Machine Learning-Based Erosion Behavior of Silicon Carbide Reinforced Polymer Composites

Silicon - The machine learning methodology is gaining immense exposure as a potential methodology for solving and modelling the machining behaviour of advanced materials. The present paper deals...     

Tunable Hierarchical Metallic‐Glass Nanostructures

Synthesizing metallic nanostructures with control over morphology, surface chemistry, and length‐scale is important for a wide range of applications. Nanostructures having large surface area paired with suitable chemistry are particularly desirable in catalytic applications to facilitate the reaction kinetics. However, the techniques used for nanostructure synthesis are often lengthy, difficult, require expensive precursors/stabilizers, and limit the control over nanostructure morphology/chemistry. Here tuning metallic‐glass nanostructures to a wide range of morphologies, where the surface is enriched with catalytic noble metal, is reported. By combining thermoplastic nanofabrication together with electrochemical processing, hierarchical metallic nanostructures with large electrochemical surface area and high catalytic activity are synthesized. Due to the versatility in processing and independent control over multiple length‐scales, the approach may serve as a tool‐box for fabricating complex hierarchical nanostructures for wide ranging applications.     

A strategic approach for preparation of oxide nanomaterials

A microwave assisted solvothermal method is described for rapid preparation of nano-oxides. This method is based on exploiting differential dielectric constants to induce preferred heating and decomposition of the oxide precursors in the presence of suitable capping agents. This strategic approach has been used to prepare nanopowders of MgO, NiO, ZnO, Al₂O₃, Fe₂O₃ and ZrO₂. Under graduate Summer Research Fellow of the Indian Academy of Sciences from IIT Madras.     

A new high-stability synthetic phosphate ester

Neutral phosphate esters are used as fire-resistant basestocks in several applications including hydraulic systems, turbines, and compressors. They are also used as grease basestocks, and in hydrocarbon-based lubricants and synthetic fluids as antiwear additives. Development aspects of a new synthetic triaryl phosphate ester is presented in this paper. This product provides superior hydrolytic stability and lower volatility than existing commercial phosphate esters. Additionally, it has excellent oxidative stability and is fire resistant. The performance characteristics of the fluid suggest use of this phosphate ester as a high stability antiwear additive or lubricant basestock, and in any application where stability is of primary importance.     

Metallic Glass Nano-composite Thin Films for High-performance Functional Applications

Metallic glass nanocomposite thin films were synthesized for an immiscible Ag-Cu alloy system by magnetron sputtering. The structure of the films was unique, consisting of homogeneously dispersed nanocrystallites in an amorphous matrix. The size and volume fraction of the nanocrystallites increased with increasing film thickness resulting in increased elastic modulus and hardness. The high electrical conductivity of the nanocomposite films was examined by a valence-band study, which showed that exchange interaction between Ag and Cu in the nanocomposite structure resulted in enhanced charge carrier concentration. The inverse correlation between electrical conductivity and film thickness was explained by surface and interface scattering of electrons with increasing volume fraction of nanocrystallites. The small temperature dependence of conductivity was attributed to the distorted Fermi surface of the nanocomposite films resulting in a greater contribution from structure scattering, which is temperature-independent.     

Electrochemical behaviour of polyaniline in aromatic sulphonic acids

This report describes the synthesis and redox behaviour of polyaniline in aqueous solutions of benzene sulphonic acid and 4-toluene sulphonic acid. The characterization of the polymer was carried out by electronic spectra, FTIR studies and ¹HNMR in DMSO-d₆.     

Self-Orthogonality of q -Ary Images of qm -Ary Codes and Quantum Code Construction

A code over GF can be imaged or expanded into a code over GF using a basis for the extension field over the base field. The properties of such an image depend on the original code and the basis chosen for imaging. Problems relating the properties of a code and its image with respect to a basis have been of great interest in the field of coding theory. In this work, a generalized version of the problem of self-orthogonality of the q-ary image of a q^m-ary code has been considered. Given an inner product (more generally, a bi-additive form), necessary and sufficient conditions have been derived for a code over a field extension and an expansion basis so that an image of that code is self-orthogonal. The conditions require that the original code be self-orthogonal with respect to several related bi-additive forms whenever certain power sums of the dual basis elements do not vanish. Numerous interesting corollaries have been derived by specializing the general conditions. An interesting result for the canonical or regular inner product in fields of characteristic two is that only self-orthogonal codes result in self-orthogonal images. Another result is that image of a code is self-orthogonal for all bases if and only if trace of the code is self-orthogonal, except for the case of binary images of 4-ary codes. The conditions are particularly simple to state and apply for cyclic codes. To illustrate a possible application, new quantum error-correcting codes have been constructed with larger minimum distance than previously known.