scholarly journals Effects of Fiber Denier, Fiber Cross-Sectional Shape and Fabric Density on Acoustical Behavior of Vertically Lapped Nonwoven Fabrics

2008 ◽  
Vol 3 (2) ◽  
pp. 155892500800300 ◽  
Author(s):  
Mevlut Tascan ◽  
Edward A. Vaughn
Keyword(s):  
Surface Area ◽  
Materials Science ◽  
Measurement Data ◽  
Unit Weight ◽  
Cross Sectional ◽  
Impedance Tube ◽  
Acoustical Properties ◽  
Nonwoven Fabrics ◽  
Fabric Structure ◽  
Sectional Shape

Acoustical insulation and absorption properties of nonwoven fabrics depend on fiber geometry and fiber arrangement within the fabric structure. The different structures of the fibers result in different total surface areas of nonwoven fabrics. Nonwoven fabrics such as vertically lapped fabrics are ideal materials for use as acoustical insulation products, because they have high total surface. Vertically lapped nonwoven technology consists of carding, perpendicular layering of the carded webs, and through-air bonding using synthetic binder fibers. The surface area of the fabric is directly related to the denier and cross-sectional shape of the fibers in the fabric. Smaller deniers yield more fibers per unit weight of the material, higher total fiber surface area, and greater possibilities for a sound wave to interact with the fibers in the fabric structure. The research in the literature uses two methods for measuring acoustical properties of fabric materials: the impedance tube and reverberation room method. Small test samples are in the impedance tube method and sound absorption coefficient is determined at each frequency. Large reverberation rooms and large test samples are used for the reverberation room method. A direct comparative acoustical properties measurement device that was designed and fabricated at Clemson University School of Materials Science & Engineering was used to measure acoustical insulation in this research. This paper provides a description of the measurement devices and acoustical measurement data for vertically lapped nonwoven fabrics made from three different polyester fiber shape and two denier levels.

The influence of cross-sectional shape and surface area on the microtensile bond test

1998 ◽  
Vol 14 (3) ◽  
pp. 212-221 ◽  
Author(s):  
Suwachai Phrukkanon ◽  
Michael F. Burrow ◽  
Martin J. Tyas
Keyword(s):  
Surface Area ◽  
Cross Sectional ◽  
Sectional Shape

Estimating the surface area of spruce and pine foliage from displaced volume and length

1987 ◽  
Vol 17 (10) ◽  
pp. 1305-1308 ◽  
Author(s):  
David G. Brand
Keyword(s):  
Surface Area ◽  
Accurate Determination ◽  
Direct Calculation ◽  
Regression Technique ◽  
Forest Research ◽  
Cross Sectional ◽  
Independent Variables ◽  
Needle Morphology ◽  
Sectional Shape

Accurate determination of the surface area of needle-leaved trees is a basic requirement for many types of physiological or growth analysis studies in forest research. While many methods are available to estimate surface area, there is still a need for an accurate, rapid measurement technique for species with three- or four-sided needle morphology. I propose a regression technique with length and displaced volume as the independent variables. The regression technique is an improvement over the use of displaced volume and length in direct geometric calculation as it does not assume a constant needle morphology. The regression technique gives more accurate results than direct calculation, is comparable in precision, and is necessary to counter bias where variation in the cross-sectional shape of foliage is related to the treatment or variable under study. Use of regression, however, requires that a subsample of foliage, representing the range of conditions to be studied, be sectioned and measured directly for surface area to develop the estimation equation.

Effect of Fiber Cross-Sectional Shape and Nano ZnO/Modified Chitosan Loading on Antibacterial Properties

2013 ◽  
Vol 761 ◽  
pp. 103-106 ◽  
Author(s):  
Natthaphop Suwannamek ◽  
Nanjaporn Ruangpaisarn ◽  
Chureerat Prahsan
Keyword(s):  
Surface Area ◽  
Cross Section ◽  
Antibacterial Properties ◽  
Cross Sectional ◽  
Nano Zno ◽  
Fiber Cross Section ◽  
Modified Chitosan ◽  
Melt Spun ◽  
The Cross ◽  
Sectional Shape

Antibacterial polypropylene cross-sectional shape fibers were melt spun with adding nano ZnO and modified chitosan. Two types of fiber cross-section, round and worm cross-sectional shape were studied including with nano ZnO and modified chitosan loading. Antibacterial properties, surface area, and fiber crystalization were investigated. The surface area of the fiber and antibacterial properties were directly related to the cross-sectional shape. The greater antibacterial properties was found at lower modified chitosan loading compared ZnO.

Residual Stress Modeling of Warm-Bent Tight-Radius CANDU Feeder Bends

2008 ◽  
Author(s):  
Y. Ding ◽  
M. Yetisir
Keyword(s):  
Residual Stress ◽  
Neutron Diffraction ◽  
Residual Stresses ◽  
Thickness Distribution ◽  
Measurement Data ◽  
Future Research ◽  
Cross Sectional ◽  
Simulation Results ◽  
Sectional Shape ◽  
Neutron Diffraction Technique

In one CANDU® nuclear station, a few feeder piping failures have occurred because of stress corrosion cracking. All the cracks were located in tight-radius bends. Root cause analyses indicated that the residual stress played a significant role in these failures. Residual stress measurements using the neutron diffraction technique have been performed to quantify the residual stresses for a large number of feeder bends. Numerical simulations have also been performed to supplement the measurement data. This paper presents the modeling work carried out for 2.5” warm-bent tight-radius feeder bends using LS-DYNA®. The warm-bending process was divided into heating, bending, springback and cooling stages. The simulation results were compared to the measurement data using the neutron diffraction technique. Good agreement was achieved between the trends of simulation results and the measured residual stresses in feeder bends. Additionally, it was found that the predicted cross-sectional shape and wall thickness distribution agreed well with the measurements. Limitations of the simulation work were summarized and recommendations for future research were made based on this study.

Ultramicrotomy as a Technique for Materials Specimen Preparation

1990 ◽  
Vol 48 (2) ◽  
pp. 428-429
Author(s):  
S.R. Glanvill
Keyword(s):  
Materials Science ◽  
Structural Information ◽  
Specimen Preparation ◽  
Preparation Technique ◽  
Cross Sectional ◽  
Surfaces And Interfaces ◽  
Beam Analysis ◽  
Flat Embedding ◽  
20 Nm ◽  
Sectional Analysis

This paper summarizes the application of ultramicrotomy as a specimen preparation technique for some of the Materials Science applications encountered over the past two years. Specimens 20 nm thick by hundreds of μm lateral dimension are readily prepared for electron beam analysis. Materials examined include metals, plastics, ceramics, superconductors, glassy carbons and semiconductors. We have obtain chemical and structural information from these materials using HRTEM, CBED, EDX and EELS analysis. This technique has enabled cross-sectional analysis of surfaces and interfaces of engineering materials and solid state electronic devices, as well as interdiffusion studies across adjacent layers.Samples are embedded in flat embedding moulds with Epon 812 epoxy resin / Methyl Nadic Anhydride mixture, using DY064 accelerator to promote the reaction. The embedded material is vacuum processed to remove trapped air bubbles, thereby improving the strength and sectioning qualities of the cured block. The resin mixture is cured at 60 °C for a period of 80 hr and left to equilibrate at room temperature.

On the cross-sectional shape of the cellulose crystallites in the tunicate Halocynthia papillosa

1990 ◽  
Vol 48 (3) ◽  
pp. 566-567
Author(s):  
J.-F. Revol ◽  
Y. Van Daele ◽  
F. Gaill
Keyword(s):  
Contrast Imaging ◽  
Animal Kingdom ◽  
Bright Field ◽  
Field Mode ◽  
Cross Sectional ◽  
Ultrathin Sections ◽  
The Cross ◽  
Sectional Shape ◽  
Valonia Ventricosa ◽  
C Nmr

The only form of cellulose which could unequivocally be ascribed to the animal kingdom is the tunicin that occurs in the tests of the tunicates. Recently, high-resolution solid-state l3C NMR revealed that tunicin belongs to the Iβ form of cellulose as opposed to the Iα form found in Valonia and bacterial celluloses. The high perfection of the tunicin crystallites led us to study its crosssectional shape and to compare it with the shape of those in Valonia ventricosa (V.v.), the goal being to relate the cross-section of cellulose crystallites with the two allomorphs Iα and Iβ.In the present work the source of tunicin was the test of the ascidian Halocvnthia papillosa (H.p.). Diffraction contrast imaging in the bright field mode was applied on ultrathin sections of the V.v. cell wall and H.p. test with cellulose crystallites perpendicular to the plane of the sections. The electron microscope, a Philips 400T, was operated at 120 kV in a low intensity beam condition.

Automated 3D measurement of fiber cross section morphology in handsheets

2012 ◽  
Vol 27 (2) ◽  
pp. 264-269 ◽  
Author(s):  
Christian Lorbach ◽  
Ulrich Hirn ◽  
Johannes Kritzinger ◽  
Wolfgang Bauer
Keyword(s):  
Image Analysis ◽  
Cross Section ◽  
Cross Sections ◽  
Image Plane ◽  
3D Measurement ◽  
Cross Sectional ◽  
Fiber Cross Section ◽  
Fiber Wall ◽  
Sectional Shape ◽  
Cross Section Geometry

Abstract We present a method for 3D measurement of fiber cross sectional morphology from handsheets. An automated procedure is used to acquire 3D datasets of fiber cross sectional images using an automated microtome and light microscopy. The fiber cross section geometry is extracted using digital image analysis. Simple sample preparation and highly automated image acquisition and image analysis are providing an efficient tool to analyze large samples. It is demonstrated that if fibers are tilted towards the image plane the images of fiber cross sections are always larger than the true fiber cross section geometry. In our analysis the tilting angles of the fibers to the image plane are measured. The resulting fiber cross sectional images are distorted to compensate the error due to fiber tilt, restoring the true fiber cross sectional shape. We use an approximated correction, the paper provides error estimates of the approximation. Measurement results for fiber wall thickness, fiber coarseness and fiber collapse are presented for one hardwood and one softwood pulp.

scholarly journals Fractal Nature of Advanced Ni-Based Superalloys Solidified on Board the International Space Station

2021 ◽  
Vol 13 (9) ◽  
pp. 1724
Author(s):  
Vojislav Mitić ◽  
Cristina Serpa ◽  
Ivana Ilić ◽  
Markus Mohr ◽  
Hans-Jörg Fecht
Keyword(s):  
International Space Station ◽  
Fractal Analysis ◽  
Power Plants ◽  
Materials Science ◽  
Structural Characteristics ◽  
Turbine Blades ◽  
Space Station ◽  
Casting Process ◽  
Cross Sectional ◽  
International Space

Materials science is highly significant in space program investigation, energy production and others. Therefore, designing, improving and predicting advanced material properties is a crucial necessity. The high temperature creep and corrosion resistance of Ni-based superalloys makes them important materials for turbine blades in aircraft engines and land-based power plants. The investment casting process of turbine blades is costly and time consuming, which makes process simulations a necessity. These simulations require fundamental models for the microstructure formation. In this paper, we present advanced analytical techniques in describing the microstructures obtained experimentally and analyzed on different sample’s cross-sectional images. The samples have been processed on board the International Space Station using the MSL-EML device based on electromagnetic levitation principles. We applied several aspects of fractal analysis and obtained important results regarding fractals and Hausdorff dimensions related to the surface and structural characteristics of CMSX-10 samples. Using scanning electron microscopy (SEM), Zeiss LEO 1550, we analyzed the microstructure of samples solidified in space and successfully performed the fractal reconstruction of the sample’s morphology. We extended the fractal analysis on the microscopic images based on samples solidified on earth and established new frontiers on the advanced structures prediction.

Study of Correctly Expanded Sonic Jet with Air Tabs

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Arun Prasad R ◽  
Thanigaiarasu S ◽  
Sembaruthi M ◽  
Rathakrishnan E
Keyword(s):  
Numerical Study ◽  
Cross Sectional ◽  
Potential Core ◽  
Convergent Nozzle ◽  
Jet Mixing ◽  
Pressure Profiles ◽  
Constant Diameter ◽  
Sonic Jet ◽  
Sectional Shape ◽  
Length Reduction

AbstractThe present numerical study is to understand the effect of air tabs located at the exit of a convergent nozzle on the spreading and mixing characteristics of correctly expanded sonic primary jet. Air tabs used in this study are two secondary jets issuing from constant diameter tubes located diametrically opposite at the periphery of the primary nozzle exit, normal to the primary jet. Two air tabs of Mach numbers 1.0 to 1.4, in steps of 0.1 are considered in this study. The mixing modification caused by air tabs are analysed by considering the mixing of uncontrolled (free) primary jet as a reference. Substantial enhancement in jet mixing is achieved with Mach 1.4 air tabs, which results in 80 % potential core length reduction. The total pressure profiles taken on the plane (YZ) normal to the primary jet axis, at various locations along the primary jet centreline revealed the modification of the jet cross sectional shape by air tabs. The stream-wise vortices and bifurcation of the primary jet caused by air tabs are found to be the mechanism behind the enhanced jet mixing.

Experimental investigation and optimization on field shaper structure parameters in magnetic pulse welding

2021 ◽  
pp. 095440542110148
Author(s):  
Yingzi Chen ◽  
Zhiyuan Yang ◽  
Wenxiong Peng ◽  
Huaiqing Zhang
Keyword(s):  
Magnetic Field ◽  
High Speed ◽  
Light Metal ◽  
Magnetic Pulse ◽  
Cross Sectional ◽  
Magnetic Pulse Welding ◽  
Pulse Welding ◽  
Sectional Shape ◽  
Welding System ◽  
The Magnetic Field

Magnetic pulse welding is a high-speed welding technology, which is suitable for welding light metal materials. In the magnetic pulse welding system, the field shaper can increase the service life of the coil and contribute to concentrating the magnetic field in the welding area. Therefore, optimizing the structure of the field shaper can effectively improve the efficiency of the system. This paper analyzed the influence of cross-sectional shape and inner angle of the field shaper on the ability of concentrating magnetic field via COMSOL software. The structural strength of various field shapers was also analyzed in ABAQUS. Simulation results show that the inner edge of the field shaper directly affects the deformation and welding effect of the tube. So, a new shape of field shaper was proposed and the experimental results prove that the new field shaper has better performance than the conventional field shaper.

Sign in / Sign up

Export Citation Format

Share Document