Displaying publications 21 - 40 of 164 in total

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  1. DFT study of glucose based glycolipid crown ethers and their complexes with alkali metal cations Na(+) and K(+)
    Nguan H, Ahmadi S, Hashim R
    J Mol Model, 2012 Dec;18(12):5041-50.
    PMID: 22752540 DOI: 10.1007/s00894-012-1497-x
    A theoretical study of a series of five glucose based glycolipid crown ethers and their complexes with Na(+) and K(+) was performed using the density functional theory with B3LYP/6-31 G* to obtain the optimized geometrical structures and electronic properties. The local nucleophilicity of the five molecules was investigated using Fukui function, while the global nucleophilicity was calculated from the ionization potential and electron affinity. The structures and coordination of the complexes were studied to identify the best match of the glycolipid crown ethers with cations. In general, it was found that the oxygen atoms pairs O2 and O3 (or O4 and O6) on the sugar ring are constrained from moving toward the cation, which results in a weaker O-cation coordination strength for the oxygen pair compared to the other oxygen atoms in the crown ether ring. The thermodynamic properties of the binding of the complexes and the exchange reaction in gas phase were evaluated. The cation selectivity pattern among the five molecules was in good agreement with the experiment.
  2. Scavenging behaviour of meranti sawdust in the removal of methylene blue from aqueous solution
    Ahmad A, Rafatullah M, Sulaiman O, Ibrahim MH, Hashim R
    J Hazard Mater, 2009 Oct 15;170(1):357-65.
    PMID: 19464117 DOI: 10.1016/j.jhazmat.2009.04.087
    Meranti (Philippine mahogany) sawdust, an inexpensive material, showed strong scavenging behaviour through adsorption for the removal of methylene blue (MB) from aqueous solution. Batch studies were performed to evaluate and optimize the effects of various parameters such as contact time, pH, initial dye concentrations and adsorbent dosage. Langmuir, Freundlich and Temkin isotherms were used to analyze the equilibrium data at different temperatures. The experimental data fitted well with the Langmuir adsorption isotherm, indicating thereby the mono layer adsorption of the dye. The monolayer sorption capacity of meranti sawdust for MB was found to be 120.48, 117.64, 149.25 and 158.73 mg/g at 30, 40, 50 and 60 degrees C, respectively. Thermodynamic calculations showed that the MB adsorption process is endothermic and spontaneous in nature. Kinetic studies showed that the adsorption followed a pseudo-second-order kinetic model. The results indicated that the meranti sawdust could be an alternative material in place of more costly adsorbents used for dye removal.
  3. Fulltext Aleocharine rove beetles (Coleoptera, Staphylinidae) associated with Leptogenys Roger, 1861 (Hymenoptera, Formicidae) I. Review of three genera associated with L. distinguenda (Emery, 1887) and L. mutabilis (Smith, 1861)
    Maruyama M, von Beeren C, Hashim R
    Zookeys, 2010.
    PMID: 21594195 DOI: 10.3897/zookeys.59.510
    Three myrmecophilous genera of Aleocharinae (Staphylinidae) associated with Leptogenys distinguenda (Emery, 1887) and Leptogenys mutabilis (Smith, 1861) are reviewed with descriptions of new taxa: Maschwitzia Kistner, 1989, Togpelenys Kistner, 1989 and Witteia Maruyama & von Beeren, gen. n. (type species: Witteia dentilabrumMaruyama & von Beeren, sp. n.). The following new combinations are proposed: Zyras (s. lat.) aenictophila (Kistner, 1997),comb. n. (exMaschwitzia), Zyras (s. lat.) dichthadiaphila (Kistner in Kistner et al., 2003), comb. n. (exMaschwitzia), Maschwitzia derougemonti (Pace, 1984), comb. n. (exWroughtonilla Wasmann, 1899), Maschwitzia watanabei (Maruyama, 2004), comb. n. (exWroughtonilla), Maschwitzia dilatata (Pace, 2005), comb. n. (exWroughtonilla), Witteia borneensis (Pace, 1986), comb. n. (ex Wroughtonilla). These genera belong to the Wroughtonilla genus group of the tribe Lomechusini.
  4. Adsorption of methylene blue on low-cost adsorbents: a review
    Rafatullah M, Sulaiman O, Hashim R, Ahmad A
    J Hazard Mater, 2010 May 15;177(1-3):70-80.
    PMID: 20044207 DOI: 10.1016/j.jhazmat.2009.12.047
    In this article, the use of low-cost adsorbents for the removal of methylene blue (MB) from solution has been reviewed. Adsorption techniques are widely used to remove certain classes of pollutants from waters, especially those which are not easily biodegradable. The removal of MB, as a pollutant, from waste waters of textile, paper, printing and other industries has been addressed by the researchers. Currently, a combination of biological treatment and adsorption on activated carbon is becoming more common for removal of dyes from wastewater. Although commercial activated carbon is a preferred adsorbent for color removal, its widespread use is restricted due to its relatively high cost which led to the researches on alternative non-conventional and low-cost adsorbents. The purpose of this review article is to organize the scattered available information on various aspects on a wide range of potentially low-cost adsorbents for MB removal. These include agricultural wastes, industrial solid wastes, biomass, clays minerals and zeolites. Agricultural waste materials being highly efficient, low cost and renewable source of biomass can be exploited for MB remediation. It is evident from a literature survey of about 185 recently published papers that low-cost adsorbents have demonstrated outstanding removal capabilities for MB.
  5. Fatty acid profiles of fin fish in Langkawi Island, Malaysia
    Osman F, Jaswir I, Khaza'ai H, Hashim R
    J Oleo Sci, 2007;56(3):107-13.
    PMID: 17898471
    Total lipid contents and fatty acid composition of 13 marine fish species namely, "jenahak" (Lutianus agentimaculatus), "kebasi" (Anadontostoma chacunda), "duri" (Arius cumatranus), "tenggiri batang" (Scomberomorus commersoni), "kembong" (Rastrelliger kanagurta), "kintan" or "sebalah" (Psettodes crumei), "kerisi" (Pristipomodes typus), "kerapu" (Epinephelus sexfasciatus), "gelama kling" (Sciaena dussumieri), "malong" (Congresax talabon), "laban" (Cynoglossus lingua), "yu 9" (Scolidon sorrakowah) and "bagi" (Aacnthurs nigrosis) commonly found in Pulau Tuba, one of the islands surrounding the popular tourist destination Langkawi in Malaysia were determined. All fish showed a considerable amount of unsaturated fatty acids particularly those with 4, 5 and 6 double bonds. Two physiologically important n-3 polyunsaturated fatty acids (PUFAs), i.e. eicosapentaenoic acid (EPA) and docasahaexaenoic acid (DHA), made up of more than 50% of the total PUFAs. For saturated fatty acids, palmitic was found to be the major one in all types of fish studied. Based on DHA, EPA and arachidonic acid (AA) contents, "gelama kling" was found to be the best source (23, 11 and 7%, respectively) followed by "kerapu" (21, 10, 9%) and "sebalah" (19, 14, 4%).
  6. Molecular dynamics simulation of monoalkyl glycoside micelles in aqueous solution: influence of carbohydrate headgroup stereochemistry
    Chong TT, Hashim R, Bryce RA
    J Phys Chem B, 2006 Mar 16;110(10):4978-84.
    PMID: 16526739
    Comparative molecular dynamics simulations of n-octyl-beta-D-galactopyranoside (beta-C8Gal) and n-octyl-beta-D-glucopyranoside (beta-C8Glc) micelles in aqueous solution have been performed to explore the influence of carbohydrate stereochemistry on glycolipid properties at the atomic level. In particular, we explore the hypothesis that differences in T(m) and T(c) for beta-C8Gal and beta-C8Glc in lyotropic systems arise from a more extensive hydrogen bonding network between beta-C8Gal headgroups relative to beta-C8Glc, due to the axial 4-OH group in beta-C8Gal. Good agreement of the 13 ns micelle-water simulations with available experimental information is found. The micelles exhibit a similar shape, size, and degree of exposed alkyl chain surface area. We find net inter- and intra-headgroup hydrogen bonding is also similar for beta-C8Gal and beta-C8Glc, although n-octyl-beta-D-galactopyranoside micelles do exhibit a slightly greater degree of inter- and intra-headgroup hydrogen bonding. However, the main distinction in the calculated microscopic behavior of beta-C8Glc and beta-C8Gal micelles lies in solvent interactions, where beta-d-glucosyl headgroups are considerably more solvated (mainly at the equatorial O4 oxygen). These results agree with preceding theoretical and experimental studies of monosaccharides in aqueous solution. A number of long water residence times are found for solvent surrounding both micelle types, the largest of which are associated with surface protrusions involving headgroup clusters. Our simulations, therefore, predict differences in hydrogen bonding for the two headgroup stereochemistries, including a small difference in inter-headgroup interactions, which may contribute to the higher T(m) and T(c) values of beta-C8Gal surfactants relative to beta-C8Glc in lyotropic systems.
  7. Survey of the exocrine system in Protanilla wallacei (Hymenoptera, Formicidae)
    Billen J, Bauweleers E, Hashim R, Ito F
    Arthropod Struct Dev, 2013 May;42(3):173-83.
    PMID: 23333930 DOI: 10.1016/j.asd.2013.01.001
    We studied the exocrine system of both workers and ergatoid queens of Protanilla wallacei using light, scanning and transmission electron microscopy. Our survey revealed the presence of 26 glands, of which 6 had never been found before in ants. Five of these represent novel discoveries for social insects in general. The overall novel discoveries comprise an epithelial stipes gland, a pharyngeal wall gland, a central petiole gland, a lateral postpetiole gland and a foot-sole gland in the hindleg pretarsi. The intramandibular epithelial gland was already reported in some bees previously, but is now for the first time also reported in ants. The exocrine system of workers and ergatoid queens is very similar, with only the spermathecal gland showing an obvious difference. This is in line with the limited anatomical as well as behavioural difference between both castes in Protanilla compared to the situation in Leptanilla.
  8. Some of the properties of flame retardant medium density fiberboard made from rubberwood and recycled containers containing aluminum trihydroxide
    Hashim R, How LS, Kumar RN, Sulaiman O
    Bioresour Technol, 2005 Nov;96(16):1826-31.
    PMID: 16051090
    The flame retardancy of medium density fiberboard (MDF) made from mixture of rubberwood fibers and recycled old corrugated containers was studied. Aluminum trihydroxide (ATH) was used as a fire retardant additive and mixed with the fibers to manufacture experimental MDF panels using wet process. Phenol formaldehyde (PF) resin in liquid, 2% based on oven dry weight of fibers, was used along with 0%, 10%, 15% and 20% of ATH. The flame retardant test was done using the limiting oxygen index (LOI) test. The other properties investigated include internal bond strength, thickness swelling and water absorption. The results showed that ATH loading increased as the LOI of MDF increased. This demonstrated that ATH could improved the fire retardant property of MDF at sufficient loading. An increase in concentration of ATH showed an increase in the IB values of MDF made without resin. MDF panels made without resin showed a progressive increase in internal bond as the composition of recycled old corrugated containers fiber increased. Addition of resin improved internal bond strength and reduced thickness swelling, and water absorption. Thickness swelling of panel increased as the composition of recycled old corrugated containers fiber increased. Scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDAX) showed that there is indication of ATH and resin filling the void space in between fibers.
  9. The interplay of socio-psychological factors on school engagement among early adolescents
    Awang-Hashim R, Kaur A, Noman M
    J Adolesc, 2015 Dec;45:214-24.
    PMID: 26513126 DOI: 10.1016/j.adolescence.2015.10.001
    The study examined a conceptual model integrating existing knowledge on the linkages between life satisfaction, affect, purpose in life, and resilience with school engagement. This model posits direct relationships between all the social psychological variables and school engagement, and also indirect relationships between life satisfaction and school engagement as mediated by all the other variables in the study. The participants were 2381 students (1119 boys and 1262 girls) with average age of 15 years, from 40 national secondary schools in Malaysia. The findings supported the theoretical conceptualization. All variables were positively associated with school engagement. The strongest relationship was observed between overall life satisfaction and school engagement. The mediating model was partially supported. The study reiterates the adage that "it takes a village to raise a child". Implications for practice and future research are discussed in the context of engagement in school learning.
  10. Degeneration patterns of the worker spermatheca during morphogenesis in ants (Hymenoptera: Formicidae)
    Gotoh A, Billen J, Hashim R, Ito F
    Evol. Dev., 2016 Mar;18(2):96-104.
    PMID: 26994860 DOI: 10.1111/ede.12182
    Reproductive division of labor is one of the crucial features in social insects, however, the developmental mechanisms leading to modifications in the reproductive apparatus of workers are still not very clear. Ants show a remarkable diversity in the morphological specialization of the worker's reproductive apparatus, that allows to distinguish four types, type 1: workers that have ovaries and a functional spermatheca, and that reproduce like queens, type 2: workers have ovaries and a vestigial spermatheca, type 3: workers have ovaries but no spermatheca, and type 4: workers lost both ovaries and spermatheca. We investigated morphogenesis of the worker spermatheca in 28 ant species by histological examination. In workers of type 1, the morphogenesis of the spermatheca is very similar to that in ant queens. In type 2, the spermathecal disc also differentiates, however, the development is interrupted and remains vestigial. In types 3 and 4, the absence of the spermatheca in the adult phase is caused by a degeneration after initial formation of the spermathecal disc or by a complete lack of the spermathecal discs. The timing of these interruption and degeneration events varies among species. The species exhibiting an earlier interrupting point of spermatheca formation in workers have a larger queen-worker dimorphism, that seems to be independent from ant phylogeny.
  11. Ultrastructure of the mandibular gland of the ant Myrmoteras iriodum
    Billen J, Hashim R, Ito F
    Arthropod Struct Dev, 2016 May 1.
    PMID: 27130260 DOI: 10.1016/j.asd.2016.04.003
    The mandibular gland in workers of the formicine ant Myrmoteras iriodum differs from other ants both in its general morphology and ultrastructural organization. The secretory cells appear in a pseudo-epithelial arrangement that gives them a clear polarity. At their apical side, the cells are characterized by a large cup-like extension of the reservoir, from which a bulbous invagination connects to a branched end apparatus. At the basal side, the cells show a labyrinth of basal invaginations, while the lateral cell contacts show clear interdigitations. The cytoplasmic composition reveals the presence of numerous round or elongate inclusions that contain crystalline material. Microtubules are abundant, and locally fibrillar regions are found. The function of the mandibular gland in M. iriodum has not yet been documented, and should be studied using gland extracts and behavioural observations.
  12. Detection of betalactamase producing bacterial genes and their clinical features
    Hashim RB, Husin S, Rahman MM
    Pak J Biol Sci, 2011 Jan 01;14(1):41-6.
    PMID: 21913496
    The present study was aimed to identify the gene of drug resistance betalactamase producing bacteria and clinical features of the infected patients at Hospital University Kebangsaan Malaysia. Blood samples from the patients were collected, processed and betalactamase producing drug resistance bacteria were identified by antibiotic sensitivity testing. Genes of the drug resistance bacteria were detected and characterized by polymerase chain reaction. A total of 34 isolates of drug resistance Betalactamase producing E. coli and Klebsiella spp. were isolated from 2,502 patients. Most common drug resistance gene TEM was found in 50% of the isolates. 11% was found positive for both TEM and SHV. Next 11% of the isolates expressed only SHV genes. Clinical features of the patients were recorded from where the bacteria isolated. Regarding community affiliations 70.5% of the infected patients were Malay 17.6% were Indian and 11.7% were Chinese. Majority of the patients has an underlying pre-morbid condition as reflected by their diagnosis. Better infection control and hygiene in hospitals, plus controlled and prudent use of antibiotics, is required to minimize the impact of drug resistance betalactamase producing bacteria and the spread of infections.
  13. Fulltext Exploring the factors and spatial patterns of national night cultural tourism consumption agglomeration zones in China
    Xiong S, Wang H, Liao Z, Hashim R
    Heliyon, 2024 Jan 30;10(2):e24132.
    PMID: 38293367 DOI: 10.1016/j.heliyon.2024.e24132
    This study is based on the theory of spatial structure and uses the geographic information system's (GISs) spatial analysis technology to investigate the spatial distribution characteristics and influencing factors of 243 national night cultural and tourism consumption agglomeration zones (NNCTCAZs) in China. Furthermore, this study employs various analytical methods, including the nearest index, geographic concentration index, imbalance index, nuclear density analysis, buffer analysis and geographic detector method. The results reveal that NNCTCAZs exhibit an imbalanced spatial distribution, with a predominant concentration in the east and southwest regions of China. Furthermore, the 'core-edge' structure of this distribution is discernible. The spatial distribution density of NNCTCAZs is uneven, with high-density areas primarily located in the Yangtze River Delta, Pearl River Delta and Sichuan-Chongqing regions. This distribution pattern exhibits the characteristics of being progressive, that is, strong in the east and west and having small agglomerations with large dispersion. In addition, these areas are mainly concentrated in the central regions of cities and the surrounding areas of popular tourist attractions. The spatial layout of NNCTCAZs is mainly influenced by the level of social development, the tourism industry and regional gross domestic product (GDP), which are considered the core determinants. Furthermore, the development level of traffic conditions plays a crucial role in shaping the spatial layout, whereas the impact of the cultural environment and economic conditions is comparatively less pronounced.
  14. Association Between Apolipoprotein B and Coronary Artery Disease Among Hypertensive Patients: A Systematic Review of the Prospective and Retrospective Studies
    Nathir I, Abd Aziz F, Hashim R
    Cureus, 2023 Dec;15(12):e49854.
    PMID: 38169767 DOI: 10.7759/cureus.49854
    The predictive value of apolipoprotein B (apo B) has been proven in the development of coronary artery disease (CAD) among normotensives only, but it has not been directly studied in hypertensive patients. The objective of this study is to explore the association between apo B and CAD among patients with hypertension. Search strategies were conducted on September 24, 2022, and involved the databases PubMed, Web of Science, and Scopus. The current systematic review included observational case-control and cohort study design involving adult humans, both hypertensives and normotensives. The selected studies were restricted to those written in the English language and published after 2000. Reviews, interventional, animal, and overlapping studies, grey literature, and articles without full text were excluded from the current study. The modified Newcastle-Ottawa Scale was used to assess the risk of bias for the screened studies after data extraction. Out of 3644 publications, only five studies were included in the review, including 5222 participants. Of those, 2335 were hypertensive, 733 of them developed CAD, and 296 normotensive subjects developed CAD. The average apo B was 1.09 g/l and 1.07 g/l for hypertensives and normotensives, respectively. The risk of developing CAD is higher in patients with hypertension, or those with higher apo B. Moreover, the risk of CAD was exacerbated in hypertensive participants with elevated apo B. This systematic review highlights the independent power of apo B on the development of CAD among both hypertensive and normotensive subjects.
  15. Fulltext The In Vitro Antibiotic Susceptibility of Malaysian Isolates of Burkholderia pseudomallei
    Ahmad N, Hashim R, Mohd Noor A
    Int J Microbiol, 2013;2013:121845.
    PMID: 24194761 DOI: 10.1155/2013/121845
    Acute melioidosis may present as localised or septicaemic infections and can be fatal if left untreated. Burkholderia pseudomallei resistant to antibiotics used for the treatment of melioidosis had been reported. The aim of this study was to determine the in vitro antibiotic susceptibility patterns of Burkholderia pseudomallei isolated in Malaysia to a panel of antibiotics used for the treatment of melioidosis and also to potential alternative antibiotics such as tigecycline, ampicillin/sulbactam, and piperacillin/tazobactam. A total of 170 Burkholderia pseudomallei isolates were subjected to minimum inhibitory concentration determination using E-test method to eleven antibiotics. All isolates were sensitive to meropenem and piperacillin/tazobactam. For ceftazidime, imipenem, amoxicillin/clavulanic acid, and doxycycline resistance was observed in 1 isolate (0.6%) for each of the antibiotics. Trimethoprim/sulfamethoxazole resistance was observed in 17 (10%) isolates. For other antibiotics, ampicillin/sulbactam, chloramphenicol, tigecycline, and ciprofloxacin resistance were observed in 1 (0.6%), 6 (3.5%), 60 (35.3%) and 98 (57.7%) isolates respectively. One isolate B170/06 exhibited resistance to 4 antibiotics, namely, ciprofloxacin, chloramphenicol, trimethoprim/sulfamethoxazole, and tigecycline. In conclusion, the Malaysian isolates were highly susceptible to the current antibiotics used in the treatment of melioidosis in Malaysia. Multiple resistances to the antibiotics used in the maintenance therapy are the cause for a concern.
  16. Fulltext Utilization of geotextile tube for sandy and muddy coastal management: a review
    Lee SC, Hashim R, Motamedi S, Song KI
    ScientificWorldJournal, 2014;2014:494020.
    PMID: 24955408 DOI: 10.1155/2014/494020
    Threats to beaches have accelerated the coastal destruction. In recent decades, geotextile tubes were used around the world to prevent coastal erosion, to encourage beach nourishment, and to assist mangrove rehabilitation. However, the applications of geotextile tube in sandy and muddy coasts have different concerns as the geological settings are different. Applications of geotextile tubes in sandy beaches were mainly to prevent coastline from further erosion and to nourish the beach. However, for the muddy coasts, mangrove rehabilitation and conservation were additional concerns in coastal management schemes. The mangrove forests are natural barriers which can be found on the muddy coasts of many tropical countries. In this paper, the viability of geotextile tubes in sandy and muddy beaches was analysed. The advantages and disadvantages of the utilization of geotextile tubes in coastal management were discussed based on the experiences from the tropical countries such as Mexico, Malaysia, and Thailand. From the case studies, impressive improvements in coastal restoration after installation of geotextile tubes were shown. Based on the discussion, several recommendations to improve the application of geotextile tubes were suggested in this paper.
  17. Fulltext Screening of aphrodisiac property in sea slug, Aplysia dactylomela
    Hashim R, Roslan NA, Zulkipli FH, Daud JM
    Asian Pac J Trop Med, 2014 Sep;7S1:S150-4.
    PMID: 25312111 DOI: 10.1016/S1995-7645(14)60222-4
    OBJECTIVE: To evaluate the aphrodisiac property of Aplysia dactylomela (A. dactylomelan), locally known as 'dugu-dugu', which is one of the sea slug species.

    METHODS: Two types of extractions were used; aqueous and lipid. Three doses of each A. dactylomelan extract, respectively; 50, 100, 200 mg/kg were administered (i.p.) to male mice for mounting behavior test. Sildenafil citrate or Viagra® (5 mg/kg) being positive control while negative control received saline solution.

    RESULTS: The animals treated with lipid extract at the respective dose exhibited mounting behavior, but the mounting frequency decreased at higher doses (100 and 200 mg/kg). However, all doses of aqueous extract did not show any mounting behavior. Meanwhile, in all doses of lipid extracts administered displayed significant difference (P<0.05) from the positive control. Despite this, only the lipid extract of 50 mg/kg showed significant difference (P<0.05) with negative control. This signifies that lipid extracts especially in dose 50 mg/kg have a substantial effect of aphrodisiac property. In addition, the presence of steroids was detected in the phytochemical screening of lipid extract.

    CONLUSIONS: The findings from this study provides preliminary scientific evidence that A. dactylomela could be used as an alternative medication of natural product for promoting sexual activity in men.

  18. Fulltext Stochastic optimized relevance feedback particle swarm optimization for content based image retrieval
    Imran M, Hashim R, Noor Elaiza AK, Irtaza A
    ScientificWorldJournal, 2014;2014:752090.
    PMID: 25121136 DOI: 10.1155/2014/752090
    One of the major challenges for the CBIR is to bridge the gap between low level features and high level semantics according to the need of the user. To overcome this gap, relevance feedback (RF) coupled with support vector machine (SVM) has been applied successfully. However, when the feedback sample is small, the performance of the SVM based RF is often poor. To improve the performance of RF, this paper has proposed a new technique, namely, PSO-SVM-RF, which combines SVM based RF with particle swarm optimization (PSO). The aims of this proposed technique are to enhance the performance of SVM based RF and also to minimize the user interaction with the system by minimizing the RF number. The PSO-SVM-RF was tested on the coral photo gallery containing 10908 images. The results obtained from the experiments showed that the proposed PSO-SVM-RF achieved 100% accuracy in 8 feedback iterations for top 10 retrievals and 80% accuracy in 6 iterations for 100 top retrievals. This implies that with PSO-SVM-RF technique high accuracy rate is achieved at a small number of iterations.
  19. Fulltext Effect of peat on physicomechanical properties of cemented brick
    Islam SM, Hashim R, Islam AB, Kurnia R
    ScientificWorldJournal, 2014;2014:328516.
    PMID: 24982941 DOI: 10.1155/2014/328516
    The popularity of low cost, lightweight, and environmentally affable masonry unit in building industry carries the need to investigate more flexible and adaptable brick component as well as to retain the requirements confirmed in building standards. In this study, potential use of local materials used as lightweight building materials in solving the economic problems of housing has been investigated. Experimental studies on peat added bricks have been carried out. It demonstrates the physicomechanical properties of bricks and investigates the influence of peat, sand, and cement solid bricks to the role of various types of constructional applications. The achieved compressive strength, spitting strength, flexural strength, unit weight, and ultrasonic pulse velocity are significantly reduced and the water absorption is increased with percentage wise replacement of peat as aggregate in the samples. The maximum 20% of (% mass) peat content meets the requirements of relevant well-known international standards. The experimental values illustrate that, the 44% volumetric replacement with peat did not exhibit any sudden brittle fracture even beyond the ultimate loads and a comparatively smooth surface is found. The application of peat as efficient brick substance shows a potential to be used for wall and a viable solution in the economic buildings design.
  20. Fulltext Long-term assessment of an innovative mangrove rehabilitation project: case study on Carey Island, Malaysia
    Motamedi S, Hashim R, Zakaria R, Song KI, Sofawi B
    ScientificWorldJournal, 2014;2014:953830.
    PMID: 25097894 DOI: 10.1155/2014/953830
    Wave energy and storm surges threaten coastal ecology and nearshore infrastructures. Although coastal structures are conventionally constructed to dampen the wave energy, they introduce tremendous damage to the ecology of the coast. To minimize environmental impact, ecofriendly coastal protection schemes should be introduced. In this paper, we discuss an example of an innovative mangrove rehabilitation attempt to restore the endangered mangroves on Carey Island, Malaysia. A submerged detached breakwater system was constructed to dampen the energy of wave and trap the sediments behind the structure. Further, a large number of mangrove seedlings were planted using different techniques. Further, we assess the possibility of success for a future mangrove rehabilitation project at the site in the context of sedimentology, bathymetry, and hydrogeochemistry. The assessment showed an increase in the amount of silt and clay, and the seabed was noticeably elevated. The nutrient concentration, the pH value, and the salinity index demonstrate that the site is conducive in establishing mangrove seedlings. As a result, we conclude that the site is now ready for attempts to rehabilitate the lost mangrove forest.
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