451 research outputs found

    Ferromagnet-superconductor proximity effect: The clean limit

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    We study theoretically the influence of ferromagnetic metals on a superconducting film in the clean limit. Using a self-consistent solution of the Bogoliubov--de Gennes equation for a ferromagnet-superconductor-ferromagnet double junction we calculate the pair potential and conductance spectra as a function of the superconducting layer thickness dd for different strengths of ferromagnets and interface transparencies. We find that the pair potential and the critical temperature are weakly perturbed by the exchange interaction and do not drop to zero for any finite dd. On the other hand, for thin superconducting films charge transport is spin polarized and exhibits a significant dependence on the ferromagnetic strength and magnetization alignment.Comment: 5 pages, 4 figure

    Josephson coupling through ferromagnetic heterojunctions with noncollinear magnetizations

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    We study the Josephson effect in clean heterojunctions that consist of superconductors connected through two metallic ferromagnets with insulating interfaces. We solve the scattering problem based on the Bogoliubov--de Gennes equation for any relative orientation of in-plane magnetizations, arbitrary transparency of interfaces, and mismatch of Fermi wave vectors. Both spin singlet and triplet superconducting correlations are taken into account, and the Josephson current is calculated as a function of the ferromagnetic layers thicknesses and of the angle α\alpha between their magnetizations. We find that the critical Josephson current IcI_c is a monotonic function of α\alpha when the junction is far enough from 0−π0-\pi transitions. This holds when ferromagnets are relatively weak. For stronger ferromagnets, variation of α\alpha induces switching between 0 and π\pi states and Ic(α)I_c(\alpha) is non-monotonic function, displaying characteristic dips at the transitions. However, the non-monotonicity is the effect of a weaker influence of the exchange potential in the case of non-parallel magnetizations. No substantial impact of spin-triplet superconducting correlations on the Josephson current has been found in the clean limit. Experimental control of the critical current and 0−π0-\pi transitions by varying the angle between magnetizations is suggested.Comment: 7 pages, 8 figure

    The Influence of Fatteners Dry and Liquid Diet on Slaughter Traits of Carcass Sides

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    The study was conducted on 700 fattening pigs, three breed half blood with Duroc as a terminal breed ((Large White x Landrace) x Duroc). The pigs were divided into the two groups according to diet: dry and liquid nutrition. Each group consisted of 350 fattening pigs and used the same feed mixtures in prefattening (CP-3) and fattening (ST). During the period from 24.8 to 60kg they were fed with a CP-3, a crude protein content of 16.37%. During the period from 60kg until the end they were fed with ST, a crude protein content of 15.3%. Muscle tissue processed half-carcasses in slaughterhouses were determined by a device that determines the value of S (fat thickness) and M (muscle thickness) using "method one point." Fat thickness skin in mm, measured 7 cm lateral to the central (median) cutting, in the amount between the second and third ribs of the tail. The thickness of the muscle in mm was measured at the same place as the thickness of the bacon. The results show that the fatling fed dry food had significantly higher carcass weight (80.41: 78.51 kg, p<0.05), backfat thickness (16.55: 15.31 mm, p<0.05), weight (muscle 55.80: 53.82, p<0.05), but a lower percentage of meat (56.6: 57.3, p<0.05) as compared to pigs fed liquid food. In finishing pigs fed dry food, between carcass weight and backfat thickness and muscle thickness a positive and significant correlation (0.4267 and 0.4290, p<0.05) was found and between carcass weight and lean meat a significant negative correlation (-0. 4236 and p<0.05). Between backfat thickness and lean meat in the carcass a negative and significant correlation (-0.8534, p<0.05) was found and between muscle thickness and lean meat a positive and significant correlation (0.2857, p<0.05). In finishing pigs fed liquid food, between carcass weight and backfat thickness and muscle thickness a positive and significant correlation (0.1800 and 0.3705, p<0.05) was found and between carcass weight and lean meat a significant negative correlation (-0. 2178; p <0.05). Between backfat thickness and percentage of meat in the carcass negative and significant correlation (-0.8692, p<0.05) was found and between muscle thickness and lean meat a positive and significant correlation (0.3168, p<0.05)

    Phenotypic Relation Growth Rate in Performance Test and Litter Size of Sows

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    In this study we investigated influence of weight gain level of gilts reached during performance test on the expression of important reproductive traits. For the purpose of research, data on the litter size from 2nd to 9th parity of 700 tested gilts were monitored. Characteristics that were examined are: growth at the end of the test, the number of piglets born alive, stillborn and weaned piglets per parity and a total from 2nd to 9th parity, and the percentage of sows entering the next farrowing. Results obtained in this study indicate that gilts with a lower weight gain in performance test have smaller number of live born (8.8:9.23 p<0.01) and reared piglets (8.46:8.55, p<0.01) in regard to the higher weight gain gilts, but a larger number of stillborn piglets (0.35:0.29). Also, gilts with the lowest weight gain during the performance test had smaller average litter size from 2nd to 9th parity. Even greater difference is determined if the average litter size from 3rd to 7th parity (9.8:10.0 and 10.4) is observed. The largest percentage of sows farrowing for the second time was in gilts with the highest weight gain during the performance test (39.5%: 14.8% and 15.5%) which expressed statistically significant difference (p<0.01). Gilts with a lower gain weight in performance test had a higher percentage of sows included in the next farrowing. Data showed a large drop in the number of sows with the second and third parity in the total sample, where the percentages of earned second and third litters were 16.5 and 45.3%, while the percentages of actual parity from the 4th to 7th parity were: 79.2; 94.7; 83.3; 96.7; 72.4 and 90.5%

    In-situ Investigation of the Early Stage of TiO2 epitaxy on (001) SrTiO3

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    We report on a systematic study of the growth of epitaxial TiO2 films deposited by pulsed laser deposition on Ti-terminated (001) SrTiO3 single crystals. By using in-situ reflection high energy electron diffraction, low energy electron diffraction, x-ray photoemission spectroscopy and scanning probe microscopy, we show that the stabilization of the anatase (001) phase is preceded by the growth of a pseudomorphic Sr-Ti-O intermediate layer, with a thickness between 2 and 4 nm. The data demonstrate that the formation of this phase is related to the activation of long range Sr migration from the substrate to the film. The role of interface Gibbs energy minimization, as a driving force for Sr diffusion, is discussed. Our results enrich the phase diagram of the Sr-Ti-O system under epitaxial strain opening the roudeficient SrTiO phase.Comment: 8 pages, 7 figure

    Distribution of Trace Elements in Plant Parts of Red Clover (\u3cem\u3eTrifolium pratense\u3c/em\u3e L.)

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    There is little information on the distribution of minerals in plant parts although factors affecting mineral content in forages have been well investigated (Fleming, 1973; Whitehead et al., 1985). The aim of this investigation was to determine the trace mineral content in plant parts of different cultivars of red clover (foreign and domestic) and to assess differences between cultivars. The existence of significant differences between cultivars would indicate the possibility of selecting cultivars to satisfy particular animal requirements for minerals

    Atomically precise lateral modulation of a two-dimensional electron liquid in anatase TiO2 thin films

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    Engineering the electronic band structure of two-dimensional electron liquids (2DELs) confined at the surface or interface of transition metal oxides is key to unlocking their full potential. Here we describe a new approach to tailoring the electronic structure of an oxide surface 2DEL demonstrating the lateral modulation of electronic states with atomic scale precision on an unprecedented length scale comparable to the Fermi wavelength. To this end, we use pulsed laser deposition to grow anatase TiO2 films terminated by a (1 x 4) in-plane surface reconstruction. Employing photo-stimulated chemical surface doping we induce 2DELs with tunable carrier densities that are confined within a few TiO2 layers below the surface. Subsequent in-situ angle resolved photoemission experiments demonstrate that the (1 x 4) surface reconstruction provides a periodic lateral perturbation of the electron liquid. This causes strong backfolding of the electronic bands, opening of unidirectional gaps and a saddle point singularity in the density of states near the chemical potential
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