cssi/SciSciGPT-SciSciNet huggingface dataset:
Doping induced insulator-metal transition in the platinum based MX complexes

Abstract Platinum halide linear chain MX (XCl, Br, I) complesxes exhibit various strengths of the charge-density-wave (CDW) ground state. One way of characterizing the strength is to study the response to charge doping. On a finite length chain, we found that PtCl preserves its CDW pattern while forming a polaron array when doped; PtI is rapidly unstable against charge doping and undergoes an insulator-metal transition easily; PtBr is in between PtCl and PtI. These trends are consistent with the CDW strength, which is strong for PtCl, medium for PtBr and very weak for PtI.
Design of Reduced-Order Robust Controllers for Smart Structural Systems

This paper presents a method of designing reducedorder robust controllers for smart structural systems. We consider two kinds of uncertainties in the structural systems, norm bounded unstructured uncertainty and the variations of structural parameters. The smart structure with lead zirconate titanate (PZT) sensors and actuators is represented by a high order analytical model. Model error due to the uncertainties in structural parameters is modeled by parametric uncertainty in natural frequencies and damping ratios. By generalizing balanced truncation method for uncertain system, the high order model with uncertainties is reduced to a low order model with preserved parametric uncertainty. Based on linear matrix inequalities (LMIs) and Popov criterion, a robust controller is designed to suppress the lowfrequency vibrations caused by external disturbances and to guarantee the stability and performance of the closed-loop system under uncertainties. The order of the controller is further reduced by a frequency weighted model reduction method using LMI. The procedure was experimentally tested on a smart structural test article.
Decreasing‐Liability Contracts

Abstract Like constructing a building, performance on many contracts occurs in phases. As time passes, the promisor sinks more costs into performance and less expenditure remains. For phased performance, we show that optimal liability for the breaching party decreases as the remaining costs of completing performance decrease. In brief, efficiency requires a decreasing‐liability contract. To implement such a contract, we recommend deducting past expenditures on incomplete performance from liability. We show that some types of progress‐payment contracts are materially equivalent to decreasing‐liability contracts. Our analysis should prove useful for elucidating progress‐payment contracts and for drafting and litigating phased contracts.
Cross-Frequency Integration for Consonant and Vowel Identification in Bimodal Hearing

Purpose Improved speech recognition in binaurally combined acoustic–electric stimulation (otherwise known as bimodal hearing) could arise when listeners integrate speech cues from the acoustic and ...
High-Resolution Submillimeter Constraints on Circumstellar Disk Structure

We present a high spatial resolution submillimeter continuum survey of 24 circumstellar disks in the Taurus-Auriga and Ophiuchus-Scorpius star formation regions using the SMA. In the context of a simple model, we use broadband spectral energy distributions and submillimeter visibilities to derive constraints on some basic parameters that describe the structure of these disks. For the typical disk in the sample we infer a radial surface density distribution Σr r-p with a median p ≈ 0.5, although consideration of the systematic effects of some of our assumptions suggest that steeper distributions with p ≈ 1 are more reasonable. The distribution of the outer radii of these disks shows a distinct peak at Rd ≈ 200 AU, with only a few cases where the disk emission is completely unresolved. Based on these disk structure measurements, the mass accretion rates, and the typical spectral and spatial distributions of submillimeter emission, we show that the observations are in good agreement with similarity solutions for steady accretion disks that have a viscosity parameter α ≈ 0.01. We provide new estimates of the spectral dependence of the disk opacity κν νβ with a mean β ≈ 1.0, corrected for optically thick emission. This typical value of β is consistent with model predictions for the collisional growth of solids to millimeter-size scales in the outer disk. Although direct constraints on planet formation in these disks are not currently available, the extrapolated density distributions inferred here are substantially shallower than those calculated based on the solar system or extrasolar planets and typically used in planet formation models. It is possible that we are substantially underestimating disk densities due to an incomplete submillimeter opacity prescription.
Effect of Wind Tunnel Acoustic Modes on Linear Oscillating Cascade Aerodynamics

The aerodynamics of a biconvex airfoil cascade oscillating in torsion is investigated using the unsteady aerodynamic influence coefficient technique. For subsonic flow and reduced frequencies as large as 0.9, airfoil surface unsteady pressures resulting from oscillation of one of the airfoils are measured using flush-mounted high- frequency-response pressure transducers. The influence coefficient data are examined in detail and then used to predict the unsteady aerodynamics of a cascade oscillating at various interblade phase angles. These results are correlated with experimental data obtained in the traveling-wave mode of oscillation and linearized analysis predictions
Life cycle assessment for dredged sediment placement strategies

Dredging to maintain navigable waterways is important for supporting trade and economic sustainability. Dredged sediments are removed from the waterways and then must be managed in a way that meets regulatory standards and properly balances management costs and risks. Selection of a best management alternative often results in stakeholder conflict regarding tradeoffs between local environmental impacts associated with less expensive alternatives (e.g., open water placement), more expensive measures that require sediment disposal in constructed facilities far away (e.g., landfills), or beneficial uses that may be perceived as risky (e.g., beach nourishment or island creation). Current sediment-placement decisions often focus on local and immediate environmental effects from the sediment itself, ignoring a variety of distributed and long-term effects from transportation and placement activities. These extended effects have implications for climate change, resource consumption, and environmental and human health, which may be meaningful topics for many stakeholders not currently considered. Life-Cycle Assessment (LCA) provides a systematic and quantitative method for accounting for this wider range of impacts and benefits across all sediment management project stages and time horizons. This paper applies a cradle-to-use LCA to dredged-sediment placement through a comparative analysis of potential upland, open water, and containment-island placement alternatives in the Long Island Sound region of NY/CT. Results suggest that, in cases dealing with uncontaminated sediments, upland placement may be the most environmentally burdensome alternative, per ton-kilometer of placed material, due to the emissions associated with diesel fuel combustion and electricity production and consumption required for the extra handling and transportation. These results can be traded-off with the ecosystem impacts of the sediments themselves in a decision-making framework.
Constructing knot tunnels using giant steps

In 2000, Goda, Scharlemann, and Thompson described a general construction of all tunnels of tunnel number 1 knots using "tunnel moves". The theory of tunnels introduced by Cho and McCullough provides a combinatorial approach to understanding tunnel moves. We use it to calculate the number of distinct minimal sequences of such moves that can produce a given tunnel. As a consequence, we see that for a sparse infinite set of tunnels, the minimal sequence is unique, but generically a tunnel will have many such constructions. Finally, we give a characterization of the tunnels with a unique minimal sequence.
CHAOTIC MIXING OF SHEAR-THINNING FLUIDS

This article investigates the effect of shear-thinning viscosity on chaotic mixing when the kinematics first begin to deviate from Newtonian flow. Computations are done for a 2-D, time-periodic flow between eccentric cylinders. The effectiveness of mixing is analyzed by examining the asymptotic coverage of a passive tracer, character and location of periodic points, and the rate of stretching of fluid elements. Small variations in the velocity field associated with non-Newtonian kinematics produce large effects in the chaotic advection of a passive tracer. The stretching rate remains exponential, but with a long time constant as the shear-thinning effect increases, often resulting in the birth of new periodic islands and a decrease in the asymptotic coverage of the tracer. Exceptions to these observations are possible: both the stretching rate and the asymptotic coverage might increase as shear thinning increases. Results also indicate that suitable manipulation of operating conditions can produce shear-thinning flows which mix as well as Newtonian flows. Since significant effects are observed with less than a 4% difference in the velocity fields, the assumption of Newtonian kinematics can lead to large errors in the design and operation of process mixing equipment for non-Newtonian fluids.
Stereocontrolled Synthesis of Bicyclic Sulfamides via Pd-Catalyzed Alkene Carboamination Reactions. Control of 1,3-Asymmetric Induction by Manipulating Mechanistic Pathways

A new annulation strategy for the synthesis of trans-bicyclic sulfamides is described. The Pd-catalyzed alkene carboamination reactions of 2-allyl and cis-2,5-diallyl pyrrolidinyl sulfamides with aryl and alkenyl triflates afford the fused bicyclic compounds in good yields and with good diastereoselectivity (up to 13:1 dr). Importantly, by employing reaction conditions that favor an anti-aminopalladation mechanism, the relative stereochemistry between the C3 and C4a stereocenters of the products is reversed relative to related Pd-catalyzed carboamination reactions that proceed via syn-aminopalladation.
Synthesis and characterization of the new cluster phase K39In80. Three K-In compounds with remarkably specific and transferable cation dispositions.

The titled compound K39In80 (Pearson symbol hP238) has been synthesized by fusion of the elements in stoichiometric proportions in Nb containers. The trigonal structure was established by single-crystal X-ray means (P3m1, Z = 2, a = b =17.211(2) A, c = 28.888(6) A). The crystal structure can be described as a three-dimensional indium network composed of five kinds of clusters: three types of empty In12 icosahedra with different exo-bonding and symmetry, A (12 exo-bonds, 3m), B (12 exo-bonds, m), and C (6 exo-bonds, 3m); an In16 icosioctahedron centered by a tetrahedral In atom (D, 3m); and a rather open In15 spacer (E, 3m). This new intermediate lies between K17In41 and K22In39. Remarkably specific and transferable potassium dispositions about each cluster anion occur in the title compound as well as in K17In41 and K22In39. This characteristic makes it easier to understand the structural relationships among these three compounds, which all exhibit a common K136 clathrate-II network of alkali metal ato...
Analysis of Corrosion Fatigue Crack Growth in Welded Tubular Joints

An improved fracture mechanics model for fatigue crack growth in welded tubular joints is developed. Primary improvements include the use of a wide-ranged equation for the fatigue crack growth rate properties and the incorporation of the influence of local weld-toe geometry into the stress intensity factor equations. The latter is shown to explain the dependence of the fatigue life on the size of tubular joints. Good agreement between predicted and measure fatigue lives of full-scale joints tested in air further supports the applicability of the fracture mechanics approach to offshore structures. Although the model should also be applicable to corrosion fatigue, additional imput data and verification testing are needed under these conditions. Factors which could improve the model are discussed.
Conjugate addition of arylsilanes to unsaturated carbonyl compounds catalyzed by rhodium in air and water.

ArSiCl3 and Ar2SiCl2, believed to be unstable in aqueous media, reacted efficiently with α,β-unsaturated ketones and esters in air and water (in the presence of sodium fluoride and a rhodium catalyst), giving good to excellent yields of the desired conjugate addition products.
Time-Frequency Analysis of Slider Dynamics and the Effect of Lubricant

The dynamics of pico sliders is investigated during scratch impact using laser Doppler vibrometry. Air-bearing frequencies and damping of the pitch-2 frequency are studied as a function of disk velocity for lubricant thickness values of 1.6 nm, 1.0 nm and 2.0 nm. Time-frequency analysis is performed to study the instantaneous air-bearing frequencies. System identification methods are used to model the response of the slider after a scratch impact. The results indicate that the slider dynamics and the damping coefficients are affected by the disk velocity and lubricant thickness and also possibly by disk micro-waviness. @DOI: 10.1115/1.1695568#
Simulating three-dimensional hydrodynamics on a cellular automata machine

We demonstrate how three-dimensional fluid flow simulations can be carried out on the Cellular Automata Machine 8 (CAM-8), a special-purpose computer for cellular automata computations. The principal algorithmic innovation is the use of a lattice gas model with a 16-bit collision operator that is specially adapted to the machine architecture. It is shown how the collision rules can be optimized to obtain a low viscosity of the fluid. Predictions of the viscosity based on a Boltzmann approximation agree well with measurements of the viscosity made on CAM-8. Several test simulations of flows in simple geometries—channels, pipes, and a cubic array of spheres-are carried out. Measurements of average flux in these geometries compare well with theoretical predictions.
Light curves of rotating, oscillating neutron stars

A technique has been developed for computing the light curve produced by a rotating, oscillating neutron star that emits radiation from circular polar cap regions, as are thought to exist in pulsars, X-ray binaries, and perhaps X-ray bursters. Several examples of light curves produced by single, low-order (l = 1, 2) oscillation modes are given. A Gaussian beaming function is used to simulate typical radio pulsar beam widths in order to investigate a neutron star oscillation model for subpulse drift in pulsars. X-ray bursts and X-ray pulsars have also been simulated to assess the possibility of detecting such oscillations in these sources with XTE and AXAF.
Solid lubricant materials for high temperatures—a review

Abstract Solid lubricants, which can be used above 300°C in air, are discussed; coatings and self-lubricating composite bearing materials are also covered. The lubricants considered are representative dichalcogenides, graphite, graphite fluoride, polyimides, soft oxides, oxidatively stable fluorides and hard coat materials. A few general design considerations relevant to solid lubrication are mentioned
SET-THEORETIC YANG–BAXTER SOLUTIONS VIA FOX CALCULUS

We construct solutions to the set–theoretic Yang–Baxter equation using braid group representations in free group automorphisms and their Fox differentials. The method resembles the extensions of groups and quandles.
Inverse Spectral Problems in Rectangular Domains

We consider the Schrodinger operator − Δ + q in domains of the form R = {x ∈ ℝ n : 0 ≤ x i ≤ a i , i = 1,…, n} with either Dirichlet or Neumann boundary conditions on the faces of R, and study the constraints on q imposed by fixing the spectrum of − Δ + q with these boundary conditions. We work in the space of potentials, q, which become real-analytic on ℝ n when they are extended evenly across the coordinate planes and then periodically. Our results have the corollary that there are no continuous isospectral deformations for these operators within that class of potentials. This work is based on new formulas for the trace of the wave group in this setting. In addition to the inverse spectral results these formulas lead to asymptotic expansions for the traces of the wave and heat kernels on rectangular domains.
Zero-Current-Switching Multilevel Modular Switched-Capacitor DC–DC Converter

This paper presents a quasi-resonant technique for multilevel modular switched-capacitor dc-dc converter (MMSCC) to achieve zero-current switching (ZCS) without increasing cost and sacrificing reliability. This ZCS-MMSCC employs stray inductance distributed in the circuit as the resonant inductor to resonate with the capacitor and provide low dv /dt and di /dt switching transition for the device. The ZCS-MMSCC does not utilize any additional components to achieve ZCS and meanwhile solves the current and voltage spike problem during the switching transition, thus leading to reliable and high-efficiency advantages over traditional MMSCC. Furthermore, the ZCS-MMSCC reduces the capacitance needed in the circuit to attain high efficiency. In this case, the bulky capacitor bank with high capacitance in a traditional MMSCC to reduce voltage difference and achieve high efficiency is no longer necessary. A 150-W four-level ZCS-MMSCC prototype has been built. Simulation and experimental results are given to demonstrate the validity and features of the proposed soft-switching switched-capacitor circuit.
Noncrossing Partitions in Surprising Locations

1. Introduction.Certain mathematical structures make a habit of reoccuring in the most diverselist of settings. Some obvious examples exhibiting this intrusive type of behaviorinclude the Fibonacci numbers, the Catalan numbers, the quaternions, and themodular group. In this article, the focus is on a lesser known example: the non-crossing partition lattice. The focus of the article is a gentle introduction to thelattice itself in three of its many guises: as a way to encode parking functions, asa key part of the foundations of noncommutative probability, and as a buildingblock for a contractible space acted on by a braid group. Since this article is aimedprimarily at nonspecialists, each area is brieﬂy introduced along the way.The noncrossing partition lattice is a relative newcomer to the mathematicalworld. First deﬁned and studied by Germain Kreweras in 1972 [33], it caught theimagination of combinatorialists beginning in the 1980s [20], [21], [22], [23], [29],[37], [39], [40], [45], and has come to be regarded as one of the standard objectsin the ﬁeld. In recent years it has also played a role in areas as diverse as low-dimensional topology and geometric group theory [9], [12], [13], [31], [32] as wellas the noncommutative version of probability [2], [3], [35], [41], [42], [43], [49],[50]. Due no doubt to its recent vintage, it is less well-known to the mathematicalcommunity at large than perhaps it deserves to be, but hopefully this short paperwill help to remedy this state of aﬀairs.2. A motivating example.Before launching into a discussion of the noncrossing partition lattice itself, wequickly consider a motivating example: the Catalan numbers. The Catalan num-bers are a favorite pastime of many amateur (and professional) mathematicians. Inaddition, they also have a connection with the noncrossing partition lattice (Theo-rem 3.1).Example 2.1(Catalan numbers). The Catalan numbers are the numbers C
Adjacency-blurring effect of scenes modeled by the radiosity method

In this paper we describe a method to simulate images through a scattering atmosphere. We compute the scattering of light from adjacent surfaces into the field-of-view (FOV) with the extended radiosity method. Our simulation takes aerosol scattering phase functions and ground bidirectional reflectance distributions (BRDF) into account. 10 refs.
Plasmon Interactions in the Quark-Gluon Plasma

We construct plasmon creation and annihilation operators for Yang–Mills theory at finite temperature. This provides a starting point for perturbation theory with resummation of hard thermal loops in a Hamiltonian framework.
What do we know about patient targeting in geriatric evaluation and management (GEM) programs

Evidence indicates that institution-based programs for interdisciplinary geriatric evaluation and management (GEMs) improve outcomes of care, but results vary considerably between studies. Targeting (i.e., selective admission of frail elderly patient subgroups who are thought particularly to benefit) has been advocated as a means to improve the cost-effectiveness of GEM programs, and results from meta-analysis give this concept some support. Our review has several objectives: 1) describing approaches to GEM targeting and development of selection criteria; 2) assessing evidence from randomized trials concerning effects of targeting on outcome; and 3) suggesting an agenda for further research and development on GEM targeting.
Supramolecular Assembly and Binding in Aqueous Solution: Useful Tips Regarding the Hofmeister and Hydrophobic Effects

The self-assembly of structurally discrete entities, and supramolecular chemistry in general, continues to expand into the aqueous realm. To do so, however, requires a firm understanding of the properties of aqueous solution, and how these “change the rules” for binding and assembly relative to organic solvents. In this mini-review we highlight the state-of-the-art understanding of the supramolecular properties of water, and how these influence the design of hosts and self-assembling systems.
Tunnel number one, genus-one fibered knots

We determine the genus one fibered knots in lens spaces that have tunnel number one. We also show that every tunnel number one, once-punctured torus bundle is the result of Dehn filling a component of the Whitehead link in the 3-sphere.
Structure of ternary imide Li2Ca(NH)2 and hydrogen storage mechanisms in amide-hydride system.

The crystal structure of the ternary imide Li2Ca(NH)2 has been determined using neutron powder diffraction data on a deuterated sample. The structure consists of infinite layers of edge-shared Ca[NH]6 octahedra, which are separated by Li cations. The mobile Li+ ions in such two-dimensional channels defined by Ca[NH]6 octahedra layers are shown to have a great impact on the hydrogenation properties of the imide. Through detailed structural analysis on the products at various stages of desorption and absorption of the amide−hydride mixture, we proposed a dehydrogenation mechanism involving the mobile small ions in both amide and hydride and a hydrogen storage mechanism for the ternary imide.
Phenylsulfonylnitromethanes as potent irreversible inhibitors of aldose reductase

Abstract Aldose reductase (AR) inhibition provides a viable pharmacologically direct mode for the treatment of diabetic complications. We have synthesized a series of N-4 substituted analogues ( 15–21 ) of the known aldose reductase inhibitor phenyl-sulfonylnitromethane. The compounds are potent inhibitors of AR with IC 50 s between 0.01 and 0.19 μM. Some of the compounds are also potent affinity labels for AR. Compound 19 exhibits the highest and almost complete irreversible inhibition of AR known to date.
ON THE COMPLEXITY OF THE HIDDEN SUBGROUP PROBLEM

We study the computational complexity of the HIDDEN SUBGROUP problem, a well-studied problem in quantum computing. First we show that several proposed generalizations or variants of this problem, including HIDDEN COSET, HIDDEN SHIFT, and ORBIT COSET, are all equivalent or reducible to HIDDEN SUBGROUP. Then we study the relationship between the decision version and search version of HIDDEN SUBGROUP over various group classes. We show that the two versions are polynomial-time equivalent over permutation groups, and over dihedral groups given the order of the group is smooth. Finally, we give nonadaptive program checkers for HIDDEN SUBGROUP and its decision version.
The Concept of Voluntary Motor Control in the Recent Neuroscientific Literature

The concept of voluntary motor control(VMC) frequently appears in the neuroscientific literature, specifically in the context of cortically-mediated, intentional motor actions. For cognitive scientists, this concept of VMC raises a number of interesting questions:(i) Are there dedicated, modular-like structures within the motor system associated with VMC? Or (ii) is it the case that VMC is distributed over multiple cortical as well as subcortical structures?(iii) Is there any one place within the so-calledhierarchy of motor control where voluntary movements could be said to originate? And (iv) in the current neurological literature how is the adjective voluntary in VMC being used? These questions are here considered in the context of how higher- and lower-levels of motor control, plan, initiate, coordinate, sequence, and modulate goal-directed motor outputs in response to changing internal and external inputs. Particularly relevant are the conceptual implications of current neurological modeling of VMC concerning causal agency.
Chemical and physical sensors based on oxygen pumping with solid-state electrochemical cells

Abstract Oxygen sensors based on ZrO 2 electrochemical cells have found extensive use in many applications. The most sensitive of these sensors employ the oxygen-pumping principle with ZrO 2 cells. Oxygen pumping, however, can also be used to generate other chemical and also physical sensors. This paper discusses several of these sensors, e.g., sensors for measuring CO, H 2 , H 2 O, hydrocarbons, gas flow, and gas pressure, and presents results from studies of the properties of some of these devices.
Evaluation of OH laser-induced fluorescence techniques for supersonic combustion diagnostics

The limitations on application of dye laser and narrowband tunable KrF excimer laser systems to planar OH fluorescence measurements in supersonic combustion test facilities are examined. Included in the analysis are effects of collisional quenching, beam absorption, fluorescence trapping, and signal strengths on achievable measurement accuracy using several excitation and detection options for either of the two laser systems. Dye-based laser systems are found to be the method of choice for imaging OH concentrations less than 10 exp 15 per cu cm, while the KrF based systems provide significant reduction in measurement ambiguity for concentrations in excess of 10 exp 15 per cu cm.
Adaptive blind separation of convolutive mixtures of independent linear signals

Abstract This paper is concerned with the problem of blind separation of independent signals (sources) from their linear convolutive mixtures. The problem consists of recovering the sources up to shaping filters from the observations of MIMO system output. The various signals are assumed to be linear non-Gaussian but not necessarily i.i.d. (independent and identically distributed). Recently an iterative, normalized higher-order cumulant maximization based approach was developed using the fourth-order normalized cumulants of the ‘beamformed’ data. This approach was source-iterative, i.e., the sources were extracted (at each sensor) and cancelled one by one, in the process yielding a decomposition of the given data at each sensor into its independent signal components. In this paper an adaptive implementation of the above approach is developed using a stochastic gradient approach. Some further enhancements including a Wiener filter implementation for signal separation and adaptive filter reinitialization are also provided. Computer simulation examples are presented to illustrate the proposed approach.
Total Positivity: Tests and Parametrizations

An introduction to total positivity (TP), with the emphasis on efficient TP criteria and parametrizations of TP matrices. Intended for general mathematical audience.
Synthesis and pharmacokinetics of potent carbamate HIV-1 protease inhibitors containing novel high affinity hydroxyethylamine isosteres

Abstract Using the hydroxyethylamine isosteres 1 and 2 containing the novel cis-octahydrothienopyridine moiety, substantial enhancement of binding potencies for HIV-1 protease inhibitors which incorporate carbamate linked heterocyclic P2 ligands has been realized. This increase in binding has led to a very potent antiviral compound (LY326188). The pharmacokinetics of selected derivatives are detailed in this report.
Optical Appearance of the Debris of a Star Disrupted by a Massive Black Hole

We show that the disruption of a star by a ~106 M☉ black hole in a galactic nucleus could under favorable circumstances produce an optically thick envelope that radiates with a thermal spectrum at the Eddington limit, ~1044 ergs s-1, for tens of years. The low apparent temperature of this envelope, ~104 K, would be easily detectable in optical surveys. If most galaxies harbor a massive black hole at their center, then the Sloan Digital Sky Survey might find hundreds of galaxies with nuclear activity of this type. Because the envelope is driven to shine near the Eddington limit, a measurement of the source redshift and total luminosity could yield the black hole mass.
A new route to 7-substituted derivatives of n-[4-(2-[2-amino-3,4-dihydro-4-oxo-7H-pyrrolo(2,3-d)pyrimidin-5-yl]ethyl)benzoyl]-L-glutamic acid [ALIMTA (LY231514, MTA)].

Alkylation of various primary amines with crotyl bromide, followed by DMAP-promoted acylation with methyl malonyl chloride to 4 and then manganic triacetate dihydrate/cupric acetate induced radical cyclization, gave 1-substituted-4-vinyl-3-carbomethoxy-2-pyrrolidinones (5). Thiation to the thiolactams 6 and guanidine cyclization then gave a series of 2-amino-3,4-dihydro-4-oxo-5-vinyl-7-substituted pyrrolo[2,3-d]pyrimidines (7). Palladium-catalyzed C−C coupling with diethyl 4-iodobenzoylglutamate led in one step via an unexpected redox reaction to the diethyl esters 9 of a series of 7-substituted derivatives of ALIMTA (LY231514, MTA), from which the target analogues 10 were readily prepared by saponification. Attempted deprotection at position 7 was successful in only one case (9d, R = CH2C6H3(OMe)2(-3‘,4‘), which resulted in a known pentultimate precursor (9, R = H) of ALIMTA. The 7-substituted derivatives 10 proved to be inactive in vitro as inhibitors of cell division.
The Blue Line Blues: Why the Vision of Transit Village May Not Materialize Despite Impressive Growth in Transit Ridership

The paper examines the Blue Line corridor, a 22-mile rail transportation route that connects downtown Los Angeles to downtown Long Beach. The line passes through some of the most neglected and poorest communities in Los Angeles County. Despite initial rhetoric by rail advocates and local politicians the line has not succeeded in improving the economic environment of adjacent communities. In this paper we use the Blue Line as a case-study in an effort to understand the real and perceived barriers to growth around inner city station areas. Based on information gathered through a series of interviews with politicians, planners, community leaders and transportation experts, and site analysis data from extensive field-work, we identify the "missing antecedents" for neighbourhood development around inner city station areas.
Alcoa Picturephone Remote Information System (APRIS)

The objective of the Alcoa Picturephone Remote Information System (APRIS) is to give to Alcoa executives the capability of using their Picturephones to retrieve information from the corporate computer data base.
On the classical solutions of two dimensional inviscid rotating shallow water system

Abstract We prove global existence and asymptotic behavior of classical solutions for two dimensional inviscid rotating shallow water system with small initial data subject to the zero relative vorticity condition. One of the key steps is a reformulation of the problem into a symmetric quasilinear Klein–Gordon system with quadratic nonlinearity, for which the global existence of classical solutions is then proved with combination of the vector field approach and the normal form method. We also probe the case of general initial data and reveal a lower bound for the lifespan that is almost inversely proportional to the size of the initial relative vorticity.
On Association Cells in Random Heterogeneous Networks

Characterizing user to access point (AP) association strategies in heterogeneous cellular networks (HetNets) is critical for their performance analysis, as it directly influences the load across the network. In this letter, we introduce and analyze a class of association strategies, which we term stationary association, and the resulting association cells. For random HetNets, where APs are distributed according to a stationary point process, the area of the resulting association cells are shown to be the marks of the corresponding point process. Addressing the need of quantifying the load experienced by a typical user, a "Feller-paradox" like relationship is established between the area of the association cell containing origin and that of a typical association cell. For the specific case of Poisson point process and max power/\SINR association, the mean association area of each tier is derived and shown to increase with channel gain variance and decrease in the path loss exponents of the corresponding tier.
Unsteady Thrust Measurement for Pulse Detonation Engines

A new approach to thrust measurement for pulse detonation engines was developed to account for the effects of system dynamics. The approach was applied to a pulse detonation engine operating at 10 and 20 Hz. System parameters such as steady-state response, effective mass of the combined pulse detonation engine and thrust measurement rig structure, and mass flow rates of the fuel/oxidizer were first determined. The system dynamics of the pulse detonation engine, deconvolved in the frequency domain, was studied. The system’s transfer function between the thrust and a corresponding pressure obtained by a single propagating detonation pressure history during pulse detonation engine operation was established and used to reconstruct the thrust response for pulsed operation. A proper reconstruction of the deconvolved thrust values was accomplished through this technique. The acceleration experienced by the pulse detonation engine thrust measurement rig was also measured. This measured acceleration when multiplie...
Resonance-free region in scattering by a strictly convex obstacle

We prove the existence of a resonance-free region in scattering by a strictly convex obstacle \(\mathcal{O}\) with the Robin boundary condition \(\partial_{\nu}u+\gamma u|_{\partial\mathcal{O}}=0\). More precisely, we show that the scattering resonances lie below a cubic curve ℑζ=−S|ζ|1/3+C. The constant S is the same as in the case of the Neumann boundary condition γ=0. This generalizes earlier results on cubic pole-free regions obtained for the Dirichlet boundary condition.
Cyclotomy and endomotives

We compare two different models of noncommutative geometry of the cyclotomic tower, both based on an arithmetic algebra of functions of roots of unity and an action by endomorphisms, the first based on the Bost-Connes (BC) quantum statistical mechanical system and the second on the Habiro ring, where the Habiro functions have, in addition to evaluations at roots of unity, also full Taylor expansions. Both have compatible endomorphisms actions of the multiplicative semigroup of positive integers. As a higher dimensional generalization, we consider a crossed product ring obtained using Manin’s multivariable generalizations of the Habiro functions and an action by endomorphisms of the semigroup of integer matrices with positive determinant. We then construct a corresponding class of multivariable BC endomotives, which are obtained geometrically from self maps of higher dimensional algebraic tori, and we discuss some of their quantum statistical mechanical properties. These multivariable BC endomotives are universal for (torsion free) Λ-rings, compatibly with the Frobenius action. Finally, we discuss briefly how Habiro’s universal Witten-Reshetikhin-Turaev invariant of integral homology 3-spheres may relate invariants of 3-manifolds to gadgets over \( \mathbb{F}_1 \) and semigroup actions on homology 3-spheres to endomotives.
R&D sensitivity to asset sale proceeds: New evidence on financing constraints and intangible investment

Abstract We examine the intersection between corporate divestitures of tangible assets and investment in intangible capital (R&D) to provide new tests for the impact financing constraints have on real activity. A positive R&D sensitivity to asset sale proceeds indicates binding financing constraints since cash inflows from tangible asset sales are negatively correlated with productivity shocks and not otherwise connected to intangible investment via non-financial channels. Using a variety of estimation approaches, we document a strong, positive link between cash inflows from fixed asset sales and corporate R&D investment, but only among firms most likely facing binding financing constraints. These results offer robust evidence that financing frictions impact the increasingly important yet understudied intangible corporate investments that drive innovative activity, and they highlight a previously unexplored but potentially valuable use of proceeds from fixed asset divestitures.
A NOVEL ECHOCARDIOGRAPHIC MEASUREMENT IN PEDIATRIC HEART TRANSPLANT RECIPIENTS WITH DILATED CARDIOMYOPATHY: CAN WE MAXIMIZE THE DONOR SUPPLY?

Purpose In normal pediatric echocardiograms, the distance from the junction of superior vena cava and right atrium to inferior vena cava and right atrium (SVC-IVC) is linearly related to height. We examine this relationship in children listed for heart transplant with dilated cardiomyopathy (DCM) compared to a previously defined normal distribution of SVC-IVC in order to maximize potential donor acceptance. Methods and Materials Measurements of SVC-IVC and left ventricular end-diastolic diameter (LVEDd) in 55 patients (pts) with DCM (age 2 months - 19 years, median 7.8 years) were correlated with height, weight, body surface area (BSA), and BSA0.5. Regression analyses were performed to find the best-fit equation and correlation coefficient. Generalized linear modeling compared DCM to normal SVC-IVC values from 254 pts. Results There was a strong linear relationship in DCM pts between SVC-IVC and height (R2=0.84) and a logarithmic relationship to weight (R2=0.80). LVEDd did not correlate to SVC-IVC or any other parameter. In 89% of DCM pts, SVC-IVC was over 2 standard deviations above predicted normal values (mean z-score = 4.3±2.1). Predicted SVC-IVC in DCM pts was different than published norms (p Conclusions SVC-IVC in pediatric DCM pts, while linearly related to height, is consistently above normal values (figure). When matching pediatric heart recipients to donors, SVC-IVC may help accurately size donor hearts, especially for bicaval anastomosis, and substantially increase the donor pool. [ figure 1 ]
The Transpired Turbulent Boundary Layer in Various Pressure Gradients and the Blow-Off Condition

An experimental study of the reduction in heat transfer to a transpiration-cooled flat surface subjected to pressure gradients (zero, negative, and positive) is presented for flow conditions similar to those encountered in gas turbines. The investigation is carried out for high injection rates and determines the blow-off conditions under which the boundary layer is lifted away from the wall by the transpired coolant. The study was conducted in a hot blow-down wind tunnel facility. The transient nature of the facility ensures that the wall remains isothermal. The Reynolds number, the ratio of the gas to wall temperatures, and the pressure gradient parameters K are chosen to be representative of the conditions found in advanced gas turbines. The effect of the pressure gradient was found to be small. However, a local strong acceleration can reduce the cooling effectiveness. The heat transfer rates or Stanton numbers on a solid surface downstream of a transpiration cooled wall are found to be sensitive to the upstream injection ratio (b) and to the pressure gradient parameter. The data indicate that the ratio of Stanton numbers with and without cooling is nonzero for values of the injection parameters larger than values obtained theoretically by Kutateladze. The predicted value of the critical injection ratio (bcr ) determined from this study agrees well with the experimental data of Liepmann and Laufer for a free mixing layer, which is similar to a transpired boundary layer near blow-off as pointed out by Coles.
Dancing with the Enemy? Relational Hazards and the Contingent Value of Repeat Exchanges in M&A Markets

I examine the problem of relational hazards between repeat exchange partners and the contingent roles of trade uncertainty and future exchange prospects in moderating the potentially conflicting effects of past exchanges on these hazards, thereby facilitating or restraining the formation of relational embeddedness. On the data of advisory relationships in U.S. mergers and acquisitions from 1981 to 2004, I find that firms that repeatedly hire the same investment banks as financial advisors tend to overpay for acquisition targets, as reflected by negative investor reactions measured in the cumulative abnormal return. In addition, the degree of overpayment increases with the frequency of prior exchanges. This adverse effect of exchange history grows if the uncertainty regarding the target firm rises. However, better prospects for future business with acquiring firms help mitigate this negative effect, although this moderating effect varies across the types of exchange experience. The findings suggest that a potentially complex and nuanced process underlies repeat exchanges, which are an oft-claimed precursor of relational embeddedness, to deliver tangible economic benefits. This study contributes to the emerging literature on the “dark side” of embeddedness and, more broadly, to the sociology of markets and organizations by substantiating the contingency mechanisms that shape the value of a repeat relationship in market exchanges.
Structure of W3(OH) from Very High Spectral Resolution Observations of 5 Centimeter OH Masers

Recent studies of methanol and ground-state OH masers at very high spectral resolution have shed new light on small-scale maser processes. The nearby source W3(OH), which contains numerous bright masers in several different transitions, provides an excellent laboratory for high spectral resolution techniques. We present a model of W3(OH) based on European VLBI Network (EVN) observations of the rotationally excited 6030 and 6035 MHz OH masers taken at 0.024 km s-1 spectral resolution. The 6.0 GHz masers are becoming brighter with time and show evidence for tangential proper motions. We confirm the existence of a region of magnetic field oriented toward the observer to the southeast and find another such region to the northeast in W3(OH), near the champagne flow. The 6.0 GHz masers trace the inner edge of a counterclockwise rotating torus feature. Masers at 6030 MHz are usually a factor of a few weaker than at 6035 MHz but trace the same material. Velocity gradients of nearby Zeeman components are much more closely correlated than in the ground state, likely due to the smaller spatial separation between Zeeman components. Hydroxyl maser peaks at very long baseline interferometric resolution appear to have structure both on scales smaller than that resolvable and on larger scales.
The association between characteristics of audit committee accounting experts, audit committee chairs, and financial reporting timeliness

Abstract We investigate the association between audit committee (AC) members' financial expertise and financial reporting timeliness, and extend the discussion by investigating how the source of accounting expertise (e.g., public accounting or CFO) differentially influences financial reporting timeliness. We predict and find that AC accounting financial expertise is associated with timelier accounting information. Further, we find that accounting expertise gained from public accounting experience is associated with timelier financial reporting; however, accounting expertise gained from CFO experience is not. We also find that AC chairs (ACCs) with accounting expertise from public accounting experience are significantly associated with timelier financial reporting while ACCs with CFO-sourced accounting expertise are not. Our results are important for two reasons. First, our results suggest that AC accounting financial expertise contributes to AC effectiveness by improving the timeliness of financial information. Second, our findings highlight how personal characteristics of accounting financial experts influence contributions toward AC effectiveness.
Angular instability due to radiation pressure in the LIGO gravitational-wave detector

We observed the effect of radiation pressure on the angular sensing and control system of the Laser Interferometer Gravitational-Wave Observatory (LIGO) interferometer’s core optics at LIGO Hanford Observatory. This is the first measurement of this effect in a complete gravitational-wave interferometer. Only one of the two angular modes survives with feedback control, because the other mode is suppressed when the control gain is sufficiently large. We developed a mathematical model to understand the physics of the system. This model matches well with the dynamics that we observe.
The mechanism responsible for extraordinary Cs ion selectivity in crystalline silicotitanate.

Combining information from time-resolved X-ray and neutron scattering with theoretical calculations has revealed the elegant mechanism whereby hydrogen crystalline silicotitanate (H-CST; H2Ti2SiO7·1.5H2O) achieves its remarkable ion-exchange selectivity for cesium. Rather than a simple ion-for-ion displacement reaction into favorable sites, which has been suggested by static structural studies of ion-exchanged variants of CST, Cs+ exchange proceeds via a two-step process mediated by conformational changes in the framework. Similar to the case of ion channels in proteins, occupancy of the most favorable site does not occur until the first lever, cooperative repulsive interactions between water and the initial Cs-exchange site, repels a hydrogen lever on the silicotitanate framework. Here we show that these interactions induce a subtle conformational rearrangement in CST that unlocks the preferred Cs site and increases the overall capacity and selectivity for ion exchange.
Parametric seeding of a microresonator optical frequency comb

We have investigated parametric seeding of a microresonator frequency comb (microcomb) by way of a pump laser with two electro-optic-modulation sidebands. We show that the pump-sideband spacing is precisely replicated throughout the microcomb's optical spectrum, and we demonstrate a record absolute line-spacing stability for microcombs of 1.6 × 10(-13) at 1 s. The spectrum of a microcomb is complex, and often non-equidistant subcombs are observed. Our results demonstrate that parametric seeding can not only control the subcombs, but can lead to the generation of a strictly equidistant microcomb spectrum.
Brownian coagulation in the transition regime

Abstract The rate of Brownian coagulation of aerosols is studied theoretically. The particle distribution function is assumed to be governed by the Fokker-Planck equation, which is solved analytically by the 13-moment method of Grad. An expression for the coagulation parameter β(ai, aj) is obtained from the solution over all ranges of particle radii ai and aj. The coagulation rates predicted by the solution agree closely with those predicted by the empirical expression of Fuchs as well as with those recently obtained experimentally by Chatterjee, Kerker, and Cooke.