1,909 research outputs found
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
Wideband Detection of the Third Moment of Shot Noise by a Hysteretic Josephson Junction
We use a hysteretic Josephson junction as an C of the third moment of shot noise of a tunnel junction. The detectable bandwidth is determined by the plasma frequency of the detector, which is about 50 GHz in the present experiment. The third moment of shot noise results in a measurable change of the switching rate when reversing polarity of the current through the noise source. We analyze the observed asymmetry assuming adiabatic response of the detector.Peer reviewe
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