Dispersion of heavy particles under sea waves

2022 ◽  
Vol 34 (1) ◽  
pp. 013305
Author(s):  
A. De Leo ◽  
A. Stocchino
Keyword(s):  
Sea Waves ◽  
Heavy Particles

scholarly journals Settling Velocity of Microplastics Exposed to Wave Action

2021 ◽  
Vol 9 (2) ◽  
pp. 142
Author(s):  
Annalisa De Leo ◽  
Laura Cutroneo ◽  
Damien Sous ◽  
Alessandro Stocchino
Keyword(s):  
Laboratory Experiments ◽  
Settling Velocity ◽  
Transport Model ◽  
Stokes Drift ◽  
Inertial Effects ◽  
Sea Waves ◽  
Heavy Particles ◽  
Analytical Formulation ◽  
Simplified Approach ◽  
Remote Areas

Microplastic (MP) debris is recognized to be one of the most serious threats to marine environments. They are found in all seas and oceanic basins worldwide, even in the most remote areas. This is further proof that the transport of MPs is very efficient. In the present study, we focus our attention on MPs’ transport owing to the Stokes drift generated by sea waves. Recent studies have shown that the interaction between heavy particles and Stokes drift leads to unexpected phenomena mostly related to inertial effects. We perform a series of laboratory experiments with the aim to directly measure MPs’ trajectories under different wave conditions. The main objective is to quantify the inertial effect and, ultimately, suggest a new analytical formulation for the net settling velocity. The latter formula might be implemented in a larger scale transport model in order to account for inertial effects in a simplified approach.

Wind speed data analysis for predictions of sea waves in Bitung Coastal Waters

2013 ◽  
pp. 35 ◽  
Author(s):  
Joanes E Koagouw ◽  
Gybert E Mamuaya ◽  
Adrie A Tarumingkeng ◽  
P A Angmalisang
Keyword(s):  
Data Analysis ◽  
Wind Speed ◽  
Coastal Waters ◽  
Transition Period ◽  
Marine Resources ◽  
Land Uses ◽  
Sea Waves ◽  
North West ◽  
North Sulawesi ◽  
The Waves

Coastal area of Bitung Municipality is one of the economical activities centers in North Sulawesi Province such as for land-uses and the exploitation of natural resources. Those activities are exaggerating day bay day and tended to be uncontrollable. The excess of those conditions, it has been recorded the change of waves in Bitung waters that has impacts to coastal areas and can affect the utilization of coastal and marine resources. This research was aimed to observe waves altitude variations in Bitung waters with Svedrup Munk and Bretchsneider (SMB) method that had been used to predict waves altitudes. The results showed that the wind speed during West Season was 0.33 m and were dominant to the East, while during East season was 0.91m from South-East to North-West, and then on transition period (March to May) was 1.08m from South-East to East. The results of those wind speed to the waves altitudes in Bitung waters is discussed in this paper© Pesisir pantai Kota Bitung merupakan salah satu pusat aktivitas ekonomi (misalnya pemanfaatan lahan dan eksploitasi sumberdaya) di Provinsi Sulawesi Utara. Aktivitas tersebut semakin hari semakin meningkat dan memiliki kecenderungan tidak terkontrol. Akibat dari keadaan tersebut, telah terjadi perubahan fenomena gelombang di perairan Bitung yang berdampak pada keberadaan daerah pesisir pantai di mana hal ini dapat mengganggu aktivitas pemanfaatan sumberdaya pesisir dan laut tersebut. Penelitian ini bertujuan untuk mengetahui variasi tinggi gelombang di perairan Bitung dengan menggunakan metode Svedrup Munk and Bretchsneider (SMB) yang biasa digunakan untuk peramalan tinggi gelombang signifikan. Hasil penelitian menunjukkan bahwa kecepatan angin pada Musim Barat sebesar 0,33 meter dan dominan ke arah Timur, sementara pada Musim Timur sebesar 0,91 meter dari arah Tenggara ke Barat Laut, serta pada Musim Peralihan (antara bulan Maret-Mei) adalah sebesar 1,08 meter dari arah Tenggara dan Timur. Pengaruh kecepatan angin tersebut terhadap gelombang laut di perairan Bitung dibahas dalam tulisan ini©

РАДИАЦИОННО СТОЙКОЕ КМОП СТАТИЧЕСКОЕ ОЗУ 16 МБИТ 1657РУ2У

2020 ◽  
Vol 96 (3s) ◽  
pp. 169-174
Author(s):  
Ю.М. Герасимов ◽  
Н.Г. Григорьев ◽  
А.В. Кобыляцкий ◽  
Я.Я. Петричкович
Keyword(s):  
Total Dose ◽  
Heavy Particles ◽  
Topological Features ◽  
Radiation Hardened ◽  
Latch Up

Рассматриваются архитектурные, схемотехнические и конструктивно-топологические особенности асинхронного радиационно стойкого ОЗУ 1657РУ2У емкостью 16 Мбит с организацией (1Мx16)/(2Mx8), изготавливаемого по коммерческой КМОП-технологии объемного кремния уровня 130 нм. СБИС ОЗУ нечувствительна к эффекту «защелкивания», имеет повышенные дозовую стойкость и сбоеустойчивость при воздействии отдельных ядерных частиц (ОЯЧ), протонов и нейтронов (ТЧ). The paper highlights architectural, schematic and topological features of the radiation hardened 16 Mbit CMOS SRAM with configurable organization 1Mx16/2Mx8, which is immune to latch-up and with improved total dose and heavy particles tolerance.

Mapping of landscape-morphological structure of the Northern-Western part of Anapa bay bar by digital high resolution aerial images

2017 ◽  
Vol 927 (9) ◽  
pp. 22-29
Author(s):  
V.I. Kravtsovа ◽  
E.R. Chalova
Keyword(s):  
High Resolution ◽  
Morphological Structure ◽  
Middle Part ◽  
Aerial Images ◽  
Medical Resource ◽  
Sea Waves ◽  
Coast Line ◽  
Waves Interaction ◽  
Account Due ◽  
Digital Landscape

Anapa bay bar is a valuable recreational-medical resource. Digital landscape-morphological mapping of its the Northern-Western part was created by digital aero survey materials for monitoring of its statement. Compiled maps show that in the Western part of region dune belt is degradated, front dune hills destroyed due to spreading of settlement Veselovka buildings to beach, and due to mass enactments carrying out at bay bar of lake Solenoe. Here it is necessary to decide the problem of defense from waves flooding by construction of artificial hills. The middle part of region, around Bugaz lagoon, is using for unregulated recreation of extreme sportsmen – windsurfing and kiting – with seasonal recreation in camping from tent-city and campers. Many short roads to sea beach, orthogonal to coast line, have been transformed to corridors of blowing and sea waves interaction to lagoon lowland with dune belt destroying. In the Eastern part of region, at Bugaz bay bar, dune belt is conserve, it changes under natural sea and wind processes action. At some places sea waves are erode windward front dune slope. Just everywhere sand accumulative trains are forming at leeward slope of front dune. Showed peculiarities of landscape morphological structure mast be taken in account due treatment of measures for bay bar defense and keeping.

scholarly journals Characteristics of Sea Waves Condition at The Northern and Eastern of Bintan Island within Period of 2015-2019

2021 ◽  
Vol 695 (1) ◽  
pp. 012038
Author(s):  
M. P. Suhana ◽  
L. F. Shafitri ◽  
R. D. Putra ◽  
A. H. Nugraha ◽  
C. J. Koenawan ◽  
...  
Keyword(s):  
Sea Waves

scholarly journals The scalar chemical potential in cosmological collider physics

2021 ◽  
Vol 2021 (2) ◽  
Author(s):  
Arushi Bodas ◽  
Soubhik Kumar ◽  
Raman Sundrum
Keyword(s):  
Particle Production ◽  
Chemical Potential ◽  
Direct Detection ◽  
Heavy Particle ◽  
Scalar Particle ◽  
Energy Scale ◽  
Fine Tuning ◽  
Tree Level ◽  
Heavy Particles ◽  
Non Gaussian

Abstract Non-analyticity in co-moving momenta within the non-Gaussian bispectrum is a distinctive sign of on-shell particle production during inflation, presenting a unique opportunity for the “direct detection” of particles with masses as large as the inflationary Hubble scale (H). However, the strength of such non-analyticity ordinarily drops exponentially by a Boltzmann-like factor as masses exceed H. In this paper, we study an exception provided by a dimension-5 derivative coupling of the inflaton to heavy-particle currents, applying it specifically to the case of two real scalars. The operator has a “chemical potential” form, which harnesses the large kinetic energy scale of the inflaton, $$ {\overset{\cdot }{\phi}}_0^{1/2}\approx 60H $$ ϕ ⋅ 0 1 / 2 ≈ 60 H , to act as an efficient source of scalar particle production. Derivative couplings of inflaton ensure radiative stability of the slow-roll potential, which in turn maintains (approximate) scale-invariance of the inflationary correlations. We show that a signal not suffering Boltzmann suppression can be obtained in the bispectrum with strength fNL ∼ $$ \mathcal{O} $$ O (0.01–10) for an extended range of scalar masses $$ \lesssim {\overset{\cdot }{\phi}}_0^{1/2} $$ ≲ ϕ ⋅ 0 1 / 2 , potentially as high as 1015 GeV, within the sensitivity of upcoming LSS and more futuristic 21-cm experiments. The mechanism does not invoke any particular fine-tuning of parameters or breakdown of perturbation-theoretic control. The leading contribution appears at tree-level, which makes the calculation analytically tractable and removes the loop-suppression as compared to earlier chemical potential studies of non-zero spins. The steady particle production allows us to infer the effective mass of the heavy particles and the chemical potential from the variation in bispectrum oscillations as a function of co-moving momenta. Our analysis sets the stage for generalization to heavy bosons with non-zero spin.

scholarly journals Fast Vacuum Fluctuations and the Emergence of Quantum Mechanics

2021 ◽  
Vol 51 (3) ◽  
Author(s):  
Gerard ’t Hooft
Keyword(s):  
Quantum Mechanics ◽  
Ground State ◽  
Quantum Interference ◽  
Direct Detection ◽  
Energy Levels ◽  
Vacuum Fluctuations ◽  
Heavy Particles ◽  
Evolving Systems ◽  
Gedanken Experiment ◽  
Classical Computer

AbstractFast moving classical variables can generate quantum mechanical behavior. We demonstrate how this can happen in a model. The key point is that in classically (ontologically) evolving systems one can still define a conserved quantum energy. For the fast variables, the energy levels are far separated, such that one may assume these variables to stay in their ground state. This forces them to be entangled, so that, consequently, the slow variables are entangled as well. The fast variables could be the vacuum fluctuations caused by unknown super heavy particles. The emerging quantum effects in the light particles are expressed by a Hamiltonian that can have almost any form. The entire system is ontological, and yet allows one to generate interference effects in computer models. This seemed to lead to an inexplicable paradox, which is now resolved: exactly what happens in our models if we run a quantum interference experiment in a classical computer is explained. The restriction that very fast variables stay predominantly in their ground state appears to be due to smearing of the physical states in the time direction, preventing their direct detection. Discussions are added of the emergence of quantum mechanics, and the ontology of an EPR/Bell Gedanken experiment.

scholarly journals Analysis of Dangerous Sea States in the Northwestern Mediterranean Area

2021 ◽  
Vol 9 (4) ◽  
pp. 422
Author(s):  
Alessio Innocenti ◽  
Miguel Onorato ◽  
Carlo Brandini
Keyword(s):  
Extreme Events ◽  
Mediterranean Area ◽  
Rayleigh Distribution ◽  
Surface Elevation ◽  
Wave Steepness ◽  
Sea Waves ◽  
Operational Forecasts ◽  
Long Time ◽  
Simulated Field

Extreme sea waves, although rare, can be notably dangerous when associated with energetic sea states and can generate risks for the navigation. In the last few years, they have been the object of extensive research from the scientific community that helped with understanding the main physical aspects; however, the estimate of extreme waves probability in operational forecasts is still debated. In this study, we analyzed a number of sea-states that occurred in a precise area of the Mediterranean sea, near the location of a reported accident, with the objective of relating the probability of extreme events with different sea state conditions. For this purpose, we performed phase-resolving simulations of wave spectra obtained from a WaveWatch III hindcast, using a Higher Order Spectral Method. We produced statistics of the sea-surface elevation field, calculating crest distributions and the probability of extreme events from the analysis of a long time-series of the surface elevation. We found a good matching between the distributions of the numerically simulated field and theory, namely Tayfun second- and third- order ones, in contrast with a significant underestimate given by the Rayleigh distribution. We then related spectral quantities like angular spreading and wave steepness to the probability of occurrence of extreme events finding an enhanced probability for high mean steepness seas and narrow spectra, in accordance with literature results, finding also that the case study of the reported accident was not amongst the most dangerous. Finally, we related the skewness and kurtosis of the surface elevation to the wave steepness to explain the discrepancy between theoretical and numerical distributions.

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