scholarly journals Organic Molecules: Is It Possible To Distinguish Aromatics From Aliphatics Collected By Space Missions in High-Speed Impacts

Sci ◽  
2020 ◽  
Vol 2 (1) ◽  
pp. 12
Author(s):  
Mark Burchell ◽  
Kathryn Harriss

A prime site of astrobiological interest within the Solar System is the interior ocean of Enceladus. This ocean has already been shown to contain organic molecules, and is thought to have the conditions necessary for more complex organic biomolecules to emerge and potentially even life itself. This sub-surface ocean has been accessed by Cassini, an unmanned spacecraft that interacted with the water plumes ejected naturally from Enceladus. The encounter speed with these plumes and their contents, was 5 km s−1 and above. Encounters at such speeds allow analysis of vapourised material from submicron-sized particles within the plume, but sampling micron-sized particles remains an open question. The latter particles can impact metal targets exposed on the exterior of future spacecraft, producing impact craters lined with impactor residue, which can then be analysed. Although there is considerable literature on how mineral grains behave in such high-speed impacts, and also on the relationship between the crater residue and the original grain composition, far less is known regarding the behaviour of organic particles. Here we consider a deceptively simple yet fundamental scientific question: for impacts at speeds of around 5−6 kms−1 would the impactor residue alone be sufficient to enable us to recognise the signature conferred by organic particles? Furthermore, would it be possible to identify the organic molecules involved, or at least distinguish between aromatic and aliphatic chemical structures? For polystyrene (aromatic-rich) and poly(methyl methacrylate) (solely aliphatic) latex particles impinging at around 5 km s-1 onto metal targets, we find that sufficient residue is retained at the impact site to permit identification of a carbon-rich projectile, but not of the particular molecules involved, nor is it currently possible to discriminate between aromatic-rich and solely aliphatic particles. This suggests that an alternative analytical method to simple impacts on metal targets is required to enable successful collection of organic samples in a fly-by Enceladus mission, or, alternatively, a lower encounter speed is required.

Sci ◽  
2020 ◽  
Vol 2 (2) ◽  
pp. 41
Author(s):  
Mark Burchell ◽  
Kathryn Harriss

A prime site of astrobiological interest within the Solar System is the interior ocean of Enceladus. This ocean has already been shown to contain organic molecules, and is thought to have the conditions necessary for more complex organic biomolecules to emerge and potentially even life itself. This sub-surface ocean has been accessed by Cassini, an unmanned spacecraft that interacted with the water plumes ejected naturally from Enceladus. The encounter speed with these plumes and their contents, was between 5 and 15 km s−1. Encounters at such speeds allow analysis of vapourised material from submicron-sized particles within the plume, but sampling micron-sized particles remains an open question. The latter particles can impact metal targets exposed on the exterior of future spacecraft, producing impact craters lined with impactor residue, which can then be analysed. Although there is considerable literature on how mineral grains behave in such high-speed impacts, and also on the relationship between the crater residue and the original grain composition, far less is known regarding the behaviour of organic particles. Here we consider a deceptively simple yet fundamental scientific question: for impacts at speeds of around 5–6 kms−1 would the impactor residue alone be sufficient to enable us to recognise the signature conferred by organic particles? Furthermore, would it be possible to identify the organic molecules involved, or at least distinguish between aromatic and aliphatic chemical structures? For polystyrene (aromatic-rich) and poly(methyl methacrylate) (solely aliphatic) latex particles impinging at around 5 km s−1 onto metal targets, we find that sufficient residue is retained at the impact site to permit identification of a carbon-rich projectile, but not of the particular molecules involved, nor is it currently possible to discriminate between aromatic-rich and solely aliphatic particles. This suggests that an alternative analytical method to simple impacts on metal targets is required to enable successful collection of organic samples in a fly-by Enceladus mission, or, alternatively, a lower encounter speed is required.


Sci ◽  
2020 ◽  
Vol 2 (3) ◽  
pp. 56
Author(s):  
Mark Burchell ◽  
Kathryn Harriss

A prime site of astrobiological interest within the Solar System is the interior ocean of Enceladus. This ocean has already been shown to contain organic molecules, and is thought to have the conditions necessary for more complex organic biomolecules to emerge and potentially even life itself. This sub-surface ocean has been accessed by Cassini, an unmanned spacecraft that interacted with the water plumes ejected naturally from Enceladus. The encounter speed with these plumes and their contents, was between 5 and 15 km s−1. Encounters at such speeds allow analysis of vapourised material from submicron-sized particles within the plume, but sampling micron-sized particles remains an open question. The latter particles can impact metal targets exposed on the exterior of future spacecraft, producing impact craters lined with impactor residue, which can then be analysed. Although there is considerable literature on how mineral grains behave in such high-speed impacts, and also on the relationship between the crater residue and the original grain composition, far less is known regarding the behaviour of organic particles. Here we consider a deceptively simple yet fundamental scientific question: for impacts at speeds of around 5−6 kms−1 would the impactor residue alone be sufficient to enable us to recognise the signature conferred by organic particles? Furthermore, would it be possible to identify the organic molecules involved, or at least distinguish between aromatic and aliphatic chemical structures? For polystyrene (aromatic-rich) and polymethylmethacrylate (solely aliphatic) latex particles impinging at around 5 km s−1 onto metal targets, we find that sufficient residue is retained at the impact site to permit identification of a carbon-rich projectile, but not of the particular molecules involved, nor is it currently possible to discriminate between aromatic-rich and solely aliphatic particles. This suggests that an alternative analytical method to simple impacts on metal targets is required to enable successful collection of organic samples in a fly-by Enceladus mission, or, alternatively, a lower encounter speed is required.


Sci ◽  
2019 ◽  
Vol 1 (2) ◽  
pp. 53 ◽  
Author(s):  
Mark Burchell ◽  
Kathryn Harriss

A prime site of astrobiological interest within the Solar System is the interior ocean of Enceladus. This ocean has already been shown to contain organic molecules and is thought to have the conditions necessary for more complex organic biomolecules to emerge and potentially even life itself. This sub-surface ocean has been accessed by Cassini, an unmanned spacecraft that interacted with the water plumes ejected naturally from Enceladus. The encounter speed with these plumes and their contents was 5 km s−1 and above. Encounters at such speeds allow analysis of vaporised material from submicron-sized particles within the plume, but sampling micron-sized particles remains an open question. The latter particles can impact metal targets exposed on the exterior of future spacecraft, producing impact craters lined with impactor residue, which can then be analysed. Although there is considerable literature on how mineral grains behave in such high-speed impacts, and also on the relationship between the crater residue and the original grain composition, far less is known regarding the behaviour of organic particles. Here we consider a deceptively simple yet fundamental scientific question: for impacts at speeds of around 5–6 kms−1 would the impactor residue alone be sufficient to enable us to recognise the signature conferred by organic particles? Furthermore, would it be possible to identify the organic molecules involved, or at least distinguish between aromatic and aliphatic chemical structures? For polystyrene (aromatic-rich) and poly (methyl methacrylate) (solely aliphatic) latex particles impinging at around 5 km s−1 onto metal targets, we found that sufficient residue is retained at the impact site to permit identification of a carbon-rich projectile, but not of the particular molecules involved, nor is it currently possible to discriminate between aromatic-rich and solely aliphatic particles. This suggests that an alternative analytical method to simple impacts on metal targets is required to enable successful collection of organic samples in a fly-by Enceladus mission.


Author(s):  
Zhan Yi ◽  
Naoki Oya ◽  
Koji Enoki ◽  
Tomio Okawa ◽  
Shuji Ohno ◽  
...  

A liquid jet is of considerable importance in many industrial fields including jet cleaning, jet engine and combustion. As an important example, the Monju nuclear power plant in Japan experienced a sodium leak in 1995. This led to a fire accident because the sodium reacted with oxygen in the air. To predict the significance of the fire accident, accurate evaluation of the amount of splashed droplets caused by the sodium jet impingement is of great importance. In this work, the relationship between the condition of a liquid jet and the amount of splashed droplets is explored experimentally. In the experiments, a liquid jet was emanated vertically downward from a circular nozzle onto a liquid film formed on a horizontal plate. Visualization using a high speed camera was performed to observe the condition of the liquid jet. From the nozzle, the mode of the liquid jet changed jet, lump and drop. Here, the jet mode means the continuous jet with smooth surface, the lump mode the continuous jet with disturbed surface and the drop mode the broken jet. Dependences of the transition length to each mode on the important parameters such as the jet velocity and the nozzle diameter were investigated. Measurement was also conducted for the splash ratio that is defined as the ratio of the amount of splashed droplets to the jet flow rate. It was found that the splash ratio is high when the liquid jet is in the drop mode at the impact point. It was shown that the splash ratio can be correlated well as a function of the impact Weber number and the Strouhal number of the droplets impinging the liquid film.


2013 ◽  
Vol 442 ◽  
pp. 52-57 ◽  
Author(s):  
Shan He Mu ◽  
Chuan Liang Cao ◽  
Xiang Lin Zhang ◽  
Zha Xiang ◽  
Xiu Mao

The paper presents an experimental study on the relationship betweenprocess parametersand surface integrity of powder-metallurgy high-speed steel S390 in ultraprecision grinding. The optimal machining parametershave been obtained based on the Taguchi quality design method.The affected layerinduced by ultraprecision grinding has a uniform white layerand an inconspicuous dark layer; there are some carbides in the white layer of some samples; a compressive residual stress field exists on the ground surface. In addition, experiments confirm that lapping can remove the white layer effectively and increase the compressive residual stresses with a growth rate of 65%.The derived results satisfy the real requirements in practice.


2021 ◽  
Vol 1 (1) ◽  
pp. 1
Author(s):  
Toguan Rambe ◽  
Seva Maya Sari ◽  
Nurhayani Rambe

The environment is a global problem, in fact it is a humanitarian problem that is so complex that it is handled collectively. Population pollution is getting denser and more crowded coupled with limited natural resources and even the influence of digital media, modern technology which is often used for profit and even exploiting natural resources for personal or group gain, thus reducing the quality of nature. Islam has strong teachings about ethics towards the environment, very devastating events have often been experienced lately, namely floods, illegal logging, forest burning and the most existing ones until now are the Covid-19 epidemic, of course we realize that the impact of These incidents are very disturbing to the sustainability of the human environment. "Besides that, a number of other forms of environmental damage must be a very valuable lesson." Humans have an important influence in the sustainability of the ecosystem and human habitat itself, the actions taken or policies. about the relationship with the environment is clearly very influential for a good environment and human life itself. ”Normatively, religion calls on all humans to preserve and have ethics towards the environment, the relationship between the two is harmonious.


2020 ◽  
Vol 20 (19) ◽  
pp. 11387-11397
Author(s):  
Isabelle Steinke ◽  
Naruki Hiranuma ◽  
Roger Funk ◽  
Kristina Höhler ◽  
Nadine Tüllmann ◽  
...  

Abstract. Quantifying the impact of complex organic particles on the formation of ice crystals in clouds remains challenging, mostly due to the vast number of different sources ranging from sea spray to agricultural areas. In particular, there are many open questions regarding the ice nucleation properties of organic particles released from terrestrial sources such as decaying plant material. In this work, we present results from laboratory studies investigating the immersion freezing properties of individual organic compounds commonly found in plant tissue and complex organic aerosol particles from vegetated environments, without specifically investigating the contribution from biological particles, which may contribute to the overall ice nucleation efficiency observed at high temperatures. To characterize the ice nucleation properties of plant-related aerosol samples for temperatures between 242 and 267 K, we used the Aerosol Interaction and Dynamics in the Atmosphere (AIDA) cloud chamber and the Ice Nucleation SpEctrometer of the Karlsruhe Institute of Technology (INSEKT), which is a droplet freezing assay. Individual plant components (polysaccharides, lignin, soy and rice protein) were mostly less ice active, or similarly ice active, compared to microcrystalline cellulose, which has been suggested by recent studies to be a proxy for quantifying the primary cloud ice formation caused by particles originating from vegetation. In contrast, samples from ambient sources with a complex organic matter composition (agricultural soils and leaf litter) were either similarly ice active or up to 2 orders of magnitude more ice active than cellulose. Of all individual organic plant components, only carnauba wax (i.e., lipids) showed a similarly high ice nucleation activity as that of the samples from vegetated environments over a temperature range between 245 and 252 K. Hence, based on our experimental results, we suggest considering cellulose as being representative for the average ice nucleation activity of plant-derived particles, whereas lignin and plant proteins tend to provide a lower limit. In contrast, complex biogenic particles may exhibit ice nucleation activities which are up to 2 orders of magnitude higher than observed for cellulose, making ambient plant-derived particles a potentially important contributor to the population of ice-nucleating particles in the troposphere, even though major uncertainties regarding their transport to cloud altitude remain.


2011 ◽  
Vol 695 ◽  
pp. 465-468 ◽  
Author(s):  
Nai Kui Gao ◽  
Pu Dong ◽  
Xin Yu ◽  
Xin Fang ◽  
Chao Gao ◽  
...  

In this paper, composites with different contents of epoxy resin/nano-SiO2were fabricated, the influence of compounding process on nano-SiO2dispersion was studied, the microstructure and the relationship between impact strength and nano-SiO2content were investigated. The results showed that the distribution of nano-SiO2particles in the composites could be improved efficiently using high-speed shearing dispersion method. To composites with or without the coupling agent treatment, the impact strength grew with increasing nano-SiO2content, and increase to a maximum value when nano-SiO2content was 3wt.%. The maximum value was 75.4%, and 45.5% higher than that of monolithic epoxy resin respectively. With the nano-SiO2 content increased continually, the impact strength of composite materials decreased. The coupling agent treatment of nano-SiO2administered to improve the impact strength of the composites.


2020 ◽  
Vol 6 (3) ◽  
pp. 23-30
Author(s):  
Alexander L. Kamenkov

Aim: Identification of the degree of influence of high-speed lines on industrial specialization. Methods: This paper examines the relationship between high-speed rail and the agglomeration economy. A literature review of the most popular points of view on the economy of agglomerations is carried out. The main task is to answer whether HSR contributes to the development of industrial uniformity or industrial diversification. The work will show a model for calculating the specialization index, and also, assess the degree of influence of distance from the high-speed rail on the specialization of the city. Results: Three options for the location of cities and the industrial specialization of these cities were identified: right next to the HSR diversified; at a distance of 270 km from HSR uniform; at a distance of more than 500 km from HSR diversified. Conclusion: It is revealed that the single dominant industry receives the greatest benefit from agglomerations. Also-in this paper, the possibility of more effective orientation of the private sector by the state government is justified.


Complexity ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-19
Author(s):  
Jianjun Zhou ◽  
Xiayang Fan ◽  
Aizhi Yu

Although many studies have analyzed the transportation infrastructure effects on economic and trade development, little is known about the relationship between transportation infrastructure and trade in the agricultural sector. We take the opening of China’s high-speed railway (HSR) as a quasi-natural experiment and use multiperiod DID model to explore the impact and mechanism of HSR on agriculture-related enterprises’ exports. The results show that HSR can promote export growth of agriculture-related enterprises by 6.9%, and it will reach 10% in 5 years. However, the effect of HSR on the export of agriculture-related enterprises only exists within 45 km around HSR stations. HSR can reduce information barriers and costs for enterprises to enter the international market by providing transportation convenience and improving market access levels. HSR also offers local areas more transportation advantage compared to other surrounding areas, which in turn makes a siphon effect on export activities. Both these mechanisms are significant within 45 km, and it is extremely obvious for poor transportation areas and enterprises with higher productivity, and the siphon effect is even stronger than market access. Heterogeneity analysis results demonstrate that HSR has different effects for different types of enterprises.


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