The sudden surge in demand to use plastic products due to COVID-19 pandemic has increased plastic pollution. It has resulted into degradation of a broad range of habitats and ecosystems by destroying ...natural functions, water quality, and environmental sustainability. However, the government agencies, scientific communities, and the public, have started to give attention to this issue. So, in the present study, we used the correlation methods to check the relationship between COVID-19 affected population with the medical plastic waste (MPW) that has developed a conceptual model of the inter-linkages between the preventive measures of COVID-19 pandemic problems and the reduction challenges of plastic waste during and after pandemic scenarios. Emerging issues in the waste management during and after the COVID-19 are established by reviewing the literature, reports, policy briefs, and information from the website concerning COVID-19. Considering MPW management issues, we selected India as a case study to analyse the plastic waste footprint (PWF) due to COVID-19 pandemic. The correlation results showed COVID-19 affected population and MPW; COVID-19 affected population and PWF have a significant relationship (R2 = 0.60; Area under ROC curve 81.4%). It suggests an urgent need for plastic waste management initiatives. Moreover, substantial plastic products, human awareness, strict government regulations, and inclusive research can check plastic waste footprints in India and worldwide. Then discuss the specific pathways through which the immediate and long-term impacts operate and highlight the issues of hampering the sustainable development goals (SDGs) progress in India and beyond. Finally, call for coordinated assessment, support and appropriate short- and long-term mitigation and the policy measures of plastic waste problems during and after the COVID-19 pandemic.
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•Single-use plastics become a new challenge in waste management during the pandemic.•Bio-medical waste threats throughout India enormously.•Upsurges medical plastic waste for COVID-19 hampers the sustainable development goals.•Needs people awareness, strict government regulations, and inclusive research•Sustainable policy recommendation is needed for plastic waste management in India.
Covalent organic frameworks (COFs) are a rapidly developing class of materials that have been of immense research interest during the last 10 years. Numerous reviews have been devoted to summarizing ...the synthesis and applications of COFs. However, the underlying dynamic covalent chemistry (DCC), which is the foundation of COF synthesis, has never been systematically reviewed in this context. Dynamic covalent chemistry is the practice of using thermodynamic equilibriums to molecular assemblies. This Critical Review will cover the state-of-the-art use of DCC to both synthesize COFs and expand the applications of COFs. Five synthetic strategies for COF synthesis are rationalized, namely, modulation, mixed linker/linkage, substoichiometric reaction, framework isomerism, and linker exchange, which highlight the dynamic covalent chemistry to regulate the growth and to modify the properties of COFs. Furthermore, the challenges in these approaches and potential future perspectives in the field of COF chemistry are also provided.
The Global Burden of Disease data suggest that respiratory diseases contribute to high morbidity in India. However, the factors responsible for high morbidity are not quite clear. Therefore, the ...Seasonal Waves Of Respiratory Disorders (SWORD) study was planned to estimate the point prevalence due to respiratory diseases in Indian OPD services and its association with risk factors and change in seasons. In this point prevalence observational multicenter study conducted during 2017-18, participating physicians recorded information of consecutive patients in response to a questionnaire. The study was conducted on four predetermined days representing transition of Indian seasons i.e., February (winter), May (summer), August (monsoon), and November (autumn). The eligible number of patients from across 302 sites in India was 25,177. The mean age of study population was 46.1±18.1 years, 14102(56.0%) were males and 11075(44.0%) females. The common diagnoses were: asthma(29.8%), chronic obstructive pulmonary disease (COPD),15.6%, respiratory tract infections (RTIs),11.3%, and tuberculosis(8.7%). All these conditions showed significant seasonal trends (Asthma 31.4% autumn vs. 26.5% summer, COPD 21.1% winter vs. 8.1% summer, RTIs 13.3% winter vs. 4.3% summer, and tuberculosis 12.5% autumn vs. 4.1% summer, p<0.001 for each respectively). After adjustment for risk factors, asthma was significantly associated with exposure to molds (OR:1.12,CI:1.03-1.22), pet animals (OR:1.07,CI:1.01-1.14), recent-travel (OR:1.22,CI:1.13-1.32), and rain-wetting (OR:1.27,CI:1.15-1.40); and RTIs with rain-wetting (OR:1.53,CI:1.34-1.74), and recent-travel (OR:1.17,CI:1.05-1.30). The SWORD study showed wide seasonal variations in outpatient attendance of patients with common respiratory conditions. Novel risk-factors associated with respiratory diseases were also identified.
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Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
In the current study, a novel strategy using cyclic shifting of temperature was developed for simultaneous saccharification and fermentation (SSF) for bioethanol production from rice straw. The ...in-situ cellulase production, saccharification and fermentation was carried out using P. janthinellum and S. cerevisiae. Bioethanol titer of 14.98 g/l was obtained using base followed by acid pretreated rice straw by employing the cyclic shifting of temperature strategy "30 °C for 2 h to 40 °C for 2 h". The holding time was further tuned to increase the productivity and the tuned condition 30 °C(1.7 h) - 40 °C(2 h) improved the bioethanol titer to 15.9 g/l. Using this strategy, resulted 5.1-fold and 2.8-fold increment of bioethanol production compared to known approaches, SSF at mutual optimum temperature and prolong prehydrolysis followed by fermentation respectively. The application of cyclic shifting of temperature strategy can unleash a great potential in enhancing the yield and efficiency for a sustainable lignocellulosic bioethanol production.
The viscosity of magma plays a crucial role in the dynamics of the Earth: from the crystallization of a magma ocean during its initial stages to modern-day volcanic processes. However, the ...pressure-dependence behavior of viscosity at high pressure remains controversial. In this study, we report the results of first-principles molecular dynamics simulations of basaltic melt to show that the melt viscosity increases upon compression along each isotherm for the entire lower mantle after showing minima at ~6 GPa. However, elevated temperatures of the magma ocean translate to a narrow range of viscosity, i.e., 0.01-0.03 Pa.s. This low viscosity implies that the crystallization of the magma ocean could be complete within a few million years. These results also suggest that the crystallization of the magma ocean is likely to be fractional, thus supporting the hypothesis that present-day mantle heterogeneities could have been generated during the early crystallization of the primitive mantle.
Owing to the pervasiveness of hydroxyl groups in natural isolates, alcohol derivatives are alluring directing groups. Herein, an alcohol-derived sulfamate ester guides the light-initiated ...xanthylation of primary, secondary, or tertiary centers. This process enables formal directed deuteration, azidation, thiolation, and vinylation reactions.
Alcohol-anchored sulfamate esters guide the alkylation of tertiary and secondary aliphatic C(3)–H bonds. The transformation proceeds directly from N–H bonds with a catalytic oxidant, a contrast to ...prior methods which have required preoxidation of the reactive nitrogen center, or employed stoichiometric amounts of strong oxidants to obtain the sulfamyl radical. These sulfamyl radicals template otherwise rare 1,6-hydrogen-atom transfer (HAT) processes via seven-membered ring transition states to enable C(3)–H functionalization during Giese reactions.
•Design methodology of a cryogenic radial turbine is proposed.•Turbine design parameters are validated with available results.•For optimization and performance prediction, ANN and ANFIS models are ...developed.•Experimental analysis is performed for performance measurement.
As a major component of cryogenic turboexpander, the design and performance estimation of a radial inflow turbine determines the effectiveness of the system. To explore the performance, this paper focuses on to investigate the effect of mass flow rate and operating temperature on isentropic efficiency, temperature drop, enthalpy drop, pressure variation, and power output of a cryogenic turboexpander. Firstly, the mean-line design of a radial inflow turbine is conducted by considering different loss models. Sobol sensitivity analysis is performed to identify the major geometrical parameters which have a significant effect on the performance of the turbine. Based on the geometrical data sets, an ANN and ANFIS models are developed to predict the ranges in which maximum efficiency of the turbine is obtained with minimum losses. The designed turbine is validated with available data in the literature. Secondly, an experimental set-up with extended measuring points for data collection is developed to investigate the performance of a turboexpander at cryogenic temperature. A detailed experimental analysis is carried out to compare the temperature drop, isentropic efficiency, and power output of the turboexpander for mass flow rate in the range of 0.03–0.08 kg/s and the inlet temperature of 130, 140, and 150 K. It is noticed that the highest temperature drop is obtained for the inlet temperature of 150 K. Thirdly, based on the experimental data, an ANN and ANFIS model is developed to predict the optimal range in which the turboexpander have maximum isentropic efficiency and temperature drop. The results deduce some valuable experimental data and also accumulate the design methodology of radial inflow turbine for cryogenic applications.
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