scholarly journals Acoustofluidic centrifuge for nanoparticle enrichment and separation

2021 ◽  
Vol 7 (1) ◽  
pp. eabc0467
Author(s):  
Yuyang Gu ◽  
Chuyi Chen ◽  
Zhangming Mao ◽  
Hunter Bachman ◽  
Ryan Becker ◽  
...  
Keyword(s):  
Material Science ◽  
Acoustic Streaming ◽  
Liquid Droplets ◽  
Nanoparticle Concentration ◽  
Engineering Material ◽  
Physical Mechanisms ◽  
Centrifugation Technique ◽  
Size Based Separation ◽  
Physical Phenomena ◽  
Size Scales

Liquid droplets have been studied for decades and have recently experienced renewed attention as a simplified model for numerous fascinating physical phenomena occurring on size scales from the cell nucleus to stellar black holes. Here, we present an acoustofluidic centrifugation technique that leverages an entanglement of acoustic wave actuation and the spin of a fluidic droplet to enable nanoparticle enrichment and separation. By combining acoustic streaming and droplet spinning, rapid (<1 min) nanoparticle concentration and size-based separation are achieved with a resolution sufficient to identify and isolate exosome subpopulations. The underlying physical mechanisms have been characterized both numerically and experimentally, and the ability to process biological samples (including DNA segments and exosome subpopulations) has been successfully demonstrated. Together, this acoustofluidic centrifuge overcomes existing limitations in the manipulation of nanoscale (<100 nm) bioparticles and can be valuable for various applications in the fields of biology, chemistry, engineering, material science, and medicine.

Focused Ion Beam Irradiation Induced Damages on CMOS and Bipolar Technologies

1998 ◽  
Author(s):  
J. Benbrik ◽  
G. Rolland ◽  
P. Perdu ◽  
B. Benteo ◽  
M. Casari ◽  
...  
Keyword(s):  
Focused Ion Beam ◽  
Ion Beam ◽  
Electronic Devices ◽  
Complete Characterization ◽  
Bipolar Transistors ◽  
Ion Beam Irradiation ◽  
Physical Mechanisms ◽  
Dc Characteristics ◽  
Electrical Degradation ◽  
Physical Phenomena

Abstract Focused Ion Beam is commonly used for IC repairs and modifications. However, FIB operation may also induce a damaging impact which can takes place far from the working area due to the charge-up phenomenon. A complete characterization joined to an in-depth understanding of the physical phenomena arising from FIB irradiation is therefore necessary to take into account spurious FIB induced effects and to enhance the success of FIB modifications. In this paper, we present the effects of FIB irradiation on the electrical DC performances of different electronic devices such as nMOS and pMOS transistors, CMOS inverters, PN junctions and bipolar transistors. From the observed behavior of the DC characteristics evolution of the devices, some suggestions about physical mechanisms inducing the electrical degradation are proposed.

Nonlinear Refractive Index of Silicon Nanoparticles: A Short Review

2014 ◽  
Vol 1 (2) ◽  
pp. 87-97
Author(s):  
Sudakshina Prusty
Keyword(s):  
Refractive Index ◽  
Nonlinear Refractive Index ◽  
Phase Modulation ◽  
Silicon Nanoparticles ◽  
Nonlinear Coefficient ◽  
Short Review ◽  
Self Phase Modulation ◽  
Physical Mechanisms ◽  
Self Focusing ◽  
Physical Phenomena

This article discusses the nonlinear refractive index of silicon nanoparticles starting from the basic formalism to some of the consequent physical phenomena like self focusing and self phase modulation. Several experimental techniques mainly based on Z-scan are discussed to measure the nonlinear refractive index. Another less explored technique for silicon nanoparticles, which studies the far-field optical fringe pattern formed by spatial self-phase modulation, is also discussed. Computation of the nonlinear refractive index is shown in detail by employing these two techniques. While Z-scan can estimate the nonlinear coefficient of a medium in a chosen time scale, the optical fringe method can predict the overall nonlinear refractive index due to all possible physical mechanisms. Some of the recent results for silicon nanoparticles using these two techniques are also discussed.

scholarly journals The Exact Endoscopic Effect on the Peristaltic Flow of a Nanofluid

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
S. M. Khaled ◽  
Abdelhalim Ebaid ◽  
Fahd Al Mutairi
Keyword(s):  
Pressure Gradient ◽  
Homotopy Perturbation Method ◽  
Nonlinear Partial Differential Equations ◽  
Pressure Rise ◽  
Approximate Solutions ◽  
Peristaltic Flow ◽  
Nanoparticle Concentration ◽  
Homotopy Perturbation ◽  
Physical Phenomena ◽  
The Mathematical Model

The problem of the peristaltic flow of a nanofluid under the effect of an endoscope is reinvestigated. The mathematical model is governed by a system of linear and nonlinear partial differential equations with prescribed boundary conditions. Really, the exact solution for any physical problem, if available, is of great importance which inevitably leads to a better understanding of the behaviour of the involved physical phenomena. An attempt for doing so has been done in the present paper, where the temperature equation is solved exactly by the help of Laplace transform and, accordingly, the exact expressions for the nanoparticle concentration, the axial velocity, the pressure gradient, and the pressure rise are established. Furthermore, it is showed in this paper that the physical interpretations of some involved phenomena are found totally different than those previously obtained by the approximate solutions using the homotopy perturbation method. In addition, several comparisons between the current results and the approximate ones have been displayed. Finally, the effect of various parameters on the temperature distribution, the nanoparticle concentration, the pressure gradient, and the pressure rise has been also discussed through graphs.

The mechanism of shape instability for a vesicle in extensional flow

2014 ◽  
Vol 750 ◽  
pp. 144-190 ◽  
Author(s):  
Vivek Narsimhan ◽  
Andrew P. Spann ◽  
Eric S. G. Shaqfeh
Keyword(s):  
Aspect Ratio ◽  
Extensional Flow ◽  
Liquid Droplets ◽  
Flow Equations ◽  
Physical Mechanisms ◽  
High Particle ◽  
The Stability ◽  
Scaling Analyses ◽  
Particle Aspect Ratio ◽  
Shape Transitions

AbstractWhen a flexible vesicle is placed in an extensional flow (planar or uniaxial), it undergoes two unique sets of shape transitions that to the best of the authors’ knowledge have not been observed for droplets. At intermediate reduced volumes (i.e. intermediate particle aspect ratio) and high extension rates, the vesicle stretches into an asymmetric dumbbell separated by a long, cylindrical thread. At low reduced volumes (i.e. high particle aspect ratio), the vesicle extends symmetrically without bound, in a manner similar to the breakup of liquid droplets. During this ‘burst’ phase, ‘pearling’ occasionally occurs, where the vesicle develops a series of periodic beads in its central neck. In this paper, we describe the physical mechanisms behind these seemingly unrelated instabilities by solving the Stokes flow equations around a single, fluid-filled particle whose interfacial dynamics is governed by a Helfrich energy (i.e. the membranes are inextensible with bending resistance). By examining the linear stability of the steady-state shapes, we determine that vesicles are destabilized by curvature changes on its interface, similar to the Rayleigh–Plateau phenomenon. This result suggests that the vesicle’s initial geometry plays a large role in its shape transitions under tension. The stability criteria calculated by our simulations and scaling analyses agree well with available experiments. We hope that this work will lend insight into the stretching dynamics of other types of biological particles with nearly incompressible membranes, such as cells.

scholarly journals Heat Transfer Enhancement due to Acoustic Fields: A Methodological Analysis

Acoustics ◽  
2019 ◽  
Vol 1 (1) ◽  
pp. 281-294 ◽  
Author(s):  
Alessandro Franco ◽  
Carlo Bartoli
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Convective Heat Transfer ◽  
Convective Heat ◽  
Convective Heat Transfer Coefficient ◽  
Thermodynamic System ◽  
Industrial Applications ◽  
General Validity ◽  
Physical Mechanisms ◽  
Physical Phenomena

The aim of this paper is to expose the main involved physical phenomena underlying the alteration of convective heat transfer in a heat exchanger subjected to imposed vibrations. This technique seems to have interesting features and industrial applications, such as for efficiency increases, heat transfer rate control and cleanliness action. However, a clear description and comprehension of how vibrations may alter the convective heat transfer coefficient in a heat exchanger has still not been reached due to the complexity of the involved physical mechanisms. For this reason, after a presentation and a schematization of the analyzed thermodynamic system, the fundamental alterations of the thermo-fluid dynamics fields are described. Then, the main involved physical phenomena are exposed for the three cases of gaseous, monophasic liquid and boiling liquid mediums. Finally, on the basis of the characteristics of these described phenomena, some considerations and indications of general validity are presented.

scholarly journals Self-organizing motors divide active liquid droplets

2019 ◽  
Vol 116 (23) ◽  
pp. 11125-11130 ◽  
Author(s):  
Kimberly L. Weirich ◽  
Kinjal Dasbiswas ◽  
Thomas A. Witten ◽  
Suriyanarayanan Vaikuntanathan ◽  
Margaret L. Gardel
Keyword(s):  
Spatial Organization ◽  
Motor Proteins ◽  
Self Organization ◽  
Liquid Droplets ◽  
Droplet Deformation ◽  
Inherent Anisotropy ◽  
Physical Mechanisms ◽  
Active Liquid ◽  
Active Motor ◽  
Outstanding Question

The cytoskeleton is a collection of protein assemblies that dynamically impose spatial structure in cells and coordinate processes such as cell division and mechanical regulation. Biopolymer filaments, cross-linking proteins, and enzymatically active motor proteins collectively self-organize into various precise cytoskeletal assemblies critical for specific biological functions. An outstanding question is how the precise spatial organization arises from the component macromolecules. We develop a system to investigate simple physical mechanisms of self-organization in biological assemblies. Using a minimal set of purified proteins, we create droplets of cross-linked biopolymer filaments. Through the addition of enzymatically active motor proteins, we construct composite assemblies, evocative of cellular structures such as spindles, where the inherent anisotropy drives motor self-organization, droplet deformation, and division into two droplets. These results suggest that simple physical principles underlie self-organization in complex biological assemblies and inform bioinspired materials design.

Meeting Report: First Autumn School on Engineering Material Science with Neutrons and Synchrotron Radiation

2006 ◽  
Vol 19 (1) ◽  
pp. 22-23
Author(s):  
Andreas Schreyer ◽  
Walter Reimers ◽  
Thomas Wroblewski ◽  
Astrid Haibel ◽  
Anke Pyzalla ◽  
...  
Keyword(s):  
Synchrotron Radiation ◽  
Material Science ◽  
Meeting Report ◽  
Engineering Material

Review—Mechanisms of Cavitation Inception

1991 ◽  
Vol 113 (2) ◽  
pp. 163-175 ◽  
Author(s):  
E. P. Rood
Keyword(s):  
Pressure Field ◽  
Hydrodynamic Cavitation ◽  
Prediction Methods ◽  
Cavitation Inception ◽  
Physical Mechanisms ◽  
Bubble Cavitation ◽  
Passive Pressure ◽  
Flow Features ◽  
Physical Phenomena ◽  
Fundamental Physical

A review is made of progress in research during the period 1979–1989 on the fundamental physical mechanisms of hydrodynamic cavitation inception. During that decade identification of the physical phenomena has been made, and techniques have been developed to reproduce on laboratory scale selected forms of full scale cavitation inception. Understanding of the mechanisms remains shallow, and analytical/numerical prediction methods are nonexistent except for the restricted case of travelling bubble cavitation inception in a passive pressure field. The control of inception is seen to be related in part to control of the underlying viscous flow features. A growing body of experimental evidence points to microscale vortex cavitation as a primal inception event.

Hexagonal manganites: Strong coupling of ferroelectricity and magnetic orders

2019 ◽  
Vol 4 (12) ◽  
Author(s):  
Bernd Lorenz
Keyword(s):  
Rare Earth ◽  
Rare Earth Ions ◽  
Strong Interactions ◽  
Physical Mechanisms ◽  
Complex Interactions ◽  
Magnetic Orders ◽  
Magnetic Ions ◽  
Hexagonal Manganites ◽  
Physical Phenomena

Abstract Hexagonal manganites belong to an exciting class of materials exhibiting strong interactions between a highly frustrated magnetic system, the ferroelectric polarization, and the lattice. The existence and mutual interaction of different magnetic ions (Mn and rare earth) results in complex magnetic phase diagrams and novel physical phenomena. A summary and discussion of the various properties, underlying physical mechanisms, the role of the rare earth ions, and the complex interactions in multiferroic hexagonal manganites are presented in this review.

scholarly journals The Russian national branding of innovations in defense industry complex as the answer to global challenges of the present

2018 ◽  
Vol 243 ◽  
pp. 00001
Author(s):  
Elena Danilova ◽  
Alexander Vorozhtsov
Keyword(s):  
Social Media ◽  
Comparative Analysis ◽  
International Collaboration ◽  
Material Science ◽  
Armed Forces ◽  
Defense Industry ◽  
Engineering Material ◽  
National Brands ◽  
Global Challenges ◽  
International Branding

In the article a comparative analysis of the international branding of armed forces is executed. The examples of effective national branding are given. Marketing technologies of defensive branch branding and formation of military culture are explored. Social media as a key instrument in the strategy of branding of defensive branch are considered. The Russian national branding of innovations in defense industry complex is analyzed. The successful Russian national brands in defense field are shown. The way of international collaboration strengthening in dual technologies in chemical and mechanical engineering, material science, nanotechnologies sphere is offered.

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