| Abstract: | A simple and inexpensive linear magnetic field sweep generating system suitable for magnetic resonance experiments is described. The circuit, utilising a modified IC bootstrap configuration, generates field sweep over a wide range of sweep durations with excellent sweep linearity. |
| URI: | http://dyuthi.cusat.ac.in/purl/2427 |
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| Dyuthi-P0287.pdf | (220.7Kb) |
| Abstract: | A single-feed rectangular-ring microstrip antenna is proposed for indoor communication under the Bluetooth protocol. The dimensions of the antenna together with the location of the feed point are optimized through field simulations in order to cover the Bluetooth bandwidth and to avoid linear polarization. The performance and the efficiency of the antenna are illustrated in a real indoor environment |
| URI: | http://dyuthi.cusat.ac.in/purl/1354 |
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| Simple low-cost ... the Bluetooth protocol.PDF | (560.9Kb) |
| Abstract: | A simple and inexpensive power supply suitable for characteristics studies of a klystron is described. The circuit is a modified form of the high voltage adjustable power supply based on LM 317. This provides the necessary cavity and repeller voltages over a wide range, with good regulation. The system is protected aa- ainst short circuits and is ideallv suitable for laboratorv, ex.Deri ments with reflex klystrons. |
| Description: | Meas. Sci. Technol. 3 (1992) 1146-1148 |
| URI: | http://dyuthi.cusat.ac.in/purl/4476 |
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| A simple regula ... f klystron oscillators.pdf | (140.9Kb) |
| Abstract: | The authors apply the theory of photothermal lens formation and also that of pure optical nonlinearity to account for the phase modulation in a beam as it traverses a nonlinear medium. It is used to simultaneously determine the nonlinear optical refraction and the thermo-optic coefficient. They demonstrate this technique using some metal phthalocyanines dissolved in dimethyl sulfoxide, irradiated by a Q-switched Nd:YAG laser with 10 Hz repetition rate and a pulse width of 8 ns. The mechanism for reverse saturable absorption in these materials is also discussed. |
| URI: | http://dyuthi.cusat.ac.in/purl/2575 |
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| Dyuthi-P0135.pdf | (748.2Kb) |
| Abstract: | The distance DG(v) of a vertex v in an undirected graph G is the sum of the distances between v and all other vertices of G. The set of vertices in G with maximum (minimum) distance is the antimedian (median) set of a graph G. It is proved that for arbitrary graphs G and J and a positive integer r 2, there exists a connected graph H such that G is the antimedian and J the median subgraphs of H, respectively, and that dH(G, J) = r. When both G and J are connected, G and J can in addition be made convex subgraphs of H. |
| Description: | Networks vol 56(2),pp 90-94 |
| URI: | http://dyuthi.cusat.ac.in/purl/4203 |
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| Simultaneous Em ... d Antimedian Subgraphs.pdf | (146.2Kb) |
| Abstract: | A novel technique for obtaining dual-hand circular polarization (CP) radiation of a single-feed circular microstrip antenna in proposed and demonstrated. By embedding two pain of arc shaped slots of proper lengths close to the boundary of a circular patch, and protruding one of the arc-shaped slots with a narrow slit, the circular microstrip antenna can perform dual-hand CP radiation using a single probe feed. Details of the antenna design |
| URI: | http://dyuthi.cusat.ac.in/purl/1352 |
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| Single-feed dua ... sed microstrip antenna.PDF | (1.125Mb) |
| Abstract: | A novel dual frequency dual-polarized square microstrip patch antenna embedded with a slot is presented. The proposed antenna offers tunability of the frequency ratio between the two frequencies by adjusting the slot dimensions. This configuration also provides a size reduction up to -51 and 35% for the two modes as compared to a square micro strip patch antenna |
| URI: | http://dyuthi.cusat.ac.in/purl/1371 |
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| Single-feed dua ... are microstrip antenna.PDF | (1.456Mb) |
| Abstract: | In this paper, a new directionally adaptive, learning based, single image super resolution method using multiple direction wavelet transform, called Directionlets is presented. This method uses directionlets to effectively capture directional features and to extract edge information along different directions of a set of available high resolution images .This information is used as the training set for super resolving a low resolution input image and the Directionlet coefficients at finer scales of its high-resolution image are learned locally from this training set and the inverse Directionlet transform recovers the super-resolved high resolution image. The simulation results showed that the proposed approach outperforms standard interpolation techniques like Cubic spline interpolation as well as standard Wavelet-based learning, both visually and in terms of the mean squared error (mse) values. This method gives good result with aliased images also. |
| Description: | International Journal of Artificial Intelligence & Applications (IJAIA), Vol.1, No.4, October 2010 |
| URI: | http://dyuthi.cusat.ac.in/purl/4574 |
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| Single Frame Im ... Learned Directionlets.pdf | (714.6Kb) |
| Abstract: | The quantum yields of singlet oxygen production and lifetimes at the gas–solid interface in silica gel material are determined. Different photosensitizers (PS) are encapsulated in parallelepipedic xerogel monoliths (PS-SG). PS were chosen according to their known photooxidation properties: 9,10-dicyanoanthracene (DCA), 9,10-anthraquinone (ANT), and a benzophenone derivative, 4-benzoyl benzoic acid (4BB). These experiments are mainly based on time-resolved 1O2 phosphorescence detection, and the obtained FD and tD values are compared with those of a reference sensitizer for production, 1H-phenalen-1- one (PN), included in the same xerogel. The trend between their ability to oxidize organic pollutants in the gas phase and their efficiency for production is investigated through photooxidation experiments of a test pollutant dimethylsulfide (DMS). The FD value is high for DCA-SG relative to the PN reference, whereas it is slightly lower for 4BB-SG and for ANT-SG. FD is related to the production of sulfoxide and sulfone as the main oxidation products for DMS photosensitized oxidation. Additional mechanisms, leading to C!S bond cleaveage, appear to mainly occur for the less efficient singlet oxygen sensitizers 4BB-SG and ANTSG. |
| URI: | http://dyuthi.cusat.ac.in/purl/711 |
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| paper16.pdf | (352.6Kb) |
| Abstract: | We have investigated the third-order nonlinearity in ZnO nanocolloids with particle sizes in the range 6-18 nm by the z-scan technique. The third-order optical susceptibility χ(3) increases with increasing particle size (R) within the range of our investigations. In the weak confinement regime, an R2 dependence of χ(3) is obtained for ZnO nanocolloids. The optical limiting response is also studied against particle size. |
| URI: | http://dyuthi.cusat.ac.in/purl/2586 |
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| Dyuthi-P0146.pdf | (755.0Kb) |
| Abstract: | In this article we present size dependent spectroscopic observations of nanocolloids of ZnO. ZnO is reported to show two emission bands, an ultraviolet (UV) emission band and another in the green region. Apart from the known band gap 380 nm and impurity 530 nm emissions, we have found some peculiar features in the fluorescence spectra that are consistent with the nanoparticle size distribution. Results show that additional emissions at 420 and 490 nm are developed with particle size. The origin of the visible band emission is discussed. The mechanism of the luminescence suggests that UV luminescence of ZnO colloid is related to the transition from conduction band edge to valence band, and visible luminescence is caused by the transition from deep donor level to valence band due to oxygen vacancies and by the transition from conduction band to deep acceptor level due to impurities and defect states. A correlation analysis between the particle size and spectroscopic observations is also discussed. |
| URI: | http://dyuthi.cusat.ac.in/purl/2639 |
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| Dyuthi-P0326.pdf | (963.7Kb) |
| Abstract: | Silver silica nanocomposites were obtained by the sol–gel technique using tetraethyl orthosilicate (TEOS) and silver nitrate (AgNO3) as precursors. The silver nitrate concentration was varied for obtaining composites with different nanoparticle sizes. The structural and microstructural properties were determined by x-ray diffractometry (XRD), Fourier transform infrared spectroscopy (FTIR) and transmission electron microscopy (TEM). X-ray photoelectron spectroscopic (XPS) studies were done for determining the chemical states of silver in the silica matrix. For the lowest AgNO3 concentration, monodispersed and spherical Ag crystallites, with an average diameter of 5 nm, were obtained. Grain growth and an increase in size distribution was observed for higher concentrations. The occurrence of surface plasmon resonance (SPR) bands and their evolution in the size range 5–10 nm is studied. For decreasing nanoparticle size, a redshift and broadening of the plasmon-related absorption peak was observed. The observed redshift and broadening of the SPR band was explained using modified Mie scattering theory |
| Description: | Nanotechnology 19 (2008) 075710 (7pp) |
| URI: | http://dyuthi.cusat.ac.in/purl/4352 |
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| Size-dependent ... silica nanocomposites.pdf | (858.7Kb) |
| Abstract: | A novel dual frequency design of a square microstrip antenna coaxially fed along the diagonal with a chip capacitor mounted at the bottom of the stub is introduced. This design provides enhanced area reduction and good cross-polarization levels. The antenna design can be used as a compact antenna system where limited size is a major requirement. The details of the antenna design and experimental results are presented |
| URI: | http://dyuthi.cusat.ac.in/purl/1382 |
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| Slot coupled sq ... al-frequency operation.PDF | (1.351Mb) |
| Abstract: | A slot line fed planar dipole antenna with a parasitic strip for wide band applications is presented. The presented antenna offers a 2:1 VSWR bandwidth from 1.66 to 2.71 GHz covering the DCS/ PCS/UMTS and IEEE 802.11b/g bands with a gain better than 6.5 dBi. The uniplanar design, simple feeding, and high gain make it a versatile antenna for wireless applications |
| Description: | MICROWAVE AND OPTICAL TECHNOLOGY LETTERS / Vol. 51, No. 3, March 2009 |
| URI: | http://dyuthi.cusat.ac.in/purl/4321 |
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| Slot Line Fed D ... Wide Band Applications.pdf | (416.4Kb) |
| Abstract: | Dual frequency operation is achieved from a compact microstrip antenna by loading a pair of narrow slots close to its radiating edges. The two frequencies have parallel polarization planes and similar radiation characteristics. The ratio between the two operating frequencies can be tuned in the range (1.14-1. 24), which is much smaller than that of similar designs. The above excellent radiation characteristics are achieved along with an area reduction of - 75% compared to the standard rectangular patch |
| URI: | http://dyuthi.cusat.ac.in/purl/1378 |
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| Slot-loaded com ... al-frequency operation.PDF | (1.081Mb) |
| Abstract: | The concept of social clause has been accepted in the GATT agreement to prescribe the labour standards. Social clause , $tands for protecting labour standards, more specificalfy prohibition of employment of children in hazardous industries, providing adequate wages. healthy and hygienic working conditions, special social welfare protection for women, prescription of hours of work and rest and provision for efficacious remedy in case of default by employer to provide these conditions to his workers. |
| Description: | SOUTHERN ECONOMIST - JUNE 1, 1997 |
| URI: | http://dyuthi.cusat.ac.in/purl/4294 |
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| Social Clause of WTO and India.pdf | (152.4Kb) |
| Abstract: | Tourism is an industry which is heavily dependent on marketing. Mouth to mouth communication has played a major role in shaping a number of destinations.This is particularly true in modern parlance.This is social networking phenomenon which is fast spreading over the internet .Many sites provide visitors a lot of freedom to express their views.Promotion of a destination depends lot on conversation and exchange of information over these social networks.This paper analyses the social networking sites their contribution to marketing tourism and hoapitality .The negetive impacts phenomena are also discussed |
| Description: | Indian Journal of Tourism and Hospitality Management Vol.11 No.2 Dec 2010 |
| URI: | http://dyuthi.cusat.ac.in/purl/4295 |
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| Social Media- A ... hospitality marketing.pdf | (337.6Kb) |
| Abstract: | The paper is an attempt to shed light on the socio-economic aspects of the local communities on the development of ecotourism in Kerala. Most of the local communities in the ecotourism destinations are tribes who have been excluded from the mainstream society and are not a part of Kerala’s overall development setting. The paper also tries to situate the community perception on the sustainable livelihood of ecotourism sites of Kerala. Data for the study is obtained from a primary survey by dividing the ecotourism destinations in Kerala into three zones, 230 from south zone, 220 from central zone and 200 from north zone with a total sample size of 650 based on the notion of community based ecotourism initiatives of the state. The result of the study confirms that ecotourism has helped to enhance the livelihood of the marginalized community. With well-knit policies it is possible to tag ecotourism of Kerala as an important tourism destination in the global tourism map |
| Description: | Research on Humanities and Social Sciences,Vol 2, No.11, 2012 |
| URI: | http://dyuthi.cusat.ac.in/purl/4591 |
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| Socio-Economic ... mentThe Case of Kerala.pdf | (701.7Kb) |
| Abstract: | This paper describes certain findings of intonation and intensity study of emotive speech with the minimal use of signal processing algorithms. This study was based on six basic emotions and the neutral, elicited from 1660 English utterances obtained from the speech recordings of six Indian women. The correctness of the emotional content was verified through perceptual listening tests. Marked similarity was noted among pitch contours of like-worded, positive valence emotions, though no such similarity was observed among the four negative valence emotional expressions. The intensity patterns were also studied. The results of the study were validated using arbitrary television recordings for four emotions. The findings are useful to technical researchers, social psychologists and to the common man interested in the dynamics of vocal expression of emotions |
| Description: | Procedia Engineering 30 (2012) 577 – 583 |
| URI: | http://dyuthi.cusat.ac.in/purl/4529 |
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| A socio friendl ... ysis of emotive speech.pdf | (336.4Kb) |
| Abstract: | Rare earth metal ion exchanged (La3+, Ce3+, RE3+) KFAU-Y zeolites were prepared by simple ion-exchange methods and have been characterized using different physico-chemical techniques. In this paper a novel application of solid acid catalysts in the dehydration/ Beckmann rearrangement of aldoximes; benzaldoxime and 4-methoxybenzaldoxime is reported. Dehydration/Beckmann rearrangement reactions of benzaldoxime and 4-methoxybenzaldoxime is carried out in a continuous down flow reactor at 473K. 4-Methoxybenzaldoxime gave both Beckmann rearrangement product (4-methoxyphenylformamide) and dehydration product (4-methoxybenzonitrile) in high overall yields. The difference in behavior of the aldoximes is explained in terms of electronic effects. The production of benzonitrile was near quantitative under heterogeneous reaction conditions. The optimal protocol allows nitriles to be synthesized in good yields through the dehydration of aldoximes. Time on stream studies show a fast decline in the activity of the catalyst due to neutralization of acid sites by the basic reactant and product molecules. |
| URI: | http://dyuthi.cusat.ac.in/purl/2253 |
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| Dyuthi-SS48.pdf | (495.6Kb) |
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