Harilal, S S; Riju, C Issac; Bindhu, C V; Nampoori, V P N; Vallabhan, C P G(World Scientific Publishing Company, 1996)
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Abstract:
Laser ablation processes in liquid benzene, toluene and carbon disulphide have been investigated by pulsed photoacoustic technique using 532 nm radiation from a frequency doubled Q-switched Nd:YAG laser. The nature of variation of photoacoustic signal amplitude with laser energy clearly indicates that different phenomena are involved in the generation of photoacoustic effect and these are discussed in detail. Our results suggest multiphoton induced photofragmentation as the most plausible interaction process occurring during laser ablation in these liquids.
Ram Kumar, P B; Dr.Pramod, K V(Cochin University of Science and Technology, May 9, 2011)
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Abstract:
The present work deals with the A study of morphological opertors with applications. Morphology is now a.necessary tool for engineers involved with imaging applications. Morphological operations have been viewed as filters the properties of which have been well studied (Heijmans, 1994). Another well-known class of non-linear filters is the class of rank order filters (Pitas and Venetsanopoulos, 1990). Soft morphological filters are a combination of morphological and weighted rank order filters (Koskinen, et al., 1991, Kuosmanen and Astola, 1995). They have been introduced to improve the behaviour of traditional morphological filters in noisy environments. The idea was to slightly relax the typical morphological definitions in such a way that a degree of robustness is achieved, while most of the desirable properties of typical morphological operations are maintained. Soft morphological filters are less sensitive to additive noise and to small variations in object shape than typical morphological filters. They can remove positive and negative impulse noise, preserving at the same time small details in images. Currently, Mathematical Morphology allows processing images to enhance fuzzy areas, segment objects, detect edges and analyze structures. The techniques developed for binary images are a major step forward in the application of this theory to gray level images. One of these techniques is based on fuzzy logic and on the theory of fuzzy sets.Fuzzy sets have proved to be strongly advantageous when representing in accuracies, not only regarding the spatial localization of objects in an image but also the membership of a certain pixel to a given class. Such inaccuracies are inherent to real images either because of the presence of indefinite limits between the structures or objects to be segmented within the image due to noisy acquisitions or directly because they are inherent to the image formation methods.
Description:
Department of
Computer Applications, Cochin University of Science & Technology
Varghese, K V; Dr.Jose, Payyappilly T(Cochin University of Science and Technology, December 12, 1990)
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Abstract:
The major objective of the study is to find out how far the differential location in the socio-economic status and the various interests determine the occupational aspirations of the college students in Ernakulum district. The study gives a detailed picture of the influence of caste and community affiliations, rural-urban background, gender differences and academic achievements on the occupational aspirations of college students. The thesis aims to see how far the economic status of the family is associated with the occupational aspirations of the college youth .The study also throws light on the influence exerted by the occupational and educational standards of the parents on the occupational aspirations of the students and brings out the relation between the occupational aspirations and interests of the college students.
Description:
School of Management
Studies, Cochin University of Science and Technology
Riju, C Issac; Bindhu, C V; Harilal, S S; Geetha K, Varier; Nampoori, V P N; Vallabhan, C P G(World Scientific Publishing Company, 1996)
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Abstract:
Pulsed photoacoustic studies in solution of C60 in toluene have been made using the 532 nm radiation from a frequency doubled Nd:YAG laser. Though C60 is found to exhibit the phenomenon of optical limiting, the results on photoacoustic measurements do not give any indication of multiphoton transitions as suggested in some of the earlier works. Results of photoacoustic measurements show that excited state absorption is the dominant process responsible for optical limiting while phenomena like nonlinear scattering may contribute to a lesser extent.
Sajeena Beevi, B; Madhu, G; Sahoo, Dipak Kumar(Cochin University Of Science And Technology, April , 2015)
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Abstract:
Solid waste generation is a natural consequence of human activity and
is increasing along with population growth, urbanization and industrialization.
Improper disposal of the huge amount of solid waste seriously affects the
environment and contributes to climate change by the release of greenhouse
gases. Practicing anaerobic digestion (AD) for the organic fraction of
municipal solid waste (OFMSW) can reduce emissions to environment and
thereby alleviate the environmental problems together with production of
biogas, an energy source, and digestate, a soil amendment. The amenability
of substrate for biogasification varies from substrate to substrate and
different environmental and operating conditions such as pH, temperature,
type and quality of substrate, mixing, retention time etc. Therefore, the
purpose of this research work is to develop feasible semi-dry anaerobic
digestion process for the treatment of OFMSW from Kerala, India for
potential energy recovery and sustainable waste management. This study
was carried out in three phases in order to reach the research purpose.
In the first phase, batch study of anaerobic digestion of OFMSW was
carried out for 100 days at 32°C (mesophilic digestion) for varying substrate
concentrations. The aim of this study was to obtain the optimal conditions
for biogas production using response surface methodology (RSM). The
parameters studied were initial pH, substrate concentration and total organic
carbon (TOC). The experimental results showed that the linear model terms
of initial pH and substrate concentration and the quadratic model terms of
the substrate concentration and TOC had significant individual effect
(p < 0.05) on biogas yield. However, there was no interactive effect between
these variables (p > 0.05). The optimum conditions for maximizing the
biogas yield were a substrate concentration of 99 g/l, an initial pH of 6.5 and
TOC of 20.32 g/l. AD of OFMSW with optimized substrate concentration of
99 g/l [Total Solid (TS)-10.5%] is a semi-dry digestion system .Under the
optimized condition, the maximum biogas yield was 53.4 L/kg VS (volatile
solid)..
In the second phase, semi-dry anaerobic digestion of organic solid
wastes was conducted for 45 days in a lab-scale batch experiment for
substrate concentration of 100 g/l (TS-11.2%) for investigating the start-up
performances under thermophilic condition (50°C). The performance of the
reactor was evaluated by measuring the daily biogas production and
calculating the degradation of total solids and the total volatile solids. The
biogas yield at the end of the digestion was 52.9 L/kg VS for the substrate
concentration of 100 g/l. About 66.7% of volatile solid degradation was
obtained during the digestion. A first order model based on the availability
of substrate as the limiting factor was used to perform the kinetic studies of
batch anaerobic digestion system. The value of reaction rate constant, k,
obtained was 0.0249 day-1.
A laboratory bench scale reactor with a capacity of 36.8 litres was
designed and fabricated to carry out the continuous anaerobic digestion of
OFMSW in the third phase. The purpose of this study was to evaluate the
performance of the digester at total solid concentration of 12% (semi-dry)
under mesophlic condition (32°C). The digester was operated with different
organic loading rates (OLRs) and constant retention time. The performance
of the reactor was evaluated using parameters such as pH, volatile fatty
acid (VFA), alkalinity, chemical oxygen demand (COD), TOC and
ammonia-N as well as biogas yield. During the reactor’s start-up period, the
process is stable and there is no inhibition occurred and the average biogas
production was 14.7 L/day. The reactor was fed in continuous mode with
different OLRs (3.1,4.2 and 5.65 kg VS/m3/d) at constant retention time of
30 days. The highest volatile solid degradation of 65.9%, with specific
biogas production of 368 L/kg VS fed was achieved with OLR of 3.1 kg
VS/m3/d.
Modelling and simulation of anaerobic digestion of OFMSW in
continuous operation is done using adapted Anaerobic Digestion Model
No 1 (ADM1).The proposed model, which has 34 dynamic state variables,
considers both biochemical and physicochemical processes and contains
several inhibition factors including three gas components. The number of
processes considered is 28. The model is implemented in Matlab® version
7.11.0.584(R2010b). The model based on adapted ADM1 was tested to
simulate the behaviour of a bioreactor for the mesophilic anaerobic
digestion of OFMSW at OLR of 3.1 kg VS/m3/d. ADM1 showed acceptable
simulating results.
Description:
DIVISION OF SAFETY AND FIRE ENGINEERING
SCHOOL OF ENGINEERING
Ritty J, Nedumpara; Thomas, K J; Jayasree, V K; Girijavallabhan, C P; Nampoori, V P N; Radhakrishnan, P(Optical Society of America, July 20, 2007)
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Abstract:
The results of a brief investigation of the amplified spontaneous emission and lasing characteristics of Coumarin 540 dye in as many as ten different solvents are reported. It has been found that C 540 dye solutions contained within a rectangular quartz cuvette give laser emission with well resolved equally spaced modes when pumped with a 476 nm beam. The modes were found to originate from the subcavities formed by the plane-parallel walls of the cuvette containing the high-gain medium. While the quantum yield remains a decisive factor, a clear correlation between the total width of the emission spectra and the refractive indices of the solvents of the respective samples has been demonstrated. The well-resolved mode structure exhibited by the emission spectra gives clear evidence of the lasing action taking place in the gain medium, and the number of modes enables us to compare the gain of the media in different samples. A detailed discussion of the solvent effect in the lasing characteristics of C540 in different solutions is given.
Ramkumar; Kannan(Cochin University of Science and Technology, June , 2014)
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Abstract:
Centrality is in fact one of the fundamental notions in graph theory
which has established its close connection with various other areas like Social
networks, Flow networks, Facility location problems etc. Even though
a plethora of centrality measures have been introduced from time to time,
according to the changing demands, the term is not well defined and we
can only give some common qualities that a centrality measure is expected
to have. Nodes with high centrality scores are often more likely to be very
powerful, indispensable, influential, easy propagators of information, significant
in maintaining the cohesion of the group and are easily susceptible
to anything that disseminate in the network.
Bindu, V; Dr.Nandakumaran,V M(Cochin University of Science and Technology, December , 2002)
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Abstract:
Chaos is a subject oftopical interest and, studied in great detail in relation to its
relevance in almost all branches of science, which include physical, chemical,
and biological fields. Chaos in the literal sense signifies utter confusion, but the
scientific community has differentiated chaos as deterministic chaos and white
noise. Deterministic chaos implies the complex behaviour of systems, which
are governed by deterministic laws. Behaviour of such systems often become
unpredictable in the long run. This unpredictability arises from the sensitivity of
the system to its initial conditions. The essential requirement for ‘sensitivity to
initial condition’ is nonlinearity of the system. The only method for
determining the future of such systems is numerically simulating its final state
from a set ofinitial conditions.
Synchronisation
Description:
International School of Photonics, Cochin University of Science and Technology
Ajoy,Mathew; Dr.Sankaranarayanan, K C(Cochin University of Science and Technology, March 27, 1987)
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Abstract:
In the introductory chapter of the dissertation
the importance of coconut cultivation for the economy
of Kerala State has been highlighted. The second and
third chapters contain analysis of changes in area,
production and productivity of coconut cultivation in
the state. The use of modern agricultural practices by
coconut farmers is analysed in chapter IV. Cost of
production and profitability are dealt with in chapter V,
while the issues relating to coconut prices and marketing
are presented in chapter VI. Diseases affecting
coconut is the theme covered under chapter VII ,
Summary and conclusions are provided at the end.
Description:
Department of Applied Economics, Cochin University of Science and Technology
Krishnan Nampoothiri, K; Dr.Rajendra Prasad, P N(Cochin University of Science And Technology, January , 1987)
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Abstract:
The co-operative credit structure in a state
set up consists of 3 tiers — Primary Societies at the base,
District Co-operative Banks at the middle and State Cooperative
Bank at the top. But, some societies at the
primary level are governed by, in addition to Co-operative
Societies Act, the Banking Regulation Act. Thus they are
under dual control. In addition, they are working under
the direct purview of Reserve Bank of India. The scope
of this study is restricted to such Primary Societies,
District Co-operative Banks and State Co-operative Bank.
For the evaluation of the working of Co-operative
Banks, the board of directors and staff were interviewed
with the help of pre-constructed and pre-tested interview
schedules. However, the share holders and customers were
not interviewed mainly because almost all respondents
were reluctant to provide copies of an exhaustive list
of share holders and non-share holder customers, for
the purpose of maintaining secrecy. This being an
individual work, it was found physically and financially
very difficult to extend the study so as to cover the
share holders and non-share holder customers. Limitations
of time were also responsible for restricting this study.
The period of study was restricted to 1980-'81
to 1983-'84 as the data relating to earlier periods were
firstly not available from all banks and secondly the
prior data was considered out of date for the purpose of
the study.
Description:
School of management studies, Cochin University of Science And Technology
Dharma Rajan, P G; Dr.Rajendra Prasad, P N(Cochin University of Science And Technology, June , 1984)
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Abstract:
Since the world demand for cashew kernels has been rising steadily for several years in the past, conferring significant price increase the processing of cashew remains a highly profitable lndustry. India being the earliest and largest supplier of cashew kernels in the world market it is our prestigious obligations to reestablish her pristine monopoly. Further the added importance ot the indutry in the Socio economic context of the State of Kerala makes various measures impervative in order to bring back to the industry its pristine glory at the late sixties to give a face lift and to stabilize the industry. This present study adopts a comprehensive frame work of
analysis compassing the major issues involved in the cultivation, distribution, import, processing and marketing of cashew undcr the private and public sector, migration of the industry and the financial requirements of the industry.
Description:
School of management studies, Cochin University of Science And Technology
Joy, E C; Dr.Joy, George(Cochin University Of Science And Technology, March 27, 1980)
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Abstract:
This thesis consists of a study of the effect of electrode films and overlayer films on the electrical properties of certain metal films. The films have been prepared on glass substrates by thermal evapouration in a vaccum 10 terr. The properties of Al films on Ag, Al,Au and Cu films on In electrodes ,and Bi/Ag bilayer films have been studied. The influence of annealing electrodes at higher temperature on the electrical properties of metal films has also been investigated. Further the effect of varying layer thickness in the bilayer films ,both annealed at higher temperature and annealed at room temperature have been examined.
Description:
Department Of Physics,Cochin University Of Science And Technology
Rani, Joseph(OPA (Overseas Publishers Association), July 15, 1994)
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Abstract:
The mechanical properties of filled natural rubber latex vulcanizates were found to be improved by the
addition of polyethylene glycols of different molecular weight and glycerol. There is a slight reduction
in the optimum cure times of the compounds containing PEG/Glycerol. The morphology study shows
that the filler distribution is more uniform in the compounds containing PEG/Glycerol.