Understanding Of Transport Behavior Research Articles

Pressure-induced extreme anisotropic behavior of thermoelectric properties in crystalline β-CuSCN

Applying hydrostatic pressure has emerged as a promising strategy for regulating the properties of thermoelectric materials, particularly in the case of β-CuSCN, which has garnered attention due to its ultra-low thermal conductivity and potential applications in thermoelectric devices. Herein, we investigate the intrinsic mechanism governing the electron-thermal transport properties of β-CuSCN under hydrostatic pressure. It was found that ZT decreased by 30 % along the in-plane direction while increasing by 24 % along the out-of-plane direction following the application of hydrostatic pressure, respectively. Our results reveal that the competitive relationship between pressure-driven effects on phonon dynamics and electronic structure influences the thermoelectric properties of β-CuSCN. For the transport mechanism, the compression alters phonon dispersion by enhancing atomic interactions, which leads to an increase in lattice thermal conductivity. On the other hand, despite strong coupling between electrical transport parameters, a net increase in power factor is achieved through pressure-induced bandgap narrowing. As a result, the thermoelectric properties demonstrate contrary variation tendency along the in-plane and out-of-plane directions. Our research deepens our understanding of transport behavior under extreme pressure conditions and provides valuable insights into the fundamental relationship between structural deformation and thermoelectric performance.

Rivalry and excludability as characteristics of tools aimed at making cycling in cities more attractive

Motivation: Urban transport systems are complex and sophisticated, while different passenger transport modes are more or less attractive, depending on their characteristics and demands of transport users. According to many municipalities, cycling is considered one of the most required ways of commuting, because it generates multiple benefits and low levels of external costs of transport. Thus, many cities try to increase the share of cycling in the modal split by the way of various interventions. Effects of these efforts are different, depending on levels of rivalry and excludability of goods provided, which influence the attractiveness of cycling. Aim: The main aim of the paper is (1) to describe key elements of and some solutions for cycling systems in urban areas with focus on two characteristics of goods: rivalry and excludability, and (2) to examine, how different levels of rivalry and excludability influence the attractiveness of cycling and contribute to required effects of cycling policy. Results: A change in levels of rivalry and excludability can lead to an increased attractive-ness of cycling. Instruments, that play a crucial role, are e.g. separated cycling infrastructure, leading to a (partially) exclusion of other transport users, as well as solutions for eliminating self-exclusion from cycling or exclusion of people with disabilities. Further research on levels of rivalry and excludability in terms of the complexity of transport systems can contribute to a better understanding of transport behaviour. This, in turn, can result in a creation of adequate solutions and it can be useful while estimating future effects.

Fast laboratory-based micro-computed tomography for pore-scale research: Illustrative experiments and perspectives on the future

Over the past decade, the wide-spread implementation of laboratory-based X-ray micro-computed tomography (micro-CT) scanners has revolutionized both the experimental and numerical research on pore-scale transport in geological materials. The availability of these scanners has opened up the possibility to image a rock's pore space in 3D almost routinely to many researchers. While challenges do persist in this field, we treat the next frontier in laboratory-based micro-CT scanning: in-situ, time-resolved imaging of dynamic processes. Extremely fast (even sub-second) micro-CT imaging has become possible at synchrotron facilities over the last few years, however, the restricted accessibility of synchrotrons limits the amount of experiments which can be performed. The much smaller X-ray flux in laboratory-based systems bounds the time resolution which can be attained at these facilities. Nevertheless, progress is being made to improve the quality of measurements performed on the sub-minute time scale. We illustrate this by presenting cutting-edge pore scale experiments visualizing two-phase flow and solute transport in real-time with a lab-based environmental micro-CT set-up. To outline the current state of this young field and its relevance to pore-scale transport research, we critically examine its current bottlenecks and their possible solutions, both on the hardware and the software level. Further developments in laboratory-based, time-resolved imaging could prove greatly beneficial to our understanding of transport behavior in geological materials and to the improvement of pore-scale modeling by providing valuable validation.

Fluid Transport Phenomena in Fibrous Materials

Fluid transport is one of the most frequently observed phenomena in the processing and end uses of fibrous materials. Fibrous materials have a unique structure of complex geometry, characterized by system anisotropy and heterogeneity. The characterization of fibrous materials, therefore, is critical in the understanding of transport behavior through fibrous structures, and is discussed after an introductory section. Subsequent sections cover topics of various transport processes through fibrous structures, including wicking and wetting, resin impregnation in liquid composite molding, filtration and separation in geotextiles, aerosol filtration in fibrous filters, micro/nano scale transport phenomena, and biomedical applications. The fibrous structure is also known for its multi-scale pore distribution from intra-fiber to inter-fiber spaces. This multi-scale effect is even more prominent when micro or nano fibrous materials are concerned, and so multi-scale approaches to address the scale effects of transport behavior in fibrous materials are discussed. Finally, the Ising model of statistical mechanics, a robust computer-simulation tool dealing with the fluid transport problems in fibrous materials, is introduced.