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Wyszukujesz frazę "Kumar, S. P." wg kryterium: Autor


Tytuł:
Application of UPFC for enhancement of voltage profile and minimization of losses using Fast Voltage Stability Index (FVSI)
Autorzy:
Kumar, S.
Renuga, P.
Powiązania:
https://bibliotekanauki.pl/articles/140514.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
flexible AC transmission system (FACTS)
real and reactive power
Unified Power Flow Controller (UPFC)
Bacterial Foraging (BF) algorithm
Opis:
Transmission line loss minimization in a power system is an important research issue and it can be achieved by means of reactive power compensation. The unscheduled increment of load in a power system has driven the system to experience stressed conditions. This phenomenon has also led to voltage profile depreciation below the acceptable secure limit. The significance and use of Flexible AC Transmission System (FACTS) devices and capacitor placement is in order to alleviate the voltage profile decay problem. The optimal value of compensating devices equires proper optimization technique, able to search the optimal solution with less computational burden. This paper presents a technique to provide simultaneous or individual controls of basic system parameter like transmission voltage, impedance and phase angle, thereby controlling the transmitted power using Unified Power Flow Controller (UPFC) based on Bacterial Foraging (BF) algorithm. Voltage stability level of the system is defined on the Fast Voltage Stability Index (FVSI) of the lines. The IEEE 14-bus system is used as the test system to demonstrate the applicability and efficiency of the proposed system. The test result showed that the ocation of UPFC improves the voltage profile and also minimize the real power loss.
Źródło:
Archives of Electrical Engineering; 2012, 61, 2; 239-250
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Oscillator Strengths of the 1s2s$\text{}^{1}$S$\text{}^{e}$ → 1s2p$\text{}^{1}$P$\text{}^{0}$ Transition in He
Autorzy:
Tiwary, S. N.
Kumar, P.
Powiązania:
https://bibliotekanauki.pl/articles/1887915.pdf
Data publikacji:
1991-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
31.10.+z
Opis:
The paper presents configuration interaction (CI) calculations of both the length and velocity forms of the oscillator strengths for 1s2s$\text{}^{1}$S$\text{}^{e}$ → 1s2p$\text{}^{1}$P$\text{}^{0}$ transition in the He atom. For the first time the agreement between the length and velocity values to within about 0.045% has been achieved.
Źródło:
Acta Physica Polonica A; 1991, 80, 1; 23-28
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effects of Heat Input on the Mechanical and Metallurgical Characteristics of TIG Welded Incoloy 800HT Joints
Autorzy:
Arun Kumar, S.
Sathiya, P.
Powiązania:
https://bibliotekanauki.pl/articles/356231.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
incoloy 800 HT
corrosion
aging
sensitization
heat input
Opis:
This study focuses on the effect of heat input on the quality characteristics of tungsten inert arc gas welded incoloy 800HT joints using inconel-82 filler wire. Butt welding was done on specimens with four different heat inputs by varying the process parameters like welding current and speed. The result indicated that higher heat input levels has led to the formation of coarser grain structure, reduced mechanical properties and sensitization issues on the weldments. The formation of titanium nitrides provided resistance to fracture and increased the tensile strength of the joints at high temperatures. Further aging was done on the welded sample at a temperature of 750°C for 500 hours and the metallographic result showed formation of carbides along the grain boundaries in a chain of discrete and globular form which increased the hardness of the material. The formation of spinel NiCr2 O4 provided oxidation resistance to the material during elevated temperature service.
Źródło:
Archives of Metallurgy and Materials; 2017, 62, 3; 1673-1679
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modified model for shear stress distribution using TRI-1 lunar soil simulant
Autorzy:
Jayalekshmi, S.
Gireesh Kumar, P.
Powiązania:
https://bibliotekanauki.pl/articles/949124.pdf
Data publikacji:
2018
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
TRI-1
lunar soil simulant
modified model
shear stress distribution
Opis:
In the present study, research is carried out on deriving modified analytical equations for finding shear stress distribution and known as Modified Shear Stress models (SSM) beneath plain wheels (small and large) on TRI-1 lunar soil simulant. In all four models, the Reece model, Bekker model, Wong-Reece model and Iagnemma model, normal stress and shear stress are determined, and the shear stress determination is based on the Janosi and Hanamoto (1961) model. There exists ample scope for modifying this model. A modified model for shear stress distribution is developed and the same is discussed in this paper.
Źródło:
Journal of Theoretical and Applied Mechanics; 2018, 56, 1; 137-146
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Design and Evaluation of the Thermal Properties of Di-, Tri- and Tetra-Azido-Esters
Autorzy:
Kumar, S.
Kumar, A.
Yamajala, K. D. B.
Gaur, P.
Kumar, D.
Banerjee, S.
Powiązania:
https://bibliotekanauki.pl/articles/358266.pdf
Data publikacji:
2017
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
azido-esters
energetic plasticizers
DFT
contact angle
Opis:
A group of polycyclic and aliphatic azido-esters (as energetic plasticizers) have been synthesized by simple synthetic routes and their molecular structures were confirmed by spectroscopic techniques. In addition, their thermal and rheological properties have been determined utilizing DSC, TGA, viscosity, and contact angle. Computational studies of these plasticizers have been performed by means of DFT (B3LYP/6-31G*) to estimate possible stable structures, energies, heat of formation, bond dissociation energies, IR and NMR spectra etc. Their compatibility with glycidyl azide polymer (GAP) binder was studied to explore their applicability in propellants. All of these molecules are novel and have been synthesized with the possibility of scale up.
Źródło:
Central European Journal of Energetic Materials; 2017, 14, 4; 844-860
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Biomass fuel cell based distributed generation system for Sagar Island
Autorzy:
Kumar, P.
Sikder, P. S.
Pal, N.
Powiązania:
https://bibliotekanauki.pl/articles/200813.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
biomass
fuel cell
distributed generation systems
inverter
cost analysis
biomasa
ogniwo paliwowe
falownik
analiza kosztów
generacja rozproszona
Opis:
Sustainable development of an area is highly dependable on reliable electrical energy supply. Due to the depletion of fossil fuels, and the contamination of the environment due to the generation of energy from primary energy sources, the energy sector is reforming and shifting towards a new era where renewable energy sources will become the primary focus of attention. At present, energy researchers and government organizations are interested in a distributed generation system using local renewable energy sources to electrify the rural areas situated far away from our mainland. Here, a biomass-based power supply system is being analyzed and compared with other potential power supply systems for Sagar Island. Sagar Island is the world’s largest river-based island situated in the Sundarban deltaic complex, where the potential of biomass is huge due to the availability of natural forests, barren coastal areas full of weeds, agricultural by-products, cattle manure and waste materials from other sources. Here, an attempt has been made to provide sustainable electrical energy to the rural areas of the isolated Sagar Island for the sustainable development of the local people. This was done by means of using biomass and a fuel cell based electricity generation system.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2018, 66, 5; 665-674
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Molecular Interactions in Binary Organic Liquid Mixtures Containing Ethyl Oleate and Ethanol at 2MHz Frequency
Autorzy:
Manukonda, S.
Kumar, G. P.
Babu, C. P.
Powiązania:
https://bibliotekanauki.pl/articles/412193.pdf
Data publikacji:
2015
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Ethyl Oleate
Ethanol
molecular interactions
adiabatic compressibility
Opis:
Molecular interactions of binary mixtures of Ethanol with a new organic compound Ethyl Oleate are investigated at a constant ultrasonic frequency of 2MHz under the temperature range of 303.15K-318.15K. The effect of mole fraction of Ethyl Oleate on velocity of sound wave and the density and viscosity of binary mixtures at various temperatures were studied. The effects on density (ρ), viscosity (η), adiabatic compressibility (βad), inter molecular free length (Lf) and internal pressure (Пi) also was studied.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2015, 40; 17-23
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Study on fungi inhabiting indoor woods and their eco-friendly management
Autorzy:
Tapwal, A.
Kalyan, P.
Kumar, S.
Chandra, S.
Powiązania:
https://bibliotekanauki.pl/articles/11389.pdf
Data publikacji:
2016
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Źródło:
International Letters of Natural Sciences; 2016, 59
2300-9675
Pojawia się w:
International Letters of Natural Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Spin-Valve Transistor - a New Magnetoelectronic Device
Autorzy:
Anil Kumar, P. S.
Lodder, J. C.
Powiązania:
https://bibliotekanauki.pl/articles/2011222.pdf
Data publikacji:
2000-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.70.-i
75.70.Pa
Opis:
A spin-valve transistor showing high sensitivity at low fields was developed. A large magnetocurrent, above 500% is realized by a magnetic field change of 2 to 4 Oe at 80 K. Hot electrons are injected into the spin-valve layer through a Si-Pt Schottky diode. These hot electrons, while traversing through the spin-valve, are spin-dependently scattered. Those electrons with right energy and momentum are collected by a collector (an Au-Si Schottky diode) constituting a collector current. The relative orientation of the magnetic layer in the spin-valve is changed by the application of a magnetic field and causes a change in collector current giving a large magnetocurrent.
Źródło:
Acta Physica Polonica A; 2000, 97, 1; 111-118
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Design and Analysis of Single Mode Photonic Crystal Fibers with Zero Dispersion and Ultra Low Loss
Autorzy:
Kumar, P.
Tripathy, A.
Roy, J. S.
Powiązania:
https://bibliotekanauki.pl/articles/963925.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
photonic crystal fibers
dispersion
birefringence
splice loss
confinement loss
effective mode area
Opis:
PCFs (Photonic Crystal Fibers) with ‘T’ – shaped core have been proposed in this paper. ‘T’ –shaped core PCF structures have been analyzed using two different background materials: silica and lead silicate. A total of 360° rotation at an interval of 90° has been introduced in the design of PCF structures. PCF structures A, B, C and D with rotation of 0°, 90°, 180° and 270° have silica as wafer. Similarly PCF structures E, F, G and H with similar rotation have lead silicate as background material. Numerical investigations shows structures ‘D’, ‘F’, ‘G’ and ‘H’ to have anomalous dispersion. PCF structures ‘F’, ‘G’, and ‘H’ have reported birefringence of the order of 10⁻². Besides, other PCF structures report birefringence of the order of 10⁻³. Ultra low confinement loss has been observed in all the investigated PCF structures. Moreover, splice loss observed by the structure is very low. Large mode area has been shown by all the designed PCF structures.
Źródło:
International Journal of Electronics and Telecommunications; 2018, 64, 4; 541-546
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Design and development of 3-stage determination of damage location using Mamdani-Adaptive Genetic-Sugeno model
Autorzy:
Sahu, S.
Kumar, P. B.
Parhi, D. R.
Powiązania:
https://bibliotekanauki.pl/articles/281979.pdf
Data publikacji:
2017
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
damage
Mamdani FIS
Sugeno FIS
Adaptive Genetic Algorithm
vibration
natural frequencies
Opis:
Damage detection in structural elements like beams is one of important research areas for health monitoring. Initiation of a fault in the form of a crack or any damage puts a limitation on the service life of a structural member. So, in this paper, a method is proposed which uses the advantages of soft computing techniques like Fuzzy Inference Systems (Mamdani and Sugeno) and Adaptive Genetic Algorithm for three stage refinement of the data base generated using dynamic responses from a cracked fixed-free aluminum alloy beam element. For the crack element reference, a finite element model of a single transverse crack has been considered. The proposed method describes both Mamdani and Sugeno Fuzzy Inference Systems for training of damage parameters. In the Adaptive Genetic Algorithm, a statistics based method has been incorporated to limit the randomness of the search process. Finally, the results from the Mamdani-Adaptive Genetic-Sugeno model (MAS) are validated with the results from the experimental analysis.
Źródło:
Journal of Theoretical and Applied Mechanics; 2017, 55, 4; 1325-1339
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Corrosion Inhibition of Mild Steel in Nitric Acid Media by some Schiff Bases Derived from Anisalidine
Autorzy:
Saxena, N.
Kumar, S.
Sharma, M. K.
Mathur, S. P.
Powiązania:
https://bibliotekanauki.pl/articles/779278.pdf
Data publikacji:
2013
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
Schiff base
degradation
inhibitor and mild steel
Opis:
Corrosion inhibition performance of mild steel in nitric acid solution containing different concentration of anisalidine derivative Schiff bases viz. N- (4-nitro phenyl) p-anisalidine (SB1), N- (4-chloro phenyl) p-anisalidine (SB2), N- (4-phenyl) p-anisalidine (SB3), N- (4-methoxy phenyl) p-anisalidine (SB4), N- (4-hydroxy phenyl) p-anisalidine (SB5) has been investigated using mass loss, thermometric and potentiostate polarization technique. Inhibition efficiencies of Schiff bases have been evaluated at different acid strength. The inhibition efficiency was found larger than their parent amines. Inhibition efficiencies of synthesized Schiff bases increase with inhibitor concentration. Inhibition efficiency increases up to 98.32% with ansalidine derivative Schiff base.
Źródło:
Polish Journal of Chemical Technology; 2013, 15, 1; 61-67
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Intelligent hybrid fuzzy logic system for damage detection of beam-like structural elements
Autorzy:
Sahu, S.
Kumar, P. B.
Parhi, D. R.
Powiązania:
https://bibliotekanauki.pl/articles/281457.pdf
Data publikacji:
2017
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
fuzzy logic
differential evolution algorithm
crack
natural frequency
Opis:
Fuzzy logic has been used in different research fields for more than three decades. It has become a robust method to solve complex and intricate problems which are otherwise difficult to solve by traditional methods. But it still requires some human experience and knowledge. In the present study, an attempt is made to design a hybrid optimization technique for automatic formation of the fuzzy knowledge based rules using an evolutionary algorithm. This hybridization technique has been applied in the field of damage detection and location of cracks in cracked structural elements. In this paper, a robust fault diagnostic tool based on a differential evolution algorithm and fuzzy logic has been proposed. Theoretical and Finite Element analyzes are done to model the crack and to find the effect of the presence of cracks on changes of vibrational characteristic (natural frequencies) of a fixed-fixed beam. The inputs to DEA-FL system are the first three relative natural frequencies, and the outputs from the system are the relative crack depth and relative crack location. For the validation of the results obtained from the proposed method and to check the robustness of the controller, experimental analysis is performed. To find average error rates, the bootstrap method has been adopted.
Źródło:
Journal of Theoretical and Applied Mechanics; 2017, 55, 2; 509-521
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The effect of magnetic field dependent viscosity on ferromagnetic convection in a rotating sparsely distributed porous medium - revisited
Autorzy:
Prakash, J.
Kumar, P.
Manan, S.
Sharma, K. R.
Powiązania:
https://bibliotekanauki.pl/articles/265547.pdf
Data publikacji:
2020
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
ferrofluid
konwekcja
pole magnetyczne
materiał porowaty
convection
rotation
magnetic field dependent viscosity
porous medium
Opis:
The effect of magnetic field dependent (MFD) viscosity on the thermal convection in a ferrofluid layer saturating a sparsely distributed porous medium has been investigated by using the Darcy-Brinkman model in the simultaneous presence of a uniform vertical magnetic field and a uniform vertical rotation. A correction is applied to the study of Vaidyanathan et al. [11] which is very important in order to predict the correct behavior of MFD viscosity. A linear stability analysis has been carried out for stationary modes and oscillatory modes separately. The critical wave number and critical Rayleigh number for the onset of instability, for the case of free boundaries, are determined numerically for sufficiently large values of the magnetic parameterM1 . Numerical results are obtained and are illustrated graphically. It is shown that magnetic field dependent viscosity has a destabilizing effect on the system for the case of stationary mode and a stabilizing effect for the case of oscillatory mode, whereas magnetization has a destabilizing effect.
Źródło:
International Journal of Applied Mechanics and Engineering; 2020, 25, 1; 142-158
1734-4492
2353-9003
Pojawia się w:
International Journal of Applied Mechanics and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł

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