scholarly journals Signal response of the Swiss plate geophone monitoring system impacted by bedload particles with different transport modes

2021 ◽  
Author(s):  
Zheng Chen ◽  
Siming He ◽  
Tobias Nicollier ◽  
Lorenz Ammann ◽  
Alexandre Badoux ◽  
...  
Keyword(s):  
Particle Size ◽  
Maximum Amplitude ◽  
Impact Angle ◽  
Bedload Transport ◽  
Frequency Change ◽  
General Increase ◽  
Transport Mode ◽  
Centroid Frequency ◽  
Signal Response ◽  
Transport Modes

Abstract. Controlled experiments were performed to investigate the acoustic signal response of the Swiss plate geophone (SPG) system impacted by bedload particles varying in size, impact angle and transport mode. The impacts of bedload particles moving by saltation, rolling, and sliding were determined by analyzing the experimental videos and corresponding vibration signals. For a particle impact on the bed or on the geophone plates, the signature of the generated signal in terms of maximum amplitude, number of impulses and centroid frequency was extracted from the raw monitoring data. So-called signal packets were determined by performing a Hilbert transform of the raw signal. The number of packets was calculated for each transport mode and for each particle size class, with sizes ranging from 28.1 mm to 171.5 mm. The results show how the number of signal impulses per particle mass, the amplitude of the signal envelope, and the centroid frequency change with increasing particle size, and they also demonstrate the effect of bedload transport mode on the signal response of the SPG system. We found that there is a general increase in the strength of the signal response or in the centroid frequency when the transport mode changes from sliding to rolling to saltation. The findings of this study help to better understand the signal response of the SPG system for different bedload transport modes, and may also contribute to an improvement of the procedure to determine bedload particle size from the SPG signal.

Controlled experiments and finite element simulations with the Swiss plate geophone bedload monitoring system: particle size identification and transport mode

2021 ◽  
Author(s):  
Zheng Chen ◽  
Siming He ◽  
Tobias Nicollier ◽  
Lorenz Ammann ◽  
Alexandre Badoux ◽  
...  
Keyword(s):  
Particle Size ◽  
Grain Size ◽  
Finite Element ◽  
Quantitative Agreement ◽  
Bedload Transport ◽  
Material Structure ◽  
Flume Experiments ◽  
Fem Simulations ◽  
Transport Mode ◽  
Signal Response

<p>The Swiss plate geophone (SPG) system is an indirect bedload transport monitoring device that records the acoustic signals generated by bedload particle impacts, with the goal to derive the bedload flux and grain size distribution. Particle drop experiments with quartz spheres in quiescent water in a flume setting were performed to investigate the dynamic signal response of the SPG system impacted by particle-like objects varying in size and impact location. Systematic flume experiments with natural bedload particles in flowing water were conducted to study the effects of impact angle and transport mode (saltating, rolling and sliding) on the SPG signals. For each impact caused by a single particle, the number of signal impulses, the amplitude, the positive area surrounded by the signal envelope, and the centroid frequency were extracted from the raw geophone monitoring data. The finite element method (FEM) was used to construct a virtual model of the SPG system and to determine the propagation characteristics of the numerical stress wave in the material structure. The experimental and numerical results showed a qualitative and partially quantitative agreement in the changes of the signal impulses, the amplitude, and the envelope area with increasing colliding sphere size. The centroid frequencies of the SPG vibrations showed qualitatively similar dependencies with increasing particle size as some field measurements for the coarser part of the investigated range of impact sizes. The effects of variable particle impact velocities and impact locations on the geophone plate were also investigated by drop experiments and compared to FEM simulations. In addition, the signal response for different bedload transport modes and varying impact angles were explored. In summary, the FEM simulations contribute to the understanding of the signal response of the SPG system and the findings in this study may eventually result in improving the bedload grain size classification and transport mode recognition.</p>

scholarly journals Bedload Transport Monitoring in Alpine Rivers: Variability in Swiss Plate Geophone Response

Sensors ◽  
2020 ◽  
Vol 20 (15) ◽  
pp. 4089 ◽  
Author(s):  
Gilles Antoniazza ◽  
Tobias Nicollier ◽  
Carlos R. Wyss ◽  
Stefan Boss ◽  
Dieter Rickenmann
Keyword(s):  
Maximum Amplitude ◽  
Detailed Comparison ◽  
Bedload Transport ◽  
Measuring Site ◽  
Power Law Function ◽  
Alpine Streams ◽  
Signal Response ◽  
Alpine Rivers ◽  
The Impact ◽  
Calibration Coefficients

Acoustic sensors are increasingly used to measure bedload transport in Alpine streams, notably the Swiss plate geophone (SPG) system. An impact experiment using artificial weights is developed in this paper to assess the variability in individual plate response and to evaluate the extent to which calibration coefficients can be transferred from calibrated plates to non-calibrated plates at a given measuring site and/or to other measuring sites. Results of the experiment over 43 plates at four measuring sites have notably shown (a) that the maximum amplitude (V) recorded by individual plates tends to evolve as a power law function of the impact energy (J), with an exponent slightly larger than 1, for all the plates at all measuring sites; (b) that there is a substantial propagation of energy across plates that should be taken into account for a better understanding of the signal response; (c) that the response of individual plates is in most cases consistent, which suggests that calibration coefficients are comparable within and in between measuring sites, but site-specific and plate-specific variabilities in signal response have to be considered for a detailed comparison.

Swiss Geophone Plate system: Quantification of the variability of signal response and of the signal propagation across plates using field-based impact experiments

2020 ◽  
Author(s):  
Gilles Antoniazza ◽  
Tobias Nicollier ◽  
Carlos R. Wyss ◽  
Stefan Boss ◽  
Dieter Rickenmann
Keyword(s):  
Maximum Amplitude ◽  
Signal Propagation ◽  
Bedload Transport ◽  
Swiss Alps ◽  
Measuring Station ◽  
Absolute Mass ◽  
Load Transport ◽  
Bed Load Transport ◽  
Signal Response ◽  
Plate System

<p>Impact sensors are increasingly used to indirectly monitor bedload transport in streams. Among them, the Swiss geophone impact plate system has notably proved its efficiency to continuously record bed load transport rates. Nevertheless, this approach still requires a robust calibration of the sensors to transform the relative signal of the geophones into an absolute mass of sediment in transport. Typically, the calibration is performed through the sampling during natural bedload transport events of all the particles that impact the plates, in order to build up rating curves between the signal recorded by the geophone sensors and the characteristics of the sediment that impact them (e.g. mass, grain size).  To better understand the system behavior it is important to quantify to what extent the signal response is similar (i) between sensors of a same geophone measuring station and (ii) between different geophone measuring stations. Also (iii), the amount of signal that propagates from impacted plates towards non-impacted plates (or ‘neighbouring noise’) needs to be quantified to improve the understanding of the system.</p><p>In this study, we investigate the above three elements by performing an impact experiment on the Swiss geophone plate system, and systematically record the signals produced at different plates by defined impacts of similar magnitude, and how the signal (maximum amplitude) propagates through neighbouring non-impacted plates. Each Swiss Geophone Plate of four measuring stations in the Swiss Alps – Vallon de Nant (VD), Albula (GR), Naviscence (VS) and Riedbach (VS) – were hit alternatively with impacts of increasing magnitude, and the signal they produced was systematically recorded over all the sensors of a given measuring station. Results of the study allow (i) to quantify the neighbouring noise that propagates from impacted plates towards non-impacted plates; (ii) to evaluate the attenuation rate of the signal for an impact of a given magnitude and (iii) to evaluate the variability in the propagation of neighbouring noise between sensors at a given measuring station and between different measuring stations.</p>

scholarly journals Achieving ‘Active’ 30 Minute Cities: How Feasible Is It to Reach Work within 30 Minutes Using Active Transport Modes?

2022 ◽  
Vol 11 (1) ◽  
pp. 58
Author(s):  
Alan Both ◽  
Lucy Gunn ◽  
Carl Higgs ◽  
Melanie Davern ◽  
Afshin Jafari ◽  
...  
Keyword(s):  
Climate Change ◽  
Population Growth ◽  
Active Transport ◽  
Public Transport ◽  
Traffic Congestion ◽  
Motor Vehicle ◽  
Spatial Relationship ◽  
Rapid Urbanization ◽  
Transport Mode ◽  
Transport Modes

Confronted with rapid urbanization, population growth, traffic congestion, and climate change, there is growing interest in creating cities that support active transport modes including walking, cycling, or public transport. The ‘30 minute city’, where employment is accessible within 30 min by active transport, is being pursued in some cities to reduce congestion and foster local living. This paper examines the spatial relationship between employment, the skills of residents, and transport opportunities, to answer three questions about Australia’s 21 largest cities: (1) What percentage of workers currently commute to their workplace within 30 min? (2) If workers were to shift to an active transport mode, what percent could reach their current workplace within 30 min? and (3) If it were possible to relocate workers closer to their employment or relocate employment closer to their home, what percentage could reach work within 30 min by each mode? Active transport usage in Australia is low, with public transport, walking, and cycling making up 16.8%, 2.8%, and 1.1% respectively of workers’ commutes. Cycling was found to have the most potential for achieving the 30 min city, with an estimated 29.5% of workers able to reach their current workplace were they to shift to cycling. This increased to 69.1% if workers were also willing and able to find a similar job closer to home, potentially reducing commuting by private motor vehicle from 79.3% to 30.9%.

Study on Process of Particle Impact on Curved Surface of Vane by Finite Element Method

2010 ◽  
Vol 139-141 ◽  
pp. 1303-1307
Author(s):  
Xiao Jing Yang ◽  
Yi Lin Chi ◽  
Guan Zhang He
Keyword(s):  
Particle Size ◽  
Energy Exchange ◽  
Surface Deformation ◽  
Plastic Property ◽  
Impact Angle ◽  
Surface Shape ◽  
Curved Surface ◽  
Particle Impact ◽  
Size Of Particles ◽  
Distribution Of Stress

The process of particle impacting and contacting curved surface of vane was studied, and the characteristics of particle size, particle initial velocity and its impacting direction affect the stress of subsurface were analyzed by using ANSYS/LS-DANY software. It is shown that the interaction between particles and surface of vane is affected by nonlinear factors such as the elastic-plastic property of material, the state of impacting and contacting and surface shape. The increment in particle size increases the stress of the surface impacted and the sphere of action is also enlarged. The influence of the size of particles is remarkable. Particle impact velocity is related to energy exchange and has influences on stress value and the area of surface deformation. Due to impact angle is related to shape of curved vane, so the distribution of stress is changed and the value of the stress in surface layer is also influenced when particles impact curved surface of vane from different directions. The research will be helpful to disclose the mechanics of the wear on the condition of particle impact.

scholarly journals Simulation of the Daily Activity Plans of Travelers Using the Park-and-Ride System and Autonomous Vehicles: Work and Shopping Trip Purposes

2020 ◽  
Vol 10 (8) ◽  
pp. 2912 ◽  
Author(s):  
Jairo Ortega ◽  
Jamil Hamadneh ◽  
Domokos Esztergár-Kiss ◽  
János Tóth
Keyword(s):  
Travel Time ◽  
Travel Behavior ◽  
Autonomous Vehicles ◽  
Daily Activity ◽  
Transport Mode ◽  
Park And Ride ◽  
Activity Chain ◽  
Private Car ◽  
Transport Modes ◽  
The Impact

The preferences of travelers determines the utility of daily activity plans. Decision-makers can affect the preference of travelers when they force private car users to use park-and-ride (P&R) facilities as a way of decreasing traffic in city centers. The P&R system has been shown to be effective in reducing uninterrupted increases in traffic congestion, especially in city centers. Therefore, the impacts of P&R on travel behavior and the daily activity plans of both worker and shopper travelers were studied in this paper. Moreover, autonomous vehicles (AVs) are a promising technology for the coming decade. A simulation of the AV as part of a multimodal system, when the P&R system was integrated in the daily activity plans, was carried out to determine the required AV fleet size needed to fulfill a certain demand and to study the impacts of AVs on the behavior of travelers (trip time and distance). Specifically, a group of travelers, who use private cars as their transport mode, was studied, and certain modifications to their daily activity plans, including P&R facilities and changing their transport mode, were introduced. Using the MATSim open-source tool, four scenarios were simulated based on the mentioned modifications. The four scenarios included (1) a simulation of the existing transport modes of the travelers, (2) a simulation of their daily activity plans when their transport modes were changed to AVs, (3) a simulation of the travelers, when P&R facilities were included in their activity chain plans, and (4) a simulation of their daily activity plans, when both P&R and AVs were included in their activity chain plans. The result showed that using the P&R system increased overall travel time, compared with using a private car. The results also demonstrated that using AVs as a replacement for conventional cars reduced travel time. In conclusion, the impact of P&R and AVs on the travel behavior of certain travelers was evaluated in this paper.

Experimental Investigation on the Influence of Particle Size in a Submerged Slurry Jet on Erosion Rates and Patterns

2017 ◽  
Author(s):  
Soroor Karimi ◽  
Amir Mansouri ◽  
Siamack A. Shirazi ◽  
Brenton S. McLaury
Keyword(s):  
Particle Size ◽  
Erosion Rate ◽  
Erosive Wear ◽  
Impact Angle ◽  
Piping System ◽  
Slurry Erosion ◽  
Material Particle ◽  
Impact Speed ◽  
Effect Of Particle Size ◽  
Sand Particles

Sand particles entrained in fluids can cause erosive wear and damage to piping materials by impacting their surfaces which could result in failure of the piping system. Several parameters have been determined to affect the erosion behavior and mechanism of solid particle erosion. Some of these parameters include surface material, particle impact speed and angle, and particle size, shape and hardness. However, the effect of particle size on the total erosion rate and local erosion pattern has not been thoroughly investigated. It has been observed that sand particles with various sizes cause different slurry erosion patterns. Changing the particle size alters the Stokes number and consequently produces different erosion patterns and magnitudes. Thus, the effects of particle size on total erosion rate and erosion pattern in a submerged slurry jet are investigated for different impingement angles. Experiments are performed on 316 stainless steel specimens for average particles sizes of 25, 75, 150, and 300 μm. The jet angle is varied to 45, 75 and 90 degrees, and the slurry jet velocity is set to 14 m/s. The erosion pattern of the specimen is examined by obtaining the 3D microscopic profile of the eroded specimen by means of an optical profiler. It is found that the erosion profile changes as the jet angle varies. It is also observed that erosion profile is significantly different for smaller particles as compared to the larger particles. Moreover, these differences become more pronounced as the jet angle decreases. The present work discusses the differences of erosion patterns produced by both large and small particles. Computational Fluid Dynamics (CFD) is also used to study the effect of particle size on particle trajectories, impact speed, and impact angle. Also, CFD results help in explaining the differences observed in the erosion profiles caused by different particle sizes.

scholarly journals The Methodology of Selecting the Transport Mode for Companies on the Slovak Transport Market

2017 ◽  
Vol 7 (1) ◽  
pp. 6-13 ◽  
Author(s):  
Lenka Černá ◽  
Vladislav Zitrický ◽  
Jozef Daniš
Keyword(s):  
Business Processes ◽  
Slovak Republic ◽  
Road Transport ◽  
The European Union ◽  
Transport Costs ◽  
Car Industry ◽  
Transport Mode ◽  
Transport Modes ◽  
Transport Volume ◽  
Selection Of

AbstractTransport volume in the Slovak Republic is growing continuously every year. This rising trend is influenced by the development of car industry and its suppliers. Slovak republic has also a geographic strategy position in middle Europe from the side of transport corridors (east-west and north-south). The development of transport volume in freight transport depends on the transport and business processes between the European Union and China and it is an opportunity for Slovak republic to obtain transit transport flows.In the Slovak Republic, road transport has a dominant position in the transport market. The volume of road transport has gradually increased over the past years. The increase of road transport is reflected on the highways and speed roads in regions which have higher economic potential. The increase of rail transport as seen on the main rail corridors is not as significant as in road transport. Trade globalization also has an influence on the increase of transport volume in intermodal transport. Predicted increase in transport volume for this transport mode is from 2,3 mil ton per year at present to 8 mil ton in the year 2020. Selection of transport mode and carrier is an important aspect for logistic management, because companies (customers) want to reduce the number of carriers which they trade and they create the system of several key carriers. Bigger transport volume and more qualitative transport service give a possibility to reduce transport costs. This trend is positive for carriers too, because the carriers can focus only on the selected customers and provide more qualitative services.The paper is focused on the selection of transport mode based on the proposed methodology. The aims of the paper are, definition of criteria which directly influence the selection of transport modes, determination of criteria based on the subjectively methods, creation of process for the selection of transport modes and practical application of proposed methodology.

scholarly journals Analysis Of Provided Service Quality In Flowers And Living Plants Transport

2015 ◽  
Vol 23 (36) ◽  
pp. 159-166
Author(s):  
Adela Poliaková
Keyword(s):  
Service Quality ◽  
Quality Of Services ◽  
Transport Mode ◽  
Specific Transport ◽  
Transport Modes ◽  
Practical Demonstration

Abstract This paper analyses quality of the living flowers and plants transportation. A part of this paper compares the demands for a particular transport mode and a practical demonstration of these transport modes within a specific transport mode. The paper presents a survey of quality of services provided by individual transport modes.

Virtual reality as a new tool for transport data collection

2021 ◽  
Vol 60 (4) ◽  
pp. 23-38
Author(s):  
Laura Agudelo-Vélez ◽  
Iván Sarmiento-Ordosgoitia ◽  
Jorge Córdoba-Maquilón
Keyword(s):  
Virtual Reality ◽  
Latin American ◽  
Latent Variable ◽  
Travel Behaviour ◽  
Urban Environments ◽  
Relevant Variable ◽  
Transport Mode ◽  
Transport Studies ◽  
Transport Modes ◽  
Mode Of Transport

Transport studies that adopt complex analyses present methodological challenges that lead to the use of innovative techniques to address the limitations of traditional methods. In the Latin American context, people consider security as a relevant variable in their daily lives. Thus, when people travel around the city and choose a mode of transport, secu-rity becomes an important factor and should therefore be included in transport studies. However, the definition of security in terms of transport in the Colombian context remains unclear. Therefore, we examined the security percep-tion effect on transport mode choice by addressing security as a latent variable consisting of three elements: environ-ment, subject and transport mode. We proposed the use of virtual reality (VR) to recreate travel routes and offer partic-ipants a scenario of choice closer to the natural conditions of a trip. The participants were provided routes in the form of immersive 3D videos recreating natural trip conditions to identify their choices and travel behaviour. Recordings were made of daily scenarios and existing urban environments portraying real and active modes of transport, giving respondents an almost-natural experience. The use of 360-degree immersive videos offers a multisensory experience allowing both the capture of socioeconomic and travel information and the collection of journey perception. The experiment evaluated two environments in Medellín, Colombia (secure (E1) and insecure (E2)) and studied the effects of lighting conditions (day (D) and night (N)). A total of four videos (E1D, E1N, E2D and E2N) depicting six transport modes in tandem were assessed by 92 participants from Medellín and Bogotá, Colombia. We found that environment-associated security perception varies depending on the time of the journey (day/night) and one’s familiarity with the environment. The research results position VR as a tool that offers high potential to support transport studies. We found that people’s movements, gestures and expressions while participating in the VR experiments resembled what was expected from journeys in reality. VR constitutes a relevant tool for transport studies, as it allows for an assessment of active transport mode perceptions. It prevents participants from being exposed to the risk associated with travel to specific places and carries out several routes in different transport modes even when participants cannot or have never undertaken journeys in the modes under assessment.

Sign in / Sign up

Export Citation Format

Share Document