cssi/SciSciGPT-SciSciNet huggingface dataset:
Synthesis and Crystal Structure of Octahydro‐5H,12H‐4,11‐methano‐1H,7H‐bis[1,2,5]oxadiazolo[3,4‐d:3′,4′‐j][1,7,3,9]dioxadiazacyclododecine

The unusual 12-membered ring compound, octahydro-5H,12H-4,11-methano-1H,7H-bis[1,2,5]oxadiazolo[3,4-d:3′,4′-j][1,7,3,9]dioxadiazacyclododecine is obtained from the acid catalyzed reaction of 3-amino-4-hydroxymethylfurazan with formaldehyde instead of the expected methylene-bridged compound, 4,4′-methylenebis[4,5-dihydro-7H-[1,2,5]oxadiazolo[3,4-d][1,3]oxazine]. The compound crystallizes in Tetragonal, P43212, a = 6.4141(4) A, b = 6.4141(4) A, c = 26.525(3) A, α = 90°, β = 90°, γ = 90°, V = 1091.27(16) A3, Z = 4, dcalc = 1.614 Mg/m3.
Proper-time methods in the presence of non-constant background fields

A formalism is developed to enable the construction of the effective action and related quantities in QED for the case of time-varying background electric fields. Some examples are studied and evidence is sought for a possible transition to a phase in which chiral symmetry is spontaneously broken.
Dynamically reconfigurable vision-based user interfaces

We describe a system that supports practical, vision-based user interfaces, addressing the issues of a usable interaction paradigm, support for application developers, and support for application deployment in real-world environments. Interfaces are defined as configurations of predefined interactive widgets that can be moved from one surface to another. Complex interfaces can be dynamically reconfigured, changing both form and location on the fly, because the functional definition of the interface is decoupled from the specification of its location in the environment. We illustrate the power of such an architecture in the context of projected interactive displays.
Graffiti goes to the movies: American fictional films featuring graffiti artists/writers and themes

Since the early 1980s, in addition to the increase in graffiti and street art in many urban contexts, a number of movies have been made that have either examined this phenomenon and the people who engage in this activity, or used graffiti and street art as a backdrop to tell a story. This article briefly reviews the scholarly literature that examines movies that portray criminals and criminal actions, and then analyzes seven American-produced fictional (drama) films using graffiti writers/artists as major characters and then draws generalizations about them. Although this is not a semiotic analysis of the films, to the extent possible, it delves into the settings, plots, characters, dialog, and how realistic the movies appear to be. In general, most of the films include unrealistic aspects and/or are of poor quality, and this contributes to misrepresentations of and stereotypes about graffiti writers/writing.
The Best-Fit Universe

Inflation provides very strong motivation for a flat Universe, Harrison-Zel’dovich (constant-curvature) density perturbations, and cold dark matter. However, there are a number of cosmological observations that conflict with the predictions of the simplest such model—one with zero cosmological constant. They include the age of the Universe, dynamical determinations of Ω, galaxy-number counts, and the apparent abundance of large-scale structure in the Universe. While the discrepancies are not yet serious enough to rule out the simplest and “most well motivated” model, the current data point to a “best-fit model” with the following parameters: ΩB Ω 0.03, QCDM Ω 0.17, ΩΛ Ω 0.8, and H o ≃ 70 km sec-1 Mpc-1, which improves significantly the concordance with observations. While there is no good reason to expect such a value for the cosmological constant, there is no physical principle that would rule such out.
Economic Analysis, Moral Philosophy, and Public Policy

This book shows through argument and numerous policy-related examples how understanding moral philosophy can improve economic analysis, how moral philosophy can benefit from economists' analytical tools, and how economic analysis and moral philosophy together can inform public policy. Part I explores the idea of rationality and its connections to ethics, arguing that when they defend their formal model of rationality, most economists implicitly espouse contestable moral principles. Part II addresses the nature and measurement of welfare, utilitarianism and cost-benefit analysis. Part III discusses freedom, rights, equality, and justice - moral notions that are relevant to evaluating policies, but which have played little if any role in conventional welfare economics. Finally, Part IV explores work in social choice theory and game theory that is relevant to moral decision making. Each chapter includes recommended reading and discussion questions.
RR Lyrae Stars in NGC 6388 and NGC 6441: A New Oosterhoff Group?

NGC 6388 and NGC 6441 are anomalies among Galactic globular clusters in that they cannot be readily placed into either Oosterhoff group I or Oosterhoff group II despite their significant numbers of RR Lyrae variables. The mean pulsation periods, 〈Pab〉, of their RRab variables, at 0.71 and 0.76 days, respectively, are even larger than for Oosterhoff II clusters. Moreover, Oosterhoff II clusters are very metal poor, whereas NGC 6388 and NGC 6441 are the most metal-rich globular clusters known to contain RR Lyrae stars. The location of the NGC 6388 and NGC 6441 RRab variables in the period-amplitude diagram implies that the RR Lyrae stars in those two clusters are brighter than expected for their metallicities. Our results therefore indicate that a universal relationship may not exist between the luminosity and the metallicity of RR Lyrae variables.
TAU 2014 contest on removing common path pessimism during timing analysis

To margin against modeling limitations in considering design and electrical complexities (e.g., crosstalk coupling, voltage drops) as well as variability (e.g., manufacturing process, environmental), "early" and "late" signal propagation delays in static timing analysis are often made pessimistic by addition of extra guard bands. While these forced "early-late splits" provide desired margins, the splits applied across the entire design introduce excessive and undesired pessimism. To this end, "common path pessimism removal (CPPR)" eliminates the redundant pessimism during timing analysis.The aim of the TAU 2014 timing contest is to seek novel ideas for fast CPPR by: (i) introducing the concept and importance of common path pessimism removal while highlighting the exponential run-time complexity of an optimal solution, (ii) encouraging novel parallelization techniques (including multi-threading), and (iii) facilitating the creation of a timing analysis and CPPR framework with benchmarks to further advance research in this area.
Modelling form factors in HQET

Abstract We present a simple and straightforward method for relating the form factors in HQET, as defined by the covariant trace formalism, to the overlaps of the rest frame wave functions of the light degrees of freedom. We also point out several inconsistencies present in recent calculations of the radiative rare B decays, and also show how these can be fixed even within the framework of the nonrelativistic quark model.
Macrocystis and its environment, knowns and unknowns

Abstract Macrocystis commonly dominates substantial expanses of the nearshore along coasts where it occurs. We discuss several physiological and ecological factors affecting Macrocystis populations, particularly as they may influence competition with other seaweed species. Successful competition for light appears to explain much of the success by Macrocystis in dominating its environment. Although nutrient limitation may sometimes curtail Macrocystis productivity, a role in competitive success has not been documented. Water temperature controls the large scale geographic distribution of Macrocystis, but usually is rather minor on a local scale. Water motion apparently does not have important affects on competition except for influences from wave exposure. Salinity changes may control Macrocystis distributions where large freshwater inputs occur into semi-enclosed embayments. Sedimentation may affect microscopic stages in the kelp life history, with differential effects on various competitive species. Encrustations and preferential grazing may affect competitiveness. Unstudied but probably influential factors include disease, plant aging and some aspects of nutrition. Interactions between all these factors are complex, but are under investigation by modelling techniques with some interesting findings that help explain and comprehend the ecology of this useful plant.
Effects of nonionic surfactants on bacterial transport through porous media.

Nonionic surfactants of the form CxEy, where x is the number of carbons in the alkyl chain and y is the number of ethylene oxide units in the polyoxyethylene (POE) chain, were studied for their ability to alter the transport of Sphingomonas pacilimobilis through an aquifer sand. The surfactants C12E4 (Brij 30) and C12E23 (Brij 35) were the focus of this study. Through a systematic study, it was shown that these nonionic surfactants were able to enhance the transport of this bacterial culture through porous media. The magnitude of the enhancement increased with decreasing solution ionic strength and increasing POE chain length. The mechanism of this enhanced transport appears to be due to expansion of the electric double layer about the bacteria and aquifer sand through displacement of the counterions by the sorbed surfactant. This expanded electric double layer increases the electrostatic repulsion, with a resultant reduction in the collision efficiency and an increase in the Langmuirian blocking paramete...
Natural Convection in Rectangular Layered Porous Cavities

A numerical study was performed to further investigate the flow and temperature fields in layered porous cavity. The cavities considered have an aspect ratio of either 0.2 (shallow cavities) or 5 (tall cavities) with two or four sublayers. Similar to the case of square cavities, convection is always initiated in the more permeable sublayer. As the base Rayleigh number increases, the strength of the convective cell increases and leads to flow penetration to the less permeable sublayer
Multiplicities in high energy interactions

This paper reviews the data on multiplicities in high energy interactions. Results from e/sup +/e/sup -/ annihilation, from neutrino interactions, and from hadronic collisions, both diffractive and nondiffractive, are compared and contrasted. The energy dependence of the mean charged multiplicity, , as well as the rapidity density at Y = 0 are presented. For hadronic collisions, the data on neutral pion production shows a strong correlation with . The heavy particle fractions increase with ..sqrt..s up to the highest energies. The charged particle multiplicity distributions for each type of reaction show a scaling behavior when expressed in terms of the mean. Attempts to understand this behavior, which was first predicted by Koba, Nielsen, and Olesen, are discussed. The multiplicity correlations and the energy variation of the shape of the KNO scaling distribution provide important constraints on models. Some extrapolations to the energies of the Superconducting Super Collider are made. 51 refs., 27 figs.
Dark and Baryonic Matter in Bright Spiral Galaxies. I. Near-Infrared and Optical Broadband Surface Photometry of 30 Galaxies*

We present photometrically calibrated images and surface photometry in the B, V, R, J, H, and K bands of 25, and in the g, r, and K bands of five nearby bright (B < 12.5 mag) spiral galaxies with inclinations of 30?-65? spanning the Hubble sequence from Sa to Scd. Data are from The Ohio State University Bright Spiral Galaxy Survey, the Two Micron All Sky Survey, and the Sloan Digital Sky Survey Second Data Release. Radial surface brightness profiles are extracted, and integrated magnitudes are measured from the profiles. Axis ratios, position angles, and scale lengths are measured from the near-infrared images. A one-dimensional bulge/disk decomposition is performed on the near-infrared images of galaxies with a nonnegligible bulge component, and an exponential disk is fit to the radial surface brightness profiles of the remaining galaxies.
Advancement of semispan testing at the National Transonic Facility

A need for low-speed, high Reynolds number test capabilities has been identified for the design and development of advanced subsonic transport high-lift systems. In support of this need, multiple investigations have been conducted in the National Transonic Facility (NTF) at NASA Langley Research Center to develop a semispan testing capability that will provide the low-speed, flight Reynolds number data currently unattainable using conventional sting-mounted, full-span models. Although a semispan testing capability will effectively double the Reynolds number capability over full-span models, it does come at the expense of contending with the issue of the interaction of the flow over the model with the wind-tunnel wall boundary layer. To address this issue, the size and shape of the semispan model mounting geometry has been investigated, and the results are presented herein. The cryogenic operating environment of the NTF produced another semispan test technique issue in that varying thermal gradients have developed on the large semispan balance. The suspected cause of these thermal gradients and methods to eliminate them are presented
Recent developments in neutrino physics

I shall attempt to summarize recent developments in the experimental situation in neutrino physics. The paper will deal with recent results, drawing on either published work or research that has been presented in preprint form, as there is an adequate supply of interesting and controversial data restricting oneself to these generally more reliable sources. The discussion of the theoretical implication of these experimental results will be presented in the following paper by Boris Kayser. The topics to be covered in this presentation are: direct measurements of {bar {nu}}{sub e} mass via beta endpoint studies; status of solar neutrino observations; status of 17-keV neutrino'' reports; and the use of {nu}p elastic scattering to determine the strange quark'' content of the proton. 2 refs., 15 figs., 9 tabs.
Intracellular localization of titanium dioxide-biomolecule nanocomposites

Emerging areas of nanotechnology hold the promise of overcoming the limitations of existing technology for intracellular manipulation. These new developments include the creation of nanocomposites that can be introduced into the cells, targeted to specific subcellular sites, and subsequently used as platforms for initiation of intracellular processes dependent on or aided by locally high concentrations of specific molecules delivered as components of the nanocomposites. Nanocomposites that combine functional properties of biomolecules with the functional properties of inorganic components could provide new tools for biology, medicine, chemistry and material sciences. Here we describe how we introduced TiO{sub 2}-DNA nanocomposites into cells, and localized titanium in the cells by mapping the Ti K{alpha} X-ray fluorescence induced at the 2-ID-E microprobe of the SRI-CAT at the Advanced Photon Source at Argonne National Laboratory.
Low-temperature long-time simulations of Ising ferromagnets using the Monte Carlo with Absorbing Markov Chains method

Abstract The Monte Carlo with Absorbing Markov Chains (MCAMC) method is introduced. This method is a generalization of the rejection-free method known as the n -fold way. The MCAMC algorithm is applied to the study of the very low-temperature properties of the lifetime of the metastable state of Ising ferromagnets. This is done both for square-lattice and cubic-lattice nearest-neighbor models. Comparison is made with exact low-temperature predictions, in particular the low-temperature predictions that the metastable lifetime is discontinuous at particular values of the field. This discontinuity for the square lattice is not seen in finite-temperatures studies. For the cubic lattice, it is shown that these ‘exact predictions’ are incorrect near the fields where there are discontinuities. The low-temperature formula must be modified and the corrected low-temperature predictions are not discontinuous in the energy of the nucleating droplet.
Hydrocarbon-free resonance transition 795-nm rubidium laser

An optical resonance transition rubidium laser (52P1/2 → 52S1/2) is demonstrated with a hydrocarbon-free buffer gas. Prior demonstrations of alkali resonance transition lasers have used ethane as either the buffer gas or a buffer gas component to promote rapid fine-structure mixing. However, our experience suggests that the alkali vapor reacts with the ethane producing carbon as one of the reaction products. This degrades long term laser reliability. Our recent experimental results with a "clean" helium-only buffer gas system pumped by a Ti:sapphire laser demonstrate all the advantages of the original alkali laser system, but without the reliability issues associated with the use of ethane.
Jordan Curves with Polynomial Inverse Moduli of Continuity

Computational complexity of two-dimensional domains whose boundaries are polynomial-time computable Jordan curves with polynomial inverse moduli of continuity is studied. It is shown that the membership problem of such a domain can be solved in P^N^P, i.e., in polynomial time relative to an oracle in NP, in contrast to the higher upper bound P^M^P for domains without the property of polynomial inverse modulus of continuity. On the other hand, the lower bound of UP for the membership problem still holds for domains with polynomial inverse moduli of continuity. It is also shown that the path problem of such a domain can be solved in PSPACE, matching its known lower bound, while no fixed upper bound was known for domains without this property.
Laboratory simulations of Mars evaporite geochemistry

Evaporite-rich sedimentary deposits on Mars were formed under chemical conditions quite different from those on Earth. Their unique chemistries record the chemical and aqueous conditions under which they were formed and possibly subsequent conditions to which they were subjected. We have produced evaporite salt mineral suites in the laboratory under two simulated Martian atmospheres: (1) present-day and (2) a model of an ancient Matian atmosphere rich in volcanic gases. The composition of these synthetic Mars evaporites depends on the atmospheres under which they were desiccated as well as the chemistries of their precursor brines. In this report, we describe a Mars analog evaporite laboratory apparatus and the experimental methods we used to produce and analyze the evaporite mineral suites.
A note on the finiteness of the set of equilibria in an exchange economy with constrained endowments

Abstract Debreu, G. (1970), proved that for smooth finite exchange economies, the set of endowment assignments which result in a finite number of price equilibria is “large” in the sense that it has null closed complement. We show that if the individual endowment space of each agent does not include all the commodities, then this conclusion need not hold. In particular, we consider the case where each agent's endowment space includes only one good. We construct a class of examples in which every economy in an open subset of the constrained endowment space gives rise to a continuum of equilibria.
Producing change in attitudes toward abortion

Abortion has been a chief method of population control from ancient days down to present times (McCary, 1967). It has been estimated that 30,000,000 abortions are induced throughout the world each year, 1,000,000 of which take place in the United States alone (Pilpel, 1969). Gebhard, et al (1958) have suggested that 22 per cent of married women have had at least one abortion. Unfortunately, nearly all of these abortions were illegally obtained; and many of these were performed under conditions which posed serious problems to the health and safety of the women. Legal abortion (in a few states) however seems to be increasingly accepted as a viable method of birth control, albeit a method of last resort. In the first year after Maryland's liberalized abortion law went into effect (1968-1969) a total of 2,134 legal abortions were performed, the great majority of these on Maryland residents. These abortions correspond to three per cent of the number of live births recorded during the same period in Maryland. Similarly, during the first year following a liberalized abortion law in Oregon (1970) there was one therapeutic abortion for every five live births. Public discussion about the legalization of abortion has increased greatly over the last few years. Institutional positions on abortion also appear to be evolving from a traditional repression into a more liberal stance. Several state legislatures in the past few years have called into question long-standing abortion laws, which once allowed therapeutic abortions only in cases where a pregnancy would endanger the mother's life. Some states, e.g., California, Colorado, Georgia, Hawaii, Maryland, New York, and Oregon, have recently modified existing laws to allow legal abortion on a wider base of extenuating circumstances. In 1967 the American Medical Association issued a revision to its official position now supporting abor
The machine-readable transcendentalists: Cultural history on the computer

THIS ESSAY reports on an effort to integrate statistics and the computer into the humanities classroom. In History 55, “Culture and Community: The Worlds of Emerson, Dickinson, and Thoreau,” at Amherst College, students were asked to carry out quantitative analyses of the U.S. census of 1850 for the towns of Amherst and Concord, Massachusetts. This assignment was conceived as a project in social history, through which students would reconstruct the contours of community life. But the investigation of the census transformed the main lines of the course, even the ways in which students interpreted the writings of the Transcendentalists. For the census represented not only a register of society, but also a cultural text produced in that society and manifesting a distinctive world view, that of the emerging social scientists of Victorian America. To study the census was thus to uncover the origins of the very frame of mind, against which writers like Emerson and Thoreau reacted. And so, a course that began in the attempt to bridge the humanities and social sciences eventually became self-reflexive: the origins of the “two cultures” lay in the very time and place we were studying. Recovering that history proved liberating. In the course of quantifying society, students transcended the intellectual divide between the humanities and sciences and achieved a deeper historical consciousness.
Flow in ultra-relativistic heavy-ion collisions

Flow develops in ultra-relativistic heavy-ion collisions via re-interactions among partons or/and hadrons. Characterizing flow is a crucial step towards understanding the formation of partonic matter. We review new measurements on anisotropic flow, including v 2 at large rapidity, v 1 , v 4 , and new ways of addressing non-flow issues. We then show the self-consistency of the data and characterize flow of pions, kaons, protons and Θ within the blast wave parametrization. Finally, we show that the data currently available suggest that flow develops at both partonic and hadronic stages.
A Bargmann-Wightman-Wigner-type quantum field theory

Abstract We show that the ( j , 0) ⊕ (0, j ) representation space associated with massive particles is a concrete realisation of a quantum field theory, envisaged many years ago by Bargmann, Wightman and Wigner, in which bosons and antibosons have opposite relative intrinsic parities. Demonstration of the result requires a careful ab initio study of the ( j , 0) ⊕ (0, j ) representation space for massive particles, introducing a wave equation with well defined transformation properties under C , P and T , and addressing the issue of nonlocality required of such a theory by the work of Lee and Wick.
Synthesis, Characterization, and Explosive Properties of the Nitrogen-Rich Borazine [H3N3B3(N3)3]

The azidoborazines [Me3N3B2(Me)2B(N3)] and [H3N3B3(N3)3] were prepared from the combination of Me3SiN3 and the chloroborazines [Me3N3B2(Me)2BCl] and (H3N3B3Cl3). The compounds have been characterized by analytical and spectroscopic methods. The molecular structure of [H3N3B3(N3)3] has been confirmed by single-crystal X-ray diffraction techniques: triclinic space group P1 with a = 8.579(1) A, b = 9.182(1) A, c = 12.043(1) A, α = 104.62(1)°, β = 90.26(1)°, γ = 110.74(1)°, and Z = 4. The thermal behavior of the azides have been examined by TGA/DTA. The explosion sensitivity of [H3N3B3(N3)3], which contains 82.58% nitrogen by weight, has been accessed by drop weight impact, spark, and friction tests. These measurements indicate that [H3N3B3(N3)3] is a relatively sensitive explosive. The Staudinger reactivity of the azides with Ph3P was examined, and [H3N3B3(N3)3] was found to produce [Ph3PNH2](N3). The molecular structure of this compound was determined by single-crystal X-ray diffraction techniques: ortho...
SWAS observations of water in molecular outflows

We present detections of the ground-state 110 → 101 transition of orthoH2O at 557 GHz in 18 molecular outflows based on data from the Submillimeter Wave Astronomy Satellite (SWAS). These results are combined with groundbased observations of the J=1-0 transitions of CO and CO obtained at the Five College Radio Astronomy Observatory (FCRAO). Data from Infrared Space Observatory (ISO) for a subset of the outflows are also discussed. Assuming the SWAS water line emission originates from the same gas traced by CO emission, we find that the outflowing gas in most outflows has an ortho-H2O abundance relative to H2 of between about 10 −7 and 10. Analysis of the water abundance as a function of outflow velocity reveals a strong dependence. The abundance of ortho-H2O increases with velocity and at the highest outflow velocities some of the outflows have relative ortho-H2O abundances of order 10 . However the mass of very high velocity gas with such elevated H2O abundances represents less that 1% of the total outflow gas mass. The ISO LWS observations of high-J rotational lines of CO and the 179.5 μm transition of ortho-H2O provide evidence for a warmer outflow component than required to produce either the SWAS or FCRAO lines. The ISO line flux ratios can be reproduced with C-shock models with shock velocities of order 25 km s and preshock densities of order 10 cm; these C-shocks have post-shock relative water abundances greater than 10. The mass associated with the ISO emission is also quite small compared with the total outflow mass, and is similar to that responsible for the highest velocity water emission detected by SWAS. Although the gas responsible for the ISO emission has elevated levels of water, the bulk of the outflowing gas has an abundance of ortho-H2O well below what would be expected if the gas has passed through a C-shock with shock velocities greater than 10 km s. Gas-phase water can
Trifluoroacetyl-Activated Nitrogen−Nitrogen Bond Cleavage of Hydrazines by Samarium(II) Iodide

Trifluoroacetyl derivatives of hydrazines undergo clean and efficient reductive cleavage of the N−N bond with SmI2 in the presence of MeOH. After N-trifluoroacetylation, acyl-, aryl-, and alkyl-substituted hydrazines are reductively cleaved by this method to afford trifluoroacetamides in yields ranging from 70 to 96%. These conditions accommodate alkene functionality, avoid racemization, and furnish chiral amines bearing a readily removable TFA protecting group.
Distribution of fluctuational paths in noise-driven systems

Abstract Dynamics of a system that performs a large fluctuation to a given state is essentially deterministic: the distribution of fluctuational paths peaks sharply at a certainoptimalpath along which the system is most likely to move. For the general case of a system driven by colored Gaussian noise, we provide a formulation of the variational problem for optimal paths. We also consider the prehistory problem, which makes it possible to analyze the shape of the distribution of fluctuational paths that arrive at a given state. We obtain, and solve in the limiting case, a set of linear equations for the characteristic width of this distribution.
Epoxide‐Opening Cascades in the Synthesis of Polycyclic Polyether Natural Products

The structural features of polycyclic polyether natural products can, in some cases, be traced to their biosynthetic origin. However in case that are less well understood, only biosynthetic pathways that feature dramatic, yet speculative, epoxide-opening cascades are proposed. We summarize how such epoxide-opening cascade reactions have been used in the synthesis of polycyclic polyethers (see scheme) and related natural products.The group of polycyclic polyether natural products is of special interest owing to the fascinating structure and biological effects displayed by its members. The latter includes potentially therapeutic antibiotic, antifungal, and anticancer properties, and extreme lethality. The polycyclic structural features of this class of compounds can, in some cases, be traced to their biosynthetic origin, but in others that are less well understood, only to proposed biosynthetic pathways that feature dramatic, yet speculative, epoxide-opening cascades. In this review we summarize how such epoxide-opening cascade reactions have been used in the synthesis of polycyclic polyethers and related natural products.
Development of a Hybrid Photo-Diode and its Front-End Electronics for the BTEV Experiment

Abstract This paper describes the development of a 163-channel Hybrid Photo-Diode to be used in the RICH Detector for the BTEV Experiment. This is a joint development project with DEP, Netherlands. It also reports on the development of associated front-end readout electronics based on the va_btev ASIC, undertaken with IDEAS, Norway. Results from bench tests of the first prototypes are presented.
Perspectives on the quantum Zeno paradox

As of October 2006, there were approximately 535 citations to the seminal 1977 paper of Misra and Sudarshan that pointed out the quantum Zeno paradox (more often called the quantum Zeno effect). In simple terms, the quantum Zeno effect refers to a slowing down of the evolution of a quantum state in the limit that the state is observed continuously. There has been much disagreement as to how the quantum Zeno effect should be defined and as to whether it is really a paradox, requiring new physics, or merely a consequence of ordinary quantum mechanics. The experiment of Itano, Heinzen, Bollinger, and Wineland, published in 1990, has been cited around 347 times and seems to be the one most often called a demonstration of the quantum Zeno effect. Given that there is disagreement as to what the quantum Zeno effect is, there naturally is disagreement as to whether that experiment demonstrated the quantum Zeno effect. Some differing perspectives regarding the quantum Zeno effect and what would constitute an experimental demonstration are discussed.
Pattern‐Based Peptide Recognition

Nature's use of sensor arrays in the mammalian olfactory and gustatory systems has encouraged supramolecular chemists to take a new approach to molecular recognition. Pattern-based recognition involves the use of sensor arrays to create fingerprints for analytes. The use of sensing arrays has paved the way for systems capable of identifying biological analytes that would have been difficult targets using the traditional "lock-and-key" approach to sensor design.
Studies of the generation and pericyclic behavior of cyclic pentadienyl carbanions. Alkylation reactions as an efficient route to functionalized cis-bicyclo[3.3.0]octenes.

Carbolithiation has been studied with alkyllithium reagents in a series of six- through nine-membered 3-methylene-1,4-cycloalkadienes, efficiently producing the corresponding cyclic pentadienyl carbanions. These pentadienyl anions display unique reactivity, depending on ring size. Cyclooctadienyl anions readily undergo disrotatory electrocyclization to cis-bicyclo[3.3.0]octenyl systems, which are trapped with a variety of electrophiles to stereoselectively provide functionalized cis-bicyclo[3.3.0]octenes. The carbolithiation and electrocyclization processes are examined using low-temperature 1H NMR experiments. An expedient synthesis of a linear triquinane illustrates this methodology. Electrocyclization of the corresponding cyclononadienyl anion requires unusually high temperatures (120 °C), and computational studies provide insights into this change in reactivity. Cycloheptadienyl and cyclohexadienyl anions, generated via carbolithiation, provide functionalized cycloheptadienes and cyclohexadienes upon ...
On the cohomology of a simple normal crossings divisor

Abstract We establish a formula which decomposes the cohomologies of various sheaves on a simple normal crossings divisor (SNC) D in terms of the simplicial cohomologies of the dual complex Δ ( D ) with coefficients in a presheaf of vector spaces. This presheaf consists precisely of the corresponding cohomology data on the components of D and on their intersections. We use this formula to give a Hodge decomposition for SNC divisors and investigate the toric setting. We also conjecture the existence of such a formula for effective non-reduced divisors with SNC support, and show that this would imply the vanishing of the higher simplicial cohomologies of the dual complex associated to a resolution of an isolated rational singularity.
Reynolds Number Effects in Combustion Noise

Abstract Acoustic emission spectra have been obtained for non-premixed turbulent combustion from two small-diameter laboratory gas burners, two commercial gas burners, and a large gas burner in the firebox of a Babcock-Wilcox Boiler (50,000 lb steam/hr). The changes in burner size and firing rate represent changes in Reynolds number, and changes in air/fuel ratio represent departure from stoichiometric proportions. The combustion efficiency was measured independently through gas analysis. The acoustic spectra obtained from the various burners exhibit a persistent shape over the Reynolds number range of 8,200-82,000. The spectra were analyzed for identification of a predictable frequency domain that is most responsive to, and readily correlated with, combustion efficiency. A simple parameter (consisting of the ratio of the average acoustic power output in the most responsive frequency bandwidth to the acoustic power level of the loudest frequency) is proposed, whose value increases significantly and unmist...
How to extract physics from HBT radius parameters

Abstract I review recent progress in the understanding of the connection between the space-time structure of the particle emitting source and the form of the two-particle correlation function in momentum space. Based on a new scheme for calculating the HBT radius parameters from the emission function, strategies are suggested to separate for rapidly expanding sources the information on the spatial and temporal structure of the source. To this end a new fitting function for the two-particle correlation function is proposed. Its usefulness is demonstrated for a typical expanding model source, and it is shown how the dependence of the resulting fit parameters on the momentum of the particle pair can be used to measure the longitudinal and transverse expansion of the source.
Testing General Relativity with High-Resolution Imaging of Sgr A*

Submilliarcsecond astrometry and imaging of the black hole Sgr A* at the Galactic Center may become possible in the near future at infrared and submillimetre wavelengths. This resolution is sufficient to observe the silhouette the supermassive black hole in the Galactic center casts upon background emission. However, more exciting is the prospect of observing "hot spots" in the accretion fbw. Here we discuss how such measurements may be used to test not only the consistency of General Relativity, but also the validity of the Kerr metric in particular.
Phase modulation at the few-photon level for weak-nonlinearity-based quantum computing

Researchers demonstrate large cross-phase shifts of 0.3 mrad per photon in a single pass through room-temperature Rb atoms confined to a hollow-core photonic bandgap fibre. The response time of less than 5 ns indicates that phase modulation bandwidths greater than 50 MHz are possible with a highly sensitive atomic-vapour-based scheme.
Reliability analysis of rotary couplers on unit-train coal cars

Failure data furnished for rotary couplers on 100-ton, unit-train coal cars were analyzed. The data were found to be compatible with a failure model based on a Weibull distribution. Failure rates for broken and worn-out couplers showed a very sharp increase at approximately 298 000 km (185 000 miles). These were couplers that were replaced at repair shops due to regular inspection. Missing couplers, i.e. those that failed in service, had a higher failure rate at the lower mileages. At the higher mileages, however, the failure rate for the worn-out couplers was the highest.
A shutter design for time domain studies using synchrotron radiation at the Advanced Photon Source

In general, a variable repetition rate of the x‐ray bunches is needed to explore time domain problems using x‐rays. In some instances, the results of several hundreds or thousands of x‐ray pulses must be averaged requiring the sample to be in the same time‐dependent state each time the monitoring pulse strikes. The important point is that before a second x‐ray pulse hits the sample, the system must return to its initial relaxed ground state prior to another spectrum pulse in order to prepare the same excited state again. Our key design principle employs a subsonic, rotating mirror whose period is slaved to the synchrotron intrapulse period. The synchrotron x‐ray bunches will be reflected a distance of about 2 m to a narrow 0.5‐mm slit just in front of the sample. A mirror rotating at a low 7500 rpm (125 Hz) is sufficient to select a single synchrotron pulse for the Advanced Photon Source. The very precise phase stability required by this method is currently available in rotating mirror devices for laser scanning.
Cesium-137 in Lake Michigan sediments: Areal distribution and correlation with other man-made materials

Abstract Grab samples of sediment were collected at 530 locations in Lake Michigan, primarily in the southeastern quarter of the lake. Each sample was analysed in the field and in the laboratory for fallout cesium-137. Twenty-five of the samples, collected near the mouth of the St Joseph River, were also analysed in the laboratory for 11 other man-made materials known to be discharged into the river. Two statistical methods were used to determine if cesium-137 can be used as an environmental tracer to predict the areal distributions of other man-made materials. The results show fallout cesium-137 to be a moderate to good tracer for locating areas of accumulation of plutonium-238, plutonium-239, zinc, copper, chronium, lead, dieldrin, DDT and PCB in sediment. Little or no correlation is found between fallout cesium-137 and strontium-90 or nickel.
A BLOW-UP CONSTRUCTION AND GRAPH COLORING

Abstract Given a graph G (or more generally a matroid embedded in a projective space), we construct a sequence of algebraic varieties whose geometry encodes combinatorial information about G . For example, the chromatic polynomial of G can be computed as an intersection product of certain classes on these varieties, or recovered in terms of the Segre classes of related subschemes of P n ; other information such as Crapo's invariant also finds a very natural geometric counterpart. The note presents this construction, and gives ‘geometric’ proofs of a number of standard combinatorial results on the chromatic polynomial and Crapo's invariant.
Enantioselective iridium-catalyzed imine vinylation: optically enriched allylic amines via alkyne-imine reductive coupling mediated by hydrogen.

The first asymmetric iridium-catalyzed C−C bond forming hydrogenation is described. By simply hydrogenating alkynes in the presence of N-arylsulfonyl imines using an iridium catalyst modified by (R)-Cl,MeO-BIPHEP, one may obtain the corresponding allylic amines 1b−21b in highly optically enriched form (92−99% ee). This protocol circumvents the use of preformed vinyl metal reagents and is applicable to aromatic, heteroaromatic, and aliphatic N-arylsulfonyl aldimines 1a−16a. The reductive coupling products, allylic amines 1b−21b, are produced as single geometrical isomers (≥99:1, E:Z). Nonsymmetric alkynes couple to imines 8a and 12a under standard conditions with excellent levels of regioselection. Absolute stereochemical assignment of allylic amines 1b−21b is based upon single-crystal X-ray diffraction analysis of 22b, the p-bromophenylsulfonyl analogue of adduct 1b, using the anomalous dispersion method. A stereochemical model accounting for the observed sense of absolute stereoinduction and regioselecti...
A new approach to systematic uncertainties and self-consistency in helium abundance determinations

Tests of big bang nucleosynthesis and early universe cosmology require precision measurements for helium abundance determinations. However, efforts to determine the primordial helium abundance via observations of metal poor H II regions have been limited by significant uncertainties (compared with the value inferred from BBN theory using the CMB determined value of the baryon density). This work builds upon previous work by providing an updated and extended program in evaluating these uncertainties. Procedural consistency is achieved by integrating the hydrogen based reddening correction with the helium based abundance calculation, i.e., all physical parameters are solved for simultaneously. We include new atomic data for helium recombination and collisional emission based upon recent work by Porter \etal and wavelength dependent corrections to underlying absorption are investigated. The set of physical parameters has been expanded here to include the effects of neutral hydrogen collisional emission. It is noted that Hγ and Hδ allow better isolation of the collisional effects from the reddening. Because of a degeneracy between the solutions for density and temperature, the precision of the helium abundance determinations is limited. Also, at lower temperatures (T 13,000 K) the neutral hydrogen fraction is poorly constrained resulting in a larger uncertainty in the helium abundances. Thus, the derived errors on the helium abundances for individual objects are larger than those typical of previous studies. Seven previously analyzed, ``high quality'' H II region spectra are used for a primordial helium abundance determination. The updated emissivities and neutral hydrogen correction generally raise the abundance. From a regression to zero metallicity, we find Yp as 0.2561 ± 0.0108, in broad agreement with the WMAP result. Alternatively, a simple average of the data yields Yp 0.2566 ± 0.0028. Tests with synthetic data show a potential for distinct improvement, via removal of underlying absorption, using higher resolution spectra. A small bias in the abundance determination can be reduced significantly and the calculated helium abundance error can be reduced by ~ 25%.
Evaluating Japanese corporate executives’ forecasts under an asymmetric loss function

Abstract We examine asymmetry in the loss function of Japanese corporate executives in their output growth forecasts and test for rationality of the forecasts under the assumption of a possibly asymmetric loss function. We find evidence of asymmetry and support for rationality under an asymmetric loss function.
A Thermodynamic Similarity Framework for Assessment of Working Fluids for Solar Rankine Power Generation

Numerous studies have compared the merits of different working fluids for use in Rankine power systems. Most often, however, these have considered a limited number of specific fluids for which the thermodynamic properties are known. In the investigation summarized here, the Redlich-Kwong fiuid model was used to develop a thermodynamic similarity framework that can be used as a comparative model for evaluating the performance of Rankine cycle working fluids. This can be viewed as a reduced order model that, based on thermodynamic similarity, quantifies the characteristics of the working fluids in terms of a single dimensional coordinate space defined by the choice of critical temperature. The advantage of this framework is that it allows exploration of the performance advantages of working fluids for which full thermodynamic properties are not yet available. Predictions of the model for common fluids were examined and conclusions regarding optimal fluids for solar Rankine systems are discussed.
Proof of Concept Centers in the United States: an exploratory look

In this paper we identify the population of 32 US university-related Proof of Concept Centers (PoCCs), and we present a model of technology development that identifies the economic role of PoCCs within that model. We examine the broad technology transfer challenges that PoCCs have been established to address. Further, we argue that PoCCs are a growing technology infrastructure in the United States, and they are important as a possible element of our national innovation system.
Next step spherical torus design studies

Abstract Studies are underway to identify and characterize a design point for a next step spherical torus (NSST) experiment. This would be a ‘proof of performance’ device which would follow and build upon the successes of the national spherical torus experiment (NSTX) ‘proof of principle’ device which has operated at PPPL since 1999. With the decontamination and decommissioning (D&D) of the tokamak fusion test reactor (TFTR) nearly completed, the TFTR test cell and facility will soon be available for a device such as NSST. By utilizing the TFTR test cell, NSST can be constructed for a relatively low cost on a short time scale. In addition, while furthering spherical torus (ST) research, this device could achieve modest fusion power gain for short pulse lengths, a significant step toward future large burning plasma devices now under discussion in the fusion community. The selected design point is Q=2 at HH=1.4, Pfusion=60 MW, 5-s pulse, with R0=1.5 m, A=1.6, Ip=10 MA, Bt=2.6 T, CS flux=16 weber. Most of the research would be conducted in DD, with a limited DT campaign during the last years of the program.
Terahertz microfluidic sensor based on a parallel-plate waveguide resonant cavity

We fabricate a terahertz resonator suitable for microfluidic sensing by machining a groove into one plate of a parallel-plate-waveguide. We demonstrate a refractive-index sensitivity of 3.7×105 nm/refractive-index-unit, the highest ever reported in any frequency range.
Velocity and Temperature Profiles for Stagnation Film Cooling

Experiments were conducted for film cooling through rows of slanted holes into the stagnation region of a two-dimensional blunt body with a circular leading edge. The rows were located at ± 15 deg +44 deg from stagnation. The holes in each row were spaced four hole diameters apart and were angled 30 deg to the surface in the spanwise direction. Detailed velocity and temperature measurements were obtained downstream of injection. Measurements were taken for three secondary-to-incident flow mass flux ratios at various streamwise and spanwise positions. The results show large initial spanwise variations and indicate that the injected secondary flow at high mass flux ratios actually leaves the surface. In addition, it was found that the aerodynamic loss caused by injection increases linearly with the mass injected and that for a given hole pattern, there is an optimum blowing rate at which the injected fluid from one row of holes does not interfere with that from the other.