Organic Farming Scenarios: Operational Analysis and Costs of implementing Innovative Technologies

The objective of this study has been to design a number of farm scenarios representing future plausible and internally consistent organic farming enterprises based on milk, pig, and plant production and use these farm scenarios as the basis for the generation of generalised knowledge on labour and machinery input and costs. Also, an impact analysis and feasibility study of introducing innovative technologies into the organic production system has been invoked. The labour demand for the production farms ranged from 61 to 253hha1 and from 194 to 396hLU1 (LU is livestock units) for work in the animal houses. Model validation results showed that farm managerial tasks amount to 14–19% of the total labour requirement. The impact of introducing new technologies and work methods related to organic farming was evaluated using two innovative examples of weed control: a weeding robot and an integrated system for band steaming. While these technologies increased the capital investment required, the labour demand was reduced by 83–85% in sugar beet and 60% in carrots, which would improve profitability by 72–85% if fully utilised. Profitability is reduced, if automation efforts result in insufficient weed removal compared to manual weeding. Specifically, the benefit gained by robotic weeding was sensitive to the weed intensity and the initial price of the equipment, but a weeding efficiency of under 25% is required to make it unprofitable. This approach demonstrates the feasibility of applying and testing operational models in organic farming systems in the continued evaluation and documentation of labour and machinery inputs

Bogoliubov theory of entanglement in a Bose-Einstein condensate

We consider a Bose-Einstein condensate which is illuminated by a short resonant light pulse that coherently couples two internal states of the atoms. We show that the subsequent time evolution prepares the atoms in an interesting entangled state called a spin squeezed state. This evolution is analysed in detail by developing a Bogoliubov theory which describes the entanglement of the atoms. Our calculation is a consistent expansion in $1/\sqrt{N}$, where $N$ is the number of particles in the condensate, and our theory predict that it is possible to produce spin squeezing by at least a factor of $1/\sqrt{N}$. Within the Bogoliubov approximation this result is independent of temperature.Comment: 14 pages, including 5 figures, minor changes in the presentatio

Sterile neutrinos in the Milky Way: Observational constraints

We consider the possibility of constraining decaying dark matter by looking out through the Milky Way halo. Specifically we use Chandra blank sky observations to constrain the parameter space of sterile neutrinos. We find that a broad band in parameter space is still open, leaving the sterile neutrino as an excellent dark matter candidate.Comment: Submitted to ApJL, 4 pages, 4 figure

Quantification of Salmonella and Yersinia on pork carcasses by simulation modelling

Stagnation in the success of control programmes in pig production in Denmark has led to an increased interest in the development of alternative control strategies such as decontamination of carcasses to further decrease the attribution of pork meat to human foodborne illness. This project sets out to develop a model for quantitative estimation of slaughterhouse output of Salmonella and Yersinia . Distributions of the occurrence of Salmonefla, Yersinia and E. coli on pork carcasses are based on the analysis of paired faecal samples and carcass swabs from 2880 animals originating from four abattoirs. By combining the estimated quantity of faecal contamination of carcasses with a semi-quantitative distribution of the number of Safmoneffa or Yersinia per gram faeces, an output distribution describing the number of Salmonella or Yersinia bacteria per carcass can be established. In order to validate the model, carcass swabs, analysed for Salmonefla and Yersinia serve as control. After the model has been validated, the effect of various decontamination methods on human exposure to foodborne pathogens in pork will be evaluated in both economic terms as well as with regard to public health impact

Methodology for prediction and estimation of consequences of possible atmospheric releases of hazardous matter: "Kursk" submarine study

International audienceThere are objects with some periods of higher than normal levels of risk of accidental atmospheric releases (nuclear, chemical, biological, etc.). Such accidents or events may occur due to natural hazards, human errors, terror acts, and during transportation of waste or various operations at high risk. A methodology for risk assessment is suggested and it includes two approaches: 1) probabilistic analysis of possible atmospheric transport patterns using long-term trajectory and dispersion modelling, and 2) forecast and evaluation of possible contamination and consequences for the environment and population using operational dispersion modelling. The first approach could be applied during the preparation stage, and the second ? during the operation stage. The suggested methodology is applied on an example of the most important phases (lifting, transportation, and decommissioning) of the "Kursk" nuclear submarine operation. It is found that the temporal variability of several probabilistic indicators (fast transport probability fields, maximum reaching distance, maximum possible impact zone, and average integral concentration of 137Cs) showed that the fall of 2001 was the most appropriate time for the beginning of the operation. These indicators allowed to identify the hypothetically impacted geographical regions and territories. In cases of atmospheric transport toward the most populated areas, the forecasts of possible consequences during phases of the high and medium potential risk levels based on a unit hypothetical release are performed. The analysis showed that the possible deposition fractions of 1011 over the Kola Peninsula, and 10?12 ? 10?13 for the remote areas of the Scandinavia and Northwest Russia could be observed. The suggested methodology may be used successfully for any potentially dangerous object involving risk of atmospheric release of hazardous materials of nuclear, chemical or biological nature

Spin Squeezing in the Ising Model

We analyze the collective spin noise in interacting spin systems. General expressions are derived for the short time behaviour of spin systems with general spin-spin interactions, and we suggest optimum experimental conditions for the detection of spin squeezing. For Ising models with site dependent nearest neighbour interactions general expressions are presented for the spin squeezing parameter for all times. The reduction of collective spin noise can be used to verify the entangling powers of quantum computer architectures based on interacting spins.Comment: 7 pages, including 3 figure

Bremsstrahlung from relativistic bare heavy ions in single crystals

We calculate the bremsstrahlung emitted by heavy bare ions penetrating single crystals at highly relativistic energies. The main component, originating in scattering of the virtual photons of screened target nuclei on the projectile, appears with energies of, approximately, 25γ MeV for a lead ion (γ ≡ E/Mc2 where E and M denote projectile energy and mass). It shows dips in yield upon variation of the incidence angle to major crystallographic directions quite similar to those of other close-encounter processes. Incoherent interaction with single target electrons gives rise to two additional but quite different bremsstrahlung components, a moderate component distributed over the same frequencies as the main component, and a strong component confined to low energies. The channeling characteristics of the total bremsstrahlung spectrum vary substantially with photon energy

Entanglement and Extreme Spin Squeezing

For any mean value of a cartesian component of a spin vector we identify the smallest possible uncertainty in any of the orthogonal components. The corresponding states are optimal for spectroscopy and atomic clocks. We show that the results for different spin J can be used to identify entanglement and to quantity the depth of entanglement in systems with many particles. With the procedure developed in this letter, collective spin measurements on an ensemble of particles can be used as an experimental proof of multi-particle entanglementComment: 4 pages, 2 figures, minor changes in the presentatio