Article
Multidisciplinary Sciences
Binxin Fu, Rosa M. Espinosa-Marzal
Summary: Nanoscale friction measurements were conducted on calcite single crystals to study the influence of surface roughness, contact aging, and different environments. The results showed that friction behavior varied significantly between dry and aqueous environments, with water environment even eliminating velocity-weakening friction caused by atomic attrition. Friction rate parameters and memory distance also exhibited differences between dry and aqueous environments, with implications for understanding fault stability and friction laws.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2022)
Article
Biology
Dominik Nemeth, Gyorgyi Ponyai
Summary: The clinical characteristics of contact hypersensitivity in the elderly patient population were analyzed in this study. Contact dermatitis was the most common diagnosis, followed by psoriasis. The most common contact allergens identified were preservatives, balsam of Peru, and nickel. It is important to conduct patch testing to verify contact hypersensitivity in older individuals, even for conditions such as contact dermatitis, venous stasis dermatitis, rosacea, and atopic dermatitis.
Article
Chemistry, Multidisciplinary
Antoine Laine, Andrea Vanossi, Antoine Nigues, Erio Tosatti, Alessandro Siria
Summary: In this study, an experimental and simulation approach was used to investigate the successive live phases of atomic scale friction by applying an oscillatory shear force with increasing amplitude. The demonstration with controlled gold nanocontacts sliding on graphite revealed phenomena bridging the gap between initial depinning and large speed sliding.
Article
Mathematics, Interdisciplinary Applications
Luning Fang, Dan Negrut
Summary: The paper introduces a phenomenological model to evaluate friction between two bodies, capable of calculating slide, roll, and spin friction loads simultaneously. It provides a comprehensive solution for friction issues in a 3D setup.
COMPUTATIONAL PARTICLE MECHANICS
(2021)
Article
Chemistry, Multidisciplinary
Niklas A. Weber, Hendrik Schmidt, Tim Sievert, Christian Jooss, Friedrich Guethoff, Vasily Moshneaga, Konrad Samwer, Matthias Krueger, Cynthia A. Volkert
Summary: This study investigates the mechanism of friction at sliding contacts, proposing that friction can be explained by considering the damping of stick-slip pulses. The findings provide a basis for reconciling controversies in literature studies on friction and suggest possible tactics for controlling friction.
Article
Computer Science, Software Engineering
Chongyao Zhao, Jinkeng Lin, Tianyu Wang, Hujun Bao, Jin Huang
Summary: This article introduces a simple and compact representation method for simulating piecewise linear inextensible Cosserat rods. The method matches the degrees of freedom and satisfies all the constraints, and solves the linear equations in nearly linear complexity by exploiting special non-zero patterns. In addition, a symmetric positive-definite preconditioner is proposed to significantly accelerate the solver. Compared with other technical choices, this method has better performance and stability.
COMPUTER GRAPHICS FORUM
(2022)
Article
Materials Science, Multidisciplinary
Joseph M. Monti, Lars Pastewka, Mark O. Robbins
Summary: Surface roughness affects the contact area and geometry of solids. Small contact patches have simple geometries and low pressure, while larger contact patches have higher pressure and can be ramified with regions out of contact. Bubbles also affect the area and perimeter of contact patches.
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
(2022)
Article
Engineering, Mechanical
Xinfeng Tan, Dan Guo, Jianbin Luo
Summary: This study demonstrates the distance-dependent friction energy dissipation between the tip and the heterogeneous polymers using bimodal atomic force microscopy method, proposes the concept of friction dissipation coefficient, and determines three different contact states. The research offers an effective method for directly detecting friction dissipation and obtaining high resolution images, overcoming the disadvantages of existing methods.
Article
Engineering, Mechanical
Arata Ishizako, Masaki Tomosada, Kazuo Hokkirigawa, Takeshi Yamaguchi
Summary: The friction coefficients between a glass plate and rubber blocks with different end-face corner radii were investigated. It was found that rubber blocks with a larger end-face corner radius exhibited higher friction coefficients under dry conditions, while rubber blocks with a smaller end-face corner radius had higher friction coefficients under lubrication conditions. Additionally, the friction coefficients for rubber blocks with a smaller end-face corner radius increased with the sliding velocity and lubricant viscosity due to the formation of a fluid-free gap at the contact interface.
TRIBOLOGY INTERNATIONAL
(2022)
Article
Engineering, Mechanical
Arata Ishizako, Hide Matsumoto, Takeshi Yamaguchi
Summary: The study investigates the friction and area of the fluid-free gap between a glass plate and rubber blocks with different end-face corner radii under glycerin lubrication. The results indicate that decreasing the end-face corner radius increases both the friction coefficient and area of the fluid-free gap, suggesting a positive correlation between the area and friction coefficient. The existence of the fluid-free gap may be attributed to the negative fluid pressure caused by rubber block deformation, resulting in increased contact pressure on the front side of the rubber block. These findings may have implications for the development of rubber products, such as shoe outsoles, that exhibit high friction under lubrication.
TRIBOLOGY INTERNATIONAL
(2023)
Article
Engineering, Mechanical
Martin Kraus, Matthias Lenzen, Marion Merklein
Summary: This study utilizes a sheet metal compression test to describe the relationship between friction values and strain, confirming that friction values change during the forming process.
Article
Computer Science, Software Engineering
Egor Larionov, Ye Fan, Dinesh K. Pai
Summary: This study proposes a new method for solving frictional contacts against deforming implicit surface representations, addressing the lack of intrinsic properties in polygonal surfaces. By using a variational formulation of dynamics and elasticity, contact constraints can be naturally included. The method also allows for decoupling of friction from elasticity, enabling different solvers to be used in each step.
ACM TRANSACTIONS ON GRAPHICS
(2021)
Article
Physics, Fluids & Plasmas
Pedro J. Martinez, Enrico Gnecco, Juan J. Mazo
Summary: This study investigates the quantifiable characteristics of wave-like features observed on polymer surfaces when examined with AFM, and demonstrates the presence of ripples and dotted regions under different parameter values. The amplitude, period, and orientation of these features are numerically estimated, revealing a cooperative process involving the scanning of multiple lines leading to the emergence of ripples.
Article
Computer Science, Interdisciplinary Applications
Julio Blanco-Lorenzo, Sheng Liu, Javier Santamaria, Paul A. Meehan, Ernesto G. Vadillo
Summary: Numerical analyses were conducted on the roller-raceway contact in a spherical roller bearing using frictional contact models of varying complexity. The study utilized models such as CECT (Conformal Exact Contact Theory) based on Kalker's exact contact theory and detailed Finite Element models. The adequacy of simplified contact solutions was evaluated by comparing them with solutions obtained from more comprehensive models. Additionally, the application of the exact contact theory, commonly used in wheel-rail systems, was demonstrated in contact mechanics analyses of rolling bearings, including implementation details. Different normal loads and friction levels were analyzed, leading to the identification of two distinct steady equilibrium configurations for the roller.
JOURNAL OF COMPUTATIONAL DESIGN AND ENGINEERING
(2023)
Article
Engineering, Mechanical
Fitsum B. Tewelde, Tianfeng Zhou, Jia Zhou, Weijia Guo, Bin Zhao, Xiangyu Ge, Wenzhong Wang, Xiaoli Wang, Xibin Wang
Summary: This study examined the impact of asymmetric surface texturing on directional friction in a dry environment. Asymmetric micro-grooves were created on an electroless nickel phosphorous (Ni-P) plated disk using a diamond cutting process. Sliding tests were conducted in both clockwise (CW) and counter-clockwise (CCW) directions against polyether-ether-ketones (PEEK) material at various texture densities. The results indicate that asymmetric surface texturing has a significant effect on directional friction. At a texture density of 70%, the friction coefficient in the CW direction increased by 28.1% compared to the CCW direction. The lowest texture density caused a 61.3% increase in friction coefficient during CW rotation compared to the reference untextured surface.
TRIBOLOGY INTERNATIONAL
(2023)
Article
Physics, Multidisciplinary
Wen Wang, Dirk Dietzel, Andre Schirmeisen
Summary: A study was conducted on the wear tracks on ionic crystals created by reciprocating single asperity scratch tests using atomic force microscopy. It was found that the wear depth exhibited nonmonotonic behavior with temperature, transitioning between two different regimes with the occurrence of quasiperiodic ripple formation. A thermally activated bond breaking model explained the wear data at low temperatures, but failed above a certain temperature threshold, which was later resolved by geometrically separating the ripple mounds from the troughs to achieve agreement with Arrhenius kinetics over the full temperature range.
PHYSICAL REVIEW LETTERS
(2021)
Article
Chemistry, Multidisciplinary
Qigang Zhong, Alexander Ihle, Sebastian Ahles, Hermann A. Wegner, Andre Schirmeisen, Daniel Ebeling
Summary: Constructing low-dimensional covalent assemblies with tailored size and connectivity is challenging but important in molecular electronics for tuning the properties of quantum materials. A versatile approach has been developed for building such structures block by block on a surface through highly selective tip-induced intermolecular reactions.
Article
Quantum Science & Technology
A. Sachenko, V. P. Kostylyov, R. M. Korkishko, V. M. Vlasyuk, I. O. Sokolovskyi, B. F. Dvernikov, V. V. Chernenko, M. Evstigneev
Summary: A new approach for modeling the parameters of high efficiency textured silicon solar cells has been proposed, incorporating factors such as non-radiative Auger recombination and electron-hole pairs recombination. The method includes a simple phenomenological expression for the external quantum efficiency and has been used to theoretically determine key parameters of the textured silicon SCs. This approach can be used to optimize the characteristics of high efficiency textured SCs based on monocrystalline silicon.
SEMICONDUCTOR PHYSICS QUANTUM ELECTRONICS & OPTOELECTRONICS
(2021)
Article
Mechanics
Peter Reimann
Summary: The observable long-time behavior of an isolated many-body system after a quantum quench is studied, and it is found that for common spin Hamiltonians, there is an absence of thermalization. The pre-quench Hamiltonian must exhibit a Z (2) symmetry, while the post-quench Hamiltonian must violate this symmetry.
JOURNAL OF STATISTICAL MECHANICS-THEORY AND EXPERIMENT
(2021)
Article
Energy & Fuels
Mykhaylo Evstigneev, Faezeh Farahani
Summary: An exact analytical expression for the probability of photon reabsorption and recycling in a solar cell is derived. The existing approximations are found to agree with the exact formula within 5%. The most accurate approximation sets the reabsorption probability to the weak-absorption limit of the cell absorptance. The maximal photoconversion efficiency of a silicon solar cell is evaluated to be 29.5% with a base thickness of 98 μm.
IEEE JOURNAL OF PHOTOVOLTAICS
(2023)
Article
Physics, Multidisciplinary
Ebru Cihan, Dirk Dietzel, Benedykt R. Jany, Andre Schirmeisen
Summary: Structural superlubricity refers to greatly reduced friction between incommensurate atomically flat surfaces. By measuring the friction of antimony nanoparticles on graphite, this study found a characteristic change in friction during the amorphous-crystalline phase transition above 420 K, which was irreversible upon cooling. The results validate the concept that structural superlubricity is determined by the effectiveness of atomic force canceling processes.
PHYSICAL REVIEW LETTERS
(2023)
Article
Physics, Fluids & Plasmas
Amir Kaffashnia, Mykhaylo Evstigneev
Summary: Diffusion of Brownian particle in a stochastic harmonic oscillator chain is studied. The particle exhibits long Lévy flights at high temperatures, in contrast to the usual Brownian motion driven by Gaussian white noise. The diffusion coefficient and the average damping force depend on the temperature, and the average flight time and flight length have a certain proportionality at high temperatures. The probability distribution of flight lengths decays with a universal exponent.
Article
Chemistry, Multidisciplinary
Daniel Martin-Jimenez, Michael G. Ruppert, Alexander Ihle, Sebastian Ahles, Hermann A. Wegner, Andre Schirmeisen, Daniel Ebeling
Summary: This study analyzes the suitability of qPlus sensors for modern multifrequency AFM techniques and demonstrates their ability to achieve submolecular resolution imaging. The results show that using torsional and flexural higher eigenmodes can produce good imaging results and reveal specific contrast features.
Article
Materials Science, Multidisciplinary
Lennart Dabelow, Patrick Vorndamme, Peter Reimann
Summary: Finding conditions for thermalization in macroscopic systems from the underlying quantum dynamics of their microscopic constituents remains a challenge in theoretical physics. This study demonstrates analytically that systems satisfying the weak eigenstate thermalization hypothesis exhibit thermalization for two specific far-from-equilibrium initial conditions, providing insights into the problem of thermalization.
Article
Physics, Fluids & Plasmas
Amir Kaffashnia, Mykhaylo Evstigneev
Summary: This study discusses the dispersionless transport of weakly damped Brownian particles in a tilted periodic potential, revealing the reason why the diffusion coefficient cannot be measured within the plateau region. It also proposes a method for accurately determining the diffusion coefficient by observing the particle trajectory only within a small part of the plateau region.
Proceedings Paper
Energy & Fuels
A. Sachenko, V. P. Kostylyov, V. M. Vlasiuk, I. O. Sokolovskyi, M. Evstigneev, A. Shkrebtii, D. Johnston, P. Michael, T. Missimer
Summary: An improved theoretical model was developed and applied to optimize characteristics of highly efficient textured solar cells. An empirical formula for external quantum efficiency was proposed to compare theoretical results with experimental spectral dependencies, allowing the optimization of key parameters in the solar cells. Theoretical results were used to optimize parameters such as base thickness and doping level of the solar cells.
2021 IEEE 48TH PHOTOVOLTAIC SPECIALISTS CONFERENCE (PVSC)
(2021)
Proceedings Paper
Energy & Fuels
Anatoliy Sachenko, Vitaliy Kostylyov, Viktor Vlasiuk, Igor Sokolovskyi, Mykhaylo Evstigneev
Summary: The performance of high-efficiency textured silicon solar cells is modeled with various recombination mechanisms considered, and key parameters are theoretically determined. The results are in good agreement with experimental results from heterojunction solar cells with record efficiency.
2021 IEEE 48TH PHOTOVOLTAIC SPECIALISTS CONFERENCE (PVSC)
(2021)
Proceedings Paper
Energy & Fuels
Anatoliy Sachenko, Vitaliy Kostylyov, Viktor Vlasiuk, Igor Sokolovskyi, Mykhaylo Evstigneev
Summary: Theoretical calculations for short-circuit current, open-circuit voltage, and photoconversion efficiency of silicon back contact solar cells (BCSC) with planar surfaces have been conducted, taking into account nonradiative trap-assisted exciton Auger recombination and recombination in the space-charge region in addition to the usual recombination channels. It is found that these two recombination mechanisms are crucial in the BCSCs in the maximum power operation regime, with model results showing good agreement with experimental results from the literature.
2021 IEEE 48TH PHOTOVOLTAIC SPECIALISTS CONFERENCE (PVSC)
(2021)
Article
Physics, Fluids & Plasmas
Peter Reimann, Lennart Dabelow
Summary: This study revisits Deutsch's groundbreaking investigation on how a closed many-body quantum system approaches thermal equilibrium, demonstrating how to carry out important steps that were missing in the paper and significantly extending the class of admitted systems.
Article
Materials Science, Multidisciplinary
Matthias Vorholzer, Dirk Dietzel, Ebru Cihan, Andre Schirmeisen
Summary: This study investigates the role of shear stress in contact aging phenomena, revealing that shear stress does have an impact on contact aging, especially exhibiting special effects under the influence of temperature.
