfectinglentiviral expression constructs and packaging mix into 293FT lentivirus producer cell lines.Lipofectamine was highly efficient in transfecting the cells compared to Transfast and Polyethyleneimine(PEI). Following cell transfection, syncytia were clearly visible at day 2. Lentiviruses were harvestedat days 1, 2 and 3 post-transfection. The highest transduction efficiency was read from LV/CMV/GFPharvested at day 2 post-transfection and LV/UbC/GFP harvested at day 3 post-transfection. Finally,the GFP expression in COS-7 cells was determined at day 2 and day 14 post-transduction for transientand stable GFP expression. It was found that the GFP expression declined overtime. However, thetransduction efficiency and duration of the transgene expression in COS-7 cells transduced with LV/CMV/GFP were higher compared to LV/UbC/GFP. In conclusion, we have successfully produced lentivirusescarrying GFP with different promoters and shown that the viruses were able to infect COS-7 cells atdifferent efficiencies. Meanwhile, the generation of the active lentiviruses will allow us to proceed to the subsequent analysis of the effect of regulatory elements in future study.
  9. Yap, C.K.
    If we were given a questionnaire of “How do we measure a researcher as a true scientist? with optional answers like (a) Having a good number of publications, (b) having attending numerous conferences, (c) with a high popularity as always appeared in mass media, and (d) good international networking and good public relations. Options (c) and (d) always come later after option (a) has been achieved, while option (b) can be simply achieved or abstract be accepted for presentation in any conference. Hitherto, publishing in any peer-reviewed journals carry a certain quality since they are highly subjected to peer review evaluation before the paper can be accepted for publication in a journal. Needless to say, those constructive comments given by the reviewers are very crucial in shaping our scientific understanding in our subject area rather than rejection experience (Yap, 2009). Having said so, option (a) will definitely be the best answer. The fact is that option (a) should not be argued whatsoever as the best answer [since publications speaks louder than anything else] and options (a), (b) and (c) are supplementary criteria to option (a) but they are not as vital as option (a). When we are asked ‘What is your scientific research performance or research output?’, the answer could always be ‘Having a good number of publications.’ Then, the next question forwarded is that ‘What is the quality and impact of your published papers to the scientific community?’ Of course, good and high impact factor journals always accept papers with high novelty in the subject area. Therefore, papers published in good journals are always highly cited and subsequently resulting in high impact (or citations) of the research done to the scientific community. However, the last question is sometimes very subjective and difficult to answer until h-index is introduced and discussed among the researchers. This paper aimed to discuss the h-index based on Elsevier’s Scopus database as an indicator of research achievement for young Malaysian scientists.
  10. Babak Mahjoub, Kamarul Arifin Ahmad, Surjatin Wiriadidjaja
    A number of different studies were reviewed to investigate the functionality of splitter plates for the
    purpose of drag reduction and vortex elimination behind a circular cylinder. The studies were carried
    out numerically or experimentally in different combinations of Reynolds range, 2D or 3D dimensions,
    with intention of drag reduction, vortex suppression or both. Results were compared to discover the
    generalities of a splitter plate’s applications and its performance in drag reduction and vortex control.
    The reduction of 12% up to 38.6% in drag coefficient suggests that all reviewed studies verified the
    effectiveness of upstream plate in drag reduction. Varied upstream plate’s gap ratios (gap between the
    plate and cylinder) were tested and the optimum position was obtained. For the finite cylinder case,
    however, the studies discovered that the effectiveness of upstream plate decreased severely and thus, are
    barely considered as a drag reductive tool for shorter cylinders. Although downstream plate influences
    drag force, its prominent application is found to be vortex shedding elimination (up to 14.7%). The
    length ratio and gap ratio of downstream plate were varied in these studies and it was found that the
    length ratio was a more important factor compared with the gap ratio in the case of vortex suppression.
  11. Fateh, A., Hejazi, F., Ramanathan, R.A., Jaffar, M.S.
    The use of the Light Rail Transit (LRT) system is currently preferred because LRT is sustainable,
    improves travel options and facilitates swift mobility in urban areas. Hence, the structural stability
    and safety of this public transportation system against seismic occurrences are indispensable. Given
    that these structures cannot be considered conventional frames because of their complex architectural
    design, focussing meticulously on reliable seismic design codes and structural rehabilitation techniques
    is vital for the design of the lateral resistance system. One Malaysian LRT station is considered in this
    study, and the seismic response of this train station when equipped with supplementary viscous damper
    devices is evaluated. Thus, the LRT station is modelled through finite element simulation. The methods
    of seismic analysis are limited to linear seismic analyses, namely, response spectrum and time history
    analyses. Results derived in this study show a significant improvement in structural response when the
    station is fitted with dampers; approximately 40% reduction in displacement is observed at the top joint
    of the roof. Furthermore, the lateral base shears decrease by approximately 70%.
  12. Zubaida Hassan, Shuhaimi Mustafa, Raha Abdul Rahim, Nurulfiza Mat Isa
    Human breast milk microbiota is essential for infant immune system development, maturation and
    protection against infection. However, there is scarce information on the fluid’s microbiological
    composition from Malaysia. The objective of the study was to isolate, identify and characterise commensal
    bacterial population present in human breast milk from Malaysia. One hundred bacteria were isolated
    from the human breast milk of healthy lactating women (n=30). After preliminary screening, 20 isolates
    were characterised using both phenotypic and molecular techniques. The results indicated that most
    frequently identified bacteria in this study were E. faecalis and S. hominis. These organisms alongside E.
    cloacae were all metabolised D-Maltose, Sucrose, D-Turanose, α-D-Glucose, D-Fructose, D-Mannose,
    D-Galactose, D-sorbitol and D-Mannitol and were able to grow at pH 5 and 6, 1% sodium lactate, 1%,
    2% and 8% NaCl. BLAST showed over 99% similarity to those deposited in Genbank. Phylogeneticrelatedness
    was depicted using neighbour-joining method and had two clades with 100% bootstrap. These
    findings provided insight into the nature, characteristics and also phylogenetic-relatedness of bacteria
    present in human milk from Malaysia. Isolation and identification of commensal bacteria from human
    milk are considered the first step for future studies on the benefit of these organisms towards human health.
  13. Fathinul Fikri, A.S., Noraini Sarina, A., Shahrin, S., Abdul Jalil, N.
    Colo-colic intussusception is a rare manifestation of a primary tumour in an adult patient. This article
    aims to document the rarity of colo-colic intussusception features on the 18 FDG- PET-CT in a patient
    with primary colonic carcinoma. An 18 FDG-PET-CT was performed for the purpose of pretreatment
    staging of a colonic carcinoma in a 61-year-old man following a diagnostic colosnoscopic biopsy. He
    presented with abdominal distension and peri-rectal bleeding for a month. The fused 18 F-FDG PET-CT
    image revealed an FDG-avid mass in the left hemicolon showing a rim of FDG avidity denoting the head
    of intussusceptum. There are also multiple FDG-avid nodules seen along the anti-mesenteric colonic fat
    suspicious for lymph nodes metastasis. Debulking of tumour revealed a mucinous adenocarcinoma of
    colon with a metastatic lymph node. 18 FDG PET-CT features of intussusception in colonic carcinoma
    have never been described before. It can potentially become a preferred diagnostic tool in delineating a
    potential tumour mass within the intussusceptions that help improve prognosis in patients with malignancy.
  14. Abas, M.F., Aftab, S.M.A., Rafie, A.S.M., Ahmad, K.A., Yusoff, H.
    The purpose of this research is to gain initial knowledge and to predict the sustainability of an all-weather
    Micro-Aerial-Vehicle (MAV). The observed parameters are: the maximum coefficient of lift, CL and the
    changes in CL after impact, the fluctuation of CL upon entering simulated rain environment, and length of
    stability recovery in terms of time and flapping cycle, t and t/T, at flapping frequencies of 8, 16, and 24
    Hz, at t/T = 3/8 and 7/8. At 24 Hz, the increase in peak CL value after impact of entering rain environment
    is 0.59. The average fluctuations in CL occurred when entering the rain environment are 410.263. The
    stability recovery time recorded is 0.006 seconds. Small birds (especially hummingbirds) have a very
    high flapping frequency that enables them to efficiently withstand external disturbances caused by nature
    and to instantly adapt to new environments.
  15. Pauline Epsipha, Mohammad, Z., Kamarul, A.A.
    Flow separation over blade surfaces is an important parameter and its reduction or elimination can improve
    better aerodynamic performance, efficiency and stall margin. In this work, numerical investigation has
    been carried out to study the flow separation and performance analysis of a transonic axial compressor
    rotor blade at off-design operating conditions. The off-design cases studied comprised of compressor
    operation at 80%, 90%, 100% and 105% on the on-design rotational speed. The results are validated with
    experimental work from literature. Additionally, 3D flow visualisations and performance parameters were
    examined in detail to understand the blade to blade relative mach number distributions and shock front
    created by the model. Finally, the benefits of unsteady simulation on axial compressor blade performance
    predictions were examined.
  16. Ng, K.C., Sheu, T.W.H., Hwang, Y.H.
    A new numerical scheme based on the particle method, namely the Moving Particle Pressure Mesh
    (MPPM) method, has been previously developed by the authors to address the limitation of the
    conventional Moving Particle Semi-implicit (MPS) method in simulating incompressible flow. In this
    paper, we shall investigate on a more practical way to extend our MPPM method to handle complex
    geometry, i.e. by employing an embedded unstructured mesh system to cope with an arbitrarily-complex
    flow domain. No-slip boundary condition is modelled via placing a series of fixed particles at the wall
    boundaries, negating the use of ghost particles which are difficult to generate. In order to verify our
    numerical procedure, the vortex-shedding process behind a cylinder is computed and it is found the
    numerical result is agreeable with the reference solution.
  17. Fathinul Fikri, A.S., Ramdave Shakher, Abdul Jalil, N.
    The presence of calcification in a particular FDG-avid soft tissue lesion may at times present uncertainty
    regarding the clinical course of the disease pathology. Calcific deposits are not specific for either benign
    or malignant aetiologies (Brant et al., 2010). Altered glucose metabolism with associated calcification
    may underpin underlying aggressive pathophysiology with necrosis as sequelae. Mantle Cell Lymphoma
    (MCL) is a subtype of non-Hodgkin’s lymphoma. It is a rare B-cell NHL that is prevalent in men over
    the age of 60. The disease may be aggressive but it can also behave in a more indolent fashion in some
    patients. MCL comprises about 5% of all NHLs. The disease is called Mantle Cell Lymphoma because the
    tumour cells originally come from the ‘mantle zone’ of the lymph node (Zhou et al., 2004). Pretreatment
    Hodgkin’s lymphoma with calcification may masquerade as other second primary pathologies, e.g.
    extraosseous osteosarcoma or myositis ossificans (Apter et al., 2002; Korek-Amorosa et al., 1974). A
    calcified perineural lymphoma prior to treatment is exceedingly rare and calcification usually occurs
    one to five years after chemotherapy or radiation therapy with an incidence of 2% (Apter et al., 2002).
    This case documents how the manifestation of a rare malignant perineural mantle cell lymphoma may
    be indistinguishable from other pathological entities based on its pattern of distribution in a combined
    FDG- PET-CT study.
  18. Ahmed A. Hussien, Mohd Z. Abdullah, Mohd A. Al-Nimr, Yusop, N.M., Nuntadusit, C., Elnaggar, M.H.
    One of the best ways to enhance heat transfer coefficient is by improving thermal properties of the
    working fluid. Gold/water nanofluid flow through horizontal minitube with very low Reynolds number
    was simulated by using Thermal Lattice Boltzmann Method (TLBM) under uniform heat flux boundary
    condition. The effect of different volume fraction of nanoparticles on the heat transfer coefficient was
    studied and compared with the base fluid (water). The results were verified using Finite Volume Method
    (FVM). The results showed enhancement of heat transfer coefficient when using gold/water nanofluid
    and this enhancement depends on the volume concentration of Gold nanoparticles. The maximum
    enhancement was 18% with 0.03 volume concentration.
  19. Misri, S., Ishak, M.R., Sapuan, S.M., Leman, Z.
    There are many contributions from synthetic fibres in the world of industrial composites over the years.
    However, they contain hazardous properties to humans causing irritation when exposed to the skin
    and eye. Inhalation of fibrous synthetic can cause lung cancer with its deadly effects. There have been
    studies and researches conducted on natural fibres to replace synthetic fibres as it is believed the latter
    are more environmental-friendly and pose less health risks to humans. The aim of this study was to
    investigate hoop tensile properties of the composite hollow shaft for different winding angles and PVC
    reinforcement produced via the filament winding technique. For this purpose, split-disk tests (according
    to ASTM D-2290 standard) were performed for the specimens produced with two different winding
    angles such as 45o and 90o winding angle. By determining the hoop tensile strength and modulus of
    these specimens, the effects of filament-winding processing parameter in winding angle were evaluated.
    Experiments successfully showed that the mechanical properties such as tensile properties of kenaf yarn
    fibre reinforced unsaturated polyester hollow tube at 90° and 45° winding angle with and without PVC.
    The value was 15% for the different winding angles and 25% for the different winding angles with and
    without PVC. The results indicate that 90° fibre winding angle kenaf yarn fibre unsaturated polyester with
    PVC has the highest hoop tensile strength compared with other composite specimens. The experiments concluded that the orientation on fibre angle has
    a significant impact on the hoop tensile strain,
    hoop tensile modulus and hoop tensile strength
  20. Ching, Chieh Kiu
    With the proliferation of Web 2.0 technologies, folksonomy which is also known as social tagging or
    collaborative tagging is widely used by learners to annotate and categorize their learning resources. In
    a folksonomy system, the tags are added by learners to the learning resources, hence the tags are often
    ambiguous, overly personalised and imprecise. In addition, conjugated words, compound words and
    nonsense words may be used in tagging and shared among a group of learners. This has resulted in an
    uncontrolled and chaotic set of tagging terms that cause learning resources searching, reuse and sharing
    to become ineffective. In this paper, we present a content-based approach which automatically generates
    tags from a learning resource using Part-Of-Speech Tagging and K-Means Clustering techniques. The
    generated tags are more precise and unambiguous which can improve learning resources searching,
    reuse and sharing among learners.
Contact Us

Please provide feedback to Administrator (tengcl@gmail.com)

External Links