Ground-Based Space Radiation Effects Studies on Single-Walled Carbon Nanotube Materials

2004 ◽  
Vol 851 ◽  
Author(s):  
R. Wilkins ◽  
M. X. Pulikkathara ◽  
Valery N. Khabashesku ◽  
E. V. Barrera ◽  
Ranji K. Vaidyanathan ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Radiation Effects ◽  
Structural Integrity ◽  
Interplanetary Space ◽  
Functional Materials ◽  
Space Radiation ◽  
High Energy ◽  
Radiation Shielding ◽  
Great Promise ◽  
Nano Composites

ABSTRACTMaterials based on carbon nanotubes hold great promise for a variety of applications relevant to space exploration and the aerospace industry. Materials used for these applications will be subject to hostile environments including increased levels of high-energy particulate radiation. The type, energy range and fluence of the radiation will depend on the environment of the space mission. While it is not feasible to conduct an exhaustive study of the effects of space radiation on the earth's surface, ground-based experiments can be designed to simulate expected radiation environments using sources representing components of the relevant radiation environments. In this paper we present a compilation of results on materials based on singlewalled carbon nanotubes (SWNT) emphasizing nano-composites with raw (non-functionalized) and with 2–5% functionalized SWNTs in a polyethylene matrix. Materials such as these are promising candidates for multi-functional materials with good structural and radiation shielding characteristics. The radiation sources discussed here are relevant to the upper atmosphere (high energy neutrons), low earth orbit (medium energy protons) and interplanetary space (high energy protons and heavy ions). The samples are characterized before and after radiation with Raman spectroscopy which gives information on the structure of the SWNT and state of sidewall functionalization. Based on results from the SWNT papers (“buckypapers”) and the composites made from functionalized and non-functionalized SWNT, our data indicates that structural integrity and any sidewall functionalization of the SWNT in the nano-composite are radiation tolerant to radiation fluences commensurate with expected exposures on long-term spaceflight. More importantly, we find that the chemistry and material science of the processes used to produce the pristine and functionalized SWNT can affect the radiation characteristics of the nano-composites.

scholarly journals Long-Term Sex- and Genotype-Specific Effects of 56Fe Irradiation on Wild-Type and APPswe/PS1dE9 Transgenic Mice

2021 ◽  
Vol 22 (24) ◽  
pp. 13305
Author(s):  
Maren K. Schroeder ◽  
Bin Liu ◽  
Robert G. Hinshaw ◽  
Mi-Ae Park ◽  
Shuyan Wang ◽  
...  
Keyword(s):  
Transgenic Mice ◽  
Radiation Effects ◽  
Motor Coordination ◽  
Space Radiation ◽  
High Energy ◽  
High Energy Particle ◽  
Wild Type ◽  
Particle Radiation ◽  
Specific Effects

Space radiation presents a substantial threat to travel beyond Earth. Relatively low doses of high-energy particle radiation cause physiological and behavioral impairments in rodents and may pose risks to human spaceflight. There is evidence that 56Fe irradiation, a significant component of space radiation, may be more harmful to males than to females and worsen Alzheimer’s disease pathology in genetically vulnerable models. Yet, research on the long-term, sex- and genotype-specific effects of 56Fe irradiation is lacking. Here, we irradiated 4-month-old male and female, wild-type and Alzheimer’s-like APP/PS1 mice with 0, 0.10, or 0.50 Gy of 56Fe ions (1GeV/u). Mice underwent microPET scans before and 7.5 months after irradiation, a battery of behavioral tests at 11 months of age and were sacrificed for pathological and biochemical analyses at 12 months of age. 56Fe irradiation worsened amyloid-beta (Aβ) pathology, gliosis, neuroinflammation and spatial memory, but improved motor coordination, in male transgenic mice and worsened fear memory in wild-type males. Although sham-irradiated female APP/PS1 mice had more cerebral Aβ and gliosis than sham-irradiated male transgenics, female mice of both genotypes were relatively spared from radiation effects 8 months later. These results provide evidence for sex-specific, long-term CNS effects of space radiation.

scholarly journals Enhanced Thermal Stability, Mechanical Properties and Structural Integrity of MWCNT Filled Bamboo/Kenaf Hybrid Polymer Nanocomposites

Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 506
Author(s):  
J. M. Prabhudass ◽  
K. Palanikumar ◽  
Elango Natarajan ◽  
Kalaimani Markandan
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Energy Absorption ◽  
Epoxy Matrix ◽  
Structural Integrity ◽  
High Energy ◽  
Natural Fibre ◽  
Impact Testing ◽  
Hibiscus Cannabinus ◽  
Natural Fibres

Recently, there has been an inclination towards natural fibre reinforced polymer composites owing to their merits such as environmental friendliness, light weight and excellent strength. In the present study, six laminates were fabricated consisting of natural fibres such as Kenaf fibre (Hibiscus cannabinus L.) and Bamboo fibre, together with multi-walled carbon nanotubes (MWCNTs) as reinforcing fillers in the epoxy matrix. Mechanical testing revealed that hybridization of natural fibres was capable of yielding composites with enhanced tensile properties. Additionally, impact testing showed a maximum improvement of ≈80.6% with the inclusion of MWCNTs as nanofiller in the composites with very high energy absorption characteristics, which were attributed to the high specific energy absorption of carbon nanotubes. The viscoelastic behaviour of hybridised composites reinforced with MWCNTs also showed promising results with a significant improvement in the glass transition temperature (Tg) and 41% improvement in storage modulus. It is worth noting that treatment of the fibres in NaOH solution prior to composite fabrication was effective in improving the interfacial bonding with the epoxy matrix, which, in turn, resulted in improved mechanical properties.

Radiation Shielding Analysis for Various Materials in the Extreme Jovian Environment

2006 ◽  
Vol 929 ◽  
Author(s):  
William Atwell
Keyword(s):  
Radiation Effects ◽  
Absorbed Dose ◽  
High Energy ◽  
Radiation Shielding ◽  
Radiation Environment ◽  
High Energy Particle ◽  
Dose Calculations ◽  
Environment Model ◽  
Computer Codes ◽  
Trapped Radiation

ABSTRACTEarlier particle experiments in the 1970s on Pioneer-10 and -11 and Voyager-1 and -2 provided Jupiter flyby particle data, which were used by Divine and Garrett to develop the first Jupiter trapped radiation environment model. This model was used to establish a baseline radiation effects design limit for the Galileo onboard electronics. Recently, Garrett et al. have developed an updated Galileo Interim Radiation Environment (GIRE) model based on Galileo electron data. In this paper, the GIRE model was utilized to generate trapped proton and electron spectra as a function of Rj (Rj = radius of Jupiter = ∼71,400 km). Using these spectra and a high-energy particle transport codes (MCNPX and HZETRN), radiation exposures and dose effects for a variety of shielding materials (Al, polyethylene [PE], and Ta plus several other elemental materials for “Graded-Z” portion of the paper) and thicknesses are presented for the Icy Moon, Europa, Ganymede, and Callisto for several orbital inclinations. In addition, an in-depth discussion and absorbed dose calculations are presented for “Graded-Z” materials and several computer codes were utilized for comparison purposes. We find overall there is generally quite good agreement between the various computer codes utilized in the study: MCNPX (Monte Carlo) vs. HZETRN (deterministic) for slab shielding and the comparison of “Graded-Z” shielding using the CEPXS, NOVICE, and NASA JPL codes. Finally, we conclude that the merits of using “Graded-Z” materials that include PE, due to cost and weight, should aid future Jupiter mission planners and spacecraft designers.

Preparation and Characterization of Polyurethane/Multi-Walled Carbon Nanotubes Composites with Multi Functional Performance

2008 ◽  
Vol 47-50 ◽  
pp. 765-768 ◽  
Author(s):  
Feng Dan Jiang ◽  
Guo Hua Hu ◽  
Li Qun Zhang
Keyword(s):  
Carbon Nanotubes ◽  
Electron Microscope ◽  
Functional Performance ◽  
Thermoplastic Polyurethane ◽  
Functional Materials ◽  
Nano Composites ◽  
Transmission Electron ◽  
Multi Walled Carbon Nanotubes ◽  
Higher Temperature ◽  
Walled Carbon Nanotubes

A melt blending process was employed to prepare nano-composites based on thermoplastic polyurethane (TPU) and multi-walled carbon nanotubes (MWNT). The content of MWNT filled in TPU was increased till 40phr (parts per hundreds of rubber). Scanning electron microscope (SEM) and transmission electron microscope (TEM) showed that the unmodified MWNT were dispersed uniformly in the TPU matrix beyond expectation. Dynamic mechanical thermal analysis (DMTA) test demonstrated that the nano-composites possessed greatly increased modulus, and the flowing temperature moved to higher temperature with increasing MWNT content. Moreover, the nano-composites exhibited improved wear resistance, evidently increased thermal conductivity, and prominently raised electrical conductivity that might mean the TPU/MWNT nano-composites have potential application as multi-functional materials.

Characterization of Nanoparticle Enhanced Multifunctional Sandwich Composites Subjected to Space Radiation

2016 ◽  
Author(s):  
Nasim Abuali Galehdari ◽  
Ajit D. Kelkar
Keyword(s):  
Sandwich Panels ◽  
Space Radiation ◽  
High Energy ◽  
Woven Fabrics ◽  
Radiation Shielding ◽  
Core Material ◽  
Radiation Absorption ◽  
Sandwich Composites ◽  
Absorption Properties ◽  
High Hydrogen

One of the major concerns in long duration space exploration is to minimize the exposure of crew and equipment to space radiation. High energy radiation not only can be hazardous to the health but also can damage the materials and electronics. Current designs are contained heavy metals to avoid occupational hazards from radiation exposures. As a result the shielding structures are heavy and not effective to attenuate all types of radiation. Therefore, the proposed lightweight sandwich composites are designed to effectively shield high energy radiations while providing structural integrity. In the manufactured hybrid sandwich composite, High Molecular Weight Poly Ethylene (HMWPE) woven fabrics are selected as face sheets due to their advanced mechanical properties and excellent physical properties along with effective shielding properties. Basically polymers due to high hydrogen content are considered as effective materials to attenuate high energy radiations. In addition, the core material is epoxy composites incorporating three weight percentages of three different nanoparticles viz. Boron Carbide, Boron Nanopowder and Gadolinium. In fact if polymers as low Z materials are used alone, they usually are not successful to attenuate highly penetrative rays. Therefore, one solution is known to infuse polymer matrix with high radiation absorption properties nanoparticles. Among several different nanomaterials, the three aforementioned nanofillers were chosen because of their good radiation absorption properties. Gadolinium has the highest thermal neutron cross section compare to any other known element and 10B-containing materials are known as excellent radiation absorbers and the composite filled with them have the advantage of convenient and safety in construction, operation and reintegration. The sandwich composites were manufactured using Heat-Vacuum Assisted Resin Transfer Molding method (H-VARTM), which is a cost effective method for high volume production of sandwich structures. To evaluate the shielding performance of manufactured sandwich panels the neutron attenuation testing was performed. The results from neutron radiation tests show more than 99% shielding performance in all of the sandwich panels. In comparison with other nanofillers, Boron Nanopowder showed highest radiation shielding efficiency (99.64%), which can be attributed to its lowest particle size and better dispersion ability into epoxy resin. The flatwise compression testing was performed on all four sandwich panels to determine the mechanical strength of materials before and after being exposure to radiation. The results demonstrate that proposed hybrid sandwich panels can preserve their mechanical integrity while being exposed to the radiation.

Cardiovascular effects of space radiation: implications for future human deep space exploration

2019 ◽  
Vol 26 (16) ◽  
pp. 1707-1714 ◽  
Author(s):  
Adam Mitchell ◽  
Dominic Pimenta ◽  
Jaspal Gill ◽  
Haris Ahmad ◽  
Richard Bogle
Keyword(s):  
Space Exploration ◽  
Radiation Risk ◽  
Space Radiation ◽  
High Energy ◽  
Galactic Cosmic Rays ◽  
Radiation Shielding ◽  
X Rays ◽  
Deep Space ◽  
Deep Space Exploration ◽  
Low Earth Orbits

Background A manned mission to Mars has been contemplated by the world's largest space agencies for a number of years. The duration of the trip would necessitate a much longer exposure to deep space radiation than any human has ever been exposed to in the past. Concern regarding cancer risk has thus far stalled the progress of deep space exploration; however, the effect of space radiation on the cardiovascular system is significantly less well understood. Discussion Damage by radiation in space is mediated by a number of sources, including X-rays, protons and heavier charged atomic nuclei (HZE ions, the high-energy component of galactic cosmic rays). Previously, only lunar mission astronauts have been exposed to significant deep space radiation, with all other missions being low earth orbits only. The effect of this radiation on the human body has been inconclusively studied, and the long-term damage caused to the vascular endothelium by this radiation due to the effect of high-energy particles is not well known. Conclusion Current radiation shielding technology, which would be viable for use in spacecraft, would not eliminate radiation risk. Similar to how a variety of shielding techniques are used every day by radiographers, again without full risk elimination, we need to explore and better understand the effect of deep space radiation in order to ensure the safety of those on future space missions.

scholarly journals A Global Review on Short Peptides: Frontiers and Perspectives

Molecules ◽  
2021 ◽  
Vol 26 (2) ◽  
pp. 430
Author(s):  
Vasso Apostolopoulos ◽  
Joanna Bojarska ◽  
Tsun-Thai Chai ◽  
Sherif Elnagdy ◽  
Krzysztof Kaczmarek ◽  
...  
Keyword(s):  
Protein Interactions ◽  
Targeted Delivery ◽  
Swot Analysis ◽  
Functional Materials ◽  
Great Promise ◽  
Short Peptides ◽  
Altered Peptide Ligands ◽  
Short Peptide ◽  
Domains Of Life

Peptides are fragments of proteins that carry out biological functions. They act as signaling entities via all domains of life and interfere with protein-protein interactions, which are indispensable in bio-processes. Short peptides include fundamental molecular information for a prelude to the symphony of life. They have aroused considerable interest due to their unique features and great promise in innovative bio-therapies. This work focusing on the current state-of-the-art short peptide-based therapeutical developments is the first global review written by researchers from all continents, as a celebration of 100 years of peptide therapeutics since the commencement of insulin therapy in the 1920s. Peptide “drugs” initially played only the role of hormone analogs to balance disorders. Nowadays, they achieve numerous biomedical tasks, can cross membranes, or reach intracellular targets. The role of peptides in bio-processes can hardly be mimicked by other chemical substances. The article is divided into independent sections, which are related to either the progress in short peptide-based theranostics or the problems posing challenge to bio-medicine. In particular, the SWOT analysis of short peptides, their relevance in therapies of diverse diseases, improvements in (bio)synthesis platforms, advanced nano-supramolecular technologies, aptamers, altered peptide ligands and in silico methodologies to overcome peptide limitations, modern smart bio-functional materials, vaccines, and drug/gene-targeted delivery systems are discussed.

scholarly journals Analysis of Shielding Performance of Radiation-Shielding Materials According to Particle Size and Clustering Effects

2021 ◽  
Vol 11 (9) ◽  
pp. 4010
Author(s):  
Seon-Chil Kim
Keyword(s):  
Particle Size ◽  
Polymer Material ◽  
Energy Region ◽  
High Energy ◽  
Radiation Shielding ◽  
High Energy Region ◽  
Particle Structure ◽  
Effect Of Particle Size ◽  
Extensive Body ◽  
Shielding Material

In the field of medical radiation shielding, there is an extensive body of research on process technologies for ecofriendly shielding materials that could replace lead. In particular, the particle size and arrangement of the shielding material when blended with a polymer material affect shielding performance. In this study, we observed how the particle size of the shielding material affects shielding performance. Performance and particle structure were observed for every shielding sheet, which were fabricated by mixing microparticles and nanoparticles with a polymer material using the same process. We observed that the smaller the particle size was, the higher both the clustering and shielding effects in the high-energy region. Thus, shielding performance can be improved. In the low-dose region, the effect of particle size on shielding performance was insignificant. Moreover, the shielding sheet in which nanoparticles and microsized particles were mixed showed similar performance to that of the shielding sheet containing only microsized particles. Findings indicate that, when fabricating a shielding sheet using a polymer material, the smaller the particles in the high-energy region are, the better the shielding performance is. However, in the low-energy region, the effect of the particles is insignificant.

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