Displaying publications 1 - 20 of 161 in total

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  1. Pedram A, Yusoff NB, Udoncy OE, Mahat AB, Pedram P, Babalola A
    Waste Manag, 2017 Feb;60:460-470.
    PMID: 27406308 DOI: 10.1016/j.wasman.2016.06.029
    This paper attempts to integrate both a forward and reverse supply chain to design a closed-loop supply chain network (CLSC). The problem in the design of a CLSC network is uncertainty in demand, return products and the quality of return products. Scenario analyses are generated to overcome this uncertainty. In contrast to the existing supply chain network design models, a new application of a CLSC network was studied in this paper to reduce waste. A multi-product, multi-tier mixed integer linear model is developed for a CLSC network design. The main objective is to maximize profit and provide waste management decision support in order to minimize pollution. The result shows applicability of the model in the tire industry. The model determines the number and the locations of facilities and the material flows between these facilities.
    Matched MeSH terms: Rubber
  2. Abd Aziz MA, Md Isa K, Ab Rashid R
    Waste Manag Res, 2017 Jun;35(6):647-655.
    PMID: 28431479 DOI: 10.1177/0734242X17697815
    This article aims to provide insights into the factors that contribute to the separation efficiency of solid particles. In this study, a pneumatic jigging technique was used to assess the separation of solid waste materials that consisted of copper, glass and rubber insulator. Several initial experiments were carried out to evaluate the strengths and limitations of the technique. It is found that despite some limitations of the technique, all the samples prepared for the experiments were successfully separated. The follow-up experiments were then carried out to further assess the separation of copper wire and rubber insulator. The effects of air flow and pulse rates on the separation process were examined. The data for these follow-up experiments were analysed using a sink float analysis technique. The analysis shows that the air flow rate was very important in determining the separation efficiency. However, the separation efficiency may be influenced by the type of materials used.
    Matched MeSH terms: Rubber
  3. Badron UH, Talip N, Mohamad AL, Affenddi AE, Juhari AA
    Trop Life Sci Res, 2014 Dec;25(2):111-25.
    PMID: 27073603 MyJurnal
    A study on the variation of leaf venation patterns was conducted on 21 taxa of the genus Ficus in Peninsular Malaysia. The results showed the existence of eight leaf venation patterns based on veinlets, the ultimate marginal and areolar venation. The majority of species, such as F. annulata, F. benghalensis, F. benjamina, F. deltoidea var. angustifolia, F. deltoidea var. kunstleri, F. depressa, F. elastica, F. hispida, F. microcarpa, F. religiosa, F. tinctoria, F. ucinata and F. vasculosa, show tri-veinlets. The others exhibit the following: bi-veinlets in F. aurata and F. heteropleura; uni-veinlets in F. lepicarpa, F. schwarzii and F. superba; and simple veinlets in F. aurantiacea and F. fulva. F. sagittata presents no veinlets for areolar venation. The presence of tracheid or swollen veins at the centre of the lamina and the presence of cystolith cells and trichomes are common anatomical characteristics that could assist in group classification of the studied species. Variations in leaf venation patterns are not only valuable in identifying a taxon group, but can also be used to differentiate between species in the genus Ficus.
    Matched MeSH terms: Rubber
  4. Jing CJ, Seman IA, Zakaria L
    Trop Life Sci Res, 2015 Dec;26(2):45-57.
    PMID: 26868709 MyJurnal
    Mating compatibility and restriction analyses of Internal Transcribed Spacer (ITS) regions were performed to determine the relations between Ganoderma boninense, the most common species associated with basal stem rot in oil palm and Ganoderma isolates from infected oil palm, two ornamental palms, sealing wax palm (Cyrtostachys renda) and MacArthur palm (Ptychosperma macarthurii), an isolate from coconut stump (Cocos nucifera), Ganoderma miniatocinctum, Ganoderma zonatum and Ganoderma tornatum. The results showed that G. boninense was compatible with Ganoderma isolates from oil palm, G. miniatocinctum and G. zonatum, Ganoderma isolates from sealing wax palm, MacArthur palm and coconut stump. G. boninense was not compatible with G. tornatum. Therefore, the results suggested that the G. boninense, G. miniatocinctum, G. zonatum, and Ganoderma isolates from oil palm, ornamental palms and coconut stump could represent the same biological species. In performing a restriction analysis of the ITS regions, variations were observed in which five haplotypes were generated from the restriction patterns. An unweighted pair-group method with arithmetic averages (UPGMA) cluster analysis showed that all the Ganoderma isolates were grouped into five primary groups, and the similarity values of the isolates ranged from 97% to 100%. Thus, a restriction analysis of the ITS regions showed that G. boninense and the Ganoderma isolates from other palm hosts were closely related. On the basis of the mating compatibility test and the restriction analysis of the ITS regions performed in this study, a diverse group of Ganoderma species from oil palm and other palm hosts are closely related, except for G. tornatum and Ganoderma isolates from tea and rubber.
    Matched MeSH terms: Rubber
  5. Linnell RMC
    Trans R Soc Trop Med Hyg, 1915;8:238-260.
    Matched MeSH terms: Rubber
  6. Ibrahim MR, Katman HY, Karim MR, Koting S, Mashaan NS
    ScientificWorldJournal, 2014;2014:240786.
    PMID: 24574875 DOI: 10.1155/2014/240786
    The main objective of this paper is to investigate the relations of rubber size, rubber content, and binder content in determination of optimum binder content for open graded friction course (OGFC). Mix gradation type B as specified in Specification for Porous Asphalt produced by the Road Engineering Association of Malaysia (REAM) was used in this study. Marshall specimens were prepared with four different sizes of rubber, namely, 20 mesh size [0.841 mm], 40 mesh [0.42 mm], 80 mesh [0.177 mm], and 100 mesh [0.149 mm] with different concentrations of rubberised bitumen (4%, 8%, and 12%) and different percentages of binder content (4%-7%). The appropriate optimum binder content is then selected according to the results of the air voids, binder draindown, and abrasion loss test. Test results found that crumb rubber particle size can affect the optimum binder content for OGFC.
    Matched MeSH terms: Rubber/chemistry*
  7. Mashaan NS, Ali AH, Karim MR, Abdelaziz M
    ScientificWorldJournal, 2014;2014:214612.
    PMID: 24688369 DOI: 10.1155/2014/214612
    An immense problem affecting environmental pollution is the increase of waste tyre vehicles. In an attempt to decrease the magnitude of this issue, crumb rubber modifier (CRM) obtained from waste tyre rubber has gained interest in asphalt reinforcement. The use of crumb rubber in the reinforcement of asphalt is considered as a smart solution for sustainable development by reusing waste materials, and it is believed that crumb rubber modifier (CRM) could be an alternative polymer material in improving hot mix asphalt performance properties. In this paper, a critical review on the use of crumb rubber in reinforcement of asphalt pavement will be presented and discussed. It will also include a review on the effects of CRM on the stiffness, rutting, and fatigue resistance of road pavement construction.
    Matched MeSH terms: Rubber/chemistry*
  8. Kamarulzaman NH, Le-Minh N, Fisher RM, Stuetz RM
    Sci Total Environ, 2019 Mar 20;657:154-168.
    PMID: 30543968 DOI: 10.1016/j.scitotenv.2018.11.451
    The impacts of rubber variations (clonal, seasonal, and pre-treatment) were investigated to assess changes in the composition of volatile organic compounds (VOCs) emitted during rubber processing. VOC emissions from 14 different rubber types were evaluated by headspace micro-chamber (μ-TEC) extraction coupled with gas chromatography-mass spectrometry (GC-MS). Headspace extracted at 120 °C, which is equivalent to the drying temperature during rubber processing, revealed a significant number of odorants in terms of concentrations as well as odorant type. Volatile fatty acids (VFAs) such as acetic, propanoic, butanoic, pentanoic and hexanoic acids, were frequently detected at concentrations greater than their odour detection thresholds. Other odorous compounds including trimethylamine, p-cresol, butanone, indole, and phenol, were also detected. Emissions collected at ambient conditions represent odorants released during material storage (or maturation) and were dominated by benzene derivatives followed by ketones, aldehydes, esters, and acids. Emission composition during storage appeared to be governed by specific rubber properties such as protein and rubber moisture content. Seasonal variations revealed greater impacts on the concentration of VOCs for all studied clones, compared to pre-treatment variations, suggesting that the VOCs composition was seasonally dependent and may represents the 'potential' emissions from rubber as they are processed. A combination of sensorial and analytical measurements were used to produce odour wheels which may be used as tool to identify key malodours in onsite rubber processing. The linking of odours and odorants can facilitate communication between receptors (the public) and plant operators inorder to minimise odour impact and develop effective abatement and on-site management practices.
    Matched MeSH terms: Rubber
  9. Li T, Cheng H, Li Y, Mou Z, Zhu X, Wu W, et al.
    Sci Total Environ, 2023 Jul 10;881:163204.
    PMID: 37044342 DOI: 10.1016/j.scitotenv.2023.163204
    Tropical primary forests are being destroyed at an alarming rate and converted for other land uses which is expected to greatly influence soil carbon (C) cycling. However, our understanding of how tropical forest conversions affect the accumulation of compounds in soil functional C pools remains unclear. Here, we collected soils from primary forests (PF), secondary forests (SF), oil-palm (OP), and rubber plantations (RP), and assessed the accumulation of plant- and microbial-derived compounds within soil organic carbon (SOC), particulate (POC) and mineral-associated (MAOC) organic C. PF conversion to RP greatly decreased SOC, POC, and MAOC concentrations, whereas conversion to SF increased POC concentrations and decreased MAOC concentrations, and conversion to OP only increased POC concentrations. PF conversion to RP decreased lignin concentrations and increased amino sugar concentrations in SOC pools which increased the stability of SOC, whereas conversion to SF only increased the lignin concentrations in POC, and conversion to OP just increased lignin concentrations in POC and decreased it in MAOC. We observed divergent dynamics of amino sugars (decrease) and lignin (increase) in SOC with increasing SOC. Only lignin concentrations increased in POC with increasing POC and amino sugars concentrations decreased in MAOC with increasing MAOC. Conversion to RP significantly decreased soil enzyme activities and microbial biomasses. Lignin accumulation was associated with microbial properties, whereas amino sugar accumulation was mainly associated with soil nutrients and stoichiometries. These results suggest that the divergent accumulation of plant- and microbial-derived C in SOC was delivered by the distribution and original composition of functional C pools under forest conversions. Forest conversions changed the formation and stabilization processes of SOC in the long run which was associated with converted plantations and management. The important roles of soil nutrients and stoichiometry also provide a natural-based solution to enhance SOC sequestration via nutrient management in tropical forests.
    Matched MeSH terms: Rubber
  10. 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
  11. Phan TN, Lan NT, Nga NT
    Med J Malaysia, 2004 May;59 Suppl B:214-5.
    PMID: 15468894
    Natural rubber from hevea brasiliensis trees (Thailand, RRIM 600 clone) of different age (8, 20, and 35 years) were characterized by size exclusion chromatography coupled with online viscometry according to their distribution of molar mass and branching index at a temperature of 70 degrees C using cyclohexane as solvent. Washing with an aqueous solution of sodium dodecylsulfate and subsequent saponification purified the natural rubber samples. With this procedure physical branching points caused by phospholipids, proteins and hydrophobic terminal units, mainly fatty acids, of the natural rubber (cis-1,4-polyisoprene) molecule, could be removed leading to completely soluble polymer samples. All samples investigated possess a very broad (10 to 50,000 kg/mol) and distinct bimodal molar mass distribution. With increasing age the peak area in the low molar mass region decreases favoring the peak area in the high molar mass region. By plotting the branching index as a function of the both, the molar mass and the age of the trees.
    Matched MeSH terms: Rubber/analysis*
  12. Rohna R, Ganesapillai T, Salbiah D, Zaiton I
    Med J Malaysia, 1999 Mar;54(1):128-31.
    PMID: 10972018
    A two years retrospective analysis of patients diagnosed as contact allergic dermatitis with positive patch test attending the Dermatology clinic was performed. Of the 346 patients with a positive patch test, 14% had occupational dermatitis. This condition affected mainly young and inexperienced workers. An inverse relationship was seen between age and prevalence of occupational allergic dermatitis. Allergic hand dermatitis was the commonest presentation in occupational allergic dermatitis. This was followed by dermatitis of the exposed skin (face, neck, hands and forearms). The common sensitising agents identified were rubber chemicals and nickel. The two main groups at risk were factory workers and medical personnel. The common allergens found in factory workers were epoxy resin, pewter, nickel and rubber chemicals. Exposure dermatitis occurred in patients working in the pewter industry. Two thirds of medical personnel with hand dermatitis were allergic to rubber gloves. One year follow up after patch testing showed that 19% of patients still suffered from chronic dermatitis. Dermatitis improved in 34% of patients. Forty-seven percent were cured and stopped attending the clinic after patch testing and adequate counselling.

    Study site: Dermatology Clinic, Hospital Kuala Lumpur
    Matched MeSH terms: Rubber
  13. Yusof Said M, Goh Tin Kay
    Med J Malaysia, 1973 Sep;28(1):52-4.
    PMID: 4273787
    Matched MeSH terms: Rubber*
  14. Ramachandran CP, Dondero TJ, Mullin SW, Sivanandam S, Stevens S
    Med J Malaya, 1971 Jun;25(4):273-7.
    PMID: 4261299
    Matched MeSH terms: Rubber
  15. Nettem S, Kumar Nettemu S, Kumar K, Reddy V, Siva Kumar P
    Malays J Med Sci, 2012 Oct;19(4):77-80.
    PMID: 23613652
    Orthodontic elastic bands are an important iatrogenic etiologic factor in the causation of periodontal attachment apparatus breakdown. Appropriate diagnosis and a well constructed treatment plan tailor-made to suit the requirements of the particular patient is imperative for management of periodontal lesions induced by subgingival retention of rubber band. There are conflicting reports regarding the reattachment and regeneration of lost periodontal supporting tissues in such cases. The present case report highlights the spontaneous reversal and correction of periodontal destruction due to iatrogenic orthodontic elastic band displacement deep into the subgingival tissues.
    Matched MeSH terms: Rubber
  16. Yip E, Cacioli P
    J Allergy Clin Immunol, 2002 Aug;110(2 Suppl):S3-14.
    PMID: 12170237 DOI: 10.1067/mai.2002.124499
    Gloves that will provide a barrier of protection from infectious organisms are an essential feature of medical practice for the protection of both patients and medical personnel. Natural rubber latex has consistently been the most satisfactory raw material for the manufacture of gloves. Certain latex proteins, carried over into the finished product by inadequate manufacturing processes, may pose a risk of provoking allergic reactions in some patients and medical workers. As with any allergy, the risk depends on the route of exposure and dose. Hence, the method of manufacture, including the means used to coat gloves to make donning easy, can influence the eventual exposure of sensitive people to latex allergens. In this article, we describe the several processes in use and their effects on latex protein content.
    Matched MeSH terms: Rubber*
  17. Yeang HY, Cheong KF, Sunderasan E, Hamzah S, Chew NP, Hamid S, et al.
    J Allergy Clin Immunol, 1996 Sep;98(3):628-39.
    PMID: 8828541 DOI: 10.1016/s0091-6749(96)70097-0
    Two major water-insoluble proteins are located on the surface of rubber particles in Hevea brasiliensis latex. A 14.6 kd protein (Hev b 1), found mainly on large rubber particles (> 350 mm in diameter), and a 24 kd protein (Hev b 3), found mainly on small rubber particles (average diameter, 70 nm), are recognized by IgE from patients with spina bifida and latex allergy. Although Hev b 1 (also called the rubber elongation factor [REF]) has previously been reported as a major latex allergen, this conclusion has been disputed on the basis of results from other studies. The allergenicity of Hev b 1 is verified in this study by testing the recombinant protein generated from its gene. Because allergenicity is confined to patients with spina bifida and not observed in adults sensitive to latex, it is not a major latex allergen. The identification of Hev b 3 as another allergen originating from rubber particles is confirmed by immunogold labeling and electron microscopy. Observations with the monoclonal antibody USM/RC2 developed against Hev b 3 show that the protein has a tendency to fragment into several polypeptides of lower molecular weight (from 24 kd to about 5 kd) when stored at -20 degrees C. There is also indication of protein aggregation from the appearance of proteins with molecular weights greater than 24 kd. Fragmentation of Hev b 3 is induced immediately on he addition of latex B-serum, which is normally compartmentalized in the lutoids in fresh latex. In the preparation of ammoniated latex (used for the manufacture of latex products), the lutoids are ruptured, and the released B-serum reacts with Hev b 3 on the rubber particles to give rise to an array of low molecular weight polypeptides that are allergenic to patients with spina bifida.
    Matched MeSH terms: Rubber/chemistry*
  18. Hamilton RG, Adkinson NF
    J Allergy Clin Immunol, 1996 Nov;98(5 Pt 1):872-83.
    PMID: 8939150
    BACKGROUND: Nonammoniated latex, ammoniated latex, and rubber glove extracts are the only sources of natural rubber (Hevea brasiliensis) latex that have potential for use as skin testing reagents in the diagnosis of latex allergy. Their diagnostic sensitivity and specificity as skin test reagents are unknown.

    OBJECTIVE: We conducted a phase 1/2 clinical study to examine the safety and diagnostic accuracy (sensitivity and specificity) of nonammoniated latex, ammoniated latex, and rubber glove extracts as skin test extracts to identify the most efficacious source material for future skin test reagent development.

    METHODS: Twenty-four adults not allergic to latex, 19 adults with hand dermatitis or pruritus, and 59 adults with a latex allergy were identified by clinical history. All provided blood and then received puncture skin tests and intradermal skin tests with nonammoniated latex, ammoniated latex, and rubber glove extracts from Malaysian H. brasiliensis latex by use of sequential titration. A glove provocation test and IgE anti-latex RAST were used to clarify positive history-negative skin test response and negative history-positive skin test response mismatches.

    RESULTS: All three extracts were biologically safe and sterile. After normalization to 1 mg/ml of total protein, all three extracts produced equivalent diagnostic sensitivity and specificity in puncture skin tests and intradermal skin tests at various extract concentrations. Optimal diagnostic accuracy was safely achieved at 100 micrograms/ml for intradermal skin tests (e.g., nonammoniated latex: puncture skin test sensitivity 96%, specificity 100%; intradermal skin test sensitivity 93%, specificity 96%). The presence of IgE antibody in skin was highly correlated with IgE anti-latex in serum (nonammoniated latex: r = 0.98, p < 0.001; ammoniated latex: r = 0.94, p < 0.001; rubber glove extract: r = 0.96, p < 0.001). All five available subjects with a positive history, negative skin test response, and absence of IgE antibody in serum had a negative glove provocation test response, indicating no clinical evidence of latex allergy. No systemic or large local allergic reactions were observed with puncture skin tests or intradermal skin tests.

    CONCLUSIONS: Equivalent diagnostic sensitivity and specificity were observed with the nonammoniated latex, ammoniated latex, and rubber glove extract skin test reagents after normalization for total protein; nonammoniated latex may be considered the reagent of choice on the basis of practical quality control and reproducibility considerations.

    Matched MeSH terms: Rubber/adverse effects*
  19. Menicagli R, Bolla G, Menicagli L, Esseiridou A
    Gulf J Oncolog, 2017 May;1(24):70-74.
    PMID: 28798007
    INTRODUCTION AND OBJECTIVES: Nasopharyngeal Carcinoma represents 0.7% of the total cancer cases in the world with an ASR index of 1.7 and is widely associated with Epstein-Barr virus. It is not common in Italy (ASR index of 0.5) while in China (ASR 1.9), one third of the clinical cases are observed in Guangdong (ASR index 11.3). It is also quite common in Malaysia and Indonesia. The activation of the cancerogenesis process happens after the exposure to some environmental parameters that epidemiological studies have indicated with various dietary habits, mainly for salted fish consumption. The purpose of this work is to highlight such as exposure to compounds, such as formaldehyde, which is present in the different working conditions of these countries and may lead to the real cause to establish the carcinogenic process.

    MATERIALS AND METHODS: The most recent publications regarding the impact of various external factors on Pub Med, Google, TOXLINE, Chem Abstract, were analyzed with the radiological data that were found in Milan hospitals database.

    RESULTS: The relationship between food consumption and nasopharyngeal cancer are not clear and statistically insignificant in Indonesia. In Malaysia, the preparation of natural rubber for the use of formaldehyde is a dangerous environmental factor. The same exposure is a risk factor in Guangdong, where many workers are employed in the wood panel industry. Incidence of cancer in these Chinese ethnic groups decreases when they migrate to other countries. In the last 5 years, few cases were recorded in Italy, without any apparent change in ethnic environmental factors or HBV infection Discussion: In the production of natural rubber, a lot of people are exposed to formaldehyde during the various steps of preparation and production such as stripping, drying and coagulation without observing proper environmental hygiene precautions. The same working conditions are present in industrial production of wood panels in Guangdong, China. The relationship between exposure to formaldehyde and nasopharyngeal cancer is demonstrated by the fact that epidemiological studies on the population of this Chinese district whose immigrant populations were not exposed to these pollutants, the appearance of these tumors decreases. Also an examination of our radiological data in Italy shows that in about one hundred sixty cases of nasopharyngeal cancer none of the patients were Indonesian or Chinese Conclusion: The preliminary results of our study suggest that EPST-BARR virus could be a risk factor if associated with exposure to compounds such as formaldehyde which is present in industrial productions of countries like Indonesia, Malaysia, and China.

    Matched MeSH terms: Rubber
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