Autor: Kumar, P. S. - Prolib Integro

Skocz do pozycji: 1.

Tytuł:: The Spin-Valve Transistor - a New Magnetoelectronic Device
Autorzy:: Anil Kumar, P. S.
Lodder, J. C.
Tematy:: 75.70.-i
75.70.Pa; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Powiązania:: https://bibliotekanauki.pl/articles/2011222.pdf Link otwiera się w nowym oknie
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.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 2.

Tytuł:: Influence of Rock Properties on Wear of M and SR Grade Rubber with Varying Normal Load and Sliding Speed
Autorzy:: Pal, S. K.
Rao, K. U. M.
Kumar, P. S.
Rajasekar, R.
Tematy:: rock
rubber
wear
shear strength
surface roughness; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:: https://bibliotekanauki.pl/articles/356996.pdf Link otwiera się w nowym oknie
Opis:: Rubbers are interesting materials and are extensively used in many mining industries for material transportation. Wear of rubber is a very complex phenomenon to understand. The present study aims to explain the influence of rock properties on wear of M and SR grade rubber used in top cover of conveyor belts. Extensive laboratory experiments were conducted under four combinations of normal load and sliding speed. The wear of both the rubber types were analyzed based on the rock properties like shear strength, abrasivity index and fractal dimension. A fully instrumented testing set up was used to study the wear of rubber samples under different operating conditions. In general, wear was higher for M grade rubber compared to SR grade rubber. Increase in shear strength of rocks depicts decreasing trend for the wear of M and SR grade rubber at lower load conditions. Moreover, a higher load combination displays no definite trend in both the rubbers. The strong correlation between the wear of rubber and frictional power for all rubber-rock combinations has given rise to the parameter A, which reflects the relative compatibility between the rubber and rock. Increase of Cerchar’s Abrasivity Index of rocks shows gradual enhancement in wear for M grade rubber in all the load and speed combinations whereas, it fails in SR grade rubber due to its higher strength. The wear of rubber tends to decrease marginally with the surface roughness of rocks at highest normal load and sliding speed in M grade rubber. However, the wear of M and SR grade rubber is influenced by the surface roughness of rocks.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 3.

Tytuł:: Adsorption kinetic, equilibrium and thermodynamic investigations of Zn(II) and Ni(II) ions removal by poly(azomethinethioamide) resin with pendent chlorobenzylidine ring
Autorzy:: Kumar, P. S.
Ethiraj, H.
Venkat, A.
Deepika, N.
Nivedha, S.
Vidhyadevi, T.
Ravikumar, L.
Sivanesan, S.
Tematy:: adsorption
models
Ni(II) ions
poly(azomethinethioamide)
Zn(II) ions; Pokaż więcej
Wydawca:: Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Powiązania:: https://bibliotekanauki.pl/articles/780002.pdf Link otwiera się w nowym oknie
Opis:: This paper reports the application of poly(azomethinethioamide) (PATA) resin having the pendent chlorobenzylidine ring for the removal of heavy metal ions such as Zn(II) and Ni(II) ions from the aqueous solutions by adsorption technology. Kinetic, equilibrium and thermodynamic models for Zn(II) and Ni(II) ions adsorption were applied by considering the effect of contact time, initial metal ion concentration and temperature data, respectively. The adsorption influencing parameters for the maximum removal of metal ions were optimized. Adsorption kinetic results followed the pseudo-second order kinetic model based on the correlation coefficient (R2) values and closed approach of experimental and calculated equilibrium adsorption capacity values. The removal mechanism of metal ions by PATA was explained with the Boyd kinetic model, Weber and Morris intraparticle diffusion model and Shrinking Core Model (SCM). Adsorption equilibrium results followed the Freundlich model based on the R2 values and error functions. The maximum monolayer adsorption capacity of PATA for Zn(II) and Ni(II) ions removal were found to be 105.4 mg/g and 97.3 mg/g, respectively. Thermodynamic study showed the adsorption process was feasible, spontaneous, and exothermic in nature.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 4.

Tytuł:: Application of UPFC for enhancement of voltage profile and minimization of losses using Fast Voltage Stability Index (FVSI)
Autorzy:: Kumar, S.
Renuga, P.
Tematy:: flexible AC transmission system (FACTS)
real and reactive power
Unified Power Flow Controller (UPFC)
Bacterial Foraging (BF) algorithm; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:: https://bibliotekanauki.pl/articles/140514.pdf Link otwiera się w nowym oknie
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.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 5.

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.
Tematy:: 31.10.+z; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Powiązania:: https://bibliotekanauki.pl/articles/1887915.pdf Link otwiera się w nowym oknie
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.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 6.

Tytuł:: Effects of Heat Input on the Mechanical and Metallurgical Characteristics of TIG Welded Incoloy 800HT Joints
Autorzy:: Arun Kumar, S.
Sathiya, P.
Tematy:: incoloy 800 HT
corrosion
aging
sensitization
heat input; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:: https://bibliotekanauki.pl/articles/356231.pdf Link otwiera się w nowym oknie
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.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 7.

Tytuł:: Modified model for shear stress distribution using TRI-1 lunar soil simulant
Autorzy:: Jayalekshmi, S.
Gireesh Kumar, P.
Tematy:: TRI-1
lunar soil simulant
modified model
shear stress distribution; Pokaż więcej
Wydawca:: Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Powiązania:: https://bibliotekanauki.pl/articles/949124.pdf Link otwiera się w nowym oknie
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.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 8.

Tytuł:: Biomass fuel cell based distributed generation system for Sagar Island
Autorzy:: Kumar, P.
Sikder, P. S.
Pal, N.
Tematy:: biomass
fuel cell
distributed generation systems
inverter
cost analysis
biomasa
ogniwo paliwowe
falownik
analiza kosztów
generacja rozproszona; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:: https://bibliotekanauki.pl/articles/200813.pdf Link otwiera się w nowym oknie
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.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 9.

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.
Tematy:: azido-esters
energetic plasticizers
DFT
contact angle; Pokaż więcej
Wydawca:: Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Powiązania:: https://bibliotekanauki.pl/articles/358266.pdf Link otwiera się w nowym oknie
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.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 10.

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.
Tematy:: Ethyl Oleate
Ethanol
molecular interactions
adiabatic compressibility; Pokaż więcej
Wydawca:: Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Powiązania:: https://bibliotekanauki.pl/articles/412193.pdf Link otwiera się w nowym oknie
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.
Dostawca treści:: Biblioteka Nauki

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