1,721,109 research outputs found
Zein/Bioactive Glass Coatings with Controlled Degradation of Magnesium under Physiological Conditions: Designed for Orthopedic Implants
No full textMagnesium and its alloys are widely considered as temporary bio-implants owing to their mechanical properties and biocompatibility. However, the high corrosion rates and degradation in the physiological environment restrict the practical application of Mg as a biomedical device. Therefore, in this study, Zein/45S5 bioactive glass (BG) coatings were deposited via electrophoretic deposition (EPD) on pretreated pure magnesium (Mg) substrates, which controls the rapid degradation of magnesium. The set of EPD parameters was first optimized on stainless steel (SS) and then the optimum EPD parameters were applied to obtain zein/BG composite coatings on Mg substrates. The morphology of the obtained coatings was studied by scanning electron microscopy (SEM). SEM results showed that both zein and BG were successfully deposited on the surface of the Mg substrate. Electrochemical measurements consisting of open circuit potential (OCP), electrochemical impedance spectroscopy (EIS), and potentiodynamic polarization confirmed that the corrosion resistance of Mg improved after the deposition of zein/BG coatings. The in-vitro bioactivity study was carried out by immersing the zein/BG coatings in simulated body fluid for 3, 7, and 21 days. SEM, energy dispersive X-ray spectroscopy (EDX), and Fourier transform infrared spectroscopy results elucidated that the hydroxyapatite layer developed after 21 days of immersion in SBF, which confirmed the bone binding ability of the coatings
Determination of relative importance of agility enablers for agile manufacturing companies by analytical hierarchy process
No full textDetermination of relative importance of agility enablers for agile manufacturing companies by analytical hierarchy process
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Chitosan/gelatin‐based bioactive and antibacterial coatings deposited via electrophoretic deposition
No full textA critical review of flood risk management and the selection of suitable measures
Get PDFModern-day flood management has evolved into a variety of flood management alternatives. The selection of appropriate flood measures is crucial under a variety of flood management practices, approaches, and assessment criteria. Many leading countries appraise the significance of risk-based flood management, but the fixed return period is still the de facto standard of flood management practices. Several measures, approaches, and design criteria have been developed over time. Understanding their role, significance, and correlation toward risk-based flood management is crucial for integrating them into a plan for a floodplain. The direct impacts of a flood are caused by direct contact with the flood, while indirect impacts occur as a result of the interruptions and disruptions of the socio-economical aspects. To proceed with a risk-based flood management approach, the fundamental requirement is to understand the risk dynamics of a floodplain and to identify the principal parameter that should primarily be addressed so as to reduce the risk. Risk is a potential loss that may arise from a hazard. On the one hand, exposure and susceptibility of the vulnerable system, and on the other, the intensity and probability of the hazard, are the parameters that can be used to quantitatively determine risk. The selection of suitable measures for a flood management scheme requires a firm apprehension of the risk mechanism. Under socio-economic and environmental constraints, several measures can be employed at the catchments, channels, and floodplains. The effectiveness of flood measures depends on the floodplain characteristics and supporting measures.Water Resource
Development of a preliminary-risk-based flood management approach to address the spatiotemporal distribution of risk under the kaldor–hicks compensation principle
Get PDFAll over the world, probability-based flood protection designs are the ones most commonly used. Different return-period design floods are standard criteria for designing structural measures. Recently, risk-based flood management has received a significant appraisal, but the fixed return period is still the de facto standard for flood management designs due to the absence of a robust framework for risk-based flood management. The objective of this paper is to discuss the economics and criteria of project appraisal, as well as to recommend the most suitable approach for a risk-based project feasibility evaluation. When it comes to flood management, decision-makers, who are generally politicians, have to prioritize the allocation of resources to different civic welfare projects. This research provides a connection between engineering, economics, and management. Taking account of socioeconomic and environmental constraints, several measures can be employed in a floodplain. The Kaldor–Hicks compensation principle provides the basis for a risk-based feasibility analysis. Floods should be managed in a way that reduces the damage from minimum investments to ensure maximum output from floodplain land use. Specifically, marginal losses due to flood damage and the expense of flood management must be minimized. This point of minimum expenses is known as the “optimum risk point” or “optimal state”. This optimal state can be estimated using a risk-based assessment. Internal rate of return, net present value, and benefit–cost ratio are indicators that describe the feasibility of a project. However, considering expected annual damage is strongly recommended for flood management to ensure a simultaneous envisage of the performance of land-use practices and flood measures. Flood management ratios can be used to describe the current ratio of expected annual damage to the expected annual damage at the optimal risk point. Further development of the approach may replace probability-based standards at the national level.Water Resource
An evaluation of risk-based agricultural land-use adjustments under a flood management strategy in a floodplain
Get PDFAgricultural damage due to floods in the Indus basin’s fertile land has been the most damaging natural disaster in Pakistan so far. Earthen dikes are protecting the vast areas of the floodplain from regular flooding. However, the floodplain is attractive to farmers due to its fertility and experiences regular crop production within and out of the dike area. This paper evaluates the flood risk in a floodplain of the Chenab river in Pakistan and recommends land-use changes to reduce the flood risk for crops and associated settlements within the study area. The objective of the land-use change is not just to reduce flood losses but also to increase the overall benefits of the floodplain in terms of its Economic Rent (ER). This preliminary study analyses the economic impacts of the risk-based land-use improvements on existing floodplain land uses. Expected Annual Damage (EAD) maps were developed using hydrodynamic models and GIS data. The developed model identified the areas where maize can be economically more productive compared to rice under flood conditions. Promising results were obtained for the settlement relocations. It was also observed that the infra-structure, running parallel to the river, plays a significant role in curtailing the extent of floods. The results show that a combination of structural and non-structural measures proves more effective. The study also recommends the inclusion of social and environmental damages as well as other types of non-structural measures to develop the most effective flood management strategy
Smart City Ranking System: A Supporting Tool to Manage Migration Trends for Australian Cities
Get PDFA key driver of Australia’s economic development is through promoting migration. A strong bottleneck to achieve the targets is a disproportional concentration of population in the metropolitan cities. To avoid congestion in these cities, emphasis is being given at the government level to promote the regional cities. With different city ranking systems, this study tries to identify linkage between the city ranking and people’s preference to live there. The proposed ranking system uses six components, namely, economy, mobility, environment, people, living, and governance. A comparison is done between the ranking systems by first assigning the same weightage to the six components and then assigning different weightages based on people’s preferences. This study considered 112 Australian cities, which were ranked by considering their performance based on the non-weighted and weighted parameters. Analytical Hierarchy Process is then used to assign the priorities/preferences of the components, factors, and indicators. The study also incorporates clustering technique to address the issue of missing data/information that is a typical problem with small cities where missing data is a common issue. The results of the comparison demonstrate that assigning weightage to ranking parameters makes the city ranking closer to the preference of people to live in a city. It is also recommended that the city ranking system and urban governance should have closer connection to each other. The lowest performing city ranking parameter should be given higher preferences in urban management and development plans
A Critical Review of Water Resources and Their Management in Bhutan
Get PDFBhutan is a small yet water-abundant country. The country suffers from frequent flooding and is lately experiencing a growing risk of localized droughts due to inappropriate water resource management and climate change. Such a situation calls for much more efficient use and management of water in Bhutan. This paper undertakes an extensive analysis of the country’s water resources for better planning and management of the available water resources. Bhutan can be divided into three zones, the Southern Foothills, the Central Inner Himalayas, and the Higher Himalayas. The top four leading industries of Bhutan are related to water, either directly or indirectly. The country at present is at a very early stage of development. The government has prioritized water resources management over recent years. Water for hydropower in Bhutan has been in focus as compared to that allocated for irrigation, industries, and environmental demand. The demand for water in Bhutan has also increased in the last decade due to population increase, changes in lifestyle, and economic advancements through tourism and hydropower projects. Climate variation, deteriorating water quality, frequent floods, and increasing urbanization threaten the sustainability of water resources. Water accessibility issues for settlements due to the country’s harsh geographical landscape is leading towards localized water scarcity. Serious attention to rainwater harvesting and groundwater recharge is required to address localized water scarcity issues
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