Abstract: | A novel and fast technique for cryptographic applications is designed and developed using the symmetric key algorithm “MAJE4” and the popular asymmetric key algorithm “RSA”. The MAJE4 algorithm is used for encryption / decryption of files since it is much faster and occupies less memory than RSA. The RSA algorithm is used to solve the problem of key exchange as well as to accomplish scalability and message authentication. The focus is to develop a new hybrid system called MARS4 by combining the two cryptographic methods with an aim to get the advantages of both. The performance evaluation of MARS4 is done in comparison with MAJE4 and RSA. |
Description: | India Conference, 2006 Annual IEEE |
URI: | http://dyuthi.cusat.ac.in/purl/3909 |
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A Novel Fast Hybrid Cryptographic System MARS4.pdf | (191.8Kb) |
Abstract: | A novel bisazomethine Schiff base was synthesised by the condensation of 3-hydroxyquinoxaline-2- carboxaldehyde and 2,3-diaminomaleonitrile. 1H NMR, 13C NMR, HPLC and FT-IR studies revealed that the compound exists in two major tautomeric forms. The Schiff base exhibits positive absorption and fluorescent solvatochromism and displays dual fluorescence with large stoke shifts. Cyclic voltammetric analysis of the compound in 1:1 methanol–THF was influenced by scan rate. Thermal analysis of the compound was undertaken using TG–DTA and DSC |
URI: | http://dyuthi.cusat.ac.in/purl/1645 |
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dyes.pdf | (678.4Kb) |
Abstract: | The thesis entitled novel heterocyclic constructions mediated by nucleophilic carbenes and related chemistry, embodies the results of the investigations carried out to explore the reactivity patterns of the 1:1 zwitterions, generated in situ from various nucleophilic carbenes and DiMethyl AcetyleneDicarboxylate(DMAD) towards aldehydes and ketones. The traditional synthesis of complex organic molecules employs stepwise formation of bonds and involves multiple steps. Besides the sequential synthesis, in several instances, the desired product can also be obtained in one pot reactions of three or more starting compounds. Such reactions in which more than two starting materials react to form a product in such a way that the majority of the atoms of the starting materials can be found in the products are called multicomponent reactions(MCRs). The results of our investigations on the application of N-heterocyclic carbenes in multicomponent reaction with DMAD and aromatic aldehydes leading to the one pot synthesis of 2-oxy-maleate and furanone derivatives. It is interesting to note that dihydrofuran and lactone motifs are present in a number of biologically active natural products and other heterocyclic compounds. It is conceivable that the novel multicomponent reactions described herein will find application in the synthesis of a variety of heterocyclic compounds, and in natural product synthesis. |
URI: | http://dyuthi.cusat.ac.in/purl/23 |
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Dyuthi-T0211.pdf | (2.751Mb) |
Abstract: | A novel H-shaped patch antenna suitable for wireless and satellite communications is presented. The new antenna has some advantages compared to conventional microstrip patch antennas, such as small size, a fewer number of modes, no harmonic resonance, and the provision of pure reactive impedances at its harmonics that can result in increasing the transmitter efficiency. The basic principles and design procedure are introduced. Two antennas at two different frequencies, 4 and 10 GHz, are designed, fabricated, and measured. The measured results show a good agreement with the predicted ones |
URI: | http://dyuthi.cusat.ac.in/purl/1380 |
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A novel H-shaped patch antenna.PDF | (275.9Kb) |
Abstract: | Hepcidin is cysteine-rich short peptide of innate immune system of fishes, equipped to perform prevention and proliferation of invading pathogens like bacteria and viruses by limiting iron availability and activating intracellular cascades. Hepcidins are diverse in teleost fishes, due to the varied aquatic environments including exposure to pathogens, oxygenation and iron concentration. In the present study, we report a 87-amino acid (aa) preprohepcidin (Hepc-CB1) with a signal peptide of 24 aa, a prodomain of 39 aa and a bioactive mature peptide of 24 aa from the gill mRNA transcripts of the deep-sea fish spinyjaw greeneye, Chlorophthalmus bicornis. Molecular characterisation and phylogenetic analysis categorised the peptide to HAMP2-like group with a mature peptide of 2.53 kDa; a net positive charge (?3) and capacity to form b-hairpin-like structure configured by 8 conserved cysteines. The present work provides new insight into the mass gene duplication events and adaptive evolution of hepcidin isoforms with respect to environmental influences and positive Darwinian selection. This work reports a novel hepcidin isoform under the group HAMP2 from a nonacanthopterygian deep-sea fish, C. bicornis |
Description: | Probiotics & Antimicro. Prot. (2013) 5:1–7 DOI 10.1007/s12602-012-9120-0 |
URI: | http://dyuthi.cusat.ac.in/purl/4071 |
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A Novel Isoform ... acterisation and Phylo.pdf | (609.9Kb) |
Abstract: | This thesis presents the microwave dielectric properties of two novel dielectric resonator materials with the composition Ca(Ca1/4Nb2/4Ti1/4)O3 and Ca(Ca1/4Ta2/4Ti1/4)O3 ceramics and their application in the fabrication of wideband antennas. The microwave dielectric properties of the ceramics were tailored by several techniques such as doping, glass addition and solid solution formations in the complex perovskite A and B-sites with suitable substitutions. Among the wide variety of DRs developed, ceramic resonators with optimum properties were identified to fabricate broadband dielectric resonator loaded microstrip patch antennas. Furthermore, wideband, high permittivity dielectric resonator antennas were fabricated and explored the possibility of tuning their characteristics by modifying the feed line geometries. |
URI: | http://dyuthi.cusat.ac.in/purl/2918 |
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Dyuthi-T0909.pdf | (18.00Mb) |
Abstract: | Lack of a valid shrimp cell line has been hampering the progress of research on shrimp viruses. One of the reasons identified was the absence of an appropriate medium which would satisfy the requirements of the cells in vitro. We report the first attempt to formulate an exclusive shrimp cell culture medium (SCCM) based on the haemolymph components of Penaeus monodon prepared in isosmotic seawater having 27 % salinity. The SCCM is composed of 22 amino acids, 4 sugars, 6 vitamins, cholesterol, FBS, phenol red, three antibiotics, potassium dihydrogen phosphate and di-sodium hydrogen phosphate at pH 6.8–7.2. Osmolality was adjusted to 720 ± 10 mOsm kg-1 and temperature of incubation was 25 8C. The most appropriate composition was finally selected based on the extent of attachment of cells and their proliferation by visual observation. Metabolic activity of cultured cells was measured by MTT assay and compared with that in L-15 (29), modified L-15 and Grace’s insect medium, and found better performance in SCCM especially for lymphoid cells with 107 % increase in activity and 85 ± 9 days of longevity. The cells from ovary and lymphoid organs were passaged twice using the newly designed shrimp cell dissociation ‘‘cocktail’’. |
Description: | Cytotechnology (2013) 65:307–322 DOI 10.1007/s10616-012-9491-9 |
URI: | http://dyuthi.cusat.ac.in/purl/4063 |
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A novel medium ... m from Penaeus monodon.pdf | (681.8Kb) |
Abstract: | In this introduction part, importance has been given to the elastomeric properties of polyurethanes. Emphasis has been laid to this property based on microphase separation and how this could be modified by modifying the segment lengths, as well as the structure of the segments. Implication was also made on the mechanical and thermal properties of these copolymers based on various analytical methods usually used for characterization of polymers. A brief overview of the challenges faced by the polyurethane chemistry was also done, pointing to the fact that though polyurethane industry is more than 75 years old, still a lot of questions remain unanswered, that too mostly in the synthesis of polyurethanes. A major challenge in this industry is the utilization of more environmental friendly “Green Chemistry Routes” for the synthesis of polyurethanes which are devoid of any isocyanates or harsh solvents.The research work in this thesis was focused to develop non-isocyanate green chemical process for polyurethanes and also self-organize the resultant novel polymers into nano-materials. The thesis was focused on the following three major aspects:(i) Design and development of novel melt transurethane process for polyurethanes under non-isocyanate and solvent free melt condition. (ii) Solvent induced self-organization of the novel cycloaliphatic polyurethanes prepared by the melt transurethane process into microporous templates and nano-sized polymeric hexagons and spheres. (iii) Novel polyurethane-oligophenylenevinylene random block copolymer nano-materials and their photoluminescence properties. The second chapter of the thesis gives an elaborate discussion on the “Novel Melt Transurethane Process ” for the synthesis of polyurethanes under non-isocyanate and solvent free melt condition. The polycondensation reaction was carried out between equimolar amounts of a di-urethane monomer and a diol in the presence of a catalyst under melt condition to produce polyurethanes followed by the removal of low boiling alcohol from equilibrium. The polymers synthesized through this green chemical route were found to be soluble (devoid of any cross links), thermally stable and free from any isocyanate entities. The polymerization reaction was confirmed by various analytical techniques with specific references to the extent of reaction which is the main watchful point for any successful polymerization reaction. The mechanistic aspects of the reaction were another point of consideration for the novel polymerization route which was successfully dealt with by performing various model reactions. Since this route was successful enough in synthesizing polyurethanes with novel structures, they were employed for the solvent induced self-organization which is an important area of research in the polymer world in the present scenario. Chapter three mesmerizes the reader with multitudes of morphologies depending upon the chemical backbone structure of the polyurethane as well as on the nature and amount of various solvents employed for the self-organization tactics. The rationale towards these morphologies-“Hydrogen Bonding ” have been systematically probed by various techniques. These polyurethanes were then tagged with luminescent 0ligo(phenylene vinylene) units and the effects of these OPV blocks on the morphology of the polyurethanes were analyzed in chapter four. These blocks have resulted in the formation of novel “Blue Luminescent Balls” which could find various applications in optoelectronic devices as well as delivery vehicles. |
URI: | http://dyuthi.cusat.ac.in/purl/2928 |
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Dyuthi-T0919.pdf | (14.64Mb) |
Abstract: | Photonic band-gap (PBG) structures are utilized in microwave components as filters to suppress unwanted signals. In this work, rectangular perforations were created in the ground plane of a microstrip line to construct a PBG structure. A gold-coated alumina substrate was utilized to switch or tune the bandstop characteristics of this structure. It was demonstrated that the bandstop characteristics were switched off from - 35 to - 1 dB at 16 GHz. Tuning of the bandstop edge with a shift of 1.5 GHz was also shown |
URI: | http://dyuthi.cusat.ac.in/purl/1409 |
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A novel method ... ning of PBG structures.PDF | (561.5Kb) |
Abstract: | HIV/AIDS is one of the most destructive epidemics in ever recorded history claims an estimated 2.4 –3.3 million lives every year. Even though there is no treatment for this pandemic Elisa and Western Blot tests are the only tests currently available for detecting HIV/AIDS. This article proposes a new method of detecting HIV/AIDS based on the measurement of the dielectric properties of blood at the microwave frequencies. The measurements were made at the S-band of microwave frequency using rectangular cavity perturbation technique with the samples of blood from healthy donors as well as from HIV/AIDS patients. An appreciable change is observed in the dielectric properties of patient samples than with the normal healthy samples and these measurements were in good agreement with clinical results. This measurement is an alternative in vitro method of diagnosing HIV/AIDS using microwaves. |
URI: | http://dyuthi.cusat.ac.in/xmlui/purl/2052 |
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A novel method of detecting...pdf | (156.8Kb) |
URI: | http://dyuthi.cusat.ac.in/purl/2924 |
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Dyuthi-T0915.pdf | (4.641Mb) |
Abstract: | In this paper, a multiband antenna using a novel fractal design is presented. The antenna structure is formed by inscribing a hexagonal slot within a circle. This base structure is then scaled and arranged within the hexagon along its sides without touching the outer structure. The proposed CPW fed, low profile antenna offers good performance in the 1.65 – 2.59 GHz, 4.16 – 4.52 GHz and 5.54 – 6.42 GHz bands and is suitable for GSM 1800/1900, Bluetooth, IMT advanced systems and upper WLAN applications. The antenna has been fabricated on a substrate of height 1.6 mm and εr = 4.4 and simulation and experimental results are found to be in good agreement |
Description: | RADIOENGINEERING,vol 22,issue 4,pp 1263 |
URI: | http://dyuthi.cusat.ac.in/purl/4330 |
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A Novel Planar ... Multiband Applications.pdf | (3.535Mb) |
Abstract: | A novel electrochemical sensor has been developed for the determination of nimesulide. The sensor is based on the NIM- molybdophosphoric acid (MPA) as the electroactive material in PVC matrix in presence of bis(2-ethyl hexyl) phthalate (BEP) as a plasticizer. The sensor showed a fast, stable, near Nernstian response for 1 × 10-2 –1 × 10-6 M NIM over the pH range 5 – 8 with a slope 55.6 ±0.5m V/decade and the response time is < 45 s. Selectivity coefficient data for some common ions show negligible interferences. The sensor was successfully applied for the determination of NIM in tablet and the results obtained are in good agreement with those obtained by the official method. |
URI: | http://dyuthi.cusat.ac.in/purl/517 |
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PEA%2025%203%202007%20375-381.pdf | (185.5Kb) |
Abstract: | The fabrication and electrochemical response characteristics of two novel potentiometric sensors for the selective determination of domperidone (DOM) are described. The two fabricated sensors incorporate DOM–PTA (phosphotungstic acid) ion pair as the electroactive material. The sensors include a PVC membrane sensor and a carbon paste sensor. The sensors showed a linear, stable, and near Nernstian slope of 56.5 and 57.8 mV/decade for PVC membrane and carbon paste sensors, respectively over a relatively wide range of DOM concentration (1.0 9 10-1–1.0 9 10-5 and 1.0 9 10-1–3.55 9 10-6 M). The response time of DOM–PTA membrane sensor was less than 25 s and that in the case of carbon paste sensor was less than 20 s.Auseful pH range of 4–6 was obtained for both types of sensors. A detection limit of 7.36 9 10-5 M was obtained for PVC membrane sensor and 1.0 9 10-6 M was obtained for carbon paste sensor. The proposed sensors showed very good selectivity toDOMin the presence of a large number of other interfering ions. The analytical application of the developed sensors in the determination of the drug in pharmaceutical formulations such as tablets was investigated. The results obtained are in good agreement with the values obtained by the standard method. The sensors were also applied for the determination ofDOMin real samples such as urine by the standard addition method. |
Description: | J Appl Electrochem (2010) 40:65–71 DOI 10.1007/s10800-009-9975-2 |
URI: | http://dyuthi.cusat.ac.in/purl/4011 |
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Novel potentiom ... minationof domperidone.pdf | (282.8Kb) |
Abstract: | An innovative phaseshifterless, wideband, micrustrip leaky-wave antenna with an electronically steerable dual-pencil-beam pattern in the H-plane is presented. The log-periodic geometry of the leaky slots of the antenna results in a wide bandwidth of 25.19%. The Jan beam can he steered up to 14° over the wide resonating band of the anteww. The beam is also steerable at a fixed frequency. by reactivelty loading the slots and a maximum steering angle of about 14° is ohserved. for different capacitor values with an improved bandwidth of 33 _i%. This concept is studied using passive components but it can be extended to varactors |
URI: | http://dyuthi.cusat.ac.in/purl/1418 |
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A novel electro ... dic leaky-wave antenna.PDF | (931.7Kb) |
Abstract: | A navel ultra-thin radar-absorbing material (RAM) using metanwterials is presented and the absorption performance is examined. Due to the high-impedance property of the metamalerials. the thickness of the RAM is about several tenths of the center wavelength of the absorption band, which is considerably thinner than conventional absorbers. The absorption bandwidth of the RAM is about several hundred megahertz |
URI: | http://dyuthi.cusat.ac.in/purl/1417 |
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A novel radar-a ... based on EBG structure.PDF | (907.3Kb) |
URI: | http://dyuthi.cusat.ac.in/purl/2797 |
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Dyuthi-T0818.pdf | (2.546Mb) |
Abstract: | A systematic investigation of the reactivity and functionalization of two heterocyclic analogs of triphenylmethane , namely tris(2-thienyl)methane and tris(2-furyl)methane have been carried out and the results are presented in this thesis entitled "NOVEL REACTIONS OF TRIS(2-THIENYL)METHANE AND TRIS(2-FURYL)METHANE.". The history of organic free radicals dates back to Gomberg's monumental discovery of the triphenylmethyl radical in 1900. The heterocyclic analogs of triarylmethane are also interesting from the vantage point of their transformation to the corresponding radicals akin to Gomberg ' s triphenylmethyl radical and also they are prone to further transformation leading to three dimensionally elongated molecules such as dendrimers. Dendritic architectures are one of the most pervasive topologies observed in nature at the macro- and microdimensional length devices. Because of their ability to combine both organic and inorganic compounds and their propensity to either encapsulate or be engineered into unimolecular functional devices , dendrimers are versatile amongst existing nanoscale building blocks and materials. |
URI: | http://dyuthi.cusat.ac.in/purl/936 |
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Dyuthi-T0219.pdf | (2.339Mb) |
Abstract: | Hindi |
Description: | Department of Hindi,CUSAT |
URI: | http://dyuthi.cusat.ac.in/purl/4764 |
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Dyuthi-T1861.pdf | (10.98Mb) |
Abstract: | Animportant step in the residue number system(RNS) based signal processing is the conversion of signal into residue domain. Many implementations of this conversion have been proposed for various goals, and one of the implementations is by a direct conversion from an analogue input. A novel approach for analogue-to-residue conversion is proposed in this research using the most popular Sigma–Delta analogue-to-digital converter (SD-ADC). In this approach, the front end is the same as in traditional SD-ADC that uses Sigma–Delta (SD) modulator with appropriate dynamic range, but the filtering is doneby a filter implemented usingRNSarithmetic. Hence, the natural output of the filter is an RNS representation of the input signal. The resolution, conversion speed, hardware complexity and cost of implementation of the proposed SD based analogue-to-residue converter are compared with the existing analogue-to-residue converters based on Nyquist rate ADCs |
Description: | International Journal of Electronics Vol. 96, No. 6, June 2009, 571–583 |
URI: | http://dyuthi.cusat.ac.in/purl/4020 |
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A novel Sigma–D ... e-to-residue converter.pdf | (707.5Kb) |
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