Recent Developments in the Bioprocessing of Minerals

Microorganisms are finding increasing use in minerals engineering. Goals include both enhancement of mineral engineering operations and remediation of mineral industry wastes. Some of the applications, such as biologically assisted leaching of sulfide ores and biooxidation of refractory sulfide gold ores. are established commercial processes. Others, such as the use of organisms for the removal of heavy metal ions from dilute aqueous streams, are nearing commercial application. Other uses of microorganisms are potentially possible. These include use of microorganisms in leaching non-sulfide ores, the flocculation or flotation of minerals and remediation of toxic chemicals discharged from mineral engineering operations. Genetic engineering of microorganisms and adaptation of existing strains are important potential tools in many of these applications, as is also the identification of new, novel and useful organisms.     

LIPIDS AND FATTY ACIDS OF FIVE FRESHWATER FOOD FISHES OF INDIA

Five species of carp important in the diet of many of the people of India were examined for principal lipids and in particular for the highly unsaturated fatty acids with potential biomedical benefits. Muscle lipid was about 1% in four species but 2.5% in muscle of Labio bata. The livers however had lipid contents in the 5–10% range. The principle lipid classes were separated and the fatty acids were determined by open-tubular (capillary) gas-liquid chromatography; forty-seven fatty acids were quantified. Saturated fatty acids were approximately 40–50% of total fatty acids in muscle lipids and monoethylenic fatty acids were 24–39%. Functionally important fatty acids of triacylglycerols in the muscle of all species included about 5% each of 18:2n-6 and 18:3n-3. The longer chain lengths 20:4n-6, 20:5n-3, and especially 22:6n-3, were found mostly in the polar lipids     

Estimation of parameters of failure distributions with fuzzy data

In this paper a simple procedure of estimation of parameters of two widely used failure distributions (the normal and Weibull distributions) and a method of finding confidence intervals for the parameters is developed. The computational burden of estimation with fuzzy data as observed by Kruse and Meyer (1988) is easily overcome by using special properties of the estimators. It is also demonstrated that the order statistics procedure of estimation can easily be modified to tackle fuzzy data.     

Development of fault tree for reliability studies of a data-processing system

In this paper a systematic approach is developed for generating the fault-tree logic, which is the basic requirement in any reliability studies of large complex systems using Monte Carlo simulation or deterministic approaches. The entire network is decomposed into sub-networks, each sub-network involving several loops, and it becomes quite easy to determine failure logic for these loops and thus for the subnetworks. Failure of such subnetworks between the source and the sink node leads to a major system failure and therefore this successive development results in a fault tree for the whole network.These loops can be automatically generated.

The failure event for each node in such an approach can also be accounted for. The advantage of the present methodology is that the fault-tree logic is automatically developed, which can be directly used as a sub-programme on a computer for various reliability studies of the system.     

In vitro studies on the effect of linear alkyl benzene sulphonate on serum albumin

Linear alkyl benzene sulphonate was found to influence the thermal and fluorescence profile of serum albumin in vitro , indicating the possibility of protein-detergent interaction in the skin irritancy of detergents.     

Microstructural Evolution and Properties of a High Strength Steel with Different Direct Quenching Processes

A high strength low alloy steel with low carbon equivalent was selected for simulating online direct quenching and coiling(DQ-C)process.The influence of stop quenching temperature on mechanical properties and microstructures was studied and compared with normal direct quenching and tempering(DQ-T)process.The study confirmed that required mechanical properties were obtained for both the processes.Properties of the experimental steel with DQ-C process could reach the same level as that of DQ-T process in general.In the DQ-C process,strength decreased with increase in stop quenching temperature.Martensite was obtained and experienced an aging process at stop quenching temperature below Mf.On fast cooling below Ms,martensite was partially transformed and carbon partitioning occurred during slow cooling.The reduction in solid solution carbon and increased amount of retained austenite led to lower strength compared with the DQ-T process.DQ-C process was more favorable for microalloy carbide precipitation.However,impact toughness under different cooling conditions was adequate because of low carbon equivalent and refined microstructure.     

RESEARCH NOTE: MYCOTOXINS IN FENNEL SEED

Ten samples of fennel seed from fields in India were examined for the presence ofaflatoxins B₁, B₂, G₁ and G₂. Five of the samples were fluorescent or became fluorescent during a 12 month storage period. Only aflatoxins B₁, B₂ and G₁ were identified. One nonfluorescent sample contained detectable aflatoxin B₁ after 12 months of storage.