Mathews, M Paul; Dr. George, Mathew(Cochin University of Science and Technology, March , 2012)
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Abstract:
Concrete is a universal material in the construction industry. With natural
resources like sand and aggregate, fast depleting, it is time to look for alternate
materials to substitute these in the process of making concrete. There are instances
like exposure to solar radiation, fire, furnaces, and nuclear reactor vessels, special
applications like missile launching pads etc., where concrete is exposed to
temperature variations In this research work, an attempt has been made to understand the
behaviour of concrete when weathered laterite aggregate is used in both
conventional and self compacting normal strength concrete. The study has been
extended to understand the thermal behaviour of both types of laterised concretes
and to check suitability as a fire protection material. A systematic study of laterised concrete considering parameters like source of laterite aggregate, grades of Ordinary Portland Cement (OPC) and types of supplementary cementitious materials (fly ash and GGBFS) has been carried out to
arrive at a feasible combination of various ingredients in laterised concrete. A mix design methodology has been proposed for making normal strength laterised self compacting concrete based on trial mixes and the same has also been validated. The physical and mechanical properties of laterised concretes have been studied with respect to different variables like exposure temperature (200°C, 400°C and 600°C) and cooling environment (air cooled and water cooled). The behaviour of ferrocement elements with laterised self compacting concrete has also been studied by varying the cover to mesh reinforcement (10mm to 50mm at an interval of 10mm), exposure temperature and cooling environment.
Description:
Division of Safety and Fire Engineering School of Engineering,Cochin University of Science and Technology.
Vinodkumar, Jacob; Dr.Bhasi, M; Dr.Gopikakumari, R(Cochin University of Science And Technology, February , 2013)
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Abstract:
Measurement is the act or the result of a quantitative comparison between a
given quantity and a quantity of the same kind chosen as a unit. It is generally
agreed that all measurements contain errors. In a measuring system where both a
measuring instrument and a human being taking the measurement using a preset
process, the measurement error could be due to the instrument, the process or the
human being involved. The first part of the study is devoted to understanding the
human errors in measurement. For that, selected person related and selected work
related factors that could affect measurement errors have been identified. Though
these are well known, the exact extent of the error and the extent of effect of
different factors on human errors in measurement are less reported.
Characterization of human errors in measurement is done by conducting an
experimental study using different subjects, where the factors were changed one at a
time and the measurements made by them recorded.
From the pre‐experiment survey research studies, it is observed that the
respondents could not give the correct answers to questions related to the correct
values [extent] of human related measurement errors. This confirmed the fears
expressed regarding lack of knowledge about the extent of human related
measurement errors among professionals associated with quality. But in postexperiment
phase of survey study, it is observed that the answers regarding the
extent of human related measurement errors has improved significantly since the
answer choices were provided based on the experimental study. It is hoped that this
work will help users of measurement in practice to better understand and manage
the phenomena of human related errors in measurement.
Description:
School of Engineering, Cochin University of Science and Technology
Saju, K K; Dr.Sreejith,P S(Cochin University of Science & Technology, July , 2009)
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Abstract:
This thesis summarizes the results on the growth and characterisation of
thin films of HA grown on TiAl6V4 (Ti) implant material at a lower
substrate temperature by a combination of Pulsed laser deposition and a
hydrothermal treatment to get sufficiently strong crystalline films
suitable for orthopaedic applications. The comparison of the properties
of the coated substrate has been made with other surface modification
techniques like anodization and chemical etching. The in-vitro study has
been conducted on the surface modified implants to assess its cell
viability. A molecular level study has been conducted to analyze the
adhesion mechanism of protein adhesion molecules on to HA coated
implants.
Description:
Division of Mechanical Engineering,
School of Engineering,
Cochin University of Science and Technology
Renjith, V R; Dr.Madhu, G(Cochin University of Science & Technology, July , 2010)
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Abstract:
The hazards associated with major accident hazard (MAH) industries
are fire, explosion and toxic gas releases. Of these, toxic gas release is the worst
as it has the potential to cause extensive fatalities. Qualitative and quantitative
hazard analyses are essential for the identitication and quantification of the
hazards associated with chemical industries. This research work presents the
results of a consequence analysis carried out to assess the damage potential of
the hazardous material storages in an industrial area of central Kerala, India. A
survey carried out in the major accident hazard (MAH) units in the industrial
belt revealed that the major hazardous chemicals stored by the various industrial
units are ammonia, chlorine, benzene, naphtha, cyclohexane, cyclohexanone
and LPG. The damage potential of the above chemicals is assessed using
consequence modelling. Modelling of pool fires for naphtha, cyclohexane,
cyclohexanone, benzene and ammonia are carried out using TNO model. Vapor
cloud explosion (VCE) modelling of LPG, cyclohexane and benzene are carried
out using TNT equivalent model. Boiling liquid expanding vapor explosion
(BLEVE) modelling of LPG is also carried out. Dispersion modelling of toxic
chemicals like chlorine, ammonia and benzene is carried out using the ALOHA
air quality model. Threat zones for different hazardous storages are estimated
based on the consequence modelling. The distance covered by the threat zone
was found to be maximum for chlorine release from a chlor-alkali industry
located in the area. The results of consequence modelling are useful for the
estimation of individual risk and societal risk in the above industrial area.Vulnerability assessment is carried out using probit functions for toxic,
thermal and pressure loads. Individual and societal risks are also estimated at
different locations. Mapping of threat zones due to different incident outcome
cases from different MAH industries is done with the help of Are GIS.Fault Tree Analysis (FTA) is an established technique for hazard
evaluation. This technique has the advantage of being both qualitative and
quantitative, if the probabilities and frequencies of the basic events are known.
However it is often difficult to estimate precisely the failure probability of the
components due to insufficient data or vague characteristics of the basic event.
It has been reported that availability of the failure probability data pertaining to
local conditions is surprisingly limited in India. This thesis outlines the
generation of failure probability values of the basic events that lead to the
release of chlorine from the storage and filling facility of a major chlor-alkali
industry located in the area using expert elicitation and proven fuzzy logic.
Sensitivity analysis has been done to evaluate the percentage contribution of
each basic event that could lead to chlorine release. Two dimensional fuzzy
fault tree analysis (TDFFTA) has been proposed for balancing the hesitation
factor invo1ved in expert elicitation .
Description:
Division of Safety and Fire Engineering,
School of Engineering,
Cochin University of Science and Technology
Abdul, Salam V H; Dr.Babu,Jose T(Cochin University of Science and Technology, November , 1999)
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Abstract:
Chapter 1 presents a brief note on the state at which the construction industry
stands at present, bringing into focus the significance of the critical study. Relevance
of the study, area of investigation and objectives of the study are outlined in this
chapter. The 2nd chapter presents a review of the literature on the relevant areas.
In the third chapter an analysis on time and cost overrun in construction
highlighting the major factors responsible for it has been done. A couple of case
studies to estimate loss to the nation on account of delay in construction have been
presented in the chapter. The need for an appropriate estimate and a competent
contractor has been emphasised for improving effectiveness in the project
implementation. Certain useful equations and thoughts have been formulated on this
area in this chapter that can be followed in State PWD and other Govt. organisations.
Case studies on project implementation of major projects undertaken by
Government sponsored/supported organizations in Kerala have been dealt with in
Chapter 4. A detailed description of the project of Kerala Legislature Complex with a
critical analysis has been given in this chapter. A detailed account of the investigations carried out on the construction of International Stadium, a sports project
of Greater Cochin Development Authority is included here. The project details of
Cochin International Airport at Nedumbassery, its promoters and contractors are also
discussed in Chapter 4.
Various aspects of implementation which led the above projects successful have
been discussed in chapter 5. The data collected were analysed through discussion and
perceptions to arrive at certain conclusions. The emergence of front-loaded contract
and its impact on economics of the project execution are dealt with in this chapter.
Analysis of delays in respect of the various project narrated in chapter 3 has been done
here. The root causes of the project time and overrun and its remedial measures are
also enlisted in this chapter.
Study of cost and time overrun of any construction project IS a part of
construction management. Under the present environment of heavy investment on
construction activities in India, the consequences of mismanagement many a time lead
to excessive expenditure which are not be avoidable. Cost consciousness, therefore has
to be keener than ever before. Optimization in investment can be achieved by
improved dynamism in construction management. The successful completion of
coristruction projects within the specified programme, optimizing three major attributes
of the process - quality, schedule and costs - has become the most valuable and
challenging task for the engineer - managers to perform. So, the various aspects of
construction management such as cost control, schedule control, quality assurance,
management techniques etc. have also been discussed in this fifth chapter.
Chapter 6 summarises the conclusions drawn from the above criticalr1 of rhajor
construction projects in Kerala.
Description:
School of Engineering,Cochin University of Science and Technology
Saira Joseph; Dr. Binu Paul(Cochin University of Science and Technology, November 20, 2016)
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Abstract:
Over the past decade, there is a great demand for permission to transmit large bandwidth
concurrent with existing narrowband signals. In 2002, the federal communications
commission (FCC) decided to permit use of ultrawideband (UWB) systems.
UWB systems are unique in their large instantaneous bandwidth and potential for lowcost
digital design that enables a single system to operate in different modes as a
communication device, radar etc. UWB systems aim at covering the frequency band of
3.1-10.6 GHz defined by the FCC. The addition of more and more features in each new
generation communication system demands universal antennas suitable for operation in
multiple bands. In this regard, designing a multiband antenna which also covers the
UWB range without deteriorating the UWB performance is of great interest. Also, a
significant issue in communication systems is to miniaturize the antenna size while
providing good performance over the operation bands.
The thesis presents three different designs of CPW-fed multiband antennas. The first
design uses a fractal concept to achieve multiband operation. In the second and third
designs, a slotted circular monopole and a spiral monopole are used respectively for
multiband operation with UWB applications. For both these cases, variations from the
basic antenna geometry are also proposed in which the frequency of operation is
lowered without increase in overall antenna size. Design guidelines are developed for
all antennas to facilitate design on substrates of different permittivity and thickness. The
antennas are analyzed in both frequency and time domain for complete characterization
Raphika, P. M.; Dr. Abdulla P.(Cochin University of Science and Technology, May 3, 2016)
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Abstract:
Filters are one of the essential components in the RF and wireless
communication systems. Small sized planar lowpass filters with good electrical
characteristics along with low cost, light weight and ease of fabrication are highly
desirable for the front end of modern communication systems to suppress harmonics
and spurious signals. Design of compact lowpass filters with improved performance
and diverse specifications for numerous applications is a huge challenge.
In this thesis, high performance planar compact lowpass filters using multiple
patch resonators on high impedance transmission line are developed. Design techniques
of different types of patch resonators and their modifications to enhance the
performance of the filters are presented.Patch resonators are designed by using high impedance short circuited stubs
and low impedance open circuited patches. In the first stage of filter realization,
compact lowpass filter having sharp roll-off using triangular and funnel patch
resonators is presented. The structure is modified further to enhance the relative
stopband bandwidth of the filter. In the third stage, another resonator has been
introduced near the feed line to achieve sharp roll-off for the same cutoff frequency,
stopband bandwidth and suppression level. To obtain compactness, high suppression
level and wide stopband in filter design, low thickness substrate is tested and proved in
the fourth stage.
Realizations of planar compact lowpass filter with very sharp roll-off near the
cutoff frequency have been presented using stepped impedance polygonal patch
resonators. By increasing the patch size and number of resonators, the stopband
bandwidth and suppression level have to be enhanced to a great extent. Enhancement
of performance characteristics of lowpass filter design is continually being extended.
By using high value capacitance patch, the stopband suppression level of the filter with
sharp roll-off rate is achieved. Elliptic function lowpass filter with ultra-sharp roll-off is
also developed using elliptic shaped patch resonators.
Throughout the study, low cost substrate having permittivity 4.4 is used for the
filter design. All the designed filters have been fabricated and predicted results are
validated by the measurements.
Baby Paul; Dr. P. Mythili(Cochin University of Science and Technology, October 8, 2015)
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Abstract:
Electrocardiogram gives the information regarding the health of
the patients by monitoring the bioelectric potentials generated by the
sinoatrial node in the heart. These signals can be collected by using
electrodes suitably placed on the body of a patient. The normal human
ECG lie in the frequency range of 0.05-100 Hz and the most useful
information is contained in the range of 0.5-45 Hz. Even though a large
amount of work has already been done in the field of ECG classification,
no classification system has made an attempt in identifying the isolated
abnormalities which pose a silent threat to patients.
An adaptive filtering technique for denoising the ECG which is
based on Genetic Algorithm (GA) tuned Sign-Data Least Mean Square
(SD-LMS) algorithm is proposed. This algorithm gave an average
signal to noise ratio improvement of 10.75 dB for baseline wander and
24.26 dB for power line interference. It is seen that the step size ‘μ’
optimized with GA helps in obtaining better SNR value without causing
any damage to the information content in the ECG.
A new wavelet for automatic classification of arrhythmias
from electrocardiogram is proposed. This new wavelet is formed as a
sum of shifted Gaussians so that it resembles a normal ECG. This shape
has been chosen with the aim of extracting maximum information from
the ECG under analysis. The classification performance was studied
using the most commonly used database, the MIT-BIH Arrhythmia
database. The shifted and summed Gaussian wavelet was then
optimized using GA. The optimum wavelet for classification was
obtained after several runs of the GA algorithm. The ECG class
labeling was done according to the Association for the Advancement of
Medical Instrumentation (AAMI). The wavelet scales corresponding to
the different frequency levels giving maximum classification
performance were identified by selecting finer scales. Probabilistic
Neural Network classifier was used for classification purpose. The
proposed classification system offered better results than that reported
in literature by giving an overall sensitivity of 97.01% for Normal beats,
75.20% for Supraventricular beats and 93.06% for Ventricular beats.
As mentioned above this technique could exclusively identify some of
the isolated abnormalities present in the patient records.