6,935 research outputs found
Der Grünauslauf als Futterquelle
Der Grünauslauf verbessert nicht nur die Gesundheit der Tiere und die Qualität der Eier. Er kann, wenn er optimal eingerichtet ist, auch zu einer Einsparung am Mischfutter führen
Is My Exercise Partner Similar Enough? Partner Characteristics as a Moderator of the Köhler Effect in Exergames
Objective: Recent research has shown the Köhler motivation gain effect (working at a task with a more capable partner where one's performance is indispensable to the group) leads to greater effort in partnered exercise videogame play. The purpose of this article was to examine potential moderators of the Köhler effect by exploring dissimilarities in one's partner's appearance, namely, having an older partner (compared with a same-age partner) and having a heavier-weight partner (compared with a same-weight partner).
Subjects and Methods: One hundred fifty-three male and female college students completed a series of plank exercises using the “EyeToy: Kinetic™” for the PlayStation® 2 (Sony, Tokyo, Japan). Participants first completed the exercises individually and, after a rest, completed the same exercises with a virtually present partner. Exercise persistence, subjective effort, self-efficacy beliefs, enjoyment, and intentions to exercise were recorded and analyzed.
Results: A significant Köhler motivation gain was observed in all partner conditions (compared with individual controls) such that participants with a partner held the plank exercises longer (P<0.001) and reported higher subjective effort (P<0.01). These results were unmoderated by partner's age and weight, with one exception: Males tended to persist longer when paired with an obese partner (P=0.08).
Conclusions: These results suggest that differences in age and weight do not attenuate the Köhler effect in exergames and may even strengthen it
The search for planetary mass companions to field brown dwarfs with HST/NICMOS
We present the results of a high-resolution spectral differential imaging
survey of 12 nearby, relatively young field L dwarfs (<1 Gyr) carried out with
HST/NICMOS to search for planetary mass companions at small physical
separations from their host. The survey resolved two brown dwarf binaries: the
L dwarf system Kelu-1AB and the newly discovered L/T transition system 2MASS
J031059+164815AB. For both systems common proper motion has already been
confirmed in follow-up observations which have been published elsewhere. The
derived separations of the binaries are smaller than 6 AU and consistent with
previous brown dwarf binary statistics. Their mass ratios of q > 0.8 confirm
the preference for equal mass systems similar to a large number of other
surveys. Furthermore, we found tentative evidence for a companion to the L4
dwarf 2MASS W033703-175807, straddling the brown dwarf/planetary mass boundary
and revealing an uncommonly low mass ratio system (q ~ 0.2) compared to the
vast majority of previously found brown dwarf binaries. With a derived minimum
mass of 10 - 15 Mjup, a planetary nature of the secondary cannot be ruled out
yet. However, it seems more likely to be a very low mass brown dwarf secondary
at the border of the spectral T/Y transition regime, primarily due to its
similarities to recently found very cool T dwarfs. This would make it one of
the closest resolved brown dwarf binaries (0.087" 0.015", corresponding
to 2.52 0.44 AU at a distance of 29 pc) with the coolest (Teff ~ 600-630
K) and least massive companion to any L or T dwarf.Comment: 33 pages, 8 figures, 2 tables, accepted for publication by Ap
Discrete Fractional Clock Generation for Systems-on-FPGA
This article describes an inexpensive way of clock generation for FPGA-based circuit cores, which reduces the number of external clock sources and eases synchronization problems. We introduce a modified version of the BRESENHAM line drawing algorithm and use it outside its original application domain for the rational division of clocks. An optimized hardware design for BRESENHAM-based clock division is presented and the quality of its output is evaluated. The optimal initialization conditions in terms of phase shift and jitter are identified and formally proven. Finally, the complexity characteristics of a generic synthesizable VHDL design based on this algorithm are examined and verified by synthesis examples. Special attention is paid to implementation results in conjunction with different FPGA families
Modeling of Workpiece Shape Deviations in face Milling of Parallel Workpiece Compounds
The mass reduction of components is one of the most effective ways to reduce fuel consumption and emissions in the automotive and aircraft industry. A lightweight strategy used for highly loaded components is the combination of different materials to workpiece compounds. In that way components can be designed depending on the local load using the most qualified material. For the production of high-performance workpiece compounds high quality requirements concerning the accuracy of dimension and shape as well as surface roughness must be fulfilled. However, machining of workpiece compounds leads to unfavorable changes of the workpiece quality in comparison to machining of the single materials. Significant shape deviations occur when different materials are machined alternately in one cutting operation. This is due to unequal material properties, cutting characteristics, chip formation mechanisms as well as characteristic interactions between the single components. This paper describes the causes of the three main criteria material height deviation, transition deviation and surface roughness deviation that significantly influence the surface quality in parallel machining. The focus is on the process understanding as well as modeling of the surface defects. The approaches and results show that the characteristic shape deviations can be predicted. With the knowledge of the causes that lead to the surface defects in parallel machining it is possible to optimize the process setup for a surface quality oriented machining process of a workpiece compound. Copyright © 2013 Elsevier B.V
Nature of the spin dynamics and 1/3 magnetization plateau in azurite
We present a specific heat and inelastic neutron scattering study in magnetic
fields up into the 1/3 magnetization plateau phase of the diamond chain
compound azurite Cu(CO)(OH). We establish that the
magnetization plateau is a dimer-monomer state, {\it i.e.}, consisting of a
chain of monomers, which are separated by dimers on the
diamond chain backbone. The effective spin couplings K
and K are derived from the monomer and dimer
dispersions. They are associated to microscopic couplings K,
K and a ferromagnetic K, possibly as
result of orbitals in the Cu-O bonds providing the superexchange
pathways.Comment: 5 pages, 4 figure
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