Interplay of Fulde-Ferrell-Larkin-Ovchinnikov and Vortex states in two-dimensional Superconductors

Clean superconductors with weakly coupled conducting planes have been suggested as promising candidates for observing the Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) state. We consider here a layered superconductor in a magnetic field of arbitrary orientation with respect to the conducting plane. In this case there is competition of spin-pair-breaking and orbital-pair-breaking effects. In previous work, phase boundaries characterized by Landau quantum numbers n > 0 have been predicted. Here, we calculate the actual structure of the stable states below Hc2 by minimizing the free energy. We find several new order parameter structures differing from both the traditional Abrikosov and FFLO solutions. Some interesting unsolved questions appear in the limit of large n.Comment: 13 pages, 3 figure

Twenty years of electronic markets research: looking backwards towards the future

Over the past 20 years the field of electronic markets has seen a considerable proliferation and differentiation. This position paper takes the opportunity of the 21st volume of “Electronic Markets” to look back at important developments and insights, suggesting a framework that captures the multiple facets and indeed empirical breadth and depths of this concept. It comprises three perspectives which include the market environment, governance choices by economic actors as well as the entrepreneurial dynamics of firms who initiate and operate market platforms as their business. In addition, we propose to study the interplay of technological, market, and institutional drivers in order to understand the phenomenon of electronic markets, which is also a precondition for designing electronic markets. Both activities involve more than an economically motivated choice between the discrete alternatives of markets and hierarchies. Rather, electronic markets are configurations across multiple, interdependent dimensions: Technology is an important force in shaping the field, but needs to be complemented by considerations of the competitive environment and the setting of rules in order to ensure efficient and effective plays of the game. Based on this framework, this position paper develops six propositions for the future of electronic markets. Overall, the advantages of intermediated structures, an ongoing technological sophistication, as well as further innovation in market mechanisms and services make electronic markets an ena-bler for many interorganizational value chains. While we are confident that the ingenuity of inventors will yield a flow of innovations, recent economic crises have shed a dark shadow over the sustainability of electronic markets. They call for suitable rules and regulation amenable to economic prosperity and stability to be agreed upon on a broad level

Synthesis of 1,1,2,2,3,3-hexamethyl-4,5-bis(methylene)cyclopentane

An efficient synthesis of the title compound 14 is reported, which employs the ZnCl2/Et2O catalyzed addition of acetyl chloride (4) to 2-methyl-2-butene (5) and the [3+ + 2] cycloaddition of the 1,1,2,3-tetramethylallyl cation to 2,3-dimethyl-2-butene as key steps

Preliminary observations on the bone histology of the Middle Triassic pseudosuchian archosaur Batrachotomus kupferzellensis reveal fast growth with laminar fibrolamellar bone tissue

The bone tissue of femur, rib, and gastralia from three different individuals of the Middle Triassic pseudosuchian Batrachotomus kupferzellensis from southern Germany is studied. The femoral bone tissue comprises laminar fibrolamellar bone tissue throughout and is stratified by three annual growth cycles, indicating that the individual died early in its fourth year of life, at which time it had reached 87% of maximum known femur length. Thus, compared with most other Pseudosuchia (e.g., phytosaurs, aetosaurs, and most crocodylomorphs, including marine taxa), Batrachotomus achieved its large body size in a very short time by fast, although interrupted, growth and not by protracted longevity. Such fast growth as well as the organization of the tissue is similar to the condition observed in ornithodirans. The pseudosuchians Effigia and Postosuchus also show fibrolamellar tissue, but vascular density is lower when compared with Batrachotomus and dominated by a longitudinal organization of primary osteons. The rib and gastralium of Batrachotomus both show an inner spongious organization surrounded by a ring of compact, avascular, highly organized parallel-fibered and/or lamellar bone largely covered by short fibers. Maximal growth cycle count in the proximal rib sample suggests an age of at least 11 years for this individual with a reduction of growth rate after the sixth cycle.SUPPLEMENTAL DATA—Supplemental materials are available for this article for free at www.tandfonline.com/UJVPCitation for this article: Klein, N., C. Foth, and R. R. Schoch. 2017. Preliminary observations on the bone histology of the Middle Triassic pseudosuchian archosaur Batrachotomus kupferzellensis reveal fast growth with laminar fibrolamellar bone tissue

Cruise ship concepts applying LNG fuel

LNG has become a feasible fuel alternative. In many aspects it is favorable to the standard marine fuels but the economics deserve case-by-case analysis. Comprehensive reports have been published for various operating areas and ship types, but very little material exists on its application on cruise ships. The aim of the thesis is to provide an overview of available technologies and identify those better suited for the cruise industry. Increasingly stringent pollution regulation can be considered the primary driver of LNG adoption. During the past few years LNG has also been considerably cheaper than HFO but this has changed in the recent months. It was found that dual fuel four stroke engines and aeroderivative gas turbines with waste heat recovery were most promising. Pure gas engines remain unpractical at this point for cruise ships. Although commonly IMO C-type tanks have been used, prismatic designs also deserve attention due to their significantly smaller footprint. The composed concepts were compared to operation on low Sulphur fuel and exhaust gas cleaning. The value of deck area is determined and used to assign a value to space lost or gained. The exhaust gas cleaning system consumables, as well as maintenance and overall plant efficiency are considered. It is concluded that LNG has merit in the cruise industry but currently the economics are not favorable. It was determined that compared to the base case of operating on low Sulphur fuel, choosing an LNG machinery system has a NPV value of $7M compared to$26M for scrubber installation. If the price of HFO in Miami were to rise from the current $279 to$330, LNG would again become the cheaper fuel (assuming its price remains constant). It is concluded that LNG has merit for the cruise industry and many feasible machinery concepts exist. Yet using the presented figures, the economics are rather in favor of exhaust gas cleaning

Assessment and Level Modelling in Fundamentals of Electrical Engineering

This paper focuses on the module “Fundamentals of Electrical Engineering,” in which students from different engineering disciplines often face difficulties. Despite efforts to enhance the course through digital media, the formation of study groups, and adjusted lecture and exercise materials, there is still a high failure rate in the subject, leading to potential student dropouts. The primary goal is to analyze students’ challenges in solving electrical engineering problems to evaluate their grasp of the fundamentals of electrical engineering and identify varying levels of competence. The findings are based on a cross-sectional study conducted at the conclusion of a university course in Germany, involving 196 students. Through item response theory (IRT) analyses, it was determined that the assessment items demonstrated satisfactory fit values. The proficiency model delineates four levels, with only 8.2% of students achieving the highest level. At this stage, students can tackle more intricate problems using circuit analysis techniques. However, a notable portion of students (40.3%) lack a basic understanding of electrical circuits, placing them at the lowest level

1005-81 Myocardial Protection by Na+/H+ Exchange Inhibition in Ischemic, Reperfused Porcine Hearts

The protective effect of the Na+/H+ exchange inhibitor HOE 694 was tested in porcine hearts subjected to 45min of regional ischemia and 24 h of reperfusion. The compound (3mg/kg) was intravenously injected in 6 pigs each either 10 min before ischemia (group A) or 10 min before reperfusion (group B). Six animals served as controls. Apart from the main end-points, infarct size and regional systolic shortening, the effect of HOE 694 on global hemodynamic parameters which included coronary blood flow and coronary venous oxygen saturation was evaluated. Although the Na+IH+ exchange inhibitor did not affect global hemodynamics, preischemic treatment with HOE 694 decreased infarct size from 65±18% (control group) to 12 ± 9% (p < 0.01) and improved systolic shortening from 8 ± 6% (control group) to 28 ± 9% P < 0.02). In addition, increase in heart rate and myocardial contracture during early reperfusion were significantly attenuated in group A. Treatment of group B did not exhibit protective effects.ConclusionNa+/H+ exchange inhibition is a very protective means in myocardial ischemia and reperfusion when administered before ischemia. In this model, it was ineffective when given before reperfusion

Electronic structure, electron-phonon coupling and superconductivity of isotypic noncentrosymmetric crystals Li2_2Pd3_3B and Li2_2Pt3_3B

Electronic structure of recently discovered isotypic ternary borides Li$_2$Pd$_3$B and Li$_2$Pt$_3$B, with noncentrosymmetric crystal structures, is studied with a view to understanding their superconducting properties. Estimates of the Fermi-surface averaged electron-phonon matrix element and Hopfield parameter are obtained in the rigid ion approximation of Gaspari and Gyorffy [Phys. Rev. Lett. {\bf 28} (1972) 801]. The contribution of the lithium atoms to the electron-phonon coupling is found to be negligible, while both boron and palladium atoms contribute equally strongly to the Hopfield parameter. There is a significant transfer of charge from lithium, almost the entire valence charge, to the B-Pd(Pt) complex. The electronic structure and superconducting properties of Li$_2$Pd$_3$B, thus, can be understood from the viewpoint of the compound being composed of a connected array of B-Pd tetrahedra decoupled from the backbone of Li atoms, which are connected by relatively short bonds. Our results suggest that conventional s-wave electron-phonon interaction without explicit consideration of SO coupling can explain qualitatively the observed $T_c$ in Li$_2$Pd$_3$B. However, such an approach is likely to fail to describe superconductivity in Li$_2$Pt$_3$B.Comment: 14 pages, 4 figures An erroneous statement following Eq. 6 in version 1 has been deleted. A statement regarding the possible inadequacy of Eq. 6 has been added following Eq. 6. At two places in the discussion Refs. 37,39 has been changed to 37-39, as it should b