scholarly journals Detection and Prediction of Internal-Caused Fire in Tunnel Cable by an Equivalent Transient Thermal Circuit Model

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Yanwen Wang ◽  
Xuran Zhang ◽  
Le Wang ◽  
Yinsheng Wang
Keyword(s):  
Carrying Capacity ◽  
Early Stage ◽  
Circuit Model ◽  
Anomalous Temperature ◽  
Experimental Platform ◽  
Thermal Circuit ◽  
The Core ◽  
Calculation Results ◽  
Relative Errors ◽  
Transient Thermal

Internal-caused cable fires are one of the most common cable fires, and anomalous temperature increase of the cable core is one of the first signs. However, when a cable is operating with electricity, the temperature of the core conductor cannot be monitored directly; therefore, this characteristic cannot be used in detection and prediction of internal-caused fire in electric cable effectively. An analogous transient thermal circuit model is created, simplified, and optimized to properly compute the temperature of the cable core. Afterward, by using the cable internal-caused fire experimental platform and adjusting current carrying capacity of the tested cable, an experiment is conducted for stimulating the very early stage of three-core cable internal-caused fire. The maximum relative errors of the transient thermal circuit model and the trisection transient thermal circuit model are less than 10% when comparing the experimental data with the calculation results, and the average relative error of the calculated value of trisection transient thermal circuit model is 1.08% after layered optimization. The algorithm model can satisfy the requirement for early detection and prediction in the very early stage of cable internal-caused fire.

Study on the Steady State Thermal Circuit Model of 10kV Three-Core Cable Based on the Shape Factor Method

2014 ◽  
Vol 1008-1009 ◽  
pp. 593-597
Author(s):  
Wen Xiang Li ◽  
Rui Bo Su ◽  
Gang Liu ◽  
Peng Wang ◽  
Yi Xuan Chen
Keyword(s):  
Heat Transfer ◽  
Steady State ◽  
Shape Factor ◽  
Field Research ◽  
Circuit Model ◽  
The Finite Element Method ◽  
Heat Transfer Characteristics ◽  
Thermal Circuit ◽  
The Core ◽  
Conductor Temperature

The core of the 10kV three-core cable is in the shape of a trefoil. Not all the radial direction of the actual heat transfer characteristics are the same. The finite element method serve as the three core cable temperature field research method in this text, in order to analyze the internal temperature distribution of three core cable, establish a steady state thermal circuit model in accordance with the characteristics of heat transfer from the cable conductor to the surface in the three-core cable , give the calculation of conductor temperature algorithm, and calculate the various parameters in the model.

Transient Thermal Circuit Model Of The Northern Spirit Cube Satellites

2021 ◽  
Author(s):  
Molly D French ◽  
Malav Naik ◽  
Andre Ulliac ◽  
Scott Selland ◽  
Carlos Lange
Keyword(s):  
Circuit Model ◽  
Thermal Circuit ◽  
Transient Thermal

Die Bahnhofsmission – Ort gelebter Ökumene. Theologische Reflexionen

2021 ◽  
Vol 81 (4) ◽  
pp. 286-296
Author(s):  
Dorothea Sattler
Keyword(s):  
Social Change ◽  
Early Stage ◽  
Individual Case ◽  
Self Reflection ◽  
Threshold Concept ◽  
The Core ◽  
Low Threshold

Abstract This article examines the questions of why the ›Bahnhofsmission‹ is suitable as a seismograph of social change, how it performs this function, what it can achieve and where its limits lie. This is done with the help of self-reflection of the practice of the ›Bahnhofsmission‹ and by unfolding practical examples. The seismograph function is described as a task of the ›Bahnhofsmission‹ that goes beyond the core of individual case assistance and is of benefit to society as a whole. This involves drawing attention to changes at an early stage in order to identify structures of poverty and injustice as causes of need for help as well as of exclusion and to contribute to the elimination of those structures. Due to their location at the station and their open, low-threshold concept, ›Bahnhofsmissionen‹ have an excellent seismographic potential. Where they succeed in raising this potential, they can become incubators for innovation.

scholarly journals How to Produce Novelty? Creating, Borrowing, Modifying, Repeating And Forgetting: The Process of Contemporary Fashion Aesthetics

2019 ◽  
pp. 101
Author(s):  
Ruhan Liao
Keyword(s):  
Media Studies ◽  
Early Stage ◽  
Cycle Duration ◽  
Subjective Experiences ◽  
The Core ◽  
Logical Sequence ◽  
The Future

The aesthetics of fashion can be regarded as the aesthetics of novelty since constant changes make novelty the core of fashion. Based on Colin Campbell’s theory, novelty is a judgment about our subjective experiences, indicating something we never experienced before. In the early stage of the fashion system, designers led fashion trends by creating brand-new items or borrowing foreign elements. Then, as the pace of fashion circulation increased, designers started to produce novelty by modifying details, or by repeating what was in fashion long before. Hence, fashion became cyclical. And the cycle duration would become shorter and shorter as the repetition sped up. At this stage, novelty is not based on whether the item is brand-new, but whether we still remember it. In the future, maybe the repeating of the old cannot maintain the feeling of novelty any more since the pace of fashion change is too quick to give enough time for the new to become old and forgotten. At that time, the novelty will not be based on whether we still remember it, but whether we want to forget it. Therefore, with the acceleration of fashion change, the method of how fashion produces novelty has gone through a logical sequence as follows: creating something brand-new, borrowing foreign elements, modifying details, repeating the forgotten old, and forgetting what is still new. Novelty has gone through a process from ‘externally determined’ to ‘internally determined’, moving to the direction of ‘self-deception determined’. Article received: April 20, 2019; Article accepted: June 15, 2019; Published online: September 15, 2019; Original scholarly paperHow to cite this article: Ruhan, Liao. "How to Produce Novelty? Creating, Borrowing, Modifying, Repeating And Forgetting: The Process of Contemporary Fashion Aesthetics." AM Journal of Art and Media Studies 19 (2019): 101-107. doi: 10.25038/am.v0i19.310

scholarly journals Effects of dielectric discontinuity on the dispersion characteristics of the tape helix slow-wave structure with two metal shields

2012 ◽  
Vol 30 (3) ◽  
pp. 329-339 ◽  
Author(s):  
Yu Zhang ◽  
Jinliang Liu ◽  
Shiwen Wang ◽  
Xuliang Fan ◽  
Hongbo Zhang ◽  
...  
Keyword(s):  
Slow Wave ◽  
Wave Structure ◽  
Wave System ◽  
Dispersion Characteristics ◽  
Slow Wave System ◽  
Phase Velocities ◽  
Electric Length ◽  
Spatial Harmonics ◽  
Calculation Results ◽  
Relative Errors

AbstractIn the tape helix slow-wave system, discontinuous dielectrics have great effects on the dispersion characteristics. In this paper, the tape helix slow-wave system, including an inner and an outer metal shield, tape helix, nylon support, and de-ionized water as filling dielectric, was analyzed. Effects of dielectric discontinuity caused by the support dielectric and filling dielectric on the dispersion characteristics were studied in detail. The dispersion relations, phase velocities, slow-wave coefficients, and electric lengths of the spatial harmonics in the system were calculated. Results showed that, if the permittivity of support dielectric was smaller than that of the filling dielectric, frequencies of the spatial harmonics in the system rose, phase velocities and slow-wave coefficients increased, the slow-wave effect of the system was weakened so that the previous electric length was shortened. The reverse condition corresponded to the reverse results, and the electromagnetic simulation also proved it. By use of the helical pulse forming line of accelerator based on the studied tape helix slow-wave system, the electric lengths of the system were tested as 188.5 ns and 200 ns in experiments where the thicknesses of nylon support were 6 mm and 3 mm, respectively. The theoretical calculation results 198 ns and 211 ns basically corresponded to experimental results, which only had relative errors as 5 and 5.5%, respectively.

Experimental investigations on the sandwich composite beams and panels with elastomeric foam core

2017 ◽  
Vol 21 (3) ◽  
pp. 865-894 ◽  
Author(s):  
AR Nazari ◽  
H Hosseini-Toudeshky ◽  
MZ Kabir
Keyword(s):  
Carrying Capacity ◽  
Sandwich Structures ◽  
Failure Mechanisms ◽  
Composite Beams ◽  
Core Material ◽  
Foam Core ◽  
Sandwich Beams ◽  
Load Carrying Capacity ◽  
The Core ◽  
Load Carrying

In this paper, the load-carrying capacity and failure mechanisms of sandwich beams and panels with elastomeric foam core and composite laminate face sheets are investigated. For this purpose, the flexural behavior of laminated composite beams and panels (applied as face sheets) is firstly investigated under three-point bending and central concentrated loads, respectively. Then, the same examination is conducted for the sandwich beams and panels, in which the proposed elastomeric foam is utilized as the core material. It is shown that the failure mechanisms which are associated to the core in the sandwich structures with crushable foams are not considered in the examined sandwich structures. The collapse of the sandwich specimens, examined here, is observed due to the failure of the skins in some steps. By multi-step collapse of these specimens via separately failure of the top and bottom skins, a considerable amount of energy is absorbed between these steps. Due to non-brittle behavior of the core material under loading, a large compression resistance is observed after failure of the top skin which led to the recovery of the load-carrying capacity in the sandwich beams. A similar behavior for the sandwich panels led to the increase of the ultimate strength after appearance of the failure lines on the top skin. The general outcomes of this investigation promise a good influence for the application of elastomeric foam as core material for sandwich structures.

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