scholarly journals Quantitative causal selection patterns in token causation

2019 ◽  
Author(s):  
Adam Morris ◽  
Jonathan Scott Phillips ◽  
Tobias Gerstenberg ◽  
Fiery Andrews Cushman
Keyword(s):  
Good Reason ◽  
Causal Judgment ◽  
Lightning Strike ◽  
Lightning Strikes ◽  
Prior Probabilities ◽  
Causal Judgments ◽  
Causal Selection

When many events contributed to an outcome, people consistently judge some more causal than others, based in part on the prior probabilities of those events. For instance, when a tree bursts into flames, people judge the lightning strike more of a cause than the presence of oxygen in the air -- in part because oxygen is so common, and lightning strikes are so rare. These effects, which play a major role in several prominent theories of token causation, have largely been studied through qualitative manipulations of the prior probabilities. Yet, there is good reason to think that people's causal judgments are on a continuum -- and relatively little is known about how these judgments vary quantitatively as the prior probabilities change. In this paper, we measure people's causal judgment across parametric manipulations of the prior probabilities of antecedent events. Our experiments replicate previous qualitative findings, and also reveal several novel patterns that are not well-described by existing theories.

scholarly journals Effect of indirect lightning strike to 66kV transmission line in Java-Bali system

2018 ◽  
Vol 197 ◽  
pp. 11001
Author(s):  
Aristo Adi Kusuma ◽  
Putu Agus Aditya Pramana ◽  
Brian Bramantyo S.D.A. Harsono ◽  
Buyung Sofiarto Munir
Keyword(s):  
Transmission Line ◽  
Transmission Lines ◽  
Lightning Strike ◽  
Actual Condition ◽  
Peak Current ◽  
Lightning Strikes ◽  
Detection Systems ◽  
Current Magnitude ◽  
Lightning Detection ◽  
Insulator Flashover

Based on Java-Bali grid disturbance data, the 66kV transmission lines that is close to or intersect with 150kV or 500kV transmission line is often experienced earth fault due to insulator flashover. The insulator flashover can be caused by indirect lightning strike since lightning strikes tend to strike higher structure. Therefore, this paper will determine the effect of indirect lightning strike on 150kV or 500kV transmission line to 66kV transmission line by modeling and simulation using application of transient analysis. Variation of lightning peak current magnitude and gap between 66kV transmission line and transmission line with higher voltage is performed during simulation. The range of peak current magnitude follows the data from lightning detection systems, while the value of gap follows the data from actual condition. It is found that higher current peak and closer gap will cause higher transient overvoltage on insulator of 66kV transmission line thus insulator flashover may occur more frequent. Addition of earth wire on 66kV transmission line and gap between each transmission by organizing the sag of conductor can be performed to minimize the insulator flashover.

scholarly journals Earth-termination system for onshore wind Turbines.

2020 ◽  
Vol 11 (7-2020) ◽  
pp. 66-72
Author(s):  
Liubov A. Belova ◽  
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
Lightning Strike ◽  
Lightning Protection ◽  
Protection Measures ◽  
Lightning Strikes ◽  
Grounding System ◽  
Initial Stage ◽  
Wind Turbine Towers ◽  
Surge Protection

The earth-termination system for towers of ground-based wind turbines in addition to protective and functional grounding provides lightning protection grounding, which is especially important since the wind turbine is susceptible to lightning strikes. If insufficient protective measures are taken, the risk of damage to a wind turbine due to a lightning strike increases. Therefore, a well-thought-out built-in grounding system for wind turbine towers is needed, which would function as necessary and guarantee long-term mechanical strength and corrosion resistance. The configuration of grounding systems for wind turbines is discussed in IEC 61400-24, which deals with the topic of lightning protection for wind turbines, including detailed information on the choice of lightning protection measures and surge protection. It is advisable to create a lightning protection concept at the initial stage of planning a wind turbine in order to avoid later costly repairs and retrofitting.

scholarly journals Evaluation of Lightning Protection Efficacy on Nigerian Installations High Voltage Installations Using Screen and Cone of Protection Methods

2019 ◽  
Vol 4 (7) ◽  
pp. 1-10
Author(s):  
M. O. Oyeleye
Keyword(s):  
High Voltage ◽  
Computer Aided Design ◽  
Travelling Waves ◽  
Screening Method ◽  
Lightning Strike ◽  
Physical Measurement ◽  
Lightning Strikes ◽  
Spatial Design ◽  
Protective System ◽  
Design Values

This study evaluated lightning protective system efficacy on 11kV-132kV substation-power line installation in Ikorodu, Lagos State, Nigeria with reference to cloud to ground(C-G) lightning strike (LS) events. It focus on interception of lightning strikes and its protection with reference to direct lightning strike (DLS) and indirect lightning strike (IDLS). Data were collected from Ikorodu 132/33 kV Transmission Substation and its four major injection stations.  This work was carried out using physical measurement of raw data obtained from the high voltage substation. Installations were scaled down and modelled dimensionally using AutoCAD software in order to measure spatial parameters in order to measure the screening of the existing substations and connected lines, as well as the existing cone angles of protection. Probability of lightning efficiency of lightning protective level (LPL) are used for screening evaluation while spike and sky wire angle of protection are used for cone of protection evaluation. Physical measurement of six substations (33/11 kV and 132/33 kV substations) in the studied area were also carried out to evaluate the effectiveness of the installed lightning arresters with respect to the protected devices using applicable standard. The results under the prevailing lightning protective system, LPS, (screening method), revealed that the existing 33/11 kV and 132/33 kV substations are not adequately protected against lightning strike; 132/33 kV substation is more vulnerable to lightning strike than 33/11kV substation and that the incoming 132kV power lines to the substation are adequately protected. The evaluation of the installed distances of all lightning arresters are within standard range and would adequately protect substation transformers against travelling waves (Indirect Stroke) events. The installed lightning arresters (LAs) would adequately protect substation transformers against travelling waves (Indirect Stroke) events. The adequate protection should be reinforced with proposed design scheme in further study in order to mitigate the disastrous effects of lightning strike. Any proposed design of protective system for electric power installations in Nigeria should be simulated using computer aided design software for scaled validation of dimensional and spatial design values in order to mitigate reported failures and uncertainties in identifying causes of observed failures in the system.

scholarly journals Changes in Lightning Fire Incidence in the Tasmanian Wilderness World Heritage Area, 1980–2016

Fire ◽  
2018 ◽  
Vol 1 (3) ◽  
pp. 38 ◽  
Author(s):  
Jenny Styger ◽  
Jon Marsden-Smedley ◽  
Jamie Kirkpatrick
Keyword(s):  
Cultural Values ◽  
Fire Regimes ◽  
World Heritage ◽  
Fuel Load ◽  
Lightning Strike ◽  
Lightning Strikes ◽  
World Heritage Area ◽  
Soil Dryness ◽  
Heritage Area ◽  
Fire Incidence

The Tasmanian Wilderness World Heritage Area (TWWHA) has globally significant natural and cultural values, some of which are dependent on the absence of fire or the presence of particular fire regimes. Planned burning is currently used to reduce the risk of loss of world heritage values from unplanned fires, but large and damaging fires still occur, with lightning as the primary ignition source. Lightning-caused fire was rare in the TWWHA before 2000. There has since been an increase in both the number of fires following lightning storms and the area burnt by these fires. In the absence of a direct measurement of lightning strike incidence, we tested whether changes in rainfall, soil dryness and fuel load were responsible for these changes in fire incidence and extent. There were no relationships between these variables and the incidence of fires associated with lightning, but the variability in the Soil Dryness Index and the mean of 25% of driest values did predict both the number and area of fires. Thus, it appears that an increase in the proportion of lightning strikes that occur in dry conditions has increased ignition efficiency. These changes have important implications for the management of the TWWHA’s values, as higher projected fuel loads and drier climates could result in a further increase in the number of fires associated with lightning.

scholarly journals The Dangerous Life of a Storm Chaser: A Lightning Strike Injury Causing Serious Injury

2020 ◽  
Vol 8 ◽  
pp. 232470962092556
Author(s):  
Jeffrey Shipman ◽  
Brittany Carver ◽  
Kelly Painter ◽  
Stacia Shipman
Keyword(s):  
Case Report ◽  
Pulmonary Edema ◽  
Tympanic Membrane ◽  
Rare Events ◽  
Lightning Strike ◽  
Injury Patterns ◽  
Lightning Strikes ◽  
Uncommon Case ◽  
Serious Injury

Lightning strikes to people are rare events that cause significant injuries and mortality when they do occur. We describe an uncommon case of a storm chaser in Oklahoma who was struck by lightning who suffered cutaneous burns, bilateral tympanic membrane ruptures, as well as pulmonary edema, which is an atypical finding in survivors. This case report highlights several injury patterns seen in lightning strike cases and provides evidence that these patients should be managed at a center with multidisciplinary services available.

scholarly journals Evaluation of a Direct Lightning Strike to the 24 kV Distribution Lines in Thailand

Energies ◽  
2019 ◽  
Vol 12 (16) ◽  
pp. 3193 ◽  
Author(s):  
Pornchai Sestasombut ◽  
Atthapol Ngaopitakkul
Keyword(s):  
Electromagnetic Transients ◽  
Lightning Strike ◽  
Significant Variable ◽  
Line System ◽  
Lightning Strikes ◽  
Underground Cables ◽  
Ground Resistance ◽  
Distribution Lines ◽  
Surge Arresters ◽  
Distribution Line

This paper evaluates the effect of a lightning strike directly on the 24 kV distribution lines in Thailand, where such strikes are one of the main causes of power outages. The voltage across the insulator, and the arrester energy absorbed due to the lightning, need to be analyzed for different grounding distances of the overhead ground wire, ground resistance, lightning impact positions, and lightning current waveforms. Analysis and simulations are conducted using the Alternative Transients Program/Electromagnetic Transients Program (ATP/EMTP) to find the energy absorbed by the arrester and the voltages across the insulator. The results indicate that when surge arresters are not installed, the voltage across the insulator at the end of the line is approximately 1.4 times that in the middle of the line. In addition, the ground resistance and grounding distance of the overhead ground wire affect the voltage across the insulator if the overhead ground wire is struck. When surge arresters are installed, a shorter grounding distance of the overhead ground wire and a lower ground resistance are not always desirable; this is because they reduce the back-flashover rate and the voltage across the insulator if lightning strikes the overhead ground wire. However, lightning strikes to the phase conductor result in high arrester energy and the possibility that the arrester will fail. Furthermore, the tail time of the lightning waveform is a significant variable when considering the energy absorbed by the arrester, whereas the front time is important for the voltage across the insulator. In case lightning strikes directly on the connected point between the overhead lines and the underground cables, the distribution line system is protected only by the lightning arrester at the connection point. The overvoltage at the connection point is lower than the basic impulse level at 24 kV of 125 kV, but the overvoltage at the end of the cable is still more than 125 kV in case the cable is longer than 400 m. When the distribution line system is protected by the lightning arrester at both the connection point and the end of the cable, it results in overvoltage throughout the cable is lower than the critical flashover of insulation. This method is the best way to reduce the failure rate of underground cables and equipment that are connected to the distribution line system.

scholarly journals Electrically conductive carbon fiber layers as lightning strike protection for non-conductive epoxy-based CFRP substrate

2020 ◽  
Vol 54 (29) ◽  
pp. 4547-4555 ◽  
Author(s):  
Siwat Manomaisantiphap ◽  
Vipin Kumar ◽  
Takao Okada ◽  
Tomohiro Yokozeki
Keyword(s):  
Carbon Fiber ◽  
High Speed ◽  
Lightning Strike ◽  
Fiber Reinforced ◽  
Electrically Conductive ◽  
Lightning Strikes ◽  
Carbon Fiber Reinforced Plastics ◽  
Reinforced Plastics ◽  
Fiber Reinforced Plastics ◽  
Hybrid Laminate

A large amount of electrically conductive fillers is needed to enhance a Carbon Fiber Reinforced Plastics (CFRP) electrical conductivity enough to withstand lightning strikes of peak currents. However, such large alien constituents hamper the inherent good mechanical properties of CFRP structures. In this work, a solution has been proposed to retain both desired properties in a CFRP laminate. Layer-wise hybrid laminate has been demonstrated as a solution for lightning strike protection of Carbon Fiber Reinforced Plastics (CFRP). Top few layers of a hybrid laminate are prepared using electrically conductive polymer-based resin (CF/C-POLY) to provide effective dissipation of lightning current while epoxy-based CFRP substrate (CF/Epoxy) provides the main structural strength. An insulating adhesive layer is used to bond CF/C-POLY and CF/Epoxy to prepare the laminate. The hybrid laminates were tested for their effectiveness against lightning strikes. Laminates were struck by modified lightning waveform of component A with peak current of -14 kA and -40 kA. The performance of the laminates against lightning strike were evaluated using high speed camera, high-speed and thermal camera. It is found that CF/C-POLY layer successfully defended the main structural component i.e. CF/Epoxy from lightning direct damage.

scholarly journals Forecast of Thunderstorm Cloud Trend Based on Monitoring Data of Thunder Mobile Positioning System

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Mingfa Wu ◽  
Chongjing Yang ◽  
Xiangke Liu
Keyword(s):  
Lightning Discharge ◽  
Monitoring Data ◽  
Practical Significance ◽  
Lightning Strike ◽  
Natural Phenomenon ◽  
Main Task ◽  
Positioning System ◽  
Lightning Strikes ◽  
Thunderstorm Cloud ◽  
Mobile Positioning

As a natural phenomenon, thunder and lightning have a major impact on human production and life. As an important part of lightning protection technology, the main task of the lightning mobile positioning system is to detect and determine the location of lightning and, at the same time, provide more accurate lightning discharge parameters for lightning research. It is a new technology that serves the entire society and is in urgent need of development. This paper aims to study the trend prediction of thunderstorm cloud based on the monitoring data of the thunder and lightning mobile positioning system. In this thesis, the inverse distance-weighted interpolation method can be used to determine the lightning area and the principle of lightning monitoring and positioning, and the classification of lightning and the practical significance of lightning mobile positioning system monitoring are also studied. Finally, the Hurst index of this paper can reveal the trend elements in the time series well through the experiment, so as to judge the lightning strikes. At the same time, it also introduces everyone’s satisfaction survey on the lightning mobile positioning system. The results of this paper show that the lightning mobile positioning system has been widely used in our country’s meteorological monitoring stations, and it plays a very important role in our national defense lightning strikes and effectively realizes the lightning strike prediction in the monitoring process, which can better enable the competent department to take timely and accurate measures to prevent lightning strikes. Experimental analysis shows that the accuracy of the lightning mobile positioning system has reached 92%, and the practicability has reached 88%.

scholarly journals Can Lightning Strike Twice? The Reassembly of the Karnak Fulgurite at Museums Victoria

2018 ◽  
Vol 2 ◽  
pp. e27043
Author(s):  
Danielle Measday ◽  
Sarah Babister ◽  
Stuart Mills
Keyword(s):  
Lightning Discharge ◽  
Lightning Strike ◽  
Original Form ◽  
Still Images ◽  
Lightning Strikes ◽  
Ground Segment ◽  
Significant Length ◽  
Glass Tubes ◽  
Field Notes ◽  
Western Victoria

In 1959, the longest recorded specimen of fulgurite in Victoria was discovered in the sandhills of Karnak in Western Victoria, Australia. Measuring 1.5 metres in vertical length, the specimen was formed by a discharge of lightning penetrating and fusing the quartz sand along its path. Considering the high number of cloud-to-ground lightning strikes, it has been estimated that up to ten fulgurites may be formed globally per second Pasek and Block 2009. Despite this, fulgurites are a rare find, particularly ones of significant length. The amorphous glass tubes created by lightning discharge are notoriously brittle and thin walled. Unequal contraction of the glass upon cooling produces fine cracks which weather over time, often resulting in the specimen breaking into segments. The Karnak fulgurite was systematically extracted from the ground segment by segment and reassembled for display in the museum, where it remained on exhibition from the early 1960s until 1990 Beasley 1964. When removed from display, the Karnak fulgurite was accidentally fractured into hundreds of pieces. For nearly 30 years it has remained fragmented and spread across multiple vials in the collection. The level of detail provided in field notes, still images and archives from the time of its collection provide a complete record of its appearance prior to the damage. The conservation and mineralogy departments of the museum collaborated on a project to return the fulgurite to its original form. This poster will track the journey of its reassembly, including mapping the original shape and dimensions of the specimen, analysis and removal of aged adhesives, and designing a mounting system for future display and storage.

Rules of Causal Judgment

2017 ◽  
Author(s):  
José C. Perales ◽  
Andrés Catena ◽  
Antonio Cándido ◽  
Antonio Maldonado
Keyword(s):  
Real Life ◽  
Statistical Information ◽  
Causal Judgment ◽  
Psychological Processes ◽  
Relevant Evidence ◽  
Clear Winner ◽  
Causal Judgments ◽  
The Media

Our environment is rich in statistical information. Frequencies and proportions—or their visual depictions—are pervasive in the media, and frequently used to support or weaken causal statements, or to bias people’s beliefs in a given direction. The topic of this chapter is how people integrate naturally available frequencies and probabilities into judgments of the strength of the link between a candidate cause and an effect. We review studies investigating various rules that have been claimed to underlie intuitive causal judgments. Given that none of these rules has been established as a clear winner, we conclude presenting a tentative framework describing the general psychological processes operating when people select, ponder, and integrate pieces of causally-relevant evidence with the goal of meeting real-life demands.

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