297 research outputs found
Concurrent Acquisition of a Single Nucleotide Polymorphism in Diverse Influenza H5N1 Clade 2.2 Sub-clades
Highly pathogenic Influenza A H5N1 was first identified in Guangdong Province in 1996, followed by human cases in Hong Kong in 1997 1,2. The number of confirmed human cases now exceeds 300 and the associated Case Fatality Rate exceeds 60% 3. The genetic diversity of the serotype continues to increase. Four distinct clades or sub-clades have been linked to human cases 4-7. The gradual genetic changes identified in the sub-clades have been attributed to copy errors by viral encoded polymerases that lack an editing function, thereby resulting in antigenic drift 8. We report here the concurrent acquisition of the same polymorphism by multiple, genetically distinct, clade 2.2 sub-clades in Egypt, Russia, Kuwait, and Ghana. These changes are not easily explained by the current theory of “random mutation” through copy error, and are more easily explained by recombination with a common source. The recombination role is further supported by the high fidelity replication in swine influenza 9 and aggregation of single nucleotide polymorphisms in H5N1 clade 2.2 hemagglutinin 10
Peningkatan Derajat Kesehatan Melalui Promosi Kesehatan Pola Hidup Bersih Dan Sehat (Phbs) Di Dusun Sawahan Desa Pendowoharjo, Kecamatan Sewon, Kabupaten Bantul
Telah dilakukan penelitian mengenai peningkatan derajat kesehatan melalui promosi kesehatan Pola Hidup Bersih Sehat (PHBS) di Dusun Sawahan Desa Pendowoharjo, Kecamatan Sewon, Kabupaten Bantul dengan metode penyuluhan dan pemantauan serta pengamatan tanpa sepengetahuan subjek uji. Penelitian ini bertujuan untuk mengetahui pengaruh dari pelaksanaan promosi kesehatan Pola Hidup Bersih Sehat (PHBS) terhadap kesehatan masyarakat Dukuh Sawahan. Hasil penelitian menunjukkan bahwa frekuensi penyuluhan dan pemantauan Pola Hidup Bersih dan Sehat (PHBS) terhadap warga dusun Sawahan menunjukkan korelasi yakni meningkatnya indikator Pola Hidup Bersih dan Sehat (PHBS) yang tercapai. Tercapainya indikator Pola Hidup Bersih dan Sehat (PHBS) menunjukkan peningkatan kesadaran warga akan pentingnya lingkungan sehat dan perilaku sehat sehingga meningkatkan derajat kesehatan warga Dusun Sawahan
Facile green synthesis of ytrium-doped BiFeO<sub>3</sub> with highly efficient photocatalytic degradation towards methylene blue
Fetal lipopolysaccharide exposure modulates diet-dependent gut maturation and sensitivity to necrotising enterocolitis in pre-term pigs
Laboratory investigation of coal bottom ash modified warm mix asphalt
Bottom Ash (BA), a coal combustion by-product, found to be a potential material when used to produce asphalt mixture. However, some of its characteristics make it a questionable material for the surface course. Therefore, this study aims to evaluate the compatibility of BA in Warm Mix Asphalt (WMA) technology through the basic mechanical properties of the asphalt mixtures for binder course layer (AC 28). Two WMA chemical additives, Cecabase RT and Evotherm 3G, were used at the concentrations of 0.3, 0.4 and 0.5% from the binder's weight. The binder properties were assessed through penetration, softening point and viscosity tests. The Marshall mix design was used to determine the optimum binder content (OBC). The additive dosage and production temperature for WMA were determined through Marshall stability, flow, air voids and specific gravity. The results show that the additives did not significantly affect the binder properties, although, at 0.4% Evotherm 3G, a drop of 17.5% in penetration was observed. Cecabase RT produced WMA with promising results but did not enhance the workability of WMA containing bottom ash (BAWMA). By lowering the production temperature of 25 °C, WMA and BAWMA at 0.4 %, Evotherm 3G demonstrated comparable workability to the conventional Hot Mix Asphalt (HMA). The data achieved through this study would be a guiding approach towards the application of BA in WMA technology for sustainable pavements
Rheological criteria assessment of a rapid setting emulsion as compared to quick set for emulsified asphalt cold mixes
Pavement deterioration is inevitable on roads. Unlike structural failures that can only be remedied by total reconstruction, road's functional failures are corrected through effective maintenance works. Preventive maintenance in the form of an emulsified asphalt cold slurry micro-surfacing is considered superior to corrective maintenance - which is a reactive approach. Exploring alternative(s) to the normal quick setting emulsion used for pavement preservation maintenance will make it more robust and cost-effective. This study conducted an assessment of the key parameters specified by the department of public works (Jabatan Kerja Raya) JKR-2008 and International Slurry Surfacing Association (ISSA A143) specifications for emulsified asphalts emulsions used for cold mixes, specifically, emulsified asphalt micro-surfacing mixtures used for pavement maintenance. Cationic quick set (CQS-1h) and Rapid Set (RS-1k) emulsions were tested in the Transportation laboratory of UTM under controlled laboratory conditions. Tests include settlement and storage stability, particle charge, residue by evaporation, sieve test, and Say bolt Furol viscosity, while the residue from evaporation was tested for microstructural and mechanical performance, results were compared with JKR-2008 and ISSA A143 standard specifications. The result indicated that although the desirability for opening traffic within 1hr is not guaranteed with RS-1k, yet, it gives promising similar properties with CQS whilst satisfying cold mix requirement
Assessment framework for pavement material and technology elements in green highway index
Sustainability concept in highway development needs to be addressed critically in order to alleviate the effect of global warming and depletion of natural resources issues. In Malaysia, there are a lot of alternative pavement materials and technology that have been introduced to the industry so that green highway can be achieved. However, Malaysia does not have any tools to assess the level of greenness for any highway projects and still lacks of awareness in sustainable highway. Thus, the main objective of this study is to develop an assessment framework for pavement material and technology elements in Malaysia green highway index. An extensive literature were reviewed and expert discussion was conducted to identify the 13 vital elements of pavement material and technology which include regional materials; reuse of top soil; reused and/or recycled of non-hazardous materials; earthwork balance; usage of industrial by-products; subgrade improvement/soil stabilization, permeable pavement, pavement design life, quiet pavement, recycled pavement or new sustainable techniques; cool pavement; soil biotechnical engineering treatment; and green techniques. Questionnaires were distributed among the 109 highway practitioners to obtain their agreement level on these elements. Then, all the data were analyzed by using factor analysis approach which generated from Statistical Package for Social Science (SPSS) software. The assessment score of each element was calculated from the findings and assessment framework for pavement material and technology elements was established. Results show that all the elements were grouped into four main factor namely environmental control, economical resources, innovation technology and erosion control with four point was considered as a maximum point score to be achieved in green highway assessment framework. Hence, the research clearly indicates that these elements are essential to be implemented in Malaysia's highway development indirectly as an encouragement to improve the performance of transportation sector
Effects of titanate coupling agent on engineering properties of asphalt binders and mixtures incorporating LLDPE-CaCO3 pellet
This study was initiated to evaluate the performance of asphalt binders and mixtures incorporating linear low-density polyethylene- calcium carbonate (LLDPE-CaCO3) pellet, either with or without titanate coupling agent. The detailed manufacturing process of modifier pellets was displayed. The coupling agent was used to enhance the cross-linking between materials by means of winding up covalent bonds or molecule chains, thus improving the performance of composites. In the preparation of modified bitumen, the preheated asphalt binder was mixed with the modifiers using a high shear mixer at 5000 rpm rotational speed for 45 min. Experimental works were conducted to evaluate the performance of asphalt binders in terms of volatile loss, viscosity, rutting potential, and low temperature cracking. Meanwhile, the asphalt mixtures were tested using the flow number test and tensile strength ratio (TSR) test. The addition of LLDPE-CaCO3 modifiers and coupling agent does not significantly affect the volatile loss of modified asphalt binders. The addition of modifiers and coupling agent has significantly improved the resistance to permanent deformation of asphalt binders. Even though, the addition of LLDPE-CaCO3 modifier and coupling agent remarkably increased the mixture stiffness that contributed to lower rutting potential, the resistance to low temperature cracking of asphalt binder was not adversely affected. The combination of 1% coupling agent with 3% PECC is optimum dosage for asphalt binder to have satisfactory performance in resistance to moisture damage and rutting
Durability of POFA-modified dense-graded cold mix asphalt
Cold mix asphalt (CMA) is a versatile and energy efficient mixture often prepared at ambient temperature. Efforts to improve the performance of CMA mixtures recorded appreciable success. Nonetheless, the critical performance measures of moisture and abrasive resistance still baffles researchers. Additionally, CMA’s design, production, testing, and site application is bedevilled by slow rate of strength gain, high void content, and absence of a globally acceptable mix design. This study aimed at assessing CMA’s durability measures using the modified Lottman (moisture damage) and Cantabro tests by adding a 3% palm oil fuel ash (POFA) as filler replacement and 3% cement. Fast-curing mixtures fabricated with a cationic quick-set (CQS-1h) and a rapid-set (RS-1K) emulsion both of medium viscosities with a nominal maximum aggregate size (NMAS) of 4.75 mm were evaluated. In addition to improving the Marshall volumetric properties, POFA’s inclusion is aimed at improving adhesion thereby enhancing the durability of the fine dense-graded cold mix asphalt (FGCMA-4.75 mm). The modified Marshall as stated in the asphalt institute (AI) manual series (MS-19) for dense-graded CMA was used for design. Results indicated that POFA reduces the void, improves stability, and enhance durability. Moreover, the CQS-1h has better durability for both control (FGCMA-C) and POFA-modified mixtures (FGCMA-P). While RS-1K has higher tensile strength in both dry and moisture-conditioned states with a higher tensile strength ratio (TSR) for both FGCMA-C and FGCMA-P mixtures. POFA’s pozzolanic capability proves effective in improving the durability and moisture damage resistance of FGCMA-P
A comparative assessment of the physical and microstructural properties of waste garnet generated from automated and manual blasting process
Cold mix asphalt (CMA) is an eco-friendly sustainable asphalt mixture, mostly for asphalt surface treatments (ASTs). However, material compatibility and poor adhesion leading to high voids, moisture damage susceptibility, and weak early strength remain challenging. Efforts to solve this limitation is beamed towards binder improvement and modification with modifiers, adhesion promoters, or polymers. Other forms of AST mixture improvement entail supplementary cementitious reinforcing or pozzolanic agents in the form of by-products. In this study, the physio-mechanical and microstructural desirability of spent garnet for use as fine aggregate in CMA was explored. Spent garnet is a by-product of abrasive blasting, often produced in large quantities and disposed of in landfills. Often, spent garnet waste gets contaminated with toxic elements either during usage or in landfills. This study aimed to investigate the properties of Automatically (AG) and Manually generated (MG) spent garnet grades. The physio-mechanical, morphologic, and chemical parameters of spent garnet were assessed to achieve this aim. The result compared with relevant specifications on cold mixtures plus Jabatan Kerja Raya (JKR) requirement. Moreover, crystallinity and composition were studied using Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), and X-ray Fluorescence (XRF). The presence of toxic heavy metals that often contaminate spent garnet deposits in landfills was evaluated too. Results suggested that both AG and MG's high sand equivalent and least water absorption of 98 %, 89 %, and 0.14 %, 0.23 % accordingly, and can replace sand in CMA. However, MG spent garnet is not desirable for chemically sensitive materials. The AG garnet was found to be Pyrope while the MG spent garnet is largely Almandine garnet – the strongest form of garnet, including traces of other garnet forms
- …