Tennant,A; Dawoud,M M; Anderson,A P(Department of Electronics, April 27, 1994)
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Abstract:
A genetic algorithm has been used for null steering in phased and
adaptive arrays . It has been shown that it is possible to steer the
array null s precisely to the required interference directions and to
achieve any prescribed null depths . A comparison with the results
obtained from the analytic solution shows the advantages of using
the genetic algorithm for null steering in linear array patterns
Ravindranathan, S; Dr.Unnikrishnan, A(Cochin University of Science & Technology, October , 1991)
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Abstract:
Neural Network has emerged as the topic of the day.
The spectrum of its application is as wide as from ECG noise
filtering to seismic data analysis and from elementary
particle detection to electronic music composition. The
focal point of the proposed work is an application of a
massively parallel connectionist model network for detection
of a sonar target. This task is segmented into: (i) generation of training patterns from sea noise that
contains radiated noise of a target, for teaching the
network;(ii) selection of suitable network topology and learning
algorithm and (iii) training of the network and its subsequent testing
where the network detects, in unknown patterns applied
to it, the presence of the features it has already
learned in. A three-layer perceptron using backpropagation
learning is initially subjected to a recursive training
with example patterns (derived from sea ambient noise with
and without the radiated noise of a target). On every
presentation, the error in the output of the network is
propagated back and the weights and the bias associated with
each neuron in the network are modified in proportion to
this error measure. During this iterative process, the network converges and extracts the target features which get
encoded into its generalized weights and biases.In every unknown pattern that the converged
network subsequently confronts with, it searches for the
features already learned and outputs an indication for their
presence or absence. This capability for target detection is
exhibited by the response of the network to various test
patterns presented to it.Three network topologies are tried with two
variants of backpropagation learning and a grading of the
performance of each combination is subsequently made.
Description:
Department of Electronics, Cochin University of Science and Technology
Chandrasekaran, M; Devarasiddappa, D(June 1, 2014)
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Abstract:
Metal matrix composites (MMC) having aluminium (Al) in the matrix phase and silicon
carbide particles (SiCp) in reinforcement phase, ie Al‐SiCp type MMC, have gained
popularity in the re‐cent past. In this competitive age, manufacturing industries strive to
produce superior quality products at reasonable price. This is possible by achieving higher
productivity while performing machining at optimum combinations of process variables. The
low weight and high strength MMC are found suitable for variety of components
Description:
Advances in production engineering and management,vol 9 no 2,pp 59-70
Dr.Babu, C A; Jayakrishnan, P R(http://www.scirp.org/journal/acs, 2014)
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Abstract:
The combined use of both radiosonde data and three-dimensional satellite derived data over ocean and land is useful for a better understanding of atmospheric thermodynamics. Here, an attempt is made to study the ther-modynamic structure of convective atmosphere during pre-monsoon season over southwest peninsular India utilizing satellite derived data and radiosonde data. The stability indices were computed for the selected stations over southwest peninsular India viz: Thiruvananthapuram and Cochin, using the radiosonde data for five pre- monsoon seasons. The stability indices studied for the region are Showalter Index (SI), K Index (KI), Lifted In-dex (LI), Total Totals Index (TTI), Humidity Index (HI), Deep Convective Index (DCI) and thermodynamic pa-rameters such as Convective Available Potential Energy (CAPE) and Convective Inhibition Energy (CINE). The traditional Showalter Index has been modified to incorporate the thermodynamics over tropical region. MODIS data over South Peninsular India is also used for the study. When there is a convective system over south penin-sular India, the value of LI over the region is less than −4. On the other hand, the region where LI is more than 2 is comparatively stable without any convection. Similarly, when KI values are in the range 35 to 40, there is a possibility for convection. The threshold value for TTI is found to be between 50 and 55. Further, we found that prior to convection, dry bulb temperature at 1000, 850, 700 and 500 hPa is minimum and the dew point tem-perature is a maximum, which leads to increase in relative humidity. The total column water vapor is maximum in the convective region and minimum in the stable region. The threshold values for the different stability indices are found to be agreeing with that reported in literature.
Ramesh, A; Dr.Madhu, G(Cochin University of Science And Technology, October 18, 2012)
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Abstract:
Cement industry ranks 2nd in energy consumption among the industries
in India. It is one of the major emitter of CO2, due to combustion of fossil fuel
and calcination process. As the huge amount of CO2 emissions cause severe
environment problems, the efficient and effective utilization of energy is a
major concern in Indian cement industry. The main objective of the research
work is to assess the energy cosumption and energy conservation of the Indian
cement industry and to predict future trends in cement production and
reduction of CO2 emissions. In order to achieve this objective, a detailed
energy and exergy analysis of a typical cement plant in Kerala was carried out.
The data on fuel usage, electricity consumption, amount of clinker and cement
production were also collected from a few selected cement industries in India
for the period 2001 - 2010 and the CO2 emissions were estimated. A complete
decomposition method was used for the analysis of change in CO2 emissions
during the period 2001 - 2010 by categorising the cement industries according
to the specific thermal energy consumption. A basic forecasting model for the
cement production trend was developed by using the system dynamic approach
and the model was validated with the data collected from the selected cement
industries. The cement production and CO2 emissions from the industries were
also predicted with the base year as 2010. The sensitivity analysis of the
forecasting model was conducted and found satisfactory. The model was then
modified for the total cement production in India to predict the cement
production and CO2 emissions for the next 21 years under three different
scenarios. The parmeters that influence CO2 emissions like population and
GDP growth rate, demand of cement and its production, clinker consumption
and energy utilization are incorporated in these scenarios. The existing growth
rate of the population and cement production in the year 2010 were used in the
baseline scenario. In the scenario-1 (S1) the growth rate of population was
assumed to be gradually decreasing and finally reach zero by the year 2030,
while in scenario-2 (S2) a faster decline in the growth rate was assumed such
that zero growth rate is achieved in the year 2020. The mitigation strategiesfor the reduction of CO2 emissions from the cement production were identified
and analyzed in the energy management scenarioThe energy and exergy analysis of the raw mill of the cement plant revealed
that the exergy utilization was worse than energy utilization. The energy analysis
of the kiln system showed that around 38% of heat energy is wasted through
exhaust gases of the preheater and cooler of the kiln sysetm. This could be
recovered by the waste heat recovery system. A secondary insulation shell was
also recommended for the kiln in the plant in order to prevent heat loss and
enhance the efficiency of the plant. The decomposition analysis of the change in
CO2 emissions during 2001- 2010 showed that the activity effect was the main
factor for CO2 emissions for the cement industries since it is directly dependent on
economic growth of the country. The forecasting model showed that 15.22% and
29.44% of CO2 emissions reduction can be achieved by the year 2030 in scenario-
(S1) and scenario-2 (S2) respectively. In analysing the energy management
scenario, it was assumed that 25% of electrical energy supply to the cement plants
is replaced by renewable energy. The analysis revealed that the recovery of waste
heat and the use of renewable energy could lead to decline in CO2 emissions 7.1%
for baseline scenario, 10.9 % in scenario-1 (S1) and 11.16% in scenario-2 (S2) in
2030. The combined scenario considering population stabilization by the year
2020, 25% of contribution from renewable energy sources of the cement industry
and 38% thermal energy from the waste heat streams shows that CO2 emissions
from Indian cement industry could be reduced by nearly 37% in the year 2030.
This would reduce a substantial level of greenhouse gas load to the environment.
The cement industry will remain one of the critical sectors for India to meet
its CO2 emissions reduction target. India’s cement production will continue to
grow in the near future due to its GDP growth. The control of population,
improvement in plant efficiency and use of renewable energy are the important
options for the mitigation of CO2 emissions from Indian cement industries
Description:
Division of safety and Fire Engineering,
School of Engineering, Cochin University of Science and Technology
Udayakumar, P; Dr.Ouseph, P P(Cochin University Of Science And Technology, July 19, 2012)
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Abstract:
The nearshore marine ecosystem is a dynamic environment impacted by
many activities, especially the coastal waters and sediments contiguous to major
urban areas. Although heavy metals are natural constituents of the marine
environment, inputs are considered to be conservative pollutants and are
potentially toxic, accumulate in the sediment, are bioconcentrated by organisms
and may cause health problems to humans via the food chain. A variety of
metals in trace amounts are essential for biological processes in all organisms,
but excessive levels can be detrimental by acting as enzyme inhibitors.
Discharge of industrial wastewater, agriculture runoff and untreated sewage
pose a particularly serious threat to the coastal environment of Kerala, but there
is a dearth of studies in documenting the contaminant metals. This study aimed
principally to assess such contamination by examining the results of heavy
metal (Cu, Pb, Cr, Ni, Zn, Cd and Hg) analysis in seawater, sediment and
benthic biota from a survey of five transects along the central and northern
coast of Kerala in 2008 covering a 10.0 km stretch of near shore environment in
each transect. Trophic transfer of metal contaminants from aquatic invertebrates
to its predators was also assessed, by employing a suitable benthic food chain
model in order to understand which all metals are undergoing biotransference
(transfer of metals from a food source to consumer).The study of present contamination levels will be useful for potential
environmental remediation and ecosystem restoration at contaminated sites and
provides a scientific basis for standards and protective measures for the coastal
waters and sediments. The usefulness of biomonitor proposed in this study
would allow identification of different bioavailable metals as well as provide an
assessment of the magnitude of metal contamination in the coastal marine
milieu. The increments in concentration of certain metals between the predator
and prey discerned through benthic food chain can be interpreted as evidence of
biotransference.
Description:
School of Environmental Studies
Cochin University of Science and Technology
Hatha, A A M; Abhirosh, Chandran; Sherin, Varghese; Ellen, Kandeler; Ambattu, Thomas; Asit, Mazumder(Elsevier, January 15, 2011)
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Abstract:
Microcosm studies were performed to evaluate the survival of Escherichia coli, Salmonella paratyphi and
Vibrio parahaemolyticus in water and sediment collected from the freshwater region of Vembanad Lake
(9 35◦N 76 25◦E) along the south west coast of India. All three test microorganisms showed significantly
(p < 0.01) higher survival in sediment compared to overlying water. The survival in different sediment
types with different particle size and organic carbon content revealed that sediment with small particle
size and high organic carbon content could enhance their extended survival (p < 0.05). The results indicate
that sediments of the Lake could act as a reservoir of pathogenic bacteria and exhibit a potential health
hazard from possible resuspension and subsequent ingestion during recreational activities. Therefore,
the assessment of bacterial concentration in freshwater Lake sediments used for contact and non contact
recreation has of considerable significance for the proper assessment of microbial pollution of the
overlying water, and for the management and protection of related health risk at specific recreational
sites. Besides, assessment of the bacterial concentration in sediments can be used as a relatively stable
indicator of long term mean bacterial concentration in the water column above
Description:
International Journal of Hygiene and Environmental Health 214 (2011) 258– 264
Bijoy, Nandan S; Jayachandran, P R(Springer, December 14, 2011)
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Abstract:
The cumulative effects of global change, including climate change, increased
population density and domestic waste disposal, effluent discharges from industrial processes,
agriculture and aquaculture will likely continue and increases the process of eutrophication in
estuarine environments. Eutrophication is one of the leading causes of degraded water quality,
water column hypoxia/anoxia, harmful algal bloom (HAB) and loss of habitat and species
diversity in the estuarine environment. The present study attempts to characterize the trophic
condition of coastal estuary using a simple tool; trophic index (TRIX) based on a linear
combination of the log of four state variables with supplementary index Efficiency Coefficient
(Eff. Coeff.) as a discriminating tool. Numerically, the index TRIX is scaled from 0 to10,
covering a wide range of trophic conditions from oligotrophic to eutrophic. Study area
Kodungallur-Azhikode Estuary (KAE) was comparatively shallow in nature with average depth
of 3.6±0.2 m. Dissolve oxygen regime in the water column was ranged from 4.7±1.3 mgL−1 in
Station I to 5.9±1.4 mgL−1 in Station IV. The average nitrate-nitrogen (NO3-N) of KAE water
was 470 mg m−3; values ranged from Av. 364.4 mg m−3 at Station II to Av. 626.6 mg m−3at
Station VII. The mean ammonium-nitrogen (NH4
+-N) varied from 54.1 mg m−3 at Station VII
to 101 mg m−3 at Station III. The average Chl-a for the seven stations of KAE was
6.42±3.91 mg m−3. Comparisons over different spatial and temporal scales in the KAE
and study observed that, estuary experiencing high productivity by the influence of
high degree of eutrophication; an annual average of 6.91 TRIX was noticed in the KAE
and seasonal highest was observed during pre monsoon period (7.15) and lowest during
post monsoon period (6.51). In the spatial scale station V showed high value 7.37 and
comparatively low values in the station VI (6.93) and station VII (6.96) and which
indicates eutrophication was predominant in land cover area with comparatively high water
residence time. Eff. Coeff. values in the KAE ranges from −2.74 during monsoon period to the
lowest of −1.98 in pre monsoon period. Present study revealed that trophic state of the estuary
under severe stress and the restriction of autochthonous and allochthonous nutrient loading
should be keystone in mitigate from eutrophication process
Jaison, C A; Dr.Sivanandan, Achari V(Cochin University of Science And Technology, October , 2012)
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Abstract:
Everywhere, on the coastal belt it is proved without doubt that the pristine ground
water quality was severely deteriorated after the 26 December 2004 Indian Ocean
Tsunami. But how far is more relevant, as it is decided by the so-called pre-tsunamic
situation of the region. In water quality studies it is this reference finger print which
earmarks regional ground water chemistry based on which the monthly variability
could rationally be interpreted. This Ph D thesis comprises the testing and evaluation of the facts: whether there is any significant difference in the water quality parameters under study between stations
and between months in Tsunami Affected Dug Wells (TADW). Whether the selected
water quality parameters vary significantly from BIS and WHO standards. Whether
the water quality index (WQI) differ significantly between Tsunami Affected Dug
Wells (TADW) and Bore Wells (BW). Whether there is any significant difference in
the water quality parameters during December 2005 and December 2008. Is there any
significant change in the Water Quality Parameters before 2001 and after tsunami
(2005) in TADW.
Description:
School of Environmental Studies, Cochin University of Science and Technology