Calculation of Acoustic Transfer Properties of Closed-Loop Type Pipeline Systems Having More Than One Output

1989 ◽  
Vol 111 (3) ◽  
pp. 331-336
Author(s):  
I. Gyo¨ri ◽  
G. Joo´
Keyword(s):  
Comparative Study ◽  
Tree Ring ◽  
Closed Loop ◽  
Analytical Description ◽  
Tree Structure ◽  
Reciprocating Compressor ◽  
Closed Loops ◽  
Pipeline Systems ◽  
Ring Structures ◽  
Transfer Properties

Expanding the previously elaborated algorithm of tree structure pipeline systems of reciprocating compressor installations, the paper introduces an analytical description and a procedure for combined tree-ring structures having more than one output points. A comparative study of the suggested method and the four-pole representation of simple closed loops is presented including a numerical example as well.

THE GEOMETRIC PHASE AND THE SCHWINGER TERM IN SOME MODELS

1992 ◽  
Vol 07 (21) ◽  
pp. 5045-5083 ◽  
Author(s):  
H. GROSSE ◽  
E. LANGMANN
Keyword(s):  
Parameter Space ◽  
Geometric Phase ◽  
Closed Loop ◽  
Parallel Transport ◽  
Quantum Mechanical System ◽  
Second Quantization ◽  
Closed Loops ◽  
Gauge Transformations ◽  
Canonical Anticommutation Relations ◽  
Inequivalent Representations

We discuss the quantization of fermions interacting with external fields and observe the occurrence of equivalent as well as inequivalent representations of the canonical anticommutation relations. Implementability of gauge and axial gauge transformations leads to generators which fulfil an algebra of current with a Schwinger term. This term can be written as a cocycle and leads to the boson-fermion correspondence. Transport of a quantum-mechanical system along a closed loop of parameter space may yield a geometric phase. We discuss models for which nonintegrable phase factors are obtained from the adiabatic parallel transport. After second quantization, one obtains, in addition, a Schwinger term. Depending on the type of transformation, a subtle relationship between these two obstructions can occur. We indicate finally how we may transport density matrices along closed loops in parameter space.

Analysis of the Idling Start of the Moving Coil Linear Compressor

2008 ◽  
Author(s):  
Yingbai Xie ◽  
Xiuzhi Huang ◽  
Liyong Lun ◽  
Ganglei Sun
Keyword(s):  
Closed Loop ◽  
Transfer Functions ◽  
Load Condition ◽  
Open Loop ◽  
Reciprocating Compressor ◽  
Piston Motion ◽  
Linear Compressor ◽  
Simulation Results ◽  
The Stability ◽  
Stability Time

The linear compressor is driven by a linear motor. Because it has no crankcase, the piston motion and its control of the linear compressor are differing from that of the conventional reciprocating compressor. For a moving coil linear compressor, mechanical and electromagnetism system are modeled. The open loop and closed loop transfer functions of the system in no-load condition are obtained derived from these equations. The Matlab software is applied to analyze the stability, time domain and frequency domain of the system. Simulation results show that the linear compressor is stable, but the overshoot is relative high, which must be adjusted. This conclusion will be benefit for the design of the idling start of the moving coil linear compressor.

Structural order and charge transfer in highly strained carbon nanobelts

2020 ◽  
Vol 44 (36) ◽  
pp. 15769-15775
Author(s):  
G. Aydın ◽  
O. Koçak ◽  
C. Güleryüz ◽  
I. Yavuz
Keyword(s):  
Charge Transfer ◽  
Closed Loop ◽  
Computational Study ◽  
Structural Order ◽  
Chiral Carbon ◽  
Highly Strained ◽  
Transfer Properties

We present a computational study of the atomic morphology, structural order and charge transfer properties of radially π-conjugated, closed-loop, and highly strained chiral carbon nanobelts (CNBs).

scholarly journals Flowering Buds of Globular Proteins: Transpiring Simplicity of Protein Organization

2002 ◽  
Vol 3 (6) ◽  
pp. 525-534 ◽  
Author(s):  
Igor N. Berezovsky ◽  
Edward N. Trifonov
Keyword(s):  
Protein Evolution ◽  
Closed Loop ◽  
Globular Proteins ◽  
Polymer Physics ◽  
Basic Unit ◽  
Amino Acid Residues ◽  
Sequence Motifs ◽  
Closed Loops ◽  
Physical Necessity ◽  
Functional Complexity

Structural and functional complexity of proteins is dramatically reduced to a simple linear picture when the laws of polymer physics are considered. A basic unit of the protein structure is a nearly standard closed loop of 25–35 amino acid residues, and every globular protein is built of consecutively connected closed loops. The physical necessity of the closed loops had been apparently imposed on the early stages of protein evolution. Indeed, the most frequent prototype sequence motifs in prokaryotic proteins have the same sequence size, and their high match representatives are found as closed loops in crystallized proteins. Thus, the linear organization of the closed loop elements is a quintessence of protein evolution, structure and folding.

Constraint Wrench Formulation for Closed-Loop Systems Using Two-Level Recursions

2007 ◽  
Vol 129 (12) ◽  
pp. 1234-1242 ◽  
Author(s):  
Himanshu Chaudhary ◽  
Subir Kumar Saha
Keyword(s):  
Lagrange Multipliers ◽  
Spanning Tree ◽  
Closed Loop ◽  
Equations Of Motion ◽  
Constraint Forces ◽  
Minimal Set ◽  
Closed Loops ◽  
Closed Loop Systems ◽  
Subsystem Level ◽  
Body Level

In order to compute the constraint moments and forces, together referred here as wrenches, in closed-loop mechanical systems, it is necessary to formulate a dynamics problem in a suitable manner so that the wrenches can be computed efficiently. A new constraint wrench formulation for closed-loop systems is presented in this paper using two-level recursions, namely, subsystem level and body level. A subsystem is referred here as the serial- or tree-type branches of a spanning tree obtained by cutting the appropriate joints of the closed loops of the system at hand. For each subsystem, unconstrained Newton–Euler equations of motion are systematically reduced to a minimal set in terms of the Lagrange multipliers representing the constraint wrenches at the cut joints and the driving torques/forces provided by the actuators. The set of unknown Lagrange multipliers and the driving torques/forces associated to all subsystems are solved in a recursive fashion using the concepts of a determinate subsystem. Next, the constraint forces and moments at the uncut joints of each subsystem are calculated recursively from one body to another. Effectiveness of the proposed algorithm is illustrated using a multiloop planar carpet scraping machine and the spatial RSSR (where R and S stand for revolute and spherical, respectively) mechanism.

Comparative Study of the Loads Acting on the Operating Cardanic Transmission in the Closed and Open Loop Configurations

2015 ◽  
Vol 744-746 ◽  
pp. 17-24
Author(s):  
Eugen Avrigean
Keyword(s):  
Finite Elements ◽  
Comparative Study ◽  
Closed Loop ◽  
Open Loop ◽  
Operating Conditions ◽  
Motor Vehicles ◽  
Normal Operating ◽  
Static Conditions

On the basis of a comparative study, this paper aims to determine the maximum loads that can occur in operating conditions on the cardanic transmission assembly of motor vehicles in the open or closed loop configurations. The research is conducted under static conditions using finite elements and shows the components with their maximum values obtained in normal operating conditions.

Efficient Parallel Computer Simulation of the Motion Behaviors of Closed-Loop Multibody Systems

2007 ◽  
Author(s):  
Shanzhong Duan ◽  
Andrew Ries
Keyword(s):  
Parallel Computing ◽  
Multibody Systems ◽  
Closed Loop ◽  
High Efficiency ◽  
Equations Of Motion ◽  
Parallel Computer ◽  
Constraint Forces ◽  
Computing Systems ◽  
Closed Loops

This paper presents an efficient parallelizable algorithm for the computer-aided simulation and numerical analysis of motion behaviors of multibody systems with closed-loops. The method is based on cutting certain user-defined system interbody joints so that a system of independent multibody subchains is formed. These subchains interact with one another through associated unknown constraint forces fc at the cut joints. The increased parallelism is obtainable through cutting joints and the explicit determination of associated constraint forces combined with a sequential O(n) method. Consequently, the sequential O(n) procedure is carried out within each subchain to form and solve the equations of motion while parallel strategies are performed between the subchains to form and solve constraint equations concurrently. For multibody systems with closed-loops, joint separations play both a role of creation of parallelism for computing load distribution and a role of opening a closed-loop for use of the O(n) algorithm. Joint separation strategies provide the flexibility for use of the algorithm so that it can easily accommodate the available number of processors while maintaining high efficiency. The algorithm gives the best performance for the application scenarios for n>>1 and n>>m, where n and m are number of degree of freedom and number of constraints of a multibody system with closed-loops respectively. The algorithm can be applied to both distributed-memory parallel computing systems and shared-memory parallel computing systems.

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