Cushioning properties of weft-knitted spacer fabrics

2017 ◽  
Vol 88 (14) ◽  
pp. 1628-1640 ◽  
Author(s):  
Tong Zhao ◽  
Hairu Long ◽  
Tianqi Yang ◽  
Yanping Liu
Keyword(s):  
Human Body ◽  
Structural Parameters ◽  
Testing Machine ◽  
Three Dimensional ◽  
Structural Features ◽  
Practical Significance ◽  
Absorption Energy ◽  
Yarn Diameter ◽  
Spacer Fabrics ◽  
Compression Resistance

Three-dimensional spacer fabrics which have a sandwich structure are formed in a single knitting process without any additional joining treatment. They consist of two separate multifilament outer layers connected by arrays of spacer monofilaments. This paper presents an experimental study on the relationships between the cushioning properties and structural parameters of weft-knitted spacer fabrics in order to lay a foundation for the development of seamless shaped impact protectors for human body impact protection. Sixteen spacer fabrics of different structural parameters were knitted on a computerized flat knitting machine and tested on a universal mechanical testing machine. The cushioning properties of the spacer fabrics were analyzed in terms of their structural features, compression stress–strain curves, energy absorption, and compression resilience. It was found that multifilament fineness, spacer yarn diameter, and spacer yarn pattern should be matching in order to form effective binding structures between the outer layers and spacer monofilaments. The results also showed that spacer fabrics knitted with a shorter spacer yarn span distance, coarser monofilaments, and higher spacer yarn density have better compression resistance and absorption energy but inferior compression resilience if their binding structures are effective. This study has practical significance in promoting the application of this type of fabric as a cushion material for human body protection.

scholarly journals Rietveld analysis of computed tomography and its application to methanol to olefin reactor beds

2015 ◽  
Vol 48 (6) ◽  
pp. 1719-1728 ◽  
Author(s):  
David Stephen Wragg ◽  
Matthew G. O'Brien ◽  
Marco Di Michiel ◽  
Francesca Lønstad-Bleken
Keyword(s):  
Computed Tomography ◽  
Structural Parameters ◽  
Three Dimensional ◽  
Rietveld Analysis ◽  
Structural Features ◽  
Data Sets ◽  
X Ray Diffraction ◽  
Olefin Conversion ◽  
Methanol To Olefin ◽  
Commercially Important

This article reports the creation of tomographic reconstructions giving three-dimensional data on the distribution of various structural features for SAPO-34 zeolite catalyst beds used in the commercially important methanol to olefin conversion process. The data were processed using parametric Rietveld refinement to treat entire slices of the tomograph as single refined data sets, allowing extraction of real structural parameters from all voxels of the reconstruction. This has the advantage over more traditional methods of X-ray diffraction computed tomography using peak intensities, that the structural parameters are independent of the intensity, meaning that information can still be extracted from poor data sets: an example is shown where part of the sample was no longer in the beam during data collection. Reconstructions using several structural parameters are presented and the results compared. Analysis of the variation of the catalystcaxis (linked to the degree of deactivation in earlier work) shows small but significant three-dimensional variations in the degree of deactivation with patterns which depend on the silicon content of the catalyst. Average data for the tomographic slices compare well with the results of earlieroperandotwo-dimensional reactor scanning experiments.

Classification analysis of young female students’ waist–abdomen–hip based on body photos

2021 ◽  
Vol 91 (11-12) ◽  
pp. 1409-1418
Author(s):  
Xiaoyu Cai ◽  
Bingfei Gu ◽  
Huazhou He
Keyword(s):  
Human Body ◽  
Body Shape ◽  
Three Dimensional ◽  
3D Scanning ◽  
Young Female ◽  
The Body ◽  
Practical Significance ◽  
Main Body ◽  
Body Type ◽  
Young Females

To improve body-type classification research and personalized clothing, this study adopted a research method of “three-dimensional (3D) scanning + photos” for the body-shape classification of young females’ waist–abdomen–hip. A total of 178 female college students were recruited for manual, photo and 3D body measurement to get the main body information. Based on the data acquired from 3D scanning, the corresponding heights, angles and other parameters of the waist, abdomen and hip were selected and used to analyze the human body in two respects of shape and height. Then the body-shape indexes and the height indexes were respectively analyzed, and 16 shape characteristic indicators and four height characteristic parameters affecting the waist, abdomen and hip were extracted. Three types in shape and two types in height were obtained, and the main classification rules of the waist–abdomen–hip shape were also concluded to identify the body type based on the body measurements extracted from body photos, which realized the automatic body-type identification based on body photos. It was of great practical significance to provide a basis for personalized customization of fast clothing and the subdivision of the human body shape, which could meet the individual customer’s requirements.

In-plane shear behavior of 3D warp-knitted spacer fabrics: Part II—Effect of structural parameters

2017 ◽  
Vol 48 (4) ◽  
pp. 772-801 ◽  
Author(s):  
Veerakumar Arumugam ◽  
Rajesh Mishra ◽  
Maros Tunak ◽  
Jiri Militky
Keyword(s):  
Shear Stress ◽  
Energy Absorption ◽  
Layer Structure ◽  
Structural Parameters ◽  
Strain Curve ◽  
Shear Behavior ◽  
Plane Shear ◽  
Yarn Diameter ◽  
Deformation Properties ◽  
Spacer Fabrics

The objective of this work is to study the in-plane shear behavior of 3D warp-knitted spacer knitted fabrics by using a picture frame fixture. This part aims to investigate the effects of structural parameters on the shear stress and energy absorption of warp-knitted spacer fabrics. A group of warp-knitted spacer fabrics was produced on a double-needle bar Raschel machine by varying their structural parameters including spacer yarn fineness, fabric thickness, and outer layer structure. The effects of fabric structural parameters on the shear properties of the spacer fabrics were tested and analyzed based on the nonlinear behavior of shear stress versus shear angle and the deformation mechanism. During loading process, the series of surface images were acquired in certain interval at different positions. These images were processed in image analysis software to obtain the full-field displacement and shear angles at chosen points on the surface of test specimen. The potential shear behavior of the fabric was identified with support of the shear stress–strain curve, work done, and efficiency at different shear stages. The regression model was used to establish the elastic deformation properties to obtain the shear results. Advance statistical evaluation and two-way analysis of variance are used to analyze the significance of various factors such as thickness, spacer yarn diameter, and surface structures on energy absorption at maximum shear load and deformation.

Methods for making stereoslides and -prints, with freeze-etched olfactory epithelium as example

1984 ◽  
Vol 42 ◽  
pp. 704-705
Author(s):  
Bert Ph. M. Menco ◽  
Ido F. Menco ◽  
Frans L.T. Verdonk
Keyword(s):  
Electron Microscope ◽  
Olfactory Epithelium ◽  
Three Dimensional ◽  
Supporting Cell ◽  
Structural Features ◽  
Extensive Study ◽  
Sprague Dawley ◽  
Freezing Method ◽  
Respiratory Epithelia ◽  
Three Dimensional Presentation

Previously we presented an extensive study of the distributions of intramembranous particles of structures in apical surfaces of nasal olfactory and respiratory epithelia of the Sprague-Dawley rat. For the same structures these distributions were compared in samples which were i) chemically fixed and cryo-protected with glycerol before cryo-fixation, after excision, and ii)ultra-rapidly frozen by means of the slam-freezing method. Since a three-dimensional presentation markedly improves visualization of structural features micrographs were presented as stereopairs. Two exposures were made by tiling the sample stage of the electron microscope 6° in either direction with an eucentric goniometer. The negatives (Agfa Pan 25 Professional) were reversed with Kodak Technical Pan Film 2415 developed in D76 1:1. The prints were made from these reversed negatives. As an example tight-junctional features of an olfactory supporting cell in a region where this cell conjoined with two other cells are presented (Fig. 1).

Study on erythrocytes by SEM photogrammetry (SEMP) technique

1990 ◽  
Vol 48 (3) ◽  
pp. 724-725
Author(s):  
Tong Wensheng ◽  
Lu Lianhuang ◽  
Zhang Zhijun
Keyword(s):  
Quantitative Analysis ◽  
Cell Membrane ◽  
Clinical Diagnosis ◽  
Human Body ◽  
Blood Cells ◽  
Three Dimensional ◽  
Normal Person ◽  
Blood Disease ◽  
Computation Technique ◽  
Important Basis

This is a combined study of two diffirent branches, photogrammetry and morphology of blood cells. The three dimensional quantitative analysis of erythrocytes using SEMP technique, electron computation technique and photogrammetry theory has made it possible to push the study of mophology of blood cells from LM, TEM, SEM to a higher stage, that of SEM P. A new path has been broken for deeply study of morphology of blood cells.In medical view, the abnormality of the quality and quantity of erythrocytes is one of the important changes of blood disease. It shows the abnormal blood—making function of the human body. Therefore, the study of the change of shape on erythrocytes is the indispensable and important basis of reference in the clinical diagnosis and research of blood disease.The erythrocytes of one normal person, three PNH Patients and one AA patient were used in this experiment. This research determines the following items: Height;Length of two axes (long and short), ratio; Crevice in depth and width of cell membrane; Circumference of erythrocytes; Isoline map of erythrocytes; Section map of erythrocytes.

scholarly journals Brain capillary structures of schizophrenia cases and controls show a correlation with their neuron structures

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Rino Saiga ◽  
Masayuki Uesugi ◽  
Akihisa Takeuchi ◽  
Kentaro Uesugi ◽  
Yoshio Suzuki ◽  
...  
Keyword(s):  
Blood Vessels ◽  
Structural Parameters ◽  
Three Dimensional ◽  
Superior Temporal Gyrus ◽  
Anterior Cingulate ◽  
Dimensional Structure ◽  
Constant Diameter ◽  
The Mean ◽  
Cartesian Coordinate ◽  
Micrometer Scale

AbstractBrain blood vessels constitute a micrometer-scale vascular network responsible for supply of oxygen and nutrition. In this study, we analyzed cerebral tissues of the anterior cingulate cortex and superior temporal gyrus of schizophrenia cases and age/gender-matched controls by using synchrotron radiation microtomography or micro-CT in order to examine the three-dimensional structure of cerebral vessels. Over 1 m of cerebral blood vessels was traced to build Cartesian-coordinate models, which were then used for calculating structural parameters including the diameter and curvature of the vessels. The distribution of vessel outer diameters showed a peak at 7–9 μm, corresponding to the diameter of the capillaries. Mean curvatures of the capillary vessels showed a significant correlation to the mean curvatures of neurites, while the mean capillary diameter was almost constant, independent of the cases. Our previous studies indicated that the neurites of schizophrenia cases are thin and tortuous compared to controls. The curved capillaries with a constant diameter should occupy a nearly constant volume, while neurons suffering from neurite thinning should have reduced volumes, resulting in a volumetric imbalance between the neurons and the vessels. We suggest that the observed structural correlation between neurons and blood vessels is related to neurovascular abnormalities in schizophrenia.

scholarly journals Coupled Fluid–Solid Numerical Simulation for Flow Field Characteristics and Supporting Performance of Flexible Support Cylindrical Gas Film Seal

Aerospace ◽  
2021 ◽  
Vol 8 (4) ◽  
pp. 97
Author(s):  
Junfeng Sun ◽  
Meihong Liu ◽  
Zhen Xu ◽  
Taohong Liao ◽  
Xiangping Hu ◽  
...  
Keyword(s):  
Flow Field ◽  
Film Thickness ◽  
Fluid Dynamic ◽  
Structural Characteristics ◽  
Structural Parameters ◽  
Equivalent Stress ◽  
Three Dimensional ◽  
High Rotational Speed ◽  
Flexible Support ◽  
Flow Field Characteristics

A new type of cylindrical gas film seal (CGFS) with a flexible support is proposed according to the working characteristics of the fluid dynamic seal in high-rotational-speed fluid machinery, such as aero-engines and centrifuges. Compared with the CGFS without a flexible support, the CGFS with flexible support presents stronger radial floating characteristics since it absorbs vibration and reduces thermal deformation of the rotor system. Combined with the structural characteristics of a film seal, an analytical model of CGFS with a flexible wave foil is established. Based on the fluid-structure coupling analysis method, the three-dimensional flow field of a straight-groove CGFS model is simulated to study the effects of operating and structural parameters on the steady-state characteristics and the effects of gas film thickness, eccentricity, and the number of wave foils on the equivalent stress of the flexible support. Simulation results show that the film stiffness increases significantly when the depth of groove increases. When the gas film thickness increases, the average equivalent stress of the flexible support first decreases and then stabilizes. Furthermore, the number of wave foils affects the average foils thickness. Therefore, when selecting the number of wave foils, the support stiffness and buffer capacity should be considered simultaneously.

scholarly journals Agent-Based Modeling Demonstrates How Local Chemotactic Behavior Can Shape Biofilm Architecture

mSphere ◽  
2019 ◽  
Vol 4 (3) ◽  
Author(s):  
Emily G. Sweeney ◽  
Andrew Nishida ◽  
Alexandra Weston ◽  
Maria S. Bañuelos ◽  
Kristin Potter ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Three Dimensional ◽  
Structural Features ◽  
Agent Based Modeling ◽  
Emergent Properties ◽  
Cellular Interactions ◽  
Biofilm Growth ◽  
Content Type ◽  
Agent Based ◽  
H Pylori

ABSTRACTBacteria are often found living in aggregated multicellular communities known as biofilms. Biofilms are three-dimensional structures that confer distinct physical and biological properties to the collective of cells living within them. We used agent-based modeling to explore whether local cellular interactions were sufficient to give rise to global structural features of biofilms. Specifically, we asked whether chemorepulsion from a self-produced quorum-sensing molecule, autoinducer-2 (AI-2), was sufficient to recapitulate biofilm growth and cellular organization observed for biofilms ofHelicobacter pylori, a common bacterial resident of human stomachs. To carry out this modeling, we modified an existing platform, Individual-based Dynamics of Microbial Communities Simulator (iDynoMiCS), to incorporate three-dimensional chemotaxis, planktonic cells that could join or leave the biofilm structure, and cellular production of AI-2. We simulated biofilm growth of previously characterizedH. pyloristrains with various AI-2 production and sensing capacities. Using biologically plausible parameters, we were able to recapitulate both the variation in biofilm mass and cellular distributions observed with these strains. Specifically, the strains that were competent to chemotax away from AI-2 produced smaller and more heterogeneously spaced biofilms, whereas the AI-2 chemotaxis-defective strains produced larger and more homogeneously spaced biofilms. The model also provided new insights into the cellular demographics contributing to the biofilm patterning of each strain. Our analysis supports the idea that cellular interactions at small spatial and temporal scales are sufficient to give rise to larger-scale emergent properties of biofilms.IMPORTANCEMost bacteria exist in aggregated, three-dimensional structures called biofilms. Although biofilms play important ecological roles in natural and engineered settings, they can also pose societal problems, for example, when they grow in plumbing systems or on medical implants. Understanding the processes that promote the growth and disassembly of biofilms could lead to better strategies to manage these structures. We had previously shown thatHelicobacter pyloribacteria are repulsed by high concentrations of a self-produced molecule, AI-2, and thatH. pylorimutants deficient in AI-2 sensing form larger and more homogeneously spaced biofilms. Here, we used computer simulations of biofilm formation to show that localH. pyloribehavior of repulsion from high AI-2 could explain the overall architecture ofH. pyloribiofilms. Our findings demonstrate that it is possible to change global biofilm organization by manipulating local cell behaviors, which suggests that simple strategies targeting cells at local scales could be useful for controlling biofilms in industrial and medical settings.

scholarly journals Multimedia Teaching Platform for Urban Planning Utilizing 3D Technology

2018 ◽  
Vol 13 (04) ◽  
pp. 187 ◽  
Author(s):  
Xuhui Wang ◽  
Quan Zhang ◽  
Yanyi Chen ◽  
Shihao Liang
Keyword(s):  
High Speed ◽  
Three Dimensional ◽  
Practical Significance ◽  
Master Plan ◽  
3D Technology ◽  
Technology Application ◽  
Teaching Platform ◽  
Multimedia Teaching ◽  
Effect Difference ◽  
Urban Rural

In recent years, 3D technology based on computer and internet has achieved high-speed development. People have realized direct and stereo observation of realistic world. Three-dimensional and visualized characteristics of the technology fit well with the teaching objective of college architecture specialized courses. Thus, 3D model has profound practical significance for its application in urban green space system and urban rural overall planning. With “urban-rural master plan” as experimental course, through design of “urban-rural master plan” multimedia teaching platform based on 3D technology and practice of the teaching platform in course teaching, this article has applied control experiment method and statistical method to make comparative analysis on the teaching effect difference of multimedia teaching platform based on 3D technology application in “urban-rural master plan” as experimental course so as to provide theoretical and data support for 3D technology application in “urban-rural master plan” and other college architecture major courses.

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