Displaying publications 81 - 100 of 161 in total

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  1. Hafizal Yazid, Sahrim Ahmad, Laggner, P., Aziz Mohamed, A., Dahlan, H.M., M. Rawi M. Z., et al.
    MyJurnal
    Thermoplastic natural rubber sample is found isotropic based on SAXS pattern. Morphological parameter was obtained based on ideal lamellar morphology using 1-D correlation function. The fitting was carried out using Porod tail model and Vonk for back-extrapolated model. It is found that the long period value is 15.7nm which is comparable to results obtained from Lorents corrected profile, 20nm. Crystalline thickness and amorphous thickness was found as 13.4 and 2.31nm respectively
    Matched MeSH terms: Rubber
  2. Koh HL, Lim PE, Midun Z
    Environ Monit Assess, 1991 Oct;19(1-3):349-59.
    PMID: 24233952 DOI: 10.1007/BF00401324
    Coastal waters in South Johore, Malaysia are polluted to various degrees. The major pollution sources are domestric wastes from human settlements, agro-based wastes from palm oil mills and rubber processing factories, industrial effluents from industrial estates and discharges from animal farms. These pollution problems have adversely affected resources such as fisheries, recreational potential as well as the general aesthetic quality of the coastal environment particularly the Inner Johore Strait. Hence proper management and control measures are urgently needed to protect and further enhance the water quality to ensure environmentally sustainable development. This study examines various management options to control the pollution in the Inner Johore Strait. The options involve partial opening as well as complete removal of the Causeway to improve the tidal flow for more effective dilution and dispersion of pollutants. Computer simulation models are used to assess the impacts of the proposed options.
    Matched MeSH terms: Rubber
  3. Bilema M, Aman MY, Hassan NA, Memon ZA, Omar HA, Yusoff NIM, et al.
    Materials (Basel), 2021 May 24;14(11).
    PMID: 34073812 DOI: 10.3390/ma14112781
    Researchers are exploring the utilisation of reclaimed asphalt pavement (RAP) as a recycled material to determine the performance of non-renewable natural aggregates and other road products such as asphalt binder, in the construction and rehabilitation stage of asphalt pavements. The addition of RAP in asphalt mixtures is a complex process and there is a need to understand the design of the asphalt mixture. Some of the problems associated with adding RAP to asphalt mixtures are moisture damage and cracking damage caused by poor adhesion between the aggregates and asphalt binder. There is a need to add rejuvenators to the recycled mixture containing RAP to enhance its performance, excepting the rutting resistance. This study sought to improve asphalt mixture performance and mechanism by adding waste frying oil (WFO) and crumb rubber (CR) to 25 and 40% of the RAP content. Moreover, the utilisation of CR and WFO improved pavement sustainability and rutting performance. In addition, this study prepared five asphalt mixture samples and compared their stiffness, moisture damage and rutting resistance with the virgin asphalt. The results showed enhanced stiffness and rutting resistance of the RAP but lower moisture resistance. The addition of WFO and CR restored the RAP properties and produced rutting resistance, moisture damage and stiffness, which were comparable to the virgin asphalt mixture. All waste and virgin materials produce homogeneous asphalt mixtures, which influence the asphalt mixture performance. The addition of a high amount of WFO and a small amount of CR enhanced pavement sustainability and rutting performance.
    Matched MeSH terms: Rubber
  4. Ahmad Saat, Zaini Hamzah, Zaharidah Abu Bakar, Zuraidah A. Munir, Siti Mariam Sumari, Misbah Hassan
    MyJurnal
    A study was carried out to determine short term diurnal radon concentration at five locations in Malaysia. Two locations (KG & AP) are former tin mining areas that has been converted to housing area and training centre respectively, one a relatively new city (SA), that was formerly a rubber and oil palm plantation area, one older cities (KB) and one housing complex by the sea (LP). The study was carried out in 2005, 2006 and 2007 using a diffused-junction photodiode sensor continuous radon monitor. The monitor is recognized by the USEPA. In each location, measurements were carried out on at least ten sites. Former tin mining areas of KG and AP shows up to seven times higher indoor average than the average in the other three locations. However the indoor average in all locations is still below the action level of 4 pCiL-1. For outdoor, the former tin mining areas average concentration was higher than the global average of 0.4 pCiL-1. For the twenty four hours temporal variation the trend indicated that former tin mining areas concentration are always higher, and at time up to six fold higher. The hourly variation of all locations follows an identical trend of high concentration during early to late morning and drop in the afternoon till evening. The outdoor twenty four hour temporal average of former tin mining areas is consistently higher than the outdoor global average of 0.4 pCiL-1. The strong correlation between indoor and outdoor concentration at AP, indicates that indoor radon might originates from outdoor environment. The study was also extended to estimate the effective dose (mSvyr-1) of Rn-222 to the public.
    Matched MeSH terms: Rubber
  5. Abdullah, M., Che Ab Aziz, Z.A., Roslan Saub, Murat, N., Sulaiman, E., Hashim, N., et al.
    Ann Dent, 2009;16(1):9-14.
    MyJurnal
    The objectives of this study were to assess the practice of molar root canal treatment (RCT) among general dental practitioners (GDPs), confidence level of GDPs in performing molar RCT and to identify factors that influence their confidence in managing molar RCI. One hundred questionnaires were distributed to GDPs in Kuala Lumpur and Selangor. Fifty questionnaires were delivered by mail and the remaining fifty were hand-delivered. All data was coded and verified. Fiftysix OOPs rcsponded to the questionnaires. Only fortyfive questionnaires were accepted (n=45) as eleven OOPs had never performed molar RCI. Most of the OOPs followed the standard quality guidelines while performing molar RCT except for vitality testing (36.4%) and rubber dam usage (27.3%). In this study, 100% of the GDPs were confident in making diagnosis of perinidicular diseases and 95.4% were confident in performing molar RCT from history taking until obturation. Patients' tolerance and availability of instruments and materials (97.7%) were two factors that most influence the GDPs' confidence level. The. least influcncing factor was undergraduate training (78.1 %). Attending seminars and lectures on endodontic, large number of molar teeth treated for ReT, patLents' affordability to pay for RCT and postgraduate training also influencc GDPs' confidence to a certain degree. From this study, it can be concluded that majority of OOPs complied standard quality guidelines except for vitality testing and rubber dam usage. Most of them were confident in performing molar RCT and were greatly influenced by the availability or"instruments and materials in their clinic and patients' tolerance in receiving molar RCI.
    Matched MeSH terms: Rubber Dams
  6. Nuriah Mohamad, Azlin Suhaida Azmi, Fathilah Ali, Mohamad Firdaus Omar
    MyJurnal
    Sulfur has been highly sought by many industries everywhere around the world for various applications. This exceptionally useful element has been largely manufactured especially in powder form each year reflecting its increase in demand in line with technological advancement and uses for various product applications. The manufacturing processes include mining as well as chemical reactions in Claus Process. Rubber industries normally use abundance of sulfur in their latex compound to introduce vulcanization. The geneal concern of sulfur for rubber vulcanization is dispersibility in the rubber matrix due to improper optimization of its preparation process prior to latex compounding. Another crucial issue is crystallization of soluble sulfur from its insoluble origin, either during or post-rubber vulcanization that constitutes to formation of sulfur bloom that grows on the surface of the rubber articles. It is known that both issues are related to the process conditions and compounding recipe that could not be fully solved. Various studies have been conducted to minimize such occurences – from process optimization to sulfur chemistry itself – and of continuous improvement and innovation to solve various threats in sulfur applications. This paper reviews on detailed description on elemental sulfur, of respective industrial applications, and most importantly highlights on sulfur trends and issues normally encountered.
    Matched MeSH terms: Rubber
  7. Juhaida MF, Paridah MT, Mohd Hilmi M, Sarani Z, Jalaluddin H, Mohamad Zaki AR
    Bioresour Technol, 2010 Feb;101(4):1355-60.
    PMID: 19833509 DOI: 10.1016/j.biortech.2009.09.048
    A study was carried out to produce polyurethane (PU) as a wood laminating adhesive from liquefied kenaf core (LKC) polyols by reacting it with toluene-2,4-diisocyanate (TDI) and 1,4-butanediol (BDO). The LKC polyurethane (LKCPU) adhesive has a molecular weight (MW) of 2666, viscosity of 5370 mPa s, and solids content of 86.9%. The average shear strength of the rubberwood (RW) bonded with LKCPU adhesive was 2.9 MPa. Most of the sheared specimens experienced a total adhesive failure. The formation of air bubbles through the liberation of carbon dioxide was observed to reduce the adhesive penetration and bonding strength which was obviously seen on the sheared specimens. The percentage of catalyst used can be varied based on the usage and working time needed. Nonetheless, the physical properties of LKCPU produced in this work had shown good potential as edge-bonding adhesive.
    Matched MeSH terms: Rubber/chemistry
  8. Mazliah, M., Noraiham, M., Anisah, A.L., Azrul, Y., Hairul, E.A.M., Jeefferie, A.R., et al.
    MyJurnal
    Incineration and disposal of carbon fiber waste from the aircraft industry lead to serious energy consumption and environmental pollution. The use of this waste as reinforcement is a wise approach to appreciate the high performance of the carbon fiber. This study is part of our effort to develop new green rubber foam from recycled carbon fiber prepreg (rCFP) reinforced natural rubber via internal mixer. It is focusing on the effect of different rCFP loading at 1, 3, 5, and 7 parts per hundred rubbers (phr) as reinforcement. The samples were prepared by melt compounding using an internal mixer and expanded via two step heat transfer foaming process. The physical properties of the green rubber foam were characterized and the results were observed to systematically correlate with the impact properties of the foam. The absorbed energy of the foam increases up to 0.3 joules with increasing relative foam density of 0.81 which is associated with the formation of smaller foam cells ~0.68mm and more spherical shape pores.
    Matched MeSH terms: Rubber
  9. Ahmad Kamil Arshad, Juraidah Ahmad, Mohd Izzat Asyraf Mohamad Kamal
    MyJurnal
    This paper details a study conducted to evaluate the performance of cold in-place recycling (CIPR) using polymer modified asphalt emulsion (PMAE). The asphalt emulsion was modified using natural rubber latex (NRL). Four proportions of reclaimed asphalt pavement (RAP) which are 0%, 25%, 50% and 75% were mixed with natural aggregates and modified asphalt emulsion using natural rubber latex (NRL). The results showed that the optimum modified asphalt emulsion for each proportion of RAP decreased due to the increase in RAP content. Results obtained from Indirect Tensile Strength (ITS) and Uniaxial Compressive Strength (UCS) test for the mixes complied with the requirements of the Road Engineering Association of Malaysia (REAM) specifications. The unsoaked and soaked ITS values obtained were 0.2 MPa and 0.15 MPa respectively, and the minimum compressive strength of CIPR mix obtained was 0.7 MPa. Based on the evaluation of performance for the four RAP proportions, it was determined that 50% of RAP gave the best combination of the CIPR mixture.
    Matched MeSH terms: Rubber
  10. Irfan M, Hasme Zam H, Mohd Khairi M
    Malays Fam Physician, 2012;7(1):28-30.
    PMID: 25606242 MyJurnal
    The incidence of rhinolith is by far very low compared to the nasal foreign bodies, especially in adult. Foreign body (FB) in the nostril will lead to unilateral nasal symptom which can start with nasal obstruction or discomfort. In younger children, they may miss to report the problem to the parents but, later on, the FB will manifest itself with unilateral nasal discharge, which at most of the time fouls smells. We report a case of a healthy adult female who presented with unilateral foul smelly nasal discharge which later was diagnosed as rhinolith, with rubber-tip pencil eraser as the nidus of calcification.
    Matched MeSH terms: Rubber
  11. Seuk-Yen Phoong, Mohd Tahir Ismail
    Sains Malaysiana, 2015;44:1033-1039.
    Over the years, maximum likelihood estimation and Bayesian method became popular statistical tools in which applied to fit finite mixture model. These trends begin with the advent of computer technology during the last decades. Moreover, the asymptotic properties for both statistical methods also act as one of the main reasons that boost the popularity of the methods. The difference between these two approaches is that the parameters for maximum likelihood estimation are fixed, but unknown meanwhile the parameters for Bayesian method act as random variables with known prior distributions. In the present paper, both the maximum likelihood estimation and Bayesian method are applied to investigate the relationship between exchange rate and the rubber price for Malaysia, Thailand, Philippines and Indonesia. In order to identify the most plausible method between Bayesian method and maximum likelihood estimation of time series data, Akaike Information Criterion and Bayesian Information Criterion are adopted in this paper. The result depicts that the Bayesian method performs better than maximum likelihood estimation on financial data.
    Matched MeSH terms: Rubber
  12. Aisami Abubakar, Mohd Yunus Shukor
    MyJurnal
    Environmental pollution is one of the major concerns in the 21st century; where billions of tonnes
    of harmful chemicals are produced by industries such as petroleum, paints, food, rubber, and
    plastic. Phenol and its derivatives infiltrate the ecosystems and have become one of the top major
    pollutants worldwide. This review covers the major aspects of immobilization of phenoldegrading
    bacteria as a method to improve phenol bioremediation. The use of various forms of
    immobilization matrices is discussed along with the advantages and disadvantages of each of the
    immobilization matrices especially when environmental usage is warranted. To be used as a
    bioremediation tool, the immobilized system must not only be effective, but the matrices must be
    non-toxic, non-polluting and if possible non-biodegradable. The mechanical, biological and
    chemical stability of the system is paramount for long-term activity as well as price is an
    important factor when the very large scale is a concern. The system must also be able to tolerate
    high concentration of other toxicants especially heavy metals that form as co-contaminants, and
    most immobilized systems are geared towards this last aspect as immobilization provides
    protection from other contaminants.
    Matched MeSH terms: Rubber
  13. Nik Hashyati Nik Hashim, Zulkefly Sulaiman, Mahmud Tengku Muda Mohamed, Mohd Yusoff Abd Samad
    MyJurnal
    Hevea brasiliensis is one of the popular industrial crops in Malaysia better known as rubber tree belongs to the family Euphorbiaceace. From more than 12 species of Hevea, only Hevea brasiliensis is economically exploited because the milky latex extracted from the tree is the primary source of natural rubber. As in other crops, various plant physiological conditions and pathogenic diseases influence rubber production. Brown bast is one of the most serious threats to natural rubber production. In general, high-yielding clones of rubber tree are often considered to be more susceptible to this physiological disorder also commonly termed Tapping Panel Dryness (TPD). It is estimated that brown bast leads to approximately 15-20% decrease in yield. There is no known cure for brown bast yet. However, many plantation practices manage brown bast in rubber by giving tapping rest and changing tapping panel. Hence, this review condenses the causal of brown bast, symptoms of diseases and also control of brown bast affected Hevea tree.
    Matched MeSH terms: Rubber
  14. Hashim SA, Samsudin FN, Wong CS, Abu Bakar K, Yap SL, Mohd Zin MF
    Arch Biochem Biophys, 2016 09 01;605:34-40.
    PMID: 27056469 DOI: 10.1016/j.abb.2016.03.032
    A modular typed dielectric barrier discharge (DBD) device is designed and tested for air and water remediation. The module is made of a number of DBD tubes that can be arranged in series or parallel. Each of the DBD tubes comprises inner electrode enclosed with dielectric barrier and arranged as such to provide a gap for the passage of gases. Non-thermal plasma generated in the gap effectively creates gaseous chemical reactions. Its efficacy in the remediation of gas stream containing high NOx, similar to diesel emission and wastewater containing latex, are presented. A six tubes DBD module has successfully removed more than 80% of nitric oxide from the gas stream. In another arrangement, oxygen was fed into a two tubes DBD to generate ozone for treatment of wastewater. Samples of wastewater were collected from a treatment pond of a rubber vulcanization pilot plant. The water pollution load was evaluated by the chemical oxygen demand (COD) and biological oxygen demand (BOD5) values. Preliminary results showed some improvement (about 13%) on the COD after treatment and at the same time had increased the BOD5 by 42%. This results in higher BOD5/COD ratio after ozonation which indicate better biodegradability of the wastewater.
    Matched MeSH terms: Rubber
  15. Chee H, Khor G, Arshad F, Wan Muda W, Mohdtaib M, Safii N, et al.
    Malays J Nutr, 2002 Mar;8(1):33-53.
    PMID: 22692438
    This paper describes the nutritional status of pre-school children and analyzes its relationship to various household socio-economic indicators. Padi, rubber and fishing villages from the Functional Groups Study (1992-1996) were selected for having a high prevalence of child undernutrition, and all children between the ages of 12 and 72 months were measured for their weights and heights in April-May 1998. The NCHS reference values were used to calculate z-scores, which were categorised according to WHO (1983) recommendations. Children between minus 2SD and minus 1SD of reference median were classified as mildly malnourished. Prevalence of underweight was higher (30.5%) than stunting (22.3%), while wasting was only 9.7%. Padi villages had the highest prevalence of undernutrition, followed by fishing, and then rubber villages. Mean household incomes were found to be significantly lower for children with worse nutritional status, and undernutrition was higher in households below the poverty line income. The odds ratios for having stunted children were significantly higher for households whose heads were agricultural own-account workers (OR 3.66, 95% CI = 1.37-9.79), agricultural waged workers (OR 2.75, 95% CI = 1.06-7.10), and non-agricultural manual workers (OR 2.49, 95% CI = 1.04-6.00) compared to non-manual workers. Various household socio-economic indicators showed significantly higher odds ratios for underweight, stunting and wasting. After adjusting for confounding effects by logistic regression analysis, however, only mother's education was found to be a significant predictor for stunting, while poverty level and access to piped water supply were significant predictors for both underweight and stunting. Households without livestock were significant predictors for wasting. Thus, this study identified specific socio-economic factors that should be prioritized for policy and research towards the amelioration of childhood malnutrition in rural areas.
    Matched MeSH terms: Rubber
  16. Kim Sooi Law, Noor Khairiah A. Karim, Noor Khairiah A. Karim, Nor Samsinar Abu Talib, Norhaliza Abd Hamid, Nur Arzuar Abdul Rahim, et al.
    Jurnal Inovasi Malaysia, 2020;3(2):100-107.
    MyJurnal
    The paramedic team of Advanced Medical and Dental Institute (IPPT), Universiti Sains Malaysia (USM) is often involved in providing medical assistance for various activities organised by the university such as during PIMPIN siswa outdoor training and sport events. Paramedics often faced difficulty in saving injured patients as the current stretcher is rather heavy (5.8 kg) and is not able to be folded to a smaller size. To overcome this problem, i-TAG, a stretcher made of durable two-layer canvas cloth with the size of 170.0 cm x 74.0 cm and equipped with 10 user-friendly rubber handle, has been invented. The upper part of the stretcher has a zip to insert the spinal board if the victim has spinal and head injuries. The i-TAG is also very light with only 1.2 kg in weight, easy to be folded and stored in emergency bags, and can be easily carried by paramedics. The i-TAG innovative product has a positive impact on health and safety services. Using i-TAG, the task to carry patients or injured victims becomes easier, faster, saves energy and subsequently increases the efficacy of the rescue and medical aid tasks by paramedics.
    Matched MeSH terms: Rubber
  17. Nur Rashyeda Ramli, Maizatul Suriza Mohamed, Idris Abu Seman, Madihah Ahmad Zairun, Nasyaruddin Mohamad
    Sains Malaysiana, 2016;45:401-409.
    This study was conducted to screen the endophytic bacteria as a biological control agent (BCA) against Ganoderma boninense. A total of 581 endophytic bacteria were successfully isolated from symptomless oil palm root tissues at Teluk Intan, Perak, Malaysia. Three endophytic bacteria, Pseudomonas aeruginosa GanoEB1, Burkholderia cepacia GanoEB2, and Pseudomonas syringae GanoEB3 were found to have a potential as BCA based on their percentage inhibition of radial growth (PIRG) in dual culture and culture filtrate tests. Two nursery trials were conducted to evaluate the capability of these bacteria to suppress Ganoderma disease in oil palm seedlings that were artificially infected with G. boninense using rubber wood block (RWB) sitting technique. The percentage of disease incidence (DI), severity of foliar symptoms (SFS) and dead seedlings were used as the assessment tools. As a result, DI and SFS have developed much slower in the seedlings that were pre-treated with bacteria compared to untreated seedlings. After 6 months of inoculation, Ganoderma disease incidence was reduced from 62-75% in the seedlings treated with P. aeruginosa GanoEB1, followed by B. cepacia GanoEB2 (31-59%) and P. syringae GanoEB3 (30-31%). Among these three endophytic bacteria, P. aeruginosa GanoEB1 was the most effective in controlling Ganoderma disease and the dead seedlings were in the range of 13.3-26.7%, followed by B. cepacia GanoEB2 (33.3% for both trials) and P. syringae GanoEB3 (33.3-40.0%) compared to untreated seedlings at 60% for both trials. A field study needs to be conducted to verify their effectiveness in controlling Ganoderma in oil palm.
    Matched MeSH terms: Rubber
  18. Johari MAF, Mazlan SA, Nasef MM, Ubaidillah U, Nordin NA, Aziz SAA, et al.
    Sci Rep, 2021 May 25;11(1):10936.
    PMID: 34035434 DOI: 10.1038/s41598-021-90484-0
    The widespread use of magnetorheological elastomer (MRE) materials in various applications has yet to be limited due to the fact that there are substantial deficiencies in current experimental and theoretical research on its microstructural durability behavior. In this study, MRE composed of silicon rubber (SR) and 70 wt% of micron-sized carbonyl iron particles (CIP) was prepared and subjected to stress relaxation evaluation by torsional shear load. The microstructure and particle distribution of the obtained MRE was evaluated by a field emission scanning electron microscopy (FESEM). The influence of constant low strain at 0.01% is the continuing concern within the linear viscoelastic (LVE) region of MRE. Stress relaxation plays a significant role in the life cycle of MRE and revealed that storage modulus was reduced by 8.7%, normal force has weakened by 27%, and stress performance was reduced by 6.88% along approximately 84,000 s test duration time. This time scale was the longest ever reported being undertaken in the MRE stress relaxation study. Novel micro-mechanisms that responsible for the depleted performance of MRE was obtained by microstructurally observation using FESEM and in-phase mode of atomic force microscope (AFM). Attempts have been made to correlate strain localization produced by stress relaxation, with molecular deformation in MRE amorphous matrix. Exceptional attention was focused on the development of molecular slippage, disentanglement, microplasticity, microphase separation, and shear bands. The relation between these microstructural phenomena and the viscoelastic properties of MRE was diffusely defined and discussed. The presented MRE is homogeneous with uniform distribution of CIP. The most significant recent developments of systematic correlation between the effects of microstructural deformation and durability performance of MRE under stress relaxation has been observed and evaluated.
    Matched MeSH terms: Rubber
  19. Ling JL, Teo SH, Mohamed Al-Fayyadh MZ, Mohamed Ali MR, Ng WM
    Arthroscopy, 2019 02;35(2):596-604.
    PMID: 30611592 DOI: 10.1016/j.arthro.2018.08.038
    PURPOSE: To assess the effectiveness of a low-cost self-made arthroscopic camera (LAC) in basic arthroscopic skills training compared with a commercial arthroscopic camera (CAC).

    METHODS: One hundred fifty-three orthopaedic residents were recruited and randomly assigned to either the LAC or CAC. They were allocated 2 practice sessions, with 20 minutes each, to practice 4 given arthroscopic tasks: task 1, transferring objects; task 2, stacking objects; task 3, probing numbers; and task 4, stretching rubber bands. The time taken for participants to complete the given tasks was recorded in 3 separate tests; before practice, immediately after practice, and after a period of 3 months. A comparison of the time taken between both groups to complete the given tasks in each test was measured as the primary outcome.

    RESULTS: Significant improvements in time completion were seen in the post-practice test for both groups in all given arthroscopic tasks, each with P < .001. However, there was no significant difference between the groups for task 1 (P = .743), task 2 (P = .940), task 3 (P = .932), task 4 (P = .929), and total (P = .944). The outcomes of the tests (before practice, after practice, and at 3 months) according to repeated measures analysis of variance did not differ significantly between the groups in task 1 (P = .475), task 2 (P = .558), task 3 (P = .850), task 4 (P = .965), and total (P = .865).

    CONCLUSIONS: The LAC is equally as effective as the CAC in basic arthroscopic skills training with the advantage of being cost-effective.

    CLINICAL RELEVANCE: In view of the scarcity in commercial arthroscopic devices for trainees, this low-cost device, which trainees can personally own and use, may provide a less expensive and easily available way for trainees to improve their arthroscopic skills. This might also cultivate more interest in arthroscopic surgery among junior surgeons.

    Matched MeSH terms: Rubber
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