Les évacuateurs de crues en labyrinthe : dimensionnement, fonctionnement, exemples et particularités

1995 ◽  
Vol 22 (5) ◽  
pp. 916-924 ◽  
Author(s):  
Nacer Eddine Zerrouk ◽  
Claude Marche
Keyword(s):  
Key Words ◽  
Flood Control ◽  
Experimental Studies ◽  
Flood Routing ◽  
Design Flood ◽  
Labyrinth Weir ◽  
Right Of Way ◽  
Attractive Option ◽  
Flow Diagrams ◽  
Calculation Procedures

The purpose of this paper is to demonstrate that labyrinth spillways can be a better option than rectilinear ones. The stages that have led to development of the labyrinth spillway are briefly reviewed as are applicable design and calculation principles. Discharge flow diagrams given by Hay and Taylor, Darvas, Lux and Hinchliff, and Magalhaes and Lorena for a trapezoidal labyrinth weir are compared. Calculation procedures and design diagrams were automated, making it possible to study flood routing through a labyrinth spillway and compare its performance to that of an equivalent rectilinear spillway. A real case was used for validation: routing through the trapezoidal labyrinth weir selected for the Keddara Dam in Algeria was compared with routing through the rectilinear spillway of the initial design. Dimensions, discharge values and expected maximum heights show calculated results agree with results of experimental studies of the structure and confirm that technically the labyrinth spillway is an attractive option. Labyrinth spillways can be particularly attractive for upgrading existing developments to satisfy more demanding design flood criteria in the limited right-of-way of an existing spillway. The Sainte Brigitte-des-Saults development in Quebec on the Nicolet Sud-Ouest River is a good case in point. Key words: flood control works, spillway, labyrinth weir, polygonal weir, nonrectilinear weir.[Journal translation]

scholarly journals Inflow Flood Simulation and Risk Analysis of Cascade Reservoirs

2018 ◽  
Vol 246 ◽  
pp. 01106
Author(s):  
Jing Huang ◽  
Jiqing Li ◽  
Pengteng Liang
Keyword(s):  
Risk Analysis ◽  
Flood Control ◽  
Flood Routing ◽  
Three Gorges ◽  
Design Flood ◽  
Flood Simulation ◽  
Cascade Reservoirs ◽  
The Three Gorges ◽  
Flood Regulation ◽  
Risk Rate

The risk of flood control in cascade reservoirs reflects the possibility of unforeseen events in upstream reservoirs under certain space-time conditions during the operation of flood control. Using @RISK software and a stochastic simulation model to simulate the inflow flood of cascade reservoirs, the flood routing of cascade reservoirs and the risk analysis of the highest water level were carried out based on the flood regulation rules of Three Gorges-Gezhouba cascade reservoirs. The results of simulation calculations show that the risk rate of the Three Gorges-Gezhouba cascade reservoir is lower than its design flood standard, which can ensure the safety of flood control.

scholarly journals Hydrological Risk Analysis of Dams: The Influence of Initial Reservoir Level Conditions

Water ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 461 ◽  
Author(s):  
Ivan Gabriel-Martin ◽  
Alvaro Sordo-Ward ◽  
Luis Garrote ◽  
Isabel Granados
Keyword(s):  
Risk Analysis ◽  
Flood Control ◽  
Evaluation Method ◽  
Risk Index ◽  
Flood Routing ◽  
Dam Safety ◽  
Global Risk ◽  
Reservoir Level ◽  
Design Flood ◽  
Relevant Variable

In this paper, we present a method to assess the influence of the initial reservoir level in hydrological dam safety and risk analysis. Traditionally, in professional practice, the procedures applied are basically deterministic. Several physical processes are defined deterministically, according to the criteria of the designer (usually in the conservative side), although there is a high degree of uncertainty regarding these processes. A relevant variable is the reservoir level considered at the beginning of flood events. Hydrological dam safety assessment methods traditionally assume that the reservoir is initially full when it receives the design flood, thus, staying in the conservative side when designing a new dam. However, the distribution of reservoir levels at the beginning of flood episodes takes more importance for evaluating the real risk for the dams in operation. We analyzed three different scenarios—initial reservoir level equal to maximum normal level, equal to a maximum conservation level, and following the probability distribution from the historical records. To do so, we presented a method applied to a gated-spillway dam located in the Tagus river basin. A set of 100,000 inflow hydrographs was generated through a Monte Carlo procedure, by reproducing the statistics of the main observed hydrograph characteristics—peak flow, volume, and duration. The set of 100,000 hydrographs was routed through the reservoir applying the Volumetric Evaluation Method as a flood control strategy. In order to compare the three scenarios, we applied an economic global risk index. The index combines the hydrological risk for the dam, linked to the maximum water level reached in the reservoir, during the flood routing, and the flood risk in the downstream river reach, linked to the discharge releases from the dam. The results showed the importance of accounting for the fluctuation of initial reservoir levels, for assessing the risk related to hydrological dam safety. Furthermore, a procedure to quantify the uncertainty associated with the effects of initial reservoir level on hydrological dam safety, has been proposed.

Results of an experimental study of hydrogel drainage containing ranibizumab in antiglaucoma operations

2021 ◽  
pp. 63-67
Author(s):  
I.I. Khusnitdinov ◽  
Keyword(s):  
Experimental Study ◽  
Hyaluronic Acid ◽  
Key Words ◽  
Experimental Research ◽  
Experimental Studies ◽  
Glaucoma Surgery ◽  
Control Group ◽  
Morphological Studies

Purpose. Еxperimental substantiation of the effectiveness of biocompatible biodegradable hydrogels based on hyaluronic acid and chitosan succinate as a carrier of ranibizumab in antiglaucoma operations. Material and methods. Hydrogel drainage (HD) was obtained immediately before surgery. A solution of ranibizumab (0.23 ml) was mixed with a solution of hyaluronic acid dialdehyde (0.5 ml), then a solution of chitosan succinate (0.5 ml) was added. Experimental studies were performed in 12 (12 eyes) healthy rabbits. The first group consisted of 6 eyes – 0.187 ml of ranibizumab per 1 ml of gel. In the control group, HD was used intraoperatively without the addition of ranibizumab (6 eyes). Morphological studies were performed on 7th, 21st, and 42nd days. Results. In experimental studies in vitro and in vivo, it was proved that ranibizumab, administered as a part of 0.1 ml of hydrogel drainage in the antiglaucoma surgery area is released within 3 weeks and suppresses vascularization, scarring of the operating area, and preserves the intrascleral cavity. The optimal concentration of ranibizumab was selected-0.02 ml in 0.1 ml of gel. Conclusion. The safety and effectiveness of the use of hydrogel drainage with ranibizumab based on hyaluronic acid dialdehyde and chitosan succinate in anti-glaucoma operations has been proven. Key words: experimental research, hydrogel drainage, ranibizumab, glaucoma surgery.

Deaf and Hard-of-hearing Users Evaluating Designs for Highlighting Key Words in Educational Lecture Videos

2021 ◽  
Vol 14 (4) ◽  
pp. 1-24
Author(s):  
Sushant Kafle ◽  
Becca Dingman ◽  
Matt Huenerfauth
Keyword(s):  
Experimental Study ◽  
Key Words ◽  
Hard Of Hearing ◽  
Experimental Studies ◽  
Design Parameters ◽  
Educational Video ◽  
Word Level ◽  
Sentence Level ◽  
First Occurrence ◽  
Educational Videos

There are style guidelines for authors who highlight important words in static text, e.g., bolded words in student textbooks, yet little research has investigated highlighting in dynamic texts, e.g., captions during educational videos for Deaf or Hard of Hearing (DHH) users. In our experimental study, DHH participants subjectively compared design parameters for caption highlighting, including: decoration (underlining vs. italicizing vs. boldfacing), granularity (sentence level vs. word level), and whether to highlight only the first occurrence of a repeating keyword. In partial contrast to recommendations in prior research, which had not been based on experimental studies with DHH users, we found that DHH participants preferred boldface, word-level highlighting in captions. Our empirical results provide guidance for the design of keyword highlighting during captioned videos for DHH users, especially in educational video genres.

Ice jam mitigation

1990 ◽  
Vol 17 (5) ◽  
pp. 675-685 ◽  
Author(s):  
Harold S. Belore ◽  
Brian C. Burrell ◽  
Spyros Beltaos
Keyword(s):  
Key Words ◽  
Carrying Capacity ◽  
Flood Control ◽  
Human Life ◽  
Water Levels ◽  
Economic Losses ◽  
River Ice ◽  
Ice Jams ◽  
Ice Jam ◽  
Ice Breakup

In Canada, flooding due to the rise in water levels upstream of an ice jam, or the temporary exceedance of the flow and ice-carrying capacity of a channel upon release of an ice jam, has resulted in the loss of human life and extensive economic losses. Ice jam mitigation is a component of river ice management which includes all activities carried out to prevent or remove ice jams, or to reduce the damages that may result from an ice jam event. This paper presents a brief overview of measures to mitigate the damaging effects of ice jams and contains a discussion on their application to Canadian rivers. Key words: controlled ice breakup, flood control, ice jams, ice management, river ice.

Calculation of the fire resistance of steel hollow structural section columns filled with plain concrete

1994 ◽  
Vol 21 (3) ◽  
pp. 382-385 ◽  
Author(s):  
T. T. Lie ◽  
D. C. Stringer
Keyword(s):  
Mathematical Models ◽  
Key Words ◽  
Fire Resistance ◽  
Experimental Studies ◽  
Plain Concrete ◽  
Building Codes ◽  
Aggregate Concrete ◽  
Parametric Studies ◽  
Hollow Structural Section ◽  
Hollow Structural Sections

Experimental studies were conducted to determine the fire resistance of circular and square hollow structural section columns filled with plain concrete. Mathematical models were developed and used to investigate the influence of important parameters that determine the fire resistance of these columns. The experimental and parametric studies provide information for the development of formulas for the calculation of the fire resistance of circular and square concentrically loaded columns filled with plain carbonate or siliceous aggregate concrete. Such formulas are suitable for incorporation into building codes. Key words: calculation, fire resistance, columns, concrete-filled, steel, hollow structural sections.

scholarly journals Do You Get the Picture? A Meta-Analysis of the Effect of Graphics on Reading Comprehension

AERA Open ◽  
2020 ◽  
Vol 6 (1) ◽  
pp. 233285842090169 ◽  
Author(s):  
Daibao Guo ◽  
Shuai Zhang ◽  
Katherine Landau Wright ◽  
Erin M. McTigue
Keyword(s):  
Reading Comprehension ◽  
Grade Level ◽  
Text Comprehension ◽  
Meta Analysis ◽  
Experimental Studies ◽  
Future Research ◽  
Significant Difference ◽  
Flow Diagrams ◽  
Positive Effect ◽  
Mixed Format

Although convergent research demonstrates that well-designed graphics can facilitate readers’ understanding of text, there are select situations where graphics have been shown to have no effect on learners’ overall text comprehension. Therefore, the current meta-analytic study examined 39 experimental studies published between 1985 and 2018 measuring graphics’ effects on readers’ comprehension. We first quantified the overall effect on reading comprehension. Then, we considered interactions with learners’ characteristics, graphic types, and assessment formats. Our analysis revealed that the inclusion of graphics had a moderate overall positive effect (Hedges’s g = 0.39) on students’ reading comprehension, regardless of grade level. Regarding graphic type, we did not find a significant difference among pictures, pictorial diagrams, and flow diagrams. Only when compared to mixed graphics, pictures had a greater effect on comprehension. Additionally, compared with true and false assessments, graphics differentially benefited students’ comprehension on open-ended comprehension assessments and mixed format assessments. Implications for future research are presented.

scholarly journals Flood Routing Process and High Dam Interception of Natural Discharge from the 2018 Baige Landslide-Dammed Lake

Water ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 605 ◽  
Author(s):  
Bin-Rui Gan ◽  
Xing-Guo Yang ◽  
Hai-Mei Liao ◽  
Jia-Wen Zhou
Keyword(s):  
Flood Control ◽  
Arrival Time ◽  
Arch Dam ◽  
Flood Routing ◽  
Hydraulic Calculation ◽  
Outburst Flood ◽  
Jinsha River ◽  
Flood Peak ◽  
Inundation Area ◽  
High Dams

The outburst flood of the Baige landslide dam caused tremendous damage to infrastructure, unfinished hydraulic buildings, roads, and bridges that were built or under construction along the Jinsha River. Can downstream hydraulic buildings, such as high dams with flood control and discharge function, accommodate outburst floods or generate more serious losses due to wave overtopping? In this study, the unsteady flow of a one-dimensional hydraulic calculation was used to simulate natural flood discharge. Assuming a high dam (Yebatan arch dam) is constructed downstream, the flood processes were carried out in two forms of high dam interception (complete interception, comprehensive flood control of blocking and draining). Moreover, three-dimensional visualization of the inundation area was performed. Simulation results indicate that the Yebatan Hydropower Station can completely eliminate the outburst flood risk even under the most dangerous situations. This station can reduce the flood peak and delay the peak flood arrival time. Specifically, the flood peak decreased more obviously when it was closer to the upstream area, and the flood peak arrival time was more delayed when the flood spread further downstream. In addition, the downstream water depth was reduced by approximately 10 m, and the inundation area was reduced to half of the natural discharge. This phenomenon shows that hydraulic buildings such as high dams can reduce the inundation area of downstream farmlands and extend the evacuation time for downstream residents during the flood process, thus reducing the loss of life and property.

Risk analysis for flood-control structure under consideration of uncertainties in design flood

2010 ◽  
Vol 58 (1) ◽  
pp. 117-140 ◽  
Author(s):  
Shiang-Jen Wu ◽  
Jinn-Chuang Yang ◽  
Yeou-Koung Tung
Keyword(s):  
Risk Analysis ◽  
Flood Control ◽  
Control Structure ◽  
Design Flood

Pembentukan Diafragma Beralun Silikon Dengan Menggunakan Teknik Punaran Anisotropik

2012 ◽  
Author(s):  
Norhayati Soin ◽  
Burhanuddin Yeop Majlis
Keyword(s):  
Key Words ◽  
Experimental Studies ◽  
Anisotropic Etching ◽  
Etching Technique ◽  
Convex Corner ◽  
Mask Design ◽  
Etching Mask ◽  
Corrugated Diaphragm

Kertas ini memaparkan kajian mengenai pembentukan diafragma beralun silikon dengan menggunakan teknik punaran anisotropik di mana larutan kalium hidroksida digunakan sebagai larutan pemunar. Kajian ini meliputi pengoptimuman topeng punaran bagi mengatasi masalah keadaan potong bawah penjuru yang berlaku pada struktur berpenjuru cembung diafragma beralun yang terpunar. Hasil yang diperolehi daripada kajian simulasi dan eksperimen membuktikan bahawa pengoptimuman topeng punaran yang telah dilakukan berkemampuan mengatasi masalah potong bawah penjuru diafragma beralun silikon. Kata kunci: diafragma beralun, punaran anisotropik, pengoptimuman topeng This paper presents the study of the formation of a perfect silicon corrugated diaphragm using anisotropic etching technique. Potassim hydroxide (KOH) solution is used as the etching solvent in this study. This study includes optimization of the etching mask, in order to avoid the problem of corner undercutting which exists on all convex corner structures on the etched corrugated diaphragm. Results from the simulation and experimental studies have proved that the optimized etching mask design was able to overcome the problem of convex corner undercutting. Key words: corrugated diaphragm, anisotropic etching, mask optimization

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