Assessment of skin damages in dairy cows

Skin damages were assessed at 48 conventional and organic farms with mainly cubicle houses. Scores from 1 – 9 were given depending on type and size of the damaged skin at 9 locations of the cow: outer hock, inner hock, knee and body all left and right hand side and the neck. Only the highest score per location is recorded and remarks of unusual findings are made separately. The most frequent and most severe affected location is the outer hock followed by the knee. Only 14 percent of all cows did not have any damage, 34 percent had only hairless patches and 24 percent of the cows did have at least one swelling. Correlations of the mean farm score for the left and right hand side are high for the outer hock and low for the body. To have the most impact in advising farmers, assessment should preferably be made at the end of the housing period, the most threatening period in animal welfare in the Netherlands. This system allows benchmarking within and between farms

Improving animal welfare by assessing college’s farms

Health and welfare is a major topic in the Netherlands in both organic and non-organic dairy farming. This report highlights issues arising from welfare assessments conducted on Dutch farms producing milk for Ben and Jerry’s (B&J) ice cream. The Netherlands is the base for the European market for B&J ice-cream. Four years ago 11 farms were asked to produce milk for B&J. High human and animal welfare was a pre-condition. In order to evaluate the animal welfare on those farms, cows were assessed at the end of the housing season and at the end of the grazing season. At a plenary meeting the farmers discussed the results and the possible improvements on their farms. Since the farmers had a desire to control things on their own farms, they wanted to assess their own farms and animals. In a number of sessions a checklist was developed by the group of farmers and tested. This so-called ‘caring dairy’ checklist is now used in all kinds of farmers groups, conventional and organic, with farmers assess each others cows and farms. A 5 hour workshop at a host farm at the beginning of the process includes a theoretical and practical part and at least a proposal from the host farmer with three points to improve. The following assessments of colleagues take 3 hours per farm, which also results in proposals to improve

Selection of elastomeric membranes for the removal of volatile organics from water

A wide range of homogeneous elastomeric membranes has been prepared using dicumylperoxide as a general cross-linking agent. The membranes have been used for both equilibrium sorption measurements and steady-state pervaporation experiments to study solution-diffusion phenomena in the removal of volatile organic components from aqueous solutions. Pervaporation experiments have been performed under identical hydrodynamic conditions in order to fix the boundary layer mass transfer coefficient at a constant and known value. For comparison of the permeabilities of different pervaporation membrane materials, this is of utmost importance. A wide range of selectivity factors up to a value of 100,000 are obtained, whereas usually the permeabilities for the organic component are in the range of 10-10-10-9m2/s and 10-14-10-12m2/s for water. The permeation and sorption data obtained for the various elastomers have been related to the chemical and physical nature of the elastomers through the solubility parameter and the glass transition temperature, respectively. Both diffusional and sorption effects seem to be important, determining the water-transport behavior in the elastomeric membranes. The solubility of the organic component appears to be independent of this combined solubility parameter. Differences in the permeabilities of the organic component can primarily be ascribed to structural parameters in the membrane material, like degree of unsaturation and presence of steric side groups

Diffusional phenomena in membrane separation processes

Nowadays membrane filtration processes are used industrially as an alternative to conventional separation methods. Membrane separation methods can be divided into classes according to their separation characteristics: (i) separation by sieving action; (ii) separation due to a difference in affinity and diffusivity; (iii) separation due to a difference in charge of molecules; (iv) carrier-facilitated transport, and (v) the process of (time-) controlled released by diffusion. In all these cases diffusion processes play an important role in the transport mechanism of the solutes. Various mechanisms have been distinguished to describe the transport in membranes: transport through bulk material (dense membranes), Knudsen diffusion in narrow pores, viscous flow in wide pores or surface diffusion along pore walls. In practice, the transport can be a result of more than only one of these mechanisms. For all of these mechanisms models have been derived. The characteristics of a membrane, e.g. its crystallinity or its charge, can also have major consequences for the rate of diffusion in the membrane, and hence for the flux obtained. Apart from the diffusion transport processes in membranes mentioned above, other important diffusion processes are related to membrane processes, viz. diffusion in the boundary layer near the membrane (concentration polarization phenomena) and diffusion during membrane formation. The degree of concentration polarization is related to the magnitude of the mass transfer coefficient which, in turn, is influenced by the diffusion coefficient. The effect of concentration polarization can be rather different for the various membrane processes. The phase inversion membrane formation mechanism is determined to a large extent by the kinetic aspects during membrane formation, which are diffusion of solvent and of non-solvent and the kinetics of the phase separation itself

The stability of supported liquid membranes

In this paper a new hypothesis about the instability mechanism of SLMs will be discussed: emulsion formation induced by lateral shear forces. Experimental results show that a water phase with a low salt concentration which flows along the membrane interface causes the removal of both solvent and carrier from the membrane. There is a significant correlation between the instability of the liquid membrane and the stability of emulsions formed with the same system. Therefore, the development of stable SLMs needs conditions in which formation of relatively stable emulsions is prevented. This can be realized by gelation of the liquid membrane. A gel network was created in the pores of the membrane in such a way that the permeability is not decreased while the stability increases to values which are very promising

Improving animal welfare by assessing college's farms

’Minimising medicine use in organic dairy herds through animal health and welfare planning’, ANIPLAN, is a CORE-Organic project (Project no. 011716) which was initiated in June 200

Vote expectations and pre-electoral tariff cuts in Flemish municipalities

Using data covering 3 election moments (1988-2000) for 294 Flemish municipalities we examine whether the decision to cut tariffs before elections depends on the government’s expectations of staying into office. Election moments are central to both the political budget cycle literature and the strategic debt models. The combination of both theories could suggest that, at least in theory, both winning and loosing governments seem to benefit from preelectoral tariff reductions and as such we expect to find a great many municipalities to engage into tariff cuts. The dataset however shows this is clearly not the case. We argue that the differences in the fiscal policy reaction of governments facing elections might have to do with their expectations of staying into office. In our analysis we make the decision to change tariffs dependent on the expected vote percentage of the government party (parties). As we do not possess reliable ex ante data on the perceived re-election probability, we estimate a vote-function to predict the percentage of votes. Our analysis shows that tariff reductions in election years are more prone when governments expect not to reach majority again in next elections

Supported liquid membranes: stabilization by gelation

A new method has been developed to increase the stability of supported liquid membranes. By applying a homogeneous gel network in the pores of the support both the mechanical stability (against liquid displacement) and the long term permeability increase substantially. The flux decreases only slightly because of the open structure of the gel network. A second technique, by which a thin dense gel layer is applied to the feed side of the membrane, results in a specific suppression of the formation of emulsion droplets. The stability of the membrane increases by this treatment to values which are very promising

Phase-separation phenomena in solutions of poly(2,6-dimethyl-1,4-phenylene oxide). I. Thermodynamic parameters of solutions in toluene

New experimental data have been collected on thermodynamic properties of solutions of poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) in toluene. The Flory-Huggins interaction parameters g have been determined from light scattering measurements. These values are in agreement with values obtained by osmotic measurements at low concentrations and they allow the calculation of a melting point curve which fits the experimental melting points. No liquid-liquid phase separation can be calculated, as was concluded in a preceding paper. Spinodals could not be detected by light scattering or DSC-measurements. This also indicates that liquid-liquid phase separation does not occur. The phase separation on cooling of a PPO-toluene solution is thus believed to be a crystallization phenomenon