Optical Properties of Wide Band Gap Indium Sulphide Thin Films Obtained by Physical Vapor Deposition

Thin films of indium sulphide containing oxygen have been synthesized following a dry physical process. The constituents are deposited by thermal evaporation on glass substrates and then annealed under argon flow. Polycrystalline β-In2S3 containing oxygen thin films are obtained as soon as the temperature of annealing is between 623 and 723 K. In this paper, these β-In2S3 thin films have optically been studied. The optical band gap is direct. Its value is not dependent on the temperature of annealing. It is about 2.8 eV, which is higher than that of β-In2S3 single crystal. This high value is related to the presence of oxygen in the films. The extinction coefficient k and the refractive index n of the films have also been found independent of the annealing temperature. These optical properties make the films studied good candidates to be substituted to CdS in Cu(In,Ga)Se2 based solar cells

Stumbling Blocks of Online Learning During COVID 19 Pandemic – Perspectives of Students of Selected Universities in London

COVID 19 Pandemic has led to mayhem across the Planet. Educational institutions are the worst affected arena. There is a paradigm shift from conventional classroom teaching to online methods. But it has its own obstructions. Thus, this research is undertaken to study the impediments of online learning faced by the students of selected universities of London. The questionnaire was administered among 200 students out of which 196 responded. The results of the Study reveal that the major obstructions which hindered online learning were lack of computer skills, internet connectivity issues, difficulty in operating the software, absence of social bonding between teachers and students, difficulty in recording lectures, difficulty in grasping practical courses such as mathematics, finance, accounting, engineering etc. To cope up with the Stumbling Blocks, the Study advocates some of the most innovative and creative ways such as application of Bloom’s Digital Taxonomy, VARK Model, 5/5/5 rule etc

Along-Path Evolution of Biogeochemical and Carbonate System Properties in the Intermediate Water of the Western Mediterranean

A basin-scale oceanographic cruise (OCEANCERTAIN2015) was carried out in the Western Mediterranean (WMED) in summer 2015 to study the evolution of hydrological and biogeochemical properties of the most ubiquitous water mass of the Mediterranean Sea, the Intermediate Water (IW). IW is a relatively warm water mass, formed in the Eastern Mediterranean (EMED) and identified by a salinity maximum all over the basin. While it flows westward, toward and across the WMED, it gradually loses its characteristics. This study describes the along-path changes of thermohaline and biogeochemical properties of the IW in the WMED, trying to discriminate changes induced by mixing and changes induced by interior biogeochemical processes. In the first part of the path (from the Sicily Channel to the Tyrrhenian Sea), respiration in the IW interior was found to have a dominant role in determining its biogeochemical evolution. Afterward, when IW crosses regions of enhanced vertical dynamics (Ligurian Sea, Gulf of Lion and Catalan Sea), mixing with surrounding water masses becomes the primary process. In the final part of the investigated IW path (the Menorca-Mallorca region), the role of respiration is further masked by the effects of a complex circulation of IW, indicating that short-term sub-regional hydrological processes are important to define IW characteristics in the westernmost part of the investigated area. A pronounced along-path acidification was detected in IW, mainly due to remineralization of organic matter. This induced a shift of the carbonate equilibrium toward more acidic species and makes this water mass increasingly less adequate for an optimal growth of calcifying organisms. The carbonate buffering capacity also decreases as IW flows through the WMED, making it more exposed to the adverse effects of a decreasing pH. The present analysis indicates that IW evolution in the sub-basins of the WMED is currently driven by complex hydrological and biogeochemical processes, which could be differently impacted by coming climate changes, in particular considering expected increases of extreme meteorological events, mainly due to the warming of the Mediterranean basin

Synthesis, characterization, and photocatalytic efficiency of a new smart PdO oxide nanomaterials for using in the recycling and sustainable wastewater treatment

Nanostructured PdO materials with promising catalytic properties were successfully synthesized by the controlled thermal decomposition in air of three Pd(II) complexes containing Pd(II) ion, ofloxacin drug and amino acid. The Pd(II) complexes which were used as precursors were [Pd(OFL)(Gly)]Cl, [Pd(OFL)(Ala)]Cl, and [Pd(OFL)2]Cl2, where Gly is glycine amino acid, Ala is alanine amino acid, and OFL is ofloxacin. Structural and morphological properties of the synthesized PdO materials were obtained using FTIR, XRD, SEM, and EDX techniques. The XRD results confirm the tetragonal structure of PdO. The obtained PdO materials were tested as a catalyst for the heterogeneous degradation of H2O2 solution. The results revealed that PdO could effectively degrade H2O2.                     KEY WORDS: PdO, Nanoparticles, Photocatalytic efficiency, Wastewater treatment   Bull. Chem. Soc. Ethiop. 2021, 35(1), 107-118. DOI: https://dx.doi.org/10.4314/bcse.v35i1.

Reduced basis isogeometric mortar approximations for eigenvalue problems in vibroacoustics

We simulate the vibration of a violin bridge in a multi-query context using reduced basis techniques. The mathematical model is based on an eigenvalue problem for the orthotropic linear elasticity equation. In addition to the nine material parameters, a geometrical thickness parameter is considered. This parameter enters as a 10th material parameter into the system by a mapping onto a parameter independent reference domain. The detailed simulation is carried out by isogeometric mortar methods. Weakly coupled patch-wise tensorial structured isogeometric elements are of special interest for complex geometries with piecewise smooth but curvilinear boundaries. To obtain locality in the detailed system, we use the saddle point approach and do not apply static condensation techniques. However within the reduced basis context, it is natural to eliminate the Lagrange multiplier and formulate a reduced eigenvalue problem for a symmetric positive definite matrix. The selection of the snapshots is controlled by a multi-query greedy strategy taking into account an error indicator allowing for multiple eigenvalues

MALDI TOF MS and currently related proteomic technologies in reconciling bacterial systematics

The chapter is on development and application of matrix assisted laser desorption ionisation time of flight mass spectrometry (MALDI-TOF) to identification and and classification of bacteria