| Abstract: | Extracellular L-glutaminase production by Beau6eria sp., isolated from marine sediment, was observed during solid state fermentation using polystyrene as an inert support. Maximal enzyme production (49.89 U:ml) occurred at pH 9.0, 27°C, in a seawater based medium supplemented with L-glutamine (0.25% w:v) as substrate and D-glucose (0.5% w:v) as additional carbon source, after 96 h of incubation. Enzyme production was growth associated. Results indicate scope for production of salt tolerant L-glutaminase using this marine fungus |
| Description: | Process Biochemistry 35 (2000) 705–710 |
| URI: | http://dyuthi.cusat.ac.in/purl/4241 |
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| L-Glutaminase p ... lid state fermentation.pdf | (310.7Kb) |
| Abstract: | We report unusual spectral narrowing and laser emission from polymer thin films doped with Coumarin 540 dye. The laser emission from the polymer films is found to be highly dependent upon the excitation length of the medium. Even a short length of 1.75 mm of the dye doped film gave rise to laser emission with FWHM of 0.3 nm for a pump intensity of 825 kW cm−2. The partial reflections from the broad lateral surfaces of the free standing films provided the optical feedback for the laser emission. Occurrence of well-resolved equally spaced resonant modes confirmed the effect of a Fabry–Perot-like optical cavity between the film surfaces. |
| URI: | http://dyuthi.cusat.ac.in/purl/2420 |
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| Dyuthi-P0267.pdf | (421.1Kb) |
| Abstract: | We report unusual spectral narrowing and laser emission from polymer thin films doped with Coumarin 540 dye. The laser emission from the polymer films is found to be highly dependent upon the excitation length of the medium. Even a short length of 1.75 mm of the dye doped film gave rise to laser emission with FWHM of 0.3 nm for a pump intensity of 825 kW cm−2. The partial reflections from the broad lateral surfaces of the free standing films provided the optical feedback for the laser emission. Occurrence of well-resolved equally spaced resonant modes confirmed the effect of a Fabry–Perot-like optical cavity between the film surfaces |
| URI: | http://dyuthi.cusat.ac.in/purl/1789 |
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| Light amplification in dye doped polymer.pdf | (402.1Kb) |
| Abstract: | Coir pith black liquor obtained as a dark brown filtrate from oxidative delignification needs to be decolourised before releasing to open environment. From this liquor industrially valuable lignin was recovered using acid precipitation method. ‘Biochar’ was produced by slow pyrolysis of coir pith at 500oC and 600oC. Water holding capacity and pH of the biochar were estimated. CHNS analysis was carried out to identify the nutrient profile. Structural characterization was done using FTIR and SEM Studies. Biochar produced at 600oC was found to be more suitable for decolourisation of the coir pith black liquor. FTIR analysis indicated peak changes while SEM analysis indicated surface area and porosity changes. Biochar decolourisation experiments were carried out on crude coir pith black liquor and also on lignin recovered coir pith black liquor. |
| Description: | Research Journal of Recent Sciences Vol. 1 (ISC-2011), 270-274 (2012) |
| URI: | http://dyuthi.cusat.ac.in/purl/4066 |
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| Lignin recovery ... Coir pith Black Liquor.pdf | (375.5Kb) |
| Abstract: | We present the spectral and nonlinear optical properties of ZnO-SiO2 nanocomposites prepared by colloidal chemical synthesis. Obvious enhancement of ultraviolet (UV) emission of the samples is observed, and the strongest UV emission of a typical ZnO-SiO2 nanocomposite is over three times stronger than that of pure ZnO. The nonlinearity of the silica colloid is low, and its nonlinear response can be improved by making composites with ZnO. These nanocomposites show self-defocusing nonlinearity and good nonlinear absorption behavior. The observed nonlinear absorption is explained through two photon absorption followed by weak free carrier absorption and nonlinear scattering. The nonlinear refractive index and the nonlinear absorption increase with increasing ZnO volume fraction and can be attributed to the enhancement of exciton oscillator strength. ZnO-SiO2 is a potential nanocomposite material for the UV light emission and for the development of nonlinear optical devices with a relatively small limiting threshold. |
| URI: | http://dyuthi.cusat.ac.in/purl/2608 |
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| Dyuthi-P0168.pdf | (705.0Kb) |
| Abstract: | In this paper, the generation of a multiwavelength laser source from a Brillouin -Erbium fiber laser in the long wavelength band (L-band) region is experimentally demonstrated. The proposed laser system utilizes a Fabrv-Perot cavity formed by fiber-loop mirrors. Twenty-four lines of Brillouin-Stokes with line spacings of 10 GHz are obtained in the L-band region |
| URI: | http://dyuthi.cusat.ac.in/purl/1419 |
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| Line of brillou ... perot cavity in L-band.PDF | (759.9Kb) |
| Abstract: | The Indian ornamental fish industry is divided into two- the domestic market and the export market. 90% of the freshwater ornamental fish exported from India are wild caught indigenous species. The study formed the criteria and indicators assessing the sustainability of wild caught ornamental fish exported from India. These indicators were then analyzed for their interactions, connections, linkages and relationships using cognitive mapping. The work is first of its kind in the ornamental fisheries |
| Description: | International Journal of Environmental Sciences Volume 3 No.6, 2013 |
| URI: | http://dyuthi.cusat.ac.in/purl/4129 |
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| Linking sustain ... namental fish industry.pdf | (352.0Kb) |
| Abstract: | ABSTRACT: Linseed oil is used in the dual roles of the plasticizer and the fatty acid component of the activator in nitrile rubber vulcanizates. The study shows that the substitution can substantially improve the mechanical properties in addition to other advantages such as increased cure rate, reduced leachability and reduced compound cost. |
| URI: | http://dyuthi.cusat.ac.in/purl/850 |
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| V Nandanan and others,Linseed oil..,1996.PDF | (4.764Mb) |
| Abstract: | Marine fungus BTMFW032, isolated from seawater and identified as Aspergillus awamori, was observed to produce an extracellular lipase, which could reduce 92% fat and oil content in the effluent laden with oil. In this study, medium for lipase production under submerged fermentation was optimized statistically employing response surface method toward maximal enzyme production. Medium with soyabean meal- 0.77% (w/v); (NH4)2SO4-0.1 M; KH2PO4-0.05 M; rice bran oil-2% (v/v); CaCl2-0.05 M; PEG 6000-0.05% (w/v); NaCl-1% (w/v); inoculum-1% (v/v); pH 3.0; incubation temperature 35 8C and incubation period-five days were identified as optimal conditions for maximal lipase production. The time course experiment under optimized condition, after statistical modeling, indicated that enzyme production commenced after 36 hours of incubation and reached a maximum after 96 hours (495.0 U/ml), whereas maximal specific activity of enzyme was recorded at 108 hours (1164.63 U/mg protein). After optimization an overall 4.6- fold increase in lipase production was achieved. Partial purification by (NH4)2SO4 precipitation and ion exchange chromatography resulted in 33.7% final yield. The lipase was noted to have a molecular mass of 90 kDa and optimal activity at pH 7 and 40 8C. Results indicated the scope for potential application of this marine fungal lipase in bioremediation. |
| Description: | New Biotechnology Volume 28, Number 6 October 2011 |
| URI: | http://dyuthi.cusat.ac.in/purl/4250 |
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| Lipase from mar ... oil effluent treatment.pdf | (940.8Kb) |
| Abstract: | The present work undertakes the preparation and physico-chemical characterisation of iron promoted sulphated zirconia (SZ) with different amounts of iron loading and their application to Friedel-Crafts benzoylation of benzene, toluene and xylene under different experimental conditions, XRD and laser Raman techniques reveal the stabilisation of the tetragonal phase of zirconia and the existence of iron in highly dispersed form as Fe203 on the catalyst surface. The surface acidic properties were determined by ammonia temperature programmed desorption (TPD) and perylene adsorption, The results were supported by the TGA studies after adsorption of pyridine and 2,6-dimethylpyridine (2,6-DMP), Strong Lewis acid sites on the surface, which are evident from TPD and perylene adsorption studies. explain the high catalytic activity of the systems towards benzoylation. The experimental results provide evidence for the truly heterogeneous nature of the reaction. The studies also establish the resistance to deactivation in the metal incorporated sulphated systems. |
| URI: | http://dyuthi.cusat.ac.in/purl/2279 |
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| Dyuthi-SS62.pdf | (696.8Kb) |
| Abstract: | Iron, aluminium and mixed iron aluminium pillared clays have been prepared by partial hydrolysis method and doped with IO% Mo, V and Cr. The samples have been characterised by XRD, FTIR and surface area and pore Volume measurements. The surface acid site distribution has been determined by temperature programmed desorption of ammonia. Vanadia incorporated systems show maximum acidity. Benzylation of o-xylene has been done as probe reaction to test catalytic activity. Benzyl chloride is a superior benzylating agent compared to benzyl alcohol in activity and selectivity. Cent percent selectivity towards monobenzylated product is obtained in all the cases. Fe pillared systems exhibit maximum activity. The catalytic activities of the systems can be correlated with the amount of strong add sites. The effects of various reaction variables on the reaction have been studied. Presence of moisture has a diminishing effect on the reaction rate. |
| URI: | http://dyuthi.cusat.ac.in/purl/2248 |
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| Dyuthi-SS41.pdf | (593.7Kb) |
| Abstract: | The liquid-phase Friedel-Crafts acylation of toluene using benzoyl chloride as benzoylating agent has heen carried out over Nix, Mn(l-x)Fe2 O4 (x=O, 0.2, 0.4, 0.6, 0.8 and 1.0) type systems under different reaction conditions. It is observed that the systems with high 'x' values are effective for the conversion of BOC and the selective formation of 4-MBP. Selectivity for 4-MBP over MnFe2O4 is more than 90% under the optimized reaction conditions. Sites of moderate acidity is effective in calalyzing the benzoylation reaction. |
| URI: | http://dyuthi.cusat.ac.in/purl/2210 |
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| Dyuthi-SS14.pdf | (504.4Kb) |
| Abstract: | Ethnic/Minority entrepreneur is a business owner who does not represent the majority population of a country. Ethnic/Minority entrepreneurship can bring benefits to individual, society, region, economy, and globe too. So, understanding the importance of ethnic/minority entrepreneurship will really be useful to all the stakeholders. The unique culture and value system of ethnic minorities are the most wanted characteristics for any successful entrepreneur in general. Many industrial nations like U.S, U.K., Germany, etc. have utilised the ethnic minorities to build their economy. The future of the minority businesses looks bright as the world economy is booming, availability of experienced and already successful minority entrepreneurs as role models, and institutional support services. In this paper, literature relating to the benefits of ethnic and minority entrepreneurship is reviewed to understand its magnitude of benefits. |
| Description: | Vol V. Issue 2. October 2009, "Indigenous Practices in Entrepreneurship - |
| URI: | http://dyuthi.cusat.ac.in/purl/4292 |
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| A literature re ... ority entrepreneurship.pdf | (470.1Kb) |
| Abstract: | Composite magnetic materials have the unique advantage of property modification for tailoring devices for various applications. Rubber ferrite composites (RFCs) prepared by incorporating ferrites in rubber matrixes have the advantage of easy mouldability and flexibility. RFCs containing various loadings of nickel zinc ferrite (NZF) (Ni1 xZnxFe2O4) in a natural rubber matrix have been prepared. The cure characteristics and the mechanical properties of these composites were evaluated. The effect of loading on the cure characteristics and tensile properties were also evaluated. It is found that the loading dependence on the cure time and mechanical properties exhibit an identical pattern. |
| URI: | http://dyuthi.cusat.ac.in/purl/2830 |
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| Dyuthi-P00386.pdf | (204.2Kb) |
| Abstract: | The Tropospheric Biennial Oscillation (TBO), a major interannual variation phenomenon in the Indo-Pacific region, is the result of strong ocean-atmosphere coupling over the Asian-Australian monsoon area. Along with other meteorological and oceanographic parameters, the tropical circulation also exhibits interannual oscillations. Even though the TBO is the result of strong air–sea interaction, the circulation cells during TBO years are, as yet, not well understood. In the present study, an attempt has been made to understand the interannual variability of the mean meridional circulation and local monsoon circulation over south Asia in connection with the TBO. The stream function computed from the zonal mean meridional wind component of NCEP=NCAR reanalysis data for the years 1950–2003 is used to represent the meanmeridional circulation. Mean meridional mass transport in the topics reverses from a weak monsoon to a strong monsoon in the presence of ENSO, but in normal TBO yearsmean transport remains weak across the Northern Hemisphere. The meridional temperature gradient, which drives the mean meridional circulation, also shows no reversal during the normal TBO cycle. The local Hadley circulation over the monsoon area follows the TBO cycle with anomalous ascent (descent) in strong (weak) monsoon years. During normal TBO years, the Equatorial region and Indian monsoon areas exhibit opposite local Hadley circulation anomalies |
| Description: | Theor. Appl. Climatol. 91, 171–179 (2008) |
| URI: | http://dyuthi.cusat.ac.in/purl/4681 |
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| Local Hadley ci ... c Biennial Oscillation.pdf | (295.8Kb) |
| Abstract: | Cooperative caching is an attractive solution for reducing bandwidth demands and network latency in mobile ad hoc networks. Deploying caches in mobile nodes can reduce the overall traffic considerably. Cache hits eliminate the need to contact the data source frequently, which avoids additional network overhead. In this paper we propose a data discovery and cache management policy for cooperative caching, which reduces the caching overhead and delay by reducing the number of control messages flooded in to the network. A cache discovery process based on location of neighboring nodes is developed for this. The cache replacement policy we propose aims at increasing the cache hit ratio. The simulation results gives a promising result based on the metrics of studies |
| Description: | Advanced Infocomm Technology (ICAIT), 2013 6th International Conference on |
| URI: | http://dyuthi.cusat.ac.in/purl/3900 |
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| A Location Aide ... Mobile Ad hoc Networks.pdf | (254.6Kb) |
| Abstract: | We propose and demonstrate a new technique for evanescent wave chemical sensing by writing long period gratings in a bare multimode plastic clad silica fiber. The sensing length of the present sensor is only 10 mm, but is as sensitive as a conventional unclad evanescent wave sensor having about 100 mm sensing length. The minimum measurable concentration of the sensor reported here is 10 nmol/l and the operating range is more than 4 orders of magnitude. Moreover, the detection is carried out in two independent detection configurations viz., bright field detection scheme that detects the core-mode power and dark field detection scheme that detects the cladding mode power. The use of such a double detection scheme definitely enhances the reliability and accuracy of the results. Furthermore, the cladding of the present fiber need not be removed as done in conventional evanescent wave fiber sensors. |
| URI: | http://dyuthi.cusat.ac.in/purl/2495 |
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| Dyuthi-P0250.pdf | (514.3Kb) |
| Abstract: | In general Indian summer monsoon rainfall did not show any significant trend in all Indian summer monsoon rainfall series, however, it was reported that the ISMR is subjected to spatial trends. This paper made an attempt to bring out long term trends of different intensity classes of summer monsoon rainfall in different regions of Indian subcontinent. The long term trend of seasonal and monthly rainfall were also made using the India Meteorological Department gridded daily rainfall data with a spatial resolution of 1° × 1° latitude-longitude grid for the period from 1st January, 1901 to 31st December, 2003. The summer monsoon rainfall shows an increasing trend in southeast, northwest and northeast regions, whereas decreasing trend in the central and west coastal regions. In monthly scale, July rainfall shows decreasing trend over west coastal and central Indian regions and significant increasing trend over northeast region at 0.1% significant level. During the month August, decreasing trend is observed in the west coastal stations at 10% significant level. In most of the stations, mean daily rainfall shows an increasing trend for low and very high intense rainfall. For the moderate rainfall, the trend is different for different regions. In the central and southern regions the trend of moderate and moderately high classes show increasing trend. And for the high and very high intensity classes, the trend is decreasing significantly. In the northeastern regions, above 10 mm/day rainfall shows significantly increasing trend with 0.1% significant level. |
| Description: | MAUSAM, 64, 3 (July 2013), 481-488 |
| URI: | http://dyuthi.cusat.ac.in/purl/3801 |
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| VH.KK.CAB_Maus.pdf | (610.0Kb) |
| Abstract: | We report the position dependent tuning of fluorescence emission from rhodamine 6G doped polymethylmethacrylate film waveguide using a side illumination technique. The transmitted fluorescence as a function of the distance from the point of illumination is measured by translating the waveguide horizontally across a monochromatic light source. This technique has been utilized to characterize the optical loss in dye doped waveguides. We observe that the optical loss coefficients for shorter and longer distances of propagation through the dye doped waveguide are different. At longer distance of propagation a decrease in optical loss coefficient is observed |
| URI: | http://dyuthi.cusat.ac.in/purl/1791 |
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| Loss characterization in rhodamine 6G.pdf | (637.8Kb) |
| Abstract: | A novel technique for backscattering reduction for both TE and TM polarisation, employing a metallo-dielectric structure based on Sierpinski carpet fractal geometry, is reported. A reduction in backscattered power of --30 dB is obtained for normal incidence in the X-band for the structure using the third iterated stage of the fractal geometry |
| URI: | http://dyuthi.cusat.ac.in/purl/1406 |
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| Low backscatter ... d on sierpinski carpet.PDF | (1.096Mb) |
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