Study on the rule of blister formation and identification technology of multi-cores copper wires in fire

2020 ◽  
Vol 10 (7) ◽  
pp. 1040-1046
Author(s):  
Axin Liang ◽  
Yang Li ◽  
Shu Yang
Keyword(s):  
Polarized Light ◽  
Experimental Results ◽  
Blister Formation ◽  
External Appearance ◽  
Metallographic Structure ◽  
Fire Scenarios ◽  
The Common ◽  
The Wire ◽  
In Fire

The common presence of the wire blisters in fire indicates that the wire was exposed to fire. Yet current overload happening before fire also causes some wire blisters. Most trace evidences on the wire from fire are required to examine melted blisters marks of the wire. Thus, it is critical to clearly identify and determine the differences between blisters merely exposure to fire and current overload for fire investigators. Two fire scenarios, fire heating and overcurrent, and 2.5 mm2 multi-cores copper wires were selected by this paper to make blisters. Then, the identification technology of blisters was studied. The experimental results suggested that the external appearance and metallographic structure taken on by blisters were not the precise evidences to identify whether blisters are merely exposed to fire or overcurrent. Therefore, the metallographical method of polarized light was used to analyse Cu2O content in blisters. Besides, such content was used to accurately identify two kinds of blisters. The content of Cu2O of the overcurrent blisters was larger than that of the fire heating blisters notably.

Review of Fire Performance Experiment of Concrete-Filled Steel Tubular Columns

2014 ◽  
Vol 638-640 ◽  
pp. 1397-1401
Author(s):  
Kai Xiang ◽  
Guo Hui Wang ◽  
Yan Chong Pan
Keyword(s):  
Load Ratio ◽  
Experimental Results ◽  
Research Progress ◽  
Future Research ◽  
Fire Performance ◽  
Cross Sectional ◽  
Tubular Columns ◽  
Cross Sectional Dimension ◽  
Cfst Columns ◽  
In Fire

This paper presents a review of research progress in fire performance of concrete-filled steel tubular (CFST) columns. Experimental results of CFST columns in fire are reviewed with influence parameters, such as heights, cross-sectional dimension, section types, concrete types, concrete strengths, load ratio, load eccentricity, fire exposed sides and so on. Some conclusions of CFST columns under fire conditions are summarized. Deficiencies in the fire performance experiments of CFST columns are identified, which provide the focus for future research in the field.

scholarly journals How Interdependence Explains the World of Teamwork

2021 ◽  
pp. 122-146
Author(s):  
Matthew Johnson ◽  
Jeffrey M. Bradshaw
Keyword(s):  
Common Factor ◽  
Theoretical Framework ◽  
Experimental Results ◽  
Coherent System ◽  
Basic Principles ◽  
The World ◽  
The Common ◽  
Machine Systems ◽  
Moving Parts

AbstractCurrent attempts to understand human-machine systems are complex and unwieldy. Multiple disciplines throw different concepts and constructs at the problem, but there is no agreed-to framework to assemble these interrelated moving parts into a coherent system. We propose interdependence as the common factor that unifies and explains these moving parts and undergirds the different terms people use to talk about them. In this chapter, we will describe a sound and practical theoretical framework based on interdependence that enables researchers to predict and explain experimental results in terms of interlocking relationships among well-defined operational principles. Our exposition is not intended to be exhaustive, but instead aims to describe the basic principles in a way that allows the gist to be grasped by a broad cross-disciplinary audience through simple illustrations.

scholarly journals Model of colposcopy using polarized light and effective early

2017 ◽  
Vol 20 (K2) ◽  
pp. 96-100
Author(s):  
Cat Ngoc Khuong Phan ◽  
Linh Quang Huynh ◽  
Quynh Ngoc Nguyen ◽  
Duong Cao Ly
Keyword(s):  
Imaging Techniques ◽  
Polarized Light ◽  
Analysis And Evaluation ◽  
Common Features ◽  
Common Diseases ◽  
Cervical Disease ◽  
Examination Methods ◽  
The Common ◽  
Image Processing Algorithms ◽  
Processing Algorithms

Cervical disease is one of the common diseases, it occurs in women and has a growing tendency. In particular, cervical cancer is one of the most common diseases. The disease can be cured if it is detected early and treated under the guidance of a physician. The usual cervical examination methods are biopsies, and colposcopy. Recently, many studies have applied imaging techniques in the analysis and evaluation of cervical pathology characteristics [1-3]. In this study, we improved the traditional colposcopy with a polarized light source, and captured images with high resolution. Based on the image obtained, we developed image processing algorithms, initially analyzed and evaluated some of the common features of cervical disease

scholarly journals Concept of a Focus-Tunable ECF Microlens and Fabrication of a Large Model Prototype

2012 ◽  
Vol 6 (4) ◽  
pp. 476-481 ◽  
Author(s):  
Joon-Wan Kim ◽  
◽  
Takashi Yoshimoto ◽  
Shinichi Yokota ◽  
Kazuya Edamura ◽  
...  
Keyword(s):  
Jet Flow ◽  
Experimental Results ◽  
Dielectric Fluid ◽  
Dc Voltage ◽  
Mems Technology ◽  
The Common ◽  
Large Model

This paper proposes a novel elastomer-based tunable liquid-filled microlens by using an Electro-Conjugate Fluid (ECF) jet and MEMS technology. The common approach for tuning an elastomer-based microlens is to change the geometry of the boundary determined by the control pressure of the chamber by using an external pump. However, this paper proposes placing the ECF micropump inside the tunable microlens. The ECF is a dielectric fluid that works as a smart fluid, generating a powerful jet flow (ECF jet) when subjected to a high DC voltage. Since the ECF jet is generated only with a pair of tiny electrodes, the pumping mechanism can be easily inside the device. We fabricated the large model prototype of an ECF focus-tunable microlens by partially utilizing MEMS technology. The experimental results showed us the feasibility of the ECF microlens.

Mounting wires as a source of ignition in electrical cabinets

2021 ◽  
pp. 27-35
Author(s):  
Геннадий Васильевич Боков ◽  
Антон Александрович Назаров ◽  
Денис Геннадьевич Боков
Keyword(s):  
Electrical Equipment ◽  
Ignition Source ◽  
Insulation Material ◽  
Single Wire ◽  
Current Value ◽  
The Wire ◽  
Characteristic Features ◽  
In Fire ◽  
Wire Insulation

Приведены результаты исследований монтажных проводов электрических шкафов на воспламеняемость под воздействием тока. Выделены три зоны сверхтока, имеющие отличительные особенности появления источника зажигания. Показано влияние изоляции провода на частоту появления воспламенения в местах присоединения его к элементу электрооборудования. Представлены данные о воспламеняемости поливинилхлоридной изоляции в диапазоне пожароопасных значений сверхтока. Предложено характеризовать электрический провод как потенциальный источник зажигания площадью, образованной зависимостью времени воспламенения изоляции в интервале возможных сверхтоков. Wires are widely used for internal installation of electrical cabinets. Number of fire cases caused by wires takes one of the first places in fire statistics. Application of wires in the cabinets has its own fire-prone aspects peculiarities as concerns initiation of electrical nature ignition source. It appears both at single wire laying and at laying in cords where wires touch each other also in connection points of electrical apparatuses and devices located in the cabinet. The article considers issues of ignition source appearance in wires taking into account specifics of their installation in electrical cabinets. Ignition source appearance in a single wire and in wires contacting each other has a difference. There are given experimental data on inflammation frequency of wire insulation material at single wire laying and also at higher resistance in electrical elements connection points. Zones that differ in characteristic features of wire as an ignition source are given in the range of possible overcurrents. Zone A is characterized by insulation ignition with low probability due to low current density that is not enough to heat the wire up to the critical temperature Т, at which thermal decomposition products of wire insulating polymeric cover ignite. Zone B is designated in the range of overcurrent ratio from 2,5 to 18 compared with the long term permissible current value, in which insulation inflammation is observed due to fast conductor heating taking into account the influence of connection points with devices and apparatuses where increased transient resistance is present. It is experimentally confirmed that with the increase in transient resistance at the point of conductor connection with electrical equipment elements, the inflammation frequency of wire insulation increases. At the same time, the overcurrent range where ignition source appears reduces. It is proposed to use the area limited by the dependence of the time before insulation inflammation from the minimum to the maximum current value at which ignition occurs as a characteristic of the wire as an ignition source.

Simulation and Modelling in Fire Safety

2020 ◽  
pp. 232-262
Author(s):  
Tomaz Hozjan ◽  
Kamila Kempna ◽  
Jan Smolka
Keyword(s):  
Virtual Reality ◽  
Fire Safety ◽  
Rapid Development ◽  
Fire Spread ◽  
Practical Training ◽  
Smoke Movement ◽  
Fire Engineering ◽  
Limited Budget ◽  
Fire Scenarios ◽  
In Fire

Actual and future concerns in fire safety in buildings and infrastructure are challenging. Modern technologies provide rapid development in area of fire safety, especially in education, training, and fire-engineering. Modelling as a tool in fire-engineering provides possibility to design specific fire scenarios and investigate fire spread, smoke movement or evacuation of occupants from buildings. Development of emerging technologies and software provides higher possibility to apply these models with interactions of augmented and virtual reality. Augmented reality and virtual reality expand effectivity of training and preparedness of first (fire wardens) and second (firefighters) responders. Limitations such as financial demands, scale and scenarios of practical training of first and second responders are much lower than in virtual reality. These technologies provide great opportunities in preparedness to crisis in a safety way with significantly limited budget. Some of these systems are already developed and applied in safety and security area e.g. XVR (firefighting, medical service).

scholarly journals Solving Noise Pollution Issue Using Plenum Window with Perforated Thin Box

Crystals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 614
Author(s):  
Hsiao Mun Lee ◽  
Andi Haris ◽  
Kian Meng Lim ◽  
Jinlong Xie ◽  
Heow Pueh Lee
Keyword(s):  
White Noise ◽  
Traffic Noise ◽  
Noise Pollution ◽  
Experimental Results ◽  
Frequency Range ◽  
Noise Mitigation ◽  
Noise Sources ◽  
Acoustic Performance ◽  
Common Noise ◽  
The Common

In the present study, a conventional plenum window was incorporated with perforated thin box in order to enhance its performance at frequency range which centralized at 1000 Hz as most of the common noise sources at city nowadays are centralizing around this frequency. The entire studies were conducted in a reverberation room. The effectiveness of jagged flap on mitigating diffracted sound was also studied. Three types of noises were examined in the current study—white noise, traffic noise and construction noises. The experimental results showed that the plenum window with perforated thin box could reduce 8.4 dBA, 8.7 dBA and 6.9 dBA of white, traffic and construction noises, respectively. The jagged flaps did not have significant effect on the plenum window’s noise mitigation performance. When frequencies were ranging from 800 Hz to 1250 Hz, when compared with the case of without perforated thin box, it was found that the perforated thin box had good acoustic performance where it was able to reduce additional 1.6 dBA, 1.6 dBA and 1.2 dBA of white, construction and traffic noises, respectively.

The Appraisal of Velcro’s Surface Quality Based on Machine Vision Systems

2011 ◽  
Vol 201-203 ◽  
pp. 2045-2048
Author(s):  
Da Xing Zhao ◽  
Qing Lin
Keyword(s):  
Machine Vision ◽  
Product Quality ◽  
Surface Quality ◽  
Detection Method ◽  
Experimental Results ◽  
Vision Systems ◽  
Examination Method ◽  
The Common ◽  
Develop Environment ◽  
Common Defect

The most important problem of the Velcro Manufacturer face is to control the surface quality, and how to improve the product quality has become the key of the enterprise. Therefore, this paper take the research on the examination method of the Velcro’s surface flaw, and propose a simply and effectively detection method on the marginal check and the flaw extraction of the buckle in the considering of the system’s real-team and the effectiveness. The experiments have been carried on the results been analyzed under the Visual c + + develop environment. Experimental results show that the system can detect the common defect of the fastening surface accurately and classify them.

Robust Multibit Image Watermarking Based on Contrast Modulation and Affine Rectification

2019 ◽  
Vol 33 (14) ◽  
pp. 1954036
Author(s):  
Xin Zhong ◽  
Frank Y. Shih
Keyword(s):  
Image Processing ◽  
Lower Bound ◽  
State Of The Art ◽  
Image Watermarking ◽  
Center Of Mass ◽  
Experimental Results ◽  
Superior Performance ◽  
The Common ◽  
Distortion Parameters ◽  
Watermarking Scheme

In this paper, we present a robust multibit image watermarking scheme to undertake the common image-processing attacks as well as affine distortions. This scheme combines contrast modulation and effective synchronization for large payload and high robustness. We analyze the robustness, payload, and the lower bound of fidelity. Regarding watermark resynchronization under affine distortions, we develop a self-referencing rectification method to detect the distortion parameters for reconstruction by the center of mass in affine covariant regions. The effectiveness and advantages of the proposed scheme are confirmed by experimental results, which show the superior performance as comparing against several state-of-the-art watermarking methods.

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