Volume 25 - 2023

COVID-19 pandemic is a major worldwide health disaster firstly reported in December 2019. The Food and Drug Administration (FDA) has offered the public hope of halting it, authorizing vaccinations for emergency use with more than 85% efficacy against serious acute respiratory syndrome (SARS-CoV-2). Recent outbreaks of SARS-CoV-2 variations including spike-protein mutations, the key vaccines viral target for immune response, have prompted a thorough investigation into the vaccine's long-term effectiveness. Consequently, this review assayed the details on SARS-CoV-2 infection mechanism and how to control the infection by different types of SARS-CoV-2 vaccines, and their effectiveness against other mutant strains. Additionally, the review summarized the different complaints which have been recorded after vaccination. In conclusion, these negative effects must be constantly weighed against the predicted advantages in terms of disease prevention. Although COVID-19 vaccination is recommended for everyone aged 5 years and older, SARS-CoV-2 is high likely to continue to be a pandemic infectious as a result of the broadcasting of variants of the virus. Therefore, a booster vaccination, wearing a mask, and social distancing should be maintained.

The application of ceramic Nanofiltration (NF) membrane in brackish water treatment is increasing due to strict water quality standards. Ceramic NF is a widely used membrane process and has replaced reverse osmosis (RO) membranes in many applications due to lower energy consumption and higher flux rates. This work aims to study the separation performance of tubular ceramic TiO2 Nanofiltration membrane at low-pressure (2 bar) for single and tertiary salt mixture separation. The results showed that the rejection of ions is ordered as follows: R (Cl1-) ion size > R calcium (Ca2+) ion size > R sodium (Na1+) ion size > R magnesium (Mg2+) ion size. Moreover, the highest Cl1- rejection was about 46%, the highest Ca2+ and Mg2+ rejection was about 44%, and the highest Na1+ rejection was about 37%. The pure water flux through the investigated ceramic NF membrane for distilled water was calculated to be 5.29 x 10-7 m3 s-1 m-2 bar-1, and this flux was dropped down for the salt mixture feed to 2.56 x 10-7 m3 s-1 m-2 bar-1 due to the presence of salt particles in the feed.

Coastal erosion is the process of wearing away material from the coastal profile due to an imbalance in the supply and export of material from a particular section of the coast which cause property damage, and the loss of land. This study investigates the rate of erosion and accretion along the southern coast of Tamil Nadu which was exposed to a lot of tourism and development activities. The shorelines were delineated for the years 2000,2005,2010,2015 and 2020 on the high-resolution multi-temporal satellite images in the Google Earth Pro software by visual interpretation. The long-term and short-term changes were studied by three statistical parameters functionalized in DSAS v 5.0 tool in ArcGIS 10.6 software such as endpoint rate, net shoreline movement and linear regression rate (Cenci et al., 2018). The positions of the shoreline in 2030 and 2040 are forecasted using the Kalman filter-based forecast tool in DSAS and the changes were analysed. During the study period, the average rate of changes in Kanyakumari is -1.26 m/year, Tirunelveli is -1.01 m/year and Tuticorin is -1.09 m/year. the transects showed significant erosion along 19.54% of Kanyakumari, 3.79% of Tirunelveli, and 17.81% of Tuticorin coasts, and significant accretion is observed in 1.31% of Kanyakumari, 1.07% of Tirunelveli and 3.02% of Tuticorin coasts. The outcome of shows that erosion is prevailing on the Kanyakumari coast and erosion is prevailing in Tuticorin.

The wastes are in many forms consist of organic materials like human, medical, food, plastics, construction waste etc. many researchers are focused on the waste management to gives more importance to the environment. The bio degradable waste was used in this research with naturals fibers. The need for hybrid composites has increased in a variety of industrial applications. A unique and useful substance is created when two or more distinct components join in this kind of composite. Because of its exceptional characteristics, research is being done on the integration of particles bio waste and fiber into polymers. The like a strong weight-to-strength ratio, immunity to rust and temperature changes, and several custom qualities. This research focuses on the property description of Calotropis Gigantea and Bio waste ashes in form of epoxy matrix and in concrete as retrofitting composite. Calotropis Gigantea and Bio waste ashes are in composite form. field emission scanning electron microscope (FESEM) The characterisation is used to make sure that the polymer's structural shape and particle dispersion are correct. The mechanical, dynamic mechanical, thermal wear and concrete strength qualities are assessed. When particles are added, the qualities improve. By raising the weight of particle at certain percentage to the matrix and concrete mixture is for to increase the mechanical properties like tension, elongation, impact. To analyze the tribological behaviour, wear analysis is carried out. The results revealed that, the laminates reinforced with Calotropis Gigantea and Bio waste ashes show maximum strength. This is correlated with the increased interaction between the fiber-matrix, waste ash and homogeneous dispersion particle and also having greater strength compare to conventional concrete. The FESEM micrographs for tensile fracture surface also provided structural morphology. The findings will provide a vivid understanding for the use of composites in various structural retrofitting applications.