Change analysis using IRS-P4 OCM data after the Orissa super cyclone

The Orissa super cyclone hit the eastern coast of India in October 1999 and resulted in drastic changes to land and coastal water areas. This Letter demonstrates the use of IRS-P4 Ocean Colour Monitor (OCM) data for mapping changes resulting from this cyclone. The results show pronounced change in the vegetation cover of Orissa province and also change in the chlorophyll and suspended matter concentrations of the ocean water. The eight spectral channel capability of OCM sensors enabled us to map land cover changes and changes in coastal water after the cyclone.     

Perovskite phase formation in sol-gel derived Pb(ZrxTi1−x)O3 thin films

Abstract

Thin films of lead zirconate titanate having the composition Pb_1.05(Zr_0.53Ti_0.47)O₃ were deposited by a solgel method on a set of crystalline and amorphous substrates. The thickness of the film was varied by controlling the sol concentration or by repeated coatings. Factors controlling phase formation in the films such as nature of the substrate material, film thickness, chemical composition of the film, heating rate and gaseous atmosphere during the heat treatment were studied. On glass substrates the pyrochlore phase was obtained in thin (0.4 um) films and the perovskite phase in thicker (>1.5 um) films. Crystalline substrates (except Si and stainless steel) yielded a perovskite phase in 0.6 um thick film. Low Zr/Ti ratio, rapid heating and introduction of nitrogen in the later stage of heat treatment also favoured the formation of the perovskite phase. It is shown that Pb deficiency in the film caused by diffusion of Pb into amorphous substrates or by other mechanisms is primarily responsible for inhibiting the pyrochlore to perovskite transformation. The initial crystallisation of the amorphous film into pyrochlore rather than a perovskite phase (as in powders) is proposed to be due to higher strain energy barrier which exists for the amorphous to perovskite transformation in the film.     

An overview of solid base heterogeneous catalysts for biodiesel production

The alcoholysis process requires high activity catalysts for biodiesel production. Heterogeneous catalysts have been proven to possess highly active nature and are environment-friendly. The present article emphasizes on various types of solid base catalysts that have been used in the recent past for the production of biodiesel by transesterification of oils. The parameters and conditions affecting the transesterification reaction and biodiesel yield have also been mentioned in the article. Heterogeneous catalysts have the capability to be recycled for many runs in the process without greatly abating the biodiesel yield. Also, such catalysts possess noncorrosive nature, thus making the biodiesel safe to be used in engine without any damage. The exploitation of waste materials as catalysts would reduce the overall production cost of biodiesel. Calcium-based catalysts in the reviewed literature have shown promising outcomes for the future use and would make the process economical for large-scale industrial applications.     

Processing and Properties of Nano-Hydroxyapatite(n-HAp)/Poly(Ethylene-Co-Acrylic Acid)(EAA) Composite Using a Phosphonic Acid Coupling Agent for Orthopedic Applications

A hydroxyapatite/poly(ethylene-co-acrylic acid) (HAp/EAA) nanocomposite has been synthesized by a solution-based method. p-Aminophenyl phosphonic acid has been used as a coupling agent in order to enhance the bonding between HAp and EAA, and hence to improve the mechanical properties of the composite. XRD study has indicated the development of compressive and tensile stresses in a nanocomposite due to thermal expansion mismatch between nano-hydroxyapatite (n-HAp) and EAA. Fourier-transform infrared spectrometry (FTIR) and thermal analysis have shown the presence of strong interfacial bonding between n-HAp and EAA. The surface roughness and the homogeneous dispersion of nanoparticles have been observed by field emission scanning electron microscopy (FESEM). A comparison of mechanical properties between phosphonic acid treated (cn-HAp/EAA) and untreated (un-HAp/EAA) nanocomposites has been made. The use of a phosphonic acid coupling agent promotes the uniform dispersion of n-HAp in the polymer matrix with a strong nanoparticle-polymer interfacial bonding, which provides a means of preparing a HAp/polymer nanocomposite for implant applications.     

Preliminary investigations on alkali leaching kinetics of red sediment ilmenite slag

The present paper deals with soda ash roasting of red sediment ilmenite (47.03% TiO₂) and leaching of obtained titanium rich slag with hydrochloric acid for preparation of synthetic rutile. The experimental conditions used for roasting are Na₂CO₃ to ilmenite ratio of 1: 1 at 1,223 K for 4 h. This soda ash slag product is subjected to hydrochloric acid leaching to remove the iron content. The optimum conditions for leaching achieved are 6M hydrochloric acid at 398 K for 2.5 h (10/1 liquid/solid mass ratio) at 100 rpm. Shrinking core model is found to be fit for the experimental results. The apparent activation energy is 37.9 kJ/mol. This process of soda ash roasting is one of the best processes for preparation of high purity synthetic rutile assaying about 97.21% TiO₂.     

Challenges of the Omicron (B.1.1.529) Variant and Its Lineages: A Global Perspective

The SARS-CoV-2 virus has shown increased ability to mutate over the past two years, especially in the regions of the spike protein and receptor binding sites. Omicron (B.1.1.529) is the fifth variant of concern (VOC) after the emergence of the Alpha, Beta, Gamma, and Delta VOCs of SARS-CoV-2. This new variant has now circulated in 128 countries and according to the Global Initiative on Sharing All Influenza Data (GISAID), these 128 countries have shared 650,657 Omicron genome sequences as of 26 January, 2022. In this article, we highlight the real challenges of Omicron and its different lineages.     

Two-Dimensional Analysis of Dam-Break Flow in Vertical Plane

This work presents numerical computations for the analysis of Dam-Break Flow using two-dimensional flow equations in a vertical plane. The numerical model uses the general approach of the simplified marker and cell method combined with the volume of fluid approach for the surface tracking. The time evolution of flow depth at the dam site and the evolution of the pressure distribution are investigated for both wet and dry bed conditions. The effect of the initially nonhydrostatic state on the long term surface profile and wave velocity are studied. These long term effects are found to be marginal in the case of wet-bed conditions, but are significant in dry-bed conditions. The dry-bed tip velocity immediately after the dam break, computed numerically, compares well with analytical results published previously. The time taken to obtain a constant flow depth at the dam site increases with decreasing initial depth ratio. The numerical result for this time elapse for dry-bed conditions is close to the experimentally obtained value.     

Regional Specialisation for Technological Innovation in R&D Laboratories: A Strategic Perspective

The present paper attempts to highlight the strategy of regional specialisation for technological innovation in R&D laboratories. The paper makes a proposition that regional specialisation should be recognised as a strategic initiative for technology development in R&D laboratories. The rationale for this strategic initiative has been substantiated with the help of illustrations from the cases of technology development efforts taken up in different laboratories in the country under the Council of Scientific and Industrial Research (CSIR), India. In this direction, CSIR and other centres of excellence have played a pioneering role in the development of various industrial clusters and artisan concentrations in different parts of the country. The implications of adoption or otherwise of this strategy initiative for technological innovation in R&D laboratories have been discussed.