Self-sufficiency with vitamins and minerals on organic dairy farms

Self-sufficiency of nutrients is a central element in the organic farming principles. In a project involving five private organic dairy farms, we aimed to achieve self-sufficiency in vitamins and minerals at farm level. All the herds are fed 100% organically grown feed, but so far supplements of minerals and vitamins based on inorganic and synthetic products are imported to all farms. The same level and type of supplement was used for the cows all year round, even though all cows were on grass for at least 150 days during the summer period. The average daily intake from the supplement for a lactating cow was 751 mg E vitamin, 111 mg Cu, and 558 mg Zn. The content of vitamin and minerals in the home-grown feeds was modelled taking into account the effect of choice of crops; conservation method; season, plant development and climate conditions at harvest; quality of the silage production, and duration of storage. The modelled contents of vitamins in the main ingredients in the feed ration were verified by measuring the actual vitamin content in the silage at harvest as well as losses during storage. As an example, at one of the farms, where the feed intake was based on 85% grass clover crops during the summer but only 68% during the winter, the home-grown feed could supply the cows with enough vitamin E according to the requirement (800 mg/day) during the summer feeding but not during the winter period. The Cu requirement (10 mg/kg DM) could not be met from home-grown feed during any season. However, supplements of vitamins and minerals secure that requirement was met. The final outcome of the project will result in strategies for achieving self-sufficiency in vitamins and minerals at individual farms through optimization of the choice of forage crops and management of feed production

Strategic management of nitrogen within an organic cropping system using digestate from biogas production of recirculated crop residues

This project investigates strategic management of nitrogen by integrating crop residue management with biogas production. The approach offers potential for diversified farmer income, as food crops, feedstock for biogas and digestate for nutrient cycling are produced simultaneously. This type of diversification provides multifunctional solutions in organic farming, especially in production without access to animal manure. Biogas production from crop residues offers the possibility of reducing both emissions and leaching of nutrients to the surrounding ecosystems, as compared to the case where crop residue is incorporated into the soil for decomposition (Baggs et al. 2000; Velthof et al. 2002). This type of multifunctional cropping system provides solutions that can also help to solve issues on conventional farms, such as N emissions, and can also provide local production of biogas

Structure of exotic three-body systems

The classification of large halos formed by two identical particles and a core is systematically addressed according to interparticle distances. The root-mean-square distances between the constituents are described by universal scaling functions obtained from a renormalized zero-range model. Applications for halo nuclei, $^{11}$Li and $^{14}$Be, and for atomic $^4$He$_3$ are briefly discussed. The generalization to four-body systems is proposed.Comment: Contribution to the International workshop "Critical Stability of Few-Body Quantum Systems". To be published in "Few-Body Systems

Investigation of external refrigeration systems for long term cryogenic storage

Selection and optimization of space cryogenic storage tank

Tunable effective g-factor in InAs nanowire quantum dots

We report tunneling spectroscopy measurements of the Zeeman spin splitting in InAs few-electron quantum dots. The dots are formed between two InP barriers in InAs nanowires with a wurtzite crystal structure grown by chemical beam epitaxy. The values of the electron g-factors of the first few electrons entering the dot are found to strongly depend on dot size and range from close to the InAs bulk value in large dots |g^*|=13 down to |g^*|=2.3 for the smallest dots. These findings are discussed in view of a simple model.Comment: 4 pages, 3 figure

Nonlocal Landau theory of the magnetic phase diagram of highly frustrated magnetoelectric CuFeO2_2

A nonlocal Landau-type free energy functional of the spin density is developed to model the large variety of magnetic states which occur in the magnetic field-temperature phase diagram of magnetoelectric CuFeO$_2$. Competition among long-range quadratic exchange, biquadratic anti-symmetric exchange, and trigonal anisotropy terms, consistent with the high-temperature rhombohedral R$\bar{3}$m crystal symmetry, are shown to all play important roles in stabilizing the unusual combination of commensurate and incommensurate spin structures in this highly frustrated triangular antiferromagnet. It is argued that strong magnetoelastic coupling is largely responsible for the nonlocal nature of the free energy. A key feature of the analysis is that an electric polarization is induced by a canting of the non-collinear incommensurate spin structure. Application of the model to ordered spin states in the triangular antiferromagnets MnBr$_2$ and NaFeO$_2$ is also discussed.Comment: 20 pages, 2 figure

EFFECTS OF SURFACE ON OXYGEN UPTAKE, POWER OUTPUT, AND HEART RATE DURING UPHILL CYCLING

An alternative to stationary cycling is to use an actual bicycle on a treadmill. While eliminating differences between bicycles, this method may limit inferential conclusions to overground cycling. The current study examined physiological and biomechanical responses while cycling uphill overground versus over treadmill. Thirteen subjects rode uphill at 6.4 km ⋅ hr-1 on a 2.5 X 3.0 m treadmill and an asphalt paved road nine min at 8-12% grade. Power output (PO), cadence (CAD), VO2, and HR, were obtained via telemetry. Mean data from minutes 3 to 6 were analyzed via Two-way (surface by time) Repeated Measures ANOVA. Mean VO2, HR, and PO were higher for treadmill riding than overground (p0.05). No interactions were found. Results of the current study indicate that cycling on a treadmill impose different demands than overground cycling even when the equipment is the same

Scaling function and universal amplitude combinations for self-avoiding polygons

We analyze new data for self-avoiding polygons, on the square and triangular lattices, enumerated by both perimeter and area, providing evidence that the scaling function is the logarithm of an Airy function. The results imply universal amplitude combinations for all area moments and suggest that rooted self-avoiding polygons may satisfy a $q$-algebraic functional equation.Comment: 9 page

Scaling of resistivities and guided vortex motion in MgB2 thin films

Longitudinal and transverse voltages have been measured on thin films of MgB2 with different superconducting transition widths. The study has been performed in zero and non-zero external magnetic fields. The non-zero transverse voltage has been observed in close vicinity of the critical temperature in zero external magnetic field, while further away from Tc this voltage becomes zero. In magnetic field it becomes a transverse voltage which is an even function with respect to the direction of the field. The usual Hall voltage starts to appear with increasing magnetic field and in large fields the even voltage disappears and only the Hall voltage is measurable (i.e. the transverse even voltage is suppressed with increasing magnetic field and increasing transport current). New scaling between transverse and longitudinal resistivities has been observed. This correlation is valid not only in the zero magnetic field but also in nonzero magnetic field where transverse even voltage is detected. Several models trying to explain observed results are discussed. The most promising one seems to be guided motion of the vortices, though further theoretical work will be required to confirm this