Comparison Of Wc-10Co-4Cr Coatings Properties Produced By Hvof And Hvolf Processes For Application In Petrochemical Industry

This research work presents the results of a comparative study conducted to compare the coatings properties of WC-10Co-4Cr coats produced by two different Oxy-fuel coating process; high velocity oxy-gas fuel (HVOF) and high velocity oxy-liquid fuel (HVOLF) thermal spraying techniques. The coats were deposited directly on low carbon steel substrate without bonding coats. Scanning electron microscopy (SEM) was performed to study microstructural analysis and to quantify the porosity and cross-sectional coat thickness. Furthermore, the mechanical properties of both coating processes were defined in terms of bond strength and micro hardness. The results show that the liquid fuel sprayed coatings (HVOLF) produced higher adhesion strength coats (~ 73 MPa) compared to (~ 68 MPa) for HVOF. Similar results observed for micro-hardness of 1255 VHN and 1032 VHN, respectively. The surface roughness and porosity were less for HVOLF 4.32μm/0.85% compared to HVOF results of 5.26μm/1.29% porosity. This superior result in coats properties of HVOLF compared to HVOF was attributed due to less decarburization in HVOLF and hence less production of hard secondary phases of W2C

Dissimilar Welding and Joining of Magnesium Alloys: Principles and Application

The growing concerns regarding fuel consumption within the aerospace and transportation industries make the development of fuel-efficient systems a significant engineering challenge. Currently, materials are selected because of their abilities to satisfy engineering demands for good thermal conductivity, strength-to-weight ratio, and tensile strength. These properties make magnesium an excellent option for various industrial or biomedical applications, given that is the lightest structural metal available. The utilization of magnesium alloys, however, requires suitable welding and joining processes that minimizes microstructural changes while maintaining good joint/bond strength. Currently, magnesium are joined using; mechanical fastening, adhesive bonding, brazing, fusion welding processes or diffusion bonding process. Fusion welding is the conventional process used for joining similar metals. However, the application of any welding technique to join dissimilar metals presents additional difficulties, the principal one being; the reaction of the two metals at the joint interface can create intermetallic compounds that may have unfavorable properties and metallurgical disruptions which deteriorates the joint performance. This chapter investigates the welding and joining technologies that are currently used to join magnesium alloys with emphasis on the development of multi-material structures for applications in the biomedical industries. Multi-material structures often provide the most efficient design solution to engineering challenges

Linking climate variability and water associated diseases through Earth Observation in coastal areas of India

Climate-related extreme weather events impinge on human life and assets in various ways wherein their contributions to the transmission of water-associated diseases introduce additional hurdles on our efforts to control them. This article examines the impacts of extreme weather events on water-associated diseases using examples from the Kerala flood of 2018, and its impact on the microbial pollution in Vembanad lake and coastal regions of Kerala, using in-situ and remote sensing-based monitoring of water quality, models, and digital platforms. The article also discusses capacity building initiatives such as citizen science, awareness building, and training programmes for supporting efforts to control the outbreaks of epidemics during extreme weather condition

Manual for Operation of Mini Secchi Disc and the Mobile App TurbAqua Developed as Part of Revival Project

The Secchi disc measures transparency of water bodies in a fast, easy and precise way. The Secchi disc is a white disc that is lowered into the water and the depth at which this disc disappears from sight is logged as Secchi depth in the App. Transparency is the depth at which disc reappears, i.e., or how deep the sunlight can penetrate into a lake. The mini Secchi disc is basically a manually-operated tape measure with a white Secchi 10 cm disk and a brass weight of 100g attached to the tape end. The weight is manufactured using a metal lathe and the disc is made of white polypropylene sheet. The measuring tape is approximately 8m long wrapped around a 3D printed bobbin. For the easy handling of the device a polypropylene finger strap and nylon lanyard are attached to the casing. For prediction of colour of the water body, a vinyl-laminated Forel Ule colour scale sticker (with colour ranging from Indigo blue to Cola brown) is placed on the outside of the casing and the entire device is held together using stainless steel or brass fixings. In addition to this, an i-Button housed in a Thermochron water proof capsule ((DS9107) is attached to one of the weights, designed for measuring the water temperature

Citizen Science Tools Reveal Changes in Estuarine Water Quality Following Demolition of Buildings

Turbidity and water colour are two easily measurable properties used to monitor pollution. Here, we highlight the utility of a low-cost device—3D printed, hand-held Mini Secchi disk (3DMSD) with Forel-Ule (FU) colour scale sticker on its outer casing—in combination with a mobile phone application (‘TurbAqua’) that was provided to laymen for assessing the water quality of a shallow lake region after demolition of four high-rise buildings on the shores of the lake. The demolition of the buildings in January 2020 on the banks of a tropical estuary—Vembanad Lake (a Ramsar site) in southern India—for violation of Indian Coastal Regulation Zone norms created public uproar, owing to the consequences of subsequent air and water pollution. Measurements of Secchi depth and water colour using the 3DMSD along with measurements of other important water quality variables such as temperature, salinity, pH, and dissolved oxygen (DO) using portable instruments were taken for a duration of five weeks after the demolition to assess the changes in water quality. Paired t-test analyses of variations in water quality variables between the second week of demolition and consecutive weeks up to the fifth week showed that there were significant increases in pH, dissolved oxygen, and Secchi depth over time, i.e., the impact of demolition waste on the Vembanad Lake water quality was found to be relatively short-lived, with water clarity, colour, and DO returning to levels typical of that period of year within 4–5 weeks. With increasing duration after demolition, there was a general decrease in the FU colour index to 17 at most stations, but it did not drop to 15 or below, i.e., towards green or blue colour indicating clearer waters, during the sampling period. There was no significant change in salinity from the second week to the fifth week after demolition, suggesting little influence of other factors (e.g., precipitation or changes in tidal currents) on the inferred impact of demolition waste. Comparison with pre-demolition conditions in the previous year (2019) showed that the relative changes in DO, Secchi depth, and pH were very high in 2020, clearly depicting the impact of demolition waste on the water quality of the lake. Match-ups of the turbidity of the water column immediately before and after the demolition using Sentinel 2 data were in good agreement with the in situ data collected. Our study highlights the power of citizen science tools in monitoring lakes and managing water resources and articulates how these activities provide support to Sustainable Development Goal (SDG) targets on Health (Goal 3), Water quality (Goal 6), and Life under the water (Goal 14

Effect of Reduced Anthropogenic Activities on Water Quality in Lake Vembanad, India

The United Nation’s Sustainable Development Goal Life Below Water (SDG-14) aims to “conserve and sustainably use the oceans, seas, and marine resources for sustainable development”. Within SDG-14, targets 14.1 and 14.2 deal with marine pollution and the adverse impacts of human activities on aquatic systems. Here, we present a remote-sensing-based analysis of short-term changes in the Vembanad-Kol wetland system in the southwest of India. The region has experienced high levels of anthropogenic pressures, including from agriculture, industry, and tourism, leading to adverse ecological and socioeconomic impacts with consequences not only for achieving the targets set out in SDG-14, but also those related to water quality (SDG-6) and health (SDG-3). To move towards the sustainable management of coastal and aquatic ecosystems such as Lake Vembanad, it is important to understand how both natural and anthropogenic processes affect water quality. In 2020, a unique opportunity arose to study water quality in Lake Vembanad during a period when anthropogenic pressures were reduced due to a nationwide lockdown in response to the global pandemic caused by SARS-CoV-2 (25 March–31 May 2020). Using Sentinel-2 and Landsat-8 multi-spectral remote sensing and in situ observations to analyse changes in five different water quality indicators, we show that water quality improved in large areas of Lake Vembanad during the lockdown in 2020, especially in the more central and southern regions, as evidenced by a decrease in total suspended matter, turbidity, and the absorption by coloured dissolved organic matter, all leading to clearer waters as indicated by the Forel-Ule classification of water colour. Further analysis of longer term trends (2013–2020) showed that water quality has been improving over time in the more northern regions of Lake Vembanad independent of the lockdown. The improvement in water quality during the lockdown in April–May 2020 illustrates the importance of addressing anthropogenic activities for the sustainable management of coastal ecosystems and water resources

Lessons learned about the effect of reduced anthropogenic activities on water quality in a large lake system and opportunities towards sustainable management

Despite considerable efforts to protect vulnerable marine, coastal, and freshwater ecosystems, anthropogenic activities remain one of the main causes of poor water quality in rivers, lakes and wetland systems worldwide [1]. To move towards the sustainable management of coastal and aquatic ecosystems, it is important to understand how both natural and anthropogenic processes affect water quality. In 2020, a unique opportunity arose to study water quality in a large lake system in the southwest of India during a period when anthropogenic pressures were reduced due to a nationwide lockdown in response to the COVID-19 pandemic. Using remote sensing and in situ observations to analyse changes in five different water quality indicators, we showed that water quality improved in large areas of Lake Vembanad during the lockdown in 2020 [2]. The lessons learned illustrate that a coordinated response in reducing anthropogenic activities, as seen during the lockdown, could help achieve the targets set out in United Nation’s Sustainable Development Goals 3, 6 and 14 and significantly reduce aquatic pollution and improve water quality by 2030

Using Multi-Spectral Remote Sensing for Flood Mapping: A Case Study in Lake Vembanad, India

Water is an essential natural resource, but increasingly water also forms a threat to the human population, with floods being the most common natural disaster worldwide. Earth Observation has the potential for developing cost-effective methods to monitor risk, with free and open data available at the global scale. In this study, we present the application of remote sensing observations to map flooded areas, using the Vembanad-Kol-Wetland system in the southwest of India as a case study. In August 2018, this region experienced an extremely heavy monsoon season, which caused once-in-a-century floods that led to nearly 500 deaths and the displacement of over a million people. We review the use of existing algorithms to map flooded areas in the Lake Vembanad region using the spectral reflectances of the green, red and near-infrared bands from the MSI sensor on board Sentinel-2. Although the MSI sensor has no cloud-penetrating capability, we show that the Modified Normalised Difference Water Index and the Automated Water Extraction Index can be used to generate flood maps from multi-spectral visible remote sensing observations to complement commonly used SAR-based techniques to enhance temporal coverage (from 12 to 5 days). We also show that local knowledge of paddy cultivation practices can be used to map the manoeuvring of water levels and exclude inundated paddy fields to improve the accuracy of flood maps in the study region. The flood mapping addressed here has the potential to become part of a solution package based on multi-spectral visible remote sensing with capabilities to simultaneously monitor water quality and risk of human pathogens in the environment, providing additional important services during natural disasters

Environmental Reservoirs of Vibrio cholerae: Challenges and Opportunities for Ocean-Color Remote Sensing

The World Health Organization has estimated the burden of the on-going pandemic of cholera at 1.3 to 4 million cases per year worldwide in 2016, and a doubling of case-fatality-rate to 1.8% in 2016 from 0.8% in 2015. The disease cholera is caused by the bacterium Vibrio cholerae that can be found in environmental reservoirs, living either in free planktonic form or in association with host organisms, non-living particulate matter or in the sediment, and participating in various biogeochemical cycles. An increasing number of epidemiological studies are using land- and water-based remote-sensing observations for monitoring, surveillance, or risk mapping of Vibrio pathogens and cholera outbreaks. Although the Vibrio pathogens cannot be sensed directly by satellite sensors, remotely-sensed data can be used to infer their presence. Here, we review the use of ocean-color remote-sensing data, in conjunction with information on the ecology of the pathogen, to map its distribution and forecast risk of disease occurrence. Finally, we assess how satellite-based information on cholera may help support the Sustainable Development Goals and targets on Health (Goal 3), Water Quality (Goal 6), Climate (Goal 13), and Life Below Water (Goal 14)

Satisfaction of adult and pediatric neurologists and neurosurgeons using telehealth during the COVID-19 pandemic in Saudi Arabia: a cross-sectional study

ObjectivesTelehealth has become increasingly important in achieving universal health coverage. It offers doctors and their patients' convenience, including providing quality care at reduced costs. During the coronavirus disease (COVID)-19 pandemic, telehealth has been a vital tool for remote healthcare services. This study aimed to assess the satisfaction of adult and pediatric neurologists and neurosurgeons using telehealth, during the COVID-19 pandemic in Saudi Arabia.MethodsThis study had 348 participants. It was conducted among adult and pediatric neurologists and neurosurgeons using telehealth technology at their clinics between February and June 2021. The self-administered questionnaire included sociodemographic data, behavior in using telehealth, and an assessment of satisfaction with telehealth; the SPSS Windows software version 26 was used to analyze the data.ResultsThe most common age group was 25–34 years (42.8%), with men dominating (68.4%). The mean satisfaction score was 25.9 (SD 3.91) out of 33 points, with 90.2% of respondents satisfied with telehealth and 9.8% dissatisfied. Working in an academic center or private hospital, being a first-time telehealth user, using messages as a telehealth method, and using telehealth daily were associated with increased satisfaction with telehealth use.ConclusionThe satisfaction of adult and pediatric neurologists and neurosurgeons with telehealth was high. Although physicians still preferred face-to-face interviews, they recognized the benefits of telehealth in strengthening the patient–provider relationship, improving productivity, and integrating into daily workflows. The satisfaction levels align with past studies, but physical examination needs should be considered. Telehealth is suitable for follow-up visits and varies across subspecialties