cssi/SciSciGPT-SciSciNet huggingface dataset:
Integrated Reservoir Characterization Study of a Carbonate Ramp Reservoir: Seminole San Andres Unit, Gaines County, Texas

An integrated reservoir characterization of Seminole San Andres Unit was conducted using outcrop and subsurface data. The high frequency cycles and rock-fabric facies identified on outcrop and cores were used to correlate wireline logs. Reservoir and simulation models of the outcrop and a two-section area of the Seminole San Andres field were constructed using rock-fabric units within high-frequency cycles (HFC`s) as a geologic framework. Simulations were performed using these models to investigate critical factors affecting recovery. High-frequency cycles and rock-fabric units are the two critical scales for modeling shallow-water carbonate ramp reservoirs. Descriptions of rock-fabric facies stacked within high-frequency cycles provide the most accurate framework for constructing geologic and reservoir models because discrete petrophysical functions can be fit to rock fabrics and fluid flow can be approximated by the k{sub vh} ratios among rock-fabric flow units. Permeability is calculated using rock-fabric-specific transforms between interparticle porosity and permeability. Core analysis data showed that separate-vug porosity has a very strong effect on relative permeability and capillary pressure measurements. The stratigraphic features of carbonates can be observed in stochastic realizations only when they are constrained by rock-fabric flow units. Simulation results from these realizations are similar in recovery but different in production andmore » injection rates. Scale-up of permeability in the vertical direction was investigated in terms of the ratio of vertical permeability to horizontal permeability (k{sub vh}). This ratio decreases exponentially with the vertical grid-block size up to the average cycle size of 20 ft (6.1 m) and remains at a value of 0.06 for a grid-block size of more than 20 ft (>6.1 m), which is the average thickness of high-frequency cycles.« less
APL as a development tool for special-purpose processors

APL used as a programming language has been implemented in computing systems to provide time-sharing with remote terminals. Since the operative principles guiding the design of APL include simplicity and practicality of application, APL is extremely effective as a development aid for special purpose processors.
Welcome to the International Year of Chemistry

Chemical educators play a crucial role in ACS: as President of ACS, I call on educators to share their expertise in chemical education and their insight on how chemical scientists should and could be communicating with the general public. I urge everyone in the chemical sciences to play a pivotal role in the International Year of Chemistry 2011. The time to engage is now.
Secular Evolution in Mira Variable Pulsations

Stellar evolution theory predicts that asymptotic giant branch (AGB) stars undergo a series of short thermal pulses that significantly change their luminosity and mass on timescales of hundreds to thousands of years. These pulses are confirmed observationally by the existence of the short-lived radioisotope technetium in the spectra of some of these stars, but other observational consequences of thermal pulses are subtle and may only be detected over many years of observations. Secular changes in these stars resulting from thermal pulses can be detected as measurable changes in period if the star is undergoing Mira pulsations. It is known that a small fraction of Mira variables exhibit large secular period changes, and the detection of these changes among a larger sample of stars could therefore be useful in evolutionary studies of these stars. The American Association of Variable Star Observers (AAVSO) International Database currently contains visual data for over 1500 Mira variables. Light curves for these stars span nearly a century in some cases, making it possible to study the secular evolution of the pulsation behavior on these timescales. In this paper we present the results of our study of period change in 547 Mira variables using data from the AAVSO. We use wavelet analysis to measure the period changes in individual Mira stars over the span of available data. By making linear fits to the period versus time measurements, we determine the average rates of period change, d ln P/dt, for each of these stars. We find nonzero d ln P/dt at the 2 σ significance level in 57 of the 547 stars, at the 3 σ level in 21 stars, and at the level of 6 σ or greater in eight stars. The latter eight stars have been previously noted in the literature, and our derived rates of period change largely agree with published values. The largest and most statistically significant d ln P/dt are consistent with the rates of period change expected during thermal pulses on the AGB. A number of other stars exhibit nonmonotonic period change on decades-long timescales, the cause of which is not yet known. In the majority of stars, the period variations are smaller than our detection threshold, meaning the available data are not sufficient to unambiguously measure slow evolutionary changes in the pulsation period. It is unlikely that more stars with large period changes will be found among heretofore well-observed Mira stars in the short term, but continued monitoring of these and other Mira stars may reveal new and serendipitous candidates in the future.
Structure sensitivity of methane oxidation over platinum and palladium

Abstract A series of supported platinum and palladium catalysts were tested for methane oxidation at 260 to 370°C, 50 Torr methane, 110 Torr oxygen, 900 Torr helium, and conversions below 2%. The intrinsic rate varies by more than 5000 from the least active to the most active catalyst, indicating that the reaction is structure sensitive. The catalytic activity of platinum depends on the distribution of the metal between a dispersed and a crystalline phase. These two phases are distinguished by absorbances at 2068 and 2080 cm−1, respectively, in the infrared spectrum of adsorbed carbon monoxide. The catalytic activity of palladium depends on the metal particle size. For the different classes of catalysts, the mean steady state turnover frequency (TOF) at 335°C and the mean apparent activation energy (Ea) are as follows: dispersed phase of platinum, TOF = 0.005 s−1 and Ea = 36 kcal/mole; crystalline phase of platinum, TOF = 0.08 s−1 and Ea = 28 kcal/mole; small particles of palladium, TOF = 0.02 s−1 and Ea = 27 kcal/mole; and large particles of palladium, TOF = 1.3 s−1 and Ea = 29 kcal/mole. The structure sensitivity may be explained by differences in the reactivity of the adsorbed oxygen on these metal surfaces.
Nuclear magnetic resonance spectroscopy: an experimentally accessible paradigm for quantum computing

Abstract We present experimental results which demonstrate that nuclear magnetic resonance spectroscopy is capable of emulating many of the capabilities of quantum computers, including unitary evolution and coherent superpositions, but without attendant wave-function collapse. This emulation is made possible by two facts. The first is that the spin active nuclei in each molecule of a liquid sample are largely isolated from the spins in all other molecules, so that each molecule is effectively an independent quantum computer. The second is the existence of a manifold of statistical spin states, called pseudo-pure states, whose transformation properties are identical to those of true pure states. These facts enable us to operate on coherent superpositions over the spins in each molecule using full quantum parallelism, and to combine the results into deterministic macroscopic observables via thermodynamic averaging. We call a device based on these principles an ensemble quantum computer . Our results show that it is indeed possible to prepare a pseudo-pure state in a macroscopic liquid sample under ambient conditions, to transform it into a coherent superposition, to apply elementary quantum logic gates to this superposition, and to convert it into the equivalent of an entangled state. Specifically, we have: • - implemented the quantum XOR gate in two different ways, one using Pound-Overhauser double resonance, and the other using a spin-coherence double resonance pulse sequence; • - demonstrated that the square root of the Pound-Overhauser XOR corresponds to a conditional rotation, thus confirming that NMR spectroscopy provides a universal set of gates; • - devised a spin-coherence implementation of the Toffoli gate, and confirmed that it transforms the equilibrium state of a four-spin system as expected; • - used standard gradient-pulse techniques in NMR to equalize all but one of the populations in a two-spin system, thus obtaining the basic pseudo-pure state that corresponds to |00〉; • - validated that one can identify which basic pseudo-pure state is present by transforming it into one-spin superpositions, whose associated spectra jointly characterize the state; • - applied the spin-coherence XOR gate to a one-spin superposition to create an entangled state, and confirmed its existence by detecting the associated double-quantum coherence via gradient-echo methods.
Output targets, the soft budget constraint and the firm under central planning

Abstract The paper considers the case of an expected profit maximizing firm which has an output target imposed on it by central planners and which may receive (partial) bailouts if its operating profit is negative. The model contains several sources of uncertainty. The paper compares the amounts of input use in the pure bailout case, the pure output target case, the bailout-with-output-target-case and the standard competitive case both theoretically and with numerical experiments.
The degeneration formula for logarithmic expanded degenerations

We define a notion of logarithmic stable maps based on Bumsig Kim's construction. Then we prove a degeneration formula under this setting by applying the method develeoped by Dan Abramovich and Barbara Fantechi for transversal maps.
Chemistry of 1,1,4,4-tetramethyl-1,4-diazonia-2,5-diboratacyclohexane

Abstract Reactivity of 1,1,4,4-tetramethyl-1,4-diazonia-2,5-diboratacyclohexane toward a variety of substances was surveyed. The halogenation to 2-iodo and 2,5-diiodo derivatives is of particular interest because subsequent iodide displacements allow substitutional elaboration of the ring system. A novel cleavage reaction of esters by the 2-iodo derivative gives stable, neutral, oxygen-bonded derivatives.
Crustal Heat Production and the Thermal Evolution of Mars

The chemical compositions of soils and rocks from the Pathfinder site and Phobos-2 orbital gamma-ray spectroscopy indicate that the Martian crust has a bulk composition equivalent to large-ion lithophile (LIL) and heat-producing element (HPE) enriched basalt, with a potassium content of about 0.5%. A variety of radiogenic isotopic data also suggest that separation of LIL-enriched crustal and depleted mantle reservoirs took place very early in Martian history (greater than 4.0 Ga). Accordingly, if the enriched Martian crust is greater than 30km thick it is likely that a large fraction (up to at least 50%) of the heat-producing elements in Mars was transferred into the crust very early in the planet's history. This would greatly diminish the possibility of early widespread melting of the Martian mantle.
Electromagnetic Scattering from a Finite Cylinder with Complex Permittivity

The scattering of electromagnetic radiation from a finite conducting cylinder with complex permittivity at an arbitrary orientation was analyzed using a first approximation to the iteration technique for the integro-differential equation first developed by Shifrin and later modified by Acquista. The classical Kerker solution for a simple infinite dielectric cylinder was extended to a more physically realistic solution accounting for a finite length cylinder with complex permittivity by a modified Drude conductivity approach. The diameter of the cylinder is on the order of one wavelength of the incident radiation. The lowest order approximation to the internal field solution for the iteration process is a function of the effective polarized electric field inside the cylinder and the polarization matrix of the scattering medium. The polarization matrix of the cylinder is determined from the electrostatic solution for a finite cylinder in a constant electric field, and is a function of the length to diameter...
Distributed algorithms for ultrasparse spanners and linear size skeletons

We present efficient algorithms for computing very sparse low distortion spanners in distributed networks and prove some non-trivial lower bounds on the tradeoff between time, sparseness, and distortion. All of our algorithms assume a synchronized distributed network, where relatively short messages may be communicated in each time step. Our first result is a fast distributed algorithm for finding an $${O(2^{{\rm log}^{*} n} {\rm log} n)}$$ -spanner with size O(n). Besides being nearly optimal in time and distortion, this algorithm appears to be the first that constructs an O(n)-size skeleton without requiring unbounded length messages or time proportional to the diameter of the network. Our second result is a new class of efficiently constructible (α, β)-spanners called Fibonacci spanners whose distortion improves with the distance being approximated. At their sparsest Fibonacci spanners can have nearly linear size, namely $${O(n(\log \log n)^{\phi})}$$ , where $${\phi = (1 + \sqrt{5})/2}$$ is the golden ratio. As the distance increases the multiplicative distortion of a Fibonacci spanner passes through four discrete stages, moving from logarithmic to log-logarithmic, then into a period where it is constant, tending to 3, followed by another period tending to 1. On the lower bound side we prove that many recent sequential spanner constructions have no efficient counterparts in distributed networks, even if the desired distortion only needs to be achieved on the average or for a tiny fraction of the vertices. In particular, any distance preservers, purely additive spanners, or spanners with sublinear additive distortion must either be very dense, slow to construct, or have very weak guarantees on distortion.
Ultrafast magnetization dynamics studies using an x-ray streak camera

The spin dynamics of ferromagnetic thin films following an excitation by ultrashort 100-fs near-infrared laser pulses has recently received much attention. Here, a new approach is described using x-ray magnetic circular dichroism to investigate demagnetization and magnetization switching processes. In contrast to magneto-optical measurements, x-ray dichroism has the advantage of determining separately the spin and orbital components of the magnetic moment. The relatively low time resolution of the synchrotron x-ray probe pulses (80 ps FWHM) is overcome by employing an ultrafast x-ray streak camera with a time resolution of < 1 ps. A description of the experimental setup including the x-ray/IR laser pulse synchronization and the streak camera is given.
Interfacial reactions in ceramic membrane reactors for syngas production

Ceramic membrane reactors based on Mixed Ionic and Electronic Conductors (MIEC) show great promise for the production of syngas from natural gas. Here, the principles behind this technology are briefly reviewed. By comparing these reactors to solid oxide fuel cells, for which the operating principles are nearly identical, we argue that surface reactions on the membrane frequently limit the performance of these devices. Concepts for increasing surface reaction rates and incorporating catalysts onto the surface are discussed.
Cost-based adaptive planning for on-road driving

This paper presents a cost-based adaptive planning agent that is operating at the route-segment level of a deliberative hierarchical planning system for autonomous road driving. At this level, the planning agent is responsible for developing fundamental driving maneuvers that allow a vehicle to travel safely amongst moving and stationary objects. This is facilitated through the use of an incrementally expanded planning graph that provides the ability to implement a dynamic cost function. This cost function varies to comply with particular road, regional, or event driven situations, and when coupled with the incremental graph expansion allows for the agent to implement hard and soft system constraints.
Pyridylalanine (Pal)-Peptide Catalyzed Enantioselective Allenoate Additions to N-Acyl Imines

An amine-catalyzed reaction has been discovered that couples alpha-allenic esters with N-acyl imines in good to excellent yields (up to 88%). Extension of this methodology from the study of achiral pyridine-based catalysis to chiral peptide-based scaffolds is presented. The approach culminated in the identification of a tetrameric peptide sequence containing an embedded pyridylalanine (Pal) residue as an efficient asymmetric catalyst for enantioselective coupling reactions. The unique allenic products are obtained with enantiomer ratios of up to approximately 95:5 (up to >98:2 following recrystallization).
The Dalkon Shield: A clinical evaluation☆

Abstract This prospective study was undertaken in order to provide a further evaluation of the effectiveness of the Dalkon Shield. In a series of 348 nulliparous and 978 multiparous patients, 10 pregnancies and 10 expulsions occurred. Shields were removed in 81 instances. The cumulative Life Table rates after 9 months for expulsion and pregnancy were 1.02% and 1.06%, respectively. The medical removal rate was 9.36%. No perforations occurred.
Long Monotone Paths in Line Arrangements

We show how to construct an arrangement of n lines having a monotone path of length Ω(n2 – (d/\sqrt{log n})), where d > 0 is some constant, and thus nearly settle the long standing question on monotone path length in line arrangements.
Testicular lymphoma is associated with a high incidence of extranodal recurrence

BACKGROUND Testicular lymphoma is a rare extranodal presentation of non-Hodgkin lymphoma. The authors report long term follow-up information regarding a group of patients with testicular lymphoma evaluated at the Mayo Clinic and describe the outcome with special attention to patterns of recurrence. METHODS The medical records of patients with testicular lymphoma seen at the Mayo Clinic between January 1970 and March 1993 were reviewed. Patients were included if they had evidence of testicular involvement at the time of diagnosis of lymphoma. Pathology specimens were reviewed for confirmation of diagnosis. RESULTS Sixty-two patients with a diagnosis of testicular lymphoma were identified. Their median age was 68 years, and 60 patients underwent orchiectomy as the initial therapeutic and diagnostic procedure. Most of patients (79%) had localized or regional disease at the time of presentation. Other treatment modalities after diagnosis included radiotherapy (37%), combination chemotherapy (37%), and combination chemotherapy and radiotherapy (16%). Although 88% of patients had no residual disease after primary treatment, 80% subsequently experienced disease recurrence. There was no significant difference in the rate of recurrence, including Ann Arbor Stage I disease. Treatment did not appear to affect the recurrence rate. At a median follow-up of 2.7 years, 60% of patients had died of disease. Late recurrences were observed, and there appeared to be no plateau in the disease free survival curve. In half (51%) of the patients with disease recurrence, only extranodal locations were involved. Thirteen patients experienced recurrence in the central nervous system, 11 of whom had parenchymal lesions. In 8 of these 13 patients, the central nervous system was an isolated site of disease recurrence. CONCLUSIONS Testicular lymphoma is a unique and aggressive extranodal non-Hodgkin lymphoma. Better treatment strategies are needed to prevent recurrences. The risk of extranodal recurrence is high, especially in the central nervous system. Cancer 2000;88:154–61. © 2000 American Cancer Society.
Oscillation of Fourier Integrals with a spectral gap

Abstract Suppose that for a real function f on the real line, the support of its Fourier transform is disjoint from an interval (−a,a). We prove the conjecture of B. Logan that under these assumptions the lower density of the sequence of sign changes of f is at least a/π. This result assumes a growth condition: f should be integrable with respect to a non-quasianalytic weight. We show that this growth restriction is best possible (for sufficiently regular weights). For functions and distributions f of faster growth, Logan's conjecture does not hold, and for this class we prove a weaker result estimating the number of sign changes from below in terms of an averaged lower density.
Completely diastereoselective radical reactions using arenechromium tricarbonyl complexes

Reaction of chromium tricarbonyl complexed aryl aldehydes and ketones with samarium(II) iodide and methyl acrylate results in formation of cyclic lactones as single diastereomers. Complete diastereoselectivity is demonstrated with aldehydes and ketones α or β to the aromatic ring with radical coupling directed anti to the chromium tricarbonyl moiety.
Silver-mediated trifluoromethylation of arenes using TMSCF3.

The silver-mediated C–H trifluoromethylation of aromatic substrates using TMSCF3 is described. The development, optimization, and scope of these transformations are reported. AgCF3 intermediates are proposed.
Design, Fabrication And Performance Of Two Grazing Incidence Telescopes For Celestial Extreme Ultraviolet Astronomy

The design and performance of grazing incidence telescopes for celestial extreme ultraviolet (EUV) astronomy are described. The telescopes basically consist of a star tracker, collimator, grazing incidence mirror, vacuum box lid, vacuum housing, filters, a ranicon detector, an electronics box, and an aspect camera. For the survey mirror a Wolter-Schwarzschild type II configuration was selected. Diamond-turning was used for mirror fabrication, a technique which machines surfaces to the order of 10 microns over the required dimensions. The design of the EUV spectrometer is discussed with particular reference to the optics for a primarily spectroscopic application and the fabrication of the f/10 optics.
Thermal Properties of Centaurs Asbolus and Chiron

We have measured the mid-infrared thermal continua from two Centaurs, inactive (8405) Asbolus and active 95P = (2060) Chiron, and have constrained their geometric albedos, p, and effective radii, R, with the standard thermal model for slow rotators. These are the first such measurements of Asbolus; we find R = 33 ± 2 km and p = 0.12 ± 0.03. This albedo is higher than all of those confidently known for active cometary nuclei. The thermal inertia is comparable to or lower than those of main-belt asteroids, the Moon, and Chiron; lower than those of the icy Galilean satellites; and much lower than those of near-Earth asteroids. For Chiron, we find R = 74 ± 4 km and p = 0.17 ± 0.02. While this albedo is consistent with the established value, previous radiometry by others implied a larger radius. This discrepancy may be partially due to a varying infrared dust coma, but all data sets have too low signal to be sure. Four Centaur albedos (out of about 30 objects) are now known. They show a diversity greater than that of the active comets, to which they are evolutionarily linked.
A Three-Part Study to Investigate the Incidence and Potential Etiologies of Tadalafil-Associated Back Pain or Myalgia

The potential mechanisms underlying back pain and/or myalgia experienced by men taking tadalafil were investigated. An integrated analysis of 10 placebo-controlled tadalafil clinical trials (N=1846) showed that the incidence of back pain and/or myalgia was 9.4% in patients receiving tadalafil 10 mg (N=394), 8.3% in patients receiving tadalafil 20 mg (N=883) and 3.7% in placebo-treated patients (N=569). One (0.3%) patient receiving tadalafil 10 mg, six (0.7%) patients receiving tadalafil 20 mg, and no patients receiving placebo discontinued treatment due to back pain and/or myalgia. In a prospective study in healthy volunteers, no substantial changes were observed in laboratory markers indicative of inflammation or muscle damage, and tadalafil did not affect renal plasma flow nor produce lumbar or gluteal myositis by positron emission tomography scan or magnetic resonance imaging. Although the mechanism of back pain and/or myalgia remains unknown, these events appear to be self-limiting and a general effect of phosphodiesterase 5 inhibition.
Flop transitions in cuprate and color superconductors: From SO(5) to SO(10) unification?

The phase diagrams of cuprate superconductors and of QCD at non-zero baryon chemical potential are qualitatively similar. The Neel phase of the cuprates corresponds to the chirally broken phase of QCD, and the high-temperature superconducting phase corresponds to the color superconducting phase. In the SO(5) theory for the cuprates the SO(3)s spin rotational symmetry and the U(1)em gauge symmetry of electromagnetism are dynamically unified. This suggests that the SU(2)L ⊗ SU(2)R ⊗ U(1)B chiral symmetry of QCD and the SU(3)c color gauge symmetry may get unified to SO(10). Dynamical enhancement of symmetry from SO(2)s ⊗ Z(2) to SO(3)s is known to occur in anisotropic antiferromagnets. In these systems the staggered magnetization flops from an easy 3-axis into the 12-plane at a critical value of the external magnetic field. Similarly, the phase transitions in the SO(5) and SO(10) models are flop transitions of a “superspin”. Despite this fact, a renormalization group flow analysis in 4 — ϵ dimensions indicates that a point with full SO(5) or SO(10) symmetry exists neither in the cuprates nor in QCD.
Mesoionic isoxazolo[2,3-a]pyrimidinediones and 1,3,4-oxadiazolo[3,2-a]pyrimidinediones as potential adenosine antagonists

Several derivatives of two novel mesoionic ring systems, i.e., isoxazolo[2,3-a]pyrimidinedione and 1,3,4-oxadiazolo[3,2-a]pyrimidinedione, were prepared for evaluation as adenosine antagonists. Whereas both ring systems are relatively stable when the 6-position (i.e., that position corresponding to the purine 1-position) is substituted by an alkyl group, neither ring system is stable when this position is unsubstituted. An example of a 6-unsubstituted non-mesoionic isoxazolopyrimidinedione exhibited similar behavior. As adenosine antagonists, the mesoionic compounds were found to be less potent than their previously evaluated mesoionic thiadiazolo[3,2-a]pyrimidinedione counterparts.
Transitional Flow Separation Upstream of a Compression Corner

Experimental measurements of transitional separation, caused by a compression corner on a two-dimensional model were analyzed in an attempt to correlate the extent of separation. A previously published correlation, based on the wetted length Reynolds number at the separation point, failed when the plate length alone was changed. A re-examination of the data showed that the true correlating parameter was the freestream unit Reynolds number. Examination of the equation of motion applicable to the dividing streamline between the boundary layer and the recirculating flow suggested that the unit Reynolds number determined the growth of turbulence in the transition region. The separated flow transition could then be related to attached-flow , boundary-layer transition on a plate, with the same external flow condition. A new correlation showed that the length of transitional separation was a function only of freestream Mach number, inviscid flow pressure rise at the compression corner, and the length over which transition develops in an attached-flow, flat-plate boundary layer with the same external flow conditions.
Hybrid Airfoil Design Procedure Validation for Full-Scale Ice Accretion Simulation

This paper presents results of the ice accretion tests performed to validate the hybrid airfoil design method. The hybrid airfoil design method was developed to facilitate the design of hybrid airfoils with full-scale leading edges and redesigned aft sections that simulate full-scale ice accretion simulation for a given ® range. Icing tests in the NASA Lewis Icing Research Tunnel were conducted with test conditions representative of e ight. A twodimensional half-scale hybrid airfoil was designed and built with a 20% plain e ap and a 5% upper and 20% lower full-scale leading-edge surface of a modern business jet wing section. This paper presents a comparison between the ice shapes accreted on the business jet and hybrid airfoil models during the tests. The test results show that ice accretion simulation could be predicted in terms of the droplet-impingement simulation alone and cone rm the assumption that the leading-edge ice accretion will be the same for the full-scale and hybrid airfoils if icing cloud properties, droplet impingement, local leading-edge e owe eld, model surface characteristics, and geometry are held constant. This assumption was found to be valid when tested under the most severe conditions of glaze ice accretion over a large time interval. A comparison between the actual ice shapes and those predicted by LEWICE 1.6 under similar conditions is also shown. The results suggest that the hybrid airfoil design method has signie cant application potential for tests where leading-edge ice accretion is desired because it provides an alternative to the myriad of issues related to ice accretion scaling.
THE QUANTUM CONTENT OF THE NORMAL SURFACES IN A THREE-MANIFOLD

The formula for the Turaev–Viro invariant of a three-manifold depends on a complex parameter t. When t is not a root of unity, the formula becomes an infinite sum. This paper analyzes convergence of this sum when t does not lie on the unit circle, in the presence of an efficient triangulation of the three-manifold. The terms of the sum can be indexed by surfaces lying in the three-manifold. The contribution of a surface is largest when the surface is normal and when its genus is the lowest.
Synthesis of 2-amino-3-fluoroacrylic acid containing peptides.

Peptides containing (E)- and (Z)-3-fluorodehydroalanine have been prepared from serine via a fluoro-Pummerer rearrangement. The resulting electrophilic moieties may be useful affinity labels for the identification of the targets of dehydroamino acid containing natural products that act by covalent mechanisms.
On non-uniform black branes

Certain black branes are unstable towards fluctuations that lead to non-uniform mass distributions. We study static, non-uniform solutions that differ only perturbatively from uniform ones. For uncharged black strings in five dimensions, we find evidence of a first-order transition from uniform to non-uniform solutions.
Maximal Galois Group of L-Functions of Elliptic Curves

We give a quantitative version of a result due to Katz about L-functions of elliptic curves over function fields over finite fields. Roughly speaking, Katz's theorem states that, on average over a suitably chosen algebraic family, the L-function of an elliptic curve over a function field becomes “as irreducible as possible” when seen as a polynomial with rational coefficients, as the cardinality of the field of constants grows. A quantitative refinement is obtained as a corollary of our main result, which gives an estimate for the proportion of elliptic curves studied whose L-functions have “big” Galois group. To do so, we make use of Kowalski's idea to apply large sieve methods in algebro-geometric contexts. Besides large sieve techniques, we use results of Hall on finite orthogonal monodromy and previous work of the author on orthogonal groups over finite fields.
Likelihoods for fixed rank nomination networks

Many studies that gather social network data use survey methods that lead to censored, missing, or otherwise incomplete information. For example, the popular fixed rank nomination (FRN) scheme, often used in studies of schools and businesses, asks study participants to nominate and rank at most a small number of contacts or friends, leaving the existence of other relations uncertain. However, most statistical models are formulated in terms of completely observed binary networks. Statistical analyses of FRN data with such models ignore the censored and ranked nature of the data and could potentially result in misleading statistical inference. To investigate this possibility, we compare Bayesian parameter estimates obtained from a likelihood for complete binary networks with those obtained from likelihoods that are derived from the FRN scheme, and therefore accommodate the ranked and censored nature of the data. We show analytically and via simulation that the binary likelihood can provide misleading inference, particularly for certain model parameters that relate network ties to characteristics of individuals and pairs of individuals. We also compare these different likelihoods in a data analysis of several adolescent social networks. For some of these networks, the parameter estimates from the binary and FRN likelihoods lead to different conclusions, indicating the importance of analyzing FRN data with a method that accounts for the FRN survey design.
Modeling tax evasion with genetic algorithms

The U.S. tax gap is estimated to exceed $450 billion, most of which arises from non-compliance on the part of individual taxpayers (GAO 2012; IRS 2006). Much is hidden in innovative tax shelters combining multiple business structures such as partnerships, trusts, and S-corporations into complex transaction networks designed to reduce and obscure the true tax liabilities of their individual shareholders. One known gambit employed by these shelters is to offset real gains in one part of a portfolio by creating artificial capital losses elsewhere through the mechanism of “inflated basis” (TaxAnalysts 2005), a process made easier by the relatively flexible set of rules surrounding “pass-through” entities such as partnerships (IRS 2009). The ability to anticipate the likely forms of emerging evasion schemes would help auditors develop more efficient methods of reducing the tax gap. To this end, we have developed a prototype evolutionary algorithm designed to generate potential schemes of the inflated basis type described above. The algorithm takes as inputs a collection of asset types and tax entities, together with a rule-set governing asset exchanges between these entities. The schemes produced by the algorithm consist of sequences of transactions within an ownership network of tax entities. Schemes are ranked according to a “fitness function” (Goldberg in Genetic algorithms in search, optimization, and machine learning. Addison-Wesley, Boston, 1989); the very best schemes are those that afford the highest reduction in tax liability while incurring the lowest expected penalty.
Interferometric observation of cosmic microwave background anisotropies

We present a formalism for analyzing interferometric observations of the cosmic microwave background anisotropy and polarization. The formalism is based on the l-space expansion of the angular power spectrum favored in recent years. Explicit discussions of maximum likelihood analysis, power spectrum reconstruction, parameter estimation, imaging, and polarization are given. As an example, several calculations for the Degree Angular Scale Interferometer and Cosmic Background Interferometer experiments are presented.
MICROPROCESSOR CONTROLLED FORCE ACTUATOR.

The mechanical and electrical design of a prototype force actuator for vibration control of large space structures (LSS) is described. The force actuator is an electromagnetic system that produces a force by reacting against a proof-mass. The actuator has two colocated sensors, a digital microcontroller, and a power amplifier. The total weight of actuator is .998 kg. The actuator has a steady state force output of approximately 2.75 N from approximately 2 Hz to well beyond 1000 Hz.
ILLIQUIDITY RISK, PROJECT CHARACTERISTICS, AND THE OPTIMAL MATURITY OF CORPORATE DEBT

I derive the optimal maturity period for corporate debt used to finance a specific project, when costly financial distress is triggered by the inability to meet coupon obligations. My model predicts a negative relation between bond risk and maturity, and it explains why high-grade bonds show greater maturity dispersion than low-grade bonds, as observed in U.S. corporate bond markets. The major determinant of bond maturity is project duration for low-risk bonds and project risk for high-risk bonds. Other determinants of bond maturity are debt burden, reorganization costs, corporate tax rate, interest rate, and project growth rate.
Joint equalization and decoding for nonlinear two-dimensional intersymbol interference channels

An algorithm that performs joint equalization and decoding for channels with nonlinear two-dimensional intersymbol interference is presented. The algorithm performs sum-product message-passing on a factor graph that represents the underlying system. The two-dimensional optical storage (Two-DOS) technology is an example of a system with nonlinear two-dimensional intersymbol interference. Simulations for the nonlinear channel model of TwoDOS show significant improvement in performance over uncoded performance. Noise tolerance thresholds for the TwoDOS channel computed using density evolution are also presented
Geometric Hodge star operator with applications to the theorems of Gauss and Green

The classical divergence theorem for an -chainlet. When combined with the general Stokes' theorem ([H1, H2]) \[\int_{\partial A} \omega = \int_A d \omega\] this result yields optimal and concise forms of Gauss' divergence theorem \[\int_{\star \partial A}\omega = (-1)^{(k)(n-k)} \int_A d\star \omega\] and Green's curl theorem \[\int_{\partial A} \omega = \int_{\star A} \star d\omega.\]
Compressible turbulence measurements in a high-speed high-Reynolds-number mixing layer

To assess the significant physics associated with compressible turbulence, extensive multiple overheat cross/normal-wire, shadowgraph image processing and conventional probe surveys were obtained in a two-dimensional, supersonic, free mixing layer, which consisted of Mach 1.8 air (Re/m=7×10 6 ) injected tangentially into a Mach 4.0 freestream (Re/m=67×10 6 ). A turbulence transformation was developed that allowed direct measurement of the total Reynolds shear stress. Profiles of three-dimensional turbulent shear, apparent mass, and heat flux data were acquired.
Arylation of Rhodium(II) Azavinyl Carbenes with Boronic Acids

A highly efficient and stereoselective arylation of in situ-generated azavinyl carbenes affording 2,2-diaryl enamines at ambient temperatures has been developed. These transition-metal carbenes are directly produced from readily available and stable 1-sulfonyl-1,2,3-triazoles in the presence of a rhodium carboxylate catalyst. In several cases, the enamines generated in this reaction can be cyclized into substituted indoles employing copper catalysis.
A Comparison and Expansion of the Bases Used for Evaluating Salespeople's Performance

Evaluating the performance of salespeople is more important today than ever before because of substantial changes in technology, team selling, services selling, and perspectives on evaluations. Therefore, in this study, we collected data from sales managers in a wide variety of industries to assess the effect of these changes on the evaluation bases managers use. Findings indicate the importance of relationships and salesperson efficiency on the value of salespeople to the firm, the effect of a growing service sector, and the effect of team selling on performance and evaluation. Finally, we discuss the increased role of customer evaluations and provide implications and suggestions for further research.
Supersonic Turbine Design and Performance

Methods for designing supersonic stator and rotor blading corrected for boundary layer displacement thickness are summarized. Computer programs based on these methods have been reported in NASA publications. Analytical blader blading of this type are presente and design limitations resulting from consideration of flow separation and supersonic srting are discussed. In additiona summary of the experimental perormance of a single-stage turbine designed by these methods is given.
Enflurane, halothane and isoflurane do not inhibit angiotensin converting enzyme activity.

We studied the effect of halothane, enflurane and isoflurane on angiotensin converting enzyme (ACE) activity using [3H].benzoyl-phenylalanyl-alanyl-proline (BPAP) as a substrate. Isolated rabbit lungs were perfused in a recirculating system in vitro with BPAP in Krebs-Ringer solution. The rate of metabolism and per cent metabolism were determined before and after treatment for 30 minutes with four MAC multiples of enflurane, halothane or isoflurane. The effects of the anaesthetics on ACE activity were determined by calculating per cent inhibition of metabolism of BPAP using data from the control and test period for each lung. The average metabolism of BPAP at 15 minutes during the control period was 76.5 per cent (± 1.92 SEM). No anaesthetic significantly inhibited metabolism of BPAP. Likewise there was no effect on BPAP first order kinetics. Although potent in. halation anaesthetics may alter the renin-angiotensinaldosterone axis, the), do not affect this crucial step.
The Wave Equation with Computable Initial Data Whose Unique Solution Is Nowhere Computable

We give a rough statement of the main result. Let D be a compact subset of ℝ3× ℝ. The propagation u(x, y, z, t) of a wave can be noncomputable in any neighborhood of any point of D even though the initial conditions which determine the wave propagation uniquely are computable. A precise statement of the result appears below.
Pulse Shaping of Octave Spanning Femtosecond Laser Pulses

Phase characterization, correction and shaping of an ultra-broad-bandwidth femtosecond laser were achieved using a grating-based pulse shaper. By using MIIPS, the compensated pulses generated a second harmonic spectrum spanning over 12,260 cm-1.
Enhancement of Thermoelectric Performance of n-Type PbSe by Cr Doping with Optimized Carrier Concentration

Ti, V, Cr, Nb, and Mo are found to be effective at increasing the Seebeck coefficient and power factor of n-type PbSe at temperatures below 600 K. It is found that the higher Seebeck coefficients and power factors are due to higher Hall mobility ≈1000 cm2 V−1s−1 at lower carrier concentration. A larger average ZT value (relevant for applications) can be obtained by an optimization of carrier concentration to ≈1018–1019 cm−3. Even though the highest room temperature power factor ≈3.3 × 10−3 W m−1 K−2 is found in 1 at% Mo-doped PbSe, the highest ZT is achieved in Cr-doped PbSe. Combined with the lower thermal conductivity, ZT is improved to ≈0.4 at room temperature and peak ZTs of ≈1.0 are observed at ≈573 K for Pb0.9925Cr0.0075Se and ≈673 K for Pb0.995Cr0.005Se. The calculated device efficiency of Pb0.995Cr0.005Se is as high as ≈12.5% with cold side 300 K and hot side 873 K, higher than those of all the n-type PbSe materials reported in the literature.
Contagion Equilibria in a Monetary Model

The model of Lagos and Wright [9] alters the meeting friction of the typical search model of money to obtain degeneracy in equilibrium holdings and enhance analytical tractability. It introduces a round of Walrasian ‘centralized’ trading after each round of bilateral random ‘decentralized’ trading. The basic premise is that, although the population meets repeatedly in the centralized market, anonymity and random pairings are frictions sufficient for money to be essential (see [9, p. 466] or [11, p. 175]; for the essentiality see [6, 8]).
RADIATION HEAT TRANSFER AND SOOT THERMOPHORESIS IN LAMINAR TUBE FLOW

ABSTRACT The transport of soot particles suspended in laminar hot gas, flowing in a tube, has been modeled numerically and studied parametrically. The objective was to assess the coupled effects of radiation heat transfer and thermophoresis on the transport of monodisperse, as well as polydisperse soot particles. The wall material was assumed to be transparent to radiation for wavelengths shorter than a threshold wavelength at high temperatures, an essential property of high temperature-resistive materials. The results indicated that, as a consequence of strongly coupled thermal radiation transport and thermophoresis, a radially nonuniform temperature profile develops as the distance from the tube inlet is increased, leading to the development of sharp, nonuniform radial soot concentration profiles. The particles tend to accumulate in the vicinity of the point of inflection of the radial temperature profiles. The pace of the development of the nonuniform radial temperature and soot concentration profiles ...
Recent high-latitude resurfacing by a climate-related latitude-dependent mantle: Constraining age of emplacement from counts of small craters

Abstract A surficial mantling deposit composed of ice and dust blankets Mars at high and mid-latitudes. The emplacement and evolution of this deposit is thought to be driven by astronomical forcings akin to, but more extreme than, those responsible for Earth’s ice ages. In order to test predictions about the age of this deposit, more than 60,000 superposed craters were counted on terrain near the rims of 16 young craters using sub-meter resolution images. A chronology for the deposition of the latitude-dependent mantle is revealed by these data and shows that: (1) the overall age and age trend of mantling deposits is consistent with first-order control by obliquity variations; (2) mantling processes are substantially younger than some equatorial rayed craters which have crater retention ages of ∼20–30 million years; (3) the mantle is younger by a factor of two to three at polar latitudes compared to its furthest equatorial extent (∼30°). Additionally, these crater counts confirm the suitability of small craters in geological analyses of youthful planetary surfaces and provide new data on the density of meters-scale craters superposed on deposits of geologically-recent craters.
Public policies, pressure groups, and dead weight costs

Abstract This paper presents a model of competition among special interest groups for political influence. Each active group exerts pressure to affect its taxes and subsidies, where activities of different groups are related by the equality between total tax collections and total tax subsidies. The dead weight costs and benefits of taxes and subsidies play a major role in our model. An increase in the dead weight cost of taxation encourages pressure by taxpayers, while an increase in the dead weight costs of subsidies discourages pressure by recipients. Various applications of the analysis are discussed.
On the minimax principle and zero-sum stochastic differential games

The problem of prior and delayed commitment in zero-sum stochastic differential games is discussed. A new formulation and solution based on the delayed-commitment model is derived and its significant implications to stochastic games and control are considered.
Probing five-dimensional black holes with D-branes

We consider a one-brane probe in the presence of a five-dimensional black hole in the classical limit. The velocity-dependent force on a slowly-moving probe is characterized by a metric on the probe moduli space. This metric is computed for large black holes using low-energy supergravity, and for small black holes using D-brane gauge theory. The results are compared.