scholarly journals The Twist Factor of Yields

2017 ◽  
Vol 5 (7) ◽  
pp. 411-422
Author(s):  
Xuyang Ma
Keyword(s):  
Twist Factor

Optimization of Drafting Conditions in the Break Drafting Zone Additional Pressure Bar on INA-V Spinning Frame

2014 ◽  
Vol 936 ◽  
pp. 1825-1829
Author(s):  
Qing Guo Feng ◽  
Jia Zhi Ren ◽  
Yi Feng Zhang
Keyword(s):  
Process Parameters ◽  
Ratio Increase ◽  
Additional Pressure ◽  
Yarn Quality ◽  
Twist Factor ◽  
Pressure Bar

To improve the yarn quality, the pressure bar was installed in the break drafting zone of the INA-V spinning frame. The process parameters were optimized in the break drafting zone with pressure bar of the INA-V spinning frame, the drafting principle in the break drafting zone with pressure bar of INA-V spinning frame was analyzed, and the sliver configuration was observed in the break drafting zone with pressure bar. The result revealed that installed the pressure bar in break drafting zone after, when the roving twist factor was small, CV%, thinness, thickness and neps of the yarn spun decrease as the break drafting ratio increase; when the twist factor of roving was larger, the break draft ratio as 1.3 time was optimum drafting conditions. The yarn quality was improved as roving twist increased.

scholarly journals Knitting Force Measurement on Flat Knitting Machines

2014 ◽  
Vol 2014 ◽  
pp. 1-9
Author(s):  
A. Fouda ◽  
A. El-Hadidy ◽  
A. El-Deeb
Keyword(s):  
Force Measurement ◽  
Data Acquisition System ◽  
Measuring System ◽  
Knitted Fabric ◽  
Optimal Production ◽  
Twist Factor ◽  
Machine Parts ◽  
Fabric Structures ◽  
Single Jersey ◽  
Production Conditions

Knittability can be defined as the ability of yarns to run on knitting machines without problems. Knittability can be achieved when less stress is applied on the knitting machine parts by the knitting yarns. This paper presents a novel measuring system for the knitting force needed to perform knitting yarns on flat knitting machine based on data acquisition system (DAS). The proposed system is used to measure the knitting force at different machine settings and different properties of the knitting yarns to determine the optimal production conditions. For this reason, three types of knitted fabric structures (single jersey, Rib 1 × 1, and full cardigan) with three different loop lengths and five different twists of ply yarn were produced. The obtained results showed the optimal yarn ply twist factor (αe) which gave minimum knitting force (less stress on needles or knitting yarns) at different loop lengths for each structure.

scholarly journals Helicity and The Alpha-Effect: Dynamo Theory and Observations

2005 ◽  
Vol 13 ◽  
pp. 95-96
Author(s):  
Kirill Kuzanyan
Keyword(s):  
Active Regions ◽  
Dynamo Theory ◽  
Solar Convection Zone ◽  
Representative Sampling ◽  
Solar Convection ◽  
Spatial And Temporal Distributions ◽  
Twist Factor ◽  
Chinese Academy Of Sciences ◽  
Alpha Effect ◽  
Academy Of Sciences

AbstractSpatial and temporal distributions of tracers of the alpha-effect in the solar convection zone, such as current helicity and twist factor averaged over solar active regions are available by vector magnetographic observations. We discuss the data obtained at Huairou Solar Observing Station of Chinese Academy of Sciences and confront them with predictions of dynamo theory. At the present time, though the observations are rough, we still have a statistically representative sampling to conclude that the observations do not contradict the theory.

Test and Analysis of SPF Pure Yarn or SPF Tencel Blending Yarn Mechanics Property

2013 ◽  
Vol 709 ◽  
pp. 225-228
Author(s):  
Fan Dong Kong ◽  
Lei Shang ◽  
Cheng Jun Liang
Keyword(s):  
Soybean Protein ◽  
Blended Yarn ◽  
Twist Factor ◽  
Protein Fiber

The soybean protein fiber is one of the green fibers. It is blended with Tencel. The strength of the blended yarn is tested. The relation between the strength and the twist factor and the blended ratio is analyzed. The optimum blended ratio and the critical twist factor is determined.

A Study on Physical Properties of Microfilament Composite Yarns

2016 ◽  
Vol 11 (3) ◽  
pp. 155892501601100 ◽  
Author(s):  
Esin Sarioğlu ◽  
Osman Babaarslan
Keyword(s):  
Tensile Properties ◽  
Textile Industry ◽  
Ring Spinning ◽  
Twist Factor ◽  
Statistical Effect ◽  
Spun Yarn ◽  
Spun Yarns ◽  
Yarn Count ◽  
Ring Spun Yarn ◽  
Sheath Material

In the textile industry, composite yarns with multifilament cores are used to impart strength. There are various spinning systems to produce composite core-spun yarns. In this study, to determine the effects of filament fineness on yarn characteristics of composite yarns, polyester filaments with medium, fine and micro fiber linear densities were used as the core portion and cotton fiber was used as the sheath material. Yarn samples were manufactured using a modified ring spinning system with four different yarn counts and constant twist factor (ae). The effect of filament linear density on yarn tensile properties, unevenness and imperfections was determined. Yarn evenness and tensile properties were compared with 100% cotton ring spun yarn and to each other. When relative amount of core increases, it was observed that composite yarns had improved tenacity and elongation compared to 100% cotton ring spun yarn. Although filament fineness was found to have a significant effect on the CVm % properties, there was no statistical effect on imperfections other than yarn count parameter.

scholarly journals Ghost Imaging with a Partially Coherent Beam Carrying Twist Phase in a Turbulent Ocean: A Numerical Approach

2019 ◽  
Vol 9 (15) ◽  
pp. 3023 ◽  
Author(s):  
Yonglei Liu ◽  
Xianlong Liu ◽  
Lin Liu ◽  
Fei Wang ◽  
Yuping Zhang ◽  
...  
Keyword(s):  
Numerical Approach ◽  
Coherent Beam ◽  
Ghost Imaging ◽  
Oceanic Turbulence ◽  
Partially Coherent ◽  
Rytov Approximation ◽  
Twist Factor ◽  
Imaging Approach ◽  
Optical Paths

Ghost imaging (GI) is an indirect imaging approach that can retrieve an object’s image even in a harsh environment through measuring the fourth-order correlation function (FOCF) between the signal and idle optical paths. In this paper, we study lensless GI with a partially coherent beam carrying twist phase, i.e., twisted Gaussian Schell-model (TGSM) beam, in the presence of oceanic turbulence. Explicit expression of the FOCF is derived based on the optical coherence theory and Rytov approximation, and the effects of the twist phase and the oceanic turbulence on the quality and visibility of image are investigated in detail through numerical examples. Our results show that the simulated oceanic turbulence strongly affects the GI. The quality of image decreases monotonously with an increase of the strength of turbulence whereas the visibility increases. When the illumination light carries a twist phase, the visibility of the image is improved while the quality of the image is reduced in contrast to those without a twist phase. By properly selecting the strength of the twist phase, the image can still be maintained at an acceptable level of quality with high visibility. Furthermore, it is found that the quality and visibility of the ghost image are less affected by the oceanic turbulence using a TGSM beam with larger twist factor. Our findings will be useful for the application of GI in an oceanic turbulent environment.

Prediction and Control of Surface Texture of Single Direction Crepe

2011 ◽  
Vol 175-176 ◽  
pp. 933-937
Author(s):  
Chao Chen ◽  
Yong Kai Liu
Keyword(s):  
Surface Texture ◽  
Structural Parameters ◽  
Regression Equations ◽  
Contributing Factors ◽  
Texture Characteristic ◽  
Twist Factor ◽  
Twist Multiplier ◽  
Texture Characteristics ◽  
Prediction And Control ◽  
And Control

A number of plain weave silk-like polyester fabrics with different surface texture were collected, data of fabric structural parameters were analyzed, and surface texture characteristics were tested. According to the relationship between structural parameters data and surface texture characteristic value, firmness and weft twist factor were found to be the main factors that affect the surface texture of single direction crepe. Finally, let tightness and weft twist multiplier be contributing factors, surface texture characteristics of single direction crepes were obtained by data analysis and regression equations.

scholarly journals Experimental synthesis of partially coherent beam with controllable twist phase and measuring its orbital angular momentum

Nanophotonics ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Haiyun Wang ◽  
Xiaofeng Peng ◽  
Hao Zhang ◽  
Lin Liu ◽  
Yahong Chen ◽  
...  
Keyword(s):  
Angular Momentum ◽  
Orbital Angular Momentum ◽  
Super Resolution ◽  
Coherent Beam ◽  
Light Modulator ◽  
Flexible Control ◽  
Precise Control ◽  
Partially Coherent ◽  
Twist Factor ◽  
Key Factor

Abstract Twist phase is a nontrivial second-order phase that only exists in a partially coherent beam. Such twist phase endows the partially coherent beam with orbital angular momentum (OAM) and has unique applications such as in super-resolution imaging. However, the manipulation and the detection of the twist phase are still far from easy tasks in experiment. In this work, we present a flexible approach to generate a famous class of twisted Gaussian Schell-model (TGSM) beam with controllable twist phase by the superposition of the complex field realizations using a single phase-only spatial light modulator. The precise control of the amplitude and phase of the field realizations allows one to manipulate the strength of the twist phase easily. In addition, we show that the twist factor, a key factor that determines the strength of twist phase and the amount of OAM, can be measured by extracting the real part of the complex degree of coherence of the TGSM beam. The experiment is carried out with the help of the generalized Hanbury Brown and Twiss experiment as the generated TGSM beam obeys Gaussian statistics. The flexible control and detection of the twist phase are expected to find applications in coherence and OAM-based ghost imaging.

scholarly journals The Ring-LWE Problem in Lattice-Based Cryptography: The Case of Twisted Embeddings

Entropy ◽  
2021 ◽  
Vol 23 (9) ◽  
pp. 1108
Author(s):  
Jheyne N. Ortiz ◽  
Robson R. de Araujo ◽  
Diego F. Aranha ◽  
Sueli I. R. Costa ◽  
Ricardo Dahab
Keyword(s):  
Public Key Cryptography ◽  
Number Fields ◽  
Canonical Embedding ◽  
Worst Case ◽  
Average Case ◽  
Twist Factor ◽  
Algebraic Lattices ◽  
Cyclotomic Number Fields ◽  
Lattice Based Cryptography ◽  
Respective Number

Several works have characterized weak instances of the Ring-LWE problem by exploring vulnerabilities arising from the use of algebraic structures. Although these weak instances are not addressed by worst-case hardness theorems, enabling other ring instantiations enlarges the scope of possible applications and favors the diversification of security assumptions. In this work, we extend the Ring-LWE problem in lattice-based cryptography to include algebraic lattices, realized through twisted embeddings. We define the class of problems Twisted Ring-LWE, which replaces the canonical embedding by an extended form. By doing so, we allow the Ring-LWE problem to be used over maximal real subfields of cyclotomic number fields. We prove that Twisted Ring-LWE is secure by providing a security reduction from Ring-LWE to Twisted Ring-LWE in both search and decision forms. It is also shown that the twist factor does not affect the asymptotic approximation factors in the worst-case to average-case reductions. Thus, Twisted Ring-LWE maintains the consolidated hardness guarantee of Ring-LWE and increases the existing scope of algebraic lattices that can be considered for cryptographic applications. Additionally, we expand on the results of Ducas and Durmus (Public-Key Cryptography, 2012) on spherical Gaussian distributions to the proposed class of lattices under certain restrictions. As a result, sampling from a spherical Gaussian distribution can be done directly in the respective number field while maintaining its format and standard deviation when seen in Zn via twisted embeddings.

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