Faculty Profile  Faculty ProfileLast Modified Time: 02:32:42 PM Sun, 23 Aug 2015 
Dr Santiago I. Betelu
 Contact Information
Dr Santiago I. Betelu
Adjunct Faculty-Mathematics
Email  betelu@unt.edu    Fax No: (940) 565-4805    http://math.unt.edu/~betelu http://math.unt.edu/~betelu   
toggle toggle  Professional Preparation
 Degree Major/Thesis/Dissertation Institution Year
Doctor of Philosophy Physics; Thesis: Plane Stokes Flows near singular points of the free surface UNCPBA, Argentina 1997
Batchelor of Science Physics; Thesis: Columnar to Equiaxed Transicion in Aluminum base Alloys UNCPBA, Argentina (Universidad Nacional del Centro de la Provincia de Buenos Aires, Argentina) 1994
toggle toggle Courses Taught By Semester --- Organized Classes will be uploaded from THECB Data file
SemesterSubjectCourse NumberSectionCourse NameCalculated Semester Credit HoursSyllabus 
Fall 2015MATH3410002Differential Equations I Download Syllabus
Fall 2015MATH1780002Probability Models Download Syllabus
Summer 5W2 2015MATH3420001Differential Equations II Download Syllabus
Summer 5W2 2015MATH3410003Differential Equations I Download Syllabus
Spring 2015MATH3410005Differential Equations I Download Syllabus
Spring 2015MATH3410002Differential Equations I Download Syllabus
Fall 2014MATH1650304Pre-Calculus Download Syllabus
Fall 2014MATH1650303Pre-Calculus Download Syllabus
Fall 2014MATH1650302Pre-Calculus Download Syllabus
Fall 2014MATH1650301Pre-Calculus Download Syllabus
Fall 2014MATH3410006Differential Equations I Download Syllabus
Fall 2014MATH3410003Differential Equations I Download Syllabus
Fall 2014MATH1650300Pre-Calculus Download Syllabus
Summer 5W2 2014MATH3420001Differential Equations II Download Syllabus
Spring 2014MATH3420001Differential Equations II Download Syllabus
Spring 2014MATH3410002Differential Equations I Download Syllabus
Fall 2013MATH3350001Introduction to Numerical Analysis Download Syllabus
Fall 2013MATH1680861Elementary Probability and Statistics Download Syllabus
Fall 2013MATH1680014Elementary Probability and Statistics Download Syllabus
Spring 2011MATH3310001Differential Equations for Engineering Majors Download Syllabus
Spring 2011MATH1710624Calculus I Download Syllabus
Spring 2010MATH3420001Differential Equations II63 
Spring 2010MATH3310001Differential Equations for Engineering Majors156 
Fall 2010MATH1780001Probability Models Download Syllabus
Fall 2010MATH1650622Pre-Calculus Download Syllabus
Fall 2009MATH3350001Introduction to Numerical Analysis75 
Fall 2009MATH3310002Differential Equations for Engineering Majors246 
toggle toggle  Research and Expertise
Assistant Professor at the Mathematics Department of the University of North Texas since July 2002
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.
Associate Professor at the Mathematics Department of the University of North Texas 2007-2011
Web Link
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 tri
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 ultra-thin 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.
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 self-similarity in fluid mechanics. Gasdynamics and porous medium flows. Thin films
and lubrication approximation. Micromagnetism and Landau-Lifshitz equations. Development of
numerical techniques.
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.
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.
toggle toggle Appointments
Duration (YYYY - YYYY or Present)RankDepartment / SchoolCollege / OfficeUniversity / Company
2013-PresentAdjunctMathematicsArts and SciencesUniversity of North texas
2007-2011Associate Professormathematics departmentArts and sciencesUniversity of North texas
2002-2007Assistant ProfessorMathematics Department University of North Texas
1998-2000Visiting Assistant professorMathematics Department University of Minnesota
1992-1997Teaching Assistant  Universidad Nacional del Centro (UNCPBA)
toggle toggle Faculty Workload
Duration (YYYY - YYYY)Percentage TeachingPercentage ResearchPercentage Service
toggle toggle Publications
  Type  Publications per page   
1  2 3 4 5 6 7 
  YearPublication  Type
Solutions of the porous medium equation with degenerate interfaces
Betelu SI, Iaia J
European Journal of Applied Mathematics - Cambridge Univ Press
Refereed(Peer reviewed) Journals
Analytical estimates of the dispersion curve in planar ionization fronts, AIP conf proc, vol 1118, pp. 68-72
M Arrayas,S Betelu, M Fontelos, J Trueba
American Institute of Physics
Conference paper
Fingering from ionization fronts in Plasmas
M. Arrayas, S. Betelu and M. A. Fontelos
SIAM J. Appl. Math. Volume 68, Issue 4, pp. 1122-1145 (2008)
Refereed(Peer reviewed) Journals
Singularities on charged viscous droplets
S. I. Betelu, M. A. Fontelos, U. Kindelan and O. Vantzos
Physics of Fluids, Volume 18, Issue 5, 051706 (4 pages) (2006).
Refereed(Peer reviewed) Journals
Explicit Stationary Solutions in Multiple Well Dynamics and Non-Uniqueness of interfacial energy densities
S. I. Betelu, N. D. Alikakos and X. Chen
European Journal of Applied Mathematics, 2006, VOL 17; PART 5, pages 525-556
Refereed(Peer reviewed) Journals
toggle toggle Presentations and Projects
  Presentations/Projects per page   
1  2 3 
Start DateEnd DatePresentation/Project
2006 2006 S. Betelu "Dynamics of electrically charged droplets"
Conference of Microfluidics, Universidad Carlos III, Madrid Spain
2006 2006 S. Betelu "Spreading of charged liquids and fission of drops"
Invited talk at the University of Athens, Mathematics Department
2004 2004 S. I. Betelú, M. A. Fontelos, and U. Kindelán, ”The shape of charged drops: symmetry breaking bifurcations and numerical results”
Fifth European Conf. On elliptic and parabolic problems, Gaeta (2004)
toggle toggle Teaching

College Algebra and Probability
University of Minnesota

Differential Equations

Electricity and Magnetism
Universidad Nacional del Centro (UNCPBA), Tandil, Argentina

Fluid Mechanics and Elasticity
Universidad Nacional del Centro (UNCPBA), Tandil, Argentina

Numerical Analysis

Partial Differential Equations with Applications, an introductory course of Precalculus
University of Minnesota



toggle toggle Mentoring/Advising
Duration (YYYY - YYYY or Present)Student NameClassificationTypeProject/Thesis/Dissertation
 Orestis VantzosDirected the thesisAdvanced numerical methods in fluid dynamics and singularities in charged fluids
toggle toggle Additional Information
English and Spanish

Programming Skills
Fortran, C++, OPENMP, Basic, LabView and Mathematica. I have experience working with supercomputers at the Supercomputing Institute of the UMN. I programmed mainly codes for data processing, image enhancement and numerical simulations in fluid dynamics.

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 non-oscillatory methods), Riemann solvers for gasdynamics, numerical
renormalization and fast marching algorithms, octrees for N-body computations as Barnes-Hut and
modifications. Numerical methods applied to image processing.
6- Construction of new explicit solutions for partial differential equations in fluid mechanics.

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