Partial activation of modular and foldable tessellated acoustic arrays for wave focusing

2019 ◽  
Vol 145 (3) ◽  
pp. 1669-1669
Author(s):  
Ningxiner Zhao ◽  
Ryan L. Harne
Keyword(s):  
Wave Focusing ◽  
Partial Activation ◽  
Acoustic Arrays

Reconfigurable Acoustic Arrays With Deployable Structure Based on a Hoberman–Miura System Synthesis

2020 ◽  
Vol 143 (6) ◽  
Author(s):  
Ningxiner Zhao ◽  
Ryan L. Harne
Keyword(s):  
Acoustic Waves ◽  
Shape Change ◽  
Near Field ◽  
Ring Structure ◽  
Wave Focusing ◽  
System Synthesis ◽  
Reconfigurable Mechanisms ◽  
Acoustic Arrays ◽  
Dimensional Shape ◽  
Low Dimensional

Abstract Curved surfaces are often used to radiate and focus acoustic waves. Yet, when tessellated into reconfigurable surfaces for sake of deployability needs, origami-inspired acoustic arrays may be challenging to hold into curved shape and may not retain flat foldability. On the other hand, deployable mechanisms such as the Hoberman ring are as low-dimensional as many origami tessellations and may maintain curved shape with ease due to ideal rigid bar compositions. This research explores an interface between a Hoberman ring and Miura-ori tessellation that maintain kinematic and geometric compatibility for sake of maintaining curved shapes for sound focusing. The Miura-ori facets are considered to vibrate like baffled pistons and generate acoustic waves that radiate from the ring structure. An analytical model is built to reveal the near field acoustic behavior of acoustic arrays resulting from a Hoberman–Miura system synthesis. Acoustic wave focusing capability is scrutinized and validated through proof-of-principle experiments. Studies reveal wave focusing phenomena distinct to this manifestation of the acoustic array and uncover design and operational influences on wave focusing effectiveness. The results encourage exploration of new interfaces between reconfigurable mechanisms and origami devices where low-dimensional shape change is desired.

scholarly journals Acoustic wave focusing by doubly curved origami-inspired arrays

2020 ◽  
Vol 31 (8) ◽  
pp. 1041-1052 ◽  
Author(s):  
Vivek Srinivas ◽  
Ryan L Harne
Keyword(s):  
Acoustic Energy ◽  
Spherical Cap ◽  
Array Design ◽  
Wave Focusing ◽  
Acoustic Arrays ◽  
Recent Developments ◽  
Surgical Treatments ◽  
Doubly Curved ◽  
Reconfigurable Structures ◽  
Focused Transducers

Spherically focused transducers have been long relied on to target acoustic energy delivery. Yet, these structures have limitations with respect to size and mobility for medical treatment applications. Recent developments in the field of reconfigurable structures reveal that the ancient art of origami inspires new platforms by which to enable spherical shapes that are additionally foldable for ease of transport. This research explores the opportunities for a unique, flat foldable doubly curved tessellated array to enable wave focusing capability similar to an ideal medical transducer shape: the spherical cap transducer. An analytical model of the doubly curved array is created and validated against data collected from a proof-of-concept array. The model is then leveraged to understand how the array design and complexity relatively govern the wave focusing capability. The findings show that doubly curved acoustic arrays do not require excessive facet refinement to achieve wave focusing similar to nominal spherically focused transducers. Yet, the optimal frequencies for which such capability is borne out vary substantially on the basis of array design. The discoveries of this research motivate future consideration of flat foldable doubly curved acoustic arrays for potential implementation into medical transducer development for hard-to-access surgical treatments.

Partial Activation of Purified Prothrombin: Derivation of Autoprothrombin I with Use of Autoprothrombin C

1962 ◽  
Vol 07 (02) ◽  
pp. 239-248 ◽  
Author(s):  
Walter H Seegers ◽  
Edmond R Cole ◽  
Ewa Marciniak
Keyword(s):  
Calcium Ions ◽  
Platelet Factor ◽  
Stability Properties ◽  
Partial Activation ◽  
Autoprothrombin C

SummaryActivation of purified prothrombin with autoprothrombin C in the absence of calcium ions produces autoprothrombin I activity. The solubility, and stability properties of this autoprothrombin I are different from those of autoprothrombin I when obtained by activating prothrombin with calcium ions, platelet factor 3, and Ac-globulin.

Guided Wave Focusing Mechanics in Pipe

2003 ◽  
Author(s):  
Takahiro Hayashi ◽  
Koichiro Kawashima ◽  
Zongqi Sun ◽  
Joseph L. Rose
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Guided Waves ◽  
Wave Structure ◽  
Guided Wave ◽  
Pipe Inspection ◽  
Specific Point ◽  
Wave Focusing ◽  
Beam Focusing ◽  
Subsequent Time

Guided waves can be used in pipe inspection over long distances. Presented in this paper is a beam focusing technique to improve the S/N ratio of the reflection from a tiny defect. Focusing is accomplished by using non-axisymmetric waveforms and subsequent time delayed superposition at a specific point in a pipe. A semi-analytical finite element method is used to present wave structure in the pipe. Focusing potential is also studied with various modes and frequencies.

Microjetting from wave focusing on oscillating drops

2007 ◽  
Vol 19 (5) ◽  
pp. 052101 ◽  
Author(s):  
S. T. Thoroddsen ◽  
T. G. Etoh ◽  
K. Takehara
Keyword(s):  
Wave Focusing

Laser induced short plane acoustic wave focusing in water

2007 ◽  
Vol 91 (5) ◽  
pp. 051128 ◽  
Author(s):  
Seung H. Ko ◽  
Sang G. Ryu ◽  
Nipun Misra ◽  
Heng Pan ◽  
Costas P. Grigoropoulos ◽  
...  
Keyword(s):  
Acoustic Wave ◽  
Wave Focusing ◽  
Plane Acoustic Wave
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