A possible solution of the grain boundary problem for applications of high-Tc superconductors

It is shown that the critical current density of high-Tc wires can be greatly enhanced by using a threefold approach, which consists of grain alignment, doping, and optimization of the grain architecture. According to model calculations, current densities of 4x10^6 A/cm2 can be achieved for an average grain alignment of 10 degree at 77K. Based on this approach, a road to competitive high-Tc cables is proposed.Comment: 3 pages, 5 figure

Role of magnetic and orbital ordering at the metal-insulator transition in NdNiO3

Soft x-ray resonant scattering at the Ni L2,3 edges is used to test models of magnetic and orbital-ordering below the metal-insulator transition in NdNiO3. The large branching ratio of the L3 to L2 intensities of the (1/2,0,1/2) reflection and the observed azimuthal angle and polarization dependence originates from a non collinear magnetic structure. The absence of an orbital signal and the non collinear magnetic structure show that the nickelates are materials for which orbital ordering is absent at the metal-insulator transition.Comment: 10 pages, 4 figures, Physical Review B rapid communication, to be publishe

Diodes with Breakdown Voltages Enhanced by the Metal-Insulator Transition of LaAlO3_3-SrTiO3_3 Interfaces

Using the metal-insulator transition that takes place as a function of carrier density at the LaAlO$_3$-SrTiO$_3$ interface, oxide diodes have been fabricated with room-temperature breakdown voltages of up to 200 V. With applied voltage, the capacitance of the diodes changes by a factor of 150. The diodes are robust and operate at temperatures up to 270 C

Spatial homogeneity and doping dependence of quasiparticle tunneling spectra in cuprate superconductors

Scanning tunneling spectroscopy (STS) studies reveal long-range (similar to 100 nm) spatial homogeneity in optimally and underdoped superconducting YBa2Cu3O7-delta (YBCO) single crystals and thin films, and macroscopic spatial modulations in overdoped (Y0.7Ca0.3)BaCu3O7-delta (Ca-YBCO) epitaxial films. In contrast, STS on an optimally doped YBa2(Cu0.9934Zn0.0026Mg0.004)(3)O-6.9 single crystal exhibits strong spatial modulations and suppression of superconductivity over a microscopic scale near the Zn or Mg impurity sites, and the global pairing potential is also reduced relative to that of optimally doped YBCO, suggesting strong pair-breaking effects of the non-magnetic impurities. The spectral characteristics are consistent with d(x2-y2) pairing symmetry for the optimally and underdoped YBCO, and with (d(x2-y2) + s) for the overdoped Ca-YBCO. The doping-dependent pairing symmetry suggests interesting changes in the superconducting ground state, and is consistent with the presence of nodal quasiparticles for all doping levels. The maximum energy gap Delta (d) is non-monotonic with the doping level, while the (2 Delta (d)/k(B)T(c)) ratio increases with decreasing doping. The similarities and contrasts between the spectra of YBCO and of Bi2Sr2CaCu2O8+x are discussed

The moral muteness of managers: an Anglo-American phenomenon? German and British managers and their moral reasoning about environmental sustainability in business

Several studies in the Anglo-American context have indicated that managers present themselves as morally neutral employees who act only in the best interest of the company by employing objective skills. The reluctance of managers to use moral arguments in business is further accentuated in the now common argument presented as a neutral fact that the company must always prioritise shareholder value. These and other commercial aims are seen as an objective reality in business, whilst questions about sustainability, environmental problems or fair trade are seen as emotional or moral ones; a phenomenon described as ‘moral muteness’. This research explores whether this ‘moral muteness’ is an Anglo-American phenomenon and/or whether managers in other countries - in this case Germany - might express themselves in a different way. The focus is on moral arguments around environmental sustainability and the implications of this study for cross-cultural management. This article is based on a qualitative, comparative cross-cultural study of British and German managers in the Food Retail and Energy Sectors. In line with the studies mentioned above, British managers placed a strong emphasis on their moral neutrality. In contrast, German managers tended to use moral arguments when discussing corporate greening, often giving such arguments more weight than financial arguments. Overall, the study suggests that the ‘moral muteness’ of managers is a British phenomenon and quite distinct from the German approach. The article ends in a short exploration of how this understanding can help managers better manage people, organisations and change across cultures

Seroprevalence of Yersinia, Hepatitis E and Trichinella among migrant and nonmigrant populations in Berlin and Brandenburg (Germany)

Pork is a potential source of infection for Yersinia, Hepatitis E virus and Trichinella. In 2014, 2484 cases of yersiniosis, 671 hepatitis E cases and 1 trichinellosis case were reported in Germany. Although migrants represent 27% of Berlin inhabitants, data is lacking on subpopulation-specific exposure risks to zoonotic diseases. We aimed to estimate the seroprevalence and to identify potential risk factors for Yersinia, Hepatitis E and Trichinella in migrants and non-migrants in Berlin/Brandenburg

Antibiotic-resistant bacteria, antibiotic resistance genes, and antibiotic residues in wastewater from a poultry slaughterhouse after conventional and advanced treatments

Slaughterhouse wastewater is considered a reservoir for antibiotic-resistant bacteria and antibiotic residues, which are not sufficiently removed by conventional treatment processes. This study focuses on the occurrence of ESKAPE bacteria (Enterococcus spp., S. aureus, K. pneumoniae, A. baumannii, P. aeruginosa, Enterobacter spp.), ESBL (extended-spectrum β-lactamase)-producing E. coli, antibiotic resistance genes (ARGs) and antibiotic residues in wastewater from a poultry slaughterhouse. The efficacy of conventional and advanced treatments (i.e., ozonation) of the in-house wastewater treatment plant regarding their removal was also evaluated. Target culturable bacteria were detected only in the influent and effluent after conventional treatment. High abundances of genes (e.g., bla$_{TEM}$, bla$_{CTX-M-15}$, bla$_{CTX-M-32}$, bla$_{OXA-48}$, bla$_{CMY}$ and mcr-1) of up to 1.48 × 10$^{6}$ copies/100 mL were detected in raw influent. All of them were already significantly reduced by 1–4.2 log units after conventional treatment. Following ozonation, mcr-1 and bla$_{CTX-M-32}$ were further reduced below the limit of detection. Antibiotic residues were detected in 55.6% (n = 10/18) of the wastewater samples. Despite the significant reduction through conventional and advanced treatments, effluents still exhibited high concentrations of some ARGs (e.g., sul1, ermB and bla$_{OXA-48}$), ranging from 1.75 × 10$^{2}$ to 3.44 × 10$^{3}$ copies/100 mL. Thus, a combination of oxidative, adsorptive and membrane-based technologies should be considered

Co-occurrence of the bla(VIM-1) and bla(SHV-12) genes on an IncHI2 plasmid of an Escherichia coli isolate recovered from German livestock

The dissemination of carbapenemase-producing Enterobacterales (CPE) is an important public health issue. The number of human CPE isolates has been steadily increasing during recent years, worldwide. Despite the fact that carbapenems are not licensed for use in veterinary medicine, increasing numbers of CPE from the veterinary sector have been reported. The transmission of CPE between pets/livestock and exposed humans as well as via food has been demonstrated. In this study, a detailed characterization of a carbapenem-resistant porcine Escherichia coli co-harbouring blaVIM-1, blaSHV-12 and blaACC-1 genes, along with other resistance genes, is provided

Flux flow of Abrikosov-Josephson vortices along grain boundaries in high-temperature superconductors

We show that low-angle grain boundaries (GB) in high-temperature superconductors exhibit intermediate Abrikosov vortices with Josephson cores, whose length $l$ along GB is smaller that the London penetration depth, but larger than the coherence length. We found an exact solution for a periodic vortex structure moving along GB in a magnetic field $H$ and calculated the flux flow resistivity $R_F(H)$, and the nonlinear voltage-current characteristics. The predicted $R_F(H)$ dependence describes well our experimental data on $7^{\circ}$ unirradiated and irradiated $YBa_2Cu_3O_7$ bicrystals, from which the core size $l(T)$, and the intrinsic depairing density $J_b(T)$ on nanoscales of few GB dislocations were measured for the first time. The observed temperature dependence of $J_b(T)=J_{b0}(1-T/T_c)^2$ indicates a significant order parameter suppression in current channels between GB dislocation cores.Comment: 5 pages 5 figures. Phys. Rev. Lett. (accepted

Wir bitten um ein differenziertes Urteil: Möglichkeiten zur Reduktion von Nondifferentiation bei Rating-Skalen

Nondifferentiation ist ein generelles Phänomen bei der Einschätzung von Meinungsgegenständen mittels Rating-Skalen: Zwischen den Meinungsgegenständen wird nicht so deutlich unterschieden, wie aufgrund der Skalen möglich. In zwei experimentellen Studien zu unterschiedlichen Meinungsgegenständen werden in der Literatur diskutierte Verfahren zur Reduzierung der Nondifferentiation zusammen mit einem hierfür bisher nicht verwendeten Verfahren (konstante Summe, KS) hinsichtlich ihres Einflusses auf Nondifferentiation verglichen. Eine erste Studie (N = 139) belegt eine signifikant erhöhte Differenzierung bei KS im Vergleich zu einem verbalen Einschub. Für eine zweite Studie werden in einer Voruntersuchung (N = 138) stark positiv und stark negativ eingeschätzte Meinungsgegenstände ausgewählt, die in der anschließenden Hauptuntersuchung (N = 200) ohne Messwiederholung bewertet werden. Hierbei werden insgesamt 3 verschiedene Verfahren zur Verbesserung der Differenzierung verwendet und einem rein verbalen Einschub gegenübergestellt. Auch hierbei erweist sich die KS generell als das Verfahren, das die höchste Differenzierung bewirkt