About Lecturer
Yaw Delali Bensah received his PhD in Material Science from the University of Cincinnati, Ohio, USA. His background specialty and research is mainly about the interfacial thermodynamics and the application of extremum principles such as the maximum entropy generation rate (MEPR) postulate to crystal growth and solidification processing routes. His work on binary materials has shed light on the possible structure of the solid-liquid interface that emanates during the growth of single and polycrystalline materials from their melts.
For the case of pure (unary) materials a connection is found for the interface mixing entropy and the Einstein-Stokes diffusion equation that leads to a breakdown criterion that makes practical quantitative assessment of the velocity possible. This result further cast deep insights into how entropy generation becomes a sole selection rule that controls pattern formation in systems which involve irreversible processes and are far from equilibrium.The main MEPR equation developed measures the irreversible entropy generation rate density (i.e., per unit volume of the interface) at the atomistic and molecular scale. He believes that this new result aboutentropy generation rate densitycalculated is connected to all forms entropy. A typicalone of such a connection is to find out how it may be linked to the Perelman entropy functional, W. It should be noted that the Perelman entropy functional played a critical role in the resolution of the Poincare conjecture and the Thurston geometrization conjecture in the solution posted by Grigori Perelman. Thus, there could be a deeper connection between thermodynamics and the mathematics of Riemann geometry and topology that has not been explored. In other works, if the connection could be unraveled, then topological and differential geometrical tools coupled with the laws of thermodynamics (particularly on extremum entropy generation principles) would pave the way to track all kinds if interface bifurcation for all systems.
Research Area
§ Dissipative structures and complex non-equilibrium thermodynamic systems in material processing
§ Energy dissipation and entropy generation and extremum principles (Maximum Entropy Production Rate) and their application in material processing
§ Morphological and interfacial patterns in crystal growth, and solidification microstructural evolution
Current work and seminal results (In the area of interfacial thermodynamics and structure of the solid/liquid interfaces for pure and binary materials)
For the first time in the study of solid-liquid interface during directional solidification the following have been obtained.
(1) A quantitative description of the transitions between atomistically smooth and diffuse interfaces.
(2)A criteria for the quantitative measurement for the diffuse interface thickness and the number of atomic layersin the solid-liquid interface.
(3) A qualitative and quantitative prediction of the transition from facet to non-facet cellular morphology as a function of solidification velocity and/or temperature gradient.
(4)The development of the necessary conditions required for the growth of an instability from a planar interface morphology during solid-liquid interface growth conditions.
Other research interests
§ Theoretical materials science
§ Applications of Belousov–Zhabotinsky (BZ reaction and mechanism) and self-organization processes in materials design.
§ Study and processing of indigenous raw materials in Ghanathat possesses economic potentials.
Publications
[8] Bensah, Y.D: Maximum entropy generation rate density and its application to microstructural evolution.http://arXiv.org/arXiv:1608.02297[cond-mat.mtrl-sci]:1-13(2016)
[7] Bensah, Y.D.,Sekhar JA: Interfacial instability of a planar Interface and diffuseness at the solid-liquid interface for pure and binary materials.http://arXiv.org/arXiv:1605.05005 [cond-mat.mtrl-sci]:1-58(2016)
[6] Bensah, Y.D.,Sekhar, J.A., Morphological Assessment with the Maximum Entropy Production Rate (MEPR) Postulate, Current Opinion in Chemical Engineering, 3, 91-98 (2014).
[5] Agyei-Tuffour, B., Bensah, Y.D., Damoah, L. N. W., Dodoo-Arhin, D., Annan, E., Efavi, J. K., Sarkodee, E. Synthesis and Microstructural Characterization of Kaolin–Polyethylene Composites, Polymer Composites, 35, 8, 1507-1515 (2014).
[4] Bensah, Y.D., Li, H. P. and Sekhar, J.A., TheSgen rate maximization postulate: Applications to process-path analysis for solidification and micropyretic synthesis,Key Engineering Materials. 521, 79-86 (2012).
[3] Efavi, J. K., Damoah, L., Bensah, Y.D.,Dodoo-Arhin, D., Tetteh, D. Development of porous ceramic bodies from kaolin deposits for industrial applications,Applied Clay Science, 65–66, 31–36(2012).
[2] Bensah, Y. D,Agyei-Tuffour., Benjamin, Damoah., L. N. W. and Efavi., J. K.Processing of waste polyethylene into polymer-ceramic composite through lipid assisted melt compounding,ARPN Journal of Engineering and Applied Sciences. 7, 6, 723-730 (2012).
[1] Bensah., Y. D and Foosnaes, T., The nature and effect of sulphur compounds on CO2 and air reactivity of petrol coke,ARPN Journal of Engineering and Applied Sciences, 5, 6, 35-43 (2010).
Conference oral presentations with extended abstracts
[1] Sekhar, J.A., Li, H.P., Weber, G., Dey, G. K., and Bensah Y. D.Relating Entropy Rate Models to Combustion Kinetic Models for Nano-Crystal Formation especially for Oncology, XI International Symposium on Self-Propagating High Temperature Synthesis, 5-9 September 2011, Attica-Greece (Oral Presentation).
[2] Sekhar, J. A., Li, H. P., Dey, G. K., Bensah, Y. D.,Oscillatory Entropic Routes to Nanostructure Formation, International conference on Nanostructured, Nanotech and advanced materials, University of Gitam-India, December 17-19, 2010 (Oral Presentation).
[3] Bensah, Y. D and Awudza, J .A. M., Performance characteristics of ethyl ester of Jatropha Curcas Linn oil as biodiesel (14th Annual Conference of the Ghana Chemical Society, 2003)
Conference poster presentations
[1] Bensah, Y.D and Sekhar, J.A. An assessment of the maximum entropy production rate for the prediction of solidification bifurcations during directional solidification, The 142nd Annual Conference and Exhibition of TMS, March 3-7, San-Antonio, Texas-USA (Poster Presentation)
[2] Bensah, Y. D., and Damoah, L.N.W., “Towards the holy grail of nanotechnology: the promise of carbon nanotube in drug delivery, Second Ghana Biomedical Convention, Accra-Ghana, August 12-14, 2009, p. 57 (Poster Presentation).
Special lecture
[1] Bensah, Y. D., Carbon Nanotubes: Materials “messiah” for novel technological advancement, Inter-Faculty Lecture, University of Ghana, Legon-Accra, Ghana, April 16, 2009 (Special Lecture).