A study on environmental corrosion of gilded heritage structures of Royal Palace Patan, Nepal

This article presents the results of corrosion study carried out on 17th century gilded sample procured from the metallic golden window of Patan Royal Palace, Nepal. The characterization techniques employed in the study provide the detailed information about the environmental pollutants responsible for the corrosion and degradation of gilded window. The analytical results have revealed that the window has been made of pure copper sheet on which traditional mercury-amalgam gilding technique has been used. Particulate matters like elemental carbon, sulphur dioxide, chlorine and organic matter have been found to be the main factors responsible for the corrosion and degradation of gilded surface. The information obtained from the present study is expected to be the source of understanding and solution for the protection and conservation of the gilded heritage of Nepal

Synthesis of nanostructured thin films for resolution and diffraction/ camera length calibration of transmission electron microscopes

TEM is one of the highly sophisticated, sensitive and accurate tool for carrying out microstructural detailed investigations of the materials in terms of their crystallographic structure, lattice imaging, phase identification, variety of defects present, particle size and shape analysis etc. at the nano scale level. The accuracy and efficiency of electron microscope depends upon the magnification and resolution of the instrument. Evaporated films of gold, magnesium oxide, and thallium chloride make excellent calibrating substances since they have d (interplaner spacing) values accurately determined by x-ray diffraction.  In the present investigations, preliminary studies on thermally evaporated thin films of high purity tin and silver  deposited on KCl substrate and carbon coated Ni/Cu TEM grids under high vacuum conditions (of the order of 10-6 torr) have been undertaken. These films were characterized for particle shape, size, lattice imaging by using TEM and HRTEM (High Resolution Transmission Electron Microscope). Selected area electron diffraction pattern  The deposition process of nanoparticles was precisely monitored to get high quality, stable and with repeatable and uniform sized particles. The aim of the study is to optimise the synthesis parameters to deposit uniformly distributed nano size gold particles using thermal evaporation technique which will be further used as a standard sample for the calibration of camera length and resolution of  TEM

Investigations of structural, chemical and physical properties of natural lac and its reinforced composites

Natural lac resin is secreted by the small parasitic insect Kerria Lacca on various host trees in India. It has been conventionally used as filling, protective, adhesive, binder and insulating material. Cultivated by tribal people for various applications, the earliest popularly known reference to its use is found in the Mahabharata epic. Because of the imminent danger of environmental degradation, mankind is now veering towards a refreshing global awareness of the need to use, natural products because of their organic, non-toxic and biodegradable nature. This way, the present study is focused to understand the physical, structural and chemical properties of these natural lac and its applied form chapadi (a mixture of lac and sand), which has been used, for more than 500 years, as an adhesive and filling material by traditional Swordsmiths in Rajasthan (India). In addition, new lac-based composites reinforced with carbon nanotubes and carbon fibres have been synthesised and studied for their structural and physical properties. Surface morphology and elemental composition of as synthesized samples have been carried out by scanning electron microscope (SEM) and energy dispersive spectrometer (EDS). FTIR spectra have been recorded in order to identify the organic functional group. Samples of CNTs and carbon fibre reinforced with pure lac have been found to be better adhesives. The study aims to understand the nature of these reinforced composites as a new material that can be used for various applications in future

Effect of MJS Spinning Variables on Yarn Quality

Air-jet spinning variables play a significant role in determining MJS (Murata Jet Spinner) yarn structure and quality. This research work is an attempt to highlight the effect of a few imperative MJS spinning parameters on yarn quality characteristics. In order to investigate the effect of the MJS spinning speed, first-nozzle pressure and feed ratio on resultant yarn quality parameters, a Box-Behnken experimental design for three factors and three levels was adopted for research design and sample preparation. An analysis of variance (ANOVA) was performed to test the statistical significance of all effects

VOLUNTARY DISCLOSURE PRACTICES: AN EMPIRICAL ANALYSIS OF FINANCIAL AND NON- FINANCIAL INFORMATION

Investor sentiments have been affected adversely time to time by various corporate scams like Stock Market scam, the CRB Public Deposit Scam, Bofor scam, Urea scam, Ketan Parikh Scam, Satyam scam, UTI Scam and The Enron Fiasco, WorldCom, Adelphia and no end to these, in spite of a strong regulatory framework. Corporate governance has become considerable point of attention to curb these fraudulent practices, where corporate reporting practices play a vital role. This paper has attempted to examine the extent of disclosure of financial and non -financial information. The Study was based on firms listed on S&P CNX Nifty. The final sample consisted Annual Reports of 50 companies which were studied a period of five years, that is 2011-2016. The study concluded that most of the firms were having a practice of disclosing financial information, but non-financial information was disclosed by few firms. Key words - Corporate governance, disclosure, financial information and non-financial informatio

Surface modification of thermally evaporated CdTe thin films for sensing application of organic compounds

The study involves the growth of bulk cadmium telluride (CdTe) by using vertical directional solidification (VDS) technique. The as grown CdTe compound has been used as a source material to deposit thin films onto glass substrates at room temperature by thermal evaporation technique under high vacuum conditions of 10-5 mbar. The thickness of film has been measured around 310 nm. Characterization of bulk CdTe compound and its thin films have been done by using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), atomic force microscopy (AFM) and photoluminescence (PL) techniques. CdTe thin films have been then used for exposure to vapors of organic compounds such as acetone, formaldehyde, methanol, ethanol, benzene, toluene and chloroform in order to ascertain the use of these films for various sensors. The optical and micro structural properties of CdTe thin films have been studied using PL and AFM techniques so as to evaluate the sensing capabilities of CdTe thin film towards specific compounds which have been used for exposure

Microstructural characteristics and optical performance of nano-structured thin films of tin oxide

Transparent conducting tin oxide thin films (thickness ~140 nm) have been synthesized by using vacuum evaporation technique under the vacuum of the order of 10-6 mbar at room temperature. These films have been deposited onto glass and single crystals of KCl substrates and subsequently annealed at different temperatures for varying time periods in high purity oxygen (99.999%) atmosphere to obtain single phase of tin oxide. X-ray diffraction measurements have been carried out on the films deposited onto glass substrates to reveal the phase formation of tin oxide. Secondary ion mass spectrometer (SIMS) and selected area electron diffraction pattern (SAEDP) measurements identify the presence of Sn, SnO and SnO2 phases in the films. Detailed XRD measurements and microstructural features recorded employing SEM, HRTEM, AFM and SIMS have been interpreted in the light of emission bands of these films occurred at 442 nm and 452 nm. The effect of vacuum conditions and annealing on nucleation and growth mechanism of tin oxide thin films has been presented and discussed in detail

Investigation of vacuum evaporated SnTe thin films for their structural, electrical and thermoelectric properties

Remarkable enhancement in figure-of-merit (ZT) value of p-type Tin Telluride (SnTe) thin films is reported in the present investigations. Under high vacuum conditions, all thin films deposited on the glass substrate by using thermal evaporation technique. Thickness of the thin films were kept 55 and 33 nm. Morphological features and the elemental composition of the thin film were investigated using scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS) technique respectively. High-resolution transmission electron microscopy (HRTEM) with selected area electron diffraction (SAED) pattern was used to investigate the microstructure of these thin films. For the identification of crystalline features, phase, and nano-crystallites size in all the thin films, the X-ray diffraction (XRD) technique had played a dominant role. The analysis of the XRD data results in a single-phase cubic structure. Atomic force microscopy (AFM) analysis revealed the 2D and 3D view of variable size grains formed on the glass substrate. Four probes method was used to determine the electrical conductivity of these thin films. Electrical measurements revealed the semi-metallic nature of the SnTe thin films. The thermoelectric measurement analysis revealed that the ZT of the thin films was found to be increased as the thickness of the film enhanced. The maximum value of ZT similar to 1.0 was obtained at room temperature for the film of thickness 55 nm

Uncertainty Measurements in Chemically Synthesized Stable Uniform Sized Gold Nanoparticles for TEM/HRTEM Calibration

83-91The accuracy of an electron microscope depends on the magnification and resolution of the microscope. Hence in order to achieve high accuracy measurement results from the electron microscopic examination, a standard specimen is required to calibrate the transmission electron microscope (TEM). In the present work, gold nanoparticles of uniform size with narrow particle size distribution were synthesized with an aim to use them as reference material (RM) for TEM/high resolution TEM calibration and then release them in market as Bhartiya Nideshak Dravya (BND). As synthesized gold nanoparticles at 20 ± 2 °C temperature and 45± 5% relative humidityand the standard sample were characterized by using HRTEM, model: FEI-Tecnai F30 G2 STWIN at suitable magnification and areas. Both images exhibit spherical shaped nanoparticles with size varying in the range from (15.35-20.15 nm) and (5.10 -7.70 nm) respectively. Stability in particles size of the chemically synthesized gold nanoparticles was studied for a period of one year time span using UV-Visible spectrometer. TEM/HRTEM measurements were carried out in automated mode under similar experimental and environmental conditions at different magnifications to get accurate particle size. Overall uncertainty is estimated in small and big size particles as per standard GUM document guidelines

Effect of finisher draw frame variables on combed cotton yarn quality

This research work is an outcome of a practical problem experienced at a fi nisher draw frame machine in the spinning preparatory section. Older storage can-spring stiffness decreases due to fatigue loading over the years. Hence, combed sliver characteristics may vary during the storage, transportation and processing on a subsequent machine. The study aims to investigate the infl uence of the can-spring stiffness factor, sliver deposition rate and sliver coils position on the combed yarn coeffi cient of variation of mass, imperfections and hairiness. For research design, the three-factor three levels Box-Behnken experimental design was adopted. Moreover, the analysis of variance was performed to check the statistical signifi cance of all observed responses