Studies on structural integrity of polyester-cotton friction spun yarn by cycling extension test

Yarns and fabrics are subjected to a low level of stresses or strains of repetitive nature in processing and actual use which leads to breakage, permanent deformation, bagging and loss of useful life of the product. The ability of the spun yarns and fabrics to withstand such stresses depends upon their structural integrity. A structurally rigid yarn (i.e. yarns in which fibres are tightly bound) would behave more like an elastic solid and consume more energy during deformation as the constituent fibres have to be deformed. Once the strain is released, the recovered energy will also be more. On the other hand if the structural integrity of the same yarn is poor, fibres would easily slip during deformation and would consume much less energy. The recoverable energy also will be much less. The present investigation reports on the structural integrity of friction spun yarns in terms of energy loss or decay by employing cyclic extension test. It has been observed that friction spun yarns in which the core is immediately wrapped by long and strong polyester fibre layer make the structure strongest as polyester is expected to form tight wrappings. The decay in deformation energies during extension cycling depends upon sheath structure i.e. its composition and location of constituent fibres in sheath layers. With increase in core fibre %, the decay has been found to increase. However, the decay values discriminate more between core% differences than between sheath fibre layer arrangements.     

Tubifex production using agro-industrial wastes and raw cattle dung

ABSTRACT

Tubifex (Tubifex tubifex) was cultured in captivity using three different wastes: rice mill sludge (RMS), dairy sludge (DS), and raw cattle dung (RCD). Three experiments were conducted: 10, 20, and 30 days. A total of 100 g of tubifex at 62.5 g m^?2 was inoculated in 1.6 m² fiberglass-reinforced plastic tanks. Comparing all production parameters, RMS > DS > RCD. Growth rate (g m^?2 d^?1) did not differ among durations. RMS- and DS-fed tubifex contained higher protein and fat than RCD-fed tubifex. Efficiency on production of g tubifex per kg of waste material was highest at 10 days, declining with time for all waste materials. This experiment suggests that RMS and DS are effective wastes for tubifex culture, with total production increasing with no reduction in growth rate through 30 days, but with efficiency declining after 10 days.     

A neural network model for prediction of strength loss in threads during high speed industrial sewing

In this paper artificial neural network (ANN) model has been designed to predict the strength loss in threads during high speed industrial sewing. Four different types of threads (Mercerized cotton, polyester staple spun, polyester-cotton core spun and polyester-polyester core spun) were taken for the study. The other input parameters include thread linear density, fabric area density, number of fabric layers, stitch density and needle size. In order to reduce the dependency of the results on a specific partition of the data into training and testing sets, a four-way cross validation tests were performed, i.e. total data was divided into training and testing set in four different ways. The predicted tenacity loss was correlated to the experimental tenacity loss and correlation coefficient between the actual and predicted tenacity loss obtained. It was observed that the neural network system is able to predict the tenacity loss of threads after sewing with good correlation and less average error. The relative contribution of each parameter to the overall prediction of the tenacity loss was studied by carrying out the sensitivity analysis of the test data set. The results of sensitivity analysis show that thread type is the most important input parameter followed by thread linear density, number of fabric layers, fabric area density, needle size and the stitch density.     

Determination of critical limits of soil nutrients for use in optimizing fertilizer rates for fish ponds in red, lateritic soil zones

Mesocosms containing lateritic soil from West Bengal, India and de-ionized water were treated with different amounts of nitrogen (N), phosphorus (P), and potassium (K) fertilizers. Concentrations of available N, P, and K in soils and gross primary productivity were measured for the mesocosms. Critical concentrations of the three nutrients were estimated by the graphical method of Cate and Nelson that has been used widely for establishing critical soil nutrient concentrations in fertilization research on terrestrial crop plants. Critical concentrations of the three nutrients were: available N, 200 mg kg⁻¹; available P, 13 mg kg⁻¹; available K, 80 mg kg⁻¹. Ponds sited in red, lateritic soil in West Bengal were treated monthly with 20, 15, and 3 kg ha⁻¹ application⁻¹ of N, P, and K, respectively. There was an increase in gross primary productivity when the critical concentrations of available N, P, and K established in the mesocosm study were attained in the pond soils. Fish production in fertilized ponds is positively correlated with gross primary productivity. Thus, the concept of critical nutrient concentrations in soils could be a valuable tool in pond fertilization research.     

Modelling regional level spatial distribution of aphid (Lipaphis erysimi) growth in Indian mustard using satellite-based remote sensing data

Abstract

We developed a procedure for preparing a model for mapping spatially distributed zones of aphid pest (Lipaphis erysimi) outbreaks at a regional level. This study employed near-surface meteorological parameters derived from National Oceanic and Atmospheric Administration (NOAA) Television and Infra-Red Operational Satellites (TIROS) Operational Vertical Sounder (TOVS) data and field observations of disease infestation. The study area comprised three sites representing semi-arid and sub-humid regions of dominant Indian mustard (Brassica juncea L.)-growing regions of India. A model based on TOVS-derived cumulative surface air temperature and minimum specific humidity (SpH) was developed to estimate the date of ‘aphid onset’ (first appearance), date of peak infestation and location of severity with respect to aphid population density. Aphid population growth rate during the linear growth phase between aphid onset to peak was computed using SpH-weighted temperature and dates of sowing of the crop (crop age). Sowing dates of mustard crop, of northwest India, were obtained from spectral growth profiles derived from time series remote sensing (RS) products of the SPOT-4 VEGETATION sensor. Estimated dates of peak aphid infestation and peak population showed a strong match with the observed data. The location of peak aphid population density was depicted in each spatial grid of 25×25 km² for parts of northwest India. The simulated aphid population build-up and date of peak population density was validated with observed data for an unknown site in the Sriganganager district, Rajasthan state, India. Comparison of predicted dates of attaining peak aphid population with observations showed a deviation of ±7 days. After validation, the regional level model was applied over a large area of a mustard-growing region for varying dates of sowing, surface air temperature and specific humidity, to show the spatial distribution of aphid growing severity zones (population density) and to predict dates of severe aphid infestation (peak population) at each grid level in the region.     

Identification and Pathogenicity of Pseudomonas aeruginosa DJ1990 on Tail and Fin Rot Disease in Spotted Snakehead

Tail and fin rot disease (TFRD) is a big issue in the production of spotted snakehead, Channa punctata Bloch. The aims of the present study were to isolate and identify the bacterial pathogen causing TFRD, to detect histopathological changes in tissues (fin, tail, liver, and kidney), and to ascertain the antibiotic sensitivity pattern of the isolate. Out of six bacterial isolates, only the isolate DJ1990 was found to be the causal candidate of TFRD in C. punctata. Identical histopathological changes were detected in tail, fin, liver, and kidney under light and scanning electron microscope in both collected diseased fish and artificially infected fish. The isolate was identified as Pseudomonas aeruginosa strain DJ1990 (National Center for Biotechnology Information Ace. No. KX709967) based on the biochemical characterization tests and 16S rDNA sequence‐based phylogeny analysis. Artificial challenge test demonstrated that the strain DJ1990 was highly virulent (100% mortality at 48 h of postinjection period at the concentration of 1.5 × 10⁷ CFU/g of body weight) for C. punctata. The isolate exhibited sensitivity to the broad‐spectrum antibiotics but was resistant against aztreonum. To the best of our knowledge, this is the first report of P. aeruginosa as a TFRD‐causing candidate in C. punctata.