On the analysis of the electrochemical spark machining process

The electrochemical spark machining (ECSM) process has been proved as a potential process for machining of low machinability high-strength electrically non-conducting materials, but the mechanism of material removal during the process, by and large, is not yet understood. In the present work, the electrochemical discharge is modelled as a phenomenon similar to that which occurs in arc discharge valves. This phenomenon is used to explain various experimental results, on the basis of circuit and arc discharge valve characteristics. The spark energy and the approximate order of hydrogen gas bubble diameter are computed by the proposed valve theory. Material removal rate is evaluated by modelling the problem as a 3-D unsteady state heat conduction problem. The problem is solved by the finite element method to compute the temperature distribution which is post-processed for estimating material removal per spark, overcut obtained in the machined cavity, and attainable maximum penetration depth. The conclusion drawn is that the application of valve theory to the ECSM process seems to be realistic. Estimated material removal rate, overcut and maximum penetration depth show a good agreement with experimental findings.     

Cuphea a rich source of medium chain triglycerides: Fatty acid composition and oil diversity in Cuphea procumbens

The phenological characteristics, oil content, and fatty acid composition of 34 selections of Cuphea procumbens have been studied. The mean seed yield per plant was 9.7 ± 0.43 g. Maximum seed yield (16.7 g) was noticed in NBC‐27, while the average number of fruits per plant was 124.9 ± 10.7. The oil content in the seeds ranged from 16.7—28.7%, maximum being in NBC‐34. The fatty acid composition revealed the presence of capric acid (C10:0) in all the selections of C. procumbens as the major constituent of the oil ranging from 87.7—94.6%. C. procumbens showed its novelty as an alternative source of capric acid and may be utilized as a renewable resource in the production of plasticizers and lubricants which wholly depend on petrochemical import. Researches are in progress in order to obtain tolerant cultivars against wild plant characteristics and some delayed seed shattering plants have been identified.     

Antioxidative activity of some vegetable peels determined in vitro by inducing liver lipid peroxidation

Vegetable peels are normally thrown away as kitchen wastes. In order to reveal their possible biological value, an in vitro investigation was performed on the antioxidative potential of some peel extracts such as Luffa cylindrica (Lc), Raphanus sativus (Rs), Daucus carota (Dc), Pisum sativum (Ps) and Trichosanthes dioica (Td) in ferrous sulphate (FeSO₄), hydrogen peroxide (H₂O₂) and carbon tetrachloride (CCl₄) induced lipid peroxidation (LPO) in liver, the major target organ of any drug. Effects were compared with that of a known antioxidant, butylated hydroxy anisole (BHA). A dose dependent inhibition was observed in all three, FeSO₄, H₂O₂ and CCl₄ induced hepatic LPO. However, with respect to one test peel (Rs), the two lower doses (125 and 250 μg/ml) were found to be ineffective. We suggest that the test peels have the potential to inhibit the lipid peroxidation and the observed differential antiperoxidative effects of the test peels could be the result of their poly phenol and flavonoid contents.     

Study of glasses/glass-ceramics in the SrO-ZnO-SiO2 system as high temperature sealant for SOFC applications

Glasses having composition (in wt.%) 51SrO-9ZnO-(40−x)SiO₂ (SZS), where x represents the additives like B₂O₃, Al₂O₃, V₂O₅, and Cr₂O₃, were prepared by melt-quench method and transformed into glass-ceramics by controlled crystallization based on differential thermal analysis (DTA) data. Glasses and glass-ceramics were characterized using dilatometry, X-ray diffraction (XRD), microhardness, and Raman spectroscopy. XRD revealed that glass-ceramics are composed of mainly Sr₂ZnSi₂O₇ and SrSiO₃ crystalline phases along with residual glassy phase. Raman spectroscopy showed that main constitutes of the glass network are the Q¹ and Q² silicate structural units. With the addition of B₂O₃ and other additives silicate glass network depolymerizes and concentration of Q¹ structural units increases at the expense of Q² units. Formation of phases during crystallization depends on the presence of different silicate structural units in the glass matrix. B₂O₃ goes into the glass network as triangular (BO₃) borate structural units and at higher concentration of B₂O₃, only a part of the B₂O₃ forms tetragonal (BO₄) structural units. Investigated glasses and glass-ceramics have thermal expansion coefficient (TEC) in the range of 105-120 × 10⁻⁷/°C which matches with TEC of other cell components. B₂O₃ containing SZS glasses show good adhesion/bonding with YSZ and Crofer 22 APU. Elemental line scans indicate that interdiffusion of Fe, Cr and Si across interface is responsible for good bonding with Crofer 22 APU and interdiffusion of Sr, Si, Y and Zr is responsible for good bonding with YSZ.     

Current status,enablersand barriers of implementing cellular manufacturing system in Indian industries

The cellular manufacturing (CM) has been proved as a well-known manufacturing strategy that helps to improve manufacturing efficiency and productivity by
utilizing the philosophy of group technology. Large number of papers has been published in the area of design issues of CM system. Unfortunately, the issues related to acceptability of CM in Indian industries are typically not examined rigorously as technical issues. This paper presents the results of a survey carried out to find the status, enabler and barrier of implementing CM system in Indian industries.     

Utilization of Food Processing By-products as Dietary,Functional, and Novel Fiber: A Review

Fast growing food processing industry in most countries across the world, generates huge quantity of by-products, including pomace, hull, husk, pods, peel, shells, seeds, stems, stalks, bran, washings, pulp refuse, press cakes, etc., which have less use and create considerable environmental pollution. With growing interest in health promoting functional foods, the demand of natural bioactives has increased and exploration for new sources is on the way. Many of the food processing industrial by-products are rich sources of dietary, functional, and novel fibers. These by-products can be directly (or after certain modifications for isolation or purification of fiber) used for the manufacture of various foods, i.e. bread, buns, cake, pasta, noodles, biscuit, ice creams, yogurts, cheese, beverages, milk shakes, instant breakfasts, ice tea, juices, sports drinks, wine, powdered drink, fermented milk products, meat products and meat analogues, synthetic meat, etc. A comprehensive literature survey has been carried on this topic to give an overview in the field dietary fiber from food by-products. In this article, the developments in the definition of fiber, fiber classification, potential sources of dietary fibers in food processing by-products, their uses, functional properties, caloric content, energy values and the labelling regulations have been discussed.     

Project network-oriented materials management policy for complex projects: a Fuzzy Set Theoretic approach

This work devises a materials management policy integrated with project network characteristics of complex projects. It proposes a relative quantitative measure, overall criticality (OC), for prioritisation of items based on penalty incurred due to their non-availability. In complex projects, practicing managers find it difficult to measure OC of items because of the subjective factors and intractable nature of penalties involved. However, using their experience, they can linguistically identify the antecedents and relate them to consequent OC. This work adopts Fuzzy Set Theory to capture managerial tacit knowledge which provides them enough flexibility to provide information in real form. Computed OC values can be used for items prioritisation and as shortage cost coefficient in inventory models. The revised materials management policy was applied to a shipbuilding project. OC values were analysed to justify the importance of incorporating project network characteristics and potential cost savings were calculated.     

Insecticidal action of Lantana camara against Callosobruchus chinensis (Coleoptera: Bruchidae)

Aerial parts of Lantana camara were investigated for their insecticidal, antiovipositional and antifeedant activity against Callosobruchus chinensis. Petroleum ether and methanol extracts of the plant showed 10–43% mortality at 1–5% concentrations. The extracts also showed complete feeding deterrent action at 5% concentrations. Loss of fecundity was also noticed in both the extracts at higher doses. The antiovipositional values were 30 mg/100 g for petroleum ether extract and 40 mg/100 g of seed for methanol extract.     

Production and Stability Studies of a Neurotoxin Produced by Clostridium sp. RKD

ABSTRACT: A neurotoxigenic Clostridium sp. (RKD) isolated from intestine of decaying fish produced a neurotoxin that was neutralized by botulinum antitoxin (A+B+E) when tested by mouse protection bioassay. An amplicon of expected size (approximately 700 bp) was generated with primers specific for BoNT/B. Toxin was maximally released in the culture supernatant in the late stationary phase and was dependent on media composition. Growth was optimal in trypticase peptone yeast-extract glucose (TPYG) medium in a pH range of 7.5 to 8.0 and at a temperature between 35°C to 40°C while toxin production was optimum at 37°C (3 to 4 × 10³ minimum lethal dose per milliliter) without any protease treatment. There was no correlation between growth and toxin production when cells were grown in media containing different concentrations of NaCl (0% to 5%). Toxin in the culture supernatant was more stable (50% reduction at 50°C in 90 min) than the partially purified fraction. Toxicity was destroyed gradually after increasing the number of freeze-thaw cycles and was almost completely inactivated after 5 cycles. It was completely inactivated by overnight treatment of 1 N NaOH while it retained 1.5% activity with a similar treatment with 1 N HCl.