Showing papers by "Shivaji University published in 1996"
TL;DR: In this paper, a spray pyrolysis method on amorphous glass substrates kept at 300 °C was used to obtain uniform, pinhole free, and strongly adherent to the substrates.
185 citations
TL;DR: In this article, electron beam evaporation of Al 2 O 3 with and without chopping, and the oxidation of aluminium films by hot water and by steam were compared for the four types of films.
55 citations
48 citations
TL;DR: In this article, as-deposited thin semiconducting Bi 2 S 3 thin films were prepared on glass substrates from nonaqueous media using spray pyrolysis.
41 citations
TL;DR: In this paper, Ni 1-x Zn x Fe 2 O 4 with x = 0.30, 0.35, 040, and 0.45 have been sintered at 1100, 1150, 1200, and 1240 °C to attain different microstructures.
Abstract: Compositions having the general formula Ni 1-x Zn x Fe 2 O 4 with x = 0.30, 0.35, 0.40, 0.45 have been sintered at 1100, 1150, 1200, and 1240 °C to attain different microstructures. The grain size D for a particular composition increases linearly with increasing sintering temperature. The lattice parameter a and magnetization M 8 are seen to be invariant with the change in sintering temperature. The coercive force H c and the remanent ratio R = M x /M 8 are seen to depend on the sintering temperature and hence on D. a and 8 S are found to increase with the increase of the Zn content, whereas H c values show a decreasing trend with the Zn content. The compositional, thermal, and microstructural variation of hysteresis parameters like M 8 , H c , and R = M r /M 8 reveal that magnetic grains in the compositions investigated are of multi-domain type. This result is supported by ac susceptibility data.
31 citations
TL;DR: In this paper, the magnetic moment (nB) values measured from hysteresis and from neutron diffraction study agree with each other, however, these are lower than the theoretical values computed from Neel's colinear model.
26 citations
TL;DR: In this paper, a photoelectrochemical cell of the configuration n-PbxCd1 − xS/Na2S-S-NaOH/C was formed and the I-V and C-V characteristics were examined to understand the nature of the charge transfer process across the electrode/electrolyte interface.
19 citations
TL;DR: In this paper, lattice parameters, magnetization and ac susceptibility measurements for the ferrite system were presented, where the ac susceptibility was measured from room temperature to 800K at a constant magnetic field of 7 oersted.
Abstract: Studies on lattice parameters, magnetization and ac susceptibility measurements for the ferrite system Cd
x
Mg1−x
Gd
y
Fe2−y
O4 (withx = 0·2, 0·3, 0·4 andy = 0·1, 0·2, 0·3, 0·4) are presented. The ac susceptibility was measured from room temperature to 800K at a constant magnetic field of 7 oersted.X
ac vsT variations show that all the samples contain predominantly multidomain (MD) particles. Magnetization measurements of the system indicate that as the Cd2+ content increases magnetization increases while the addition of Gd3+ reduces the magnetization. The observations further indicate the existence of Y-K type of magnetic ordering in the system.
17 citations
TL;DR: In this article, electrical resistivity and thermoelectric power measurements are made on the systems Ni 0.8 2+ Zn 0.4 2+ Mn x 2+ Sn x 4+ Fe 2-2x 3+ O 4 2-
Abstract: Electrical resistivity and thermoelectric power measurements are made on the systems Ni 0.8 2+ Zn 0.2 2+ Mn x 2+ Sn x 4+ Fe 2-2x 3+ O 4 2- , Ni 0.6 2+ Zn 0.4 2+ Mn x 2+ Sn x 4+ Fe 2-2x 3+ O 4 2- , and Ni 0.6 2+ Zn 0.4 2+ Mn x 2+ Ti x 4+ Fe 2-2x 3+ O 4 2- with x = 0, 0.1, 0.2, 0.3, and 0.4 in the temperature range of 300 to 800 K. The increase in resistivity with composition is attributed to increasing concentrations of substitutions in each system. Impurity conduction is favoured in each system up to 425 K except for x = 0.3 and 0.4 concentrations of MnSn in the second system. These samples of the second system show anomalous behaviour in this temperature region. At higher temperatures conduction is due to hopping of polarons. Anomalous behaviour is also observed in the MnTi substitute system for x = 0.4. Thermoelectric power is found to be negative over the whole range of temperatures indicating that the majority charge carriers are electrons. The temperature variation of thermoelectric power suggests that these ferrites of different systems are nondegenerate semiconductors. The binding energy of the polaron is found to be in the range of 0.1 eV in the case of MnSn substituted samples, in the case of MnTi substituted samples, it is of the order of 0.2 eV. This is attributed to the formation of stable bonds of Ti 4+ with Fe 2+ .
16 citations
TL;DR: In this paper, electrical resistivity and thermoelectric power for Mn substituted ferrites with general formula Zn0·3Ni0·7+xMnxFe2−2xO4.
Abstract: The d.c. electrical resistivity ‘ρ’ and thermoelectric power ‘α’ are studied as a function of temperature for Mn substituted ferrites with general formula Zn0·3Ni0·7+xMnxFe2−2xO4. At lower Mn concentrations, the increase in d.c. resistivity is attributed to the hindering of Verwey mechanism Fe2+ ⇌ Fe3+ due to stable bonds of Mn3+ + Fe2+ pair. The decrease in resistivity at higher Mn concentrations (i.e. whenx > 0·15) is attributed to the formation of Mn3+ cluster and Ni2+ ⇌ Ni3+. The activation energy values show one to one correspondence with resistivity values. The compositional variation of thermoelectric power showsn-type behaviour for the samples withx < 0·2 whereasp-type behaviour for the samples withx ⩾ 0·2. Thep −n transition is attributed to the formation of Ni3+, Fe2+ + vacancies which act asp-type carriers. The temperature dependences ofα, ρ, and mobility clearly confirm the conduction mechanism to be due to polaron hopping.
14 citations
TL;DR: In this article, the composites having the general formula Ni1 − xZnxAltFe2 − tO4 were prepared using the standard ceramic method and they were sintered at four different temperatures to attain different microstructures.
TL;DR: In this paper, a photoelectrochemical (PEC) cell was formed using WO3 thin film as a photoanode and 0·1 M Na2SO4 as an electrolyte.
Abstract: WO3 thin films have been prepared by employing spray pyrolysis technique. Photoelectrochemical (PEC) cell was formed using WO3 thin film as a photoanode and 0·1 M Na2SO4 as an electrolyte. Different physical parameters of the PEC cell such as flat band potential, donor density, hole diffusion length and band gap energy were determined by using Gartner’s model.
TL;DR: In this article, a simple and efficient method for synthesis of phenacyl esters in quantitative yield and high purity under mild reaction condition by using phase transfer catalyst and dibenzo-[18]-crown-6.
TL;DR: In this paper, the lattice parameter a, magnetization M s are seen to decrease with increasing Al 3+ content whereas the coercive force H c shows an increasing trend with Al 3+, whereas the coercivity H c and the remanent ratio R = M R /M s are found to be invariant with changes in sintering temperature.
TL;DR: In this article, the electrosynthesis of yttrium chalcogenide films on a variety of substrates in a nonaqueous bath, using sodium acetate as a complexing agent, was reported.
TL;DR: In this article, the d.c. electrical resistivity and thermoelectric power as a function of temperature for Mn-substituted ferrites with general formula Cd0.5Ni 0.5+xMnxFe2−2xO4 have been studied.
Abstract: The d.c. electrical resistivity (ρ) and thermoelectric power (α) as a function of temperature for Mn-substituted ferrites with general formula Cd0.5Ni0.5+xMnxFe2–2xO4 have been studied. At lower Mn concentrations (x≤0.2) the increase in d.c. resistivity with x is attributed to hindering of the Fe3⇌Fe2+ transition. The hindering is caused by the formation of Mn3+Fe2+ stable pair at the octahedral site. The decrease in resistivity with higher concentration of Mn (x>0.2) is attributed to the formation of Ni3+ and to the Mn3+—Mn4+ transition. The observed high value of activation energy for the present system is related to Mn3+ Jahn-Teller trapping. The compositional variation of thermo-emf shows n-type conduction for samples with x≤0.2, and p-type conduction for samples with x>0.2. The n-to p-type transition is explained by the formation of p-type carriers such as Ni3+ and Fe2+ cation vacancies. The electron hopping model of electrical conductivity is applicable for samples with x≤0.2, whereas above...
TL;DR: The results indicate that the phenobarbital induced cytochrome P450 is more susceptible to sulfamethazine than benzo[a]pyrene induced cy tochrome P 450.
TL;DR: In this paper, the wall permeability of Ni0.6Zn0.4Fe2O4 with variable weight percent addition of TiO2 exhibits wall bulging effect.
Abstract: Compositions of Ni0.6Zn0.4Fe2O4 with variable weight percent addition of TiO2 exhibit wall permeability dominance. With increase of TiO2 concentration the permeability decreases which is related to the impedance to the domain wall motion. The permeability obeys the Globus model with evident wall bulging effect.
TL;DR: This paper gives a counter example to invalidate a claim of Nair and Nair (1989) regarding a characterization of bivariate mean residual-life function (BMRLF) and, based on the form of the BMRLF, introduces probability models for bivariate life-time data.
Abstract: This paper gives a counter example to invalidate a claim of Nair and Nair (1989) regarding a characterization of bivariate mean residual-life function (BMRLF). The authors characterize BMRLF of an absolutely continuous life-time distribution and, based on the form of the BMRLF, introduce probability models for bivariate life-time data.
TL;DR: In this article, polyaniline films have been electrodeposited onto stainless steel substrates and on the top of the polyanoiline, thin layers of Sn and Cu are vacuum deposited.
TL;DR: In this paper, the phase stabilities of copper ferrite with substitution of Ti and Ge tetravalent ions were studied. And the observed results were explained on the basis of cation distribution and covalent bond formation of copper and germanium ions.
Abstract: Phase stabilities in copper ferrite are studied with substitution of Ti and Ge tetravalent ions. In Ti-substituted samples (Cu1+x Ti x Fe2x O4) the parent tetragonal structure is retained up to x=0.15, and for higher content of Ti it changes to cubic. In the case of Ge-substituted samples (Cu1+x Ge x Fe2–2x O4), the cubic structure is observed for 0.0
TL;DR: Fluorescein labeled oligonucleotide probes with non-nucleotide linker have been synthesized and used to monitor hybrid formation to detect DNA sequences in solution to monitor triple helix formation and the behaviour of F-Probe in solution.
Abstract: Fluorescein labeled oligonucleotide probes with non-nucleotide linker have been synthesized and used to monitor hybrid formation to detect DNA sequences in solution. Fluorescence anisotropy, r, was adopted as an index to monitor triple helix formation and the behaviour of F-Probe in solution. An appreciable increase in anisotropy was observed upon use of non-nucleotide linker in the fluorescence probe as compared to that of the F-Probe without non-nucleotide linker.
TL;DR: In this article, double exposure holographic interferometry technique (DEHI) is used to study the surface deformation of a steel plate when Mg is deposited by electrolysis method.
Abstract: Double exposure holographic interferometry technique (DEHI) is used to study the surface deformation of a steel plate when Mg is deposited by electrolysis method. MgCl2 solution of different normalities have ben used and steel plate is exposed for different deposition times. It is observed that the fringe spacing changes with concentration. It is also noticed that with increase of deposition time fringe spacing decreases. This effect is due to increase in thickness of Mg films deposited on steel plate surface. Attempt has been made to measure thickness of deposited films and the mass of Mg deposited on the steel plate.
TL;DR: A solution of n-octylaniline in chloroform extracts rhenium selectively from 0.12-0.16 M nitric acid medium through backstripping with 5% aqueous ammonia solution and estimated spectrophotometrically with 5-chloro- 2-hydroxythiobenzhydrazide (5-Cl-2-OHTBH).
Journal Article•
TL;DR: Teleutospores covered by thick mycelial mat but ovary remained free from infection and some spores showed direct germination to form infective hyphae.
Abstract: Ovary covered by thick mycelial mat but ovary remained free from infection. Teleutospores onecelled, spherical, yellowish-brown (orange-yellow in mass), thick-walled, smooth, 5-8 urn in diameter. Spore germinated in situ. Germinating spores produced 2-3 septate promycelium, rarely many septate and measuring 15-25 x 2.5 urn; some spores showed direct germination to form infective hyphae; promycelium produced lateral branches, one from each cell, rarely terminal cell produced three branches (sterigmata); sterigmata stout, hyaline, fusiform or sigmoid and produced terminally one or rarely two sporidia; sporidia one-celled, hyaline, thin-walled, slightly apiculate, non-repetitive and 4-4.5 urn in diameter.
TL;DR: In this article, a simple and efficient method for synthesis of phenacyl esters in quantitative yield and high purity under mild reaction condition by using phase transfer catalyst and dibenzo-[18]-crown-6.
Abstract: In view of the importance of phenacyl esters as a protecting groups, a simple and efficient method is now reported here for synthesis of phenacyl esters in quantitative yield and high purity under mild reaction condition by using phase transfer catalyst and dibenzo-[18]-crown-6. It has been demonstrated that the spatial coordination of ion and ligand cavity plays important role in using crown ethers.