scholarly journals Acoustic Eaton lens array and its fluid application

2017 ◽  
Vol 31 (08) ◽  
pp. 1750081 ◽  
Author(s):  
Sang-Hoon Kim ◽  
Pham-Van Sy ◽  
Mukunda P. Das
Keyword(s):  
Numerical Simulation ◽  
Shallow Water ◽  
Sea Level ◽  
Tsunami Wave ◽  
Impedance Matching ◽  
Stop Band ◽  
Lens Array ◽  
Entire Process ◽  
Rounded Form ◽  
Tsunami Model

A principle of an acoustic Eaton lens array and its application as a removable tsunami wall is proposed theoretically. The lenses are made of expandable rubber pillars or balloons and create a stop-band by rotating the incoming tsunami wave and reduce the pressure by canceling each other. The diameter of each lens is larger than the wavelength of the tsunami near the coast, that is, order of a kilometer. The impedance matching on the border of the lenses results in a little reflection. Before a tsunami, the balloons are buried underground in shallow water near the coast in folded or rounded form. Upon sounding of the tsunami alarm, water and air are pumped into the pillars, which expand and erect the wall above the sea level within a few hours. After the tsunami, the water and air are released from the pillars, which are then buried underground for reuse. Electricity is used to power the entire process. A numerical simulation with a linear tsunami model was carried out.

NUMERICAL SIMULATION OF TWO-PHASES FLOW ON PUMPS INLET SYSTEM FOR SHALLOW WATER

2019 ◽  
Author(s):  
Livio Sebastián Maglione ◽  
Guillermo Muschiatto ◽  
Raúl Alberto DEAN
Keyword(s):  
Numerical Simulation ◽  
Shallow Water ◽  
Inlet System ◽  
Two Phases ◽  
Two Phases Flow

Sedimentology, faunal content and pollen record of Middle Pleistocene palustrine and lagoonal sediments from the Peri-Adriatic basin, Abruzzi, eastern central Italy

2016 ◽  
Vol 86 (3) ◽  
pp. 359-372 ◽  
Author(s):  
Pierluigi Pieruccini ◽  
Claudio Di Celma ◽  
Federico Di Rita ◽  
Donatella Magri ◽  
Giorgio Carnevale ◽  
...  
Keyword(s):  
Shallow Water ◽  
Sea Level ◽  
Central Italy ◽  
Freshwater Wetlands ◽  
Middle Pleistocene ◽  
Pollen Record ◽  
Vegetation Development ◽  
Oxygen Isotope Stage ◽  
Open Forest ◽  
Facies Succession

AbstractA 25 m-thick outcrop section exposed at Torre Mucchia, on the sea-cliff north of Ortona, eastern central Italy, comprises a rare Middle Pleistocene succession of shallow-water and paralic sediments along the western Adriatic Sea. An integrated study of the section, including facies and microfacies analyses, and characterization of paleobiological associations (mollusks, fishes, ostracods, foraminifers and pollen), enable a detailed reconstruction of the paleoenvironmental and paleoclimatic conditions during deposition. The shallow-water deposits include a transgressive, deepening- and fining-upward shoreface to offshore-transition facies succession overlain by a regressive shoreface-foreshore sandstone body with an erosive base and a rooted and pedogenically altered horizon at the top that imply deposition during sea-level fall. This forced regressive unit is overlain by paralic strata forming a transgressive succession comprising palustrine carbonates and back-barrier lagoonal mudstones. The palustrine carbonates exhibit some of the typical features encountered in palustrine limestones deposited within seasonal freshwater wetlands (marl prairies). Following the sea-level rising trend, the freshwater marshes were abruptly replaced by a barrier-lagoon system that allowed deposition of the overlying mud-rich unit. Within these deposits, the faunal assemblages are consistent with a low-energy brackish environment characterized by a relatively high degree of confinement. The pollen record documents the development of open forest vegetation dominated by Pinus and accompanied by a number of mesophilous and thermophilous tree taxa, whose composition supports a tentative correlation with Marine Oxygen Isotope Stage 17. The new pollen record from Torre Mucchia improves our understanding of the vegetation development in the Italian Peninsula during the Middle Pleistocene and sheds new light on the role played by the most marked glacial periods in determining the history of tree taxa.

RECENT DEVELOPMENTS IN THE NUMERICAL SIMULATION OF SHALLOW WATER EQUATIONS II: TEMPORAL DISCRETIZATION

1994 ◽  
Vol 04 (04) ◽  
pp. 533-556 ◽  
Author(s):  
V. AGOSHKOV ◽  
E. OVCHINNIKOV ◽  
A. QUARTERONI ◽  
F. SALERI
Keyword(s):  
Numerical Simulation ◽  
Finite Element ◽  
Finite Difference ◽  
Shallow Water ◽  
Shallow Water Equations ◽  
Numerical Results ◽  
Finite Difference Approximation ◽  
Difference Approximation ◽  
Recent Developments ◽  
Numerical Approaches

This paper deals with time-advancing schemes for shallow water equations. We review some of the existing numerical approaches, propose new schemes and investigate their stability. We present numerical results obtained using the time-advancing schemes proposed, with finite element and finite difference approximation in space variables.

scholarly journals Upper Arenig trilobite biostratigraphy and sea-level changes at Lynna River near Volkhov, Russia

2003 ◽  
Vol 50 ◽  
pp. 105-114
Author(s):  
T. Hansen ◽  
A.T. Nielsen
Keyword(s):  
Shallow Water ◽  
Sea Level Rise ◽  
Sea Level ◽  
Abundance Ratio ◽  
Basal Part ◽  
Sea Level Changes ◽  
Faunal Turnover ◽  
Lower Ordovician ◽  
Water Conditions ◽  
Tentative Interpretation

Over 5000 trilobites have been collected from Lower Ordovician rocks exposed at the Lynna River in the Volkhov region, east of St. Petersburg, Russia. Bed-by-bed sampling has been carried out through the upper part of Volkhov Formation (top of Jeltiaki Member and the entire Frizy Member), the Lynna Formation and the basal part of the Obukhovo Formation. This interval, which is 7.5 metres thick, correlates with the upper part of the Arenig Series, and presumably even ranges into the very base of the Llanvirn. A preliminary biostratigraphical investigation of top Jeltiaki Member (BIIβ), Frizy Member (BIIγ) and basal Lynna Formation (BIIIα) reveals a rather continuous faunal turnover lacking sharp boundaries, and the biostratigraphical zonation (BIIβ–BIIIα) is primarily defined by the index trilobite taxa. The trilobite ranges are generally in agreement with the pattern described by Schmidt in 1907. The abundance ratio between Asaphus and the ptychopygids seems to be related to changes in relative sea level with Asaphus preferring the most shallow water conditions. A tentative interpretation of sea-level changes suggests an initial drowning at the base of BIIγ, immediately followed by a lowstand that in turn was succeeded by a moderate sea-level rise and then a significant fall. The last marks the BIIγ/BIIIα boundary. Correlation with sections in Scandinavia suggests that the basal part of BIIγ is strongly condensed.

A mathematical analysis of tsunami generation in shallow water due to seabed deformation

2011 ◽  
Vol 141 (3) ◽  
pp. 551-608 ◽  
Author(s):  
Tatsuo Iguchi
Keyword(s):  
Velocity Field ◽  
Shallow Water ◽  
Water Wave ◽  
Initial Velocity ◽  
Tsunami Generation ◽  
Wave Problem ◽  
Initial Displacement ◽  
Water Wave Problem ◽  
Submarine Earthquakes ◽  
Tsunami Model

In numerical computations of tsunamis due to submarine earthquakes, it is frequently assumed that the initial displacement of the water surface is equal to the permanent shift of the seabed and that the initial velocity field is equal to zero and the shallow-water equations are often used to simulate the propagation of tsunamis. We give a mathematically rigorous justification of this tsunami model starting from the full water-wave problem by comparing the solution of the full problem with that of the tsunami model. We also show that, in some cases, we have to impose a non-zero initial velocity field, which arises as a nonlinear effect.

Regression derivatives and their application for registration of a tsunami wave arrival by sea-level records

2019 ◽  
pp. 28-41
Author(s):  
Сергей Мартикович Агаян ◽  
Шамиль Рафекович Богоутдинов ◽  
Ольга Васильевна Иванченко ◽  
Дмитрий Альфредович Камаев
Keyword(s):  
Time Series ◽  
Data Processing ◽  
Sea Level ◽  
Discrete Time ◽  
Mathematical Analysis ◽  
Visual Analysis ◽  
Tsunami Wave ◽  
Information Support ◽  
Discrete Time Series ◽  
Wave Arrival

Структура дискретного временного ряда тесно связана со свойствами процесса, который он описывает. В рамках дискретного математического анализа имеется несколько подходов к анализу структуры дискретных рядов: геометрические меры, динамические коридоры и концепция тренда. Для дискретного временного ряда, заданного в общем случае на нерегулярной сетке, с характером тренда тесным образом связана регрессионная производная: области ее положительного (отрицательного) значения соответствуют возрастающим (убывающим) трендам, а границы между ними - экстремумам. В настоящей работе исследуются возможности применения методов дискретного математического анализа для разработки процедуры регистрации вступления волны цунами по оперативным данным измерения уровня моря. The research addresses the possibility of application of the methods of discrete mathematical analysis to develop a procedure for recording tsunami wave arrival on the base of the operational data for measuring sea level. As a basis for constructing a tsunami wave registration procedure, this research uses a schematization of the actions of the oceanographer on-duty during visual analysis of the sea level records. The task of automatic registration of a tsunami wave by sea level recording arises in various situations of information support of the oceanographer on duty. Requirements for the processing of sea level records depend on the situation. The structure of a discrete time series is closely related to the properties of the described process. As part of the discrete mathematical analysis, there are several approaches to the analysis of the structure of discrete series: geometric measures, dynamic corridors and the trend concept. For a discrete time series, given in the general case on an irregular grid, the regression derivative is closely related to the nature of the trend: the areas of its positive (negative) values correspond to the increasing (decreasing) trends, and the boundaries between them are extremes. The content of this research is a presentation of data processing techniques using regression derivatives, constructing data processing procedures based on derivatives, as well as a demonstration of their applicability to the problem of recording tsunami wave arrival according to the measuring of sea level.

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