Abstract: | We present the analytical investigations on a logistic map with a discontinuity at the centre. An explanation for the bifurcation phenomenon in discontinuous systems is presented. We establish that whenever the elements of an n-cycle (n > 1) approach the discontinuities of the nth iterate of the map, a bifurcation other than the usual period-doubling one takes place. The periods of the cycles decrease in an arithmetic progression, as the control parameter is varied. The system also shows the presence of multiple attractors. Our results are verified by numerical experiments as well. |
URI: | http://dyuthi.cusat.ac.in/purl/2535 |
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Dyuthi-P0110.pdf | (1.206Mb) |
Abstract: | Optical limiting and thermal lensing studies are carried out in C70–toluene solutions. The measurements are performed using 9-ns pulses generated from a frequencydoubled Nd:YAG laser at 532 nm. Optical limiting studies in fullerene molecules lead to the conclusion that reverse saturable absorption is the major mechanism for limiting. Analysis of thermal lensing measurements showed a quadratic dependence of thermal lens signal on incident laser energy, which also supports the view that optical limiting in C70 arises due to sequential two-photon absorption via excited triplet state (reverse saturable absorption). |
URI: | http://dyuthi.cusat.ac.in/purl/2402 |
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Dyuthi-P0223.pdf | (107.1Kb) |
Abstract: | Results of exhaustive study of the effect of metallic flanges on H-plane radiation characteristics of V-slot waveguide antenna are presented . It has been established that the beam can be sharpened or broadened by varying the flange angle . The adjustment of the flange angle and flange width would further improve the radiation pattern , yielding optimum efficiency from the flanged system |
URI: | http://dyuthi.cusat.ac.in/purl/1436 |
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An experimental ... slot waveguide antenna.PDF | (1.063Mb) |
Abstract: | This paper presents the results of a field experiment conducted in Kerala, South India, to test the effectiveness of coir geotextiles for embankment protection. In the context of sustainable watershed management, coir is a cheap and locally available material 5 that can be used to strengthen traditional earthen bunds or protect the banks of village ponds from erosion. Particularly in developing countries, where coir is abundantly available and textiles can be produced by small-scale industry, this is an attractive alternative for conventional methods |
Description: | Hydrol. Earth Syst. Sci. Discuss., 2, 2327–2348, 2005 |
URI: | http://dyuthi.cusat.ac.in/purl/4632 |
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Experimental st ... n watershed management.pdf | (2.507Mb) |
Abstract: | Inspite of having two hotspots of biodiversity India is way long back in the ornamental fish trade. Large number of species can only foster the needs of the industry. The study aims to (1) to find the various indigenous, exotic ornamental fish species and ornamental shrimp species being exported from India, (2) to provide an overview of the trends in the Indian ornamental fish export industry. 287 indigenous fish species, 92 exotic fish species and 44 ornamental shrimps have been found to get exported from India. The export trend of the industry for the past ten years shows a declining state which is also reflected in the annual and compound annual growth rate. Ornamental fish industry has enormous potential in tropical countries like India. To expand trade, new technologies and policies will have to be developed which will help in attaining a sustainable industry. |
Description: | Agric. Biol. J. N. Am., 2012, 3(11): 439-451 |
URI: | http://dyuthi.cusat.ac.in/purl/4122 |
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Export trend of ... namental fish industry.pdf | (291.4Kb) |
Abstract: | In Statistical Machine Translation from English to Malayalam, an unseen English sentence is translated into its equivalent Malayalam sentence using statistical models. A parallel corpus of English-Malayalam is used in the training phase. Word to word alignments has to be set among the sentence pairs of the source and target language before subjecting them for training. This paper deals with certain techniques which can be adopted for improving the alignment model of SMT. Methods to incorporate the parts of speech information into the bilingual corpus has resulted in eliminating many of the insignificant alignments. Also identifying the name entities and cognates present in the sentence pairs has proved to be advantageous while setting up the alignments. Presence of Malayalam words with predictable translations has also contributed in reducing the insignificant alignments. Moreover, reduction of the unwanted alignments has brought in better training results. Experiments conducted on a sample corpus have generated reasonably good Malayalam translations and the results are verified with F measure, BLEU and WER evaluation metrics. |
Description: | 2012 International Conference on Advances in Computing and Communications |
URI: | http://dyuthi.cusat.ac.in/purl/4160 |
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Extension schem ... cal Machine Translator.pdf | (219.2Kb) |
Abstract: | Four species of bacteria which included Pseudomonas fluorescens, Vibrio cho!erae and Vibrio costicola were observed to produce glutaminase both as extracellular and intracellular fractions. Comparatively both the fractions were higher in mineral media supplemented with 1% glutamine than in nutrient broth added with or without glutamine. Extracellular glutaminase production was about 2.6-6.8 times greater than the intracellular production by all the tested strains |
Description: | BIOTECHNOLOGY LETTERS Volume 14 No.6 (june 1992) pp.471-474 |
URI: | http://dyuthi.cusat.ac.in/purl/4248 |
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Extracellular L ... ion By Marine Bacteria.pdf | (201.2Kb) |
Abstract: | Beauveria sp. BTMF S10 isolated from marine sediment produced extracellular L-glutaminase. Maximal L- glutaminase yield (46.9 U/ml) was obtained in a medium supplemented with 1% (w/v) yeast extract and sorbitol, 9% (w/v) sodium chloride and 0.2% (w/v) methionine, initial pH 9.0 and at 27 °C after 108 h. This enzyme was inducible and growth-associated. |
Description: | World Journal of Microbiology & Biotechnology 15: 751±752, 1999. |
URI: | http://dyuthi.cusat.ac.in/purl/4247 |
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Extracellular p ... d from marine sediment.pdf | (70.09Kb) |
Abstract: | A potential fungal strain producing extracellular β-glucosidase enzyme was isolated from sea water and identified as ^ëéÉêJ Öáääìë=ëóÇçïáá BTMFS 55 by a molecular approach based on 28S rDNA sequence homology which showed 93% identity with already reported sequences of ^ëéÉêÖáääìë=ëóÇçïáá in the GenBank. A sequential optimization strategy was used to enhance the production of β-glucosidase under solid state fermentation (SSF) with wheat bran (WB) as the growth medium. The two-level Plackett-Burman (PB) design was implemented to screen medium components that influence β-glucosidase production and among the 11 variables, moisture content, inoculums, and peptone were identified as the most significant factors for β-glucosidase production. The enzyme was purified by (NH4)2SO4 precipitation followed by ion exchange chromatography on DEAE sepharose. The enzyme was a monomeric protein with a molecular weight of ~95 kDa as determined by SDS-PAGE. It was optimally active at pH 5.0 and 50°C. It showed high affinity towards éNPG and enzyme has a hã and sã~ñ of 0.67 mM and 83.3 U/mL, respectively. The enzyme was tolerant to glucose inhibition with a há of 17 mM. Low concentration of alcohols (10%), especially ethanol, could activate the enzyme. A considerable level of ethanol could produce from wheat bran and rice straw after 48 and 24 h, respectively, with the help of p~ÅÅÜ~êçãóÅÉë=ÅÉêÉîáëá~É in presence of cellulase and the purified β-glucosidase of ^ëéÉêÖáääìë=ëóÇçïáá BTMFS 55. |
Description: | Biotechnology and Bioprocess Engineering 2009, 14: 457-466 DOI/10.1007/s12257-008-0116-2 |
URI: | http://dyuthi.cusat.ac.in/purl/4256 |
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Extracellular β ... al Experimental Design.pdf | (390.7Kb) |
Abstract: | The fabrication and characterization of a Rhodamine 6G-doped polymer optical fiber amplifier have been carried out. Two different schemes were employed to characterize the optical fiber: the stripe illumination technique to study the fiber as a gain medium and another technique to study its performance as an amplifier. We observed a spectral narrowing from 42 to 7 nm when the pump energy was increased to 6 mJ in the stripe illumination geometry. A gain of 18 dB was obtained in the amplifier configuration. The effects of pump power and dye concentration on the performance of the fiber as an amplifier were also studied. |
URI: | http://dyuthi.cusat.ac.in/purl/2466 |
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Dyuthi-P0263.pdf | (749.2Kb) |
Abstract: | Rhodamine 6G and Rhodamine B dye mixture doped polymer optical fiber amplifier (POFA), which can operate in a broad wavelength region (60 nm), has been successfully fabricated and tested. Tunable operation of the amplifier over a broad wavelength region is achieved by mixing different ratios of the dyes. The dye doped POFA is pumped axially using 532 nm, 10 ns laser pulses from a frequency doubled Q-switched Nd: YAG laser and the signals are taken from an optical parametric oscillator. A maximum gain of 22.3 dB at 617 nm wavelength has been obtained for a 7 cm long dye mixture doped POFA. The effects of pump energy and length of the fiber on the performance of the fiber amplifier are also studied. There exists an optimum length for which the amplifier gain is at a maximum value. |
URI: | http://dyuthi.cusat.ac.in/purl/2500 |
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Dyuthi-P0272.pdf | (515.8Kb) |
Abstract: | A methylene-blue-sensitized polymer blend of polyvinyl alcohol and polyacrylic acid is fabricated and tested for holographic recording. It was found to have good characteristics such as high sensitivity, storage stability, ease of fabrication, and environmental stability. Optimization of the ratio of polyvinyl alcohol polyacrylic acid, the sensitizer concentration, pH, energy, diffraction efficiency measurements, etc., have been done. pH is found to have a great influence on the recovery of the dye in this matrix. The results of experimental investigations into the properties of this new material are reported. |
URI: | http://dyuthi.cusat.ac.in/purl/715 |
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Fabrication and characterization .pdf | (293.8Kb) |
Abstract: | A methylene-blue-sensitized polymer blend of polyvinyl alcohol and polyacrylic acid is fabricated and tested for holographic recording. It was found to have good characteristics such as high sensitivity, storage stability, ease of fabrication, and environmental stability. Optimization of the ratio of polyvinyl alcohol polyacrylic acid, the sensitizer concentration, pH, energy, diffraction efficiency measurements, etc., have been done. pH is found to have a great influence on the recovery of the dye in this matrix. The results of experimental investigations into the properties of this new material are reported. |
URI: | http://dyuthi.cusat.ac.in/purl/609 |
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Fabrication and characterization .pdf | (293.8Kb) |
Abstract: | Two-dimensional electronic systems play a crucial role in modern electronics and offer a multitude of opportunities to study the fundamental phenomena at low dimensional physics. A quantum well heterostructure based on polyaniline (P) and iodine doped polyaniline (I) thin films were fabricated using radio frequency plasma polymerization on indium tin oxide coated glass plate. Scanning probe microscopy and scanning electron microscopy studies were employed to study the morphology and roughness of the polymer thin films. Local electronic density of states (LDOS) of the P–I–P heterostructures is probed using scanning tunnelling spectroscopy (STS). A step like LDOS is observed in the P–I–P heterostructure and is attributed to the quantum well confinement of electrons in the polymer heterostructure. |
Description: | J. Phys. D: Appl. Phys. 42 (2009) 165309 (7pp) |
URI: | http://dyuthi.cusat.ac.in/purl/4416 |
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Fabrication of ... erized aniline and its.pdf | (853.9Kb) |
Abstract: | The fabrication and analytical applications of two types of potentiometric sensors for the determination of ketoconazole (KET) are described. The sensors are based on the use of KET-molybdophosphoric acid (MPA) ion pair as electroactive material. The fabricated sensors include both polymer membrane and carbon paste electrodes. Both sensors showed a linear, stable and near Nernstian slope of 57.8mV=decade and 55.2mV=decade for PVC membrane and carbon paste sensors respectively over a relatively wide range of KET concentration (1×10-2-5×10-5 and 1×10-2-1×10-6). The sensors showed a fast response time of <30 sec and <45 sec. A useful pH range of 3–6 was obtained for both types of sensors. A detection limit of 2.96 10 5M was obtained for PVC membrane sensor and 6.91 10 6M was obtained for carbon paste sensor. The proposed sensors proved to have a good selectivity for KET with respect to a large number of ions. The proposed sensors were successfully applied for the determination of KET in pharmaceutical formulations. The results obtained are in good agreement with the values obtained by the standard method. |
URI: | http://dyuthi.cusat.ac.in/xmlui/purl/1989 |
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Fabrication of potentiometric....pdf | (210.2Kb) |
Abstract: | In this paper we address the problem of face detection and recognition of grey scale frontal view images. We propose a face recognition system based on probabilistic neural networks (PNN) architecture. The system is implemented using voronoi/ delaunay tessellations and template matching. Images are segmented successfully into homogeneous regions by virtue of voronoi diagram properties. Face verification is achieved using matching scores computed by correlating edge gradients of reference images. The advantage of classification using PNN models is its short training time. The correlation based template matching guarantees good classification results |
Description: | Nature & Biologically Inspired Computing, 2009. NaBIC 2009. World Congress on |
URI: | http://dyuthi.cusat.ac.in/purl/4142 |
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Face Recognitio ... listic Neural Networks.pdf | (216.3Kb) |
Abstract: | n this paper we address the problem of face detection and recognition of grey scale frontal view images. We propose a face recognition system based on probabilistic neural networks (PNN) architecture. The system is implemented using voronoi/ delaunay tessellations and template matching. Images are segmented successfully into homogeneous regions by virtue of voronoi diagram properties. Face verification is achieved using matching scores computed by correlating edge gradients of reference images. The advantage of classification using PNN models is its short training time. The correlation based template matching guarantees good classification results. |
URI: | http://dyuthi.cusat.ac.in/purl/4183 |
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Face Recognitio ... listic Neural Networks.pdf | (218.8Kb) |
Abstract: | A series of novel naphthyridine derivatives 3 and 4 was prepared from substituted pyridine 2 and ketones using ZnCl2 as catalyst under microwave irradiation conditions. All the compounds were evaluated for AChE inhibitory activity and promising compounds 3d, 3e, 4b, and 4g was identified. Representative compounds 3d and 3e were found to show insignificant THLE-2 liver cell viability/toxicity. The binding mode between X-ray crystal structure of human AChE and compounds was studied using molecular docking method and fitness scores were found to be in good correlation with the activity data. |
Description: | Med Chem Res (2012) 21:1785–1795 DOI 10.1007/s00044-011-9695-0 |
URI: | http://dyuthi.cusat.ac.in/purl/4162 |
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A facile and si ... ivity, and molecular m.pdf | (1.024Mb) |
Abstract: | A simple and facile strategy for the synthesis of highly substituted imidazoles has been developed by multi-component condensation of 1,2-diketone, aldehyde, amine, and ammonium acetate in presence of tetrabutyl ammonium bromide as catalyst |
Description: | Res Chem Intermed (2012) 38:359–365 DOI 10.1007/s11164-011-0352-5 |
URI: | http://dyuthi.cusat.ac.in/purl/4137 |
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A facile strate ... iumbromide as catalyst.pdf | (308.6Kb) |
Abstract: | Given a non empty set S of vertices of a graph, the partiality of a vertex with respect to S is the di erence between maximum and minimum of the distances of the vertex to the vertices of S. The vertices with minimum partiality constitute the fair center of the set. Any vertex set which is the fair center of some set of vertices is called a fair set. In this paper we prove that the induced subgraph of any fair set is connected in the case of trees and characterise block graphs as the class of chordal graphs for which the induced subgraph of all fair sets are connected. The fair sets of Kn, Km;n, Kne, wheel graphs, odd cycles and symmetric even graphs are identi ed. The fair sets of the Cartesian product graphs are also discussed |
Description: | arXiv preprint arXiv:1304.5378 |
URI: | http://dyuthi.cusat.ac.in/purl/4230 |
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Fair Sets of Some Classes of Graphs.pdf | (443.4Kb) |
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