Nano, micro, and macro-scale effects on cochlear tuning

2019 ◽  
Vol 145 (3) ◽  
pp. 1908-1908
Author(s):  
Aritra Sasmal ◽  
Karl Grosh
Keyword(s):  
Scale Effects ◽  
Macro Scale ◽  
Cochlear Tuning

Comparing Micro- and Macro-Level Rheological Properties of Polymeric and Reclaimed Asphalt Pavement-Modified Asphalt Binders

2021 ◽  
pp. 036119812110288
Author(s):  
Tandra Bagchi ◽  
Zahid Hossain ◽  
Mohammed Ziaur Rahaman ◽  
Gaylon Baumgardner
Keyword(s):  
Mechanical Properties ◽  
Scale Effects ◽  
Asphalt Pavement ◽  
Linear Trend ◽  
Asphalt Binders ◽  
Reclaimed Asphalt Pavement ◽  
Reclaimed Asphalt ◽  
Multi Scale ◽  
Macro Scale ◽  
Scale Properties

Multi-scale evaluation of the rheological and mechanical properties of asphalt binder has substantial importance in understanding the binder’s micro- and macro-scale properties. This study compares the macro- and micro-scale mechanistic properties of asphalt binders. Test samples used in this study include performance grade binders (PG 64-22) from two different sources along with their modified counterparts. The modifiers include polyphosphoric acid (PPA), styrene-butadiene-styrene (SBS), a combination of SBS and PPA, and reclaimed asphalt pavement. To achieve the goal of this study, atomic force microscope technology was utilized to estimate the asphalt binder’s micro-mechanical properties (e.g., Derjaguin, Muller, Toropov modulus and deformation). On the other hand, data on the macro-scale properties—such as rutting factor (G*/sinδ), consistency and penetration—of the selected binders were analyzed and compared with the aforementioned micro-level properties. The comparative analyses indicated that the micro-mechanical properties of asphalt binders followed a linear trend with the macro-scale properties. The findings of this study are expected to help researchers and pavement professionals in modeling asphalt materials when multi-scale effects are deemed to be necessary.

Vortical Structures and Mixing Characteristics of Flow in Randomly Packed Porous Media During Transition to Turbulence

2021 ◽  
Author(s):  
Reza M. Ziazi ◽  
James A. Liburdy
Keyword(s):  
Porous Media ◽  
Scale Effects ◽  
Turbulent Transport ◽  
Flow Characteristics ◽  
Transition Process ◽  
Industrial Applications ◽  
Transition To Turbulence ◽  
Vortical Structures ◽  
Macro Scale ◽  
Mixing Characteristics

Abstract Transition to turbulence in randomly arranged porous media is observed in nature and industrial applications. The flow characteristics of these flows during transition are not well identified. This work describes the parameters influencing on overall mixing during the transition process from the perspective of scale of vortical structures and dispersion characteristics by addressing the following questions: (a) what are the dominant mechanisms evolution of scale of vortices, and (b) how does the inertial effects of vortical structures enhance the flow transport properties through tortuosity and dispersion. Time-resolved PIV is used to investigate the flow in the macro-scale Reynolds numbers from 100 to 1000 to show the pore- versus macro-scale effects on the scale of the flow dispersion, and their contribution in interpreting the overall flow mixing. Lagrangian mixing characteristics based on Eulerian local pore velocity variances is used to demonstrate the bed characteristics for flow in randomly distributed porous media flows. The dispersion asymptotically approaches 0.085 % of VintDH longitudinally which shows the turbulent transport is increased by enhancing the Reynolds number that matches very well with the literature.

scholarly journals A Novel Multi-Scale Particle Morphology Descriptor with the Application of SPHERICAL Harmonics

Materials ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3286
Author(s):  
Wei Xiong ◽  
Jianfeng Wang ◽  
Zhuang Cheng
Keyword(s):  
Surface Roughness ◽  
Scale Effect ◽  
Scale Effects ◽  
Particle Surface ◽  
Relative Length ◽  
Particle Morphology ◽  
Length Scale ◽  
Multi Scale ◽  
Rate Of Increase ◽  
Macro Scale

Particle morphology is of great significance to the grain- and macro-scale behaviors of granular soils. Most existing traditional morphology descriptors have three perennial limitations, i.e., dissensus of definition, inter-scale effect, and surface roughness heterogeneity, which limit the accurate representation of particle morphology. The inter-scale effect refers to the inaccurate representation of the morphological features at the target relative length scale (RLS, i.e., length scale with respective to particle size) caused by the inclusion of additional morphological details existing at other RLS. To effectively eliminate the inter-scale effect and reflect surface roughness heterogeneity, a novel spherical harmonic-based multi-scale morphology descriptor Rinc is proposed to depict the incremental morphology variation (IMV) at different RLS. The following conclusions were drawn: (1) the IMV at each RLS decreases with decreasing RLS while the corresponding particle surface is, in general, getting rougher; (2) artificial neural network (ANN)-based mean impact values (MIVs) of Rinc at different RLS are calculated and the results prove the effective elimination of inter-scale effects by using Rinc; (3) Rinc shows a positive correlation with the rate of increase of surface area RSA at all RLS; (4) Rinc can be utilized to quantify the irregularity and roughness; (5) the surface morphology of a given particle shows different morphology variation in different sections, as well as different variation trends at different RLS. With the capability of eliminating the existing limitations of traditional morphology descriptors, the novel multi-scale descriptor proposed in this paper is very suitable for acting as a morphological gene to represent the multi-scale feature of particle morphology.

Heat Transfer Enhancement in Nanofluid Suspensions

2004 ◽  
Author(s):  
Peter Vadasz ◽  
Johnathan J. Vadasz ◽  
Saneshan Govender
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Scale Effects ◽  
Nano Scale ◽  
Sufficient Detail ◽  
Macro Scale ◽  
Wave Effects ◽  
Conduction Theory ◽  
Wave Phenomena ◽  
Liquid Layering

The investigation into possible applications of the thermal wave conduction theory to explain the spectacular enhancement of heat flux by a factor of between 1.4 to 2.5 in nanofluid suspensions is presented. While other possible explanations have been proposed to settle this discrepancy they were not investigated into sufficient detail for providing a definite answer and they all apply at the nano-scale level rather than bridging between the nano-scale effects and the macro-system investigated. The possible mechanisms proposed so far are Brownian motion, liquid layering at the liquid/particle interface, ballistic phonon effects, nanoparticle clustering as well as convection and wave effects. Furthermore, most available methods for measuring thermal conductivity assume and make use explicitly of the Fourier mechanism of heat transfer. If somehow the nano-level heat transfer effects impact profoundly on the resulting heat flux at the macro-level, possibly via wave phenomena, the whole concept behind the measurement device might be flawed. The present paper presents a possible way by which the transitions from nano-scale via the micro-scales towards the macro-scale occur, hence bridging the gap from nano devices to macro systems performance.

scholarly journals Microbial-Induced Carbonate Precipitation: A Review on Influencing Factors and Applications

2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Junhui Zhang ◽  
Xiuzhi Shi ◽  
Xin Chen ◽  
Xiaofeng Huo ◽  
Zhi Yu
Keyword(s):  
Calcium Carbonate ◽  
Ph Value ◽  
Scale Effects ◽  
Bacterial Species ◽  
Carbonate Precipitation ◽  
Optimization Strategy ◽  
Calcium Carbonate Precipitation ◽  
Growth Environment ◽  
Macro Scale ◽  
Rock And Soil

Based on recent literary sources, this survey discusses the effects of main factors influencing the microbial-induced calcium carbonate precipitation (MICP), including the bacterial species, bacterial concentration, temperature, and pH value. While the MICP technology has been widely adopted to improve rock and soil characteristics, it has excellent development prospects in many other fields. The breakthrough solutions in the MICP technology are improving geotechnical and foundation sand properties, repairing cement-based materials, using mineralized film mulching to protect cultural relics, enhancing properties of tailings, desert control, and heavy metal environmental restoration, etc., are discussed. The experimental findings prove that MICP can improve the strength, stiffness, liquefaction resistance, erosion resistance, and permeability of geotechnical materials and maintain the good permeability and permeability of the soil and improve the growth environment of plants. It is an environment-friendly bioengineering technology. Because microbial mineralization involves a series of biochemical and ionic chemical reactions, there are many reaction steps in the solidification process and the solidification effect of MICP is restricted and affected by many factors. The comprehensive analysis and optimization strategy on MICP industrial implementation should account for micro- and macro-scale effects: the type of bacteria, the concentration of bacteria and cementation solutions, ambient temperature, pH value, and other factors directly affect the crystallization type, morphology, and size of calcium carbonate from the microscopic standpoint, while the macro-scale factors control the rock and soil mineralization. The limitations and prospects of the MICP technology are outlined.

Analysis of Integral Transform Solutions for Thermally Developing Flow in Microchannels With Isothermal Wall

2011 ◽  
Author(s):  
D. J. N. M. Chalhub ◽  
L. A. Sphaier
Keyword(s):  
Heat Transfer ◽  
Mass Transfer ◽  
Heat And Mass Transfer ◽  
Flow Problem ◽  
Integral Transform ◽  
Scale Effects ◽  
Experimental Studies ◽  
Macro Scale ◽  
Optimum Solution ◽  
Solution Methodology

There is a growing interest for applications of heat and mass transfer in microchannels. Consequently, several numerical and experimental studies related to transport phenomena in microchannels have been carried-out. The flow problem in microchannels is different from the macro-scale problems due to rarefaction effects, surface roughness, viscous dissipation heating as well as other effects. As a result, a number of studies have been proposed for investigating the micro-flow problem and how each of these phenomena affect heat and mass transfer characteristics. Naturally, there is particular focus on how the observed micro-scale phenomena differ from the traditionally known macro-scale effects. In the realm of simulation studies for heat transfer in micro-sized channels, this paper proposes a comparison between hybrid solution strategies for solving steady heat transfer problems within microchannels. The Generalized Integral Transform Technique (GITT) is employed as the main solution methodology; however, different solution approaches are investigated in order to determine advantages and drawbacks of each alternative. The presented results can serve as guidance for choosing an optimum solution methodology for thermally developing heat transfer in microchannels using GITT implementations.

Defects of Porous Self-Structured Anodic Alumina Oxide on Industrial Aluminum Grades

2018 ◽  
Vol 284 ◽  
pp. 1134-1139 ◽  
Author(s):  
Yu.V. Yuferov ◽  
F.M. Zykov ◽  
E. Malshakova
Keyword(s):  
Scale Effects ◽  
Video Recording ◽  
Step Method ◽  
Industrial Grade ◽  
Macro Scale ◽  
Anodic Alumina Oxide ◽  
Anodization Process ◽  
Alumina Oxide ◽  
Micrometer Scale ◽  
Industrial Aluminum

In this paper, an experimental examination of defects in anodization of aluminum of the industrial grade A7E is presented. A two-step method of anodizing was used in an electrolyte containing 20% wt. % sulfuric acid at 0 ° C at constant voltage. Micro-video recording was carried out in both anodizing stages to examine anodizing process on a micrometer scale, and to determine the corresponding macro-scale effects indicating incorrect anodization process. Macro-scale effects in the form of gas evolution were detected. Subsequently confirmed on the surface of the coating from which it occurred, using scanning electron microscopy. Methods for preparing samples subject to anodization are proposed to reduce the number of defects. The results should lead to industrial implementation of inexpensive and high-quality nanoporous anode materials with a variety of applications.

Macro-scale effects over filtered and residual stresses in gas-solid riser flows

2019 ◽  
Vol 195 ◽  
pp. 553-564 ◽  
Author(s):  
Joseph Mouallem ◽  
Seyed R.A. Niaki ◽  
Norman Chavez-Cussy ◽  
Christian C. Milioli ◽  
Fernando E. Milioli
Keyword(s):  
Residual Stresses ◽  
Scale Effects ◽  
Macro Scale ◽  
Riser Flows

Photo-thermal study of a layer of randomly distributed gold nanoparticles: from nano-localization to macro-scale effects

2017 ◽  
Vol 50 (43) ◽  
pp. 435302 ◽  
Author(s):  
Luigia Pezzi ◽  
Giovanna Palermo ◽  
Alessandro Veltri ◽  
Ugo Cataldi ◽  
Thomas Bürgi ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Scale Effects ◽  
Thermal Study ◽  
Macro Scale
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