Classification of zero-energy resonances by dissociation of Feshbach molecules

We study the dissociation of Feshbach molecules by a magnetic field sweep across a zero-energy resonance. In the limit of an instantaneous magnetic field change, the distribution of atomic kinetic energy can have a peak indicating dominance of the molecular closed-channel spin configuration over the entrance channel. The extent of this dominance influences physical properties such as stability with respect to collisions, and so the readily measurable presence or absence of the corresponding peak provides a practical method of classifying zero-energy resonances. Currently achievable ramp speeds, e.g. those demonstrated by Duerr et al. [Phys. Rev. A 70, 031601 (2005)], are fast enough to provide magnetic field changes that may be interpreted as instantaneous. We study the transition from sudden magnetic field changes to asymptotically wide, linear ramps. In the latter limit, the predicted form of the atomic kinetic energy distribution is independent of the specific implementation of the two-body physics, provided that the near-resonant scattering properties are properly accounted for.Comment: 10 pages, 5 eps figure

Comparison of methods for determining the fatty acid composition of photosynthetic tissues

The fatty acid (FA) composition of photosynthetic tissue differs from that in other plant or animal tissues. In leaves, the lipid fraction constitutes less than 10% of the dry weight and is mostly located in the chloroplasts. An extraction solvent should dissolve polar lipids readily, but should also overcome interactions between the lipids and the tissue matrix. A mixture of chloroform/methanol (C/M) is commonly used. However, less toxic alternative methods such as hexane/isopropanol (H/I) and ethanol (E) have been suggested. In this preliminary study we compared the effectiveness of these three methods which are used as standard extraction protocols for FA analysis of plant material at three different European Universities. C/M extraction gave the highest total FA content and H/I the lowest, suggesting that C/M is indeed the best general-purpose lipid extraction solvent. Significant differences were also observed for FA composition including the ratio of saturated to unsaturated FA indicating selectivity of the various solvents in extracting different individual FA. Further and more detailed investigations are required to confirm this hypothesi

Free vibrations of an unbounded periodically reinforced elastic layer

The object of analysis is an unbounded layer made of two isotropic, linear elastic materials and periodically laminated along the Ox1 axis (cf. Fig.1). The layer is resting on the rigid base. It is assumed that the laminas are homogeneous and their number is very large. Hence we deal with a certain microstructured layer. The aim of this contribution is to propose a certain mass discretized model for the analysis of vibrations of the layer. It is shown that there exist two kinds of these vibrations which are independent of x2 and x3 coordinates

Coherence time of a Bose-Einstein condensate

Temporal coherence is a fundamental property of macroscopic quantum systems, such as lasers in optics and Bose-Einstein condensates in atomic gases and it is a crucial issue for interferometry applications with light or matter waves. Whereas the laser is an "open" quantum system, ultracold atomic gases are weakly coupled to the environment and may be considered as isolated. The coherence time of a condensate is then intrinsic to the system and its derivation is out of the frame of laser theory. Using quantum kinetic theory, we predict that the interaction with non-condensed modes gradually smears out the condensate phase, with a variance growing as A t^2+B t+C at long times t, and we give a quantitative prediction for A, B and C. Whereas the coefficient A vanishes for vanishing energy fluctuations in the initial state, the coefficients B and C are remarkably insensitive to these fluctuations. The coefficient B describes a diffusive motion of the condensate phase that sets the ultimate limit to the condensate coherence time. We briefly discuss the possibility to observe the predicted phase spreading, also including the effect of particle losses.Comment: 17 pages, 8 figures; typos correcte

Non-diffusive phase spreading of a Bose-Einstein condensate at finite temperature

We show that the phase of a condensate in a finite temperature gas spreads linearly in time at long times rather than in a diffusive way. This result is supported by classical field simulations, and analytical calculations which are generalized to the quantum case under the assumption of quantum ergodicity in the system. This super-diffusive behavior is intimately related to conservation of energy during the free evolution of the system and to fluctuations of energy in the prepared initial state.Comment: 16 pages, 7 figure

Nation and/or Homeland: Identity in 19th-Century Music and Literature between Central and Mediterranean Europe

The aim of this book is to focus on the development of national awareness elaborated around a series of different case studies, in which the terms nation, homeland and people have been applied. This Romantic lexicon identifies similar but various conceptions of the national idea in some countries dominated by Italian, German and Slavic cultures, and in some groups or minorities such as the Jews and the Vlachs in Central and Mediterranean Europe. In order to clarify the cultural framework, the authors explore the construction of identity through folk tunes, poetry inspired by popular culture, and opera in which the national myths or heroes appear. In the self-making tradition, the national traits are sustained by the process of embodiment of any regional utterance, and also by disregarding the \u201cother\u201d, in particular the minorities. The symbols of the nation, as an achievement of the power that flourishes from the sense of belonging, are defined \u201cper differentiam\u201d. Theoretical perspectives are shaped by the new approaches to this topic, taking into consideration the artistic issues as socio-historical events and subsequently evaluating them in their aesthetic quality

The technique of inhalation anaethesia in experimental investigation in the rat

The rat is the most frequently used animal in scientific inquiry conducted for the purpose of advancing basic knowledge that may lead to an improvement in the results of treatment. Understanding of the pharmacological properties of inhalation anaesthetics, in combination with monitoring of their concentration in the inspired and end-tidal gas, together provide safe and precise control of the depth of the anaesthesia. However, accurate application of the inhalation method of anaesthesia requires special equipment for the delivery and effective scavenging of inhalation anaesthetics

The pathophysiology of intracerebral haemorrhage

Spontaneous intracerebral haemorrhage carries a high mortality rate and treatment of the disease raises more questions then answers. Mass effect, ischaemia and toxicity of blood components are responsible for brain tissue damage. Initially occurring disturbances of cerebral blood flow have a temporary character and do not play a key role in the pathology of intracerebral haematoma. Oedema formatting in the 24–48 hours after intracerebral bleeding is the result of multidirectional processes. The pathological mechanism that underlines it is the function of activation of systemic complement and cascade of coagulation. In the light of these findings, further clinical and experimental investigations should be focused on these factors

Solitons as the early stage of quasicondensate formation during evaporative cooling

We calculate the evaporative cooling dynamics of trapped one-dimensional Bose-Einstein condensates for parameters leading to a range of condensates and quasicondensates in the final equilibrium state. We confirm that solitons are created during the evaporation process, but always eventually dissipate during thermalisation. The distance between solitons at the end of the evaporation ramp matches the coherence length in the final thermal state. Calculations were made using the classical fields method. They bridge the gap between the phase defect picture of the Kibble-Zurek mechanism and the long-wavelength phase fluctuations in the thermal state