Performance evaluation of Cu-Ni 90/10 alloyed structures exposed to various seawater compositions and their remaining service life estimation

The Cu-Ni 90/10 alloy is extensively used in seawater applications mainly because of its excellent heat transferability, resistance toward corrosion and marine fouling. The corrosion resistance of Cu-Ni 90/10 has been found to be far superior in open natural seawater, however, several premature failures have often been reported during their exposure in the pollutant-rich seawater typically found near harbours, jetties and coastlines. This paper investigates the corrosion behaviour of Cu-Ni 90/10 alloyed coupons exposed to natural seawater, and pollutant-rich harbour seawater in a submerged position. Moreover, this research also investigates the corrosion mechanism on marine heat exchanger tubes of material that failed prematurely while operating in similar seawater compositions. The field experimental results for short-term corrosion results from coupons, and the long-term corrosion results from heat exchanger tubes have been evaluated, to formulate a relationship and corrosion modelling

An epidemiological, strategic and response analysis of the COVID-19 pandemic in South Asia: A population-based observational study

Introduction: South Asia has had a dynamic response to the ongoing COVID-19 pandemic. The overall burden and response have remained comparable across highly-burdened countries within the South Asian Region. Methodology: Using a population-based observational design, all eight South Asian countries were analyzed using a step-wise approach. Data were obtained from government websites and publicly-available repositories for population dynamics and key variables. Results: South Asian countries have a younger average age of their population. Inequitable distribution of resources centered in urban metropolitan cities within South Asia is present. Certain densely populated regions in these countries have better testing and healthcare facilities that correlate with lower COVID-19 incidence per million populations. Trends of urban-rural disparities are unclear given the lack of clear reporting of the gaps within these regions. COVID-19 vaccination lag has become apparent in South Asian countries, with the expected time to complete the campaign being unfeasible as the COVID-19 pandemic progresses. Conclusion: With a redesigning of governance policies on preventing the rise of COVID-19 promptly, the relief on the healthcare system and healthcare workers will allow for adequate time to roll out vaccination campaigns with equitable distribution. Capacity expansion of public health within the Region is required to ensure a robust healthcare response to the ongoing pandemic and future infectious disease outbreak

Performance evaluation of Cu-Ni 90/10 alloyed structures exposed to various seawater compositions and their remaining service life estimation

The Cu-Ni 90/10 alloy is extensively used in seawater applications mainly because of its excellent heat transferability, resistance toward corrosion and marine fouling. The corrosion resistance of Cu-Ni 90/10 has been found to be far superior in open natural seawater, however, several premature failures have often been reported during their exposure in the pollutant-rich seawater typically found near harbours, jetties and coastlines. This paper investigates the corrosion behaviour of Cu-Ni 90/10 alloyed coupons exposed to natural seawater, and pollutant-rich harbour seawater in a submerged position. Moreover, this research also investigates the corrosion mechanism on marine heat exchanger tubes of material that failed prematurely while operating in similar seawater compositions. The field experimental results for short-term corrosion results from coupons, and the long-term corrosion results from heat exchanger tubes have been evaluated, to formulate a relationship and corrosion modelling

GEOFIZIČKA ISTRAŽIVANJA POTENCIJALNOGA KLIZIŠTA U PODRUČJU MAYOON, DISTRIKT HUNZA, GILGIT-BALTISTAN, PAKISTAN

The Mayoon landslide in the Hunza District is a slowly developed, non-catastrophic landslide that has gained its importance in the last few years after its rapid activation and fast slip rate. The area is characterized by high earthquake hazards (zone 3 with a peak ground acceleration value of 2.4–3.2 m/s2) by the Building Code of Pakistan due to frequent earth quakes. The past high earthquake activity in the area has displaced the foliated rocks towards the south and is responsible for opening the bedrock joints. The head and body of the landslide are covered by unconsolidated material and have fractures of varying lengths and widths. The non-invasive geophysical techniques, including Ground Penetrating Radar (GPR) and Electrical Resistivity Soundings (ERS), are deployed to evaluate the Mayoon landslide subsurface. The subsurface is interpreted into a two-layer model. Bright reflectors and highly variable resistivity characterize the top layer (Layer-1). This layer is associated with a loose, highly heterogeneous, fragmented material deposited under glacial settings over the existing bedrock. Hyperbolic reflections and intermediate resistivity characterize the bottom layer (Layer-2). This layer is associated with foliated metamorphic bedrock. The hyperbolic reflections show faults/fractures within the bedrock. The extension of these fractures/faults with depth is uncertain due to decay in the GPR signal with depth. The intermediate resistivity shows the bedrock is weathered and foliated. Reflections within Layer-1 have disrupted directly above the fractures/faults suggesting a possible movement. A bright reflection between the two layers highlights the presence of the debonded surface. Loose material within Layer-1 coupled with debonding possesses a significant hazard to generate a landslide under unfavourable conditions, such as an intense rainstorm or earthquake activity.Klizište Mayoon u distriktu Hunza pripada skupini sporo razvijajućih, nekatastrofičnih klizišta. Važnost mu je porasla u nekoliko zadnjih godina nakon što se klizanje znatno ubrzalo. Cijelo područje obilježeno je visokim potresnim rizikom (zona 3, s najvećim ubrzanjem tla 2,4 – 3,2 m/s2), a u skladu s pakistanskim propisima o gradnji. Snažni potresi u prošlosti pomaknuli su blokove metamorfnih stijena prema jugu i uzrokovali otvaranje brojnih pukotina u stijenama podine. Čelo i tijelo klizišta prekriveno je nekonsolidiranim materijalom te ima pukotine različitih širina i dužina. Prostor klizišta istražen je neinvazivnim geofizičkim tehnikama poput georadara i mjerenja električne otpornosti. Podzemlje je prikazano dvoslojnim modelom. Prvi sloj (1) predstavljen je snažnim reflektorom i vrlo promjenjivom otpornošću. Sastavljen je od rastresitih, vrlo heterogenih, fragmentiranih materijala taloženih tijekom glacijala preko stijenske podine. Ispod je drugi sloj (2) obilježen hiperboličkim refleksima te umjerenom otpornošću i pruža se unutar folijacijskih, metamorfnih stijena. Oblik refleksa upozorava na rasjede i pukotine podine, no oni se teško prate s povećanjem dubine. Otpornost također upućuje na trošenje i folijaciju. Refleksi u sloju 1 prekidaju se iznad rasjeda i pukotina upozoravajući na moguće gibanje. Snažni refleksi između dvaju slojeva naglašavaju postojanje granice između njih. Rastresiti materijal u sloju 1, zajedno s postojanjem takve granice, predstavlja znatan rizik nastanka klizišta, posebice u rizičnim uvjetima poput olujnoga pljuska ili potresa

Global variation of COVID-19 mortality rates in the initial phase

Objective: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused devastation in over 200 countries. Italy, Spain, and the United States (US) were most severely affected by the first wave of the pandemic. The reasons why some countries were more strongly affected than others remain unknown. We identified the most-affected and less-affected countries and states and explored environmental, host, and infrastructure risk factors that may explain differences in the SARS-CoV-2 mortality burden.Methods: We identified the top 10 countries/US states with the highest deaths per population until May 2020. For each of these 10 case countries/states, we identified 6 control countries/states with a similar population size and at least 3 times fewer deaths per population. We extracted data for 30 risk factors from publicly available, trusted sources. We compared case and control countries/states using the non-parametric Wilcoxon rank-sum test, and conducted a secondary cluster analysis to explore the relationship between the number of cases per population and the number of deaths per population using a scalable EM (expectation-maximization) clustering algorithm.Results: Statistically significant differences were found in 16 of 30 investigated risk factors, the most important of which were temperature, neonatal and under-5 mortality rates, the percentage of under-5 deaths due to acute respiratory infections (ARIs) and diarrhea, and tuberculosis incidence (p \u3c 0.05).Conclusion: Countries with a higher burden of baseline pediatric mortality rates, higher pediatric mortality from preventable diseases like diarrhea and ARI, and higher tuberculosis incidence had lower rates of coronavirus disease 2019-associated mortality, supporting the hygiene hypothesis

Post-operative pain management modalities employed in clinical trials for adult patients in LMIC; a systematic review

Background: Unrelieved postoperative pain afflicts millions each year in low and middle income countries (LMIC). Despite substantial advances in the study of pain, this area remains neglected. Current systematic review was designed to ascertain the types of clinical trials conducted in LMIC on postoperative pain management modalities over the last decade.Methods: A comprehensive search was performed in June 2019 on PubMed, Cochrane Library, CINAHL Plus, and Web of Science databases to identify relevant trials on the management of postoperative pain in LMIC. Out of 1450 RCTs, 108 studies were reviewed for quality evidence using structured form of critical appraisal skill program. Total of 51 clinical trials were included after applying inclusion/exclusion criteria.Results: Results are charted according to the type of surgery. Eleven trials on laparoscopic cholecystectomy used multimodal analgesia including some form of regional analgesia. Different analgesic modalities were studied in 4 trials on thoracotomy, but none used multimodal approach. In 11 trials on laparotomy, multimodal analgesia was employed along with the studied modalities. In 2 trials on hysterectomy, preemptive pregabalin or gabapentin were used for reduction in rescue analgesia. In 13 trials on breast surgical procedures and 10 on orthopaedic surgery, multimodal analgesia was used with some form of regional analgesia.Conclusion: We found that over the past 10 years, clinical trials for postoperative pain modalities have evolved in LMIC according to the current postoperative pain management guidelines i.e. multi-modal approach with some form of regional analgesia. The current review shows that clinical trials were conducted using multimodal analgesia including but not limited to some form of regional analgesia for postoperative pain in LMIC however this research snapshot (of only three countries) may not exactly reflect the clinical practices in all 47 countries. Post Operative Pain Management Modalities Employed in Clinical Trials for Adult Patients in LMIC; A Systematic Review

Advances and perspectives on solid oxide fuel cells : From nanotechnology to power electronics devices

Solid oxide fuel cells (SOFCs) hold an important place in energy conversion and storage systems due to their fuel flexibility, high efficiency, and environmental sustainability. The scorching temperature (≥800 °C) to operate SOFCs results in shorter life span due to rapid deterioration of accompanying components. Nanomaterials have attained considerable attention in recent years due to their great technological importance in fuel cell technology. Nanoengineering of the architectures of known materials and adopting composite approach can effectively enhance the active sites for electrode reactions. The use of nanotechnology will make SOFCs environment friendly and sustainable through green manufacturing processes of nanotechnology. Overviews of the contributions of nanotechnology and power electronics technologies to SOFCs, the transition of SOFCs from macro- to nanotechnology, the significance of nanomaterials in SOFCs, dynamic modeling, the function of optimization techniques, and the requirement for power electronics converters in SOFCs are all provided in this piece of work. The applications of SOFCs in different sectors, prominent institutes/labs and companies involved in SOFCs’ research, future challenges, and perspectives are also highlighted.© 2023 The Authors. Energy Technology published by Wiley-VCH GmbH. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.fi=vertaisarvioitu|en=peerReviewed

High Temperature Superconductors

One of the pioneers who introduced superconductivity of metal solids was Kamerlingh Onnes (1911). Researchers always struggled to make observations towards superconductivity at high temperatures for achieving goals of evaluating normal room temperature superconductors. The physical properties are based entirely on the behavior of conventional and metal superconductors as a result of high-temperature superconductors. Various synthetic approaches are employed to fabricate high-temperature superconductors, but solid-state thermochemical process which involves mixing, calcinating, and sintering is the easiest approach. Emerging novel high-temperature superconductors mainly engaged with technological applications such as power transmission, Bio-magnetism, and Tokamaks high magnetic field. Finally, in this chapter, we will discuss a brief outlook, future prospects, and finished with possible science fiction and some opportunities with high-temperature superconductors

Whether CEO Succession Via Hierarchical Jumps is Detrimental or Blessing in Disguise? Evidence from Chinese Listed Firms

This study investigates the impact of hierarchical jumps in the CEO’s succession on firms’ financial performance. To contemplate deeply, hierarchical jumps have been categorized into high and low level evaluating the positive impact of high-level hierarchical jump on firms’ performance. Moreover, this study has also formulated hierarchical intensity signifying the idea that despite neglecting senior board members during hierarchical jumps, still marginal increment in the firms’ growth has been observed. Using panel regression technique along with 2sls instrumental regression, this research reveals that hierarchical jumps in CEOs successions are more conducive only if the incumbent CEOs are selected irrespective of age, degree or high hierarchical position within the hierarchical ladder. Lastly, this study enunciates that firms having high total assets boost their performance via hierarchical jumps emphatically