Autor: Kumar, M. - Prolib Integro

Skocz do pozycji: 1.

Tytuł:: Modeling of experimental data for the adsorption of methyl orange from aqueous solution using a low cost activated carbon prepared from Prosopis juliflora
Autorzy:: Kumar, M.
Tamilarasan, R.
Tematy:: activated carbon
adsorption
isotherm
kinetics and methyl orange; Pokaż więcej
Wydawca:: Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Powiązania:: https://bibliotekanauki.pl/articles/778002.pdf Link otwiera się w nowym oknie
Opis:: This paper presents the feasibility for the removal of methyl orange (MO) dye from aqueous solution using an activated carbon prepared from Prosopis juliflora bark. Batch adsorption experiments were carried out as a function of pH, contact time, adsorbate concentration, adsorbent dosage and temperature. The commonly applicable isotherms namely Freundlich and Langmuir equations are used for the prediction of isotherm parameters. A comparison of linear least-square method and a trial-and-error non-linear method are examined in Freundlich and Langmuir (Four forms) isotherms. The nature of adsorption isotherm feasibility was evaluated with dimensionless separation factors (RL). The dynamics of adsorption process was analyzed with Lagergren’s Pseudo-first order and Pseudo-second order kinetic equations. Thermodynamic parameters like the change in enthalpy (ΔHo), change in entropy (ΔSo) and change in Gibbs free energy (ΔGo) were evaluated and ΔGo shows a negative value whereas ΔHo shows the positive value indicating that the adsorption process was spontaneous and endothermic in nature. The functional group characterization of the adsorbent was done using Fourier transform infrared spectroscopy (FTIR). The thermal stability of activated carbon was analyzed using Thermo gravimetric analysis (TGA) and Differential thermal analysis (DTA).
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 2.

Tytuł:: Color image encryption using singular value decomposition in discrete cosine Stockwell transform domain
Autorzy:: Vaish, A.
Kumar, M.
Tematy:: discrete cosine Stockwell transform
image encryption
singular value decomposition
mean square error
structural similarity index measurement; Pokaż więcej
Wydawca:: Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Powiązania:: https://bibliotekanauki.pl/articles/173700.pdf Link otwiera się w nowym oknie
Opis:: In this paper, an image encryption technique using singular value decomposition (SVD) and discrete cosine Stockwell transform (DCST) is proposed. The original source image is encrypted using bands of DCST along with the SVD decomposed images. The number of bands in DCST, parameters used to mask the singular values, the way of permutation used to shuffle the values of SVD transformed images and the way of arrangement of SVD matrices are used as encryption keys. It is necessary to have correct knowledge of all the keys along with their respective values, for correct decryption of encrypted images. The robustness and the quality measurement of proposed work are analyzed by comparing it with some existing works.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 3.

Tytuł:: Morphological characterization of biocontrol isolates of Trichoderma to study the correlation between morphological characters and biocontrol efficacy
Autorzy:: Kumar, M.
Sharma, P.
Wydawca:: Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Powiązania:: https://bibliotekanauki.pl/articles/11742.pdf Link otwiera się w nowym oknie
Opis:: The morphological characterization was carried out for 5 isolates of Trichoderma harzianum and 7 isolates of Trichoderma viride and tested for their biocontrol efficacy. The isolates belonging to T.harzianum were analogous in colony colour, culture smell, mycelial colour, conidiation, conidial shape, conidial wall and conidial colour. Correspondingly the isolates of T.viride showed certain similarity in colony colour, colony edge, culture smell, conidiophore branching, conidial wall, conidial colour and chlamydospores. Inter specific differences through cluster analysis based on morphological characters grouped the twelve isolates into three major clusters where all the isolates of T.harzianum formed a single cluster while the isolates of T.viride were bifurcated into two groups. The clustering was substantiated by similarity index which showed maximum similarity among T.harzianum isolates with only less than 20% variation among themselves. Similarly the clusters having isolates of T.viride also had less variation within them. The biocontrol efficacy of these twelve isolates of Trichoderma was experimented by dual culture test under laboratory condition and there existed some relation between the biocontrol efficacy of these isolates and morphology.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 4.

Tytuł:: An analytical approach for transmission expansion planning with generation variations
Autorzy:: Kumar, M.
Kaur, R.
Tematy:: central electricity authority(CEA)
distributed generation (DG)
economic index (Ei)
power system operator (PSO)
power world simulator (PWS)
renewable energy sources (RES)
ransmission expansion planning (TEP); Pokaż więcej
Wydawca:: EEEIC International Barbara Leonowicz Szabłowska
Powiązania:: https://bibliotekanauki.pl/articles/136231.pdf Link otwiera się w nowym oknie
Opis:: Today, the transmission expansion planning for an existing power system under different constraints, is one of the major challenge for power engineers. There are several reasons; one of the reasons is rapid growth in load and inadequate capacity addition. Hence, it is important and essential to implement an algorithm for the transmission expansion which works well and have a good feasibility under certain assumptions and available constraints. Transmission expansion planning used in proposed paper works on an analytical algorithm which has been implemented for specific load condition with variations in generation. For that purpose, an economical factor has been measured that considers economical aspects of the line to be added for expansion. The prescribed analytical approach is also implemented for its feasibility check on a practical case study system.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 5.

Tytuł:: Effects of thermal radiation and heat generation on hydromagnetic flow of nanofluid over an exponentially stretching sheet in a porous medium with viscous dissipation
Autorzy:: Murugesan, Thiagarajan
Kumar, M. Dinesh
Tematy:: MHD
Nanofluid
exponentially stretching sheet
heat generation
porous medium
thermal radiation
viscous dissipation; Pokaż więcej
Wydawca:: Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Powiązania:: https://bibliotekanauki.pl/articles/1059429.pdf Link otwiera się w nowym oknie
Opis:: This paper studies, the impacts of heat generation on MHD flow of radiative nanofluid over an exponentially stretching sheet in a porous medium with viscous dissipation are numerically analyzed. Two sorts of nanofluids, generated by solid nanoparticles with water such as alumina-water nanofluid and silver-water nanofluid were investigated. With the use of similarity transformations, to obtain a system of nonlinear ordinary differential equations. The resulting boundary value problem is solved numerically using the Nachtsheim-Swigert shooting technique scheme together with fourth-order Runge-Kutta integration method. Numerical results are obtained for the velocity, temperature distribution and concentration profiles for selected values of the governing physical parameters of combined magnetic interaction and porosity parameter, heat generation parameter, viscous dissipation parameter, thermal radiation parameter, solid volume fraction parameter, chemical reaction parameter and Lewis number are discussed. Quantities of engineering interest such as Skin friction coefficient, Nusselt number, and Sherwood number are also obtained numerically and are tabulated.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 6.

Tytuł:: Viscous dissipation and Joule heating effects on MHD flow of a Thermo-Solutal stratified nanofluid over an exponentially stretching sheet with radiation and heat generation/absorption
Autorzy:: Murugesan, Thiagarajan
Kumar, M. Dinesh
Tematy:: Nanofluid
double stratification
exponentially stretching sheet
heat generation/absorption
viscous-ohmic dissipation; Pokaż więcej
Wydawca:: Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Powiązania:: https://bibliotekanauki.pl/articles/1075514.pdf Link otwiera się w nowym oknie
Opis:: The present study is focused on the influence of viscous and joules dissipation on magnetohydrodynamic flow of a double-stratified nanofluid past an exponentially stretching sheet in the presence of thermal radiation and heat generation/absorption effects. The governing nonlinear partial differential equations are transformed into a system of nonlinear ordinary differential equations using similarity variables and then solved numerically for these equations is procured by employing the Nachtsheim-Swigert shooting technique scheme together with Runge-Kutta Fourth-Order method. A parametric analysis has been carried out to investigate the impacts of physical parameters taken in the problem. The pattern worked for the nanofluid transport equations unified the impacts of thermophoresis and Brownian motion. Numerical results are obtained for the velocity, temperature and concentration in the boundary layer region is studied in elaborate. The impact of physical interest such as local skin friction coefficient, local nusselt number, and local Sherwood number are also investigated numerically and are tabulated. It is remarked that Schmidt number and thermal stratification parameter decreases the dimensionless temperature, during the solutal stratification parameter decreases the dimensionless concentration.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 7.

Tytuł:: Optimisation of the Sublimation Textile Printing Process Using the Taguchi Method
Optymalizacja procesu druku sublimacyjnego na tekstyliach metodą Taguchi
Autorzy:: Kumar, Jeyaraman Anandha
Kumar, M. Senthil
Tematy:: knitted fabric
sublimation printing
experimental design
Taguchi design
water vapour resistance
dzianina
druk sublimacyjny
projekt eksperymentalny
projekt Taguchi
opór pary wodnej; Pokaż więcej
Wydawca:: Sieć Badawcza Łukasiewicz - Instytut Biopolimerów i Włókien Chemicznych
Powiązania:: https://bibliotekanauki.pl/articles/1419905.pdf Link otwiera się w nowym oknie
Opis:: In this paper, printing parameters for the sublimation printing of polyester fabrics like the number of strokes, the sublimation paper weight in grams per square metre, the fusing temperature and time were optimised using the Tauguchi experimental design technique. In the evaluations the signal-to-noise ratio was used. Sixteen experiments were performed with respect to the L 16 Orthogonal array design for the Tauguchi approach. The results show a considerable improvement in the signal-to-noise ratio as compared to the initial conditions. Through this study, not only can optimum printing conditions for sublimation printed polyester fabr ics be obtained but also the significant factors that affect water vapour resistance.
W pracy zoptymalizowano, przy użyciu eksperymentalnej techniki projektowania Tauguchi, parametry druku sublimacyjnego tkanin poliestrowych, takie jak: liczba pociągnięć, gramatura papieru sublimacyjnego w gramach na metr kwadratowy, temperatura i czas stapiania. W ocenach wykorzystano stosunek sygnału do szumu. Przeprowadzono 16 eksperymentów w odniesieniu do projektu macierzy ortogonalnej L 16 dla podejścia Tauguchi. Wyniki wskazały na znaczną poprawę stosunku sygnału do szumu w porównaniu z warunkami początkowymi. Dzięki zaprezentowanym badaniom można nie tylko uzyskać optymalne warunki drukowania na tkaninach poliestrowych drukowanych sublimacyjnie, ale także uwypuklić istotne czynniki wpływające na odporność na parę wodną.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 8.

Tytuł:: Study of Ni-20Cr coatings for high temperature applications - a review
Badania powłok Ni-20Cr do zastosowań wysokotemperaturowych - przegląd literatury
Autorzy:: Kumar, M.
Singh, H.
Singh, N.
Tematy:: hot corrosion
nickel-chromium coatings
surface engineering
boilers
korozja wysokotemperaturowa
powłoki niklowo-chromowe
inżynieria powierzchni
kotły; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:: https://bibliotekanauki.pl/articles/352736.pdf Link otwiera się w nowym oknie
Opis:: Hot corrosion is a serious problem in various high temperature applications. The thermal spray coatings provides possible solution to counter the problem of hot corrosion in high temperature environment and enhances the life of equipment. Ni-20Cr alloy compositions require long initiation time at which the hot corrosion process moves from the initiation stage to the propagation stage. In this review, the performance of Ni-Cr coatings by different investigators has been presented to understand the mechanism of hot corrosion under different environments.
Wysokotemperaturowa korozja jest poważnym problemem w zastosowaniach wysokotemperaturowych. Możliwym rozwiązaniem problemu korozji w warunkach wysokiej temperatury poprzez zwiększenie żywotności urządzeń jest zastosowanie termicznych powłok natryskowych. Stopy o składzie Ni-20Cr wymagają długiego czasu inicjacji, po którym proces korozji wysokotemperaturowej z etapu inicjacji przechodzi do etapu propagacji. W tym przeglądzie zostały zaprezentowane badania zachowania powłok niklowo-chromowych wykonane przez różnych badaczy, żeby zrozumieć mechanizm korozji wysokotemperaturowej w warunkach różnych środowisk.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 9.

Tytuł:: Mechanical & Thermal Properties of Epoxy Based Hybrid Composites Reinforced with Jute / Sansevieria cylindrica Fibres
Autorzy:: Kumar, M. A.
Reddy, G. R.
Tematy:: jute fiber
hybrid composites
mechanical properties
Sc fiber
thermal properties; Pokaż więcej
Wydawca:: Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Powiązania:: https://bibliotekanauki.pl/articles/411940.pdf Link otwiera się w nowym oknie
Opis:: Tensile properties are studied to assess the influence of fiber weight. Room temperature cured epoxy was impregnated with jute/Sc in order to evaluate the performance of hybrid composites. Jute/Sc fibers are taken in the 1:1 weight ratios to suspend on epoxy resin with different fiber lengths such as 1, 2, 3 and 4 cm. The variations of aforementioned properties on hybrid composites with different fiber lengths have been studied. Significant improvement in tensile strengths of the jute/Sc hybrid composites has been observed by the alkali treatments. Thermal properties such as TGA and DSC are studied to investigate the influence of change in fibre length on treated and untreated hybrid composites in which 4 °C rise in decomposition temperature, 3 °C rise for glass transition temperature respectively.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 10.

Tytuł:: Kernel function based regression approaches for estimating the oxygen transfer performance of plunging hollow jet aerator
Autorzy:: Kumar, M.
Tiwari, N. K.
Ranjan, S.
Tematy:: volumetric oxygen transfer coefficient
multiple nonlinear regression
Gaussian process regression
support vector regression
współczynnik wnikania tlenu
regresja nieliniowa
proces gaussowski
regresja wektora wsparcia; Pokaż więcej
Wydawca:: Stowarzyszenie Komputerowej Nauki o Materiałach i Inżynierii Powierzchni w Gliwicach
Powiązania:: https://bibliotekanauki.pl/articles/368684.pdf Link otwiera się w nowym oknie
Opis:: Purpose: To evaluate the capability of various kernels employed with support vector regression (SVR) and Gaussian process regression (GPR) techniques in estimating the volumetric oxygen transfer coefficient of plunging hollow jets. Design/methodology/approach: In this study, a data set of 81 observations is acquired from laboratory experiments of hollow jets plunging on the surface of water in the tank. The jet variables: jet velocity, jet thickness, jet length, and water depth are varied accordingly and the values of volumetric oxygen transfer coefficient is computed. An empirical relationship expressing the oxygenation performance of plunging hollow jet aerator in terms of jet variables is formulated using multiple nonlinear regression. The performance of this nonlinear relationship is compared with various kernel function based SVR and GPR models. Models developed with the training data set (51 observations) are checked on testing data set (24 observations) for performance comparison. Sensitivity analysis is carried out to examine the influence of jet variables in effecting the oxygen transfer capabilities of plunging hollow jet aerator. Findings: The overall comparison of kernels yielded good estimation performance of Radial Basis Function kernel (RBF) and Pearson VII Function kernel (PUK) using the SVR technique which is followed by nonlinear regression, and other kernel function based regression models. Research limitations/implications: The results of the study pertaining to the performance of kernels are based on the current experimental conditions and the estimation potential of the regression models may fluctuate beyond the selection of current data range due to datadependant learning of the soft computing models. Practical implications: Volumetric oxygen transfer coefficient of plunging hollow jets can be predicted precisely using SVR model by employing RBF as kernel function as compared to empirical correlation and other kernel function based regression models. Originality/value: The comparative analysis of kernel functions is conducted in this study. In previous studies, the predictive modelling approaches are implemented in simulating the aeration properties of cylindrical solid jets only, while this paper simulates the volumetric oxygen transfer coefficient of diverging hollow jets with the jet variables by utilizing polynomial, normalized polynomial, PUK, and RBF kernels in SVR and GPR.
Dostawca treści:: Biblioteka Nauki

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