scholarly journals Homogenization of a unidirectional composite reinforced with two types of transtropic hollow fibers

2021 ◽  
Vol 5 (7 (113)) ◽  
pp. 52-58
Author(s):  
Anastasiia Stoliarova ◽  
Andriy Pozhuyev ◽  
Oksana Spytsia ◽  
Alla Bohuslavska
Keyword(s):  
Elastic Constants ◽  
Hollow Fiber ◽  
Volume Content ◽  
Composite Structures ◽  
Hollow Fibers ◽  
Design Stage ◽  
Calculation Error ◽  
Reinforcement Structure ◽  
Effective Elastic Constants ◽  
Elastic Characteristics

A method for determining effective elastic constants of a composite unidirectionally reinforced with two types of transtropic hollow fibers is developed. Determining these characteristics is an integral step in the design of composite structures. The approach is based on analytical formulas for determining the elastic characteristics of a two-component composite with a transtropic matrix and hollow fiber. Hexagonal fiber lay-up with periodic reinforcement structure is considered. Double homogenization is used. The composite is conventionally divided into hexagonal regions of two types. The first is a hollow fiber of one material and the surrounding matrix. Similarly, the second one – with a hollow fiber of another material. In the first homogenization, elastic constants of the transtropic material of each of the two regions are determined. In the repeated homogenization, the region of the first type is taken as a “conditional” fiber, the region of the second type is taken as a “conditional” matrix. Effective elastic constants for a composite reinforced with two types of isotropic hollow fibers are calculated. The proposed method gives a good convergence of the results with calculations by known formulas. The maximum relative calculation error for the longitudinal elastic characteristics compared to known formulas does not exceed 0.05 %. The dependences of some effective elastic constants on the volume content of hollow fibers of various types are constructed. Using this approach, three-component composites can be modeled varying the materials of the matrix, hollow fibers and their volume content. This allows predicting the strength of such composites under certain deformations at the design stage

Enterovirus Concentration Using Automated Hollow Fiber Ultrafiltration

1982 ◽  
Vol 14 (4-5) ◽  
pp. 257-272 ◽  
Author(s):  
G Belfort ◽  
A Paluszek ◽  
L S Sturman
Keyword(s):  
Drinking Water ◽  
Hollow Fiber ◽  
Enhanced Recovery ◽  
Tap Water ◽  
Membrane Surface ◽  
Creeping Flow ◽  
Hollow Fibers ◽  
Virus Concentration ◽  
Concentration Technique ◽  
Solution Interface

The Automated Hollow Fiber Ultrafiltration (AHFU) method is proposed here as a simple, efficient and rapid virus concentration technique from tap and drinking water sources. The results reported here extend the testing of the AHFU method to include two Picornaviruses [Poliovirus 2 (vaccine) and Echovirus 1] and Reovirus 3. Their respective mean virus recoveries from between 3 and 100 l of tap water is 88 ± 26, 79 ± 60, and 104 ± 48%. Various approaches including membrane surface modification, changes in backwash hydrodynamics, modification of the feed and backwash composition, and the use of S35-methionine labelled Poliovirus 2, are used to study the recovery of sorbed Poliovirus 2 from the hollow fiber/solution interface. An increase in the backwash pH to between 9.5 and 10.5 significantly improved Poliovirus 2 recovery. This, together with the labelled experiments, indicates that the virus-membrane interactions are probably electrostatic in nature. Convective polarization during filtration probably brings the virus close enough to the surface for these interactions to occur since virus losses were not detected for a non-permeation recycle experiment. Because very low Reynold's numbers are used, the flow is in the creeping-flow-regime for both filtration and backwashing (axial and radial). Unless significantly higher Reynolds could be used, enhanced recovery due to purely hydrodynamic forces is unlikely. High Reynold's numbers, of course, are limited by the pressure constraints of the hollow fibers.

Effective Elastic Constants of Fiber-Eutectics and Transformation Particles Composite Ceramic

2010 ◽  
Vol 177 ◽  
pp. 182-185 ◽  
Author(s):  
Bao Feng Li ◽  
Jian Zheng ◽  
Xin Hua Ni ◽  
Ying Chen Ma ◽  
Jing Zhang
Keyword(s):  
Elastic Modulus ◽  
Elastic Constant ◽  
Effective Stress ◽  
Elastic Constants ◽  
Transverse Isotropy ◽  
Analytical Formula ◽  
Composite Ceramic ◽  
Phase Model ◽  
Composite Ceramics ◽  
Effective Elastic Constants

The composite ceramics is composed of fiber-eutectics, transformation particles and matrix particles. First, the recessive expression between the effective stress in fiber-eutectic and the flexibility increment tensor is obtained according to the four-phase model. Second, the analytical formula which contains elastic constant of the fiber-eutectic is obtained applying Taylor’s formula. The eutectic is transverse isotropy, so there are five elastic constants. Third, the effective elastic constants of composite ceramics are predicted. The result shows that the elastic modulus of composite ceramic is reduced with the increase of fibers fraction and fibers diameter.

Effective elastic constants of hexagonal array of soft fibers

2017 ◽  
Vol 139 ◽  
pp. 395-405 ◽  
Author(s):  
Piotr Drygaś ◽  
Simon Gluzman ◽  
Vladimir Mityushev ◽  
Wojciech Nawalaniec
Keyword(s):  
Elastic Constants ◽  
Hexagonal Array ◽  
Effective Elastic Constants

scholarly journals Polymeric Hollow Fibers: State of the Art Review of Their Preparation, Characterization and Applications in Different Research Areas

2017 ◽  
Vol 4 (1) ◽  
Author(s):  
K.C. Khulbe ◽  
C. Feng ◽  
T. Matsuura ◽  
M. Khayet
Keyword(s):  
Hollow Fiber ◽  
Manufacturing Industry ◽  
Hollow Fiber Membrane ◽  
Waste Water Treatment ◽  
Hollow Fibers ◽  
Hollow Fiber Membranes ◽  
Seawater Desalination ◽  
Fiber Morphology ◽  
Fiber Technology ◽  
Fiber Membranes

In this article an attempt is made to review critically the papers published recently on polymeric hollow fibers and hollow fiber membranes. Hollow fiber membranes emerged in early nineteen sixties at almost the same time as the announcement of the cellulose acetate reverse osmosis membrane for seawater desalination by Loeb and Sourirajan. Since then, the hollow fiber technology has progressed along with the industrial membrane separation processes. Today, hollow fiber membranes are being used in every sector of the manufacturing industry, including gas and vapor separation, seawater desalination and waste water treatment. The fabrication of a hollow fiber membrane with a desirable pore–size distribution and performance is not an easy task. There are many factors controlling fiber morphology during the phase inversion process and, at present, we are not able to say that we fully understand the phenomena involved in the fabrication of hollow fibers. Nevertheless, there has been a large amount of knowledge accumulated during the past fifteen years, which has been supported by an equally large amount of efforts by many researchers. This paper attempts to summarize those works. The authors could however look into only those reports which have appeared in scientific journals and few patents, and they are fully aware that there must be much more information that has not surfaced to the journal publication. It is also the authors’ intention to show the future direction including the research topics that have been studied only little or not at all.

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