A study of partial discharge characteristics in oil impregnated pressboard insulation

An attempt has been made to study the effect of time and test procedure on the behaviour of partial discharge (PD) pulses causing failure of oil-pressboard system under power frequency voltages using circular disc shaped samples and uniform field electrodes. Weibull statistics have been used to handle the large amount of PD data. The PD phenomena has been found to be stress and time dependent. On the basis of stress level, three different regions are identified and in one of the regions, the rate of deterioration of the sample is at a maximum. The work presents some interesting features of Weibull parameters as related to the condition of insulation studied in addition to its usual PD characteristics

Effect of Interfacial Microstructure of Adsorbed Poly(ethylene glycol) Monooleate on Steel Substrate on Sliding Friction in Oil in Water Emulsion

The concentration of a nonionic surfactant and water pH were varied in an oil-in-water emulsion to minimize the friction coefficient between a steel ball sliding on a steel flat. At a surfactant concentration near the CMC (critical micelle concentration) the oil droplet size was found to be minimum. In this paper we study the microstructure of the surfactant molecules self-assembled on the steel substrate in water to comment on the ability of the surfactant aggregate to attract and retain oil. We find that a near semicylindrical hemimiceller microstructure with hydrocarbon tails projecting into bulk water as obtained at CMC in near neutral water is best able to capture and retain oil in yielding a low coefficient of friction.

A Research on New Method of Transportation Technics for Heavy Oil and Practice in Oil Field

介绍一种可应用于高粘度稠油管输的新工艺。即用自行研制的蒸汽引射器采用无界引射方式,将蒸汽直接注入到输油管道中,利用蒸汽释放的热量提高稠油温度降低粘度,从而达到降低稠油输送压降的目的,它比间接加热输送工艺所用的蒸汽量或耗煤量大大减少。方法在辽河油田输油管线上进行了工业现场试验,取得了很好的效果。

A coupled model for multiphase fluid flow and sedimentation deformation in oil reservoir and its numerical simulation

A mathematical model for coupled multiphase fluid flow and sedimentation deformation is developed based on fluid-solid interaction mechanism. A finite difference-finite element numerical approach is presented. The results of an example show that the fluid-solid coupled effect has great influence on multiphase fluid flow and reservoir recovery performances, and the coupled model has practical significance for oilfield development.

Effect of aureomycin on the behaviour of certain free amino acids in oil sardine (Sardinella longiceps) held in ice storage

The course of development of a few free amino acids under the influence of aureomycin in oil sardine (Sardinella lingiceps) held in ice storage was investigated. The levels of leucines and valine regularly increased in the control and aureomycin treated fush throughout the storage period. Alanines and threonine showed similar trend in both control and fish treated with 20ppm aureomycin. These amino acids however showed a gradual fall in fish treated at 5 ppm level. The changes in tyrosine+tryptophane were found to be irregular. Most of the amino acids studied indicated a remarkable change in trend by about the 16th day of ice storage in the case of fish treated with 50ppm aureimycin.

On the canning of Sardinella fimbriata Sardinella gibbosa and Sardinella sirm in oil pack

This note gives details of experiments conducted on the canning of certain species of sardines viz. Sardinella fimbriata, Sardinella gibbosa and Sardinella sirm which are landed in commercial quantities in the East Coast of Madras State and which have not so far been tried for canning. The experiments conclusively prove that these species of sardines can also be canned in oil pack and good canned products manufactured out of them.

Preliminary observations on changes in nucleotides in oil sardine and certain Penaeid prawns during chill storage

Preliminary study has been made of the changes in common 5' nucleotides in oil sardine (Sardinella longiceps) and two Penaeid prawns of Indian waters during chill storage. The course of nucleotide degradation has been followed in the fresh fish and shell fish during ice storage. The level of inosine monophosphate (IMP) in prawns showed significant but steady decrease during ice storage and this appears to serve as useful indication of length of storage. Comparison has been made on the pattern of nucleotide changes in block frozen fish and individually quick frozen fish stored at -23°C.

Lipid breakdown in oil sardine (Sardinella longiceps) during frozen storage

The problem of hydrolysis of lipids and consequent accumulation of free fatty acids and development of rancidity due to oxidation of the lipids are major problems in frozen storage of oil sardine (Sardinella longiceps). The course of the phospholipid breakdown, production of free fatty acids and the changes taking place in the major unsaturated fatty acids during frozen storage are described in this paper. The rate of free fatty acid production is faster in the fish, with the higher fat content. Unlike in lean fish, the neutral lipids are found to contribute substantially to the free fatty acid production. The fatty acids most affected during storage are C sub(20:5) and C sub(22:6). The polyene indices were found to decrease during storage. These effects are more pronounced in the fish with the higher fat content.

Canning of tuna in oil

This paper provides the experimental details of canning of tuna in oil. The species utilized in the experiments were the skipjack (Katsuwonus pelamis), yellowfin tuna (Neothunnus macropterus) and bigeye tuna Parathunnus obesus mebachi) ranging it weight from 2.5-82 kg. The method worked out is applicable to all species of different size grades.

Studies on cannning of mackerel fillets in oil

Canning operations suitable for packing mackerel (Rastrelliger kanagurta) in the form of skinless and boneless fillets in oil were studied and the process standardised. The technique of lye peeling for skin removal could be successfully applied. The storage life of the final product was tested over a period of one year and found to be quite comparable to other similar fish products.

Reversed micelle formation in a model liquid-liquid extraction system

The formation of reversed micelles and the roles of extractant and extracted complexes were investigated in the Cyanex923/n-heptane/H2SO4 system. Interfacial tension (gamma), electrical conductivity (kappa), and water content measurements showed that Cyanex923 had a tendency to self-assemble, forming reversed micelles. The changes in electrical conductivity with concentration of H2SO4 in the organic phase (CH2SO4,(0)) exhibited an S-type curve: a correlation was found between the change in electrical conductivity and the water content as a function of CH2SO4,(0),.

Polychaete burrows harbour distinct microbial communities in oil-contaminated coastal sediments

Previous studies have shown that the bioturbating polychaete Hediste (Nereis) diversicolor can affect the composition of bacterial communities in oil-contaminated sediments, but have not considered diversity specifically within bioturbator burrows or the impact on microbial eukaryotes. We tested the hypothesis that H. diversicolor burrows harbour different eukaryotic and bacterial communities compared with un-bioturbated sediment, and that bioturbation stimulates oil degradation. Oil-contaminated sediment was incubated with or without H. diversicolor for 30 days, after which sediment un-affected by H. diversicolor and burrow DNA/RNA samples were analysed using quantitative reverse transcription PCR (Q-RT-PCR) and high-throughput sequencing. Fungi dominated both burrow and un-bioturbated sediment sequence libraries; however, there was significant enrichment of bacterivorous protists and nematodes in the burrows. There were also significant differences between the bacterial communities in burrows compared with un-bioturbated sediment. Increased activity and relative abundance of aerobic hydrocarbon-degrading bacteria in the burrows coincided with the significant reduction in hydrocarbon concentration in the bioturbated sediment. This study represents the first detailed assessment of the effect of bioturbation on total microbial communities in oil-contaminated sediments. In addition, it further shows that bioturbation is a significant factor in determining microbial diversity within polluted sediments and plays an important role in stimulating bioremediation.