cssi/SciSciGPT-SciSciNet huggingface dataset:
Canonical Lagrangian dynamics and general relativity

Building towards a more covariant approach to canonical classical and quantum gravity we outline an approach to constrained dynamics that de-emphasizes the role of the Hamiltonian phase space and highlights the role of the Lagrangian phase space. We identify a 'Lagrangian one-form' to replace the standard symplectic one-form, which we use to construct the canonical constraints and an associated constraint algebra. The method is particularly useful for generally covariant systems and systems with a degenerate canonical symplectic form, such as Einstein–Cartan gravity, to which we apply it explicitly. We find that one can compute the constraint algebra and demonstrate the closure of the constraints without gauge fixing the Lorentz group or introducing primary constraints on the phase space variables. Ultimately our aim is towards a more covariant approach for canonical quantum gravity, and we discuss a possible route to quantization. Applying these techniques and using methods from geometric quantization, we find a new representation of the pre-quantum operator corresponding to the Hamiltonian constraint, which in contrast to the standard representation, is a kinematical operator that simply generates timelike diffeomorphisms on functionals of the Lagrangian phase space. This opens the possibility for a kinematical spacetime–diffeomorphism invariant Hilbert space.
Role of Radiative Transport in the Propagation of Laser Supported Combustion Waves

We report results of an investigation into the roles played by thermal and radiative transport in the propagation of Laser Supported Combustion (LSC) waves. We replace the volume radiation losses assumed by Raizer with detailed treatment of radiation in 19 frequency groups, the flux of each being calculated from the temperature in discrete cells along the LSC wave axis and allowed to deposit in other cells according to temperature dependent absorption coefficients for air. Calculations of LSC wave structure and propagation velocity as a function of laser intensity are compatible with available experimental data. a = c = CP = f = h = h = hi(a) = K = k = KV =
Asymmetric Synthesis of Diverse Glycolic Acid Scaffolds via Dynamic Kinetic Resolution of α-Keto Esters

The dynamic kinetic resolution of α-keto esters via asymmetric transfer hydrogenation has been developed as a technique for the highly stereoselective construction of structurally diverse β-substituted-α-hydroxy carboxylic acid derivatives. Through the development of a privileged m-terphenylsulfonamide for (arene)RuCl(monosulfonamide) complexes with a high affinity for selective α-keto ester reduction, excellent levels of chemo-, diastereo-, and enantiocontrol can be realized in the reduction of β-aryl- and β-chloro-α-keto esters.
Development of an advanced vaneless inlet particle separator for helicopter engines

Design and development of an advanced integral engine particle separator are presented to meet the challenging operational requirements of helicopter engines of the future. The vaneless, low-weight, high-efficiency separator makes it possible to achieve new levels of engine reliability, durability, and life cycle costs. This paper presents the analytical methods developed, the design process, and the extensive experimental validation of the design.
Ultra-rapid landscape response and sediment yield following glacier retreat, Icy Bay, southern Alaska

Abstract Glacial retreat and opening of Taan Fjord (an arm of Icy Bay, Alaska) in the last two decades drove a base level fall of ∼ 400 m at the outlets of four tributary valleys in the region of the current Tyndall Glacier terminus. Response in the tributary valleys to this base level fall includes evacuation of stored sediment, incision of slot gorges into bedrock, and landsliding on valley walls. Fluvial transfer of eroded bedrock, glacial deposits, and stored nonglacial fluvial deposits after 1983 resulted in progradation of fan deltas toward the fjord centerline at the outlet of each of the four catchments. In the largest nonglacial tributary valley, ∼ 0.08 km 3 (∼ 8%) of the 0.59 km 3 of > 500-m-thick stored fluvial and colluvial deposits has been transferred to the adjacent fjord. A percentage of the fjord sedimentation in the last two decades thus includes material eroded from bedrock and stored in the landscape during the previous glacial expansions. Distal deltaic deposits extend across the fjord floor and likely interfinger with distal proglacial deltaic deposits sourced from the Tyndall Glacier. A paraglacial landscape response, such as the one exhibited in upper Taan Fjord where sediment delivery to fjords from tributary sources in synchrony with sediment produced by primary bedrock erosion by glaciers, helps to explain the order-of-magnitude discrepancy between sediment yields from Alaskan tidewater glaciers on 10 0 - to 10 2 -year timescales and sediment yields and exhumation rates on 10 4 - to 10 6 -year timescales.
H-Infinity Controller Design for Structural Damping

This paper describes a multivariable controller design procedure that uses mixed-sensitivity H-infinity control theory. The design procedure is based on the assumption that structural noise can be modeled as entering a state-space system through a random input matrix. The design process starts with a full-order flexible state-space model that undergoes a frequency-weighted balanced truncation to obtain a reduced-order model with excellent low frequency matching. Weighting functions are then created to specify the desired frequency range for disturbance rejection and controller bandwidth. A structural noise input matrix is also designed to identify system modes where maximal damping is desired. An augmented plant is then assembled using the reduced-order model, weighting functions and structural noise input matrix to create a mixed-sensitivity configuration. A state-space controller is then realized using an H-infinity design algorithm. A two-input, three-output, doubly cantilevered beam system provides a design example. A 174th-order, discrete-time, state-space model of the cantilevered beam system was used to generate a reduced 40th- order model. A 55th-order Hinfinity controller was then designed with a controller bandwidth of approximately 300 Hz. This non-square modern controller uses feedback signals from two piezoelectric sensors, each collocated with one of two piezoelectric actuators, and one highly non-collocated accelerometer. The two piezoelectric actuators provide the control actuation. Frequency analysis and time-domain simulations are utilized to demonstrate the damping performance.
Hybrid computers in the analysis of feedback control systems

In the pursuit of accuracy, speed and economy in the simulation of mathematical models of physical systems, analysts are continuously searching for more sophisticated mathematical techniques and computer systems. When the complexity of the mathematical models increases, their simulations on pure analog or pure digital computers are frequently cumbersome. The main reason for this is that some of the operations in mathematical model are inherently best handled either on the digital or the analog computer.
Real cyclotomic fields of prime conductor and their class numbers

Surprisingly, the class numbers of cyclotomic fields have only been determined for fields of small conductor, e.g. for prime conductors up to 67, due to the problem of finding the "plus part," i.e. the class number of the maximal real subfield. Our results have improved the situation. We prove that the plus part of the class number is 1 for prime conductors between 71 and 151. Also, under the assumption of the generalized Riemann hypothesis, we determine the class number for prime conductors between 167 and 241. This technique generalizes to any totally real field of moderately large discriminant, allowing us to confront a large class of number fields not previously treatable.
Evolution of Cognitive Function via Redeployment of Brain Areas

The creative reuse of existing neural components may have played a significant role in the evolutionary development of cognition. There are obvious evolutionary advantages to such redeployment, and the data presented here confirm three important empirical predictions of this account of the development of cognition: 1) A typical brain area will be used by many cognitive functions in diverse task categories, (2) evolutionarily older brain areas will be deployed in more cognitive functions, and (3) more recent cognitive functions will use more, and more widely scattered, brain areas. These findings have implications not just for our understanding of the evolutionary origins of cognitive function but also for the practice of both clinical and experimental neuroscience.
Two Antimicrobial Alkaloids from Heartwood of Liriodendron tulipifera L

Alcoholic extracts of the heartwood of Liriodendron tulipifera have demonstrated antimicrobial activity against Staphylococcus aureus, Mycobacterium smegmatis, Candida albicans, and Aspergillus niger. The antimicrobial activity was associated only with the alkaloidal fraction. Separation of the active alkaloidal fraction by chromatography led to the isolation and identification of dehydroglaucine and liriodenine as the active components. Several other alkaloidal derivatives were prepared and tested. In addition to the active alkaloids, michelabine was also identified in the tertiary nonphenolic base fraction along with the lignan, lirioresinol-B-dimethyl ether, and two N-acetylnoraporphine alkaloids from the nonbasic fraction.
Current resources for evidence-based practice, September/October 2014.

The Evidence on Evidence-Based Practice The phrase evidence-based practice (EBP) is used so frequently in health care that the words have lost their meaning for many clinicians. Often used as a synonym for good, EBP is too frequently used to promote health care that may not include practices based on current evidence. However, as an approach that has been linked in numerous studies to better outcomes of care, EBP is a subject worthy of true understanding. So what is evidence-based practice?
The elusive vanadate (V3O9)3-: Isolation, crystal structure, and nonaqueous solution behavior

The isolation, crystal structure, and nonaqueous solution characteristics of the first trinuclear vanadate are presented. The crystal structure reveals a six-membered cyclic arrangement of alternating vanadium and oxygen atoms for the anion of [(C4H9)4N]3(V3O9). The 51V NMR spectrum of this compound in CD3CN exhibits multiple peaks. The relative intensities of each resonance can be altered by concentration and temperature changes, the later of which are reversible. Addition of [(C4H9)4N]Br and NaClO4 also perturbs the equilibria between species observed. Conductivity data for [(C4H9)4N]3(V3O9) in CH3CN as a function of concentration display pronounced curvature and indicate formation of a neutral species in solution at the highest concentrations studied. Stoichiometric mixtures of [(C4H9)4N]3(V3O9) with the known vanadates [(C4H9)4N]3(HV4O12), [(C4H9)4N]3(V5O14), and [(C4H9)4N]3(H3V10O28) are prepared and examined by 51V NMR. Equilibration between the various vanadates is observed and characterized. Reson...
Parochial interests and the centralized provision of local public goods: evidence from congressional voting on transportation projects ☆

Abstract Local public goods financed from a national tax base provide concentrated benefits to recipient jurisdictions but disperse costs, creating incentives for legislators to increase own-district spending but to restrain aggregate spending due to the associated tax costs. While these common pool incentives underpin a variety of theoretical analyses, which tend to predict inefficiencies in the allocation of public goods, there is little direct evidence that individual legislators respond to such incentives. To test for reactions to such incentives, this paper analyzes 1998 Congressional votes over transportation project funding. The empirical results provide evidence that legislators respond to common pool incentives: the probability of supporting the projects is increasing in own-district spending and decreasing in the tax burden associated with aggregate spending. Having found that legislators do respond to such incentives, I use the parameter estimates to calculate the efficient level of public goods, which suggest over-spending in aggregate, especially in politically powerful districts, and large associated deadweight loss.
Origin of the Three-Body Parameter Universality in Efimov Physics

In recent years extensive theoretical and experimental studies of universal few-body physics have advanced our understanding of universal Efimov physics. Whereas theory had been the driving force behind our understanding of Efimov physics for decades, recent experiments have contributed an unexpected discovery. Specifically, measurements have found that the so-called three-body parameter determining several properties of the system is universal, even though fundamental assumptions in the theory of the Efimov effect suggest that it should be a variable property that depends on the precise details of the short-range two- and three-body interactions. The present Letter resolves this apparent contradiction by elucidating previously unanticipated implications of the two-body interactions. Our study shows that the three-body parameter universality emerges because a universal effective barrier in the three-body potentials prevents the three particles from simultaneously getting close together. Our results also show limitations on this universality, as it is more likely to occur for neutral atoms but less likely to extend to light nuclei.
Collaborative Relay Beamforming for Secrecy

In this paper, collaborative use of relays to form a beamforming system with the aid of perfect channel state information (CSI) and to provide physical-layer security is investigated. In particular, a decode-and-forward-based relay beamforming design subject to total and individual relay power constraints is studied with the goal of maximizing the secrecy rate. The total power constraint leads to a closed-form solution. The design under individual relay power constraints is formulated as an optimization problem which is shown to be easily solved using two different approaches, namely semidefinite programming and second-order cone programming. Furthermore, a simplified and suboptimal technique which reduces the computation complexity under individual power constraints is presented.
WINDS, B-FIELDS, AND MAGNETOTAILS OF PULSARS

We investigate the emission of rotating magnetized neutron stars due to the acceleration and radiation of particles in the relativistic wind and in the magnetotail of the star. We consider that the charged particles are accelerated by driven collisionless reconnection. Outside the light cylinder, the star's rotation acts to wind up the magnetic field to form a predominantly azimuthal, slowly decreasing with distance, magnetic field of opposite polarity on either side of the equatorial plane normal to the star's rotation axis. The magnetic field annihilates across the equatorial plane, with the magnetic energy going to accelerate the charged particles to relativistic energies. For a typical supersonically moving pulsar, the star's wind extends outward to the standoff distance with the interstellar medium. At larger distances, the power output of the pulsar's wind Ėw of the electromagnetic field and relativistic particles is redirected and collimated into the magnetotail of the star. In the magnetotail it is proposed that equipartition is reached between the magnetic energy and the relativistic particle energy. For such conditions, synchrotron radiation from the magnetotails may be a significant fraction of Ėw for high-velocity pulsars. An equation is derived for the radius of the magnetotail rm(z') as a function of distance z' from the star. For large distances z', on the order of the distance traveled by the star, we argue that the magnetotail has a "trumpet" shape because of the slowing down of the magnetotail flow. We compare results with the Guitar Nebula and Mouse Nebula and conclude that the tail of the Mouse Nebula may be connected with the long magnetotail behind the pulsar. We argue that the shock waves and elongated structures may also be observed in misdirected or shutoff pulsars and may be used as a tool for finding these objects.
ON THE ANGULAR MOMENTUM EVOLUTION OF FULLY CONVECTIVE STARS: ROTATION PERIODS FOR FIELD M-DWARFS FROM THE MEarth TRANSIT SURVEY

We present rotation period measurements for 41 field M-dwarfs, all of which have masses inferred (from their parallaxes and Two Micron All Sky Survey K-band magnitudes) to be between the hydrogen burning limit and 0.35 M ? and thus should remain fully convective throughout their lifetimes. We measure a wide range of rotation periods, from 0.28 to 154 days, with the latter commensurate with the typical sensitivity limit of our observations. Using kinematics as a proxy for age, we find that the majority of objects likely to be thick disk or halo members (and hence, on average, older) rotate very slowly, with a median period of 92 days, compared with 0.7 days for those likely to be thin disk members (on average, younger), although there are still some rapid rotators in the thick disk sample. When combined with literature measurements for M-dwarfs, these results indicate an increase in spin-down times with decreasing stellar mass, in agreement with previous work, and that the spin-down time becomes comparable to the age of the thick disk sample below the fully convective boundary. We additionally infer that the spin-down must remove a substantial amount of angular momentum once it begins in order to produce the slow rotators we observe in the thick disk candidates, suggesting that fully convective M-dwarfs may still experience strong winds.
Enhancing SOFC cathode performance by surface modification through infiltration

Solid oxide fuel cells (SOFCs) have the potential to be one of the cleanest and most efficient energy technologies for direct conversion of chemical fuels to electricity. Economically competitive SOFC systems appear poised for commercialization, but widespread market penetration will require continuous innovation of materials and fabrication processes to enhance system lifetime and reduce cost. One early technical opportunity is minimization of resistance to the oxygen reduction reaction (ORR) at the cathode, which contributes the most to performance degradation and efficiency loss in the existing SOFCs, especially at temperatures <700 °C. Detailed study over the past 15 years has revealed the positive impact of catalyst infiltration on SOFC cathode performance, both in power density and durability metrics. However, realizable performance improvements rely upon strongly-coupled relationships in materials and morphology between the infiltrate and the backbone, and therefore efficacious systems cannot be simply generated with a set of simple heuristics. This article reviews recent progress in enhancing SOFC cathode performance by surface modification through a solution-based infiltration process, focusing on two backbone architectures – inherently functional and skeletal – infiltrated using wet-chemistry processes. An efficient cathode consists of a porous mixed-conducting backbone and an active coating catalyst; the porous backbone provides excellent ionic and electronic conductivity, while the infiltrated surface coating possesses high catalytic activity and stability. As available, performance comparisons are emphasized and reaction schematics for specific infiltrate/backbone systems are summarized. While significant progress has been achieved in enhancing surface catalytic activity and durability, the detailed mechanisms of performance enhancement are insufficiently understood to obtain critical insights and a scientific basis for rational design of more efficient catalysts and novel electrode architectures. Recent progress in characterization of surfaces and interfaces is briefly discussed with challenges and perspectives in surface modification of SOFC electrodes. Surface modification through infiltration is expected to play an increasingly important role in current and next-generation commercial SOFC development, and this review illustrates the sophisticated technical considerations required to inform judicious selection of an infiltrate for a given SOFC system.
Benzotetramisole: a remarkably enantioselective acyl transfer catalyst.

A commercially available pharmaceutical, tetramisole, was found to be a competent enantioselective acylation catalyst. Its benzannellated analogue, benzotetramisole (BTM), produced outstanding enantioselectivities in kinetic resolution of secondary benzylic alcohols.
Turbo coded modulation for wireless communications with antenna diversity

We introduce turbo coded modulation for wireless communication systems with transmit and receive antenna diversity. We describe a simple way of applying turbo coded modulation to multiple antenna systems. We present examples to illustrate the performance of the turbo coded modulation scheme and observe significant performance gains over the appropriately interleaved space-time trellis codes.
A note on maximizing the spread of influence in social networks

We consider the spread maximization problem that was defined by Domingos and Richardson (2001, 2002) [7,22]. In this problem, we are given a social network represented as a graph and are required to find the set of the most ''influential'' individuals that by introducing them with a new technology, we maximize the expected number of individuals in the network, later in time, that adopt the new technology. This problem has applications in viral marketing, where a company may wish to spread the rumor of a new product via the most influential individuals in popular social networks such as Myspace and Blogsphere. The spread maximization problem was recently studied in several models of social networks (Kempe et al. (2003, 2005) [14,15], Mossel and Roch (2007) [20]). In this short paper we study this problem in the context of the well studied probabilistic voter model. We provide very simple and efficient algorithms for solving this problem. An interesting special case of our result is that the most natural heuristic solution, which picks the nodes in the network with the highest degree, is indeed the optimal solution.
Dynamics of an incommensurate harmonic chain

The dynamics of a one-dimensional harmonic chain in a strong, incommensurate, sinusoidal potential and a uniform force $F$ is investigated. A threshold force ${F}_{t}$ exists, above which the mean velocity $\overline{v}$ of the chain satisifes $\overline{v}\ensuremath{\propto}{(F\ensuremath{-}{F}_{t})}^{\ensuremath{\zeta}}$ where $\ensuremath{\zeta}=0.68\ifmmode\pm\else\textpm\fi{}0.05$. We present evidence that no coherent velocity oscillations occur in the infinite system. The possible relevance of this work to experimental observations of charge-density waves is discussed.
China's Integration into the World Economy: implications for developing countries

With China's accession to the World Trade Organization in late 2001, many of its trading partners have become concerned that the resulting increased competition in the world's goods and capital markets will adversely affect their own growth prospects. This paper argues that China's closer integration into the world economy will impose adjustment costs on its trading partners in the short to medium term, but that the benefits it generates are likely to dominate in the long run.
Aerodynamics of planetary entry configurations in air and assumed martian atmospheres.

Approximate and characteristics methods to predict effect of gas composition on forces and static stability of planetary entry configurations in air and assumed Martian atmospheres
Post offering earnings performance of firms that issue seasoned equity: The role of growth opportunities

Abstract This study finds that growth firms experience significant unanticipated deterioration in their earnings performance following their seasoned equity offerings (SEO), but mature firms do not share the same negative experience. This finding is consistent with the findings of long run post offering stock price underperformance documented in the literature. However, it is inconsistent with the findings of a weak positive impact of growth opportunities on the stock price reaction to the SEO announcement. The negative role of growth opportunities also contradicts the predictions of signaling models that growth potential of the issuing firm has a positive impact on the information content of the SEO. Overall, the findings in this study are consistent with the general implication of the overvaluation hypothesis that managers issue equity securities when they know their firm is not as valuable as what the market believes.
Studies on isoxazole and pyrazole formation by the reaction of trifluoromethyl-substituted anilines with oxime and hydrazone dianions

5-(2-Aminophenyl)isoxazoles are obtained in good yields by the reaction of 2-(trifluoromethyl)aniline with dilithio derivatives of oximes of acetone, 3-pentanone, propiophenone, and cyclohexanone. An analogous synthesis of a substituted isoxazole from 4-(trifluoromethyl)aniline and 3-pentanone oxime and the synthesis of a substituted pyrazole from 2-(trifluoromethyl)aniline and 3-pentanone hydrazone are less efficient.
Constraints on stellar-dynamical models of the Orion Nebula Cluster

The results obtained by Kroupa, Petr & McCaughrean (1999) for specific models of young compact binary-rich clusters are generalised using dynamical scaling relations, to infer the candidate set of possible birth models leading to the Orion Nebula Cluster (ONC), of which the Trapezium Cluster is the core. It is found that candidate sets of solutions exist which allow the ONC to be in virial equilibrium, expanding or contracting. The range of possible solutions is quite narrow. These results will serve as guidelines for future, CPU-intensive calculations of the stellar-dynamical and astrophysical evolution of the entire ONC. These, in turn, will be essential to quantify observables that will ultimately discriminate between models, thus allowing us to understand if the ONC is in the process of assembling a rich Galactic cluster, and, if this is the case, how it occurs.
High-Resolution Near-Infrared Images and Models of the Circumstellar Disk in HH 30

We present Hubble Space Telescope near-infrared camera and multiobject spectrometer observations of the reflection nebulosity associated with the T Tauri star HH 30. The images show the scattered-light pattern characteristic of a highly inclined, optically thick disk with a prominent dust lane whose width decreases with increasing wavelength. The reflected nebulosity exhibits a lateral asymmetry in the upper lobe on the opposite side to that reported in previously published Wide Field Planetary Camera 2 images. The radiation transfer model that most closely reproduces the data has a flared accretion disk with dust grains larger than standard interstellar medium grains by a factor of approximately 2.1. A single hot spot on the stellar surface provides the necessary asymmetry to fit the images and is consistent with previous modeling of the light curve and images. Photometric analysis results in an estimated extinction of AV 80; however, since the photometry measures only scattered light rather than direct stellar flux, this a lower limit. The radiative transfer models require an extinction of AV = 7900.
Mandates and the Affordability of Health Care

This paper examines the economic rationale of affordability exemptions in the context of a health insurance mandate. I provide an economic definition of affordability and discuss how it is implemented in the contexts of food, housing, and health care. Affordability standards are frequently used in making food and housing policy, but both empirically and theoretically health care operates quite differently than these other merit goods. This helps explain why the use of affordability in health policymaking is so different from its use in these other contexts. I conclude with some suggestions about how to improve affordability exemption rules in health policymaking.
EXPERIMENTAL SIGNATURES OF SPLIT FERMIONS IN EXTRA DIMENSIONS

The smallness and hierarchy of the fermion parameters could be explained in theories with extra dimensions where doublets and singlets are localized at slightly separated points. Scattering cross sections for collisions of such fermions vanish exponentially at energies high enough to probe the separation distance. This is because the separation puts a lower bound on the attainable impact parameter in the collision. The NLC, and in particular the combination of the e+e- and e-e- modes, can probe this scenario, even if the inverse fermion separation is of order tens of TeVs.
Sponsored Search Marketing: Dynamic Pricing and Advertising for an Online Retailer

Consider a retailer using sponsored search marketing together with dynamic pricing. The retailer's bid on a search keyword affects the retailer's rank among the search results. The higher the rank, the higher the customer traffic and the customers' willingness to pay will be. Thus, the question arises: When a retailer bids higher to attract more customers, should the accompanying price also decrease to strengthen the bid's effect on demand or increase to take advantage of higher willingness to pay? We find that the answer depends on how fast the retailer increases its bid. In particular, as the end of the season approaches, the optimal bid exhibits smooth increases followed by big jumps. The optimal price increases only when the optimal bid increases sharply, including the instances where the bid jumps up. Such big jumps arise, for example, when the customer traffic is an S-shaped function of the retailer's bid. This paper was accepted by Serguei Netessine, operations management.
Allergic mucociliary dysfunction

This brief summary of several studies relating to allergic mucociliary dysfunction suggests that (1) mucociliary transport in the lower airways (and possibly in the nose) is impaired in subjects with allergic airway disease, (2) acute antigen challenge causes a further impairment of mucociliary transport that is related to chemical mediators, and (3) the elaboration of abnormal respiratory secretions is, at least in part, responsible for acute allergic mucociliary dysfunction. It is apparent from the currently available information that some of the in vivo and in vitro studies carried out in patients with allergic asthma would have to be applied to patients with allergic rhinitis. With respect to the management of patients with allergic rhinitis and asthma, the use of antiallergic agents such as cromolyn sodium or specific mediator antagonists (as they become available) seems to be justified when considering the important role of mucociliary dysfunction in the manifestations of allergic airway disease.
Unconstrained Energy Functionals for Electronic Structure Calculations

The performance of conjugate gradient schemes for minimizing unconstrained energy functionals in the context of condensed matter electronic structure density functional calculations is studied. The unconstrained functionals allow a straightforward application of conjugate gradients by removing the explicit orthonormality constraints on the quantum-mechanical wave functions. However, the removal of the constraints can lead to slow convergence, in particular when preconditioning is used. The convergence properties of two previously suggested energy functionals are analyzed, and a new functional is proposed, which unifies some of the advantages of the other functionals. A numerical example derived from a diamond crystal confirms the analysis.
Cyclometalated metal–organic frameworks as stable and reusable heterogeneous catalysts for allylic N-alkylation of amines

Metal–organic frameworks (MOFs) functionalized via Ir(I) cyclometalation are shown to be effective as heterogeneous catalysts for the allylic N-alkylation of various amines. The MOF catalysts are one of the first and most effective MOF-based heterogeneous organometallic catalysts for the direct formation of C–N bonds. In addition, these MOFs represent a rare, stable and reusable, class of reactive Ir catalysts.
Vetoes for inspiral triggers in LIGO data

Presented is a summary of studies by the LIGO Scientific Collaboration’s Inspiral Analysis Group on the development of possible vetoes to be used in the evaluation of data from the first two LIGO science data runs. Numerous environmental monitor signals and interferometer control channels have been analysed in order to characterize the interferometers’ performance. The results of studies on selected data segments are provided in this paper. The vetoes used in the compact binary inspiral analyses of LIGO’s S1 and S2 science data runs are presented and discussed.
Generating well-shaped d -dimensional Delaunay meshes

A d-dimensional simplicial mesh is a Delaunay triangulation if the circumsphere of each of its simplices does not contain any vertices inside. A mesh is well shaped if the maximum aspect ratio of all its simplices is bounded from above by a constant. It is a long-term open problem to generate well-shaped d-dimensional Delaunay meshes for a given polyhedral domain. In this paper, we present a refinement-based method that generates well-shaped d-dimensional Delaunay meshes for any PLC domain with no small input angles. Furthermore, we show that the generated well-shaped mesh has O(n) d-simplices, where n is the smallest number of d-simplices of any almost-good meshes for the same domain. Here a mesh is almost-good if each of its simplices has a bounded circumradius to the shortest edge length ratio.
Percolation of diffusionally evolved two-phase systems.

Percolation thresholds and critical exponents for universal scaling laws are computed for microstructures that derive from phase-transformation processes in two dimensions. The computed percolation threshold for nucleation and growth processes, ${p}_{c}\ensuremath{\approx}0.6612$, is similar to those obtained by random placement of disks and greater than that of spinodal decomposition, ${p}_{c}\ensuremath{\approx}0.4987$. Three critical exponents for scaling behavior were computed and do not differ significantly from universal values. The time evolution of a characteristic microstructural length was also computed: For spinodal decomposition, this length grows according to a power law after a short incubation period; for nucleation and growth, there are several transitions in the nature of the growth law. We speculate that the transitions in nucleation and growth derive from competing effects of coalescence at short times and then subsequent coarsening. Short-range order is present, but different, for both classes of microstructural evolution.
Helium-ion-induced release of hydrogen from graphite

Abstract The ion-induced release of hydrogen from AXF-5Q graphite was studied for 300- to 500-eV helium ions. The hydrogen was implanted into the graphite with a low energy (~ 200 eV) and to a high fluence. This achieved a thin (~10 nm), saturated near-surface region. The release of hydrogen was measured as a function of helium fluence. A model that includes ion-induced detrapping, retrapping, and surface recombination was used to analyze the experimental data. The release cross section varied from 1.8 × 10 −16 cm 2 at 300 eV to 1.4 × 10 −16 cm 2 at 500 eV, while the depletion depth varied from 0.8 nm at 300 eV to 1.2 nm at 500 eV.
Potential of MODIS ocean bands for estimating CO2 flux from terrestrial vegetation: A novel approach

[1] A physiologically-driven spectral index using two ocean-color bands of MODIS satellite sensor showed great potential to track seasonally changing photosynthetic light use efficiency (LUE) and stress-induced reduction in net primary productivity (NPP) of terrestrial vegetation. Based on these findings, we developed a simple “continuous field” model solely based on remotely sensed spectral data that could explain 88% of variability in flux-tower based daily NPP. For the first time, such a procedure is successfully tested at landscape level using satellite imagery. These findings highlight the unexplored potential of narrow-band satellite sensors to improve estimates of spatial and temporal distribution in terrestrial carbon flux.
Small attachable interferometric strain gages

Laser-based interferometry from two tiny reflective indentations can be used to measure in-plane strain/displacement over a very short gage length (on the order of 100 μm). If the specimen material is not reflective, then some other means of generating the interference patterns must be found. This paper describes two kinds of attachable gages: plated acetate replicas of indentations and reflective foils that are indented after application. In either case, the gage is applied with the techniques used for foil-resistance gages and the gage itself is very small. The manufacturing procedures are described. The results of experiments comparing the strain to that measured with foil-resistance gages are presented. Finally, the small interferometric gage is used to measure strain on one of the metal strips in a foil-resistance gage.
Strangelets and strange quark matter

Abstract I summarize the properties of finite lumps of strange quark matter (strangelets) with emphasis on the two scenarios for producing strange matter in relativistic heavy ion collisions. As an outlook, I discuss the possibility of short-lived strange composites and charmed matter.
Polaritonic materials fabricated and tested with ultrashort-pulse lasers

Using femtosecond laser machining, we have fabricated photonic bandgap materials that influence propagation of phonon-polaritons in ferroelectric crystals. Broadband polaritons were generated with impulsive stimulated Raman scattering (ISRS) using an ultrashort laser pulse, and the spatial and temporal evolution of the polaritons were imaged as they propagated through the fabricated structures with polariton real-space imaging. These techniques offer a new approach to optical materials design.
Turbulent boundary layer equations

Abstract We study a boundary layer problem for the Navier–Stokes-alpha model obtaining a generalization of the Prandtl equations which we conjecture to represent the averaged flow in a turbulent boundary layer. We study the equations for the semi-infinite plate, both theoretically and numerically. Solutions agree with some experimental data in a part of the turbulent boundary layer. To cite this article: A. Cheskidov, C. R. Acad. Sci. Paris, Ser. I 334 (2002) 423–427.
Steady-State Unbalance Response of a Three-Disk Flexible Rotor on Flexible, Damped Supports

Experimental data are presented for the unbalance response of a flexible, ball bearing supported rotor to speeds above the third lateral bending critical. Values of squeeze film damping coefficients obtained from measured data are compared to theoretical values obtained from short bearing approximation over a frequency range from 5000 to 31,000 cycles/min. Experimental response for an undamped rotor is compared to that of one having oil squeeze film dampers at the bearings. Unbalances applied varied from 0.62 to 15.1 gm-cm.
Entanglement Dynamics of Second Quantized Quantum Fields

We study the entanglement dynamics in the system of coupled boson fields. We demonstrate that there are different natural notions of locality in this context leading to inequivalent notions of entanglement. We concentrate on the particle picture, when entanglement of one particle is determined by one-particle density matrix. We study, in detail, the effect of interaction preserving populations of individual one-particle states. We show that if the system is initially in a disentangled state with the definite total number of particles and the dimension of the one-particle Hilbert space is more than two, then only potentials of the special form admit complete entanglement, which is shown to be reached at NOON states. If the system is initially in Glauber’s coherent state, complete entanglement is not reached despite the presence of two entangling channels in this case. We conclude with studying the time evolution of entanglement of photons in a cavity with multiple quantum dots in the limit of large number of photons. We show that in a relatively short time scale the completely entangled states belong to the class of graph states and are formed due to the interaction with dots in resonance with the cavity modes.
Preparation and electrochemical characterization of WSe2 electrodes having a wide range of doping densities

Abstract The preparation and electrochemical characterization of n-type and p-type tungsten diselenide (WSe 2 ) crystal electrodes with doping densities ranging from 5×10 15 to 3×10 19 cm −3 is reported. The growth of these layered crystals was accomplished using chemical vapor transport. The doping of the crystals is described; it was found that using Cl 2 as the transport agent and rhenium as dopant produced n-type crystals, while the p-type were obtained using I 2 as transporting agent and niobium as dopant. The exceptional stability and the layered lattice structure of these crystals are desirable features not found in most small bandgap semiconductors. These features permit accurate electrochemical (Mott-Schottky) determinations of the interfacial energetics. Electrodes prepared from these crystals were characterized electrochemically, which indicated ideal behavior of the space charge region (SCR) over wide range of potential and frequency, and photoelectrochemically, which revealed fill factors from 0.37 to 0.65. Doping densities, within a given batch of crystals, were found to be relatively uniform. Band edge potentials did not shift due to doping, frequency or the presence of metallocene redox couples. The utility of this series of semiconductor electrodes for fundamental studied is discussed.
Fractal electromagnetic showers

Abstract We study the self-similar structure of electromagnetic showers and introduce the notion of the fractal dimension of a shower. Studies underway of showers in various materials and at various energies are presented, and the range over which the fractal scaling behaviour is observed is discussed. Applications to fast shower simulations and identification, particularly in the context of extensive air showers, are also discussed.
BLITZEN: a highly integrated massively parallel machine

Abstract The goal of the BLITZEN project is to construct a physically small, massively parallel, high-performance machine. This paper presents the architecture, organization, and feature set of a highly integrated SIMD array processing chip which has been custom designed and fabricated for this purpose at the Microelectronics Center of North Carolina. The chip has 128 processing elements (PEs), each with 1K bits of static RAM. Unique local control features include the ability to modify the global memory address with data local to each PE, and complementary operations based on a condition register. With a 16K PE system (only 128 custom chips are needed for this), operating at 20 MHz, data I/O can take place at 10,240 megabytes per second through a new method using a 4-bit bus for each set of 16 PEs. A 16K PE system can perform IEEE standard 32-bit floating-point multiplication at a rate greater than 450 megaflops. Fixed-point addition on 32-bit data exceeds the rate of three billion operations per second. Since the processors are bit-serial devices, performance rates improve with shorter word lengths. The BLITZEN chip is one of the first to incorporate over 1.1 million transistors on a single die. It was designed with 1.25-pm, two-level metal, CMOS design rules on an 11.0 by 11.7-mm die.
Towards a paradigm for fuzzy logic control

Abstract The purpose of this paper is to lay a foundation for fuzzy logic control (FLC) design, constructing a class of fuzzy logic controllers that is suitable for a broad range of controls applications. Some scalar definitions in FLC are extended to the n-dimensional case, including vector fuzzy number and membership vector. A rigorous mathematical expression is given for the function g(x) (called the ‘reasoning surface’) manufactured by a fuzzy associative memory (FAM). For the existence and uniqueness of solutions in any closed-loop system with a fuzzy logic controller, it is shown that the FAM function g(x) must be Lipschitz: this places restrictions on the allowed rules in the FLC. It is argued that, for effective control design, the membership functions should not be uniformly spaced, the triangular membership functions generally suffice, and product inferencing should be used. Under these conditions, the FLC manufactures a piecewise-multilinear Lipschitz FAM function g(x) that is a generalized proportional-plus-derivative-plus-offset controller. The scalar and two-dimensional cases are studied in detail.
Defining the Chaperone's Role as Escort, Educator or Parent

ABSTRACT The concept of family learning in museums emphasizes the interaction between related adults and children through the process of free-choice learning. The complexity of family learning in the context of school visits presents new questions for museum staff on the role of chaperones and the extent to which chaperone-led groups might function as family units. Do chaperones operate as escorts, educators, or parents on a museum field trip? This article provides a brief overview of existing field trip and chaperone research findings, raises some critical questions on the role of parents as chaperones, and describes the results from a study on chaperone behavior in the museum. Results from observations of 289 chaperones in a children's museum setting suggest that chaperone behavior is not necessarily influenced by exhibition context, but parents and chaperones do differ in preferred family learning interactions with children in museum exhibitions.
Bayesian mechanism design for budget-constrained agents

We study Bayesian mechanism design problems in settings where agents have budgets. Specifically, an agent's utility for an outcome is given by his value for the outcome minus any payment he makes to the mechanism, as long as the payment is below his budget, and is negative infinity otherwise. This discontinuity in the utility function presents a significant challenge in the design of good mechanisms, and classical "unconstrained" mechanisms fail to work in settings with budgets. The goal of this paper is to develop general reductions from budget-constrained Bayesian MD to unconstrained Bayesian MD with small loss in performance. We consider this question in the context of the two most well-studied objectives in mechanism design---social welfare and revenue---and present constant factor approximations in a number of settings. Some of our results extend to settings where budgets are private and agents need to be incentivized to reveal them truthfully.
Cassini/Huygens at Saturn and Titan

Abstract The Cassini/Huygens Project is a joint undertaking between NASA, the European Space Agency, and the Italian Space Agency to conduct an in-depth exploration of the Saturnian system. The spacecraft consists of an orbiter vehicle and an atmospheric probe which has completed its mission in the atmosphere and on the surface of Titan, the largest moon of Saturn. The spacecraft was launched on October 15, 1997, has completed its nearly 7 years of interplanetary flight, and by the time of the 56th IAC, it will have completed 17 of its planned 75 orbits during its 4-year prime orbital mission. This paper gives an overview of the mission, and describes in detail the accomplishments and events over the past year, including the spectacularly successful descent of the European Space Agency's Huygens probe to the surface of Titan. Initial scientific results from both the Huygens mission as well as from the first one-and-a-quarter years of orbiting Saturn are summarized. The plans for the remainder of the orbiter's tour of the Saturn system and the many flybys of Titan and the smaller icy satellites are described.