6,366 research outputs found
A Proposal to Measure the Quasiparticle Poisoning Time of Majorana Bound States
We propose a method of measuring the fermion parity lifetime of Majorana
fermion modes due to quasiparticle poisoning. We model quasiparticle poisoning
by coupling the Majorana modes to electron reservoirs, explicitly breaking
parity conservation in the system. This poisoning broadens and shortens the
resonance peak associated with Majorana modes. In a two lead geometry, the
poisoning decreases the correlation in current noise between the two leads from
the maximal value characteristic of crossed Andreev reflection. The latter
measurement allows for calculation of the poisoning rate even if temperature is
much higher than the resonance width.Comment: 5 pages, 5 figure
Milwaukee Longitudinal School Choice Evaluation: Annual School Testing Summary Report 2010-11
Effective at the start of the 2010-11 school year, 2009 Wisconsin Act 28 requires private schools participating in the Milwaukee Parental Choice Program (MPCP) to administer the state test, the Wisconsin Knowledge and Concepts Examinations (WKCE) in reading, mathematics and science to all MPCP pupils in the same grades as public school students tested under Title 1 of the federal No Child Left Behind Act. Prior to the 2010-11 school year, 2005 Wisconsin Act 125 required private schools participating in the MPCP to administer a nationally normed standardized test of their choosing annually in reading, mathematics, and science to the MPCP students enrolled in the 4th, 8th, and 10th grades. Schools are currently given the option to continue to administer other nationally normed tests if they wish, in addition to the WKCE. The law further directs MPCP schools to submit copies of the test scores from all tests and examinations administered to their pupils in 2010-11 to the School Choice Demonstration Project (SCDP) for processing and reporting to the Legislative Audit Bureau. During the 2010-11 school year, all 102 MPCP schools that were required to administer tests did so and provided the results to the SCDP. Specifically, the SCDP received 10,657 WKCE test scores. Sixty-three schools submitted only the WKCE test scores and the remaining 39 schools submitted both nationally normed tests, such as the Iowa Test of Basic Skills and the WKCE. Five MPCP schools were not required to send in scores as they enrolled no MPCP students in mandatory testing grades
The magneto-optical Faraday effect in spin liquid candidates
We propose an experiment to use the magneto-optical Faraday effect to probe
the dynamic Hall conductivity of spin liquid candidates. Theory predicts that
an external magnetic field will generate an internal gauge field. If the source
of conductivity is in spinons with a Fermi surface, a finite Faraday rotation
angle is expected. We predict the angle to scale as the square of the frequency
rather than display the standard cyclotron resonance pattern. Furthermore, the
Faraday effect should be able to distinguish the ground state of the spin
liquid, as we predict no rotation for massless Dirac spinons. We give a
semiquantitative estimate for the magnitude of the effect and find that it
should be experimentally feasible to detect in both
-(ET)Cu(CN) and, if the spinons form a Fermi surface,
Herbertsmithite. We also comment on the magneto-optical Kerr effect and show
that the imaginary part of the Kerr angle may be measurable.Comment: 5 pages, 1 figur
Remote data acquisition for condition monitoring of wind turbines
While the number of offshore wind turbines is growing and turbines getting bigger and more expensive, the need for good condition monitoring systems is rising. From the research it is clear that failures of the gearbox, and in particular the gearwheels and bearings of the gearbox, have been responsible for the most downtime of a wind turbine. Gearwheels and bearings are being simulated in a multi-sensor environment to observe the wear on the surface
Effect of velocity on roll/slip for low and high load conditions in polymer composite
In the last decade polymer composites are often used without lubrication on both low and high speed applications. Some of the application areas are marine, automotive and agriculture used as bearings and cams where roll-slip is the dominant mechanism. Limited studies are made for composites relating such applications where rolling/sliding condition influences the tribological behavior of the material. Investigating the roll-slip phenomenon for identifying the influence of velocity on frictional behavior can mark a boundary to map the use of composites with respect to its application. Moreover, the design of the material can be optimized to match the operating conditions. In the current research the polymer composite (with polyester matrix) has been tested under rolling-sliding condition for two different loads with 61N and 210N and with different speeds ranging from 10 rpm to 700 rpm. Ideal conditions in terms of roughness, slip ratio, surface temperature and ambient temperature were maintained to reduce the frictional heating. Using a 20% slip ratio the behavior of the material was observed for the tribological characteristics where the rate of increase of friction force follows a exponential pattern with increasing speeds. Nevertheless, on testing with high speeds a steady rate of increase in the friction curve was observed. Friction behavior of composites under different speeds is briefed with the microstructural characteristics for low and high loads
Catholic Literary Theory: The Conditional Existentialism of Four Protagonists and Their Creators
According to Catholic literary theory, the novelist, like the Divine Mystery to a certain extent, creates her characters freely and free with the possibility and probability that they may speak against their creator and even finally rebel. This dissertation reflects upon the relative infiniteness of four literary authors - Flannery O\u27Connor, Mary McCarthy, Walker Percy, and Cormac McCarthy. In the three novels and one imaginative memoir considered in particular, these authors create their existentialist protagonists, who in their turn reflect the conditional existentialism of their creators. This dissertation, thus, seeks to resurrect, with modern sensibilities, the pre-renaissance and renaissance commonplace that the poet is a creator, and to examine how this schema figures into the Catholic belief that man is created in the Divine Mystery\u27s image without a loss of human freedom. Celebrating this mystery of existence, Catholic literary theory suggests that the Catholic universe is for all at all times, and not only for those who identify themselves as Catholics. The value of this dissertation for the field of literary studies lies in that insofar as the poet and novelist has lost her identity as creating out of love because God, the Divine Mystery, created her out of love, then philosophy, history, theology, and literature, itself, are in mortal danger. This is the appeal that writers like O\u27Connor and Percy conscientiously make and writers like Mary McCarthy and Cormac McCarthy confirm despite themselves
POOR METAPHORS: HOW LANGUAGE MAKES, AND HOW ANALYZING POPULAR STEREOTYPES CAN CHALLENGE, SOCIAL ATTITUDES THAT QUESTION THE VALUE OF THE ECONOMICALLY OPPRESSED IN A DEMOCRATIC SOCIETY
This rhetorical project analyzes the historical and contemporary prevalence of some of the popular metaphors that have come to characterize recipients of government assistance programs such as food stamps, also known as the Supplemental Nutrition Assistance Program. By synthesizing the metaphor theory of George Lakoff and Mark Johnson with the sociological concepts of doxa, habitus, and heretical discourse posited by Pierre Bourdieu, this project not only spotlights these negative metaphors but also offers ways of disrupting their tacit influence over people’s perceptions, which otherwise are in danger of reproducing themselves. The metaphors discussed seek to reduce the poor on government assistance to the level of parasites, animals, and sinner criminals. In the American political landscape of the latter half of the twentieth century and into the early twenty-first century, these rhetorical attacks have become more frequent, and a good reason for this increase in frequency has to do with an anthropological theoretical framework known as the “culture of poverty,” which many agree was an institutionalized effort to blame the victims of poverty for their own oppression. However, despite the overall failure of the War on Poverty to lift all Americans into prosperity, some of the ideas that flourished during the late 1960s were acts of heretical discourse and can be adapted to help those on government assistance today challenge the assumptions that the wider society holds regarding the poor. Heretical discourse can be an effective way of enhancing democratic engagement in a given population, with the ultimate aim of challenging stereotypes by questioning the metaphors that undergird them
Tribological behaviour of polymer bearings under dry and water lubrication
This study attempts to evaluate the performance of polymer journal bearings (PET and UHMWPE) sliding against Inconel stainless steel in both dry and lubricated condition. Four types of ‘lubricant’ are included: distilled water; demineralized water; tap water and river water. The tests were carried out in a so called “Stribeck” configuration with a projected pressure of about 0.3 MPa at room temperature and sliding speed ranging from 0 to 1.07 m/s respectively. The study indicates that polymer bearings with four types of water lubricant give better tribological behaviour compared to those in dry sliding contact. Besides, with water lubrication, UHMWPE shows low friction at starting, but it does not go down much over the course of the tests. Meanwhile, although PET indicates quite higher friction at the beginning, it then shows a clearly decreasing trend
Dry sliding wear properties of Jute/polymer composites in high loading applications
In the last few decades natural fiber composites has gained its importance due to its low cost and their availability as additives with minimal processing. Amongst the various natural sources the Jute fiber is chosen in the present research due to its fiber structure and good physical and mechanical properties. In this background natural fiber composites of unsaturated polyester were reinforced with jute fibers.
While most research on green composites focuses on the structural characteristics, the present work investigates the suitability of the material to be used as a tribocomposite. Tailor made hybrid composites were made with chemically treated (NaOH) jute fiber and 2 wt % PTFE filler (tribo lubricant) to obtain the better tribological characteristics in high loading condition. Tribotests were performed on flat on flat configuration where 100Cr6 steel was used as counterface material.
A pv limit of 400 MPa-mm/s (10KN and 100 mm/s) was attainedin a flat-on-flat configuration for studying the tribological properties. The static and dynamic coefficient of friction was found to be 0.15 and 0.07 respectively.An exponential increase in temperature was observed throughout the test. The material failure was observed within 500 m of sliding distance where pulverization of matrix due to thermal degradation is evident. Wear mechanisms such as fiber breakage, polymer degradation, fiber thinning and fiber separation was observed. From the present investigation the low cost Jute fabric composites havinglow frictional coefficient seemed to be a alternative to the bearing materials working at higher contact pressure and low velocity
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