Time Scales of Sediment Focusing in Large Lakes as Revealed by Measurement of Fallout Cs-137

1990 ◽  
pp. 210-223 ◽  
Author(s):  
D. N. Edgington ◽  
J. A. Robbins
Keyword(s):  
Time Scales ◽  
Sediment Focusing ◽  
Large Lakes

LVSEM: Past Present and Future

1990 ◽  
Vol 48 (1) ◽  
pp. 364-365
Author(s):  
James B. Pawley
Keyword(s):  
Field Emission ◽  
Line Width ◽  
Time Scales ◽  
Silicon Oxide ◽  
Beam Current ◽  
High Brightness ◽  
High Beam ◽  
Fixed Charges ◽  
Beam Voltage ◽  
Deposited Metal

Past: In 1960 Thornley published the first description of SEM studies carried out at low beam voltage (LVSEM, 1-5 kV). The aim was to reduce charging on insulators but increased contrast and difficulties with low beam current and frozen biological specimens were also noted. These disadvantages prevented widespread use of LVSEM except by a few enthusiasts such as Boyde. An exception was its use in connection with studies in which biological specimens were dissected in the SEM as this process destroyed the conducting films and produced charging unless LVSEM was used.In the 1980’s field emission (FE) SEM’s came into more common use. The high brightness and smaller energy spread characteristic of the FE-SEM’s greatly reduced the practical resolution penalty associated with LVSEM and the number of investigators taking advantage of the technique rapidly expanded; led by those studying semiconductors. In semiconductor research, the SEM is used to measure the line-width of the deposited metal conductors and of the features of the photo-resist used to form them. In addition, the SEM is used to measure the surface potentials of operating circuits with sub-micrometer resolution and on pico-second time scales. Because high beam voltages destroy semiconductors by injecting fixed charges into silicon oxide insulators, these studies must be performed using LVSEM where the beam does not penetrate so far.

A Two Time Scales Turbulence Model of Turbulent Bubbly Flows

2013 ◽  
Vol 40 (3) ◽  
pp. 185-203
Author(s):  
Dhahri Maher ◽  
Bellakhel Ghazi ◽  
Chahed Jamel
Keyword(s):  
Time Scales ◽  
Turbulence Model ◽  
Bubbly Flows

Sparsity and Time Scales

1983 ◽  
Author(s):  
Joe H. Chow ◽  
Petar V. Kokotovic
Keyword(s):  
Time Scales

Agent-Based Computational Model

2017 ◽  
Author(s):  
Joshua M. Epstein
Keyword(s):  
Computational Model ◽  
Bounded Rationality ◽  
Time Scales ◽  
Spatially Explicit ◽  
Agent Based ◽  
Affective Component ◽  
Elementary Type ◽  
Social Component ◽  
Different Time Scales

This part describes the agent-based and computational model for Agent_Zero and demonstrates its capacity for generative minimalism. It first explains the replicability of the model before offering an interpretation of the model by imagining a guerilla war like Vietnam, Afghanistan, or Iraq, where events transpire on a 2-D population of contiguous yellow patches. Each patch is occupied by a single stationary indigenous agent, which has two possible states: inactive and active. The discussion then turns to Agent_Zero's affective component and an elementary type of bounded rationality, as well as its social component, with particular emphasis on disposition, action, and pseudocode. Computational parables are then presented, including a parable relating to the slaughter of innocents through dispositional contagion. This part also shows how the model can capture three spatially explicit examples in which affect and probability change on different time scales.

The genus Synura (Synurales, Synurophyceae) in small urban rivers of Nizhniy Novgorod

2017 ◽  
Vol 51 ◽  
pp. 57-70 ◽  
Author(s):  
E. S. Gusev ◽  
O. S. Perminova ◽  
N. A. Startseva ◽  
A. G. Okhapkin
Keyword(s):  
Taxonomic Composition ◽  
Morphological Data ◽  
Small Rivers ◽  
Urban Rivers ◽  
Large Lakes ◽  
Volga River ◽  
Volga River Basin ◽  
Means Of Transmission ◽  
Special Studies ◽  
The City

The latest special studies of the genus Synura in Russia were conducted in the 1970s. In the last decade, 14 new species of the genus were described based on molecular and morphological data. The total number of valid taxa of the genus has increased to 49. Only 18 taxa of Synura are known in Russia up to date, and the diver sity of the genus on this huge territory is strongly underestimated. Previous studies of the genus were focused mainly on large lakes or reservoirs. To reveal a more complete flora, it is necessary to include other habitats into account. Small urban rivers can be prospective habitats for interesting taxa including synuralean algae. Our study focuses on the taxonomic composition of the genus Synura in four small rivers in Nizhniy Novgorod (European Russia): Chyornaya, Levinka, Borzovka and Rzhavka. All the rivers flow in the city and fall under strong anthropogenic impact. The genus Synura was studied by means of transmission and scanning electron microscopy during 2011, 2012, 2014, 2015. In total, eight species and one form of Synura have been found: S. conopea, S. curtispina, S. echinulata, S. glabra, S. macropora, S. petersenii, S. spinosa f. spinosa, S. spinosa f. longispina, S. uvella. All nine taxa were observed in the river Chyornaya. Five taxa were found in the rivers Levinka, Borzovka and Rzhavka. One species (Synura conopea) is a new record to the flora of Russia. It was found in all studied rivers. Four taxa (S. conopea, S. glabra, S. macropora, S. spinosa f. longispina) are new records to the Middle Volga river basin.

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