Non-Equilibrium Phonon Transport Across Nanoscale Interfaces

Despite the ubiquity of applications of heat transport across nanoscale interfaces, including integrated circuits, thermoelectrics, and nanotheranostics, an accurate description of phonon transport in these systems remains elusive. Here we present a theoretical and computational framework to describe phonon transport with position, momentum and scattering event resolution. We apply this framework to a single material spherical nanoparticle for which the multidimensional resolution offers insight into the physical origin of phonon thermalization, and length-scale dependent anisotropy of steady-state phonon distributions. We extend the formalism to handle interfaces explicitly and investigate the specific case of semi-coherent materials interfaces by computing the coupling between phonons and interfacial strain resulting from aperiodic array of misfit dislocations. Our framework quantitatively describes the thermal interface resistance within the technologically relevant Si-Ge heterostructures. In future, this formalism could provide new insight into coherent and driven phonon effects in nanoscale materials increasingly accessible via ultrafast, THz and near-field spectroscopies.Comment: 6 pages, 3 figure

Industrial Metal Finishing for Corrosion Control

Industrial Metal Finishing, which includes electro-deposition of metals and alloys, electroless plating, immersion plating, chemical and electropolishing of metals, anodizing etc. form a major component of surface engineering. Corrosion protection is one main reason for the existence of Industrial Metal finishing Although these processes began for decorative and aesthetic purposes, their contribution to corrosion prevention and engineering applications, especially in electronics,aerospace, auto-motive and agriculture industries is markedly increasing. The evolution of industrial metal finishing from an art to a science has been a gradual process. The ABC of corro-sion protection, principle and mechanism, and the latest developments in terms of 6 Es (Environment-friendly, Econ-omical, Excellent. Energy -saving, Extremely fast, and Expertsystem ) have been briefly introduced. Relevant references have been cited for ease of access to the original and detailed literature

Common fixed points and invariant approximation of R-subweakly commuting maps in convex metric spaces

Sufficient conditions for the existence of a common fixed point of R-subweakly commuting mappings are established within the framework of a convex metric space. As applications, we obtain various results on the best approximation for this class of mappings generalizing the results known from the literature.Встановлено достатні умови існування спільної нерухомої точки R-субслабко комутуючих відображень у рамках опуклого метричного простору. Як застосування, одержано різні результати щодо найкращих наближень для згаданого класу відображень, які узагальнюють інші відомі з літератури результати

Clausius formula and the Second law in the process of thermalization

An adiabatic thermalization between $n$ bodies is an irreversible process, leading to a rise in the total entropy of the bodies and yields a final common temperature $T_F$. We express the Clausius formula that computes the entropy change between the initial non-equilibrium state and the final equilibrium state, using another equilibrium state of the $n$ bodies for the given initial entropy, that corresponds to a temperature $T_f$. The second law inequality follows from the fact $T_f < T_F$, under the assumption of positive heat capacities of the bodies. We derive this inequality for the discrete case of $n$ bodies as well as the continuum case of an unequally heated rod. As an example, we illustrate our results for the case of temperature-independent heat capacity.Comment: 10 pages, 1 figur

Mesoporous Carbons for Energy-Efficient Water Splitting to Produce Pure Hydrogen at Room Temperature

Theoretical and experimental aspects of the use of mesoporous carbons in carbon-assisted water electrolysis (CAWE) to produce pure hydrogen at room temperature are presented. It is shown that the electrical energy requirements for CAWE can be as low as 20% of the energy needed for conventional water electrolysis, the extra energy coming from the electrochemical oxidation of carbon occurring at room temperature. Although CO2 is produced at the anode in this process, it is well separated from pure H2 produced at the cathode. Experimental results are reviewed for a variety of carbons with the major focus on the results obtained with carbon BP2000, which has both mesopores and micropores and a nanocarbon produced by the hydrothermal treatment of microcrystalline cellulose