scholarly journals Innovation in 3D Braiding Technology and Its Applications

Textiles ◽  
2021 ◽  
Vol 1 (2) ◽  
pp. 185-205
Author(s):  
Caroline Emonts ◽  
Niels Grigat ◽  
Felix Merkord ◽  
Ben Vollbrecht ◽  
Akram Idrissi ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Two Dimensional ◽  
Tubular Structures ◽  
Process Step ◽  
Technical Textiles ◽  
Medical Textiles ◽  
Hexagonal Arrangement ◽  
Additional Process ◽  
Near Net Shape ◽  
High Degree

Braids are generally divided into 2D braids and 3D braids. Two-dimensional braids include flat braids and circular braids. Circular braids represent three-dimensional textiles, as they enclose a volume, but consist of a two-dimensional yarn architecture. Three-dimensional braids are defined by a three-dimensional yarn architecture. Historically, 3D braids were produced on row and column braiding machines with Cartesian or radial machine beds, by bobbin movements around inlay yarns. Three-dimensional rotary braiding machines allow a more flexible braiding process, as the bobbins are moved via individually controlled horn gears and switches. Both braiding machines at the Institut für Textiltechnik (ITA) of RWTH Aachen University, Germany, are based on the principal of 3D rotary machines. The fully digitized 3D braiding machine with an Industry 4.0 standard enables the near-net-shape production of three-dimensionally braided textile preforms for lightweight applications. The preforms can be specifically reinforced in all three spatial directions according to the application. Complex 3D structures can be produced in just one process step due to the high degree of design freedom. The 3D hexagonal braiding technology is used in the field of medical textiles. The special shape of the horn gears and their hexagonal arrangement provides the densest packing of the bobbins on the machine bed. In addition, the lace braiding mechanism allows two bobbins to occupy the position between two horn gears, maximizing the number of bobbins. One of the main applications is the near-net-shape production of tubular structures, such as complex stent structures. Three-dimensional braiding offers many advantages compared to 2D braiding, e.g., production of complex three-dimensional geometries in one process step, connection of braided layers, production of cross-section changes and ramifications, and local reinforcement of technical textiles without additional process steps. In the following review, the latest developments in 3D braiding, the machine development of 3D braiding machines, as well as software and simulation developments are presented. In addition, various applications in the fields of lightweight construction and medical textiles are introduced.

The aerodynamic theory of sails. I. Two-dimensional sails

1961 ◽  
Vol 261 (1306) ◽  
pp. 402-422 ◽  
Keyword(s):  
Lift Coefficient ◽  
Linear Equations ◽  
Three Dimensional ◽  
Angle Of Incidence ◽  
Two Dimensional ◽  
Inviscid Incompressible Fluid ◽  
Two Dimensional Flow ◽  
Linearized Theory ◽  
High Degree ◽  
Additional Equation

This paper deals with the preliminaries essential for any theoretical investigation of three-dimensional sails—namely, with the two-dimensional flow of inviscid incompressible fluid past an infinitely-long flexible inelastic membrane. If the distance between the luff and the leach of the two-dimensional sail is c , and if the length of the material of the sail between luff and leach is ( c + l ), then the problem is to determine the flow when the angle of incidence α between the chord of the sail and the wind, and the ratio l / c are both prescribed; especially, we need to know the shape of, the loading on, and the tension in, the sail. The aerodynamic theory follows the lines of the conventional linearized theory of rigid aerofoils; but in the case of a sail, there is an additional equation to be satisfied which ex­presses the static equilibrium of each element of the sail. The resulting fundamental integral equation—the sail equation—is consequently quite different from those of aerofoil theory, and it is not susceptible to established methods of solution. The most striking result is the theoretical possibility of more than one shape of sail for given values of α and l / c ; but there appears to be no difficulty in choosing the shape which occurs in reality. The simplest result for these realistic shapes is that the lift coefficient of a sail exceeds that of a rigid flat plate (for which l / c = 0) by an amount approximately equal to 0.636 ( l / c ) ½ . It seems very doubtful whether analytical solutions of the sail equation will be found, but a method is developed in this paper which comes to the next best thing; namely, an explicit expression, as a matrix quotient, which gives numerical values to a high degree of accuracy at so many chord-wise points. The method should have wide application to other types of linear equations.

scholarly journals One-, Two-, and Three-Dimensional Supramolecular Assemblies Based on Tubular and Regular Polygonal Structures of Pillar[n]arenes

CCS Chemistry ◽  
2019 ◽  
pp. 50-63 ◽  
Author(s):  
Shixin Fa ◽  
Takahiro Kakuta ◽  
Tada-aki Yamagishi ◽  
Tomoki Ogoshi
Keyword(s):  
Surface Modification ◽  
Supramolecular Chemistry ◽  
Three Dimensional ◽  
Supramolecular Assemblies ◽  
Two Dimensional ◽  
Macrocyclic Compounds ◽  
Tubular Structures ◽  
One Dimensional ◽  
Symmetrical Shape

Pillar[ n]arenes, which were first reported by our group in 2008, are promising macrocyclic compounds in supramolecular chemistry. The simple, tubular, and highly symmetrical shape of pillar[ n]arenes has allowed various supramolecular assemblies with well-defined structures to be constructed. The pillar-shaped structures of pillar[ n]arenes are suitable for surface modification and formation of one-dimensional (1D) channels. The regular polygonal prism shape of organized pillar[ n]arenes contributes to the construction of highly assembled structures such as two-dimensional (2D) sheets and three-dimensional (3D) spheres. In this minireview, we describe supramolecular assemblies with various dimensions. First, we discuss 1D supramolecular assemblies based on tubular structures of pillar[ n]arenes. Second, 2D supramolecular sheet formation based on regular polygonal structures is described. Finally, 3D supramolecular assemblies such as vesicles and 3D frameworks constructed from pillar[ n]arenes are discussed.

Analysis of Three-Dimensional Reality Modeling Algorithm in Animation Design

2014 ◽  
Vol 602-605 ◽  
pp. 3235-3238
Author(s):  
Bai Chuan Cai ◽  
Rong Fang Mei ◽  
Jian Guo Mei ◽  
Bo Yang
Keyword(s):  
Design Process ◽  
Optimization Algorithm ◽  
Three Dimensional ◽  
Two Dimensional ◽  
Feature Points ◽  
Refinement Method ◽  
Three Dimensional Coordinate ◽  
High Degree ◽  
Modeling Algorithm

During animation design process, when the overlap of animation graphics is overtopping, inaccurate three-dimensional feature points appear in the established model, which resulting in low fidelity of model. For this drawbacks, a three-dimensional reality animation design modeling based on an optimization algorithm of animation modeling fidelity is proposed. Triangle refinement method is utilized to refine feature points distributed disorderly in the three-dimensional animation model, so as to obtain a three-dimensional animation composed of triangles, according to the method of calculating the intersection of intersecting triangles, optimal triangles can be achieved, i.e. the new three-dimensional coordinate points are acquired. Afterwards, two-dimensional coordinate calculation is processed for the new added points to get the exact coordinates of the point in the three-dimensional animation model, eventually obtain a three-dimensional animation model with high degree of fidelity.

A NOVEL FAST IMAGE ENCRYPTION SCHEME BASED ON 3D CHAOTIC BAKER MAPS

2004 ◽  
Vol 14 (10) ◽  
pp. 3613-3624 ◽  
Author(s):  
YAOBIN MAO ◽  
GUANRONG CHEN ◽  
SHIGUO LIAN
Keyword(s):  
Real Time ◽  
Image Encryption ◽  
Security Analysis ◽  
Three Dimensional ◽  
Two Dimensional ◽  
Real Time Image ◽  
Encryption Schemes ◽  
High Degree ◽  
Time Image ◽  
Baker Map

Symmetric block encryption schemes, designed on invertible two-dimensional chaotic maps on a torus or a square, prove feasible and secure for real-time image encryption according to the commonly used criteria given in the literature. In this paper, a typical map of this kind, namely, the baker map, is further extended to be three-dimensional and then used to speed up image encryption while retaining its high degree of security. The proposed algorithm is described in detail, along with its security analysis and implementation. Experimental results show that this three-dimensional baker map is 2–3 times faster than the two-dimensional one, showing its great potential in real-time image encryption applications.

Experimental Investigation and Model Predictions of a NiMnGa Alloy’s Response to Three Dimensional Magneto-Mechanical Loading

2015 ◽  
Author(s):  
Jason L. Dikes ◽  
Heidi P. Feigenbaum ◽  
Constantin Ciocanel ◽  
Roger Guiel
Keyword(s):  
Experimental Data ◽  
Mechanical Loading ◽  
Three Dimensional ◽  
Experimental Investigations ◽  
Two Dimensional ◽  
Loading Conditions ◽  
Magnetic Shape Memory ◽  
Model Predictions ◽  
3D Loading ◽  
High Degree

Researchers have attempted to model the magneto-mechanical behavior of magnetic shape memory alloys (MSMAs) for over a decade, but all of the models developed to date have only been validated against experimental data generated under two-dimensional loading conditions. As efforts have been underway to develop models able to predict the most general (i.e. 3D) loading conditions for the material, there is a need for experimental data to support the calibration and validation of these models. This paper presents magneto-mechanical data from experiments where a MSMA specimen whose microstructure accommodates three martensite variants is subjected to three-dimensional magneto-mechanical loading. To the best of our knowledge, all prior experimental investigations on MSMA have been performed on samples accommodating two martensite variants and exposed to two-dimensional magneto-mechanical loads. The experimental results from the 3D loading of the three variant MSMA specimen are used to calibrate and validate a 3D model developed by this group [LaMaster et al. (2014)]. This model assumes that three martensite variants coexist in the material. The LaMaster et al. model captures the general trends seen in the experimental data, but does not predict the data with a high degree of accuracy. Possible reasons for the mismatch between experimental data and model predictions are discussed.

High Degree of Discordance Between Three-Dimensional and Two-Dimensional Lumbar Spine Bone Mineral Density in Turner's Syndrome

2005 ◽  
Vol 8 (4) ◽  
pp. 461-466 ◽  
Author(s):  
Andrea Z. Lage ◽  
Cynthia A. Brandão ◽  
Judite R.T. Mendes ◽  
Martha K. Huayllas ◽  
Bernardo Liberman ◽  
...  
Keyword(s):  
Bone Mineral Density ◽  
Lumbar Spine ◽  
Bone Mineral ◽  
Three Dimensional ◽  
Spine Bone Mineral Density ◽  
Turner's Syndrome ◽  
Two Dimensional ◽  
Turner’S Syndrome ◽  
Mineral Density ◽  
High Degree

High Resolution Microscopy of Multi-Layered Biological Crystals

1982 ◽  
Vol 40 ◽  
pp. 80-83
Author(s):  
H.A. Cohen ◽  
T.W. Jeng ◽  
W. Chiu
Keyword(s):  
High Resolution ◽  
Low Dose ◽  
Three Dimensional ◽  
Data Interpretation ◽  
Two Dimensional ◽  
Biological Objects ◽  
Density Maps ◽  
Density Map ◽  
Complex Crystal ◽  
High Resolution Microscopy

This tutorial will discuss the methodology of low dose electron diffraction and imaging of crystalline biological objects, the problems of data interpretation for two-dimensional projected density maps of glucose embedded protein crystals, the factors to be considered in combining tilt data from three-dimensional crystals, and finally, the prospects of achieving a high resolution three-dimensional density map of a biological crystal. This methodology will be illustrated using two proteins under investigation in our laboratory, the T4 DNA helix destabilizing protein gp32*I and the crotoxin complex crystal.

Instrumentation For Quantitative Microscopy

1977 ◽  
Vol 35 ◽  
pp. 206-209
Author(s):  
B. Ralph ◽  
A.R. Jones
Keyword(s):  
Volume Fraction ◽  
Three Dimensional ◽  
Two Dimensional ◽  
Automatic Data ◽  
Phase Volume Fraction ◽  
Statistical Confidence ◽  
Resultant Data ◽  
Automatic Data Collection ◽  
Third Dimension ◽  
Evolution Of Microstructure

In all fields of microscopy there is an increasing interest in the quantification of microstructure. This interest may stem from a desire to establish quality control parameters or may have a more fundamental requirement involving the derivation of parameters which partially or completely define the three dimensional nature of the microstructure. This latter categorey of study may arise from an interest in the evolution of microstructure or from a desire to generate detailed property/microstructure relationships. In the more fundamental studies some convolution of two-dimensional data into the third dimension (stereological analysis) will be necessary.In some cases the two-dimensional data may be acquired relatively easily without recourse to automatic data collection and further, it may prove possible to perform the data reduction and analysis relatively easily. In such cases the only recourse to machines may well be in establishing the statistical confidence of the resultant data. Such relatively straightforward studies tend to result from acquiring data on the whole assemblage of features making up the microstructure. In this field data mode, when parameters such as phase volume fraction, mean size etc. are sought, the main case for resorting to automation is in order to perform repetitive analyses since each analysis is relatively easily performed.

A linearity test for thick specimens imaged by HVEM over a 180° angular range

1991 ◽  
Vol 49 ◽  
pp. 552-553
Author(s):  
Yu Liu
Keyword(s):  
Phase Contrast ◽  
Three Dimensional ◽  
Angular Range ◽  
Two Dimensional ◽  
Back Projection ◽  
Line Integral ◽  
Exponential Law ◽  
Transmission Electron ◽  
Absorption Law ◽  
Linearity Test

The image obtained in a transmission electron microscope is the two-dimensional projection of a three-dimensional (3D) object. The 3D reconstruction of the object can be calculated from a series of projections by back-projection, but this algorithm assumes that the image is linearly related to a line integral of the object function. However, there are two kinds of contrast in electron microscopy, scattering and phase contrast, of which only the latter is linear with the optical density (OD) in the micrograph. Therefore the OD can be used as a measure of the projection only for thin specimens where phase contrast dominates the image. For thick specimens, where scattering contrast predominates, an exponential absorption law holds, and a logarithm of OD must be used. However, for large thicknesses, the simple exponential law might break down due to multiple and inelastic scattering.

An Image Reconstruction System Applied to High Voltage Microscopy

1975 ◽  
Vol 33 ◽  
pp. 292-293
Author(s):  
D. E. Johnson
Keyword(s):  
High Voltage ◽  
Prior Information ◽  
Block Diagram ◽  
Three Dimensional ◽  
Real Space ◽  
Two Dimensional ◽  
Efficient Manner ◽  
Fourier Methods ◽  
Tilt Series ◽  
Methods Of Reconstruction

Increased specimen penetration; the principle advantage of high voltage microscopy, is accompanied by an increased need to utilize information on three dimensional specimen structure available in the form of two dimensional projections (i.e. micrographs). We are engaged in a program to develop methods which allow the maximum use of information contained in a through tilt series of micrographs to determine three dimensional speciman structure.In general, we are dealing with structures lacking in symmetry and with projections available from only a limited span of angles (±60°). For these reasons, we must make maximum use of any prior information available about the specimen. To do this in the most efficient manner, we have concentrated on iterative, real space methods rather than Fourier methods of reconstruction. The particular iterative algorithm we have developed is given in detail in ref. 3. A block diagram of the complete reconstruction system is shown in fig. 1.

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