Friction and wear behaviour of ceramic-hardened steel couples under reciprocating sliding motion

The friction and wear behaviour of ZrO2-Y203, ZrO2-Y203-CeO2 and ZrO2-A1203 composite ceramics against hardened steel AISI-52100 were investigated using a pin on plate configuration under reciprocating motion. The reproducibility of the results was examined in this configuration. Wear characteristics were separated into system and material contributions. Under the conditions used, all the ceramic components exhibited rather low wear rates (less than 10-6mm3N-1m-1). The frictional behaviour of ceramic-metal couples depended on a metallic layer transferred from the steel plate to the ceramic pin. A relation was determined between surface hardness and friction of ceramic-metal pairs. It was shown that the affinity for the transfer of the metal towards ceramic surfaces depended on the physical properties of the materials. In the tribosystems investigated, the effect of the hardness of the ceramics on friction and wear behaviour is found to be more important than that of toughness of the ceramics

AI for Archives: Using Facial Recognition to Enhance Metadata

The goal of this research project was to determine the most effective facial recognition applications that could be implemented into digital archive image collections from libraries, museums, and cultural heritage institutions. Computer scientists and librarians at Florida International University collaborated to conduct qualitative assessments of both face detection and face search using photographs from FIU’s digital collections. Specifically, the facial recognition platforms OpenCV, Face++, and Amazon AWS were analyzed. This project seeks to assist LYRASIS community members who wish to incorporate facial recognition and other artificial intelligence technology into their digital collections and repositories as a method to reduce research time and enhance their collections with more complete metadata

Comparative analysis of the transversities and the longitudinally polarized distribution functions of the nucleon

A first empirical extraction of the transversity distributions for the $u$- and $d$-quarks has been done by Anselmino {\it et al.} based on the combined global analysis of the measured azimuthal asymmetries in semi-inclusive deep inelastic scatterings and those in $e^+ e^- \to h_1 h_2 X$ processes. Although with large uncertainties, the determined transversity distributions already appear to reveal a remarkable qualitative difference with the corresponding longitudinally polarized distributions. We point out that this difference contains very important information on internal spin structure of the nucleon.Comment: 12 pages, 2 figure

A Highly Sensitive CMOS Digital Hall Sensor for Low Magnetic Field Applications

Integrated CMOS Hall sensors have been widely used to measure magnetic fields. However, they are difficult to work with in a low magnetic field environment due to their low sensitivity and large offset. This paper describes a highly sensitive digital Hall sensor fabricated in 0.18 μm high voltage CMOS technology for low field applications. The sensor consists of a switched cross-shaped Hall plate and a novel signal conditioner. It effectively eliminates offset and low frequency 1/f noise by applying a dynamic quadrature offset cancellation technique. The measured results show the optimal Hall plate achieves a high current related sensitivity of about 310 V/AT. The whole sensor has a remarkable ability to measure a minimum ±2 mT magnetic field and output a digital Hall signal in a wide temperature range from −40 °C to 120 °C

Project assessment: an international perspective

Project Assessment is an American Psychological Association (APA, 2018) initiative aimed at facilitating assessment of the five comprehensive learning goals of the APA guidelines for the undergraduate psychology major (2013). We believe that Project Assessment holds great promise for both U.S. and international use; moreover, we suggest that Project Assessment can benefit from consideration of international assessment initiatives, particularly those aimed at increasing mobility in our interconnected world. Internationally, particularly in Europe where all but one country adheres to the Bologna Process and many countries adhere to the related EuroPsy guidelines, assessment of psychology higher education is driven by a broader range of stakeholders than is typically considered in the United States. Indeed, Bologna countries explicitly consider input from external stakeholders such as employers when developing curricula and assessing outcomes, and they prioritize the assessment of skills at least as much as knowledge. In this paper, we outline the Bologna Process, EuroPsy, and similar collaborative agreements in other world regions. We highlight what the United States can learn from these projects, particularly the involvement of a broader range of stakeholders and an emphasis on mobility of degrees and graduates. While doing so, we explore evidence on internationally implemented assessment practices and on the extent to which harmonized curricula and assessment practices have increased mobility. As many world regions pursue Bologna-like structures, often with funding from the European Union, we believe that it is essential that those pursuing U.S. initiatives like Project Assessment actively join the global conversation about higher education in psychology. (PsycInfo Database Record (c) 2021 APA, all rights reserved

Carnosinase-1 overexpression, but not aerobic exercise training, affects the development of diabetic nephropathy in BTBR ob/ob mice

Manipulation of circulating histidine-containing dipeptides (HCD) has been shown to affect the development of diabetes and early-stage diabetic nephropathy (DN). The aim of the present study was to investigate whether such interventions, which potentially alter levels of circulating HCD, also affect the development of advanced-stage DN. Two interventions, aerobic exercise training and overexpression of the human carnosinase-1 (hCN1) enzyme, were tested. BTBR ob/ob mice were either subjected to aerobic exercise training (20 wk) or genetically manipulated to overexpress hCN1, and different diabetes- and DN-related markers were compared with control ob/ob and healthy (wild-type) mice. An acute exercise study was performed to elucidate the effect of obesity, acute running, and hCN1 overexpression on plasma HCD levels. Chronic aerobic exercise training did not affect the development of diabetes or DN, but hCN1 overexpression accelerated hyperlipidemia and aggravated the development of albuminuria, mesangial matrix expansion, and glomerular hypertrophy of ob/ob mice. In line, plasma, kidney, and muscle HCD were markedly lower in ob/ob versus wild-type mice, and plasma and kidney HCD in particular were lower in ob/ob hCN1 versus ob/ob mice but were unaffected by aerobic exercise. In conclusion, advanced glomerular damage is accelerated in mice overexpressing the hCN1 enzyme but not protected by chronic exercise training. Interestingly, we showed, for the first time, that the development of DN is closely linked to renal HCD availability. Further research will have to elucidate whether the stimulation of renal HCD levels can be a therapeutic strategy to reduce the risk for developing DN

RQM description of the charge form factor of the pion and its asymptotic behavior

The pion charge and scalar form factors, $F_1(Q^2)$ and $F_0(Q^2)$, are first calculated in different forms of relativistic quantum mechanics. This is done using the solution of a mass operator that contains both confinement and one-gluon-exchange interactions. Results of calculations, based on a one-body current, are compared to experiment for the first one. As it could be expected, those point-form, and instant and front-form ones in a parallel momentum configuration fail to reproduce experiment. The other results corresponding to a perpendicular momentum configuration (instant form in the Breit frame and front form with $q^+=0$) do much better. The comparison of charge and scalar form factors shows that the spin-1/2 nature of the constituents plays an important role. Taking into account that only the last set of results represents a reasonable basis for improving the description of the charge form factor, this one is then discussed with regard to the asymptotic QCD-power-law behavior $Q^{-2}$. The contribution of two-body currents in achieving the right power law is considered while the scalar form factor, $F_0(Q^2)$, is shown to have the right power-law behavior in any case. The low-$Q^2$ behavior of the charge form factor and the pion-decay constant are also discussed.}Comment: 30 pages, 10 figure

The solution of two-dimensional free-surface problems using automatic mesh generation

A new method is described for the iterative solution of two-dimensional free-surface problems, with arbitrary initial geometries, in which the interior of the domain is represented by an unstructured, triangular Eulerian mesh and the free surface is represented directly by the piecewise-quadratic edges of the isoparametric quadratic-velocity, linear-pressure Taylor-Hood elements. At each time step, the motion of the free surface is computed explicitly using the current velocity field and, once the new free-surface location has been found, the interior nodes of the mesh are repositioned using a continuous deformation model that preserves the original connectivity. In the event that the interior of the domain must be completely remeshed, a standard Delaunay triangulation algorithm is used, which leaves the initial boundary discretisation unchanged. The algorithm is validated via the benchmark viscous flow problem of the coalescence of two infinite cylinders of equal radius, in which the motion is due entirely to the action of capillary forces on the free surface. This problem has been selected for a variety of reasons: the initial and final (steady state) geometries differ considerably; in the passage from the former to the latter, large free-surface curvatures - requiring accurate modelling - are encountered; an analytical solution is known for the location of the free surface; there exists a large body of literature on alternative numerical simulations. A novel feature of the present work is its geometric generality and robustness; it does not require a priori knowledge of either the evolving domain geometry or the solution contained therein

Multistep Parametric Processes in Nonlinear Optics

We present a comprehensive overview of different types of parametric interactions in nonlinear optics which are associated with simultaneous phase-matching of several optical processes in quadratic nonlinear media, the so-called multistep parametric interactions. We discuss a number of possibilities of double and multiple phase-matching in engineered structures with the sign-varying second-order nonlinear susceptibility, including (i) uniform and non-uniform quasi-phase-matched (QPM) periodic optical superlattices, (ii) phase-reversed and periodically chirped QPM structures, and (iii) uniform QPM structures in non-collinear geometry, including recently fabricated two-dimensional nonlinear quadratic photonic crystals. We also summarize the most important experimental results on the multi-frequency generation due to multistep parametric processes, and overview the physics and basic properties of multi-color optical parametric solitons generated by these parametric interactions.Comment: To be published in Progress in Optic