Mechanical vaccum pumps

This presentation gives an overview of the technology of contemporary primary and secondary mechanical vacuum pumps. For reference a brief history of vacuum and a summary of important and basic vacuum concepts are first presented

On the Abundance of Circumbinary Planets

We present here the first observationally based determination of the rate of occurrence of circumbinary planets. This is derived from the publicly available Kepler data, using an automated search algorithm and debiasing process to produce occurrence rates implied by the seven systems already known. These rates depend critically on the planetary inclination distribution: if circumbinary planets are preferentially coplanar with their host binaries, as has been suggested, then the rate of occurrence of planets with $R_p>6R_\oplus$ orbiting with $P_p<300$\ d is $10.0 ^{+18}_{-6.5}$\% (95\% confidence limits), higher than but consistent with single star rates. If on the other hand the underlying planetary inclination distribution is isotropic, then this occurrence rate rises dramatically, to give a lower limit of 47\%. This implies that formation and subsequent dynamical evolution in circumbinary disks must either lead to largely coplanar planets, or proceed with significantly greater ease than in circumstellar disks. As a result of this investigation we also show that giant planets (${>}10R_\oplus$) are significantly less common in circumbinary orbits than their smaller siblings, and confirm that the proposed shortfall of circumbinary planets orbiting the shorter period binaries in the Kepler sample is a real effect.Comment: Accepted for publication in MNRAS (1st August 2014). 12 pages. Update to match final version, including clarifications and new figures. Results are unchange

Exploring the S-Matrix of Massless Particles

We use the recently proposed generalised on-shell representation for scattering amplitudes and a consistency test to explore the space of tree-level consistent couplings in four-dimensional Minkowski spacetime. The extension of the constructible notion implied by the generalised on-shell representation, i.e. the possibility to reconstruct at tree level all the scattering amplitudes from the three-particle ones, together with the imposition of the consistency conditions at four-particle level, allow to rediscover all the known theories and their algebra structure, if any. Interestingly, this analysis seems to leave room for high-spin couplings, provided that at least the requirement of locality is weakened. We do not claim to have found tree-level consistent high-spin theories, but rather that our methods show signatures of them and very likely, with a suitable modification, they can be a good framework to perform a systematic search.Comment: 44 pages, 1 figur

MorpheuS: Generating Structured Music with Constrained Patterns and Tension

Automatic music generation systems have gained in popularity and sophistication as advances in cloud computing have enabled large-scale complex computations such as deep models and optimization algorithms on personal devices. Yet, they still face an important challenge, that of long-term structure, which is key to conveying a sense of musical coherence. We present the MorpheuS music generation system designed to tackle this problem. MorpheuS' novel framework has the ability to generate polyphonic pieces with a given tension profile and long- and short-term repeated pattern structures. A mathematical model for tonal tension quantifies the tension profile and state-of-the-art pattern detection algorithms extract repeated patterns in a template piece. An efficient optimization metaheuristic, variable neighborhood search, generates music by assigning pitches that best fit the prescribed tension profile to the template rhythm while hard constraining long-term structure through the detected patterns. This ability to generate affective music with specific tension profile and long-term structure is particularly useful in a game or film music context. Music generated by the MorpheuS system has been performed live in concerts.Comment: IEEE Transactions on Affective Computing. PP(99

Implementation of a Large System-Wide Hepatitis C Virus Screening and Linkage to Care Program for Baby Boomers.

BackgroundWe implemented and evaluated a large health system-wide hepatitis C virus (HCV) screening and linkage to care program for persons born between 1945 and 1965 ("baby boomers").MethodsAn electronic health record (EHR) clinical decision support (CDS) tool for HCV screening for baby boomers was introduced in August 2015 for patients seen in the outpatient University of California, Los Angeles healthcare system setting. An HCV care coordinator was introduced in January 2016 to facilitate linkage to HCV care. We compared HCV testing in the year prior (August 2014-July 2015) to the year after (August 2015-July 2016) implementation of the CDS tool. Among patients with reactive HCV antibody testing, we compared outcomes related to the care cascade including HCV ribonucleic acid (RNA) testing, HCV RNA positivity, and linkage to HCV specialty care.ResultsDuring the study period, 19606 participants were screened for HCV antibody. Hepatitis C virus antibody screening increased 145% (from 5676 patients tested to 13930 tested) after introduction of the CDS intervention. Screening increased across all demographic groups including age, sex, and race/ethnicity, with the greatest increases among those in the older age groups. The addition of an HCV care coordinator increased follow-up HCV RNA testing for HCV antibody positive patients from 83% to 95%. Ninety-four percent of HCV RNA positive patients were linked to care postimplementation.ConclusionsIntroduction of an EHR CDS tool and care coordination markedly increased the number of baby boomers screened for HCV, rates of follow-up HCV RNA testing, and linkage to specialty HCV care for patients with chronic HCV infection

Using goals to model strategy map for business IT alignment

Strategy Map (SM) is one of the widely used methods to create business aligned IT strategy map providing valuable insights to business executives. However, problem with strategy map method is that it is not easy to use which can lend itself to various interpretations. This is because linkages between the strategic objectives in the four strategy map perspectives are not explicit which makes SM ambiguous. Goal modelling approaches from Requirements Engineering (RE) have proven rigorous in elicitation and representation of information system requirements. In an attempt to make explicit the causal relationships of SM linkages meaningful this research proposes the use of goal modelling approach i*

Isotropic-medium three-dimensional cloaks for acoustic and electromagnetic waves

We propose a generalization of the two-dimensional eikonal-limit cloak derived from a conformal transformation to three dimensions. The proposed cloak is a spherical shell composed of only isotropic media; it operates in the transmission mode and requires no mirror or ground plane. Unlike the well-known omnidirectional spherical cloaks, it may reduce visibility of an arbitrary object only for a very limited range of observation angles. In the short-wavelength limit, this cloaking structure restores not only the trajectories of incident rays, but also their phase, which is a necessary ingredient to complete invisibility. Both scalar-wave (acoustic) and transverse vector-wave (electromagnetic) versions are presented.Comment: 17 pages, 12 figure

pi-N charge exchange and pi(+)-pi(0) scattering at low energies

pi-N and pi-pi interactions near threshold are uniquely sensitive to the chiral symmetry breaking part of the strong interaction. The pi-N sigma-term value with its implications for nucleon quark structure and the recent controversy concerning the size of the scalar quark condensate have renewed the experimental interest in these two fundamental systems. We report new differential cross sections for the reaction $pi^-p \to \pi^0n$ at 27.5 MeV pion incident kinetic energy, measured between $\theta_{CM} = 0^\circ$ and $55^\circ$. Our results are in excellent agreement with the existing comprehensive pi-N phase shift analysis. We also report on a Chew-Low analysis of exclusive $\pi^+ p \to \pi^+\pi^0p$ data at 260 MeV pion incident energy.Comment: Talk given by D. Pocanic at QULEN97, Osaka, 20-23 May 1997; 4 pages, 2 PostScript figures, writen in LaTeX 2e, uses packages "epsfig" and "espcrc1