scholarly journals Causes and effects of morphological changes of the regulated channel of the river Toplica

2005 ◽  
pp. 109-125
Author(s):  
Vojislav Djekovic ◽  
Grozdana Gajic
Keyword(s):  
Cross Section ◽  
Morphological Changes ◽  
Natural Process ◽  
Morphological Development ◽  
Field Type ◽  
General Stability ◽  
Urbanized Areas ◽  
Selection Of ◽  
Taking Care

The regulation of small torrential watercourses outside the urbanized areas is often based on the so-called field type of regulation. In the selection of this concept, after the regulation works, the new channel is left to the natural process of the morphological formation of the water cross-section taking care not to disturb the general stability of the regulated channel. We present the process of morphological development of the regulated channel of the river Toplica, tributary of the river Kolubara, in the period 1982-2004 i.e. from immediately after the regulation works to the present day.

scholarly journals Vegetation as one of the factors of morphological changes in regulated riverbeds

2003 ◽  
pp. 113-118
Author(s):  
Vojislav Djekovic ◽  
Ratko Ristic
Keyword(s):  
Water Level ◽  
Cross Section ◽  
Dynamic Characteristics ◽  
Vegetation Cover ◽  
Strong Influence ◽  
Morphological Changes ◽  
Morphological Development ◽  
Experimental Section ◽  
Level Recorder ◽  
Water Level Recorder

Morphological changes of natural and regulated riverbeds have strong influence on economy development in the zones close to the riverbanks. Understanding of these processes and possibility of prediction are the basis for safe usage of areas close to the riverbanks. River Toplica bed regulation is chosen as experimental section for investigation of morphological changes. Steady survey profiles were established after finishing the regulation works, as basic points for further observations of changes in the riverbed. Water level recorder was positioned a few hundred meters down the stream. Main causes for morphological development along the riverbed were determined on the basis of changes in geometry of cross-section profiles and water level. Influence of vegetation cover in the riverbanks and hydro-dynamic characteristics of the flow have been analyzed.

Large Area DPB Free (111) β-SiC Thick Layer Grown on (0001) α-SiC Nominal Surfaces by the CF-PVT Method

2005 ◽  
Vol 483-485 ◽  
pp. 225-228 ◽  
Author(s):  
Didier Chaussende ◽  
Laurence Latu-Romain ◽  
Laurent Auvray ◽  
M. Ucar ◽  
Michel Pons ◽  
...  
Keyword(s):  
Growth Rate ◽  
Optical Microscopy ◽  
Cross Section ◽  
Thick Layer ◽  
Vapour Transport ◽  
Large Area ◽  
Continuous Feed ◽  
Heating Up ◽  
Cross Section Geometry ◽  
Selection Of

Thick (111) oriented β-SiC layers have been grown by hetero-epitaxy on a (0001) a-SiC substrate with the Continuous Feed-Physical Vapour Transport (CF-PVT) method. The growth rate was 68 µm/h at a pressure of 2 torr and a temperature of 1950°C. The nucleation step of the β-SiC layer during the heating up of the process was studied in order to manage first the a to b heteropolytypic transition and second the selection of the b-SiC orientation. With a adapted seeding stage, we grew a 0.4mm thick layer almost free of Double Positioning Boundaries on a 30mm diameter sample. First observations of the layer by cross-polarised optical Microscopy are presented both in planar view and in cross section geometry.

scholarly journals Use of factors of photoperiod duration and growth regulators to increase the yield of mixoploid plants in C0 generation in meadow clover (Trifolium pratense L.)

2021 ◽  
Vol 901 (1) ◽  
pp. 012024
Author(s):  
M Yu Novoselov ◽  
L V Drobysheva ◽  
O A Starshinova
Keyword(s):  
Apical Dominance ◽  
High Efficiency ◽  
Trifolium Pratense ◽  
Morphological Changes ◽  
Continuous Illumination ◽  
Experimental Plant ◽  
Trifolium Pratense L ◽  
Naphthylacetic Acid ◽  
Spraying Plants ◽  
Selection Of

Abstract It has been established that the studied mode of cultivation of meadow clover under controlled environmental conditions, with continuous illumination with an intensity of 18-20 thousand lux and a constant temperature of + 25 °C, causes significant morphological changes in meadow clover. Compared with the optimal (control), the proposed growing regime halves the development time of plants and by the same amount reduces the severity of morphological traits, while simultaneously causing apical dominance in 54% of plants. Spraying plants with phytohormone in the form of naphthylacetic acid in all studied concentrations reduced the growing season by 4-8 days and increased pollen fertility by 8-10%. The optimal concentration of naphthylacetic acid (NLA) was revealed to suppress the growth of secondary meristems in meadow clover under the conditions of an experimental plant growing regime. The most significant effect on the manifestation of apical dominance was shown by the use of naphthylacetic acid at a concentration of 0.001%. The combined use of the proposed growing regime and treatment with naphthylacetic acid at a concentration of 0.001% increased the yield of plants with apical dominance from 54.5% to 76%. The developed method has shown high efficiency for the creation of tetraploid forms of meadow clover. When growing clover C0 generation and selection of mixoploid plants, the yield of mixoploids increased 5.4 times, the survival rate of seedlings increased by 21%, the time to obtain one generation and the selection of mixoploids decreased by 58%.

Dynamics and 2D temperature distribution of plasma obtained by femtosecond laser-induced breakdown

2021 ◽  
Author(s):  
Afaque M. Hossain ◽  
Martin Ehrhardt ◽  
Martin Rudolph ◽  
Dmitry V Kalanov ◽  
Pierre Lorenz ◽  
...  
Keyword(s):  
Femtosecond Laser ◽  
Morphological Changes ◽  
Exponential Dependence ◽  
Morphological Development ◽  
Initial State ◽  
Toroidal Plasma ◽  
Velocity Gradients ◽  
Baroclinic Torque ◽  
Laser Induced Breakdown ◽  
High Pressure Zone

Abstract Recently, plasma produced by focusing femtosecond laser in gases has been introduced as an etching tool in materials processing. Proper control of the plasma in this application necessitates the apt understanding of the different morphological features of the plasma. In this contribution we show that, the plasma produced in air goes through several stages of morphological development – from ellipsoidal to spherical to toroidal plasma, whereas in argon, axial compression of an ellipsoidal plasma is observed. To explain this dissimilarity, we have quantified the temperature by emission spectroscopy (Planck analysis with Wien’s approximation). The evolution of temperature shows a triple exponential dependence in time which can be correlated with different stages of morphological changes of the plasma. Open Source Field Operation and Manipulation (OpenFOAM) simulations using experimentally determined temperature values show that – (i) the reverse pressure gradient propagates radially inwards and compresses the plasma in both air and argon and forms a localized high pressure zone at the center that generates a secondary pressure wave in air, but not in argon, and (ii) the baroclinic torque that is generated because of the Richtmyer-Meshkov instability, dominates the rate of vorticity in air, whereas effects of flow compressibility and velocity gradients dominate the vortices in argon. Knowledge of the initial state and the dynamics of the subsequent stages of the plasma formation can be utilized for control and optimization of laser-induced plasma applications.

The nuclear pore complex, nuclear transport, and apoptosisThis paper is one of a selection of papers published in this Special Issue, entitled The Nucleus: A Cell Within A Cell.

2006 ◽  
Vol 84 (3-4) ◽  
pp. 279-286 ◽  
Author(s):  
Birthe Fahrenkrog
Keyword(s):  
Nuclear Pore Complex ◽  
Nuclear Import ◽  
Morphological Changes ◽  
Nuclear Transport ◽  
Nuclear Pore ◽  
Simple Fact ◽  
Cell Death Program ◽  
A Cell ◽  
Cellular Compartments ◽  
Selection Of

The nuclear pore complex (NPC) is the sole gateway between the nucleus and the cytoplasm of interphase eukaryotic cells, and it mediates all trafficking between these 2 cellular compartments. As such, the NPC and nuclear transport play central roles in translocating death signals from the cell membrane to the nucleus where they initiate biochemical and morphological changes occurring during apoptosis. Recent findings suggest that the correlation between the NPC, nuclear transport, and apoptosis goes beyond the simple fact that NPCs mediate nuclear transport of key players involved in the cell death program. In this context, the accessibility of key regulators of apoptosis appears to be highly modulated by nuclear transport (e.g., impaired nuclear import might be an apoptotic trigger). In this review, recent findings concerning the unexpected tight link between NPCs, nuclear transport, and apoptosis will be presented and critically discussed.

The effects of two-body correlations in 16O on the bremsstrahlung weighted cross section

1980 ◽  
Vol 58 (8) ◽  
pp. 1099-1118
Author(s):  
D. Duplain ◽  
B. Goulard
Keyword(s):  
Cross Section ◽  
Cluster Expansion ◽  
Second Order ◽  
Body Density ◽  
The One ◽  
Selection Of

The bremsstrahlung weighted cross section σ−1, is calculated for,16O using the linked cluster expansion to introduce two-body correlations. All diagrams up to second order in the G-matrix are calculated. A particular choice is made among these diagrams which are grouped in order to preserve the normalization of the one-body density and of the two-body density. This selection of diagrams is shown to be consistent with an expansion in the number of hole-lines. The correlated value obtained in this way, σ−1 = 14.99 mb, is close to the experimental value σ−1 = 15.10 mb although the calculation might still be subject to improvement.

scholarly journals Study of fetal and postnatal morphological development of the brain sulci

2013 ◽  
Vol 11 (1) ◽  
pp. 1-11 ◽  
Author(s):  
Koshiro Nishikuni ◽  
Guilherme Carvalhal Ribas
Keyword(s):  
Morphological Changes ◽  
Fetal Brain ◽  
Postnatal Period ◽  
Postnatal Life ◽  
Morphological Development ◽  
Fetal Life ◽  
Brain Hemispheres ◽  
Collateral Sulcus ◽  
Fetal Brain Development ◽  
The Brain

Object The surface of the developing fetal brain undergoes significant morphological changes during fetal growth. The purpose of this study was to evaluate the morphological development of the brain sulci from the fetal to the early postnatal period. Methods Two hundred fourteen brain hemispheres from 107 human brain specimens were examined to evaluate the timing of sulcal formation, from its appearance to its complete development. These brains were obtained from cadavers ranging in age from 12 weeks of gestation to 8 months of postnatal life. Results The order of appearance of the cerebral sulci, and the number and percentages of specimens found in this study were as follows: longitudinal cerebral fissure at 12 weeks (10/10, 100%); callosal sulcus at 12 weeks (10/10, 100%); hippocampal sulcus at 15 weeks (7/10, 70%); lateral sulcus at 17 weeks (20/22, 90.9%); circular insular sulcus at 17 weeks (18/22, 81.8%); olfactory sulcus at 17 weeks (18/22, 81.8%); calcarine sulcus at 17 weeks (14/22, 63.6%); parietooccipital sulcus at 17 weeks (11/22, 50%); cingulate sulcus at 19 weeks (16/20, 80%); central sulcus at 21 weeks (22/38, 57.9%); orbital sulcus at 22 weeks (9/16, 56.2%); lunate sulcus at 24 ± 2 weeks (12/16, 75%); collateral sulcus at 24 ± 2 weeks (8/16, 50%); superior frontal sulcus at 25 ± 2 weeks (5/6, 83.3%); rhinal sulcus at 25 ± 2 weeks (3/6, 50%); precentral sulcus at 26 ± 3 weeks (2/4, 50%); postcentral sulcus at 26 ± 3 weeks (2/4, 50%); superior temporal sulcus at 26 ± 3 weeks (2/4, 50%); central insular sulcus at 29 ± 2 weeks (4/4, 100%); intraparietal sulcus at 29 ± 2 weeks (2/4, 50%); paraolfactory sulcus at 29 ± 2 weeks (2/4, 50%); inferior frontal sulcus at 30 ± 3 weeks (2/4, 50%); transverse occipital sulcus at 30 ± 3 weeks (2/4, 50%); occipitotemporal sulcus at 30 ± 3 weeks (2/4, 50%); marginal branch of the cingulate sulcus at 30 ± 3 weeks (2/4, 50%); paracentral sulcus at 30 ± 3 weeks (2/4, 50%); subparietal sulcus at 30 ± 3 weeks (2/4, 50%); inferior temporal sulcus at 31 ± 3 weeks (3/6, 50%); transverse temporal sulcus at 33 ± 3 weeks (6/8, 75%); and secondary sulcus at 38 ± 3 weeks (2/4, 50%). Conclusions The brain is subjected to considerable morphological changes throughout gestation. During fetal brain development the cortex begins to fold in, thereby increasing the cortical surface. All primary sulci are formed during fetal life. The appearance of each sulcus follows a characteristic timing pattern, which may be used as one of the reliable guides pertinent to gestational age and normal fetal development.

scholarly journals Pervasive White Matter Fiber Degeneration in Ischemic Stroke

Stroke ◽  
2020 ◽  
Vol 51 (5) ◽  
pp. 1507-1513 ◽  
Author(s):  
Natalia Egorova ◽  
Thijs Dhollander ◽  
Mohamed Salah Khlif ◽  
Wasim Khan ◽  
Emilio Werden ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
White Matter ◽  
Cross Section ◽  
Corticospinal Tract ◽  
Brain Volume ◽  
Morphological Changes ◽  
Axonal Loss ◽  
Fiber Density ◽  
Whole Brain ◽  
Brain Volume Loss

Background and Purpose— We examined if ischemic stroke is associated with white matter degeneration predominantly confined to the ipsi-lesional tracts or with widespread bilateral axonal loss independent of lesion laterality. Methods— We applied a novel fixel-based analysis, sensitive to fiber tract–specific differences within a voxel, to assess axonal loss in stroke (N=104, 32 women) compared to control participants (N=40, 15 women) across the whole brain. We studied microstructural differences in fiber density and macrostructural (morphological) changes in fiber cross-section. Results— In participants with stroke, we observed significantly lower fiber density and cross-section in areas adjacent, or connected, to the lesions (eg, ipsi-lesional corticospinal tract). In addition, the changes extended beyond directly connected tracts, independent of the lesion laterality (eg, corpus callosum, bilateral inferior fronto-occipital fasciculus, right superior longitudinal fasciculus). Conclusions— We conclude that ischemic stroke is associated with extensive neurodegeneration that significantly affects white matter integrity across the whole brain. These findings expand our understanding of the mechanisms of brain volume loss and delayed cognitive decline in stroke.

Sign in / Sign up

Export Citation Format

Share Document