Purification of cadmium by selective volatilization in vacuum in presence of oxide phase on its melt

Purification of cadmium in the presence of a thin (~0·001?mm) oxide layer on the surface of the molten metal was carried out using a simple system designed and fabricated locally. The analytical results revealed that the distillation through oxide layer gave better separation for Co, Ni, Cu, Zn, Ag, Sn, Hg and Tl, when compared to the distillation without oxide layer. This was attributed due to the impurity metal oxide phases formation on the surface of the molten metal. The influence of oxygen flow time on the distillation rate of cadmium was established. There was no excess oxygen (O) retained in the distillate after two consecutive vacuum distillations through oxide route. The experiments were conducted at the level of nearly 1·5?kg a batch to study the impurities behaviour due to upscaling. The detailed chemical analysis of 58 impurity elements in Cd in presence and absence of oxide layer was carried out by glow discharge mass spectrometry (GDMS).     

Characterization of Microstructures across the Heat-Affected Zone of the Modified 9Cr-1Mo Weld Joint to Understand Its Role in Promoting Type IV Cracking

In the postweld heat-treated (PWHT) fusion welded modified 9Cr-1Mo steel joint, a soft zone was identified at the outer edge of the heat-affected zone (HAZ) of the base metal adjacent to the deposited weld metal. Hardness and tensile tests were performed on the base metal subjected to soaking for 5 minutes at temperatures below Ac₁ to above Ac₃ and tempering at the PWHT condition. These tests indicated that the soft zone in the weld joint corresponds to the intercritical region of HAZ. Creep tests were conducted on the base metal and cross weld joint. At relatively lower stresses and higher test temperatures, the weld joint possessed lower creep rupture life than the base metal, and the difference in creep rupture life increased with the decrease in stress and increase in temperature. Preferential accumulation of creep deformation coupled with extensive creep cavitation in the intercritical region of HAZ led to the premature failure of the weld joint in the intercritical region of the HAZ, commonly known as type IV cracking. The microstructures across the HAZ of the weld joint have been characterized to understand the role of microstructure in promoting type IV cracking. Strength reduction in the intercritical HAZ of the joint resulted from the combined effects of coarsening of dislocation substructures and precipitates. Constrained deformation of the soft intercritical HAZ sandwich between relatively stronger constitutes of the joint induced creep cavitation in the soft zone resulting in premature failure.     

Electron-beam Irradiation Preserves the Quality of White Button Mushroom (Agaricus bisporus) Slices

ABSTRACT: The effect of electron-beam irradiation on microbial counts, color, texture, and enzyme activity of mushroom slices was evaluated at dose levels of 0.5, 1, 3.1, and 5.2-kGy. Irradiation levels above 0.5 kGy reduced total plate counts, yeast and mold, and psychrotrophic counts to below detectable levels and prevented micro-bial-induced browning. Firmness of all samples was similar during storage except for the 5.2-kGy sample. Color was preserved by irradiation as evidenced by the higher L values. Electron-beam irradiation at these levels did not affect the polyphenol oxidase activity. Irradiation at 1 kGy was most effective in extending shelf-life of mushroom slices.     

ACCEPTABILITY OF CURRY LEAF (MURRAYA KOENIGII) INCORPORATED PRODUCTS AND ATTITUDE TOWARD CONSUMPTION

This study explores the possibility of incorporating dried curry leaf powder (CLP) at 5 or 10% level to common dishes to increase the intake of greens as a source of micronutrients. Initially, a group of 83 women was surveyed for frequency of consumption of green leafy vegetables. The dried CLP was analyzed for protein (12.5%), fat (5.4%), total ash (9.7%), insoluble fiber (55.6%), soluble fiber (4.4%), iron (12.0 mg/100 g), phosphorus (373 mg/100 g) and calcium (2.04%) contents. Dried CLP was incorporated into chapati (unleavened Indian bread), seasoned potatoes and cooked rice as a part of spice mixture and acceptability of the products evaluated by 53 panel members who responded to the initial survey. The addition of CLP affected the color and appearance of the products. At the lower level (5%) of incorporation, the texture, odor and taste of chapati were not affected. The spice mixture with CLP was highly accepted by the panel members. The majority of respondents consumed green leafy vegetables only once, twice or three times a week, and 50% perceived the level of consumption to be inadequate. The respondents expressed willingness to use CLP‐incorporated products in their diet for health reasons.     

EFFECT OF REPLACEMENT OF SUGAR WITH SUCRALOSE AND MALTODEXTRIN ON RHEOLOGICAL CHARACTERISTICS OF WHEAT FLOUR DOUGH AND QUALITY OF SOFT DOUGH BISCUITS

ABSTRACT

The effect of replacement of 30% sugar with 0.05% sucralose and of different levels of maltodextrin (MD) on dough rheology and quality of biscuits was studied. The results showed that replacement of sugar with increasing amount of MD from 10 to 40% along with 0.05% sucralose influenced dough rheology. The farinograph water absorption increased up to 20% addition of MD and thereafter decreased. Objective evaluation of biscuits showed that the spread ratio of biscuits with 10% MD was 7.1, 20% MD was 7.8, 30% MD was 9.4 and 40% MD was 10.5, in comparison to control biscuits (9.9) with 30% sugar. The best overall quality score was reported for the control biscuits with 30% sugar, 69 out of the maximum score of 80, followed by 30% MD (65), 40% MD (60.5), 20% MD (54) and 10% MD (49.5). The results showed the possibility of replacing sugar in biscuit with sucralose and MD.

PRACTICAL APPLICATIONS

This article discusses the changes as a result of replacement of sugar with sucralose and maltodextrin (MD) in the rheological characteristics of wheat flour dough. The level of sucralose and MD required to replace sugar from control recipe in order to produce rheological characteristics of wheat flour dough comparable with that of the control has been highlighted in the article. This information will have a practical application in the production of sugar‐free soft dough biscuits.     

Modification of fatigue strain‐life equation for sheet metals considering anisotropy due to crystallographic texture

The fatigue behaviour of cold rolled and annealed sheet metals are influenced by the anisotropy of mechanical properties due to crystallographic texture. However, the existing fatigue strain‐life models are primarily meant for isotropic material behaviour. In the present work, the Coffin‐Manson equation for strain‐life is modified to include the effect of anisotropy using phenomenological plasticity models. It is observed that the variation of strain hardening exponent is critical to model the strain‐life behaviour. Variation of strain hardening exponent with orientation is modelled using existing anisotropic yield criteria. The prediction of fatigue life using the proposed model correlates well with the experimental results of Al6061‐T6 along different orientations. The proposed model can be used to predict the fatigue properties along any orientation from the fatigue data along one orientation and monotonic mechanical properties along longitudinal, transverse and diagonal directions.     

Swift heavy ion irradiation induced modification of structure and surface morphology of BiFeO3 thin film

BiFeO₃ (BFO) thin films of thickness about 800 nm deposited on Si (100) substrates by sol–gel spin coating method were irradiated by 200 MeV Ag ions. Modification of structure and surface morphology of the films under irradiation was studied using glancing incidence X-ray diffraction (GIXRD) and atomic force microscope (AFM). Fluence dependence of GIXRD peak intensity indicated formation of 10 nm diameter cylindrical amorphous columns in crystalline BFO due to 200 MeV Ag ion irradiation. AFM analysis indicated that the pristine film consists of agglomerated grains with diffuse grain boundary. Irradiation led to reduced agglomeration of the grains with the formation of sharper grain boundaries. The rms roughness (σ _rms) estimated from AFM analysis increased from 6·2 in pristine film to 12·7 nm when the film irradiated at a fluence of 1 × 10¹¹ ions cm ^???2 . Further irradiation led to decrease of σ _rms which finally saturated at a value of 7–8 nm at high ion fluences. The power spectral density analysis indicated that the evolution of surface morphology of the pristine film is governed by the combined effect of evaporation condensation and volume diffusion processes. Swift heavy ion irradiation seems to increase the dominance of volume diffusion in controlling surface morphology of the film at high ion fluences.     

Study of influence of notch root radius on fracture behaviour of extra deep drawn steel sheets

Fracture tests are carried out on extra deep drawn steel CT specimens containing notches with different values of notch root radius (ρ= 0.07–0.75 mm). Experimental findings clearly show a critical notch root radius (ρ_c) below which the fracture toughness remains independent of ρ and above which it varies linearly with ρ. The 3D finite element analysis shows that the location of maximum stress level causing crack initiation is in the vicinity of notch tip. The maximum stress level is independent of ρ; however, its location is shifted away from notch tip along unbroken ligament length with increase in ρ.