Effects of Extreme Radiation Environment on Composite Materials

2006 ◽  
Vol 929 ◽  
Author(s):  
J. Zhou ◽  
Jerrel Moore ◽  
Vernon Calvin ◽  
Richard Wilkins ◽  
Sofia Martinez Vilarino ◽  
...  
Keyword(s):  
Thermal Properties ◽  
Space Radiation ◽  
Radiation Shielding ◽  
Space Environment ◽  
Radiation Environment ◽  
Mechanical And Thermal Properties ◽  
Shielding Effectiveness ◽  
Potential Applications ◽  
Effects Of Radiation ◽  
Effective Radiation

ABSTRACTFuture manned space travel will go beyond the Lower Earth Orbit into deep space exploration and providing protection from space radiation is a major challenge. It is essential to study the effects of the space environment on materials to ensure safe and successful missions.This paper summarized the studies of two materials, in-site regolith composites and LTM 45 composites, for potential applications in space radiation environments. The effects of radiation on the mechanical and thermal properties of the composites were investigated. The radiation shielding effectiveness of in-situ composites and low temperature molding materials was analyzed. The work was part of the efforts in study and development of the multifunctiaonal materials for long-term radiation exposures to ensure effective radiation shielding and maintaining integrity of materials' mechanical and thermal properties for future space missions.

scholarly journals Effect of different lignocellulosic fibres on poly(ε-caprolactone)-based composites for potential applications in orthotics

RSC Advances ◽  
2015 ◽  
Vol 5 (30) ◽  
pp. 23798-23809 ◽  
Author(s):  
Fabrizio Sarasini ◽  
Jacopo Tirillò ◽  
Debora Puglia ◽  
José M. Kenny ◽  
Franco Dominici ◽  
...  
Keyword(s):  
Thermal Properties ◽  
Comparative Assessment ◽  
Mechanical And Thermal Properties ◽  
Biodegradable Composites ◽  
Potential Applications

A comparative assessment of three lignocellulosic fibres obtained from leaf, bast and fruit on the mechanical and thermal properties of fully biodegradable composites has been performed.

scholarly journals Practicalities of dose management for Japanese astronauts staying at the International Space Station

2020 ◽  
Vol 49 (1_suppl) ◽  
pp. 194-199
Author(s):  
T. Komiyama
Keyword(s):  
Radiation Exposure ◽  
International Space Station ◽  
Space Station ◽  
Space Radiation ◽  
Radiation Environment ◽  
International Space ◽  
Dose Limits ◽  
Dose Management ◽  
Effects Of Radiation ◽  
Tissue Reactions

Japanese astronauts started staying at the International Space Station (ISS) in 2009, with each stay lasting for approximately 6 months. In total, seven Japanese astronauts have stayed at the ISS eight times. As there is no law for protection against space radiation exposure of astronauts in Japan, the Japan Aerospace Exploration Agency (JAXA) created its own rules and has applied them successfully to radiation exposure management for Japanese ISS astronauts, collaborating with ISS international partners. Regarding dose management, JAXA has implemented several dose limits to protect against both the stochastic effects of radiation and dose-dependent tissue reactions. The scope of the rules includes limiting exposure during spaceflight, exposure during several types of training, and exposure from astronaut-specific medical examinations. We, therefore, are tasked with calculating the dose from all exposure types applied to the dose limits annually for each astronaut. Whenever a Japanese astronaut is at the ISS, we monitor readings of an instrument in real-time to confirm that the exposed dose is below the set limits, as the space radiation environment can fluctuate in relation to solar activity.

scholarly journals Measuring space radiation shielding effectiveness

2017 ◽  
Vol 153 ◽  
pp. 04001 ◽  
Author(s):  
Amir Bahadori ◽  
Edward Semones ◽  
Michael Ewert ◽  
James Broyan ◽  
Steven Walker
Keyword(s):  
Space Radiation ◽  
Radiation Shielding ◽  
Shielding Effectiveness ◽  
Space Radiation Shielding ◽  
Measuring Space

Investigating Effect of Space Radiation Environment on Piezoelectric Sensors: Cobalt-60 Irradiation Experiment

2017 ◽  
Vol 1 (1) ◽  
Author(s):  
Mary Anderson ◽  
Andrei N. Zagrai ◽  
Joshua D. Daniel ◽  
David J. Westpfahl ◽  
Dale Henneke
Keyword(s):  
Gamma Radiation ◽  
Radiation Exposure ◽  
Piezoelectric Ceramic ◽  
Structural Damage ◽  
Space Radiation ◽  
Low Earth Orbit ◽  
Space Environment ◽  
Piezoelectric Sensors ◽  
Radiation Environment ◽  
Space Radiation Environment

Piezoelectric sensors are used in many structural health monitoring (SHM) methods to interrogate the condition of the structure to which the sensors are affixed or embedded. Among SHM methods utilizing thin wafer piezoelectric sensors, embedded ultrasonics is seen as a promising approach to assess condition of space structures. If SHM is to be implemented in space vehicles, it is imperative to determine the effects of the extreme space environment on piezoelectric sensors in order to discern between actual structural damage and environmental effects. The near-Earth space environment comprises extreme temperatures, vacuum, atomic oxygen, microgravity, micrometeoroids and debris, and significant amounts of radiation. Gamma radiation can be used to emulate the space radiation environment. In this contribution, the effects of gamma radiation on piezoelectric ceramic sensors are investigated for equivalent gamma radiation exposure of more than a year on low Earth orbit (LEO). Two experiments were conducted in which cobalt-60 was utilized as the source of radiation. Freely supported piezoelectric sensors were exposed to increasing levels of gamma radiation. Impedance data were collected for the sensors after each radiation exposure. The results show that piezoelectric ceramic material is affected by gamma radiation. Over the course of increasing exposure levels to cobalt-60, the impedance frequencies of the free sensors increased with each absorbed dose. The authors propose that the mechanism causing these impedance changes is due to gamma rays affecting piezoelectric, electric, and elastic constants of the piezoelectric ceramic. A theoretical model describing observed effects is presented.

scholarly journals Antibacterial Property of Cellulose Acetate Composite Materials Reinforced with Aluminum Nitride

Antibiotics ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1292
Author(s):  
Thefye P. M. Sunthar ◽  
Francesco Boschetto ◽  
Hoan Ngoc Doan ◽  
Taigi Honma ◽  
Kenji Kinashi ◽  
...  
Keyword(s):  
Thermal Properties ◽  
Aluminum Nitride ◽  
Cellulose Acetate ◽  
Surface Characterization ◽  
Antibacterial Properties ◽  
Mechanical And Thermal Properties ◽  
Synthetic Compound ◽  
Weight Percentage ◽  
Alternative Materials ◽  
Potential Applications

Cellulose acetate (CA) is a synthetic compound that is derived from the acetylation of cellulose. CA is well known as it has been used for many commercial products such as textiles, plastic films, and cigarette filters. In this research, antibacterial CA composites were produced by addition of aluminum nitride (AlN) at different weight percentage, from 0 wt. % to 20 wt. %. The surface characterization was performed using laser microscope, Raman and FTIR spectroscopy. The mechanical and thermal properties of the composite were analyzed. Although the mechanical strength tended to decrease as the concentration of AlN increased and needed to be optimized, the melting temperature (Tm) and glass transition temperature (Tg) showed a shift toward higher values as the AlN concentration increased leading to an improvement in thermal properties. AlN additions in weight percentages >10 wt. % led to appreciable antibacterial properties against S. epidermidis and E. coli bacteria. Antibacterial CA/AlN composites with higher thermal stability have potential applications as alternative materials for plastic packaging in the food industry.

A Review of Polypropylene Nanoclay Nanocomposites: Preparation, Properties and Applications

2013 ◽  
Vol 465-466 ◽  
pp. 944-948 ◽  
Author(s):  
Mohd Hilmi Othman ◽  
Hasan Sulaiman ◽  
Md. Saidin bin Wahab
Keyword(s):  
Thermal Properties ◽  
Clay Content ◽  
Mechanical And Thermal Properties ◽  
Recent Application ◽  
Potential Applications ◽  
Processing Techniques ◽  
Processing Properties ◽  
Master Batch

This paper presents a review on the preparation, processing, properties and the recent applications of polypropylene-nanoclay nanocomposites. The material has attracted many researchers to explore more about the processing techniques, optimizations, and mainly the potential applications reflecting the advantages of these promising materials. The review consists of preparation of nanocomposites master batch, properties such as mechanical and thermal properties the effects of compatibilizers and clay content, as well as the recent application of these composites. The findings of this review might lead to more curiosity and investigating regarding to the above matters.

A space radiation shielding model of the Martian radiation environment experiment (MARIE)

2004 ◽  
Vol 33 (12) ◽  
pp. 2219-2221 ◽  
Author(s):  
W. Atwell ◽  
P. Saganti ◽  
F.A. Cucinotta ◽  
C.J. Zeitlin
Keyword(s):  
Space Radiation ◽  
Radiation Shielding ◽  
Radiation Environment ◽  
Space Radiation Shielding ◽  
Environment Experiment
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