Abstract: | The impedance bandwidth of a high permittivity cylindrical dielectric resonator antenna excited by a micro strip line was significantly improved by modifying the feed geometry. The 10 dB return loss bandwidth is enhanced from 12 to 26% without much affecting the gain and other radiation properties of the antenna. Good agreement has been observed between the predicted and measured results |
URI: | http://dyuthi.cusat.ac.in/purl/1579 |
Files | Size |
---|---|
Broadband cylin ... dified microstrip line.PDF | (1.018Mb) |
Abstract: | A new dual port microstrip antenna geometry for dual frequency operation is presented. The structure consists of the intersection of two circles of the same radius with their centres displaced by a small fraction of the wavelength . This antenna provides wide impedance bandwidth and excellent isolation between its ports. The gain of the antenna is comparable to that of a standard circular microstrip antenna operating at the same resonant frequency. A theoretical analysis for calculating the resonant frequencies of the two ports is also presented |
URI: | http://dyuthi.cusat.ac.in/purl/1350 |
Files | Size |
---|---|
Broadband dual frequency microstrip antennas.PDF | (838.1Kb) |
Broadband dual frequency microstrip antennas.PDF | (838.1Kb) |
Abstract: | A microstrip antenna with large bandwidth is developed using a parasitic technique . Compared to the available wide-baud antennas,the proposed antenna structure is very compact and gives a lessdistorted radiation pattern with frequency . An impedance bandwidth,eight times that of a conventional patch antenna of the same size, Isachieved. The concept of coupled microstrip line model Is extended fortheoretical interpretation of the impedance loci |
URI: | http://dyuthi.cusat.ac.in/purl/1360 |
Files | Size |
---|---|
Broad-Band Gap Coupled Microstrip Antenna.PDF | (2.586Mb) |
Abstract: | A novel slope -strip feeding technique for a microstrip antenna is presented in order to achieve a broad bandwidth. The experimental results show that the optimal bandwidth attained is 53.4% for less than -10-dB return loss |
URI: | http://dyuthi.cusat.ac.in/purl/1405 |
Files | Size |
---|---|
A broadband slo ... crostrip patch antenna.PDF | (188.9Kb) |
Abstract: | The Present thesis deals with the numerical as well as experimental investigations conducted on the resonance and radiation characteristics of Drum shaped monopole antenna, Funnel shaped monopole antenna and the shorted coplanar antenna.An introduction to the over view of antennas, state of the art planar antenna technologies, different feeding techniques and introduction of coplanar waveguides have been discussed. |
Description: | Department of Electronics, Cochin University of Science and Technology |
URI: | http://dyuthi.cusat.ac.in/xmlui/purl/1953 |
Files | Size |
---|---|
Dyuthi-T0382.pdf | (8.779Mb) |
Abstract: | Hindi |
Description: | Department of Hindi, CUSAT |
URI: | http://dyuthi.cusat.ac.in/purl/4780 |
Files | Size |
---|---|
Dyuthi-T1877.pdf | (10.52Mb) |
Abstract: | The effective organization and utilisation of resources produced by the students, faculty and research scholars in university departments assume greater significance. Institutional repositories are developed by many institutions to provide resources and materials that support students in their studies. The present study recognizes the value of such a repository in the Engineering and Technology discipline in Cochin University of Science and Technology. The paper explains the need for a digital repository ofproject reports. The authors present a modelfor digital repository, and the organization.and administration of such a repository. The study also analyses the various other factors associated with the proposed depository. |
Description: | XXV IASLIC Conference I Chennai I 2005 I pp.117-120 |
URI: | http://dyuthi.cusat.ac.in/purl/4467 |
Files | Size |
---|---|
Building Digita ... s A Proposal for cusat.pdf | (196.0Kb) |
URI: | http://dyuthi.cusat.ac.in/purl/5566 |
Files | Size |
---|---|
Dyuthi T-2608.pdf | (4.403Mb) |
Abstract: | The detection of buried objects using time-domain freespace measurements was carried out in the near field. The location of a hidden object was determined from an analysis of the reflected signal. This method can be extended to detect any number of objects. Measurements were carried out in the X- and Ku-bands using ordinary rectangular pyramidal horn antennas of gain 15 dB. The same antenna was used as the transmitter and recei er. The experimental results were compared with simulated results by applying the two-dimensional finite-difference time-domain(FDTD)method, and agree well with each other. The dispersi e nature of the dielectric medium was considered for the simulation. |
URI: | http://dyuthi.cusat.ac.in/purl/2983 |
Files | Size |
---|---|
Dyuthi-P00419.pdf | (131.7Kb) |
Abstract: | The first chapter of the thesis gives a general introduction about flexible electronics, dielectrics and composites. The recent developments in flexible electronics also discussed in this chapter. The preparation and characterization techniques used for the butyl rubber ceramic composites are given in chapter 2. The synthesis and characterization of butyl rubber filled with low permittivity ceramic composites are described in chapter 3. The chapter 4 deals with the synthesis and characterization of butyl rubber-high permittivity ceramic composites. The effect of high permittivity ceramic fillers such as TiO2, Sr2Ce2Ti5O15 and SrTiO3 on dielectric, thermal and mechanical properties was studied. The present investigation deals with synthesis, characterization and properties of butyl rubber composites with low, high and very high ceramic fillers and also the effect of particle size on dielectric, thermal and mechanical properties of selected composites. |
URI: | http://dyuthi.cusat.ac.in/purl/4928 |
Files | Size |
---|---|
Dyuthi-T2004.pdf | (7.858Mb) |
Abstract: | This thesis Entitled Buyer information and brand choice behaviour in markets with asymmetries.The period of transition set in by globalization and liberalization has ensued a onsiderable degree of homogeneity with western societies with respect to quantity and quality of goods and services.The study is aimed at finding out how the buyers adapt to the prevalent complex and dynamic market configuration by taking an archetypical situation of information gathering and brand- choice decision of select household consumer durables.The study was based on a set of 301 sample respondents who were either first time purchasers or repeat purchasers for household use, of the items under study in the sample area comprising of rural, urban and semi-urban areas. Data were collected using interview schedule and analysis of the same was done with standard statistical computer programs.Buyer confidence as perceived by buyers with respect to information acquisition and brand-choice represents the felt competence to effectively function in the market.In general, lower levels of education, income and occupation showed lower levels of search. The oldest were also low searchers. The repeat purchasers of the product searched less than the first purchasers. The most important source of information was word of mouth or information from others followed by television advertisements. The least important source of information was billboards, displays and similar forms of advertisements.The second factor is characterized by items representing ‘social attributes’ like, use by many others, use by peers, recommendation by significant others and reputation of the brand. The third factor represents ‘susceptibility to incentives and promotions’. |
Description: | Department of Applied Economics, Cochin University of Science and Technology |
URI: | http://dyuthi.cusat.ac.in/purl/3039 |
Files | Size |
---|---|
Dyuthi-T1013.pdf | (6.027Mb) |
Abstract: | Data caching is an important technique in mobile computing environments for improving data availability and access latencies particularly because these computing environments are characterized by narrow bandwidth wireless links and frequent disconnections. Cache replacement policy plays a vital role to improve the performance in a cached mobile environment, since the amount of data stored in a client cache is small. In this paper we reviewed some of the well known cache replacement policies proposed for mobile data caches. We made a comparison between these policies after classifying them based on the criteria used for evicting documents. In addition, this paper suggests some alternative techniques for cache replacement |
Description: | International Journal of Ad hoc, Sensor & Ubiquitous Computing (IJASUC) Vol.3, No.4, August 2012 |
URI: | http://dyuthi.cusat.ac.in/purl/3870 |
Files | Size |
---|---|
CACHE REPLACEMENT STRATEGIES FOR MOBILE.pdf | (112.5Kb) |
Abstract: | The overall focus of the thesis involves the synthesis and characterization of CdSe QDs overcoated with shell materials for various biological and chemical sensing applications. Second chapter deals with the synthesis and characterization of CdSe and CdSe/ZnS core shell QDs. The primary attention of this work is to develop a simple method based on photoinduced charge transfer to optimize the shell thickness. Synthesis of water soluble CdSe QDs, their cytotoxicity analysis and investigation of nonlinear optical properties form the subject of third chapter. Final chapter deals with development of QD based sensor systems for the selective detection of biologically and environmentally important analytes from aqueous media. |
URI: | http://dyuthi.cusat.ac.in/purl/2923 |
Files | Size |
---|---|
Dyuthi-T0914.pdf | (9.610Mb) |
Abstract: | This study is focussed on public and private sector The study is confined to industrial Public companies in the states of Kerala and Orissa along with companies in India. undertakings only. sector and private sector private sector companies in other states were studied. Even though the original plan of 190 companies as the sample size could not be accomplished, as the responses were very poor, but data could be collected frmn 6 public and 5 private sector companies in Kerala, 8 public and 8 private sector companies in Orissa along with 27 private sector companies in other states totalling to 54 companies. The number of years of data collected varies from 2 years to 6 years. Factors which are affecting capital expenditures and hence leading to the performance of private sector compared to public sector companies are studied. After the study and analysis, comparisons are made between public sector and private sector, and suitable recomendations are made so that public sector industries can also perform equally well as the private sector industries in India. |
Description: | School of Management Studies, Cochin University of Science & Technology |
URI: | http://dyuthi.cusat.ac.in/purl/3365 |
Files | Size |
---|---|
Dyuthi-T1342.pdf | (4.195Mb) |
Abstract: | We have investigated the crystallization characteristics of melt compounded nanocomposites of poly(ethylene terephthalate) (PET) and single walled carbon nanotubes (SWNTs). Differential scanning calorimetry studies showed that SWNTs at weight fractions as low as 0.03 wt% enhance the rate of crystallization in PET, as the cooling nanocomposite melt crystallizes at a temperature 10 °C higher as compared to neat PET. Isothermal crystallization studies also revealed that SWNTs significantly accelerate the crystallization process. WAXD showed oriented crystallization of PET induced by oriented SWNTs in a randomized PET melt, indicating the role of SWNTs as nucleating sites. |
URI: | http://dyuthi.cusat.ac.in/purl/793 |
Files | Size |
---|---|
Anoop Anand,K a ... nanotubes...,April2006.PDF | (3.893Mb) |
Abstract: | Poly(ethylene terephthalate) (PET) nanocomposites with single-walled carbon nanotubes (SWNTs) have been prepared by a simple melt compounding method. With increasing concentration (0-3 wt %) of SWNTs, the mechanical and dynamic mechanical properties improved, corresponding to effective reinforcement. Melt rheological characterization indicated the effective entanglements provided by SWNTs in the melt state as well. Thermogravimetric analysis suggested no influence of SWNTs on the thermal stability of PET. Electrical conductivity measurements on the composite films pointed out that the melt compounded SWNTs can result in electrical percolation albeit at concentrations exceeding 2 wt %. |
URI: | http://dyuthi.cusat.ac.in/purl/794 |
Files | Size |
---|---|
Anoop Anand,K a ... Nanotubes...,March2007.PDF | (4.901Mb) |
Abstract: | Controlling the inorganic nitrogen by manipulating carbon / nitrogen ratio is a method gaining importance in aquaculture systems. Nitrogen control is induced by feeding bacteria with carbohydrates and through the subsequent uptake of nitrogen from the water for the synthesis of microbial proteins. The relationship between addition of carbohydrates, reduction of ammonium and the production of microbial protein depends on the microbial conversion coefficient. The carbon / nitrogen ratio in the microbial biomass is related to the carbon contents of the added material. The addition of carbonaceous substrate was found to reduce inorganic nitrogen in shrimp culture ponds and the resultant microbial proteins are taken up by shrimps. Thus, part of the feed protein is replaced and feeding costs are reduced in culture systems.The use of various locally available substrates for periphyton based aquaculture practices increases production and profitability .However, these techniques for extensive shrimp farming have not so far been evaluated. Moreover, an evaluation of artificial substrates together with carbohydrate source based farming system in reducing inorganic nitrogen production in culture systems has not yet been carried-out. Furthermore, variations in water and soil quality, periphyton production and shrimp production of the whole system have also not been determined so-far.This thesis starts with a general introduction , a brief review of the most relevant literature, results of various experiments and concludes with a summary (Chapter — 9). The chapters are organised conforming to the objectives of the present study. The major objectives of this thesis are, to improve the sustainability of shrimp farming by carbohydrate addition and periphyton substrate based shrimp production and to improve the nutrient utilisation in aquaculture systems. |
Description: | School of Industrial Fisheries, Cochin University of Science and Technology |
URI: | http://dyuthi.cusat.ac.in/purl/2893 |
Files | Size |
---|---|
Dyuthi-T0890.pdf | (9.455Mb) |
Abstract: | Carbon storage potential of teak plantation was estimated by studying plantations in Nilambur undergoing prescribed thinning schedules. Nilambur in Kerala State has the reputation of establishing the first teak plantation in India. The area has a humid tropical climate with around 300 cm annual rainfall received from the two monsoons. The soil is well drained coarse textured oxisol with high content of sesquioxides. An average teak tree at Nilambur was found to attain a height of 6.93 m and dbh of 6.3 cm at 5 year which was seen to increase to 22.83 m and 45.85 cm, respectively at the final felling stage of 50 years. Biomass was found to increase from 65.38 kg tree-1 at the first stage to 1085.70 kg tree-1 at the final stage of felling. Significant increase in growth and biomass production was noted after 30th year of plantation.Carbon sequestration in various compartments of teak followed the pattern bole > branch > root > bark in the initial stages and bole > root > branch > bark in the latter stages. Carbon sequestration increased with age and at 50 years 332.88 kg tree- 1 carbon was found to be stored in bole, 60.63 in branch, 80.06 in root and 26.57 kg tree-1 in bark compartment giving a total of 508.14 kg tree-1 of carbon.Allometric models to predict carbon sequestration with height and dbh as independent variable and carbon sequestered as dependent variable were tested to obtain the best fit model. The best regression model for predicting carbon sequestered in the bole compartment was √Y = 1.502 + 0.344 D, that for bark √Y = 1.163 + 0.082 D, for branch ln Y =1.308 lnD-1.116, for root √Y = 0.858 + 0.170 D, for above ground compartment √Y = 2.113 + 0.379 D and that for predicting the total carbon sequestered in the teak in all its vegetative parts was √Y = 2.289 + 0.415 D. Carbon sequestration potential of teak plantations in Kerala was calculated based on the estimated carbon sequestration at prescribed felling stages and the area prescribed for felling in 2014. The calculated figure was 0.21 million tons of carbon which was equivalent to Certified Emission Reduction (CER) potential of 0.81 million units corresponding to 61.48 crores of rupees at current exchange rates |
URI: | http://dyuthi.cusat.ac.in/purl/5165 |
Files | Size |
---|---|
Dyuthi-T2199.pdf | (10.93Mb) |
URI: | http://dyuthi.cusat.ac.in/purl/5535 |
Files | Size |
---|---|
Dyuthi T-2578.pdf | (17.55Mb) |
Dyuthi Digital Repository Copyright © 2007-2011 Cochin University of Science and Technology. Items in Dyuthi are protected by copyright, with all rights reserved, unless otherwise indicated.