91 research outputs found

    Quality management of the bamboo resource and its contribution to environmental conservation in Malaysia

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    Purpose – The aim of this study was to contribute towards the systematic management of the natural stand bamboo resource at Nami, Kedah, Malaysia and to improve the forest environment rather than leaving it neglected and unmanaged. In addition, the study examines the commercial value of the abundant bamboo culms for a sustained industry in Malaysia. Design/methodology/approach – A one-hectare experimental plot of Gigantochloa scortechinii (buluh semantan) was established with a split plot design of fertilizer treatments 0, 2 and 5?kg of NPK 15:15:15 and felling intensities of 0, 40, 60 and 80 percent. The experiment was conducted for four years. Parameters such as the number of shoots, culms and basal area were observed throughout the study. Findings – From this study significant results were obtained and management principles were formulated. Due to the effect of fertilizer application, there was an increment of 30 percent of shoots sprouted per clump per application. Thinning should be done selectively and mature culms aged more than three years old well spaced within the clump need to be felled first. Originality/value – This new knowledge would be of value to managers and policy makers in formulating the proper management plan for the exploitation of future resources in the country

    Estimation of Electrical Performance of a Polymer Insulator with Deposited Moss on the Surface under Impulse Voltage Condition in Foggy Weather

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    This paper presents a study about electric field behaviour of 10kV polymer insulator with moss deposition under foggy condition. The aim of this simulation experiment was to determine if this field affect the initiation of pollution flashover. To study this effect, simulations were carried out using High Frequency Structure Simulator (HFSS). The simulation experiment includes the results of electric field distribution along the insulator and also the magnitude of electric field at three different locations in identifying the parts of the insulator's surface that likely to initiate pollution flashover. The moss deposited polymer insulator displayed uniformed and considerably intense distribution of electric field with the clean insulator. The field result showed the likelihood in discharging a corona effect. In short, the results indicated that electric field along the insulator surface would likely be influenced by moss deposition and foggy air

    Performance and emissions of diesel engine fuelled with water-in-diesel emulsion

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    Power generation using combustion engine cause severe air pollution. Research for a high efficient engine with less harmful emission is highly demanded. Water-in-Diesel (W/D) emulsion has a potential to reduce fuel consumption and harmful exhaust emission, especially nitrogen oxides (NOX) and particulate matter (PM). Experimental study was conducted by operating single cylinder MR MARK MC-D6500E diesel generator at different loading conditions while using two types of W/D emulsion containing different water contents (10 and 20 vol.%) with 1 (one) vol.% of surfactant (span 80) as additive to stabilize the fuel. The effect of water on fuel consumption, exhaust temperature and emission has been studied and the results have been compared to conventional diesel fuel. The result showed NOx and PM were reduced up to 51% and 14% respectively by using W/D emulsion. Fuel consumption also was up to 10% improved by using W/D emulsion

    The Effects of Surface Curvature on Cartilage Behaviour in Indentation Test: A Finite Element Study

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    Computational modelling of the behaviour of articular cartilage is important in order to improve the understanding of disease processes such as arthritis, and the suitability of biomaterials in surgical treatment. In previous computational studies, the cartilage surface of axisymmetric models was assumed to be flat in order to evaluate the cartilage behaviour. This assumption was inappropriate since the synovial joint possessed curvature geometrical shape and may contribute to inaccurate results. Therefore, this study aims to examine the effects of the cartilage surface curvature to the cartilage behavior in indentation test using finite element analysis. Axisymmetric biphasic poroelastic finite element models of flat and various cartilage surface radii, including both concave and convex shapes of the curve, were generated to simulate creep indentation test in order to investigate possible effect to the contact stress and pore pressure of the cartilage. Based on the results, the smaller cartilage surface of 10 mm radius produced higher difference of the cartilage behaviour where it generated 39% difference in pore pressure and 6% difference in contact stress, compared to the flat cartilage. This could indicate that the cartilage curvature does affect the cartilage behavior in indentation test particularly the pore pressure of cartilage

    Synthesis and Characterization of Silver-Coated Polymeric Scaffolds for Bone Tissue Engineering: Antibacterial and In Vitro Evaluation of Cytotoxicity and Biocompatibility

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    In bone tissue engineering, multifunctional composite materials are very challenging. Bone tissue engineering is an innovative technique to develop biocompatible scaffolds with suitable orthopedic applications with enhanced antibacterial and mechanical properties. This research introduces a polymeric nanocomposite scaffold based on arabinoxylan-co-acrylic acid, nano-hydroxyapatite (nHAp), nano-aluminum oxide (nAl₂O₃), and graphene oxide (GO) by free-radical polymerization for the development of porous scaffolds using the freeze-drying technique. These polymeric nanocomposite scaffolds were coated with silver (Ag) nanoparticles to improve antibacterial activities. Together, nHAp, nAl₂O₃, and GO enhance the multifunctional properties of materials, which regulate their physicochemical and biomechanical properties. Results revealed that the Ag-coated polymeric nanocomposite scaffolds had excellent antibacterial properties and better microstructural properties. Regulated morphological properties and maximal antibacterial inhibition zones were found in the porous scaffolds with the increasing amount of GO. Moreover, the nanosystem and the polymeric matrix have improved the compressive strength (18.89 MPa) and Young’s modulus (198.61 MPa) of scaffolds upon increasing the amount of GO. The biological activities of the scaffolds were investigated against the mouse preosteoblast cell lines (MC3T3-E1) and increasing the quantities of GO helps cell adherence and proliferation. Therefore, our findings showed that these silver-coated polymeric nanocomposite scaffolds have the potential for engineering bone tissue

    Characterization preliminary breakdown in the measured lightning electric fields on Malaysia data

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    This paper presents a characteristic of lightning electric fields. The lightning electric fields were captured by two parallel plats sensor and the characterization for preliminary breakdown pulse (PBP) was studied. A total of 207 data were recorded and 10 data are selected and been utilized in this paper accordingly. In PBP signal data, time before return stroke, ending time and maximum peak of PBP were analyzed. The time duration between the PBP and the occurrence of return stroke was obtained as 0.64 ms and 4.05 ms and then compared with results from other researchers

    Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

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    BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London

    Why Are Outcomes Different for Registry Patients Enrolled Prospectively and Retrospectively? Insights from the Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF).

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    Background: Retrospective and prospective observational studies are designed to reflect real-world evidence on clinical practice, but can yield conflicting results. The GARFIELD-AF Registry includes both methods of enrolment and allows analysis of differences in patient characteristics and outcomes that may result. Methods and Results: Patients with atrial fibrillation (AF) and ≥1 risk factor for stroke at diagnosis of AF were recruited either retrospectively (n = 5069) or prospectively (n = 5501) from 19 countries and then followed prospectively. The retrospectively enrolled cohort comprised patients with established AF (for a least 6, and up to 24 months before enrolment), who were identified retrospectively (and baseline and partial follow-up data were collected from the emedical records) and then followed prospectively between 0-18 months (such that the total time of follow-up was 24 months; data collection Dec-2009 and Oct-2010). In the prospectively enrolled cohort, patients with newly diagnosed AF (≤6 weeks after diagnosis) were recruited between Mar-2010 and Oct-2011 and were followed for 24 months after enrolment. Differences between the cohorts were observed in clinical characteristics, including type of AF, stroke prevention strategies, and event rates. More patients in the retrospectively identified cohort received vitamin K antagonists (62.1% vs. 53.2%) and fewer received non-vitamin K oral anticoagulants (1.8% vs . 4.2%). All-cause mortality rates per 100 person-years during the prospective follow-up (starting the first study visit up to 1 year) were significantly lower in the retrospective than prospectively identified cohort (3.04 [95% CI 2.51 to 3.67] vs . 4.05 [95% CI 3.53 to 4.63]; p = 0.016). Conclusions: Interpretations of data from registries that aim to evaluate the characteristics and outcomes of patients with AF must take account of differences in registry design and the impact of recall bias and survivorship bias that is incurred with retrospective enrolment. Clinical Trial Registration: - URL: http://www.clinicaltrials.gov . Unique identifier for GARFIELD-AF (NCT01090362)
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