Billiard dynamics: an updated survey with the emphasis on open problems

This is an updated and expanded version of our earlier survey article [E. Gutkin, "Billiard dynamics: a survey with the emphasis on open problems," Regular Chaotic Dyn. 8, 1-13 (2003)]. Section I introduces the subject matter. Sections II s3 s4 expose the basic material following the paradigm of elliptic, hyperbolic, and parabolic billiard dynamics. In Sec. V, we report on the recent work pertaining to the problems and conjectures exposed in the survey [E. Gutkin, "Billiard dynamics: a survey with the emphasis on open problems," Regular Chaotic Dyn. 8, 1-13 (2003)]. Besides, in Sec. V we formulate a few additional problems and conjectures. The bibliography has been updated and considerably expanded.     

Remarks on Symplectic Connections

This note contains a short survey on some recent work on symplectic connections: properties and models for symplectic connections whose curvature is determined by the Ricci tensor, and a procedure to build examples of Ricci-flat connections. For a more extensive survey, see Bieliavsky et al. [Int. J. Geom. Methods Mod. Phys. 3, 375–420 2006]. This note also includes a moment map for the action of the group of symplectomorphisms on the space of symplectic connections, an algebraic construction of a large class of Ricci-flat symmetric symplectic spaces, and an example of global reduction in a non-symmetric case.     

The effects of long-term exposure to railway and road traffic noise on subjective sleep disturbance

The exposure-response relationships between subjective annoyance with sleep disturbance from railway trains and road traffic noise were established from an extensive social survey by CENVR (Center for Environmental Noise and Vibration Research) in Korea. The objectives of this research are to determine the long-term effects of noise on sleep and to compare the exposure-response relationships from different noise sources with those from other studies and to elucidate the effects of some modifying factors on subjective responses to noise. From an investigation of the percentage of a highly sleep-disturbed population (%HSD) in response to railway and road traffic noise, it was found that sleep is affected more by railway noise than by road traffic noise. The effects of non-acoustical factors on the responses were examined and sensitivity was shown to be a significant modifying factor, as it pertains to subjective sleep disturbance. A comparison of the response curves from an analysis of pooled data from predominantly European surveys by Miedema and Vos [Behav. Sleep Med. 5, 1-20 (2007)] with the response curves from this survey showed more of a subjective sleep disturbance response in this survey to railway noise, whereas there was no significant difference in terms of a response to road traffic noise.     

Isoparametric finite elements for free vibration analysis of shell segments and non-axisymmetric shells

In reference [1] the eight-node isoparametric shell element with a reduced number of integration points was reported to be incapable of capturing rapid local changes in curvature. In the study reported here, eight- and ten-mode elements have been employed to represent shells having geometries with sharp curvatures or with sharp corner connections. The effect of different numbers of integration points on the performances of these elements has been surveyed. The information obtained from this survey has been used in predicting the natural frequencies of an oval cross-section hollow shell and a hollow turbine blade.     

Metallic solutions of the continuum model for conducting polymers

In the continuum approximation of the Su-Schrieffer-Heeger model for degenerate and nondegenerate ground state systems, an exhaustive survey of solutions of the standard gap equations is given. With special emphasis on the electronic energy spectrum, the pertinent results of Takahashi [1] are extended to the whole μ, k-plane. Periodic metallic phases and their grand potentials are discussed.     

Chemical Far Infrared Spectroscopy

Abstract

A number of books, symposia, proceedings, special publications [1–9], and review papers in English covering catalytic surfaces [10, 11], solid surface characterization [12–191, thin film analysis [20–22], surface structure and bonding [23, 24], angular distribution of photoelectrons [25, 26], use of synchrotron radiation [27, 281, ion beam effects [29], different methods of surface study [30, 31], experimental and theoretical aspects of ultraviolet photoelectron spectroscopy (UPS) [32], and angle resolved UPS [33, 34] are available in literature. Reviews in other languages, namely Japanese [35–41], German [42–46], French [47–50], Italian [51], Russian [52], and Polish [53], are also available. But the present situation demands a thorough and up-to-date literature survey of the surface study by photoelectron spectroscopy in order to assess what has been done and what is left to be done. This paper is aimed at that goal.     

Optical gap solitons: Past,present, and future; theory and experiments

Optical gap solitons refer to nonlinear waves propagating in optical fibers whose linear refractive index has a periodic variation. Stationary gap solitons came to light first in 1987 [Chen and Mills, Phys. Rev. Lett. 58, 160 (1987)]; two years later, they re-emerge in Christodoulides and Joseph [Phys. Rev. Lett. 62, 1746 (1989)] and are first extended to a more general traveling wave form in Aceves and Wabnitz [Phys. Lett. A 141, 37 (1989)]. But it was not until seven years later, that the first experimental demonstration [Eggleton et al., Phys. Rev. Lett. 76, 1627 (1996); J. Opt. Soc. Am. B 14, 2980 (1997)] was reported. Since then, there has been an increase in the study of the dynamics and applications of such solitons. This paper is a brief survey of some of the ongoing and future research on optical gap solitons. (c) 2000 American Institute of Physics.     

The angular momentum controversy: What’s it all about and does it matter?

A controversy has arisen as to how to define quark and gluon angular momentum, important in understanding the internal structure of the nucleon. For a review of the controversy, see [1]. I survey some of the ideas put forward and try to assess their physical implications.     

The electric dipole moment of the muon

The forthcoming experiment [1] on the anomalous magnetic moment of the muon will be able to search also for an electric dipole momentd _μ of the muon with increased sensitivity. A brief survey is given on what various models of CP violation predict ford _μ.     

The Structure of Water and Its Solutions

The nature of the structure of liquid water has been a matter of scientific interest since before the beginning of this century. Since 1933 the suggestion of Bernal and Fowler [1] that the structure of water is due to the hydrogen bonding between molecules has been the basis of all structural models. In this article we discuss some of the evidence that has been provided by the study of the vibrational spectra of liquid water that bears on the nature of the structure.

There has been no attempt to conduct a complete literature survey but rather to select and discuss examples that serve to illustrate the scope of infrared and Raman studies in the study of the structure of water in aqueous solutions.     

Colour Plasma Displays by UV-Excited Phosphors A Review

Though intense work on the development of a full colour flat TV display panel based on gas discharges has produced considerable progress over the last 10 years no practicable technological solutions have been found [1–2]. Of the different approaches the alternating current (ac) discharge has been proved suitable for the alphanumerical and graphical display technique and the direct current (dc) discharge for colour TV panels. To reach such aims as improved optical efficiency, colour gamut and increased life time as well as simpler manufacturing technology and more effective addressing for reducing costs, long-term basic research in the field of gas discharges and phosphors and the development of special technologies is necessary [3–8]. The present review is an attempt to give a survey of this situation. In Chap. 1 the trends of development, general problems of colour, display types and TV are dealt with, and in Chap. 2 and 3 the literature on dc and ac-display panels is reviewed.     

The Sasaki join and admissible Kähler constructions

We give a survey of our recent work (Boyer and Tønnesen-Friedman (2013) [50], [51], [30], Boyer and Tønnesen-Friedman (2014) [33], [29], [36]) describing a method which combines the Sasaki join construction of Boyer et al. (2007) [31] with the admissible Kähler construction of Apostolov et al. (2006, 2004, 2008) [26], [27], [14], [25] to obtain new extremal and new constant scalar curvature Sasaki metrics, including Sasaki–Einstein metrics. The constant scalar curvature Sasaki metrics also provide explicit solutions to the CR Yamabe problem. In this regard we give examples of the lack of uniqueness when the Yamabe invariant $\lambda \left(M\right)$ is positive.     

Oxygen sensing by fluorescence quenching of [Cu(btmgp)I]

A fluorescence study of acetonitrile solutions of bis(tetramethylguanidine)propane, copper(I)-iodide and [Cu(btmgp)I] was performed and the chemical reaction of the latter species with O₂ was investigated at room temperature. The actual quenching process via O₂ gassing was studied and an exponential dependence of the fluorescence intensity with respect to the complex concentration was observed.Furthermore the survey was deepened on time resolved fluorescence properties of solved [Cu(btmgp)I] in a wider concentration range. The applicability of this complex for O₂ sensing inside a microreactor system was proven by confocal fluorescence measurements. It was shown that the investigated system can be used for oxygen sensing in the copper concentration range from 10⁻² to 10⁻⁹ mol/l.     

Numerical information processing under the global rule expressed by the Euler-Riemann ζ function defined in the complex plane

When nonzero, the ζ function is intimately connected with numerical information processing. Two other functions play a key role, namely, η(s)=∑n≥1(-1)n+1/ns and λ(s)=∑(n≥0)1/(2n+1)s. The paper opens on a survey of some of the seminal work of Euler [Me?moires Acad. Sci., Berlin 1768, 83 (1749)] and of the amazing theorem by Voronin [Math. USSR, Izv. 9, 443 (1975)] Then, as a follow-up of Chatelin [Qualitative Computing. A Computational Journey into Nonlinearity (World Scientific, Singapore, in press)], we present a fresh look at the triple (η,ζ,λ) which suggests an elementary analysis based on the distances of the three complex numbers z, z/2, and 2/z to 0 and 1. This metric approach is used to contextualize any nonlinear computation when it is observed at a point describing a complex plane. The results applied to ζ, η, and λ shed a new epistemological light about the critical line. The suggested interpretation related to ζ carries computational significance.     

Helicobacter pylori in vivo diagnosis after food intake: results of simultaneous [15N]urea urine and [13C]acetate breath tests

The protocols for 13C and 15N H. pylori tests stipulate that the diagnostic agent should be taken on an empty stomach. It is presumed that food intake prior to the tests leads to less reliable test results due to a prolongation of the gastric residence time of the diagnostic agent urea. This might allow the bacteria to split a higher proportion of urea, resulting in an increased number of false positives. 12 probands received 150mg [15N]urea and 75 mg sodium [13C]acetate in 75 ml orange juice as a test drink. [15N]Urea served as an agent to diagnose gastric H. pylori colonization. The 15N tests were evaluated using a urine sample of the second hour after test start. [13C]Acetate served as a marker of the gastric emptying of water-soluble food including the urea under the influence of food intake. Breath air samples were taken to calculate the gastric emptying half life (EHL) and the apparent resorption time (RT) of the urea. The double tests were carried out four times within four weeks using identical test protocols but different standardized time periods of pretest fasting: overnight, two hours prior to test, one hour prior to test, and no fasting at all. The food intake amount was standardized. Five probands testing positive in the overnight fasting test were also found to be positive in the other test variants with more or less empty stomachs. Seven other probands testing negative after overnight fasting tested negative in the other test variants as well. It is concluded that food intake prior to the test drink does not have much of an influence on the gastric residence time of urea and so on the qualitative H. pylori test results. Due to identical behaviour of [13C]urea and [15N]urea in the stomach, this influence is believed to be independent on the labelling isotope. For survey purpose, no fasting conditions are required for the H. pylori tests.     

LAMOST光谱J152238.11+333136.1 P-Cygni轮廓分析

LAMOST一期巡天成功获取河外星系光谱超过150 000条,大样本光谱数据为探索奇异、稀有的天体从而完善现有的天体演化理论提供了必要的数据条件;而先进的信息技术为从海量的数据中挖掘这些珍稀样本提供了有效途径。针对采用基于DoPS的数据挖掘方法,从LAMOST DR5星系光谱数据获得的离群数据挖掘结果中,呈现出疑似P-Cygni轮廓特征的光谱J152238.11+333136.1进行了深入讨论。首先针对该光谱的基本信息、疑似P-Cygni轮廓特征以及相应的离群数据挖掘方法进行了简要表述,光谱在Hβ和[OⅢ]λ4860处呈现P-Cygni轮廓,在NeⅢλ3869和HeⅠλ5874处呈现反P-Cygni轮廓;其次,对该特征的真实性及其生成机制从以下4个角度展开讨论。(1)交叉同源观测。Sloan巡天2004年(相差11年)的同源观测,其光谱上并未呈现对应的特征,据推测可能是正在进行的演化活动或者光纤定位误差所致;(2)通过分析光谱质量、减天光残差等方法,分析P-Cygni特征是否为观测或数据处理所致。NeⅢλ3869和HeⅠλ5874处呈现反P-Cygni轮廓可信度较低;同时,通过比较目标光谱与超级天光,以及相邻光纤观测到的光谱在对应波长处的光谱特征,说明存在P-Cygni轮廓为减天光过程导致的可能性;(3)光谱子型差异。IRAS和WISE等近红外同源观测,显示其为Seyfert 2型星系,光学波段发射线强比[NⅡ]/Hα,[OⅢ]/Hβ显示其为HⅡ区,结合光学、红外测光图像特征,推测目标可能是两个星系进行并合活动;(4)从导致P-Cygni轮廓的物理机制的角度,分析了由星系并合触发外流、由恒星形成(爆发)电离气体触发的外流以及由Wolf-Rayet特征星系的超星风等原因引起的可能性。     

Generality of deterministic chaos, exponential spectra, and Lorentzian pulses in magnetically confined plasmas

The dynamics of transport at the edge of magnetized plasmas is deterministic chaos. The connection is made by a previous survey [M. A. Pedrosa et al., Phys. Rev. Lett. 82, 3621 (1999)] of measurements of fluctuations that is shown to exhibit power spectra with exponential frequency dependence over a broad range, which is the signature of deterministic chaos. The exponential character arises from Lorentzian pulses. The results suggest that the generalization to complex times used in studies of deterministic chaos is a representation of Lorentzian pulses emerging from the chaotic dynamics.     

Nitrogen stable isotope composition of leaves and roots of plants growing in a forest and a meadow

In controlled N-nutrition experiments, differences in delta15N composition of leaves and roots are regularly found. In this paper we report results from a survey of nitrogen stable isotope signatures of leaves and roots of 16 plant species growing under natural conditions in a meadow and a forest understorey, which differed in nitrate and ammonium availability. Significant differences between leaf and root were observed. The range of delta15N [leaf-root] values was -0.97 to +0.86 per thousand, small compared to published values from controlled N-nutrition experiment, but almost as large as the range of leaf delta15N values (-1.04 to +1.08 per thousand). Forbs showed the largest differences between leaves and roots and showed a significant difference with respect to habitat. Grasses and legumes did not show significant differences in delta15N [leaf-root] between the two habitats. Care must be taken when using leaf delta15N values as representative for whole-plant 15N composition in these two habitats.     

Analysis of interfacial thermal stresses for damaged structures: new theoretical model

The use of the composites for the reinforcement of the beams and structures metallic and non-metallic, is one of the recent methods of the rehabilitation by composites, what permits to replace the classic techniques of the assembly based on soldering, bonding, etc. But this technique gives stresses concentrations to the level of the zone of the assembly. The methods of rehabilitation by composites permit to prolong the life span of these structures under a reduced exploitation cost and with less pollution to the environment. In this article, an original survey on the stresses between the structure and the composite (fiber reinforced polymer [FRP]) was finalized, taking account, as well, of the mechanical and thermal loadings, as well as the effects of deformation shear lag. This originality puts in evidence a new theoretical model which takes into account the thermal effect of the stresses concentration that has not been treated seriously by the previous studies.