Discrimination of Disposable Vapes from Batteries Using the Magnetic Polarizability Tensor

Disposable vapes pose an environmental and fire hazard to waste streams when disposed of incorrectly. The lithium battery inside disposable vapes can produce an exothermic reaction when the lithium inside the battery is inadvertently exposed to air and moisture. New sensing technologies may be needed to screen waste streams for these vape hazards and this paper considers the potential of inductive techniques based on the magnetic polarisability tensor (MPT) representation. The MPT can be described by three complex components based on a target regardless of orientation. In this paper, the rank 2 MPT is measured and calculated for 10 vapes and 37 batteries for 28 logarithmically spaced frequencies from 119 Hz to 95.4 KHz. The 168 features of each object are reduced down to 2 features using principal component analysis (PCA) and linear discriminant analysis. The reduction of the features allows for the visualisation and grouping of the objects. Three clear groups of objects can be seen when the maximum feature scales the measurement and a two-component PCA transform is applied. The first group is the vapes, which are grouped away from the other batteries. The second is the batteries, which are grouped by size. Finally, zinc batteries are grouped away from the rest due to their case material.<br/

High temperature magnetic characterisation of structural steels using Epstein frame

Abstract: Electromagnetic non-destructive testing techniques provide an attractive solution to the problem of monitoring microstructural changes in steels undergoing heat treatment as they are non-contact, have a short response time and are relatively inexpensive. However, to take full advantage of these techniques it is necessary to be able accurately measure the magnetisation characteristics of the materials of interest at temperatures up to the Curie point. This paper details the development of a novel high temperature Epstein frame for installation in a furnace with the design informed and results validated by finite element modelling. Hysteresis loop characteristics are successfully measured for a dual phase steel up to the Curie point for heating and cooling. Results show the developed system has the potential to provide valuable data to inform online electromagnetic monitoring systems

High temperature magnetic characterisation of structural steels using Epstein frame

From IOP Publishing via Jisc Publications RouterHistory: received 2021-05-25, revised 2021-07-06, oa-requested 2021-07-07, accepted 2021-07-27, open-access 2021-08-23, epub 2021-08-23, ppub 2021-12Publication status: PublishedFunder: Engineering and Physical Sciences Research Council; doi: http://dx.doi.org/10.13039/501100000266; Grant(s): EP/S018107/1, EP/P027210/01Funder: Research Fund for Coal and Steel; Grant(s): 847296Abstract: Electromagnetic non-destructive testing techniques provide an attractive solution to the problem of monitoring microstructural changes in steels undergoing heat treatment as they are non-contact, have a short response time and are relatively inexpensive. However, to take full advantage of these techniques it is necessary to be able accurately measure the magnetisation characteristics of the materials of interest at temperatures up to the Curie point. This paper details the development of a novel high temperature Epstein frame for installation in a furnace with the design informed and results validated by finite element modelling. Hysteresis loop characteristics are successfully measured for a dual phase steel up to the Curie point for heating and cooling. Results show the developed system has the potential to provide valuable data to inform online electromagnetic monitoring systems

【02】目次

9%Cr steels have been in use in power generation for over 20 years. Over this time, there have been a number of incidents of failure by Type IV cracking at welds initiating sub-surface, making surface inspection procedures unsuitable for crack detection. Replication to identify creep cavitation damage can potentially give an early warning of imminent cracking, but has proved unsuccessful in high Cr martensitic steels. Electromagnetic (EM) inspection can provide fast inspection of welded components with minimal surface preparation and some increase in inspection depth. This paper shows the results of accelerated creep tests carried out on a P91 pressure vessel, with EM inspections during regular test interruptions. The results show that EM inspection gave indications of damage in the latter stages of creep cavitation. EM is considered to have the potential for quick assessment of component through thickness damage, flagging up locations of potential problems for more detailed investigation