scholarly journals GENERATION AND SPATIAL PROPAGATION OF LANDSLIDE GENERATED IMPULSE WAVES

2017 ◽  
pp. 13 ◽  
Author(s):  
Frederic M Evers ◽  
Willi H Hager
Keyword(s):  
Free Water ◽  
Propagation Path ◽  
Mass Wasting ◽  
Wave Characteristics ◽  
Wave Basin ◽  
Width Effect ◽  
Spatial Propagation ◽  
Impulse Waves ◽  
Experimental Runs ◽  
Measurement Approach

Large subaerial mass wasting into water may generate large waves along coast lines and in bays. Hazard assessment of such an events is based on the decay rate of these impulse waves along their propagation path to populated areas and infrastructure along the shoreline. The spatial propagation processes of impulse waves generated by deformable slides was investigated in a wave basin. A videometric measurement approach allowed for a detailed tracking of the free water surface and key wave characteristics during the experimental runs including the wave height. Based on selected tests, the slide width effect on spatial wave propagation is discussed.

Non-Gaussian Wave Groups Generated in an Offshore Wave Basin

2012 ◽  
Vol 134 (4) ◽  
Author(s):  
Z. Cherneva ◽  
C. Guedes Soares
Keyword(s):  
Gaussian Process ◽  
Frequency Spectrum ◽  
Local Spectrum ◽  
Wave Groups ◽  
High Wave ◽  
Time Frequency ◽  
Wave Basin ◽  
The Mean ◽  
Non Gaussian ◽  
Experimental Runs

The main goal of the present paper is to study the differences of the descriptors of the wave groups in the nonlinear case in comparison with the same parameters for a Gaussian process. The data analyzed are from a deep water basin of Marintek. They consist of sequence of five identical independent experimental runs of unidirectional waves measured at ten fixed points situated in different distances from the wave maker. Each series contain about 1800 waves. Thus the statistics collected from a given gauge comprise about 9000 waves combined in a number of wave groups. Because the series describe a process significantly different from the Gaussian one, an upper and lower envelopes are introduced as lines which connect the peaks of the crests and the lower points of the troughs respectively. Spline functions are applied to calculate these envelopes. Then, the mean high run and mean group length are estimated for different levels, their ensemble average over five experimental runs is found for every gauge and is compared with the results of the theory of Gaussian process. It is found that the values of the mean time intervals of the groups correlate with coefficient of kurtosis of the process. It is determined also that mean group length is shorter and the mean high run is larger for the nonlinear wave groups in comparison with the Gaussian wave groups. The modification of wave groups in space and time is investigated in the work as well. Wigner time-frequency spectrum with Choi-Williams kernel is applied to describe the process of entire modulation and demodulation of the groups. It is found that before formation of the high wave a wave down-shifting takes place. At this stage the local spectrum is relatively narrow and the group shrinks continuously. Close to the focus the time-frequency spectrum is very wide and the group has a triangle form. Further the high wave breaks and the wave group acquires the form of “three sisters.” The transform of the group continues by its disintegration, the local spectrum stands narrow and an up-shifting is observed.

scholarly journals TIDAL INLET CURRENT--OCEAN WAVE INTERACTION

1972 ◽  
Vol 1 (13) ◽  
pp. 33 ◽  
Author(s):  
Lyndell Z. Hales ◽  
John B. Herbich
Keyword(s):  
Gravity Waves ◽  
Functional Relationship ◽  
Three Dimensional ◽  
Wave Interaction ◽  
Tidal Inlet ◽  
Surface Gravity Waves ◽  
Wave Characteristics ◽  
Wave Basin ◽  
Ocean Region ◽  
A Current

An experimental study was conducted in a three-dimensional wave basin to investigate the manner in which surface gravity waves propagating toward a tidal inlet are altered. Dimensional analysis of the pertinent variables indicates that a functional relationship exists between as many as five dimensionless terms, and the functional relationship is displayed in graphical non-dimensional form to apply to all scales. Results indicate the ebb current increases the steepness in the ocean region to such an extent that the wave begins to lose energy by the crest spilling down the front of the wave, and the wave characteristics in the inlet proper may never reach the breaking limit unless factors other than a current alone are involved.

Assessing General Ecological Behavior

2000 ◽  
Vol 16 (1) ◽  
pp. 44-52 ◽  
Author(s):  
Florian G. Kaiser ◽  
Anders Biel
Keyword(s):  
Internal Consistency ◽  
Cross Cultural ◽  
Questionnaire Data ◽  
Situational Influences ◽  
Behavior Difficulties ◽  
Differential Behavior ◽  
Ecological Behavior ◽  
Political Actions ◽  
Measurement Approach

Summary: The General Ecological Behavior (GEB) scale was developed for cross-cultural applications ( Kaiser & Wilson, in press ). The present study compares ecological behavior in Sweden and Switzerland. Questionnaire data from 247 Swedish and 445 Swiss participants are presented. Reliability and internal consistency analyses revealed that the GEB scale was applicable to both the Swedish and Swiss samples. In general, Swiss behave more ecologically than Swedes. Nevertheless, several ecological behaviors turned out to be easier to conduct in Sweden than in Switzerland and vice versa. The GEB scale takes differential behavior difficulties into account that are most likely caused by situational influences. At the same time, the proposed behavior measurement approach guides the search for potentially useful political actions that make it easier for people to behave ecologically in some societies and, thus, can be adopted by others.

Microwave resonance method for measuring microliter volumes of free moisture in aviation fuels

2020 ◽  
pp. 49-56
Author(s):  
Vitaly V. Volkov ◽  
Michael A. Suslin ◽  
Jamil U. Dumbolov
Keyword(s):  
Solid Surface ◽  
Free Water ◽  
Resonance Method ◽  
Cavity Resonator ◽  
Maximum Error ◽  
Aviation Fuel ◽  
Fuel Quality ◽  
Microwave Resonance ◽  
Free Moisture ◽  
Microwave Losses

One of the conditions for ensuring the safety of air transport operation is the quality of aviation fuel refueled in aircraft. Fuel quality control is a multi-parameter task that includes monitoring the free moisture content. Regulatory documents establish the content of free water no more than 0.0015% by weight. It is developed a direct electrometric microwave resonance method for controlling free moisture in aviation fuels, which consists in changing the shape of the water drops by pressing them on a solid surface inside a cylindrical cavity resonator. This can dramatically increase dielectric losses. Analytical and experimental analysis of the proposed method is carried out. The control range from 0,5 to 30 μl of absolute volume of moisture in aviation fuels with a maximum error of not morethan 25 % is justified. The sensitivity of the proposed method for monitoring microwave losses in free moisture drops transformed into a thin layer by pressing is an order of magnitude greater than the sensitivity of the method for monitoring microwave losses in moisture drops on a solid surface in a resonator. The proposed method can be used as a basis for the development of devices for monitoring the free moisture of aviation fuels in the conditions of the airfield and laboratory. The direction of development of the method is shown.

Sign in / Sign up

Export Citation Format

Share Document