Dynamic Measurements of Micro-Meter Particle Detachment on Glass Surfaces

2012 ◽  
Author(s):  
Asmaa Sadek Kassab ◽  
Victor M. Ugaz ◽  
Maria D. King ◽  
Yassin A. Hassan
Keyword(s):  
High Speed ◽  
Single Layer ◽  
Dynamic Measurements ◽  
Complex Motion ◽  
Short Term ◽  
High Speed Imaging ◽  
Increasing Trend ◽  
Different Types ◽  
Glass Surfaces ◽  
Initial Movement

This work presents a high resolution study of the condition under which a transient fluid flow causes spherical glass beads particles of 10–100 μm in size to detach from glass surfaces. The general approach is to conduct well-controlled experiments, to observe individual microparticle motion in short term resuspension, within a period up to 5s, and to focus on the basic detachment mechanisms of the resuspended particles to fully understand and quantify the behavior of particles immediately before liftoff. Particle tracking obtained from high-speed imaging of individual particle with 4000 frames/s, reveal three different types of motion: rolling/bouncing, immediate liftoff (where the particle showed immediate liftoff without any initial rolling/bouncing) and complex motion where particles travel with rolling/bouncing motion on the surface for a certain distance before liftoff. The longer it will take the particle to start its initial movement the more rapid is the liftoff once motion is initiated. The majority of particle trajectories from the glass substrate were parallel to the surface with complex motion, covering 25% of the total distance traveled in rolling/bouncing motion before liftoff. Additionally, Single layer detachment showed that the detachment percentage initially follow an exponentially increasing trend for a period of ∼ 1s, followed by a plateau phase for a period of 5s.

Modeling of Fabric Impact With High Speed Imaging and Nickel-Chromium Wires Validation

2011 ◽  
Vol 78 (5) ◽  
Author(s):  
Sidney Chocron ◽  
Trenton Kirchdoerfer ◽  
Nikki King ◽  
Christopher J. Freitas
Keyword(s):  
Numerical Simulations ◽  
High Speed ◽  
Numerical Models ◽  
Single Layer ◽  
Diagnostic Techniques ◽  
High Speed Photography ◽  
High Speed Imaging ◽  
Nickel Chromium ◽  
Validation Set ◽  
The Waves

Ballistic tests were performed on single-yarn, single-layer and ten-layer targets of Kevlar® KM2 (600 and 850 denier), Dyneema® SK-65 and PBO® (500 denier). The objective was to develop data for validation of numerical models so, multiple diagnostic techniques were used: (1) ultra-high speed photography, (2) high-speed video and (3) nickel-chromium wire technique. These techniques allowed thorough validation of the numerical models through five different paths. The first validation set was at the yarn level, where the transverse wave propagation obtained with analytical and numerical simulations was compared to that obtained in the experiments. The second validation path was at the single-layer level: the propagation of the pyramidal wave observed with the high speed camera was compared to the numerical simulations. The third validation consisted of comparing, for the targets with ten layers, the pyramid apex and diagonal positions from tests and simulations. The fourth validation, which is probably the most relevant, consisted of comparing the numerical and experimental ballistic limits. Finally for the fifth validation set, nickel-chromium wires were used to record electronically the waves propagating in the fabrics. It is shown that for the three materials the waves recorded during the tests match well the waves predicted by the numerical model.

scholarly journals POWER REDUCTION TECHNIQUES IN VLSI

2020 ◽  
Vol 5 (2) ◽  
pp. 123-129
Author(s):  
Mehar Sharma ◽  
Neeraj Gupta ◽  
Rashmi Gupta
Keyword(s):  
Power Dissipation ◽  
High Speed ◽  
Power Reduction ◽  
Vlsi Circuits ◽  
Abstraction Level ◽  
Reduction Techniques ◽  
Increasing Trend ◽  
Different Types ◽  
The Given

The paper investigates different level of techniques used for power reduction in VLSI. Before,most of the researches were oriented towards bringing about high speed and miniaturization.At present, because of the increasing trend of compact devices, the requirement for low powerconsuming circuits have also increased. This necessitates the need to align the research forreducing power dissipation in VLSI circuits. In the given paper we will briefly discuss aboutthe different types of power reduction techniques at design abstraction level which are adoptedin industries now-a-days. The comparison of traditional techniques and present techniquesare also covered in this paper.

Experimental Measurement of In-Plane Rolling Nonpneumatic Tire Vibrations Using High-Speed Imaging

2019 ◽  
Vol 47 (3) ◽  
pp. 196-210
Author(s):  
Meghashyam Panyam ◽  
Beshah Ayalew ◽  
Timothy Rhyne ◽  
Steve Cron ◽  
John Adcox
Keyword(s):  
High Speed ◽  
Image Correlation ◽  
Dynamic Mode Decomposition ◽  
Dynamic Mode ◽  
High Speed Imaging ◽  
Correlation Algorithm ◽  
Mode Decomposition ◽  
Series Of Experiments ◽  
Plane Deformations ◽  
Dominant Frequencies

ABSTRACT This article presents a novel experimental technique for measuring in-plane deformations and vibration modes of a rotating nonpneumatic tire subjected to obstacle impacts. The tire was mounted on a modified quarter-car test rig, which was built around one of the drums of a 500-horse power chassis dynamometer at Clemson University's International Center for Automotive Research. A series of experiments were conducted using a high-speed camera to capture the event of the rotating tire coming into contact with a cleat attached to the surface of the drum. The resulting video was processed using a two-dimensional digital image correlation algorithm to obtain in-plane radial and tangential deformation fields of the tire. The dynamic mode decomposition algorithm was implemented on the deformation fields to extract the dominant frequencies that were excited in the tire upon contact with the cleat. It was observed that the deformations and the modal frequencies estimated using this method were within a reasonable range of expected values. In general, the results indicate that the method used in this study can be a useful tool in measuring in-plane deformations of rolling tires without the need for additional sensors and wiring.

Comprehensive Effects of Short-Term Rental Platforms Across Hotel Types in U.S. and International Destinations

2021 ◽  
pp. 193896552110335
Author(s):  
John W. O’Neill ◽  
Jihwan Yeon
Keyword(s):  
Service Providers ◽  
Comprehensive Analysis ◽  
Competitive Market ◽  
Substitution Effects ◽  
Short Term ◽  
Hotel Performance ◽  
The World ◽  
Different Types ◽  
Location Type ◽  
The Impact

In recent years, short-term rental platforms in the lodging sector, including Airbnb, VRBO, and HomeAway, have received extensive attention and emerged as potentially alternative suppliers of services traditionally provided by established commercial accommodation providers, that is, hotels. Short-term rentals have dramatically increased the available supply of rooms for visitors to multiple international destinations, potentially siphoning demand away from hotels to short-term rental businesses. In a competitive market, an increase in supply with constant demand would negatively influence incumbent service providers. In this article, we examine the substitution effects of short-term rental supply on hotel performance in different cities around the world. Specifically, we comprehensively investigate the substitution effects of short-term rental supply on hotel performance based on hotel class, location type, and region. Furthermore, we segment the short-term rental supply based on its types of accommodations, that is, shared rooms, private rooms, and entire homes, and both examine and quantify the differential effects of these types of short-term rentals on different types of hotels. This study offers a comprehensive analysis regarding the impact of multiple short-term rental platforms on hotel performance and offers both conceptual and practical insights regarding the nature and extent of the effects that were identified.

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