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  1. Fulltext ANA negative (Ro) lupus erythematosus with multiple major organ involvement: a case report
    Che Maraina CH, Kamaliah MD, Ishak M
    Asian Pac J Allergy Immunol, 2002 Dec;20(4):279-82.
    PMID: 12744629
    Anti-nuclear antibody (ANA) negative systemic lupus erythematosus (SLE) occurs in about 4-13% of SLE cases. A small group of ANA negative SLE patients with positive anti-Ro antibodies usually present with typical vasculitic skin lesions which can be associated with photosensitivity, renal disease, congenital heart block or neonatal lupus. We present a case of a persistently ANA negative patient who presented with joint pain, rashes, mouth ulcer and alopecia. Clinical diagnosis of systemic lupus erythematosus was made even though ANA was negative. She was started on steroids and went into remission. Later, she developed several episodes of convulsions associated with fever and prominent vasculitic lesions. The patient was also found to have microscopic hematuria, proteinuria, anemia and thrombocytopenia. Renal biopsy showed lupus nephritis class 1B. Due to the prominent skin lesions, we performed anti-extractable nuclear antigens (ENA) antibodies test and anti-Ro turned out to be positive. The final diagnosis was ANA negative SLE (Ro lupus) with cutaneous, renal, musculoskeletal, hematological and cerebral Involvement.
  2. Fulltext An Experimental Study of Briquetting Process of Torrefied Rubber Seed Kernel and Palm Oil Shell
    Hamid MF, Idroas MY, Ishak MZ, Zainal Alauddin ZA, Miskam MA, Abdullah MK
    Biomed Res Int, 2016;2016:1679734.
    PMID: 27419127 DOI: 10.1155/2016/1679734
    Torrefaction process of biomass material is essential in converting them into biofuel with improved calorific value and physical strength. However, the production of torrefied biomass is loose, powdery, and nonuniform. One method of upgrading this material to improve their handling and combustion properties is by densification into briquettes of higher density than the original bulk density of the material. The effects of critical parameters of briquetting process that includes the type of biomass material used for torrefaction and briquetting, densification temperature, and composition of binder for torrefied biomass are studied and characterized. Starch is used as a binder in the study. The results showed that the briquette of torrefied rubber seed kernel (RSK) is better than torrefied palm oil shell (POS) in both calorific value and compressive strength. The best quality of briquettes is yielded from torrefied RSK at the ambient temperature of briquetting process with the composition of 60% water and 5% binder. The maximum compressive load for the briquettes of torrefied RSK is 141 N and the calorific value is 16 MJ/kg. Based on the economic evaluation analysis, the return of investment (ROI) for the mass production of both RSK and POS briquettes is estimated in 2-year period and the annual profit after payback was approximately 107,428.6 USD.
  3. Fulltext An investigation on longitudinal residual strains distribution of thin-walled press-braked cold formed steel sections using 3D FEM technique
    Mutafi A, Yidris N, Ishak MR, Zahari R
    Heliyon, 2018 Nov;4(11):e00937.
    PMID: 30839801 DOI: 10.1016/j.heliyon.2018.e00937
    Steel sections are normally shaped via cold work manufacturing processes. The extent of cold work to shape the steel sections might induce residual stresses in the region of bending. Previously, researchers had performed studies on the influences of local buckling on the failure behavior of steel compression members which shown that failure will happen when most of the yielding has extended to the middle surface in the bend region of the sections. Therefore, these cold work methods may have major effect on the behavior of the steel section and also its load-bearing capability. In addition, another factor may play significant role in formed section's load-bearing capacity which is the longitudinal residual strain. The longitudinal residual strain raised during forming procedure can be used to define the section imperfection of the formed section and its relation to the existence of defects. Therefore, the main motivation of this research paper is to perform three-dimensional finite element (3D-FE) to investigate peak longitudinal residual strains of a thin-walled steel plate with large bending angle along member length. A 3D finite element simulation in ABAQUS has been employed to simulate this forming process. The study concluded that the longitudinal residual strain at the section corner edge was higher than those at the rest of the corner region. These strains at the edge were higher than the yield strain


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    of the formed section which occurred due to the lack of transverse restraint. This made the plate edge tended to bend toward the normal direction when it was under a high transverse bending. This causes a significant difference in longitudinal strain at the plate edge.
  4. Characteristics of thermoplastic sugar palm Starch/Agar blend: Thermal, tensile, and physical properties
    Jumaidin R, Sapuan SM, Jawaid M, Ishak MR, Sahari J
    Int J Biol Macromol, 2016 Aug;89:575-81.
    PMID: 27177458 DOI: 10.1016/j.ijbiomac.2016.05.028
    The aim of this work is to study the behavior of biodegradable sugar palm starch (SPS) based thermoplastic containing agar in the range of 10-40wt%. The thermoplastics were melt-mixed and then hot pressed at 140°C for 10min. SEM investigation showed good miscibility between SPS and agar. FT-IR analysis confirmed that SPS and agar were compatible and inter-molecular hydrogen bonds existed between them. Incorporation of agar increased the thermoplastic starch tensile properties (Young's modulus and tensile strength). The thermal stability and moisture uptake increased with increasing agar content. The present work shows that starch-based thermoplastics with 30wt% agar content have the highest tensile strength. Higher content of agar (40wt%) resulted to more rough cleavage fracture and slight decrease in the tensile strength. In conclusion, the addition of agar improved the thermal and tensile properties of thermoplastic SPS which widened the potential application of this eco-friendly material. The most promising applications for this eco-friendly material are short-life products such as packaging, container, tray, etc.
  5. Characterizing the genetic risk for type 2 diabetes in a Malaysian multi-ethnic cohort
    Abdullah N, Abdul Murad NA, Attia J, Oldmeadow C, Mohd Haniff EA, Syafruddin SE, et al.
    Diabet Med, 2015 Oct;32(10):1377-84.
    PMID: 25711284 DOI: 10.1111/dme.12735
    AIMS: To characterize the association with Type 2 diabetes of known Type 2 diabetes risk variants in people in Malaysia of Malay, Chinese and Indian ancestry who participated in the Malaysian Cohort project.
    METHODS: We genotyped 1604 people of Malay ancestry (722 cases, 882 controls), 1654 of Chinese ancestry (819 cases, 835 controls) and 1728 of Indian ancestry (851 cases, 877 controls). First, 62 candidate single-nucleotide polymorphisms previously associated with Type 2 diabetes were assessed for association via logistic regression within ancestral groups and then across ancestral groups using a meta-analysis. Second, estimated odds ratios were assessed for excess directional concordance with previously studied populations. Third, a genetic risk score aggregating allele dosage across the candidate single-nucleotide polymorphisms was tested for association within and across ancestral groups.
    RESULTS: After Bonferroni correction, seven individual single-nucleotide polymorphisms were associated with Type 2 diabetes in the combined Malaysian sample. We observed a highly significant excess in concordance of effect directions between Malaysian and previously studied populations. The genetic risk score was strongly associated with Type 2 diabetes in all Malaysian groups, explaining from 1.0 to 1.7% of total Type 2 diabetes risk variance.
    CONCLUSION: This study suggests there is substantial overlap of the genetic risk alleles underlying Type 2 diabetes in Malaysian and other populations.
    Study name: The Malaysian Cohort (TMC) project
  6. Development and characterization of sugar palm nanocrystalline cellulose reinforced sugar palm starch bionanocomposites
    Ilyas RA, Sapuan SM, Ishak MR, Zainudin ES
    Carbohydr Polym, 2018 Dec 15;202:186-202.
    PMID: 30286991 DOI: 10.1016/j.carbpol.2018.09.002
    Sugar palm fibre (SPF) was treated with NaClO2, bleached with NaOH and subsequently hydrolyzed with acid to obtain sugar palm nanocrystalline cellulose (SPNCCs). Bionanocomposites in the form of films were prepared by mixing sugar palm starch (SPS) and sorbitol/glycerol with different nanofiller SPNCCs compositions (0-1.0 wt%) using solution casting method. The resulting fibres and nanocomposites were characterized in terms of morphology (FESEM and TEM), footprint, crystallinity (XRD), light transmittance, biodegradability, physical, water barrier, thermal (TGA, DSC and DMA) and mechanical properties. The length (L), diameter (D) and L/D values of the SPNCCs were 130 ± 30.23, 8.5 ± 1.82 nm, and 15.3, respectively. The SPS/SPNCCs nanocomposite films exhibited higher crystallinity, tensile strength, Young's modulus, thermal and water-resistance compared to the neat SPS film. The results showed that the tensile strength and moduli of the bionanocomposites increased after being reinforced with SPNCCs and the optimum nanofiller content was 0.5%.
  7. Development and characterization of sugar palm starch and poly(lactic acid) bilayer films
    Sanyang ML, Sapuan SM, Jawaid M, Ishak MR, Sahari J
    Carbohydr Polym, 2016 08 01;146:36-45.
    PMID: 27112848 DOI: 10.1016/j.carbpol.2016.03.051
    The development and characterization of environmentally friendly bilayer films from sugar palm starch (SPS) and poly(lactic acid) (PLA) were conducted in this study. The SPS-PLA bilayer films and their individual components were characterized for their physical, mechanical, thermal and water barrier properties. Addition of 50% PLA layer onto 50% SPS layer (SPS50-PLA50) increased the tensile strength of neat SPS film from 7.74 to 13.65MPa but reduced their elongation at break from 46.66 to 15.53%. The incorporation of PLA layer significantly reduced the water vapor permeability as well as the water uptake and solubility of bilayer films which was attributed to the hydrophobic characteristic of the PLA layer. Furthermore, scanning electron microscopy (SEM) image of SPS50-PLA50 revealed lack of strong interfacial adhesion between the SPS and PLA. Overall, the incorporation of PLA layer onto SPS films enhances the suitability of SPS based films for food packaging.
  8. Effect of plasticizer type and concentration on physical properties of biodegradable films based on sugar palm (arenga pinnata) starch for food packaging
    Sanyang ML, Sapuan SM, Jawaid M, Ishak MR, Sahari J
    J Food Sci Technol, 2016 Jan;53(1):326-36.
    PMID: 26787952 DOI: 10.1007/s13197-015-2009-7
    In this study, sugar palm starch (SPS) films were developed using glycerol (G), sorbitol (S) or their combination (GS) as plasticizers at the ratio of 15, 30 and 45 (wt)% using casting technique. The addition of plasticizers to SPS film-forming solutions helped to overcome the brittle and fragile nature of unplasticized SPS films. Increased plasticizer concentration resulted to an increase in film thickness, moisture content and solubility. On the contrary, density and water absorption of plasticized films decreased with increasing plasticizer concentration. Raising the plasticizer content from 15 to 45 % showed less effect on the moisture content and water absorption of S-plasticized films. Films containing glycerol and glycerol-sorbitol plasticizer (G, and GS) demonstrated higher moisture content, solubility and water absorption capacity compared to S-plasticized films. The results obtained in this study showed that plasticizer type and concentration significantly improves film properties and enhances their suitability for food packaging applications.
  9. Evaluation of Practicing sustainable Industrial Solid Waste Minimization by Manufacturing Firms in Malaysia: Strengths and Weaknesses
    Mallak SK, Bakri Ishak M, Mohamed AF
    J Air Waste Manag Assoc, 2016 Sep 13.
    PMID: 27624195 DOI: 10.1080/10962247.2016.1221366
    Malaysia is facing an increasing trend in industrial solid waste generation due to industrial development.Thus there is a paramount need in taking a serious action to move toward sustainable industrial waste management. The main aim of this study is to assess practicing solid waste minimization by manufacturing firms in Shah Alam industrial state, Malaysia. This paper presents a series of descriptive and inferential statistical analysis regarding the level and effects of practicing waste minimization methods, and seriousness of barriers preventing industries from practicing waste minimization methods. For this purpose the survey questions were designed such that both quantitative (questionnaire) and qualitative (semi-structures interview) data were collected concurrently. Analysis showed that, the majority of firms (92%) dispose their wastes rather than practice other sustainable waste management options. Also waste minimization methods such as segregation of wastes, on-site recycle and reuse, improve housekeeping and equipment modification were found to have significant contribution in waste reduction (p<0.05). Lack of expertise (M=3.50), lack of enough information (M= 3.54), lack of equipment modification (M= 3.16) and lack of specific waste minimization guidelines (M=3.49) have higher mean scores comparing with other barriers in different categories. These data were interpreted for elaborating of SWOT and TOWS matrix to highlight strengths, weaknesses, threats and opportunities. Accordingly, ten policies were recommended for improvement of practicing waste minimization by manufacturing firms as the main aim of this research. Implications This manuscript critically analysis waste minimization practices by manufacturing firms in Malaysia. Both qualitative and quantitative data collection and analysis were conducted to formulate SWOT and TOWS matrix in order to recommend policies and strategies for improvement of solid waste minimization by manufacturing industries. The results contribute to the knowledge and the findings of this study provide a useful baseline information and data on industrial solid waste generation and waste minimization practice.
  10. Fulltext Fabrication, Functionalization, and Application of Carbon Nanotube-Reinforced Polymer Composite: An Overview
    Mohd Nurazzi N, Asyraf MRM, Khalina A, Abdullah N, Sabaruddin FA, Kamarudin SH, et al.
    Polymers (Basel), 2021 Mar 26;13(7).
    PMID: 33810584 DOI: 10.3390/polym13071047
    A novel class of carbon nanotube (CNT)-based nanomaterials has been surging since 1991 due to their noticeable mechanical and electrical properties, as well as their good electron transport properties. This is evidence that the development of CNT-reinforced polymer composites could contribute in expanding many areas of use, from energy-related devices to structural components. As a promising material with a wide range of applications, their poor solubility in aqueous and organic solvents has hindered the utilizations of CNTs. The current state of research in CNTs-both single-wall carbon nanotubes (SWCNT) and multiwalled carbon nanotube (MWCNT)-reinforced polymer composites-was reviewed in the context of the presently employed covalent and non-covalent functionalization. As such, this overview intends to provide a critical assessment of a surging class of composite materials and unveil the successful development associated with CNT-incorporated polymer composites. The mechanisms related to the mechanical, thermal, and electrical performance of CNT-reinforced polymer composites is also discussed. It is vital to understand how the addition of CNTs in a polymer composite alters the microstructure at the micro- and nano-scale, as well as how these modifications influence overall structural behavior, not only in its as fabricated form but also its functionalization techniques. The technological superiority gained with CNT addition to polymer composites may be advantageous, but scientific values are here to be critically explored for reliable, sustainable, and structural reliability in different industrial needs.
  11. Finite element analysis of different surgical approaches in various occlusal loading locations for zygomatic implant placement for the treatment of atrophic maxillae
    Ishak MI, Abdul Kadir MR, Sulaiman E, Abu Kasim NH
    Int J Oral Maxillofac Surg, 2012 Sep;41(9):1077-89.
    PMID: 22575179 DOI: 10.1016/j.ijom.2012.04.010
    The aim of this study was to compare two different types of surgical approaches, intrasinus and extramaxillary, for the placement of zygomatic implants to treat atrophic maxillae. A computational finite element simulation was used to analyze the strength of implant anchorage for both approaches in various occlusal loading locations. Three-dimensional models of the craniofacial structures surrounding a region of interest, soft tissue and framework were developed using computed tomography image datasets. The implants were modelled using computer-aided design software. The bone was assumed to be linear isotropic with a stiffness of 13.4 GPa, and the implants were assumed to be made of titanium with a stiffness of 110 GPa. Masseter forces of 300 N were applied at the zygomatic arch, and occlusal loads of 150 N were applied vertically onto the framework surface at different locations. The intrasinus approach demonstrated more satisfactory results and could be a viable treatment option. The extramaxillary approach could also be recommended as a reasonable treatment option, provided some improvements are made to address the cantilever effects seen with that approach.
  12. Goniothalamin induces apoptosis in vascular smooth muscle cells
    Chan KM, Rajab NF, Ishak MH, Ali AM, Yusoff K, Din LB, et al.
    Chem Biol Interact, 2006 Feb 1;159(2):129-40.
    PMID: 16297902
    Restenosis represents a major impediment to the success of coronary angioplasty. Abnormal proliferation of vascular smooth muscle cells (VSMCs) has been shown to be an important process in the pathogenesis of restenosis. A number of agents, particularly rapamycin and paclitaxel, have been shown to impact on this process. This study was carried out to determine the mechanisms of cytotoxicity of goniothalamin (GN) on VSMCs. Results from MTT cytotoxicity assay showed that the IC(50) for GN was 4.4 microg/ml (22 microM), which was lower compared to the clinically used rapamycin (IC(50) of 25 microg/ml [27.346 microM]). This was achieved primarily via apoptosis where up to 25.83 +/- 0.44% of apoptotic cells were detected after 72 h treatment with GN. In addition, GN demonstrated similar effects as rapamycin in inhibiting VSMCs proliferation using bromodeoxyuridine (BrdU) cell proliferation assay after 72 h treatment at IC(50) concentration (p > 0.05). In order to understand the mechanisms of GN, DNA damage detection using comet assay was determined at 2h post-treatment with GN. Our results showed that there was a concentration-dependent increase in DNA damage in VSMCs prior to cytotoxicity. Moreover, GN effects were comparable to rapamycin. In conclusion, our data show that GN initially induces DNA damage which subsequently leads to cytotoxicity primarily via apoptosis in VSMCs.
  13. Growth kinetic study on normal and microtic chondrocytes of human auricular cartilage
    Ishak MF, Aminuddin BS, Asma A, Lokman BS, Ruszymah BH, Goh BS
    Med J Malaysia, 2008 Jul;63 Suppl A:117-8.
    PMID: 19025013
    Chondrocytes were isolated from normal and microtic human auricular cartilage after ear surgery carried out at Universiti Kebangsaan Malaysia Medical Centre. Chondrocytes were cultured and expanded until passage 4. After reached confluence, cultured chondrocytes at each passage (P1, P2, P3 and P4) were harvested and assigned for growth profile analysis. There was no significant difference in cell viability between both normal and microtic samples (p = 0.84). Both samples showed no significant differences for growth profile parameters in terms of growth rate, population doubling time and total number of cell doubling, except in passage 1, where there is significant difference in cell growth rate (p = 0.004). This preliminary data has indicated that chondrocytes from microtic cartilage has the potential to be used in the reconstruction of human pinna in the future.
  14. Fulltext Helicobacter pylori related functional dyspepsia in a defined Malaysian population
    Nafeeza MI, Isa MR, Kudva MV, Ishak MS, Mazlam MZ, Haron A, et al.
    Malays J Med Sci, 2000 Jan;7(1):22-6.
    PMID: 22844211 MyJurnal
    The objective of the study was to determine the prevalence of H. pylori in functional dyspepsia among the three main races in Malaysia. Gastric antral biopsies from 233 (98 males, 135 females; age range: 17-75 years, mean age 39.5 years) patients attending the Universiti Kebangsaan Malaysia (UKM) gastroenterology clinic were assessed for the presence of H. pylori by culture and histology. About a third of the cases (79 of 233 (34%); 34 males, 45 females; mean age 42.6 yrs) were positive for H. pylori. The presence of H. pylori was always associated with antral gastritis. Malay patients were least likely to be positive for H. pylori (10 of 88 (11.4%); 5 males, 5 females; mean age 35.7 yrs) compared to the Chinese (43 of 95 (45%); 19 males; 24 females; mean age 40.2 yrs) and Indian patients (23 of 41 (56%); 10 males, 13 females; mean age 48.1 yrs). We found that H. pylori were most common among Chinese followed by Indians. However, the relative risk for the Indians was 8.58 and 6.29 for the Chinese compared to Malays. We conclude that the prevalence of H. pylori in patients with functional dyspepsia differs considerably with respect to ethnic groups.
  15. Isolation and characterization of nanocrystalline cellulose from sugar palm fibres (Arenga Pinnata)
    Ilyas RA, Sapuan SM, Ishak MR
    Carbohydr Polym, 2018 Feb 01;181:1038-1051.
    PMID: 29253930 DOI: 10.1016/j.carbpol.2017.11.045
    Cellulose was extracted from sugar palm fibres (Arenga pinnata) by conducting delignification and mercerization treatments. Subsequently, sugar palm nanocrystalline celluloses (SPNCCs) were isolated from the extracted cellulose with 60wt% concentrated sulphuric acid. The chemical composition of sugar palm fibres were determined at different stages of treatment. Structural analysis was carried out by Brunauer-Emmett-Teller (BET), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR). Morphological analysis of extracted cellulose and isolated nanocrystalline cellulose (NCCs) was investigated by using field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM), and transmission electron microscopy (TEM). The thermal stability of sugar palm fibres at different stages of treatment was investigated by thermogravimetric analysis (TGA). The results showed that lignin and hemicellulose were removed from the extracted cellulose through the delignification and mercerization process, respectively. The isolated SPNCCs were found to have length and diameters of 130±30nm and 9±1.96nm, respectively.
  16. Fulltext Knowledge of sexual and reproductive health among adolescents attending school in Kelantan, Malaysia
    Ab Rahman A, Ab Rahman R, Ibrahim MI, Salleh H, Ismail SB, Ali SH, et al.
    Southeast Asian J. Trop. Med. Public Health, 2011 May;42(3):717-25.
    PMID: 21706952
    The objectives of this study were to describe the knowledge of sexual and reproductive health among adolescents attending school and to compare the levels of knowledge between males and females and between older and younger groups of adolescents. A cross-sectional study was conducted among 1,034 secondary school students using a self administered validated questionnaire. The items with the fewest correct responses included: whether one can get pregnant after a single act of sexual intercourse (30.4%), whether sexual intercourse causes sexually transmitted diseases (STDs) (12.4%) and whether washing the vagina after sexual intercourse prevents pregnancy (17.0%). Their main source of sexual information was friends (64.4%). An independent t-test revealed the mean knowledge score was significantly higher among females than males on items assessing whether the genitalia may be touched freely by family members, females having attained menarche may become pregnant if having sex, whether pregnancy will occur if there is penetration of the penis into the vagina, whether premarital sexual intercourse causes pregnancy and if there is a relationship between abandoned babies and premarital pregnancies. The mean knowledge score assessing whether pregnancy can be prevented using condoms was higher among males than females. The mean knowledge scores were significantly higher among form four and form five students than forms one, two and three students. Lack of knowledge regarding important aspects of sexual and reproductive health warrant the need to strengthen sexual and reproductive health education.
  17. LOC285629 regulates cell proliferation and motility in colorectal cancer cells
    Nasir SN, Abu N, Ab Mutalib NS, Ishak M, Sagap I, Mazlan L, et al.
    Clin Transl Oncol, 2018 Jun;20(6):775-784.
    PMID: 29098557 DOI: 10.1007/s12094-017-1788-x
    PURPOSE: Colorectal cancer (CRC) is one of the most widely diagnosed cancers in men and women worldwide. With the advancement of next-generation sequencing technologies, many studies have highlighted the involvement of long non-coding RNAs (lncRNAs) in cancer development. Growing evidence demonstrates that lncRNAs play crucial roles in regulating gene and protein expression and are involved in various cancers, including CRC. The field of lncRNAs is still relatively new and a lot of novel lncRNAs have been discovered, but their functional roles are yet to be elucidated. This study aims to characterize the expression and functional roles of a novel lncRNA in CRC.

    METHOD: Several methods were employed to assess the function of LOC285629 such as gene silencing, qPCR, proliferation assay, BrdU assay, transwell migration assay, ELISA and protein profiler.

    RESULTS: Via in silico analyses, we identified significant downregulation of LOC285629, a novel lncRNA, across CRC stages. LOC285629 expression was significantly downregulated in advanced stages (Stage III and IV) compared to Stage I (Kruskal-Wallis Test; p = 0.0093). Further in-house validation showed that the expression of LOC285629 was upregulated in colorectal cancer tissues and cell lines compared to the normal counterparts, but was downregulated in advanced stages. By targeting LOC285629, the viability, proliferative abilities, invasiveness and resistance of colorectal cancer cells towards 5-fluorouracil were reduced. It was also discovered that LOC285629 may regulate cancer progression by targeting several different proteins, namely survivin, BCL-xL, progranulin, PDGF-AA, enolase 2 and p70S6 K.

    CONCLUSION: Our findings suggest that LOC285629 may be further developed as a potential therapeutic target for CRC treatment.

  18. Fulltext Lattice Boltzmann Method of Different BGA Orientations on I-Type Dispensing Method
    Abas A, Gan ZL, Ishak MH, Abdullah MZ, Khor SF
    PLoS One, 2016;11(7):e0159357.
    PMID: 27454872 DOI: 10.1371/journal.pone.0159357
    This paper studies the three dimensional (3D) simulation of fluid flows through the ball grid array (BGA) to replicate the real underfill encapsulation process. The effect of different solder bump arrangements of BGA on the flow front, pressure and velocity of the fluid is investigated. The flow front, pressure and velocity for different time intervals are determined and analyzed for potential problems relating to solder bump damage. The simulation results from Lattice Boltzmann Method (LBM) code will be validated with experimental findings as well as the conventional Finite Volume Method (FVM) code to ensure highly accurate simulation setup. Based on the findings, good agreement can be seen between LBM and FVM simulations as well as the experimental observations. It was shown that only LBM is capable of capturing the micro-voids formation. This study also shows an increasing trend in fluid filling time for BGA with perimeter, middle empty and full orientations. The perimeter orientation has a higher pressure fluid at the middle region of BGA surface compared to middle empty and full orientation. This research would shed new light for a highly accurate simulation of encapsulation process using LBM and help to further increase the reliability of the package produced.
  19. Fulltext Lattice Boltzmann Model of 3D Multiphase Flow in Artery Bifurcation Aneurysm Problem
    Abas A, Mokhtar NH, Ishak MH, Abdullah MZ, Ho Tian A
    Comput Math Methods Med, 2016;2016:6143126.
    PMID: 27239221 DOI: 10.1155/2016/6143126
    This paper simulates and predicts the laminar flow inside the 3D aneurysm geometry, since the hemodynamic situation in the blood vessels is difficult to determine and visualize using standard imaging techniques, for example, magnetic resonance imaging (MRI). Three different types of Lattice Boltzmann (LB) models are computed, namely, single relaxation time (SRT), multiple relaxation time (MRT), and regularized BGK models. The results obtained using these different versions of the LB-based code will then be validated with ANSYS FLUENT, a commercially available finite volume- (FV-) based CFD solver. The simulated flow profiles that include velocity, pressure, and wall shear stress (WSS) are then compared between the two solvers. The predicted outcomes show that all the LB models are comparable and in good agreement with the FVM solver for complex blood flow simulation. The findings also show minor differences in their WSS profiles. The performance of the parallel implementation for each solver is also included and discussed in this paper. In terms of parallelization, it was shown that LBM-based code performed better in terms of the computation time required.
  20. Mapping discourses using Q methodology in Matang Mangrove Forest, Malaysia
    Hugé J, Vande Velde K, Benitez-Capistros F, Japay JH, Satyanarayana B, Nazrin Ishak M, et al.
    J Environ Manage, 2016 Dec 01;183(Pt 3):988-997.
    PMID: 27692515 DOI: 10.1016/j.jenvman.2016.09.046
    The sustainable management of natural resources requires the consideration of multiple stakeholders' perspectives and knowledge claims, in order to inform complex and possibly contentious decision-making dilemmas. Hence, a better understanding of why people in particular contexts do manage natural resources in a particular way is needed. Focusing on mangroves, highly productive tropical intertidal forests, this study's first aim is to map the diversity of subjective viewpoints among a range of stakeholders on the management of Matang Mangrove Forest in peninsular Malaysia. Secondly, this study aims to feed the reflection on the possible consequences of the diversity of perspectives for the future management of mangroves in Malaysia and beyond. The use of the semi-quantitative Q methodology allowed us to identify three main discourses on mangrove management: i. the optimization discourse, stressing the need to improve the current overall satisfactory management regime; ii. the 'change for the better' discourse, which focuses on increasingly participatory management and on ecotourism; and iii. the conservative 'business as usual' discourse. The existence of common points of connection between the discourses and their respective supporters provides opportunities for modifications of mangrove management regimes. Acknowledging this diversity of viewpoints, reflecting how different stakeholders see and talk about mangrove management, highlights the need to develop pro-active and resilient natural resource management approaches.
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