Abstract: | Nearly half of lanthanum sites in lanthanum manganites were substituted with monovalent ion-sodium and the compound possessed distorted orthorhombic structure. Ferromagnetic ordering at 300K and the magnetic isotherms at different temperature ranges were analyzed for estimating magnetic entropy variation. Magnetic entropy change of 1.5 J kg 1 K 1 was observed near 300 K. An appreciable magnetocaloric effect was also observed for a wide range of temperatures near 300K for small magnetic field variation. Heat capacity was measured for temperatures lower than 300K and the adiabatic temperature change increases with increase in temperature with a maximum of 0.62K at 280 K |
Description: | APPLIED PHYSICS LETTERS 104, 092407 (2014) |
URI: | http://dyuthi.cusat.ac.in/purl/4427 |
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Near fifty perc ... mperature applications.pdf | (1.450Mb) |
Abstract: | In the title molecule, C16H11N5, the mean planes of the quinoxaline and indazole fragments form a dihedral angle of 10.62 (5). In the crystal, weak intermolecular N—H..........N hydrogen bonds link the molecules into zigzag chains extending in the [001] direction. The crystal packing also exhibits pye interactions [centroid–centroid distances of 3.7080 (2) and 3.8220 (5) A ˚ ], which form stacks of the molecules parallel to the a axis |
URI: | http://dyuthi.cusat.ac.in/purl/1649 |
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leeju.pdf | (199.0Kb) |
Abstract: | Modeling of chaotic systems, based on the output time series, is quite promising since the output often represents the characteristic behaviour of the total system. It has been an interesting topic for researchers over the past few years. So far, some methods are developed for the identification of chaotic systems. Because of the intense complexity of chaotic systems, the performance of existing algorithms is not always satisfactory. Application of chaotic system theory to socially relevant problems like environmental studies is the need of the hour Neural networks have the required self-learning capability to tune the network parameters (i.e. weights) for identifying highly non-linear and chaotic systems. In the present work, effectiveness of modeling a chaotic system using dynamic neural networks has been demonstrated. From the rich literature available for non-linear modeling with neural networks, the Recurrent Neural Network (RNN) structure is selected. The Extended Kalman Filter (EKF) algorithm is used to train the RNN. Further, the Expectation Maximization algorithm is used to effectively arrive at the initial states and the state covariance. Particle filter algorithm with its two important variants namely Sampling Importance Resampling (SIR) and Rao Blackwellised algorithms are also used for training the given RNN. Four standard chaotic systems, Lorenz, Rossler, Chua and Chen, are modelled with the three algorithms. The best algorithm is found to be EKF-EM based on the least mean square error criterion. Validation of RNN model with EKFEM algorithm is done in time domain by Estimation of embedding dimension, Phase plots, Lyapunov Exponents, Kaplan -Yorke dimension and Bifurcation diagrams. Analysis of the chaotic systems is also performed in the transform domain using Fourier, Wavelet and Mapped Real Transforms. viii Natural chaotic systems are analyzed based on the selected model structure and training algorithm, taken for analysis. Sunspot, Venice Lagoon and North Atlantic oscillations are the three of the natural chaotic systems modelled with the selected RNN model structure and EKF-EM algorithm. |
URI: | http://dyuthi.cusat.ac.in/purl/5162 |
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Dyuthi-T2196.pdf | (6.188Mb) |
Description: | International School of Photonics, Cochin University of Science and Technology |
URI: | http://dyuthi.cusat.ac.in/purl/2556 |
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Dyuthi-T0700.pdf | (11.28Mb) |
Abstract: | Pyridoxal 5'-phosphate (PLP) is the major coenzymatic form of pyridoxine. There are over one hundred known pyridoxal 5'-phosphate-dependent reactions, most of which are involved in the metabolism of various amino acids . Pyridoxamine 5'-phosphate can function in aminotransf erase reactions by the cyclic regeneration of the two active phosphate forms. Pyridoxal 5'-phosphate-dependent reactions studied in the nervous system are involved in the catabolism of various amino acids. The putative neurotransmitters , dopamine, norepinephrine , serotonin , histamine , aminobutyric acid and taurine , as well as the sphingoiipids and poly amines are synthesized by PLP-dependent enzymes. Of these enzymes, three ( glutamic acid decarboxylase , 5-hydroxytryptophan decarboxylase and crnithine decarboxylase) seem to have crucial roles (Fig. '). The clinical effects of pyridoxine deficiency can be explained on the basis of the known decreases in the activities of these enzymes |
URI: | http://dyuthi.cusat.ac.in/purl/600 |
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K Dakshinamurti and others (1985) PDF.PDF | (14.43Mb) |
Abstract: | Veuruenducrim lri v j p .rim, deficienc:v. NEUROSCI BIOBEHAV REV 12(3/4) 189-193. 1988.- Dihydroxyphenylalanine decarboxvlase and 5-hydroxytryptophan decarboxvlase respectively have high and low affinities for pyridoxal phosphate. In the pyridoxinedeficient animal. hypothalamic serotonin content is significantly reduced without any change in catecholamine levels. Hypothalamic neurotransmitters affect the hvpothalamo-pituitary-end organ axes. Specifically, the decrease in hypothalamic serotonin in the pyridoxine-deficient rat results in tertiary hypothyroidism. In addition. pineal function is affected in deficient animals due to decreased synthesis of melatonin. |
URI: | http://dyuthi.cusat.ac.in/purl/598 |
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K Dakshinamurti and others (1988) PDF.PDF | (4.117Mb) |
URI: | http://dyuthi.cusat.ac.in/purl/577 |
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Simon Chiu and others(1981)11dec7.PDF | (2.020Mb) |
Abstract: | This thesis Entitled Neuronal degeneration in streptozotocin induced diabetic rats: effect of aegle marmelose and pyridoxine in pancreatic B cell proliferation and neuronal survival. Diabetes mellitus, a chronic metabolic disorder results in neurological dysfunctions and structural changes in the CNS. Antioxidant therapy is a challenging but necessary dimension in the management of diabetes and neurodegenerative changes associated with it. Our results showed regional variation and imbalance in the expression pattern of dopaminergic receptor subtypes in diabetes and its role in imbalanced insulin signaling and glucose regulation. Disrupted dopaminergic signaling and increased hyperglycemic stress in diabetes contributed to the neuronal loss. Neuronal loss in diabetic rats mediated through the expression of pattern of GLUT-3, CREB, IGF-1, Akt-1, NF,B, second messengers- cAMP, cGMP, IP3 and activation of apoptotic factors factors- TNF-a,caspase-8. Disrupted dopaminergic receptor expressions and its signaling in pancreas contributed defective insulin secretion in diabetes. Activation of apoptotic factors- TNF- a,caspase-8 and defective functioning of neuronal survival factors, disrupted second messenger signaling modulated neuronal viability in diabetes. Hyperglycemic stress activated the expression of TNF-a,caspase-8, BAX and differential expression of anti oxidant enzymes- SOD and GPx in liver lead to apoptosis. Treatment of diabetic rats with insulin, Aegle marmelose and pyridoxine significantly reversed the altered dopaminergic neurotransmission, GLUT3, GLUT2, IGF-1 and second messenger signaling. Antihyperglycemic and antioxidant activity of Aegle marmelose and pyridoxine enhanced pancreatic B cell proliferation, increased insulin synthesis and secretion in diabetic rats. Thus our results conclude the neuroprotective and regenerating ability of Aegle marmelose and pyridoxine which in turn has a novel therapeutic role in the management of diabetes. |
Description: | Center for neuroscience, Department of Biotechnology, Cochin University of Science and Technology |
URI: | http://dyuthi.cusat.ac.in/purl/3040 |
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Dyuthi-T1014.pdf | (26.10Mb) |
Abstract: | Neuroscience is the study of'tbe ne rvous system , including the i - ; . in, spinal cord and peripheral nerves . Neurons are the basic cells of the brain and nervous system which exerts its functional role through various neurotransmitters and receptor systems . The activity of a nen ren depends on the balance between the number of excitatory and inhibito r y processes affecting it, both processes occurring individually and sin ,tlte-' ,ieously. The functional bal,ince of different neurotransmitters such as Acct >>lcholine (Ach), Dopamine (DA), Serotonin (5-1-17), Nor epinepbri,te (N.1 j, Epinephrine (LPI), Glutamate and Gamma amino butyric acid (GA BA) regulates the growth , division and other vital functions ofa normal cell / organisin (Sudha, 1 998). The micro-environ ; nertt of the cell is controlled / the macro-environment that surrounds the individual. Any change in the cell environment causes imbalance in cell homeostasis and f,ntction. Pollution is a significant cause of imbalance caused iii the inacYcenvironment. Interaction with polluted environments can have an adverse impact on the health of humans. The alarming rise in enviromilmieil cont.iniin :rtion has been linked to rises in levels of pesticides, ndltstr al effluents, domestic Waste, car exhausts and other anthropogenic activities. Persistent exposures to contaminant cause a negative imp,-, on brain health and development . Pollution also causes a change in the neurotransmitters and their receptor function leading to earl.;' recurrence of neurodcge,terative disorders such as flypoxia , Alzbeimers's and Huntington 's disease early in life. |
URI: | http://dyuthi.cusat.ac.in/purl/649 |
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Dr. P Natarajan and others(.PDF | (7.142Mb) |
URI: | http://dyuthi.cusat.ac.in/purl/658 |
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C S P and others (1999).PDF | (7.034Mb) |
URI: | http://dyuthi.cusat.ac.in/purl/657 |
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C S P and others (2005).PDF | (7.537Mb) |
Abstract: | The recent developments in neurobiology have rendered new prominence and potential to study about the structure and function of brain and related disorders. Human behaviour is the net result of neural control of the communication between brain cells. Neurotransmitters are chemicals that are used to relay, amplify and modulate electrical signals between neurons and/or another cell. It mediates rapid intercellular communication through the nervous system by interacting with cell surface receptors. These receptors often trigger second messenger signaling pathways that regulate the activity of ion channels. The functional balance of different neurotransmitters such as Acetylcholine (Ach), Dopamine (DA), Serotonin (5-HT), Norepinephrine (NE), Epinephrine (EPI), Glutamate and Gamma amino butyric acid (GABA) regulates the growth, division and other vital functions of a normal cell / organism (Sudha, 1998). Any change in neurotransmitters' functional balance will result in the failure of cell function and may lead to the occurrence of diseases. Abnormalities in the production or functioning of neurotransmitters have been implicated in a number of neurological disorders like Schizophrenia, Alzheimer's, Epilepsy, Depression and Parkinson's disease. Changes in central and peripheral neuronal signaling system is also noted in diabetes, cancer, cell proliferation, alcoholism and aging. Elucidation of neurotransmitters receptor interaction pathways and gene expression regulation by second messengers and transcriptional factors in health and disease conditions can lead to new small molecules for development of therapeutic agents to improve neurological disease conditions. Increased awareness of the global effects of neurological disorders should help health care planners and the neurological community set appropriate priorities in research, prevention, and management of these diseases. |
URI: | http://dyuthi.cusat.ac.in/purl/656 |
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C S P and others (2006)25oct.PDF | (7.318Mb) |
Abstract: | The primary objective of this work is to develop an efficient accelerator system for low temperature vulcanization of rubbers. Although xanthates are known to act as accelerators for low temperature vulcanization, a systematic study on the mechanism of vulcanization, the mechanical properties of the vulcanizates at varying temperatures of vulcanization, cure characteristics etc are not reported. Further. xanthate based curing systems are not commonly used because of their chance for premature vulcanization during processing. The proposed study is to develop a novel accelerator system for the low temperature vulcanization of rubbers having enough processing safely. lt is also proposed to develop a method for the prevulcanisation of natural rubber latex at room temperature. As already mentioned the manufacture of rubber products at low temperature will improve its quality and appearance. Also, energy consumption can be reduced by low temperature vulcanization. in addition, low temperature vulcanization will be extremely useful in the area of repair of defective products, since subjecting finished products to high temperatures during the process of repair will adversely affect the quality of the product. Further. room temperature curing accelerator systems will find extensive applications in surface coating industries. |
Description: | Department of Polymer science & Rubber Technology, Cochin University of Science And Technology |
URI: | http://dyuthi.cusat.ac.in/purl/3626 |
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Dyuthi-T1606.pdf | (2.543Mb) |
Abstract: | A simple technique to improve the impedance bandwidth of a circular microstrip patch antenna using two sectorial slots is proposed. Using this design more than 5% impedance bandwidth is obtained. The added advantage of this new antenna is that it can be fed by a 50- microstrip line |
URI: | http://dyuthi.cusat.ac.in/purl/1366 |
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A new broadband circular patch antenna.PDF | (1.429Mb) |
Abstract: | A simple technique to improve the impedance bandwidth of a circular microstrip patch antenna using two sectorial slots is proposed. Using this design more than 5% impedance bandwidth is obtained. The added advantage of this new antenna is that it can be fed by a 50 microstrip line. |
URI: | http://dyuthi.cusat.ac.in/jspui/handle/dyuthi/1558 |
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A new broadband circular patch antenna.PDF | (1.429Mb) |
Abstract: | A new compact dual-band, dual-polarized microstrip antenna is presented. 7'iris antenna resonates at two frequencies with different polarizations: a linearly polarized one for terrestrial communication, and a circularly polarized one for satellite mobile communication. This antenna also provides an area reduction of 70% compared to a standard rectangular patch antenna |
URI: | http://dyuthi.cusat.ac.in/purl/1376 |
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A new compact d ... zed microstrip antenna.PDF | (1.044Mb) |
Abstract: | A new microstrip antenna geometry with considerable reduction in size, with similar radiation characteristics to those of an equivalent rectangular patch antenna is proposed. A relationship has been suggested for fmding out the resonant frequency of the new geometry, and its validity has been established by the experimental results. Without increasing the aperture area, this geometry also offers a facility for considerably reducing the resonant frequency compared to conventional patches. |
URI: | http://dyuthi.cusat.ac.in/purl/673 |
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New compact microstrip antenna Jacob.pdf | (248.7Kb) |
Abstract: | This paper presents the design of a new type of corner reflector (CR) antenna and the experimental investigation of its radiation characteristics. The design involves the addition of planar parallel periodic strips to the two sides of a CR antenna. The position, angular orientation, and number of strips have a notable effect on the H-plane radiation characteristics of the antenna. Certain configurations of the new antenna are capable of producing very sharp axial beams with gain on the order of 5 dB over the square corner reflector antenna. A configuration that can provide symmetric twin beams with enhanced gain and reduced half-power beam width (HPBW) is also presented. |
URI: | http://dyuthi.cusat.ac.in/purl/2980 |
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Dyuthi-P00415.pdf | (146.7Kb) |
Abstract: | In this paper, a novel fast method for modeling mammograms by deterministic fractal coding approach to detect the presence of microcalcifications, which are early signs of breast cancer, is presented. The modeled mammogram obtained using fractal encoding method is visually similar to the original image containing microcalcifications, and therefore, when it is taken out from the original mammogram, the presence of microcalcifications can be enhanced. The limitation of fractal image modeling is the tremendous time required for encoding. In the present work, instead of searching for a matching domain in the entire domain pool of the image, three methods based on mean and variance, dynamic range of the image blocks, and mass center features are used. This reduced the encoding time by a factor of 3, 89, and 13, respectively, in the three methods with respect to the conventional fractal image coding method with quad tree partitioning. The mammograms obtained from The Mammographic Image Analysis Society database (ground truth available) gave a total detection score of 87.6%, 87.6%, 90.5%, and 87.6%, for the conventional and the proposed three methods, respectively. |
Description: | Journal of Digital Imaging, Vol 23, No 5 (October), 2010: pp 538-546 |
URI: | http://dyuthi.cusat.ac.in/purl/4573 |
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A New Fast Frac ... ications in Mammograms.pdf | (229.2Kb) |
Abstract: | A new fast stream cipher, MAJE4 is designed and developed with a variable key size of 128-bit or 256-bit. The randomness property of the stream cipher is analysed by using the statistical tests. The performance evaluation of the stream cipher is done in comparison with another fast stream cipher called JEROBOAM. The focus is to generate a long unpredictable key stream with better performance, which can be used for cryptographic applications. |
Description: | INDICON, 2005 Annual IEEE |
URI: | http://dyuthi.cusat.ac.in/purl/3865 |
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A New Fast Stream Cipher MAJE4.pdf | (1.449Mb) |
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