cssi/SciSciGPT-SciSciNet huggingface dataset:
Unsteady Flow and Shock Motion in a Transonic Compressor Rotor

The results of an experimental and numerical comparison of the unsteadiness and shock motion that occurs in the tip region within a modern, low-aspect-ratio, high-through-e ow, axial-e ow transonic fan rotor are presented. The unsteadiness studied here is associated with local phenomena within the blade passage and not related to blade row interaction. Unsteady static pressures were measured at the casing over the rotor that operates at a tip relative Mach number of 1.6. An unsteady three-dimensional Navier ‐ Stokes computational study was performed with tip clearance comparable to the test rotor. The fully three-dimensional, unsteady, Reynolds-averaged Navier ‐ Stokes equations were solved with time steps, each nominally of 2.8 3 10 25 s in duration or approximately e ve times blade pass frequency. The results in the clearance gap were retained from the computational solution and compared with the experimental measurements. Both indicated deterministic unsteadiness near the location of the shock. High levels of unsteadiness were also measured downstream of the shock in the path of the clearance vortex, but this phenomenon was not predicted by the computation. The unsteadiness near the shock was shown to be a result of movement of the shock. The amplitude and frequency of shock position oscillation was estimated from the results to be about 2% chord and 2 kHz, respectively. Analysis of loss caused by the shock unsteadiness suggested that losses because of shock motion were insignie cant relative to the steady shock loss at the relative Mach number studied.
An interpretation-oriented theorem prover over integers

A special purpose theorem prover for establishing the validity of expressions over integer variables was developed as part of a program verifier. It is built around a powerful system for manipulating and simplifying integer expressions.
Area Minimizing Sets Subject to a Volume Constraint in a Convex Set

For a given convex subset Ω of Euclidean n-space, we consider the problem of minimizing the perimeter of subsets of Ω subject to a volume constraint. The problem is to determine whether in general a minimizer is also convex. Although this problem is unresolved, we show that if Ω satisfies a “great circle” condition, then any minimizer is convex. We say that Ω satisfies a great circle condition if the largest closed ball B contained in Ω has a great circle that is contained in the boundary of Ω. A great circle of B is defined as the intersection of the boundary of B with a hyperplane passing through the center of B.
Superfast vocal muscles control song production in songbirds

Birdsong is a widely used model for vocal learning and human speech, which exhibits high temporal and acoustic diversity. Rapid acoustic modulations are thought to arise from the vocal organ, the syrinx, by passive interactions between the two independent sound generators or intrinsic nonlinear dynamics of sound generating structures. Additionally, direct neuromuscular control could produce such rapid and precisely timed acoustic features if syringeal muscles exhibit rare superfast muscle contractile kinetics. However, no direct evidence exists that avian vocal muscles can produce modulations at such high rates. Here, we show that 1) syringeal muscles are active in phase with sound modulations during song over 200 Hz, 2) direct stimulation of the muscles in situ produces sound modulations at the frequency observed during singing, and that 3) syringeal muscles produce mechanical work at the required frequencies and up to 250 Hz in vitro. The twitch kinematics of these so-called superfast muscles are the fastest measured in any vertebrate muscle. Superfast vocal muscles enable birds to directly control the generation of many observed rapid acoustic changes and to actuate the millisecond precision of neural activity into precise temporal vocal control. Furthermore, birds now join the list of vertebrate classes in which superfast muscle kinetics evolved independently for acoustic communication.
A SIGNIFICANT PROBLEM WITH USING THE AMATI RELATION FOR COSMOLOGICAL PURPOSES

We consider the distribution of many samples of gamma-ray bursts when plotted in a diagram with their bolometric fluence (S bolo) versus the observed photon energy of peak spectral flux (E peak, obs). In this diagram, all bursts that obey the Amati relation (a luminosity relation where the total burst energy has a power-law relation to E peak, obs) must lie above some limiting line, although observational scatter is expected to be substantial. We confirm that early bursts with spectroscopic redshifts are consistent with this Amati limit. But we find that the bursts from BATSE, Swift, Suzaku, and Konus are all greatly in violation of the Amati limit, and this is true whether or not the bursts have measured spectroscopic redshifts. That is, the Amati relation has definitely failed. In the S bolo-E peak, obs diagram, we find that every satellite has a greatly different distribution. This requires that selection effects are dominating these distributions, which we quantitatively identify. For detector selections, the trigger threshold and the threshold for the burst to obtain a measured E peak, obs combine to make a diagonal cutoff with the position of this cutoff varying greatly detector to detector. For selection effects due to the intrinsic properties of the burst population, the distribution of E peak, obs makes bursts with low and high values rare, while the fluence distribution makes bright bursts relatively uncommon. For a detector with a high threshold, the combination of these selection effects serves to allow only bursts within a region along the Amati limit line to be measured, and these bursts will then appear to follow an Amati relation. Therefore, the Amati relation is an artifact of selection effects within the burst population and the detector. As such, the Amati relation should not be used for cosmological tasks. This failure of the Amati relation is in no way prejudicial against the other luminosity relations.
THE LICK-CARNEGIE EXOPLANET SURVEY: A URANUS-MASS FOURTH PLANET FOR GJ 876 IN AN EXTRASOLAR LAPLACE CONFIGURATION*

Continued radial velocity (RV) monitoring of the nearby M4V red dwarf star GJ 876 with Keck/High Resolution Echelle Spectrograph has revealed the presence of a Uranus-mass fourth planetary companion in the system. The new planet has a mean period of P{sub e} = 126.6 days (over the 12.6-year baseline of the RV observations), and a minimum mass of m{sub e} sin i{sub e} = 12.9 {+-} 1.7 M {sub +}. The detection of the new planet has been enabled by significant improvements to our RV data set for GJ 876. The data have been augmented by 36 new high-precision measurements taken over the past five years. In addition, the precision of all of the Doppler measurements have been significantly improved by the incorporation of a high signal-to-noise template spectrum for GJ 876 into the analysis pipeline. Implementation of the new template spectrum improves the internal rms errors for the velocity measurements taken during 1998-2005 from 4.1 m s{sup -1} to 2.5 m s{sup -1}. Self-consistent, N-body fits to the RV data set show that the four-planet system has an invariable plane with an inclination relative to the plane of the sky of i = 59.{sup 0}5. The fit is notmore » significantly improved by the introduction of a mutual inclination between the planets 'b' and 'c', but the new data do confirm a non-zero eccentricity, e{sub d} = 0.207 {+-} 0.055 for the innermost planet, 'd'. In our best-fit coplanar model, the mass of the new component is m{sub e} = 14.6 {+-} 1.7 M {sub +}. Our best-fitting model places the new planet in a three-body resonance with the previously known giant planets (which have mean periods of P{sub c} = 30.4 and P{sub b} = 61.1 days). The critical argument, {psi}{sub Laplace} = {lambda} {sub c} - 3{lambda} {sub b} + 2{lambda} {sub e}, for the Laplace resonance librates with an amplitude of {Delta}{psi}{sub Laplace} = 40{sup 0} {+-} 13{sup 0} about {psi}{sub Laplace} = 0{sup 0}. Numerical integration indicates that the four-planet system is stable for at least a billion years (at least for the coplanar cases). This resonant configuration of three giant planets orbiting an M dwarf primary differs from the well-known Laplace configuration of the three inner Galilean satellites of Jupiter, which are executing very small librations about {psi}{sub Laplace} = 180{sup 0} and which never experience triple conjunctions. The GJ 876 system, by contrast, comes close to a triple conjunction between the outer three planets once per every orbit of the outer planet, 'e'.« less
History and identity among the Hemshin

By continuing to speak Armenian, the small community of Hemshin in northeastern Turkey has become the only community of Armenian-speaking Muslims. Furthermore, by developing after their conversion to Islam a group identity distinct from that of its neighbours, they have constituted an exception to one of the more typical paradigms in the Ottoman Empire, whereby Armenian converts to Islam were assimilated completely into the surrounding Muslim environment. Yet, while maintaining Armenian components in their culture, a majority of Hemshin dissociate themselves from their Armenian ancestry. The rural exodus has emptied many of the villages, but among the younger generation, including those born in the cities, a growing number seeks to preserve Hemshinli traditions.
Ramsey Numbers and the Size of Graphs

For two graphs $H$ and $G$, the Ramsey number $r(H, G)$ is the smallest positive integer $n$ such that every red-blue edge coloring of the complete graph $K_n$ on $n$ vertices contains either a red copy of $H$ or a blue copy of $G$. Motivated by questions posed by Erdos and Harary, in this note we study how the Ramsey number $r(K_s, G)$ depends on the size of the graph $G$. For $s \geq 3$, we prove that for every $G$ with $m$ edges, $r(K_s,G) \geq c(m/\log m)^{(s+1)/(s+3)}$ for some positive constant $c$ depending only on $s$. This lower bound improves an earlier result of Erdos, Faudree, Rousseau, and Schelp, and it is tight up to a polylogarithmic factor when $s=3$. We also study the maximum value of $r(K_s,G)$ as a function of $m$.
The social costs of monopoly and regulation: Posner reconsidered again

Abstract This paper establishes three analytical propositions that measure the aggregate resources wasted by firms competing in a rent-seeking contest. The propositions are derived from a model of monopoly rent-seeking where firms are assumed to compete in a contest in which the outcome is determined probabilistically. The model embodies an assumption that the rent-seeking rivals are differentially situated in terms of the ease with which monopoly can be obtained. The paper considers a special case where an incumbent in a monopoly franchise conferred by a governmental body enjoys a unique comparative advantage in the effectiveness of its rent-seeking expenditures. In that case it is shown, inter alia, that the maximum value of the monopoly rent dissipated by all the rent-seeking rivals can be measured with reasonable accuracy if the number of rivals and the marginal advantage of the incumbent are known or can be reliably estimated.
SELF-STABILIZING ANONYMOUS LEADER ELECTION IN A TREE

We propose a new self-stabilizing anonymous leader election algorithm in a tree graph. We show the correctness of the protocol and show that the protocol terminates in O(n4) time starting from any arbitrary initial state. The protocol can elect either a leaf node or a non leaf node (starting from the same initial state) depending on the behavior of the daemon. The protocol generalizes the result in [1] and at the same time is much simpler and terminates in polynomial number of moves.
Copper chloride−cyanopyridine complexes as catalysts for the decomposition of fluorophosphonate esters

Abstract We have synthesized a number of copper complexes of O-alkylpyridine-2-carboximidates from the reaction of 2-cyanopyridine, copper(II) chloride dihydrate and various alcohols. These compounds have been tested as catalysts for the decomposition of the fluorophosphonates. The catalytic results show rate accelerations which approach 500–1000-fold over background (no metal catalysis).
Sexual reproduction in Histoplasma capsulatum.

Growth of fungi on plates of soil and hair has been found to stimulate many dermatophytes and related fungi to reproduce sexually (5, 8). In our laboratory such studies have led to the discovery of the ascigerous state of: Microsporum cookei Ajello (1)-Nannizzia cajetani Ajello (2); M. vanbreuseghemii Georg, Ajello, Friedman & Brinkman-N. grubyia Georg, Ajello, Friedman & Brinkman (6); Trichophyton georgiae Varsavsky & Ajello-Arthroderma ciferrii Varsavsky & Ajello (10); T. gloriae Ajello-A. gloriae Ajello (3); and T. mentagrophytes var. granulosum Neveu-Lemaire-A. benhamiae Ajello & Cheng (4). Most recently we began growing single and paired cultures of various systemic pathogens on plates of soil with several types of keratinaceous substrata. The results of our work with Histoplasma capsulatum Darling, are presented in this report.
Minimum weight design of rotorcraft blades with multiple frequency and stress constraints

Minimum weight designs of helicopter rotor blades with constraints on multiple coupled flap-lag natural frequencies are studied. Constraints are imposed on the minimum value of the blade autorotational inertia to ensure sufficient rotary inertia to autorotate in case of engine failure and on stresses to guard against structural failure due to blade centrifugal forces. Design variables include blade taper ratio, dimensions of the box beam located inside the airfoil and magnitudes of nonstructural weights. The program CAMRAD is used for the blade modal analysis; the program CONMIN is used for the optimization. A linear approximation involving Taylor series expansion is used to reduce the analysis effort. The procedure contains a sensitivity analysis consisting of analytical derivatives for objective function and constraints on autorotational inertia and stresses. Central finite difference derivatives are used for frequency constraints. Optimal designs are obtained for both rectangular and tapered blades. Using this method, it is possible to design a rotor blade with reduced weight, when compared to a baseline blade, while satisfying all the imposed design requirements.
Relativistic Bottomonium Spectrum from Anisotropic Lattices

We report on our results from a fully relativistic simulation of the quenched bottomonium spectrum. Using an anisotropic formulation of Lattice QCD, we were able to retain a very fine resolution into the temporal direction for a range of different lattice spacings. At fixed renormalized anisotropy we study the scaling properties of the spectrum and compare our results with non-relativistic calculations.
Preparation of the First Molecular Carbon Monoxide Complex of Uranium, (Me3SiC5H4)3UCO

Migratory insertion of an anionic group onto coordinate carbon monoxide or an isocyanide is an important mechanistic postulate in organoactinide chemistry. In contrast to transition metals, where carbon monoxide complexes abound, only three examples of carbon monoxide coordination to uranium have been observed in matrix isolation studies at cyrogenic temperatures. These studies showed that U(CO)/sub 6/ can exist below ca. 20 K and that nu/sub CO/ of 1961 cm/sup -1/ is similar to that found for W(CO)/sub 6/, nu/sub CO/ is 1987 cm/sup -1/ under similar conditions. The nu/sub CO/ is lowered substantially from gaseous CO (nu = 2145 cm/sup -1/) which implies that uranium metal is a ..pi..-donor, though the bonds are either kinetically labile, thermodynamically weak, or both. In UF/sub 4/(CO) the nu/sub CO/ of 2182 cm/sup -1/ at 20 K/sup 2c/ shows that the tetravalent compound does not engage in ..pi..-back-bonding to CO. In another study, UO/sub 2/ has been shown to absorb CO at temperatures below 20 K; the CO stretching frequency was not measured. In this paper, evidence is given for (Me/sub 3/SiC/sub 5/H/sub 4/)/sub 3/UCO, the first molecular actinide complex of carbon monoxide in solution and solid phase. 8 references.
Interference Control in Cellular Systems

Some of the fundamentals of cellular system design are reviewed. Co-channel interference is calculated for different cluster configurations and propagation factors are explained Trunking efficiency is introduced and the advantages of a flexible cell size are shown.
Elastic energy, fluctuations and temperature for granular materials

We probe, using a model system, elastic and kinetic energies for sheared granular materials. For large enough P/Ey (pressure/Young's modulus) and P/ρv2 (P/kinetic energy density) elastic dominates kinetic energy, and energy fluctuations become primarily elastic in nature. This regime has likely been reached in recent experiments. We consider a generalization of the granular temperature, Tg, with both kinetic and elastic terms and that changes smoothly from one regime to the other. This Tg is roughly consistent with a temperature adapted from equilibrium statistical mechanics.
Cones and asymptotic invariants of multigraded systems of ideals

Abstract We show that the only regularity property satisfied by asymptotic invariants of abstract multigraded systems of ideals is convexity, which is imposed formally.
The Demographics of Broad Line Quasars in the Mass-Luminosity Plane II. Black Hole Mass and Eddington Ratio Functions

We employ a flexible Bayesian technique to estimate the black hole (BH) mass and Eddington ratio functions for Type 1 (i.e., broad line) quasars from a uniformly selected data set of ~58, 000 quasars from the Sloan Digital Sky Survey (SDSS) DR7. We find that the SDSS becomes significantly incomplete at M BH 3 × 108 M ☉ or L/L Edd 0.07, and that the number densities of Type 1 quasars continue to increase down to these limits. Both the mass and Eddington ratio functions show evidence of downsizing, with the most massive and highest Eddington ratio BHs experiencing Type 1 quasar phases first, although the Eddington ratio number densities are flat at z < 2. We estimate the maximum Eddington ratio of Type 1 quasars in the observable universe to be L/L Edd ~ 3. Consistent with our results in Shen & Kelly, we do not find statistical evidence for a so-called sub-Eddington boundary in the mass-luminosity plane of broad-line quasars, and demonstrate that such an apparent boundary in the observed distribution can be caused by selection effect and errors in virial BH mass estimates. Based on the typical Eddington ratio in a given mass bin, we estimate growth times for the BHs in Type 1 quasars and find that they are comparable to or longer than the age of the universe, implying an earlier phase of accelerated (i.e., with higher Eddington ratios) and possibly obscured growth. The large masses probed by our sample imply that most of our BHs reside in what are locally early-type galaxies, and we interpret our results within the context of models of self-regulated BH growth.
Non-extreme Calabi-Yau black holes

Abstract Non-extreme black hole solutions of four dimensional, N = 2 supergravity theories with Calabi-Yau prepotentials are presented, which generalize certain known double-extreme and extreme solutions. The boost parameters characterizing the nonextreme solutions must satisfy certain constraints, which effectively limit the functional independence of the moduli scalars. A necessary condition for being able to take certain boost parameters independent is found to be block diagonality of the gauge coupling matrix. We present a number of examples aimed at developing an understanding of this situation and speculate about the existence of more general solutions.
Antisperm Antibodies: Etiology, Pathogenesis, Diagnosis, and Treatment

Conclusion(s): There is sufficient evidence that ASA impair fertility in couples with unexplained infertility. A number of different methodologies are available, which may be used in their detection. However, in many cases, test interpretation is subjective. Although there is not enough evidence to support systemic treatment for ASA, application of a variety of assisted reproductive technologies improves outcome. (Fertil Sterilt 1998;70:799–810. ©1998 by American Society for Reproductive Medicine.)
Multiperiod competition with switching costs solution by Lagrange multipliers

Abstract This paper applies the method of Lagrange multipliers to solve a model of dynamic games of Beggs and Klemperer (1992) on price determination of duopolists facing a market with no consumer switching products. The consumers are first assumed to be myopic, basing their choice of products on only current prices, and then allowed to take future prices into account. The solutions in the two cases illustrate that the method is simpler than dynamic programming because there are fewer parameters to solve and one saves the trouble of differentiating the value function in solving the first-order condition for the optimum control function.
A Low-Cost Audio Computer for Information Dissemination Among Illiterate People Groups

We present Literacy in Technology (LIT), a low power, low cost audio processor for information dissemination among illiterate people groups in developing regions. The 265 K gate, 8 million transistor, 23 mm2, ARM Cortex M0 processor uses a novel memory hierarchy consisting of an on chip 128 kB true LRU cache and off-chip NAND Flash. LIT reduces initial acquisition cost through a high-level of integration that results in a low board-level component count. In addition, it also reduces recurring cost through design decisions that lower energy consumption. LIT's multiple power operational modes and power management schemes are specifically designed for efficient operation on Carbon Zinc batteries. These are commonly found in developing regions and allow LIT to be priced at a point that is viable for illiterate people groups in developing regions.
The Budyko and complementary relationships in an idealized model of large-scale land–atmosphere coupling

Abstract. Two well-known relationships in hydrology and hydrometeorology, the Budyko and complementary relationships, are examined within an idealized prototype representing the physics of large-scale land–atmosphere coupling developed in prior work. These relationships are shown to hold on long (climatologic) timescales because of the tight coupling that exists between precipitation, atmospheric radiation, moisture convergence and advection. The slope of the CR is shown to be dependent on the Clausius–Clapeyron relationship between saturation-specific humidity and temperature, with important implications for the continental hydrologic cycle in a warming climate; e.g., one consequence of this dependence is that the CR may be expected to become more asymmetric with warming, as higher values of the slope imply a larger change in potential evaporation for a given change in evapotranspiration. In addition, the transparent physics of the prototype permits diagnosis of the sensitivity of the Budyko and complementary relationships to various atmospheric and land surface processes. Here, the impacts of anthropogenic influences, including large-scale irrigation and global warming, are assessed.
AGN obscuring tori supported by infrared radiation pressure

Explicit 2D axisymmetric solutions are found to the hydrostatic equilibrium, energy balance, and photon diffusion equations within obscuring tori around active galactic nuclei (AGNs). These solutions demonstrate that infrared radiation pressure can support geometrically thick structures in AGN environments subject to certain constraints: the bolometric luminosity must be roughly ~0.03-1 times the Eddington luminosity; and the Compton optical depth of matter in the equatorial plane should be ~1, with a tolerance of about an order of magnitude up or down. Both of these constraints are at least roughly consistent with observations. In addition, angular momentum must be redistributed so that the fractional rotational support against gravity rises from the inner edge of the torus to the outer in a manner specific to the detailed shape of the gravitational potential. This model also predicts that the column densities observed in obscured AGNs should range from ~1022 to ~1024 cm-2.
The surface chemistry of catalysis: new challenges ahead

Surface scientists have over the last few decades greatly advanced the atomic level understanding of the surface chemical reactions associated with heterogeneous catalysis. Nonetheless, many fundamental questions still remain unanswered. In this review, a critical analysis of the state of the art of this field is provided, and a number of future research directions are suggested.
Evidence for bromine-lithium exchange in a local high concentration gradient

Abstract The product ratios for bromine-lithium exchange of 3,3′-dibromostilbene (6) with one equivalent of n-butyl lithium, s-butyl lithium or t-butyl lithium in THF and in Et2O to give after quenching with methanol 3-bromostilbene (7) and stilbene (8), have been investigated. In the most reactive cases the ratio of 8:7 is significantly greater than expected for a statistical reaction. The apparently accelerated exchange of 7-Li relative to 6 is attributed to reaction in a high local concentration of the butyl lithium reagent.
Comparison of symbolic and ordinary powers of ideals

All given rings in this paper are commutative, associative with identity, and Noetherian. Recently, L. Ein, R. Lazarsfeld, and K. Smith [ELS] discovered a remarkable and surprising fact about the behavior of symbolic powers of ideals in affine regular rings of equal characteristic 0: if h is the largest height of an associated prime of I , then I (hn) ⊆ I n for all n ≥ 0. Here, if W is the complement of the union of the associated primes of I , I (t) denotes the contraction of I t RW to R, where RW is the localization of R at the multiplicative system W . Their proof depends on the theory of multiplier ideals, including an asymptotic version, and, in particular, requires resolution of singularities as well as vanishing theorems. We want to acknowledge that without their generosity and quickness in sharing their research this manuscript would not exist. Our objective here is to give stronger results that can be proved by methods that are, in some ways, more elementary. Our results are valid in both equal characteristic 0 and in positive prime characteristic p, but depend on reduction to characteristic p. We use tight closure methods and, in consequence, we need neither resolution of singularities nor vanishing theorems that may fail in positive characteristic. For the most basic form of the result, all that we need from tight closure theory is the definition of tight closure and the fact that in a regular ring, every ideal is tightly closed. We note that the main argument here is closely related to a proof given in [Hu, 5.14–16, p. 45] that regular local rings in characteristic p are UFDs,
The reintegration of criminal deportees in society

This article deals with reintegrating deportees in Jamaica. There is the belief among the citizenry, the media, and the government that the deportees are fueling the crime rate. Jamaica has one of the highest homicide rates in the world. Some 15,618 deportees were sent to Jamaica from various countries between 2005 and 2009. The purveyors of the deportee-crime link ignore the influence of garrison communities on the crime rate which are political communities governed by criminals. Another view argues that the deportees have a minimal impact on the crime rate. None of the viewpoints can be substantiated without a representative survey with a rigorous methodology on the deportee-crime link. The various viewpoints also ignore the need to reintegrate the deportees. Only one church group the Cornerstone Ministries has a reintegration program. The government has a temporary piecemeal program that provides assistance and temporary housing rather than reintegration. Some societies (e.g. China, New Zealand, and Australia) have reintegration programs for ex-offenders which give them a stake in conformity by reaccepting them in the community after punishment. These models can be applied to Jamaica with the creation of a national reintegration program taking into account the cultural differences.
Almost rectilinear halo orbits

Numerical studies over the entire range of mass-ratios in the circular restricted 3-body problem have revealed the existence of families of three-dimensional ‘halo’ periodic orbits emanating from the general vicinity of any of the 3 collinear Lagrangian libration points. Following a family towards the nearer primary leads, in 2 different cases, to thin, almost rectilinear, orbits aligned essentially perpendicular to the plane of motion of the primaries. (i) If the nearer primary is much more massive than the further, these thin L3-family halo orbits are analyzed by looking at the in-plane components of the small osculating angular momentum relative to the larger primary and at the small in-plane components of the osculating Laplace eccentricity vector. The analysis is carried either to 1st or 2nd order in these 4 small quantities, and the resulting orbits and their stability are compared with those obtained by a regularized numerical integration. (ii) If the nearer primary is much less massive than the further, the thin L1-family and L2-family halo orbits are analyzed to 1st order in these same 4 small quantities with an independent variable related to the one-dimensional approximate motion. The resulting orbits and their stability are again compared with those obtained by numerical integration.
Domain Walls in Superfluid 3He-B

We consider domain walls between regions of superfluid 3He-B in which one component of the order parameter has the opposite sign in the two regions far from one another. We report calculations of the order parameter profile and the free energy for two types of domain wall, and discuss how these structures are relevant to superfluid 3He confined between two surfaces.
Tandem Pummerer Diels-Alder sequence for the preparation of α-thio substituted naphthalene derivatives

Abstract The α-thiocarbocation generated from the Pummerer reaction of an o -benzoyl substituted sulfoxide is intercepted by the adjacent keto group to produce an α-thio-isobenzofuran as a transient intermediate which undergoes a subsequent Diels-Alder cycloaddition with added dienophiles.
On the Origin of Exponential Disks at High Redshift

The major-axis and ellipse-fit intensity profiles of spiral galaxies larger than 03 in the Hubble Space Telescope Ultra Deep Field (UDF) are generally exponential, whereas the major-axis profiles in irregular disk galaxies, called clump clusters in our previous studies, are clearly not. Here we show that the deprojected positions of star-forming clumps in both galaxy types are exponential, as are the deprojected luminosity profiles of the total emissions from these clumps. These exponentials are the same for both types when normalized to the outer isophotal radii. The results imply that clumps form or accrete in exponential radial distributions, and when they disperse they form smooth exponential disks. The exponential scale lengths for UDF spirals average ~1.5 kpc for a standard cosmology. This length is smaller than the average for local spirals by a factor of ~2. Selection effects that may account for this size difference among spirals are discussed. Regardless of these effects, the mere existence of small UDF galaxies with grand-design spiral arms differs significantly from the situation in local fields, where equally small disks are usually dwarf irregulars that rarely have spiral arms. Spiral arms require a disk mass comparable to the halo mass in the visible region, something that local spirals have but local dwarf irregulars do not. Our UDF result then implies that galaxy disks grow from the inside out, starting with a dense halo and dense disk that can form spiral arms and then adding lower density halo and disk material over time. Bars that form early in such small, dense, gas-rich disks should disperse more quickly than bars that form later in fully developed disks.
Propagation of Acoustic Waves In a Fluid-Filled Borehole Surrounded By a Concentrically Layered Transversely Isotropic Formation

The method of real axis integration is applied to compute the acoustic waveform due to a point source in a fluid‐filled borehole surrounded by a concentrically layered transversely isotropic formation. The problem is of interest in acoustic logging because the earth, due to its intrinsic horizontally layering structure, is essentially a transversely isotropic medium. The presence of an invasion zone introduces concentric layering in the vicinity of the borehole. Due to the axial symmetry of the problem, only two characteristic waves are excited in the transversely isotropic medium. The effects of the anisotropy and concentric layering on the acoustic waveforms are studied.
Secret key generation from mobility

We consider secret key generation from relative localization information of a pair of nodes in a mobile wireless network in the presence of a mobile eavesdropper. Our scheme consists of two phases: in the first phase, legitimate node pair exchanges beacon signals to establish localization information based on noisy observations of these beacons; in the second phase, nodes generate secret key bits via a public discussion. Our problem can be categorized under the source models of information theoretic secrecy, where the distance between the legitimate nodes acts as the observed common randomness. We characterize the achievable secret key bit rate in terms of the observation noise variance at the legitimate nodes and the eavesdropper. This work provides a framework that combines information theoretic secrecy and wireless localization, and proves that the localization information provides a significant additional resource for secret key generation in mobile wireless networks.
Forward-Flight Analysis of Slatted Rotors Using Navier-Stokes Methods

The objective of this study is to evaluate the aerodynamic effects of leading-edge slats on rotor blades under high-speed forward- ight conditions. A partial-span leading-edge slat is proposed for the inboard portion of the existing UH-60A rotor. Some two-dimensional slat studies are done to optimize the slat orientation at low subsonic Mach numbers. A multizone unsteady three-dimensional compressible Navier ­ Stokes solver is developed to compute such rotor/slat con gurations. The rotor wake is captured from  rst principles. Some forward- ight results are presented for the UH-60A slatted rotor and compared with the baseline rotor case. The surface pressures and the force coef cients indicate that the slat is bene cial in reducing the retreating side dynamic stall. It was found that the slat reduces the torque and pitching moments on the retreating side compared to the baseline con guration.
Calculating tumor trajectory and dose-of-the-day using cone-beam CT projections.

Purpose: Cone-beam CT (CBCT) projection images provide anatomical data in real-time over several respiratory cycles, forming a comprehensive picture of tumor movement. The authors developed and validated a method which uses these projections to determine the trajectory of and dose to highly mobile tumors during each fraction of treatment. Methods: CBCT images of a respiration phantom were acquired, the trajectory of which mimicked a lung tumor with high amplitude (up to 2.5 cm) and hysteresis. A template-matching algorithm was used to identify the location of a steel BB in each CBCT projection, and a Gaussian probability density function for the absolute BB position was calculated which best fit the observed trajectory of the BB in the imager geometry. Two modifications of the trajectory reconstruction were investigated: first, using respiratory phase information to refine the trajectory estimation (Phase), and second, using the Monte Carlo (MC) method to sample the estimated Gaussian tumor position distribution. The accuracies of the proposed methods were evaluated by comparing the known and calculated BB trajectories in phantom-simulated clinical scenarios using abdominal tumor volumes. Results: With all methods, the mean position of the BB was determined with accuracy better than 0.1 mm, and root-mean-square trajectory errors averagedmore » 3.8% ± 1.1% of the marker amplitude. Dosimetric calculations using Phase methods were more accurate, with mean absolute error less than 0.5%, and with error less than 1% in the highest-noise trajectory. MC-based trajectories prevent the overestimation of dose, but when viewed in an absolute sense, add a small amount of dosimetric error (<0.1%). Conclusions: Marker trajectory and target dose-of-the-day were accurately calculated using CBCT projections. This technique provides a method to evaluate highly mobile tumors using ordinary CBCT data, and could facilitate better strategies to mitigate or compensate for motion during stereotactic body radiotherapy.« less
HOXB13 is downregulated in colorectal cancer to confer TCF4-mediated transactivation.

Mutations in the Wnt signalling cascade are believed to cause aberrant proliferation of colorectal cells through T-cell factor-4 (TCF4) and its downstream growth-modulating factors. HOXB13 is exclusively expressed in prostate and colorectum. In prostate cancers, HOXB13 negatively regulates β-catenin/TCF4-mediated transactivation and subsequently inhibits cell growth. To study the role of HOXB13 in colorectal tumorigenesis, we evaluated the expression of HOXB13 in 53 colorectal tumours originated from the distal left colon to rectum with their matching normal tissues using quantitative RT–PCR analysis. Expression of HOXB13 is either lost or diminished in 26 out of 42 valid tumours (62%), while expression of TCF4 RNA is not correlated with HOXB13 expression. TCF4 promoter analysis showed that HOXB13 does not regulate TCF4 at the transcriptional level. However, HOXB13 downregulated the expression of TCF4 and its target gene, c-myc, at the protein level and consequently inhibited β-catenin/TCF-mediated signalling. Functionally, forced expression of HOXB13 drove colorectal cancer (CRC) cells into growth suppression. This is the first description of the downregulation of HOXB13 in CRC and its mechanism of action is mediated through the regulation of TCF4 protein stability. Our results suggest that loss of HOXB13 may be an important event for colorectal cell transformation, considering that over 90% of colorectal tumours retain mutations in the APC/β-catenin pathway.
Prediction of the Normal Boiling Points of Organic Compounds from Molecular Structures with a Computational Neural Network Model

Computational methods were used to link the molecular structures of diverse, industrially important, organic compounds from three different data sets to their normal boiling points. The data were p...
Thermodynamic properties of Ti–Al intermetallics

Abstract Thermodynamic properties of the titanium–aluminum system have been investigated over the entire composition range. A solid-state reversible galvanic cell employing a calcium fluoride (CaF 2 ) solid electrolyte and an Al–CaAlF 7 reference electrode was used in the temperature range 820–900 K for solid alloys containing 31.3, 47.9, 64.7, 73.6 and 99.0 atom percent aluminum. Experimental results of the activities of Al in the alloys showed a large negative deviation from ideal behavior. For instance the activity of Al in an alloy with 0.48 atomic fraction of Al was determined to be 2.98×10 −3 at 850 K.
Sequential ene, Diels–Alder reactions of AF4-yne with 1,3,5-cycloheptatriene

Abstract (4,5-Dehydro)-1,1,2,2,9,9,10,10-octafluoro [2.2]paracyclophane (AF4-yne) undergoes an ene reaction with 1,3,5-cycloheptatriene, the adduct of which subsequently undergoes a further Diels–Alder reaction with a second equivalent of AF4-yne to give two stereoisomeric 2:1 adducts. A very small amount of the classic 1:1 Diels–Alder adduct also can be isolated from the reaction. Structure assignments of all products were determined by NMR through a series of H1–H1, H1–C13 one bond, and H1–C13 two and three bond correlation experiments as well as H1–H1 NOE experiments.
Balloon-Borne Hard X-Ray Imaging and Future Surveys

Abstract Several payloads for hard X-ray (20–600 keV) imaging with coded aperture telescopes have been developed for balloon flight observations of cosmic x-ray sources. We briefly review the characteristics of these, particularly the EXITE2 system. The recent NASA program to develop an extended long duration (100d) balloon flight capability employing super-pressure balloons would allow a qualitatively new hard x-ray imaging experiment: the Energetic X-ray Imaging Survey Telescope-Long Integration Time Experiment (EXIST-LITE). The longer continuous viewing times (per source) available from an LDB platform than from low earth orbit would enable both surveys and objectives complementary to the EXIST mission proposed for a MIDEX satellite. We summarize the scientific objectives of EXIST-LITE, a possible instrumentation approach incorporating a large area array of Cd-Zn-Te (CZT) detectors, and our program for the development and balloon flight testing of relatively thick (5mm) CZT detector arrays.
CYCLIC AND NON-CYCLIC ASPECTS OF EROSION

Geology has always centered around an effort to decipher records. Until 50 years ago these records were almost exclusively those of the constructional processes, conspicuously those made by sedimentation. Erosion has always been a great destroyer of records. Down to the last half century it was scarcely thought of as offering any compensation by recording a history of its own. Within that time its records have been analyzed with increasing insight. They are made rapidly and in great abundance but always at the surface. Hence, they are much like characters written on wax tablets, always destroyed to make way for newer letters. Only occasionally is a tablet discarded and buried and the writing thus preserved. Such a record is an unconformity. Erosional history mentions relatively few large facts of early geologic date, but of recent events the account is very full, even more so than the parallel account written in . . .
Synergistic methodologies for the synthesis of 3-aroyl-2-arylbenzo(b)thiophene-based selective estrogen receptor modulators. Two concise syntheses of raloxifene

Difunctionalized benzo[b]thiophene intermediates are prepared which allow fully independent elaboration of the 2-aryl position or the tether position of benzo[b]thiophene-based selective estrogen receptor modulators (SERMs). Two concise syntheses of the SERM raloxifene (Evista®) are presented.
A new stable compensator design for exact and approximate loop transfer recovery

Abstract In this paper, a new compensator structure for loop transfer recovery (LTR) is proposed. The proposed compensator (a) is open-loop stable, (b) guarantees closed-loop stability and above all (c) requires much smaller values of gain than the conventional observer-based controller for the same degree of loop-transfer recovery. The fact that the new compensator requires much smaller values of gain than the conventional controller results in several practical advantages, the most important among them being the reduction in controller band-width and freedom from the woes of saturation. The trade-off between the value of gain and the degree of loop transfer recovery as well as the bounds on singular values of sensitivity and complementary sensitivity functions is shown clearly. Both full and reduced order compensators for LTR when the design specifications are reflected either at the input or at the output point of the given plant are considered. Numerical examples illustrate the advantages of the new compensator structure. The new compensator structure is inspired by a careful and clear understanding of how loop transfer recovery occurs when conventional observer based controllers are used. To motivate and deduce our new compensator structure, a unified treatment of observer theory for LTR is presented. In the context of such a unification, some new results are also given.
Chiral SmA* materials for display applications?

— The potential of chiral SmA* materials for electro-optics applications exploiting the electroclinic effect will be explored. In this context, the nature of the de Vries smectics will be discussed, and characterization and application of some rare SmA* materials exhibiting a large and relatively temperature-insensitive electroclinic coefficient will be described.
A Variational Formulation, a Work-Energy Relation and Damping Mechanisms of Active Constrained Layer Treatments

The purposes of this paper are to formulate active constrained layer (ACL) damping treatments through a variational approach, to study the work-energy relation of ACL, and to identify damping mechanisms of ACL treatments. Application of the extended Hamilton principle to ACL results in the equations of motion of ACL and the charge equation of electrostatics for the piezoelectric constraining layer. The work-energy equation together with the charge equation shows that the power dissipated through the active damping is the product of the electric field and the axial velocity of the piezoelectric constraining layer at the boundaries. This unique feature suggests that a set-sensing and actuating piezoelectric constraining layer may be an appropriate design in dissipating vibration energy without causing instability. To identify the damping mechanisms, a sensitivity analysis shows that the effectiveness ofA CL damping primarily depends on the active and passive damping forces transmitted to the vibrating structure through the viscoelastic layer. The active damping force transmitted depends on the controller transfer function as well as a system parameter, termed active damping sensitivity factor, which depends entirely on the configuration of the passive constrained layer and the sensor. Finally, numerical results on ACL beams are obtained to illustrate the theoretical predictions above.
Reductive acylation of 2- and 3-nitropyrroles—efficient syntheses of pyrrolylamides and pyrrolylimides

Abstract An efficient one-pot synthesis of pyrrolylamides and pyrrolylimides is described under mild reaction conditions by the catalytic hydrogenation of 2- and 3-nitropyrroles.
Observations of anthropogenic cloud condensation nuclei

Abstract Cloud condensation nuclei (CCN) concentrations and spectral measurements obtained with the DRI instantaneous CCN spectrometer (Hudson, 1989, J. atmos. ocean. Technol.6, 1055–1065) are presented. Anthropogenic CCN production mechanisms were readily identifiable while natural CCN production could not be detected.
Vibration Suppression Using a Constrained Rate-Feedback-Threshold Control Strategy

A finite time, minimum force rate-feedback-threshold controller is developed to bring a system with or without known external disturbances back into an 'allowable' state bound in finite time. The disturbances are assumed to be expandable in terms of Fourier series. The optimal control is defined by a two-point boundary value problem coupled to a set of definite integral constraints. Quasi-closed form solutions are derived which replace the solution of the two-point boundary value problem and definite integral constraints with the solution of algebraic equations and the calculation of matrix exponentials. Examples are provided which demonstrate the threshold control technique and compare the quasi-closed form solutions with numerical and MACSYMA generated exact solutions.