scholarly journals Influence of the channel roughness factor change on the maximal design levels of a small watercourse in a given river cross (Nelma river example)

2021 ◽  
pp. 74-80
Author(s):  
N. Akhmedova ◽  
V. Naumov
Keyword(s):  
Roughness Factor

Сопротивление русла потоку, которое принято характеризовать коэффициентом шероховатости, значительно влияет на основные гидравлические характеристики водного объекта при оценке его пропускной способности. Любой малый водоток имеет свои особенности, так как достаточно быстро реагирует на изменения, происходящие на всей площади водосбора, поэтому требует отдельного исследования. В настоящей статье мы предприняли попытку рассчитать значение коэффициента шероховатости в половодье по данным наблюдений для р. Нельма. Установлено, что справочный коэффициент шероховатости дает завышенные значения максимального уровня воды. Расчеты показали, что с увеличением числа Фруда коэффициент шероховатости русла понижался. Полученные нами результаты могут быть использованы при разработке и уточнении методов определения основных расчетных гидрологических характеристик водотоков, устанавливаемых в целях безопасного использования прилегающих к ним территорий.

A method for measuring the surface roughness factor of metals

1972 ◽  
Vol 12 (5) ◽  
pp. 463-468 ◽  
Author(s):  
M. Pražák ◽  
B. Eremiás
Keyword(s):  
Surface Roughness ◽  
Roughness Factor

APPARENT DENSITIES AND INTERNAL SURFACE AREAS OF SELECTED CARBON BLACKS

1962 ◽  
Vol 40 (2) ◽  
pp. 184-188 ◽  
Author(s):  
P. L. Walker Jr. ◽  
W. V. Kotlensky
Keyword(s):  
Surface Area ◽  
Pore Diameter ◽  
Internal Surface ◽  
Nitrogen Adsorption ◽  
Roughness Factor ◽  
Internal Surface Area ◽  
Average Pore ◽  
Carbon Blacks ◽  
Surface Areas ◽  
Nitrogen Adsorption Isotherms

It is shown that the open pore volume within carbon blacks can be calculated from nitrogen adsorption isotherms (77°K) on the blacks. From this volume and a helium density, the apparent density of a black can be calculated. Other properties of the blacks which then can be calculated are free surface area, internal surface area, surface roughness factor, and the average pore diameter of the internal surface. These data are presented for five selected carbon blacks.

Effect of the roughness factor on the surface oxidation of ruthenium catalysts

1991 ◽  
Vol 44 (1) ◽  
pp. 159-164 ◽  
Author(s):  
M. A. Quiroz ◽  
U. Morales ◽  
L. Salgado ◽  
Y. Meas
Keyword(s):  
Surface Oxidation ◽  
Ruthenium Catalysts ◽  
Roughness Factor

Contact length in grinding: Part 2: Evaluation of contact length models

1997 ◽  
Vol 211 (1) ◽  
pp. 77-85 ◽  
Author(s):  
H. S. Qi ◽  
W. B. Rowe ◽  
B Mills
Keyword(s):  
Roughness Parameter ◽  
Contact Length ◽  
Speed Ratio ◽  
Depth Of Cut ◽  
Model Parameters ◽  
Roughness Factor ◽  
Workpiece Material ◽  
Curve Fit ◽  
Material Hardness ◽  
High Degree

A non-linear curve fit method was used to identify model parameters for the prediction of contact length in grinding. The evaluation shows that the model based on a surface roughness factor demonstrates a high degree of correlation with experimental trends and behaviour. It was found that the roughness parameter R r is insensitive to depth of cut, speed ratio and material hardness, but is sensitive to the wheel-workpiece material combinations and whether grinding is conducted with or without coolant.

scholarly journals Evaluation of Photoresist Image Adhesion Strength Using the Surface Roughness Factor(SRF) of Copper Substrate.

1997 ◽  
Vol 63 (607) ◽  
pp. 643-649 ◽  
Author(s):  
Sohji SAKATA ◽  
Toshio HATSUDA ◽  
Akihiro KAWABE ◽  
Hiromitsu OHNO ◽  
Yuko HIROHATA ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Adhesion Strength ◽  
Copper Substrate ◽  
Roughness Factor

scholarly journals ROUGHNESS FACTOR FOR MULTI-LAYER ARMOUR AS OVERTOPPING ESTIMATOR

2020 ◽  
pp. 25
Author(s):  
Leopoldo Franco ◽  
Yuri Pepi ◽  
Stefano de Finis ◽  
Verdiana Iorio ◽  
Giorgio Bellotti ◽  
...  
Keyword(s):  
Structural Characteristics ◽  
Storm Surges ◽  
Random Wave ◽  
Roughness Factor ◽  
Coastal Structures ◽  
Wave Overtopping ◽  
Wave Flume ◽  
Physical Model Tests ◽  
Rubble Mound ◽  
Rubble Mound Breakwaters

Nowadays one of the most challenging problem for engineers is to adapt existing coastal structures to climate changes. Wave overtopping is highly sensitive to the increasing extreme water depths due to higher storm surges coupled with sea level rise. One way to face these problems for rubble mound breakwaters is to add one or more layers to the existing armour. Prediction of wave overtopping of coastal structures is presently obtained from empirical formulae in EurOtop (2018). For the case of overtopping over multi-layer armour, no validated method exists, so prediction must be based upon assumptions and judgement, with related uncertainties. This study is focused on the effects of different types of armour, the number of layer and other structural characteristics on the roughness factor f. The main effects of porosity and roughness will be investigated. This paper analyzes the results of several new physical model tests of different rubble mound breakwaters reproduced at the new medium scale random wave flume of the Department of Engineering of Roma Tre University.Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/8cOdqkqQ-9s

scholarly journals Influence of power density micro-morphology of sputtered Mo films. Estimation by measurement of surface roughness factor.

Shinku ◽  
1991 ◽  
Vol 34 (3) ◽  
pp. 204-207
Author(s):  
Yasushi MAKABE ◽  
Yuko HIROHATA ◽  
Tomoaki HINO ◽  
Toshiro YAMASHINA
Keyword(s):  
Surface Roughness ◽  
Power Density ◽  
Roughness Factor ◽  
Micro Morphology
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