Ice storage characteristics of cultured Macrobrachium rosenbergii (de Man)

Cultured Macrobrachium rosenbergii (Scampi; 30-40 g) in headless shell-on form was stored in ice (Prawn:ice=1:2) in a plywood box insulated with 2 cm thick expanded polystyrene and subjected to detailed examination of quality by chemical, microbiological and organoleptic evaluation at regular intervals to assess the storage life. The prime quality life of prawns in ice was found to be 8 days followed by a phase of lowered quality, but still acceptable till the end of 13 days.

Sulfide binding characteristics of blood serum in Calyptogena pacifica and Vesicomya gigas

The sulfide binding characteristics of blood serum were studied in vitro in two deep-sea vesicomyid clams, Calyptogena pacifica and Vesicomya gigas. Both the C. pacifica and the V. gigas serum concentrated sulfide at least an order of magnitude above ambient levels. V. gigas accumulated sulfide faster than C. pacifica, reaching saturation at 5000 M after an hour. C. pacifica bound sulfide at half the rate of V. gigas, reaching saturation in about two hours at a substantially higher concentration of sulfide. The observed distribution of the animals near cold seeps in the Monterey Submarine Canyon can be explained by their different sulfide binding abilities. The hypothesis that cold seeps are actually much more unstable sources of sulfide than previously assumed is explored.

Study on the morphometric and meristic characteristics of splendid silver belly Leiognathus splendens (Cuvier) from Bombay coast

Ten morphometric and six meristic characters of Leiognathus splendens (Cuvier) of Bombay Coast have been studied sexwise. Regression and sexwise difference if any between the compared morphometric characteristics have been worked out. Range, mode, standard deviation, co-efficient of variation of 6 meristic characters have been analysed. There was no significant difference between the sexes in morphometric and any deviation in the meristic characters.

Frozen storage characteristics of cultured Macrobrachium rosenbergii (de Man)

Cultured Macrobrachium rosenbergii (Scampi, about 30 g each) in headless shell-on form was individually quick frozen in a spiral freezer. The frozen samples were glazed and packed in polythene bags, which were further packed in master carton and stored at -18°C. Samples were drawn at regular intervals and subjected to biochemical, bacteriological and organoleptic analysis to study its storage characteristics. The data on the above parameters showed that the samples were in prime acceptable condition when stored up to 23 weeks. No appreciable change in colour and odour was noticed in the raw muscle. Afterwards, organoleptic evaluation of the cooked muscle revealed slight change in the flavour. Texture also appeared little tougher. These changes in organoleptic characters were well supported by the biochemical bacteriological changes in the muscle.

Preparation of prawn pickle and its storage characteristics

Prawn pickle was produced using smaller variety of prawn. Vinegar and salt was used to preserve the prawn muscle against spoilage. Different spices were used to get desired attractive flavour. Benzoic acid to the extent of 200 ppm was used as preservative. Several trials were carried out using different amounts of spices and different methods of preparation. After each trial the sample was subjected to sensory evaluation by judges consisting of five members who had previous experience of acting as panel members. Several trials were carried out to arrive at a final recipe as judged best by the taste panel. Utilizing this final recipe, a product was prepared and subjected to biochemical, bacteriological and organoleptic evaluation and found to be quite acceptable after seven months of storage in glass jar at ambient temperature. The product was subjected to large scale consumer acceptance trial involving 140 consumers, 42% of them ranked it excellent, 41% rated very good, 12% rated good while 5% of the consumers rated it as average.

Physical soil characteristics of waterlogged and saline lands of five districts of Haryana, India

Physical characteristics of waterlogged and saline soils of five districts, namely Rohtak, Faridabad, Gurgaon, Sonipat and Jhajjar, of Haryana were studied to evaluate the aquaculture potential. The soil samples from 76 sites were procured and analysed for pH, electrical conductivity, soil particles and water retention capacity, since the knowledge of these parameters is essential for the preliminary evaluation of a site for aqua-farming. Six soil types were identified and clay-loam was observed to be the maximum at 45 (59.21%) sites, followed by silty-clay loam at 14 (18.42%), sandy-clay loam at six (7.89%), silty-loam at four (5.26%), sandy-loam at four (5.26%) and loam at three (3.94%) sites. The pH of soil indicated moderate to high alkaline conditions ranging between 8.01and 9.00 at 53 (69.73%) sites, 9.01 and 10.00 at 17 (22.36%) sites, and low between 7.01 and 8.00 at six (7.89%) sites. The electrical conductivity was found to range between <1 and 10 mmho cmˉ¹ with the value of <1.0 mmho cmˉ¹ at 36 (47.36%) sites. The water retention capacity was observed mostly to be moderate. The paper describes the interrelationship between these parameters with reference to the suitability for aqua-farming.

Preparation of an extruded fish snack using twin screw extruder and the storage characteristics of the product

A value-added extruded fish product was prepared with corn flour (80%) and fish (sciaenid) powder (20%), using a twin-screw extruder. The effect of different parameters like moisture, temperature, fish powder concentration, speed of the extruder and die-diameter on expansion ratio and crisp texture were studied. The storage characteristics of the final product were studied using three different types of packaging under nitrogen flushing. The study revealed that aluminum foil is the best packaging material to keep the product acceptable for more than three months.

Storage characteristics of solar-dried Indian mackerel

Fresh Rastrelliger kanagurta (Indian mackerel) was thoroughly washed, eviscerated, cleaned and salted overnight with dry salt (fish : salt :: 5:1). Salted mackerel was dried in solar drier and on cement floor under direct sun for three days. The temperature inside the drier was 948°C higher than the ambient temperature. The rate of drying was higher in solar drier than on cement floor. The dried fish packed in 300-gauge polythene bags was subjected to biochemical, microbiological and organoleptic evaluation at regular intervals to assess the storage life. The overall quality of fish dried in solar drier was better than that of the fish dried on cement floor under direct sun.

Influence of lattice temperature on SOI MOSFET's output characteristics

An explanation for the observed variations in the output behaviour of SOI transistors with different buried oxide thicknesses is presented. At low drain bias, the temperature effects are relatively insignificant while at high drain bias, the temperature effects dominate the nonlinear behaviour of the output characteristics.

MOS and bipolar gated thyristor: A thyristor with IGBT switching characteristics

The IGBT has become the device of choice in many high-voltage-power electronic applications, by virtue of combining the ease of MOS gate control with an acceptable forward voltage drop. However, designers have retained an interest in MOS gated thyristor structures which have a turn-off capability. These offer low on-state losses as a result of their latching behaviour. Recently, there have been various proposals for dual-gate devices that have a thyristor on-state with IGBT-like switching. Many of these dual gated structures rely on advanced MOS technology, with inherent manufacturing difficulties. The MOS and bipolar gated thyristor offers all the advantages of dual gated performance, while employing standard IGBT processing techniques. The paper describes the MBGT in detail, and presents experimental and simulation results for devices based on realistic commercial processes. It is shown that the MBGT represents a viable power semiconductor device technology, suitable for a diverse range of applications. © IEE, 1998.

Improving discharge characteristics of indirect integral collector storage systems with multi-element storage

Desired performance of unpressurized integral collector storage systems hinges on the appropriate selection of storage volume and the immersed heat exchanger. This paper presents analytical results expressing the relation between storage volume, number of heat exchanger transfer units and temperature limited performance. For a system composed of a single storage element, the limiting behavior of a perfectly stratified storage element is shown to be superior to a fully-mixed storage element, consistent with more general analysis of thermal storage. Since, however, only the fully-mixed limit is readily obtainable in a physical system, the present paper also examines a division of the storage volume into separate compartments. This multi-element storage system shows significantly improved discharge characteristics as a result of improved elemental area utilization and temperature variation between elements, comparable in many cases to a single perfectly-stratified storage element. In addition, the multi-element system shows increased robustness with respect to variations in heat exchanger effectiveness and initial storage temperature.

The influence of peel angle on the mechanics of peeling flexible adherends with arbitrary load-extension characteristics

The peel test is commonly used to determine the strength of adhesive joints. In its simplest form, a thin flexible strip which has been bonded to a rigid surface is peeled from the substrate at a constant rate and the peeling force which is applied to the debonding surfaces by the tension in the tape is measured. Peeling can be carried out with the peel angle, i.e. the angle made by the peel force with the substrate surface, from any value above about 10° although peeling tests at 90 and 180° are most common. If the tape is sufficiently thin for its bending resistance to be negligibly small then as well as the debonding or decohesion energy associated with the adhesive in and around the point of separation, the relation between the peeling force and the peeling angle is influenced both by the mechanical properties of the tape and any pre-strain locked into the tape during its application to the substrate. The analytic solution for a tape material which can be idealised as elastic perfectly-plastic is well established. Here, we present a more general form of analysis, applicable in principle to any constitutive relation between tape load and tape extension. Non-linearity between load and extension is of increasing significance as the peel angle is decreased: the model presented is consistent with existing equations describing the failure of a lap joint between non-linear materials. The analysis also allows for energy losses within the adhesive layer which themselves may be influenced by both peel rate and peel angle. We have experimentally examined the application of this new analysis to several specific peeling cases including tapes of cellophane, poly-vinyl chloride and PTFE. © 2005 Elsevier Ltd. All rights reserved.

Evaluation of biochemical characteristics of a traditional salt fermented fish product of northeast India with special reference to its flavour components

'Lona ilish', is a traditional salt fermented fish product, widely consumed and very popular in north-east part of India and Bangladesh. It is prepared exclusively from a high fat fish, Hilsa (Tenualosa) ilisha. 'Lona ilish' was prepared in the laboratory following traditional process. After 150 days of fermentation, a better quality 'lona ilish' was obtained. Biochemical characteristics of market sample was estimated and compared with the laboratory prepared one. A variation in biochemical composition was observed. Sensory quality of the final product of laboratory prepared 'lona ilish' was compared with the market sample and found that the laboratory prepared product scored better than the market sample. The moisture (49.89%) and salt (15.48%) of the final product was found to be satisfactory for stability of the 'lona ilish' at ambient temperature. Analysis of volatile compounds of 'lona ilish' was done using GC-MS. It was concluded that, aldehydes, ketones and esters may possibly contribute characteristic aromas to the overall flavour of the salt fermented hilsa.