Correlation between measurement of an ice detector and the mass of ice accreted on two different sized conductors

1999 ◽  
Vol 26 (6) ◽  
pp. 869-875 ◽  
Author(s):  
J Druez ◽  
P McComber ◽  
M Farzaneh
Keyword(s):  
Field Data ◽  
Test Site ◽  
Ice Accretion ◽  
Electrical Conductor ◽  
Alarm Signal ◽  
Alarm Signals ◽  
Detector Signal ◽  
At Resonance ◽  
Data Points ◽  
Electrical Conductors

In cold regions, atmospheric icing is an important parameter for the design and reliability of exposed structures. A test site, located on Mt. Valin (Québec) Canada, is used to obtain field data on icing events. This test site mainly includes two test lines supporting four types of electrical conductors, instrumentation, and an ice detector. The ice detector monitors ice accretion by measuring the shift in frequency, at resonance, of a vibrating cylindrical probe, under the effect of the mass of ice accreted. This instrument, which is electrically de-iced, sends a cumulative alarm signal for each ice mass accretion reaching a preset value. The correlation between the ice detector signal and the mass of ice accreted on two different sized conductors is presented for three typical icing events monitored during the 1994-1995 season. In order to improve the correlation, a procedure rejects the data points corresponding to the shedding of ice during an icing event. The comparison between the mass of ice accreted on different conductors and the ice detector signal is a convenient way to calibrate the instrument. Then, these results could be used for predicting the ice mass accreted on similar cables, using the number of alarm signals from the ice detector. Results indicate the need to take into consideration the cable diameter and the apparent area of the probe with respect to the direction of droplets in the calibration of such ice detector.Key words: ice accretion, ice detector, electrical conductor, correlation, calibration, icing model, ice prediction, in-cloud icing, precipitation icing.

Preliminary field data of selected deep-rooted vegetation effects on the slope-vegetation-atmosphere interaction: results from an in-situ test 

2021 ◽  
Author(s):  
Vito Tagarelli ◽  
Federica Cotecchia ◽  
Osvaldo Bottiglieri
Keyword(s):  
Soil Water ◽  
Pore Water ◽  
Field Data ◽  
Test Site ◽  
Grass Species ◽  
In Situ Test ◽  
South Eastern ◽  
Atmosphere Interaction ◽  
The Stability

<p>The soil-vegetation-atmosphere interaction is becoming more and more the subject of intense scientific research, motivated by the wish of using smart vegetation implants as sustainable mitigation measure for erosive phenomena and slope instability processes. <br>The use of novel naturalistic interventions making use of vegetation has been already proven to be successful in the reduction of erosion along sloping grounds, or in increasing the stability of the shallow covers of slopes, whereas the success of vegetation as slope stabilization measure still needs to be scientifically proven for slopes location of deep landslides, whose current activity is climate-induced, as frequent in the south-eastern Apennines. Recently, though, peculiar natural perennial grass species, which develop deep root systems, have been found to grow in the semi-arid climate characterizing the south-eastern Apennines and to determine a strong transpirative flow. Therefore, their peculiar leaf architecture, their crop density, combined with their perennial status and transpiration capacity, make such grass species suitable for the reduction of the net infiltration rates, equal to the difference between the rainfall rate and the sum of the runoff plus the evapotranspiration rate. As such, the grass species here of reference have been selected as vegetation measure intended to determine a reduction of the piezometric levels in the slope down to large depths, in order to increase the stability of deep landslide bodies. <br>At this stage, only preliminary field data representing the interaction of clayey soils with the above cited vegetation species are available. These have been logged within a full scale in-situ test site, where the deep-rooted crop spices have been seeded and farmed. The test site (approximatively 2000 m<sup>2</sup>) has been set up in the toe area of the climate-induced Pisciolo landslide, in the eastern sector of the Southern Apennines.<br>The impact of the vegetation on the hydro-mechanical state of the soil is examined in terms of the spatial and temporal variation of the soil water content, suction an pore water pressure from ground level down to depth, both within the vegetated test site and outside it, where only spare wild vegetation occur, in order to assess the effects of the implant of the selected vegetation. The soil water contents, suctions and pore water pressures have been also analyzed taking into account of the climatic actions, monitored by means of a meteorological station. </p>

scholarly journals From examination of natural events to a proposal for risk mitigation of lahars by a cellular-automata methodology: a case study for Vascún valley, Ecuador

2020 ◽  
Vol 20 (1) ◽  
pp. 1-20 ◽  
Author(s):  
Valeria Lupiano ◽  
Francesco Chidichimo ◽  
Guillermo Machado ◽  
Paolo Catelan ◽  
Lorena Molina ◽  
...  
Keyword(s):  
Cellular Automata ◽  
Cellular Automaton ◽  
Field Data ◽  
Risk Mitigation ◽  
Environmental Disaster ◽  
Safety Measures ◽  
Rainfall Events ◽  
Data Points ◽  
Tungurahua Volcano

Abstract. Lahars are erosive floods, mixtures of water and pyroclastic detritus, known for being the biggest environmental disaster and causing a large number of fatalities in volcanic areas. Safety measures have been recently adopted in the threatened territories by constructing retaining dams and embankments in key positions. More disastrous events could be generated by the difficulty of maintaining these works in efficiency and for the changed risk conditions originating from their presence and the effects of their functioning. LLUNPIY/3r, a version of the cellular-automaton model LLUNPIY for lahar simulations, is presented. The growing frequency of lahars in the Vascún valley of Tungurahua volcano (Ecuador), probably due to the effects of the climatic change, has recently produced smaller and less dangerous events, sometimes favored by the collapse of ponds generated by small landslides. An investigation is performed here in order to reproduce such situations in a controlled way by the use of LLUNPIY/3r simulations. Using precise field data, points are individuated where dams by backfill, which are easy to collapse, can produce the formation of ponds; LLUNPIY/3r simulations permit projecting the triggering of small lahars by minor rainfall events or projecting, in the case of more rainfall, the anticipation of lahar detachment, avoiding simultaneous and dangerous confluence with other lahars.

Inversion of controlled source audio‐frequency magnetotellurics data for a horizontally layered earth

Geophysics ◽  
1999 ◽  
Vol 64 (6) ◽  
pp. 1689-1697 ◽  
Author(s):  
Partha S. Routh ◽  
Douglas W. Oldenburg
Keyword(s):  
Field Data ◽  
Near Field ◽  
Dipole Source ◽  
Earth Model ◽  
Far Field ◽  
Audio Frequency ◽  
Controlled Source ◽  
The Earth ◽  
Data Points ◽  
Corrected Data

We present a technique for inverting controlled source audio‐frequency magnetotelluric (CSAMT) data to recover a 1-D conductivity structure. The earth is modeled as a set of horizontal layers with constant conductivity, and the data are apparent resistivities and phases computed from orthogonal electric and magnetic fields due to a finite dipole source. The earth model has many layers compared to the number of data points, and therefore the solution is nonunique. Among the possible solutions, we seek a model with desired character by minimizing a particular model objective function. Traditionally, CSAMT data are inverted either by using the far‐field data where magnetotelluric (MT) equations are valid or by correcting the near‐field data to an equivalent plane‐wave approximation. Here, we invert both apparent resistivity and phase data from the near‐field transition zone and the far‐field regions in the full CSAMT inversion without any correction. Our inversion is compared with that obtained by inverting near‐field corrected data using an MT algorithm. Both synthetic and field data examples indicate that a full CSAMT inversion provides improved information about subsurface conductivity.

Comparison and Analysis of Identification of Soil Stratigraphy in Shanghai between CPTU Test and Laboratory Test

2012 ◽  
Vol 204-208 ◽  
pp. 732-737
Author(s):  
Jun Peng Wang ◽  
Yong Nan Wu ◽  
Yao Liu
Keyword(s):  
Grain Size ◽  
Laboratory Test ◽  
Size Distribution ◽  
Field Data ◽  
Test Site ◽  
Penetration Test ◽  
Road Tunnel ◽  
Piezocone Penetration Test ◽  
Comparison And Analysis ◽  
Soft Deposit

This article presents a comparison and analysis between piezocone penetration test (CPTU) and laboratory test in identifying soil stratigraphy of Shanghai. In China, stratigraphy for soft deposit is mainly obtained from plasticity index and grain size distribution of borehole samples in the laboratory (refer to code method). Identification of soil stratigraphy with CPTU was developed and improved in recent decades. The analysis is carried out with the field data at test site of Yan’an Road Tunnel in Shanghai. The stratigraphy charts proposed by Robertson in 1990 (refer to Robertson charts (1990)) are used to identify soil strata. The results are comparison with that from the code method. The results show that Robertson charts (1990) can be suitable to identify the stratigraphy of soft deposit of Shanghai. Moreover, the discussion on discrepancies between them is also conducted.

scholarly journals ROAD SURFACE DETECTION FROM MOBILE LIDAR DATA

2018 ◽  
Vol IV-5 ◽  
pp. 95-101 ◽  
Author(s):  
M. Yadav ◽  
B. Lohani ◽  
A. K. Singh
Keyword(s):  
Point Cloud ◽  
Three Dimensional ◽  
Test Site ◽  
Road Surface ◽  
Lidar Data ◽  
Rural Roads ◽  
The Road ◽  
Surface Detection ◽  
Rural Road ◽  
Data Points

<p><strong>Abstract.</strong> The accurate three-dimensional road surface information is highly useful for health assessment and maintenance of roads. It is basic information for further analysis in several applications including road surface settlement, pavement condition assessment and slope collapse. Mobile LiDAR system (MLS) is frequently used now a days to collect detail road surface and its surrounding information in terms three-dimensional (3D) point cloud. Extraction of road surface from volumetric point cloud data is still in infancy stage because of heavy data processing requirement and the complexity in the road environment. The extraction of roads especially rural road, where road-curb is not present is very tedious job especially in Indian roadway settings. Only a few studies are available, and none for Indian roads, in the literature for rural road detection. The limitations of existing studies are in terms of their lower accuracy, very slow speed of data processing and detection of other objects having similar characteristics as the road surface. A fast and accurate method is proposed for LiDAR data points of road surface detection, keeping in mind the essence of road surface extraction especially for Indian rural roads. The Mobile LiDAR data in <i>XYZI</i> format is used as input in the proposed method. First square gridding is performed and ground points are roughly extracted. Then planar surface detection using mathematical framework of principal component analysis (PCA) is performed and further road surface points are detected using similarity in intensity and height difference of road surface pointe in their neighbourhood.</p><p>A case study was performed on the MLS data points captured along wide-street (two-lane road without curb) of 156<span class="thinspace"></span>m length along rural roadway site in the outskirt of Bengaluru city (South-West of India). The proposed algorithm was implemented on the MLS data of test site and its performance was evaluated it terms of recall, precision and overall accuracy that were 95.27%, 98.85% and 94.23%, respectively. The algorithm was found computationally time efficient. A 7.6 million MLS data points of size 27.1<span class="thinspace"></span>MB from test site were processed in 24 minutes using the available computational resources. The proposed method is found to work even for worst case scenarios, i.e., complex road environments and rural roads, where road boundary is not clear and generally merged with road-side features.</p>

scholarly journals Testing of Auditory Clinical Alarms in ICU/CCU

2020 ◽  
Vol 2 ◽  
pp. 9-17
Author(s):  
Thangavelu S. D. ◽  
Supriyanto E. ◽  
Yunus J.
Keyword(s):  
Test Signal ◽  
Alarm System ◽  
Alarm Signal ◽  
Single Tone ◽  
Alarm Signals ◽  
Clinical Alarms ◽  
Usability Tests ◽  
Sample Proportion ◽  
The One ◽  
Almost All

Almost all medical devices in ICU/CCU have a built-in clinical alarm system to alert when there are changes in a patient’s condition. The objective of this study is to investigate the effectiveness of the existing alarm system in ICU/CCU. Two summative usability tests were conducted to test the effectiveness of existing and new alarm signals based on IEC 60601-1-8:2006 standard. Further formative test is conducted to study the perception of urgency associated with a number of tones in the alarm signals. The findings indicate that the existing auditory alarm signal in ICU/CCU does not indicate the urgency of the alarm conditions. The simulation test indicates that the respondents preferred 282Hz, 500Hz and 800Hz for low, medium and high-risk alarm respectively. The one-sample proportion z test on urgency mapping indicates that the proportion of responses for the highest risk is more than 50% for a single tone test signal. These results show that a single tone test signal being perceived as the highest risk is regardless of frequency. It can be concluded the auditory alarm designed based on this IEC 60608-1-8:2006 standard is not effective. As such it is proposed that the incorporation of the new alarm frequencies and tones will improve the effectiveness of the alarm signal

scholarly journals A Simple Red Tide Monitoring Method using Sentinel-2 Data for Sustainable Management of Brackish Lake Koyama-ike, Japan

Water ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 1044 ◽  
Author(s):  
Yuji Sakuno ◽  
Akihiro Maeda ◽  
Akihiro Mori ◽  
Shuji Ono ◽  
Akihiro Ito
Keyword(s):  
Spectral Reflectance ◽  
Sustainable Management ◽  
Field Data ◽  
Red Tide ◽  
Red Tides ◽  
Brackish Lake ◽  
Monitoring Method ◽  
Proposed Model ◽  
Data Points ◽  
Sentinel 2

We proposed and validated a method for monitoring red tides in the brackish Lake Koyama-ike, Japan, using Sentinel-2 Multispectral Instrument (MSI) data with a 10 m spatial resolution. To achieve this objective, we acquired 36 spectral reflectance/Chla data points in the field from 2012 to 2018. We obtained a high correlation of Chla (R2 = 0.83) using the proposed red tide model (RIKY = [MSI Band 5 – MSI Band 4]/[MSI Band 5 + MSI Band 4]) and field data. Based on our results, the proposed model was also validated using five Sentinel-2/Chla datasets from April to August 2017. Chla and red tide distribution characteristics estimated from Sentinel-2 data hardly appeared from April to July, and then spread rapidly throughout the lake (more than 70%) in August. Thus, Sentinel-2 data proved to be a very powerful tool in monitoring red tides in Lake Koyama-ike.

scholarly journals Electrical conductivity of HCl-bearing aqueous fluids to 700 ºC and 1 GPa

2020 ◽  
Vol 175 (12) ◽  
Author(s):  
Steffen Klumbach ◽  
Hans Keppler
Keyword(s):  
Electrical Conductivity ◽  
Elevated Temperatures ◽  
Pure Water ◽  
Negative Temperature ◽  
Hydrothermal Activity ◽  
Hydrothermal Systems ◽  
Ambient Conditions ◽  
Data Points ◽  
Hcl Concentration ◽  
Electrical Conductors

AbstractSubsurface magmatic–hydrothermal systems are often associated with elevated electrical conductivities in the Earthʼs crust. To facilitate the interpretation of these data and to allow distinguishing between the effects of silicate melts and fluids, the electrical conductivity of aqueous fluids in the system H2O–HCl was measured in an externally heated diamond anvil cell. Data were collected to 700 °C and 1 GPa, for HCl concentrations equivalent to 0.01, 0.1, and 1 mol/l at ambient conditions. The data, therefore, more than double the pressure range of previous measurements and extend them to geologically realistic HCl concentrations. The conductivities $$\sigma$$ σ (in S/m) are well reproduced by a numerical model log $$\sigma$$ σ  = −2.032 + 205.8 T−1 + 0.895 log c + 3.888 log $$\rho$$ ρ  + log$$\Lambda_{0}$$ Λ 0 (T,$$\rho$$ ρ ), where T is the temperature in K, c is the HCl concentration in wt. %, and $$\rho$$ ρ is the density of pure water at the corresponding pressure and temperature conditions. $$\Lambda_{0}$$ Λ 0 (T,$$\rho$$ ρ ) is the limiting molar conductivity (in S cm2 mol−1) at infinite dilution, $$\Lambda_{0}$$ Λ 0 (T,$$\rho$$ ρ ) = 2550.14 − 505.10$$\rho$$ ρ  − 429,437 T−1. A regression fit of more than 800 data points to this model yielded R2 = 0.95. Conductivities increase with pressure and fluid densities due to an enhanced dissociation of HCl. However, at constant pressures, conductivities decrease with temperature because of reduced dissociation. This effect is particularly strong at shallow crustal pressures of 100–200 MPa and can reduce conductivities by two orders of magnitude. We, therefore, suggest that the low conductivities sometimes observed at shallow depths below the volcanic centers in magmatic–hydrothermal systems may simply reflect elevated temperatures. The strong negative temperature effect on fluid conductivities may offer a possibility for the remote sensing of temperature variations in such systems and may allow distinguishing the effects of magma intrusions from changes in hydrothermal circulation. The generally very high conductivities of HCl–NaCl–H2O fluids at deep crustal pressures (500 MPa–1 GPa) imply that electrical conductors in the deep crust, as in the Altiplano magmatic province and elsewhere, may at least partially be due to hydrothermal activity.

OPC Client Application for CNC System Reliability Testing

2013 ◽  
Vol 333-335 ◽  
pp. 447-451
Author(s):  
Dou Pan Lv ◽  
Qiang Liu ◽  
Chong Peng
Keyword(s):  
System Reliability ◽  
Field Data ◽  
Client Application ◽  
Cnc System ◽  
Opc Server ◽  
System A ◽  
Opc Client ◽  
Opc Technology ◽  
Data Points ◽  
Ole For Process Control

In order to realize the batched and long-term testing for different models of CNC system, a testing system was built based on the Supervisory Control And Data Acquisition (SCADA) system architecture. It principally adopted the OLE for Process Control (OPC) technology to develop the client application. Through the millisecond access to the OPC server, the client monitors and stores all the field data points. Furthermore, the objective and accurate test data of CNC system reliability is retained. The client has been applied in analyzing the variation of all the field data points. It shows the testing method is effective.

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