Preliminary evaluation of perennial forage legumes for organic farming in Finland

In 1998-2001 fourteen forage legume species were evaluated for their productivity in mixed organic swards. The aim was to find new alternatives for red clover. Medicago falcata produced the highest dry matter yield (about 11 000 kg/ha/year). Dry matter production of Trifolium pratense, Trifolium hybridum and Medicago sativa varied from 2 200 to 10 600 kg/ha/year

Preliminary evaluation of annually cultivated forage legumes for organic farming in Finland

In 1998-2001 nineteen forage legume species (Lupinus, Medicago, Melilotus, Pisum, Trifolium and Vicia species) were evaluated at two sites of Eastern Finland (Mikkeli and Juva). Species were studied for their annual productivity in pure stands and in mixtures with cereals (barley and oats) and Italian ryegrass. Swards were cut either twice or once (whole grain silage stage of barley)

Management of red clover content of organic grassland

The clover content is an important factor in organic grassland management to optimize yield, feeding value and pre-crop effect of the ley. The variation of red clover (Trifolium pratense) content in swards of different age is often rather high in Finland. In the ongoing field experiment (1999-2002) staggered sowing of red clover seed was tested to regulate the clover content of the mixed sward. Sowing strategy did not have clear effect on the clover content or the yield of the sward. However the seeding rate affected the clover density of the field (plants/m²) in the first year. After two years the differences were equated. The best strategy to control the clover amount in the mixed swards seems sowing of 2 or 3 kg/ha (100 or 150 seeds/m²) clover seeds in establishment and then oversow on a first second ley year 1 or 2 kg/ha (50 or 100 seeds/m²)

Inhomogeneous Big Bang Nucleosynthesis and Mutual Ion Diffusion

We present a study of inhomogeneous big bang nucleosynthesis with emphasis on transport phenomena. We combine a hydrodynamic treatment to a nuclear reaction network and compute the light element abundances for a range of inhomogeneity parameters. We find that shortly after annihilation of electron-positron pairs, Thomson scattering on background photons prevents the diffusion of the remaining electrons. Protons and multiply charged ions then tend to diffuse into opposite directions so that no net charge is carried. Ions with Z>1 get enriched in the overdense regions, while protons diffuse out into regions of lower density. This leads to a second burst of nucleosynthesis in the overdense regions at T<20 keV, leading to enhanched destruction of deuterium and lithium. We find a region in the parameter space at 2.1E-10<eta<5.2E-10 where constraints 7Li/H<10^{-9.7} and D/H<10^{-4.4} are satisfied simultaneously.Comment: 9 pages, minor changes to match the PRD versio

Large Scale Inhomogeneities from the QCD Phase Transition

We examine the first-order cosmological QCD phase transition for a large class of parameter values, previously considered unlikely. We find that the hadron bubbles can nucleate at very large distance scales, they can grow as detonations as well as deflagrations, and that the phase transition may be completed without reheating to the critical temperature. For a subset of the parameter values studied, the inhomogeneities generated at the QCD phase transition might have a noticeable effect on nucleosynthesis.Comment: 15 LaTeX pages + 6 PostScript figures appended at the end of the file, HU-TFT-94-1

Adaptive, self-underpressurizing suction roll for fast web handling concepts

In web handling one of the most demanding area is nip or pocket area for incoming or outgoing web. Depending on speed of web and rotating roll surfaces, boundary layers transport air causing negative or positive relative pressure difference between top and bottom sides of the web. Numerous publications and studies show that this effect causes web deflections, which can lead to web instabilities and deteriorations in web handing.Pocket areas are also difficult from the viewpoint of fluid flow analysis since tangential points of the pocket geometry will lead to singularities in nom1al situation. This means that pressures are "infinite" and cannot be handled without "leakage effects" coming from surface roughness, or in this case, roll grooving.Typically one possibility to avoid web handling problems in pocket areas is to increase substantially such "surface roughness" which can receive or convey air transported by viscous boundary layers. One form of this extra "surface roughness space'' is roll grooving which is simply a helping duct or escape for air, especially in pocket areas.In this paper we present a roll and a method not only to overcome pocket effects, but also a technique where boundary layers together with optimized roll groove structure can create a suction roll mechanism. This forms an underpressure between the roll and the web surface stabilizing the web.Roll functioning is based on carefully designed but simple groove geometry where closing and opening pockets correspondingly create sealing and underpressurizing areas. Adequate and deep groove design ensures good air conveying utilizing air-surface friction forces. The roll arc covered by fabric is underpressurized as a whole.Both CFD and experimental results show that underpressure develops adaptively according "Bernoulli's law" i.e. second power with roll surface speed. Roll is especially designed to work with supporting permeable fabrics. Since underpressurizing power is coming from rotational speed and boundary layers, no external vacuum or suction devices are needed. Since whole wrap area is underpressurized from closing nip to opening nip, roll performance is ideal for such web handling situations where excessive web tensioning and web straining should be avoided.In paper making industry with continuously increasing web speeds, more cost-effective web handling systems are needed. There, the web supporting is in essential position. With permeable, supporting paper making fabrics, web handling possibilities can be improved significantly when roll pocket effects can be controlled efficiently

On Bubble Growth and Droplet Decay in Cosmological Phase Transitions

We study spherically symmetric bubble growth and droplet decay in first order cosmological phase transitions, using a numerical code including both the complete hydrodynamics of the problem and a phenomenological model for the microscopic entropy producing mechanism at the phase transition surface. The small-scale effects of finite wall width and surface tension are thus consistently incorporated. We verify the existence of the different hydrodynamical growth modes proposed recently and investigate the problem of a decaying quark droplet in the QCD phase transition. We find that the decaying droplet leaves behind no rarefaction wave, so that any baryon number inhomogeneity generated previously should survive the decay.Comment: 10 pages (revtex), 10 figures as uuencoded postscrip

Symmetry breaking in driven and strongly damped pendulum

We examine the conditions for appearance of symmetry breaking bifurcation in damped and periodically driven pendulum in the case of strong damping. We show that symmetry breaking, unlike other nonlinear phenomena, can exist at high dissipation. We prove that symmetry breaking phases exist between phases of symmetric normal and symmetric inverted oscillations. We find that symmetry broken solutions occupy a sufficiently smaller region of pendulum's parameter space in comparison to the statements made in earlier considerations [McDonald and Plischke, Phys. Rev. B 27 (1983) 201]. Our research on symmetry breaking in a strongly damped pendulum is relevant to an understanding of phenomena of dynamic symmetry breaking and rectification in a pure ac driven semiconductor superlattices.Comment: 11 pages, 4 color figures, RevTeX