Geometry of Non-Hausdorff Spaces and Its Significance for Physics

Hausdorff relation, topologically identifying points in a given space, belongs to elementary tools of modern mathematics. We show that if subtle enough mathematical methods are used to analyze this relation, the conclusions may be far-reaching and illuminating. Examples of situations in which the Hausdorff relation is of the total type, i.e., when it identifies all points of the considered space, are the space of Penrose tilings and space-times of some cosmological models with strong curvature singularities. With every Hausdorff relation a groupoid can be associated, and a convolutive algebra defined on it allows one to analyze the space that otherwise would remain intractable. The regular representation of this algebra in a bundle of Hilbert spaces leads to a von Neumann algebra of random operators. In this way, a probabilistic description (in a generalized sense) naturally takes over when the concept of point looses its meaning. In this situation counterparts of the position and momentum operators can be defined, and they satisfy a commutation relation which, in the suitable limiting case, reproduces the Heisenberg indeterminacy relation. It should be emphasized that this is neither an additional assumption nor an effect of a quantization process, but simply the consequence of a purely geometric analysis.Comment: 13 LaTex pages, no figure

HTC Scientific Computing in a Distributed Cloud Environment

This paper describes the use of a distributed cloud computing system for high-throughput computing (HTC) scientific applications. The distributed cloud computing system is composed of a number of separate Infrastructure-as-a-Service (IaaS) clouds that are utilized in a unified infrastructure. The distributed cloud has been in production-quality operation for two years with approximately 500,000 completed jobs where a typical workload has 500 simultaneous embarrassingly-parallel jobs that run for approximately 12 hours. We review the design and implementation of the system which is based on pre-existing components and a number of custom components. We discuss the operation of the system, and describe our plans for the expansion to more sites and increased computing capacity

Staling in two canned lager beers stored at different temperatures from sensory analyses and consumer ranking

Two canned lagers, lager A (5% abv with late hop character) and lager B (4% abv) stored for 0, 7, 14, 21 and 28 days at 4, 12, 30 and 37°C were scored by trained sensory assessors (10) for liking and stale and related attributes of: cabbagy, cardboard, catty, grainy, honey, leathery, metallic, musty, skunky, and sour. Principal component analysis explained 80% data variance in 3 significant (p < 0.05) and 75% in 4 significant factors for A and B, respectively. In both lagers, aging correlated significantly with stale, cabbagy and musty and in A with metallic and sour and in B with catty and skunky. Partial least squares regression (PLS1) models showed good explanations: stale had regression coefficients of 0.88 (calibration) and 0.84 (validation) for A, and 0.96 and 0.91 respectively, for B; for liking 0.92 and 0.90 for A and 0.96 and 0.93 for B. For both lagers, liking was positively correlated with honey and grainy, and inversely with staling attributes. Lagers from 30°C were ranked for liking by 40 consumers against fresh as a hidden reference. Significant (p = 0.05) ranking of A, but not B, correlated with that of trained assessors

Relationships of overall estery aroma character in lagers with volatile headspace congener concentrations

In lager beers the intensity of “estery” aroma character is re-garded as an important component of sensory quality, but its origins are somewhat uncertain. Overall “estery” aroma intensity was predicted from capillary gas chromatographic (GC) data following solid phase micro extraction (SPME) of headspaces. Estery character was scored in 23 commercial lagers using rank-rating, allowing assessors (13) constant access to a range of appropriate standards. From univariate data analysis, all asses-sors behaved similarly and lagers fell into three significantly different groups: low (1), high (1) and intermediate (21). The quantification of 36 flavour volatiles by SPME of headspaces was reproducible and principal component analysis explained 91% total variance. Multiple linear regression could utilise only a restricted (26) set of flavour volatiles, whereas partial least square regression, that considered all flavour components, showed significant differences and improved prediction. How-ever, an artificial neural network that could compensate for non-linearities and interactions in ester perception gave the most robust prediction at R2 = 0.88

Electron mobility in surface- and buried- channel flatband In_0.53Ga_0.47As MOSFETs with ALD Al₂O₃ gate dielectric.

In this paper, we investigate the scaling potential of flatband III-V MOSFETs by comparing the mobility of surface and buried In&lt;sub&gt;0.53&lt;/sub&gt;Ga&lt;sub&gt;0.47&lt;/sub&gt;As channel devices employing an Atomic Layer Deposited (ALD) Al&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;3&lt;/sub&gt; gate dielectric and a delta-doped InGaAs/InAlAs/InP heterostructure. Peak electron mobilities of 4300 cm&lt;sup&gt;2&lt;/sup&gt;/V·s and 6600 cm&lt;sup&gt;2&lt;/sup&gt;/V·s at a carrier density of 3×1012 cm&lt;sup&gt;-2&lt;/sup&gt; for the surface and buried channel structures respectively were determined. In contrast to similarly scaled inversion-channel devices, we find that mobility in surface channel flatband structures does not drop rapidly with electron density, but rather high mobility is maintained up to carrier concentrations around 4x10&lt;sup&gt;12&lt;/sup&gt; cm&lt;sup&gt;-2&lt;/sup&gt; before slowly dropping to around 2000 cm&lt;sup&gt;2&lt;/sup&gt;/V·s at 1x10M&lt;sup&gt;13&lt;/sup&gt; cm&lt;sup&gt;-2&lt;/sup&gt;. We believe these to be world leading metrics for this material system and an important development in informing the III-V MOSFET device architecture selection process for future low power, highly scaled CM

Rotating Hele-Shaw cells with ferrofluids

We investigate the flow of two immiscible, viscous fluids in a rotating Hele-Shaw cell, when one of the fluids is a ferrofluid and an external magnetic field is applied. The interplay between centrifugal and magnetic forces in determining the instability of the fluid-fluid interface is analyzed. The linear stability analysis of the problem shows that a non-uniform, azimuthal magnetic field, applied tangential to the cell, tends to stabilize the interface. We verify that maximum growth rate selection of initial patterns is influenced by the applied field, which tends to decrease the number of interface ripples. We contrast these results with the situation in which a uniform magnetic field is applied normally to the plane defined by the rotating Hele-Shaw cell.Comment: 12 pages, 3 ps figures, RevTe

Post-school education and social class destinations in Scotland in the 1950s

Data from the 1947 Scottish Mental Survey are used to investigate the relationship between type of secondary school attended and both post-school education up to age 27 and also occupational status by age 27, controlling for social background (social class, parental education, gender), intelligence at age 12, and attitude to school work. The survey was based on a representative sample of all children born in Scotland in 1936. They were first surveyed in 1947 and then almost annually to 1963. The focus of the paper is on the legacies of several waves of reform to secondary education in the first half of the twentieth century. The main research questions are whether the reforms extended access to educational attainment up to age 27 and thus widened access to high-status occupations. These questions are investigated using mainly multiple linear regression. The conclusions are that access was extended, but that people who had attended the older-established secondaries that pre-dated the reforms were more successful educationally and occupationally than people who attended newer foundations, even controlling for social background and intelligence. This effect was especially pronounced for pupils of above-average intelligence, the old schools providing them with particularly pronounced opportunities in adulthood

Re-Inventing Public Education:The New Role of Knowledge in Education Policy-Making

This article focuses on the changing role of knowledge in education policy making within the knowledge society. Through an examination of key policy texts, the Scottish case of Integrated Children Services provision is used to exemplify this new trend. We discuss the ways in which knowledge is being used in order to re-configure education as part of a range of public services designed to meet individuals' needs. This, we argue, has led to a 'scientization' of education governance where it is only knowledge, closely intertwined with action (expressed as 'measures') that can reveal problems and shape solutions. The article concludes by highlighting the key role of knowledge policy and governance in orienting education policy making through a re-invention of the public role of education

Experiments of Interfacial Roughening in Hele-Shaw Flows with Weak Quenched Disorder

We have studied the kinetic roughening of an oil--air interface in a forced imbibition experiment in a horizontal Hele--Shaw cell with quenched disorder. Different disorder configurations, characterized by their persistence length in the direction of growth, have been explored by varying the average interface velocity v and the gap spacing b. Through the analysis of the rms width as a function of time, we have measured a growth exponent beta ~= 0.5 that is almost independent of the experimental parameters. The analysis of the roughness exponent alpha through the power spectrum have shown different behaviors at short (alpha_1) and long (alpha_2) length scales, separated by a crossover wavenumber q_c. The values of the measured roughness exponents depend on experimental parameters, but at large velocities we obtain alpha_1 ~= 1.3 independently of the disorder configuration. The dependence of the crossover wavenumber with the experimental parameters has also been investigated, measuring q_c ~ v^{0.47} for the shortest persistence length, in agreement with theoretical predictions.Comment: 20 pages, 22 figure