Zinc salts of ethyl, isopropyl and butyl xanthates were prepared in the laboratory. The
effect of these xanthates with zinc diethyldithiocarbamate (ZDC) on the vulcanization
of HAF filled NR compound has been studied at different temperatures. The
rubber compounds with the three xanthate accelerators and ZDC were cured at various
temperatures from 60°C to 150°C. The sheets were moulded and properties such as tensile
strength , tear strength , cross-link density, elongation -at-break, compression set, heat
build up, abrasion resistance, flex resistance , etc. were evaluated . The properties
showed that zinc xanthate/ZDC accelerator combination has a positive synergistic effect
on the mechanical properties of NR compounds. The curing of HAF filled NR compound
containing zinc xanthate /ZDC is slightly slower than the curing of the corresponding gum
compounds . It is observed that, by gradually increasing the amount of the accelerator, the
cure time of black filled NR compound can be made equal to that of the gum compou
Due to the emergence of multiple language support on
the Internet, machine translation (MT) technologies are
indispensable to the communication between speakers using
different languages. Recent research works have started to
explore tree-based machine translation systems with syntactical
and morphological information. This work aims the development
of Syntactic Based Machine Translation from English to
Malayalam by adding different case information during
translation. The system identifies general rules for various
sentence patterns in English. These rules are generated using the
Parts Of Speech (POS) tag information of the texts. Word
Reordering based on the Syntax Tree is used to improve the
translation quality of the system. The system used Bilingual
English –Malayalam dictionary for translation.
Description:
2012 International Conference on Data Science & Engineering (ICDSE)
Prathapachandra Kurup, M R; Sreesha, Sasi; Sithambaresan, M; Fun, H K(Elsevier, 2010)
[+]
[-]
Abstract:
Four manganese(II) complexes Mn2(paa)2(N3)4 (1), [Mn(paa)2(NCS)2] 3/2H2O (2), Mn(papea)2(NCS)2 (3),
[Mn(dpka)2(NCS)2] 1/2H2O(4) of three neutral N,N donor bidentate Schiff bases were synthesized and physico-
chemically characterized by means of partial elemental analyses, electronic, infrared and EPR spectral
studies. Compounds 3 and 4 were obtained as single crystals suitable for X-ray diffraction. Compound 4
recrystallized as Mn(dpka)2(NCS)2. Both the compounds crystallized in the monoclinic space groups P21
for 3 and C2/c for 4. Manganese(II) is found to be in a distorted octahedral geometry in both the monomeric
complexes with thiocyanate anion as a terminal ligand coordinating through the nitrogen atom. EPR spectra
in DMF solutions at 77 K show hyperfine sextets with low intensity forbidden lines lying between each
of the two main hyperfine lines and the zero field splitting parameters (D and E) were calculated.
Rani, Joseph(John Wiley & Sons, Inc., November 1, 2000)
[+]
[-]
Abstract:
ABSTRACT: p-Phenylenediamine was chemically attached to low molecular weight chlorinated
paraffin wax. The polymer-bound p-phenylenediamine was characterized by
vapor-phase osmometry (VPO), proton magnetic resonance spectroscopy ('H-NMR),
infrared spectroscopy (IR), and thermogravimetric analysis (TGA). The efficiency and
permanence of the polymer-bound p-phenylenediamine as an antioxidant was compared
with a conventional amine-type antioxidant in natural rubber vulcanizates. The
vulcanizates showed improved aging resistance in comparison to vulcanizates containing
a conventional antioxidant. The presence of liquid polymer-bound p-phenylenediamine
also reduces the amount of the plasticizer required for compounding.
Sreekumar, K; Rajesh Krishnan, G(Taylor & Francis, February 22, 2010)
[+]
[-]
Abstract:
Poly(amidoamine) dendrimers were synthesized on cross-linked aminomethyl polystyrene. Palladium
complexes of supported dendrimers prepared by ligand exchange method were reduced to dendrimernanoparticle
conjugates supported on polystyrene resin. The supported nanoparticles were used as
heterogeneous catalysts for the Suzuki coupling between aryl boronic acids and aryl halides. Various factors
affecting the catalysts performance were studied. Higher generation dendrimers gave well-defined
nanoparticles without agglomeration and these particles showed good catalytic performance
Mohammed Yusuff, K K; Mayadevi, S(Taylor & Francis, 1997)
[+]
[-]
Abstract:
Some new transition metal complexes of the Schiff base
quinoxaline-2-car boxalidene-2-aminophenol (HQAP) have been
synthesized and characterized by elemental analyses, conductance
and magnetic measurements and IR and UV-Visible spectral studies.
The complexes have the following empirical formulae: [Mn(QAP121,
[Fe(QAPl2C1I, [Co(QAPl21, [Ni(QAP121 and [Cu(QAP121. A tetrahedral
structure has been assigned for the manganese(=), cobalt(II1,
nickel(II1 and copper(II1 complexes. For the iron(IIIl complex an
octahedral dimeric structure has been suggested
Anantharaman, M R; Seshan, K; Chakrabarty, D K; Keer, H V(Springer, February 20, 1981)
[+]
[-]
Abstract:
Acicular FeC~O4-2H20 was precipitated from glycerol and starch
media. Thermal decomposition of this oxalate in dry and moist nitrogen yielded
primarily FeO and Fe 3Oa respectively. Characterization was attempted through
DTA, TG, x-ray diffraction, TEM and magnetization studies. It was found
that the oxalate can be completely decomposed to FeaO~ in moist nitrogen
(PH~o ,"-" 35 torr) at 775 K and then oxidised by dry air to acicular "/-Fe~Oa at
575 K. The resulting material has saturation magnetization (,-,., 70 emu/g),
coercive field (N300 Oe) and squareness ratio ( ,~, 0-60-0-65), which values art
comparable with those of the commercial samples
Description:
Bull. Mater. Sci,, Vol, 3, Number 3, November 1981, pp. 275-280.
Sreesha, Sasi; Prathapachandra Kurup, M R; Suresh, E(Springer, January 1, 2007)
[+]
[-]
Abstract:
The cobalt(III) complex, [Co(L)2(N3)2]2(ClO4)2, L being a Schiff base N-[phenyl(pyridin-2-yl)methylene]aniline has been synthesized and the crystal structure determined using X-ray crystallography. The complex crystallizes in triclinic system, space group P-1 with unit cell parameters a=10.9367(9) , b=18.0817(17) , c=20.1629(16) , α=111.341(2), β=91.622(2), γ=107.5030(10), V=3499.1(5) 3 and Z=2. It crystallizes with two independent molecules in the asymmetric unit. The two cobalt atoms are hexa-coordinate and have a distorted octahedral geometry, satisfied by four nitrogen atoms from two molecules of the Schiff base and two nitrogen atoms from the monodentate azide group. The perchlorate ions are non-coordinating.
Sreekumar, K; Sudheesh Kumar, K(Taylor & Francis, June 1, 2007)
[+]
[-]
Abstract:
Various polyurethanes containing photoactive bis(azo) and bis(o-nitrobenzyl)
groups in the main chain were synthesized by polyaddition reactions of diols such
as bis(4-hydroxyphenylazo)-2,20-dinitrodiphenylmethane, 4-hydroxy-3-methylphenylazo-
40-hydroxyphenylazo-2,20-dinitrodiphenylmethane and bis(4-hydroxy-3-
methylphenylazo)-2,20-dinitrodiphenylmethane with hexamethylene di-isocyanate
(HMDI), in dimethyl acetamide (DMAc) in the presence of di-n-butyltin dilaurate
(DBTDL) as catalyst. All of them were characterized by IR, UV-vis, 1H NMR and
13C NMR spectra and also by thermogravimetric analysis (TGA), differential scanning
calorimetry (DSC) and gel permeation chromatography (GPC).
Description:
International Journal of Polymeric Materials, 58:160–166, 2009
Girish Kumar,K; Karthikeyan, G; Mohanraj, K; Elango, K P(Pleiades, 2006)
[+]
[-]
Abstract:
A series of nonelectrolytic lanthanide(III) complexes,
[
ML
2
Cl
3
]
·
2
H
2
O, where M is lanthanum(III),
praseodymium(III), neodymium(III), samarium(III), gadolinium(III), terbium(III), dysprosium(III), and
yttrium(III), containing sulfamethoxazole ligand (L) are prepared. The structure and bonding of the ligand are
studied by elemental analysis, magnetic susceptibility measurements, IR,
1
H NMR,
TG
/
DTA
, X-ray diffraction
studies, and electronic spectra of the complexes. The stereochemistry around the metal ions is a monocapped
trigonal prism in which four of the coordination sites are occupied by two each from two chelating ligands, sulfonyl
oxygen, and nitrogen of the amide group and the remaining three positions are occupied by three chlorines.
The ligand and the new complexes were tested in
vitro to evaluate their activity against the bacteria
Escherichia
coli
and
Staphylococcus
aureus.
Prathapachandra Kurup, M R; Laly, K; Suja, Krishnan(Elsevier, November 10, 2009)
[+]
[-]
Abstract:
Five Mn(II) complexes of bis(thiosemicarbazones) which are represented as [Mn(H2Ac4Ph)Cl2]
(1), [Mn(Ac4Ph)H2O] (2), [Mn(H2Ac4Cy)Cl2]·H2O (3), [Mn(H2Ac4Et)Cl2]·3H2O (4) and
[Mn(H2Ac4Et)(OAc)2]·3H2O (5) have been synthesized and characterized by elemental analyses,
electronic, infrared and EPR spectral techniques. In all the complexes except [Mn(Ac4Ph)H2O], the
ligands act as pentadentate neutral molecules and coordinate to Mn(II) ion through two thione sulfur
atoms, two azomethine nitrogens and the pyridine nitrogen, suggesting a heptacoordination. While in
compound [Mn(Ac4Ph)H2O], the dianionic ligand is coordinated to the metal suggesting six coordination
in this case. Magnetic studies indicate the high spin state of Mn(II). Conductivity measurements reveal
their non-electrolyte nature. EPR studies indicate five g values for [Mn(Ac4Ph)H2O] showing zero field
splitting.
Prathapachandra Kurup, M R; Neema, Ani Mangalam(Elsevier, July 27, 2008)
[+]
[-]
Abstract:
Four oxovanadium and one dioxovanadium complex with 2-hydroxyacetophenone N(4)-
phenylthiosemicarbazone (H2L) which are represented as [VOLphen]·2H2O (1), [VOLbipy] (2),
[VOLdmbipy] (3), [VOL]2 (4) and [VO2HL]·CH3OH (5) have been synthesized and characterized by
elemental analyses, electronic, infrared and EPR spectral techniques. In all the complexes 1–4 the
ligand coordinates through phenolic oxygen, azomethine nitrogen and thiolate sulfur. But in complex
[VO2HL]·CH3OH, coordination takes place in thione form instead of thiolate sulfur. All the complexes
except [VO2HL]·CH3OH are EPR active due to the presence of an unpaired electron. In frozen DMF at 77 K,
all the oxovanadium(IV) complexes show axial anisotropy with two sets of eight line patterns
Iron pillared Montmorillonite has been synthesised and it is then wet impregnated with vanadia with different vanadia
composition. These catalysts are characterised using conventional techniques such as XRD analysis,FTIR analysis and
surface area and pore volume measurements. Acidity is measured using spectrophotometric monitoring of adsorption of
perylene, thermogravimetric desorption of 2.6 dimethylpyridine and temperature programmed desorption of ammonia.
Activity studies are done in the liquid phase. It has been concluded that Lewis acidic sites are responsible for the benzylation
of toluene when the benzylating agent is benzyl chloride while Bronsted acidic sites are responsible when the reagent is
benzyl alcohol.
The (Ba1-x Srx) (Nd1/2, Nb1/2) O3 ceramics have been prepared by the conventional
ceramic route for different values of x. Addition of a small amount of
CeO2(1 wt%) as a sintering aid increased the density of the samples. The structure
and microstructure of the sintered samples are studied by X-ray diffraction
and SEM methods. The dielectric properties of the samples are measured in the
microwave frequency region as a function of composition. The dielectric constant
decreases as x increases. The coefficient of thermal variation of resonant
frequency decreases as the Sr content increases and goes to the negative side.
The dielectric properties of (Ba1-x Srx) (Nd1/2, Nb1/2) O3 are in the range suitable
for application as dielectric resonators in microwave circuits
Sunajadevi, K R; Sugunan, S(Elsevier, October , 2004)
[+]
[-]
Abstract:
Chromia loaded sulfated titania has been synthesized via sol–gel route with different chromia loadings. These catalysts are characterized using conventional techniques such as XRD analysis, FTIR analysis, surface area and pore volume measurements, EDX, SEM and UV–Vis diffuse reflectance spectral analysis. Acidity is measured using spectrophotometric monitoring of adsorption of perylene, thermogravimetric desorption of 2,6-dimethylpyridine and temperature programmed desorption of ammonia. Activity studies are done in the liquid phase. It has been concluded that Lewis acid sites are responsible for the benzylation of arenes with benzyl chloride.
A series of rare-earth neodymia supported vanadium oxide catalysts with various V205 loadings ranging from 3 to 15 wt.% were prepared
by the wet impregnation method using ammonium metavanadate as the vanadium precursor. The nature of vanadia species formed on the
support surface is characterized hy a series of different physicochemical techniques like X-ray diffraction (XRD). Fourier transform infrared
spectroscopy (FTIR). BET surface area, diffuse reflectance UV-vis spectroscopy (DR UV-vis), thermal analysis (TG-DTG/DTA) and SEM.
The acidity of the prepared systems were verified by the stepwise temperature programmed desorprion of ammonia (NH3-TPD) and found that
the total acidity gets increased with the percentage of vanadia loading. XRD and FT1R results shows the presence of surface dispersed vanadyl
species at lower loadings and the formation of higher vanadate species as the percentage composition of vanadia is increased above 9 wt.%.
The low surface area of the support. calcination temperature and the percentage of vanadia loading are found to influence the formation of
higher vanadia species. The catalytic activity of the V205-Nd203 catalysts was probed in the liquid phase hydroxylation of phenol and the
result show that the present catalysts are active at lower vanadia concentrations.
Mohammed Yusuff, K K; Anas, K(Elsevier, Applied Catalysis A :General 264 (2004) 213–217, December 25, 2003)
[+]
[-]
Abstract:
CoMo/gama-Al2O3 catalysts for hydrodesulphurisation activity were prepared by making use of the molecular designed dispersion (MDD)
method. Molybdenum and cobalt pyrrolidine-N-carbodithioate (Pydtc) complexes were used for the incorporation of metals on the support.
The catalysts were characterized by elemental analysis, low temperature oxygen chemisorption, temperature programmed reduction (TPR)
and laser Raman spectroscopy. The hydrodesulphurisation activity of all the catalysts were carried out and results were compared with those
of the catalysts prepared through the conventional method. Higher molybdenum dispersion, smaller molybdenum clusters, lower reduction
temperature of catalyst and better hydrodesulphurisation activity were observed for the catalysts prepared through the MDD method
The title reaction was undertaken to establish the interaction between amantadine and molybdate at physiological pH. Identical FTIR spectra, TG-DTA curves and CHN data of the complexes formed from three solutions at pH 1.5, 7.4 and 8.0 indicate that the same complex was formed at all the three pHs. The FTIR spectrum shows shift in peaks corresponding to primary amino group of the drug due to coordination to molybdate. An octahedral geometry is assigned to the complex. The kinetics of the complexation has been studied at low concentrations of the reactants using UV-visible spectrophotometry. At pH 7.4, the initial rate varies linearly with [molybdate]. A plot of initial rate versus [drug] is linear passing through origin. These results indicate that the drug and molybdate react at pH 7.4 even at low concentrations. At pH 1.5, the rate increases linearly with increase in [drug] but decreases with [molybdate]. The effect of pH and ionic strength on the rate of the reaction has also been studied. A suitable mechanism has been proposed for the reaction. Reaction between the drug and molybdate even at low concentrations and the fact that the amino group of amantadine required to be free for its function as antiviral, is bound to molybdate in the complex suggests that simultaneous administration of the drug and molybdate supplements should be avoided.