The contact strip of pantograph is an essential component that directly contacts with overhead catenary wire and collects current, it is crucial to seek a convenient and accurate wear predictive ...model for this important component. Combining mechanistic analysis and data-driven approaches, this study established a heuristic wear model of strip, which has been validated the flexibility and accuracy through parameter analysis and test data. Furthermore, based on the wear model, a correlation analysis of multiple influencing factors on pantograph strip wear is conducted and the value of Fip is calculated. The analysis results showed that current and arcing have the greatest influence on wear and provided a reference for setting the static force of pantograph under different operating conditions.
Nanomaterial-enhanced paper-based biosensors Ge, Xiaoxiao; Asiri, Abdullah Mohamed; Du, Dan ...
TrAC, Trends in analytical chemistry (Regular ed.),
06/2014, Letnik:
58
Journal Article
Recenzirano
•We present nanoparticle-based lateral-flow test-strip devices.•We review nanomaterial-based paper biosensors.•We discuss future opportunities for nanomaterial-based paper biosensors.
...Nanomaterial-enhanced paper-based biosensors, including lateral-flow test-strip (LFTS), and paper microfluidic devices, provide powerful analytical platforms for the development of affordable, portable, low-cost technologies for point-of-care and in-field assays. By combining with different kinds of nanoparticles (NPs), the nanomaterial-based LFTS and paper microfluidic devices are showing great potential in enhancing detection sensitivity and selectivity. In this review, we provide a general overview of paper-based biosensing techniques, in which various NPs are involved, especially applications in biomedical and environmental studies. The first part provides detailed examples in LFTSs, while the second part gives a brief overview of paper microfluidics. Nanomaterial-enhanced paper-based biosensors could be used in physicians’ office laboratories, nursing homes, hospitals, and the home. They may also make a great impact in global health in diagnosing health conditions in developing countries.
Strip sensor performance in prototype modules built for ATLAS ITk Helling, C.; Allport, P.; Affolder, A.A. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
10/2020, Letnik:
978, Številka:
C
Journal Article
Recenzirano
Odprti dostop
ATLAS experiment is preparing an upgrade of its detector for High-Luminosity LHC (HL-LHC) operation. The upgrade involves installation of the new all-silicon Inner Tracker (ITk). In the context of ...the ITk preparations, more than 80 strip modules were built with prototype barrel sensors. They were tested with electrical readout on a per-channel basis. In general, an excellent performance was observed, consistent with previous ASIC-level and sensor-level tests. However, the lessons learned included two phenomena important for the future phases of the project. First was the need to store and test the modules in a dry environment due to humidity sensitivity of the sensors. The second was an observation of high noise regions for 2 modules.
The high noise regions were tested further in several ways, including monitoring the performance as a function of time and bias voltage. Additionally, direct sensor-level tests were performed on the affected channels. The inter-strip resistance and bias resistance tests showed low values, indicating a temporary loss of the inter-strip isolation. A subsequent recovery of the noise performance was observed. We present the test details, an analysis of how the inter-strip isolation affects the module noise, and the relationship with sensor-level quality control tests.
Abstract
Contact state between work roll and backup roll has significant influnce on surface fatigue and strip steel shape. In this work, the contact behaviours between work roll and backup roll of a ...hot strip mill were investigated. The contact stress distributions along the axial and radial direction were calculated. The effect of uneven contact stress distribution on strip steel profile was analysed. The risk of roll fatigue caused by contact stress concentration was pointed out. In order to improve the contact stress distribution, a design method of the backup roll profile was proposed. Both finite element calculation and industrial test have been carried out and showed that the new profile was excellent in reducing the peaks of the contact stress, homogenizing backup roll wear and improving strip profile.
Evaluation of passive CMOS strip sensors Diehl, Leena; Arling, Jan-Hendrik; Baselga, Marta ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
09/2022, Letnik:
1039
Journal Article
Recenzirano
Silicon sensors will continue to be the central tracking elements for upcoming particle physics detectors. They will have to cover large areas and thus be a main cost driver. The silicon sensors ...currently used are available only from very few manufacturers, thus detector technologies and designs that can be realized through established commercial industrial production processes and are cost-effective are becoming increasingly relevant. The CMOS technology is one of the important candidates. Since typically CMOS foundries are equipped for producing much smaller sizes than the currently used wafer-scale strip sensors, several neighbouring reticles have to be connected via a stitching process to obtain large sensors. In this study, strip sensors were designed and developed with the passive p-CMOS 150 nm process including stitching of up to five reticles. After initial electrical characterizations the sensors were tested in the laboratory with a 90Sr source and infrared lasers. The key investigation was to evaluate the impact of stitching on the sensor performance. The results presented will demonstrate that the stitching does not show any negative effect on the sensor performance before and after irradiation, and the stitching process is successful.
In the cold rolling process of steel strip products, strip breakage is an undesired production failure which can lead to yield loss, reduced work speed and equipment damage. To perform a root cause ...analysis, conventional physics-based approaches which focus on mechanical and metallurgical principles have been applied in a retrospective manner. With the advancement of data acquisition technologies, numerous process monitoring data is collected by various sensors deployed along this process; however, conventional approaches cannot take advantage of these data. In this paper, a machine learning-based approach is proposed to characterise and model strip breakage in a predictive manner. First, to match the temporal characteristic of strip breakage which occurs instantaneously, historical multivariate time-series data of a cold rolling process were extracted in a run-to-failure manner, and a sliding window strategy was adopted for data annotation. Second, breakage-centric features were identified from three facets - physics-based approaches, empirical knowledge and data-driven features. Finally, these features were used as inputs for strip breakage modelling using recurrent neural networks (RNNs), which are specialised in discovering underlying patterns embedded in time-series data. An experimental study using real-world data collected from a cold-rolled electrical steel strip manufacturer revealed the effectiveness of the proposed approach.
Urban road verges can contain significant biodiversity, contribute to structural connectivity between other urban greenspaces, and due to their proximity to road traffic are well placed to provide ...ecosystem services. Using the UK as a case study we review and critically evaluate a broad range of evidence to assess how this considerable potential can be enhanced despite financial, contractual and public opinion constraints. Reduced mowing frequency and other alterations would enhance biodiversity, aesthetics and pollination services, whilst delivering costs savings and potentially being publically acceptable. Retaining mature trees and planting additional ones is favourable to residents and would enhance biodiversity, pollution and climate regulation, carbon storage, and stormwater management. Optimising these services requires improved selection of tree species, and creating a more diverse tree stock. Due to establishment costs additional tree planting and maintenance could benefit from payment for ecosystem service schemes. Verges could also provide areas for cultivation of biofuels and possibly food production. Maximising the contribution of verges to urban biodiversity and ecosystem services is economical and becoming an increasingly urgent priority as the road network expands and other urban greenspace is lost, requiring enhancement of existing greenspace to facilitate sustainable urban development.
•Urban road verges are often overlooked when discussing urban greenspace.•Verges can contribute significantly to urban biodiversity and ecosystem services.•Contractual obligations and public reaction concerns limit current contributions.•Current planting schemes, and tree species selection, further limit contributions.•Alternative management can cost-effectively enhance biodiversity & ecosystem services.
•Hydrothermal features of nanofluid in a tube with novel strip inserts are assessed.•The two-phase Eulerian–Lagrangian approach is employed for simulation.•Use of strip inserts rises Nu number and ...friction factor compared with plain tube.•Nu number and friction factor are greater for the non-staggered alignment.•The nanofluid has a greater merit than pure water for utilization in this geometry.
In this research, hydrothermal characteristics and energy efficiency of the water–Ag nanofluid in a circular tube equipped with twisted conical strip inserts are investigated through the two-phase Eulerian–Lagrangian approach. The novel inserts under study are a combination of twisted tape inserts and conical strip inserts. Both staggered and non-staggered alignments for the strip inserts are examined. The effects of different forces including drag force, thermophoretic force, Brownian force and lift force are considered. Application of the strip inserts intensifies flow mixing and disturbance in boundary layer and therefore, increases Nusselt number and friction factor compared with the plain tube. The non-staggered alignment disturbs the boundary layer with a greater intensity than the staggered alignment, such that a completely swirling flow is developed for this configuration. The results show that heat transfer for the non-staggered alignment is higher than that for the staggered alignment, while the merit characteristic is greater for the staggered alignment. Moreover, the temperature and velocity distributions are more uniform for the non-staggered alignment. Additionally, Nusselt number augments by increasing either concentration or Reynolds number, whereas friction factor decreases with Reynolds number increment and intensifies by increasing the concentration. The nanofluid has a greater merit than pure water for utilization in this geometry. Meanwhile, the non-staggered alignment causes a more intense nanoparticle migration compared with the staggered alignment.
The H-polarized eigenmodes of dielectric waveguide scattering by a finite system of graphene strips are considered in the THz frequency range. The waveguide has one perfectly electric conducting ...wall. The solution is based on the singular integral equations with Nystrom discretization. Such an approach is efficient and has guaranteed convergence. Dependences of the scattering characteristics on the frequency and the radiation patterns are presented. We study the properties of periodic graphene strip grating with the same values of the chemical potential on every strip and with different values of the chemical potential on every strip. In the first case, the radiation patterns with relatively high side-lobe level are obtained. In the second case, the side-lobe level is reduced to −20 dB.
This paper proposes an outlier-resistant non-fragile (ORNF) observer-based boundary control strategy for the hot strip mill (HSM) cooling process. First, measurement outliers and observer parameter ...perturbations are unavoidable due to the disturbances or faults of the HSM cooling process, so the ORNF observer is developed using the saturation function and the non-fragile control theory to improve the observation accuracy. Then, a sampled-data (SD) measurement is utilized, which avoids frequent updating of temperature sensors. Furthermore, a SD boundary control strategy is proposed by using the above observed temperature information, which only requires an actuator to be installed on one side of the system to regulate the temperature, reducing the control cost of the HSM cooling process effectively. Finally, sufficient conditions to ensure the stability of the HSM cooling process are derived through rigorous mathematical proof, and simulation results are presented to verify the effectiveness and superiority of the proposed method.
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