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Our Faculty
undefined   David S. Rumschitzki
Herbert G. Kayser Professor
Biomedical Engineering,Chemical Engineering


Office Location: Steinman Hall T - 319
Phone: (212) 650-5430
Fax: (212) 650-6660
E-mail: david@ccny.cuny.edu
   
Education:
B.S.(Ch.E.& Math.), 1978, Cooper Union.
M.S.(Ch.E.), 1979, Ph.D.(Ch.E.), 1984, University of California at Berkeley.

NSF Presidential Young Investigator 
1996- 97 Alexander von Humboldt Fellow
1996 Melville Medal of the ASME - Best original paper on a Mechanical Engineering topic - includes all journals published by the ASME
1995- 1996 Best Paper Award, ASME Bioengineering Division
1987-1993 National Science Foundation Presidential Young Investigator
Areas of Expertise:
Reaction engineering; transport and reaction aspects of artery disease; hydrodynamics of two phase flow in tubes
Current Research Interests:
A chemical engineer's perspective, considering chemical and biological changes as kinetic reactions and focusing on transport, can often offer a fresh approach to problems in biology. Our group has been studying the initiation of arterial disease. We have developed kinetic models from the extensive historic data of Brown and Goldstein for the processes by which many human cells take up and process blood-borne cholesterol and for how they maintain cholesterol homeostasis. In addition, together with Professor Shu Chien (University of California, San Diego ) and S. Weinbaum, we have been developing very successful models to decipher the earliest stages of arterial (intimal) cholesterol lesion formation. These models, in conjunction with animal experiments at UCSD, explain the transendothelial transport of lipoprotein cholesterol and subsequent spread within the artery wall. Current work is linking this transport to the kinetics of formation and growth of subendothelial extracellular lipid liposomes and to the cellular processes discussed above for dissipating them. The aim is to show how these steps comprise the earliest steps and how they can lead to lesion formation.

Another area that our group has focused on is the stability, both linear and nonlinear, of two-phase core-annular flows. The geometric distribution of two fluids in a conduit or pore is crucial to problems as diverse as recovering oil from rock pores to low cost pipe-transport of heavy crudes to the plugging of alveoli that hampers breathing in premature babies. In the absence of flow, we have shown that if one fluid is electrolytic, double layers at the wall and at the fluid-fluidinterfacecan stabilize the capillary instability. For situations with flow, we have developed methods for asymptotically thin films that clearly separate out the physical effect that compete to determine the interface's stability. Combination with Bretherton's theory gives a stability relation for liquid-liquid displacements. Asymptotic nonlinear results show how a base flow can interact both linearly and nonlinearly to stabilize other linearly destabilizing mechanisms and can mitigrate the tendency in the absence of a second fluid for the interface to lapse into chaotic motions. Current boundary-integral calculations hope to follow growing instabilities to break up. In addition we are investigating the effects of pore corrugation and other nonidealities.

Finally, recent work with Dr. Lee Walters at the Scripps Research Institute is aimed at developing new experimental techniques for increasing the time-resolution of FTIR spectroscopy by at least an order of magnitude to the sub-millisecond regime. The goal is to observe early time intermediates in protein refolding
Professional Experience:
spn.co
Selected Recent Publications:

Fung, S.C., Querini, C.A., Liu, K., Rumschitzki, D.S. and Ho, T.C., "In situ coking kinetics obtained from a new flow through microbalance and reaction kinetics monitored by GC," Studies in Surf.Sci. Catal.: Catalyst Deactivation, 88, 305 (1994)
Huang, Y., Rumschitzki, D., Chien, S. and Weinbaum, S., "A fiber matrix model for the growth of macromolecular leakage spots in the arterial intima," ASME J. of Biomechanical Eng., 116(4), 430, 1994
Rumschitzki, D.S. and Liu, K., "Zwietering's maximum-mixedness reactor and the continuously stirred tank reactor," Chemical Engineering Science, 49(23), 3883, 1994
Wong, H., Rumschitzki, D. and Maldarelli, C., "On the surface mass balance at a deforming interface," Physics of Fluids, 8(11), 3203 (1996)
Chauhan, A., Maldarelli, C., Rumschitzki, D. and Papageorgiou, D., "The temporal and spatial instability of an inviscid compound jet," Rheologica Acta, 35, 567 (1996)
Huang, Y., Rumschitzki, D., Chien, S. and Weinbaum, S., "A fiber matrix model for the filtration through fenestral pores in a compressible arterial wall," Amer. J. Physiol., 272 (41), H2023 (1997)
Yin, Yongyi, Lim, K.-H., Weinbaum, S., Chien, S.and Rumschitzki, D.S., "A model for the initiation and growth of extracellular lipid liposomes in arterial intima," Amer. J. Physiol., 272(41), H1033 (1997)
Liu, K., Fung, S.C., Ho, T.C. and Rumschitzki, D.S., "Identification of coke precursors in n-heptane reforming with a multi-outlet fixed bed reactor and a novel vibrational microbalance," Journal of Catalysis, 169, 455 (1997)
Liu, K., Fung, S.C., Ho, T.C. and Rumschitzki, D.S., "Kinetics of catalyst coking in n-heptane reforming over Pt-Re/Al 2O3," Indust. & Eng. Chem. Res., 36(8), 3264 (1997)
Liu, K., Fung, S.C., Ho, T.C. and Rumschitzki, D.S., "An experimental protocol for studying kinetics and catalyst deactivation: Application to heptane reforming," Studies in surface science and catalysis: Catalyst Deactivation , 111, 625 (1997)
Wong, H., Rumschitzki, D. and Maldarelli, C., "Theory and experiment on the low Reynolds number expansion, contraction and detachment of a bubble pinned at the tip of a submerged capillary," Journal of Fluid Mechanics, 356, 93 (1998)
Huang, Y., Jan, K.M., Rumschitzki, D. and Weinbaum, S., "Structural changes in rat aortic intima due to transmural pressure," ASME J. Biomech. Eng., 120, 476 (1998)
Wong, H., Rumschitzki, D. and Maldarelli, C., "Marangoni effects on the motion of an expanding or contracting bubble pinned at a submerged tube tip," Journal of Fluid Mechanics, 379, 279 (1998)
Chauhan, A. Maldarelli, C., Papageorgiou, D. and Rumschitzki, D., "The temporal instability of a compound thread,": Journal of Fluid Mechanics, in press (1999)
Wei, H. H. and Rumschitzki, D., "The linear stability of a core annular flow in a corrugated tube," IUTAM Symposium on nonlinear wave behavior in multi-phase flows, Kluwer, in press (2000)
Chauhan, A., Maldarelli, C., Papageorgiou, D., and Rumschitzki, D., "The spatial instability of a viscous, compound, two-phase jet," submitted for the Journal of Fluid Mechanics (2000)
Liu, K., Fung, S.C., Ho, T.C. and Rumschitzki, D., "Heptane reforming over Pt-Re/Al2O3: Reaction network, kinetics and apparent selective catalyst deactivation ;" J. Catalysis, 206, 188-201 March (2002)
Wei, H.H. and Rumschitzki, D., "The linear instability of a core-annular flow in an asymptotically corrugated tube, " Journal of Fluid Mechanics, 466, 113-147 (2002)
Wei, H.H. and Rumschitzki, D., "The weakly non-linear instability of a core-annular flow in a corrugated tube, " Journal of Fluid Mechanics, 466, 149-177 (2002)
Liu, K., Fung, S.C., Ho, T.C. and Rumschitzki, D., "Hydrogasification of coke in heptane reforming over Pt-Re/Al2O3," I & EC Research, 42, 1543-50 (2003)
Chauhan, A., Rumschitzki, D., Maldarelli, C. and Papageorgiou, D., "An experimental investigation of the convective instability in a jet," Chemical Eng. Sci., 58(11), 2421-32 (2003)
Wei, H.H. and Rumschitzki, D. S., "The effect of insoluble surfactants on the linear instability of a core-annular flow," in press, Journal of Fluid Mechanics (2005)
Chauhan, A., Rumschitzki, D., Maldarelli, C. and Papageorgiou, D., "The absolute instability of a compound, two-phase jet," in press Journal of Fluid Mechanics (2005)
Shou, Y., Jan, K.M. and Rumschitzki, D.S., "Transport in rat vessels: I. The hydraulic conductivities of the aorta, pulmonary artery and inferior vena cava with intact and denuded endothelia," in second round of reviews, American J. Physiol., (2005)
Shou, Y., Jan, K.M. and Rumschitzki, D. S., "Transport in rat vessel walls II: Macromolecular leakage and focal spot size growth in arteries and veins," in review, American J. Physiol., (2005)

 
 
 
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