17 research outputs found

    Study of Gasohol as Alternative Fuel for Gasoline Substitution: Characteristics and Performances

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    Gasohol is a mixture of premium petrol (gasoline) with alcohol, in this case ethanol. The use of gasohol can reduce fuel consumption without having to modify the existing engine. Therefore, this research is conducted to study the characteristics and performance of gasohol in various mixing ratios, which includes analysis of physical properties and the use of gasohol in the machine. Results show that the addition of technical ethanol at 7.0169%v increases the value of gasohol vapor pressure on the value of 8.6682 psi (7.7 psi for regular gasoline). Gasohol with technical ethanol content above 30%v decreases vapor pressure, promotes phase separation, and causes a sharp drop in temperature from 40%v distillation. In term of corrosivity, gasohol with up to 50%v ethanol content has the same corrosion level with regular gasoline, which is corrosion level 1A. Based on gasohol characteristics test, it is known that gasohol with technical ethanol content below 20%v can be used as a fuel substitute for gasoline. Real-time performance test of gasohol in engines has shown that the addition of ethanol content in gasohol tend to increase the engine power at a certain compression ratio, but it also increases fuel consumption because the heat value of ethanol is lower than gasoline. Machine in gasohol with ethanol content below 20%v can operate smoothly without having to modify the engine. Based on the studies that have been done, gasohol in the range of 10%v ethanol content is well-functioned as a substitute for gasoline fuel and meets fuel specifications required by the General Director of Oil and Gas. The feasibility of using gasohol as an alternative fuel can be studied further

    Earthquakes and tsunamis caused by low-angle normal faulting in the Banda Sea, Indonesia

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    As the world's largest archipelagic country in Earth's most active tectonic region, Indonesia faces a substantial earthquake and tsunami threat. Understanding this threat is a challenge because of the complex tectonic environment, the paucity of observed data and the limited historical record. Here we combine information from recent studies of the geology of Indonesia's Banda Sea with Global Positioning System observations of crustal motion and an analysis of historical large earthquakes and tsunamis there. We show that past destructive earthquakes were not caused by the supposed megathrust of the Banda outer arc as previously thought but are due to a vast submarine normal fault system recently discovered along the Banda inner arc. Instead of being generated by coseismic seafloor displacement, we find the tsunamis were more likely caused by earthquake-triggered submarine slumping along the fault's massive scarp, the Weber Deep. This would make the Banda detachment representative not only as a modern analogue for terranes hyper-extended by slab rollback but also for the generation of earthquakes and tsunamis by a submarine extensional fault system. Our findings suggest that low-angle normal faults in the Banda Sea generate large earthquakes, which in turn can generate tsunamis due to earthquake-triggered slumping. Low-angle normal faults in the Banda Sea have caused large earthquakes that indirectly generated tsunamis due to earthquake-triggered submarine slumping, according to an analysis of historical earthquake and tsunami events and GPS observations.Peer reviewe

    Tsunami risk communication and management: Contemporary gaps and challenges

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    Very large tsunamis are associated with low probabilities of occurrence. In many parts of the world, these events have usually occurred in a distant time in the past. As a result, there is low risk perception and a lack of collective memories, making tsunami risk communication both challenging and complex. Furthermore, immense challenges lie ahead as population and risk exposure continue to increase in coastal areas. Through the last decades, tsunamis have caught coastal populations off-guard, providing evidence of lack of preparedness. Recent tsunamis, such as the Indian Ocean Tsunami in 2004, 2011 Tohoku and 2018 Palu, have shaped the way tsunami risk is perceived and acted upon. Based on lessons learned from a selection of past tsunami events, this paper aims to review the existing body of knowledge and the current challenges in tsunami risk communication, and to identify the gaps in the tsunami risk management methodologies. The important lessons provided by the past events call for strengthening community resilience and improvement in risk-informed actions and policy measures. This paper shows that research efforts related to tsunami risk communication remain fragmented. The analysis of tsunami risk together with a thorough understanding of risk communication gaps and challenges is indispensable towards developing and deploying comprehensive disaster risk reduction measures. Moving from a broad and interdisciplinary perspective, the paper suggests that probabilistic hazard and risk assessments could potentially contribute towards better science communication and improved planning and implementation of risk mitigation measures

    Tsunami risk communication and management: Contemporary gaps and challenges

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    Supplementary data: The following is the Supplementary data to this article: Acrobat PDF file (2MB) available at: https://ars.els-cdn.com/content/image/1-s2.0-S2212420921007329-mmc1.pdfCopyright © 2022 The Authors. Very large tsunamis are associated with low probabilities of occurrence. In many parts of the world, these events have usually occurred in a distant time in the past. As a result, there is low risk perception and a lack of collective memories, making tsunami risk communication both challenging and complex. Furthermore, immense challenges lie ahead as population and risk exposure continue to increase in coastal areas. Through the last decades, tsunamis have caught coastal populations off-guard, providing evidence of lack of preparedness. Recent tsunamis, such as the Indian Ocean Tsunami in 2004, 2011 Tohoku and 2018 Palu, have shaped the way tsunami risk is perceived and acted upon. Based on lessons learned from a selection of past tsunami events, this paper aims to review the existing body of knowledge and the current challenges in tsunami risk communication, and to identify the gaps in the tsunami risk management methodologies. The important lessons provided by the past events call for strengthening community resilience and improvement in risk-informed actions and policy measures. This paper shows that research efforts related to tsunami risk communication remain fragmented. The analysis of tsunami risk together with a thorough understanding of risk communication gaps and challenges is indispensable towards developing and deploying comprehensive disaster risk reduction measures. Moving from a broad and interdisciplinary perspective, the paper suggests that probabilistic hazard and risk assessments could potentially contribute towards better science communication and improved planning and implementation of risk mitigation measures.COST (European Cooperation in Science and Technology); Royal Society, UK (grant number CHL\R1\180173); Severo Ochoa Centers of Excellence Program (CEX 2018-000797-S) funded by MCIN/ AEI /10.13039/501100011033; Lloyd's Tercentenary Research Foundation, the Lighthill Risk Network, and the Lloyd's Register Foundation-Data Centric Engineering Programme of the Alan Turing Institute

    Surface-Initiated Polymer Brushes in the Biomedical Field: Applications in Membrane Science, Biosensing, Cell Culture, Regenerative Medicine and Antibacterial Coatings

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    In Situ Self-Assembled Polyoxotitanate Cages on Flexible Cellulosic Substrates: Multifunctional Coating for Hydrophobic, Antibacterial, and UV-Blocking Applications

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    Surface coating is a powerful approach to fabricate multifunctional materials that are essential for numerous applications. However, to achieve such multifunctional coating with a facile single-step procedure, especially on flexible substrates, is still a big challenge, as current fabrication protocols usually require sophisticated equipment and complicated procedures. Here a novel coating technology involving in situ self-assembly of the polyoxotitanate (POT) cage [Ti18Mn4O30(OEt)20Phen3] is reported to fabricate multifunctional cotton fabrics in a single-step. The in situ generated spherical microparticles of 0.8 µm average diameter are firmly mounted on the underlying cotton substrate, imparting the coated surface with robust hydrophobicity (water contact angle of 148.1 ± 5.4°), antibacterial activity (against E. coli, S. epidermidis and S. aureus) and excellent UV-blocking performance (89% blocked at 350 nm). This coating technology is efficient, straightforward, requires no specialized equipment, and most importantly, is readily extendable to other flexible substrates. Combined with the rapidly developing area of POT cages and similar molecular materials, the reported technology based on in situ self-assembly holds great promise for further advancing the fabrication of multifunctional flexible devices via a single-step coating operation

    Layer-by-layer click deposition of functional polymer coatings for combating marine biofouling

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    10.1021/bm300757eBiomacromolecules1392769-2780BOMA

    Increasing bacterial affinity and cytocompatibility with four-arm star glycopolymers and antimicrobial ?-polylysine

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    10.1039/c7py00441aPolymer Chemistry8213364-337

    A probabilistic tsunami hazard assessment for Indonesia

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    Probabilistic hazard assessments are a fundamental tool for assessing the threats posed by hazards to communities and are important for underpinning evidence-based decision-making regarding risk mitigation activities. Indonesia has been the focus of intense tsunami risk mitigation efforts following the 2004 Indian Ocean tsunami, but this has been largely concentrated on the Sunda Arc with little attention to other tsunami prone areas of the country such as eastern Indonesia. We present the first nationally consistent probabilistic tsunami hazard assessment (PTHA) for Indonesia. This assessment produces time-independent forecasts of tsunami hazards at the coast using data from tsunami generated by local, regional and distant earthquake sources. The methodology is based on the established monte carlo approach to probabilistic seismic hazard assessment (PSHA) and has been adapted to tsunami. We account for sources of epistemic and aleatory uncertainty in the analysis through the use of logic trees and sampling probability density functions. For short return periods (100 years) the highest tsunami hazard is the west coast of Sumatra, south coast of Java and the north coast of Papua. For longer return periods (500–2500 years), the tsunami hazard is highest along the Sunda Arc, reflecting the larger maximum magnitudes. The annual probability of experiencing a tsunami with a height of > 0.5 m at the coast is greater than 10% for Sumatra, Java, the Sunda islands (Bali, Lombok, Flores, Sumba) and north Papua. The annual probability of experiencing a tsunami with a height of > 3.0 m, which would cause significant inundation and fatalities, is 1–10% in Sumatra, Java, Bali, Lombok and north Papua, and 0.1–1% for north Sulawesi, Seram and Flores. The results of this national-scale hazard assessment provide evidence for disaster managers to prioritise regions for risk mitigation activities and/or more detailed hazard or risk assessment
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