cssi/SciSciGPT-SciSciNet huggingface dataset:
Instanton content of the SU(3) vacuum

Abstract We study the topological content of the SU(3) vacuum using the renormalization group (RG) mapping method. RG mapping is a simple smoothing algorithm, in which a series of APE-smearing steps are done while the topological content of the configuration is carefully monitored. This monitoring process makes it possible to separate true topological objects from vacuum fluctuations and allows an extrapolation to zero smearing steps. Using RG mapping we have measured the instanton distribution and topological susceptibility for SU(3) gauge theory. We arrive at a value for the topological susceptibily, χ 1/4 of 203(5) MeV. The size distribution peaks at ρ =0.3 fm, and is in good agreement with the prediction of instanton liquid models.
A Convenient and Efficient Preparation of 2‐Acetyl‐4,5‐difluorothiophene

Abstract A convenient, five‐step preparation of 2‐acetyl‐4,5‐difluorothiophene from 2,3‐dibromothiophene is described.
Experimental verification of the Hall effect during magnetic reconnection in a laboratory plasma.

In this Letter we report a clear and unambiguous observation of the out-of-plane quadrupole magnetic field suggested by numerical simulations in the reconnecting current sheet in the magnetic reconnection experiment. Measurements show that the Hall effect is large in the collisionless regime and becomes small as the collisionality increases, indicating that the Hall effect plays an important role in collisionless reconnection.
Freeze-etching simplified.

Summary A new freeze-etching module, which permits easy preparation of 4 simultaneous replicas and more than 40 replicas per day, has been developed. In standard use, rough fracturing in a vacuum with the tip of a pointed knife replaces the use of a razor blade. A sharp-pointed carbon rod permits routine satisfactory evaporation of platinum-carbon shadow films. In order to improve shadow quality and prevent excessive contamination of the vacuum system, shielded shadowing guns that are easily removed, dismantled, cleaned, and reloaded have been devised. Satisfactory specimens of yeast cells, barteria, algae, nematodes, mouse brain, parasitized red blood cells, and virus-infected tobacco cells have been prepared in the new module.
Building unbiased estimators from non-Gaussian likelihoods with application to shear estimation

We develop a general framework for generating estimators of a given quantity which are unbiased to a given order in the difference between the true value of the underlying quantity and the fiducial position in theory space around which we expand the likelihood. We apply this formalism to rederive the optimal quadratic estimator and show how the replacement of the second derivative matrix with the Fisher matrix is a generic way of creating an unbiased estimator (assuming choice of the fiducial model is independent of data). Next we apply the approach to estimation of shear lensing, closely following the work of Bernstein and Armstrong (2014). Our first order estimator reduces to their estimator in the limit of zero shear, but it also naturally allows for the case of non-constant shear and the easy calculation of correlation functions or power spectra using standard methods. Both our first-order estimator and Bernstein and Armstrong's estimator exhibit a bias which is quadratic in true shear. Our third-order estimator is, at least in the realm of the toy problem of Bernstein and Armstrong, unbiased to 0.1% in relative shear errors Δg/g for shears up to |g|=0.2.
Postmortem fetal MR imaging: comparison with findings at autopsy.

The purpose of this study was to prospectively compare findings from postmortem fetal MR imaging with findings at autopsy.Twenty-six fetuses were imaged on a 1.5-T MR scanner using two-dimensional and high-resolution three-dimensional fast spin-echo techniques immediately before autopsy. The MR images were reviewed independently by three radiologists who evaluated then for major and minor malformations. These findings were then compared with those at autopsy.The 26 subjects had 47 major and 11 minor malformations. All three radiologists correctly identified 37 of the major malformations on the MR images (detection rate, 79%), and at least one of the three reviewers correctly identified 43 of the abnormalities (detection rate, 91%). Only one of the 11 minor anomalies was identified by any reviewer. Reviewers made six false-positive diagnoses. In two cases, both with major CNS malformations, MR imaging was superior to autopsy in defining in situ relationships.Although autopsy remains the study of choice for...
Compensatory Vascular Remodeling During Atherosclerotic Lesion Growth Depends on Matrix Metalloproteinase-9 Activity

Objective— The compensatory arterial remodeling associated with atherosclerotic plaques is thought to rely on the activity of matrix metalloproteinases (MMP). To assess the role of MMP-9, we analyzed the effect of MMP-9 genetic deficiency on the development and remodeling of experimental atherosclerotic lesions induced in the apolipoprotein E (apoE) knockout (−/−) mouse model. Methods and Results— We analyzed remodeling parameters and cellular composition of experimental carotid artery atherosclerotic lesions in apoE−/− and apoE−/− MMP-9−/− double-knockout (DKO) mice at 0, 3, 7, and 14 days after induction by flow cessation. Morphometric image analysis of arterial tissue sections indicated that overall artery size, measured as area encompassed by the external elastic lamina, increased 3.1-fold in the apoE−/− mice but only 1.6-fold in the DKO mice (P<0.0001) by 14 days. At the same time, the net lesion area occupied by macrophages was similar. Statistical analysis indicated that the overall expansion of th...
Dispatch sequences for embedded control models

We consider the problem of mapping a set of control components to an executable implementation. The standard approach to this problem involves mapping control blocks to periodic tasks, and then generating a schedule. This schedule is platform-dependent, and its execution requires real-time operating system support. We propose an alternative approach which involves generating a dispatch sequence of control blocks in a platform-independent manner. Our solution relies on assigning relative complexity and relative importance measures to control components, and is an adaptation of the classical scheduling algorithms such as earliest-deadline-first. We show the benefits of our approach using simulation experiments on two case studies.
Lanthanum‐Magnesium and Lanthanum‐Manganese Donor‐Acceptor‐Codoped Semiconducting Barium Titanate

BaTiO3 powder doped with La donor and codoped with Mn or Mg acceptor was sintered at 1350°C/1 h in air. For Ladoped BaTiO3, the room-temperature resistivity decreased to a minimum at [La3+] ∼ 0.15 mol%. For La-Mn-codoped BaTiO3, the minimum resistivity occurred at [La3+] - 2[Mn2+] ∼ 0.15 mol%. When the ceramic was changed to a fine-grained insulator by high donor doping ([La3+] >0.15 mol%), its semiconductivity was restored, and the relatively homogeneous, coarse-grained microstructure recurred by codoping with either Mg or Mn acceptor, with the transition at [La3+] - 2[Mg2+] = 0.15 mol% or [La3+] - 2[Mn2+] = 0.15 mol%. The analogy of a compensation effect between La-Mn- and La-Mg-codoped BaTiO3 suggested that Mn acceptor added to BaTiO3 exists as Mn2+ ion in the bulk grain region; its influence on the positive temperature coefficient of resistivity behavior is then discussed.
Cyclical productivity in a model of labor hoarding

Abstract This paper develops a dynamic model of labor hoarding to explain two empirical facts, the cyclical behavior of total factor productivity and the dynamic correlations of sectoral productivity with aggregate variables. The model features convex costs of adjusting the labor force, which induce firms to vary the intensity of labor utilization over the cycle. In particular, cyclical variations in labor ‘effort’ take place as a response to expected future changes in industry conditions. I test the restrictions imposed by the model for several two-digit manufacturing industries under different assumptions about market structure and returns to scale. Then, using the assumption that aggregate variables carry information about future changes in industry conditions. I simulate the model's dynamic response of hours and productivity to aggregate innovations and compare them to those estimated from the data.
A SUM-PRODUCT ESTIMATE IN FINITE FIELDS, AND APPLICATIONS

Let A be a subset of a finite field $$ F := \mathbf{Z}/q\mathbf{Z} $$ for some prime q. If $$ |F|^{\delta} < |A| < |F|^{1-\delta} $$ for some δ > 0, then we prove the estimate $$ |A + A| + |A \cdot A| \geq c(\delta)|A|^{1+\varepsilon} $$ for some e = e(δ) > 0. This is a finite field analogue of a result of [ErS]. We then use this estimate to prove a Szemeredi-Trotter type theorem in finite fields, and obtain a new estimate for the Erdos distance problem in finite fields, as well as the three-dimensional Kakeya problem in finite fields.
Asymmetric conjugate additions to chiral bicyclic lactams. A stereoselective, concise synthesis of chiral 2-alkyl-3,4-aziridinopyrrolidines

Abstract Stereoselective, conjugate additions of primary amines to chiral α-iodo α, β-unsaturated bicyclic lactams are described. Typical yields of the resulting aziridinolactams ranged from 60–90% with facial diastereoselectivities of >98:2 in all cases. Selected optically pure aziridinobicyclic lactams were transformed, by reductive cleavage, into chiral 2-alkyl, 3, 4-aziridinopyrrolidines.
Gender Integration of Occupations in the Federal Civil Service: Extent and Effects on Male-Female Earnings

Using the U.S. Office of Personnel Management's Central Personnel Data File, the author shows that from 1976 through 1992 gender integration of occupations proceeded more rapidly and steadily in the federal civil service than in the general economy. During that period, increasing numbers of women moved into traditionally male occupations, especially in professional and administrative work. Little of that progress, the author finds, was attributable to changes in women's education or seniority. Although average grades (indicating levels of responsibility) in male-dominated occupations declined as women entered them, gender integration of occupations helped to narrow male-female pay disparities in the federal service more than in the general economy.
Luminescent homoatomic exciplexes in dicyanoargenate(I) ions doped in alkali halide crystals. ‘Exciplex tuning’ by site-selective excitation and variation of the dopant concentration

Abstract The photoluminescence spectra of dicyanoargenate(I) ions doped in KCl host crystals show several ultraviolet and visible emission bands. Each emission band becomes dominant at a characteristic excitation wavelength; i.e. the energy of the emission can be tuned. Both the experimental and theoretical results suggest the formation of Ag–Ag bonded excimers and exciplexes between adjacent Ag(CN) 2 − ions in the host lattice. The experimental evidence includes the broadness, the absence of detailed structure, and the low band energies of the luminescent bands. Ab-initio and extended Huckel calculations show that the lowest unoccupied molecular orbital (LUMO) is bonding with respect to Ag–Ag bonds while the highest occupied molecular orbital (HOMO) is antibonding. Further, the calculations indicate the existence of exciplexes with shorter Ag–Ag bond distances, higher binding energies, and larger Ag–Ag overlap populations than the corresponding ground state oligomers. The results in this study give rise to a new optical phenomenon which is called ‘exciplex tuning’. Tuning of the emission over the 285–610 nm wavelength range has been achieved in KCl/Ag(CN) 2 − crystals by site-selective excitation and varying the Ag(CN) 2 − dopant concentration.
Direct Amino Acid-Catalyzed Asymmetric Desymmetrization of meso-Compounds: Tandem Aminoxylation/O−N Bond Heterolysis Reactions

A practical organocatalytic process for the synthesis of optically active, highly substituted α-hydroxy-ketones was achieved through asymmetric desymmetrization (ADS) of prochiral ketones. The ADS and O−N bond reduction reaction of prochiral ketone with nitrosobenzene in the presence of a catalytic amount of chiral amine or amino acid produced the tandem ADS/O−N bond reduced products as single diastereomers with good yields and excellent enantiomeric excesses.
Four Polyanionic Compounds in the K–Au–Ga System: A Case Study in Exploratory Synthesis and of the Art of Structural Analysis

The K-Au-Ga system has been investigated at 350 °C for <50 at. % K. The potassium gold gallides K(0.55)Au(2)Ga(2), KAu(3)Ga(2), KAu(2)Ga(4) and the solid solution KAu(x)Ga(3-x) (x = 0-0.33) were synthesized directly from the elements via typical high-temperature reactions, and their crystal structures were determined by single crystal X-ray diffraction: K(0.55)Au(2)Ga(2) (I, I4/mcm, a = 8.860(3) A, c = 4.834(2) A, Z = 4), KAu(3)Ga(2) (II, Cmcm, a = 11.078(2) A, b = 8.486(2) A, c = 5.569(1) A, Z = 4), KAu(2)Ga(4) (III, Immm, a = 4.4070(9) A, b = 7.339(1) A, c = 8.664(2) A, Z = 2), KAu(0.33)Ga(2.67) (IV, I-4m2, a = 6.0900(9) A, c = 15.450(3) A, Z = 6). The first two compounds contain different kinds of tunnels built of puckered six- (II) or eight-membered (I) ordered Au/Ga rings with completely different cation placements: uniaxial in I and III but in novel 2D-zigzag chains in II. III contains only infinite chains of a potassium-centered 20-vertex polyhedron (K@Au(8)Ga(12)) built of ordered 6-8-6 planar Au/Ga rings. The main structural feature of IV is dodecahedral (Au/Ga)(8) clusters. Tight-binding electronic structure calculations by linear muffin-tin-orbital methods were performed for idealized models of I, II, and III to gain insights into their structure-bonding relationships. Density of states curves reveal metallic character for all compounds, and the overall crystal orbital Hamilton populations are dominated by polar covalent Au-Ga bonds. The relativistic effects of gold lead to formation of bonds of greater population with most post-transition elements or to itself, and these appear to be responsible for a variety of compounds, as in the K-Au-Ga system.
CYCLOTOMIC BIRMAN–WENZL–MURAKAMI ALGEBRAS, I: FREENESS AND REALIZATION AS TANGLE ALGEBRAS

The cyclotomic Birman–Wenzl–Murakami algebras are quotients of the affine BMW algebras in which the affine generator satisfies a polynomial relation. We show that the cyclotomic BMW algebras are free modules over any admissible, integral ground ring, and that they are isomorphic to cyclotomic versions of the Kauffman tangle algebras.
Cost-benefit analysis for global public–private partnerships: an evaluation of the desirability of intergovernmental organizations entering into public–private partnerships

This paper explains the use of cost-benefit analysis for the evaluation of global public–private partnerships that combine international intergovernmental organizations with national governments, businesses, and the non-profit organizations of civil society. The partnerships allocate resources to projects that are socially desirable from an international perspective, yet without the global partnerships will not be performed. Cost-benefit analysis can identify and compare the social and the private costs and benefits of the projects, thereby identifying cases where global public–private partnerships will provide socially desirable results when markets alone will not. Cost-benefit analysis can assess the necessity and the sufficiency of strategies proposed by the partnerships. The paper discusses modifications to cost-benefit analysis required for its use in evaluations of the global public–private partnerships, explaining the need for market-centered valuations, but also explaining the role of alternative social valuations.
Pluripotent patents make prime time: an analysis of the emerging landscape

An examination of three patents in the fast-moving iPS space may help determine their ultimate value.
Total synthesis of apoptolidin: construction of enantiomerically pure fragments.

A general strategy for the total synthesis of the antitumor agent apoptolidin (1) is proposed, and the chemical synthesis of the defined key building blocks (4, 5, 6, 8, and 9) in their enantiomerically pure forms is described. The projected total synthesis calls for a dithiane coupling reaction to construct the C20−C21 bond, a Stille coupling reaction to form the C11−C12 bond, and a Yamaguchi macrolactonization to assemble the macrolide ring, as well as two glycosidation reactions to fuse the carbohydrate units onto the molecule. First and second generation syntheses to the required fragments for apoptolidin (1) are described.
The new binary intermetallic YbGe2.83

The new compound YbGe{sub 2.83} was obtained from the reaction of Yb and Ge in liquid indium. The crystal structure of YbGe{sub 2.83} adopts the trigonal, P3m1 space group with a=b=8.3657(12) A and c=7.0469(14) A. The structure of YbGe{sub 2.83} is a variant of the CaAl{sub 2}Si{sub 2} structure type with ordered vacancies. Germanium atoms form double layers of puckered hexagons creating slabs that sandwich the Yb atoms. YbGe{sub 2.83} can be classified as a Zintl compound with the formula Yb{sup (2+x)+}(Ge{sub 2.83}){sup (2+x)-}. The deficiencies at the Ge sites cause a mixed/intermediate valent state of ytterbium (Yb{sup 2.35+}). Valence bond sum calculations suggest an average valence of Yb ions in YbGe{sub 2.83} of 2.51 consistent with an intermediate valence compound. - Graphical abstract: The new binary compound YbGe{sub 2.83} is a variant of the CaAl{sub 2}Si{sub 2} structure type with ordered vacancies. Zintl formalism and valence bond sum calculations suggest intermediate valence of Yb ions in YbGe{sub 2.83}.
Modal control of the planar motion of a long flexible beam in orbit

Attitude control techniques for the pointing and stabilization of very large, inherently flexible spacecraft systems are investigated. The attitude dynamics and control of a long, homogeneous flexible beam whose center of mass is assumed to follow a circular orbit is analyzed. In this study, first order effects of gravity-gradient are included, whereas external perturbations and related orbital station keeping maneuvers are neglected. A mathematical model which describes the system deflections within the orbital plane has been developed by treating the beam as having a maximum of three discretized mass particles connected by massless, elastic structural elements. The uncontrolled dynamics of this system are simulated and, in addition, the effects of the control devices are considered. The concept of distributed modal control, which provides a means for controlling a system mode independently of all other modes, is examined. The effect of varying the number of modes in the model as well as the number and location of the control devices are also considered.
Structural characterization of horseradish peroxidase using EXAFS spectroscopy: evidence for Fe=O ligation in compounds I and II

Extended X-ray absorption fine structure spectroscopy has been utilized to determine the structural environment of the heme iron sites in horseradish peroxidase compounds I and II. For comparison, analogous studies have been undertaken on putative ferryl (Fe/sup IV/=O) porphyrin model compounds and on crystallographically characterized Cr/sup IV/=O and Cr/sup V/ identical with N porphyrins. In a preliminary communication, they suggested that a short ca. 1.6 A Fe-O bond is present in the high valent forms of both the enzyme and the synthetic porphyrins. The present work demonstrates unambiguously that a short, ca. 1.64 A, Fe-O bond length is present both in HRP compounds I and II and in their synthetic analogues. This structure is consistent only with an oxo-ferryl (Fe=O) complex as the active oxygen species in horseradish peroxidase. The structural details, their implications for heme protein mediated oxygen activation, and the difference between their results and those recently published by other workers.
A New Frequency Multiplier

A novel arrangement of n transformers delivers power at n times the line frequency. Ratings compare with transformers of the same weight. Waveform and voltage regulation are excellent. An experimental 7X unit with 60-cycle input gave 3.6 kw of 420-cycle output at approximately 90% efficiency. An additional 5X stage gave 2,100 cycles. Applications include high-speed a-c motors, fluorescent lighting, induction heating, control, and communication equipment.
Inertial effects in laser-driven ablation

The gasdynamic partial differential equations (PDE's) governing the motion of an ablatively accelerated target (rocket) contain an inertial force term that arises mathematically from acceleration of the reference frame in which the PDE's are written, and more physically from the requirement that part of the ablated mass (the deflagration wave zone) needs to be accelerated along with the unablated mass (payload). We give a simple, intuitive description of this effect, and estimate its magnitude and parametric dependences by means of approximate analytical formulas inferred from our computer hydrocode calculations. Often this inertial term is negligible, but for problems in the areas of laser fusion and laser equation of state studies we find that it can reduce the attainable hydrodynamic efficiency of acceleration and implosion by up to 25% for typical conditions.
Selection of Component Modes for Craig-Bampton Substructure Representations

Three measures of modal dynamic importance are studied for the purpose of ranking Craig-Bampton substructure fixed interface mode shapes based upon their contribution to forces at the substructure interface, modal velocity, or modal displacement. These measures can be employed to identify mode shapes which are dynamically important and thus should be retained in a reduced analytical representation, or identified during a modal survey of the substructure. The first method considered, Effective Interface Mass, has been studied previously. However, new results are presented showing the relation between Effective Interface Mass and a commonly used control dynamics measure of modal importance called approximate balanced singular values. In contrast to the general case of approximate balanced singular values, Effective Interface Mass always gives an absolute measure of the dynamic importance of mode shapes. The EIM method is extended to consider modal velocity and modal displacement outputs. All three measures are applied to a simple substructure called the General Purpose Spacecraft. It is shown that each of these measures provides an efficient method for ranking the dynamic importance of Craig-Bampton fixed interface modes such that a reduced representation will accurately reproduce the substructure's response in the frequency range of interest.
Halogen exchange between aryl grignard reagents and aryl halides in the presence of nickel(II) chloride

Abstract A unique halogen exchange reaction between aryl Grignard reagents and aryl halides, which occurred during an attempted cross-coupling reaction using non-ligated nickel(II) chloride as a catalyst, has been observed. The halogen exchange takes place between arylmagnesium iodides and aryl bromides but not between arylmagnesium bromides and aryl chlorides.
4‐Substituted ortho‐(Silylated phenyl)sydnones via a Lithiation‐Induced Silicon Migration and Subsequent Reaction with Electrophiles

Abstract Treatment of 3‐(2‐bromophenyl)‐4‐silylsydnones 1 with n‐butyllithium effects rearrangement to the corresponding ortho‐silylphenylsydnone anions 2, which can be trapped with electrophiles to afford 4‐substituted ortho‐silylphenylsydnones 4a–h in 41–89% yield.
Influence of fast waves on the collective scattering of microwaves in fusion plasmas

Microwave scattering by the fluctuations of fusion plasmas is one of the most promising α-diagnostic techniques. Previous investigations have concentrated on the fluctuations near the slow wave branch in the lower hybrid range of frequencies. The small signal and the lack of sensitivity to the contribution of α-particles to the total cross-section near the slow branch severely limits the effectiveness of this technique. In this paper, we report results of investigations of scattering by fluctuations in the lower hybrid range of frequencies near the fast branch. Surprisingly, when both fast and slow branches exist, the scattering amplitudes are comparable. More important, the α-contribution is larger for the fast branch and the fast branch has a larger parameter space where it exists. Specifically, the slow branch exists only above the lower hybrid frequency, while the fast branch can exist at all frequencies up to the electron cyclotron range of frequencies. We find numerically that the scattering amplitudes near the fast branch below the lower hybrid frequency are several orders of magnitude larger than those near the slow branch above that frequency where it can exist. This may make microwave scattering by fast waves a more attractive α-diagnostic technique.
Entanglement in dilute flux-line liquids

We construct, within the framework of classical statistical mechanics, a mean-field theory of dilute flux-line liquids which goes beyond linear hydrodynamics. Within our approach, we find that interactions between vortices produce a massive term in the Hamiltonian of the internal modes of the flux lines which confines their transverse fluctuations. This suggests that the flux-line liquid, at least in the low density limit considered in this paper, might very well be in a weakly entangled state, where the average width $〈{u}^{2}{〉}^{1/2}$ of flux lines can be much larger than the average distance between the lines but does not diverge with the sample thickness L. Consequences on the physics of flux-line liquids are briefly discussed.
What is wrong with the interpretation of recent nano-filament experiments?

In a recent paper, W. She, J. Yu and R. Feng reported the slight deformations observed upon transmission of a light pulse through a short length of a silica glass nano-filament. Relating the shape and magnitude of these deformations to the momentum of the light pulse inside and outside the filament, these authors concluded that, within the fiber, the photons carry the Abraham momentum. We present an alternative evaluation of force and momentum in a system similar to the experimental setup of She et al. Using precise numerical calculations that take into account not only the electromagnetic momentum inside and outside the filament, but also the Lorentz force exerted by a light pulse in its entire path through the nano-waveguide, we conclude that the net effect should be a pull (rather than a push) force on the end face of the nano-filament.
Odd Oxidation States of Palladium and Platinum

Abstract Recent research has uncovered a variety of compounds of palladium or platinum in formal oxidation states I and III. These are generally dimeric with some form of metal-metal interaction and many of them show unique chemical behavior.
Onset of petalling in a thin spacecraft wall perforated by an orbital debris particle

All long-duration spacecraft in low-earth-orbit are subject to high speed impacts by meteoroids and orbital debris. As a result, the threat of damage from such high-speed impacts is a major design consideration in the development and construction of long duration earth-orbiting spacecraft. Recent studies have shown that the nature of a spacecraft wall perforation can range from a flat hole with a jagged edge (i.e. a so-called cookie-cutter hole) to a hole accompanied by bulging, cracking, and petaling. If a cracking event were to occur on-orbit, unstable crack growth could develop which could lead to an unzipping of the impacted spacecraft module. It is, therefore, imperative to be able to determine whether or not a spacecraft wall perforation will be accompanied by petaling and cracking. This paper presents the results of a study whose objective was to develop an empirical model that could be used to determine whether a spacecraft wall perforation would be in the form of a petaled hole or a cookie-cutter hole. A petaling limit function was developed to predict the onset of petaling in terms of impact conditions and spacecraft wall system geometry.© (1998) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Dependence of enhanced asymmetry-induced transport on collision frequency

A single-particle code with collisional effects is used to study how asymmetry-induced radial transport in a non-neutral plasma depends on collision frequency. For asymmetries of the form ϕ1(r) cos(kz) cos(ωt−lθ), two sources for the transport have been identified: resonant particles and axially trapped particles. The simulation shows that this latter type, which occurs near the radius where ω matches the azimuthal rotation frequency ωR, is usually dominant at low collision frequency ν but becomes negligible at higher ν. This behavior can be understood by noting that axially trapped particles have a lower trapping frequency than resonant particles. In the low ν (banana) regime, the radial oscillations have amplitude Δr ≈ vr/ωT, so axially trapped particles dominate, and the transport may even exceed the resonant particle plateau regime level. As ν increases, collisions start to interrupt the slower axially trapped particle oscillations, while the resonant particles are still in the banana regime, so the a...
Millimeter Wavelength Brightness Fluctuations of the Atmosphere above the South Pole

We report measurements of the millimeter wavelength brightness fluctuations produced by the atmosphere above the South Pole made with the Arcminute Cosmology Bolometer Array Receiver (ACBAR). The data span the 2002 austral winter during which ACBAR was mounted on the Viper Telescope at the South Pole. We recover the atmospheric signal in the presence of instrument noise by calculating the correlation between signals from distinct elements of the ACBAR bolometer array. With this method, it is possible to measure atmospheric brightness fluctuations with a high signal-to-noise ratio even under the most stable atmospheric conditions. The observed atmospheric signal is characterized by the parameters of the Kolmogorov-Taylor (KT) model, which are the amplitude and power-law exponent describing the atmospheric power spectrum and the two components of the wind angular velocity at the time of the observation. The KT model is typically a good description of the observed fluctuations, and fits to the data produce values of the Kolmogorov exponent that are consistent with theoretical expectations. By combining the wind angular velocity results with measurements of the wind linear velocity, we find that the altitude of the observed atmospheric fluctuations is consistent with the distribution of water vapor determined from radiosonde data. For data corresponding to frequency passbands centered on 150, 219, and 274 GHz, we obtain median fluctuation power amplitudes of (10, 38, 74) mK2 rad-5/3 in Rayleigh-Jeans temperature units. Comparing with previous work, we find that these median amplitudes are approximately an order of magnitude smaller than those found at the South Pole during the austral summer and at least 30 times lower than found at the ALMA site in the Atacama desert.
Geometric reasoning about assembly tools

Planning for assembly requires reasoning about various tools used by humans, robots, or other automation to manipulate, attach, and test parts and subassemblies. This paper presents a general framework to represent and reason about geometric accessibility issues for a wide variety of such assembly tools. Central to the framework is a use volume encoding a minimum space that must be free in an assembly state to apply a given tool, and placement constraints on where that volume must be placed relative to the parts on which the tool acts. Determining whether a tool can be applied in a given assembly state is then reduced to an instance of the FINDPLACE problem. In addition, the author presents more efficient methods to integrate the framework into assembly planning. For tools that are applied either before or after their target parts are mated, one method pre-processes a single tool application for all possible states of assembly of a product in polynomial time, reducing all later state-tool queries to evaluations of a simple expression. For tools applied after their target parts are mated, a complementary method guarantees polynomial-time assembly planning. The author presents a wide variety of tools that can be described adequately usingmore » the approach, and surveys tool catalogs to determine coverage of standard tools. Finally, the author describes an implementation of the approach in an assembly planning system and experiments with a library of over one hundred manual and robotic tools and several complex assemblies.« less
DEFORMATIONS OF SPECIAL LAGRANGIAN SUBMANIFOLDS

In [7], R. C. McLean showed that the moduli space of nearby submanifolds of a smooth, compact, orientable special Lagrangian submanifold L in a Calabi-Yau manifold X is a smooth manifold and its dimension is equal to the dimension of ℋ1(L), the space of harmonic 1-forms on L. In this paper, we will show that the moduli space of all infinitesimal special Lagrangian deformations of L in a symplectic manifold with non-integrable almost complex structure is also a smooth manifold of dimension b1(L), the first Betti number of L.
Stereospecific synthesis of the phosphonate isostere of 2-deoxyribose-3-phosphate

A stereospecific synthesis of the phosphonatenisostere of 2-deoxyribose-3-phosphate is described with BF3OEt2 mediated epoxide opening reaction as a key step.
The Thermodynamic Pressure of a Dilute Fermi Gas

We consider a gas of fermions with non-zero spin at temperature T and chemical potential μ. We show that if the range of the interparticle interaction is small compared to the mean particle distance, the thermodynamic pressure differs to leading order from the corresponding expression for non-interacting particles by a term proportional to the scattering length of the interparticle interaction. This is true for any repulsive interaction, including hard cores. The result is uniform in the temperature as long as T is of the same order as the Fermi temperature, or smaller.
Human movement coordination implicates relative direction as the information for relative phase

The current studies explore the informational basis of the coupling in human rhythmic movement coordination tasks. Movement stability in these tasks is an asymmetric U-shaped function of mean relative phase; 0° is maximally stable, 90° is maximally unstable and 180° is intermediate. Bingham (2001, 2004a, 2004b) hypothesized that the information used to perform coordinated rhythmic movement is the relative direction of movement, the resolution of which is determined by relative speed. We used an experimental paradigm that entails using a circular movement to produce a linear motion of a dot on a screen, which must then be coordinated with a linearly moving computer controlled dot. This adds a component to the movement that is orthogonal to the display. Relative direction is not uniquely defined between orthogonal components of motion, but relative speed is; it was therefore predicted that the addition of the component would only introduce a symmetric noise component and not otherwise contribute to the U-shape structure of movement stability. Results for experiment 1 supported the hypothesis; movement that involved the additional component was overall less stable than movement that involved only the parallel component along which relative direction can be defined. Two additional studies ruled out alternative explanations for the pattern of data in experiment 1. Overall, the results strongly implicate relative direction as the information underlying performance in rhythmic movement coordination tasks.
Post-Post-Transition Theories: Walking on Multiple Paths

This article reviews recent ethnographic works on the former Soviet Union, Eastern and Central Europe, and Mongolia that explore the experiences of people enduring drastic transformations following the collapse of socialism in 1990 and the consequent implementation of a neoliberal “shock therapy.” The anthropologists working on postsocialist societies have shown that transition theories are inherently faulty and their implementation often had damaging results. The current condition is not a period of transition or “bridge” between socialism and capitalism. Instead individuals’ activities, memory, social networks, and culturally specific values lead to uncertainty as a state of dynamic being. This article argues that uncertainty is a complex conceptual space that offers further opportunities to step away from the evolutionary mode of thinking and to develop theories of multiple ways of being.
Recent advances in passive and semi-passive direct methanol fuel cells

Abstract A review of the recent advances in experimental and numerical studies on direct methanol fuel cells fed with high concentration methanol (DMFC) has been conducted. The key issues such as methanol crossover, water management, and fuel supply in the fuel cell have been discussed and some important results are presented.
Optical amplification and pulse interleaving for low-noise photonic microwave generation.

We investigate the impact of pulse interleaving and optical amplification on the spectral purity of microwave signals generated by photodetecting the pulsed output of an Er:fiber-based optical frequency comb. It is shown that the microwave phase noise floor can be extremely sensitive to delay length errors in the interleaver, and the contribution of the quantum noise from optical amplification to the phase noise can be reduced ∼10 dB for short pulse detection. We exploit optical amplification, in conjunction with high power handling modified unitraveling carrier photodetectors, to generate a phase noise floor on a 10 GHz carrier of −175 dBc/Hz, the lowest ever demonstrated in the photodetection of a mode-locked fiber laser. At all offset frequencies, the photodetected 10 GHz phase noise performance is comparable to or better than the lowest phase noise results yet demonstrated with stabilized Ti:sapphire frequency combs.
GJ 3236: A New Bright, Very Low Mass Eclipsing Binary System Discovered by the MEARTH Observatory

We report the detection of eclipses in GJ 3236, a bright (I = 11.6), very low mass binary system with an orbital period of 0.77 days. Analysis of light and radial velocity curves of the system yielded component masses of 0.38 {+-} 0.02 M{sub sun} and 0.28 {+-} 0.02 M{sub sun}. The central values for the stellar radii are larger than the theoretical models predict for these masses, in agreement with the results for existing eclipsing binaries, although the present 5% observational uncertainties limit the significance of the larger radii to approximately 1{sigma}. Degeneracies in the light curve models resulting from the unknown configuration of surface spots on the components of GJ 3236 currently dominate the uncertainties in the radii, and could be reduced by obtaining precise, multiband photometry covering the full orbital period. The system appears to be tidally synchronized and shows signs of high activity levels as expected for such a short orbital period, evidenced by strong H{alpha} emission lines in the spectra of both components. These observations probe an important region of mass-radius parameter space around the predicted transition to fully convective stellar interiors, where there are a limited number of precise measurements available in the literature.
Light-harvesting dendrimers

Natural photosynthetic systems collect sunlight using a vast array of light-harvesting chromophores that channel the absorbed energy to a single reaction center. Recently, it has been realized that dendritic macromolecules can exhibit similar properties, though on a more modest scale. The preparation of dendritic structures and assemblies composed of numerous light-collecting chromophores that transfer their energy to a single energy ‘sink’ at the core has been achieved in a number of diverse and creative ways. These novel structures are being used as model systems in light-emitting diodes, signal amplifiers, fluorescent sensors, frequency converters, and other photonic devices.
The Sandia X-ray laser program

The Sandia x‐ray laser program is based on the intense keV radiation produced by stagnating gas puff implosions. The laser scheme uses this radiation to photoionize Ne‐like ions to F‐like ions, and produce a 3p‐3s population inversion via recombination. An annular stagnation shell is used to separate the pump from the lasant. Converter technology is being developed to try the Na‐Ne line matching scheme. Experimental and computational results will be presented.
Demand and supply chain planning in grocery retail: an operations planning framework

Purpose – The purpose of this paper is to develop a holistic operations planning framework for grocery retailing. The authors aim to identify, describe and structure coherent demand and supply chain (SC) planning problems in a comprehensive architecture. Design/methodology/approach – The authors reviewed key literature on retail SC management and sales planning. This built a foundation for the development of an integrated operations planning framework. The findings were evaluated through discussions with retailers and communications with retail planners, including personal interviews with 28 leading European grocery retailers and with people in related positions from the consumer goods industry and consultancies. Findings – The core of this paper is the development of a coherent demand and SC planning matrix. It demonstrates planning interdependencies and defines a framework for retail operations. The grocery planning framework integrates retail specifics, as well as hierarchical and sequential aspects of decision making. That is why this planning architecture also forms the foundation for research and development of advanced decision support systems. Practical implications – Planning tasks are identified in interrelated planning modules permitting coordinated and decentralised decision making, which is necessary for operational and complexity reasons. The planning framework assists retail planners in understanding their decision problem from a comprehensive perspective. Better coordination of different modules and further development of retail-tailored analytical models will improve planning quality. Originality/value – This is the first paper that structures retail demand and SC planning questions coherently in one framework, matching demand and supply from a long- to short-term perspective and from supplier to customer.
Computation of nonlinear one-dimensional waves in near-sonic flows

A nonlinear analysis is developed for sound propagation in a variable area duct in which the mean flow approaches choking conditions. A quasi-one-dimensional model is used; results of the standard linear theory are compared with the nonlinear results to assess the significance of the nonlinear terms. The nonlinear analysis represents the acoustic disturbance as a sum of interacting harmonics. Numerical results show that the basic signal is unaffected by the presence of higher harmonics if the throat Mach number is not too large, but as the Mach number approaches unity more harmonics are needed to describe the acoustic propagation. The strong interactions among harmonics in the numerical results occur in a region which is generally consistent with the nonlinear inner-expansion region of Callegari and Myers.
Synthesis of 5′-functionalized adenosine: suppression of cyclonucleoside formation

Abstract A new method of preparation for 5′-amino-2′,3′-isopropylidene adenosine 1 , an important precursor to many adenosine derivatives, is described. This procedure suppresses the undesired intramolecular cyclization and does not require chemical protection of the exocyclic amino group of the adenine ring. The use of a 5′-phophate triester activating group is representative of natural biological substitution at this position, which likely contributes to its greater stability and selective reactivity. This sequence is efficient and should allow easy access to compounds of type 1 in high yield.
A multilayer model of time dependent deformation following an earthquake on a strike slip fault

A multilayer model of the Earth to calculate finite element of time dependent deformation and stress following an earthquake on a strike slip fault is discussed. The model involves shear properties of an elastic upper lithosphere, a standard viscoelastic linear solid lower lithosphere, a Maxwell viscoelastic asthenosphere and an elastic mesosphere. Systematic variations of fault and layer depths and comparisons with simpler elastic lithosphere over viscoelastic asthenosphere calculations are analyzed. Both the creep of the lower lithosphere and astenosphere contribute to the postseismic deformation. The magnitude of the deformation is enhanced by a short distance between the bottom of the fault (slip zone) and the top of the creep region but is less sensitive to the thickness of the creeping layer. Postseismic restressing is increased as the lower lithosphere becomes more viscoelastic, but the tendency for the width of the restressed zone to growth with time is retarded.
Cohomology Pairings on the Symplectic Reduction of Products

Let M be the product of two compact Hamiltonian T-spaces X and Y. We present a formula for evaluating integrals on the symplectic reduction of M by the diagonal T action. At every regular value of the moment map for X × Y, the integral is the convolution of two distributions associated to the symplectic reductions of X by T and of Y by T. Several examples illustrate the computational strength of this relationship. We also prove a linear analogue which can be used to find cohomology pairings on toric orbifolds.
Photoionization Cross Section of the Neutral Iron Atom

Calculations are presented for the photoionization cross section of the neutral iron atom for photon energies from threshold to 10 keV. Our results are based upon the use of nonrelativistic wave functions and the dipole approximation. Correlations are included to low orders by the use of many-body perturbation theory; and the cross section including correlations is found to differ greatly from that obtained from the Hartree-Fock approximation. Hartree-Fock results are also presented for comparison. We roughly estimate our cross section, including correlations near threshold, to be accurate to within a factor of 2 when integrated over a few eV.
The Herbig Ae Star HD 163296 in X-Rays

Chandra X-ray imaging spectroscopy of the nearby Herbig Ae star HD 163296 at 100 AU angular resolution is reported. A point-like, soft (kT approximately 0.5 approximately kev), emission-line source is detected at the location of the star with an X-ray luminosity of 4.0e29 erg/s. In addition, faint emission along the direction of a previously-detected Ly-alpha-emitting jet and Herbig-Haro outflow may be present. The relatively low luminosity, lack of a hard spectral component, and absence of strong X-ray variability in HD 163296 can be explained as originating from optically-thin shock-heated gas accreting onto the stellar surface along magnetic field lines. This would require a (dipole) magnetic field strength at the surface of HD 163296 of at least approximately 100 approximately G and perhaps as high as several kG.