Analyse expérimentale de l'effet d'un couvert de glace sur la propagation de l'onde de rupture de barrage

2000 ◽  
Vol 27 (5) ◽  
pp. 1082-1087 ◽  
Author(s):  
Musandji Fuamba ◽  
Claude Marche ◽  
Tung Quach
Keyword(s):  
Pressure Wave ◽  
Ice Cover ◽  
Force Balance ◽  
Dam Safety ◽  
Safety Factors ◽  
Ice Load ◽  
Winter Conditions ◽  
The Stability ◽  
Stability Of Structures

Lengthy winter conditions such as those known in the province of Quebec require that one takes the presence of an ice cover into account in the determination of instantaneous safety factors for dams established in cascade and under the effect of a break wave. Not only should the ice load on the structure be considered but also the effects of the pressure wave that is propagated under the ice cover. This study shows that the method currently used to determine the stability of structures subject to a break wave is incomplete. The results obtained in laboratory indeed indicate that the presence of the ice cover increases the sur-elevation and sur-pressure values of both components of the break wave. This might perturb the stabilizing force balance of the downstream dam and increases its risk of failure.Key words: dam safety, break wave, ice cover, sur-pressure, dynamic load.[Journal translation]

scholarly journals Determination of Safety Factors for Mango Fruit Paperboard Transport Crates under Refrigerated Conditions

2018 ◽  
Vol 11 (1) ◽  
pp. 34-43
Author(s):  
Bernd Sadlowsky ◽  
Viktoria Köstner ◽  
Margot Mazur ◽  
Sina-Kristin Thun ◽  
Péter Böröcz
Keyword(s):  
Safety Factor ◽  
Food Industry ◽  
Safety Factors ◽  
Mango Fruit ◽  
Dynamic Stresses ◽  
Corrugated Board ◽  
Material Costs ◽  
The Stability ◽  
Industry Sectors

The use of corrugated board packaging is very popular in most industry sectors, but the food industry is one of the main consumers. Special requirements are placed on corrugated board in the food industry since the level of humidity necessary may be as high as 85-90% rH and this can greatly influence on the performance of the packaging. This influencing circumstance is taken into account in this paper when estimating a safety factor aimed at reducing risk. Knowing the safety factor can save transport and material costs, and can also prevent serious damage during the distribution of goods. The aim of this study is to determine the influence of humidity, pre-compression and load carriers on the stability of corrugated board mango fruit crates and thus to determine the safety factor. The results show that it is possible to calculate the safety factor by measuring realistic static stresses. Further researches into determining the dynamic stresses are required so as completing the calculation of the safety factor.

DETERMINATION OF LOAD-BEARING STRUCTURE'S MAXIMUM LOAD ONTO FOUNDATION GROUND FOR THE CRNA RIJEKA SMALL POWER PLANT

2020 ◽  
Author(s):  
Biljana Buhavac ◽  
Suada Pamuk
Keyword(s):  
Power Plant ◽  
Maximum Load ◽  
Small Power ◽  
Load Bearing ◽  
Engine Room ◽  
Geotechnical Design ◽  
The Stability ◽  
Stability Of Structures ◽  
Supporting Structures

The paper presents the determination of the maximum load of load-bearing structures with terrain contact according to EN 1997-1 (Geotechnical design) and EN 1998-5 (Foundations, supporting structures and geotechnical issues). Processed is a concrete example of SPP Crna rijeka which will be based in rock material, and which does not require “additional“ interventions for the stability of structures (water intake with sedimentation tank and engine room).

scholarly journals Determination of economically viable option of liquidation the consequences of external dump deformation

2021 ◽  
Vol 280 ◽  
pp. 08014
Author(s):  
Yevheniy Babets ◽  
Oleh Anisimov ◽  
Oleksandr Shustov ◽  
Vitalina Komirna ◽  
Iryna Melnikova
Keyword(s):  
Mechanical Properties ◽  
Physical And Mechanical Properties ◽  
Safety Factors ◽  
Viable Option ◽  
The Third ◽  
The Stability ◽  
The Cost ◽  
Technical And Economic Indicators ◽  
Processing Enterprise

The safety factors for different variants of operation development were obtained, on the basis of which the technical and economic indicators were established and the most expedient way of restoration of dump operations in conditions of the formed landslide was chosen. The solutions were proposed for the external dump No 2 of the Central Ore Mining and Processing Enterprise (COMPE), that allow to continue its future operation. When working in the conditions of the formed landslide, three variants of the further dump operation are modeled: the first one - with landslide removal and unloading of the upper dump horizons, the second one - without landslide removal and involvement of disturbed lands in land allotment, the third one - with the landslide loading. Based on the built sections of the dump and defined physical and mechanical properties, the stability factors were obtained for different options of the operation development, which made it possible to determine the appropriate option to eliminate the effects of the dump slide deformations. As a result of the calculations, the cost flows for each of the proposed options of the formation of the end contour of the dump No 2 are determined.

Determining the Norton’s Equivalent Model of Distribution System with Distributed Generation (DG) for Stability Analysis

2019 ◽  
Vol 12 (2) ◽  
pp. 190-198
Author(s):  
Sunny Katyara ◽  
Lukasz Staszewski ◽  
Faheem Akhtar Chachar
Keyword(s):  
Distributed Generation ◽  
Normal Condition ◽  
Distribution System ◽  
Distribution Networks ◽  
Equivalent Model ◽  
Stability Factor ◽  
Matlab Simulation ◽  
The Stability ◽  
Stability Issues

Background: Since the distribution networks are passive until Distributed Generation (DG) is not being installed into them, the stability issues occur in the distribution system after the integration of DG. Methods: In order to assure the simplicity during the calculations, many approximations have been proposed for finding the system’s parameters i.e. Voltage, active and reactive powers and load angle, more efficiently and accurately. This research presents an algorithm for finding the Norton’s equivalent model of distribution system with DG, considering from receiving end. Norton’s model of distribution system can be determined either from its complete configuration or through an algorithm using system’s voltage and current profiles. The algorithm involves the determination of derivative of apparent power against the current (dS/dIL) of the system. Results: This work also verifies the accuracy of proposed algorithm according to the relative variations in the phase angle of system’s impedance. This research also considers the varying states of distribution system due to switching in and out of DG and therefore Norton’s model needs to be updated accordingly. Conclusion: The efficacy of the proposed algorithm is verified through MATLAB simulation results under two scenarios, (i) normal condition and (ii) faulty condition. During normal condition, the stability factor near to 1 and change in dS/dIL was near to 0 while during fault condition, the stability factor was higher than 1 and the value of dS/dIL was away from 0.

Synthesis and solvatochromic studies of 2- amino-3-phenolazo1-(4-sulfophenyl)-3-methyi-5-pyrozolone and use it for the determination of trace amount of Nickel (II) in blood samples

2016 ◽  
Vol 5 (10) ◽  
pp. 4920
Author(s):  
Amar M. Ali ◽  
Hussain. J. Mohammed*
Keyword(s):  
Stability Constant ◽  
Trace Amount ◽  
Benzenesulfonic Acid ◽  
Determination Method ◽  
Blood Samples ◽  
Determination Of Nickel ◽  
Normal Human ◽  
The Stability ◽  
Normal Human Blood

A new, simple, sensitive and rapid spectrophotometric method is proposed for the determination of trace amount of Nickel (II). The method is based on the formation of a 1:2 complex with 4-(4-((2-hydroxy-6-nitrophenyl) diazenyl) -3-methyl-5-oxo-2, 5-dihydro-1H-pyrazol-1-yl) benzenesulfonic acid (2-ANASP) as a new reagent is developed. The complex has a maximum absorption at 516 nm and εmax of 1. 84 X 105 L. mol-1. cm-1. A linear correlation (0. 25 – 4. 0μg. ml-1) was found between absorbance at λmax and concentration. The accuracy and reproducibility of the determination method for various known amounts of Nickel (II) were tested. The results obtained are both precise (RSD was 1. 2 %) and accurate (relative error was 0. 787 %). The effect of diverse ions on the determination of Nickel (II) to investigate the selectivity of the method were also studied. The stability constant of the product was 0. 399 X 106 L. mol-1. The proposed method was successfully applied to the analysis of diabetes blood and normal human blood. 

scholarly journals Determination of Objective Weights Using a New Method Based on the Removal Effects of Criteria (MEREC)

Symmetry ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 525 ◽  
Author(s):  
Mehdi Keshavarz-Ghorabaee ◽  
Maghsoud Amiri ◽  
Edmundas Kazimieras Zavadskas ◽  
Zenonas Turskis ◽  
Jurgita Antucheviciene
Keyword(s):  
Essential Elements ◽  
New Method ◽  
Multi Criteria Decision Making ◽  
Analysis Of Means ◽  
Simulation Based ◽  
Criteria Weights ◽  
The Stability ◽  
Computational Analyses ◽  
Weighting Methods

The weights of criteria in multi-criteria decision-making (MCDM) problems are essential elements that can significantly affect the results. Accordingly, researchers developed and presented several methods to determine criteria weights. Weighting methods could be objective, subjective, and integrated. This study introduces a new method, called MEREC (MEthod based on the Removal Effects of Criteria), to determine criteria’ objective weights. This method uses a novel idea for weighting criteria. After systematically introducing the method, we present some computational analyses to confirm the efficiency of the MEREC. Firstly, an illustrative example demonstrates the procedure of the MEREC for calculation of the weights of criteria. Secondly, a comparative analysis is presented through an example for validation of the introduced method’s results. Additionally, we perform a simulation-based analysis to verify the reliability of MEREC and the stability of its results. The data of the MCDM problems generated for making this analysis follow a prevalent symmetric distribution (normal distribution). We compare the results of the MEREC with some other objective weighting methods in this analysis, and the analysis of means (ANOM) for variances shows the stability of its results. The conducted analyses demonstrate that the MEREC is efficient to determine objective weights of criteria.

scholarly journals Determination of Transverse Shear Stiffness of Sandwich Panels with a Corrugated Core by Numerical Homogenization

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 1976
Author(s):  
Tomasz Garbowski ◽  
Tomasz Gajewski
Keyword(s):  
Transverse Shear ◽  
Shear Stiffness ◽  
The Finite Element Method ◽  
Homogenization Procedure ◽  
Plate Structures ◽  
Corrugated Board ◽  
Energy Equivalence ◽  
The Stability ◽  
Global Stiffness Matrix

Knowing the material properties of individual layers of the corrugated plate structures and the geometry of its cross-section, the effective material parameters of the equivalent plate can be calculated. This can be problematic, especially if the transverse shear stiffness is also necessary for the correct description of the equivalent plate performance. In this work, the method proposed by Biancolini is extended to include the possibility of determining, apart from the tensile and flexural stiffnesses, also the transverse shear stiffness of the homogenized corrugated board. The method is based on the strain energy equivalence between the full numerical 3D model of the corrugated board and its Reissner-Mindlin flat plate representation. Shell finite elements were used in this study to accurately reflect the geometry of the corrugated board. In the method presented here, the finite element method is only used to compose the initial global stiffness matrix, which is then condensed and directly used in the homogenization procedure. The stability of the proposed method was tested for different variants of the selected representative volume elements. The obtained results are consistent with other technique already presented in the literature.

scholarly journals Charge Transfer Complexes of Ketotifen with 2,3-Dichloro-5,6-dicyano-p-benzoquinone and 7,7,8,8-Tetracyanoquodimethane: Spectroscopic Characterization Studies

Molecules ◽  
2021 ◽  
Vol 26 (7) ◽  
pp. 2039
Author(s):  
Gamal A. E. Mostafa ◽  
Ahmed Bakheit ◽  
Najla AlMasoud ◽  
Haitham AlRabiah
Keyword(s):  
Charge Transfer ◽  
Spectroscopic Characterization ◽  
Molar Ratio ◽  
Charge Transfer Complexes ◽  
Physical Parameters ◽  
Spectrophotometric Methods ◽  
Theoretical Approaches ◽  
The Stability ◽  
Ct Complexes

The reactions of ketotifen fumarate (KT) with 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ) and 7,7,8,8-tetracyanoquinodimethane (TCNQ) as π acceptors to form charge transfer (CT) complexes were evaluated in this study. Experimental and theoretical approaches, including density function theory (DFT), were used to obtain the comprehensive, reliable, and accurate structure elucidation of the developed CT complexes. The CT complexes (KT-DDQ and KT-TCNQ) were monitored at 485 and 843 nm, respectively, and the calibration curve ranged from 10 to 100 ppm for KT-DDQ and 2.5 to 40 ppm for KT-TCNQ. The spectrophotometric methods were validated for the determination of KT, and the stability of the CT complexes was assessed by studying the corresponding spectroscopic physical parameters. The molar ratio of KT:DDQ and KT:TCNQ was estimated at 1:1 using Job’s method, which was compatible with the results obtained using the Benesi–Hildebrand equation. Using these complexes, the quantitative determination of KT in its dosage form was successful.

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