9,510 research outputs found
Root biomass and carbon storage in differently managed multispecies temporary grasslands
Species-rich grasslands may potentially increase carbon (C) storage in soil and an experiment was established to investigate C storage in highly productive temporary multi-species grasslands. Plots were established with three mixtures: 1) a herb mixture containing salad burnet (Sanguisorba minor L.), fenugreek (Trogonella foenum-gruecum), chicory (Chicorium intybus L.), caraway (Carum carvi L.), birdsfoot trefoil (Lotus corniculatus L.), chervil (Anthriscus cerefolium L.), plantain (Plantago lanceolata L.), lucerne (Medicago sativa L.) and melilot (Melilotus officinalis), 2) 50% of the herb mixture and 50% of a white clover (Trifolium repens L.)/perennial ryegrass (Lolium perenne L.) mixture, and 3) 5% of the herb mixture and 95% of the white clover/ryegrass mixture. Management factors were number of cuts per year and fertilizer application. Aboveground biomass increased considerably with increasing content of herbs and with fertilizer application in plots with a 4-cut strategy. With a 6-cut strategy without fertilizer herbs had no effect on the aboveground biomass. In the herb mixture biomass of small roots was lower than in mixtures with white clover and ryegrass. There was a tendency towards increased biomass in the large root fraction with increasing herb content. The experiment indicated increased CO2 evolution following cultivation of multispecies grasslands
Management of forb species mixtures for high biomass production
Including forb species in grassland mixtures may secure a more biodiversity-friendly production of biomass. This experiment showed interesting future perspectives in terms of production of low-cost biomass for e.g. biogas production, which can be obtained by reducing the number of cuttings without compromising yield levels. No significant differences in dry matter (DM) yields of chicory, birdsfoot trefoil, yarrow and a 13 species mixture were observed between the situations with four compared to one autumn cut per year. Especially the 13 species mixture showed great potential in terms of yield and suppression of unsown species, for which reasons it should be developed further through knowledge on the species in pure stands
Effect of seed mixture composition and management on competitiveness of herbs in temporary grasslands
In multispecies grasslands the proportion of different herb species may vary considerably due to low competitiveness of some herbs. To examine the possibility for increasing the competitiveness an experiment with three factors were set up: 1) amount of herb seed in a perennial ryegrass (Lolium perenne), white clover (Trifolium repens) mixture, 2) slurry application and 3) cutting frequency. The experiment was carried out over two years. The herbs mix contained salad burnet (Sanguisorba minor), fenugreek (Trogonella foenum-gruecum), chicory (Chicorium intybus), caraway (Carum carvi), birdsfoot trefoil (Lotus corniculatus), chervil (Anthriscus cerefolium), plantain (Plantago lanceolata), Lucerne (Medicago sativa) and melilot (Melilotus officinalis). The proportion of herb seeds was 5, 25, 50 or 100 %. The herb species were most competitive in the first harvest year. In the second year the proportion of all herb species were very low in the mixtures, where white clover and perennial ryegrass were represented. The proportion of many herbs were higher at a 7-cut than at a 4-cut management, and application of cattle slurry also affected the competitiveness. In general chicory, caraway and plantain were the strongest competitors, salad burnet and birdsfoot trefoil were intermediate, and melilot, fenugreek and chervil were very weak competitors
Progress on the Ohio State University Get Away Special G-0318: DEAP
The Get Away Special program became a major presence at the Ohio State University with the award of GAS-0318 by the American Institute of Aeronautics and Astronautics. There are some twenty engineering researchers and students currently working on the project. GAS-0318 payload is an experimental manufacturing process known as Directional Electrostatic Accretion Process (DEAP). This high precision portable microgravity manufacturing method will revolutionize the manufacture and repair of spacecraft and space structures. The cost effectiveness of this process will be invaluable to future space development and exploration
Effects of blood withdrawal and reinfusion on biomarkers of erythropoiesis in humans: Implications for anti-doping strategies
To discriminate autologous blood doping procedures from normal conditions, we examined the hematological response to blood withdrawal and reinfusion. We found that biomarkers of erythropoiesis are primarily affected in the anemic period. Therefore, individual variations in [Hb] exceeding 15% between samples obtained shortly before any major competition would be indicative of autologous blood manipulation
Size-dependent nonlocal effects in plasmonic semiconductor particles
Localized surface plasmons (LSP) in semiconductor particles are expected to
exhibit spatial nonlocal response effects as the geometry enters the nanometer
scale. To investigate these nonlocal effects, we apply the hydrodynamic model
to nanospheres of two different semiconductor materials: intrinsic InSb and
-doped GaAs. Our results show that the semiconductors indeed display
nonlocal effects, and that these effects are even more pronounced than in
metals. In a InSb particle at , the LSP
frequency is blueshifted 35%, which is orders of magnitude larger than the
blueshift in a metal particle of the same size. This property, together with
their tunability, makes semiconductors a promising platform for experiments in
nonlocal effects.Comment: 7 pages, 3 figures, 1 table, corrected typos in text and figure
Quantum interference and entanglement induced by multiple scattering of light
We report on the effects of quantum interference induced by transmission of
an arbitrary number of optical quantum states through a multiple scattering
medium. We identify the role of quantum interference on the photon correlations
and the degree of continuous variable entanglement between two output modes. It
is shown that the effect of quantum interference survives averaging over all
ensembles of disorder and manifests itself as increased photon correlations
giving rise to photon anti-bunching. Finally, the existence of continuous
variable entanglement correlations in a volume speckle pattern is predicted.
Our results suggest that multiple scattering provides a promising way of
coherently interfering many independent quantum states of light of potential
use in quantum information processing.Comment: 5 pages including 4 figure
Low-loss criterion and effective area considerations for photonic crystal fibers
We study the class of endlessly single-mode all-silica photonic crystal
fibers with a triangular air-hole cladding. We consider the sensibility to
longitudinal nonuniformities and the consequences and limitations for realizing
low-loss large-mode area photonic crystal fibers. We also discuss the
dominating scattering mechanism and experimentally we confirm that both macro
and micro-bending can be the limiting factor.Comment: Accepted for Journal of Optics A - Pure and Applied Optic
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