Ni-Cr-Ti protective coating

Ni-Cr-Ti protective films were prepared by a plasma beam sputter deposition process at 250 °C. Ni-Cr-Ti thin films (50 nm) have been used to study the microstructure by transmission electron microscopy and the grain growth during heating in the heating stage of an electron microscope and after baking in an oxygen flow in an oven. Energy-dispersive spectroscopy analysis in the transmission electron microscope was used to study compositional variations in the films. Ni-Cr-Ti films 300 nm thick deposited on polished hot-worked tool steel (AISI H11) substrates have been studied by Auger electron spectroscopy and depth profiling before and after heat treatment in oxygen in an oven at temperatures from 600 to 800 °C. Basic microstructural, morphological, compositional and mechanical properties have been studied on Ni-Cr-Ti protective coatings 3 μm thick. Oxidation and electrochemical properties have also been studied.     

Threshold voltage degradation in plasma-damaged CMOS transistors — Role of electron and hole traps related to charging damage

The paper presents results of study of threshold voltage (V_T) degradation in CMOS transistors damaged by high-field charging. Fowler-Nordheim stress induced V_T degradation in devices with latent charging damage due to plasma processing was found to be strongly dependent on device type and diagnostic stress conditions. “Direct” and “reverse” antenna effect for NMOS, and anomalous behavior of PMOS devices are explained with polarity dependent trapping and the model includes generation of hole traps, an effect not considered previously.     

Diffusion of Cd And Zn In InP between 550 and 650°C

A large number of diffusions have been carried out in sealed quartz ampoules in the temperature range 550–650°C using Zn and Cd in InP. Three-fronted profiles were observed at 650°C for both Cd and Zn and the diffused samples were extensively analysed using Hall measurements, electron beam induced current, electrochemical carrier concentration profiling and thermal probing. These electrical measurements identified the p/n junction unambiguously and indicated a region of high compensation between the p/n junction and the third line. The weight of P added to the ampoule had little effect up to 0.4mg in 0.75cm³ volume at which point a dramatic reduction in diffusion depth for all fronts occurred for increasing P. Diffusion coefficients for Cd and Zn were estimated and plotted as a function of temperature.     

Ground-state properties of solid H2 at high pressures

A simple variational calculation, based on a Heitler-London wave function, is used to describe the high-pressure properties of solid hydrogen at O K. The system properties are expressed as a power series in , which is utilized to investigate the onset of classical behavior. The high-pressure results for the energy and the pressure-volume relation are in close agreement with a recent calculation which used the Domb-Salter approximation. Information is given on the pressure dependence of the two-body correlations in the solid.     

Passive cutaneous anaphylaxis in the domestic fowl

Histochemical demonstration of beta-glucuronidase was carried out in the normal and regenerating tail of the house lizard, Hemidactylus flaviviridis. Greater enzyme activity was particularly discernible in the stratum germinativum of the skin of the normal and fully regenerated tail. During regeneration most of the cellular elements of the blastema and the differentiating regenerate exhibited enzyme activity. Distribution of the enzyme beta-glucuronidase is correlated with the high degree of cellular proliferation. The role of the enzyme in the catabolism of mucopolysaccharides is also implicated during the wound-healing phase. In the full-grown regenerate the intensity and distribution of the enzyme activity were found to be the same as those observed in the normal tail.     

Concentration effect of photostabilizers on poly(1-butene) film

Effect of addition of various concentrations of stabilizers on poly (1-butene) [IPB] film has been studied, by measuring rate of protection and protective effectiveness through light scattering technique and UV spectral measurements. It has been observed that after a certain percentage of stabilizer addition there was not any further change.     

Selective area LPE growth and open tube diffusion in InGaAs/InP

Techniques are described in which selective chemical etching, localised LPE growth and localised diffusion in In_0.53Ga_0.47As and InP were carried out. Spun-on silica films were employed as masks in these processes and its performance was found to be comparable with pyrolytic or rf deposited films. Localised LPE growth of In_0.53Ga_0.47As and in-situ etching enabled well-controlled islands of In_0.53Ga_0.47As embedded in InP to be produced. Orientation dependent growth rates were also identified. An open-tube diffusion technique based on an LPE growth system has been successfully used for diffusion of Zn into InP and In_0.53 Ga_0.47As from Sn solutions. A strong variation of diffusion depth in InP with Zn concentration in Sn has been observed at low Zn concentrations but a constant depth is approached for Zn concentrations greater than ∼0.08 atomic fraction.     

An experimental study on solid-liquid flow through rectangular ducts

Reduction in energy consumption has been the main concern of the workers in the field of solid-liquid flow. Investigators have tried to achieve this objective in various ways. Two of the well-known methods are: the addition of polymer solutions to the solid-liquid mixture and the fitting of helical ribs inside regular circular pipes. In the latter case, the reduction is considerable, but it results in a very low rate of transportation. Chiu and Seman have reported considerable reduction of head loss in a square duct when compared to the flow through a circular pipe. In the present work, an experimental study has been underaken to compare the head loss for solid-liquid flow in a circular pipe, with that for rectangular ducts of four different aspects ratios (width/height ratios), keeping the cross-sectional area of each one of them to be the same. When the perforance of a circular pipe is compared with that of the other rectangular ducts, it seems that the square duct shows a better performance in the low operating range of velocity, whereas the rectangular duct of aspect ratio 1.5 presents a still better performance, from the energy requirement point of view, for practically the entire velocity-range within which the experiment was conducted.     

Monitoring forest fires over the Indian region using Defense Meteorological Satellite Program-Operational Linescan System nighttime satellite data

Monitoring and management of forest fires is very important in countries like India where 55% of the total forest cover is prone to fires annually. The present study aims at effective monitoring of forest fires over the Indian region using Defense Meteorological Satellite Program-Operational Linescan System (DMSP-OLS) nighttime satellite data and to evaluate the active fire detection capabilities of the sensor. Nightly DMSP-OLS fire products were generated from February to May 2005 (peak fire season) and analyzed to study the occurrence and behavior of fires over different forest physiognomies in Indian region. Fire products generated from DMSP-OLS were validated with ground observations of fire records from state forest departments to evaluate the accuracy of fire products. Further, inter-comparison of the DMSP-OLS derived fire products with contemporary fire products from Moderate resolution Imaging Spectroradiometer (MODIS) (both daytime and nighttime products) in addition to fires and burnt areas derived from Indian Remote sensing Satellite (IRS-P6) Advanced Wide Field Sensor (AWiFS) data has been done to analyze spatial agreement of fire locations given by the above sensors.Results from the DMSP-OLS fire products (derived from February to May 2005) over Indian region showed high forest fires in southern dry deciduous forests during February-March; central Indian dry and mixed deciduous forests during March-April; northeastern tropical forests during February-April and northern pine forests during May. Spatial pattern in fires showed a typical seasonal shift in fire activity from the southern dry deciduous forests to the northern pine forests and temperate forests as the fire season progressed. Statistical evaluation of DMSP-OLS fire products with ground observations showed an over all accuracy of 98%. Comparison of DMSP-OLS derived fires with consecutive MODIS and AWiFS derived fires for individual days indicated that 69% of the fires continued from current day (DMSP-OLS pass around ∼ 7 pm to ∼ 10 pm local time) to the next day (MODIS and AWiFS pass ∼ 10:30 am local time). Comparison of DMSP-OLS derived fires with burnt areas estimated from AWiFS showed that 98% of DMSP-OLS derived fires on the current day fell within the burnt area of AWiFS on subsequent day. Since the worst forest fires are those that extend from the current to the consecutive days, DMSP-OLS derived fires provide a valuable augmentation to the fires derived from other sensors operating in daytime.