Acoustic demultiplexer based on Fano and induced transparency resonances in slender tubes

2020 ◽  
Vol 90 (1) ◽  
pp. 10902
Author(s):  
Abdelkader Mouadili ◽  
El Houssaine El Boudouti ◽  
Bahram Djafari-Rouhani
Keyword(s):  
Closed Form ◽  
The Other ◽  
Selective Transfer ◽  
Output Line ◽  
Input Line ◽  
Induced Transparency

We give an analytical demonstration of the possibility to realize a simple phononic demultiplexer based on Fano and acoustic induced transparency resonances. The demultiplexer consists of a Y-shaped waveguide with an input line and two output lines. Each output line contains two stubs grafted either at a given position or at two positions far from the input line. We derive in closed form the expressions for a selective transfer of a single propagating mode through one line keeping the other line unaffected.

Closed-Form Synthesis of Force-Generating Planar Four-Bar Linkages

1995 ◽  
Author(s):  
R. Randall Soper ◽  
Michael Scardina ◽  
Paul Tidwell ◽  
Charles Reinholtz ◽  
Michael A. Lo Presti
Keyword(s):  
Closed Form ◽  
The Other ◽  
Design Parameters ◽  
Synthesis Methods ◽  
Function Generator ◽  
Mechanical Advantage ◽  
Nonlinear Mechanical ◽  
Two Parameters ◽  
Selection Of ◽  
Weight Force

Abstract This paper presents a technique for synthesizing four-bar linkages to produce a specified resisting force or torque. The resisting energy is provided by a weight acting on the other grounded link. The linkage serves as a nonlinear mechanical advantage function generator. Force and velocity synthesis methods have been extensively discussed in the literature. The general approach, however, has been to assume that the specified force or velocity occurs at a prescribed position. This results in the loss of design parameters that are being used unnecessarily to control position. In this application, force input to the linkage is specified as a function of only the input link position and the magnitude and direction of the weight force. Mechanical advantage synthesis can be achieved at as many as seven precision points. The method presented in this paper allows free selection of two parameters and viewing one infinity of solutions.

Identifying Sets of Four and Five Positions That Generate Distinctive Center-Point Curves

2009 ◽  
Author(s):  
David H. Myszka ◽  
Andrew P. Murray
Keyword(s):  
Closed Form ◽  
The Other ◽  
Specific Design ◽  
Opposite Pole ◽  
Center Point ◽  
Point Curve ◽  
Position Synthesis ◽  
Two Sides ◽  
Cubic Function

The fixed pivots of a planar 4R linkage that can achieve four design positions are constrained to a center-point curve. The curve is a circular cubic function and plots can take one of five different forms. The center-point curve can be generated with a compatibility linkage obtained from an opposite pole quadrilateral of the four design positions. This paper presents a method to identify design positions that generate distinctive shapes of the center-point curves. The form of the center-point curve is dependent on whether the shape of the opposite pole quadrilateral is an open or closed form of a rhombus, kite, parallelogram, or when the sum of two sides equals the other two. Interesting cases of three and five position synthesis are also explored. Four and five position cases are generated that have center points at infinity allowing a PR dyad with line of slide in any direction to achieve the design positions. Further, a center-point curve for five specific design positions is revealed.

scholarly journals Reliability of Sampling Inspection Schemes Applied to Replacement Steam Generators

2006 ◽  
Vol 129 (1) ◽  
pp. 109-117 ◽  
Author(s):  
Guy Roussel ◽  
Leon Cizelj
Keyword(s):  
Closed Form ◽  
Steam Generator ◽  
The State ◽  
The Other ◽  
Prior Density ◽  
Steam Generators ◽  
Numerical Examples ◽  
Closed Form Solutions ◽  
Sampling Inspection ◽  
Steam Generator Tubing

The basis for determining the size of the random sample of tubes to be inspected in replacement steam generators is revisited in this paper. A procedure to estimate the maximum number of defective tubes left in the steam generator after no defective tubes have been detected in the randomly selected inspection sample is proposed. A Bayesian estimation is used to obtain closed-form solutions for uniform, triangular, and binomial prior densities describing the number of failed tubes in steam generators. It is shown that the particular way of selecting the random inspection sample (e.g., one sample from both SG, one sample from each SG, etc.) does not affect the results of the inspection and also the information obtained about the state of the uninspected tubing, as long as the inspected steam generators belong to the same population. Numerical examples further demonstrate two possible states of the knowledge existing before the inspection of the tubing. First, virtually no knowledge about the state of the steam generator tubing before the inspection is modeled using uniform and triangular prior densities. It is shown that the knowledge about the uninspected part of the tubing strongly depends on the size of the sample inspected. Further, even small inspection samples may significantly improve our knowledge about the uninspected part. On the other hand, rather strong belief on the state of the tubing prior to the inspection is modeled using binomial prior density. In this case, the knowledge about the uninspected part of the tubing is virtually independent on the size of the sample. Furthermore, it is shown qualitatively and quantitatively that such inspection brings no additional knowledge on the uninspected part of the tubing.

Synthesis of Seven-Link Mechanisms

1973 ◽  
Vol 95 (2) ◽  
pp. 533-540 ◽  
Author(s):  
D. Kohli ◽  
A. H. Soni
Keyword(s):  
Closed Form ◽  
Nonlinear Equations ◽  
Degrees Of Freedom ◽  
The Other ◽  
Linear Superposition ◽  
Two Degrees Of Freedom ◽  
Closed Form Solutions ◽  
Highly Nonlinear ◽  
Principle Of Linear Superposition

The mechanisms derived from the seven-link chains with five links in their two loops and having two degrees of freedom are examined for six synthesis problems. Using displacement matrices, closed form synthesis equations are derived. It is shown that three synthesis problems may be solved using the principle of linear superposition, and closed form solutions may be obtained. The other three synthesis problems involve highly nonlinear equations and must be solved numerically.

Scattering by hard and soft parallel half-planes

1981 ◽  
Vol 59 (12) ◽  
pp. 1879-1885 ◽  
Author(s):  
R. A. Hurd ◽  
E. Lüneburg
Keyword(s):  
Plane Wave ◽  
Closed Form ◽  
Half Plane ◽  
Diffraction Problem ◽  
Closed Form Solution ◽  
Normal Derivative ◽  
Form Solution ◽  
The Other ◽  
Total Field

We consider the diffraction of a scalar plane wave by two parallel half-planes. On one half-plane the total field vanishes whilst on the other its normal derivative is zero. This is a new canonical diffraction problem and we give an exact closed-form solution to it. The problem has applications to the design of acoustic barriers.

DIVISIBLE LOAD DISTRIBUTION IN A NETWORK OF PROCESSORS

2008 ◽  
Vol 09 (01n02) ◽  
pp. 31-51 ◽  
Author(s):  
SAMEER BATAINEH
Keyword(s):  
Closed Form ◽  
Load Distribution ◽  
Closed Form Solution ◽  
Form Solution ◽  
The Other ◽  
Optimum Number ◽  
Sequencing Problem ◽  
Divisible Load ◽  
Finish Time ◽  
Optimum Sequence

The paper presents a closed form solution for an optimum scheduling of a divisible job on an optimum number of processor arranged in an optimum sequence in a multilevel tree networks. The solution has been derived for a single divisible job where there is no dependency among subtasks and the root processor can either perform communication and computation at the same time. The solution is carried out through three basic theorems. One of the theorems selects the optimum number of available processors that must participate in executing a divisible job. The other solves the sequencing problem in load distribution by which we are able to find the optimum sequence for load distribution in a generalized form. Having the optimum number of processors and their sequencing for load distribution, we have developed a closed form solution that determines the optimum share of each processor in the sequence such that the finish time is minimized. Any alteration of the number of processors, their sequences, or their shares that are determined by the three theorems will increase the finish time.

scholarly journals Study of Superficial Layers Obtained by Selective Transfer in the Friction Couples

2017 ◽  
Vol 2 (6) ◽  
pp. 54
Author(s):  
Filip Ilie
Keyword(s):  
Superficial Layer ◽  
Transfer Mechanism ◽  
The Other ◽  
X Rays ◽  
Selective Transfer ◽  
Friction Couple ◽  
Material Transfer ◽  
Structure Defects ◽  
Wear Process ◽  
Friction Surfaces

In the friction process of two materials and in the presence of some proper lubricants, the wear process manifest itself as a material transfer from an element of the friction couple on the other, process specific to the selective transfer mechanism. The selective transfer can be sure achieved in a friction couple if there is a favorable energy, the relative movement and if in the friction area is a material made by copper and the lubricant is adequate (glycerin).The selective transfer mechanism is characterized by the physicochemical processes, which take place in the contact zones of the friction couples, and which to allow the selective transfer of some elements of the materials from a surface to the other, forming a thin superficial layer with the superior properties at wear and friction. This is a condition for any friction couple of high efficiently and a normal self-adjusting phenomena. The forming of this layer on the contact surfaces makes as fiction force to be reduced. It is in closely related to the structure formed by the selective transfer, between the metallic friction surfaces and with the properties these surface layers metallic. The most important parameters concerning the physical state of the superficial layers are micro-tensions, the structure and its modification on friction surfaces, the structure defects as well as the way of distribution of the additions and of the alloying elements from alloy. The purpose of the present paper is research these parameters by the structural analysis with X-rays, as the research method of the thin superficial layers.

Kinematic Analysis of a Planar Mechanism Driven by Two Orthogonal Layout Actuators

2012 ◽  
Vol 490-495 ◽  
pp. 2305-2309
Author(s):  
Xiao Rong Zhu ◽  
Yi Lu ◽  
Hui Ping Shen
Keyword(s):  
Closed Form ◽  
Kinematic Analysis ◽  
Machine Tools ◽  
Jacobi Matrix ◽  
The Other ◽  
Stiffness Index ◽  
Forward Kinematics ◽  
Performance Indices ◽  
Hand Dexterity ◽  
Mobile Base

In this paper, a planar five-bar mechanism driven by two orthogonal layout actuators is proposed. The inverse and forward kinematics can be described in closed form. The Jacobi matrix, singularity and workspace of the mechanism are investigated. In addition, charts of some performance indices, such as dexterity, velocity, payload capability and stiffness index, are plotted. The results show that the mechanism has a flatter singularity-free workspace, which is usually our research object. On the other hand, Dexterity, Payload capability and stiffness index of the mechanism are basically the same distribution on the workspace, which are axis symmetric. But, the trend of velocity index is opposite. The proposed mechanism can be applied to the field of machine tools or used as the mobile base for a spatial manipulator. The results of the paper are very useful for the design and application of the new mechanism

Helical Shift Mechanics of Rubber V-Belt Variators

2011 ◽  
Vol 133 (4) ◽  
Author(s):  
Francesco Sorge ◽  
Marco Cammalleri
Keyword(s):  
Theoretical Model ◽  
Numerical Solution ◽  
Closed Form ◽  
Operating Conditions ◽  
The Other ◽  
Experimental Comparison ◽  
Axial Thrust ◽  
Shooting Technique ◽  
Strongly Nonlinear ◽  
Tension Level

A very common configuration of V-belt variators for motorcycles considers the correction of the belt tensioning depending on the resistant torque by means of suitable helical-shaped tracks allowing the driven half-pulleys to close/open. The theoretical model for belt-pulley coupling is rather complex for this configuration, where one half-pulley may run in advance and the other one behind with respect to the belt, and requires the repeated numerical solution of a strongly nonlinear differential system by a sort of shooting technique, until all the operating conditions are fulfilled (angular contact extent, torque, and axial force). After solving the full equations, the present study develops closed-form approximations, which are characterized by an excellent correspondence with the numerical plots, and suggests a simple and practical formulary for the axial thrust as a function of the torque and of the tension level. Then, the results of a theoretical–experimental comparison are also reported, and they indicate a fine agreement between the model and the real operation.

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