Displaying publications 1121 - 1140 of 4000 in total

Abstract:
Sort:
  1. Dabbagh A, Abdullah BJ, Abu Kasim NH, Ramasindarum C
    Int J Hyperthermia, 2014 Feb;30(1):66-74.
    PMID: 24286257 DOI: 10.3109/02656736.2013.854930
    The emergence of thermal modalities has promoted the use of heat-sensitive phantoms for calibration, measurement, and verification purposes. However, development of durable phantoms with high precision ability to represent the temperature distribution remains a challenge. This study aims to introduce a reusable phantom that provides an accurate assessment of the heated region in various thermal modalities.
  2. Purmal K, Alam MK, Pohchi A, Abdul Razak NH
    PLoS One, 2013;8(12):e84202.
    PMID: 24367643 DOI: 10.1371/journal.pone.0084202
    Intermaxillary (IMF) screws feature several advantages over other devices used for intermaxillary fixation, but using cone beam computed tomography (CBCT) scans to determine the safe and danger zones to place these devices for all patients can be expensive. This study aimed to determine the optimal interradicular and buccopalatal/buccolingual spaces for IMF screw placement in the maxilla and mandible. The CBCT volumetric data of 193 patients was used to generate transaxial slices between the second molar on the right to the second molar on the left in both arches. The mean interradicular and buccopalatal/buccolingual distances and standard deviation values were obtained at heights of 2, 5, 8 and 11 mm from the alveolar bone crest. An IMF screw with a diameter of 1.0 mm and length of 7 mm can be placed distal to the canines (2 - 11 mm from the alveolar crest) and less than 8 mm between the molars in the maxilla. In the mandible, the safest position is distal to the first premolar (more than 5 mm) and distal to the second premolar (more than 2 mm). There was a significant difference (p<0.05) between the right and left quadrants. The colour coding 3D template showed the safe and danger zones based on the mesiodistal, buccopalatal and buccolingual distances in the maxilla and mandible.The safest sites for IMF screw insertion in the maxilla were between the canines and first premolars and between the first and second molars. In the mandible, the safest sites were between the first and second premolars and between the second premolar and first molar. However, the IMF screw should not exceed 1.0 mm in diameter and 7 mm in length.
  3. Othman N, In LL, Harikrishna JA, Hasima N
    PLoS One, 2013;8(12):e81735.
    PMID: 24339958 DOI: 10.1371/journal.pone.0081735
    Bcl-xL is an anti-apoptotic protein that is frequently found to be overexpressed in non-small cell lung cancer leading to an inhibition of apoptosis and poor prognosis. Recently, the role of miRNAs in regulating apoptosis and cell survival during tumorigenesis has become evident, with cancer cells showing perturbed expression of various miRNAs. In this study, we utilized miRNA microarrays to determine if miRNA dysregulation in bcl-xL silenced lung adenocarcinoma cells could be involved in regulating cell death. Short interfering RNA-based transfection of A549 and SK-LU1 lung adenocarcinoma cells was successful in inducing a reduction in bcl-xL expression levels, resulting in a decrease in cell viability. A total of 10 miRNAs were found to be significantly differentially expressed when compared between siRNA-transfected and non-transfected cells including hsa-miR-181a, hsa-miR-769-5p, hsa-miR-361-5p, hsa-miR-1304 and hsa-miR-608. When overexpression studies on hsa-miR-608 was performed via transfection of miRNA mimics, cell death was found to be induced in A549 and SK-LU1 cells in comparison to untreated cells. This effect was reversed when knockdown studies involving anti-sense inhibitors were introduced. Combination of siRNA based silencing of bcl-xL (siBcl-xL) followed by anti-sense inhibitor transfection led to a decrease in the apoptotic population of A549 and SK-LU1 cells in comparison to cells only treated with siBcl-xL, illustrating the connection between bcl-xL, hsa-miR-608 and cell death. Gene target prediction analysis implicated the PI3K/AKT, WNT, TGF-β, and ERK signaling pathways as targets of bcl-xL induced miRNA alterations. We have demonstrated that bcl-xL silencing in A549 and SK-LU1 cells leads to the occurrence of cell death through the dysregulation of specific miRNAs. This study also provides a platform for anti-sense gene therapy whereby miRNA expression can be exploited to increase the apoptotic properties in lung adenocarcinoma cells.
  4. Eshraghi A, Osman NA, Gholizadeh H, Ali S, Shadgan B
    Biomed Eng Online, 2013;12:119.
    PMID: 24237942 DOI: 10.1186/1475-925X-12-119
    Research has tremendously contributed to the developments in both practical and fundamental aspects of limb prosthetics. These advancements are reflected in scientific articles, particularly in the most cited papers. This article aimed to identify the 100 top-cited articles in the field of limb prosthetics and to investigate their main characteristics. Articles related to the field of limb prosthetics and published in the Web of Knowledge database of the Institute for Scientific Information (ISI) from the period of 1980 to 2012. The 100 most cited articles in limb prosthetics were selected based on the citation index report. All types of articles except for proceedings and letters were included in the study. The study design and level of evidence were determined using Sackett's initial rules of evidence. The level of evidence was categorized either as a systematic review or meta-analysis, randomized controlled trial, cohort study, case-control study, case series, expert opinion, or design and development. The top cited articles in prosthetics were published from 1980 to 2012 with a citation range of 11 to 90 times since publication. The mean citation rate was 24.43 (SD 16.7) times. Eighty-four percent of the articles were original publications and were most commonly prospective (76%) and case series studies (67%) that used human subjects (96%) providing level 4 evidence. Among the various fields, rehabilitation (47%), orthopedics (29%), and sport sciences (28%) were the most common fields of study. The study established that studies conducted in North America and were written in English had the highest citations. Top cited articles primarily dealt with lower limb prosthetics, specifically, on transtibial and transradial prosthetic limbs. Majority of the articles were experimental studies.
  5. Ku PX, Abu Osman NA, Wan Abas WA
    Gait Posture, 2014 Feb;39(2):672-82.
    PMID: 24331296 DOI: 10.1016/j.gaitpost.2013.07.006
    Postural control has been widely evaluated for the normal population and different groups over the past 20 years. Numerous studies have investigated postural control in quiet standing posture among amputees. However, a comprehensive analysis is lacking on the possible contributing factors to balance. The present systematic review highlights the current findings on variables that contribute to balance instability for lower extremity amputees. The search strategy was performed on PubMed, Web of Science, Medline, Scopus, and CINAHL and then followed by additional manual searching via reference lists in the reviewed articles. The quality of the articles was evaluated using a methodological quality assessment tool. This review included and evaluated a total of 23 full-text articles. Despite the inconsistencies in the methodological design of the studies, all articles scored above the acceptable level in terms of quality. A majority of the studies revealed that lower extremity amputees have increased postural sway in the standing posture. Asymmetry in body weight, which is mainly distributed in the non-amputated leg, was described. Aside from the centre of pressure in postural control, sensory inputs may be a related topic for investigation in view of evidence on their contribution, particularly visual input. Other balance-related factors, such as stump length and patients' confidence level, were also neglected. Further research requires examination on the potential factors that affect postural control as the information of standing postural is still limited.
  6. Haque N, Rahman MT, Abu Kasim NH, Alabsi AM
    ScientificWorldJournal, 2013;2013:632972.
    PMID: 24068884 DOI: 10.1155/2013/632972
    Cell-based regenerative therapies, based on in vitro propagation of stem cells, offer tremendous hope to many individuals suffering from degenerative diseases that were previously deemed untreatable. Due to the self-renewal capacity, multilineage potential, and immunosuppressive property, mesenchymal stem cells (MSCs) are considered as an attractive source of stem cells for regenerative therapies. However, poor growth kinetics, early senescence, and genetic instability during in vitro expansion and poor engraftment after transplantation are considered to be among the major disadvantages of MSC-based regenerative therapies. A number of complex inter- and intracellular interactive signaling systems control growth, multiplication, and differentiation of MSCs in their niche. Common laboratory conditions for stem cell culture involve ambient O₂ concentration (20%) in contrast to their niche where they usually reside in 2-9% O₂. Notably, O₂ plays an important role in maintaining stem cell fate in terms of proliferation and differentiation, by regulating hypoxia-inducible factor-1 (HIF-1) mediated expression of different genes. This paper aims to describe and compare the role of normoxia (20% O₂) and hypoxia (2-9% O₂) on the biology of MSCs. Finally it is concluded that a hypoxic environment can greatly improve growth kinetics, genetic stability, and expression of chemokine receptors during in vitro expansion and eventually can increase efficiency of MSC-based regenerative therapies.
  7. Aziz NA, Muhamad S, Manaf MR, Hamid MZ
    Int J Prev Med, 2013 Jun;4(6):664-70.
    PMID: 23930184
    BACKGROUND: Primary health care workers (PHCW) are the front-liners in any infectious disease outbreaks. The recent outbreak of H1N1 influenza demonstrated that uptake of H1N1 vaccination remained low amongst PCHW despite its proven effectiveness. This trend is worrying as PHCW are the first point of contact in any emerging outbreak of future influenza epidemic. To investigate factors influencing willingness of H1N1 vaccination amongst PHCW.
    METHODS: A cross-sectional survey using self-reported questionnaire assessing perception and practice towards H1N1 Influenza A vaccination. A score of 34/50 was used as a cut-off score that divide good and poor perception. Logistic regression analysis used to explore the association between acceptance to be vaccinated and chosen variables.
    RESULTS: The mean age was 33.91 (SD: 8.20) with mean year of service of 9.23 (SD: 8.0). Acceptance of H1N1 vaccination was 86.3%. A total of 85.9% perceived the vaccination can prevent serious disease. Willingness to be vaccinated influenced by perception at risk of having illness (OR: 10.182, CI: 1.64-63.23, P 0.013) and need for vaccination (OR: 11.35, CI: 4.67-27.56, P < 0.0001).
    CONCLUSIONS: PCHW were generally willing to be vaccinated should H1N1 Influenza epidemic emerges in the future. However, acceptance of vaccination was influenced by factors of benefit to prevent illness and reduction of spread of the illness. Fear of side-effects remained a barrier toward acceptance which should be taken into account in planning of preparation for future wave of outbreak.
  8. Baskaran G, Masdor NA, Syed MA, Shukor MY
    ScientificWorldJournal, 2013;2013:678356.
    PMID: 24194687 DOI: 10.1155/2013/678356
    Heavy metals pollution has become a great threat to the world. Since instrumental methods are expensive and need skilled technician, a simple and fast method is needed to determine the presence of heavy metals in the environment. In this study, an inhibitive enzyme assay for heavy metals has been developed using crude proteases from Coriandrum sativum. In this assay, casein was used as a substrate and Coomassie dye was used to denote the completion of casein hydrolysis. In the absence of inhibitors, casein was hydrolysed and the solution became brown, while in the presence of metal ions such as Hg²⁺ and Zn²⁺, the hydrolysis of casein was inhibited and the solution remained blue. Both Hg²⁺ and Zn²⁺ exhibited one-phase binding curve with IC₅₀ values of 3.217 mg/L and 0.727 mg/L, respectively. The limits of detection (LOD) and limits of quantitation (LOQ) for Hg were 0.241 and 0.802 mg/L, respectively, while the LOD and LOQ for Zn were 0.228 and 0.761 mg/L, respectively. The enzyme exhibited broad pH ranges for activity. The crude proteases extracted from Coriandrum sativum showed good potential for the development of a rapid, sensitive, and economic inhibitive assay for the biomonitoring of Hg²⁺ and Zn²⁺ in the aquatic environments.
  9. Azman NZ, Siddiqui SA, Low IM
    Mater Sci Eng C Mater Biol Appl, 2013 Dec 1;33(8):4952-7.
    PMID: 24094209 DOI: 10.1016/j.msec.2013.08.023
    Characteristics of X-ray transmissions were investigated for epoxy composites filled with 2-10 vol% WO3 loadings using synchrotron X-ray absorption spectroscopy (XAS) at 10-40 keV. The results obtained were used to determine the equivalent X-ray energies for the operating X-ray tube voltages of mammography and radiology machines. The results confirmed the superior attenuation ability of nano-sized WO3-epoxy composites in the energy range of 10-25 keV when compared to their micro-sized counterparts. However, at higher synchrotron radiation energies (i.e., 30-40 keV), the X-ray transmission characteristics were similar with no apparent size effect for both nano-sized and micro-sized WO3-epoxy composites. The equivalent X-ray energies for the operating X-ray tube voltages of the mammography unit (25-49 kV) were in the range of 15-25 keV. Similarly, for a radiology unit operating at 40-60 kV, the equivalent energy range was 25-40 keV, and for operating voltages greater than 60 kV (i.e., 70-100 kV), the equivalent energy was in excess of 40 keV. The mechanical properties of epoxy composites increased initially with an increase in the filler loading but a further increase in the WO3 loading resulted in deterioration of flexural strength, modulus and hardness.
  10. Zaki R, Bulgiba A, Nordin N, Azina Ismail N
    Iran J Basic Med Sci, 2013 Jun;16(6):803-7.
    PMID: 23997908
    Reliability measures precision or the extent to which test results can be replicated. This is the first ever systematic review to identify statistical methods used to measure reliability of equipment measuring continuous variables. This studyalso aims to highlight the inappropriate statistical method used in the reliability analysis and its implication in the medical practice.
  11. Xin LZ, Govindasamy V, Musa S, Abu Kasim NH
    Med Hypotheses, 2013 Oct;81(4):704-6.
    PMID: 23932760 DOI: 10.1016/j.mehy.2013.07.032
    Dental tissues contains stem cells or progenitors that have high proliferative capacity, are clonogenic in vitro and demonstrate the ability to differentiate to multiple type cells involving neurons, bone, cartilage, fat and smooth muscle. Numerous experiments have demonstrated that the multipotent stem cells are not rejected by immune system and therefore it may be possible to use these cells in allogeneic settings. In addition, these remarkable cells are easily abundantly available couple with less invasive procedure in isolating comparing to bone marrow aspiration. Here we proposed dental stem cells as candidate for cardiac regeneration based on its immature characteristic and propensity towards cardiac lineage via PI3-Kinase/Aktsignalling pathway.
  12. Loh SH, Sanagi MM, Wan Ibrahim WA, Hasan MN
    J Chromatogr A, 2013 Aug 9;1302:14-9.
    PMID: 23809804 DOI: 10.1016/j.chroma.2013.06.010
    A new microextraction procedure termed agarose gel liquid phase microextraction (AG-LPME) combined with gas chromatography-mass spectrometry (GC-MS) was developed for the determination of selected polycyclic aromatic hydrocarbons (PAHs) in water. The technique utilized an agarose gel disc impregnated with the acceptor phase (1-octanol). The extraction procedure was performed by allowing the solvent-impregnated agarose gel disc to tumble freely in the stirred sample solution. After extraction, the agarose gel disc was removed and subjected to centrifugation to disrupt its framework and to release the impregnated solvent, which was subsequently withdrawn and injected into the GC-MS for analysis. Under optimized extraction conditions, the new method offered high enrichment factors (89-177), trace level LODs (9-14ngL(-1)) and efficient extraction with good relative recoveries in the range of 93.3-108.2% for spiked drinking water samples. AG-LPME did not exhibit any problems related to solvent dissolution, and it provided high extraction efficiencies that were comparable to those of hollow fiber liquid phase microextraction (HF-LPME) and significantly higher than those of agarose film liquid phase microextraction (AF-LPME). This technique employed a microextraction format and utilized an environmentally compatible solvent holder that supported the green chemistry concept.
  13. Arifin N, Abu Osman NA, Wan Abas WA
    J Appl Biomech, 2014 Apr;30(2):300-4.
    PMID: 23878204 DOI: 10.1123/jab.2013-0130
    The measurements of postural balance often involve measurement error, which affects the analysis and interpretation of the outcomes. In most of the existing clinical rehabilitation research, the ability to produce reliable measures is a prerequisite for an accurate assessment of an intervention after a period of time. Although clinical balance assessment has been performed in previous study, none has determined the intrarater test-retest reliability of static and dynamic stability indexes during dominant single stance. In this study, one rater examined 20 healthy university students (female=12, male=8) in two sessions separated by 7 day intervals. Three stability indexes--the overall stability index (OSI), anterior/posterior stability index (APSI), and medial/ lateral stability index (MLSI) in static and dynamic conditions--were measured during single dominant stance. Intraclass correlation coefficient (ICC), standard error measurement (SEM) and 95% confidence interval (95% CI) were calculated. Test-retest ICCs for OSI, APSI, and MLSI were 0.85, 0.78, and 0.84 during static condition and were 0.77, 0.77, and 0.65 during dynamic condition, respectively. We concluded that the postural stability assessment using Biodex stability system demonstrates good-to-excellent test-retest reliability over a 1 week time interval.
  14. Teo CH, Pawita AH, Khairul O, Atiah Ayunni AG, Noor Hazfalinda H
    Malays J Pathol, 2013 Jun;35(1):77-85.
    PMID: 23817398 MyJurnal
    Post mortem changes are important in estimating post mortem interval (PMI). This project's aim was to study the effect of burial and type of clothing on rate of decomposition, which can contribute to estimating PMI for victims. 12 rabbits (Oryctolagus cuniculus) carcasses were separated into 3 groups: no clothing, light clothing and heavy clothing. Control subjects were placed on the ground surface while test subjects were buried at 30 cm depth graves. Soil samples prior and after decomposition were collected for soil pH and moisture analysis. Post mortem change was assessed using a Total Body Score system. The head, neck and limb regions were found to decay faster than the body trunk region. Mummifi cation occurred on body parts that were exposed directly to the atmosphere while adipocere formed on some buried subjects. Burial delayed decomposition due to lower insect activity and lower soil temperature. The soil layer also blocked the accessibility of majority of the arthropods, causing further delay in decomposition. Clothing enhanced decay for bodies on ground surface because it provided protection for maggots and retained moisture on tissues. However, clothing delayed decomposition in buried bodies because it physically separated the bodies from soil and arthropods. Higher sun exposure and repetitive exhumation showed acceleration of decomposition. The decomposition process increased soil pH and moisture percentage values. Soil pH initially increased until pH 8.0-8.4 followed by a slight decrease while soil moisture percentage changed inconsistently. Burial was significant in affecting post mortem change, F(1,11)=12.991, p<0.05 while type of clothing was not significant, F(2,9)=0.022, p=0.978 and combination of both type of clothing and burial factors were also not significant, F(2,3)=0.429, p=0.686. For validation, an accuracy of 83.33% was achieved based on soil pH and soil moisture percentage analysis.
  15. Loh SH, Sanagi MM, Wan Ibrahim WA, Hasan MN
    Talanta, 2013 Mar 15;106:200-5.
    PMID: 23598117 DOI: 10.1016/j.talanta.2012.12.032
    A new microextraction procedure termed multi-walled carbon nanotube-impregnated agarose film microextraction (MWCNT-AFME) has been developed. The method utilized multi-walled carbon nanotubes (MWCNTs) immobilized in agarose film to serve as adsorbent in solid phase microextraction (SPME). The film was prepared by mixing the MWCNTs in agarose solution and drying the mixture in oven. Extraction of selected polycyclic aromatic hydrocarbons was performed by inserting a needle through circular MWCNT-impregnated agarose films (5 mm diameter) and the assembly was dipped into an agitated sample solution prior to micro high performance liquid chromatography-ultraviolet analysis. Back extraction was then performed using ultrasonication of the films in 100 μL of solvent. The film was discarded after single use, thus avoiding any analyte carry-over effect. Due to the mesoporous nature of the agarose film, the MWCNTs were immobilized easily within the film and thus allowing for close contact between adsorbent and analytes. Under the optimized extraction conditions, the technique achieved trace LODs in the range of 0.1 to 50 ng L(-1) for the targeted analytes, namely fluoranthene, phenanthrene and benzo[a]pyrene. The method was successfully applied to the analysis of spiked green tea beverage samples with good relative recoveries in the range of 91.1 to 107.2%. The results supported the feasibility of agarose to serve as adsorbent holder in SPME which then minimizes the consumption of chemicals and disposal cost of organic wastes.
  16. Nor Azlin MN, Syed Aljunid SJ, Noor Azahz A, Amrizal MN, Saperi S
    Med J Malaysia, 2012 Oct;67(5):473-7.
    PMID: 23770861 MyJurnal
    This study aimed to estimate cost of in-patient medical care due to stroke in a tertiary hospital in Malaysia. A retrospective analysis of stroke patients admitted to Universiti Kebangsaan Malaysia Medical Centre (UKMMC) between January 2005 and December 2008 were conducted. Cost evaluation was undertaken from the health provider's perspective using a top-down costing approach. Mean length of stay (LOS) was 6.4 ± 3.1 days and mean cost of care per patient per admission was MYR 3,696.40 ± 1,842.17 or 16% of per capita GDP of the country. Human resources made up the highest cost component (MYR 1,343.90, SD: 669.8 or 36% of the total cost), followed by medications (MYR 867.30, SD:432.40) and laboratory services (MYR 337.90, SD:168.40). LOS and cost of care varied across different stroke severity levels (p<0.01). A regression analysis shown significant influence of stroke severity on cost of care, with the most severe stroke consumed MYR 1,598.10 higher cost than the mild stroke (p<0.001). Cost of medical care during hospital admission due to stroke is substantial. Health promotion and primary prevention activities need to take priority to minimise stroke admission in future.
  17. Mortaza N, Abu Osman NA, Jamshidi AA, Razjouyan J
    PLoS One, 2013;8(5):e64308.
    PMID: 23717593 DOI: 10.1371/journal.pone.0064308
    Use of functional knee braces has been suggested to provide protection and to improve kinetic performance of the knee in Anterior cruciate ligament(ACL)-injured patients. However, many athletes might refrain from wearing the braces because of the fear of performance hindrance in the playing field. The aim of this study was to examine the effect of three functional knee brace/sleeves upon the isokinetic and functional performance of ACL-deficient and healthy subjects. Six anterior cruciate ligament deficient (29.0 ± 5.3 yrs., 175.2 ± 5.4 cm, and 73.0 ± 10.0 kg) and six healthy male subjects (27.2 ± 3.7 yrs., 176.4 ± 6.4 cm, and 70.3 ± 6.9 kg) were selected. The effect of a custom-made functional knee brace, and two neoprene knee sleeves, one with four metal supports and one without support were examined via the use of isokinetic and functional tests in four sets (non-braced,wearing functional knee brace,and wearing the sleeves). Cross-over hop and single leg vertical jump test were performed and jump height, and hop distance were recorded. Peak torque to body weight ratio and average power in two isokinetic velocities(60°.s(-1),180°.s(-1)) were recorded and the brace/sleeves effect was calculated as the changes in peak torque measured in the brace/sleeves conditions, expressed as a percentage of peak torque measured in non-braced condition. Frequency content of the isokinetic torque-time curves was also analyzed. Wilcoxon signed rank test was used to compare the measured values in four test conditions within each control and ACL-deficient group,and Mann-Whitney U test was used for the comparison between the two groups. No significant differences in peak torque, average power, torque-time curve frequency content, vertical-jump and hop measurements were found within the experimental and the non-braced conditions (p>0.05). Although the examined functional knee brace/sleeves had no significant effect on the knee muscle performance, there have been some enhancement regarding the extension peak torques and power generating capacity of the ACL-deficient subjects that could be helpful in reducing the bilateral asymmetry in these patients.
  18. Juanarita J, Azmi MN, Azhany Y, Liza-Sharmini AT
    Asian Pac J Trop Biomed, 2012 Sep;2(9):755-6.
    PMID: 23570008 DOI: 10.1016/S2221-1691(12)60223-8
    A 24 year-old Malay lady presented with high grade fever, myalgia, generalized rashes, severe headache and was positive for dengue serology test. Her lowest platelet count was 45 × 10(9) cells/L. She complained of sudden onset of painlessness, profound loss of vision bilaterally 7 days after the onset of fever. On examination, her right eye best corrected vision was 6/30 and left eye was 6/120. Her anterior segment examination was unremarkable. Funduscopy revealed there were multiple retinal haemorrhages found at posterior pole of both fundi and elevation at fovea area with subretinal fluid. Systemic examination revealed normal findings except for residual petechial rashes. She was managed conservatively. Her vision improved tremendously after 2 months. The retinal hemorrhages and foveal elevation showed sign of resolving. Ocular manifestations following dengue fever is rare. However, bilateral visual loss can occur if both fovea are involved.
  19. Lah EF, Musa RN, Ho TM
    Asian Pac J Trop Biomed, 2012 Sep;2(9):679-83.
    PMID: 23569994 DOI: 10.1016/S2221-1691(12)60209-3
    To examined the immediate and 24 hours post- irradiation germicidal effects of UV-C lamp on eggs and adults of house dust mites Dermatophagoides pteronyssinus (D. pteronyssinus) and Dermatophagoides farinae (D. farinae).
  20. Abushammala MF, Basri NE, Elfithri R
    Environ Monit Assess, 2013 Dec;185(12):9967-78.
    PMID: 23797636
    Methane (CH₄) emissions and oxidation were measured at the Air Hitam sanitary landfill in Malaysia and were modeled using the Intergovernmental Panel on Climate Change waste model to estimate the CH₄ generation rate constant, k. The emissions were measured at several locations using a fabricated static flux chamber. A combination of gas concentrations in soil profiles and surface CH₄ and carbon dioxide (CO₂) emissions at four monitoring locations were used to estimate the CH₄ oxidation capacity. The temporal variations in CH₄ and CO₂ emissions were also investigated in this study. Geospatial means using point kriging and inverse distance weight (IDW), as well as arithmetic and geometric means, were used to estimate total CH₄ emissions. The point kriging, IDW, and arithmetic means were almost identical and were two times higher than the geometric mean. The CH₄ emission geospatial means estimated using the kriging and IDW methods were 30.81 and 30.49 gm(−2) day(−1), respectively. The total CH₄ emissions from the studied area were 53.8 kg day(−1). The mean of the CH₄ oxidation capacity was 27.5 %. The estimated value of k is 0.138 year(−1). Special consideration must be given to the CH₄ oxidation in the wet tropical climate for enhancing CH₄ emission reduction.
Filters
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links