9,816 research outputs found
Ferrolubricants
Ferrolubricants have magnetized angstrom-size iron particles which stick oil to moving surfaces at all times, significantly reducing frictional wear. Magnetic fluids can be produced in families of various fluids having widely-varying chemical and physical properties
A self-lubricating bearing
An improved bearing structure is described which includes a permanently magnetized porous body filled with an interstitial magnetic lubricant for extending the operational life of self-lubricating bearings. The bearing structure is characterized by a permanently magnetized retainer formed of a porous material and filled with an interstitial magnetic lubricant, whereby the pores serve as lubricant reservoirs from which the lubricant continuously is delivered to a film disposed between contiguous bearing surfaces
LEO atomic oxygen effects on spacecraft materials: STS-5 results
Effects of low Earth orbit (LEO) atomic oxygen were measured on a variety of spacecraft materials which obtained exposure on STS-5. Material degradation dependency on temperature was found in one material. Of the five paints flown, only S13GLO was unaffected. Generally, the glossy paints became Lambertian and the diffuse coatings improved. Scanning electron microscope examinations indicated removal of urethane and epoxy paint binder materials. Reaction products were evident on the surfaces of Z302 paint and Mylar. Thin films showed thickness losses ranging from negligible loss in Teflon to considerable loss in Mylar and Kapton. Glossy films such as black Kapton and white Tedlar became diffused. Kevlar 29 rope lost tensile strength and silver solar cell interconnect material oxidized. Oxidation on the backside of an elevated specimen indicated that reflections of oxygen atoms were occurring and that reflecting surfaces, probably Kapton, were not fully accommodating the incident atoms
Teaching Sport Psychology to the XBox Generation: Further evidence for game-based learning
Objective: To extend recent research examining the impact of game-based activities on the learning experience of undergraduate psychology students. Design: A counterbalanced repeated measures design was employed to evaluate students’ learning experiences following their involvement in active game-based learning activities. Method: Students on a Level 5 sport psychology module (N=134) were asked to participate in four practical classes demonstrating the impact of psychological factors (e.g. anxiety) on sports performance. Two sessions were designed for each practical: one included the use of active video games (e.g. Kinect Sports); the other included a traditional active game-based activity (e.g. Reaction Time Game). Students were randomly assigned to one of two groups in order to facilitate counterbalancing and to ensure that all students completed two active video game (AVG) and two non-AVG tasks. Following each practical, students provided ratings of perceived usefulness, interest/engagement, and enjoyment using a seven-point Likert scale. These data will be analysed via one way repeated measures analyses of covariance (ANCOVA), with students’ experience of AVGs being the covariate. The impact of sessions on students’ academic motivation and performance were also assessed and analysed via one-way ANOVAs. Results: Data is currently being collected alongside a semester one module. Results will be reported during the presentation. Conclusions: It is anticipated that the findings will provide further evidence to support the use of AVGs in the teaching of undergraduate psychology, and that the increased sophistication of AVG technology may be harnessed to provide multiple benefits for students in higher education
Characterization of ASEC BSR 2 ohm-cm silicon solar cells with dielectric wraparound contacts as a function of temperature and intensity
Twenty high performance BSR 2 ohm-cm silicon solar cells manufactured by ASEC were evaluated at 1 AU conditions and at low temperature and low intensities representative of deep space. These cells showed evidence of series resistance of 1 AU conditions and approximately 50% had reduced power outputs under deep space conditions. Average efficiency of these cells was 12.4% of 1 AU conditions of 1 SC/+25 C
Electron-temperature dependence of dissociative recombination of electrons with CO(+)-(CO)n-series ions
A microwave afterglow mass spectrometer apparatus is used to determine the dependence on electron temperature T sub e of the recombination coefficients alpha sub n of the dimer and trimer ions of the series CO+.(CO) sub n. It is found that alpha sub 1 = (1.3 + or - 0.3)x 0.000001 (T sub e(K)/300) to the -0.34; and alpha sub 2 = (1.9 + or - 0.4)x 0.000001 (T sub e(K)/300) to the -0.33 cu cm/sec. These dependences on T sub e are quite different from those obtained previously for polar-cluster ions of the hydronium and ammonium series but are similar to that for simple diatomic ions
A Bayesian inference approach for determining player abilities in football
We consider the task of determining a football player's ability for a given
event type, for example, scoring a goal. We propose an interpretable Bayesian
model which is fit using variational inference methods. We implement a Poisson
model to capture occurrences of event types, from which we infer player
abilities. Our approach also allows the visualisation of differences between
players, for a specific ability, through the marginal posterior variational
densities. We then use these inferred player abilities to extend the Bayesian
hierarchical model of Baio and Blangiardo (2010) which captures a team's
scoring rate (the rate at which they score goals). We apply the resulting
scheme to the English Premier League, capturing player abilities over the
2013/2014 season, before using output from the hierarchical model to predict
whether over or under 2.5 goals will be scored in a given game in the 2014/2015
season. This validates our model as a way of providing insights into team
formation and the individual success of sports teams.Comment: 31 pages, 14 figure
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