Vanadia/ceria catalysts (2–10 wt% of V2O5) were prepared by wet impregnation of ammonium metavanadate in oxalic acid solution. Structural characterization was done with energy dispersive X-ray analysis (EDX), powder X-ray diffraction (XRD), BET surface area measurements, FT-IR spectroscopy and nuclear magnetic spectral analysis (51V MASNMR). XRD and 51V MASNMR results show highly dispersed vanadia species at lower loadings and the formation of CeVO4 phase at higher V2O5 loading. The catalytic activity of catalysts was conducted in liquid phase oxidation of ethylbenzene with H2O2 as oxidant. The oxidation activity is increased with loading up to 8 wt% V2O5 and then decreased with further increase in V2O5 content to 10 wt%. Different vanadia species evidenced by various techniques were found to be selective towards ethylbenzene oxidation. The CeVO4 formation associated with increased concentration of vanadia on ceria results the production of acetophenone along with 2-hydroxyacetophenone.
Radhika, T; Dr.Mohanan, P V; Dr.Sugunan, S(Cochin University of Science and Technology, November 23, 2005)
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Abstract:
The selective oxidation of alkylaromatics is one of the main processes since the reaction products are important as intermediates in numerous industrial organic chemicals. Side-chain oxidation of alkyl aromatic compounds catalyzed by heterogeneous catalysts using cleaner peroxide oxidants is an especially attractive goal since classical synthetic laboratory procedures preferably use permanganate or acid dichromate as stoichiometric oxidants. In spite of many studies, there are very few which use hydrogen peroxide as a source of oxygen in the C-H activation of alkanes. Eflective utilization of ethylbenzene, available in the xylene stream of the petrochemical industry to more value added products is a promising one in chemical industry. The oxidation products of ethylbenzene are widely employed as intermediates in organic, steroid and resin synthesis.
Description:
Department of Chemistry, Cochin University of Science andTechnology,
Hyunkieu,Yang; Sangseol,Lee(Microwave and Optical Technology Letters, December 5, 2001)
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Abstract:
The cutoff wavenumbers of higher order modes in circular
eccentric guides are computed with the variational analysis combined
with a conformal mapping. A conformal mapping is applied to the
variational formulation, and the variational equation is solved by the
finite-element method. Numerical results for TE and TM cutoff
wavenumbers are presented for different distances between the centers
and ratio of the radii. Comparisons with numerical results found in the
literature validate the presented method
Dr.Babu, C A; Asha, Philip S; Hareeshkumar, P V(www.elsevier.com/, January , 2007)
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Abstract:
Numerous low - pressure systems form in the Arabian Sea and Bay of Bengal. These low-pressure systems are
highly useful in bringing the rainfall over the Indian sub continent. The developments of these systems are accompanied
by the reduction in air temperature and an increase in atmospheric humidity. The radio refractivity, which is a function
of the atmospheric pressure, temperature and humidity, also changes following the development of these systems. Variation
of radio refractive index and its vertical gradient are analysed for many low pressure systems formed over the Arabian
Sea and Bay of Bengal. It is found that the atmosphere becomes super refractive associated with the formation of these
systems, caused by the increase in humidity and decrease in temperature. The maximum gradient is observed near the
surface layers, especially in the lowest 1 km. Super refraction leads to increased radar detection range and extension of
radio horizon
Dr.Babu, C A; Jayakrishnan, P R(Taylor & Francis,http://www.tandfonline.com/loi/tres20, December 12, 2012)
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Abstract:
This study attempted to quantify the variations of the surface marine atmospheric
boundary layer (MABL) parameters associated with the tropical Cyclone Gonu formed
over the Arabian Sea during 30 May–7 June 2007 (just after the monsoon onset).
These characteristics were evaluated in terms of surface wind, drag coefficient, wind
stress, horizontal divergence, and frictional velocity using 0.5◦ × 0.5◦ resolution Quick
Scatterometer (QuikSCAT) wind products. The variation of these different surface
boundary layer parameters was studied for three defined cyclone life stages: prior
to the formation, during, and after the cyclone passage. Drastic variations of the
MABL parameters during the passage of the cyclone were observed. The wind strength
increased from 12 to 22 m s−1 in association with different stages of Gonu. Frictional
velocity increased from a value of 0.1–0.6 m s−1 during the formative stage of the
system to a high value of 0.3–1.4 m s−1 during the mature stage. Drag coefficient
varied from 1.5 × 10−3 to 2.5 × 10−3 during the occurrence of Gonu. Wind stress
values varied from 0.4 to 1.1 N m−2. Wind stress curl values varied from 10 × 10−7 to
45 × 10−7 N m−3. Generally, convergent winds prevailed with the numerical value of
divergence varying from 0 to –4 × 10−5 s−1. Maximum variations of the wind parameters
were found in the wall cloud region of the cyclone. The parameters returned to
normally observed values in 1–3 days after the cyclone passage
Description:
International Journal of Remote Sensing
Vol. 34, No. 7, 10 April 2013, 2417–2431
Madhusoodana Kurup,B; Thomas, Joice V; Sreedevi, C(Indian Journal of Marine Sciences, September , 2006)
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Abstract:
Variations of the infaunal polychates populations due to bottom trawling were studied during December 2000 to November 2002 at depth ranging from 0-50 m along Cochin-Munambam area (Kerala, long. 76degree10'94" to 75degree 56' and lat.9degree58' to 10degree10'), in the southwest coast of India.Infaunal polychaetes from the sediment samples were collected both before and after experimental trawling in order to assess the variations on their abundance (no.m-2),biomass(g.m-2) and diversity due to bottom trawling .Highest variations in polychaetes were recorded at station 9 in May 2002 where polychaete abundance increased to 20710 no.m-2 after trawling from 2787 no.m-2 before trawling.Biomass showed highest variations at station 3 in December 2000 where biomass increased from 7.16g.m-2 recorded before trawling to 34.53 g.m-2 in the samples collected after trawling .Multivariate community analysis carried out based on both species abundance and biomass of plychaetes also confirm the wide variations in the similarities of the stations comparing both before and after trawling
Prathapachandra Kurup, M R; Neema, Ani Mangalam(Elsevier, 2011)
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Abstract:
Six new copper complexes of di-2-pyridyl ketone nicotinoylhydrazone (HDKN) have been synthesized.
The complexes have been characterized by a variety of spectroscopic techniques and the structure of
[Cu(DKN)2]·H2O has been determined by single crystal X-ray diffraction. The compound [Cu(DKN)2]·H2O
crystallized in the monoclinic space group P21 and has a distorted octahedral geometry. The IR spectra
revealed the presence of variable modes of chelation for the investigated ligand. The EPR spectra
of compounds [Cu2(DKN)2( -N3)2] and [Cu2(DKN)2( -NCS)2] in polycrystalline state suggest a dimeric
structure as they exhibited a half field signal, which indicate the presence of a weak interaction between
two Cu(II) ions in these complexes
Prathapachandra Kurup, M R; Sheena Mary, Y; Raju, K; Yohannan Panicker, C; Neema, Ani Mangalam; Hema, Tresa Varghese; Sheeja, S R(Elsevier, March 16, 2010)
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Abstract:
FT-IR spectrum of quinoline-2-carbaldehyde benzoyl hydrazone (HQb H2O) was recorded and analyzed.
The synthesis and crystal structure data are also described. The vibrational wavenumbers were examined
theoretically using the Gaussian03 package of programs using HF/6-31G(d) and B3LYP/6-31G(d) levels of
theory. The data obtained from vibrational wavenumber calculations are used to assign vibrational bands
obtained in infrared spectroscopy of the studied molecule. The first hyperpolarizability, infrared intensities
and Raman activities are reported. The calculated first hyperpolarizability is comparable with the
reported values of similar derivatives and is an attractive object for future studies of non-linear optics.
The geometrical parameters of the title compound obtained from XRD studies are in agreement with
the calculated values. The changes in the CAN bond lengths suggest an extended p-electron delocalization
over quinoline and hydrazone moieties which is responsible for the non-linearity of the molecule
Description:
Journal of Molecular Structure 973 (2010) 36–46 http://dx.doi.org/10.1016/j.molstruc.2010.03.016
Junaid, Bushiri M; Mahadevan Pillai, V P; Pradeep, T; Jayasree, R S; Nayar, V U(Elsevier, 1997)
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Abstract:
FTIR and Raman spectra of FeClMoO4 single crystal and polycrystalline Na2MoO4, Na2MoO4·2H2O and
Na2MoO4·2D2O are recorded and analysed. The band positions for different modes suggest that MoO4 tetrahedron
is more distorted in FeClMoO4. The larger splitting observed for the bending modes and partial retention of
degeneracy of the asymmetric stretching mode indicate that angular distortion is greater than liner distortion in
MoO4 2 ion in FeClMoO4 confirming x-ray data. The non-appearance of the n1 and n2 modes in the IR and partial
retention of the degeneracies of various modes show that MoO4 2 ion retains Td symmetry in Na2MoO4. Wavenumber
values of the n1 mode indicate that the distortion of MoO4 tetrahedra in the four crystals are in the order
FeClMoO4\ Na2MoO4·2H2O\Na2MoO4·2D2O\Na2MoO4. The water bands suggest the presence of two
crystallographically distinct water molecules in Na2MoO4·2H2O. They form strong hydrogen bonds
Junaid, Bushiri M; Antony, C J; Michel, Fleck(Elsevier, May 27, 2007)
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Abstract:
The Raman and FTIR spectra of [C(NH2)3]2M(SO4)2 ·6H2O (withM= Co, Fe, Ni) were recorded and analysed. The observed spectral bands
are assigned in terms of vibrations of guanidinium ions, sulphate groups and water molecules. The analysis shows that the sulphate tetrahedra
are distorted from their free state symmetry Td to C1. This is attributed to the presence of hydrogen bonds from water molecules. The order of
distortion of the metal oxygen octahedra influenced the distortion of the sulphate tetrahedra. The appearance of 1– 3 modes of water molecules
above 3300 cm−1 indicates the presence of weak hydrogen bonds
Surekhamol, I S; Dr.Bright Singh,I S(Cochin University of Science and Technology, November , 2012)
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Abstract:
Aquaculture is a global industry providing food and employment thereby contributing to the economy. For the sustenance of aquaculture, disease management is a major requirement. Among the bacterial pathogens Vibrio harveyi remains to be the major one especially in shrimp culture systems. Rapid
and mass mortality of shrimp larvae due to Vibrio harveyi infection is well known, and the pathogen causes serious economic losses in grow out systems as well. It suggests that a well defined management strategy has to be built up to protect the crop from Vibrio harveyi infection in aquaculture systems. Antibiotics have been the choice for quite some times which led to residues in meat and development of multidrug resistant bacteria which invited ban on their application. In this context several alternate options have been thought off such as probiotics, immunostimulants and vaccines. Phage therapy is yet another option. Phages being natural parasites of bacteria and are abundant in aquatic environments their application to control bacterial pathogens in aquaculture has commendable potential in lieu of antibiotics. For that matter the therapeutic effect of phages has been proven in several antibiotic resistant pathogens inclusive of Vibrio harveyi.
Description:
National Centre for Aquatic Animal
Health, School of Environmental Studies, Cochin University of Science and Technology
Bright Singh, I S; Rosamma, Philip; Rejish Kumar, V J; Jayaprakash, N S(Blackwell Publishing Ltd, March 1, 2006)
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Abstract:
Surveys for bacteriological analysis of larval samples
to isolate the associated vibrios were carried out during
1985^1992, 2001 and 2002 in three di¡erent
hatcheries located on the southwest coast of India.
Vibrio isolates were examined for their species diversity,
virulence based on haemolysis in prawn blood
agar, lipolysis, proteolysis and chitinolysis and antibiotic
sensitivity.Vibrio cholerae was the predominant
species in the apparently healthy larval samples,
whereas V. alginolyticus and V. vulni¢cus dominated
during disease and morbidity. No correlation was
found between the hydrolytic properties and haemolytic
activity of the vibrios associated with the larvae.
All isolates were resistant to erythromycin and resistance
to oxytetracycline, ampicillin and streptomycin
sulphate was prevalent among the larger section of
the Vibrio population. This suggested that antibiotic
application may not be of much use to protect the larvae
fromvibriosis. This is the ¢rst report on the diversity
of Vibrio species associated with Macrobrachium
rosenbergii larvae and their virulence characteristics
based on haemolysis in prawn blood agar
Pedicle screw insertion technique has made revolution in the surgical treatment of spinal fractures and spinal disorders. Although X- ray fluoroscopy based navigation is popular, there is risk of prolonged exposure to X- ray radiation. Systems that have lower radiation risk are generally quite expensive. The position and orientation of the drill is clinically very important in pedicle screw fixation. In this paper, the position and orientation of the marker on the drill is determined using pattern recognition based methods, using geometric features, obtained from the input video sequence taken from CCD camera. A search is then performed on the video frames after preprocessing, to obtain the exact position and orientation of the drill. An animated graphics, showing the instantaneous position and orientation of the drill is then overlaid on the processed video for real time drill control and navigation
Poulose Jacob,K; Preetha Theresa, Joy(IEEE, February 16, 2014)
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Abstract:
Cache look up is an integral part of cooperative
caching in ad hoc networks. In this paper, we discuss a
cooperative caching architecture with a distributed cache look up
protocol which relies on a virtual backbone for locating and
accessing data within a cooperate cache. Our proposal consists of
two phases: (i) formation of a virtual backbone and (ii) the cache
look up phase. The nodes in a Connected Dominating Set (CDS)
form the virtual backbone. The cache look up protocol makes use
of the nodes in the virtual backbone for effective data
dissemination and discovery. The idea in this scheme is to reduce
the number of nodes involved in cache look up process, by
constructing a CDS that contains a small number of nodes, still
having full coverage of the network. We evaluated the effect of
various parameter settings on the performance metrics such as
message overhead, cache hit ratio and average query delay.
Compared to the previous schemes the proposed scheme not only
reduces message overhead, but also improves the cache hit ratio
and reduces the average delay
Description:
Advanced Communication Technology (ICACT), 2014 16th International Conference on
Bright Singh, I S; Rosamma, Philip; Sreedharan, K(SBM, January 16, 2012)
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Abstract:
Aeromonas spp. are ubiquitous aquatic organisms, associated with multitude of diseases in several species of
animals, including fishes and humans. In the present study, water samples from two ornamental fish culture
systems were analyzed for the presence of Aeromonas. Nutrient agar was used for Aeromonas isolation, and
colonies (60 No) were identified through biochemical characterization. Seven clusters could be generated
based on phenotypic characters, analyzed by the programme NTSYSpc, Version 2.02i, and identified as:
Aeromonas caviae (33.3%), A. jandaei (38.3%) and A. veronii biovar sobria (28.3%). The strains isolated
produced highly active hydrolytic enzymes, haemolytic activity and slime formation in varying proportions.
The isolates were also tested for the enterotoxin genes (act, alt and ast), haemolytic toxins (hlyA and aerA),
involved in type 3 secretion system (TTSS: ascV, aexT, aopP, aopO, ascF–ascG, and aopH), and
glycerophospholipid-cholesterol acyltransferase (gcat). All isolates were found to be associated with at least
one virulent gene. Moreover, they were resistant to frequently used antibiotics for human infections. The
study demonstrates the pathogenic potential of Aeromonas, associated with ornamental fish culture systems
suggesting the emerging threat to public health
Nampoori, V P N; Litty, Irimpan; Radhakrishnan, P(Journal of Applied Physics, American Institute of Physics,, 2008)
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Abstract:
We describe the structure of luminescence spectrum in the visible region in nano-ZnO in colloidal
and thin film forms under weak confinement regime by modeling the transition from excited state
energy levels of excitons to their ground state. Measurements on nanocrystallites indicate the
presence of luminescence due to excitonic emissions when excited with 255 nm. The relevant
energy levels showing the transitions corresponding to the observed peaks in the emission spectrum
of ZnO of particle size 18 nm are identified.