scholarly journals Islands of the upper River Ob: morphometric characteristic, evolution and dynamics

2019 ◽  
pp. 80-90 ◽  
Author(s):  
G. B. Golubtsov ◽  
R. S. Chalov
Keyword(s):  
Channel Length ◽  
Morphological Aspect ◽  
Channel Stability ◽  
Channel Deformations ◽  
River Islands ◽  
Lateral Channel ◽  
Empirical Relations ◽  
Active Channel ◽  
Channel Type

The studied reach of the upper River Ob is quite complicated in the morphological aspect and characterized by very low channel stability and high discharge of sand load. Unconstrained conditions for lateral channel migration promotes active channel deformations not only at long-term scale, but also seasonally. Channel deformations contribute to the transformation of the channel and its morphodynamic type in time. The upper River Ob is intensively used as a water course, so any reorganization of the channel and river islands should be taken into account to support navigation. Morphometric and morphodynamic analysis of the islands made it possible to develop their morphological classification. Morphometric parameters of islands, being associated with the characteristics of the channel itself, are one of the main classification features. Empirical relations were obtained that link the dimensions (Lo, Bo) and shape of islands (Lo/Bo) with the morphodynamic channel type and its stability, the degree of branching of the channel (number of islands no per 1 km of channel length x). The features of island dynamics are also determined by the morphodynamic type of the channel and are associated with the morphometric characteristics of the islands themselves and their position in the channel, which determines the transgressive, regressive and transverse shift or their stable position in time.

Application of the method of mathematical modeling for forecasting channel deformations at the underwater crossing of the main pipeline

2020 ◽  
Vol 10 (6) ◽  
pp. 599-609
Author(s):  
Valery А. Gruzdev ◽  
◽  
Georgy V. Mosolov ◽  
Ekaterina A. Sabayda ◽  
◽  
...  
Keyword(s):  
Mathematical Modeling ◽  
Mathematical Model ◽  
Roughness Coefficient ◽  
Computational Domain ◽  
Channel Deformations ◽  
Geological Surveys ◽  
Kuban River ◽  
The Stability ◽  
Protective Structures

In order to determine the possibility of using the method of mathematical modeling for making long-term forecasts of channel deformations of trunk line underwater crossing (TLUC) through water obstacles, a methodology for performing and analyzing the results of mathematical modeling of channel deformations in the TLUC zone across the Kuban River is considered. Within the framework of the work, the following tasks were solved: 1) the format and composition of the initial data necessary for mathematical modeling were determined; 2) the procedure for assigning the boundaries of the computational domain of the model was considered, the computational domain was broken down into the computational grid, the zoning of the computational domain was performed by the value of the roughness coefficient; 3) the analysis of the results of modeling the water flow was carried out without taking the bottom deformations into account, as well as modeling the bottom deformations, the specifics of the verification and calibration calculations were determined to build a reliable mathematical model; 4) considered the possibility of using the method of mathematical modeling to check the stability of the bottom in the area of TLUC in the presence of man-made dumping or protective structure. It has been established that modeling the flow hydraulics and structure of currents, making short-term forecasts of local high-altitude reshaping of the bottom, determining the tendencies of erosion and accumulation of sediments upstream and downstream of protective structures are applicable for predicting channel deformations in the zone of the TLUC. In all these cases, it is mandatory to have materials from engineering-hydro-meteorological and engineering-geological surveys in an amount sufficient to compile a reliable mathematical model.

scholarly journals Precise Regulation of the Basal PKCγ Activity by DGKγ Is Crucial for Motor Coordination

2020 ◽  
Vol 21 (21) ◽  
pp. 7866
Author(s):  
Ryosuke Tsumagari ◽  
Kenta Maruo ◽  
Sho Kakizawa ◽  
Shuji Ueda ◽  
Minoru Yamanoue ◽  
...  
Keyword(s):  
Transient Receptor Potential ◽  
Motor Coordination ◽  
Receptor Potential ◽  
Motor Dysfunction ◽  
Interacting Protein ◽  
Lipid Kinase ◽  
Transient Receptor ◽  
Type 3 ◽  
Channel Type

Diacylglycerol kinase γ (DGKγ) is a lipid kinase to convert diacylglycerol (DG) to phosphatidic acid (PA) and indirectly regulates protein kinase C γ (PKCγ) activity. We previously reported that the basal PKCγ upregulation impairs cerebellar long-term depression (LTD) in the conventional DGKγ knockout (KO) mice. However, the precise mechanism in impaired cerebellar LTD by upregulated PKCγ has not been clearly understood. Therefore, we first produced Purkinje cell-specific DGKγ KO (tm1d) mice to investigate the specific function of DGKγ in Purkinje cells and confirmed that tm1d mice showed cerebellar motor dysfunction in the rotarod and beam tests, and the basal PKCγ upregulation but not PKCα in the cerebellum of tm1d mice. Then, the LTD-induced chemical stimulation, K-glu (50 mM KCl + 100 µM, did not induce phosphorylation of PKCα and dissociation of GluR2 and glutamate receptor interacting protein (GRIP) in the acute cerebellar slices of tm1d mice. Furthermore, treatment with the PKCγ inhibitor, scutellarin, rescued cerebellar LTD, with the phosphorylation of PKCα and the dissociation of GluR2 and GRIP. In addition, nonselective transient receptor potential cation channel type 3 (TRPC3) was negatively regulated by upregulated PKCγ. These results demonstrated that DGKγ contributes to cerebellar LTD by regulation of the basal PKCγ activity.

Short- and Long-Term Outcomes of Duodenal Switch with a Moderate Common Channel Length

2019 ◽  
Vol 229 (4) ◽  
pp. e74
Author(s):  
Alaa Sada ◽  
Wendy S. Reidt ◽  
Michael L. Kendrick ◽  
Elizabeth B. Habermann ◽  
Travis J. Mckenzie ◽  
...  
Keyword(s):  
Duodenal Switch ◽  
Channel Length ◽  
Common Channel ◽  
Long Term Outcomes ◽  
Short And Long Term

scholarly journals Meteorological controls on glacier mass balance: empirical relations suggested by measurements on glacier de Sarennes, France

1997 ◽  
Vol 43 (143) ◽  
pp. 131-137 ◽  
Author(s):  
C. Vincent ◽  
M. Vallon
Keyword(s):  
Mass Balance ◽  
Time Scale ◽  
Meteorological Data ◽  
Empirical Relation ◽  
Glacier Mass Balance ◽  
Glacier Surface ◽  
Surface Conditions ◽  
The Past ◽  
Empirical Relations

AbstractGlacial mass-balance reconstruction for a long-term time-scale requires knowledge of the relation between climate change and mass-balance fluctuations. A large number of mass-balance reconstructions since the beginning of the century are based on statistical relations between monthly meteorological data and mass balance. The question examined in this paper is: are these relationships reliable enough for long-term time-scale extrapolation? From the glacier de Sarennes long mass-balance observations series, we were surprised to discover large discrepancies between relations resulting from different time periods. The importance of the albedo in relation to ablation and mass balance is highlighted, and it is shown that it is impossible to ignore glacier-surface conditions in establishing the empirical relation between mass-balance fluctuations and climatic variation; to omit this parameter leads to incorrect results for mass-balance reconstruction in the past based on meteorological data.

Responses of Floods to Holocene Climatic Change in the Upper Mississippi Valley

1985 ◽  
Vol 23 (3) ◽  
pp. 287-300 ◽  
Author(s):  
James C. Knox
Keyword(s):  
Climatic Changes ◽  
Mississippi Valley ◽  
Channel Migration ◽  
Valley Bottom ◽  
Lateral Channel ◽  
History Of ◽  
And Storage ◽  
Recurrence Frequency ◽  
Large Floods

Dimensions of Holocene relict channels and sedimentological characteristics of point bars associated with these relict channels were used to reconstruct a Holocene history of long-term changes in magnitudes of 1.58-yr floods in Upper Mississippi Valley watersheds of southwestern Wisconsin. The reconstructed record of floods shows relatively large and persistent (nonrandom) departures from contemporary long-term average flood magnitudes. The flood history indicates climatic changes that are broadly similar to climatic changes indicated from fossil pollen in the same region. The Holocene floods ranged from about 10–15% larger to 20–30% smaller than contemporary floods of the same recurrence frequency. Large floods were characteristic between about 6000 – 4500 and 3000 – 2000 yr B.P., and during a brief interval after 1200 yr B.P. Small floods were common between about 8000 – 6500, 4500 – 3000, and 2000 – 1200 yr B.P. These fluvial responses were found to be closely associated with a long-term episodic mobility and storage of sediments in the Wisconsin watersheds. During periods of relatively large floods, relatively rapid lateral channel migration either reworked or removed extensive tracts of valley bottom alluvium. In contrast, during periods of relatively small floods, relatively slow lateral channel migration is apparent and the channel and floodplain system appear to have been relatively stable.

scholarly journals The analysis of the channel deformations in the lower pool of the Votkinsk reservoir

2020 ◽  
Vol 163 ◽  
pp. 06005
Author(s):  
Svetlana Dvinskikh ◽  
Dmitriy Klimenko ◽  
Olga Larchenko ◽  
Konstantin Minkin
Keyword(s):  
Discharge Rate ◽  
Water Discharge ◽  
Lower Pool ◽  
Hydroelectric Station ◽  
Hydrological Regime ◽  
Growth Cycle ◽  
Low Flow ◽  
Channel Deformations ◽  
Sand And Gravel

The sand and gravel mix is mined at the Votkinsk reservoir. This leads to horizontal and vertical channel deformations. To study them, we examined the Golyanovsk section of the sand and gravel mix (SAGM) field in the lower pool of the reservoir. We used the channel surveys made in 2012-2016, 2018 and 2019 as the source of cartographic materials. The lower pool section of the Votkinsk hydroelectric complex, within which the Golyanovsk SAGM field is located, is characterized by a fully regulated effluent and an unsteady hydrological regime. Therefore, the hydrological regime of the considered area is particularly complex and depends on the water consumption in the alignment of the Votkinsk hydroelectric station and the level of the Nizhnekamsk reservoir. The average long-term water discharge for the navigation period is 2200 m3/s, the average long-term minimum monthly discharge rate is 1800 m3/s. The field survey of the area was carried out during the low water period in accordance. This period was characterized by minimum levels at around 64.79-65.24 m BS. The water discharge varied between 1720-1780 m3/s. With this flow, the Kama River is characterized by fairly low flow speed: no more than 1.29 m/s on the rod and 0.2-0.5 m/s on the riverbank shallows. The channel deposits are represented by pebble-gravel soils of various sizes. Throughout 2001-2019 an increase in the particle size has occurred. This is due to the change of the channel-forming process from accumulation to erosion. Horizontal deformations are represented by the reformation of the riverbanks, vertical – by accumulation and erosion of bottom. Drawdown levels are the result of natural deformations of the channel. According to the monitoring data, the duration of the “drawdown – growth” cycle is 2-3 years. The duration of the “drawdown – growth” cycle is 2-3 years.

Short-term and long-term memory operations of synapse thin-film transistors using an In–Ga–Zn–O active channel and a poly(4-vinylphenol)–sodium β-alumina electrolytic gate insulator

RSC Advances ◽  
2016 ◽  
Vol 6 (58) ◽  
pp. 52913-52919 ◽  
Author(s):  
Yeo-Myeong Kim ◽  
Eom-Ji Kim ◽  
Won-Ho Lee ◽  
Ji-Young Oh ◽  
Sung-Min Yoon
Keyword(s):  
Thin Film ◽  
Thin Film Transistors ◽  
Thin Film Transistor ◽  
Gate Insulator ◽  
Long Term Memory ◽  
Short Term ◽  
Term Memory ◽  
New Type ◽  
Active Channel

In this work, we proposed new type of synapse device with thin-film transistor (TFT) configuration using an In–Ga–Zn–O (IGZO) as active channel and a poly(4-vinylphenol)–sodium β-alumina (PVP–SBA) as gate insulator for emulating brain-like functions.

scholarly journals Planform river channel perturbations resulting from active landsliding in the High Himalaya of Bhutan

2020 ◽  
Author(s):  
Larissa de Palézieux ◽  
Kerry Leith ◽  
Simon Loew
Keyword(s):  
Early Period ◽  
Pink Noise ◽  
River Channels ◽  
Channel Migration ◽  
Stream Power ◽  
Study Region ◽  
Term Evolution ◽  
Lateral Channel ◽  
Mountainous Landscapes

Abstract. Large creeping landslides are persistent features in mountainous landscapes. Evaluating the long-term evolution of these features and associated present-day hazards is however difficult. We use a Fourier transform to characterize planform channel sinuosity and find that the amplitude at given wavelengths follows the power law of pink noise (1 / fnoiseα) with an exponent of α = 1.1, which is consistent with a fractal distribution. This allows us to distinguish local landslide perturbations from the background sinuosity of the unperturbed channels. In order to quantify the interaction of landslides with river channels, we use a new metric for landslide-induced channel offset, which allows us to identify exceptional amplitudes associated with landslide activity. We find that 83 % of the 226 mapped large creeping landslides in the High Himalaya of Bhutan have generated lateral channel migration in the direction of the landslide displacement. Assuming landslide initiation is associated with knickpoint propagation, our derived stream power normalized rates of landslide-induced channel offset range from 2 · 10−1 to 2 · 10−2 m−0.9. These rates are consistent with an early period of relatively rapid landslide displacement followed by a long period of stabilization, and finally, a gradual acceleration of more mature landslides. Assuming constant bedrock erodibility, displacement rates derived from the landslides in our study region may provide inside into the evolution of large creeping landslides over a period of 1 Myr.

scholarly journals Long-Term Impacts of Forest Road Crossings of Wetlands in Pennsylvania

1997 ◽  
Vol 14 (3) ◽  
pp. 109-116
Author(s):  
Robert L. Miller ◽  
David R. Dewalle ◽  
Robert P. Brooks ◽  
James C. Finley
Keyword(s):  
Basal Area ◽  
Public Lands ◽  
Land Ownership ◽  
Riparian Wetlands ◽  
Channel Stability ◽  
Forest Road ◽  
The Road ◽  
Northwest Region ◽  
Ownership Types

Abstract A survey was conducted of 70 forest road crossings of wetlands in Pennsylvania to describe the characteristics of these crossings and to evaluate the long-term impacts of the crossings on habitat quality, channel stability, vegetation, wetland width and channel sediment embeddedness above and below the crossings. Sampling was stratified into five physiographic provinces and three land ownership types. Difficulty was encountered in identifying sites for the survey especially in the glaciated northwest region and on private and industry lands. The majority of samples obtained were from unglaciated provinces and public lands. Wetlands identified were primarily linear riparian wetlands associated with first- and second-order channels. Crossings encountered were largely gravel-covered culverts used to provide access to adjacent management areas. Only 35 of 814 comparisons of mean environmental conditions above and below the wetland crossings were found to be significant. Significant differences that did occur suggested that stream bed fine sediment levels were higher, basal area lower, and herbaceous cover higher in the immediate vicinity of some crossings simply due to the presence of the road and fill banks. North. J. Appl. For. 14(3):109-116.

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