Rani, Joseph(Department of Polymer Science and Rubber Technology, November 8, 2006)
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Abstract:
Copper doped methylene blue sensitized poly(vinyl alcohol) (MBPVA)–acrylamide films were fabricated to improve the
storage life of recorded gratings. The films were fabricated using gravity settling method and the copper chloride
concentration was optimized as 3:18 10 3 mol/l for a dye concentration of 6:2 10 4 mol/l. The gratings recorded on the
optimized film constitution could be stored for months with stable diffraction efficiency (24%) without any chemical or
thermal fixing techniques. The resolution of the material is found to be unaffected with the addition of copper chloride.
Sreekumar,K(Japaneese society of Applied physics, November 8, 2006)
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Abstract:
Copper doped methylene blue sensitized poly(vinyl alcohol) (MBPVA)–acrylamide films were fabricated to improve the
storage life of recorded gratings. The films were fabricated using gravity settling method and the copper chloride
concentration was optimized as 3:18 10 3 mol/l for a dye concentration of 6:2 10 4 mol/l. The gratings recorded on the
optimized film constitution could be stored for months with stable diffraction efficiency (24%) without any chemical or
thermal fixing techniques. The resolution of the material is found to be unaffected with the addition of copper chloride.
Mohammed Yusuff, K K; Rani, Abraham(Elsevier,Journal of Molecular Catalysis A: Chemical 198 (2003) 175–183, December 2, 2002)
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Abstract:
Copper(II) complexes of two biologically important ligands, viz., embelin (2,5-dihydroxy-3-undecyl-2,5-cyclohexadien
1,4-dione) and 2-aminobenzimidazole were entrapped in the cages of zeolite Y by the flexible ligand method. The capability
of these compounds in catalyzing the reduction of oxygen (industrially known as deoxo reaction) was explored and the
results indicate an enhancement of the catalytic properties from that of the simple copper ion exchanged zeolite. These
point to the ability of the ligands in enhancing the oxygen binding capability of the metal ion. Elemental analyses, Fourier
transform infrared (FTIR), diffuse reflectance and EPR spectral studies, magnetic susceptibility measurements, TG, surface
area analyses and powder X-ray diffraction studies were used in understanding the presence, composition and structure of
the complexes inside the cages. The study also reveals the increased thermal and mechanical stability of the complexes as a
result of encapsulation.
Rapheal, P F; Manoj, E; Prathapachandra Kurup, M R(Elsevier, 2007)
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Abstract:
Ten copper(II) complexes {[CuL1Cl] (1), [CuL1NO3]2 (2), [CuL1N3]2 · 2/3H2O (3), [CuL1]2(ClO4)2 · 2H2O (4), [CuL2Cl]2 (5), [CuL2N3] (6), [Cu(HL2)SO4]2 · 4H2O (7), [Cu(HL2)2] (ClO4)2 · 1/2EtOH (8), [CuL3Cl]2 (9), [CuL3NCS] · 1/2H2O (10)} of three NNS donor thiosemicarbazone ligands {pyridine-2-carbaldehyde-N(4)-p-methoxyphenyl thiosemicarbazone [HL1], pyridine-2-carbaldehyde-N(4)-2-phenethyl thiosemicarbazone [HL2] and pyridine-2-carbaldehyde N(4)-(methyl), N(4)-(phenyl) thiosemicarbazone [HL3]} were synthesized and physico-chemically characterized. The crystal structure of compound 9 has been determined by X-ray diffraction studies and is found that the dimer consists of two square pyramidal Cu(II) centers linked by two chlorine atoms.
Anu,Gopinath; Chandramohanakumar,N(Department of Chemical Oceanography,School of Marine Sciences, 2002)
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Abstract:
The present study focuses on the biochemical aspects of six islands belonging to Lakshadweep Archipelago – namely Kavaratti, Kadamath, Kiltan, Androth, Agathy and Minicoy. Lakshadweep, which is an area biologically significant due to isolation from the major coastline, remains as one of the least studied areas in Indian Ocean. The work, processed out the distributional pattern of trace metals among the biotic (corols, sea weeds and sea grass) and abiotic component (sediments) of ecosystem. An effort is made to picturise the spatial distribution pattern of different forms of nitrogen and phosphorus in the various sedimentary environments of the study area. Studies on the biogeochemical and nutrient aspects of the concerned study area scanty. In Lakshadweep, the local life is very dependent on reefs and its resources. The important stress which produce a threatening effort on the existence for coral reefs are anthropogenic-namely-organic and inorganic pollution from sewage, agricultural and industrial waters, sediment damage from excessive land cleaning, and over exploitation particularly through destructive fishing methods. In addition these one other more localized or less service anthropogenic stress: pollution by oil and other hydrocarbons, complex organic molecular and heavy metal pollution, and destructive engineering practices.
Pravinkumar,P A; Mohanan,P; K G Nair(Indian Journal of Radio & Space Physics, December , 1981)
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Abstract:
A technique for improving the coupling between a feed horn and reflector by using corrugated metallic flanges is presented.
Experimental data for flanges of varying parameters are given and theoretical explanation is supplemented
Chitra, R N; Kuriakose, V C(American Institute of Physics, 2008)
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Abstract:
A new geometry (semiannular) for Josephson junction has been proposed and theoretical studies have shown that the new geometry is useful for electronic applications [1, 2]. In this work we study the voltage‐current response of the junction with a periodic modulation. The fluxon experiences an oscillating potential in the presence of the ac‐bias which increases the depinning current value. We show that in a system with periodic boundary conditions, average progressive motion of fluxon commences after the amplitude of the ac drive exceeds a certain threshold value. The analytic studies are justified by simulating the equation using finite‐difference method. We observe creation and annihilation of fluxons in semiannular Josephson junction with an ac‐bias in the presence of an external magnetic field.
Cryptosystem using linear codes was developed in 1978 by Mc-Eliece.
Later in 1985 Niederreiter and others developed a modified version of cryptosystem using concepts of
linear codes. But these systems were not used frequently because of its larger key size. In this study we
were designing a cryptosystem using the concepts of algebraic geometric codes with smaller key size.
Error detection and correction can be done efficiently by simple decoding methods using the
cryptosystem developed. Approach: Algebraic geometric codes are codes, generated using curves.
The cryptosystem use basic concepts of elliptic curves cryptography and generator matrix. Decrypted
information takes the form of a repetition code. Due to this complexity of decoding procedure is
reduced. Error detection and correction can be carried out efficiently by solving a simple system of
linear equations, there by imposing the concepts of security along with error detection and correction.
Results: Implementation of the algorithm is done on MATLAB and comparative analysis is also done
on various parameters of the system. Attacks are common to all cryptosystems. But by securely
choosing curve, field and representation of elements in field, we can overcome the attacks and a stable
system can be generated. Conclusion: The algorithm defined here protects the information from an
intruder and also from the error in communication channel by efficient error correction methods.
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.
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.
Sunil K Narayanankutty(Marcel Dekker , Inc., 2004)
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Abstract:
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.
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.
Bijoy, S Nandan(The university of Waikato, November 4, 2008)
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Abstract:
Soth west 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 internationallyrenowed for their aesthetic and scientific values including being a repository for several species fish and shell fishes. this is more significant in thatthre wetlands( Vembanad, Sasthamcotta & Ashtamudi) have recently been designated as Ramsar sites og international importance.Thirty major backwaters forming the crux of the coastal wetlands from an abodefor over 200 residentry and migratory fish and shellfish species. the fishing activities in these water bodies provide the livilihoodto 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 mostof the wetlands during the study, where the gross production varied from 0.22gC/m3/ day in Kadinamkulam to 1.10gC/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 premonsoon compared to the monsoon and post monsoon periods in most of the wetlands.the average fish yield per ha.varied from 246kg in valapattanam to 2747kg 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 argentimaculatus, Mystus sp., tachysurus sp. and Hemiraamphus sp. . The majority of these back waters are highly stressed, especially during the pre monsoon period when the retting activity at its peak. The study has clearly reflected that a more restrained and cautions approach is needed to manage and preserve the unique backwater ecosystems of south west india.