Advanced Techniques for Surface Engineering of Industrial Materials

This paper deals with the various advanced surface modification techniques. It has been pointed out that each techniques has its own merits and demerits and a proper choice has to made depending upon the properties and quality expected from for specific applications

Self-Propagating High-Temperature Synthesis(SHS) of Advanced High Temperature Materials

Over the last few years, our research group at National Metallurgical Laboratory Jamshedpur had contributed significantly on the fabrication of various advanced high temperature materials monolithic and composites namely ZrB2, TiC, ZrB;-A1zO 3 and AlzO3-SiC by self-propagating hightemperature synthesis (SHS) technique. In this paper, the SHS processes developed at National Metallurgical Laboratory, Jamshedpur are reviewed Ultra fine ZrB2, TiC, TiC-Ni powder were prepared. New in-situ composites in the ZrBz-A1203, Alz03-SiC,., TiC-Ni were prepared by the SHS techniques.The studies were focused on the SHS processing, mechanism of phase formation, microstructure evaluation, sintering of SHS produced powder and their property eval-uation. A new combustion synthesis technique using a rapid heating self-propagating high temperature synthesis (RH-SHS) was made for the fabrication of in-situ AlzO3-SiCu, composite. Process for the in-situ preparation of 96% dense ZrBz-Al103 by the SHS was developed

Effect of Silver on the Sintering Characteristics of High T Ceramic Superconductors

A detailed investigation on the densification behaviour of Y-Ba-Cu-oxide (YBCO)-AgX and Bi-Pb-Sr-Ca-Cu-oxide (BPSCCO)-AgX composite powder synthesised by a chemical pyrophoric decomposition technique is made. It has been observed that Ag plays a significant role on the lowering of sintering temperatures and melting points of these superconductors. In YBCO-AgX, for 0< x<_0.6 the rate of densification increases and for 0.6<x<1.2 the rate of densification decreases. The densification behaviour is due to oxygen absorption at the interface of YBCO and Ag grains and a low temperature eutectic Ag,,OX formed which promotes liquid phase sintering. Studies on the sintering characteristics under inert atmosphere indicate increased densification with the silver addition. The removal of oxygen from Ag,OX to the inert sintering atmosphere enhances the densification rates . This is also confirmed from the weight loss of the pellets observed in the TG experiments. Sintering studies of BPSCCO-AgX composites show decrease of densification with the Ag content in the matrix. The degradation of superconducting properties is attributed to the change of chemical compositions of the composites. The evaporation loss of Bi, Pb, Sr and Cu during sintering is observed to be the cause of degradation. The evaporation losses are increased with x

High resolution ultra sound and color Doppler in evaluation of thyroid nodule with fine needle aspiration cytology correlation

Background: Thyroid gland is the first to develop in fetal life and is largest of all the endocrine glands. It is superficial in location which helps in its excellent visualization of normal anatomy and pathologic condition by high resolution real time grey scale sonography. The purpose of this study was to evaluate the usage of grey scale ultrasound and color Doppler with FNAC correlation for differentiation of benign and malignant thyroid nodule.Methods: This prospective study was carried out on sixteen patients who came to our department from period of 1 February to  31 march 2016.Grey scale ultrasound of neck  and Doppler followed by USG guided FNAC of thyroid swelling was done.Results: Out of 16 cases, 3 were malignant, 10 were benign, and 3 were indeterminate. One case was diagnosed as benign lesion on sono which came out to be malignant on pathology as follicular carcinoma. The cases were presented as hypoechoic lesion with regular margins with peripheral and internal vascularity. Due to well defined margins it was diagnosed as benign adenoma but turned out to be malignant on pathology as follicular carcinoma. Colloid goiter was most common presentation on ultrasound and it showed wide spectrum of appearance, majority being nodular with anechoic echotexture.Conclusions: High resolution grey scale ultra sound with color Doppler has emerged as initial modality of choice for evaluating the patient with thyroid enlargement

Nanostructured Materials Research at NML

NML is coordinating the CSIR Network Project on 'Nanostructured Advanced Materials'. Eight other participating CSIR labs are AMPRE, Bhopal; CEERI, Pilani; CGCRI, Kolkata; CMERI, Durgapur; IMMT, Bhubaneswar; NAL, Bangalore; NCL, Pune; NPL, New Delhi.The project has been divided into four modules: (i) Biomaterials and Processes (ii) Ceramics, Composite and Hard coatings (iii) Magnetic Materials and (iv) Structural Materials. The major emphasis on the project has been given on the development of newer process, product and devices

Failure analysis of counter shafts of a centrifugal pump

An analysis of the premature failure of two counter shafts used in centrifugal pumps for lifting slurry has been carried out. Chemical analysis, microstructural characterisation, fractography, hardness measurement, tensile and Charpy impact tests were used for the analysis. The chemical compositions for the shafts were as per recommendation. The microstructure of one of the shafts was ferritic–pearlitic and its mechanical properties were inferior to the recommended values. For the other shaft the microstructure was tempered bainite; although the impact energy satisfied the specification, the other properties (hardness, UTS) were inferior. It was concluded that the improper heat treatment was the prime cause for the premature failure of the shafts

Electrochemical and mechanical behavior of laser processed Ti–6Al–4V surface in Ringer’s physiological solution

Laser surface modification of Ti–6Al–4V with an existing calcium phosphate coating has been conducted to enhance the surface properties. The electrochemical and mechanical behaviors of calcium phosphate deposited on a Ti–6Al–4V surface and remelted using a Nd:YAG laser at varying laser power densities (25–50 W/mm 2 ) have been studied and the results are presented. The electrochemical properties of the modified surfaces in Ringer’s physiolog- ical solution were evaluated by employing both potentio- dynamic polarization and electrochemical impedance spectroscopy (EIS) methods. The potentiodynamic polar- izations showed an increase in the passive current density of Ti–6Al–4V after laser modification at power densities up to 35 W/mm 2 , after which it exhibited a decrease. A reduction in the passive current density (by more than an order) was observed with an increase in the laser power density from 25 to 50 W/mm 2 . EIS studies at the open circuit potential (OCP) and in the passive region at 1.19 V showed that the polarization resistance increased from 8.274 9 10 3 to 4.38 9 10 5 X cm 2 with increasing laser power densities. However, the magnitudes remain lower than that of the untreated Ti–6Al–4V at OCP. The average hardness and modulus of the laser treated Ti–6Al–4V, evaluated by the nanoindentation method, were deter- mined to be 5.4–6.5 GPa (with scatter \±0.976 GPa) and 124–155 GPa (with scatter \±13 GPa) respectively. The corresponding hardness and modulus of untreated Ti–6Al–4V were *4.1 (±0.62) and *148 (±7) GPa respec- tively. Laser processing at power densities [35 W/mm 2 enhanced the surface properties (as passive current density is reduced) so that the materials may be suitable for the bio-medical applications

Dynamics of Hot QCD Matter -- Current Status and Developments

The discovery and characterization of hot and dense QCD matter, known as Quark Gluon Plasma (QGP), remains the most international collaborative effort and synergy between theorists and experimentalists in modern nuclear physics to date. The experimentalists around the world not only collect an unprecedented amount of data in heavy-ion collisions, at Relativistic Heavy Ion Collider (RHIC), at Brookhaven National Laboratory (BNL) in New York, USA, and the Large Hadron Collider (LHC), at CERN in Geneva, Switzerland but also analyze these data to unravel the mystery of this new phase of matter that filled a few microseconds old universe, just after the Big Bang. In the meantime, advancements in theoretical works and computing capability extend our wisdom about the hot-dense QCD matter and its dynamics through mathematical equations. The exchange of ideas between experimentalists and theoreticians is crucial for the progress of our knowledge. The motivation of this first conference named "HOT QCD Matter 2022" is to bring the community together to have a discourse on this topic. In this article, there are 36 sections discussing various topics in the field of relativistic heavy-ion collisions and related phenomena that cover a snapshot of the current experimental observations and theoretical progress. This article begins with the theoretical overview of relativistic spin-hydrodynamics in the presence of the external magnetic field, followed by the Lattice QCD results on heavy quarks in QGP, and finally, it ends with an overview of experiment results.Comment: Compilation of the contributions (148 pages) as presented in the `Hot QCD Matter 2022 conference', held from May 12 to 14, 2022, jointly organized by IIT Goa & Goa University, Goa, Indi