Sea urchin spines as a model-system for permeable, light-weight ceramics with graceful failure behavior. Part I. Mechanical behavior of sea urchin spines under compression

2009 ◽  
Vol 6 (3) ◽  
pp. 203-213 ◽  
Author(s):  
V. Presser ◽  
S. Schultheiß ◽  
C. Berthold ◽  
K. G. Nickel
Keyword(s):  
Mechanical Behavior ◽  
Sea Urchin ◽  
Model System ◽  
Failure Behavior ◽  
Light Weight ◽  
Sea Urchin Spines

scholarly journals On the Relation of Amorphous Calcium Carbonate and the Macromechanical Properties of Sea Urchin Spines

2020 ◽  
Vol 22 (4) ◽  
pp. 1900922 ◽  
Author(s):  
Christoph Lauer ◽  
Sebastian Haußmann ◽  
Patrick Schmidt ◽  
Carolin Fischer ◽  
Doreen Rapp ◽  
...  
Keyword(s):  
Calcium Carbonate ◽  
Sea Urchin ◽  
Amorphous Calcium Carbonate ◽  
Sea Urchin Spines

scholarly journals Mechanical Behavior of Fiber-Reinforced SiC/RBSN Ceramic Matrix Composites: Theory and Experiment

1993 ◽  
Vol 115 (1) ◽  
pp. 91-102 ◽  
Author(s):  
A. Chulya ◽  
J. P. Gyekenyesi ◽  
R. T. Bhatt
Keyword(s):  
Mechanical Behavior ◽  
Ceramic Matrix Composites ◽  
In Situ Monitoring ◽  
Matrix Cracking ◽  
Test Problems ◽  
Interface Debonding ◽  
Failure Behavior ◽  
Fiber Reinforced ◽  
History Effects ◽  
Pull Out

The mechanical behavior of continuous fiber-reinforced SiC/RBSN composites with various fiber contents is evaluated. Both catastrophic and noncatastrophic failures are observed in tensile specimens. Damage and failure mechanisms are identified via in-situ monitoring using NDE techniques throughout the loading history. Effects of fiber/matrix interface debonding (splitting) parallel to the fibers are discussed. Statistical failure behavior of fibers is also observed, especially when the interface is weak. Micromechanical models incorporating residual stresses to calculate the critical matrix cracking strength, ultimate strength, and work of pull-out are reviewed and used to predict composite response. For selected test problems, experimental measurements are compared to analytic predictions.

Investigation on the mechanical behavior of areca sheath fibers/jute fibers/glass fabrics reinforced hybrid composite for light weight applications

2018 ◽  
Vol 49 (8) ◽  
pp. 1036-1060 ◽  
Author(s):  
S Jothibasu ◽  
S Mohanamurugan ◽  
R Vijay ◽  
D Lenin Singaravelu ◽  
A Vinod ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Mechanical Behavior ◽  
Core Layer ◽  
Skin Layer ◽  
Woven Fabric ◽  
Jute Fiber ◽  
Deformation Analysis ◽  
Light Weight ◽  
Fiber Glass ◽  
Jute Fibers

Hybrid polymeric composites are gaining important consideration with versatile applications due to their good mechanical properties. The present study is an attempt to evaluate the hybridization effects of different laminate stacking sequence involving areca sheath fiber/jute fiber/glass-woven fabric through the study of mechanical properties of four different resulting composites. The fibers were alkali-treated and were used in composites fabrication that was done using the hand lay-up method. This assessment of mechanical properties and study of fractured surfaces indicated a significant improvement in mechanical properties of the composites with jute fiber as intermittent layers, areca sheath fiber as a core layer, and glass fabrics as skin layer reinforced epoxy composites. An attempt to prove the application suitability of “L” frame for flower stand application was fabricated using the best mechanical behavior performer composite, and the ANSYS (deformation) analysis was also performed.

Cutaneous reaction to sea urchin spines

2021 ◽  
Vol 2 (4) ◽  
Author(s):  
Cassidy Johnston ◽  
Keyword(s):  
Treatment Regimen ◽  
Sea Urchin ◽  
Scuba Diving ◽  
Skin Tumors ◽  
Cutaneous Reaction ◽  
Full Recovery ◽  
Oral Doxycycline ◽  
Dorsal Aspect ◽  
Common Skin ◽  
Sea Urchin Spines

A 35-year-old male returned from vacation in Hawaii where he went scuba diving and snorkeling. While snorkeling, he stepped on a sea urchin and sustained injuries to the dorsal aspect of his right foot. He began to swim back to shore when he felt significant pain and began removing visible spines when he reached shore. He saw a physician in Hawaii who removed remaining spines and started a treatment regimen of cephalexin 500 mg QID. Patient followed up 2 weeks later with his home dermatologist for persistent granuloma and was given 15-day course of oral doxycycline 50 mg BID with near full recovery within 2 weeks. Even physicians practicing inland need to be aware of coastal injuries and reactions as they can mimic other common skin tumors such as keratoacanthomas.

The Centriole-Centrosome Complex is Affected by Microgravity During Cell Division and in Cilia of Sea Urchin Embryos: Results from Space Flight Experiments

1998 ◽  
Vol 4 (S2) ◽  
pp. 1132-1133
Author(s):  
Heide Schatten ◽  
Amitabha Chakrabarti ◽  
Meghan Taylor ◽  
Michael Crosser ◽  
Kirk Mitchell
Keyword(s):  
Cell Division ◽  
Sea Urchin ◽  
Space Flight ◽  
Space Shuttle ◽  
Sea Urchins ◽  
Culture Conditions ◽  
Model System ◽  
Research Facility ◽  
Cilia Formation ◽  
Pluteus Stage

Sea urchins have been used for over a century as a remarkable animal model system in which to study cell, molecular, and developmental biology. The studies presented here have used sea urchin eggs and embryos for pioneering experiments to explore the effects of microgravity on the cytoskeleton during a space flight on the space shuttle Endeavor. The culture conditions followed those described previously utilizing the Aquatic Research Facility (ARF) to fertilize and culture eggs and embryos up to the pluteus stage under controlled temperature (12°C) and fixation conditions. To achieve a final fixation with 0.5% glutaraldehyde and 4μM taxol, concentrated fixation fluid was injected at preselected time points to preserve microtubules, centrioles, centrosomes, microfilaments, mitochondria, and cell membranes.The analysis of the results revealed that the centriole-centrosome complex during cell division and cilia formation showed alterations in samples that had been exposed to microgravity while control cells cultured in a centrifuge at lg in space and those cultured on ground appeared normal.

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