cssi/SciSciGPT-SciSciNet huggingface dataset:
Effects of buoyancy on premixed flame stabilization

The stabilization limits of v-flame and conical flames are investigated in normal gravity (+g) and reversed gravity (upside-down burner, −g) to compare with observations of flame stabilization during microgravity experiments. The results show that buoyancy has the most influence on the stabilization of laminar v-flames. Under turbulent conditions, the effects are less significant. For conical flames stabilized with a ring, the stabilization domain of the +g and −g cases are not significantly different. Under reversed gravity, both laminar v-flames and conical flames show flame behaviors that were also found in microgravity. The v-flames reattached to the rim and the conical flame assumed a top-hat shape. One of the special cases of −g conical flame is the buoyancy-stabilized laminar flat flame that is detached from the burner. This flame implies a balance between the flow momentum and buoyant forces. The stretch rates of these flames are sufficiently low (< 20 s−1) such that the displacement speeds SL are almost equal to the laminar burning speed SL0. An analysis based on evaluating the Richardson number is used to determine the relevant parameters that describe the buoyancy/momentum balance. A perfect balance i.e. Ri = 1 can be attained when the effect of heat loss from the flame zone is low. For the weaker lean cases, our assumption of adiabaticity tends to overestimate the real flame temperature. This interesting low-stretch laminar flame configuration can be useful for fundamental studies of combustion chemistry.
Long-term renal risk factors in children with meningomyelocele

We studied renal function and structure in 42 patients with meningomyelocele, 28 treated with intermittent catheterization and 14 with ileal loop diversion. Patients were observed for a minimum of 60 months. Nine of the 28 patients who underwent intermittent catheterization had evidence of unilateral or bilateral reflux, and all patients with ileal loop diversion had free ureteral reflux. Bacteriuria was present in 38%±5% of cultures obtained from patients with catheterization and in 70%±7% of cultures from those with diversion (P
In-reactor stress relaxation in bending of 20% cold-worked 316 stainless steel

Abstract A test is in progress to measure in-reactor stress relaxation of 20% cold-worked 316 stainless steel in bending through the sequential irradiation in the experimental reactor EBR-II of two materials capsules. This paper details the results from the first capsule, the second capsule has completed irradiation and is awaiting examination. Approximately 50% total relaxation was measured following irradiation to 2 × 10 21 n/cm 2 , E > 0.1 MeV at 370°C. The extent of relaxation was independent of specimen orientation to rolling direction, independent of initial stress level and only weakly dependent on neutron dose at this fluence level.
Optical information processing for encryption and security systems

This article provides a discussion of new optical information processing techniques for encryption, security, and anti-counterfeiting that have been shown to perform well for a variety of problems and applications.
Structural determinations of the haloacetyl halides by experimental and computational methods

Abstract The far infrared spectra of a series of haloacetyl halides, CH2XC(O)X, in the vapor phase have been recorded at a resolution of 0.10 cm−1 in the 350 to 35 cm−1 region. The fundamental asymmetric torsional frequencies of the more stable trans (two halogen atoms oriented trans to one another) and high energy conformers have been observed. From these data the asymmetric torsional potential functions governing internal rotation about the CC bond have been determined. Only fluoroacetyl fluoride and fluoroacetyl chloride have the cis conformation for the high energy form whereas all of the other haloacetyl halides have the gauche conformation for the high energy form. For those molecules in this series which have the gauche form as the high energy rotamer it is shown that a reliable value for the torsional dihedral angle can be obtained from the potential functions determined from the direct observation of the fundamental and associated “hot bands” of the torsional modes for each conformer in the far infrared spectra of the gases. It is shown how complete equilibrium geometries, which have been determined by ab initio Hartree-Fock gradient calculations, can be used in conjunction with microwave and/or electron diffraction studies to obtain more reliable experimental structural parameters for these molecules. Finally, the reliability of the utilized ab initio techniques at predicting trends in the optimized geometries and potential functions governing internal rotation are assessed.
Direct synthesis of furans by 3+2 cycloadditions between rhodium(II) acetate stabilized carbenoids and acetylenes

Abstract Whan appropriate substituents are used, rhodium(II) acatate catalyzed decomposition of diazocarbonyls in the presence of acetylenes results in the formation of furans, derived from dipolar intermediates.
A comprehensive question retrieval application to serve classroom teachers

CTSS (Classroom Teacher Support System) was developed to aid teachers. The concept consists of retrieving questions according to specified attributes from a centralized data bank, assembling them into tests or exercises, and scoring student answers. Since scoring mark-sense answer sheets is a well-understood and widespread application, the emphasis was placed on solving systems problems related to producing lists of questions which meet the teacher's needs as he perceives them. To achieve this, the system permits items to be classified along several dimensions so that they can be selected by the computer according to criteria set by the teacher requesting a test. (The word "test" is used here to designate a list of questions, regardless of how it is to be used by the teacher who receives it.)
Interpretation of Solar Magnetic Field Strength Observations

This study based on longitudinal Zeeman effect magnetograms and spectral line scans investigates the dependence of solar surface magnetic fields on the spectral line used and the way the line is sampled to estimate the magnetic flux emerging above the solar atmosphere and penetrating to the corona from magnetograms of the Mt. Wilson 150-foot tower synoptic program (MWO). We have compared the synoptic program λ5250 A line of Fe i to the line of Fe i at λ5233 A since this latter line has a broad shape with a profile that is nearly linear over a large portion of its wings. The present study uses five pairs of sampling points on the λ5233 A line. Line profile observations show that the determination of the field strength from the Stokes V parameter or from line bisectors in the circularly polarized line profiles lead to similar dependencies on the spectral sampling of the lines, with the bisector method being the less sensitive. We recommend adoption of the field determined with the line bisector method as the best estimate of the emergent photospheric flux and further recommend the use of a sampling point as close to the line core as is practical. The combination of the line profile measurements and the cross-correlation of fields measured simultaneously with λ5250 A and λ5233 A yields a formula for the scale factor δ −1 that multiplies the MWO synoptic magnetic fields. By using ρ as the center-to-limb angle (CLA), a fit to this scale factor is δ −1=4.15−2.82sin 2(ρ). Previously δ −1=4.5−2.5sin 2(ρ) had been used. The new calibration shows that magnetic fields measured by the MDI system on the SOHO spacecraft are equal to 0.619±0.018 times the true value at a center-to-limb position 30°. Berger and Lites (2003, Solar Phys. 213, 213) found this factor to be 0.64±0.013 based on a comparison using the Advanced Stokes Polarimeter.
Morse groups in symmetric spaces corresponding to the symmetric group

We describe the Morse groups of the nearby cycles sheaves on the nilcones in three classical symmetric spaces.
Measurements of e+e− pair production at the Bevalac

It has come to be generally recognized that a relativistic nuclear collision (RNC) can only be described as a complex dynamic evolution of the not-so-many-body system, whether the components of the system are taken at the hadronic level or at the quark level. The evolution proceeds from an initial state of two separated nuclei, through stages of: first nucleon-nucleon collisions; increasing rates of collisions and particle production (heating and compression); gradually decreasing rates of collision and particle production rates (cooling and expansion); and, finally, decoupling of various particle types from the overall system (freeze out). (Parentheses enclose the adiabatic thermodynamic terms that may in some circumstances be relevant descriptions for parts of this process.) It is, in particular, the operation of the dynamics during the stages of high excitation energy and high particle density that are of interest in studying such collisions. Unfortunately we cannot build a detector that will produce information about a particular part of this process. Our detectors integrate over the entire space-time history of a collision — only the dynamics itself determines how the final-state phase space will be populated with particles.
Adjoint based aerodynamic optimization of supersonic biplane airfoils

This paper addresses the aerodynamic performance of Busemann type supersonic biplane at off-design conditions. An adjoint based optimization technique is used to optimize the aerodynamic shape of the biplane to reduce the wave drag at a series of Mach numbers ranging from 1.1 to 1.7, at both acceleration and deceleration conditions. The optimized biplane airfoils dramatically reduces the effects of the choked flow and flow-hysteresis phenomena, while maintaining a certain degree of favorable shockwave interaction effects at the design Mach number. Compared to a diamond shaped single airfoil of the same total thickness, the wave drag of our optimized biplane is lower at almost all Mach numbers, and is significantly lower at the design Mach number.
Regio- and stereochemistry of inter- and intramolecular titanium-mediated coupling of imides and mono-substituted olefins

Abstract The intramolecular titanium-mediated coupling reaction of α-substituted succinimides and mono-substituted olefins took place with complete regiocontrol, but without diastereoselectivity. The corresponding intermolecular coupling exhibited lack of regio- and diastereocontrol. Also included were stereochemical studies of catalytic hydrogenation and NaBH3CN reduction of the cyclization products.
Improved clock buffer with high PSRR for SC circuit applications

Clock feedthrough in SC circuits results in low PSRR figures, incompatible with high-performance signal processing. A high-PSRR CMOS clock buffer is presented here, which blocks this power supply (PS) noise coupling path. The presented circuit is a significant improvement over an earlier circuit proposed by the same author, but having a PSRR of over 40 dB now.
On Bi-grid Local Mode Analysis of Solution Techniques for 3-D Euler and Navier-Stokes Equations

A procedure is presented for utilizing a bi-grid stability analysis as a practical tool for predicting multigrid performance in a range of numerical methods for solving Euler and Navier?Stokes equations. Model problems based on the convection equation, the diffusion equation, and Burger's equation are used to illustrate the superiority of the bi-grid analysis as a predictive tool for multigrid performance in comparison to the smoothing factor derived from conventional von Neumann analysis. For the Euler equations, bi-grid analysis is presented for three upwind difference based factorizations, namely spatial, eigenvalue, and combination splits, and two central difference based factorizations, namely LU and ADI methods. In the former, both the Steger?Warming and van Leer flux-vector splitting methods are considered. For the Navier?Stokes equations, only the Beam?Warming (ADI) central difference scheme is considered. In each case, estimates of multigrid convergence rates from the bi-grid analysis are compared to smoothing factors obtained from single-grid stability analysis. Effects of grid aspect ratio and flow skewness are examined. Both predictions are compared with practical multigrid convergence rates for 2-D Euler and Navier?Stokes solutions based on the Beam?Warming central difference scheme, and 3-D Euler solutions with various upwind difference schemes. It is demonstrated that bi-grid analysis can be used as a reliable tool for the prediction of practical multigrid performance.
Basal body/centriolar DNA: molecular genetic studies in Chlamydomonas.

Abstract In Chlamydomonas reinhardtii, mutations on an unusual linkage group, the uni linkage group (ULG), affect structure and function of basal bodies. The ULG shows Mendelian segregation, but its genetic map is circular. Molecular cloning of fragments of the ULG was accomplished by taking advantage of restriction fragment length polymorphisms generated by crosses to Chlamydomonas smithii. These clones were used as probes to determine the size and form of the ULG chromosome; it is a 6–9 megabase linear molecule. Use of the probes for in situ DNA hybridization in cells localized the ULG chromosome to basal bodies.
A practical soft type system for scheme

A soft type system infers types for the procedures and data structures of dynamically typed programs. Like conventional static types, soft types express program invariants and thereby provide valuable information for program optimization and debugging. A soft type checker uses the types inferred by a soft type system to eliminate run-time checks that are provably unnecessary; any remaining run-time checks are flagged as potential program errors. Soft Scheme is a practical soft type checker for R4RS Scheme. Its underlying type system generalizes conventional Hindley-Milner type inference by incorporating recursive types and a limited form of union type. Soft Scheme accommodates all of R4RS Scheme including uncurried procedures of fixed and variable arity, assignment, and continuations.
A Rigorous Dynamical-Systems-Based Analysis of the Self-Stabilizing Influence of Muscles

In this paper, dynamical systems analysis and optimization tools are used to investigate the local dynamic stability of periodic task-related motions of simple models of the lower-body musculoskeletal apparatus and to seek parameter values guaranteeing their stability. Several muscle models incorporating various active and passive elements are included and the notion of self-stabilization of the rigid-body dynamics through the imposition of musclelike actuation is investigated. It is found that self-stabilization depends both on muscle architecture and configuration as well as the properties of the reference motion. Additionally, antagonistic muscles (flexor-extensor muscle couples) are shown to enable stable motions over larger ranges in parameter space and that even the simplest neuronal feedback mechanism can stabilize the repetitive motions. The work provides a review of the necessary concepts of stability and a commentary on existing incorrect results that have appeared in literature on muscle self-stabilization.
Solar EUV Spectrum Calculated for Quiet Sun Conditions

We present spectral synthesis calculations of the solar extreme UV (EUV) in spherical symmetry carried out with the ‘Solar Modeling in 3D’ code. The calculations are based on one-dimensional atmospheric structures that represent a temporal and spatial mean of the chromosphere, transition region, and corona. The synthetic irradiance spectra are compared with the recent calibration spectrum taken with the EUV Variability Experiment during the Whole Heliospheric Interval. The good agreement between the synthetic and observed quiet Sun spectrum shows that the employed atmospheric structures are suitable for irradiance calculations. The validation of the quiet Sun spectrum for the present solar minimum is the first step toward the modeling of the EUV variations.
Foreground and source of a cluster of ultra-high-energy cosmic rays

We investigate the origin of a nearly pointlike cluster of five ultra-high-energy cosmic rays (UHECRs) in the vicinity of R.A. ≈ 1692 and decl. ≈ 568, using Sloan Digital Sky Survey and other data. No particular source candidates are found near the estimated source direction, but the direction is exceptional in having a likely merging pair of galaxy clusters at 140 h-1 Mpc, with an unusually low foreground density. Large-scale shocks or another product of the merging galaxy clusters may accelerate the UHECRs, or the merging galaxy clusters may be coincidental and the UHECRs may be accelerated in a rare event of an unexceptional progenitor. Low magnetic deflections in the foreground void may explain why this is the only identified pointlike cluster of so many UHECRs.
In situ vacuum testing - A must for certain elastomeric materials.

In situ vacuum testing requirement for valid measurement of vacuum induced changes in mechanical and thermal properties of various filled elastomers
A general preparative method for carbonyl-protected γ-lithioketones via reductive lithiation. Synthetic uses of the bishomoenolate equivalents

Abstract The mixed cuprates, generated by reductive lithiation of bis(phenylthio)acetals using lithium 4,4′-di- tert -butylbiphenylide (LDBB), followed by addition of cuprous bromide - dimethyl sulfide complex, undergo conjugate addition to enones in the presence of trimethylsilyl chloride to produce γ-(phenylthio)ketones. Protection of the ketone as its dioxolane, and reductive lithiation with LDBB provides carbonyl-protected γ-lithioketones. Primary, secondary, tertiary, and vinylic organolithiums have been prepared in this way and the protected ketone function can be in a ring. Previously, only primary straight chain γ-lithioketone equivalents were known. This method is the most versatile and general available for the production of such carbanions, which behave as bishomoenolate equivalents. The organometallics react with aldehydes to yield alcohols. The vinyllithiums react with N,N -dimethylformamide to produce an enal containing a protected ketone group. The mixed cuprates, formed upon treatment of the organolithiums with cuprous bromide - dimethyl sulfide complex, undergo allylation with allyl bromide, conjugate addition to enals and enones in the presence of trimethylsilyl chloride to produce monoprotected 1,7-dicarbonyl compounds, and acetylation to yield monoprotected 1,5-diketones. The monoprotected dicarbonyl compounds are readily deprotected and in a number of cases the resulting diketones can be induced to undergo base induced intramolecular aldol condensations to enones.
COSMOLOGICAL IMPLICATIONS OF FAST RADIO BURST/GAMMA-RAY BURST ASSOCIATIONS

If a small fraction of fast radio bursts (FRBs) are associated with gamma-ray bursts (GRBs), as recently suggested by Zhang, the combination of redshift measurements of GRBs and dispersion measure (DM) measurements of FRBs opens a new window to study cosmology. At z < 2 where the universe is essentially fully ionized, detections of FRB/GRB pairs can give an independent measurement of the intergalactic medium portion of the baryon mass fraction, Ω b f IGM, of the universe. If a good sample of FRB/GRB associations are discovered at higher redshifts, the free electron column density history can be mapped, which can be used to probe the reionization history of both hydrogen and helium in the universe. We apply our formulation to GRBs 101011A and 100704A that each might have an associated FRB, and constrained Ω b f IGM to be consistent with the value derived from other methods. The methodology developed here is also applicable, if the redshifts of FRBs not associated with GRBs can be measured by other means.
Intramolecular Cyclizations via Arylnitrenium Ions. Formation of a Six-Membered Ring Rather than a Macrocycle

The stereochemistry of 1-(3-benzyloxyphenyl)-2-(4-nitrophenyl)ethane has been studied. MMX calculations predicted, and 2D NOESY confirmed, that the bent conformation (global energy minimum) was such that six-membered ring formation, and not macrocyclization, would occur using the corresponding nitrenium ion, and this was found to be the case. Acid-catalyzed decomposition of 1-(3-benzyloxyphenyl)-2-(4-azidophenyl)ethane followed by treatment with (CF3CO)2O gave 48% of 2-benzyloxy-6-trifluoroacetamido-9,10-dihydrophenanthrene and 18% of 1-(3-benzyloxyphenyl)-2-(4-trifluoroacetamidophenyl)ethane. Blocking the original point of attack with a bromine atom led to the prediction (MMX, 2D NOESY) that, once again, small ring formation would take place, with macrocyclization possible but less likely. Again, this was found to be so. It is suggested that simple MMX calculations may provide a very rapid, empirical indicator of which precursors would have a readily accessible conformation that could result in intramolc...
The Turn-On of Mass Transfer in AM CVn Binaries: Implications for RX J0806+1527 and RX J1914+2456

We report on evolutionary calculations of the onset of mass transfer in AM CVn binaries, treating the donor's evolution in detail. We show that during the early contact phase, while the mass transfer rate, , is increasing, gravity wave emission continues to drive the binary to shorter orbital period, Porb. We argue that the phase where > 0 and > 0 (ν = 1/Porb) can last between 103 and 106 yr, significantly longer than previously estimated. These results are applied to RX J0806+1527 (Porb = 321 s) and RX J914+2456 (Porb = 569 s), both of which have measured > 0. Thus, a > 0 does not select between the unipolar inductor and accretion-driven models proposed as the source of X-rays in these systems. For the accretion model, we predict for RX J0806 that ≈ (1.0-1.5) × 10-28 Hz s-2 and argue that timing observations can probe at this level with a total ≈20 yr baseline. We also place constraints on each system's initial parameters given current observational data.
The vacuum theta-angle is zero in non-abelian gauge theories

Abstract We argue that gauge transformations with arbitrary fractional winding numbers should be allowed in a non-Abelian gauge theory. This eliminates the topological distinction between large and small gauge transformations. We prove that the states which satisfy the Gauss's law constraint are strictly invariant under gauge transformations, i.e. no phase shift occurs. In other words, the vacuum θ-angle is zero. Our observation does not resolve the strong CP problem.
The use of classical Lax–Friedrichs Riemann solvers with discontinuous Galerkin methods

While conducting a von Neumann stability analysis of discontinuous Galerkin methods we discovered that the classic Lax-Friedrichs Riemann solver is unstable for all time-step sizes. We describe a simple modification of the Riemann solver's dissipation returns the method to stability. Furthermore, the method has a smaller truncation error than the corresponding method with an upwind flux for the RK2-DG(1) method
New evidence on the convergence of international income from a group of 29 countries

We evaluate the empirical evidence regarding stochastic convergence in income across a group of 29 countries. Our results are based on a new unit root test developed by Popp (2008) that estimates the break-date more accurately and does not suffer from size distortions in the presence of a break. Our results reveal considerably less evidence of stochastic convergence compared with previous studies.
Multiple-Scattering Analysis of the Three-Body Scattering Problem

Scalar-particle scattering by one scalar, spherically symmetric potential having a finite radius is discussed; methods for obtaining the scattering amplitude are reviewed. Application to the square-well potential is made. Methods for obtaining the total scattering amplitude in terms of individual amplitudes are applied to S-wave scattering by each of two spherically symmetric potentials of finite radius. Solution using the total Green's function for scattering from one potential is presented. The separable potential approximation for S-wave scattering is tested using two completely overlapping identical square wells. Integrals used to evaluate off-energy-shell scattering amplitudes for a square-well potential are evaluated, and a method used to treat S-wave scattering by two potentials is generalized to include scattering of all partial waves. (L.N.N.)
Structural Acoustic Optimization of a Composite Cylindrical Shell Using FEM/BEM

A finite element/boundary element design tool is used to perform a structural acoustic optimization on an eight-ply graphite epoxy cylindrical shell. The shell is subject to two external monopole sources vibrating at a single frequency. The goal of the optimization is the minimization of the sum of the squared pressure amplitudes within the enclosed acoustic cavity. The ply angles serve as the design variables in optimization. The optimal design was obtained after 15 iterations with a 2 dB reduction in the average interior sound pressure level. The ply angle orientation shifted from an initially symmetric lay-up to an unsymmetric lay-up in the final design.
Anytime reliable codes for stabilizing plants over erasure channels

The problem of stabilizing an unstable plant over a noisy communication link is an increasingly important one that arises in problems of distributed control and networked control systems. Although the work of Schulman and Sahai over the past two decades, and their development of the notions of “tree codes” and “anytime capacity”, provides the theoretical framework for studying such problems, there has been scant practical progress in this area because explicit constructions of tree codes with efficient encoding and decoding did not exist. To stabilize an unstable plant driven by bounded noise over a noisy channel one needs real-time encoding and real-time decoding and a reliability which increases exponentially with delay, which is what tree codes guarantee. We prove the existence of linear tree codes with high probability and, for erasure channels, give a construction with an expected decoding complexity that is constant per time instant. We give sufficient conditions on the rate and reliability required of the tree codes to stabilize vector plants and argue that they are asymptotically tight. This work takes an important step towards controlling plants over noisy channels, and we demonstrate the efficacy of the method through a simulation.
Hausdorff dimension of the multiplicative golden mean shift

Abstract We compute the Hausdorff dimension of the “multiplicative golden mean shift” defined as the set of all reals in [ 0 , 1 ] whose binary expansion ( x k ) satisfies x k x 2 k = 0 for all k ⩾ 1 , and show that it is smaller than the Minkowski dimension.
The electrochemistry of molten K2S2O7 + K2SO4 + V2O5 electrolytes

Abstract Cyclic voltammetry, equilibrium potential techniques, and X-ray diffraction were utilized to examine molten K 2 S 2 O 7 + K 2 SO 4 + V 2 O 5 electrolytes in contact with SO 2 + O 2 + N 2 gas environments at 370 to 400° C. The effect of K 2 SO 4 and V 2 O 5 additives on the electrochemistry of K 2 S 2 O 7 and their role in the overall electrochemistry was determined. The role of SO 2 and O 2 in the electrochemistry was also established.
Hypervelocity Stars III. The Space Density and Ejection History of Main Sequence Stars from the Galactic Center

We report the discovery of three new unbound hypervelocity stars (HVSs), stars traveling with such extreme velocities that dynamical ejection from a massive black hole (MBH) is their only suggested origin. We also detect a population of possibly bound HVSs. The significant asymmetry we observe in the velocity distribution—we find 26 stars with vrf > 275 km s−1 and one star with vrf < − 275 km s−1—shows that HVSs must be short-lived, probably 3-4 M☉ main-sequence stars. Any population of hypervelocity post-main-sequence stars should contain stars falling back onto the Galaxy, contrary to the observations. The spatial distribution of HVSs also supports the main-sequence interpretation: longer lived 3 M☉ HVSs fill our survey volume; shorter lived 4 M☉ HVSs are missing at faint magnitudes. We infer that there are 96 ± 10 HVSs of mass 3-4 M☉ within R < 100 kpc, possibly enough HVSs to constrain ejection mechanisms and potential models. Depending on the mass function of HVSs, we predict that SEGUE may find up to 5-15 new HVSs. The travel times of our HVSs favor a continuous ejection process, although a ~120 Myr old burst of HVSs is also allowed.
Supporting and transforming leadership in online creative collaboration

Behind every successful online creative collaboration, from Wikipedia to Linux, is at least one effective project leader. Yet, we know little about what such leaders do and how technology supports or inhibits their work. My dissertation investigates online creative collaboration in the novel context of animated movie-making, focusing on the role of leadership. I first conducted two empirical studies of existing leadership practice in online communities of animators. I am currently designing two Web-based collaborative systems based on these findings. My evaluation compares both systems with existing practice to elicit broader principles of online creative collaboration.
Economic integration in Eastern Europe

The Council for Mutual Economic Assistance (CMEA) was established by Bulgaria, Czechoslovakia, Hungary, Poland, Romania and the Soviet Union in 1948 as a response to the Marshall Plan. But unlike the Marshall Plan it provided no financial assistance to its member countries and its activities were limited to trade in the framework of bilateral and multilateral negotiations. Because of centralized decisionmaking, the lack of price signals and the bilateral balancing of trade flows, the CMEA countries failed to exploit their trade potential. And although the smaller CMEA countries benefited from receiving Soviet energy and raw materials at low prices in exchange for often poor quality manufactured goods, these gains were more than offset by the losses suffered because of insufficient technical change and the straightjacket of the socialist planning system. For the future of the CMEA, four alternatives present themselves: maintaining the present arrangements, marketizing the CMEA, reforming the CMEA and dissolving the CMEA. In view of differences in the extent and the speed of the reform efforts in Eastern European countries, the last alternative appears most appropriate. At the same time, the more developed CMEA countries should seek association with the EC, followed by membership.
Reading the Spectra of the Most Peculiar Type Ia Supernova 2002cx

In spite of the apparent lack of Si ii and S ii features in its spectra, SN 2002cx was classified as a peculiar Type Ia supernova (SN Ia) on the basis of its overall photometric and spectroscopic behavior. Spectra obtained near maximum light contained Fe iii features, as in SN 1991T-like events, but the blueshifts of the Fe iii absorptions were exceptionally low. The luminosity was also low. We use the supernova synthetic-spectrum code SYNOW to study line identifications in SN 2002cx. We find that the maximum-light spectra appear to contain weak features of Si ii, S ii, Si iii, and Ca ii, which strengthens the connection with SN 1991T-like events. We show that later spectra obtained 12, 25, and 56 days after maximum consist of P Cygni resonance-scattering features due to permitted Fe ii and Co ii lines. SN 2002cx had been thought to have made the transition from a permitted-line to a forbidden-line spectrum between 25 and 56 days. Owing to the low expansion velocities, the postmaximum spectral features are narrower and easier to identify than they are in other SNe Ia. SN 2002cx will lead to improved line identifications in other SNe Ia and will clarify when the transition from a permitted- to a forbidden-line spectrum occurs. In the context of current SN Ia explosion models, we suggest that the properties of SN 2002cx might be consistent with three-dimensional deflagration models, which are not favored for normal SNe Ia.
Intrinsic pulsatility of luteinizing hormone release from the human pituitary in vitro

An in vitro perifusion system was used to investigate the spontaneous luteinizing hormone (LH) release from 10 human fetal (21–23 weeks of gestation) and 1 adult female pituitaries. The pattern of LH
To pay or not to pay: Positive incentives as a calibrating device in the white indenture system

Abstract This paper analyzes the indentured servitude labor market of colonial America. It is argued that this system developed endogenous market responses to such things as limitations of the legal system and changes in contemporary labor market conditions. In particular, this paper shows the role that so-called positive incentives played as a calibrating device, allowing the economic system to run more smoothly. The analysis uses a model of choice under uncertainty, hence expanding the rationality inherent in the indenture system.
Characterization of acoustic disturbances in linearly sheared flows

The equation describing the plane wave propagation, the stability, or the rectangular duct mode characteristics in a compressible inviscid linearly sheared parallel, but otherwise homogeneous flow, is shown to be reducible to Whittaker's equation. The resulting solutions, which are real, viewed as functions of two variables, depend on a parameter and an argument, the values of which have precise physical meanings depending on the problem. The exact solutions in terms of Whittaker functions are used to obtain a number of known results of plane wave propagation and stability in linearly sheared flows as limiting cases in which the speed of sound goes to infinity (incompressible limit) or the shear layer thickness, or wave number, goes to zero (vortex sheet limit). The usefulness of the exact solutions is then discussed in connection with the problems of plane wave propagation and the stability of a finite thickness layer with a linear velocity profile.
Factors that modify risks of radiation-induced cancer.

The collective influence of biologic, physical, and other factors that modify risks of radiation-induced cancer introduces uncertainties and assumptions that limit precision of estimates of human cancer risk that can be calculated for populations exposed to low-dose radiation. The important biologic characteristics include the tissue sites and cell types, baseline cancer incidence, latent periods, time-to-tumor recognition, and individual host (e.g., age and sex) and competing etiologic influences. Physical factors include radiation dose, dose rate, and radiation quality. Statistical factors include time-response projection models, risk coefficients, and dose-response relationships. Sources that modify risk also include other carcinogens and biologic factors (e.g., hormonal conditions, immune status, hereditary factors). Discussion includes examples of known influences that modify radiation-associated cancer risks and how they have been dealt with in the risk-estimation process, including extrapolation to low doses, use of relative risk models, and other uncertainties.
Hermetic wafer bonding based on rapid thermal processing

Abstract Hermetic wafer bonding based on rapid thermal processing (RTP) has been demonstrated for the first time. Microcavities encapsulated between glass and silicon substrate have been sealed with aluminum solder by using RTP at 990°C for 2 s. Reliability experiments of IPA leak and autoclave accelerated tests show that 100% of survival rate can be achieved. The best encapsulation results are accomplished when the aluminum bonding solder is 150 μm wide and 4.5 μm thick. Furthermore, it is found that the activation energy for Al-glass RTP bonding system is 3.5 eV and the lowest successful bonding temperature is 760°C with a processing time of 30 min. In the device-packaging demonstrations, a microheater and a surface micromachined heatuator have been successfully packaged by the RTP bonding method and are operational after the bonding process. This work demonstrates that RTP bonding can provide low thermal budget, insensitivity to rough surfaces, and excellent bonding characteristics. As such, it has promising potential for wafer-level MEMS fabrication and packaging.
Compactness of the space of left orders

A left order on a magma (e.g. semigroup) is a total order of its elements that is left invariant under the magma operation. A natural topology can be introduced on the set of all left orders of an arbitrary magma. We prove that this topological space is compact. Interesting examples of nonassociative magmas, whose spaces of right orders we analyze, come from knot theory and are called quandles. Our main result establishes an interesting connection between topological properties of the space of left orders on a group, and the classical algebraic result by Conrad [4] and Łoś [13] concerning the existence of left orders.
Weakened outside shareholder rights in dual-class firms and timely loss reporting

Abstract In this paper, we examine timely loss reporting for U.S. firms with a dual-class share structure, i.e., firms characterized by a divergence (wedge) between insiders’ voting rights and cash flow rights. In our primary analysis, we find compelling evidence that the wedge (quantified by excess voting rights) is associated with less timely loss reporting for these firms. In our secondary analysis, in which we match our sample of dual-class share observations with a sample of single-class share observations, we find similar results. Our paper informs public policy by showing that weakened outside shareholder rights matter, even in the U.S., where, despite a strong investor protection environment, dual-class firms are less timely in recognizing bad news in reported earnings.
Option Pricing and Distribution Characteristics

A number of flexible distributions (generalized beta of the second kind, inverse hyperbolic sine (IHS), $$g$$ g -and- $$h$$ h , Weibull, Burr-3, Burr-12, generalized gamma, reciprocal gamma) are examined in the setting of option-pricing to explore potential improvements over the standard assumption of lognormal returns. Price formulas are presented specific to each assumed distributional form. The IHS option price formula has not previously been presented in the literature. An empirical application follows where implied risk-neutral density functions for each distribution are estimated from options on the S&P 500 Index. The distributions' performance relative to one another is then evaluated with the more flexible distributions performing similarly and outperforming their special and limiting cases, including the Black-Scholes which is based on the lognormal.
Uniqueness of solutions to Schrödinger equations on complex semi-simple Lie groups

In this note we study the time-dependent Schrodinger equation on complex semi-simple Lie groups. We show that if the initial data is a bi-invariant function that has sufficient decay and the solution has sufficient decay at another fixed value of time, then the solution has to be identically zero for all time. We also derive Strichartz and decay estimates for the Schrodinger equation. Our methods also extend to the wave equation. On the Heisenberg group we show that the failure to obtain a parametrix for our Schrodinger equation is related to the fact that geodesics project to circles on the contact plane at the identity.
Numerical Investigation of Stall Flutter

Unsteady, separated, high Reynolds number flow over an airfoil undergoing oscillatory motion is investigated numerically. The compressible form of the Reynolds-averaged governing equations is solved using a high-order, upwind biased numerical scheme. The turbulent flow region is computed using a one-equation turbulence model. The computed results show that the key to the accurate prediction of the unsteady loads at stall flutter conditions is the modeling of the transitional flow region at the leading edge. A simplified criterion for the transition onset is used. The transitional flow region is computed with a modified form of the turbulence model. The computed solution, where the transitional flow region is included, shows that the small laminar/transitional separation bubble forming during the pitch-up motion has a decisive effect on the near-wall flow and the development of the unsteady loads. Detailed comparisons of computed fully turbulent and transitional flow solutions with experimental data are presented.
Dinuclear zinc-catalyzed enantioselective Aza-Henry reaction.

The dinuclear zinc catalyst 1a was found to catalyze the addition of nitroalkanes to carbamate-protected imines. This aza-Henry reaction proceeds with high enantioselectivity when various carbamate-protected imines are used. α,β-Unsaturated imines proved to be a particularly useful class of substrate routinely giving the α-nitro amine products in high enantiomeric excess.
An analytic method for strong motion studies in layered media

Abstract An analytic method is presented for calculating strong motion spectra and response to arbitrary input in layered media. The method is based on the removal of secular terms at resonance of the equations with polynomial non-linearity. The non-linear effects are introduced by the frequency shifts calculated from the secular term according to the method by Millman and Keller. The procedure, through a convenient parametrizarion of the frequency, allows one to deal with linear equations. This possibility permits the extension of the method to multilayer systems by the use of transfer matrices. The response to an arbitrary input motion is obtained from the response spectrum in the frequency domain by the use of (Fast) Fourier Transform.
Market segmentation for customer satisfaction studies via a new latent structure multidimensional scaling model

It has been well documented in the marketing literature that customer satisfaction is critical to any businesses' success. However, it is far less clear as on how marketers comprehend customer differences in customer satisfaction evaluations, and leverage such understanding in forming their marketing strategies. Only recently have researchers begun to explore the notion of individual or segment differences in the formation of overall satisfaction judgments. To extend the exploration of unobserved customer heterogeneity in customer satisfaction studies with multiple attributes, we propose a latent structure multidimensional scaling (MDS) model to visually depict unobserved customer heterogeneity with respect to the theoretical components of customer satisfaction judgments. Our model is developed on the basis of the well-established expectancy–disconfirmation theory of customer satisfaction. We describe the proposed MDS model and discuss the technical aspects of the model structure and maximum likelihood estimation. Copyright © 2005 John Wiley & Sons, Ltd.
Implications of bulk causality for holography in AdS

Gravitational time delay in asymptotically anti de Sitter spaces has consequences for holographic duality. We argue that the requirement of bulk causality implies that it is not possible for a collection of boundary observers, performing local measurements, to extract information from precursors. Using similar arguments, we derive an integrated weak energy constraint on spacetimes which can admit a holographic dual.
Evolution of Secondary Electron Emission Characteristics of Spacecraft Surfaces

Helical Motion In this motion, the center of gravity of the  ight vehicle traverses a helical  ight path.The longitudinalaxis of the vehicle is orientated in the same directionas the axis of the helix but displacedfrom it by a constantdistance.A  xed body axial spin rate equal to the angular rate of rotation of the helical  ight path is present. The resulting motion is sometimes referred to as lunar motion because the same surface of the body is always orientated toward the central axis of the maneuver; in aircraft maneuver terminology it is equivalent to a barrel roll. A three-dimensional view of the motion is given in Fig. 4. Again, with gravity neglected, we can write u D w D 0; P u D P v D P w D 0, and q D r D 0. It follows that XF D YF D 0 and that ZF D pv. Because is now 0 deg, d3⁄4=dt ; P ®, and R are all zero. This result is again consistent with that predicted by Eqs. (4–6), (10), and (11). Note that, because of the presence of axial spin, this is not the same case as that considered in Ref. 2.
A Verilog Piecewise-Linear Analog Behavior Model for Mixed-Signal Validation

Full chip mixed-signal validation requires simulating the entire design through a large number of test vectors, which makes fast, event-based Verilog models of analog circuits essential. We describe an extensible approach to creating these models that maps continuous signals into piecewise linear waveforms by creating analog events which contain a value and slope. By breaking analog circuits into sub-blocks with mostly unidirectional ports, we avoid explicit time integration, thus fitting well into an event-driven digital framework. The result is Verilog analog functional models that are pin-accurate, fast to simulate, and capture the key dynamics in analog circuits. A 250 Ms/s open-loop track and hold circuit, 2.5 V-1.8 V buck converter, and 1 GHz PLL models are demonstrated.
Varying coefficient model for modeling diffusion tensors along white matter tracts

Diffusion tensor imaging provides important information on tissue structure and orientation of fiber tracts in brain white matter in vivo. It results in diffusion tensors, which are 3×3 symmetric positive definite (SPD) matrices, along fiber bundles. This paper develops a functional data analysis framework to model diffusion tensors along fiber tracts as functional data in a Riemannian manifold with a set of covariates of interest, such as age and gender. We propose a statistical model with varying coefficient functions to characterize the dynamic association between functional SPD matrix-valued responses and covariates. We calculate weighted least squares estimators of the varying coefficient functions for the Log-Euclidean metric in the space of SPD matrices. We also develop a global test statistic to test specific hypotheses about these coefficient functions and construct their simultaneous confidence bands. Simulated data are further used to examine the finite sample performance of the estimated varying co-efficient functions. We apply our model to study potential gender differences and find a statistically significant aspect of the development of diffusion tensors along the right internal capsule tract in a clinical study of neurodevelopment.