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Wyszukujesz frazę "Prasad, R." wg kryterium: Autor


Tytuł:
Anti-synchronization in different new chaotic systems via active nonlinear control
Autorzy:
Khan, A.
Prasad, R. P.
Powiązania:
https://bibliotekanauki.pl/articles/229711.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
new chaotic system
anti-synchronization
active nonlinear control
Opis:
In this paper, we discuss anti-synchronization between two identical new chaotic systems and anti-synchronization between another two identical new chaotic systems by active nonlinear control. The sufficient conditions for achieving the anti-synchronization of two new chaotic systems are derived based on Lyapunov stability theory. Numerical simulations are provided for illustration and verification of the proposed method.
Źródło:
Archives of Control Sciences; 2013, 23, 2; 229-242
1230-2384
Pojawia się w:
Archives of Control Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Entropy generation and thermodynamic analysis of solar air heaters with artificial roughness on absorber plate
Autorzy:
Prasad, R. K.
Sahu, M. K.
Powiązania:
https://bibliotekanauki.pl/articles/240173.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
entropy generation analysis
entropy generation number
irreversibility
Bejan number
analiza generowania entropii
liczba generacyjna entropii
nieodwracalność
liczba Bejana
Opis:
This paper presents mathematical modelling and numerical analysis to evaluate entropy generation analysis (EGA) by considering pressure drop and second law efficiency based on thermodynamics for forced convection heat transfer in rectangular duct of a solar air heater with wire as artificial roughness in the form of arc shape geometry on the absorber plate. The investigation includes evaluations of entropy generation, entropy generation number, Bejan number and irreversibilities of roughened as well as smooth absorber plate solar air heaters to compare the relative performances. Furthermore, effects of various roughness parameters and operating parameters on entropy generation have also been investigated. Entropy generation and irreversibilities (exergy destroyed) has its minimum value at relative roughness height of 0.0422 and relative angle of attack of 0.33, which leads to the maximum exergetic efficiency. Entropy generation and exergy based analyses can be adopted for the evaluation of the overall performance of solar air heaters.
Źródło:
Archives of Thermodynamics; 2017, 38, 3; 23-48
1231-0956
2083-6023
Pojawia się w:
Archives of Thermodynamics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Climate change research - what do we need really?
Autorzy:
Prasad, P.R.C.
Powiązania:
https://bibliotekanauki.pl/articles/12022.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Opis:
This research note focuses on the current climate change research scenario and discusses primarily what is required in the present global climate change conditions. Most of the climate change research and models predict adverse future conditions that have to be faced by humanity, with less emphasis on mitigation measures. Moreover, research ends as reports on the shelves of scientists and researchers and as publications in journals. At this juncture the major focus should be on research that helps in reducing the impact rather than on analysing future scenarios of climate change using different models. The article raises several questions and suggestions regards climate change research and lays emphasis on what we really need from climate change researchers.
Źródło:
Papers on Global Change; 2015, 22
2300-8121
1730-802X
Pojawia się w:
Papers on Global Change
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Trends in mean maximum temperature, mean minimum temperature and mean relative humidity for Lautoka, Fiji during 2003–2013
Autorzy:
Ghani, S.S.
Iqubal, M.A.
Prasad, R.
Deo, A.
Powiązania:
https://bibliotekanauki.pl/articles/887464.pdf
Data publikacji:
2017
Wydawca:
Szkoła Główna Gospodarstwa Wiejskiego w Warszawie. Wydawnictwo Szkoły Głównej Gospodarstwa Wiejskiego w Warszawie
Źródło:
Scientific Review Engineering and Environmental Sciences; 2017, 26, 4[78]
1732-9353
Pojawia się w:
Scientific Review Engineering and Environmental Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Kinetics studies and mechanism evolution of the epoxidation of styrene over nanoporous Au doped TS-1
Autorzy:
Saxena, S.
Dwivedi, R.
Bhadauria, S.
Chumbhale, V. R.
Prasad, R.
Powiązania:
https://bibliotekanauki.pl/articles/778059.pdf
Data publikacji:
2010
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
kinetyka
epoksydowanie
Au/TS-1
styren
tlenek styrenu
kinetics
epoxidation
styrene
Styrene Oxide
Opis:
A kinetic investigation of the slurry phase epoxidation of styrene with hydrogen peroxide has been carried out, for the first time, over nanoporous Au doped TS-1 catalyst, in a batch reactor, in the temperature range of 313-333 K. It was found that product selectivity and the rate of reaction are greatly influenced by concentrations of styrene and hydrogen peroxide. Kinetics studies reveal that the mechanism of the reaction is of the "Redox" type. The rate equation, r = k 1k2POPH/ (k1PO+ k2PH) deduced, assuming a steady state involving two stage oxidation-reduction process, represent the data most satisfactorily for the conversion of styrene to styrene oxide. A tentative mechanism of the process has also been suggested.
Źródło:
Polish Journal of Chemical Technology; 2010, 12, 4; 72-78
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Biogenic silver nanoparticles from Trichodesma indicum aqueous leaf extract against Mythimna separata and evaluation of its larvicidal efficacy
Autorzy:
Buhroo, A.A.
Nisa, G.
Asrafuzzaman, S.
Prasad, R.
Rasheed, R.
Bhattacharyya, A.
Powiązania:
https://bibliotekanauki.pl/articles/65016.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
insect
pest control
biogenic substance
silver nanoparticle
Trichodesma indicum
water extract
leaf extract
Mythimna separata
Oriental armyworm
pest
larvicidal activity
Opis:
Th e present exploration is focused on the bio-fabrication of silver nanoparticles (Ag NPs) using Trichodesma indicum aqueous leaf extract as a reducing agent. Th e synthesized Ag NPs were productively characterized by UV-vis spectroscopy, XRD, and TEM studies. Th e photosynthesis of Ag NPs was done at room temperature for 24 h and at 60°C. Th e green synthesis of spherical-shaped Ag NPs bio-fabricated from T. indicum with a face centred cubic structure showed average particle sizes of 20–50 nm, which is inconsistent with the particle size calculated by the XRD Scherer equation and TEM analysis. We further explored the larvicidal effi cacy of biosynthesized Ag NPs with leaf extracts of T. indicum against Mythimna separata. Th e results showed that Ag NPs (20–50 nm) of T. indicum possess good larvicidal activity against M. separata with an LC50 of 500 ppm. Th us, we can advocate that Ag NPs of 20–50 nm size extracted from T. indicum may be considered in the pest management programme of M. separata in future.
Źródło:
Journal of Plant Protection Research; 2017, 57, 2
1427-4345
Pojawia się w:
Journal of Plant Protection Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Entropy analysis of third-grade MHD convection flows from a horizontal cylinder with slip
Autorzy:
Madhavi, K.
Prasad, V. R.
Gaffar, S. A.
Venkatadri, K.
Powiązania:
https://bibliotekanauki.pl/articles/139843.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
third-grade viscoelastic fluid model
thermal jump
entropy generation
Bejan number
Hartmann number
lepkosprężysty model cieczy trzeciego stopnia
skok termiczny
generowanie entropii
liczba Bejana
liczba Hartmanna
Opis:
In thermos fluid dynamics, free convection flows external to different geometries, such as cylinders, ellipses, spheres, curved walls, wavy plates, cones, etc., play major role in various industrial and process engineering systems. The thermal buoyancy force associated with natural convection flows can play a critical role in determining skin friction and heat transfer rates at the boundary. In thermal engineering, natural convection flows from cylindrical bodies has gained exceptional interest. In this article, we mathematically evaluate an entropy analysis of magnetohydrodynamic third-grade convection flows from permeable cylinder considering velocity and thermal slip effects. The resulting non-linear coupled partial differential conservation equations with associated boundary conditions are solved with an efficient unconditionally stable implicit finite difference Keller-Box technique. The impacts of momentum and heat transport coefficients, entropy generation and Bejan number are computed for several values of non-dimensional parameters arising in the flow equations. Streamlines are plotted to analyze the heat transport process in a two-dimensional domain. Furthermore, the deviations of the flow variables are compared with those computed for a Newtonian fluid and this has important implications in industrial thermal material processing operations, aviation technology, different enterprises, energy systems and thermal enhancement of industrial flow processes.
Źródło:
Archive of Mechanical Engineering; 2018, LXV, 3; 417-440
0004-0738
Pojawia się w:
Archive of Mechanical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
MHD free convection-radiation interaction in a porous medium - part I: numerical investigation
Autorzy:
Vasu, B.
Gorla, R. S. R.
Murthy, P. V. S. N.
Prasad, V. R.
Bég, O. Anwar
Siddiqa, S.
Powiązania:
https://bibliotekanauki.pl/articles/266199.pdf
Data publikacji:
2020
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
pole magnetyczne
metoda Keller-Box
nośnik porowaty
implicit finite difference scheme
Keller-Box method
magnetic field
horizontal circular cylinder
Opis:
A numerical investigation of two dimensional steady magnetohydrodynamics heat and mass transfer by laminar free convection from a radiative horizontal circular cylinder in a non-Darcy porous medium is presented by taking into account the Soret/Dufour effects. The boundary layer conservation equations, which are parabolic in nature, are normalized into non-similar form and then solved numerically with the well-tested, efficient, implicit, stable Keller–Box finite-difference scheme. We use simple central difference derivatives and averages at the mid points of net rectangles to get finite difference equations with a second order truncation error. We have conducted a grid sensitivity and time calculation of the solution execution. Numerical results are obtained for the velocity, temperature and concentration distributions, as well as the local skin friction, Nusselt number and Sherwood number for several values of the parameters. The dependency of the thermophysical properties has been discussed on the parameters and shown graphically. The Darcy number accelerates the flow due to a corresponding rise in permeability of the regime and concomitant decrease in Darcian impedance. A comparative study between the previously published and present results in a limiting sense is found in an excellent agreement.
Źródło:
International Journal of Applied Mechanics and Engineering; 2020, 25, 1; 198-218
1734-4492
2353-9003
Pojawia się w:
International Journal of Applied Mechanics and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
MHD free convection-radiation interaction in a porous medium - part II: soret/dufour effects
Autorzy:
Vasu, B.
Gorla, Rama Subba Reddy
Murthy, P. V. S. N.
Prasad, V. R.
Beg, O. A.
Siddiqa, S.
Powiązania:
https://bibliotekanauki.pl/articles/266156.pdf
Data publikacji:
2020
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
materiały porowate
pole magnetyczne
magnetohydrodynamika
non-Darcy porous media transport
magnetic field
horizontal circular cylinder
Soret number
Dufour number
Opis:
This paper is focused on the study of two dimensional steady magnetohydrodynamics heat and mass transfer by laminar free convection from a radiative horizontal circular cylinder in a non-Darcy porous medium by taking into account of the Soret/Dufour effects. The boundary layer equations, which are parabolic in nature, are normalized into non-similar form and then solved numerically with the well-tested, efficient, implicit, stable Keller–Box finite-difference scheme. Numerical results are obtained for the velocity, temperature and concentration distributions, as well as the local skin friction, Nusselt number and Sherwood number for several values of the parameters, namely the buoyancy ratio parameter, Prandtl number, Forchheimer number, magnetohydrodynamic body force parameter, Soret and Dufour numbers. The dependency of the thermophysical properties has been discussed on the parameters and shown graphically. Increasing the Forchheimer inertial drag parameter reduces velocity but elevates temperature and concentration. Increasing the Soret number and simultaneously reducing the Dufour number greatly boosts the local heat transfer rate at the cylinder surface. A comparative study of the previously published and present results in a limiting sense is made and an excellent agreement is found between the results.
Źródło:
International Journal of Applied Mechanics and Engineering; 2020, 25, 2; 157-175
1734-4492
2353-9003
Pojawia się w:
International Journal of Applied Mechanics and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Squeezing and Sub-Poissonian Effects of Light in Third Harmonic Generation
Autorzy:
Pratap, R.
Giri, D.
Prasad, A.
Powiązania:
https://bibliotekanauki.pl/articles/1198558.pdf
Data publikacji:
2014-05
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
42.50.Ar
42.50.Dv
42.65.Ky
Opis:
The squeezing and sub-Poissonian effects of light in third harmonic generation are investigated based on the fully quantum mechanical approach up to the first order Hamiltonian interaction in gt, where g is the coupling constant between the modes per second and t is the interaction time between the waves during the process in a nonlinear medium. The coupled Heisenberg equations of motion involving real and imaginary parts of the quadrature operators are established. The occurrence of amplitude squeezing effects in both the quadratures of the radiation field in the fundamental mode is investigated and found to be dependent on the selective phase values of the field amplitude. The photon statistics of the pump mode in this process have also been investigated and found to be sub-Poissonian in nature. It is shown that for particular phase values the amplitude squeezing and sub-Poissonian photon statistics of light occur simultaneously. It is observed that there is no possibility to produce squeezed light in the harmonic mode up to first-order interaction in gt. Further, it is found that the normal squeezing in the harmonic mode directly depends upon the amplitude-cubed squeezing of the initial pump field to the case of second-order interaction in gt. This gives a method of converting higher-order (amplitude-cubed) squeezing of the fundamental mode into normal squeezing of the harmonic mode and vice versa.
Źródło:
Acta Physica Polonica A; 2014, 125, 5; 1126-1131
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A study of molybdenum addition on W-Ni-Fe based heavy alloys sintered with spark plasma sintering
Autorzy:
Prasad, B. S. L.
Annamalai, R.
Powiązania:
https://bibliotekanauki.pl/articles/200737.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
tungsten heavy alloys
sintering
mechanical properties
fracture mode
ciężkie stopy wolframu
spiekanie
właściwości mechaniczne
tryb pękania
Opis:
Tungsten heavy alloys comprising tungsten, nickel and ferrous were modified, where molybdenum was added in varying weight proportions keeping the ratio of Ni: Fe (8:2) constant. The powders were mixed in a high-energy ball mill and were further fabricated using the spark plasma sintering (SPS) method at a peak temperature of 1000°C with heating rate of 100°C/min. The details of the microstructure and mechanical properties of these various alloy compositions were studied. With the increasing weight composition of the Mo in the alloy, the relative density of the alloy increased with a significant improvement in all the mechanical properties. The yield strength (YS), ultimate tensile strength (UTS) and hardness improved significantly with increase in the proportion of Mo; however, a reduction in elongation percentage was observed. The maximum strength of 1250 MPa UTS was observed in the alloy with a Mo proportion of 24%. The heavy alloy unmixed with Mo has shown distinct white and grey regions, where white (W) grain is due to tungsten and grey region is a combinatorial effect of Ni and Fe. Upon addition of Mo, the white and gray phase differences started to minimize resulting in deep gray and black ‘C’-phase structures because of homogenization of the alloy. The main fracture mode found during this investigation in the alloys was inter-granular mode.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2019, 67, 2; 167-172
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
MHD and rotation effects on flow past an accelerated vertical plate with variable temperature and mass diffusion in the presence of chemical reaction
Autorzy:
Muthucumaraswamy, R.
Dhanasekar, N.
Eswara Prasad, G.
Powiązania:
https://bibliotekanauki.pl/articles/955271.pdf
Data publikacji:
2013
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
przyspieszenie
izoterma
płyta pionowa
wymiana ciepła
dyfuzja
pole magnetyczne
reakcja chemiczna
rotation
accelerated
isothermal
vertical plate
heat transfer
diffusion
magnetic field
chemical reaction
Opis:
An exact analysis of rotation effects on an unsteady flow of an incompressible and electrically conducting fluid past a uniformly accelerated infinite isothermal vertical plate, under the action of a transversely applied magnetic field is presented. The plate temperature is raised linearly with time and the concentration level near the plate is also raised to C’w. The dimensionless governing equations are solved using the Laplace-transform technique. The velocity profiles, temperature and concentration are studied for different physical parameters such as the magnetic field parameter, chemical reaction parameter, thermal Grashof number, mass Grashof number, Schmidt number, Prandtl number and time. It is observed that the velocity increases with increasing values of the thermal Grashof number or mass Grashof number. It is also observed that the velocity increases with decreasing values of the magnetic field parameter or rotation parameter Ω.
Źródło:
International Journal of Applied Mechanics and Engineering; 2013, 18, 4; 1087-1097
1734-4492
2353-9003
Pojawia się w:
International Journal of Applied Mechanics and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of waste rubber powder as filler for plywood application
Autorzy:
Ong, H. R.
Khan, M. R.
Yousuf, A.
Jeyaratnam, N.
Prasad, D. M. R.
Powiązania:
https://bibliotekanauki.pl/articles/779508.pdf
Data publikacji:
2015
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
waste rubber powder
melamine-urea formaldehyde resin
filler
wood adhesive
plywood
Opis:
The study investigated the suitability of waste rubber powder (WRP) use as filler in adhesive formulation for plywood application. Melamine Urea Formaldehyde (MUF) was employed as resin for formulating the wood adhesive. To improve chemical properties and bonding quality of adhesive, WRP was treated by different chemicals like 20% nitric acid, 30% hydrogen peroxide and acetone solution. The treated WRP were analysed by XRD and it showed that inorganic compounds were removed and carbon was remained as major component under the treatment of 20% HNO3. The treatment improved the mechanical properties like shear strength and formaldehyde emission of plywood (high shear strength and low formaldehyde emission). The physico-chemical interaction between the wood, resin and filler was investigated using fourier transform infrared spectroscopic (FTIR) technique and the interactions among N-H of MUF and C=O of wood and WRP were identified. The morphology of wood-adhesive interface was studied by field emission scanning electron microscope (FESEM) and light microscope (LM). It showed that the penetration of adhesives and fillers through the wood pores was responsible for mechanical interlocking. Therefore, chemically treated WRP proved its potential use as filler in MUF based adhesive for making plywood.
Źródło:
Polish Journal of Chemical Technology; 2015, 17, 1; 41-47
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dielectric studies of nano structured BaTi1-xSnxO3 solid solutions
Autorzy:
Bitra, H. Ch. R.
Prasad, B. B. V. S. V.
Powiązania:
https://bibliotekanauki.pl/articles/412300.pdf
Data publikacji:
2014
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
BTSx
XRD
SEM
dielectric constant
Opis:
BaTi1-xSnxO3 (BTSx) ceramics had been prepared by temperature sintering technique. Initially, the samples were calcined at a temperature at 900 °C for 2 hours, after that ball milling was done and then the samples were sintered at a temperature of 1150 °C for 3 hours. X-ray diffractometry, Scanning Electron Microscopy, Energy Dispersive Spectroscopy and Dielectric measurements were carried out and structural, micro structural and elemental analyses were discussed in brief.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2014, 13, 2; 191-201
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experimental investigation to study the viscosity and dispersion of conductive and non-conductive nanopowders’ blended dielectrics
Autorzy:
Santarao, K.
Prasad, C. L. V. R. S. V.
Swami Naidu, G.
Powiązania:
https://bibliotekanauki.pl/articles/102844.pdf
Data publikacji:
2017
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
nanofluid
viscosity
dispersion
sonication
silicon carbide nano powder
boric acid nano powder
Opis:
Nano fluids are nanotechnology-based colloidal dispersions engineered by stably suspending nanoparticles. The characteristics of nano fluids such as thermal and electrical conductivities, viscosity, specific heat, dispersion etc. were studied and analyzed by earlier researches at different particle concentrations with different nano fluids. It was established that nano fluids have a significant impact on the process due the improvised characteristics. Nano fluid viscosity and dispersion deserve the same attention as thermal conductivity in cases of nano dielectric fluids that are used in EDM as they influence the MRR. In this work, The viscosity and dispersion of the conductive and nonconductive Nano powders blended dielectrics are investigated as a function of volume fraction so as to evaluate the behavior of these nano fluids at different particle volume concentrations. Kerosene and deionized water based nano fluids blended with conductive (SiC) and non-conductive (boric acid) Nano particles are selected for the current study. It is observed that as the percentage volume fraction of nano particles (both SiC and boric acid) increased, the viscosity was found increasing when blended with DI water. But the viscosity behavior with kerosene blended with SiC and boric acid is not same. The existing experimental results about the nano fluids viscosity shows clearly that viscosity have a specific trend in variation with an increase of volume concentration. Boric acid blended with DIW and kerosene shows similar trend in dispersion. However, in case of SiC blended with DIW and kerosene showed some contradictory results giving scope for further investigation. The outcome of these experimental investigations will augment the works that are going on in studying its influence on MRR in EDM processes using nano blended dielectric medium.
Źródło:
Advances in Science and Technology. Research Journal; 2017, 11, 1; 154-160
2299-8624
Pojawia się w:
Advances in Science and Technology. Research Journal
Dostawca treści:
Biblioteka Nauki
Artykuł

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