A calibration method for monitoring bedload transport rate using Japanese pipe-type hydrophone considering installation condition and aging

2020 ◽  
Author(s):  
Hiroaki Izumiyama ◽  
Taro Uchida ◽  
Takuma Iuchi ◽  
Nobuya Yoshimura ◽  
Takao Yamakoshi
Keyword(s):  
Sound Pressure ◽  
Calibration Method ◽  
Bedload Transport ◽  
Transport Rate ◽  
Mountainous Regions ◽  
Proportionality Constant ◽  
Mountain Watersheds ◽  
Time Integral ◽  
River Bed ◽  
The Difference

<p>Observation of bedload is quite important for understanding temporal and spatial variation of sediment transport in mountainous regions. In government-owned mountain watersheds in Japan, Japanese pipe-type hydrophones (Hydrotech Co., Ltd.) have been installed as a surrogate monitoring tool since about 2009 and continuous observations have been conducted. According to positive correlation between sound pressure and bedload transport rate, observed sound pressure is used to be integrated with respect to time and its value is converted into bedload transport rate using proportionality constant. However, it remains challenging to obtain precise bedload transport rate with high accuracy, because we should consider the difference of the way to fix the hydrophone on river bed among installed sites, deformation of steel pipe due to collision of sediment particles, and the difference of initial performance and aging of microphone. Hence, we have to calibrate frequently the proportionality constant. In this study, we investigate a calibration method which is easily conducted by engineers. Because it takes time and effort to obtain time integral of sound pressure, we try to calibrate the proportionality constant with the maximum sound pressure, which can be obtained easily.</p>

scholarly journals Vibrational and Acoustical Characteristics of Ear Pinna Simulators That Differ in Hardness

2021 ◽  
Vol 11 (3) ◽  
pp. 327-334
Author(s):  
Ryota Shimokura ◽  
Tadashi Nishimura ◽  
Hiroshi Hosoi
Keyword(s):  
External Auditory Canal ◽  
Sound Pressure ◽  
Bone Conduction ◽  
Calibration Method ◽  
Vibration Acceleration ◽  
Spectral Peaks ◽  
Ear Cartilage ◽  
A Current ◽  
Air Conduction ◽  
Dominant Frequencies

Because cartilage conduction—the transmission of sound via the aural cartilage—has different auditory pathways from well-known air and bone conduction, how the output volume in the external auditory canal is stimulated remains unknown. To develop a simulator approximating the conduction of sound in ear cartilage, the vibrations of the pinna and sound in the external auditory canal were measured using pinna simulators made of silicon rubbers of different hardness (A40, A20, A10, A5, A0) as measured by a durometer. The same procedure, as well as a current calibration method for air conduction devices, was applied to an existing pinna simulator, the Head and Torso Simulator (hardness A5). The levels for vibration acceleration and sound pressure from these pinna simulators show spectral peaks at dominant frequencies (below 1.5 kHz) for the conduction of sound in cartilage. These peaks were likely to move to lower frequencies as hardness decreases. On approaching the hardness of actual aural cartilage (A10 to A20), the simulated levels for vibration acceleration and sound pressure approximated the measurements of human ears. The adjustment of the hardness used in pinna simulators is an important factor in simulating accurately the conduction of sound in cartilage.

Acceptable Levels of Tonal and Broad-Band Repetitive and Continuous Sounds during the Performance of Nonauditory Tasks

1995 ◽  
Vol 81 (3) ◽  
pp. 803-816 ◽  
Author(s):  
Ulf Landström ◽  
Anders Kjellberg ◽  
Marianne Byström
Keyword(s):  
Reaction Time ◽  
Sound Pressure ◽  
Broad Band ◽  
Reaction Time Task ◽  
Simple Reaction Time Task ◽  
Reasoning Test ◽  
Band Noise ◽  
Time Test ◽  
The Difference ◽  
Reaction Time Test

Three groups of 24 subjects were exposed to a 1000–Hz tone or broad band noise in a sound chamber. During the exposures subjects were engaged in an easy reaction time test or a difficult grammatical reasoning test. For each exposure and work subjects adjusted the noise to a tolerance level defined by its interference with task performance. During the simple reaction-time task significantly higher sound-pressure levels were accepted than during the reasoning test. At the tonal exposure, much lower levels were accepted than during the exposure to broad-band noise. For continuous sound exposures much higher levels were accepted than for noncontinuous exposures. For tonal exposures the difference was approximately 5 dB, for the broad-band exposures approximately 9 dB. In a separate study the effects of the noncontinuity of the noise and pauses were analysed. The raised annoying effect of the noncontinuous noise was not more affected by the noncontinuity of the noise periods than by the noncontinuity of the pauses. The results imply that the annoying reactions to the sound will be increased for repetitive noise and that the reaction is highly influenced by the over-all noncontinuity of the exposure.

scholarly journals Semi-automated calibration method for modelling of mountain permafrost evolution in Switzerland

2016 ◽  
Vol 10 (6) ◽  
pp. 2693-2719 ◽  
Author(s):  
Antoine Marmy ◽  
Jan Rajczak ◽  
Reynald Delaloye ◽  
Christin Hilbich ◽  
Martin Hoelzle ◽  
...  
Keyword(s):  
Large Scale ◽  
Calibration Method ◽  
Swiss Alps ◽  
Climate Projections ◽  
European Alps ◽  
Permafrost Degradation ◽  
Future Evolution ◽  
Mountainous Regions ◽  
Automated Calibration ◽  
The Future

Abstract. Permafrost is a widespread phenomenon in mountainous regions of the world such as the European Alps. Many important topics such as the future evolution of permafrost related to climate change and the detection of permafrost related to potential natural hazards sites are of major concern to our society. Numerical permafrost models are the only tools which allow for the projection of the future evolution of permafrost. Due to the complexity of the processes involved and the heterogeneity of Alpine terrain, models must be carefully calibrated, and results should be compared with observations at the site (borehole) scale. However, for large-scale applications, a site-specific model calibration for a multitude of grid points would be very time-consuming. To tackle this issue, this study presents a semi-automated calibration method using the Generalized Likelihood Uncertainty Estimation (GLUE) as implemented in a 1-D soil model (CoupModel) and applies it to six permafrost sites in the Swiss Alps. We show that this semi-automated calibration method is able to accurately reproduce the main thermal condition characteristics with some limitations at sites with unique conditions such as 3-D air or water circulation, which have to be calibrated manually. The calibration obtained was used for global and regional climate model (GCM/RCM)-based long-term climate projections under the A1B climate scenario (EU-ENSEMBLES project) specifically downscaled at each borehole site. The projection shows general permafrost degradation with thawing at 10 m, even partially reaching 20 m depth by the end of the century, but with different timing among the sites and with partly considerable uncertainties due to the spread of the applied climatic forcing.

scholarly journals Comparing two years of Saharan dust source activation obtained by regional modeling and satellite observations

2012 ◽  
Vol 12 (10) ◽  
pp. 27667-27691
Author(s):  
I. Tegen ◽  
K. Schepanski ◽  
B. Heinold
Keyword(s):  
Regional Scale ◽  
Dust Emission ◽  
Saharan Dust ◽  
Strong Increase ◽  
Dust Source ◽  
Low Level ◽  
Mountainous Regions ◽  
Emission Fluxes ◽  
Low Level Jets ◽  
The Difference

Abstract. A regional-scale dust model is used to simulate Saharan dust emissions and atmospheric distributions in the years 2007 and 2008. The model results are compared to dust source activation events compiled from infrared dust index imagery from the geostationary Meteosat Second Generation (MSG) satellite. The observed morning maximum in dust source activation frequencies indicates that the breakdown of nocturnal low-level jets is responsible for a considerable number of dust source activation events in the Sahara. The comparison shows that the time of the day of the onset of dust emission is delayed in the model compared to the observations. Also, the simulated number of dust emission events associated with nocturnal low level jets in mountainous regions is underestimated in the model. The MSG dust index observations indicate a strong increase in dust source activation frequencies in the year 2008 compared to 2007, the difference between the two years is less pronounced in the model. The quantitative comparison of simulated dust optical thicknesses with observations at stations of the sunphotometer network AERONET shows, however, good agreement for both years, indicating that the number of observed dust activation events is only of limited use for estimating actual dust emission fluxes in the Sahara.

scholarly journals The Effect of Frequency Acoustic Stimulation Sound on Intrauterine Weakening of Pregnant Sheep

2017 ◽  
Vol 3 (6) ◽  
pp. 125
Author(s):  
Djamil Suherman ◽  
Hermanto Tri Joewono ◽  
I Komang Wiarsa Sardjana
Keyword(s):  
Abdominal Wall ◽  
Sound Pressure ◽  
Acoustic Stimulation ◽  
Uterine Wall ◽  
Sound Frequency ◽  
Pregnant Sheep ◽  
Post Test ◽  
The Difference ◽  
Level Of Sound Pressure ◽  
Veterinary Faculty

Research to determine changes in intrauterine sound pressure in pregnant sheep after administration acoustic stimulation outside of the abdominal wall at some frequency sounds. The study was conducted at the Animal Hospital of Veterinary Faculty of Airlangga University. Pre test experimental design with pre- and post-test one group to assess intra-uterine sound pressure changes. The study was conducted at two lambs pregnant aterm after acoustic stimulation at a distance of 10 cm from the surface of the abdominal wall to the sound pressure 80,85,90,95 and 100 decibels and sound frequency of 31.5, 63, 125, 250, 500, 1000, 2000, 4000, 6000 and 8000 hertz. The results showed that the difference between the sound pressure outside of the abdominal wall with intrauterine sound pressure on both the pregnant sheep by an average of 16.7570 ± 8.0797 decibels. This shows their weakening sound after passing through the abdominal wall and the uterine wall. By using a paired t-test, this weakening statistically significant. At frequencies from 31.5 to 1000 hertz weakening values from 5.2 to 17.1 decibels while in 2000-8000 hertz frequency weakening value of 20.2 to 30.8 decibels. The conclusion that the stimulation of noise from outside the walls of the abdomen weakening sound after penetrating the abdominal wall and the uterine wall. Weakening occur at every level of sound pressure and at every level of a given frequency. Weakening value becomes greater at frequencies above 1000 hertz.                                                                                                       Keywords: weakening, sound pressure, sound frequency, pregnant sheep.

scholarly journals Comparing two years of Saharan dust source activation obtained by regional modelling and satellite observations

2013 ◽  
Vol 13 (5) ◽  
pp. 2381-2390 ◽  
Author(s):  
I. Tegen ◽  
K. Schepanski ◽  
B. Heinold
Keyword(s):  
Regional Scale ◽  
Dust Emission ◽  
Saharan Dust ◽  
Strong Increase ◽  
Regional Modelling ◽  
Dust Source ◽  
Low Level ◽  
Mountainous Regions ◽  
Low Level Jets ◽  
The Difference

Abstract. A regional-scale dust model is used to simulate Saharan dust emissions and atmospheric distributions in the years 2007 and 2008. The model results are compared to dust source activation events compiled from infrared dust index imagery from the geostationary Meteosat Second Generation (MSG) satellite. The observed morning maximum in dust source activation frequencies indicates that the breakdown of nocturnal low level jets is an important mechanism for dust source activation in the Sahara. The comparison shows that the time of the day of the onset of dust emission is delayed in the model compared to the observations. Also, the simulated number of dust emission events associated with nocturnal low level jets in mountainous regions is underestimated in the model. The MSG dust index observations indicate a strong increase in dust source activation frequencies in the year 2008 compared to 2007. The difference between the two years is less pronounced in the model. Observations of dust optical thickness, e.g. at stations of the sunphotometer network AERONET, do not show such increase, in agreement with the model results. This indicates that the number of observed dust activation events is only of limited use for estimating actual dust emission fluxes in the Sahara. The ability to reproduce interannual variability of Saharan dust with models remains an important challenge for understanding the controls of the atmospheric dust load.

scholarly journals Variability of bedload transport rate during flood flows in the Zagożdżonka River

2010 ◽  
Vol 42 (1) ◽  
pp. 69-77 ◽  
Author(s):  
Zbigniew Popek
Keyword(s):  
Laboratory Experiments ◽  
Bedload Transport ◽  
Transport Rate ◽  
Environmental Restoration ◽  
Bed Shear Stress ◽  
Measurement Results ◽  
Gauge Station ◽  
Flood Flows ◽  
Bedload Sediment ◽  
Flood Flow

Variability of bedload transport rate during flood flows in the Zagożdżonka River The paper presents the measurement results of bedload sediment transport during the flood flows observed in the Zagożdżonka River. The point for measuring the bedload transport, equipped with sediment catcher, devices for continuous measurements, and automated data recording, was localized above the Czarna gauge station in catchment studied by the Department of Hydraulic Engineering and Environmental Restoration, Warsaw University of Life Sciences - SGGW. The results of bedload transport measurements during one of the flood flow waves were compared to those calculated by using the Bagnold's formula. To determine the critical bed-shear stress, the Author's formula resulting from laboratory experiments, was used. Calculated variability of bedload transport rate during analyzed flood flow wave apparently differed from that directly measured. Nevertheless, mass of bedload achieved from calculations was lower by 6% than that from measurements, which can be considered as good result consistence.

scholarly journals Investigating the Impact of Digital Elevation Models on Sentinel-1 Backscatter and Coherence Observations

2020 ◽  
Vol 12 (18) ◽  
pp. 3016
Author(s):  
Ignacio Borlaf-Mena ◽  
Maurizio Santoro ◽  
Ludovic Villard ◽  
Ovidiu Badea ◽  
Mihai Andrei Tanase
Keyword(s):  
Remote Sensing ◽  
Laser Scanning ◽  
Digital Elevation Models ◽  
Shuttle Radar Topography Mission ◽  
Synthetic Aperture ◽  
Mountainous Regions ◽  
Aerial Laser Scanning ◽  
Digital Elevation ◽  
The Difference ◽  
The Impact

Spaceborne remote sensing can track ecosystems changes thanks to continuous and systematic coverage at short revisit intervals. Active remote sensing from synthetic aperture radar (SAR) sensors allows day and night imaging as they are not affected by cloud cover and solar illumination and can capture unique information about its targets. However, SAR observations are affected by the coupled effect of viewing geometry and terrain topography. The study aims to assess the impact of global digital elevation models (DEMs) on the normalization of Sentinel-1 backscattered intensity and interferometric coherence. For each DEM, we analyzed the difference between orbit tracks, the difference with results obtained with a high-resolution local DEM, and the impact on land cover classification. Tests were carried out at two sites located in mountainous regions in Romania and Spain using the SRTM (Shuttle Radar Topography Mission, 30 m), AW3D (ALOS (Advanced Land Observation Satellite) World 3D, 30 m), TanDEM-X (12.5, 30, 90 m), and Spain national ALS (aerial laser scanning) based DEM (5 m resolution). The TanDEM-X DEM was the global DEM most suitable for topographic normalization, since it provided the smallest differences between orbital tracks, up to 3.5 dB smaller than with other DEMs for peak landform, and 1.4–1.9 dB for pit and valley landforms.

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