Browsing by Author "R.K. Pandey"

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Application of light scattering for the determination of molecular parameters: Polystyrene balls
(2002) Ritesh Kumar Dubey; R.K. Pandey; D.N. Tripathi
Average molecular weight, radius of gyration and second virial coefficient have been determined for polystyrene balls using the static laser light scattering method. Reported results are quite reasonable and therefore, could be used to estimate other physical parameters for the sample.
Central composite design for the enzymatic detection of arsenic (III) in aqueous solution from vegetable -waste
(Springer Verlag, 2008) O. Prakash; M. Talat; S.H. Hasan; R.K. Pandey
Urease has been used for the quantitative estimation of As (III) in water. For the parametric optimization of this process Response Surface Methodology was used with the help of two-level-two-full factorial (22), Central Composite Design. Regression coefficient, regression equation and Analysis of Variance (ANOVA) was obtained using MINITAB® 15 software. Predicted values obtained were close to experimental value indicating suitability of model. The 3D Response Surface Plot and Isoresponse Contour Plot were helpful to predict the results by performing only limited set of experiments. Enzyme Urease was extracted from the discarded seeds of pumpkin. It was purified to apparent homogeneity (5.2 fold) by heat treatment at 48±0.1 °C and gel filtration through Sephadex G-200. Effect of As(III) on the activity of homogeneous enzyme preparation (Sp Activity 353 U/mg protein, A 280/A260 = 1.12) was investigated. Inhibition caused by As (III) was non-competitive, irreversible and biphasic. © 2008 Springer-Verlag.
Characterization and antioxidant property of cereal enriched bio-yoghurt
(Journal of Pure and Applied Microbiology, 2016) DIpti Rai; R.K. Pandey; Ajay Kumar Maurya; D.C. Rai; DIlip Kumar; Manju Tiwari
The study was designed to evaluate the effect of cereals viz. oats, sorghum and amaranth on the storage quality parameters of synbiotic yoghurt. The products were developed by incorporating optimum level of oats (3.0%), sorghum (1.0%), amaranth (1.6%) and oats (3.0%), separately and were aerobically packaged in low-density polyethylene cups and assessed for various storage quality parameters under refrigerated (4±1°C) conditions for 28 days of storage. The products were evaluated for various physicochemical, microbiological and sensory parameters at regular intervals of 0, 7, 14, 21 and 28 days. Microbial population (log cfu/g) of both Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus were in the same range in all yoghurt samples while cereals flour supplementation increased the count of Lactobacillus plantarum. The average pH of samples decreased from 4.5 to 4.3 during 28 days storage period. DPPHradical-scavenging activity (77.97%) in cereal enriched yoghurt (synbiotic yoghurt) was significantly higher than probiotic (71.4%) and control sample (57%). Total phenolic was highest in synbiotic yoghurt in comparison with other yoghurt samples during the entire storage period. Supplementation of cereal flour along with probiotic bacteria Lactobacillus plantarum thus improved the functionality of yoghurt.
Composition, surface morphology and structure of n-CdSe films prepared by repeated cycles of electrodeposition
(Kluwer Academic Publishers, 1991) R.K. Pandey; S.R. Kumar; A.J.N. Rooz; S. Chandra
A modified selective electrodeposition technique employing three cycles of deposition, annealing and in situ etching has been used to grow n-CdSe films. The results of our investigations on the composition, surface morphology and structure of the films are also discussed. In comparison to the CdSe films obtained by a single cycle of electrodeposition, it is shown that the repeated cycle of deposition yields a more regular and less porous film with larger grain sizes. © 1991 Chapman and Hall Ltd.
Effect of size and charge on ordering of a highly charged concentrated macroions in suspension
(Springer India, 1995) R.K. Pandey; D.N. Tripathi
An efficient fast Fourier transform method has been employed to determine correlation function [g(r*)] using the structure factor [S(Q*)] calculated with the rescaled mean spherical approximation (RMSA) and the DLVO potential. Based on this function a parametric (size and charge) study of the ordering in a highly charged and concentrated macroions (an ideal colloid) has been made. The strength of the correlation increases with the increase in the charge on macroions and it saturates after acertain value. Similarly, a critical diameter of the particle depending on the charge on it has been found at which normal feature of the ordering disappears. © 1995 the Indian Academy of Sciences.
Geochronology and geochemistry of pelitic granulite from the South Delhi Terrane of the Aravalli Delhi Mobile Belt, NW India: implications for petrogenesis and geodynamic model
(Cambridge University Press, 2023) M. Kumar; D. Prakash; C.K. Singh; S. Singh; R.K. Pandey; Pradip K. Singh; B. Mahanta
An attempt has been made to illustrate the evolution of pelitic granulite from south of the Balaram-Abu road, which lies in the South Delhi Terrane (SDT) of the Aravalli-Delhi Mobile Belt (ADMB), using geochemistry and geochronology. The current work offers a plausible explanation for the protolith of pelitic granulite, nature of the sediments and its provenance. The elemental geochemistry of the pelitic granulites reveals that the protolith is an arkosic to shaley type. The rare earth elements pattern shows that there is a negative Eu anomaly and a small excess of LREE over HREE. This means that the source of sediments probably has the same elements as the upper crust. However, the amounts of Sr, Nd and Pb vary a lot, which shows that the sediments supplied from two different types of sources (felsic and mafic) in different proportions from a Proterozoic terrain. The monazite geochronology indicates that the metamorphic overprint occurred between 797Ma and 906Ma. Additionally, the ages correlate to the debris that was formed between the 1188Ma and 1324Ma from magmatic/sedimentary sources for pelitic granulite. The present research provides a more in-depth understanding of the evolutionary history of the pelitic granulite that comprises the SDT in the ADMB region during the Proterozoic era. © 2023 The Author(s).
Grid stabilization with PMU signals - A survey
(Institute of Electrical and Electronics Engineers Inc., 2015) Deepak Kumar Gupta; R.K. Pandey
This paper presents critical survey along with the novel concept of smart power flow controller with Phasor Measurement Units (PMUs) signals for stability enhancement of a large power system. Also, the current status of Wide Area Measurement Systems (WAMS) and developments in real time applications of synchrophasor technology in power system has been adequately addressed. It has been noticed that with the help of synchrophasor technology, the system operators are now able to not only monitor and understand the transient/dynamic behaviour of the power system in real time at the control centres but also take quick restoration measures which was not possible in conventional SCADA system. PMUs deployment has shown encouraging results in recent contingencies, by way of assisting system operator with relatively better visualization, for Indian system. Thus, visibility of the network state at milliseconds level has enhanced the security, reliability and stability of the power system. This paper provides understanding of PMUs application and some novel research concept. © 2014 IEEE.
Handbook of semiconductor electrodeposition
(CRC Press, 2017) R.K. Pandey; S.N. Sahu; S. Chandra
Aiming to bridge the gap in understanding between professional electrochemists and hard-core semiconductor physicists and material scientists, this book examines the science and technology of semiconductor electrode-positioning. Summarizing state-of-the-art information concerning a wide variety of semiconductors, it reviews fundamental electrodeposition concepts and terminology. © 1996 by Taylor & Francis All Rights Reserved.
Large power network signature analysis with PMU signal-dynamic clustering approach
(Institute of Electrical and Electronics Engineers Inc., 2016) R.K. Pandey; Satish Kumar; Chandan Kumar
The paper presents signature analysis of large power network with Phasor Measurement Unit (PMU) signal using dynamic clustering approach. This concept may become more useful for system operators having large numbers of PMUs deployment in utility power network for observing the variations due to dynamical changes. It is well known as more numbers of PMUs are introduced in the network, there is an exponential increase in data which may require a special technique to understand the behaviour of entire system within time for generating quick control actions for system regulation. In present work, the concept of Clustering Algorithms (CA) to mine the synchrophasor data from PMUs has been applied with practical utility data (POWERGRID). Due to large data generated by PMUs, it becomes imperative to mine data so that important information from dataset can be utilized for monitoring of grid health followed by modified control in order to realize effective system operation. The procedure for extracting information from this data has been discussed through clustering algorithms. © 2015 IEEE.
Legendre Collocation Method for Generalized Fractional Advection Diffusion Equation
(CRC Press, 2023) Sandeep Kumar; R.K. Pandey
In this chapter, the collocation method is extended for a new class of fractional advection diffusion equation (GFADE). The GFADE is defined in terms of the generalized fractional derivatives(GFD) using scale and weight functions. The numerical solution of such GFADE is derived via a collocation method using Legendre polynomials. Convergence and error analysis of polynomial approximation are obtained. Numerical examples with homogeneous and nonhomogeneous boundary conditions are presented to confirm the theoretical findings. Through comparative study of the simulation results, we find that our proposed numerical method is simple, efficient and easy to implement. © 2023 Taylor & Francis Group, LLC.
MILK PRODUCTION PERFORMANCE AND ECONOMICS OF DAIRY FARMING IN EASTERN UTTAR PRADESH, INDIA
(Veterinary Practitioner, 2024) R.P. Yadav; R.K. Pandey; Ram Niwas
Milk production largely depends on various input components which incurred in production process. Various factors affect the milk production directly or indirectly. Milk yield is negatively correlated to low cost of production. Cost shows economic soundness of a dairy unit. Cost of milk production is analysed by cost incurred on various components as feed cost, labour cost, supervision cost and miscellaneous cost and relationship between these components and herd size of a unit. A study was conducted with collection and estimation of data of various cost components of producing milk at the Dairy farm, BHU, Varanasi. Results of studies found as gross cost Rs. 8.65/litre per day in which feed cost for a litre milk was estimated as 56% of total cost with green and dry roughages about 56% and 41.73% of total feed cost. A positive and highly significant (P < 0.01) correlation coefficient was observed between the number of animal head (x), SLU (X1) and total feed cost (r = 0.7255 and r=0.6335), respectively. The next higher cost was on labour as 23% per animal and 29% per SLU. Other components such as labour and maintenance cost were shown a positive relationship with number of animal head (x) and SLU(x1), respectively in the study. © 2024, Veterinary Practitioner. All rights reserved.
Modified-multi stage LQR (M-MSLQR)UPFC controller for inter-area oscillations damping-design and analysis
(Institute of Electrical and Electronics Engineers Inc., 2017) R.K. Pandey; Deepak Kumar Gupta
This paper presents analysis and design of modified-multi stage LQR (M-MSLQR) unified power flow controller (UPFC). A systematic analysis of M-MSLQR UPFC has been presented utilizing state space model developed in the generalized framework for two area system. An improved design concept is proposed as M-MSLQR UPFC over MSLQR which results in relatively low peak overshoot/undershoot and settling time of all states. The proposed controller considers state predominant approach with real part as well as the imaginary part of the eigenvalues of the system for the selection of Q matrix. This method gives fast tracking of all system state variables for a given perturbation. PSO is used for initial tuning of input control parameters of UPFC. The approach is modular and general enough to include any subsystem with detailed representation. The controller proposed can readily be extended to multi-area system with some augmentation including interface of system dynamics. The simulation result shows improved performance and may be used for better stability and reliability of power system. © 2016 IEEE.
Multi agent system driven SSSC for ATC enhancement
(Institute of Electrical and Electronics Engineers Inc., 2017) R.K. Pandey; K. Vamshi Kumar
This paper presents the performance evaluation of Multi Agent System (MAS) driven SSSC. The concept of ATC enhancement has been proposed with SSSC employing MAS which quickly re-establishes power flow over the existing transmission line with almost real time power control mode. Multi Agent System (MAS) works on soft signalling based distributed technology which is capable of solving complex problems by adding intellectual attributes. Interconnected transmission system line loading has to be maintained within the design limits irrespective of external conditions like heavy loading, and this is possible only if the excess load is shifted from one line to another. The redistribution of loading can be obtained by proper coordination among multiple controllers using agents which monitor, communicate and govern the control of power flow controllers (SSSC) to obtain desired loading under dynamic conditions. This operational mode enhances existing ATC values of other lines in the network. Power flow controllers when used in combination with MAS can be viewed as smart controller. The system has been simulated by modeling the system in Matlab Simulink. The multi-Agent system is implemented by using an open source agent building toolkit Java Agent Development framework (JADE). Both Matlab simulation and multi-Agent system are connected together via MACSimJX toolbox. © 2016 IEEE.
Novel mutations in calcium/calmodulin-dependent protein kinase IV (CAMK4) gene in infertile men
(2012) A. Khattri; V.P. Reddy; R.K. Pandey; D.V.S. Sudhakar; N.J. Gupta; B.N. Chakravarty; M. Deenadayal; L. Singh; K. Thangaraj
Calcium/calmodulin-dependent protein kinase IV (CAMK4) is a multifunctional serine/threonine protein kinase, which plays an important role in the spermatogenesis by phosphorylating protamines. It has been shown to be involved in the regulation of human sperm motility. Moreover, the Camk4 knockout mice were infertile because of severely reduced sperm count and morphological abnormalities. As no study is available on the association of this gene with male infertility, we analysed all the exons of CAMK4 gene in ethnically matched 283 infertile and 268 fertile Indian men. We identified twenty nucleotide substitutions, of which twelve were novel. Of these novel variants, eight were exclusively detected in infertile men. Moreover, two infertile men-specific mutations were non-synonymous replacing amino acids at the highly conserved region. In silico analysis predicted both of these mutations as 'deleterious'. In addition to nucleotide substitutions, we identified five novel insertion-deletion mutations; of these, g.150264_66delGCG was exclusively found in two oligoasthenoteratozoospermic men. In silico analysis of infertile men exclusive mutations predicted that they can alter/diminish the potential binding sites of splicing factors, which may affect the mRNA splicing and protein translation. Our study suggests that the mutations in CAMK4 may lead to abnormal semen parameters. © 2012 The Authors. International Journal of Andrology © 2012 European Academy of Andrology.
On the convergence of a fourth-order method for a class of singular boundary value problems
(2009) R.K. Pandey; Arvind K. Singh
In the present paper we extend the fourth order method developed by Chawla et al. [M.M. Chawla, R. Subramanian, H.L. Sathi, A fourth order method for a singular two-point boundary value problem, BIT 28 (1988) 88-97] to a class of singular boundary value problems (p (x) y′)′ = p (x) f (x, y), 0 < x ≤ 1y′ (0) = 0, α y (1) + β y′ (1) = γ where p (x) = xb0 q (x), b0 ≥ 0 is a non-negative function. The order of accuracy of the method is established under quite general conditions on f (x, y) and is also verified by one example. The oxygen diffusion problem in a spherical cell and a nonlinear heat conduction model of a human head are presented as illustrative examples. For these examples, the results are in good agreement with existing ones. © 2008 Elsevier B.V. All rights reserved.
Operational improvement of weak HVDC system with unified power flow controller
(Institute of Electrical and Electronics Engineers Inc., 2014) R.K. Pandey; A. Siddarthan
The paper presents an investigation of HVDC system behavior under variety of AC system conditions. The Effective Short Circuit Ratio (ESCR) of both converter terminals has been varied and faults introduced to understand the behaviour of HVDC system. It has been observed that the converter behavior deteriorates with low ESCR and power transfer may not take place as desired due to operational instability. However, under such scenario introduction of Unified Power Flow Controller (UPFC) as supplementary controller in the adjacent AC network certainly improves converter operation. The tuning of UPFC control parameters plays a predominant role for recovery after the faults in weak AC system conditions. Such studies, if conducted on regular basis in AC/DC network, may help the system operator for effective network operational planning with adequate control strategy. The effectiveness of UPFC in HVDC network has been critically examined from stabilization view point. © 2014 IEEE.
Photoelectrochemical and solar cell studies of n-CdSe films grown by repeated electrodeposition cycles
(1991) R.K. Pandey; S.R. Kumar; A.J.N. Rooz; S. Chandra
Photoelectrochemical studies of the n-CdSe films prepared by a repeated electrodeposition process employing in situ etching, cathodic deposition and annealing are reported. The influence of the anodic etching current density on the photoanodic behaviour of the films is also discussed. It is shown that better solar cell performance can be obtained by using the repeated electrodeposition process compared with the normal single-step electrodeposition. The solar cell studies have also been correlated with the experimentally determined minority carrier diffusion length and the surface morphology of the films. © 1991.
Photoelectrochemical cell for solar energy conversion using electrocodeposited CdSe films
(1980) S. Chandra; R.K. Pandey
Photoelectrochemical cells (PEC) using cadmium selenide films deposited on stainless steel and titanium substrates are studied. The CdSe films are obtained by electrocodeposition of Cd2+ and Se2+ ions on the substrates by self‐sustained electrolysis of an aqueous solution containing these ions. The electrolytic deposition parameters are optimised. For titanium substrates, SeO2 concentration ≈ 5 mg/50 ml gives best CdSe film PEC. The electrolysis temperature and current density have negligible effect. For stainless steel, SeO2 concentration ≈ 5 to 10 mg/50 ml and electrolysis temperature range 32 to 40 °C is best. In this case also, the electrolysis current density has negligible effect. Copyright © 1980 WILEY‐VCH Verlag GmbH & Co. KGaA
PSS tuning with firefly driven knowledge domain- A smart control concept
(Institute of Electrical and Electronics Engineers Inc., 2016) R.K. Pandey; Deepak Kumar Gupta
This paper presents the tuning of power system stabilizers (PSS) with Firefly driven knowledge domain states mapping in multi area power system. Tuning of PSS parameters has been done by Firefly algorithm (FA) by minimizing performance indices as an objective function. Tuning of PSS parameters by FA have been done in offline mode at different operating conditions such as dynamic load change. The objective function for tuning the parameters of PSS is integral time multiplied by squared error (ITSE). These sets of tuned parameters at different operating conditions are termed as knowledge domain. The states response violates from desired limits as the dynamic change in the system operating conditions occurs. Retuning of controller parameters have been done straight away from the respective knowledge domain to provide precise damping of signals of interest as quick as possible. The process is viewed as knowledge domain mapping. The system study has been performed on six area sample power system developed with UPFC connected between area two and three and PSS to rest of all the areas. The proposed concept demonstrates auto tuning of PSS for quick oscillation damping as the operating condition changes. © 2015 IEEE.
Rescaled mean spherical approximation structure factor for an aqueous suspension of polystyrene spheres
(Springer India, 1992) R.K. Pandey; D.N. Tripathi
Rescaled mean spherical approximation (RMSA) has been used to calculate the structure factor for the aqueous suspension of polystyrene macroions with the interaction potential taken according to Derjaguin and Landau (1941) and Verwey and Overbeek (1948) (DLVO) model. The effects of charge over the macroion and size on the surface potential and therefore, the structure factor have been studied. The breakdown of the DLVO potential with an excess charge over the macroion (≥800e) has been reported. The oscillation in the first peak height of structure factor versus wave vector curve with size has been correlated with the Debye length. © 1992 the Indian Academy of Sciences.