scholarly journals Exploring Biogenic Dispersion Inside Star Clusters with System Dynamics Modeling

2020 ◽  
Author(s):  
Javier Burgos ◽  
Carolina Sierra
Keyword(s):  
Organic Molecules ◽  
Star Clusters ◽  
System Dynamics Modeling ◽  
Dynamics Modeling ◽  
Extrasolar Systems ◽  
The Impact ◽  
First Time ◽  
Impact Events ◽  
Complex Organic ◽  
The Universe

The discovery of a growing number of exoplanets and even extrasolar systems supports the scientific consensus that it is possible to find other signs of life in the universe. The present work proposes for the first time, an explicit mechanism inspired by the dynamics of biological dispersion, widely used in ecology and epidemiology, to study the dispersion of biogenic units, interpreted as complex organic molecules, between rocky or water exoplanets (habitats) located inside star clusters. The results of the dynamic simulation suggest that for clusters with populations lower than 4 M+/ly3 it is not possible to obtain biogenic worlds after 5 Gyr. Above this population size, biogenic dispersion seems to follow a power law, the larger the density of worlds lesser will be the impact rate (β ) value to obtain at least one viable biogenic Carrier habitat after 5 Gyr. Finally, when we investigate scenarios by varying β, a well-defined set of density intervals can be defined in accordance to its characteristic β value, suggesting that biogenic dispersion has a behavior of “minimal infective dose” of “minimal biogenic effective” events by interval i.e. once this dose has been achieved, doesn’t matter if additional biogenic impact events occur on the habitat.

scholarly journals A Sustainable Improvement of ω-Bromoalkylphosphonates Synthesis to Access Novel KuQuinones

Organics ◽  
2021 ◽  
Vol 2 (2) ◽  
pp. 107-117
Author(s):  
Mattia Forchetta ◽  
Valeria Conte ◽  
Giulia Fiorani ◽  
Pierluca Galloni ◽  
Federica Sabuzi
Keyword(s):  
Metal Oxides ◽  
Phosphonic Acid ◽  
Organic Molecules ◽  
Building Blocks ◽  
Reaction Conditions ◽  
Phosphonic Acids ◽  
Sustainable Improvement ◽  
Phosphonate Esters ◽  
First Time ◽  
Complex Organic

Owing to the attractiveness of organic phosphonic acids and esters in the pharmacological field and in the functionalization of conductive metal-oxides, the research of effective synthetic protocols is pivotal. Among the others, ω-bromoalkylphosphonates are gaining particular attention because they are useful building blocks for the tailored functionalization of complex organic molecules. Hence, in this work, the optimization of Michaelis–Arbuzov reaction conditions for ω-bromoalkylphosphonates has been performed, to improve process sustainability while maintaining good yields. Synthesized ω-bromoalkylphosphonates have been successfully adopted for the synthesis of new KuQuinone phosphonate esters and, by hydrolysis, phosphonic acid KuQuinone derivatives have been obtained for the first time. Considering the high affinity with metal-oxides, KuQuinones bearing phosphonic acid terminal groups are promising candidates for biomedical and photo(electro)chemical applications.

scholarly journals Organic Molecules: Is It Possible to Distinguish Aromatics from Aliphatics Collected by Space Missions in High-Speed Impacts?

Sci ◽  
2020 ◽  
Vol 2 (2) ◽  
pp. 41
Author(s):  
Mark Burchell ◽  
Kathryn Harriss
Keyword(s):  
High Speed ◽  
Organic Molecules ◽  
Chemical Structures ◽  
Surface Ocean ◽  
Life Itself ◽  
Organic Particles ◽  
Open Question ◽  
The Impact ◽  
The Relationship ◽  
Complex Organic

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.

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
Keyword(s):  
High Speed ◽  
Organic Molecules ◽  
Chemical Structures ◽  
Surface Ocean ◽  
Life Itself ◽  
Organic Particles ◽  
Open Question ◽  
The Impact ◽  
The Relationship ◽  
Complex Organic

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.

scholarly journals SYSTEM DYNAMICS MODELING FOR CONSTRUCTION MANAGEMENT RESEARCH: CRITICAL REVIEW AND FUTURE TRENDS

2019 ◽  
Vol 25 (8) ◽  
pp. 730-741 ◽  
Author(s):  
Mingqiang Liu ◽  
Yun Le ◽  
Yi Hu ◽  
Bo Xia ◽  
Martin Skitmore ◽  
...  
Keyword(s):  
System Dynamics ◽  
Strategic Management ◽  
Construction Management ◽  
State Of The Art ◽  
Project Planning ◽  
System Dynamics Modeling ◽  
Dynamics Modeling ◽  
Planning And Control ◽  
And Control ◽  
The Impact

As a result of growing complexities in the construction industry, system dynamics modeling (SDM) has been increasingly used in construction management (CM) research to explore complicated causal relationships at the various levels of construction and management processes. Given the rapid growth of SDM applications over the past two decades, a systematic review is needed to ascertain the state of the art and further trends in the area. This paper provides the results of a systematic analysis of 103 papers from 41 selected peer-reviewed journals from 1997 to 2016. The contributions of the papers are first analyzed, structured and formulated in terms of the year of publication, software involved, the combined use with other methods, and research design. With the assistance of the a keyword co-occurrence network analysis, eight research topics involving different internal and external complexities are identified, including: (1) sustainability, (2) project planning and control, (3) performance and effectiveness, (4) strategic management, (5) site and resource management, (6) risk analysis and management, (7) knowledge management, and (8) organization and stakeholder management. The analysis results reveal the pivotal role of SDM in streamlining different complicated casual relationships at the activity, project, and industry levels across the eight topics and its significant potential in uncovering the impact of complicated contextual conditions on project planning and control, effectiveness and performance, strategic management, and sustainability at the project and industry levels. Lastly, trends and recommendations for SDM applications are provided for future CM research. This paper provides a state of the art of SDM in CM applications and insights into opportunities and useful references for the future.

Formaldehyde chemistry in cometary ices: the case of HOCH2OH formation

2014 ◽  
Vol 16 (44) ◽  
pp. 24200-24208 ◽  
Author(s):  
F. Duvernay ◽  
A. Rimola ◽  
P. Theule ◽  
G. Danger ◽  
T. Sanchez ◽  
...  
Keyword(s):  
Laboratory Experiments ◽  
Organic Molecules ◽  
Complex Organic ◽  
The Universe

Laboratory experiments devoted to simulate the chemistry occurring in interstellar and cometary ice analogues are of paramount importance to understand the formation of complex organic molecules that are detected throughout the universe.

scholarly journals Organic Molecules: Is It Possible to Distinguish Aromatics from Aliphatics Collected by Space Missions in High-Speed Impacts?

Sci ◽  
2020 ◽  
Vol 2 (3) ◽  
pp. 56
Author(s):  
Mark Burchell ◽  
Kathryn Harriss
Keyword(s):  
High Speed ◽  
Organic Molecules ◽  
Chemical Structures ◽  
Surface Ocean ◽  
Life Itself ◽  
Organic Particles ◽  
Open Question ◽  
The Impact ◽  
The Relationship ◽  
Complex Organic

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.

scholarly journals Developing a policy simulator at the acute–aged care interface

2006 ◽  
Vol 30 (4) ◽  
pp. 450 ◽  
Author(s):  
Leonard C Gray ◽  
Gerald A Broe ◽  
Stephen J Duckett ◽  
Diane M Gibson ◽  
Catherine Travers ◽  
...  
Keyword(s):  
Computer Simulation ◽  
System Dynamics ◽  
Aged Care ◽  
System Dynamics Modeling ◽  
Policy Environment ◽  
Dynamics Modeling ◽  
Policy Issues ◽  
Care Systems ◽  
Key Policy ◽  
The Impact

This paper describes the development of a computer simulation of the interactions between the acute and aged care systems in Australia, using system dynamics modeling enhanced by agentbased techniques. National and regional simulations will be developed, enabling the impact of a variety of policy scenarios to be forecast over the next 10 years. The paper includes a description of the relevant policy environment and some of the associated key policy issues.

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