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Wyszukujesz frazę "Kumar, J." wg kryterium: Autor


Tytuł:
Probabilistic analysis of two reliability models of a single-unit system with preventive maintenance beyond warranty and degradation
Analiza probabilistyczna dwóch modeli niezawodności systemu jednoelementowego wykorzystujących pojęcia pogwarancyjnej obsługi profilaktycznej oraz degradacji
Autorzy:
Niwas, R.
Kadyan, M. S.
Kumar, J.
Powiązania:
https://bibliotekanauki.pl/articles/301952.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:
probabilistic analysis
reliability
preventive maintenance
warranty
degradation
analiza probabilistyczna
niezawodność
obsługa profilaktyczna
gwarancja
degradacja
Opis:
This paper presents two reliability models of a single-unit system with the concept of preventive maintenance (PM) beyond warranty and degradation. In both the models, repair of any failure during warranty is cost-free to the users, provided failures are not due to the negligence of users. There is a single repairman who always remains with the system. Beyond warranty, the unit goes under PM and works as new after PM (in both models). In model-1, the unit works as new after its repair beyond warranty whereas; in model-2, the unit becomes degraded. After failure, the degraded unit is replaced by a new one. The failure time of the system follows negative exponential distribution while PM, replacement and repair time distributions are taken as arbitrary with different probability density functions. Supplementary variable technique is adopted to derive the expressions for some economic measures such as reliability, mean time to system failure (MTSF), availability and profit function. Using Abel’s lemma, the behaviour of the system in steady-state has been examined. To highlight the behaviour of reliability and profit function, numerical results are considered for particular values of various parameters and repair cost. Profit comparison of both the models is also made to see the usefulness of the concept of degradation.
W artykule przedstawiono dwa modele niezawodności systemu jednoelementowego wykorzystujące pojęcia pogwarancyjnej obsługi profilaktycznej oraz degradacji. Oba modele zakładają, że w okresie gwarancyjnym użytkownik nie ponosi żadnych kosztów związanych z naprawą uszkodzeń, chyba że uszkodzenie powstało wskutek zaniedbania ze strony użytkownika. Obsługi są wykonywane przez jedną ekipę remontową, która zawsze pozostaje na stanowisku. Po upływie okresu gwarancyjnego, urządzenie podlega obsłudze profilaktycznej i po jej przeprowadzeniu działa jak nowe (w obu modelach). Model 1 zakłada, że element po naprawie pogwarancyjnej działa jak nowy, natomiast w Modelu 2, element ulega degradacji. Zdegradowany element, który uległ uszkodzeniu, zostaje wymieniony na nowy. Rozkład czasu uszkodzenia jest rozkładem wykładniczym ujemnym, a rozkłady czasu obsługi profilaktycznej, wymiany i naprawy są traktowane jako arbitralne, o różnych funkcjach gęstości prawdopodobieństwa. Zastosowana technika dodatkowej zmiennej pozwoliła na wyprowadzenie wyrażeń dla niektórych miar ekonomicznych, takich jak niezawodność, średni czas do uszkodzenia systemu (MTSF), gotowość i funkcja zysków. Zachowanie systemu w stanie ustalonym badano z wykorzystaniem lematu Abela. Aby przedstawić zachowanie funkcji niezawodności i zysków, analizowano wyniki numeryczne dla poszczególnych wartości różnych parametrów oraz kosztów naprawy. Porównanie zyskowności badanych modeli umożliwiło weryfikację przydatności pojęcia degradacji.
Źródło:
Eksploatacja i Niezawodność; 2015, 17, 4; 535-543
1507-2711
Pojawia się w:
Eksploatacja i Niezawodność
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Seasonal changes of sedimentation rates and sediment characteristics status in the Gulf of Mannar Coral Island, India
Autorzy:
Yogesh Kumar, J.S.
Geetha, S.
Sornaraj, R.
Powiązania:
https://bibliotekanauki.pl/articles/11860.pdf
Data publikacji:
2014
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
seasonal change
sedimentation rate
sediment status
Mannar Gulf
Coral Island
coral reef
marine sediment
Thoothukudi group
Vembar group
India
Opis:
Corals are known to flourish in various turbid environments around the world. The quantitative distinction between clear and turbid water in coral habitats is not well defined nor are the amount of sediment in suspension and rates of sedimentation used to evaluate the condition of reef environments well established. This study of sedimentation rate, sediment composition and pH, OC deposition was on a fringing reef flat off Thoothukudi and Vembar group of islands, Gulf of Mannar, India. In the present study the sedimentation rate ranged from 1.97 mg/cm2/day to 12.31 mg/cm2/day. The percentage of sand in the sediment was higher than silt and clay. The organic carbon level in all the study stations ranged from 0.03 to 2.54. The sediment pH of the six studied stations was highly acidic in nature at all the study sites in the Gulf of Mannar.
Źródło:
International Letters of Natural Sciences; 2014, 01
2300-9675
Pojawia się w:
International Letters of Natural Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Cost analysis of a two-unit cold standby system subject to degradation, inspection and priority
Analiza kosztów dwu-elementowego systemu z rezerwą zimną z uwzględnieniem degradacji, kontroli stanu systemu oraz priorytetowości zadań
Autorzy:
Kumar, J.
Kadyan, M. S.
Malik, S. Ch.
Powiązania:
https://bibliotekanauki.pl/articles/301970.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:
degradacja
kontrola stanu
priorytetowość
analiza zysku
degradation
inspection
priority
profit analysis
Opis:
The present paper deals with a reliability model incorporating the idea of degradation, inspection and priority. The units may fail completely directly from normal mode. There is a single server who visits the system immediately when required. The original unit undergoes for repair upon failure while only replacement of the duplicate unit is made by similar new one. The original unit does not work as new after repair and so called degraded unit. The system is considered in up-state if any one of new/duplicate/degraded unit is operative. The server inspects the degraded unit at its failure to see the feasibility of repair. If repair of the degraded unit is not feasible, it is replaced by new one similar to the original unit in negligible time. The priority for operation to the new unit is given over the duplicate unit. The distribution of failure time follow negative exponential where as the distributions of inspection, repair and replacement times are assumed as arbitrary. The system is observed at suitable regenerative epochs by using regenerative point technique to evaluate mean time to system failure (MTSF), steady-state availability, busy period and expected number of visits by the server. A particular case is considered to see graphically the trend of mean time to system failure (MTSF), availability and profit with respect to different parameters.
Niniejsza praca dotyczy modelu niezawodności uwzględniającego zagadnienia degradacji, kontroli stanu oraz priorytetowości zadań. Elementy mogą ulegać całkowitemu uszkodzeniu bezpośrednio z trybu normalnego. Istnieje jeden konserwator, który odwiedza system, gdy tylko zachodzi taka potrzeba. W przypadku uszkodzenia, element oryginalny podlega naprawie, podczas gdy element zapasowy (duplikat) podlega jedynie wymianie na nowy, podobny. Po naprawie, element oryginalny nie działa już jako element nowy lecz jako element zdegradowany. System uważa się za zdatny jeżeli pracuje którykolwiek z trzech typów elementów: nowy/rezerwowy/zdegradowany. W przypadku uszkodzenia elementu zdegradowanego, konserwator przeprowadza kontrolę stanu elementu, aby stwierdzić możliwość realizacji naprawy. Jeżeli naprawa elementu zdegradowanego jest niemożliwa, zostaje on wymieniony, w czasie pomijalnym, na element nowy, podobny do elementu oryginalnego. Nowy element uzyskuje priorytet pracy w stosunku do elementu rezerwowego. Rozkład czasu uszkodzenia jest rozkładem wykładniczym ujemnym, a rozkłady czasów kontroli stanu, naprawy i wymiany przyjmuje się jako rozkłady dowolne. System obserwuje się w odpowiednich okresach odnowy wykorzystując technikę odnowy RPT (regenerative point technique) w celu ocenienia średniego czasu do uszkodzenia systemu (MTSF), gotowości stacjonarnej, okresu zajętości oraz oczekiwanej liczby wizyt konserwatora. Przebiegi MTSF, gotowości i zysków w funkcji różnych parametrów przedstawiono w formie graficznej na podstawie studium przypadku.
Źródło:
Eksploatacja i Niezawodność; 2012, 14, 4; 278-283
1507-2711
Pojawia się w:
Eksploatacja i Niezawodność
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical study on two dimensional distribution of streamwise velocity in open channel turbulent flows with secondary current effect
Autorzy:
Mohan, S.
Kundu, S.
Ghoshal, K.
Kumar, J.
Powiązania:
https://bibliotekanauki.pl/articles/38616700.pdf
Data publikacji:
2021
Wydawca:
Instytut Podstawowych Problemów Techniki PAN
Tematy:
velocity distribution
open channel flow
turbulent flow
RANS equations
secondary current
finite difference method
Opis:
For studying mechanism of sediment transport in river flows, open channel flow is a prototype. Flow has always three components of velocity for all types of channel geometry and for a time independent uniform flow along streamwise or main flow direction, all the components of velocity are functions of lateral and vertical coordinates. The present study investigates the two dimensional distribution of streamwise (or longitudinal) velocity starting from the Reynolds averaged Navier–Stokes equation for a turbulent open channel flow which is steady and uniform along the main flow direction. Secondary flows both along the vertically upward direction and along the lateral direction are considered which are also taken as functions of lateral and vertical coordinates. Inclusion of the secondary current brings the effect of dip phenomenon in the model. The resulting second order partial differential equation is solved numerically. The model is validated for all the cross-sectional, transverse and centreline velocity distribution by comparing with existing relevant set of experimental data and also with an existing model. Comparison results show good agreement with data as well as with the previous model proving the efficiency of the model. It is found that the transverse velocity distribution depends on the formation of circular vortex in the cross-sectional plane and becomes periodic as the number of circular vortex increases for increasing aspect ratios.
Źródło:
Archives of Mechanics; 2021, 73, 2; 175-200
0373-2029
Pojawia się w:
Archives of Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of electric field on dispersion of a solute in an MHD flow through a vertical channel with and without chemical reaction
Autorzy:
Umavathi, J. C.
Kumar, J. P.
Gorla, R. S. R.
Gireesha, B. J.
Powiązania:
https://bibliotekanauki.pl/articles/265686.pdf
Data publikacji:
2016
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
dyspersja Taylora
magnetohydrodynamika
reakcja chemiczna
Taylor dispersion
immiscible fluids
conducting fluid
MHD
chemical reaction
Opis:
The longitudinal dispersion of a solute between two parallel plates filled with two immiscible electrically conducting fluids is analyzed using Taylor’s model. The fluids in both the regions are incompressible and the transport properties are assumed to be constant. The channel walls are assumed to be electrically insulating. Separate solutions are matched at the interface using suitable matching conditions. The flow is accompanied by an irreversible first-order chemical reaction. The effects of the viscosity ratio, pressure gradient and Hartman number on the effective Taylor dispersion coefficient and volumetric flow rate for an open and short circuit are drawn in the absence and in the presence of chemical reactions. As the Hartman number increases the effective Taylor diffusion coefficient decreases for both open and short circuits. When the magnetic field remains constant, the numerical results show that for homogeneous and heterogeneous reactions, the effective Taylor diffusion coefficient decreases with an increase in the reaction rate constant for both open and short circuits.
Źródło:
International Journal of Applied Mechanics and Engineering; 2016, 21, 3; 683-711
1734-4492
2353-9003
Pojawia się w:
International Journal of Applied Mechanics and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Assessment of water physico-chemical characteristics and statistical evaluation of Narmada Estuarine Region, Gujarat, India
Analiza i statystyczne opracowanie fizyczno-chemicznych właściwości wody z estuarium Narmada, Gujarat, Indie
Autorzy:
Nirmal Kumar, I. J.
Basil, G.
Nirmal Kumar, R.
Sajish, P. R.
Shailendra, V.
Powiązania:
https://bibliotekanauki.pl/articles/292696.pdf
Data publikacji:
2012
Wydawca:
Instytut Technologiczno-Przyrodniczy
Tematy:
analiza głównych składowych
estuarium Narmada
parametry fizyczno-chemiczne
sezonowość
statystyka wielowymiarowa
multivariate statistics
Narmada estuary
physico-chemical parameters
principal component analysis
seasonality
Opis:
Investigations on physicochemical parameters (temperature, pH, salinity, dissolved oxygen), including dissolved nutrients (PO4-P, NO3-N, SiO4-Si) and chlorophyll-a were carried out in the water off the mouth of the Narmada estuary from July 2008 to June 2009. The multivariate statistics and principal component analysis applied to the datasets, indicated two factors during the whole study period influencing variability in the water to the extent of 72%. Principal axis factoring and alpha factoring have been used to observe the mode of association of parameters and their interrelationships, for evaluating water quality. The results indicated the addition of phosphates and silicates to the coastal water by the Narmada estuary from natural sources during study period. The study indicated that the Narmada estuary adds sufficiently well-oxygenated, nutrient-rich water to the coastal region.
Analizę parametrów fizyczno-chemicznych (temperatura, pH, zasolenie, tlen rozpuszczony), stężenia pierwiastków biogennych (PO4-P, NO3-N, SiO4-Si) i chlorofilu prowadzono w wodach estuarium Narmada od lipca 2008 do czerwca 2009. Statystyka wielowymiarowa i analiza głównych składowych, zastosowana do zbioru wyników, wskazała dwa czynniki, które w 72% odpowiadały za zmienność składu chemicznego wody w całym okresie badań. Do oceny jakości wody zastosowano analizę czynnikową celem określenia powiązań między parametrami i ich wzajemnych zależności. Wyniki pokazały, że w okresie badawczym estuarium Narmada dostarczało do wód przybrzeżnych fosforany i krzemiany pochodzące z naturalnych źródeł. Przeprowadzone badania dowodzą, że estuarium Narmada zasila strefę brzegową w dobrze natlenione i bogate w pierwiastki biogenne wody.
Źródło:
Journal of Water and Land Development; 2012, no. 16 [I-VI]; 43-48
1429-7426
2083-4535
Pojawia się w:
Journal of Water and Land Development
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mucocele – A benign lesion of accessory salivary gland
Autorzy:
Chengappa, Dewan
Vijayendranath, Nayak S.
Raghavendra, Kini
Prasanna, Kumar Rao J.
Boricha, Vishal Kumar
Manjunath, Rai
Powiązania:
https://bibliotekanauki.pl/articles/1157168.pdf
Data publikacji:
2018
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Diagnosis
excision
lower lip
minor salivary glands
mucocele
Opis:
Mucoceles are the most common soft tissue lesions seen in the oral cavity. They usually occur due to injury to the minor salivary glands. Spontaneous regression of mucocele can happen if its superficial or else surgical excision is recommended. Herein we report a case of oral mucocele of lower labial mucosa.
Źródło:
World Scientific News; 2018, 94, 2; 305-307
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Unique fuzzy optimal value of fully fuzzy linear programming problems
Autorzy:
Kaur, J.
Kumar, A.
Powiązania:
https://bibliotekanauki.pl/articles/206342.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Instytut Badań Systemowych PAN
Tematy:
fully fuzzy linear programming
unique fuzzy optimal value
fuzzy number
Opis:
Kumar, Kaur and Singh (2011), proposed a new method to find the exact fuzzy optimal solution of fully fuzzy linear programming (FFLP) problems with equality constraints. In this paper, an FFLP problem is chosen to show that the fuzzy optimal value, obtained by using the existing method, is not necessarily a unique fuzzy number i.e., the fuzzy optimal value of the FFLP problem, obtained by the existing method, does not conform to the uniqueness property of fuzzy optimal value. To overcome this shortcoming of the existing method, a new method is proposed for solving FFLP problems with equality constraints. To show the advantage of the proposed method the results of the chosen FFLP problem, obtained by using the existing and the proposed methods, are compared.
Źródło:
Control and Cybernetics; 2012, 41, 2; 497-508
0324-8569
Pojawia się w:
Control and Cybernetics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Algebraic Riccati equation based Q and R matrices selection algorithm for optimal LQR applied to tracking control of 3rd order magnetic levitation system
Autorzy:
Kumar E, V.
Jerome, J.
Powiązania:
https://bibliotekanauki.pl/articles/140600.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
algebraic Riccatti equation
linear quadratic regulator
magnetic levitation
system
weighting matrices
command following
cost function
Opis:
This paper presents an analytical approach for solving the weighting matrices selection problem of a linear quadratic regulator (LQR) for the trajectory tracking application of a magnetic levitation system. One of the challenging problems in the design of LQR for tracking applications is the choice of Q and R matrices. Conventionally, the weights of a LQR controller are chosen based on a trial and error approach to determine the optimum state feedback controller gains. However, it is often time consuming and tedious to tune the controller gains via a trial and error method. To address this problem, by utilizing the relation between the algebraic Riccati equation (ARE) and the Lagrangian optimization principle, an analytical methodology for selecting the elements of Q and R matrices has been formulated. The novelty of the methodology is the emphasis on the synthesis of time domain design specifications for the formulation of the cost function of LQR, which directly translates the system requirement into a cost function so that the optimal performance can be obtained via a systematic approach. The efficacy of the proposed methodology is tested on the benchmark Quanser magnetic levitation system and a detailed simulation and experimental results are presented. Experimental results prove that the proposed methodology not only provides a systematic way of selecting the weighting matrices but also significantly improves the tracking performance of the system.
Źródło:
Archives of Electrical Engineering; 2016, 65, 1; 151-168
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An adaptive particle swarm optimization algorithm for robust trajectory tracking of a class of under actuated system
Autorzy:
Kumar, V. E.
Jerome, J.
Powiązania:
https://bibliotekanauki.pl/articles/141105.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
inverted pendulum
LQR controller
particle swarm optimization (PSO)
genetic algorithm
adaptive inertia weight factor
state feedback control
Opis:
This paper presents an adaptive particle swarm optimization (APSO) based LQR controller for optimal tuning of state feedback controller gains for a class of under actuated system (Inverted pendulum). Normally, the weights of LQR controller are chosen based on trial and error approach to obtain the optimum controller gains, but it is often cumbersome and tedious to tune the controller gains via trial and error method. To address this problem, an intelligent approach employing adaptive PSO (APSO) for optimum tuning of LQR is proposed. In this approach, an adaptive inertia weight factor (AIWF), which adjusts the inertia weight according to the success rate of the particles, is employed to not only speed up the search process but also to increase the accuracy of the algorithm towards obtaining the optimum controller gain. The performance of the proposed approach is tested on a bench mark inverted pendulum system, and the experimental results of APSO are compared with that of the conventional PSO and GA. Experimental results prove that the proposed algorithm remarkably improves the convergence speed and precision of PSO in obtaining the robust trajectory tracking of inverted pendulum.
Źródło:
Archives of Electrical Engineering; 2014, 63, 3; 345-365
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Participatory Ergonomics and an Evaluation of a Low-Cost Improvement Effect on Cleaners’ Working Posture
Autorzy:
Kumar, R.
Chaikumarn, M.
Lundberg, J.
Powiązania:
https://bibliotekanauki.pl/articles/90257.pdf
Data publikacji:
2005
Wydawca:
Centralny Instytut Ochrony Pracy
Tematy:
participatory ergonomics
cleaning
OWAS
postural analysis
low-cost improvement
ergonomia
pozycja przy pracy
sprzątanie miejsc pracy
czystość i porządek
praca biurowa
Opis:
Cleaning is a highly physically demanding job with a high frequency of awkward postures and working environments as contributing risk factors. Participatory ergonomics is a method in which end-users take an active role in identifying risk factors and solutions. The aim of this study was to apply the participatory ergonomics method to identify cleaning problems and to evaluate the effect of a low-cost improvement on cleaners’ working postures in an office environment. The results show that the cleaning problem was identified, and the low-cost ergonomics solution suggested by the cleaners was implemented. Thus an improved working environment reduced the number of awkward cleaning postures and the Ovako Working Posture Analysis System (OWAS) action category for floor mopping decreased. It can be concluded that working in an improved environment can lead to better working postures which, in turn, leads to the cleaners’ better health and better cleaning results.
Źródło:
International Journal of Occupational Safety and Ergonomics; 2005, 11, 2; 203-210
1080-3548
Pojawia się w:
International Journal of Occupational Safety and Ergonomics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Thermal convection in a ferromagnetic fluid layer with magnetic field dependent viscosity: a correction applied
Autorzy:
Prakash, J.
Kumar, R.
Kumari, K.
Powiązania:
https://bibliotekanauki.pl/articles/178325.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
ferromagnetic convection
magnetic field dependent viscosity
stationary convection
Rayleigh number
Opis:
The effect of magnetic field dependent (MFD) viscosity on thermal convection in a horizontal ferromagnetic fluid layer has been investigated numerically. A correction is applied to Sunil et al. [24] which is very important in order to predict the correct behavior of MFD viscosity. Linear stability analysis has been carried out for stationary convection. The MFD viscosity parameter δ as well as the measure of nonlinearity of magnetization M3, both have a stabilizing effect on the system. Numerical results are also obtained for large values of magnetic parameter M1 and predicted graphically.
Źródło:
Studia Geotechnica et Mechanica; 2017, 39, 3; 39-46
0137-6365
2083-831X
Pojawia się w:
Studia Geotechnica et Mechanica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Novel Approach to the Solution of Matrix Games with Payoffs Expressed by Trapezoidal Intuitionistic Fuzzy Numbers
Autorzy:
Verma, T.
Kumar, A.
Kacprzyk, J.
Powiązania:
https://bibliotekanauki.pl/articles/384798.pdf
Data publikacji:
2015
Wydawca:
Sieć Badawcza Łukasiewicz - Przemysłowy Instytut Automatyki i Pomiarów
Tematy:
trapezoidal intuitionistic fuzzy numbers
mathematical programming problem
two person zerosum game
α cut
β cut
Opis:
We propose a novel approach to the solution of fuzzy matrix games with payoffs given as trapezoidal intuitionistic fuzzy numbers. We extend Li’s [36, Chapter 9] work based on a cut-set based method for finding an optimal solution to overcome the fact that the assumptions and properties assumed therein do not guarantee in general, first, the very existence of an optimal solution, and second, its attainment via a mathematical programming formulation proposed. We first briefly mention those problems in Li’s [36] approach, and then propose a new, corrected and general method, called the Mehar mehod, based on a modified mathematical pro- gramming formulation of a matrix game with payoffs represented by trapezoid intuitionistic fuzzy numbers. For illustration, we solve Li’s [36] example, and compare his and our results.
Źródło:
Journal of Automation Mobile Robotics and Intelligent Systems; 2015, 9, 3; 25-46
1897-8649
2080-2145
Pojawia się w:
Journal of Automation Mobile Robotics and Intelligent Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analytical solution of a fractional model of fluid flow through narrowing system in terms of Mittag-Leffler function
Autorzy:
Choudhary, A.
Kumar, D.
Singh, J.
Powiązania:
https://bibliotekanauki.pl/articles/264897.pdf
Data publikacji:
2020
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
transformata Hankela
funkcja Bessela
pochodna Caputo
narrowing system
generalized Caputo fractional derivative
Sumudu transform
finite Hankel transform
Bessel function
Mittag-Leffler function
Opis:
In this work, we discuss a fractional model of a flow equation in a simple pipeline. Pipeline narrowing is a crucial aspect in drinking water distribution processes, sewage system and in oil-well schemes. The solution of the mathematical model is determined with the aid of the Sumudu transform and finite Hankel transform. The results derived in the current study are in compact and graceful forms in terms of the Mittag-Leffler type function, which are convenient for numerical and theoretical evaluation.
Źródło:
International Journal of Applied Mechanics and Engineering; 2020, 25, 1; 1-11
1734-4492
2353-9003
Pojawia się w:
International Journal of Applied Mechanics and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optimal sizing and cost analysis of hybrid power system for a stand-alone application in Coimbatore region: a case study
Autorzy:
Bogaraj, T.
Kanakaraj, J.
Kumar, K. M.
Powiązania:
https://bibliotekanauki.pl/articles/141602.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
hybrid power system
optimal sizing
cost analysis
renewable energy sources
net present cost
levelised cost of energy
HOMER
Opis:
This paper presents the optimal sizing of PV/Wind/Fuel Cell/Battery Hybrid Energy System for energizing a Small Scale Industrial Application or a village domestic load of 200 kW. HOMER software is used for simulation of the complete system. The solar radiation data and wind speed data used in this paper are for the place of Coimbatore, Tamil Nadu, India which is located 11.0183° N longitude and 76.9725° E latitude. The optimized sizes of components of Hybrid Power System (HPS) are found based on Levelised Cost of Energy (LCE) and total Net Present Cost (NPC). The results are presented and compared for five different combinations of HPS components. Suggestions are also presented to choose the low cost system which produces energy at low LCE.
Źródło:
Archives of Electrical Engineering; 2015, 64, 1; 139-155
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
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:
Test Methods and Instrumentation for Assessing Reaction to Fire Properties of Railway Rolling Stock
Metody badań i aparatura stosowana do oceny właściwości reakcji taboru kolejowego na ogień
Autorzy:
Gregory, S.
Grayson, S. J.
Kumar, S.
Powiązania:
https://bibliotekanauki.pl/articles/215416.pdf
Data publikacji:
2013
Wydawca:
Instytut Kolejnictwa
Tematy:
railway
EN 45545-2
fire
linings
flooring
cables
seats
właściwości palno-dymowe materiałów
badania
aparatura badawcza
jednolite procedury badawcze
Opis:
This paper briefly reviews the current instruments used in assessing the fire performance of railway rolling stock and those to be used in new European regulatory tests. The latter are a result of major developments towards harmonizing Railway Vehicle fire performance testing and classifications, initially developed under European Public Procurement directives and latterly via the Technical Specification for Interoperability (TSI). In many senses the interoperability of railway vehicles between different EU countries makes harmonization a very desirable requirement. The test specifications to be utilized for this process are described in EN 45545. The formation of the European Union and the subsequent agreements that several products should be tested using harmonized testing methods throughout the EU make the EU market the developed world's biggest market for most constructed products. Each member state is currently able to continue to classify the products using the traditional (often national) methods alongside the new methods during a transition period.
Autor przekrojowo omawia rozwój metod badawczych przeznaczonych do badań właściwości palno-dymowych materiałów. Przedstawia przede wszystkim badania i aparaturę stosowaną w Wielkiej Brytanii, a także metody rozwinięte w projektach europejskich oraz testy uwzględnione w nowej normie europejskiej EN 45545:2013. Podkreśla korzystny wpływ ujednolicenia procedur badawczych i wymagań na rozwój europejskiego rynku kolejowego.
Źródło:
Problemy Kolejnictwa; 2013, 160; 35-50
0552-2145
2544-9451
Pojawia się w:
Problemy Kolejnictwa
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A comprehensive review of renewable energy production from biomass-derived bio-oil
Autorzy:
Sharma, M.
Singh, J.
Baskar, C.
Kumar, A.
Powiązania:
https://bibliotekanauki.pl/articles/80718.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
renewable energy
biomass
bio-oil
bioenergy
biomass source
fast pyrolysis
hydrothermal liquefaction
climate change
energy security
Źródło:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology; 2019, 100, 2
0860-7796
Pojawia się w:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Pomegranate fruit quality assessment using machine intelligence and wavelet features
Autorzy:
Kumar, A.
Rajpurohit, V.S.
Jirage, B.J.
Powiązania:
https://bibliotekanauki.pl/articles/2137.pdf
Data publikacji:
2018
Wydawca:
Instytut Ogrodnictwa
Tematy:
pomegranate
Punica granatum
fruit
quality assessment
artificial neural network
support vector machine
Źródło:
Journal of Horticultural Research; 2018, 26, 1
2300-5009
Pojawia się w:
Journal of Horticultural Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Multi-objective optimization of in-situ bioremediation of groundwater using a hybrid metaheuristic technique based on differential evolution, genetic algorithms and simulated annealing
Wielozadaniowa optymalizacja bioremediacji wód gruntowych in situ z zastosowaniem hybrydowej techniki metaheurystycznej opartej na zróżnicowanej ewolucji, algorytmach genetycznych i symulowanym wyżarzaniu
Autorzy:
Kumar, D.
Ch, S.
Mathur, S.
Adamowski, J.
Powiązania:
https://bibliotekanauki.pl/articles/292714.pdf
Data publikacji:
2015
Wydawca:
Instytut Technologiczno-Przyrodniczy
Tematy:
differential evolution
fuzzy logic
genetic algorithm
groundwater
hybrid algorithm
in situ bioremediation
simulated annealing
support vector machine (SVM)
bioremediacja in situ
algorytm hybrydowy
algorytm genetyczny
logika rozmyta
maszyna wektorów nośnych SVM
wyżarzanie symulowane
wody gruntowe
zróżnicowana ewolucja
Opis:
Groundwater contamination due to leakage of gasoline is one of the several causes which affect the groundwater environment by polluting it. In the past few years, In-situ bioremediation has attracted researchers because of its ability to remediate the contaminant at its site with low cost of remediation. This paper proposed the use of a new hybrid algorithm to optimize a multi-objective function which includes the cost of remediation as the first objective and residual contaminant at the end of the remediation period as the second objective. The hybrid algorithm was formed by combining the methods of Differential Evolution, Genetic Algorithms and Simulated Annealing. Support Vector Machines (SVM) was used as a virtual simulator for biodegradation of contaminants in the groundwater flow. The results obtained from the hybrid algorithm were compared with Differential Evolution (DE), Non Dominated Sorting Genetic Algorithm (NSGA II) and Simulated Annealing (SA). It was found that the proposed hybrid algorithm was capable of providing the best solution. Fuzzy logic was used to find the best compromising solution and finally a pumping rate strategy for groundwater remediation was presented for the best compromising solution. The results show that the cost incurred for the best compromising solution is intermediate between the highest and lowest cost incurred for other non-dominated solutions.
Zanieczyszczenie wód gruntowych wyciekami benzyny jest jedną z kilku przyczyn wpływających na środowisko wód podziemnych. W ostatnich latach bioremediacja in situ przyciągała uwagę badaczy z powodu jej zdolności do usuwania zanieczyszczeń w ich siedlisku i niskich kosztów procesu. Przedstawiona praca proponuje użycie nowego algorytmu hybrydowego do optymalizacji wielozadaniowej funkcji, która obejmuje koszty remediacji jako pierwsze zadanie i resztową zawartość zanieczyszczeń po zakończeniu procesu jako drugie z zadań. Algorytm hybrydowy powstał z połączenia metod różnicowej ewolucji, algorytmu genetycznego i symulowanego wyżarzania. Maszyna wektorów nośnych (SVM) została użyta jako wirtualny symulator biologicznej degradacji zanieczyszczeń w wodach gruntowych. Wyniki uzyskane z algorytmy hybrydowego porównano z wynikami zróżnicowanej ewolucji (DE), algorytmu genetycznego (NSGA II) i symulowanego wyżarzania (SA). Stwierdzono, że proponowany algorytm był w stanie zapewnić najlepsze rozwiązanie. Użyto metody z zakresu logiki rozmytej dla znalezienia najlepszego rozwiązania kompromisowego i na końcu przedstawiono dla tego rozwiązania strategię szybkości pompowania celem remediacji wód gruntowych. Wyniki pokazały, że koszty ponoszone na rozwiązanie kompromisowe są pośrednie między najwyższymi i najniższymi kosztami innych rozwiązań.
Źródło:
Journal of Water and Land Development; 2015, 27; 29-40
1429-7426
2083-4535
Pojawia się w:
Journal of Water and Land Development
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The onset of convection in a rotating multicomponent fluid layer
Autorzy:
Prakash, J.
Singh, V.
Kumar, R.
Kumari, K.
Powiązania:
https://bibliotekanauki.pl/articles/281283.pdf
Data publikacji:
2016
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
multicomponent convection
principle of exchange of stabilities
oscillatory motions
complex growth rate
concentration Rayleigh number
Lewis number
Opis:
The onset of convective instability is analysed in a rotating multicomponent fluid layer in which density depends on n stratifying agents (one of them is heat) having different diffusivities. Two problems have been analysed mathematically. In the first problem, a sufficient condition is derived for the validity of the principle of the exchange of stabilities. Further, when the complement of this condition holds good, oscillatory motions of neutral or growing amplitude can exist, and thus it is important to derive upper bounds for the complex growth rate of such motions when at least one of the bounding surfaces is rigid so that exact solutions of the problem in closed form are not obtainable. Thus, as the second problem, bounds for the complex growth rates are also obtained. Above results are uniformly valid for quite general nature of the bounding surfaces.
Źródło:
Journal of Theoretical and Applied Mechanics; 2016, 54, 2; 477-488
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Biodegradable Sansevieria cylindrica Leaves fiber/ Tamarind fruit fiber based Polymer hybrid composites on characterization
Autorzy:
Reddy, G. R.
Kumar, M. A.
Jayaramudu, J.
Powiązania:
https://bibliotekanauki.pl/articles/411831.pdf
Data publikacji:
2014
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
hybrid composites
mechanical properties
thermal
SEM
Opis:
This paper deals with the preparation and characterization of epoxy tamarind fruit (Tf) and Sansevieria cylindrica (Sc) hybrid composites containing fiber 0:20, 5:15, 10:10, 15:5 and 20:0 of (Tf:Sc) combinations loading. Sansevieria cylindrica leaves were used in this paper for extracting fiber out of it and in the similar manner ripen Tamarind fruit was used to extract fiber. Two different fibers viz. tamarind fruit/ Sansevieria cylindrica fibers were loaded into the epoxy system to develop the hybrid composites. The tensile and flexural properties of the resulting 20 wt. % loading of Tf/Sc/epoxy hybrid composites were examined. The resulting hybrid composites of 20 wt. % Tf/Sc with varying combinations exhibit the optimum improvement of mechanical properties and dielectric strength. 2 °C rise in decomposition temperature and 5 °C rise glass transition temperature were observed from the TGA and DSC thermal analysis. The fractured cross sections of flexural samples were assessed their performance as a function of fiber loading of Tf/Sc/epoxy hybrid composites by SEM analysis.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2014, 20, 2; 116-118
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Scrutinization of Joule heating and viscous dissipation on MHD flow and melting heat transfer over a stretching sheet
Autorzy:
Kumar, K. G.
Gireesha, B. J.
Manjunatha, S.
Powiązania:
https://bibliotekanauki.pl/articles/264626.pdf
Data publikacji:
2018
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
metoda numeryczna
dyssypacja lepkości
płyn mikropolarny
Joule heating
viscous dissipation
stretching sheet
micro polar dusty fluid
numerical method
Opis:
The present paper deals with an analysis of the combined effect of Joule heating and viscous dissipation on an MHD boundary layer flow and melting heat transfer of a micro polar fluid over a stretching surface. Governing equations of the problem are transformed into a set of coupled nonlinear ordinary differential equations by applying proper transformations and then they are solved numerically using the RKF-45 method. The method is verified by a comparison with the established results with limiting solution. The influence of the various interesting parameters on the flow and heat transfer is analyzed in detail through plotted graphs.
Źródło:
International Journal of Applied Mechanics and Engineering; 2018, 23, 2; 429-443
1734-4492
2353-9003
Pojawia się w:
International Journal of Applied Mechanics and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Solution and Generalized Ulam-Hyers Stability of a Reciprocal Type Functional Equation in Non-Archimedean Fields
Autorzy:
Kumar, B. V. Senthil
Ravi, K.
Rassias, J. M.
Powiązania:
https://bibliotekanauki.pl/articles/1193002.pdf
Data publikacji:
2016
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Generalized Hyers-Ulam stability
Reciprocal function
Reciprocal type functional equation
Opis:
In this paper, we obtain the general solution of a reciprocal type functional equation of the type f(x+y)=f((k_1 x+k_2 y)/k)f((k_2 x+k_1 y)/k)/(f((k_1 x+k_2 y)/k)+f((k_2 x+k_1 y)/k) ) and investigate its generalized Ulam-Hyers stability in non-Archimedean fields where k>2, k_1 and k_2 are positive integers with k=k_1+k_2 and k_1≠k_2. We also establish Hyers-Ulam-Rassias stability, Ulam-Gavruta-Rassias stability and J.M. Rassias stability controlled by the mixed product-sum of powers of norms for the same equation.
Źródło:
World Scientific News; 2016, 31; 48-58
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Screening and characterization of Fibrinolytic protease producing Bacillus circulans from mangrove sediments pitchavaram, South East Coast of India
Autorzy:
Sadeesh Kumar, R.
Rajesh, R.
Gokulakrishnan, S.
Subramanian, J.
Powiązania:
https://bibliotekanauki.pl/articles/11234.pdf
Data publikacji:
2015
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Opis:
Regulation and production of Fibrinolytic enzymes from bacterial sources especially from Bacillus strains has taken a leading role in the medical sciences for the treatment of cardiovascular disorders as it removes thrombus or clots adding to its significant role in curing human health issues saving millions. Significant progress has been made during the last few years on the studies of fibrinolytic enzymes in identifying, cloning, purification, characterization and overproduction of these for commercialization in medical sciences and in fields like detergents development. Production of fibrinolytic enzyme from Bacillus circulans was done using Nutrient broth medium. In addition, a strong fibrinolytic enzyme was purified from the cultivation media. The purified enzyme was almost homogeneous with other species of same genus, as examined by SDS−PAGE and sephadex G-75 column chromatography. The enzyme had an optimal pH of 7-12, an optimal temperature of 50 °C, for fibrin hydrolysis. The molecular mass estimated by gel filtration was 24 to36 KDa. Further studies for characterization and structural elucidation are necessary for their medicinal applications and molecular biological characteristics.
Źródło:
International Letters of Natural Sciences; 2015, 01
2300-9675
Pojawia się w:
International Letters of Natural Sciences
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
Tytuł:
Thermal analysis of generalized Burgers nanofluid over a stretching sheet with nonlinear radiation and non uniform heat source/sink
Autorzy:
Kumar, K. G.
Ramesh, G. K.
Gireesha, B. J.
Powiązania:
https://bibliotekanauki.pl/articles/240767.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
burgers nanofluid
non-uniform heat source/sink
non-linear radiation
magnetic field
stretching surface
pole magnetyczne
powierzchnia
rozciąganie
promieniowanie
nanofluid
Opis:
The work deals with the heat analysis of generalized Burgers nanofluid over a stretching sheet. The Rosseland approximation is used to model the non-linear thermal radiation and incorporated non-uniform heat source/sink effect. The governing equations reduced to a set of nonlinear ordinary differential equations under considering the suitable similarity transformations. The obtained ordinary differential equations equations are solved numerically by Runge-Kutta-Fehlberg order method. The effect of important parameters on velocity, temperature and concentration distributions are analyzed and discussed through the graphs. It reveals that temperature increases with the increase of radiation and heat source/sink parameter.
Źródło:
Archives of Thermodynamics; 2018, 39, 2; 97-122
1231-0956
2083-6023
Pojawia się w:
Archives of Thermodynamics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dynamical properties of a modified chaotic Colpitts oscillator with triangular wave non-linearity
Autorzy:
Suresh, Rasappan
Sathish Kumar, Kumaravel
Regan, Murugesan
Niranjan Kumar, K. A.
Narmada Devi, R.
Obaid, Ahmed J.
Powiązania:
https://bibliotekanauki.pl/articles/27312004.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
chaos
Colpitts oscillator
Lyapunov exponent
diffusion
stability
synchronization
triangular wave non-linearity
Opis:
The purpose of this paper is to introduce a new chaotic oscillator. Although different chaotic systems have been formulated by earlier researchers, only a few chaotic systems exhibit chaotic behaviour. In this work, a new chaotic system with chaotic attractor is introduced for triangular wave non-linearity. It is worth noting that this striking phenomenon rarely occurs in respect of chaotic systems. The system proposed in this paper has been realized with numerical simulation. The results emanating from the numerical simulation indicate the feasibility of the proposed chaotic system. More over, chaos control, stability, diffusion and synchronization of such a system have been dealt with.
Źródło:
Archives of Control Sciences; 2023, 33, 1; 25--53
1230-2384
Pojawia się w:
Archives of Control Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Finite element studies on free vibration of laminated composite cylindrical skew panels
Autorzy:
Srinivasa, C. V.
Suresh, Y. J.
Prema Kumar, W. P.
Powiązania:
https://bibliotekanauki.pl/articles/955177.pdf
Data publikacji:
2014
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
panel cylindryczny
laminat
wolne wibracje
element skończony
częstotliwość podstawowa
cylindrical skew panel
panel angle
skew angle
antisymmetric laminates
free vibration
finite element
fundamental frequency
Opis:
This paper presents the finite element studies on free vibration of isotropic and laminated composite cylindrical skew panels. The analysis is performed using CQUAD4 and CQUAD8 elements of MSC/NASTRAN. The effects of the panel angle, skew angle, aspect ratio and length-to-thickness-ratio on fundamental frequency of isotropic cylindrical skew panels are studied. The effects of additional parameters such as the fiber orientation angle, numbers of layers and stacking sequence on the fundamental frequency of antisymmetric composite laminates are also studied. It is found that the CQUAD8 element yields better results than the CQUAD4 element in the validation and convergence studies. The CQUAD8 element is employed for the remaining part of the studies. The fundamental frequencies are found to increase with the panel angle and skew angle. When the number of layers in the laminate is large, the variation of the fundamental frequency with the number of layers is not appreciable. The boundary conditions are found to have a significant influence on the fundamental frequency.
Źródło:
International Journal of Applied Mechanics and Engineering; 2014, 19, 1; 165-180
1734-4492
2353-9003
Pojawia się w:
International Journal of Applied Mechanics and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of positions of the geotextile on the load-settlement behaviour of circular footing resting on single stone column by 2D Plaxis software
Autorzy:
Yadav, J. S.
Kumar, K.
Dutta, R. K.
Garg, A.
Powiązania:
https://bibliotekanauki.pl/articles/2055761.pdf
Data publikacji:
2021
Wydawca:
Stowarzyszenie Komputerowej Nauki o Materiałach i Inżynierii Powierzchni w Gliwicach
Tematy:
clay bed
circular footing
stone column
geotextile
numerical analysis
kolumny kamienne
geotkanina
analiza numeryczna
Opis:
Purpose: This study aims to study the load – settlement behaviour of circular footing rested on encased single stone column. Design/methodology/approach: The effect of vertical, horizontal and combined verticalhorizontal encasement of stone column on the load carrying capacity were examined numerically. The effect of stone column dimension (80 mm and 100 mm), length (400 mm and 500 mm), and spacing of reinforcement on the load carrying capacity and reinforcement ratio were assessed. Findings: The obtained results revealed that the load carrying capacity of geotextile encased stone columns are more than ordinary stone columns. For vertically encased stone columns as the diameter increases, the advantage of encasement decreases. Whereas, for horizontally encased stone column and combined vertical- horizontal encased stone column, the performance of encasement intensifies as the diameter of stone column increases. The improvement in the load carrying capacity of clay bed reinforced with combined verticalhorizontal encased stone columns are higher than vertical encased stone columns or horizontal encased stone column. The maximum performance of encasement was observed for VHESC1 of D = 80 mm. Research limitations/implications: For this study, the diameter of footing and stone column was kept same. The interface strength factor between stone column and clay bed was not considered. Practical implications: The encased stone column could be use improve the laod bearing capacity of weak soils. Originality/value: Many studies are available in literature regarding use of geosynthetic as vertical encasement and horizontal encasement of stone column. The study on combined effect of vertical and horizontal encasement of stone column on load carrying capacity of weak soil is very minimal. Keeping this in view, the present work was carried out.
Źródło:
Journal of Achievements in Materials and Manufacturing Engineering; 2021, 107, 2; 75--85
1734-8412
Pojawia się w:
Journal of Achievements in Materials and Manufacturing Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Big Data Mining Approach For Finding Top Rated URL
Autorzy:
Shyam Mohan, J. S.
Shanmugapriya, P.
Kumar, Bhamidipati Vinay Pawan
Powiązania:
https://bibliotekanauki.pl/articles/108631.pdf
Data publikacji:
2015
Wydawca:
Społeczna Akademia Nauk w Łodzi
Tematy:
big data
data mining
Opis:
Finding out the widely used URL’s from online shopping sites for any particular category is a difficult task as there are many heterogeneous and multi-dimensional data set which depends on various factors. Traditional data mining methods are limited to homogenous data source, so they fail to sufficiently consider the characteristics of heterogeneous data. This paper presents a consistent Big Data mining search which performs analytics on text data to find the top rated URL’s. Though many heuristic search methods are available, our proposed method solves the problem of searching compared with traditional methods in data mining. The sample results are obtained in optimal time and are compared with other methods which is effective and efficient.
Źródło:
Journal of Applied Computer Science Methods; 2015, 7 No. 1; 17-32
1689-9636
Pojawia się w:
Journal of Applied Computer Science Methods
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Characterization of weld fusion zone for TIG welded P91and P92 steels
Autorzy:
Pandey, C.
Mahapatra, M. M.
Kumar, P.
Thakare, J. G.
Powiązania:
https://bibliotekanauki.pl/articles/353653.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
P91
P92
fusion zone
microstructure
TIG
Opis:
The welding of nuclear grade P91 and P92 steel plate of thickness 5.2 mm were performed using the autogenous tungsten inert gas (TIG) welding process. The welded joint of P91 and P92 steel plate were subjected to the varying post weld heat-treatment (PWHT) including the post weld heat treatment (PWHT) and re-austenitizing based tempering (PWNT). A comparative study was performed related to the microstructure evolution in fusion zone (FZ) of both the welded joint using the scanning electron microscope and optical microscope in a different condition of heat treatment. The hardness test of the FZ for both joints was also conducted in a different condition of heat treatment. P92 steel welded joint have observed the higher tendency of the δ ferrite formation that led to the great variation in hardness of the P92 FZ. The homogeneous microstructure (absence of δ ferrite) and acceptable hardness was observed after the PWNT treatment for both the welded joint.
Źródło:
Archives of Metallurgy and Materials; 2018, 63, 4; 1755-1761
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experimental and finite element studies on free vibration of skew plates
Autorzy:
Srinivasa, C. V.
Suresh, Y. J.
Prema Kumar, W. P.
Powiązania:
https://bibliotekanauki.pl/articles/955136.pdf
Data publikacji:
2014
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
laminat
analiza elementów skończonych
płyta kompozytowa
częstotliwość drgań
skew plates
antisymmetric laminates
free vibration
experimental method
finite element analysis
Opis:
The present paper deals with the experimental studies carried out on free vibration of isotropic and laminated composite skew plates. The natural frequencies were also determined using QUAD8 finite element of MSC/NASTRAN and a comparison was made between the experimental values and the finite element solution. The effects of the skew angle and aspect ratio on the natural frequencies of isotropic skew plates were studied. The effects of the skew angle, aspect ratio, fiber orientation angle and laminate sequence (keeping the number of layers constant) on the natural frequencies of antisymmetric composite laminates were also studied. The experimental values of natural frequencies are in good agreement with the FE solutions. The natural frequencies are found to increase with an increase in the skew angle. The variation of natural frequencies with the aspect ratio is small and negligible both for isotropic and laminated composite skew plates.
Źródło:
International Journal of Applied Mechanics and Engineering; 2014, 19, 2; 365-377
1734-4492
2353-9003
Pojawia się w:
International Journal of Applied Mechanics and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Luminescent Macrocyclic Lanthanide Complexes Bearing N-Oxides: Potential Fluorescent Labels for Modern Medical Diagnostics
Autorzy:
Pietraszkiewicz, M.
Karpiuk, J.
Gąsiorowski, R.
Pietraszkiewicz, O.
Rout, Ashok Kumar
Powiązania:
https://bibliotekanauki.pl/articles/1945551.pdf
Data publikacji:
1996-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
33.50.Dq
78.55.Kz
82.50.Fv
Opis:
Macrocyclic and macropolycyclic ligands incorporating heteroaromatic N-oxides (3,3'-biisoquinoline-2,2'-dioxide) form strongly luminescent complexes with lanthanide ions: Eu(III) and Tb(III). Most of these complexes are stable water solutions, with excellent luminescent properties, regarding luminescence lifetimes in the range of 0.2-0.7 ms, and the quantum yields for emission up to 0.25. Several complexes are stable also in the presence of affecting ions, such as Ca(II), or phosphates. These features make them attractive as potential fluorescent labels for time-resolved fluoroimmunoassays.
Źródło:
Acta Physica Polonica A; 1996, 90, 1; 207-213
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Parameter Characterization in Processing of Silver - Aluminum Based Electrical Contact Materials
Autorzy:
Praveen Kumar, S.
Parameshwaran, R.
Ananthi, A.
Jenil Jaba Sam, J.
Powiązania:
https://bibliotekanauki.pl/articles/352711.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
electrical contactor
silver
aluminum
tin oxide
conduction
Opis:
An electrical contractor is one which plays significant role in day todays life in industries as well as in home appliances. In current scenario the materials for conducting purpose has an overwhelming research capability. Now a day the silver based electrical contact composite material have provided the potential applications in aerospace and automobile industries. Among silver based contact material the silver cadmium oxide and silver tin oxide plays a vital role in fabrication of electrical contactors. In this research an attempt has been made to study the influence of adding Aluminum with silver based electrical contact composite materials by two different processing routes namely stir-casting and powder metallurgy. Silver and aluminum matrix plays a virtual role in composite world owing to their highest conductivity. Optimum parameters were identified for attaining the maximum properties such as conductivity, hardness, density, and porosity of composition. By this better conducting property and mechanical property of the electrical contact can be improved by this system. Thus a screening test has be conducted with addition of Al with silver tin oxide compositions hence this paper aims to process the aluminum – silver based electrical contact materials by stir casting processing and powder metallurgy route and compare the results obtained.
Źródło:
Archives of Metallurgy and Materials; 2017, 62, 3; 1895-1901
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An unsteady flow and melting heat transfer of a nanofluid over a stretching sheet embedded in a porous medium
Autorzy:
Kumar, K. G.
Gireesha, B. J.
Rudraswamy, N. G.
Krishnamurthy, M. R.
Powiązania:
https://bibliotekanauki.pl/articles/947337.pdf
Data publikacji:
2019
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
efekt topnienia
reakcja chemiczna
podłoże porowate
przepływ niestabilny
melting effect
chemical reaction
nanofluid
porous medium
stretching sheet
unsteady flow
Opis:
An unsteady flow and melting heat transfer of a nanofluid over a stretching sheet was numerically studied by considering the effect of chemical reaction and thermal radiation. The governing non-linear partial differential equations describing the flow problem are reduced to a system of non-linear ordinary differential equations using the similarity transformations and solved numerically using the Runge–Kutta–Fehlberg fourth–fifth order method. Numerical results for concentration, temperature and velocity profiles are shown graphically and discussed for different physical parameters. Effect of pertinent parameters on momentum, temperature and concentration profiles along with local Sherwood number, local skin-friction coefficient and local Nusselt number are well tabulated and discussed.
Źródło:
International Journal of Applied Mechanics and Engineering; 2019, 24, 2; 245-258
1734-4492
2353-9003
Pojawia się w:
International Journal of Applied Mechanics and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of Substrate Temperature on the Structural and Optical Properties of Nanocrystalline Cadmium Selenide Thin Films Prepared by Electron Beam Evaporation Technique
Autorzy:
Suthan Kissinger, N.
Suthagar, J.
Saravana Kumar, B.
Balasubramaniam, T.
Perumal, K.
Powiązania:
https://bibliotekanauki.pl/articles/1535702.pdf
Data publikacji:
2010-10
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
68.37.Hk
81.05.Dz
Opis:
Cadmium selenide (CdSe) thin films on glass substrates were prepared by physical vapour deposition under vacuum using the electron beam evaporated technique for different substrate temperatures: room temperature, 100, 200, 300°C, respectively. X-ray diffraction analysis indicates that the films are polycrystalline, having hexagonal (wurtzite) structure irrespective of their substrate temperature. All the films show most preferred orientation along (0 0 2) plane parallel to the substrates. The microstructural parameters such as particle size, stress, strain and dislocation density were calculated. The grain size of deposited CdSe films is small and is within the range of 18 to 42 nm. The optical absorption spectra of electrom beam deposited CdSe films were studied in the wavelength region of 250-2500 nm. The energy gap $(E_{g})$ values (allowed direct transitions), calculated from the absorption spectra, ranged between 1.77 and 1.92 eV. The surface morphological quality of electron beam evaporated CdSe films were analyzed by scanning electron microscopy and atomic force microscopy.
Źródło:
Acta Physica Polonica A; 2010, 118, 4; 623-628
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Antidepressant activity of ethanolic extract of oleo gum resins of Ferula asafoetida Linn
Autorzy:
Kumar, T. Bharath
Reddy, V. Jayasankar
Rushendran, R.
Mamatha, T.
Roja, J.
Roopavani, T.
Powiązania:
https://bibliotekanauki.pl/articles/972623.pdf
Data publikacji:
2017
Wydawca:
Instytut Medycyny Wsi
Tematy:
antidepressant activity
models of depression
brain monoamines
antioxidant activity
Ferula asafoetida
Opis:
Objective. The study was undertaken to evaluate the antidepressant activity of ethanolic extract of Ferula asafoetida oleo gum resins. Materials and Methods. Five groups of rats (180–200g) and mice (20–30g) of both genders, each group comprising six animals, were used (i.e., normal, positive control, standard, FAEE 200mg/kg, and FAEE 400mg/kg treated groups). Forced swimming test (FST), Tail suspension test (TST), Potentiation of Norepinephrine-Induced Toxicity (PNEIT), Haloperidol- Induced Catalepsy (HIC), and Reserpine-Induced Hypothermia (RIH), were used as the validate models of depression in rodents. The study was confirmed by brain monoamines estimation (i.e. Dopamine, Norepinephrine and 5-HT), MAO levels and invivo antioxidant studies (CAT and SOD). Results. FAEE treated animals showed a significant and dose dependent effect on a decrease in immobility time in FST, TST, and decrease in catalepsy time in HIC. FAEE and imipramine (15mg/kg) showed a significant increase in body temperature in RIH, and also showed a potent lethality in PNEIT. FAEE treated animals showed a significant increase in the levels of brain monoamines, in vivo antioxidants, and a significant decrease in MAO levels. Conclusion. Results of present study indicate that FAEE has potent antidepressant-like activity, and this effect may be due to the anti-oxidant property of Ferulic acid and umbelliferone, or may be due to neuroprotective activity of other major phytoconstituents, e.g. flavonoids, phenolic acids and polysulfide compounds. To identify the particular compound responsible for the antidepressant-like activity required further molecular level studies.
Źródło:
Journal of Pre-Clinical and Clinical Research; 2017, 11, 1; 50-60
1898-2395
Pojawia się w:
Journal of Pre-Clinical and Clinical Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Spatio-temporal variations in sulfur-oxidizing and sulfate-reducing bacterial activities during upwelling, off South-West coast of India
Autorzy:
Kamaleson, A.S.
Gonsalves, M.-J.
Kumar, S.
Jineesh, V.K.
LokaBharathi, P.A.
Powiązania:
https://bibliotekanauki.pl/articles/47551.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
spatio-temporal variability
sulphate reduction
sulphur oxidation
bacterial activity
microbial degradation
environment parameter
upwelling
Arabian Sea
India
coastal water
Źródło:
Oceanologia; 2019, 61, 4
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Biological degradation of metribuzin and profenofos by some efficient bacterial isolates
Autorzy:
Tamilselvan, C.
Joseph, S.J.
Mugunthan, G.
Sathish Kumar, A.
Syed Musthaq Ahamed, S.
Powiązania:
https://bibliotekanauki.pl/articles/11692.pdf
Data publikacji:
2014
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
biological degradation
metribuzin
profenofos
bacterial isolate
Pseudomonas aeruginosa
Staphylococcus aureus
Bacillus subtilis
Opis:
The soil sample was collected from the paddy field of Sriperumbudur, Tamilnadu which is having a history of repeated pesticide applications. The isolation of efficient pesticide degrading bacteria was identified as Pseudomonas aeruginosa, Staphylococcus aureus and Bacillus subtilis. The growth of the three pesticide degrading isolates was assessed in Minimal salt broth containing 25 ppm of pesticides. Two popularly used pesticides Metribuzin and Profenofos were selected for this study. Among the three bacterial isolates, the bacteria Bacillus subtilis utilized the pesticides effectively and showed maximum growth. The growth of the three pesticides degrading isolates Pseudomonas aeruginosa, Staphylococcus aureus and Bacillus subtilis was assessed in Minimal salt broth containing 25 ppm of pesticides at different temperature levels (25 °C, 30 °C, 35 °C, 40 °C, 45 °C, 50 °C & 55 °C) and pH levels (pH 4, pH 5, pH 6, pH 7 & pH 8) and carbon sources (Lactose, Dextrose, Fructose, Mannose & Galactose) and nitrogen sources Peptone, Yeast extract, Beef extract, Malt extract and Casein respectively. The maximum growth rate of bacteria was recorded at 35 °C and pH 6. The maximum growth of bacteria was in the presence of Dextrose followed by Fructose, Galactose and Mannose. The least growth was recorded in Lactose broth culture. The maximum growth of bacteria was in the presence of Malt extract followed by Peptone, Yeast extract and Casein. The least growth was recorded in Beef extract broth culture. The bacterial isolates showed maximum growth in the Minimal salt broth containing Profenofos followed by Metribuzin.
Źródło:
International Letters of Natural Sciences; 2014, 09
2300-9675
Pojawia się w:
International Letters of Natural Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Construction of the nest of Amazilia rutila De Lattre (Trochillidae) and its anti-predatory defensive strategy in a medium deciduous forest in Campeche, Mexico
Autorzy:
López-Castilla, Héctor M.J.
Ríos-Oviedo, Ángel
Cetzal-Ix, William
Basu, Saikat Kumar
Powiązania:
https://bibliotekanauki.pl/articles/2176775.pdf
Data publikacji:
2019-12-31
Wydawca:
Uniwersytet Pedagogiczny im. Komisji Edukacji Narodowej w Krakowie
Tematy:
Asclepias curassavica
Cnidoscolus aconitifolius
hummingbird
Mangifera indica
Yucatan peninsula
koliber
Półwysep Jukatan
Opis:
The Yucatan peninsula (YP) is part of a biogeographical area characterised by its diversity of flora and fauna, among which are the birds, mainly hummingbirds, which are indicators of the state of conservation of the ecosystems. In birds, the site establishment and construction of nest plays a fundamental role for reproduction and survival rate, the selection of materials occurs opportunistically, but birds tend to use fresh leaves of plants with antimicrobial properties or that allow the depletion of ectoparasites in their nests. In this sense, for the first time we recorded for the cinnamon hummingbird (Amazilia rutila De Lattre), the materials used for the construction of its nest and the site of establishment of the nest in the host plants in two sites of a medium sub-deciduous forest in, Mexico. We recorded the construction of nests of A. rutila in two locations in Campeche; in the first site the nest was found in a chaya bush Cnidoscolus aconitifolius (Mill.) I.M. Johnst. (Euphorbiaceae); most possibly as an anti-predatory strategy for trichomes in the form of sharp hairs and spines that the plants possess in their stems and leaves. In the second site, the nest was found in a mango tree Mangifera indica L. (Anacardiaceae). The main vegetative material identified for the construction of the nests in both locations, were made from pappus (thin and cottony filament that possess the seeds for the dispersion) from Asclepias curassavica L. (Apocynaceae).
Półwysep Jukatan (YP) jest częścią obszaru biogeograficznego charakteryzującego się różnorodnością flory i fauny. Wśród fauny licznie występują ptaki, głównie kolibry, będące wskaźnikami stanu zachowania ekosystemów. Dla ptaków zakładanie i budowa gniazda odgrywa podstawową rolę w rozmnażaniu i przeżywalności. Wybór materiałów na gniazda odbywa się oportunistycznie, ale ptaki zwykle używają świeżych liści, o właściwościach rzeciwdrobnoustrojowych lub pozwalających na odstraszenie pasożytów zewnętrznych z ich gniazd. W tym kontekście, dla kolibra cynamonowego (Amazilia rutila De Lattre) po raz pierwszy opisaliśmy materiały użyte do budowy gniazda oraz miejsce założenia gniazda w roślinach żywicielskich, w dwóch lokalizacjach lasu liściastego w Meksyku. Obserwowaliśmy budowę gniazd A. rutila w dwóch lokalizacjach w Campeche. W pierwszym miejscu gniazdo znaleziono w zaroślach Chaya Cnidoscolus aconitifolius (Mill.) I.M. Johnst. (Euphorbiaceae); ostre włoski i kolce, które mają rośliny z tego rodzaju na swoich łodygach i liściach, najprawdopodobniej występują tu jako anty-drapieżna strategia dla włosieni. W drugim miejscu gniazdo znaleziono na drzewie mango Mangifera indica L. (Anacardiaceae). Główny materiał roślinny zidentyfikowany do budowy gniazd w obu lokalizacjach został wykonany z puchu – pappus (cienkiego i bawełnianego filamentu służącego do dyspersji nasion) z Asclepias curassavica L. (Apocynaceae).
Źródło:
Annales Universitatis Paedagogicae Cracoviensis Studia Naturae; 2019, 4; 67-77
2543-8832
2545-0999
Pojawia się w:
Annales Universitatis Paedagogicae Cracoviensis Studia Naturae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Evaluation of anti-fibrotic activity of ethanolic extract of Nelumbo nucifera gaertn. Seed against doxorubicin and unilateral ureter obstruction-induced renal fibrosis
Autorzy:
Rushendran, R.
Jayasankar Reddy, V.
Bharath Kumar, T.
Mamatha, T.
Roja, J.
Roopavani, T.
Powiązania:
https://bibliotekanauki.pl/articles/972628.pdf
Data publikacji:
2017
Wydawca:
Instytut Medycyny Wsi
Tematy:
renal fibrosis
anti-fibrosis
nelumbo nucifera
pirfenidone
kidney
Opis:
Objective. The study were undertaken to evaluate anti-fibrotic activity of ethanolic extract of Nelumbo nucifera seed (NNSEE) against doxorubicin and Unilateral Ureter Obstruction-induced renal fibrosis. Materials and method. Animals were divided into five groups with six animals in each group, i.e. Normal, Positive control, Standard (Pirfenidone 200mg/kg), Test-I (NNSEE 200mg/kg), and Test-II (NNSEE 400mg/kg). Renal fibrosis was developed by doxorubicin and UUO-induced methods. After induction of renal fibrosis, profibrotic responses in biochemical parameters were observed, e.g. BUN, serum creatinine levels were elevated, while total protein and GFR levels decreased. Antioxidant (SOD and CAT) levels are also attenuates and hyalinized glomeruli cells, damage to tubular cells were noted in histopathology, which are all responsible for the development of renal fibrosis. Results. The result showed that the anti-fibrotic activity of NNSEE at a dose of 200 and 400mg/kg b.wt was comparable with the standard treatment 200mg/kg b.wt of pirfenidone (anti-fibrotic drug). These data supplemented with histopathological studies of rat kidney sections. NNSEE had reversed all the manifestation of renal fibrosis. Conclusion. Results of the study indicate that the NNSEE has potent anti-fibrotic activity, as well as antioxidant property, in dose dependent manner that may be due to the presence of major phytochemical constituents such as alkaloids, polyphenols.
Źródło:
Journal of Pre-Clinical and Clinical Research; 2017, 11, 1; 66-75
1898-2395
Pojawia się w:
Journal of Pre-Clinical and Clinical Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Particle-inflow-gun-mediated genetic transformation of buffel grass [Cenchrus ciliaris L.]: optimizing biological and physical parameters
Autorzy:
Bhat, V
Dalton, S.J.
Kumar, S.
Bhat, B.V.
Gupta, M.G.
Morris, P.
Powiązania:
https://bibliotekanauki.pl/articles/2048302.pdf
Data publikacji:
2001
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
buffel grass
promoter
genetic transformation
physical parameter
Cenchrus ciliaris
biological parameter
grass
biotechnology
Źródło:
Journal of Applied Genetics; 2001, 42, 4; 405-412
1234-1983
Pojawia się w:
Journal of Applied Genetics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Occupational health and metabolic risk factors: A pilot intervention for transport workers
Autorzy:
Naug, Helen L.
Colson, Natalie J.
Kundur, Avinash
Santha Kumar, Abishek
Tucakovic, Lada
Roberts, Michael
Singh, Indu
Powiązania:
https://bibliotekanauki.pl/articles/2177422.pdf
Data publikacji:
2016-05-05
Wydawca:
Instytut Medycyny Pracy im. prof. dra Jerzego Nofera w Łodzi
Tematy:
obesity
transport workers
lifestyle education
education interventions
sedentary behavior
metabolic risk
Opis:
Objectives Heavy vehicle transport workers have a high risk of obesity and obesity-related disorders including cardiovascular disease and diabetes. Sedentary nature of their work makes a healthy work and lifestyle balance difficult to achieve. Educational interventions that promote behavioral changes have been shown to be effective in various group settings. The aims of this study were to determine the prevalence of metabolic risk factors among a population of urban bus drivers; to deliver a 3-month educational intervention specifically tailored for the workplace environment of transport workers; and to evaluate the efficacy of the intervention through quantitative measurements and qualitative feedback. Material and Methods Thirty-three bus drivers from depots in south Queensland were recruited for the study. Baseline metabolic data were collected through anthropometric measurements, blood collection and diet/lifestyle questionnaires. Metabolic risk factors that were analyzed included: waist circumference, blood pressure, fasting glucose, blood triglycerides and high density lipoprotein cholesterol (HDL-C). Three interactive seminars were delivered over a 3-month period. At the end of the period, data collection was repeated. Results At the commencement of the study, 35% of the participants exhibited ≥ 3 of the metabolic risk factors that characterize metabolic syndrome. This is higher than the reported prevalence in the general Australian population (22.1%). A total 21 of the 33 participants remained committed to the intervention and provided pre and post intervention data. Of these, 28% (N = 6) showed a decrease in one or more of the risk factors associated with metabolic syndrome. There was a significant increase in the average HDL-C after the intervention. Qualitative feedback indicated that the workers benefited from the program, especially regarding their awareness of the risks associated with their profession. Conclusions This pilot study demonstrates that lifestyle education seminars specifically tailored for the workplace can have an impact on the health behaviors of transport workers.
Źródło:
International Journal of Occupational Medicine and Environmental Health; 2016, 29, 4; 573-584
1232-1087
1896-494X
Pojawia się w:
International Journal of Occupational Medicine and Environmental Health
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Applicability of artificial intelligence in smart healthcare systems for automatic detection of Parkinson’s Disease
Autorzy:
Pallathadka, Harikumar
Padminivalli V., S.J.R.K.
Vasavi, M.
Nancy, P.
Naved, Mohd
Kumar, Harish
Ray, Samrat
Powiązania:
https://bibliotekanauki.pl/articles/38709253.pdf
Data publikacji:
2024
Wydawca:
Instytut Podstawowych Problemów Techniki PAN
Tematy:
Parkinson’s disease
detection
machine learning
relief algorithm
LDA algorithm
SVM-RBF
accuracy
sensitivity
specificity
choroba Parkinsona
wykrywanie
nauczanie maszynowe
algorytm ulgi
Algorytm LDA
dokładność
wrażliwość
specyficzność
Opis:
Parkinson’s disease is associated with memory loss, anxiety, and depression in the brain. Problems such as poor balance and difficulty during walking can be observed in addition to symptoms of impaired posture and rigidity. The field dedicated to making computers capable of learning autonomously, without having to be explicitly programmed, is known as machine learning. An approach to the diagnosis of Parkinson’s disease, which is based on artificial intelligence, is discussed in this article. The input for this system is provided through photographic examples of Parkinson’s disease patient handwriting. Received photos are preprocessed using the relief feature option to begin the process. This is helpful in the process of selecting characteristics for the identification of Parkinson’s disease. After that, the linear discriminant analysis (LDA) algorithm is employed to reduce the dimensions, bringing down the total number of dimensions that are present in the input data. The photos are then classified via radial basis function-support vector machine (SVM-RBF), k-nearest neighbors (KNN), and naive Bayes algorithms, respectively.
Źródło:
Computer Assisted Methods in Engineering and Science; 2024, 31, 2; 175-185
2299-3649
Pojawia się w:
Computer Assisted Methods in Engineering and Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Satellite estimates of the long-term trend in phytoplankton size classes in the coastal waters of North-Western Bay of Bengal
Autorzy:
Miranda, J.
Lotliker, A.A.
Baliareingh, S.K.
Jena, A.K.
Samanta, A.
Sahu, K.C.
Kumar, T.S.
Powiązania:
https://bibliotekanauki.pl/articles/2079007.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
phytoplankton
size class
coastal water
long-term variability
satellite data
statistical analysis
Bengal Bay
Opis:
The study presents long-term variability in satellite retrieved phytoplankton size classes (PSC) at two coastal sites, off Gopalpur and Visakhapatnam, in the north-western Bay of Bengal. The abundance-based models by Brewin et al. (2010) (B10) and Sahay et al. (2017) (S17), for retrieval of PSC (micro, nano, and picophytoplankton), from satellite data, were validated. Both the models performed well in the retrieval of nano and microphytoplankton. However, B10 performed poorly in retrieving picophytoplankton. The statistical analysis indicated better performance of the S17 model and hence was applied to Moderate Resolution Imaging Spectroradiometer onboard Aqua satellite (MODISA) data to understand the temporal (at monthly climatology) and spatial variability (from nearshore to offshore). The spatial distribution indicated nearshore dominance of micro and offshore dominance of picophytoplankton. In nearshore waters off Gopalpur, microphytoplankton dominated throughout the year except for months of south-west monsoon (June and July) where the dominance of picophytoplankton was observed. All PSC exhibited similar distribution at an annual scale with a primary peak during pre-monsoon (March and April) and a secondary peak during post-monsoon (September— November). However, microphytoplankton concentration during post-monsoon was higher off Gopalpur in comparison to Visakhapatnam. The higher microphytoplankton concentration during pre-monsoon was attributed to recurrent phytoplankton blooms. Whereas, post-monsoon increment could be attributed to enhanced phytoplankton growth by availing nutrients sourced from monsoonal precipitation induced terrigenous influx. The outcome of the present study recommends the use of the S17 model for satellite retrieval of PSC from the north-western Bay of Bengal.
Źródło:
Oceanologia; 2021, 63, 1; 40-50
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Radiotracer investigation of a pulp and paper mill effl uent treatment plant
Autorzy:
Sarkar, M.
Sangal, V. K.
Bhunia, H.
Bajpai, P. K.
Pant, H. J.
Sharma, V. K.
Kumar, A.
Naithani, A. K.
Powiązania:
https://bibliotekanauki.pl/articles/147197.pdf
Data publikacji:
2017
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
aeration tank
secondary clarifier
residence time distributions
RTD
radiotracer
convolution
Opis:
The pulp and paper industry is highly dependent on water for most of its processes, producing a significant amount of wastewater that should be treated to comply with environmental standards before its discharge into surface-water reservoirs. The wastewater generated primarily consists of substantial amounts of organic, inorganic, toxic and pathogenic compounds in addition to nutrients, which are treated in an effluent treatment plant that often combines primary, secondary, tertiary and advanced treatments. However, the treatment methods vary from industry to industry according to the process utilized. The effective performance of effluent treatment plants is crucial from both environmental and economic points of view. Radiotracer techniques can be effectively used to optimize performance and detect anomalies like dead zones, bypassing, channelling, etc. in wastewater treatment plants. Experiments on the distribution of residence time were performed on the aeration tank and secondary clarifier of a full-scale pulp and paper mill to study the flow behaviour as well as locate system anomalies and hence evaluate the performance of the treatment plants using the radiotracer I-131. The convolution method was applied to model the system with an imperfect impulse radiotracer input. The aeration tank was working efficiently in the absence of any dead zones or bypassing. Various hydrodynamic models available in the literature were applied on the aeration tank and secondary clarifier to obtain the hydraulic representation of the systems.
Źródło:
Nukleonika; 2017, 62, 4; 289-294
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Generation of shock waves in dense plasmas by high-intensity laser pulses
Autorzy:
Pasley, J.
Bush, I. A.
Robinson, A. P. L.
Rajeev, P. P.
Mondal, S.
Lad, A. D.
Ahmed, S.
Narayanan, V.
Ravindra Kumar, D
Kingham, R. J.
Powiązania:
https://bibliotekanauki.pl/articles/147346.pdf
Data publikacji:
2015
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
shock waves
radiation hydrodynamics
laser–plasma interactions
fast ignition
inertial confinement fusion
Doppler spectroscopy
Opis:
When intense short-pulse laser beams (I > 1022 W/m2, τ < 20 ps) interact with high density plasmas, strong shock waves are launched. These shock waves may be generated by a range of processes, and the relative significance of the various mechanisms driving the formation of these shock waves is not well understood. It is challenging to obtain experimental data on shock waves near the focus of such intense laser–plasma interactions. The hydrodynamics of such interactions is, however, of great importance to fast ignition based inertial confinement fusion schemes as it places limits upon the time available for depositing energy in the compressed fuel, and thereby directly affects the laser requirements. In this manuscript we present the results of magnetohydrodynamic simulations showing the formation of shock waves under such conditions, driven by the j × B force and the thermal pressure gradient (where j is the current density and B the magnetic field strength). The time it takes for shock waves to form is evaluated over a wide range of material and current densities. It is shown that the formation of intense relativistic electron current driven shock waves and other related hydrodynamic phenomena may be expected over time scales of relevance to intense laser–plasma experiments and the fast ignition approach to inertial confi nement fusion. A newly emerging technique for studying such interactions is also discussed. This approach is based upon Doppler spectroscopy and offers promise for investigating early time shock wave hydrodynamics launched by intense laser pulses.
Źródło:
Nukleonika; 2015, 60, 2; 193-198
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł

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