scholarly journals Characterisation of the Water Renewal in a Macro-Tidal Marina Using Several Transport Timescales

Water ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 2050 ◽  
Author(s):  
Jean-Rémy Huguet ◽  
Isabelle Brenon ◽  
Thibault Coulombier
Keyword(s):  
Water Exchange ◽  
Return Flow ◽  
Physical Processes ◽  
Floating Structures ◽  
Water Renewal ◽  
Tidal Regime ◽  
South West ◽  
Exchange Processes ◽  
Wide Range ◽  
Ecological Applications

In this paper, we investigate the water renewal of a highly populated marina, located in the south-west of France, and subjected to a macro-tidal regime. With the use of a 3D-numerical model (TELEMAC-3D), three water transport timescales were studied and compared to provide a fully detailed description of the physical processes occurring in the marina. Integrated Flushing times (IFT) were computed through a Eulerian way while a Lagrangian method allowed to estimate Residence Times (RT) and Exposure Times (ET). From these timescales, the return-flow (the fraction of water that re-enters the marina at flood after leaving the domain at ebb) was quantified via the Return-flow Factor (RFF) and the Return Coefficient (RC) parameters. The intrinsic information contained in these parameters is thoroughly analysed, and their relevance is discussed. A wide range of weather-marine conditions was tested to provide the most exhaustive information about the processes occurring in the marina. The results highlight the significant influence of the tide and the wind as well as the smaller influence of the Floating Structures (FS) on the renewal. Besides, this study provides the first investigation of the water exchange processes of La Rochelle marina. It offers some content that interest researchers and environmental managers in the monitoring of pollutants as well as biological/ecological applications.

scholarly journals Modelling the atmosphere of lava planet K2-141b: implications for low- and high-resolution spectroscopy

2020 ◽  
Vol 499 (4) ◽  
pp. 4605-4612
Author(s):  
T Giang Nguyen ◽  
Nicolas B Cowan ◽  
Agnibha Banerjee ◽  
John E Moores
Keyword(s):  
Steady State ◽  
Ocean Circulation ◽  
Scale Height ◽  
High Resolution Spectroscopy ◽  
Return Flow ◽  
High Dispersion ◽  
Magma Ocean ◽  
Steady State Flow ◽  
Wide Range ◽  
Very High

ABSTRACT Transit searches have uncovered Earth-size planets orbiting so close to their host star that their surface should be molten, so-called lava planets. We present idealized simulations of the atmosphere of lava planet K2-141b and calculate the return flow of material via circulation in the magma ocean. We then compare how pure Na, SiO, or SiO2 atmospheres would impact future observations. The more volatile Na atmosphere is thickest followed by SiO and SiO2, as expected. Despite its low vapour pressure, we find that a SiO2 atmosphere is easier to observe via transit spectroscopy due to its greater scale height near the day–night terminator and the planetary radial velocity and acceleration are very high, facilitating high dispersion spectroscopy. The special geometry that arises from very small orbits allows for a wide range of limb observations for K2-141b. After determining the magma ocean depth, we infer that the ocean circulation required for SiO steady-state flow is only 10−4 m s−1, while the equivalent return flow for Na is several orders of magnitude greater. This suggests that a steady-state Na atmosphere cannot be sustained and that the surface will evolve over time.

scholarly journals Spontaneous and forced decay of atomic nuclei realized in two stages

2020 ◽  
pp. 122-135
Author(s):  
Viacheslav S. Okunev
Keyword(s):  
Stable Isotopes ◽  
Kinetic Energy ◽  
Nuclear Reactions ◽  
External Influence ◽  
Physical Processes ◽  
Atomic Nuclei ◽  
Wide Range ◽  
Fragmentation Reactions ◽  
Two Stages ◽  
Principle Of Similarity

The main purpose of the work is to determine the possibility of cluster decays of superheavy atomic nuclei. The universality of the principle of similarity allows you to apply it to the analysis of not studied physical processes. Analogies are observed in forced and spontaneous decays of atomic nuclei. It is shown that in two stages, processes initiated by external influence are realized: fragmentation reactions, forced fission of stable nuclei, and impact radioactivity. Nuclear reactions of fragmentation and forced fission of stable isotopes of lead and bismuth are realized under the action of particles (hadrons) and light atomic nuclei with a kinetic energy of more than 108 eV. Shock radioactivity is observed in the collision of macroobjects having a crystalline structure at speeds of at least ∼1 km/s. Also, in two stages, some radioactive decays of atomic nuclei are realized, including extremely rare cluster decays. Based on the analogies of the processes considered, some cautious predictions are made about the possibility of cluster decays of atomic nuclei in a wide range of atomic masses.

scholarly journals Life, Birth and Death in Democritus. Atomistic Reflections Between Physics and Ethics

2017 ◽  
Vol 8 (1) ◽  
pp. 141-154
Author(s):  
Miriam Campolina Diniz Peixoto
Keyword(s):  
Human Behaviour ◽  
Physical Processes ◽  
Wide Range ◽  
The Subject ◽  
Birth Death

The subject of life, birth and death constitutes one of the main topics in Democritus’ reflection on human questions. He seeks to understand what men think about the processes of birth and death and how they, accordingly, determine their behavior and attitudes. His reflections comprise a wide range of perspectives and aspects that include examining human behaviour and investigating how it reveals a certain temperament or inclination, inquiring about the nature of these processes and extending the analyses of the processes of birth and death to whole beings through the couple generation-corruption. In the present paper, I intend to examine the main theses and arguments which appear in the testimonies and fragments through which Democritus’ thought was transmitted from antiquity. Furthermore, I will also discuss the hypotheses that for Democritus the most important opposition was not life-death, but rather birth-death and that, at the same time, his idea of nature and life comprises both processes in the perspective of atomistic philosophy. I shall show that corruption has to be considered in two different ways, that is, in the context of physical processes that keep the kosmos in its persistence and in the context of the existence of natural beings, both living and lifeless.

scholarly journals The fall and rise of consciousness science

2018 ◽  
Author(s):  
Anil Seth
Keyword(s):  
Twentieth Century ◽  
Empirical Study ◽  
Neurological Disorders ◽  
Neural Mechanisms ◽  
Central Feature ◽  
Hard Problem ◽  
Physical Processes ◽  
Wide Range ◽  
Third Person ◽  
The Universe

At the birth of psychology as a science, consciousness was its central problem. But throughout the twentieth century, ideological and methodological concerns pushed the explicit empirical study of consciousness to the sidelines. Since the 1990s, studying consciousness has regained a legitimacy and impetus befitting its status as the central feature of our mental lives. Nowadays consciousness science encompasses a rich interdisciplinary mixture drawing together philosophical, theoretical, computational, experimental, and clinical perspectives. While solving the metaphysically ‘hard’ problem of why consciousness is part of the universe may seem as intractable as ever, scientists have learned a great deal about the neural mechanisms underlying conscious states. Further progress will depend on specifying closer explanatory mappings between (first person subjective) phenomenological descriptions and (third person objective) descriptions of biological and physical processes. Such progress will help reframe our understanding of our place in nature, and may also accelerate clinical approaches to a wide range of psychiatric and neurological disorders.

scholarly journals The Nordre Strømfjord shear zone and the Arfersiorfik quartz diorite in Arfersiorfik, the Nagssugtoqidian orogen, West Greenland

2006 ◽  
Vol 11 ◽  
pp. 145-162 ◽  
Author(s):  
Kai Sørensen ◽  
John A. Korstgård ◽  
William E. Glassley ◽  
Bo Møller Stensgaard
Keyword(s):  
Shear Zone ◽  
Volcanic Rocks ◽  
Quartz Diorite ◽  
Ductile Deformation ◽  
Chemical Compositions ◽  
West Greenland ◽  
South West ◽  
Wide Range ◽  
Inland Ice ◽  
Zone Deformation

The Nordre Strømfjord shear zone in the fjord Arfersiorfik, central West Greenland, consists of alternating panels of supracrustal rocks and orthogneisses which together form a vertical zone up to 7 km wide with sinistral transcurrent, ductile deformation, which occurred under middle amphibolite facies conditions. The pelitic and metavolcanic schists and paragneisses are all highly deformed, while the orthogneisses appear more variably deformed, with increasing deformation evident towards the supracrustal units. The c. 1.92 Ga Arfersiorfik quartz diorite is traceable for a distance of at least 35 km from the Inland Ice towards the west-south-west. Towards its northern contact with an intensely deformed schist unit it shows a similar pattern of increasing strain, which is accompanied by chemical and mineralogical changes. The metasomatic changes associated with the shear zone deformation are superimposed on a wide range of original chemical compositions, which reflect magmatic olivine and/ or pyroxene as well as hornblende fractionation trends. The chemistry of the Arfersiorfik quartz diorite suite as a whole is comparable to that of Phanerozoic plutonic and volcanic rocks of calc-alkaline affinity.

scholarly journals Physical Transport Processes that Affect the Distribution of Oil in the Gulf of Mexico: Observations and Modeling

Oceanography ◽  
2021 ◽  
Vol 34 (1) ◽  
pp. 58-75
Author(s):  
Michel Boufadel ◽  
◽  
Annalisa Bracco ◽  
Eric Chassignet ◽  
Shuyi Chen ◽  
...  
Keyword(s):  
Gulf Of Mexico ◽  
Physical Environment ◽  
Large Scale ◽  
Transport Processes ◽  
Small Scale ◽  
Surface Mixed Layer ◽  
Physical Processes ◽  
Mixing Processes ◽  
Near Surface ◽  
Wide Range

Physical transport processes such as the circulation and mixing of waters largely determine the spatial distribution of materials in the ocean. They also establish the physical environment within which biogeochemical and other processes transform materials, including naturally occurring nutrients and human-made contaminants that may sustain or harm the region’s living resources. Thus, understanding and modeling the transport and distribution of materials provides a crucial substrate for determining the effects of biological, geological, and chemical processes. The wide range of scales in which these physical processes operate includes microscale droplets and bubbles; small-scale turbulence in buoyant plumes and the near-surface “mixed” layer; submesoscale fronts, convergent and divergent flows, and small eddies; larger mesoscale quasi-geostrophic eddies; and the overall large-scale circulation of the Gulf of Mexico and its interaction with the Atlantic Ocean and the Caribbean Sea; along with air-sea interaction on longer timescales. The circulation and mixing processes that operate near the Gulf of Mexico coasts, where most human activities occur, are strongly affected by wind- and river-induced currents and are further modified by the area’s complex topography. Gulf of Mexico physical processes are also characterized by strong linkages between coastal/shelf and deeper offshore waters that determine connectivity to the basin’s interior. This physical connectivity influences the transport of materials among different coastal areas within the Gulf of Mexico and can extend to adjacent basins. Major advances enabled by the Gulf of Mexico Research Initiative in the observation, understanding, and modeling of all of these aspects of the Gulf’s physical environment are summarized in this article, and key priorities for future work are also identified.

scholarly journals Prototyping Artificial Intelligent Classifiers using Deep Learning

2020 ◽  
Author(s):  
Herman Njoroge Chege
Keyword(s):  
Deep Learning ◽  
Citizen Science ◽  
Parameter Tuning ◽  
Biological Species ◽  
Biodiversity Monitoring ◽  
Practical Applications ◽  
Wide Range ◽  
Image Dataset ◽  
Ecological Applications

Point 1: Deep learning algorithms are revolutionizing how hypothesis generation, pattern recognition, and prediction occurs in the sciences. In the life sciences, particularly biology and its subfields,  the use of deep learning is slowly but steadily increasing. However, prototyping or development of tools for practical applications remains in the domain of experienced coders. Furthermore, many tools can be quite costly and difficult to put together without expertise in Artificial intelligence (AI) computing. Point 2: We built a biological species classifier that leverages existing open-source tools and libraries. We designed the corresponding tutorial for users with basic skills in python and a small, but well-curated image dataset. We included annotated code in form of a Jupyter Notebook that can be adapted to any image dataset, ranging from satellite images, animals to bacteria. The prototype developer is publicly available and can be adapted for citizen science as well as other applications not envisioned in this paper. Point 3: We illustrate our approach with a case study of 219 images of 3 three seastar species. We show that with minimal parameter tuning of the AI pipeline we can create a classifier with superior accuracy. We include additional approaches to understand the misclassified images and to curate the dataset to increase accuracy. Point 4: The power of AI approaches is becoming increasingly accessible. We can now readily build and prototype species classifiers that can have a great impact on research that requires species identification and other types of image analysis. Such tools have implications for citizen science, biodiversity monitoring, and a wide range of ecological applications.

scholarly journals Nearshore Wave Transformation Domains from Video Imagery

2019 ◽  
Vol 7 (6) ◽  
pp. 186 ◽  
Author(s):  
Umberto Andriolo
Keyword(s):  
Sediment Transport ◽  
Intensity Variation ◽  
Wave Transformation ◽  
Physical Processes ◽  
Pixel Intensity ◽  
Wave Characteristics ◽  
Wide Range ◽  
Different Types ◽  
Propagation Properties ◽  
Wave Properties

Within the nearshore area, three wave transformation domains can be distinguished based on the wave properties: shoaling, surf, and swash zones. The identification of these distinct areas is relevant for understanding nearshore wave propagation properties and physical processes, as these zones can be related, for instance, to different types of sediment transport. This work presents a technique to automatically retrieve the nearshore wave transformation domains from images taken by coastal video monitoring stations. The technique exploits the pixel intensity variation of image acquisitions, and relates the pixel properties to the distinct wave characteristics. This allows the automated description of spatial and temporal extent of shoaling, surf, and swash zones. The methodology was proven to be robust, and capable of spotting the three distinct zones within the nearshore, both cross-shore and along-shore dimensions. The method can support a wide range of coastal studies, such as nearshore hydrodynamics and sediment transport. It can also allow a faster and improved application of existing video-based techniques for wave breaking height and depth-inversion, among others.

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