548 research outputs found
Periodic fading of medium wave radio signals
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Bright blue emissions on UV-excitation of LaBO3 (B=In, Ga, Al) perovskite structured phosphors for commercial solid-state lighting applications
Bright blue photoluminescence (PL) was obtained from Bi3+-activated LaBO3 (B = In, Ga, Al) perovskite nanophosphors. A cost-effective and low-temperature chemical route was employed for preparing Bi3+ doped LaBO3 (B=In, Ga, Al) which were then annealed at 1000 °C. The phase formation, morphological studies and luminescent properties of the as-prepared samples were performed by X-ray diffraction (XRD), scanning electron microscopy (SEM), photoluminescence and optical absorption spectroscopy. Comparison of emission intensities, lifetime studies, energy band gaps and color purity of all samples (pure and Bi3+ doped) were investigated for promising applications in UV light-emitting diodes, variable frequency drive (VFD), field emission display (FED), and other photoelectric fields
Epidemiology of ChiVMV and loss assessment in capsicum (Capsicum annum var. grossum Sendt)
The survey was conducted during rabi season (2021) to determine the incidence of mosaic disease of capsicum in major capsicum growing districts namely, Chikkaballapura, Kolar, Bengaluru rural and Ramanagar. The per cent incidence of mosaic disease based on symptoms in field was recorded, highest in Ramanagar (54.85%) and the least incidence of mosaic disease was observed in Chikkaballapura (26.85%). Transmission and host range studies under glasshouse conditions revealed that ChiVMV is transmitted mechanically. Among 16 host plants tested, 7 plant species (Nicotiana tabacum cv. Samsun, N. glutinosa, N. occidentalis, Datura metel, Physalis floridana, S. nigrum, Capsicum annum) were infected with the Chilli veinal mottle virus disease and the symptom could be seen in 20-25 days. The per cent transmission of ChiVMV by aphid Aphis gossypii was studied. The results showed that ChiVMV can be transmitted by A. gossypii. However, five aphids per plant showed highest per cent transmission (100%). The effect of different dates of inoculation on different plant growth parameters was also studied, the highest per cent disease transmission was observed in T1: Inoculation 15 days after sowing (100.00%)
Radiation and Mass Transfer Effects on Transient Free Convection Flow of a Dissipative Fluid past Semi-Infinite Vertical Plate with Uniform Heat and Mass Flux
Effect of radiation and mass transfer on the transient free convection flow of a dissipative past semi-infinite vertical
plate with uniform heat and mass flux is analyzed, by taking into account the effect of viscous dissipation. This type
of problems finds application in many technological and engineering fields such as plasma studies, petroleum
industries, MHD energy generators, cooling of nuclear reactors, the boundary layer control in aerodynamics, crystal
growth and furnace engineering. The Rosseland approximation is used to describe the radiative heat transfer in the
limit of the optically thick fluid. The non-linear, coupled equations are solved using an implicit finite difference
scheme of Crank-Nicolson type. Transient temperature, concentration and velocity profiles, local and average skinfriction
coefficient, Nusselt number and Sherwood number are presented graphically and discussed. It is observed
that, when the radiation parameter increases the velocity and temperature decrease accompanied by simultaneous
reduction in both momentum and thermal boundary layers
Study of Magnetic Properties of A_2B^'NbO_6 (A=Ba,Sr, (BaSr): and B^'=Fe and Mn) double perovskites
We have studied the magnetic properties of Ba_2FeNbO_6 and Ba_2MnNbO_6. it is
seen that Ba_2FeNbO_6 is an antiferromagnet with a weak ferromagnetic behaviour
at 5K while Ba_2MnNbO_6 shows two magnetic transitions one at 45 K and the
other at 12K. Electron spin resonance (ESR) measurements at room temperature
show that the Mn compound does not show any Jahn-Teller distortion. It is also
seen that the Neel temperature of the A_2FeNbO_6 (A=Ba,Sr, BaSr) compounds do
not vary significantly. However variations in the average A-site ionic radius
influence the formation of short range correlations that persist above T_N.Comment: 10 oages, 5 figures, MMM, to appear in J.Appl.Phy
Finite Difference Analysis of Radiative Free Convection Flow Past an Impulsively Started Vertical Plate with Variable Heat and Mass Flux
A numerical solution of the unsteady radiative free convection flow of an incompressible viscous fluid past an
impulsively started vertical plate with variable heat and mass flux is presented here. This type of problem finds
application in many technological and engineering fields such as rocket propulsion systems, spacecraft re-entry
aerothermodynamics, cosmical flight aerodynamics, plasma physics, glass production and furnace engineering. The
fluid is gray, absorbing-emitting but non-scattering medium and the Rosseland approximation is used to describe the
radiative heat flux in the energy equation. The governing non-linear, coupled equations are solved using an implicit
finite difference scheme. Numerical results for the velocity, temperature, concentration, the local and average skinfriction,
the Nusselt and Sherwood number are shown graphically, for different values of Prandtl number, Schmidt
number, thermal Grashof number, mass Grashof number, radiation parameter, heat flux exponent and the mass flux
exponent. It is observed that, when the radiation parameter increases, the velocity and temperature decrease in the
boundary layer. The local and average skin-friction increases with the increase in radiation parameter. For increasing
values of radiation parameter the local as well as average Nusselt number increases
Large Fibroepithelial Polyp of Vulva
A rare case of a large fibroepithelial polyp (FEP) of the vulva is described. The polypoidal growth was 10 cm in its largest diameter, having a long pedicle with features of inflammation secondary to infection, and was found arising from the left labia majora. The patient did not manifest any signs of recurrence following excision. A large and infected FEP of the vulva is a rare occurrence and hence reported
Preparation, Characterization and In Vitro Drug Release Studies of 6-mercaptopurine Thin Film
Oral thin films of 6-mercaptopurine were fabricated from mucoadhesive polymer, chitosan and polyvinylpyrrolidone for the purpose of prolonging drug release and improving its bioavailability. All fabricated film formulations prepared were smooth and translucent, with good flexibility. The weight and thickness of all the formulations were found to be uniform. These films were also evaluated for surface pH, folding endurance, swelling percentage (% S) and in vitro disintegration time. Scanning Electron Microscopy (SEM) and Fourier Transform Infrared (FTIR) were used to evaluate the physico-chemical nature of the films. In-vitro drug release have shown enhanced release profiles for thin films compared to pure drug and the release patterns have been found to be pH dependant. The results of the study reveals that fabrication of 6-MP oral thin film by using solvent cast technology is a simple and an efficient method for drug delivery to achieve desired therapeutic compliance.Keywords: 6-mercaptopurine; In Vitro Drug Release; SEM; FTI
Influence of Energy Balance on Reproductive Performance and Milk Production of Dairy Cows at Pre-partum and Early Lactation Periods
Abstract: The objective of this study was to evaluate the influence of energy balance in dairy cows at pre-partum and early lactation periods on their subsequent reproductive and productive performance. High producing, Ayrshire cows were randomly selected from the heavy pregnant, dry cow herd of Ambewela dairy farm in Up-Country, Sri Lanka. The serum NEFA (non esterifie fatty acid) and milk BHBA (beta hydroxyl butyric acid) concentrations were used as indicators of energy status of the cows. Days for the first AI, open days and conception rate were used to evaluate the reproductive performance. Sub-clinical ketosis (milk BHBA≥200 µmol/L) was recorded among 25 and 31.25% cows at 5 days pre-partum and during 100 days post-partum periods, respectively. Further, they took significantly longer period to reach the first AI and showed significantly greater (p<0.0001) open days compared to the cows those did not show signs of sub-clinical ketosis (milk BHBA<100 µmol/L) during the period. Cows those recorded≥200 µmol/L BHBA level in milk during the lactation period from 10 to 60 days took longest period for the first AI and had the highest open days. Only 36% cows were pregnant at 100 days post-partum. Further, none of the cows showed sub-clinical ketosis during 100 days post-partum was pregnant. They had higher circulating NEFA levels at 5 days pre-partum and 10 days post-partum periods and significantly lower (p<0.05) in milk production compared to their pregnant counterparts. This study indicated that the magnitude and duration of the prepartum energy status (i.e., negative energy balance) has a detrimental effect on subsequent reproductive and productive performances in high producing dairy cows
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