1,750 research outputs found

    Challenges of Electric Power Management in Hybrid and Electric Vehicles

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    How much do we really lose?—Yield losses in the proximity of natural landscape elements in agricultural landscapes

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    Natural landscape elements (NLEs) in agricultural landscapes contribute to biodiversity and ecosystem services, but are also regarded as an obstacle for large‐scale agricultural production. However, the effects of NLEs on crop yield have rarely been measured. Here, we investigated how different bordering structures, such as agricultural roads, field‐to‐field borders, forests, hedgerows, and kettle holes, influence agricultural yields. We hypothesized that (a) yield values at field borders differ from mid‐field yields and that (b) the extent of this change in yields depends on the bordering structure. We measured winter wheat yields along transects with log‐scaled distances from the border into the agricultural field within two intensively managed agricultural landscapes in Germany (2014 near Göttingen, and 2015–2017 in the Uckermark). We observed a yield loss adjacent to every investigated bordering structure of 11%–38% in comparison with mid‐field yields. However, depending on the bordering structure, this yield loss disappeared at different distances. While the proximity of kettle holes did not affect yields more than neighboring agricultural fields, woody landscape elements had strong effects on winter wheat yields. Notably, 95% of mid‐field yields could already be reached at a distance of 11.3 m from a kettle hole and at a distance of 17.8 m from hedgerows as well as forest borders. Our findings suggest that yield losses are especially relevant directly adjacent to woody landscape elements, but not adjacent to in‐field water bodies. This highlights the potential to simultaneously counteract yield losses close to the field border and enhance biodiversity by combining different NLEs in agricultural landscapes such as creating strips of extensive grassland vegetation between woody landscape elements and agricultural fields. In conclusion, our results can be used to quantify ecocompensations to find optimal solutions for the delivery of productive and regulative ecosystem services in heterogeneous agricultural landscapes

    Medical Psychology, Madness and Melancholy

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    The Biological Standard of Living in the two Germanies.

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    Physical stature is used as a proxy for the biological standard of living in the two Germanies before and after unification in an analysis of a cross-sectional sample (1998) of adult heights, as well as among military recruits of the 1990s. West Germans tended to be taller than East Germans throughout the period under consideration. Contrary to official proclamations of a classless society, there were substantial social differences in physical stature in East-Germany. Social differences in height were greater in the East among females, and less among males than in the West. The difficulties experienced by the East-German population after 1961 is evident in the increase in social inequality of physical stature thereafter, as well as in the increasing gap relative to the height of the West-German population. After unification, however, there is a tendency for East-German males, but not of females, to catch up with their West-German counterparts

    Domestic ventilation rates, indoor humidity and dust mite allergens : are our homes causing the asthma pandemic?

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    This paper is concerned with historical changes in domestic ventilation rates, relative humidity and the associated risk of house dust mite colonization. A controlled trial evaluated allergen and water vapour control measures on the level of house dust mite (HDM) Der p1 allergen and indoor humidity, concurrently with changes in lung function in 54 subjects who completed the protocol. Mechanical heat recovery ventilation units significantly reduced moisture content in the active group, while HDM allergen reservoirs in carpets and beds were reduced by circa 96%. Self reported health status confirmed a significant clinical improvement in the active group. The study can form the basis for assessing minimum winter ventilation rates that can suppress RH below the critical ambient equilibrium humidity of 60% and thus inhibit dust mite colonization and activity in temperate and maritime in' uenced climatic regions

    Suzaku monitoring of the Wolf-Rayet binary WR 140 around periastron passage: An approach for quantifying the wind parameters

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    Suzaku observations of the Wolf-Rayet (W-R) binary WR 140 (WC7pd+O5.5fc) were made at four different times around periastron passage in 2009 January. The spectra changed in shape and flux with the phase. As periastron approached, the column density of the low-energy absorption increased, which indicates that the emission from the wind-wind collision plasma was absorbed by the dense W-R wind. The spectra can be mostly fitted with two different components: a warm component with kBT = 0.3-0.6 keV and a dominant hot component with kBT ∼ 3 keV. The emission measure of the dominant, hot component is not inversely proportional to the distance between the two stars. This can be explained by the O star wind colliding before it has reached its terminal velocity, leading to a reduction in its wind momentum flux. At phases closer to periastron, we discovered a cool plasma component in a recombining phase, which is less absorbed. This component may be a relic of the wind-wind collision plasma, which was cooled down by radiation, and may represent a transitional stage in dust formation

    Methods for Aiding Height Determination in Pseudolite-Based Reference Systems Using Batch Least-Squares Estimation

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    There are many situations in which GPS is either unable to provide the desired level of accuracy or is unavailable. Use of a pseudolite-based reference system for navigation can be a means for positioning during these times. While there are advantages in using a pseudolite-based reference system, there are still implementation issues and deficiencies that must be addressed. In many cases, a pseudolite system with ground-based transmitters has difficulty determining the height of the receiver accurately. This is due to the poor vertical observability inherent in the geometry of the system. A common approach in naval applications for solving the problem of poor vertical observability is to use a height constraint, which is well known when travelling on a surface of water. For a ground-based vehicle, knowledge of the surface topography can be obtained, but it cannot be readily used in the same manner as in marine cases, since the height is often a varying function of position. This research investigates and develops five methods of incorporating the known surface topography in a non-linear batch least squares estimation algorithm using carrier-phase measurements from pseudolites. The floating point carrier-phase ambiguities are estimated in this process. Real and simulated data sets are used to evaluate the performance of the five algorithms. In simulation, all methods performed equally well on a flat surface. When simulating a hill, constraining the solution to lie in a plane tangent to the surface topography appeared to aid the solution with the best knowledge of the terrain. Use of a pseudo-measurement, a commonly used approach, did not provide the best results, and indicates the inadequacy of using this method for pseudolite-based systems. Results using data from a real system on a ground-based vehicle demonstrated sub-decimeter level positioning accuracy in all three dimensions
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