bluuebunny/crossref_metadata_2025 huggingface dataset:
Red Wines of Médoc: What is Wine Tasting Worth?
Authors: Ginsburgh Victor , Monzak Muriel , Monzak Andras
Published: August 2013

Winemaking is a highly complex technology. It needs inputs over which there is no control (good weather conditions), initial endowments which can hardly be modified (soil, exposure of the slopes), inputs which take 20 to 30 years before producing good quality outputs (vines), manual operations (picking), mechanical operations (crushing, racking) and chemical processes (during fermentation). In the paper, we disentangle the production technology, and try to quantify the impact on prices (qualities) of each of the many inputs (including weather conditions) and steps used in producing wine in Médoc. We show that technology and weather conditions are able to explain two thirds of the variance of prices; when reputation effects (based on the wine classification made in 1855) are included, this proportion rises to almost 85%. This suggests either that “classified” producers are able to charge higher prices, or that the classification is a measure of quality reflected by prices. We also show that two of the more recent attempts at classifying wines are not as good at explaining prices than the official (and old) 1855 classification. (JEL Classification: L66, Z19, C5, D4)
Portrait of Political Party Polarization – ERRATUM
Authors: MOODY JAMES , MUCHA PETER J.
Published: August 2013

The supplemental online material accompanying this article was not the final version. The final version is now published online. The publisher regrets the error.
Savage numbers and the evolution of civilization in Victorian prehistory
Authors: BARANY MICHAEL J.
Published: August 2013

This paper identifies ‘savage numbers’ – number-like or number-replacing concepts and practices attributed to peoples viewed as civilizationally inferior – as a crucial and hitherto unrecognized body of evidence in the first two decades of the Victorian science of prehistory. It traces the changing and often ambivalent status of savage numbers in the period after the 1858–1859 ‘time revolution’ in the human sciences by following successive reappropriations of an iconic 1853 story from Francis Galton's African travels. In response to a fundamental lack of physical evidence concerning prehistoric men, savage numbers offered a readily available body of data that helped scholars envisage great extremes of civilizational lowliness in a way that was at once analysable and comparable, and anecdotes like Galton's made those data vivid and compelling. Moreover, they provided a simple and direct means of conceiving of the progressive scale of civilizational development, uniting societies and races past and present, at the heart of Victorian scientific racism.
Gamma camera imaging for studying intestinal absorption and whole-body distribution of selenomethionine
Authors: Madsen Jan L. , Sjögreen-Gleisner Katarina , Elema Dennis R. , Søndergaard Lasse R. , Rasmussen Palle , Fuglsang Stefan , Ljungberg Michael , Damgaard Morten
Published: August 2013

Se metabolism in humans is not well characterised. Currently, the estimates of Se absorption, whole-body retention and excretion are being obtained from balance and tracer studies. In the present study, we used gamma camera imaging to evaluate the whole-body retention and distribution of radiolabelled selenomethionine (SeMet), the predominant form of Se present in foods. A total of eight healthy young men participated in the study. After consumption of a meal containing 4 MBq [75Se]l-SeMet ([75Se]SeMet), whole-body gamma camera scanning was performed for 45 min every hour over a 6 h period, every second hour for the next 18 h and once on each of the subsequent 6 d. Blood, urine and faecal samples were collected to determine the plasma content of [75Se]SeMet as well as its excretion in urine and faeces. Imaging showed that 87·9 (sd 3·3) % of the administered activity of [75Se]SeMet was retained within the body after 7 d. In contrast, the measured excretion in urine and faeces for the 7 d period was 8·2 (sd 1·1) % of the activity. Time–activity curves were generated for the whole body, stomach, liver, abdomen (other than the stomach and the liver), brain and femoral muscles. Gamma camera imaging allows for the assessment of the postprandial absorption of SeMet. This technique may also permit concurrent studies of organ turnover of SeMet.
Opening to the East: Shipping Between Europe and Asia, 1770–1830
Authors: Solar Peter M.
Published: August 2013

Shipping costs between Europe and Asia were reduced by two-thirds between the 1770s and the 1820s. Copper sheathing and other technical improvements which allowed ships to make more frequent voyages over longer lifetimes accounted for part of the cost reduction. British hegemony in the Indian Ocean, which ended an eighteenth-century arms race, accounted for the rest by allowing the substitution of smaller ships which cost less to build and required fewer men per ton. These changes were at least as important as the elimination of monopoly profits in narrowing intercontinental price differentials during the early nineteenth century.
A Dam Problem: TVA's Fight Against Malaria, 1926–1951
Authors: Kitchens Carl
Published: August 2013

The TVA has been applauded for its anti-malaria programs in the Southeast during the 1930s and 1940s. However, the TVA developed their anti-malaria programs because they created lakes suitable for mosquito breeding. To estimate the relationship between the TVA and malaria, I construct a county-level panel data from the Southeast United States. I find that the net effect of the TVA was to increase malaria rates following its construction. Using statistical life value estimates, I find that the hidden malaria cost of the TVA offset 24 percent of the fiscal stimulus multiplier generated by the TVA.
Taste Endures! The Rankings of Roger de Piles (†1709) and Three Centuries of Art Prices
Authors: Graddy Kathryn
Published: August 2013

Roger de Piles (1635–1709) was a French art critic who decomposed the style and ability of 58 different artists into areas of composition, drawing, color, and expression, rating each artist on a 20-point scale in each category. Based on evidence from two data sets that together span from the mid-eighteenth century to the present, this article shows that De Piles' overall ratings have withstood the test of a very long period of time, with estimates indicating that the works of his higher-rated artists achieved both greater returns and higher critical acclaim than the works of his lower-rated artists.
Exact solution to neutrino-plasma two-flavor dynamics
Authors: HAAS FERNANDO , MENDONÇA JOSÉ T.
Published: August 2013

It is shown that the two-flavor neutrino oscillation equations admit an exact analytic solution for arbitrarily chosen normalized electron neutrino population, provided the electron plasma density is adjusted in a certain way. The associated formula for the electron plasma density is applied to the cases of exponentially decaying or oscillating electron neutrino populations.
Target-based drug discovery for human African trypanosomiasis: selection of molecular target and chemical matter
Authors: GILBERT IAN H.
Published: August 2013

Target-based approaches for human African trypanosomiasis (HAT) and related parasites can be a valuable route for drug discovery for these diseases. However, care needs to be taken in selection of both the actual drug target and the chemical matter that is developed. In this article, potential criteria to aid target selection are described. Then the physiochemical properties of typical oral drugs are discussed and compared to those of known anti-parasitics.
Parity of esteem begins at home: translating empirical psychiatric research into effective public mental health
Authors: Kirkbride J. B. , Jones P. B.
Published: August 2013

There is increasing recognition that parity of esteem between mental and physical health disorders is essential to improve the course, outcome and quality of life of individuals within different populations. Achieving this parity now underpins the objectives of several nations. Here, we argue that parity of esteem between mental and physical health can only be realized when parity of esteem also exists across mental health disorders, particularly in terms of service commissioning and planning. Using first-episode psychosis and early intervention in psychosis services as a motivating example, we demonstrate how carefully conducted psychiatric epidemiology can be translated to develop precise forecasts of the anticipated incidence of first-episode psychosis in different populations, based on an understanding of underlying local needs and inequalities. Open-access prediction tools such as PsyMaptic will allow commissioners of mental health services to more effectively allocate resources across services, based on empirical evidence and local need, thus reducing inequalities in access to mental health care.
Crises and Crashes: Argentina 1825-2002
Authors: Cerro Ana María , Meloni Osvaldo
Published: August 2013

The objective of this paper is twofold. First, it identifies and categorizes the currency crises suffered by Argentina from 1825 to 2002. Second, it looks for regularities in the behaviour of key macroeconomic variables in the neighbourhood of crises by means of graphic analysis, non-parametric and econometric techniques. We found that expansions in public expenditures as well as increases in the debt to GDP ratio and falls in the rate of growth of bank deposits contribute to spur the probability of crisis. Unfavourable external conditions, jointly with domestic imbalances, help to explain very deep crises or crashes.
Forest ecosystem services and biodiversity in contrasting Himalayan forest management systems
Authors: MÅREN INGER E. , BHATTARAI KHEM R. , CHAUDHARY RAM P.
Published: August 2013

In developing countries, the landscape surrounding agricultural land is important for maintaining biodiversity and providing ecosystem services. Forests provide a full suite of goods and services to subsistence farmers in the Himalayan agro-ecological system. The effects of biomass outtake on woody species richness and composition were analysed in forests under communal and government management. Interviews on forest use and perception of forest condition and ecosystem service delivery were conducted in farmer households bordering the forests. Significantly more woody species were found in the community managed forests. Species richness was negatively correlated with walking distance from the nearest village and increasing levels of anthropogenic disturbance. Community forests were generally less degraded than government managed forests, giving support to common pool resource management. Woody vegetation represented a crucial source of fuelwood, timber, fodder, and edible, aromatic and medicinal plants. Using a multidisciplinary framework to analyse ecosystem integrity and ecosystem service delivery enabled a finer understanding of these complex agro-ecological systems, giving support to evidence-based management and conservation planning for the future.
(In-)stability of singular equivariant solutions to the Landau–Lifshitz–Gilbert equation
Authors: VAN DEN BERG JAN BOUWE , WILLIAMS J. F.
Published: August 2013

In this paper, we use formal asymptotic arguments to understand the stability properties of equivariant solutions to the Landau–Lifshitz–Gilbert model for ferromagnets. We also analyse both the harmonic map heatflow and Schrödinger map flow limit cases. All asymptotic results are verified by detailed numerical experiments, as well as a robust topological argument. The key result of this paper is that blowup solutions to these problems are co-dimension one and hence both unstable and non-generic.
THYROTOXICOSIS IN PREGNANCY
Authors: WRIGHT H V , WILLIAMS D J
Published: August 2013

Thyrotoxicosis affects approximately 1:500 women of reproductive age. Untreated or poorly controlled thyrotoxicosis in pregnancy is associated with significant maternal and perinatal morbidity. Recognition and diagnosis of new onset thyrotoxicosis in pregnancy can be challenging as many of the symptoms can be misattributed to physiological adaptation of normal pregnancy. Women with hyperemesis gravidarum (HG) often have biochemical, but not clinical evidence of thyrotoxicosis, which does not need treatment with anti-thyroid drugs (ATDs). For women with clinical thyrotoxicosis, uncertainty regarding the risks of teratogenicity due to ATDs has led to new guideline recommendations for their use in pregnancy. Women with autoimmune diseases such as type I diabetes and who have thyroid peroxidase antibodies (TPOAb) are at an increased risk of developing postpartum thyroiditis, which can result in permanent hypothyroidism. This review summarises the management of thyrotoxicosis in pregnancy and highlights controversial areas for which conclusive evidence is still lacking.
Effect of mood stabilizers on DNA methylation in human neuroblastoma cells
Authors: Asai Tatsuro , Bundo Miki , Sugawara Hiroko , Sunaga Fumiko , Ueda Junko , Tanaka Gen , Ishigooka Jun , Kasai Kiyoto , Kato Tadafumi , Iwamoto Kazuya
Published: August 2013

Unraveling the epigenetic status of neuronal cells in the brain is critical to our understanding of the pathophysiology of psychiatric disorders, which may reflect a complex interaction between genetic and environmental factors. Several epigenetic studies of mood disorders have been conducted with postmortem brains. However, proper interpretation of the results is hampered by our scant understanding of the effects of mood stabilizers on the epigenetic status of neuronal cells. We performed both comprehensive and gene-specific analyses to examine DNA methylation in human neuroblastoma SK-N-SH cells treated with three mood stabilizers: lithium, valproate and carbamazepine. Measurement of the level of DNA methylation of about 27 000 CpG sites revealed a profound epigenetic effect of lithium, compared with the two other mood stabilizers. In addition, we found that the mood stabilizers have common epigenetic targets and a propensity to increase DNA methylation. Gene-specific analysis involved detailed analysis of the methylation of promoter regions of SLC6A4 and BDNF, both of which have been reported to show altered DNA methylation in bipolar disorder patients or suicide victims, by extensive bisulfite sequencing. We did not observe significant changes in DNA methylation at BDNF promoter IV. However, we found that CpG sites of SLC6A4, which were hypermethylated in patients with bipolar disorder, were hypomethylated in the neuroblastoma cells treated with mood stabilizers. Our results will contribute to a better understanding of the epigenetic changes associated with mood disorders, and they also provide new insight into the mechanisms of action of mood stabilizers.
Complexity of super-coherence problems in ASP
Authors: ALVIANO MARIO , FABER WOLFGANG , WOLTRAN STEFAN
Published: August 2013

Adapting techniques from database theory in order to optimize Answer Set Programming (ASP) systems, and in particular the grounding components of ASP systems, is an important topic in ASP. In recent years, the Magic Set method has received some interest in this setting, and a variant of it, called Dynamic Magic Set, has been proposed for ASP. However, this technique has a caveat, because it is not correct (in the sense of being query-equivalent) for all ASP programs. In a recent work, a large fragment of ASP programs, referred to assuper-coherent programs, has been identified, for which Dynamic Magic Set is correct. The fragment contains all programs which possess at least one answer set, no matter which set of facts is added to them. Two open question remained: How complex is it to determine whether a given program is super-coherent? Does the restriction to super-coherent programs limit the problems that can be solved? Especially the first question turned out to be quite difficult to answer precisely. In this paper, we formally prove that deciding whether a propositional program is super-coherent is Π3P-complete in the disjunctive case, while it is Π2P-complete for normal programs. The hardness proofs are the difficult part in this endeavor: We proceed by characterizing the reductions by the models and reduct models which the ASP programs should have, and then provide instantiations that meet the given specifications. Concerning the second question, we show that all relevant ASP reasoning tasks can be transformed into tasks over super-coherent programs, although this transformation is more of theoretical than practical interest.
Optimal multibinding unification for sharing and linearity analysis
Authors: AMATO GIANLUCA , SCOZZARI FRANCESCA
Published: August 2013

In the analysis of logic programs, abstract domains for detecting sharing properties are widely used. Recently, the new domain ${\mathtt{ShLin}^{\omega}}$ has been introduced to generalize both sharing and linearity information. This domain is endowed with an optimal abstract operator for single-binding unification. The authors claim that the repeated application of this operator is also optimal for multibinding unification. This is the proof of such a claim.
Barriers and bridges to the adoption of biodegradable plastic mulches for US specialty crop production
Authors: Goldberger Jessica R. , Jones Robert Emmet , Miles Carol A. , Wallace Russell W. , Inglis Debra A.
Published: August 2013

Commercial farmers have been using polyethylene plastic mulch since the 1950s. Despite the affordability and effectiveness of polyethylene mulch, the disposal process is financially and environmentally costly. Biodegradable plastic mulches, an ecologically sustainable alternative to polyethylene mulch films, were introduced in the 1980s. Biodegradable plastic mulches can be tilled into the soil or composted at the end of the season, reducing the labor and environmental costs associated with plastic removal and disposal. However, research results are mixed as to the effectiveness, degradability and ease-of-use of biodegradable plastic mulches. In 2008–2012, researchers, funded by a USDA Specialty Crop Research Initiative grant, conducted surveys and focus groups in three different agricultural regions of the USA to better understand the barriers and bridges to the adoption of biodegradable plastic mulches for specialty crop production systems. Data on the experiences and views of specialty crop growers, agricultural extension agents, agricultural input suppliers, mulch manufacturers and other stakeholders showed that the major adoption barriers were insufficient knowledge, high cost and unpredictable breakdown. The major bridges to adoption were reduced waste, environmental benefits and interest in further learning. These findings are discussed with reference to the classic innovation diffusion model, specifically work on the innovation–decision process and the attributes of innovations. The study results can be used to guide the activities of those involved in the design, development and promotion of biodegradable plastic mulches for US specialty crop production systems.
Heritability of Resting State EEG Functional Connectivity Patterns
Authors: Schutte Nienke M. , Hansell Narelle K. , de Geus Eco J. C. , Martin Nicholas G. , Wright Margaret J. , Smit Dirk J. A.
Published: August 2013

We examined the genetic architecture of functional brain connectivity measures in resting state electroencephalographic (EEG) recordings. Previous studies in Dutch twins have suggested that genetic factors are a main source of variance in functional brain connectivity derived from EEG recordings. In addition, qualitative descriptors of the brain network derived from graph analysis — network clustering and average path length — are also heritable traits. Here we replicated previous findings for connectivity, quantified by the synchronization likelihood, and the graph theoretical parameters cluster coefficient and path length in an Australian sample of 16-year-old twins (879) and their siblings (93). Modeling of monozygotic and dizygotic twins and sibling resemblance indicated heritability estimates of the synchronization likelihood (27–74%) and cluster coefficient and path length in the alpha and theta band (40–44% and 23–40% respectively) and path length in the beta band frequency (41%). This corroborates synchronization likelihood and its graph theoretical derivatives cluster coefficient and path length as potential endophenotypes for behavioral traits and neurological disorders.
STAT3 promotes corticospinal remodelling and functional recovery after spinal cord injury
Authors: Lang Claudia , Bradley Peter M , Jacobi Anne , Kerschensteiner Martin , Bareyre Florence M
Published: August 2013

If and how neurons remodel their connections after CNS injury critically influences recovery of function. Here, we investigate the role of the growth‐initiating transcription factor STAT3 during remodelling of the injured corticospinal tract (CST). Endogenous STAT3 expression in lesioned cortical projection neurons is transient but can be sustained by viral gene transfer. Sustained activation of STAT3 enhances remodelling of lesioned CST fibres and induces de novo formation of collaterals from unlesioned CST fibres. In a unilateral pyramidotomy paradigm, this recruitment of unlesioned fibres leads to the formation of midline crossing circuits that establish ipsilateral forelimb activation and functional recovery.
Sirtuins and ageing—new findings
Authors: Guarente Leonard
Published: August 2013

Sirtuins are a promising avenue for orally administered drugs that might deliver the anti‐aging benefits normally provided by calorie restriction.
Quantum Corrections Crossover and Ferromagnetism in Magnetic Topological Insulators
Authors: Bao Lihong , Wang Weiyi , Meyer Nicholas , Liu Yanwen , Zhang Cheng , Wang Kai , Ai Ping , Xiu Faxian
Published: August 2013

Revelation of emerging exotic states of topological insulators (TIs) for future quantum computing applications relies on breaking time-reversal symmetry and opening a surface energy gap. Here, we report on the transport response of Bi2Te3 TI thin films in the presence of varying Cr dopants. By tracking the magnetoconductance (MC) in a low doping regime we observed a progressive crossover from weak antilocalization (WAL) to weak localization (WL) as the Cr concentration increases. In a high doping regime, however, increasing Cr concentration yields a monotonically enhanced anomalous Hall effect (AHE) accompanied by an increasing carrier density. Our results demonstrate a possibility of manipulating bulk ferromagnetism and quantum transport in magnetic TI, thus providing an alternative way for experimentally realizing exotic quantum states required by spintronic applications.
Synthesis of high molar mass poly(n-butyl acrylate) and poly(2-ethylhexyl acrylate) by SET-LRP in mixtures of fluorinated alcohols with DMSO
Authors: Samanta Shampa R. , Percec Virgil
Published: August 2013

SET-LRP ofn-butyl acrylate (nBA) and 2-ethylhexyl acrylate (EHA) initiated with bis(2-bromopropionyl)ethane (BPE) to synthesize high molar mass poly(nBA) and poly(EHA) was carried out in binary mixtures of 2,2,2-trifluoroethanol (TFE) or 2,2,3,3-tetrafluoropropanol (TFP) with DMSO at 50 °C.
Mitochondrial genetic background modulates bioenergetics and susceptibility to acute cardiac volume overload
Authors: Fetterman Jessica L. , Zelickson Blake R. , Johnson Larry W. , Moellering Douglas R. , Westbrook David G. , Pompilius Melissa , Sammy Melissa J. , Johnson Michelle , Dunham-Snary Kimberly J. , Cao Xuemei , Bradley Wayne E. , Zhang Jinju , Wei Chih-Chang , Chacko Balu , Schurr Theodore G. , Kesterson Robert A. , Dell’italia Louis J. , Darley-Usmar Victor M. , Welch Danny R. , Ballinger Scott W.
Published: August 2013

Dysfunctional bioenergetics has emerged as a key feature in many chronic pathologies such as diabetes and cardiovascular disease. This has led to the mitochondrial paradigm in which it has been proposed that mtDNA sequence variation contributes to disease susceptibility. In the present study we show a novel animal model of mtDNA polymorphisms, the MNX (mitochondrial–nuclear exchange) mouse, in which the mtDNA from the C3H/HeN mouse has been inserted on to the C57/BL6 nuclear background and vice versa to test this concept. Our data show a major contribution of the C57/BL6 mtDNA to the susceptibility to the pathological stress of cardiac volume overload which is independent of the nuclear background. Mitochondria harbouring the C57/BL6J mtDNA generate more ROS (reactive oxygen species) and have a higher mitochondrial membrane potential relative to those with C3H/HeN mtDNA, independent of nuclear background. We propose this is the primary mechanism associated with increased bioenergetic dysfunction in response to volume overload. In summary, these studies support the ‘mitochondrial paradigm’ for the development of disease susceptibility, and show that the mtDNA modulates cellular bioenergetics, mitochondrial ROS generation and susceptibility to cardiac stress.
Stochastic and deterministic causes of streamer branching in liquid dielectrics
Authors: Jadidian Jouya , Zahn Markus , Lavesson Nils , Widlund Ola , Borg Karl
Published: August 2013

Streamer branching in liquid dielectrics is driven by stochastic and deterministic factors. The presence of stochastic causes of streamer branching such as inhomogeneities inherited from noisy initial states, impurities, or charge carrier density fluctuations is inevitable in any dielectric. A fully three-dimensional streamer model presented in this paper indicates that deterministic origins of branching are intrinsic attributes of streamers, which in some cases make the branching inevitable depending on shape and velocity of the volume charge at the streamer frontier. Specifically, any given inhomogeneous perturbation can result in streamer branching if the volume charge layer at the original streamer head is relatively thin and slow enough. Furthermore, discrete nature of electrons at the leading edge of an ionization front always guarantees the existence of a non-zero inhomogeneous perturbation ahead of the streamer head propagating even in perfectly homogeneous dielectric. Based on the modeling results for streamers propagating in a liquid dielectric, a gauge on the streamer head geometry is introduced that determines whether the branching occurs under particular inhomogeneous circumstances. Estimated number, diameter, and velocity of the born branches agree qualitatively with experimental images of the streamer branching.
Potential and flux field landscape theory. I. Global stability and dynamics of spatially dependent non-equilibrium systems
Authors: Wu Wei , Wang Jin
Published: August 2013

We established a potential and flux field landscape theory to quantify the global stability and dynamics of general spatially dependent non-equilibrium deterministic and stochastic systems. We extended our potential and flux landscape theory for spatially independent non-equilibrium stochastic systems described by Fokker-Planck equations to spatially dependent stochastic systems governed by general functional Fokker-Planck equations as well as functional Kramers-Moyal equations derived from master equations. Our general theory is applied to reaction-diffusion systems. For equilibrium spatially dependent systems with detailed balance, the potential field landscape alone, defined in terms of the steady state probability distribution functional, determines the global stability and dynamics of the system. The global stability of the system is closely related to the topography of the potential field landscape in terms of the basins of attraction and barrier heights in the field configuration state space. The effective driving force of the system is generated by the functional gradient of the potential field alone. For non-equilibrium spatially dependent systems, the curl probability flux field is indispensable in breaking detailed balance and creating non-equilibrium condition for the system. A complete characterization of the non-equilibrium dynamics of the spatially dependent system requires both the potential field and the curl probability flux field. While the non-equilibrium potential field landscape attracts the system down along the functional gradient similar to an electron moving in an electric field, the non-equilibrium flux field drives the system in a curly way similar to an electron moving in a magnetic field. In the small fluctuation limit, the intrinsic potential field as the small fluctuation limit of the potential field for spatially dependent non-equilibrium systems, which is closely related to the steady state probability distribution functional, is found to be a Lyapunov functional of the deterministic spatially dependent system. Therefore, the intrinsic potential landscape can characterize the global stability of the deterministic system. The relative entropy functional of the stochastic spatially dependent non-equilibrium system is found to be the Lyapunov functional of the stochastic dynamics of the system. Therefore, the relative entropy functional quantifies the global stability of the stochastic system with finite fluctuations. Our theory offers an alternative general approach to other field-theoretic techniques, to study the global stability and dynamics of spatially dependent non-equilibrium field systems. It can be applied to many physical, chemical, and biological spatially dependent non-equilibrium systems.
Stopping and transport of fast electrons in superdense matter
Authors: Okabayashi A. , Habara H. , Yabuuchi T. , Iwawaki T. , Tanaka K. A.
Published: August 2013

Studied is the stopping and transport of relativistic fast electrons in the vicinity of compressed dense plasma core relevant to fast ignition. Electromagnetic cascade Monte-Carlo is coupled to 2D-PIC simulation. The 2D PIC simulates input electron energy spectrum and angular dependence. The electron energy distributions after passing through the plasma core are calculated at different viewing angles, which well agree with the experiment below several MeV energy range. The implications of calculated results as to collisional damping on several MeV electrons are discussed with the theory based on the stopping power model. The spatial distribution of plasma temperature is also estimated via deposited energy by fast electrons, showing the strong heating at the core surface.
Modification of the mean near-wall velocity profile of a high-Reynolds number turbulent boundary layer with the injection of drag-reducing polymer solutions
Authors: Elbing Brian R. , Perlin Marc , Dowling David R. , Ceccio Steven L.
Published: August 2013

The current study explores the influence of polymer drag reduction on the near-wall velocity distribution in a turbulent boundary layer (TBL) and its dependence on Reynolds number. Recent moderate Reynolds number direct numerical simulation and experimental studies presented in White et al. [Phys. Fluids 24, 021701 (2012)]10.1063/1.3681862 have challenged the classical representation of the logarithmic dependence of the velocity profile for drag-reduced flows, especially at drag reduction levels above 40%. In the present study, high Reynolds number data from a drag reduced TBL is presented and compared to the observations of White et al. [Phys. Fluids 24, 021701 (2012)]10.1063/1.3681862. Data presented here were acquired in the TBL flow on a 12.9-m-long flat plate at speeds to 20.3 m s−1, achieving momentum thickness based Reynolds number to 1.5 × 105, which is an order of magnitude greater than that available in the literature. Polyethylene oxide solutions with an average molecular weight of 3.9 × 106 g mol−1 were injected into the flow at various concentrations and volumetric fluxes to achieve a particular level of drag reduction. The resulting mean near-wall velocity profiles show distinctly different behavior depending on whether they fall in the low drag reduction (LDR) or the high drag reduction (HDR) regimes, which are nominally divided at 40% drag reduction. In the LDR regime, the classical view that the logarithmic slope remains constant at the Newtonian value and the intercept constant increases with increasing drag reduction appears to be valid. However, in the HDR regime the behavior is no longer universal. The intercept constant continues to increase linearly in proportion to the drag reduction level until a Reynolds-number-dependent threshold is achieved, at which point the intercept constant rapidly decreases to that predicted by the ultimate profile. The rapid decrease in the intercept constant is due to the corresponding increase in the profile slope in the HDR regime. There was significant scatter in the observed slope in the HDR regime, but the scatter did not appear to be Reynolds number dependent. Finally, the ultimate profiles for flows at maximum drag reduction were examined and did not exhibit a logarithmic functional relationship, which is the classical empirical relationship suggested by Virk [J. Am. Inst. Chem. Eng. 21, 625–656 (1975)]10.1002/aic.690210402.
Computation of transit times using the milestoning method with applications to polymer translocation
Authors: Hawk Alexander T. , Konda Sai Sriharsha M. , Makarov Dmitrii E.
Published: August 2013

Milestoning is an efficient approximation for computing long-time kinetics and thermodynamics of large molecular systems, which are inaccessible to brute-force molecular dynamics simulations. A common use of milestoning is to compute the mean first passage time (MFPT) for a conformational transition of interest. However, the MFPT is not always the experimentally observed timescale. In particular, the duration of the transition path, or the mean transit time, can be measured in single-molecule experiments, such as studies of polymers translocating through pores and fluorescence resonance energy transfer studies of protein folding. Here we show how to use milestoning to compute transit times and illustrate our approach by applying it to the translocation of a polymer through a narrow pore.
Tunneling splittings in vibronic energy levels of ${\rm CH}_{\rm 3} {\rm F}^{\rm + } \left( {{\rm \tilde X}{}^{\rm 2}{\rm E}} \right)$ CH 3F+X̃2E studied by high resolution photoelectron spectroscopy and ab initio calculation
Authors: Gao Shuming , Dai Zuyang , Sun Wei , Li Hua , Wang Jia , Mo Yuxiang
Published: August 2013

The energy levels of ${\rm CH}_{\rm 3} {\rm F}^{\rm + } \left( {{\rm \tilde X}{}^{\rm 2}{\rm E}} \right)$ CH 3F+X̃2E, which show strong vibronic coupling effect (Jahn-Teller effect), have been measured up to 3500 cm−1 above the ground vibrational state using one-photon zero-kinetic energy photoelectron spectroscopic method. Theoretical calculations have also been performed to calculate the spin-vibronic energy levels using a diabatic model and ab initio adiabatic potential energy surfaces (APESs) including the energy gradients and derivative couplings between the APESs. The calculations showed that the tunneling splittings of the vibrational energy levels occur due to the deep potential energy wells formed by the Jahn-Teller deformation. The calculated spin-vibronic energy levels are in good agreement with the experimental data. For example, the energy splitting for the first excited vibrational energy level is calculated as 111 cm−1 that is confirmed by the experimental value. The experimental spectrum was assigned based on the fundamental vibrational modes calculated at the energy minimum. The fundamental vibrational modes related to the H–C–F bending, H–C–H bending, C–F stretching, and C–H stretching vibrations have been observed.
Excited states of aniline by photoabsorption spectroscopy in the 30 000–90 000 cm−1 region using synchrotron radiation
Authors: Rajasekhar B. N. , Veeraiah A. , Sunanda K. , Jagatap B. N.
Published: August 2013

The photoabsorption spectrum of aniline (C6H5NH2) in gas phase in the 30 000–90 000 cm−1 (3.7–11.2 eV) region is recorded at resolution limit of 0.008 eV using synchrotron radiation source for the first time to comprehend the nature of the excited valence and Rydberg states. The first half of the energy interval constitutes the richly structured valence transitions from the ground to excited states up to the first ionization potential (IP) at 8.02 eV. The spectrum in the second half consists of vibrational features up to second IP (9.12 eV) and structureless broad continuum up to the third IP (10.78 eV). The electronic states are assigned mainly to the singlets belonging to π → π* transitions. A few weak initial members of Rydberg states arising from π → 4s, np or nd transitions are also identified. Observed vibrational features are assigned to transitions from the ground state A′ to the excited states 1A″, 3A′, 5A,″ 6A′, and 10A″ in Cs symmetry. Time dependent density functional theory (TDDFT) calculations at B3LYP level of theory are employed to obtain the vertical excitation energies and the symmetries of the excited states in equilibrium configuration. The computed values of the transition energies agree fairly well with the experimental data. Further the calculated oscillator strengths are used to substantiate the assignments of the bands. The work provides a comprehensive picture of the vacuum ultraviolet photoabsorption spectrum of aniline up to its third ionization limit.
2-dimensional ion velocity distributions measured by laser-induced fluorescence above a radio-frequency biased silicon wafer
Authors: Moore Nathaniel B. , Gekelman Walter , Pribyl Patrick , Zhang Yiting , Kushner Mark J.
Published: August 2013

The dynamics of ions traversing sheaths in low temperature plasmas are important to the formation of the ion energy distribution incident onto surfaces during microelectronics fabrication. Ion dynamics have been measured using laser-induced fluorescence (LIF) in the sheath above a 30 cm diameter, 2.2 MHz-biased silicon wafer in a commercial inductively coupled plasma processing reactor. The velocity distribution of argon ions was measured at thousands of positions above and radially along the surface of the wafer by utilizing a planar laser sheet from a pulsed, tunable dye laser. Velocities were measured both parallel and perpendicular to the wafer over an energy range of 0.4–600 eV. The resulting fluorescence was recorded using a fast CCD camera, which provided resolution of 0.4 mm in space and 30 ns in time. Data were taken at eight different phases during the 2.2 MHz cycle. The ion velocity distributions (IVDs) in the sheath were found to be spatially non-uniform near the edge of the wafer and phase-dependent as a function of height. Several cm above the wafer the IVD is Maxwellian and independent of phase. Experimental results were compared with simulations. The experimental time-averaged ion energy distribution function as a function of height compare favorably with results from the computer model.
A circuit analysis of an in situ tunable radio-frequency quantum point contact
Authors: Müller T. , Choi T. , Hellmüller S. , Ensslin K. , Ihn T. , Schön S.
Published: August 2013

A detailed analysis of the tunability of a radio-frequency quantum point contact setup using a C − LCR circuit is presented. We calculate how the series capacitance influences resonance frequency and charge-detector resistance for which matching is achieved as well as the voltage and power delivered to the load. Furthermore, we compute the noise contributions in the system and compare our findings with measurements taken with an etched quantum point contact. While our considerations mostly focus on our specific choice of matching circuit, the discussion of the influence of source-to-load power transfer on the signal-to-noise ratio is valid generally.
Equilibrium configuration of the 1u state of hydrogen molecular ion in a magnetic field
Authors: Song Xuanyu , Gong Cheng , Wang Xiaofeng , Qiao Haoxue
Published: August 2013

Using the variational method based on the Gaussian basis set, the authors investigate the 1u state of hydrogen molecular ion in a non-parallel magnetic field with respect to the fixed molecular axis. At sufficiently small field strength, the equilibrium configuration prefers the perpendicular orientation, in which the (relative) orientation θ between the magnetic field and the molecular axis is 90°. With increasing field strength, the orientation θ of the equilibrium configuration decreases, and is neither the parallel orientation nor the perpendicular orientation at field strength between 109 G and 2.35 × 1010 G. Meanwhile, more and more configurations with large orientations become unstable with respect to the dissociation H + p.
Distinguishing features of shallow angle plunging jets
Authors: Deshpande Suraj S. , Trujillo Mario F.
Published: August 2013

Numerical simulations employing an algebraic volume-of-fluid methodology are used to study the air entrainment characteristics of a water jet plunging into a quiescent water pool at angles ranging from θ = 10° to θ = 90° measured from the horizontal. Our previous study of shallow angled jets [S. S. Deshpande, M. F. Trujillo, X. Wu, and G. L. Chahine, “Computational and experimental characterization of a liquid jet plunging into a quiescent pool at shallow inclination,” Int. J. Heat Fluid Flow 34, 1–14 (2012)]10.1016/j.ijheatfluidflow.2012.01.011 revealed the existence of a clearly discernible frequency of ingestion of large air cavities. This is in contrast with chaotic entrainment of small air pockets reported in the literature in case of steeper or vertically plunging jets. In the present work, the differences are addressed by first quantifying the cavity size and entrained air volumes for different impingement angles. The results support the expected trend – reduction in cavity size (D43) as θ is increased. Time histories of cavity volumes in the vicinity of the impingement region confirm the visual observations pertaining to a near-periodic ingestion of large air volumes for shallow jets (10°, 12°), and also show that such cavities are not formed for steep or vertical jets. Each large cavity (defined as Dc/Dj ≳ 3) exists in close association with a stagnation point flow. A local mass and momentum balance shows that the high stagnation pressure causes a radial redirection of the jet, resulting in a flow that resembles the initial impact of a jet on the pool. In fact, for these large cavities, their speed matches closely Uimpact/2, which coincides with initial cavity propagation for sufficiently high Froude numbers. Furthermore, it is shown that the approximate periodicity of air entrainment scales linearly with Froude number. This finding is confirmed by a number of simulations at θ = 12°. Qualitatively, for steeper jets, such large stagnation pressure region does not exist, and the deflection of the entire incoming jet is non-existent. In fact, for θ = 25°, 45°, 90°, the jet penetrates the pool nearly undisturbed and consequently large cavities are not formed.
Large time behavior for the support of momentum density of the Camassa-Holm equation
Authors: Jiang Zaihong , Zhou Yong , Zhu Mingxuan
Published: August 2013

In this paper we study the large time behavior for the support of momentum density of the Camassa-Holm equation. More precisely, we deduce the limit of the support of momentum density as t goes to +∞ in some sense.
Local structures and structural phase change in Ni-Zr-Nb glassy alloys composed of Ni5Zr5Nb3 icosahedral clusters
Authors: Fujima Nobuhisa , Hoshino Toshiharu , Fukuhara Mikio
Published: August 2013

We construct a local structural model for Ni-Zr-Nb glassy alloys, Ni48Zr40Nb24, which contains eight icosahedra of Ni5Zr5Nb3 as the structural units. We fully optimize the 112-atom structures by first principles calculation, and find two characteristic phases in the structures depending on the alignment of the icosahedra: an amorphous phase where the icosahedral structure well remains and a periodic phase corresponding to crystallization where the icosahedra change to fcc-like cuboctahedra. Nb atom-clustering may play a key role in anti-crystallization.
The influence of strain on dewetting of silicon films
Authors: Borowik Łukasz , Chevalier Nicolas , Mariolle Denis , Bertin François , Chabli Amal , Barbé Jean-Charles
Published: August 2013

The influence of strain on the thermally induced dewetting mechanism of silicon films is reported. This study shows that the initial strain level in the silicon film significantly affects the final size and shape of the silicon agglomerates resulting from the film dewetting. With the increase of the biaxial strain up to 1.6%, the size of the silicon agglomerates is significantly reduced while their density increases. Moreover, the shape of the agglomerates becomes elongated when the strain favors one of the in-plane crystallographic directions to minimize the total energy of the system. A quantitative analysis of the dewetting mechanism is presented in terms of the agglomerates size and density versus the strain level. Finally, phenomenological laws are extracted, which predict the size and shape of the agglomerates.
Generation of alkali-free and high-proton concentration layer in a soda lime glass using non-contact corona discharge
Authors: Ikeda Hiroshi , Sakai Daisuke , Funatsu Shiro , Yamamoto Kiyoshi , Suzuki Toshio , Harada Kenji , Nishii Junji
Published: August 2013

Formation mechanisms of alkali-free and high-proton concentration surfaces were investigated for a soda lime glass using a corona discharge treatment under an atmospheric pressure. Protons produced by high DC voltage around an anode needle electrode were incorporated into a sodium ion site in the anode side glass. The sodium ion was swept away to the cathode side as a charge carrier. Then it was discharged. The precipitated sodium was transformed to a Na2CO3 powder when the surface contacted with air. The sodium ion in the glass surface layer of the anode side was replaced completely by protons. The concentration of OH groups in the layer was balanced with the amount of excluded sodium ions. The substitution reaction of sodium ions with protons tends to be saturated according to a square root function of time. The alkali depletion layer formation rate was affected by the large difference in mobility between sodium ions and protons in the glass.
Release path temperatures of shock-compressed tin from dynamic reflectance and radiance measurements
Authors: La Lone B. M. , Stevens G. D. , Turley W. D. , Holtkamp D. B. , Iverson A. J. , Hixson R. S. , Veeser L. R.
Published: August 2013

Dynamic reflectance and radiancemeasurements were conducted for tin samples shock compressed to 35 GPa and released to 15 GPa using high explosives. We determined the reflectance of the tin samples glued to lithium fluoride windows using an integrating sphere with an internal xenon flashlamp as an illumination source. The dynamic reflectance (R) was determined at near normal incidence in four spectralbands with coverage in visible and near-infrared spectra.Uncertainties in R/R0 are <2%, and uncertainties in absolute reflectance are<5%. In complementary experiments, thermal radiance from the tin/glue/lithium fluoride interface was recorded with similar shock stress and spectral coverage as the reflectance measurements. The two sets of experiments were combined to obtain the temperature history of the tin surface with an uncertainty of <2%. The stress at the interface was determined from photonic Doppler velocimetry and combined with the temperatures to obtain temperature-stress release paths for tin. We discuss the relationship between the experimental release paths and release isentropes that begin on the principal shock Hugoniot.