cssi/SciSciGPT-SciSciNet huggingface dataset:
DARK MATTER HALOS AND EVOLUTION OF BARS IN DISK GALAXIES: COLLISIONLESS MODELS REVISITED

We construct and evolve three one-parameter families and one two-parameter family of steady-state models of stellar disks embedded in live dark matter (DM) halos in order to study the dynamical and secular phases of bar evolution. These models are tested against those published in the literature in order to extend them and to include the gaseous component in the follow-up paper. Specifically, we are interested in the angular momentum, J, redistribution in the disk-halo system during these two evolutionary phases without distinguishing between the resonant and non-resonant effects. We confirm the previous results and quantify for the first time the dual role that the DM halos play in the bar evolution: more centrally concentrated halos dilute the dynamical processes of the initial bar growth, such as the spontaneous bar instability and the vertical buckling instability, and slow down the J transfer, while facilitating it in the secular phase. The rate of J transfer in the disk and the halo is followed up in order to identify sites and times of peak activity in J emission and absorption. Within the corotation radius, R cr, the disk J remains nearly constant in time, as long as R cr stays within the disk?a sign that the lost angular momentum to the outer disk and the halo is being compensated by an influx of fresh J due to the outward motion of R cr. We demonstrate that this is feasible as long as the bar slowdown dominates the loss of J inside R cr. Next, we find that in some models the bar pattern speed stalls for prolonged time periods, i.e., the bar exhibits a constant rate of tumbling when R cr is located outside the disk. This phenomenon appears concurrent with the near absence of J transfer between the disk and the halo, and is associated with the halo emitting J at the corotation resonance and absorbing it at the inner Lindblad resonance. Furthermore, we confirm that stellar bars generally display the corotation-to-bar size ratios in the range of ~1-1.4, but only between the times of the first buckling and R cr leaving the disk. Hence, the corotation-to-disk size ratio emerges as an important dynamic discriminator between various stages of barred disk evolution. Finally, we analyze a number of correlations between the basic parameters of a barred disk and a halo, some already reported in the literature and some new.
Projecting to a Slow Manifold: Singularly Perturbed Systems and Legacy Codes

We consider dynamical systems possessing an attracting, invariant "slow manifold" that can be parameterized by a few observable variables. We present a procedure that, given a process for integrating the system step by step and a set of values of the observables, finds the values of the remaining system variables such that the state is close to the slow manifold to some desired accuracy. It should be noted that this is not equivalent to "integrating down to the manifold" since the latter process may significantly change the values of the observables. We consider problems whose solution has a singular perturbation expansion, although we do not know what it is nor have any way to compute it (because the system is not necessarily expressed in a singular perturbation form). We show in this paper that, under some conditions, computing the values of the remaining variables so that their (m + 1)st time derivatives are zero provides an estimate of the unknown variables that is an mth-order approximation to a poin...
Eruption of a Bifurcated Solar Filament

We study the partial eruption of a solar filament observed by the Solar Dynamics Observatory (SDO) and the Solar TErrestrial RElations Observatory-Ahead (STEREO-A) spacecraft on 9 May 2012. This filament was located in Active Region NOAA 11475 and consisted of two distinct branches, separated in height above the active region’s primary polarity-inversion line. For two days prior to the filament eruption, several threads of filament material were observed to connect the lower branch to the upper branch with evidence of a transfer of mass along them. The eruption commenced as a slow rise of the upper branch that began at 9 May 2012 23:40 UT, with the main eruption occurring half an hour later, producing a coronal mass ejection (CME). During the eruption, the upper branch was observed to rotate approximately 120 degrees in a counter-clockwise direction. We suggest that the mass transfer events also comprised a transfer of magnetic flux that led the upper branch of the filament to lose equilibrium as a result of a helical kink instability or torus instability.
Adaptive Damping in Shape Memory TiNi during Cavitation

Recent studies by this author and others has demonstrated that cavitation-erosion of NiTi coatings or bulk NiTi is exceptional. Studies were undertaken to ascertain whether this property is a consequence of either the general intermetallic properties of NiTi or by an adaptive stress-dissipation mechanism of the cavitation-generated shock wave by A microstructural mechanism related to the shape memory effect. In cavitation, an oscillating pressure field causes the formation and implosion of air bubbles. As a surface easily nucleates bubbles, the subsequent implosion of the bubbles generates stresses approaching several MPa, which are large enough to ablate material, and are also high enough to generate stress-induced Martensite or Austenite, depending on whether the applied stress is tensile or compressive. The implication is that the stress wave may be partially accommodated by the stress-induced transformation, which can dissipate the energy as heat on retransformation to the materials unstressed phase. Calculations concerning the variation of the cavitation-induced stresses and temperature distribution with depth into the TiNi coupled with the associated problems of heat transfer will be presented. It will be shown that an adaptive mechanism is plausible.
Individual Differences in Negotiation A Nearly Abandoned Pursuit Revived

The commonsense notion that personal characteristics influence how effectively we negotiate has presented researchers with a mystery: Throughout the decades, scholars have concluded that there are few reliable findings to support it. In this article, I review existing research as well as new research in which my colleagues and I join a growing minority revisiting this nearly abandoned topic. The categories of individual differences previously studied include background characteristics, abilities, personality traits, motivations, and expectations and beliefs. Reviewing this work presents an optimistic conclusion: The strongest and most reliable predictors of negotiation performance are also the most open to personal change. Namely, positive expectations and comfort with negotiation consistently predict better performance. Another consistent finding is that abilities such as cognitive intelligence and creativity help for win-win agreements. Results suggest promise for a topic that is important to researcher...
Cohomology and deformation of module-algebras

Abstract An algebraic deformation theory of module-algebras over a bialgebra is constructed. The cases of module-coalgebras, comodule-algebras, and comodule-coalgebras are also considered.
An Exploratory Study of Operant Conditioning Theory as a Predictor of Online Product Selection

The present research applies operant conditioning theory to the question of what products and services consumers will shop for and buy online. Operant conditioning theory explains differences between products that are used to alleviate uncomfortable experiences (negative reinforcement) and those providing enjoyable experiences (positive reinforcement). The preliminary results described in this study confirmed the importance of operant conditioning as a factor in the behavior of online shoppers. For example, when asked to provide an open-ended list of products that they had shopped for, our respondents mentioned products that produce positive reinforcement 476 times versus only 4 mentions for those that create negative reinforcement. Furthermore, for a list of seventeen common product categories, the results showed that respondents were not only less likely to shop for negative reinforcement products but also even less likely to purchase negative products online than positive products. The results of this exploratory study lay the groundwork for future research by introducing negative and positive reinforcement as a predictor of Internet shopping behavior.
Electroweak precision constraints on the littlest Higgs model with T parity

We compute the leading corrections to the properties of W and Z bosons induced at the one-loop level in the SU(5)/SO(5) Littlest Higgs model with T parity, and perform a global fit to precision electroweak data to determine the constraints on the model parameters. We find that a large part of the model parameter space is consistent with data. Values of the symmetry breaking scale f as low as 500 GeV are allowed, indicating that no significant fine tuning in the Higgs potential is required. We identify a region within the allowed parameter space in which the lightest T-odd particle, the partner of the hypercharge gauge boson, has the correct relic abundance to play the role of dark matter. In addition, we find that a consistent fit to data can be obtained for large values of the Higgs mass, up to 800 GeV, due to the possibility of a partial cancellation between the contributions to the T parameter from Higgs loops and new physics.
A particle method for history-dependent materials

Abstract A broad class of engineering problems including penetration, impact and large rotations of solid bodies causes severe numerical problems. For these problems, the constitutive equations are history dependent so material points must be followed; this is difficult to implement in a Eulerian scheme. On the other hand, purely Lagrangian methods typically result in severe mesh distortion and the consequence is ill conditioning of the element stiffness matrix leading to mesh lockup or entanglement. Remeshing prevents the lockup and tangling but then interpolation must be performed for history dependent variables, a process which can introduce errors. Proposed here is an extension of the particle-in-cell method in which particles are interpreted to be material points that are followed through the complete loading process. A fixed Eulerian grid provides the means for determining a spatial gradient. Because the grid can also be interpreted as an updated Lagrangian frame, the usual convection term in the acceleration associated with Eulerian formulations does not appear. With the use of maps between material points and the grid, the advantages of both Eulerian and Lagrangian schemes are utilized so that mesh tangling is avoided while material variables are tracked through the complete deformation history. Example solutions in two dimensions are given to illustrate the robustness of the proposed convection algorithm and to show that typical elastic behavior can be reproduced. Also, it is shown that impact with no slip is handled without any special algorithm for bodies governed by elasticity and strain hardening plasticity.
Heavy meson hyperfine splittings. A puzzle for heavy quark chiral perturbation theory

Abstract We show that there is a large discrepancy between the expected light flavor dependence of the heavy pseudoscalar-vector mass splittings and the measured values. We demonstrate that the contribution from the one-loop calculation does not agree with the measured value. We show that because agreement with experiment requires the leading dependence on SU(3) symmetry breaking to be nearly cancelled, the heavy quark mass dependence is unknown and the expected dependence on the light quark mass is not realized.
A new approach to fused furan ring systems and benzofurans: intramolecular cyclization reactions of unsaturated acyloxy sulfone derivatives

Unsaturated acyloxy sulfones 3 undergo intramolecular cyclization upon deprotonation with LHMDS in THF. Dehydration and double bond isomerization of the products upon exposure to acid, gave the fused ring furans, 4, in good yields. This strategy could be readily adapted to 12 from the cyclization reactions of acyloxy sulfones 11 prepared from phenols. Finally, this approach could be successfully modified to access dihydropyrans and benzopyrans.
Novel Method of Reducing Ketones Using Sodium Hydroxide in Isopropanol

Ketones are readily reduced to secondary alcohols with sodium hydroxide in refluxing isopropanol.
Large N superconformal gauge theories and supergravity orientifolds

Maldacena's duality between conformal field theories and supergravity is applied to some conformal invariant models with eight supercharges appearing in the F-theory moduli space on a locus of constant coupling. This includes Sp(2N) gauge theories describing the world-volume dynamics of D3-branes in the presence of D7-branes and an orientifold plane. Other examples of this kind are models with exceptional global symmetries which have no perturbative field theory description. In all these cases the duality is used to describe perturbations by primary marginal and relevant operators.
Estimating elasticities of residential energy demand from panel county data using dynamic random variables models with heteroskedastic and correlated error terms

Abstract A dynamic random variables model correcting for heteroskedastic and correlated error terms over time and space and dynamic demand and using panel county data offers consistent and efficient elasticity estimates of residential electricity and natural gas demands. The model developed by Swamy [Swamy, P.A.V.B., 1974. Linear models with random coefficients. In: P. Zarembka (Eds.), Frontiers in Econometrics, Academic Press, London, pp. 143–168.] with a modification suggested by Maddala et al. [Maddala, G.S., Trost, R.P., Li, H., Joutz, F., 1997. Estimation of short-run and long-run elasticities of energy demand from panel data using shrinkage estimators. Journal of Business and Economic Statistics 15, 90–100.] uses a panel of selected California counties for the years 1983–1997 to yield elasticity estimates that differ from those obtained from more standard panel data procedures.
The cracking and decohesion of thin films

The cracking and decohesion of thin films can be characterized by critical values of a nondimensional parameter governed by the residual stress, the film thickness, and a fracture resistance. This article reviews the status of understanding concerning the magnitude of this number for various types of adherent film on either brittle or ductile substrates. Important effects of elastic properties, substrate thickness, and yield strength are described.
Embedding of the operator space OH and the logarithmic ‘little Grothendieck inequality’

We use Voiculescu’s concept of free probability to construct a completely isomorphic embedding of the operator space OH in the predual of a von Neumann algebra. We analyze the properties of this embedding and determine the operator space projection constant of OHn: $$\frac{1}{108}\sqrt{\frac{n}{1+\ln{n}}} \le \inf_{P:\mathcal{B}(\ell_2)\to{OH}_n, P^2=P} \left\|P\right\|_{cb} \le 288\pi\sqrt{\frac{2n}{1+\ln{n}}}.$$ The lower estimate is a recent result of Pisier and Shlyakhtenko that improves an estimate of order 1/(1+lnn) of the author. The additional factor \(1 / \sqrt{1+\ln{n}}\) indicates that the operator space OHn behaves differently than its classical counterpart \(\ell_2^n\). We give an application of this formula to positive sesquilinear forms on \(\mathcal{B}(\ell_2)\). This leads to logarithmic characterization of C*-algebras with the weak expectation property introduced by Lance.
Moduli spaces of gauge theories from Dimer models: proof of the correspondence

Recently, a new way of deriving the moduli space of quiver gauge theories that arise on the world–volume of D3–branes probing singular toric Calabi–Yau cones was conjectured. According to the proposal, the gauge group, matter content and tree–level superpotential of the gauge theory is encoded in a periodic tiling, the dimer graph. The conjecture provides a simple procedure for determining the moduli space of the gauge theory in terms of perfect matchings. For gauge theories described by periodic quivers that can be embedded on a two–dimensional torus, we prove the equivalence between the determination of the toric moduli space with a gauged linear sigma model and the computation of the Newton polygon of the characteristic polynomial of the dimer model. We show that perfect matchings are in one–to–one correspondence with fields in the linear sigma model. Furthermore, we prove that the position in the toric diagram of every sigma model field is given by the slope of the height function of the corresponding perfect matching.
Quantum mechanics on manifolds embedded in Euclidean space

Abstract Quantum particles confined to surfaces in higher-dimensional spaces are acted upon by forces that exist only as a result of the surface geometry and the quantum mechanical nature of the system. The dynamics are particularly rich when confinement is implemented by forces that act normal to the surface. We review this confining potential formalism applied to the confinement of a particle to an arbitrary manifold embedded in a higher-dimensional Euclidean space. We devote special attention to the geometrically induced gauge potential that appears in the effective Hamiltonian for motion on the surface. We emphasize that the gauge potential is only present when the space of states describing the degrees of freedom normal to the surface is degenerate. We also distinguish between the effects of the intrinsic and extrinsic geometry on the effective Hamiltonian and provide simple expressions for the induced-scalar potential. We discuss examples including the case of a three-dimensional manifold embedded in a five-dimensional Euclidean space.
Improved reflectance and stability of Mo-Si multilayers

Commercial EUV lithographic systems require multilayers with higher reflectance and better stability than those published to date. This work represents our effort to meet these specifications. Interface-engineered Mo-Si multilayers with 70% reflectance and 0.545-nm bandwidth at 13.5-nm wavelength and 71% reflectance with 0.49-nm bandwidth at 12.7-nm wavelength were developed. These results were achieved with 50 bilayers. These new multilayers consist of alternating Mo and Si layers separated by thin boron carbide layers. Depositing boron carbide on the interfaces leads to reduction in molybdenum silicide formation of the Mo-on-Si interfaces. Bilayer contraction is reduced by 30%, implying that there is less intermixing of Mo and Si to form silicide. As a result, the Mo-on-Si interfaces are sharper in interface-engineered multilayers than in standard Mo-Si multilayers. The optimum boron carbide thicknesses have been determined and appear to be different for the Mo-on-Si and Si-on-Mo interfaces. The best results were obtained with 0.4-nm-thick boron carbide layers for the Mo-on-Si interfaces and 0.25-nm-thick boron carbide layers for the Si-on-Mo interfaces. The increase in reflectance is consistent with multilayers having sharper and smoother interfaces. A significant improvement in oxidation resistance of EUV multilayers has been achieved with ruthenium-terminated Mo-Si multilayers. The best capping-layer design consists of a Ru layer separated from the top Si layer by a boron carbide diffusion barrier. This design achieves high reflectance and the best oxidation resistance during EUV exposure in a water-vapor (oxidizing) environment. Electron-beam exposures of 4.5 h (in an effort to simulate EUV exposure perturbation of the top layers) in the presence of 5×10 - 7 -Torr water-vapor partial pressure show no measurable reflectance loss and no increase in the oxide thickness of Ru-terminated multilayers.
Solving the simplest theory of quantum gravity

We solve what is quite likely the simplest model of quantum gravity, the worldsheet theory of an infinitely long, free bosonic string in Minkowski space. Contrary to naive expectations, this theory is non-trivial. We illustrate this by constructing its exact factorizable S-matrix. Despite its simplicity, the theory exhibits many of the salient features expected from more mature quantum gravity models, including the absence of local off-shell observables, a minimal length, as well as (integrable relatives of) black holes. All these properties follow from the exact S-matrix. We show that the complete finite volume spectrum can be reconstructed analytically from this S-matrix with the help of the thermodynamic Bethe Ansatz. We argue that considered as a UV complete relativistic 2-dimensional quantum field theory the model exhibits a new type of renormalization group flow behavior, “asymptotic fragility”. Asymptotically fragile flows do not originate from a UV fixed point.
AN IMPROVED KALAI-KLEITMAN BOUND FOR THE DIAMETER OF A POLYHEDRON ∗

Kalai and Kleitman [Bull. Amer. Math. Soc. (N.S.), 26 (1992), pp. 315--316] established the bound $n^{\log(d) + 2}$ for the diameter of a $d$-dimensional polyhedron with $n$ facets. Here we improve the bound slightly to $(n-d)^{\log(d)}$.
ACCRETION ONTO THE FIRST STELLAR-MASS BLACK HOLES

The first stars, forming at redshifts z > 15 in minihalos with M ~ 105-6 M ☉ may leave behind remnant black holes, which could conceivably have been the seeds for the supermassive black holes observed at z 7. We study remnant black hole growth through accretion, including for the first time the radiation emitted due to accretion, with adaptive mesh refinement cosmological radiation-hydrodynamical simulations. The effects of photoionization and heating dramatically affect the large-scale inflow, resulting in negligible mass growth. We compare cases with accretion luminosity included and neglected to show that accretion radiation drastically changes the environment within 100 pc of the black hole, increasing gas temperatures by an order of magnitude. Gas densities are reduced and further star formation in the same minihalo is prevented for the 200 million years we followed. Without radiative feedback included most seed black holes do not gain mass as efficiently as has been hoped for in previous theories, implying that black hole remnants of population III stars in minihalos are not likely to be miniquasars. Most importantly, however, our calculations demonstrate that if these black holes are indeed accreting close to the Bondi-Hoyle rate with 10% radiative efficiency they have a dramatic local effect in regulating star formation in the first galaxies. This suggests a novel mechanism for massive black hole formation—stellar-mass black holes may have suppressed fragmentation and star formation after falling into halos with virial temperatures ~104 K, facilitating massive black hole formation at their centers.
A versatile sol–gel synthesis route to metal–silicon mixed oxide nanocomposites that contain metal oxides as the major phase

Abstract The general synthesis of metal–silicon mixed-oxide nanocomposite materials, including a variety of both main group and transition metals, in which the metal oxide is the major component is described. In a typical synthesis, the metal-oxide precursor, MClx · yH2O(x = 2–6, y = 0–7), was mixed with the silica precursor, tetramethoxysilane (TMOS), in ethanol and gelled using an organic epoxide. The successful preparation of homogeneous, monolithic materials depended on the oxidation state of the metal as well as the epoxide chosen for gelation. The composition of the resulting materials was varied from M/Si = 1–5 (mol/mol) by adjusting the amount of TMOS added to the initial metal-oxide precursor solution. Supercritical processing of the gels in CO2 resulted in monolithic, porous aerogel nanocomposite materials with surface areas ranging from 100–800 m2 g−1. The bulk materials are composed of metal oxide/silica particles that vary in size from 5–20 nm depending on the epoxide used for gelation. Metal oxide and silica dispersion throughout the bulk material is extremely uniform on the nanoscale. The versatility and control of the synthesis method will be discussed as well as the properties of the resulting metal–silicon mixed oxide nanocomposite materials.
Grana-like structures of Synechococcus cedorum.

DURING photosynthetic studies in this laboratory, the desire for an organism possessing a simple internal structure prompted us to investigate the blue-green algae. It has occasionally been reported that these organisms contain grana or chloroplasts; but the most widely accepted opinion is that all their pigments are uniformly distributed throughout the cytoplasm1.
The Interplay Between Massive MIMO and Underlaid D2D Networking

In a device-to-device (D2D) underlaid cellular network, the uplink spectrum is reused by the D2D transmissions, causing mutual interference with the ongoing cellular transmissions. Massive MIMO is appealing in such a context as the base station's (BS's) large antenna array can nearly null the D2D-to-BS interference. The multi-user transmission in massive MIMO, however, may lead to increased cellular-to-D2D interference. This paper studies the interplay between massive MIMO and underlaid D2D networking in a multi-cell setting. We investigate cellular and D2D spectral efficiencies under both perfect and imperfect channel state information (CSI) at the receivers that employ partial zero-forcing. Compared to the case without D2D, there is a loss in cellular spectral efficiency due to D2D underlay. With perfect CSI, the loss can be completely overcome if the number of canceled D2D interfering signals is scaled with the number of BS antennas at an arbitrarily slow rate. With imperfect CSI, in addition to pilot contamination, a new asymptotic effect termed underlay contamination arises. In the non-asymptotic regime, simple analytical lower bounds are derived for both the cellular and D2D spectral efficiencies.
A Single Mode Approximation in The Solution of Nonlinear Combustion Instability Problems

Nonlinear combustion stability problems in liquid propellant rocket engines, describing unsteady combustion response by Crocco time lag hypothesis
Optical forces and optical torques on various materials arising from optical lattices in the Lorentz-Mie regime

By combining the Maxwell stress tensor with the finite-difference time-domain (FDTD) method, we calculate the optical force and optical torque on particles from optical lattices. We compare our method to the two-component method and the electrostatic approximation (ESA). We also discuss how particle's refractive index, shape, size, and the morphology of an optical lattice influence optical forces and the condition to form stable optical trapping wells. In addition to optical forces, optical torque from one dimensional (1D) optical lattice is discussed for particles having anisotropic shapes; metastable and stable equilibrium orientation states are found. A detailed understanding of the optical force and torque from optical lattices has significant implications for optical trapping, micromanipulation, and sorting of particles.
Type-specialized staged programming with process separation

Staging is a powerful language construct that allows a program at one stage to manipulate and specialize a program at the next. We propose ML as a new staged calculus designed with novel features for staged programming in modern computing platforms such as embedded systems. A distinguishing feature of ML is a model of process separation, whereby different stages of computation are executed in different process spaces. Our language also supports dynamic type specialization via type abstraction, dynamic type construction, and a limited form of type dependence. ML is endowed with a largely standard metatheory, including type preservation and type safety results. We discuss the utility of our language via code examples from the domain of wireless sensor network programming.
Lightweight remote procedure call

Lightweight Remote Procedure Call (LRPC) is a communication facility designed and optimized for communication between protection domains on the same machine. In contemporary small-kernel operating systems, existing RPC systems incur an unnecessarily high cost when used for the type of communication that predominates—between protection domains on the same machine. This cost leads system designers to coalesce weakly related subsystems into the same protection domain, trading safety for performance. By reducing the overhead of same-machine communication, LRPC encourages both safety and performance. LRPC combines the control transfer and communication model of capability systems with the programming semantics and large-grained protection model of RPC. LRPC achieves a factor-of-three performance improvement over more traditional approaches based on independent threads exchanging messages, reducing the cost of same-machine communication to nearly the lower bound imposed by conventional hardware. LRPC has been integrated into the Taos operating system of the DEC SRC Firefly multiprocessor workstation.
Relative importance of solid-phase phosphorus and iron on the sorption behavior of sediments.

Of all the metal oxide particles, amorphous iron oxides have the greatest adsorption capacity for phosphate. Coastal sediments are often coated with terrigenous amorphous iron oxides, and those con...
Improved Structural Damage Identification Using Random Decrement Signatures: Application to FEM Data

This article describes detection of structural damage using statistical properties of randomdec signatures. Proposed technique is model free and does not require input measurements. The technique is evaluated using acceleration data obtained from a finite element model of a frame-like structure. Damage in the model is represented by a structural member with nonlinear stiffness characteristic due to opening and closing cracks. The results suggest that reliability of damage detection would depend on the orientation of the crack and the richness of the response. Copyright © 2008 John Wiley & Sons, Ltd.
Asymmetric Hydrodynamic Impact and Dynamic Response of Vessels

Theoretical simulations are compared with drop test experiments of vessel free-fall impact on calm water, with zero and nonzero initial heel angles. The impact force and moment are predicted by using a theory described in Xu et al. (1998). The resulting motions of vessels at asymmetric impact include vertical water entry and transverse rolling. The downward deceleration equation combines the hydrostatic and hydrodynamic forces and the weight of hull, while the rolling equation takes into account the restoring moments due to asymmetry. Another simplified approach of a water entry dynamics and injury model (Gollwitzer and Peterson, 1996) is also applied to evaluate the impact acceleration for symmetric cases. The experiments were conducted at the Coastal Systems Station, Panama City, Florida, using a 2 ft × 8 ft (0.61 m × 2.44 m) prismatic hull model with 20 deg deadrise. The comparisons between the asymmetric impact theory and experiment shows varying degrees of qualitative and quantitative agreement.
Using Subsidies to Promote the Adoption of Children from Foster Care

Since 1978 the federal government has implemented a variety of programs to promote the adoption of children from foster care. A key part of these programs has been the use of subsidies to lower the cost of adopting and parenting children who have been in foster care. Although subsidies are a key part of federal policy, there has been little empirical research on the effect of subsidies on adoption rates. This paper uses data from the Adoption and Foster Care Analysis and Reporting System to estimate the impact of subsidy rates on adoption rates. Subsidies to families have a positive and statistically significant effect on adoption rates.
A Convenient Synthesis of Benzo[c]naphtho[2,1-p]chrysene.

The polycyclic aromatic hydrocarbon (PAH) benzo[c]-naphtho[2,1-p]chrysene (1) has recently attracted renewed attention as a potential precursor for the synthesis of bowl-shaped fullerene substructures. The published synthetic approaches to 1, however, are lengthy and entail one or more photocyclizations of stilbene-type compounds that suffer from competing [2 + 2]cycloaddition reactions at normal concentrations and are thereby rendered quite inefficient. The authors report here a convenient four-step synthesis of 1 that can be performed on a multigram scale starting from the commercially available {alpha}-tetralone (2) and 2-bromonaphthalene. 12 refs.
Generative Power of CCGs with Generalized Type-Raised Categories

This paper shows that a class of Combinatory Categorial Grammars (CCGs) augmented with a linguistically-motivated form of type raising involving variables is weakly equivalent to the standard CCGs not involving variables. The proof is based on the idea that any instance of such a grammar can be simulated by a standard CCG.
Political participation of ethnic minorities in the 1980s

Currently political participation, especially voter registration and turnout, varies substantially with ethnicity. Blacks and non-Hispanic whites participate at roughly equal rates, while Latinos and Asian-Americans are substantially less active. This variation may be the direct product of cultural factors, or it may reflect differences in the distribution of various determinants of participation, most notably education, citizenship, and age. Using data collected in 1984 on samples of California's black, Latino, Asian-American, and non-Hispanic white populations, we conclude that such variables fully account for lower Latino participation rates. Even with these controls, however, Asian-Americans remain less likely to vote. Because ethnic group consciousness is one of the variables related to activity, we conclude that ethnicity does have an indirect effect on participation as a basis for mobilization. In addition, we establish that noncitizens engage in nonelectoral activities, and we project future political participation rates of Latinos and Asian-Americans under several scenarios.
Blogviz: Mapping the dynamics of Information Diffusion in Blogspace

Blogviz is a visualization model for mapping the transmission and internal structure of top links across the blogosphere. It explores the idea of meme propagation by assuming a parallel with the spreading of most cited URLs in daily weblog entries. The main goal of Blogviz is to unravel hidden patterns in the topics diffusion process. What's the life cycle of a topic? How does it start and how does it evolve through time? Are topics constrained to a specific community of users? Who are the most influential and innovative blogs in any topic? Are there any relationships amongst topic proliferators?
Argon laser iridotomy in primary angle-closure or pupillary block glaucoma.

This paper describes the use of a pulsed argon laser to perform iridotomies in 87 patients. Diagnoses include: primary angle closure glaucoma, narrow angle in the fellow eye of patients with primary angle closure glaucoma, pupillary block, and after incomplete surgical iridectomies. Laser iridotomy was achieved in 79% of patients. Blue eyes were slightly more difficult to penetrate. Success was almost 100% in those with pupillary block. Penetration was most difficult in patients with primary angle closure glaucoma (64%), but more easily accomplished in the fellow eyes of such cases (87%). In 13 patients surgical peripheral iridectomy was performed on one eye while the other eye was treated with laser iridotomy. No apparent significant long term differences were noted between the two eyes of the same individual. Complications of laser iridotomy include corneal burns, pupil distortion, synechia formation, lenticular opacities, iritis, marked pigment dispersion, sudden rise in intraocular pressure, and retinal burns. At this time a longer follow-up is required before it can be stated that a laser PI is more advantageous than a surgical PI. However, the laser's simplicity and ease of administration appear to warrant its continued use at this time.
Reflexivity of Banach C(K)-modules via the reflexivity of Banach lattices

We extend the well known criteria of reflexivity of Banach lattices due to Lozanovsky and Lotz to the class of finitely generated Banach $$C(K)$$ -modules. Namely we prove that a finitely generated Banach $$C(K)$$ -module is reflexive if and only if it does not contain any subspace isomorphic to either $$l^{1}$$ or $$c_{0}$$ .
Size dependent changes in tumor phosphate metabolism after radiation therapy as detected by 31P NMR spectroscopy.

Abstract In Vivo 31 P NMR spectroscopy was used to study changes in phosphate metabolism that occur after irradiation of the C 3 H fibrosarcoma, FSaII. Previously, we have shown that small FSaII tumors (less than 250 mm 3 ) have a greater phosphocreatinine/inorganic phosphate (PCrPi) ratio and a lower hypoxic cell fraction (HCF) than large FSaII tumors (greater than 250 mm 3 ). Six small tumors (113 ± 26 mm 3 ) were treated with radiation doses chosen to induce local control in >50% of animals, (70–100 Gy, single fraction). Minimal changes in the tumor 31 P NMR spectrum were seen over eight days of monitoring. During this interval, tumor regression began a minimum of 36 hours after radiation. This contrasted with large tumors (650–1000 mm 3 ) wherein a significant increase in the PcrPi ratio was seen 44 hr after irradiation. In tumors of this size range, a tumor growth delay of 4 to 7 days is obtained after a single 70 Gy fraction of radiation. Since small FSaII tumors have a minimal HCF (≌4%), radiation induced reoxygenation would not be expected to have a large effect on their average cellular metabolism. Large tumors of this histology have a high HCF (≥40%), and may therefore be expected to have a significant average change in tumor cell metabolism with reoxygenation. The 31 P NMR observations of small and large tumors after irradiation are compatible with radiation induced reoxygenation in the larger tumors.
Directionality of Continuum Gamma Rays from Solar Flares

Using hard X-ray burst spectrometer total counts as calibration, the changes in the brightness of gamma rays above 300 keV as a function of the heliocentric angle of a flare are investigated. The normalized gamma-ray brightness, on the average, increases with the heliocentric angle; a flare at the limb is estimated to be 13 times brighter in beam gamma rays than a similar flare near the central meridian. Both pancakelike electron distributions and downward beam distributions can be adjusted to produce the deduced limb brightening.
The fundamental plane of quasars

Abstract We present results from an archival study of 70 medium-redshift QSOs observed with the Wide Field Planetary Camera 2 on board the Hubble Space Telescope . The QSOs have magnitudes M V ⩽ −23 (total nuclear plus host light) and redshifts 0.06 ⩽ z ⩽ 0.46. A close relationship between QSO host and nucleus is found by examining multiple parameters at once. A principal components analysis shows that three nuclear and host properties are related in a kind of fundamental plane: nuclear luminosity and the size and effective surface magnitude of the bulge. Using optical nuclear luminosity, this relationship explains 95.9% of the variance in the overall sample, while 94.9% of the variance is accounted for if we use X-ray nuclear luminosity. The form of this QSO fundamental plane shows similarities to the well-studied fundamental plane of elliptical galaxies, and we examine the possible relationship between them as well as the difficulties involved in establishing this connection. The key to the relationship might lie in the fueling mechanism of the central black hole.
From the Mahler Conjecture to Gauss Linking Integrals

We establish a version of the bottleneck conjecture, which in turn implies a partial solution to the Mahler conjecture on the product v(K) = (Vol K)(Vol K°) of the volume of a symmetric convex body $$K \in {\mathbb{R}}^{n}$$ and its polar body K°. The Mahler conjecture asserts that the Mahler volume v(K) is minimized (non-uniquely) when K is an n-cube. The bottleneck conjecture (in its least general form) asserts that the volume of a certain domain $$K^{\diamond} \subseteq K \times K^{\circ}$$ is minimized when K is an ellipsoid. It implies the Mahler conjecture up to a factor of (π/4) n γ n , where γ n is a monotonic factor that begins at 4/π and converges to $${\sqrt2}$$ . This strengthens a result of Bourgain and Milman, who showed that there is a constant c such that the Mahler conjecture is true up to a factor of c n . The proof uses a version of the Gauss linking integral to obtain a constant lower bound on Vol K ◇, with equality when K is an ellipsoid. It applies to a more general conjecture concerning the join of any two necks of the pseudospheres of an indefinite inner product space. Because the calculations are similar, we will also analyze traditional Gauss linking integrals in the sphere S n-1 and in hyperbolic space H n-1.
Revenue Recognition, Earnings Management, and Earnings Informativeness in the Semiconductor Industry

SYNOPSIS: Manufacturers that sell products to distributors experience product return and pricing adjustment uncertainties until the products are resold to end-customers. Such manufacturers recognize revenue when products are delivered to distributors (sell-in), when distributors resell products (sell-through), or under some combination of these methods (sell-in for some distributor sales and sell-through for others). This study examines the implications of these revenue recognition methods for a sample of semiconductor firms during 2001–2008. Semiconductor firms face rapid product obsolescence, declining prices over product life cycles, and unexpected industry downturns, which naturally lead to product return and pricing adjustment uncertainties. I find that sell-through and combination firms are less likely to manage earnings compared to sell-in firms. I also find that earnings are more informative for sell-through firms compared to both sell-in and combination firms. These findings suggest that manufact...
Approach to the synthesis of nogalarol via the cycloaddition of a carbene-chromium complex with a functionalized alkyne

Abstract The alkyne, 4 , prepared stereoselectively in 7 steps from acetyl furan, reacts with (methoxy)(phenyl)carbenepentacarbonylchromium(0), 15 , to give the model ( 16 ) for nogalarol ( 1b ) in 43% yield.
Quality competition, welfare, and regulation

In this paper, we study the supply of quality in imperfectly competitive markets, and explore the role of regulation in markets where firms may use both quality and price to compete for customers. In a model where firms first choose qualities and then prices, we find that quality decisions have strategic effects: firms react to quality disadvantages by price reductions. Because of this strategic effect, firms do not have the correct incentive to set socially efficient quality levels. Price and quality competition results in a socially suboptimal quality level. Efficiency can be restored by lump-sum transfers and price regulatory policies. Simple price regulation may result in lower price and higher quality.
Reductive synthesis of aminal radicals for carbon-carbon bond formation.

Aminal radicals were generated by reduction of the corresponding amidine or amidinium ion. The intermediate radicals participate in C–C bond-forming reactions to produce fully substituted aminal stereocenters. No toxic additives or reagents are required. More than 30 substrate combinations are reported, and chemical yields are as high as 99%.
Experimental and numerical studies of the aeroacoustics of axisymmetric supersonic inlets

Abstract A series of experiments were conducted at an outdoor facility to evaluate the aerodynamic and acoustic performance of a supersonic inlet with a modified auxiliary door geometry. A 1/14 scale model of an axisymmetric, mixed-compression, supersonic inlet designed for civil transportation (P-inlet) was used in conjunction with a 10.4 cm (4.1 in) turbofan engine simulator, to test a new auxiliary door geometry designed to reduce engine fan noise radiated to the forward sector. The flow distortion at the fan face was reduced by modifying the auxiliary inlet doors. The new door geometry uses door passages with increased circumferential span to improve the distribution of the flow entering through the doors. To provide a basis for comparison, a baseline inlet with an auxiliary door geometry representative of the original designs was also tested. The results show that the new door geometry is successful in reducing circumferential distortion of the flow Mach number near the fan face by 30% compared to the baseline configuration. In addition, far field radiation of the blade passing frequency tone and overall noise is reduced by an average of 4 dB(SPL)in the forward sector (0° to 110° from the inlet axis). A 3-D, viscous numerical simulation of the baseline door configuration reveals a large region of flow separation downstream of the auxiliary door. This flow separation leads to a significant increase in circumferential distortion at the fan face.
Analysis of Kapitza-Dirac diffraction patterns beyond the Raman-Nath regime

We study Kapitza-Dirac diffraction of a Bose-Einstein condensate from a standing light wave for a square pulse with variable pulse length but constant pulse area. We find that for sufficiently weak pulses, the usual analytical short-pulse prediction for the Raman-Nath regime continues to hold for longer times, albeit with a reduction of the apparent modulation depth of the standing wave. We quantitatively relate this effect to the Fourier width of the pulse, and draw analogies to the Rabi dynamics of a coupled two-state system. Our findings, combined with numerical modeling for stronger pulses, are of practical interest for the calibration of optical lattices in ultracold atomic systems.
Wind Interaction Models for the Afterglows of GRB 991208 and GRB 000301C

The simplest model of the afterglows of gamma-ray bursts (GRBs) envisions a spherical blast wave, with a power-law distribution of electron energy above some cutoff, running into a constant-density medium. A refinement involves a narrow jet, often invoked to explain the steep decline and/or steepening of light curves observed in some afterglows. The constant (ambient) density jet model has been applied to GRBs 991208 and 000301C, based to a large extent on radio observations. We show that, for these two sources, a spherical-wind model (with an r-2 density ambient medium) can fit the radio data as well as the jet model. The relatively steep decline and the fairly abrupt steepening of the R-band light curves of, respectively, GRB 991208 and GRB 000301C can be accounted for with a nonstandard, broken power-law distribution of electron energy. Our model predicts a slower late decline for the radio flux than does the jet model.
Ejecta Pattern of the Impact of Comet Shoemaker–Levy 9

The collision of Comet Shoemaker–Levy 9 (SL 9) with Jupiter created crescent-shaped ejecta patterns around impact sites. Although the observed impact plumes rose through a similar height of ∼3000 km, the radii of the created ejecta patterns differ from impact to impact and generally are larger for larger impacts. The azimuthal angle of the symmetry axis of the ejecta pattern is larger than that predicted by the models of oblique impacts, due to the action of the Coriolis force that rotates ejecta patterns counterclockwise from the south. We study the formation of ejecta patterns using a simple model of ballistic plume above a rotating plane. The ejected particles follow ballistic trajectories and slide horizontally for about an hour after reentry into the jovian atmosphere. The lateral expansion of the plume is stopped by the friction force, which is assumed to be proportional to the square of the horizontal velocity. Two different mass–velocity distributions used in the simulations produce qualitatively similar results. The simulated ejecta patterns fit very well the “crescents” observed at the impact sites. The sizes and azimuthal angles of symmetry axis of ejecta patterns depend on a parameterL, which has dimension of length and is related to the mass of the fragment. Thus more massive impacts produce larger ejecta patterns that are rotated through a wider angle.