Papers by Prof. R.K Pandit
Peri-urban areas vary from area to area therefore, planning must be adapted specifically to the l... more Peri-urban areas vary from area to area therefore, planning must be adapted specifically to the local context and should therefore consider the fact that, as population grows and settlements increase in size, they will begin to compete with neighbouring settlements. Simplified sewerage is an important sanitation option in peri-urban areas of developing countries, especially as it is often the only technically feasible solution in these high density areas. This paper attempts to disseminate this technology more widely in the developing world, so that it can be used in peri-urban sanitation programmes and project to improve the health of poor communities.
Springer Transactions in Civil and Environmental Engineering, 2016
Sustainability is the most frequently referred term among urban thinkers. Rapid urbanization has ... more Sustainability is the most frequently referred term among urban thinkers. Rapid urbanization has compelled us to think about urban sustainability. Various factors affect urban environmental conditions. The idea of sustainable development lays emphasis on encompassing all the three parameters of sustainability. There must be balance between socioeconomic activities and environment in an urban setting. Process of development should enhance the quality of human life. Indore city has a population of more than two million. Over the period of time, Indore has been regenerated dynamically. Regeneration has affected the sustainability of Indore city. The paper lays stress on social sustainability, focusing on the importance of safe society for a livable community and sustainable development. It is the responsibility of architects and urban planners to aim for creating safe environment which is attractive to citizens and rich in ecological sense. Research paper deals with the above aspect and inspect of Indore city through a process of dividing it into four major sections based on demographics and crime rate. The researcher seeks to evaluate the relationship of urban regeneration (UR), social sustainability, and environmental design of Indore city. The research makes use of obtainable sources and information from previous findings and research. The primary data is obtained as information from questionnaire. Then, the data is subjected to ANOVA and Amos software of SPSS 21 and linear regression analysis. Finally the paper proves that both urban regeneration and physical environmental design have considerable impact on social sustainability.
Nonlinearity, 2014
The periodic 3D Navier-Stokes equations are analyzed in terms of dimensionless, scaled, L 2mnorms... more The periodic 3D Navier-Stokes equations are analyzed in terms of dimensionless, scaled, L 2mnorms of vorticity D m (1 ≤ m < ∞). The first in this hierarchy, D 1 , is the global enstrophy. Three regimes naturally occur in the D 1 − D m plane. Solutions in the first regime, which lie between two concave curves, are shown to be regular, owing to strong nonlinear depletion. Moreover, numerical experiments have suggested, so far, that all dynamics lie in this heavily depleted regime [1] ; new numerical evidence for this is presented. Estimates for the dimension of a global attractor and a corresponding inertial range are given for this regime. However, two more regimes can theoretically exist. In the second, which lies between the upper concave curve and a line, the depletion is insufficient to regularize solutions, so no more than Leray's weak solutions exist. In the third, which lies above this line, solutions are regular, but correspond to extreme initial conditions. The paper ends with a discussion on the possibility of transition between these regimes.
Physical Review E, 2015
We carry out the most extensive and high-resolution direct numerical simulation, attempted so far... more We carry out the most extensive and high-resolution direct numerical simulation, attempted so far, of homogeneous, isotropic turbulence in two-dimensional fluid films with air-drag-induced friction and with polymer additives. Our study reveals that the polymers (a) reduce the total fluid energy, enstrophy, and palinstrophy, (b) modify the fluid energy spectrum both in inverse-and forward-cascade régimes, (c) reduce small-scale intermittency, (d) suppress regions of large vorticity and strain rate, and (e) stretch in strain-dominated regions. We compare our results with earlier experimental studies and propose new experiments.
Journal of chemical neuroanatomy, 2014
The anorexigenic hormone leptin plays an important role in the control of food intake and feeding... more The anorexigenic hormone leptin plays an important role in the control of food intake and feeding-related behavior, for an important part through its action in the hypothalamus. The adipose-derived hormone modulates a complex network of several intercommunicating orexigenic and anorexigenic neuropeptides in the hypothalamus to reduce food intake and increase energy expenditure. In this review we present an updated overview of the functional role of leptin in respect to feeding and feeding-related behavior per distinct hypothalamic nuclei. In addition to the arcuate nucleus, which is a major leptin sensitive hub, leptin-responsive neurons in other hypothalamic nuclei, including the, dorsomedial-, ventromedial- and paraventricular nucleus and the lateral hypothalamic area, are direct targets of leptin. However, leptin also modulates hypothalamic neurons in an indirect manner, such as via the melanocortin system. The dissection of the complexity of leptin's action on the networks i...
Physical Review E, 2014
We present a detailed direct numerical simulation of statistically steady, homogeneous, isotropic... more We present a detailed direct numerical simulation of statistically steady, homogeneous, isotropic, two-dimensional magnetohydrodynamic (2D MHD) turbulence. Our study concentrates on the inverse cascade of the magnetic vector potential. We examine the dependence of the statistical properties of such turbulence on dissipation and friction coefficients. We extend earlier work significantly by calculating fluid and magnetic spectra, probability distribution functions (PDFs) of the velocity, magnetic, vorticity, current, stream-function, and magnetic-vector-potential fields and their increments. We quantify the deviations of these PDFs from Gaussian ones by computing their flatnesses and hyperflatnesses. We also present PDFs of the Okubo-Weiss parameter, which distinguishes between vortical and extensional flow regions, and its magnetic analog. We show that the hyperflatnesses of PDFs of the increments of the stream-function and the magnetic vector potential exhibit significant scale dependence and we examine the implication of this for the multiscaling of structure functions. We compare our results with those of earlier studies.
Journal of immunology (Baltimore, Md. : 1950), Jan 15, 1997
Within human head and neck squamous cell carcinomas (HNSCC) that produce granulocyte-macrophage C... more Within human head and neck squamous cell carcinomas (HNSCC) that produce granulocyte-macrophage CSF are CD34+ cells that exhibit natural suppressive (NS) activity. The present study aimed to identify how these NS cells mediate suppression and how to diminish their presence. CD34+ cells that were immunomagnetically isolated from fresh surgical HNSCC specimens produced a soluble product that blocked normal T cell stimulation through the TCR/CD3 complex. This inhibitory activity could be neutralized with Abs to TGF-beta1. Since prior studies showed that the CD34+ NS cells within HNSCC cancers are myelomonocytic progenitor cells, the feasibility of using cytokines that can induce myeloid cell differentiation to diminish the presence of CD34+ NS cells was tested. Adding low doses of 100 U/ml IFN-gamma plus 10 U/ml TNF-alpha to bulk cultures of dissociated HNSCC cancers diminished the frequency of CD34+ cells. Studies with CD34+ cells that were isolated from the HNSCC cancers showed that ...
We uncover universal statistical properties of the trajectories of heavy inertial particles in th... more We uncover universal statistical properties of the trajectories of heavy inertial particles in three-dimensional, statistically steady, homogeneous, and isotropic turbulent flows by extensive direct numerical simulations. We show that the probability distribution functions (PDFs) P (φ), of the angle φ between the Eulerian velocity u and the particle velocity v, at this point and time, shows a power-law region in which P (φ) ∼ φ −γ , with a new universal exponent γ ≃ 4. Furthermore, the PDFs of the trajectory curvature κ and modulus θ of the torsion ϑ have power-law tails that scale, respectively, as P (κ) ∼ κ −hκ , as κ → ∞, and P (θ) ∼ θ −h θ , as θ → ∞, with exponents hκ ≃ 2.5 and h θ ≃ 3 that are universal to the extent that they do not depend on the Stokes number St (given our error bars). We also show that γ, hκ and h θ can be obtained by using simple stochastic models. We characterize the complexity of heavy-particle trajectories by the number NI(t, St) of points (up until time t) at which ϑ changes sign. We show that nI(St) ≡ limt→∞ N I (t,St) t ∼ St −∆ , with ∆ ≃ 0.4 a universal exponent.
We obtain, by extensive direct numerical simulations, trajectories of heavy inertial particles in... more We obtain, by extensive direct numerical simulations, trajectories of heavy inertial particles in two-dimensional, statistically steady, homogeneous, and isotropic turbulent flows, with friction. We show that the probability distribution function P(κ), of the trajectory curvature κ, is such that, as κ → ∞, P(κ) ∼ κ −hr , with hr = 2.07 ± 0.09. The exponent hr is universal, insofar as it is independent of the Stokes number St and the energy-injection wave number kinj. We show that this exponent lies within error bars of their counterparts for trajectories of Lagrangian tracers. We demonstrate that the complexity of heavy-particle trajectories can be characterized by the number NI(t, St) of inflection points (up until time t) in the trajectory and nI(St
Heart Rate and Rhythm, 2011
Page 1. Chapter 14 An Overview of Spiral-and Scroll-Wave Dynamics in Mathematical Models for Card... more Page 1. Chapter 14 An Overview of Spiral-and Scroll-Wave Dynamics in Mathematical Models for Cardiac Tissue Rupamanjari Majumder, Alok Ranjan Nayak, and Rahul Pandit 14.1 Introduction Mammalian hearts are among ...
Physical Review B, 1997
The transition-metal oxide La 2 NiO 4 is studied using a multiband Hubbard model with a Hund coup... more The transition-metal oxide La 2 NiO 4 is studied using a multiband Hubbard model with a Hund coupling J. We obtain its mean-field phase diagram in the U-͑correlation strength on Ni sites͒ ⌬ ͑charge-transfer energy͒ plane. For Jϭ0 we have a continuous transition from a paramagnetic metal ͑PMM͒ to a paramagnetic insulator ͑PMI͒. On increasing J, the magnetic moment M and the band gap E G change discontinuously at JϭJ c (U,⌬). For Jϭ1, the insulating phase ͑AFI͒ is antiferromagnetic, but we have, in addition, both paramagnetic ͑PMM͒ and antiferromagnetic ͑AFM͒ metallic phases. The insulator-metal ͑AFI-AFM and AFI-PMM͒ phase boundaries are first order, but the metal-metal ͑AFM-PMM͒ boundary is second order; and it seems to meet the first-order boundary at a critical end point. A reentrant PMM-AFM-PMM sequence is also seen. ͓S0163-1829͑97͒01316-7͔
Physical Review B, 1984
Page 1. PHYSICAL REVIE% 8 VGLUME 30, NUMBER 1 Helicity moduli of three-dimensional dilute XFmodel... more Page 1. PHYSICAL REVIE% 8 VGLUME 30, NUMBER 1 Helicity moduli of three-dimensional dilute XFmodels Anupam Garg,* Rahul Pandit, and Sara A. Solla Laboratory ofAtomic and Solid State Physics, Cornell Uniuersity, Ithaca, ¹wFork 14853 ...
Phase Transitions in Complex Fluids, 1998
Physical Review B, 1983
In this paper we continue the study, initiated in the preceding paper, of a classical, one-dimens... more In this paper we continue the study, initiated in the preceding paper, of a classical, one-dimensional, Heisenberg antiferromagnet with a single-ion anisotropy and a Dzyaloshinski-Moriya term. We show that in certain ranges of coupling constants domain walls in such antiferromagnets can be approximated by sine-Gordon or double-sine-Gordon solitons. These solitons can be used to explain certain qualitative features in the
Understanding Complex Systems, 2009
Cardiac arrhythmias such as ventricular tachycardia (VT) or ventricular fibrillation (VF) are the... more Cardiac arrhythmias such as ventricular tachycardia (VT) or ventricular fibrillation (VF) are the leading cause of death in the industrialised world. There is a growing consensus that these arrhythmias arise because of the formation of spiral waves of electrical activation in cardiac tissue; unbroken spiral waves are associated with VT and broken ones with VF. Several experimental studies have been carried out to determine the effects of inhomogeneities in cardiac tissue on such arrhythmias. We give a brief overview of such experiments, and then an introduction to partialdifferential-equation models for ventricular tissue. We show how different types of inhomogeneities can be included in such models, and then discuss various numerical studies, including our own, of the effects of these inhomogeneities on spiral-wave dynamics. The most remarkable qualitative conclusion of our studies is that the spiral-wave dynamics in such systems depends very sensitively on the positions of these inhomogeneities.
PLoS ONE, 2014
Sudden cardiac death is often caused by cardiac arrhythmias. Recently, special attention has been... more Sudden cardiac death is often caused by cardiac arrhythmias. Recently, special attention has been given to a certain arrhythmogenic condition, the long-QT syndrome, which occurs as a result of genetic mutations or drug toxicity. The underlying mechanisms of arrhythmias, caused by the long-QT syndrome, are not fully understood. However, arrhythmias are often connected to special excitations of cardiac cells, called early afterdepolarizations (EADs), which are depolarizations during the repolarizing phase of the action potential. So far, EADs have been studied mainly in isolated cardiac cells. However, the question on how EADs at the single-cell level can result in fibrillation at the tissue level, especially in human cell models, has not been widely studied yet. In this paper, we study wave patterns that result from single-cell EAD dynamics in a mathematical model for human ventricular cardiac tissue. We induce EADs by modeling experimental conditions which have been shown to evoke EADs at a single-cell level: by an increase of L-type Ca currents and a decrease of the delayed rectifier potassium currents. We show that, at the tissue level and depending on these parameters, three types of abnormal wave patterns emerge. We classify them into two types of spiral fibrillation and one type of oscillatory dynamics. Moreover, we find that the emergent wave patterns can be driven by calcium or sodium currents and we find phase waves in the oscillatory excitation regime. From our simulations we predict that arrhythmias caused by EADs can occur during normal wave propagation and do not require tissue heterogeneities. Experimental verification of our results is possible for experiments at the cell-culture level, where EADs can be induced by an increase of the L-type calcium conductance and by the application of I Kr blockers, and the properties of the emergent patterns can be studied by optical mapping of the voltage and calcium. Citation: Vandersickel N, Kazbanov IV, Nuitermans A, Weise LD, Pandit R, et al. (2014) A Study of Early Afterdepolarizations in a Model for Human Ventricular Tissue. PLoS ONE 9(1): e84595.
PLoS ONE, 2012
We present a comprehensive numerical study of spiral-and scroll-wave dynamics in a state-of-the-a... more We present a comprehensive numerical study of spiral-and scroll-wave dynamics in a state-of-the-art mathematical model for human ventricular tissue with fiber rotation, transmural heterogeneity, myocytes, and fibroblasts. Our mathematical model introduces fibroblasts randomly, to mimic diffuse fibrosis, in the ten Tusscher-Noble-Noble-Panfilov (TNNP) model for human ventricular tissue; the passive fibroblasts in our model do not exhibit an action potential in the absence of coupling with myocytes; and we allow for a coupling between nearby myocytes and fibroblasts. Our study of a single myocytefibroblast (MF) composite, with a single myocyte coupled to N f fibroblasts via a gap-junctional conductance G gap , reveals five qualitatively different responses for this composite. Our investigations of two-dimensional domains with a random distribution of fibroblasts in a myocyte background reveal that, as the percentage P f of fibroblasts increases, the conduction velocity of a plane wave decreases until there is conduction failure. If we consider spiral-wave dynamics in such a medium we find, in two dimensions, a variety of nonequilibrium states, temporally periodic, quasiperiodic, chaotic, and quiescent, and an intricate sequence of transitions between them; we also study the analogous sequence of transitions for three-dimensional scroll waves in a three-dimensional version of our mathematical model that includes both fiber rotation and transmural heterogeneity. We thus elucidate random-fibrosis-induced nonequilibrium transitions, which lead to conduction block for spiral waves in two dimensions and scroll waves in three dimensions. We explore possible experimental implications of our mathematical and numerical studies for plane-, spiral-, and scroll-wave dynamics in cardiac tissue with fibrosis.
Physical Review Letters, 1997
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Physical Review Letters, 2005
We study turbulence in the one-dimensional Burgers equation with a white-in-time, Gaussian random... more We study turbulence in the one-dimensional Burgers equation with a white-in-time, Gaussian random force that has a Fourier-space spectrum ∼ 1/k, where k is the wave number. From very-highresolution numerical simulations, in the limit of vanishing viscosity, we find evidence for multiscaling of velocity structure functions which cannot be falsified by standard tests. We find a new artifact in which logarithmic corrections can appear disguised as anomalous scaling and conclude that bifractal scaling is likely.
Physical Review Letters, 2013
We show that a shell-model version of the three-dimensional Hall-magnetohydrodynamic (3D Hall-MHD... more We show that a shell-model version of the three-dimensional Hall-magnetohydrodynamic (3D Hall-MHD) equations provides a natural theoretical model for investigating the multiscaling behaviors of velocity and magnetic structure functions. We carry out extensive numerical studies of this shell model, obtain the scaling exponents for its structure functions, in both the low-k and high-k powerlaw ranges of 3D Hall-MHD, and find that the extended-self-similarity (ESS) procedure is helpful in extracting the multiscaling nature of structure functions in the high-k regime, which otherwise appears to display simple scaling. Our results shed light on intriguing solar-wind measurements.
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Papers by Prof. R.K Pandit