Accurate and efficient gravitational waveforms for certain galactic compact binaries

Stellar-mass compact binaries in eccentric orbits are almost guaranteed sources of gravitational waves for Laser Interferometer Space Antenna. We present a prescription to compute accurate and efficient gravitational-wave polarizations associated with bound compact binaries of arbitrary eccentricity and mass ratio moving in slowly precessing orbits. We compare our approach with those existing in the literature and present its advantages.Comment: 10 pages, 7 figures, to be published in MNRA

Aligned Spins: Orbital Elements, Decaying Orbits, and Last Stable Circular Orbit to high post-Newtonian Orders

In this article the quasi-Keplerian parameterisation for the case that spins and orbital angular momentum in a compact binary system are aligned or anti-aligned with the orbital angular momentum vector is extended to 3PN point-mass, next-to-next-to-leading order spin-orbit, next-to-next-to-leading order spin(1)-spin(2), and next-to-leading order spin-squared dynamics in the conservative regime. In a further step, we use the expressions for the radiative multipole moments with spin to leading order linear and quadratic in both spins to compute radiation losses of the orbital binding energy and angular momentum. Orbital averaged expressions for the decay of energy and eccentricity are provided. An expression for the last stable circular orbit is given in terms of the angular velocity type variable $x$.Comment: 30 pages, 2 figures, v2: update to match published versio

Local Current Distribution and "Hot Spots" in the Integer Quantum Hall Regime

In a recent experiment, the local current distribution of a two-dimensional electron gas in the quantum Hall regime was probed by measuring the variation of the conductance due to local gating. The main experimental finding was the existence of "hot spots", i.e. regions with high degree of sensitivity to local gating, whose density increases as one approaches the quantum Hall transition. However, the direct connection between these "hot spots" and regions of high current flow is not clear. Here, based on a recent model for the quantum Hall transition consisting of a mixture of perfect and quantum links, the relation between the "hot spots" and the current distribution in the sample has been investigated. The model reproduces the observed dependence of the number and sizes of "hot spots" on the filling factor. It is further demonstrated that these "hot spots" are not located in regions where most of the current flows, but rather, in places where the currents flow both when injected from the left or from the right. A quantitative measure, the harmonic mean of these currents is introduced and correlates very well with the "hot spots" positions

Influence of growing sites and physicochemical features on the incidence of lenticel breakdown in 'Gala' and 'Galaxy' apples.

The origin of lenticels during apple fruit development growing in different altitudes, the physicochemical and physiological fruit features at harvest and storage, were studied in order to correlate these aspects to lenticel breakdown. "Gala" and "Galaxy" apples were harvested from orchards located at three traditional growing regions in Brazil: Vacaria, RS (971 m a.s.l.), Fraiburgo, SC (1048 m a.s.l.) and São Joaquim, SC (1353 m a.s.l.), during the 2008/09 season. The fruit were kept in cold storage (CS) at 0 ◦C and 90% RH for up to 120 days or at controlled atmosphere (CA) at 1.5% O2, 2.5% CO2, 0 ◦C and 90% RH for up to 210 days. Colour index was higher in ?Galaxy? apples and in fruit grown in São Joaquim, where the minimum temperatures were approximately 10 ◦C. The firmness was reduced at CS and CA, butit remained greater than 40 N in all the treatments. Acidity, except for ?Galaxy? apples, and sugars were influenced by the climatic conditions of the growing sites. There was no relationship between the lenticels dyeing and the incidence of lenticel breakdown. Contrary to the expectations, higher incidence of the disorder was noticed in ?Gala? apples grown in São Joaquim (SC) at the end of the both types of storage. The lenticel breakdown was featured by symptoms such as concentric depression around the lenticels, cell obliteration of the epidermis and subepidermal layers, with wide spaces formed by cell lysis. The origin of lenticels has no influence on the disorder development. It was not possible to establish a relationship among physicochemical, physiological and anatomical features from distinct growing sites and the predisposition to lenticel breakdown disorder

Direct observation of micron-scale ordered structure in a two-dimensional electron system

We have applied a novel scanned probe method to directly resolve the interior structure of a GaAs/AlGaAs two-dimensional electron system in a tunneling geometry. We find that the application of a perpendicular magnetic field can induce surprising density modulations that are not static as a function of the field. Near six and four filled Landau levels, stripe-like structures emerge with a characteristic wave length ~2 microns. Present theories do not account for ordered density modulations on this length scale.Comment: 5 pages, 4 figures. To appear in Phys. Rev.

Physiological and perceptual responses to Nintendo® Wii Fit™ in young and older adults

Physically active video gaming (AVG) provides a technologically-modern, convenient means of increasing physical activity (PA). This study examined cardiovascular, metabolic, and perceptual responses in young adult (AP) and older adult (OP) participants engaging in Wii Fitä AVG play, and compared PA levels during play to recommended PA levels. Heart rate (HR), percent heart rate reserve (%HRR), oxygen consumption (VO2), energy expenditure (EE), rating of perceived exertion (RPE), enjoyment level (EL), and step count data were obtained from 10 YP and 10 OP during 15 minutes of rest and four 15-minute bouts of Wii Fitä activities (yoga, balance, aerobics, strength). For all participants, AVG significantly increased HR, VO2, and EE measures above rest, with significant between-activity differences. Responses were similar between YP and OP, except that the activities were more intense for OP, in terms of %HRR and RPE. Most games elicited responses consistent with light-intensity PA, though peak HR and VO2 values for aerobic and strength games met or approached recommended PA intensities. Wii Fitä appears to provide an enjoyable form of light PA for both YP and OP, which can reduce inactive screen time and provide beneficial cardiovascular, musculoskeletal, and metabolic stimulation

Chaos in Andreev Billiards

A new type of classical billiard - the Andreev billiard - is investigated using the tangent map technique. Andreev billiards consist of a normal region surrounded by a superconducting region. In contrast with previously studied billiards, Andreev billiards are integrable in zero magnetic field, {\it regardless of their shape}. A magnetic field renders chaotic motion in a generically shaped billiard, which is demonstrated for the Bunimovich stadium by examination of both Poincar\'e sections and Lyapunov exponents. The issue of the feasibility of certain experimental realizations is addressed.Comment: ReVTeX3.0, 4 pages, 3 figures appended as postscript file (uuencoded with uufiles

Local atomic structure and discommensurations in the charge density wave of CeTe3

The local structure of CeTe3 in the incommensurate charge density wave (IC-CDW) state has been obtained using atomic pair distribution function (PDF) analysis of x-ray diffraction data. Local atomic distortions in the Te-nets due to the CDW are larger than observed crystallographically, resulting in distinct short and long Te-Te bonds. Observation of different distortion amplitudes in the local and average structures are explained by the discommensurated nature of the CDW since the PDF is sensitive to the local displacements within the commensurate regions whereas the crystallographic result averages over many discommensurated domains. The result is supported by STM data. This is the first quantitative local structural study within the commensurate domains in an IC-CDW system.Comment: 4 pages, 4 figure

Imaging of Low Compressibility Strips in the Quantum Hall Liquid

Using Subsurface Charge Accumulation scanning microscopy we image strips of low compressibility corresponding to several integer Quantum Hall filling factors. We study in detail the strips at Landau level filling factors $\nu =$ 2 and 4. The observed strips appear significantly wider than predicted by theory. We present a model accounting for the discrepancy by considering a disorder-induced nonzero density of states in the cyclotron gap.Comment: 5 pages, 3 figure