Ashes for organic farming

Nowadays only eight percent of the cultivated field area is used for organic farming. The Ministry of Agriculture and Forestry has published the guidelines for the program of organic farming to diversify the supply and the consumption of organic food. The aim is to increase organically arable land to 20% by the year 2020.The demand of organic fertilizer products is strongly increasing. Interest in forestry by-products (ash, bark, zero fiber, etc.) for use in organic production has recently been exceptionally high. For example, development of pelleted fertilizers with zero fiber, ash and a nitrogen-containing fertilizer material is in progress.The ash fertilizer contains many valuable nutrients in fairly optimal ratios: these include phosphorus, potassium, manganese, magnesium, sulfur, zinc, calcium, boron, cobalt, copper and smaller amounts of other trace elements. Ashes contain phosphorus in large amounts, which is useful in organic production. More important nutrients than phosphorus and potassium are apparently trace elements. Neutralizing value of the ash is quite rapid comparedto many liming materials allowed in organic farming. The price quality ratio of ash as a liming material is also good.The use of clean wood ash is permissible in organic production. Peat and straw ash cannot be used in organic production because of the fact that in the EU peat is not considered a renewable resource. Restrictions include only inputs from outside of the organic farm

Thermal conductance of a proximity superconductor

We study heat transport in hybrid normal metal - superconductor - normal metal (NSN) structures. We find the thermal conductance of a short superconducting wire to be strongly enhanced beyond the BCS value due to inverse proximity effect. The measurements agree with a model based on the quasiclassical theory of superconductivity in the diffusive limit. We determine a crossover temperature below which quasiparticle heat conduction dominates over the electron-phonon relaxation.Comment: 4+ pages, 3 figure

Origin of Hysteresis in a Proximity Josephson Junction

We investigate hysteresis in the transport properties of Superconductor - Normal metal - Superconductor (S-N-S) junctions at low temperatures by measuring directly the electron temperature in the normal metal. Our results demonstrate unambiguously that the hysteresis results from an increase of the normal metal electron temperature once the junction switches to the resistive state. In our geometry, the electron temperature increase is governed by the thermal resistance of the superconducting electrodes of the junction

Low-temperature characterization of Nb-Cu-Nb weak links with Ar ion-cleaned interfaces

We characterize niobium-based lateral Superconductor (S) - Normal metal (N) - Superconductor weak links through low-temperature switching current measurements and tunnel spectroscopy. We fabricate the SNS devices in two separate lithography and deposition steps, combined with strong argon ion cleaning before the normal metal deposition in the last step. Our SNS weak link consists of high-quality sputtered Nb electrodes that are contacted with evaporated Cu. The two-step fabrication flow enables great flexibility in the choice of materials and pattern design. A comparison of the temperature-dependent equilibrium critical supercurrent with theoretical predictions indicates that the quality of the Nb-Cu interface is similar to that of evaporated Al-Cu weak links. Aiming at increased sensitivity, range of operation temperatures, and thermal isolation, we investigate how these SNS structures can be combined with shadow-evaporated aluminum tunnel junctions for sensor applications that utilize the superconducting proximity effect. To this end, we demonstrate a hybrid magnetic flux sensor based on a Nb-Cu-Nb SNS junction, where the phase-dependent normal metal density of states is probed with an Al tunnel junction.Comment: 5 pages, 3 figure

Contribution of smoking-attributable mortality to life expectancy differences by marital status among Finnish men and women, 1971-2010

BACKGROUND Smoking is known to vary by marital status, but little is known about its contribution to marital status differences in longevity. We examined the changing contribution of smoking to mortality differences between married and never married, divorced or widowed Finnish men and women aged 50 years and above in 1971-2010. DATA AND METHODS The data sets cover all persons permanently living in Finland in the census years 1970, 1975 through 2000 and 2005 with a five-year mortality follow-up. Smoking-attributable mortality was estimated using an indirect method that uses lung cancer mortality as an indicator for the impact of smoking on mortality from all other causes. RESULTS Life expectancy differences between the married and the other marital status groups increased rapidly over the 40-year study period because of the particularly rapid decline in mortality among married individuals. In 1971-1975 37-48% of life expectancy differences between married and divorced or widowed men were attributable to smoking, and this contribution declined to 11-18% by 2006-2010. Among women, in 1971-1975 up to 16% of life expectancy differences by marital status were due to smoking, and the contribution of smoking increased over time to 10-29% in 2006-2010. CONCLUSIONS In recent decades smoking has left large but decreasing imprints on marital status differences in longevity between married and previously married men, and small but increasing imprints on these differences among women. Over time the contribution of other factors, such as increasing material disadvantage or alcohol use, may have increased.Peer reviewe