Abstract: | Distribution and chemistry of major inorganic forms of nutrients along with physico-chemical parameters were investigated. Surface sediments and overlying waters of the Ashtamudi and Vembanad Lakes were taken for the study, which is situated in the southwest coast of India. High concentrations of dissolved nitrogen and phosphorus compounds carried by the river leads to oxygen depletion in the water column. A concurrent increase in the bottom waters along with decrease in dissolved oxygen was noticed. This support to nitrification process operating in the sediment-water interface of the Ashtamudi and Vembanad Lake. Estuarine sediments are clayey sand to silty sand both in Ashtamudi and Vembanad in January and May. Present study indicates that the sediment texture is the major controlling factor in the distribution of these nutrient forms. For water samples nitrite, inorganic phosphate was high in Vembanad in January and May compared to Ashtamudi. For sediments, enhanced level of inorganic phosphate and nitrite was found in Vembanad during January and May. It had been observed that the level of N and P is more in sediments. A comparative assessment of the Ashtamudi and Vembanad Lake reveals that the Vembanad wetland is more deteriorated compared to the Ashtamudi wetland system |
Description: | Indian Journal of Marine Sciences Vol. 38(4), December 2009, pp 451-456 |
URI: | http://dyuthi.cusat.ac.in/purl/4615 |
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Nutrient dynami ... lakes of Kerala, India.pdf | (1.039Mb) |
Abstract: | Pulsed photoacoustic measurements have been carried out in liquid CS2 using 532 nm radiation from a frequency doubled Nd:YAG laser. Variation of signal amplitude with laser fluence clearly indicates the role of multiphoton processes in the generation of photoacoustic effect. It is also shown that four photon induced dissociation and five photon induced ionization are likely processes in CS2 and 532 nm radiation. |
URI: | http://dyuthi.cusat.ac.in/purl/2634 |
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Dyuthi-P0193.pdf | (264.3Kb) |
Abstract: | Two-photon absorption in Rhodamine 6G using the second harmonic of a pulsed Q-switched Nd:YAG laser has been studied by photoacoustic technique. It is observed that there is a competition between one-photon and two-photon absorption processes. At lower concentration the two-photon process is predominant over the one-photon process. |
URI: | http://dyuthi.cusat.ac.in/purl/2493 |
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Dyuthi-P0291.pdf | (252.6Kb) |
Abstract: | Observation of laser induced two-photon photoemission optogalvanic (TPPOG) effect from tungsten electrode in a discharge cell using 564 nm radiation obtained from a pulsed dye laser is described. The magnitude of the POG signal is studied as a function of laser energy under various discharge parameters. Competition between one-photon and two-photon processes has been observed when nitrogen gas is used in the discharge cell. |
URI: | http://dyuthi.cusat.ac.in/purl/2492 |
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Dyuthi-P0296.pdf | (201.4Kb) |
Abstract: | Symbiotic diatom-diazotrophic cyanobacteria association (DDA) of Rhizosolenia hebetata and Rhizosolenia formosa with endosymbiotic cyanobacteria Richelia intracellularis was noticed and documented for the first time during a bloom of the cyanobacterium Trichodesmium erythraeum in the oligotrophic shelf waters along Kochi and Mangalore transects, southeastern Arabian Sea (SEAS), during spring intermonsoon (April 2012). Although the host is frequently seen, the symbiont is rarely reported in the Indian EEZ. The presence of nitrogen-fixing symbiotic association of Rhizosolenia-Richelia along with Trichodesmium erythraeum highlights the significance of DDAs on the nutrient and energy budgets of phytoplankton in the oligotrophic environments of the Arabian Sea during spring intermonsoon |
Description: | International Journal of Oceanography Volume 2013, Article ID 350594, 6 pages |
URI: | http://dyuthi.cusat.ac.in/purl/3933 |
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Occurrence and ... a Diatom-Diazotrophic.pdf | (2.738Mb) |
Abstract: | A dual port dual polarized octagonal microstrip patch antenna suitable for dual band applications is discussed theoretically and experimentally. The antenna exhibits good impedance bandwidth, gain and broad radiation patterns. Parameters predicted by the Conformal Finite Difference Time Domain algorithm show good agreement with the simulated results and experimental observations |
Description: | Proc. XXVIII URSI General Assembly |
URI: | http://dyuthi.cusat.ac.in/purl/4337 |
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Octagonal Micro ... Dual Band Applications.pdf | (878.3Kb) |
Abstract: | The paper proposes an octagon shaped Microstrip Patch Antenna suitable for dual band applications. The striking features of this compact, planar antenna are sufficient isolation between the two operating bands and an area reduction of - 29% in comparison to a conventional circular patch antenna operating in the same band |
Description: | Antennas and Propagation Society International Symposium, 2002. IEEE |
URI: | http://dyuthi.cusat.ac.in/purl/4328 |
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Octagon Shaped ... Dual Band Applications.pdf | (161.2Kb) |
Abstract: | Optical Character Recognition plays an important role in Digital Image Processing and Pattern Recognition. Even though ambient study had been performed on foreign languages like Chinese and Japanese, effort on Indian script is still immature. OCR in Malayalam language is more complex as it is enriched with largest number of characters among all Indian languages. The challenge of recognition of characters is even high in handwritten domain, due to the varying writing style of each individual. In this paper we propose a system for recognition of offline handwritten Malayalam vowels. The proposed method uses Chain code and Image Centroid for the purpose of extracting features and a two layer feed forward network with scaled conjugate gradient for classification |
Description: | Emerging Trends in Electrical and Computer Technology (ICETECT), 2011 International Conference on |
URI: | http://dyuthi.cusat.ac.in/purl/4196 |
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Offline Handwri ... n Chain Code Histogram.pdf | (1.324Mb) |
Abstract: | Materials belonging to the family of manganites are technologically important since they exhibit colossal magneto resistance. A proper understanding of the transport properties is very vital in tailoring the properties. A heavy rare earth doped manganite like Gd0·7Sr0·3MnO3 is purported to be exhibiting unusual properties because of smaller ionic radius of Gd. Gd0·7Sr0·3MnO3 is prepared by a wet solid state reaction method. The conduction mechanism in such a compound has been elucidated by subjecting the material to low temperature d.c. conductivity measurement. It has been found that the low band width material follows a variable range hopping (VRH) model followed by a small polaron hopping (SPH) model. The results are presented here |
Description: | Bull. Mater. Sci., Vol. 35, No. 1, February 2012, pp. 41–45. |
URI: | http://dyuthi.cusat.ac.in/purl/4432 |
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On conduction m ... of Gd basedmanganites.pdf | (148.3Kb) |
Abstract: | The D-eigenvalues of a graph G are the eigenvalues of its distance matrix D, and the D-energy ED(G) is the sum of the absolute values of its D-eigenvalues. Two graphs are said to be D-equienergetic if they have the same D-energy. In this note we obtain bounds for the distance spectral radius and D-energy of graphs of diameter 2. Pairs of equiregular D-equienergetic graphs of diameter 2, on p = 3t + 1 vertices are also constructed. |
URI: | http://dyuthi.cusat.ac.in/purl/1537 |
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On distance energy of graphs.PDF | (2.514Mb) |
Abstract: | The D-eigenvalues of a graph G are the eigenvalues of its distance matrix D, and the D-energy ED(G) is the sum of the absolute values of its D-eigenvalues. Two graphs are said to be D-equienergetic if they have the same D-energy. In this note we obtain bounds for the distance spectral radius and D-energy of graphs of diameter 2. Pairs of equiregular D-equienergetic graphs of diameter 2, on p = 3t + 1 vertices are also constructed. |
URI: | http://dyuthi.cusat.ac.in/purl/626 |
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7) ON DISTANCE ENERGY OF GRAPHS.pdf | (2.976Mb) |
Abstract: | A feasible way of implementing a temporal database is by mapping temporal data model onto a conventional data model followed by a commercial database management system. Even though extensions were proposed to standard SQL for supporting temporal databases, such proposals have not yet come across standardization processes. This paper attempts to implement database operators such as aggregates and universal quantifier for temporal databases, implemented on top of relational database systems, using currently available SQL standards. |
URI: | http://dyuthi.cusat.ac.in/xmlui/purl/2006 |
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On Implementing Joins....pdf | (261.1Kb) |
Abstract: | This paper presents a novel approach to recognize Grantha, an ancient script in South India and converting it to Malayalam, a prevalent language in South India using online character recognition mechanism. The motivation behind this work owes its credit to (i) developing a mechanism to recognize Grantha script in this modern world and (ii) affirming the strong connection among Grantha and Malayalam. A framework for the recognition of Grantha script using online character recognition is designed and implemented. The features extracted from the Grantha script comprises mainly of time-domain features based on writing direction and curvature. The recognized characters are mapped to corresponding Malayalam characters. The framework was tested on a bed of medium length manuscripts containing 9-12 sample lines and printed pages of a book titled Soundarya Lahari writtenin Grantha by Sri Adi Shankara to recognize the words and sentences. The manuscript recognition rates with the system are for Grantha as 92.11%, Old Malayalam 90.82% and for new Malayalam script 89.56%. The recognition rates of pages of the printed book are for Grantha as 96.16%, Old Malayalam script 95.22% and new Malayalam script as 92.32% respectively. These results show the efficiency of the developed system |
Description: | (IJACSA) International Journal of Advanced Computer Science and Applications, Vol. 3, No. 7, 2012 |
URI: | http://dyuthi.cusat.ac.in/purl/4106 |
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An Online Chara ... ha Script to Malayalam.pdf | (548.4Kb) |
Abstract: | This paper presents an efficient Online Handwritten character Recognition System for Malayalam Characters (OHR-M) using Kohonen network. It would help in recognizing Malayalam text entered using pen-like devices. It will be more natural and efficient way for users to enter text using a pen than keyboard and mouse. To identify the difference between similar characters in Malayalam a novel feature extraction method has been adopted-a combination of context bitmap and normalized (x, y) coordinates. The system reported an accuracy of 88.75% which is writer independent with a recognition time of 15-32 milliseconds |
Description: | 2009 World Congress on Nature & Biologically Inspired Computing (NaBIC 2009) |
URI: | http://dyuthi.cusat.ac.in/purl/4314 |
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On-Line Handwri ... using Kohonen Networks.pdf | (379.0Kb) |
Abstract: | Zinc aluminate nanoparticles with average particle size of 40 nm were synthesized using a sol–gel combustion method. X-ray diffractometry result was analysed by Rietveld refinement method to establish the phase purity of the material. Different stages of phase formation of the material during the synthesis were investigated using differential scanning calorimetry and differential thermogravimetric analysis. Particle size was determined with transmission electron microscopy and the optical bandgap of the nanoparticles was determined by absorption spectroscopy in the ultraviolet-visible range. Dielectric permittivity and a.c. conductivity of the material were measured for frequencies from 100 kHz to 8 MHz in the temperature range of 30–120◦C. The presence of Maxwell– Wagner type interfacial polarization was found to exist in the material and hopping of electron by means of quantum mechanical tunneling is attributed as the reason for the observed a.c. conductivity |
Description: | Bull. Mater. Sci., Vol. 34, No. 2, April 2011, pp. 251–259 |
URI: | http://dyuthi.cusat.ac.in/purl/4374 |
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On structural, ... luminate nanoparticles.pdf | (577.6Kb) |
Abstract: | For a set S of vertices and the vertex v in a connected graph G, max x2S d(x, v) is called the S-eccentricity of v in G. The set of vertices with minimum S-eccentricity is called the S-center of G. Any set A of vertices of G such that A is an S-center for some set S of vertices of G is called a center set. We identify the center sets of certain classes of graphs namely, Block graphs, Km,n, Kn −e, wheel graphs, odd cycles and symmetric even graphs and enumerate them for many of these graph classes. We also introduce the concept of center number which is defined as the number of distinct center sets of a graph and determine the center number of some graph classes |
Description: | arXiv preprint arXiv:1312.3182 |
URI: | http://dyuthi.cusat.ac.in/purl/4226 |
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On The Center S ... of Some Graph Classes.pdf | (198.9Kb) |
Abstract: | Activation energy for crystallization (Ec) is a pertinent parameter that decides the application potential of many metallic glasses and is proportional to the crystallization temperature. Higher crystallization temperatures are desirable for soft magnetic applications, while lower values for data storage purposes. In this investigation, from the heating rate dependence of peak crystallization temperature Tp, the Ec values have been evaluated by three different methods for metglas 2826 MB (Fe40Ni38B18Mo4) accurately. The Ec values are correlated with the morphological changes, and the structural evolution associated with annealing temperatures is discussed. |
URI: | http://dyuthi.cusat.ac.in/purl/2842 |
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Dyuthi-P00395.pdf | (452.8Kb) |
Abstract: | The temperature and frequency dependence of dielectric permittivity and dielectric loss of nanosized Mn1−xZnxFe2O4 (for x = 0, 0.2, 0.4, 0.6, 0.8, 1) were investigated. The impact of zinc substitution on the dielectric properties of the mixed ferrite is elucidated. Strong dielectric dispersion and broad relaxation were exhibited by Mn1−xZnxFe2O4. The variation of dielectric relaxation time with temperature suggests the involvement of multiple relaxation processes. Cole–Cole plots were employed as an effective tool for studying the observed phenomenon. The activation energies were calculated from relaxation peaks and Cole–Cole plots and found to be consistent with each other and indicative of a polaron conduction |
Description: | J. Phys.: Condens. Matter 21 (2009) 146006 (12pp) |
URI: | http://dyuthi.cusat.ac.in/purl/4393 |
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On the dielectr ... se zinc mixed ferrites.pdf | (4.818Mb) |
Abstract: | The set of vertices that maximize (minimize) the remoteness is the antimedian (median) set of the profile. It is proved that for an arbitrary graph G and S V (G) it can be decided in polynomial time whether S is the antimedian set of some profile. Graphs in which every antimedian set is connected are also considered. |
URI: | http://dyuthi.cusat.ac.in/purl/4217 |
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On the generali ... blemantimedian subsets.pdf | (142.4Kb) |
Abstract: | Magnetic nanowires (NWs) are ideal materials for the fabrication of various multifunctional nanostructures which can be manipulated by an external magnetic fi eld. Highly crystalline and textured nanowires of nickel (Ni NWs) and cobalt (Co NWs) with high aspect ratio (~330) and high coercivity have been synthesized by electrodeposition using nickel sulphate hexahydrate (NiSO4·6H2O) and cobalt sulphate heptahydrate (CoSO4·7H2O) respectively on nanoporous alumina membranes. They exhibit a preferential growth along〈110〉. A general mobility assisted growth mechanism for the formation of Ni and Co NWs is proposed. The role of the hydration layer on the resulting one-dimensional geometry in the case of potentiostatic electrodeposition is verified. A very high interwire interaction resulting from magnetostatic dipolar interactions between the nanowires is observed. An unusual low-temperature magnetisation switching for fi eld parallel to the wire axis is evident from the peculiar high fi eld M(T) curve |
Description: | Nano Res (2008) 1: 465 473 |
URI: | http://dyuthi.cusat.ac.in/purl/4372 |
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On the Growth M ... ir Magnetic Properties.pdf | (912.6Kb) |
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