scholarly journals BREAKING CRITERION ON NON-UNIFORMLY SLOPING BEACH

1986 ◽  
Vol 1 (20) ◽  
pp. 25
Author(s):  
Takashi Izumiya ◽  
Masahiko Isobe
Keyword(s):  
Experimental Data ◽  
Water Depth ◽  
Wave Period ◽  
Breaking Point ◽  
Bottom Slope ◽  
The Mean ◽  
Sloping Beach ◽  
Step Type

This paper deals with the breaker height on non-uniformly sloping beaches. A large number of experiments were carried out to obtain a breaking criterion on bar and step-type beaches. Based on the experimental data, a relationship among the breaker height, water depth, and wave period is investigated for various bottom configurations. As a result, the breaker height on non-uniformly sloping beaches is found to be well predicted by substituting an equivalent bottom slope in Goda's breaker index which has been obtained for uniformly sloping beaches. The equivalent bottom slope is defined as the mean slope in the distance of 5hg offshoreward from a breaking point, where hg denotes the water depth at the breaking point. The method for calculating the breaker height on natural beaches is also presented.

scholarly journals DEFORMATION UP TO BREAKING OF PERIODIC WAVES ON A BEACH

1976 ◽  
Vol 1 (15) ◽  
pp. 26 ◽  
Author(s):  
Ib A. Svendson ◽  
J. Buhr Hansen
Keyword(s):  
Wave Height ◽  
Water Depth ◽  
Wave Length ◽  
Empirical Relation ◽  
Breaking Point ◽  
Periodic Waves ◽  
Depth Ratio ◽  
Surface Profiles ◽  
Deep Water Wave ◽  
Sloping Beach

An experimental description is presented for 'the transformation of periodic waves which approach breaking on a gently sloping beach. The data include the variation of wave height, phase velocity, wave surface profiles, and the maximum value of the wave height to water depth ratio (H/h)max around the breaking point. The results are compared with the theories of sinusoidal and cnoidal wave shoaling, and the latter is shown in most cases to agree remarkably well when the laminar energy loss along the walls and bottom of the wave tank is included. An empirical relation is established between wave length to water depth ratio L/h at the breaking point and the deep water wave steepness H0/L0. Also the maximum wave height to water depth ratio at breaking shows considerably less scattering than found previously, when plotted versus S = hx L/h, hx being bottom slope.

PARAMETERIZATION OF NONLINEAR WAVE TRANSFORMATION ABOVE UNDERWATER STRUCTURES

2017 ◽  
Author(s):  
Yana Saprykina ◽  
Yana Saprykina
Keyword(s):  
Nonlinear Wave ◽  
Water Depth ◽  
Significant Wave Height ◽  
Relative Length ◽  
Wave Period ◽  
Wave Transformation ◽  
Mean Wave Period ◽  
The Mean ◽  
Underwater Structure ◽  
Underwater Structures

On the base of laboratory experiment a nonlinear wave transformation above underwater reef and trench was investigated. It was revealed that underwater trench and reef can decrease the mean wave period. Dependencies of changes of mean wave period and significant wave height on relative length of underwater structure and water depth above it were obtained. The changes of symmetry of waves passing above underwater structures are discussed.

PARAMETERIZATION OF NONLINEAR WAVE TRANSFORMATION ABOVE UNDERWATER STRUCTURES

2017 ◽  
Author(s):  
Yana Saprykina ◽  
Yana Saprykina
Keyword(s):  
Nonlinear Wave ◽  
Water Depth ◽  
Significant Wave Height ◽  
Relative Length ◽  
Wave Period ◽  
Wave Transformation ◽  
Mean Wave Period ◽  
The Mean ◽  
Underwater Structure ◽  
Underwater Structures

On the base of laboratory experiment a nonlinear wave transformation above underwater reef and trench was investigated. It was revealed that underwater trench and reef can decrease the mean wave period. Dependencies of changes of mean wave period and significant wave height on relative length of underwater structure and water depth above it were obtained. The changes of symmetry of waves passing above underwater structures are discussed.

scholarly journals Application of Artificial Intelligence (AI) for Sustainable Highway and Road System

Symmetry ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 60
Author(s):  
Md Arifuzzaman ◽  
Muhammad Aniq Gul ◽  
Kaffayatullah Khan ◽  
S. M. Zakir Hossain
Keyword(s):  
Experimental Data ◽  
High Performance ◽  
Adhesion Force ◽  
Model Development ◽  
Real Life ◽  
Bayesian Optimization ◽  
Support Vector ◽  
Adhesive Properties ◽  
Bayesian Optimization Algorithm ◽  
The Mean

There are several environmental factors such as temperature differential, moisture, oxidation, etc. that affect the extended life of the modified asphalt influencing its desired adhesive properties. Knowledge of the properties of asphalt adhesives can help to provide a more resilient and durable asphalt surface. In this study, a hybrid of Bayesian optimization algorithm and support vector regression approach is recommended to predict the adhesion force of asphalt. The effects of three important variables viz., conditions (fresh, wet and aged), binder types (base, 4% SB, 5% SB, 4% SBS and 5% SBS), and Carbon Nano Tube doses (0.5%, 1.0% and 1.5%) on adhesive force are taken into consideration. Real-life experimental data (405 specimens) are considered for model development. Using atomic force microscopy, the adhesive strength of nanoscales of test specimens is determined according to functional groups on the asphalt. It is found that the model predictions overlap with the experimental data with a high R2 of 90.5% and relative deviation are scattered around zero line. Besides, the mean, median and standard deviations of experimental and the predicted values are very close. In addition, the mean absolute Error, root mean square error and fractional bias values were found to be low, indicating the high performance of the developed model.

scholarly journals Kinetics of drying of basil leaves (Ocimum basilicum L.) in the infrared

2012 ◽  
Vol 16 (12) ◽  
pp. 1346-1352 ◽  
Author(s):  
Renata C. dos Reis ◽  
Ivano A. Devilla ◽  
Diego P. R. Ascheri ◽  
Ana C. O. Servulo ◽  
Athina B. M. Souza
Keyword(s):  
Experimental Data ◽  
Ocimum Basilicum ◽  
Coefficient Of Determination ◽  
Chisquare Test ◽  
The Mean ◽  
Drying Curves ◽  
The One ◽  
Increasing Temperature ◽  
Air Circulation ◽  
Kinetics Of

The objective of this paper was to model the drying curves of the leaves of basil (Ocimum basilicum L.) in the infrared at temperatures of 50, 60, 70 and 80 ºC and to evaluate the influence of drying temperature on the color of dried leaves. Drying was conducted in infrared dryer with temperature and greenhouse air circulation. Experimental data were fitted to eight mathematical models. The magnitude of the coefficient of determination (R²), the mean relative error (P), the estimated mean error (SE) and chisquare test (χ2) were used to verify the degree of fitness of the models. From the study it was concluded that: a) the behavior of the drying curves of basil leaves was similar to most agricultural products, the drying times in the infrared were less than the drying times in an oven with air circulation, b) the mathematical drying model proposed by Midilli et al. (2002) was the one which best adjusted to the experimental data, c) the diffusion coefficient ranged from 9.10 x 10-12 to 2.92 x 10-11 m² s-1 and d) the color of the samples was highly influenced by drying, becoming darker due to loss of chlorophyll with increasing temperature.

scholarly journals Dynamics of the Blade Channel of an Inducer Under Cavitation-Induced Instabilities

2018 ◽  
Vol 141 (4) ◽  
Author(s):  
Angelo Pasini ◽  
Ruzbeh Hadavandi ◽  
Dario Valentini ◽  
Giovanni Pace ◽  
Luca d'Agostino
Keyword(s):  
Experimental Data ◽  
Spectral Analysis ◽  
Main Flow ◽  
Operating Conditions ◽  
Flow Instabilities ◽  
Mean Flow ◽  
Flow Oscillations ◽  
Rotating Frames ◽  
The Mean ◽  
High Head

A high-head three-bladed inducer has been equipped with pressure taps on the hub along the blade channels with the aim of more closely investigating the dynamics of cavitation-induced instabilities developing in the impeller flow. Spectral analysis of the pressure signals obtained from two sets of transducers mounted both in the stationary and rotating frames has allowed to characterize the nature, intensity, and interactions of the main flow instabilities detected in the experiments: subsynchronous rotating cavitation (RC), cavitation surge (CS), and a high-order axial surge oscillation. A dynamic model of the unsteady flow in the blade channels has been developed based on experimental data and on suitable descriptions of the mean flow and the oscillations of the cavitating volume. The model has been used for estimating at the inducer operating conditions of interest the intensity of the flow oscillations associated with the occurrence of the CS mode generated by RC in the inducer inlet.

scholarly journals Determination of the Firing Pin Critical Velocity and the Critical Power in the Percussive Initiation of Primer Caps

2016 ◽  
Vol 7 (4) ◽  
pp. 33-66
Author(s):  
Andrzej FARYŃSKI ◽  
Andrzej DŁUGOŁĘCKI ◽  
Jarosław DĘBIŃSKI ◽  
Łukasz SŁONKIEWICZ
Keyword(s):  
Experimental Data ◽  
Critical Velocity ◽  
Hot Spot ◽  
Pulse Power ◽  
Critical Parameters ◽  
Simplified Model ◽  
Initiation Mechanism ◽  
The Mean ◽  
Institute Of Technology ◽  
Explosive Reaction

This work involved testing of the probability of initiating a KWM-3 type of primer cap as a function of the firing pin velocity upon impact. The tested firing pin was accelerated to the required velocity by a falling mass. The measurements under this work were made with a measurement system and methodologies developed at Air Force Institute of Technology (AFIT) in Warsaw (Poland). The percussive pulse velocity and power was altered by modifying the percussive mass to keep the initiating pulse energy constant at two levels: Ewe = 272 mJ and 343 mJ. The firing pin velocity values estimated by experimental data to bring a 50% probability of percussive primer cap initiation were within the interval vi50% = 0.34÷0.51 m/s. It was found that the mean primer cap ignition delay rose from approx. 0.7 ms at a percussion velocity of 1.5 m/s to 6 ms at 0.17 m/s. The experimental data suggest the values of Ewe x vi50% = 0.136. A simplified model was proposed for the deformation of the primer cap base and compressed pyrotechnical mixture shape. The model served to determine the approximate time trend for the penetration of the primer cap by the firing pin, including velocity, power and emitted energy, by assuming a complete energy transfer from the percussive mass to the primer cap. The mean initiating pulse power calculated from the model at the vi50% interval was Pavg = 120÷180 W, whereas the maximum initiating pulse power was Pmax = 170÷250 W. The calculated time values for firing pin penetration were very close to the aforementioned primer cap ignition delays at the respective velocity and percussive mass values. This indirectly indicates nearly complete energy transmission from the percussive masses to the primer caps. A location was identified within the compressed pyrotechnical mixture shape volume which could form the hot spot for initiation of the explosive reaction. Based on the calculation results using the simplified model, and assuming that the energy and diffusive heat flux output to and from the explosive reaction initiation hot spot were equivalent, the expression of Ewe x vi50% derived from the result was approx. 0.18. This means that the two critical parameters of primer cap initiation: (i) velocity, which can be identified with vi50% (and the respective power) and (ii) Ewe50%, i.e. the energy threshold below which the probability of primer cap initiation is less than 0.5, are interrelated. Aside from the initiation mechanism proposed and applied to calculate the firing pin critical velocity, this work discusses several other initiation mechanisms, all of which were ruled out during the testing process.

scholarly journals Statistics of nascent and mature RNA fluctuations in a stochastic model of transcriptional initiation, elongation, pausing, and termination

2020 ◽  
Author(s):  
Tatiana Filatova ◽  
Nikola Popovic ◽  
Ramon Grima
Keyword(s):  
Experimental Data ◽  
Fluorescence Microscopy ◽  
Stochastic Model ◽  
Explicit Dependence ◽  
Transcriptional Initiation ◽  
Estimate Parameter ◽  
Mean And Variance ◽  
The Mean ◽  
Nascent Rna ◽  
Parameter Values

AbstractRecent advances in fluorescence microscopy have made it possible to measure the fluctuations of nascent (actively transcribed) RNA. These closely reflect transcription kinetics, as opposed to conventional measurements of mature (cellular) RNA, whose kinetics is affected by additional processes downstream of transcription. Here, we formulate a stochastic model which describes promoter switching, initiation, elongation, premature detachment, pausing, and termination while being analytically tractable. By computational binning of the gene into smaller segments, we derive exact closed-form expressions for the mean and variance of nascent RNA fluctuations in each of these segments, as well as for the total nascent RNA on a gene. We also derive exact expressions for the first two moments of mature RNA fluctuations, and approximate distributions for total numbers of nascent and mature RNA. Our results, which are verified by stochastic simulation, uncover the explicit dependence of the statistics of both types of RNA on transcriptional parameters and potentially provide a means to estimate parameter values from experimental data.

scholarly journals Normalization in dynamic speckle analysis for non-destructive monitoring of speed of processes

2021 ◽  
Vol 2091 (1) ◽  
pp. 012002
Author(s):  
Elena Stoykova ◽  
Dimana Nazarova ◽  
Lian Nedelchev ◽  
Mikhail Levchenko ◽  
Nataliya Berberova-Buhova ◽  
...  
Keyword(s):  
Experimental Data ◽  
Mean Value ◽  
High Contrast ◽  
Object Surface ◽  
Laser Illumination ◽  
Dynamic Speckle ◽  
The Mean ◽  
Spatially Varying ◽  
Non Destructive

Abstract The paper is dedicated to analysis of normalized intensity-based pointwise algorithms for processing dynamic speckle images with spatially varying speckle statistics in non-destructive visualization of regions of faster or slower changes across an object. Both existing and newly proposed algorithms are analyzed. Extraction of speed of changes is done by acquiring correlated in time speckle images formed on the object surface under laser illumination. The studied algorithms have been applied to simulated low and high contrast speckle data. Their performance has been compared to processing of binary patterns as another approach for dealing with varying speckle statistics in the acquired images. The efficiency of the algorithms have been checked on the experimental data, including data in a compressed format. We have proven that the algorithms with normalization at successive instants by a sum of two intensities or a single intensity outperform as a whole the algorithms which apply the time-averaged estimates of the mean value and the variance of speckle intensity.

scholarly journals Assessment of CFD turbulence models for free surface flow simulation and 1-D modelling for water level calculations over a broad-crested weir floodway

Water SA ◽  
2019 ◽  
Vol 45 (3 July) ◽  
Author(s):  
Ahmed M Helmi
Keyword(s):  
Experimental Data ◽  
Free Surface ◽  
Water Level ◽  
Dimensional Analysis ◽  
Turbulence Model ◽  
Turbulence Models ◽  
Cfd Simulations ◽  
One Dimensional ◽  
The Mean ◽  
The One

Floodways, where a road embankment is permitted to be overtopped by flood water, are usually designed as broad-crested weirs. Determination of the water level above the floodway is crucial and related to road safety. Hydraulic performance of floodways can be assessed numerically using 1-D modelling or 3-D simulation using computational fluid dynamics (CFD) packages. Turbulence modelling is one of the key elements in CFD simulations. A wide variety of turbulence models are utilized in CFD packages; in order to identify the most relevant turbulence model for the case in question, 96 3-D CFD simulations were conducted using Flow-3D package, for 24 broad-crested weir configurations selected based on experimental data from a previous study. Four turbulence models (one-equation, k-ε, RNG k-ε, and k-ω) ere examined for each configuration. The volume of fluid (VOF) algorithm was adopted for free water surface determination. In addition, 24 1-D simulations using HEC-RAS-1-D were conducted for comparison with CFD results and experimental data. Validation of the simulated water free surface profiles versus the experimental measurements was carried out by the evaluation of the mean absolute error, the mean relative error percentage, and the root mean square error. It was concluded that the minimum error in simulating the full upstream to downstream free surface profile is achieved by using one-equation turbulence model with mixing length equal to 7% of the smallest domain dimension. Nevertheless, for the broad-crested weir upstream section, no significant difference in accuracy was found between all turbulence models and the one-dimensional analysis results, due to the low turbulence intensity at this part. For engineering design purposes, in which the water level is the main concern at the location of the flood way, the one-dimensional analysis has sufficient accuracy to determine the water level.

Sign in / Sign up

Export Citation Format

Share Document