A hysteresis model for an orthogonal thin-film magnetometer

The operation of a ferromagnetic thin-film magnetometer using the anisotropic magnetoresistance effect in a permalloy film is discussed. Measurements showed the presence of a hysteresis effect not predicted by available models. It is shown that the sensitivity of the magnetometer is predicted by applying F.S. Greene and R.B. Yarbrough's (1970) orthogonal susceptibility model, and that the hysteresis can be explained by assuming dispersion in the magnitude of anisotropy. The orthogonal susceptibility model must be evaluated numerically, accounting for a finite driving field. The effect of an inhomogeneous demagnetizing field in the film is discussed in relation to magnitude dispersion of the anisotrop

Isolated Photons in Deep Inelastic Scattering

Photon radiation at large transverse momenta at colliders is a detailed probe of hard interaction dynamics. The isolated photon production cross section in deep inelastic scattering was measured recently by the ZEUS experiment, and found to be considerably larger than theoretical predictions obtained with widely used event generators. To investigate this discrepancy, we perform a dedicated parton-level calculation of this observable, including contributions from fragmentation and large-angle radiation. Our results are in good agreement with all aspects of the experimental measurement.Comment: 4 pages, 3 figure

Measuring temporal variations in presence

In the current study we have applied the concept of presence to 3DTV research. More specifically, we took this concept to reflect the increased perceptual linkage between the observer and the mediated environment, supporting an illusion of non-mediation. We applied the continuous assessment methodology to reveal time-variant properties of presence, which were hitherto largely ignored, and to assess some of the contributing factors that have been suggested as determinants of presence. Our results indicate that subjective presence ratings are subject to considerable temporal variation depending on the stimulus material used. The continuous assessment methodology may be regarded as a useful measurement tool that is sensitive to this time-varying information in subjective presence judgements, provided that any conclusions are based on averaged results obtained from an adequate number of observers. We also found qualitative evidence suggesting that increasing the extent of sensory information provided to an observer, through the addition of stereoscopic and motion parallax cues (simulated via camera movement), may enhance the observer's sense of presence

Fruit dry weight and quality of 'bing' sweet cherries grown without source limitations

Understanding the seasonal pattern of potential fruit growth is important for identification and timing of possible management operations, and quantification of this pattern is an important prerequisite to serve as input for crop growth models. `Bing¿ sweet cherry trees were heavily thinned at 63 degree-days (DD) (=8 days) after full bloom so weight and quality of the remaining fruit could be monitored under conditions of limiting and non-limiting carbohydrate supply. The effect of fruit thinning on mean shoot growth and trunk cross-sectional area also was analysed to detect possible translocation from reproductive to vegetative growth. Mean Fruit Dry Weight (MFDW) of tagged fruit was estimated weekly, based on fruit diameter, to identify the moment of the onset of competition between fruit within trees. At harvest, Fruit Number to Leaf Area Ratio (FNLAR, fruits m-2 LA) was 52% lower in heavily-thinned trees than in non-thinned trees. Yield per tree was higher (

Relationship between fruit weight and the fruit-to-leaf area ratio, at the spur and whole-tree level, for three sweet cherry varieties

Fruit weight is the main quality parameter of sweet cherries and leaf area/fruit is the most important characteristic influencing fruit weight. The objective of this study was to determine the relationship between Mean Fruit Weight (MFW) and the Fruit Number to Leaf Area Ratio (FNLAR) for `Bing¿, `Van¿ and `Lapins¿, grown under tatura-trellis and vase training systems, at both the spur and whole-tree level. The research was performed through regression analysis with FNLAR as the independent variable and MFW as the dependent variable. There were no significant interactions between training system and cultivar for the effect of FNLAR on MFW at either the spur or whole-tree level. Also, there were no significant differences between training systems. The R2 for the relationships per cultivar were higher at the whole-tree level than at the spur level. At both levels, `Lapins¿ had the highest fruit weight potential and `Van¿ the lowest. At the spur level, the slopes of the regression were similar for the different cultivars, but at the whole-tree level, `Van¿ was less sensitive. The better fit at the whole-tree level suggests that fruits of a spur are supplied not only by the leaves on that spur, but also from other less fruit-loaded spurs, from non-fruiting shoots and from reserve

Towards the re-verification of process tank calibrations

Re-verification is needed to ensure that the calibration (the relationship between measured level and measured volume) that is obtained during commissioning hasn’t changed over time. This can be achieved, in part, by metering in solution and correlating with marks identified a priori. Mark identification and correlation are discussed and possible error sources are outlined

The diurnal evolution of the urban heat island of Paris: a model-based case study during Summer 2006

The urban heat island (UHI) over Paris during summer 2006 was simulated using the Advanced Regional Prediction System (ARPS) updated with a simple urban parametrization at a horizontal resolution of 1 km. Two integrations were performed, one with the urban land cover of Paris and another in which Paris was replaced by cropland. The focus is on a five-day clear-sky period, for which the UHI intensity reaches its maximum. The diurnal evolution of the UHI intensity was found to be adequately simulated for this five day period. The maximum difference at night in 2 m temperature between urban and rural areas stemming from the urban heating is reproduced with a relative error of less than 10%. The UHI has an ellipsoidal shape and stretches along the prevailing wind direction. The maximum UHI intensity of 6.1 K occurs at 23:00 UTC located 6 km downstream of the city centre and this largely remains during the whole night. An idealized one-column model study demonstrates that the nocturnal differential sensible heat flux, even though much smaller than its daytime value, is mainly responsible for the maximum UHI intensity. The reason for this nighttime maximum is that additional heat is only affecting a shallow layer of 150 m. An air uplift is explained by the synoptic east wind and a ramp upwind of the city centre, which leads to a considerable nocturnal adiabatic cooling over cropland. The idealized study demonstrates that the reduced vertical adiabatic cooling over the city compared to cropland induces an additional UHI build-up of 25%. The UHI and its vertical extent is affected by the boundary-layer stability, nocturnal low-level jet as well as radiative cooling. Therefore, improvements of representing these boundary-layer features in atmospheric models are important for UHI studies

Effect of fruit-to-leaf area ratio on fruit quality and vegetative growth of 'bing' sweet cherry trees at optimal leaf area index

Fruit yield and quality determine grower income from commercial sweet cherry orchards. The objective of this study was to determine the effect of Fruit Number to Leaf Area Ratio (FNLAR, fruit m-2 LA) on Mean Fruit Weight (MFW), firmness (F), soluble solids content (SSC), titratable acidity (TA) and SSC:TA ratio of `Bing¿ sweet cherries trees of near-optimal leaf area index (LAI). The effect of FNLAR on Mean Shoot Growth (MSG) and trunk cross-sectional area increment (TCSAI) also was analysed to determine possible competition between reproductive and vegetative growth. Regression analysis was used with FNLAR as the independent variable. While SSC:TA, MSG and TCSAI were not significantly correlated to FNLAR (P>0.05), MFW, TA and SSC decreased linearly with increasing FNLAR (

The PLATO End-to-End CCD Simulator -- Modelling space-based ultra-high precision CCD photometry for the assessment study of the PLATO Mission

The PLATO satellite mission project is a next generation ESA Cosmic Vision satellite project dedicated to the detection of exo-planets and to asteroseismology of their host-stars using ultra-high precision photometry. The main goal of the PLATO mission is to provide a full statistical analysis of exo-planetary systems around stars that are bright and close enough for detailed follow-up studies. Many aspects concerning the design trade-off of a space-based instrument and its performance can best be tackled through realistic simulations of the expected observations. The complex interplay of various noise sources in the course of the observations made such simulations an indispensable part of the assessment study of the PLATO Payload Consortium. We created an end-to-end CCD simulation software-tool, dubbed PLATOSim, which simulates photometric time-series of CCD images by including realistic models of the CCD and its electronics, the telescope optics, the stellar field, the pointing uncertainty of the satellite (or Attitude Control System [ACS] jitter), and all important natural noise sources. The main questions that were addressed with this simulator were the noise properties of different photometric algorithms, the selection of the optical design, the allowable jitter amplitude, and the expected noise budget of light-curves as a function of the stellar magnitude for different parameter conditions. The results of our simulations showed that the proposed multi-telescope concept of PLATO can fulfil the defined scientific goal of measuring more than 20000 cool dwarfs brighter than mV =11 with a precision better than 27 ppm/h which is essential for the study of earth-like exo-planetary systems using the transit method.Comment: 5 pages, submitted for the Proceedings of the 4th HELAS International Conference: Seismological Challenges for Stellar Structur