Aiswarya, N.; Dr. M.R. Prathapachandra Kurup(Cochin University of Science and Technology, April 10, 2016)
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Abstract:
The current scenario of coordination chemistry is witnessing the exploitation
of coordination bonds and noncovalent interactions to generate self-assemblies of
various dimensions having not only aesthetic values but also countless applications
and that paved way for supramolecular chemistry/crystal engineering. Most of
such fascinating work employs Schiff bases obtained by the condenzation of an
amine and a carbonyl compound. The use of diamines in the synthesis of highnuclearity
complexes utilizes the bridging capacity of phenoxo atoms. Whereas in
the case of N2O donor tridentate Schiff bases (N-substituted diamines with
salicylaldehyde or its derivatives), coligands are employed to generate structures of
variable composition apart from satisfying the coordination number. Among the
various coligands known, pseudohalides (azido, cyanato, thiocyanato, dicyanamido)
deserve special attention on account of its versatile modes of binding. In addition
to the structural variety, such Schiff base complexes have its signature in the field
of catalysis, luminescence, gas adsorption and magnetic materials which make the
arena conspicuous. The recognition of plasticity of copper(II) metal with respect to
its coordination number and its ubiquitous nature as active sites in many metalloenzymes
fuelled us to work with this metal. The results of our efforts to explore
the role of various interaction forces constitute the subject matter of the thesis
entitled “Crystalline architectures of copper(II) complexes derived from halogen
substituted carbonyl compounds: Interplay of covalent and non-covalent forces”.
The work embodied in this thesis was carried out by the author in the Department of
Applied Chemistry, CUSAT, Kochi, during the period 2011-2016 and is divided into
eight chapters.
Jinsa, Jacob Mary; Dr.Prathapachandra Kurup,M R(Cochin University Of Science And Technology, September , 2013)
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Abstract:
Thiosemicarbazones have emerged as an important class of ligands
over a period of time, for a variety of reasons, such as variable donor
properties, structural diversity and biological applications. Interesting as
the coordination chemistry may be, the driving force for the study of these
ligands has undoubtedly been their biological properties and the majority
of the 3000 or so publications on thiosemicarbazones since 2000 have
alluded to this feature. Thiosemicarbazones with potential donor atoms in
their structural skeleton fascinate coordination chemists with their versatile
chelating behavior. The thiosemicarbazones of aromatic aldehydes and
ketones form stable chelates with transition metal cations by utilizing both
their sulfur and azomethine nitrogen as donor atoms. They have been
shown to possess a diverse range of biological activities including
anticancer, antitumor, antibacterial, antiviral, antimalarial and antifungal
properties owing to their ability to diffuse through the semipermeable
membrane of the cell lines. The enhanced effect may be attributed to the
increased lipophilicity of the metal complexes compared to the ligand
alone.
Description:
Department of Applied Chemistry, Cochin University of Science and Technology
Jessy Emmanuel; Dr.Prathapachandra Kurup,M R(Cochin University Of Science And Technology, July 26, 2012)
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Abstract:
Supra molecular architectures of coordination complexes of liydrazones
through non covalent interactions have been explored. Molecular self—assernbly
driven by weak interactions such as hydrogen— bonding, K '”T[, C-1-I‘ "TE, van
der Waals interactions, and so forth are currently of tremendous research
interest in the fields of molecule based materials. The directional properties of
the hydrogembonding interaction associate discrete molecules into aggregate
structures that are sufficiently stable to be considered as independent chemical
species. Chemistry can borrow nature’s strategy to utilize hydrogen-bonding as
Well as other noncovalent interactions as found in secondary and tertiary
structures of proteins such as the double helix folding of DNA, hydrophobic
selflorganization of phospholipids in cell membrane etc. In supramolecular
chemistry hydrogen bonding plays an important role in forming a variety of
architectures. Thus, the wise modulation and tuning of the complementary sites
responsible for hydrogen—bond formation have led to its application in
supramolecular electronics, host-guest chemistry, self-assembly of molecular
capsules, nanotubes etc. The work presented in this thesis describes the synthesis and
characterization of metal complexes derived from some substituted
aroylhydrazones. The thesis is divided into seven chapters.
Description:
Department of Applied Chemistry, Cochin University of Science and
Technology
Shynu, S V; Augustin, G; Aanandan,C K; Mohanan, P; Vasudevan, K(IET, March 16, 2006)
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Abstract:
A new electronically reconfigurable dual frequency microstrip patch antenna with highly simplified varactor tuning circuitry is presented. The proposed design allows relatively independent selection of the two operating frequencies. Tuning ranges of 7.1 and 4.1% are realised for the two resonant frequencies without the use of any matching circuits.
Sudha Kartha, C; Vijayakumar, K P; Angel, Susan Cherian; Abe, T; Kashiwaba, Y(Elsevier, 2012)
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Abstract:
Thin film solar cells having structure CuInS2/In2S3 were fabricated using chemical spray pyrolysis (CSP) technique
over ITO coated glass. Top electrode was silver film (area 0.05 cm2). Cu/In ratio and S/Cu in the precursor solution
for CuInS2 were fixed as 1.2 and 5 respectively. In/S ratio in the precursor solution for In2S3 was fixed as 1.2/8. An
efficiency of 0.6% (fill factor -37.6%) was obtained. Cu diffusion to the In2S3 layer, which deteriorates junction
properties, is inevitable in CuInS2/In2S3 cell. So to decrease this effect and to ensure a Cu-free In2S3 layer at the top of
the cell, Cu/In ratio was reduced to 1. Then a remarkable increase in short circuit current density was occurred from 3
mA/cm2 to 14.8 mA/cm2 and an efficiency of 2.13% was achieved. Also when In/S ratio was altered to 1.2/12, the
short circuit current density increased to 17.8 mA/cm2 with an improved fill factor of 32% and efficiency remaining
as 2%. Thus Cu/In and In/S ratios in the precursor solutions play a crucial role in determining the cell parameters
Ammini, Joseph; Dr.Ramachandran Nair,P V(Cochin University of Science and Technology, December , 1983)
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Abstract:
The present study on naoplankton is based on the isolation and development of unialgai culturas from the inshore waters at Cochin. characterization of their growth assimilation products. ecophysioiogy and evaluation of nutritional quality. The work was carried out during the period 1980-1983. The nanoplankters were isolated and grown in the labratory as batch cultures to study the increase in cell population, the photosynthetic pigment: ana physioiogical activity. The chemical composition of these organisms and their rate of excretion were also determined. The environmental factors physical and chemical that influence the growth of these Cultures were defined by conducting independentexperiments. These cultures of the isolated nanoplankters have raised indoor and fed to the larvae of edible oyster to test their suitability as live-food.
Gopakumar, S D; Dr. Gopinathan, C P(Cochin University of Science & Technology, August , 2004)
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Abstract:
The present study is an attempt to standardize the environmental condition like pH, salinity and photoperiod, and also the feed for the maximum production of rotifers. Considering the deficiency of essential fatty acids in rotifers, enrichment experiments were carried out and fatty acids profile were analysed. Attempts were made to improve the production of clown fish (Amphiprion sebae) juveniles using enriched rotifers. Attempts were also made to rear various larval stages of Penaeus monodon with enriched rotifers as a substitute for Artemia nauplii.
Hamza, V.K.; Dr. Zakkariya, K.A.(Cochin University of Science and Technology, March 9, 2014)
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Abstract:
Earlier studies on measurement of customer satisfaction are based on either transaction specific or overall approaches. The transaction specific approach evaluates customer satisfaction with single components in the whole purchase process but the overall satisfaction was based on all the encounters or experiences to the customer throughout the purchase process. Consumers will comment on particular events of their purchase process when asked about transaction-specific satisfaction and they will comment their overall impression and general experiences in overall satisfaction (Bitner & Hubbert 1994) Through a critical review on the literature, it has been identified a new approaches to customer satisfaction, say, cumulative approaches that can be more useful than overall and transaction specific approaches for strategic decision making (Fornell et al 1996). The cumulative approach to customer satisfaction doesn’t study earlier due to the difficulty in operationalization of the concept. But the influencers of customer satisfaction are context specific and the prevailing models doesn’t give the sources of variations in the satisfaction, the importance of cumulative approaches to customer satisfaction has emerges that lights to a new research. The current study has focused to explore the influencers of overall customer satisfaction to form individual elements that can be used to identify the cumulative customer satisfaction.
Priya Rajan, S; Dr.Mohanan, P V(Cochin University Of Science And Technology, May , 2013)
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Abstract:
The scope of the work was to synthesis few biologically active derivatives
of curcumin. The derivatives were prepared by altering the keto-enol centre of
curcumin by various reagents. This particular reaction centre for preparing
derivative was selected keeping in mind the controversy regarding the major site
responsible for antioxidant mechanism of curcumin. Most of the mechanistic study
done earlier was by varying the constituents in one or both of the phenol ring
present in the curcumin. The alterations at the keto-enol moiety may throw an
insight into the role of the diketo moiety towards the antioxidant mechanism. Since
recently curcumin has been suggested as a chemotherapeutic agent for various
ailments, we also decided to check the DNA intercalating property of the
derivatives synthesised.
Description:
Department of Applied Chemistry
Cochin University of Science and Technology
Blends of styrene butadiene rubber (SBR) with maleic anhydride
grafted whole tire reclaim (MA-g-WTR) have been prepared and the
cure and mechanical properties have been studied with respect to the
reclaim content. The grafting was carried out in the presence of
dicumylperoxide (DCP) in a Brabender Plasticorder at 150'C. The
presence of anhydride group on the WTR was confirmed by infrared
spectrometry (IR) study. The properties were compared with those of
the blends containing unmodified WTR. Though the cure time was marginally higher, the mechanical properties of the blends containing
grafted WTR were better than that of the unmodified blends.
Anantharaman, M R; Mathew, George; Philip, Kurian(Wiley Subscription Services, Inc., A Wiley Company, September 22, 2010)
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Abstract:
Ultra fine nickel ferrite have been synthesized
by the sol-gel method. By heat treating different portions
of the prepared powder separately at different
temperatures, nano-sized particles of nickel ferrite with
varying particle sizes were obtained. These powders were
characterised by the X-ray diffraction and then incorporated
in the nitrile rubber matrix according to a specific
recipe for various loadings. The cure characteristics and
the mechanical properties of these rubber ferrite composites
(RFCs) were evaluated. The effect of loading and the
grain size of the filler on the cure characteristics and tensile
properties were also evaluated. It is found that the
grain size and porosity of the filler plays a vital role in
determining the mechanical properties of the RFCs
Sunil,K Narayanankutty(Taylor & Francis, November 13, 2000)
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Abstract:
Cure characteristics and mechanical properties of short nylon fiber reinforced
acrylonitrile butadiene rubber-reclaimed rubber composites were studied. Minimum
torque, (maximum-minimum) torque and cure rate increased with fiber
concentration. Scorch time and cure time decreased by the addition of fibers.
Properties like tensile strength, tear strength, elongation at break, abrasion loss
and heat build up were studied in both orientations of fibers. Tensile and tear
properties were enhanced by the addition of fibers and were higher in the longitudinal
direction. Heat build up increased with fiber concentration and were
higher in the longitudinal direction. Abrasion resistance was improved in presence
of short fibers and was higher in the longitudinal direction. Resilience increased
on the introduction of fibers. Compression set was higher for blends.
Sunil,K Narayanankutty(OPA (Overseas Publishers Association), January 7, 1997)
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Abstract:
Cure characteristics of short polyester fiber-polyurethane composites with respect to
different bonding agents (MD resins) based on 4, 4' diphenylmethanediisocyanate (MDI)
and various diols like propyleneglycol (PG), polypropyleneglycol (PPG) and glycerol
(GL) were studied. Tmax. - Tmin. of composites having MD resin were found to be
higher than the composite without MD resin. Minimum torque and Tmax. - Tmin.,
scorch time and optimum cure time were increased with the increase of MDI equivalence.
Optimum ratio of MDI / -of in the resin was found to be within the range of
1-1.5. It was observed from the cure characteristics that for getting better adhesion
between short polyester fiber and the polyurethane matrix the best choice of MD resin
was one based on MDI and 1:1 equivalent mixture of polypropyleneglycol and glycerol.
Anantharaman, M R; Prema, K H; Philip, Kurian; Vijutha, Sunny(Taylor & Francis, 2010)
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Abstract:
Rubber ferrite composites were prepared by incorporating nickel ferrite in a neoprene
rubber matrix. Kinetics of the cure reaction were determined from the rheometric torque
values and found to follow first-order kinetics. Analysis of the swelling behavior of
the rubber ferrite composites in toluene elucidates the mechanism of solvent penetration
and sorption characteristics, and reveals the extent of the physical interaction of
the ferrite particles with the neoprene rubber matrix. Mechanical properties of rubber
ferrite composites were determined, which support the reinforcing nature of nickel ferrite
to the neoprene rubber matrix. These results show that magnetic composites with
the required processing safety can be prepared economically by incorporating higher
amounts of nickel ferrite in the neoprene rubber matrix
Description:
International Journal of Polymeric Materials, 59:173–183, 2010
Rani, Joseph; Dr.Joseph,Francis D(Cochin University of Science and Technology, December , 1987)
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Abstract:
There are a large number of commercial examples and property advantages of immiscible elastomer blends.73 Blends of natural rubber (NR) and polybutadiene (BR) have shown various
advantages including heat stability, improved elasticity and abrasion resistance. Ethylene-propylene-diene-rubber (EPDM) blended with styrene-butadiene rubber (SBR) has shown improvements in ozone and chemical resistance with better compression set properties. Blends of EPDM and nitrile rubber (NBR) have been cited as a compromise for obtaining moderate oil and ozone resistance with improved low temperature properties. Neoprene (CR)/BR blends offer improved low temperature properties and abrasion resistance with better processing characteristics etc. However, in many of the commercial two-phase elastomer blends, segregation of the crosslinking agents, carbon black or antioxidants preferentially into one phase
can result in failure to attain optimum properties. Soluble and insoluble compounding ingredients are found to be preferentially concentrated in one phase. The balance of optimum curing of both phases therefore presents a difficult problem. It has been the aim of this study to improve the
performance of commercially important elastomer blends such as natural rubber (NR)/styrene-butadiene rubber (SBR) and natural rubber/polybutadiene rubber (BR) by industrially viable procedures
Description:
Department Of Polymer Science And Rubber technology
Bijoy, Nandan S(The University of Waikato, Private Bag 3105, Hamilton, New Zealand, November 4, 2008)
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Abstract:
The South West (S.W.) coast of India is blessed with a series of wetland systems popularly
referred to as backwaters covering a total area of 46128.94 ha. These backwaters are
internationally renowned for their aesthetic and scientific values including being a repository
for several species fish and shell fishes. This is more significant in that three wetlands
(Vembanad, Sasthamcotta and Ashtamudi) have recently been designated as Ramsar sites of
international importance. Thirty major backwaters forming the crux of the coastal wetlands
form an abode for over 200 resident or migratory fish and shellfish species. The fishing
activities in these water bodies provide the livelihood to about 200,000 fishers and also provide
full-time employment to over 50,000 fishermen. This paper describes the changes on the
environmental and biodiversity status of selected wetlands, during 1994-2005 period. The pH
was generally near neutral to alkaline in range. The salinity values indicated mixohaline
condition ranging from 5.20-32.38 ppt. in the 12 wetlands. The productivity values were
generally low in most of the wetlands during the study, where the gross production varied
from 0.22 gC/m3/day in Kadinamkulam to 1.10 gC/m3/day in the Kayamkulam. The diversity
of plankton and benthos was more during the pre-monsoon compared to the monsoon and
post-monsoon periods in most of the wetlands. The diversity of plankton and benthos was
more during the pre-monsoon compared to the monsoon and post-monsoon periods in most of
the wetlands. The average fish yield per ha. varied from 246 kg. in Valapattanam to 2747.3 kg.
in Azhikode wetland. Retting of coconut husk in most of the wetlands led to acidic pH
conditions with anoxia resulting in the production of high amounts of sulphide, coupled with
high carbon dioxide values leading to drastic reduction in the incidence and abundance of
plankton, benthic fauna and the fishery resources. The major fish species recorded from the
investigation were Etroplus suratensis, E. maculatus, Channa marulius, Labeo dussumieri, Puntius
sp. Lutianus argentimaculatus, Mystus sp., Tachysurus sp. and Hemiramphus sp. The majority of
these backwaters are highly stressed, especially during the pre monsoon period when the
retting activity is at its peak. The study has clearly reflected that a more restrained and cautious
approach is needed to manage and preserve the unique backwater ecosystems of South-west
India
Description:
Proceedings of the Conserv-Vision Conference, University of Waikato, 2-4 July 2007