Strengths of ceramic fiber bundles: Theory and practice

2017 ◽  
Vol 100 (11) ◽  
pp. 5306-5317 ◽  
Author(s):  
Evan B. Callaway ◽  
Frank W. Zok
Keyword(s):  
Theory And Practice ◽  
Ceramic Fiber ◽  
Fiber Bundles

scholarly journals True Strength of Ceramic Fiber Bundles: Experiments and Simulations

Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 64
Author(s):  
Leandro Neckel ◽  
Cristian A. Faller ◽  
Matej Babič ◽  
Oscar R. K. Montedo ◽  
Carlos P. Bergmann ◽  
...  
Keyword(s):  
Fiber Bundle ◽  
Input Parameter ◽  
Load Sharing ◽  
Ceramic Fiber ◽  
Fiber Bundles ◽  
Initial Amount ◽  
Single Filament ◽  
Computational Procedures ◽  
Initial Fiber

A study on the strength of ceramic fiber bundles based on experimental and computational procedures is presented. Tests were performed on single filaments and bundles composed of two fibers with different nominal fiber counts. A method based on fiber rupture signals was developed to estimate the amount of filament rupture during the test. Through this method, the fiber bundle true strength was determined and its variation with the initial fiber count observed. By using different load-sharing models and the single filament data as input parameter, simulations were also developed to verify this behavior. Through different approaches between experiments and simulations, it was noted that the fiber bundle true strength increased with the fiber count. Moreover, a variation of the fibers’ final proportion in the bundles relative to the initial amount was verified in both approaches. Finally, discussions on the influence of different load-sharing models on the results are presented.

Dupuytren's Contracture and Microvessels

1981 ◽  
Vol 39 ◽  
pp. 470-471
Author(s):  
C. W. Klscher ◽  
D. Speer
Keyword(s):  
Hypertrophic Scar ◽  
Active Form ◽  
Scar Tissue ◽  
Vascular Supply ◽  
Fiber Bundles ◽  
Dupuytren’S Contracture ◽  
Palmar Fascia ◽  
Immune Disease ◽  
Dupuytren's Contracture ◽  
Longitudinal Fiber

Dupuytren's Contracture is a nodular proliferation of the longitudinal fiber bundles of palmar fascia with its attendant contraction. The factors attributed to its etiology have included trauma, diabetes, alcoholism, arthritis, and auto-immune disease. The tissue has been observed by electron microscopy and found to contain myofibroblasts.Dupuytren's Contracture constitutes a scar, and as such, excessive collagen can be observed, along with an active form of fibroblast.Previous studies of the hypertrophic scar have led us to propose that integral in the initiation and sustenance of scar tissue is a profusion of microvascular regeneration, much of which becomes and remains occluded producing a hypoxia which stimulates fibroblast synthesis. Thus, when considering a study of Dupuytren's Contracture, we predicted finding occluded microvessels at or near the fascial scarring focus.Three cases of Dupuytren's Contracture yielded similar specimens, which were fixed in Karnovskys fluid for 2 to 20 days. Upon removal of the contracture bands care was taken to include the contiguous fatty and areolar tissue which contain the vascular supply and to identify the junctional area between old and new fascia.

Ultrastructural Features of the Oral Apparatus of Stentor

1976 ◽  
Vol 34 ◽  
pp. 142-143
Author(s):  
Elizabeth F. Howell
Keyword(s):  
Plasma Membrane ◽  
Osmium Tetroxide ◽  
Buccal Cavity ◽  
Fiber Bundles ◽  
Microtubular Root ◽  
Stentor Coeruleus ◽  
Root Fiber

The ultrastructure of the normal oral apparatus of Stentor has not been extensively studied. I report here on the ultrastructure of the buccal cavity of Stentor coeruleus.Stentor coeruleus was fixed in either a buffered mixture of osmium tetroxide and glutaraldehyde, or in buffered glutaraldehyde alone. Cells were then dehydrated and embedded in a mixture of Epon and Araldite.An extensive adoral zone of membranelles surrounds the anterior of the cell, and each membranelle consists of 2 parallel rows of cilia. These extend down into the buccal cavity. Two microtubular root fibers, or nemadesmata (Figs. 2 and 5), extend deeply into the cytoplasm from the base of each ciliary kinetosome. Mitochondria are usually closely associated with the root fiber bundles, and small vesicles are present between the nemadesmata of adjacent kinetosomes (Fig. 5). In the cytopharyngeal, non-ciliated areas of the buccal cavity, microtubular ribbons which extend into the cytoplasm are aligned perpendicular to the plasma membrane of the buccal cavity (Figs. 1 and 2).

Microstructures of SiC and Si3N4 with fibrous inclusions

1986 ◽  
Vol 44 ◽  
pp. 492-493
Author(s):  
N. J. Tighe ◽  
J. Sun ◽  
R.-M. Hu
Keyword(s):  
Vapor Deposition ◽  
Chemical Vapor ◽  
Crack Deflection ◽  
Fiber Bundles ◽  
High Temperature Strength ◽  
Graphite Fiber ◽  
Triple Junctions ◽  
Transmission Electron ◽  
Compact Graphite ◽  
Deposition Techniques

Particles of BN,and C are added in amounts of 1 to 40% to SiC and Si3N4 ceramics in order to improve their mechanical properties. The ceramics are then processed by sintering, hot-pressing and chemical vapor deposition techniques to produce dense products. Crack deflection at the particles can increase toughness. However the high temperature strength and toughness are determined byphase interactions in the environmental conditions used for testing. Examination of the ceramics by transmission electron microscopy has shown that the carbon and boron nitride particles have a fibrous texture. In the sintered aSiC ceramic the carbon appears as graphite fiber bundles in the triple junctions and as compact graphite particles within some grains. Examples of these inclusions are shown in Fig. 1A and B.

Addressing the Content Vocabulary With Core: Theory and Practice for Nonliterate or Emerging Literate Students

2012 ◽  
Vol 21 (3) ◽  
pp. 74-81 ◽  
Author(s):  
Debbie Witkowski ◽  
Bruce Baker
Keyword(s):  
Communication Skills ◽  
High Performance ◽  
Theory And Practice ◽  
Written Communication ◽  
Academic Tasks ◽  
Meaningful Participation ◽  
Core Theory ◽  
Communication Needs ◽  
Core Vocabulary ◽  
Personal Success

Abstract In the early elementary grades, the primary emphasis is on developing skills crucial to future academic and personal success—specifically oral and written communication skills. These skills are vital to student success as well as to meaningful participation in the classroom and interaction with peers. Children with complex communication needs (CCN) may require the use of high-performance speech generating devices (SGDs). The challenges for these students are further complicated by the task of learning language at a time when they are expected to apply their linguistic skills to academic tasks. However, by focusing on core vocabulary as a primary vehicle for instruction, educators can equip students who use SGDs to develop language skills and be competitive in the classroom. In this article, we will define core vocabulary and provide theoretical and practical insights into integrating it into the classroom routine for developing oral and written communication skills.

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