Current Strip Research Articles

A Study on Dispersion Characteristics for Inverted Microstrip Lines

Inverted microstrip lines are studied for their dispersion characteristics for three different values of permittivity of the substrate using Galerkin Technique in Spectral Domain. This structure is very much useful as the current strip is attached at the lower surface of the dielectric substrate. Therefore it is rarely exposed to the outer medium results no effect due to external hazards and almost zero possibility to expose to electro- magnetic interference. Basis functions for the unknown strip current are chosen according to the ones specified in [1]. Basis functions in [1] were for slot magnetic currents and consequently they are modified for the particular problem by considering the modified boundary conditions for Maxwell’s field equations for this structure. For the theoretical development the Fourier transformation of the basis functions from space domain to spectral domain are considered. Variation of effective permittivity with available dielectric thickness has also been studied and the result shows a saturating tendency with increase in dielectric thickness.

Double dare: Climate change and volcanic activity threatens local populations of Meta menardi (Araneae, Tetragnathidae) in Sicily

Meta menardi (Latreille, 1804) and M. bourneti Simon, 1922 (Araneae: Tetragnathidae) are ubiquitous inhabitants of the twilight zone of most hypogean sites across Europe. The two species are broadly distributed in Italy, including Sicily, where they show a remarkable segregation along the altitudinal gradient of Mount Etna. Thanks to our recent sampling activities in this area, we create a georeferenced dataset allowing the application of Species Distribution Modelling aiming at evaluating the current and the future habitat in light of the impacts caused by climate change on the local populations. We predicted a relatively wide suitable area for M bourneti, ranging from the sea level up to 1100 m a.sl., whereas for M. menardi the suitable area encompasses a narrow mid altitude strip, extending halfway between the areas suitable for M. bourneti, and the highly unsuitable volcanic uplands, heavily disturbed by the volcanic activity. The averaged future predictions for 2070 under RCP 8.5 scenario, show that M. bourneti will expand its range upwards, in areas that are now suitable for M. menardi. In turn, predictions for M. menardi indicate an extreme reduction of the current strip of suitable habitat, likely determining its local extinction. Our findings are further corroborated by the analysis of the bioclimatic niche of the two species assessed via multidimensional Hutchinsonian hypervolume, being much smaller in M. menardi compared to of M. bourneti. In light of our results, it seems likely that having wider climatic preference, M. bourneti will substitute M. menardi in most of its current range in Sicily. Future interventions aiming at the conservation of M. menardi on Mount Etna are strongly advised.

Achieving high strength and large elongation in a strip casting microalloyed steel by ageing treatment

The microstructure and mechanical properties of a Nb–V microalloyed steel produced by strip casting in as-coiled and aged conditions were investigated using scanning electron microscopy, electron backscatter diffraction, X-ray diffraction, transmission electron microscopy, atom probe tomography and tensile tests. Tensile test results show that, after ageing at 650 °C for 5 min, accompanying an increase of yield strength from 698 ± 3.6 MPa to 758 ± 7.9 MPa, the elongation increases from 7.1 ± 0.4% to 12.6 ± 0.4% simultaneously. Microstructural analysis shows that both the as-coiled and aged specimens possess a microstructure predominantly comprising a mixture of acicular ferrite and bainitic ferrite. Hardness tests for specimens aged at different temperatures show very similar peak hardness values but higher ageing temperature requires less time for peak ageing. Ageing treatment leads to a decrease of dislocation density, which is responsible for the enhancement of elongation for aged specimens, while Nb–N-rich and Nb–V–N-rich clusters develop successively during ageing, which contributes to the increase of yielding strength after ageing. The strengthening contributions from solid solution, dislocations, grain boundaries and clusters were calculated, and the results indicated that dislocations and grain boundaries are the dominant strengthening mechanisms for the current strip casting steels.

Optimized scintillation strip design for the DANSS upgrade

DANSS is a one cubic meter plastic scintillator detector with a primary goal of sterile neutrino searches at a commercial nuclear reactor. Due to its highly advantageous location, fine segmentation and ability to change the distance to the neutrino production origin, DANSS is ahead of many similar experiments around the world in terms of the counting rate, signal to background ratio and sterile neutrino exclusion regions. Yet a moderate energy resolution of the detector prevents further progress in the physics program. The main challenge of the planned upgrade is to achieve an energy resolution of 12% at 1 MeV. The new design of the main sensitive element — the plastic scintillation strip — is the most important step forward. The strip prototypes were manufactured and tested at the pion beam of the PNPI synchrocyclotron. More than twice higher light output together with fairly flat detector response uniformity, longitudinal timing information and other optimizations will help to reach the upgrade goal. This paper discusses the drawbacks of the current strip version, outlines the new features of the proposed upgrade, describes the beam test procedure and presents the test results reflecting the advantages of the new strip design in comparison with the current version.

The Dimension of Phaseless Near-Field Data by Asymptotic Investigation of the Lifting Operator

In this paper, the question of evaluating the dimension of data space in an inverse source problem from near-field phaseless data is addressed. The study is developed for a 2D scalar geometry made up by a magnetic current strip whose square magnitude of the radiated field is observed in near non-reactive zone on multiple lines parallel to the source. With the aim of estimating the dimension of data space, at first, the lifting technique is exploited to recast the quadratic model as a linear one. After, the singular values decomposition of such linear operator is introduced. Finally, the dimension of data space is evaluated by quantifying the number of “relevant” singular values. In the last part of the article, some numerical simulations that corroborate the analytical estimation of data space dimension are shown.

An SVD Approach for Estimating the Dimension of Phaseless Data on Multiple Arcs in Fresnel Zone

In this article, we tackle the question of evaluating the dimension of the data space in the phase retrieval problem. With the aim to achieve this task, we first exploit the lifting technique to recast the quadratic model as a linear one. After that, we evaluate analytically the singular values of the lifting operator, and we quantify the dimension of the data space by counting the number of “significant” singular values. In the last part of the article, we show some numerical results in order to corroborate our analytical prediction on the singular values’ behavior of the lifting operator and on the dimension of the data space. The analysis is performed for a 2D scalar geometry consisting of an electric current strip whose square magnitude of the radiated field is observed on multiple arcs of circumference in Fresnel zone.

Parasitic resistance as a predictor of faulty anodes in electro galvanizing: a comparison of machine learning, physical and hybrid models

In industrial electro galvanizing lines aged anodes deteriorate zinc coating distribution over the strip width, leading to an increase in electricity and zinc cost. We introduce a data-driven approach in predictive maintenance of anodes to replace the cost- and labor-intensive manual inspection, which is still common for this task. The approach is based on parasitic resistance as an indicator of anode condition which might be aged or mis-installed. The parasitic resistance is indirectly observable via the voltage difference between the measured and baseline (theoretical) voltage for healthy anode. Here we calculate the baseline voltage by means of two approaches: (1) a physical model based on electrical and electrochemical laws, and (2) advanced machine learning techniques including boosting and bagging regression. The data was collected on one exemplary rectifier unit equipped with two anodes being studied for a total period of two years. The dataset consists of one target variable (rectifier voltage) and nine predictive variables used in the models, observing electrical current, electrolyte, and steel strip characteristics. For predictive modelling, we used Random Forest, Partial Least Squares and AdaBoost Regression. The model training was conducted on intervals where the anodes were in good condition and validated on other segments which served as a proof of concept that bad anode conditions can be identified using the parasitic resistance predicted by our models. Our results show a RMSE of 0.24 V for baseline rectifier voltage with a mean ± standard deviation of 11.32 ± 2.53 V for the best model on the validation set. The best-performing model is a hybrid version of a Random Forest which incorporates meta-variables computed from the physical model. We found that a large predicted parasitic resistance coincides well with the results of the manual inspection. The results of this work will be implemented in online monitoring of anode conditions to reduce operational cost at a production site.

PHYSICO-TECHNOLOGICAL ASPECTS OF WORK OF LUBRICANT FILMS IN THE TRIBOSYSTEM "OVERHEAD LINE – CURRENT COLLECTOR CONTACT STRIP"

Purpose . The article aimed at comprehensive analysis of the processes occurring in the lubricant films of the friction surfaces of the tribosystem «overhead line – current collector contact strip» (OLCCCS) and identification of the features of such systems. Methodology . The systematic analysis was used as the main methodology for studying the physico-technological aspects of work of the lubricant films in the tribosystem «overhead line – current collector contact strip». Findings . The theory of electro-friction interaction is now at such a stage that is characterized by a large amount of accumulated empirical data, hypotheses and models that cannot adequately represent phenomena in a sliding, high-current electrical contact. The sliding electrical contact of the tribosystem «overhead line – current collector contact strip» during the operation is affected by many factors, one of which is the processes in the lubricating layers of the friction pair. The work leads to a new level of understanding of the peculiarities of the processes occurring in the lubricating layers and their effect on the work of a sliding, high-current electrical contact, which can become the guarantee of significant increase in the efficiency of such systems and, as a consequence, substantially increase the reliability and safety of the work of the electric stock. Originality . It is proposed to consider the processes of electro-friction interaction of electrical contacts from the position of synergy using the theory of fractals as the core one for the quantitative description of self-organizing structures. Practical value . Taking into account the empirical experience of operation of the tribosystem «overhead line – current collector contact strip» in combination with theoretical knowledge allows us to propose three possible directions for solving tribological problems in high-current sliding electrical contacts. They are: 1) change in contact geometry and surface topography, for example, the use of regular macrorelief of contact surfaces; 2) development of conductive composites which are characterised with self-lubrication, for example the use of composite materials containing solid conductive lubricants; 3) development of effective lubricants for electric high-current sliding contacts, which may require some complication of the component design.

Bifurcations of buckled, clamped anisotropic rods and thin bands under lateral end translations

Motivated by observations of snap-through phenomena in buckled elastic strips subject to clamping and lateral end translations, we experimentally explore the multi-stability and bifurcations of thin bands of various widths and compare these results with numerical continuation of a perfectly anisotropic Kirchhoff rod. Our choice of boundary conditions is not easily satisfied by the anisotropic structures, forcing a cooperation between bending and twisting deformations. We find that, despite clear physical differences between rods and strips, a naive Kirchhoff model works surprisingly well as an organizing framework for the experimental observations. In the context of this model, we observe that anisotropy creates new states and alters the connectivity between existing states. Our results are a preliminary look at relatively unstudied boundary conditions for rods and strips that may arise in a variety of engineering applications, and may guide the avoidance of jump phenomena in such settings. We also briefly comment on the limitations of current strip models.

On Goss Orientation in Strip Cast Grain‐Oriented Silicon Steel

In this study, the origin of Goss texture during intermediate annealing and Goss texture development during secondary annealing of strip cast grain‐oriented silicon steel are studied by electron backscattered diffraction (EBSD). The study indicates that Goss grains originate inside the shear bands of deformed {111}<112> and {111}<110> grains. Compared to {111}<110> grains, {111}<112> grains provide more number of nucleation sites for Goss grains. During subsequent recrystallization process, Goss grains exhibit a smaller growth rate than the average value of all the recrystallized grains. The development mechanism of Goss texture is concluded as oriented nucleation. Prior to secondary annealing, high fraction of high‐energy boundaries (20°–45° misorientation angle) are observed in the vicinity of Goss grains, while significantly low fraction of Σ5 + Σ7 + Σ9 boundaries are observed. During secondary annealing, the domination of high energy boundaries around Goss grains is maintained, but the fraction of Σ5 + Σ7 + Σ9 boundaries decrease to be similar to the matrix grains. After the onset of the abnormal grain growth, the growing Goss grains continue to consist of high fraction of high‐energy boundaries. These results are consistent with the high energy (HE) boundary model, which is used to explain the abnormal grain growth in the current strip casting route.

Performance verification of the CMS Phase-1 Upgrade Pixel detector

The CMS tracker consists of two tracking systems utilizing semiconductor technology: the inner pixel and the outer strip detectors. The tracker detectors occupy the volume around the beam interaction region between 3 cm and 110 cm in radius and up to 280 cm along the beam axis. The pixel detector consists of 124 million pixels, corresponding to about 2 m 2 total area. It plays a vital role in the seeding of the track reconstruction algorithms and in the reconstruction of primary interactions and secondary decay vertices. It is surrounded by the strip tracker with 10 million read-out channels, corresponding to 200 m 2 total area. The tracker is operated in a high-occupancy and high-radiation environment established by particle collisions in the LHC . The current strip detector continues to perform very well. The pixel detector that has been used in Run 1 and in the first half of Run 2 was, however, replaced with the so-called Phase-1 Upgrade detector. The new system is better suited to match the increased instantaneous luminosity the LHC would reach before 2023. It was built to operate at an instantaneous luminosity of around 2×1034 cm−2s−1. The detector's new layout has an additional inner layer with respect to the previous one; it allows for more efficient tracking with smaller fake rate at higher event pile-up. The paper focuses on the first results obtained during the commissioning of the new detector. It also includes challenges faced during the first data taking to reach the optimal measurement efficiency. Details will be given on the performance at high occupancy with respect to observables such as data-rate, hit reconstruction efficiency, and resolution.

Fibre optic sensing system for monitoring of current collectors and overhead contact lines of railways

Abstract. Fibre optic sensors are excellent tools to use for monitoring high-voltage current collectors. Because of their small cross section and electrical neutrality, they are easily integrated into the current collector strip and are well specialized for detection of high-speed load events. The conventional contact force measurement with four force sensors below the collector strips can also be simplified by using fibre optic force and acceleration sensors.

Strip model for steel plate shear walls with beam-connected web plates

Steel plate shear walls comprise web plates connected to beams and columns, also referred to as vertical and horizontal boundary elements, respectively. When loaded laterally, web plates induce high flexural and axial demands in the columns due to the development of an inclined tension field. An alternative lateral force-resisting system is proposed in which the steel plate shear wall web plates are attached only to the beams to avoid high flexural demands in the columns resulting from the inclined tension. In this study, beam-connected web plate behavior is characterized using validated finite element models, a simplified strip model is proposed to simulate hysteretic web plate behavior, and equations for the inclination angle of the partial tension field and compressive strength of strips are presented. A comparison between the finite element model, the current strip model from the literature, and the new proposed strip model is provided. Results indicate that the proposed model successfully estimates beam and column demands, base shear capacity, and energy dissipation capacity of the beam-connected web plate for a wide range of web plate aspect ratios and height-to-thickness ratios.

Analytical Model for the Wide-Strip Rolling Mills Working Rolls Wear-Out Failures

The paper proposes a mathematical model for the gradual shape deterioration of wide-strip rolling mills working rolls active generatrixes subject to wear within the working zone during tandem rolling strips of a specified gauge. While modeling, the authors have determined the theoretical dependency needed to estimate the mean life of working rolls according to the transverse strip gauge interference criterion. Gauge interference of tandem-rolled strip transverse section shall be derived from the sum of the values of current shape of upper and lower working rolls active generatrixes, which are calculated based on strip width. In its turn, an active section of each roll shall be calculated for every following strip as a difference between the current roll radius values at the crown middle and that above/below the strip edge, while the shape deterioration rate of active roll generatrixes shall be defined by the difference between the roll wear rates in these sections. To estimate the rate of roll wear during rolling every following strip of the specified gauge, the base dependency of the structure-energy concept describing wear of stationary tribocouplings is used, which has been obtained by simultaneous solution of fundamental equations of molecule-mechanical and structure-energy friction theories. The moment of working roll failure (expected life) is determined based on the condition of achieving the nominal limit by gauge interference of a current strip.

Heat generation in plane strain compression of a thin rigid plastic layer

This paper presents a theoretical investigation into heat generation in the continued quasi-static plane strain compression of a thin metal strip between two rigid, parallel perfectly rough dies. The strip material is rigid perfectly plastic. The length of the dies is supposed to be much larger than the current strip thickness. The plastic work rate approaches infinity in the vicinity of perfectly rough friction surfaces. Since the plastic work rate is involved in the heat conduction equation, this significantly adds to the difficulties of solutions of this equation. In particular, commercial finite element packages are not capable of solving such boundary value problems. The present approximate solution is given in Lagrangian coordinates. In this case, the original initial/boundary value problem reduces to the standard second initial/boundary value problem for the nonhomogeneous heat conduction equation. Therefore, the Green’s function is available in the literature. An example is presented to illustrate the general solution.

A strip holding system for finite element simulation of Almen strip testing

We propose a strip holding system that can provide a clear boundary condition for a specimen (strip) during finite element simulation of Almen strip testing. The proposed strip holding system does not need a mounting block and bolts to grasp the strip before and during the test. Both ends of the strip are grabbed by two plane clamps to set a clear boundary condition for the strip during finite element simulation. We performed a series of Almen strip tests with a current strip holding system and the proposed strip holding system at different impingement velocities and exposure times. The lengthwise deflection shapes of the peened strip and saturation curves were measured and compared. The results revealed that the saturation curves obtained with the proposed strip holding system were about 6.2–19.6% larger on average than those obtained with the current strip holding system, but there was an error tendency between the two saturation curves. It denotes that the conventional strip holding system currently in use can be replaced with the proposed strip holding system if we capitalize on the error tendency.

Adapting ACT for jail diversion: current evidence and needed research

Results In one review [1], 7 of 10 randomized trials found that ACT was no more effective in reducing arrests and jail stays than usual care and in one trial it was less effective. Another recent trial [2] found that receipt of ACT was not a significant predictor of a range of criminal justice outcomes including offenses, arrests, incarcerations, or court summons. Current FACT programs strip away some highfidelity components of ACT (such as 24 h availability, daily team meetings, an employment specialist) and add new elements not found in typical ACT teams (such as a probation or parole officer on the team, recruitment from criminal justice settings, supervised residential treatment component for high risk consumers with substance abuse comorbidities.) Current evidence for the effectiveness of these FACT models is sparse. Some uncontrolled studies suggest positive effects, but the one randomized trial reported to date found no differences between a FACT-like intervention and usual care. Conclusion ACT alone or its FACT adaptations do not appear to be able to keep mentally ill offenders out of jail. Interventions are also needed that target criminal behavior and life-styles. Further research on the effectiveness of these FACT-plus models can grow the evidence base for how to reduce the criminalization of mental illness.

Development of a B-factory monolithic active pixel detector-the continuous-acquisition pixel prototypes

Future vertex detection at an upgraded KEK-B factory, currently the highest luminosity collider in the world, will require a detector technology capable of withstanding the increased track density and the larger radiation exposure. Near the beam pipe, the current silicon strip detectors have projected occupancies in excess of 100%. Advances in monolithic active-pixel sensors (MAPS) look very promising to address this problem. These devices are also quite attractive due to the possibility of making them very thin-essential for improved tracking and vertexing in the low-momenta environment of a B-factory. In the context of the Belle vertex detector upgrade, the major obstacles to realizing such a device have been concerns about radiation hardness and readout speed. Two prototypes implemented in the TSMC 0.35 /spl mu/m process have been developed to address these issues. Denoted the continuous-acquisition pixel (CAP), the two variants of this architecture are distinguished in that CAP2 includes an eight-deep sampling pipeline within each 22.5 /spl mu/m/sup 2/ pixel. Experience with this deep submicron process indicates tolerable threshold voltage shifts for ionizing radiation in excess of 20 Mrad. In order to maintain low occupancy and insensitivity to radiation-induced increased leakage current, correlated double sampling with a 10 /spl mu/s frame period is needed. Device description, hit resolution, and irradiation results are presented.

Excitation of a parallel-plate dielectric waveguide using a coaxial probe-basic characteristics and experiments

In this paper, we study the basic characteristics of a probe excitation to a parallel-plate dielectric waveguide (PPDW), and present design data and experimental results. A coaxial probe has been used in microstrip lines and rectangular waveguides. The present study shows that it is also an effective method to excite/couple a PPDW, thus facilitating the introduction of a new class of PPDW technology in microwave/millimeter-wave integrated circuits. We use here a spectral-domain analysis for analytical modeling of the probe transition, where the probe is approximated by a current strip of an equivalent width. Applying the method of image, the structure is transformed to an infinite-long thin strip inside a dielectric slab, which reduces the transition analysis into a simpler planar geometry. Basic characteristics of the probe excitation, and a complete design data for the radiation loss, excitation efficiency, and input impedance for various transition parameters are computed. Prototype design experiments were conducted, which show that quite efficient excitation can be achieved using; the probe, with insertion loss as low as 0.1 dB. This is contrary to some misconceptions that a probe transition to the fundamental PPDW mode is quite inefficient due to parallel-plate mode radiation.

Evolution of magnetization reversal on patterned magnetic elements

An in situ observation of magnetic domain structure evolution in the presence of an external magnetic field induced from a live current strip produced underneath patterned permalloy thin films is presented. The signal due to the electrostatic force was avoided during the magnetic force microscope imaging by adding an electrically grounded metal film in-between the patterned films and the current strip. Magnetization reversal on a 6 /spl mu/m permalloy disk was imaged, whereas magnetic domain structure on higher aspect ratios of ellipse and rectangle permalloy elements showed great changes hut a much higher field was required for magnetization saturation due to their high coercive and saturation fields.