cssi/SciSciGPT-SciSciNet huggingface dataset:
Near-limit oscillations of spherical diffusion flames

We examine the dynamic characteristics of the diffusion flame surrounding a droplet of liquid fuel in a reduced oxidant environment. The study is motivated by the experimental observations of candle flames in microgravity, which bear some similarity to the spherical diffusion flame that surrounds a burning liquid fuel droplet. The microgravity experiments reveal that, when the oxidant concentration in the chamber is sufficiently low, oscillations develop before extinction. A similar phenomenon is predicted here. An oscillatory state results for a sufficiently low oxidant concentration when radiative losses from the flame are appreciable. The frequencies of oscillations we predict are in good agreement with the experimental observations.
3-Manifolds and 3d Indices

We identify a large class R of three-dimensional N = 2 superconformal field theories. This class includes the effective theories T_M of M5-branes wrapped on 3-manifolds M, discussed in previous work by the authors, and more generally comprises theories that admit a UV description as abelian Chern–Simons-matter theories with (possibly non-perturbative) superpotential. Mathematically, class R might be viewed as an extreme quantum generalization of the Bloch group; in particular, the equivalence relation among theories in class R is a quantum-field-theoretic “2 to 3 move.” We proceed to study the supersymmetric index of theories in class R, uncovering its physical and mathematical properties, including relations to algebras of line operators and to 4d indices. For 3-manifold theories T_M, the index is a new topological invariant, which turns out to be equivalent to non-holomorphic SL(2,ℂ) Chern–Simons theory on M with a previously unexplored “integration cycle.”
Completions of quantum coordinate rings

Given an iterated skew polynomial ring C[y 1 ; τ 1 , δ 1 ]...[y n ;τ n ,δ n ] over a complete local ring C with maximal ideal m, we prove, under suitable assumptions, that the completion at the ideal m+(y 1 , y 2 ;.., y n ) is an iterated skew power series ring. Under further conditions, the completion becomes a local, noetherian, Auslander regular domain. Applicable examples include quantum matrices, quantum symplectic spaces, and quantum Euclidean spaces.
GPS Navigation : Combining Pseudorange with Continuous Carrier Phase Using a Kalman Filter

The notion of aiding GPS code-ranging information with carrier phase measurements has been around for quite some time. The integration of these two complementary forms of data can provide highly precise position solutions corrupted by very little high-frequency error, which is advantageous particularly for high- dynamical situations. This paper presents two schemes, based on the Kalman filter, for integrating GPS code and carrier measurements efficiently. One of these schemes involves a general combination of the two types of measurements, where the vehicle motion is described as a random process. In the other, the continuous carrier phase measurements provide a dynamically exact reference trajectory in much the same manner as in an inertial system, and the pseudorange data is then used to update this reference trajectory via a Kalman filter. This method of integration looks especially attractive as a means of achieving good dynamical response while still retaining the benefits of filtering the pseudorange data.
Willfully Blind for Good Reason

Willful blindness is not an appropriate substitute for knowledge in crimes that require a mens rea of knowledge because an actor who contrives his own ignorance is only sometimes as culpable as a knowing actor. This paper begins with the assumption that the classic willfully blind actor—the drug courier—is culpable. If so, any plausible account of willful blindness must provide criteria that find this actor culpable. This paper then offers two limiting cases: a criminal defense lawyer defending a client he suspects of perjury and a pain doctor who suspects his patient may be lying about her pain. The paper argues that each of these actors is justified in cultivating ignorance about his client’s or patient’s truthfulness. If this is right, then a good theory of willful blindness must distinguish these cases. The article argues that neither Husak & Callender’s motivation-based account of willful blindness nor the recklessness account is able to do so. The paper proposes the following alternative: contrived ignorance constitutes culpable blindness when the decision to remain blind or to cultivate blindness is not itself justified. This Justification approach meshes with our intuitions about willfully blind drug couriers as well as willfully blind lawyers and doctors.
Structure and Evolution of Zel’dovich Pancakes as Probes of Dark Energy Models

We examine how coupled dark matter and dark energy modify the development of Zel'dovich pancakes. We study how the various effects of these theories, such as a fifth force in the dark sector and a modified particle Hubble drag, produce variations in the redshifts of caustic formation and the present-day density profiles of pancakes. We compare our results in direct simulation to a perturbation theory approach for the dark energy scalar field. We determine the range of initial scalar field amplitudes for which perturbation theory is accurate in describing the development of the pancakes. Notably, we find that perturbative methods which neglect kinetic terms in the scalar field equation of motion are not valid for arbitrarily small perturbations. We also examine whether models that have been tuned to match the constraints of current observations can produce new observable effects in the nonlinear structure of pancakes. Our results suggest that a fully realistic three-dimensional simulation will produce significant new observable features, such as modifications to the mass function and halo radial density profile shapes, that can be used to distinguish these models from standard concordance cosmology and from each other.
A DESIGN PROCEDURE FOR WIND POWERED HEATING-SYSTEMS

Abstract This paper presents a generalized design procedure for the month-by-month prediction of performance of wind powered residential heating systems. In its initial form, the technique is restricted to the simulation of residential heating systems using conventional horizontal axis wind turbines that dissipate their output into water based thermal storage systems (via electrical resistance heaters or fluid dissipation devices). The procedure using a graphical formulation (Wf-chart) is designed to give the monthly heating energy fraction supplied by a wind heating system with a minimum of site, wind turbine, and system input parameters. Such information is useful for simple performance studies or as input for economic assesment of wind heating systems. In addition example results of the calculational procedure for a typical wind heating system are presented.
Global paths of time-periodic solutions of the Benjamin–Ono equation connecting pairs of traveling waves

We classify all bifurcations from traveling waves to non-trivial time-periodic solutions of the Benjamin-Ono equation that are predicted by linearization. We use a spectrally accurate numerical continuation method to study several paths of non-trivial solutions beyond the realm of linear theory. These paths are found to either re-connect with a different traveling wave or to blow up. In the latter case, as the bifurcation parameter approaches a critical value, the amplitude of the initial condition grows without bound and the period approaches zero. We then prove a theorem that gives the mapping from one bifurcation to its counterpart on the other side of the path and exhibits exact formulas for the time-periodic solutions on this path. The Fourier coefficients of these solutions are power sums of a finite number of particle positions whose elementary symmetric functions execute simple orbits (circles or epicycles) in the unit disk of the complex plane. We also find examples of interior bifurcations from these paths of already non-trivial solutions, but we do not attempt to analyze their analytic structure.
A Potential Interconnection Method in Molecular Electronics

A method to electrically connect molecular devices is proposed, which has the potential to develop into an interconnection technology for 3-dimensional molecular electronic circuits. The method is based on electric-bias-induced polarization and electric-pulse-induced chemical reactions. Two molecules to be connected are oppositely biased to induce opposite charges in them. The opposite charges will create electrostatic attraction that pulls together or aligns the two molecules. An electric pulse is then applied across the two molecules to trigger a chemical linking reaction between them. The electric pulse overcomes the activation energy for such a reaction. Chemical linking reactions to produce conjugated molecular chains are proposed for several conjugated molecules, such as phenylene, ethylene, and acetylene based molecules, with different end groups, such as phenyl and acetyl groups. Applications of this method in assembling 3-terminal molecular devices and 3-dimesional molecular electronic circuits are speculated. Major challenges in realizing this interconnection method are also outlined.
Infrared Moon: A Review

T brightness temperature of the lunar surface has been determined using telescopes on Earth, on balloons, and on aircraft. Observations revealed more than a thousand anomalous regions (hot spots) during an eclipse. It was also discovered that certain of the mare and portions of mare regions show an anomalous thermal behavior. In 1966 and 1968 Surveyors I, III, V, VI, and VII performed in situ thermal measurements. With the two Apollo landings in 1969, we have passed from a remote sensing to a physical sampling era. Apollo 11 and 12 provided samples of the lunar surface from which certain of its thermophysical properties will be determined. In the coming Apollo missions, it can be expected that a landing will be made on or at least near one of the so-called hot spots, and on one of the enhanced mare locations. The purpose of this paper is to describe the infrared measurements that have been made of the lunar surface. The earliest measurement was made one hundred years ago. The first significant work was done between 1924 and 1928 by Pettit and Nicholson of the Mount Wilson Observatory; their work has been reviewed in detail by others." They reported measurements of brightness temperatures under various conditions: distribution of temperature along the lunar diameter at full moon, the subsolar point temperatures as a function of phase, the antisolar point (nighttime) temperature and the transient temperature during a total lunar eclipse for a point near the disk center and at the limb. In the theoretical work that followed, Wesselink and Jaeger and Harper » assumed that the thermophysical properties of the lunar surface were constant with depth and temperature. Even with a two-layer model, it was not possible to match simultaneously the lunation and eclipse measurements with one set of thermal parameters. These early theoretical studies, however, did suggest that the uppermost layer of the moon was of a porous or dustlike nature. Further measurements of eclipse cooling were made by Sinton and Strong in 1953, and in 1958 and 1959 Sinton constructed isothermal contour maps over the lunar surface at nine different phases. The lunar infrared measurements up to 1960, including a description of certain theoretical models, have been discussed by Sinton. During the lunar eclipse of March 13, 1960, Shorthill, Borough, and Conley discovered that several rayed craters cooled less rapidly than their environs, and in particular, that Tycho was about 40° K warmer than its environs an hour into the umbral phase. This surprising observation in the infrared, revealing differential properties over localized regions, provided an impetus to the author as well as several others to make additional measurements. Subsequently, extensive measurements were made during eclipses and during the lunar daytime. Measurements during the lunar night are less extensive. Some results of these measurements will be discussed as well as -a new thermophysical model developed by Winter and Saari which fits both the lunation and eclipse data.
Rate constants for the gas‐phase reactions of Cl atoms with a series of hydrofluorocarbons and hydrochlorofluorocarbons at 298 ± 2 K

A relative rate method has been used to determine rate constants for the gas-phase reactions of a series of hydrofluorocarbons (HFCs) and hydrochlorofluorocarbons (HCFCs) at 298 ± 2 K and atmospheric pressure of air. Based on a rate constant for the reaction of the Cl atom with CH4 of (1.0 ± 0.2) − 10−13 cm3 molecule−1 s−1 at 298 K, the following Cl atom reaction rate constants (in units of 10−15 cm3 molecule−1 s−1) were obtained: CH3F, 340 ± 70; CH3CHF2, 240 ± 50; CH2FCl, 110 ± 25; CHFCl2, 21 ± 4; CHCl2CF3, 14 ± 3; CHFClCF3, 2.7 ± 0.6; CH3CFCl2, 2.4 ± 0.5; CHF2Cl, 2.0 ± 0.4; CH2FCF3, 1.6 ± 0.3; CH3CF2Cl, 0.37 ± 0.08; and CHF2CF3, 0.24 ± 0.05. These Cl atom reaction rate constants are compared with literature data and with the corresponding OH radical reaction rate constants. © John Wiley & Sons, Inc.
Chemistry and pharmacokinetics of diarylthiophenes and terphenyls as selective COX-2 inhibitors

Abstract DuP697, 2-bromo-4-(4′-sulfonylmethyl)phenyl-5-(4′-fluoro)phenylthiophene, is a selective type 2 cyclooxygenase (COX-2) inhibitor. Its relatively weak COX-2 selectivity coupled with a poor human pharmacokinetic profile led us to seek improvements on the in vitro selectivity while at the same time, addressing some of its pharmacokinetic liabilities. In this paper we discuss some strategies at solving the PK issue within a class of COX-2 inhibitors. The result of these efforts led to the discovery of a new class of COX-2 inhibitors the terphenyls, which prove to be superior alternatives to the diarylthiophenes.
List Randomization for Sensitive Behavior: An Application for Measuring Use of Loan Proceeds

Abstract Policymakers and microfinance institutions (MFIs) often claim to target poor entrepreneurs who then invest loan proceeds in their businesses. Typically in non-research settings these claims are assessed using readily available but unverified self-reports from client loan applications. Alternatively, independent surveyors could directly elicit how borrowers spent their loan proceeds. That too, however, could suffer from deliberate misreporting. We use data from the Peru and the Philippines in which independent surveyors elicited loan use both directly (i.e., by asking how individuals spent their loan proceeds) and indirectly (i.e., through a list-randomization technique that allows individuals to hide their answer from the surveyor). We find that direct elicitation under-reports the non-enterprise uses of loan proceeds.
Total synthesis of (+/-)-merrilactone A via catalytic Nazarov cyclization.

The total synthesis of merrilactone A (a neurotrophic agent) has been achieved. In the approach reported, simultaneous creation of the C-4 and C-5 stereocenters was accomplished stereospecifically using an unprecedented variant of the Nazarov cyclization. Additional studies focused upon this Lewis acid-catalyzed cyclization of a silyloxyfuran-containing intermediate are presented.
Optimal Parametric Search on Graphs of Bounded Tree-Width

We give linear-time algorithms for a class of parametric search problems on weighted graphs of bounded tree-width. We also discuss the implications of our results to approximate parametric search on planar graphs.
Single-flask polyfunctionalization of the imidazole ring; a streamlined route to the antitumor agent carmethizole

Abstract Three sequential treatments of an N-protected tribromoimidazole with n-BuLi / electrophile in a 1-pot process leads to N-protected 2,4,5-trisubstituted imidazoles. The method can be applied to the preparation of the immediate of carmethizole.
Fractional Quantum Hall Effect and Nonabelian Statistics

It is argued that fractional quantum Hall effect wavefunctions can be interpreted as conformal blocks of two-dimensional conformal field theory. Fractional statistics can be extended to nonabelian statistics and examples can be constructed from conformal field theory. The Pfaffian state is related to the 2D Ising model and possesses fractionally charged excitations which are predicted to obey nonabelian statistics.
Vector and Axial Form Factors Applied to Neutrino Quasielastic Scattering

We calculate the quasielastic cross sections for neutrino scattering on nucleons using up to date fits to the nucleon elastic electromagnetic form factors G E p , G E n , G M p , G M n , and weak form factors. We show the extraction of F A ( q 2 ) . We show the that F A ( q 2 ) has a different contribution to the anti-neutrino cross section, and how the anti-neutrino data can be used to check F A ( q 2 ) extracted from neutrino scattering. (Presented by Howard Budd at NuInt04, Mar. 2004, Laboratori Nazionali del Gran Sasso - INFN - Assergi, Italy [ http://nuint04.lngs.infn.it/ ])
Series solution and minimal surfaces in AdS

According to the Alday-Maldacena program the strong coupling limit of Super Yang-Mills scattering amplitudes is given by minimal area surfaces in AdS spacetime with a boundary consisting of a momentum space polygon. The string equations in AdS systematically reduce to coupled Toda type equations whose Euclidean classical solutions are then of direct relevance. While in the simplest case of AdS3 exact solutions were known from earlier studies of the sinh-Gordon equation, there exist at present no similar exact forms for the generalized Toda equations related to AdSd with d ≥ 4. In this paper we develop a series method for the solution to those equations and evaluate their contribution to the finite piece of the worldsheet area. For the known sinh-Gordon case the method is seen to give results in excellent agreement with the exact answer.
Nucleophilic cycloaromatization of ynamide-terminated enediynes.

Introduction of a nitrogen atom at one of the acetylenic termini of 10-, 11-, 12-, and 13-membered benzannulated cyclic enediynes results in a complete suppression of the conventional radical Bergman reaction in favor of a polar cycloaromatization. The latter reaction is catalyzed by acids and proceeds via initial protonation of an ynamide fragment. The resulting ketenimmonium cation then cyclizes to produce naphthyl cation, which rapidly reacts with nucleophiles or undergoes Friedel−Crafts addition to aromatic compounds. In alcohols, addition of the nucleophilic solvent across the activated triple bond competes with the cyclization reaction. The ratio of cyclized to solvolysis products decreases with the increase in ring size.
Formation of ring-retaining products from the OH radical-initiated reactions of benzene and toluene

The aromatic ring-retaining products formed from the gas–phase reactions of the OH radical with benzene and toluene, in the presence of NOx, have been identified and their formation yields determined. These products, and their formation yields, are as follows: from benzene – phenol, 0.236 ± 0.044; nitrobenzene, {(0.0336 ± 0.0078) + (3.07 ± 0.92) × 10−16[NO2]}; from toluene – benzaldehyde, 0.0645 ± 0.0080; benzyl nitrate, 0.0084 ± 0.0017; o−cresol, 0.204 ± 0.027; m− + p−cresol, 0.048 ± 0.009; m-nitrotoluene, {(0.0135 ± 0.0029) + (1.90 ± 0.25) × 10−16[NO2]}, where the NO2 concentration is in molecule cm−3 units. The formation yields of o- and p-nitrotoluene from toluene were ca. 0.07 and 0.35 that of m-nitrotoluene, respectively. The observations that the nitro-aromatic yields do not extrapolate to zero as the NO2 concentration approaches zero are not consistent with current chemical mechanisms for these OH radical-initiated reactions, and suggest that under the experimental conditions employed in this study the hydroxycyclohexadienyl radicals formed from OH radical addition to the aromatic ring react with NO2 rather than with O2. However, these data concerning the nitroaromatic yields are consistent with our previous conclusions that many of the nitrated polycyclic aromatic hydrocarbons present in ambient air are formed, at least in part, in the atmosphere from OH radical reactions.
Sparse complete sets for NP: Solution of a conjecture of Berman and Hartmanis

Abstract A set S ⊂ Σ ∗ is sparse if there is a polynomial p such that the number of strings in S of length at most n is at most p(n). All known NP-complete sets, such as SAT, are polynomial-time isomorphic and are not sparse. The main result of this paper is that if there is a sparse NP-complete set under polynomial-time many-one reductions, then P = NP. We also show that if there is a sparse NP-complete set under polynomial-time Turing reductions, then the polynomial-time hierarchy collapses to Δ2P.
Na3[Ti2P2O10F] : A new oxyfluorinated titanium phosphate with an ionic conductive property

Titanium phosphate, Na3[Ti2P2O10F]·xH2O (1), has been synthesized under hydrothermal conditions and structurally characterized using powder X-ray diffraction, neutron diffraction, and selected area electron diffraction (SAED). 1 crystallizes in the tetragonal space group I4/mmm with a = 6.4207(1) A and c = 10.6762(2) A and can be described by the stacking of a square-net sheet consisting of alternative linkage of TiFO5 octahedra and PO4 tetrahedra. The TiFO5 octahedron is highly distorted, with a short “titanyl” Ti−O bond and a long Ti−F bond. The “titanyl” oxygen is almost doubly bonded to Ti; the square-net sheets are linked only by sharing common F atoms, which lead to a rather opened framework containing 2D channels in the ab plane. The counter cations Na+ and water molecules reside in the channels. At high temperature, the adsorbed water molecules escape from the channels, leading to an anhydrous phase Na3[Ti2P2O10F] (2) with exactly the same structural framework as that of 1. 2 is stable at high tem...
Host–guest chemistry of calixarene capsules

Reversible encapsulation is one of the more recent forms of molecular recognition. Small molecule targets are completely surrounded by larger molecular assemblies and steric barriers keep the guest from escaping the host. Calix[4]arenes make useful modules for capsule construction and the review traces their history. Applications in physical organic chemistry, materials science and spectroscopy are described.
Subsurface magnetic field and flow structure of simulated sunspots

We present a series of numerical sunspot models addressing the subsurface field and flow structure in up to 16?Mm deep domains covering up to two days of temporal evolution. Changes in the photospheric appearance of the sunspots are driven by subsurface flows in several Mm depth. Most of magnetic field is pushed into a downflow vertex of the subsurface convection pattern, while some fraction of the flux separates from the main trunk of the spot. Flux separation in deeper layers is accompanied in the photosphere with light bridge formation in the early stages and formation of pores separating from the spot at later stages. Over a timescale of less than a day we see the development of a large-scale flow pattern surrounding the sunspots, which is dominated by a radial outflow reaching about 50% of the convective rms velocity in amplitude. Several components of the large scale flow are found to be independent from the presence of a penumbra and the associated Evershed flow. While the simulated sunspots lead to blockage of heat flux in the near surface layers, we do not see compelling evidence for a brightness enhancement in their periphery. We further demonstrate that the influence of the bottom boundary condition on the stability and long-term evolution of the sunspot is significantly reduced in a 16 Mm deep domain compared to the shallower domains considered previously.
Percolation with multiple giant clusters

We study mean-field percolation with freezing. Specifically, we consider cluster formation via two competing processes: irreversible aggregation and freezing. We find that when the freezing rate exceeds a certain threshold, the percolation transition is suppressed. Below this threshold, the system undergoes a series of percolation transitions with multiple giant clusters ('gels') formed. Giant clusters are not self-averaging as their total number and their sizes fluctuate from realization to realization. The size distribution Fk, of frozen clusters of size k, has a universal tail, Fk ~ k?3. We propose freezing as a practical mechanism for controlling the gel size.
Inverse continuity on the boundary of the numerical range

Let . We consider the mapping , defined on the unit sphere in . The map has a multi-valued inverse , and the continuity properties of are considered in terms of the structure of the set of pre-images for points in the numerical range. It is shown that there may be only finitely many failures of continuity of , and conditions for where these failure occur are given. Additionally, we give a necessary and sufficient condition for weak inverse continuity to hold for and a sufficient condition for .
Generation and cycloaddition of heteroatom-substituted 2-azaallyl anions with alkenes and alkynes. Synthesis of 1-pyrrolines and pyrroles

Abstract Imidates and thioimidates 1 bearing an N-(1-tri- n -butylstannyl)alkyl group (e.g., 7 – 9 ) were transmetalated with n -BuLi to generate heteroatom-substituted 2-azaallyl anions 2 . These anions underwent [2πs+4πs] cycloadditions with alkenes to produce 1-pyrrolines 4 after loss of alkoxide or thiolate. The pyrrolines were further deprotonated in situ with n -BuLi to generate 1-metalloenamines 5 , which could be quenched with water or CH 3 I to produce 1-pyrrolines 4 or 6 . The use of diphenylacetylene in the cycloaddition resulted in the formation of a pyrrole.
Quenching of reaction by cellular flows

We consider a reaction-diffusion equation in a cellular flow. We prove that in the strong flow regime there are two possible scenarios for the initial data that is compactly supported and the size of the support is large enough. If the flow cells are large compared to the reaction length scale, propagating fronts will always form. For small cell size, any finitely supported initial data will be quenched by a sufficiently strong flow. We estimate that the flow amplitude required to quench the initial data of support L0 is \(A > CL_0^4 \ln \left( {L_0 } \right).\) The essence of the problem is the question about the decay of the L∞-norm of a solution to the advection-diffusion equation, and the relation between this rate of decay and the properties of the Hamiltonian system generated by the two-dimensional incompressible fluid flow.
Inflation targeting and core inflation

. This paper examines the interaction of core inflation and inflation targeting as a monetary policy regime. Interest in core inflation has grown because of inflation targeting. Core inflation is defined in numerous ways giving rise to many potential measures; this paper defines core inflation as the best forecaster of inflation. A cross-country study finds before the start of inflation targeting, but not after, core inflation differs between non-inflation targeters and inflation targeters. Through conditional regressions, inflation expectations as measured by core inflation have not changed with the advent of inflation targeting nor do they differ from non-targeters. JEL classification: E52 and E31 Cible de maitrise de l’inflation et inflation sous-jacente. Ce texte examine l’interaction entre l’inflation sous-jacente et l’utilisation de cibles de maitrise de l’inflation dans un regime de politique monetaire. L’interet pour l’inflation sous-jacente a crua proportion que l’utilisation de cibles a cru. L’inflation sous-jacente est definie de bien des manieres et se prete a plusieurs mesures potentielles; ce texte la definit comme le meilleur predicteur de l’inflation. Une etude transversale de plusieurs pays revele que l’inflation sous-jacente differe entre les pays qui ont des cibles et ceux qui n’en n’ont pas avant qu’on commence a cibler mais pas apres. Via des regressions conditionnelles, on montre que les anticipations d’inflation telles que mesurees par l’inflation sous-jacente n’ont pas change avec l’arrivee du ciblage et qu’elles ne different pas de celles des pays qui ne ciblent pas.
Dense memory with high order neural networks

Abstract General high order neural networks [LD…] (models which are multinomial as opposed to linear in gain functions) offer high storage capacity [PPH] and fast convergence [GM] at the expense combinatorial growth of connections. This paper presents a specific high order neural network design which can store using n neurons any number M,1≤M≤2n, of any of the binomial n-strings; in a schematic representation the model requires only 5n+M(1+2n) edges. Each stored n-string represents a memory as a constant attractor trajectory of an n-dimensional differential equation dynamical system, a memory model neural network. With sufficiently high gains, the only stable attractors are the memories. Thus the memory model amounts to a solution of a version of the fundamental memory problem posed in [LMP] and elsewhere. The memory model can be used in error-correcting decoding of any binary string code and can accept noisy nonbinary signals.
SparsePak: A Formatted Fiber Field Unit for the WIYN Telescope Bench Spectrograph. I. Design, Construction, and Calibration

ABSTRACT We describe the design and construction of a formatted fiber field unit, SparsePak, and characterize its optical and astrometric performance. This array is optimized for spectroscopy of low surface brightness extended sources in the visible and near‐infrared. SparsePak contains 82, 4 \documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \usepackage[OT2,OT1]{fontenc} \newcommand\cyr{ \renewcommand\rmdefault{wncyr} \renewcommand\sfdefault{wncyss} \renewcommand\encodingdefault{OT2} \normalfont \selectfont} \DeclareTextFontCommand{\textcyr}{\cyr} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} \landscape $\farcs$\end{document} 7 fibers subtending an area of \documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pif...
Matrix isolated HF: the high-resolution infrared spectrum of a cryogenically solvated hindered rotor

Abstract The spectra of the infrared fundamentals of HF and DF isolated in solid Ar were recorded at high resolution, and general agreement with previous measurements was found. The temperature behavior of the spectra show that both species are nearly free rotors, in agreement with previous observations. The positions and splittings of these features, however, show that the rotation is at least slightly hindered and that more than one matrix site is observed. These spectra have been simulated using recent ArHF and Ar 2 intermolecular potentials in a calculation of the rotational energy states of various matrix sites. The Hutson H6(4, 3, 2) potential gives reasonable to excellent agreement between the predicted and observed features, including the redshift from the gas phase to the matrix, and the spectra are interpreted in terms of two sites: a single substitution site, which perturbs the rotational spectrum slightly, and a distorted interstitial site which is more hindering.
Simple, Accurate, Approximate Orbits in the Logarithmic and a Range of Power-Law Galactic Potentials

Curves in a family derived from powers of the polar-coordinate formula for ellipses are found to provide good fits to bound orbits in a range of power-law potentials. This range includes the well-known 1/r (Keplerian) and logarithmic potentials. These approximate orbits, called p-ellipses, retain some of the basic geometric properties of ellipses. They satisfy and generalize Newton's apsidal precession formula, which is one of the reasons for their surprising accuracy. Because of their simplicity the p-ellipses make very useful tools for studying trends among power-law potentials, and especially the occurrence of closed orbits. The occurrence of closed or nearly closed orbits in different potentials highlights the possibility of period resonances between precessing, eccentric orbits and circular orbits, or between the precession period of multilobed closed orbits and satellite periods. These orbits and their resonances promise to help illuminate a number of problems in galaxy and accretion disk dynamics.
Industry Costs and Consolidation: Efficiency Gains and Mergers in the Railroad Industry

Since partial deregulation in 1980, there has been a massive consolidation of firms in the U.S. railroad industry premised largely on efficiency gains. We estimate a cost function and use it to calculate cost effects for specific mergers and for all mergers at the industry level from 1983–2003. Our central results are that consolidation in the railroad industry accounts for about an 11.4 percent reduction in industry costs (more than $4 Billion in 1992 prices), and that while there are tremendous differences across mergers with respect to the direction, level, timing, and source of cost impacts, most mergers result in cost savings.
IMPORTANCE OF BRAIN DOPAMINE FOR THE STIMULANT ACTIONS OF AMPHETAMINE

Publisher Summary This chapter describes the importance of brain dopamine for the stimulant actions of amphetamine. The antiamphetamine actions of α-methyltyrosine (αMT), an inhibitor of tyrosine hydroxylase, are well documented. It has been reported that DBH inhibitors produce behavioral depression and block the central stimulation produced by amphetamines and related drugs. The behavioral depressant and NE depleting actions of these inhibitors do not appear to be casually related. Intra-peritoneal administration of various DBH inhibitors reduces locomotor activity in rodents and markedly elevates plasma corticosterone and blood glucose concentrations. It is found that blockade of DBH with U-14, 624 did not influence amphetamine-induced stimulation of activity. It is found that because disruption of both NE and D synthesis by αMT blocks d -amphetamine-stimulated activity while disruption of only NE synthesis does not, it appears that the stimulation produced by amphetamine is primarily dependent upon a dopaminergic mechanism. This conclusion, however, is based upon the premise that antiamphetamine properties of αMT are related to the ability of this drug to inhibit tyrosine hydroxylase.
Specifications and their use in defining subtypes

Specifications are useful because they allow reasoning about objects without concern for their implementations. Type hierarchies are useful because they allow types that share common properties to be designed as a family. This paper is concerned with the interaction between specifications and type hierarchies. We present a way of specifying types, and show how some extra information, in addition to specifications of the objects' methods, is needed to support reasoning. We also provide a new way of showing that one type is a subtype of another. Our technique makes use of information in the types' specifications and works even in a very general computational environment in which possibly concurrent users share mutable objects.
Cultural deprivation reflected in linguistic acquisition and development.

Cultural deprivation has been found to affect the acquisition, development, and utilization of language for the child. Social class, home and environment variables are among the most significant as underlying dimensions of language patterns. Their influences are considered and discussed, as is language, as a series of conditional responses reinforced in the developmental process.
An experimental test for gender differences in beneficent behavior

Abstract We examine data from a laboratory test in which each subject is given the task of dividing a sum of money between him-or-herself and one other. We find no evidence for gender differences in generosity.
Balanced allocation on graphs

It is well known that if n balls are inserted into n bins, with high probability, the bin with maximum load contains (1 + o(1)) log n/log log n balls. Azar, Broder, Karlin, and Upfal [1] showed that instead of choosing one bin, if d ≥ 2 bins are chosen at random and the ball in serted into the least loaded of the d bins, the maximum load reduces drastically to log log n/log d + O(1). In this paper, we study the two choice balls and bins process when balls are not allowed to choose any two random bins, but only bins that are connected by an edge in an underlying graph. We show that for n balls and n bins, if the graph is almost regular with degree ne, where e is not too small, the previous bounds on the maximum load continue to hold. Precisely, the maximum load is log log n + O(1/e) + O(1). So even if the graph has degree nΩ(1/log log n), the maximum load is O(log log n). For general Δ-regular graphs, we show that the maximum load is log log n + O(log n/log (Δ/log4n)) + O(1) and also provide an almost matching lower bound of log log n + log n/log (Δ log n). Further this does not hold for non-regular graphs even if the minimum degree is high.Vocking [29] showed that the maximum bin size with d choice load balancing can be further improved to O(log log n/d) by breaking ties to the left. This requires d random bin choices. We show that such bounds can be achieved by making only two random accesses and querying d/2 contiguous bins in each access. By grouping a sequence of n bins into 2n/d groups, each of d/2 consecutive bins, if each ball chooses two groups at random and inserts the new ball into the least-loaded bin in the lesser loaded group, then the maximum load is O(log log n/d) with high probability. Furthermore, it also turns out that this partitioning into aligned groups of size d/2 is also essential in achieving this bound, that is, instead of choosing two aligned groups, if we simply choose random but possibly unaligned random sets of d/2 consecutive bins, then the maximum load jumps to Ω(log log n/log d) even if the two sets are always chosen to be disjoint.
Using tracer thermochronology to measure modern relief change in the Sierra Nevada, California

Abstract We examine relief change in two major Sierra Nevada drainages, the Kings and the San Joaquin. The modern distribution of bedrock cooling ages is derived by fitting isochrones to a dense distribution of existing cooling ages. This analysis indicates southwest tilting of the range by 3.4° ± 0.8°, which is consistent with other geologic evidence for tilting after ∼ 5 Ma. The detrital cooling ages from the Kings show an excess of young ages relative to what would be expected from uniform erosion, whereas the San Joaquin drainage shows excess old ages. These results indicate increasing relief in the Kings. The results in the San Joaquin are more difficult to interpret due to the dense network of dams, which trap sediment. However, we analyze the effect of storage behind the dams and suggest steady or declining relief in the San Joaquin. The residence time of sediment in these drainages indicates that these relief estimates are averaged over the last 100 to 10 ka. We suggest that relief change is related to localized surface uplift in the southern Sierra Nevada, including the Kings drainage, caused by ongoing lower lithosphere removal. The San Joaquin drainage may be north of the lithospheric anomaly, which is consistent with stagnating or decaying relief there.
Dynamic intersystem crossing in solid bis(phenanthroline)bis(cyanotrihydroborato)iron(II)

Variable-temperature Moessbauer, magnetic susceptibility, and infrared studies of Fe(phen)/sub 2/(NCBH/sub 3/)/sub 2/ reveal the occurrence of a reversible, gradual singlet/quintet intersystem crossing above room temperature. Moessbauer spectra of the complex in the transition region are interpreted as showing the occurrence of a novel (for Fe(II)), fast singlet/quintet interconversion. 24 references, 5 figures, 3 tables.
Infrared Spectra of Thallium Hydrides in Solid Neon, Hydrogen, and Argon

Laser-ablated Tl atoms react with dihydrogen in excess neon, pure hydrogen, and excess argon to form primarily the TlH diatomic molecule. Ultraviolet irradiation increases weak bands that are identified as TlH2 and TlH3 on the basis of D2 and HD substitution and density functional theory (DFT) isotopic frequency calculations. Sample annealing fosters the dimerization of TlH to give Tl2H2 with a rhombic ring structure and the TlTlH2 isomer. The markedly lower yield of TlH3 in these experiments compared to AlH3 in earlier investigations is due to the expected decrease in stability for the Tl(III) oxidation state. The Tl+(H2)n cation complex is also observed, and trends within the group 13 metals are summarized. Excitation at 193 nm gives the 2S1/2 → 2P1/2,3/2 doublet for unreacted Tl atoms, which is blue-shifted 660 cm-1 from the gas-phase value in solid D2 but only 210 cm-1 in solid H2, owing to the smaller, more repulsive D2 matrix cage.
Visible Light-Promoted Metal-Free C–H Activation: Diarylketone-Catalyzed Selective Benzylic Mono- and Difluorination

We report herein an operationally simple method for the direct conversion of benzylic C–H groups to C–F. We show that visible light can activate diarylketones to abstract a benzylic hydrogen atom selectively. Adding a fluorine radical donor yields the benzylic fluoride and regenerates the catalyst. The selective formation of mono- and difluorination products can be achieved by catalyst control. 9-Fluorenone catalyzes benzylic C–H monofluorination, while xanthone catalyzes benzylic C–H difluorination. The scope and efficiency of this new C–H fluorination method are significantly better than those of the existing methods. This is also the first report of selective C–H gem-difluorination.
Local Interference Can Accelerate Gossip Algorithms

In this paper, we show how interference can be exploited to perform gossip computations for average-based consensus over a larger local neighborhood, rather than only pairs of nodes. We use a new channel coding technique called computation coding to compute sums reliably over the wireless medium. Since many nodes can simultaneously average in a single round, our neighborhood gossip algorithm converges faster than the standard nearest neighbor gossip algorithm. For a network with n nodes and size m neighborhoods, neighborhood gossip requires O(n2/m2) rounds while standard gossip requires Θ(n2) rounds. Furthermore, we show that if the power path loss coefficient is less than 4, the total transmit energy employed by neighborhood gossip is polynomially smaller than that employed by standard gossip.
Room-Temperature Ni(0)-Catalyzed Cross-Coupling Reactions of Aryl Arenesulfonates with Arylboronic Acids

Room-temperature Ni(0)-catalyzed cross-coupling reactions of aryl arenesulfonates with arylboronic acids are described. The Ni(0) catalyst, derived from Ni(COD)2 and PCy3, proved to be a general one for the Suzuki−Miyaura cross-coupling of a variety of aryl arenesulfonates. The mild reaction condition, the readily availability of the catalyst, and excellent coupling yields make aryl arenesulfonates potentially useful substrates in organic synthesis.
Electron acceleration in solar flares

Abstract Observations suggest that electron acceleration in impulsive solar flares occurs in magnetic reconnection regions in the corona above the soft X-ray flare loops. Acceleration by a super-Dreicer electric field in a reconnecting current sheet appears to be the most direct way of producing electrons in the energy range between tens of keV and tens of MeV. Theoretical models for collisionless particle acceleration in large-scale current sheets formed in quadrupolar magnetic geometries are reviewed. Recent calculations of particle orbits and energy gains are described, stressing the use of global balance relations and exact MHD solutions for the magnetic fields and plasma flows in the current sheet. The results support the viewpoint that electrons that generate the continuum gamma-ray and hard X-ray emissions in impulsive solar flares are accelerated in a turbulent reconnecting current sheet.
Multilayer Optical Learning Networks

A new approach to learning in a multilayer optical neural network based on holographically interconnected nonlinear devices is presented. The proposed network can learn the interconnections that form a distributed representation of a desired pattern transformation operation. The interconnections are formed in an adaptive and self-aligning fashioias volume holographic gratings in photorefractive crystals. Parallel arrays of globally space-integrated inner products diffracted by the interconnecting hologram illuminate arrays of nonlinear Fabry-Perot etalons for fast thresholding of the transformed patterns. A phase conjugated reference wave interferes with a backward propagating error signal to form holographic interference patterns which are time integrated in the volume of a photorefractive crystal to modify slowly and learn the appropriate self-aligning interconnections. This multilayer system performs an approximate implementation of the backpropagation learning procedure in a massively parallel high-speed nonlinear optical network.
First ground‐based measurements of OI 6300 Å daytime aurora over Boston in response to the 30 October 2003 geomagnetic storm

[1] High spectral resolution measurements of OI 6300 A emissions during daytime on 30 October 2003 from Boston revealed prolonged auroral activity from 1415–1900 LT. The solar zenith angles varied from 70°–115° during that interval. Intense enhancement in brightness of 38 Kilo Rayleighs were observed at 1509 LT, which were six times larger than the normal daytime emission rates for that day. During this event the solar zenith angle was 74° and the solar background continuum was 4 × 106 Rayleighs A−1. Such large enhancement in brightness were due to the daytime aurora generated in response to an X-class Coronal Mass Ejection on the Sun. The measured daytime airglow emissions show good agreement, both, in the magnitudes and in the temporal variability with the emissions modeled by using as inputs the Ne, Te and Ti profiles that were measured by the Millstone Hill Incoherent Scatter Radar (ISR) located approximately 60 km away from the spectrograph.
On optimal nonlinear estimation — Part II: Discrete observation☆

A general representation for the joint conditional probability density of an arbitrary random signal process under discrete-time observation is obtained. This representation forms the cornerstone of the paper, and from it all other results are deduced. The conditional densities of prediction and smoothing are expressed in terms of filtering via the application of the general representation. The prediction and smoothing of a random process with linear dynamics and arbitrary a priori distribution are given to illustrate the applicability of the previous results in obtaining effectively computable formulas.
Synthesis of 6′-Aminohexyl 2-Acetamido-2-deoxy-D-galactoside Isomers and a Unique Isomerization Catalyzed by Ion Exchange Resin

Abstract The 6-aminohexyl α- and β-pyranosides and β-furanoside of 2-acetamido-2-deoxy-D-galactose (N-acetyl-D-galactosamine) were prepared. N-Acetyl-D-galactosamine was reacted with acetyl chloride in the cold. The per-O-acetyl 1-chloro derivative was then reacted with 6-(N-trifluoroacetyl) aminohexanol in the presence of mercuric cyanide. Glycoside products were isolated by gel chroraatography, de-O-acetylated, and de-N-trifluoroacety-lated. The β-pyranoside, which is the major product, was obtained in 29% overall yield, as well as the β-furanoside. The α-pyranoside was prepared in 70% overall yield by reacting 2-acetamido-1, 3, 4, 6-tetra-O-acetyl-2-deoxy-α-D-galacto-pyranose, which is a byproduct of the above synthetic scheme (22%), with 6-(N-trifluoroacetyl)aminohexanol in the presence of boron trifluoride etherate. A strong cation exchange resin (Dowex 50X8, H+ form) catalyzed interconversion of the β-furanoside and the β-pyranoside, with the latter predominating at equilibrium. The α-pyranoside was...