Santiago Ignacio Betelu
Research projects:
Quantum factorization
benchmark
Singularities
in charged droplets
Spreading of
charged fluids
Molecular simulation
of interface cusps formation
Summary of other
projects
REFEREED PUBLICATIONS
30.BM
Law, M McBride, P Sean; J Wang, HS Wi,; G Paneru, S Betelu; U Baku; T Youichi; B Flanders; F Bresme; M Hiroki; T Takanori, A Makoto
Line
tension
and its influence on droplets and particles at
surfaces
Progress
in
surface science (2017)
29 SI Betelu, J Iaia,
'Solutions of the porous medium equation with
degenerate interfaces',
European Journal of Applied Mathematics (2013)
28 S. I. Betelu, M. A. Fontelos,
U. Kindelan and O. Vantzos,
''Singularities on charged viscous droplets,
Physics of Fluids, 18, 051706 (2006)
27 S. I. Betelu, N. D. Alikakos
and X. Chen,
'Explicit Stationary Solutions in Multiple Well
Dynamics and NonUniqueness of interfacial energy
densities',
European Journal of Applied Mathematics (2006)
26 S. I. Betelu and M. A. Fontelos,
'Spreading of a charged microdroplet'
Physica D Nonlinear
Phenomena, 209, Issues 14, 15 pp. 2835 (2005)
25 S. I. Betelu, M. A. Fontelos
and U. Kindelan,
''The shape of charged drops: Symmetry breaking
bifurcations and numerical results'',
Progress in Nonlinear Differential Equations and
their Applications, 63, pp. 5158 (2005)
24 S. I. Betelu and M. A. Fontelos,
''Capillarity driven spreading of circular drops of
shear thinning fluid'',
Mathematical and computer modelling, 40 (78),
729734 (2004).
23 Niethammer
M, Betelu S, Sapiro G, et
al.
'Area based medial axis of planar curves',
International Journal of Computer Vision, 60 (3),
203224 (2004).
22 S. I.
Betelu and J. R. King,
``Explicit solutions of a twodimensional fourth order
nonlinear diffusion equation'',
Mathematical and Computer Modelling, 37 (34),
395403. (2003).
21 S. I. Betelu and M. A. Fontelos,
''Capillarity driven spreading of powerlaw fluids'',
Applied Mathematics Letters 16 (8), 13151320 (2003).
20 S. Betelu, R. Gulliver and W. Littman,
"Boundary control of PDEs via curvature flows: the
view from the boundary, II"
Applied Mathematics and Optimization, 46 167178
(2002)
19 S. I. Betelu, D. G. Aronson,
''Focusing of noncircular selfsimilar shock waves'',
Physical Review Letters, Vol. 87 No. 7 (2001).
18 S. B. Angenent, D. G. Aronson, S. I.
Betelu and J. S. Lowengrub,
''Focusing of an elongated hole in porous medium
flow'',
Physica D, Vol. 151,
pp.228252 (2001).
17 S. I. Betelu, D. G. Aronson and S. B. Angenent
''Renormalization study of twodimensional convergent
solutions of the porous medium equation'',
Physica D, 138, p.
344359, (2000).
16 S. I.
Betelu, G. Sapiro and A.
Tannenbaum,
''On the computation of Affine Skeletons of Plane
Curves and the Detection of Skew Symmetries'',
Pattern Recognition, Vol 34 pp. 943952 (2000).
15 S. I. Betelu, G. Sapiro, A. Tannenbaum and P. Giblin,
''Noiseresistant affine skeletons of planar curves'',
Lect Notes Comput Sc
1842, pp. 742754, (2000).
14 J. Y.
Wang, S. Betelu, and B. M. Law
'Line tension approaching a firstorder wetting
transition: Experimental results from contact angle
measurements'
Physical Review E, Vol 63 (2000).
13 S.
Betelu, J. Diez,
'A two dimensional similarity solution for capillary
driven flows',
Physica D 126, p.136
(1999).
12 S.
Betelu,
'A twodimensional corner solution for a nonlinear
diffusion equation'
Applied Math. Letters, 13, pp. 119123 (2000).
11 J. Wang, S. Betelu and
B. Law,
'Line tension effects near firstorder wetting
transitions'
Physical Review Letters, 83, number 18 pp. 36773680
(1999)
10 S. Betelu, Law B. M. and Huang C. C.,
'Spreading dynamics of terraced droplets',
Phys. Rev. E, 59 p. 6699 (1999) ONLINE
9 J.
Diez, L. P. Thomas, S. Betelu, R. Gratton, B. Marino, J. Gratton, D. G. Aronson and
S. B. Angenent,
''Noncircular focussing
flow in viscous gravity currents'',
Phys. Rev. E 58 p. 61826187 (1998)
8 J.
Diez, S. Betelu and R. Gratton,
''The crumbling of a viscous prism with an inclined
free surface'',
Arch. Appl. Mech. 68 p. 407421 (1998)
7 S.
Betelu, R. Gratton and
J. Diez,
''Observation of cusps during the levelling of free
surfaces in viscous flows'',
J. Fluid Mech. 377, 137149 (1998)
6 S.
Betelu, J. Diez and R. Gratton,
''Cusped ripples at the plane surface of a viscous
liquid'',
Arch. Appl. Mech. 69 p.3646 (1998)
5 S.
Betelu , J. Diez, L. Thomas, R. Gratton, B. Marino,
''A boundaryelements method for viscous gravity
currents '',
Int. J. for Numerical Methods in Fluids 25, 1,
(1997).
3 B.
Marino, L. Thomas, R. Gratton,
J. Diez, S. Betelu,
''Waiting time solutions of a nonlinear diffusion
Equation: Experimental study of a creeping flow near a
waiting front'',
Phys. Rev. E. 54, (1996)
3 R. Gratton, J. Diez, L. Thomas,
B. Marino, S. Betelu,
''Quasiselfsimilarity for wetting drops '',
Phys. Rev. E 53,.3563 (1996).
2 L.
Thomas, R. Gratton, B.
Marino, S. Betelu , J. Diez,
''Measurement of the slope of a liquid free surface
along a line by a schlieren
system with anamorphic elements '',
Measurements Science and Technology 7, 1 (1996)
1 S. Betelu , J.
Diez, L. Thomas, R. Gratton,
B. Marino,
''Instantaneous viscous flow in a corner bounded by
free surfaces '',
Phys. Fluids 8, 2269 (1996)
____________________________________________________________________________
EDUCATION
1) 19891994: BS in Physics at UNCPBA,
Argentina (Universidad Nacional del Centro de la Provincia de Buenos Aires).
Thesis: Columnar to Equiaxed
Transicion in Aluminum
base Alloys.
2) 19941997: Ph.D. in Physics at
UNCPBA, Argentina.
Thesis: Plane Stokes Flows near singular points of
the free surface.
RESEARCH EXPERIENCE:
Research during my Ph.D
in Argentina from May 1994 to November 1997:
1 Theoretical Fluid Mechanics: simulation of the
spreading of viscous liquids on plane substrates.
Computations with boundary elements methods, finite
differences and construccion
of explicit solutions to the Stokes equations.
2 Experimental Fluid Mechanics: design and
implementation of optical diagnostics based on
interferometry, schlieren
and shadowgraphy for the
measurement on viscous flows. Experiments in spreadings and cusps formation
in flows of small Reynolds number.
Postdoctoral Position at Kansas State University
from November 1997 to November 1998,
as a Research Associate at the Physics Department:
1 Experimental ellipsometry
for the measurement of ultrathin films of fluids on
silicon substrates. Developped
software for analysis of ellipsometric
data. Preparation and cleaning of silicon surfaces and
theoretical modeling of liquid crystals spreading.
2 Design of optical measurements and experiments for
the measurement of line tension including fabrication of
silane monolayers, and
design of an interferometric microscope.
Visiting Assistant Professor at the Mathematics
Department of the University of Minnesota from
November 1998 to July 2000:
1 Modelling of porous medium flows with 2D finite
differences, numerical renormalization and ENO discretizations, and
construction of exact and approximate 2D selfsimilar solutions for thin
film flows of viscous liquids on plane surfaces.
2 In collaboration with the Electrical and Computer
Engineering Department, I did research on skeletonization of planar
shapes, symmetry detection in digital images, image
enhancement and processing of 3D data.
Postdoctoral position at the Institute of
Mathematics and its Applications from July 2000
to July 2002
1 Image processing, smoothing of 3D textured surfaces,
Mathematics in Multimedia.
2 Scaling and selfsimilarity in fluid mechanics. Gasdynamics and porous medium
flows. Thin films and lubrication approximation. Micromagnetism and LandauLifshitz equations. Development
of numerical techniques.
Assistant (20022008) and associate
(20082011) Professor at the Mathematics Department
of the University of North Texas
1 Applied fluid dynamics. Lubrication theory,
spreading of liquids on solid substrates, partial
differential equations of nonlinear degenerate
diffusion.
2 Numerical analysis of the Allen Cahn equations
applied to the curvature flow of curves with triple
joints: finite differences methods and boundary value
problems.
3 Electrically charged fluids with free surfaces:
lubrication theory, boundary elements methods and
asymptotic analysis.
4 Variational methods
for image interpolation.
5 Study of the dynamics of electrically charged
fluids.
Current research:
1 Design of algorithms for image processing based on
partial differential equations.
2 Fractal patterns in fluid flow.
3 Study of the shape of the free surface of charged
anisotropic and multiphase materials.
4 Investigation on automatic PDE solvers.
5 Parallel computing of solutions of PDEs
6 Modeling biological neural networks
TEACHING EXPERIENCE
Assistant Professor at the UNT: I teach courses
of Calculus, Differential Equations, Probabilities,
Statistics, Numerical Analysis. I also directed the thesis
of Orestis Vantzos entitled "Mathematical
modeling of charged liquid droplets: numerical
simulation and stability analysis". I also created a new
course on numerical analysis (contents here).
Visiting Assistant professor at the Mathematics
Department of the University of Minnesota.
I taught courses in Partial Differential Equations with
Applications, an introductory course of Precalculus, and College Algebra
and Probability. I was responsible for the lectures,
organizing the teaching assistants, and preparing the
exams (19982000). This last year I was the coordinator
of the course.
Teaching Assistant at the Universidad Nacional
del Centro (UNCPBA), Tandil,
Argentina.
I taught courses of Electricity and Magnetism, Fluid
Mechanics and Elasticity. I was
responsible for laboratory and problemsolving sessions
(19921997).
TECHNICAL SKILLS
1 Design of optical measurements with interferometry, schlieren and ellipsometry.
2 Digital image acquisition and processing. Data
analysis.
3 Preparation of silicon substrates and fabrication of
silane monolayers.
4 Design of experiments in fluid mechanics.
5 Numerical simulation in fluid mechanics with finite
differences, boundary elements methods, FFT methods, ENO
(essencially nonoscillatory
methods), Riemann solvers for gasdynamics,
numerical renormalization and fast marching algorithms,
octrees for Nbody computations as BarnesHut and
modifications. Numerical methods applied to image
processing.
6 Construction of new explicit solutions for partial
differential equations in fluid mechanics.
7 Design of algorithms for image processing.
8 Construction of inexpensive, passively cooled GPU
systems for physical simulations and education.
9 High Performance Computing with Infiniband, Data
Vortex and GPUs.
PROGRAMMING SKILLS
Fortran, C, C++, Opencl,
MPI, Matlab, Mathematica. I
have experience working with supercomputers
at the Supercomputing Institute of the UMN, at the UNT
and UT. I programmed mainly codes for numerical
simulations in fluid dynamics, biology, quantum
mechanics and signal processing.
LANGUAGES: English and Spanish
