Influence of Pongamia, Mahua and Neem cakes on finger millet productivity and soil fertility

A field experiment conducted at Bio-fuel park, Agricultural Research Station, Madenur, Hassan in Kharif season of 2009 to asses the performance of finger millet (Eleusine coracana L.) under different organic manure treatment consisting of four treatments viz., recommended FYM and NPK through inorganic fertilizers as control, Pongamia, Mahua and Neem cake with 5 replications laid in randomized complete block design. The results revealed that application of recommended FYM along with neem cake equivalent to 100% recommended N performedbetter in respect of finger millet productivity and maintenance of soil fertility followed by recommended FYM with 100% NPK through fertilizers. Nutrient supplementation with different oilcakes proved superior in respect of soil sustainability

THIRTY FIVE YEARS OF OPERATIONAL RESEARCH PROJECT FOR DRYLAND AGRICULTURE : ACHIEVEMENTS AND IMPACTS (1976 to 2012)

Not AvailableAgriculture is the backbone of Indian economy and rainfed agro-ecosystem occupies an important place in Indian agriculture, covering 68 per cent of the cultivated area (96 m.ha) supporting 40 per cent human, 60 per cent livestock population and producing 44 per cent of the food requirements thus playing a pivotal role in India’s food security. Five out of ten Agro-Climatic Zones in Karnataka were classified as dry zones covering 63 per cent of the total geographical area and 71 per cent of the net sown area, with substantial contribution to agricultural production from dry lands. About 57 per cent of food grain production in Karnataka comes from rainfed areas while, 97 per cent of total pulses and 80 per cent oilseeds were produced in dry land areas. Research on dryland agriculture in the red soil regions of Karnataka was started in 1970 with the establishment of All India Coordinated Research Project for Dryland Agriculture (AICRPDA) at Gandhi Krishi Vignana Kendra (GKVK), Bangalore,Not Availabl

Water diffusion in a soft contact lens polymer and its tolerance to UV radiation studied by positron lifetime technique

The kinetics of water sorption, the topology or the free-volume changes due to the presence of sorbed water in a soft contact lens polymer, poly(2-hydroxyethyl methacrylate), were investigated by using the positron lifetime technique. It was found that the ortho-positronium lifetime increases in the beginning of sorption because of microstructural swelling of the polymer matrix. After reaching a maximum, the lifetime decreases and becomes constant, maybe because of the filling of the free-volume holes with water molecules. The diffusion process is found to be non-Fickian. By using the dual-mode sorption model, the Fickian-controlled part and the relaxation-controlled part of diffusion were separated. Further, the positron results seem to indicate the existence of water clusters in the sorbed lens material. The tolerance or stability of the soft lens material to UV radiation seems to be satisfactory as revealed by positron results. (C) 2004 Wiley Periodicals, Inc

Positron lifetime study of diffusion kinetics in electron irradiated polycarbonate

Positron lifetime and gravimetric measurements of iodine sorption and diffusion behaviour in electron-irradiated polycarbonate and un-irradiated polycarbonate are investigated. The increase in ortho-positronium lifetime on electron-irradiation shows that scission of carbonate groups in the main-chain and formation of free radicals is the predominant process. The UV absorption measurement supports this. The free volume in polycarbonate after electron-irradiation seems to be not composed of independent pores but of interconnected channels. The positron results on iodine diffusion in un-irradiated polycarbonate shows a slower diffusion rate, whereas in electron-irradiated polycarbonate faster diffusion is observed. The gravimetric measurement of iodine diffusion attains an early saturation in electron-irradiated polycarbonate as compared to un-irradiated polycarbonate although in both cases the diffusion is nearly Fickian. An exponential type of correlation has been observed between fractional free volume and diffusion coefficient validating Fujita's free volume theory for un-irradiated and electron-irradiated polycarbonate

Water sorption studies in a RGP contact lens polymer paraperm by positron lifetime technique

The kinetics of moisture uptake in a rigid gas permeable contact lens material Paraperm has been investigated. The free volume changes accompanied by the sorption of water have been monitored using Positron Lifetime Spectroscopy (PLS) technique. The positron results indicate the swelling in the initial stages of sorption which seems to be balanced by the rearrangement of chains in the presence of water molecules and filling of vacant free volume sites with water at the later stages of sorption. The sorption curve suggests that diffusion process in this polymer follows dual‐mode sorption model. Using this model we have been able to separate the Fickian controlled diffusion and relaxation controlled diffusion. Further, the positron results combined with sorption results indicate that Fujita's free volume theory seems to be not valid for the diffusion process in the present sample under study. The variation of permeability as a function of free volume suggests the amount of water in a contact lens is a measure of its permeability

Structural relaxation in polyethylene in the presence of silver oxide investigated by positron-lifetime spectroscopy

Structural relaxation in high-density virgin polyethylene and silver oxide doped polyethylene has been investigated using positron annihilation lifetime technique at 30 degreesC and 100 degreesC ageing temperatures. The ortho-positronium (o-Ps) pick-off lifetime and its intensity show no changes with isothermal ageing time for the virgin sample at 30 degreesC. In the case of the doped sample at 30 degreesC, the o-Ps intensity shows exponential relaxation in the short-time range. At 100 degreesC, the o-Ps lifetime remains almost constant, whereas the o-Ps intensity exhibits an exponential character in the virgin and doped samples, which can be fitted with exponential decay curves. The relaxation times have been evaluated from the structural relaxation function constructed using o-Ps intensity values, and the stretching exponent beta has been estimated using the Kohlrausch-Williams-Watts (KWW) function. Positron results indicate that the stretching exponent beta seems to be temperature dependent

A free volume microprobe study of water sorption in a contact lens polymer

The kinetics of moisture uptake in a rigid gas-permeable contact lens material, Fluoroperm60, has been investigated. The free volume changes accompanied by the sorption of water were monitored using the positron lifetime spectroscopy (PLS) technique. The positron results indicated swelling in the initial stages of sorption and the filling of vacant free volume sites with water in the later stages of sorption. The sorption curve suggests that the diffusion process in this polymer follows the dual-mode sorption model. Using this model, it was possible to separate Fickian-controlled diffusion and relaxation-controlled diffusion. Furthermore, the positron results combined with the sorption results indicated that Fujita's free volume theory does not seem to be valid for the diffusion process in the present sample under study. The variation of the permeability as a function of the free volume suggests that the amount of water in a contact lens is a measure of its permeability

A positron lifetime study of structural relaxation in UV irradiated poly (ethylene terephthalate)

Structural relaxation in UV irradiated poly (ethylene terephthalate) (PET-UV) has been investigated using positron lifetime techniques. Positron lifetime results show that the structural relaxation processes in PET-UV encompass three different time regimes, unlike the unirradiated poly (ethylene terephthalate) (PET) where only two relaxation times were observed. The relaxation functions constructed from the measured ortho positronium intensity, I3, exhibit non-exponential character that can be best fitted with two additive exponentials. To determine the extent of deviation from exponential relaxation, we have used the Narayanaswamy model (KWW function) and evaluated the stretching parameter β. From the relaxation times derived from the exponential decay curves, the activation energies have been calculated and from these activation energies it seems possible to label the different kinetic units of the UV irradiated poly (ethylene terephthalate) structure participating in the relaxation processes

Influence of strain on the thermal behaviour of poly(chlorotrifluoroethylene)

The effects of uniaxial drawing on the free volume of poly(chlorotrifluoroethylene) have been investigated using the positron annihilation lifetime technique. Annealing measurements were made both in unstrained and maximum strained conditions of the polymer to understand the influence of residual stress on the thermal behaviour. The results indicate uncoiling of the molecular chains upon stretching accompanied by orientation of the polymeric chains. The results further indicate an increase of the glass transition temperature of the drawn film and a negative thermal expansion beyond the glass transition temperature, supported by an increase in activation energy for the strained polymer. (C) 1999 Society of Chemical Industry

Influence of gamma irradiation on the formation of methanol induced micro-cracks in polycarbonate

The effects of γ-irradiation on the methanol diffusion behaviour in polycarbonate have been investigated by UV-visible, Fourier Transform Infra-red (FTIR) Spectroscopy, Positron Annihilation Lifetime Spectroscopy (PALS), Differential Scanning Calorimetry (DSC), Sorption, and Optical Microscopy. Positron results show that the free volume size and its content decreases after γ-irradiation which is due to cross-linking of chains. The cross-linking process is further confirmed by DSC measurements, which indicate an increase in glass transition temperature (Tg) after γ-irradiation. Sorption results reveal that methanol diffuses faster in virgin polycarbonate as compared to cross-linked polycarbonate (after gamma irradiation) in agreement with the results of supplementary techniques. Interestingly, the optical microscopic examination of the sample surfaces provides clear evidence of decreased micro-crack formation in γ-irradiated polycarbonate as compared to the virgin sample. This decrease in crack formation can be related to the decrease in the rate of methanol diffusion