Pramila Rao · D. Sujatha · K. Rathina Raj · S. Vishwanatha · K. Narasimhamurthy · P. Saibaba · D. Narasimha Rao · S. Divakar

 Subchronic toxicity dietary studies were conducted in albino rats on the safety aspects of residual β-cyclodextrin in egg samples treated for cholesterol removal at concentrations of 250, 125 and 20 ppm for a period of 90 days. Daily food intake, body weight gain, relative organ weights, histopathology, haematology and serum enzyme activities were studied. The study however, did not reveal any toxicity at any of the levels tested. It can therefore be concluded from the present study that β-cyclodextrin-treated egg samples do not cause any toxicity. Received: 28 September 1999     

Weathering grade classification of lesser Himalayan granites,Western India

Lesser Himalayan granites show various stages of weathering. Primary cracks, grain boundaries and joints have initiated and controlled the weathering processes and resulted in the decomposition of the granites. Feldspars and mica act as key minerals for the initiation of weathering. Later stages of weathering are dominated by the varying nature of weathered clay.     

Thermal stability of CeO<Subscript>2</Subscript>/ZrO<Subscript>2</Subscript> multilayer thin films prepared by pulsed laser deposition

Multilayers of CeO₂/ZrO₂ thin films were deposited on Si (100) substrates using pulsed laser deposition at an optimized oxygen partial pressure of 3×10⁻² mbar and at room temperature. The CeO₂ layer thickness was 10 nm, while the ZrO₂ layer thickness was varied as 10, 20 and 30 nm. CeO₂ and ZrO₂ layers were deposited alternately to obtain 25 bilayers. High temperature x-ray diffraction (HTXRD) results showed that the multilayer films had cubic ceria and tetragonal ZrO₂. Thermal expansion coefficients were calculated for CeO₂ and t-ZrO₂ and found to increase with the decrease of ZrO₂ layer thickness. The cross sectional transmission electron microscopy (XTEM) of CeO₂/ZrO₂ multilayer also indicated that ceria was found to be in cubic phase while zirconia contained predominantly tetragonal phase along with cubic phase in thermally annealed specimen.     

Palladium‐nanoparticle intercalated vermiculite for selective hydrogenation of α,β‐unsaturated aldehydes

Palladium nanoparticles were generated in the interlamellar region of swelling 2:1 type vermiculite clay using an adsorption excess isotherm. An adsorption excess isotherm was constructed for vermiculite after exchanging the exchangeable Na⁺ ions in the interlamellar region using a binary liquid mixture (ethanol:toluene). Based on adsorption excess isotherm, 1% w/w palladium was intercalated into the interlamellar space of vermiculite. The Pd‐intercalated vermiculite was characterized by X‐ray diffraction, transmission electron microscopy and atomic absorption spectroscopy. The 1% w/w Pd‐intercalated vermiculite was tested for its catalytic activity towards selective hydrogenation reactions involving some α,β‐unsaturated carbonyl compounds using a pulse reactor and its catalytic activity was compared with commercial 1% Pd/C. The intercalated catalyst was found to be very selective towards the desired product of unsaturated alcohols. Copyright © 2007 Society of Chemical Industry     

Chemical composition and antifungal activity of essential oils from three Himalayan Erigeron species

Three Himalayan Erigeron (Asteraceae) species viz Erigeron mucronatus, Erigeron annuus and Erigeron karwinskianus growing in sub-alpine region revealed occurrence of isomeric polyacetylenic constituents viz., matricaria and lachnophyllum esters which accounted for 83.3%, 69.3% and 30.1% of the essential oils from these species, respectively, in addition to mono- and sesquiterpenoids as minor constituents. The antifungal activity tested by poisoned food (PF) techniques against Fusarium oxysporum, Helminthosporium maydis, Rhizoctonia solani, Alternaria solani and Sclerotinia sclerotiorum demonstrated significant inhibition of the mycelial growth of all strains (p < 0.05). The oils (500 μg/mL) showed significant antifungal effect against tested fungi in the growth inhibition range of 37.6–85.5% with respective IC₅₀ values ranging from 88.8 to 660.0 μg/mL as compared to standard fungicides (100% inhibition) with IC₅₀ value in the range of 32.2–129.4 μg/mL. Significant inhibition of spore germination was noticed for F. oxysporum, Curvularia lunata and Albugo candida which were highly susceptible to E. annuus oil with their IC₅₀ values 120.7, 253.5 and 300.4 μg/mL, respectively. Thus, the results obtained in this study demonstrate the potential of essential oils from Himalayan Erigeron species as non-toxic, eco-friendly and biodegradable natural fungicides.     

Effect of different starches on rheological and microstructural properties of (II) commercial processed cheese

A range of commercial processed cheese samples containing starch were prepared on a Rapid Visco Analyser (RVA) and on a pilot plant scale. This work clearly demonstrated that it was possible to manufacture processed cheese with part of the protein replaced with potato starch, while maintaining similar rheological attributes (firmness) to those of the control and an acceptable melt index. Sensory evaluation showed that, although the reduced‐protein cheese samples had a good, clean, fresh flavour that was comparable with that of the control, at high starch concentrations the starch‐containing processed cheese had a pasty texture and tended to stick to the wrapper.     

Studies of interfaces in Al65Cu20Fe15

The study of interfaces in quasicrystalline alloys is relatively new. Apart from the change in orientation, symmetry and chemistry which can occur across homophase and heterophase boundaries in crystalline materials, we have the additional, exciting possibility of an interface between quasicrystalline and its rational approximant. High resolution electron microscopy is a powerful technique to study the structural details of such interfaces. We report the results of a HREM study of the interface between the icosahedral phase and the related Al₁₃Fe₄ type monoclinic phase in melt spun and annealed Al₆₅Cu₂₀Fe₁₅ alloy.     

Dynamic Self‐Repair Architectures for Defective Through‐silicon Vias

Three‐dimensional integration technology results in area savings, platform power savings, and an increase in performance. Through‐silicon via (TSV) assembly and manufacturing processes can potentially introduce defects. This may result in increases in manufacturing and test costs and will cause a yield problem. To improve the yield, spare TSVs can be included to repair defective TSVs. This paper proposes a new built‐in self‐test feature to identify defective TSV channels. For defective TSVs, this paper also introduces dynamic self‐repair architectures using code‐based and hardware‐mapping based repair.     

Kinetics of Thiamin Degradation in Solutions under Ambient Storage Conditions

Thiamin is being incorporated into a variety of nutritionally enhanced beverages. Although thiamin degradation during thermal processing has been extensively studied, minimal data exist regarding its stability in solution during ambient storage. This study collected kinetic data for thiamin degradation in solutions as a function of pH, buffer type, and buffer concentration at 25 °C. Thiamin was incorporated into sodium phosphate and citrate buffer solutions, each prepared at 0.02 and 0.1 M and pH 4, 5, 6, and 7. Experimental solutions were stored in an incubator at 25 °C. Thiamin concentrations were analyzed at 9 time points over a 42‐wk period. Thiamin degradation data were modeled using pseudo‐1st‐order kinetics. Thiamin stability generally decreased as pH and buffer concentration increased in both phosphate and citrate buffers. In 0.1 M phosphate buffer, the time for a 10% loss of thiamin decreased from 79 wk at pH 4 to 3 wk at pH 7. At pH 6 and 7, thiamin stability was greater in citrate buffer than in phosphate buffer. However, at pH 4 and 5, thiamin stability was greater in phosphate buffer than citrate buffer. To optimize thiamin stability in low pH beverages, phosphate buffer would be more appropriate to use than citrate buffer, whereas citrate buffer should be used for better thiamin stability in high pH beverages.     

The effect of temperature on the surface tension and adsorption functions of the Fe-S-O melts – an analysis based on interaction parameters

The present investigation analyses the thermodynamic behaviour of the surfaces and adsorption as a function of temperature and composition in the Fe-S-O melts based on the Butler's equations. The calculated values of the surface tensions exhibit an elevation or depression depending on the type of the added solute at a concentration which coincides with that already present in the system. Generally, the desorption of the solutes as a function of temperature results in an initial increase followed by a decrease in the values of the surface tension. The observations are analyzed based on the surface interaction parameters which are derived in the present research.