cssi/SciSciGPT-SciSciNet huggingface dataset:
Orthophosphates and Diphosphates Containing Zinc and Copper and Zinc and Cobalt

Solid solutions of diphosphates of zinc and copper and of zinc and cobalt were synthesized from mixtures of pure diphosphates at temperatures up to 1000°C. Their X-ray diffractometry patterns varied continuously from one end member to the other. Solid solutions of orthophosphates of composition Zn3−xCox(PO4)2, with x= 0.4–1.6, were formed at temperatures up to 950°C; all exhibited the structure of γ-Zn3(PO4)2. Solid solutions of orthophosphates of composition Zn3−xCux(PO4)2 exhibited more-complex behavior. At 1000°C and copper contents of 20–80 mol%, a phase that is related to Cu3(PO4)2, termed here the “e-phase,” predominated. At 850°–950°C and in the region from 20 mol% to ∼33 mol% of copper, the solid solutions (the “η-phase”) adopted the structure of graftonite. At 800°–900°C and 10–15 mol% of copper, the solid solutions exhibited a new structure (the “δ-phase”), which we found to be related to the mineral sarcopside. At temperatures 950°C, the solutions that contained 5–15 mol% of copper (the “β-phase”) had the structure of β-Zn3(PO4)2, whereas at 800°–850°C, solutions with 5 mol% of copper (the “-phase”) exhibited the structure of γ-Zn3(PO4)2. Attempts to synthesize Cu+ZnPO4 and Cu+Cu2+Zn3(PO4)3 were unsuccessful.
Solution-Processed Inorganic Solar Cell Based on in Situ Synthesis and Film Deposition of CuInS2 Nanocrystals

A novel, reproducible, and simple solution-based process for the fabrication of CuInS2 absorber layers and CdS buffer layers for photovoltaics is presented. In this process, a precursor solution is deposited on a substrate, after which sintered NCs are formed in situ at temperatures as low as 250 °C. Solar cell efficiencies of up to 4% have been demonstrated using this novel fabrication method.
QCD and asymptotic freedom: Perspectives and prospects

QCD is now a mature theory, and it is possible to begin to view its place in the conceptual universe of physics with an appropriate perspective. There is a certain irony in the achievements of QCD. For the problems which initially drove its development — specifically, the desire to understand in detail the force that holds atomic nuclei together, and later the desire to calculate the spectrum of hadrons and their interactions — only limited insight has been achieved. However, I shall argue that QCD is actually more special and important a theory than one had any right to anticipate. In many ways, the importance of the solution transcends that of the original motivating problems. After elaborating on these quasiphilosophical remarks, I discuss two current frontiers of physics that illustrate the continuing vitality of the ideas. The recent wealth of beautiful precision experiments measuring the parameters of the standard model have made it possible to consider the unification of couplings in unprecedented quantitative detail. One central result emerging from these developments is a tantalizing hint of virtual supersymmetry. The possibility of phase transitions in matter at temperatures of order ~102 MeV, governed by QCD dynamics, is of interest from several points of view. Besides having a certain intrinsic grandeur, the question “Does the nature of matter change qualitatively, as it is radically heated?” is important for cosmology, relevant to planned high-energy heavy-ion collision experiments, and provides a promising arena for numerical simulations of QCD. Recent numerical work seems to be consistent with expectations suggested by renormalization group analysis of the potential universality classes of the QCD chiral phase transition; specifically, that the transition is second-order for two species of massless quarks but first order otherwise. There is an interesting possibility of long-range correlations in heavy ion collisions due to the creation of large regions of the misaligned chiral condensate. Finally, at the end, there is a brief discussion on the relation between scaling violations and running of the coupling. Some statements made later in the conference seemed to indicate that the relationship between these concepts is commonly misunderstood, so I’m smuggling this bit in even though it wasn’t part of the original talk.
A geomagnetic estimate of mean paleointensity

[1] A statistical hypothesis about Earth's magnetic field is tested against paleomagnetism by combining it with the present field to estimate mean paleointensity. The estimate uses the satellite era geomagnetic multipole power spectrum Rn, which gives the mean square magnetic induction represented by spherical harmonics of degree n averaged over the sphere of radius a = 6371.2 km. The hypothesis asserts that low-degree multipole powers of the core source field, Rnc, are distributed as chi-square with 2n + 1 degrees of freedom and theoretical expectation values {Rnc} = K(n + 1/2)[n(n + 1)]−1(c/a)2n + 4, where c is the 3480 km radius of Earth's core. The implied field is usually mainly dipolar and can be primarily axial. Amplitude K is estimated by fitting theoretical to observational spectra of degrees 1–12. The resulting calibrated expectation spectrum is summed through degree 12 to estimate expected square intensity {F2}. This sum also estimates mean square paleointensity, averaged over geologic time as well as the sphere, in so far as the present field spectrum is a fair sample of that generated in the past by core geodynamic processes. Previously, we excluded dominant degrees 1 and 2 from the fit, but not the sum, to “predict” mean paleointensity from the 1980 Magsat nondipole field. The new estimate fits all Rn of degrees 1–12 self-consistently and yields {F2} = (37.3 ± 4.3 μT)2. Expected paleointensity {F} is about 34.4 ± 4.9 μT; expected virtual axial dipole moment is about (6.51 ± 0.94) × 1022 Am2. These estimates are within the range of published paleomagnetic determinations of mean paleointensity; therefore the statistical hypothesis passes this test.
Cross-Correlating the Sloan Digital Sky Survey with the Microwave Sky

While most of the microwave background (CMB) fluctuations on angular scales greater than a few arcminutes were generated at z > 800, the low-redshift universe does distort the microwave background. Since the Sloan Digital Sky Survey (SDSS) traces the structures in the low-redshift universe, we can gain additional insights into the physics of the low-redshift universe by cross-correlating microwave background maps with template maps produced from the SDSS. We present a formalism for cross-correlating data from the Microwave Anisotropy Probe (MAP) with the Sloan Survey for the thermal Sunyaev-Zeldovich (SZ) effect, the Integrated Sachs-Wolfe (ISW) effect, and weak lensing. This formalism is used to compute the signal-to-noise ratio for cross-correlating these effects with various classes of tracer objects from the SDSS. The anticipated samples of SDSS quasars and galaxies with photometrically determined redshifts are found to be good tracers for cross-correlating with the CMB. We find that the SZ-galaxy cross-correlation would give good constraints on pressure fluctuations in supercluster-scale gas. Cross-correlating weakly lensed quasars with maps of the convergence of the CMB is found to give strong constraints on Ω0 as well as the equation of state, w. We find that the ISW cross-correlation gives a poor signal-to-noise ratio using these techniques.
Design criteria for GaAs MESFETs related to stationary high field domains

Abstract Using a modified theory of the high-field domains which takes into account the field-dependent diffusion we show that the existence of the high-field domain at drain side of the gate in GaAs MESFETs leads to a new set of design criteria which should be met to achieve the optimum performance. We derive these criteria and estimate the drain-to-source breakdown voltage and the maximum power of the device as functions of the doping density and device dimension. We also estimate the optimum gate length, the thickness of the active layer, the drain-to-gate separation and the doping level as functions of frequency. It is demonstrated that a larger than conventional drain-to-gate separation might be necessary for power devices to house a fully developed highfield domain and to avoid a premature breakdown at the drain. Our estimates indicate that the maximum power at 10 GHz can reach a theoretical limit of about 20 watts for class A operation.
Efficient synthesis of photolabile alkoxy benzoin protecting groups

An effective implementation of the Corey-Seebach dithiane addition for the synthesis of photolabile alkoxy benzoin adducts is reported. The method allows for the facile synthesis of photolabile 3′,5′-dimethoxybenzoin protected compounds in near quantitative yield and is general in that it can be used for the synthesis of both symmetrical and unsymmetrical benzoins. Importantly, the dithiane intermediate reported is a versatile starting material for the synthesis of many photolabile compounds and should serve as a useful protecting group in complex synthetic schemes requiring multiple orthogonal protecting groups.
Multiresolution analysis in statistical mechanics. I. Using wavelets to calculate thermodynamic properties

The wavelet transform, a family of orthonormal bases, is introduced as a technique for performing multiresolution analysis in statistical mechanics. The wavelet transform is a hierarchical technique designed to separate data sets into sets representing local averages and local differences. Although one-to-one transformations of data sets are possible, the advantage of the wavelet transform is as an approximation scheme for the efficient calculation of thermodynamic and ensemble properties. Even under the most drastic of approximations, the resulting errors in the values obtained for average absolute magnetization, free energy, and heat capacity are on the order of 10%, with a corresponding computational efficiency gain of two orders of magnitude for a system such as a 4×4 Ising lattice. In addition, the errors in the results tend toward zero in the neighborhood of fixed points, as determined by renormalization group theory.
THEORETICAL MODELS OF SUPERBURSTS ON ACCRETING NEUTRON STARS

We carry out a general relativistic global linear stability analysis of the amassed carbon fuel on the surface of an accreting neutron star to determine the conditions under which superbursts occur. We reproduce the general observational characteristics of superbursts, including burst fluences, recurrence times, and the absence of superbursts on stars with accretion rates 1044 ergs) superbursts that are inconsistent with observations, in agreement with previous investigations. Also, because of pycnonuclear burning of carbon, they do not have superbursts in the range of accretion rates at which superbursts are actually observed unless the crust is very impure. Stars with less efficient neutrino emission (due to modified Urca reactions, for example) produce bursts that agree better with observations. Stars with highly inefficient neutrino emission in their cores produce bursts that agree best with observations. Furthermore, we find that neutron stars with large radii (R ~ 16 km) produce very energetic superbursts that conflict with observations, even if the core neutrino emission mechanism is highly inefficient. Superburst characteristics are quite sensitive to several other parameters as well, most notably the composition of the accreted gas, concentration of carbon in the ignition region, and degree of crystallization of the crust. All systems that accrete primarily hydrogen and in which superbursts are observed show evidence of H- and He-burning delayed mixed bursts. We speculate that delayed mixed bursts provide sufficient amounts of carbon fuel for superbursts and are thus a prerequisite for having superbursts. We compare our global stability analysis to approximate one-zone criteria used by other authors and identify a particular set of approximations that give accurate results for most choices of parameters.
Media theory: Representations and examples

In this paper we develop a representational approach to media theory. We construct representations of media by well-graded families of sets and partial cubes and establish the uniqueness of these representations. Two particular examples of media are also described in detail.
Role of matrix protein in the type D retrovirus replication cycle: importance of the arginine residue at position 55.

Abstract We previously reported that a mutant of Mason–Pfizer monkey virus (M-PMV), which has an amino acid substitution in the matrix (MA) protein at position 55, MA-R55W, showed altered viral morphogenesis, reduced glycoprotein incorporation, and loss of infectivity. In this report, we show that two additional amino acid substitutions at this site in MA, R55F and R55Y, also result in similar altered morphogenesis, Env incorporation, and infectivity, demonstrating that these changes are not specific for the substitution of tryptophan in place of arginine 55. Attempts to isolate second site infectious revertants from cells transfected with the R55W mutant genome resulted only in the recovery of infectious viruses in which the codon at position 55 had reverted to one encoding arginine. In contrast, no revertants were obtained from the phenylalanine and tyrosine mutants in which three nucleotide changes had been engineered into the arginine codon. These results confirm that the arginine residue at position 55 is critical for intracellular targeting of M-PMV Gag molecules and support the concept that as part of a cytoplasmic transport retention signal R55 interacts with cellular trafficking components rather than other regions of Gag.
Numerical simulation of the growth of instabilities in supersonic free shear layers

The behavior of the initial region of a supersonic plane shear layer is analyzed through numerical solution of the two-dimensional Navier-Stokes equations, as well as the three-dimensional equations under the finite-span assumption. A modified MacCormack scheme that is fourth-order accurate in space and second-order in time is employed. Small amplitude oscillations in the normal velocity are found to grow as they convect downstream, and eventually lead to organized vortical structures. Normal velocity disturbances are found to be more efficient than streamwise or spanwise disturbances. The growth rate of these disturbances, as well as the intensity of velocity fluctuations, are found to decrease as the convective Mach number of the shear layer increases. The Mach number of the vortical structures with respect to the faster stream is found to be considerably less than the theoretical value of the convective Mach number.
Mechanistic interpretations of UO2 oxidation

Abstract The literature dealing with experiments and modeling of UO2 oxidation at temperatures > ∼ 600°C is reviewed and a detailed model is proposed. Mechanistic modeling is subjected to the principle of detailed balancing, which provides a framework for the elementary reactions contained in the reaction scheme. This principle interrelates the rate constants of the model, provides a link to gas-solid thermochemistry, and constrains the forms of the rate laws applied to the elementary steps of the model. Previous mechanistic models are analyzed in these terms and the rate constants deduced from them are assessed. A more general oxidation mechanism is proposed and compared to typical data. The types of new experiments needed to elucidate the mechanism are suggested.
Explicit, near-optimal guidance for power-limited transfers between coplanar circular orbits

Within the limits of the classical, two-body, inverse-square-gravity model, explicit guidance solutions are presented for power-limited transfers of a spacecraft between two coplanar circular orbits, performed under the Keplerian class of continuous-thrust programs. The Keplerian class is parameterized by an arbitrary, differentiable, explicit function of time, named the throttling function, and leads to a special type of analytically soluble two-dimensional orbital motion. The primary characteristics of such motion are the resulting qualitative and computational simplicity, exact guidance, conditional power-limited near-optimality, and unlimited two-dimensional maneuverability. It is shown that, for a given transfer duration, the Quadratic subclass of the Keplerian class, for which the throttling function is a quadratic polynomial, can be used to obtain open- and closed-loop solutions that satisfy the boundary conditions exactly, but at the expense of sacrificing some optimality. If, in addition, the transfer duration is sufficiently high, then the Tangential subclass, corresponding to a constant throttling function and tangential thrust, can be used to obtain open- and closed-loop guidance solutions that are identical, very simple to compute in real time, and practically as cheap as the corresponding minimum-fuel solutions.
Templated synthesis of nanostructured materials

Templating is one of the most important techniques for the controlled synthesis of nanostructured materials. This powerful tool uses a pre-existing guide with desired nanoscale features to direct the formation of nanomaterials into forms that are otherwise difficult to obtain. As a result, templated synthesis is capable of producing nanostructures with unique structures, morphologies and properties. In this review, we summarize the general principles of templated synthesis and cover recent developments in this area. As a wide variety of synthesis techniques are utilized to produce nanomaterials using template-based methods, the discussion is organized around the various types of common templates. We examine the use of both physical and chemical hard colloidal templates, soft templates, and other non-colloidal templates, followed by our perspective on the state of the field and potential future directions.
Systematic Identification of Culture Conditions for Induction and Maintenance of Naive Human Pluripotency

Embryonic stem cells (ESCs) of mice and humans have distinct molecular and biological characteristics, raising the question of whether an earlier, “naive” state of pluripotency may exist in humans. Here we took a systematic approach to identify small molecules that support self-renewal of naive human ESCs based on maintenance of endogenous OCT4 distal enhancer activity, a molecular signature of ground state pluripotency. Iterative chemical screening identified a combination of five kinase inhibitors that induces and maintains OCT4 distal enhancer activity when applied directly to conventional human ESCs. These inhibitors generate human pluripotent cells in which transcription factors associated with the ground state of pluripotency are highly upregulated and bivalent chromatin domains are depleted. Comparison with previously reported naive human ESCs indicates that our conditions capture a distinct pluripotent state in humans that closely resembles that of mouse ESCs. This study presents a framework for defining the culture requirements of naive human pluripotent cells.
The Preparation of 1H-Pyrazole-1-carboxylic Acid, 1, 1-Dimethylethyl Esters from Dilithiated C(α), N-Hydrazones of Hydrazinecarboxylic Acid, 1, 1-Dimethylethyl Ester

Abstract C(α), N-Hydrazones of hydrazinecarboxylic acid, 1, 1-dimethylethyl ester [C(α), N-carbo-t-butoxyhydrazones] were metalated with excess lithium diisopropylamide, and the dianion-type intermediates were condensed with select aromatic esters followed by acid cyclization to substituted 1H-pyrazole-1-carboxylic acid, 1, 1-dimethylethyl esters (N-carbo-t-butoxypyrazoles).
Modeling the spread of internet worms via persistently unpatched hosts

This article considers the effects of Internet worms on persistently unpatched hosts and hosts for which vulnerabilities are refreshed. Previous models have been homogeneous; that is, all hosts transitioned through the same set of states. The model considered in this article is heterogeneous and more realistic in that subpopulations of hosts are assumed to have inherently different characteristics. Equilibrium conditions are obtained for which an Internet worm will self-propagate indefinitely, which lead to thresholds below which worms will become extinct.
Effect of synthetic ovine corticotropin-releasing factor: Prolonged duration of action and biphasic response of plasma adrenocorticotropin and cortisol

The duration of the response to synthetic ovine corticotropin-releasing factor (CRF) was studied in 13 healthy male volunteer subjects. Placebo or CRF (0.3, 3, or 30 micrograms/kg BW) was administered as an iv bolus or, in the case of the largest dose, a 30-sec infusion in single blind fashion in the late afternoon. Basal plasma immunoreactive ACTH (IR-ACTH) and IR-cortisol were 10.8 +/- 7.7 pg/ml and 5.0 +/- 1.8 micrograms/dl (mean +/- SD), respectively. IR-ACTH rose rapidly after CRF, reached an initial peak at 15 min, fell rapidly until 1.5 h after CRF, and then either fell more slowly (after the lowest dose) or rose to a second major peak at 2-3 h before falling back to baseline. After 0.3, 3, and 30 micrograms/kg CRF, IR-ACTH remained elevated for 4, 7, and 8 h, respectively. The effect on plasma IR-cortisol was similar, but more prolonged. The magnitude of both peaks of IR-ACTH, the duration of the response, and the area under the curve all appeared dose dependent. The same was true for IR-cortisol, except that the first peak height was similar after all three doses. The duration of CRF's action is probably due to its long circulating half-life. The biphasic response curve may reflect initial secretion of a readily releasable pool of ACTH, followed by later secretion of a second pool of newly synthesized and/or matured peptide. The next morning's normal circadian rise in both IR-ACTH and IR-cortisol was delayed and diminished after 3 micrograms/kg CRF; there was no increase in IR-ACTH after 30 micrograms/kg CRF, and the IR-cortisol level was diminished. Inhibition of the normal circadian rise may reflect inhibition of ACTH secretion by the sustained high plasma cortisol levels.
Successful treatment of psoriasis and psoriatic arthritis with etanercept and methotrexate in a patient newly unresponsive to infliximab

A 30 year-old woman presented with moderate-to-severe psoriasis and psoriatic arthritis. Both her cutaneous and arthritic signs and symptoms were refractory to methotrexate, cyclosporine, or both of these drugs in combination. After receipt of infliximab her psoriasis cleared, yet her arthritic symptoms remained. After five infusions her psoriasis became refractory to infliximab. Infliximab was discontinued, and the patient was treated with a combination of methotrexate and etanercept. Twelve weeks later both her psoriasis and psoriatic arthritis had completely resolved. This case demonstrates that TNF inhibition represents a viable option in patients with psoriasis and psoriatic arthritis unresponsive to either methotrexate or cyclosporine, or both drugs in combination. Further, etanercept in combination with methotrexate may be an effective option for patients with psoriasis and psoriatic arthritis who become refractory to infliximab.
Quantum adiabatic machine learning

We develop an approach to machine learning and anomaly detection via quantum adiabatic evolution. This approach consists of two quantum phases, with some amount of classical preprocessing to set up the quantum problems. In the training phase we identify an optimal set of weak classifiers, to form a single strong classifier. In the testing phase we adiabatically evolve one or more strong classifiers on a superposition of inputs in order to find certain anomalous elements in the classification space. Both the training and testing phases are executed via quantum adiabatic evolution. All quantum processing is strictly limited to two-qubit interactions so as to ensure physical feasibility. We apply and illustrate this approach in detail to the problem of software verification and validation, with a specific example of the learning phase applied to a problem of interest in flight control systems. Beyond this example, the algorithm can be used to attack a broad class of anomaly detection problems.
Elk, Mule Deer, and Cattle Foraging Relationships on Foothill and Mountain Rangeland

Abstract Foraging niche overlap among Rocky Mountain elk ( Cervus elaphus nelsoni ), Rocky Mountain mule deer ( Odocoileus hemionus hemionus ), and cattle ( Bos taurus ) was studied for 2 years on 37 000 ha of nonforested foothill and mountain habitat in northwestern Wyoming. Microhistological analysis was used to quantify botanical composition of ungulate diets from monthly fecal collections. Feeding habitat use was determined through monthly surveys from fixed-wing aircraft to record nonsolitary animals in nonforested habitat. Kulcyznski’s similarity index was used to calculate dietary and feeding habitat overlap among the 3 ungulates, and these 2 indices were multiplied together to estimate foraging niche overlap. In all seasons, elk and cattle consumed grass-dominated diets (mean = 61% and 81%, respectively), although elk diets were more diverse. Mule deer consumed more forbs and shrubs than either elk or cattle ( P Festuca idahoensis , Pseudoroegneria spicata , and Achnatherum spp.). Foraging niche overlap also was high (41%–51%) between elk in winter and cattle in summer and fall. Therefore, if competitive or complementary relationships existed between elk and cattle, these interactions most likely occurred on sagebrush grasslands where cattle use in summer–fall was followed by elk use in winter–spring. We recommend that resource managers focus their forage utilization and range trend monitoring in foothill sagebrush grasslands.
In-line fiber Fabry-Perot interferometer with high-reflectance internal mirrors

A finesse of 21 has been measured for a fiber Fabry-Perot interferometer (FFPI) with multilayer TiO/sub 2//SiO/sub 2/ internal mirrors. Experimental reflectance and transmittance data for the thermally tuned interferometer were fit with calculated curves using values of 86% for the reflectance and 7.2% (0.33 dB) for the excess optical loss of each mirror. Applications in sensing and communications are discussed. >
A characterization of Gorenstein Hilbert functions in codimension four with small initial degree

The main goal of this paper is to characterize the Hilbert functions of all (artinian) codimension 4 Gorenstein algebras that have at least two independent relations of degree four. This includes all codimension 4 Gorenstein algebras whose initial relation is of degree at most 3. Our result shows that those Hilbert functions are exactly the so-called {\em SI-sequences} starting with $(1,4,h_2,h_3,...)$, where $h_4 \leq 33$. In particular, these Hilbert functions are all unimodal. We also establish a more general unimodality result, which relies on the values of the Hilbert function not being too big, but is independent of the initial degree.
A magnitude/phase-locked loop approach to parameter estimation of periodic signals

Presents a parameter estimator that is designed to estimate the frequencies, magnitudes, and phases of the components of a periodic signal. The structure of the algorithm is reminiscent of a phase-locked loop, although significant differences can be observed. The performance of the estimator is analyzed, and useful design guidelines are provided. A version of the algorithm is presented that combines different components of the signal and/or signals from multiple sensors in order to estimate the fundamental frequency. In this manner, the algorithm is able to maintain tracking of the fundamental frequency despite changes in signal characteristics. The results are verified in simulations and the algorithms are found to be simple and effective for estimation and tracking of time-varying parameters. Experimental results are reported where periodic signals are collected from an active noise control testbed.
Game Theory Models for Organizational/Public Conflict

Abstract: This paper applies game theory to conflicts between organizations and publics. Non-cooperative games--the duel (Chernobyl), the game of tag (Ford Pinto), and the escalation game (A. H. Robins' Dalkon Shield)--are contrasted with a cooperative bargaining game between an organization and its publics (Procter & Gamble's Rely tampon recall). Resume: Cette etude applique la Theorie des jeux aux situations de conflits ou de crises entre des organisations et des parties du public. Modeles noncooperatifs--le duel (Chernobyl), le jeu de recherche et poursuite (Ford Pinto), et le jeu d'escalade (le Dalkon Shield de A. H. Robins)--sont contrastes avec un jeu cooperatif de negociation entre une organisation et sa clientele (le retrait du Rely tampon de Procter & Gamble).
Nanomanufacturing Methods for the Reduction of Noise in Carbon Nanotube-Based Piezoresistive Sensor Systems

Carbon nanotube (CNT)-based piezoresistive strain sensors have the potential to outperform traditional silicon-based piezoresistors in MEMS devices due to their high strain sensitivity. However, the resolution of CNT-based piezoresistive sensors is currently limited by excessive 1/f or flicker noise. In this paper, we will demonstrate several nanomanufacturing methods that can be used to decrease noise in the CNT-based sensor system without reducing the sensor’s strain sensitivity. First, the CNTs were placed in a parallel resistor network to increase the total number of charge carriers in the sensor system. By carefully selecting the types of CNTs used in the sensor system and by correctly designing the system, it is possible to reduce the noise in the sensor system without reducing sensitivity. The CNTs were also coated with aluminum oxide to help protect the CNTs from environmental effects. Finally, the CNTs were annealed to improve contact resistance and to remove adsorbates from the CNT sidewall. The optimal annealing conditions were determined using a design-of-experiments (DOE). Overall, using these noise mitigation techniques it is possible to reduce the total noise in the sensor system by almost 3 orders of magnitude and increase the dynamic range of the sensors by 48dB. [DOI: 10.1115/1.4023159]
Orbifold Cohomology as Periodic Cyclic Homology

It is known from the work of Feigin–Tsygan, Weibel and Keller that the cohomology groups of a smooth complex variety X can be recovered from (roughly speaking) its derived category of coherent sheaves. In this paper we show that for a finite group G acting on X the same procedure applied to G-equivariant sheaves gives the orbifold cohomology of X/G. As an application, in some cases we are able to obtain simple proofs of an additive isomorphism between the orbifold cohomology of X/G and the usual cohomology of its crepant resolution (the equality of Euler and Hodge numbers was obtained earlier by various authors). We also state some conjectures on the product structures, as well as the singular case; and a connection with a recent work by Kawamata.
Tuning of the pro‐oxidant and antioxidant activity of trolox through the controlled release from biodegradable poly(trolox ester) polymers

In a variety of biomedical applications (e.g., tissue engineering, drug delivery, etc.), the role of a bioactive ma- terial is to serve as a platform by which one can modulate the cellular response into a desired role. Of the methods by which one may achieve this control (e.g., shape, structure, binding, growth factor release), the control of the cellular redox state has been under evaluated. Ideally, the ability to tune the redox state of a cell provides an additional level of control over a variety of cellular responses including, cell differentiation, proliferation, and apoptosis. Yet, in order to achieve such control, it is important to know both the over- all oxidative status of the cell and what molecular targets are being oxidized. In this work, poly (trolox ester) nanopar- ticles were evaluated for their ability to either inhibit or induce cellular oxidative stress in a dose-dependent fashion. This polymer delivery form possessed a unique ability to suppress protein oxidation, a feature not seen in the free drug form, emphasizing the advantage of the delivery/ dosage formulation has upon regulating cellular response.
One-pot transformation of esters to analytically pure ketones: methodology and application in process development

A convenient, single-pot protocol for the transformation of esters into analytically pure ketones is described herein. This method circumvents the need for purification and affords near quantitative yields for all substrates investigated. As a test of its utility, the method is used to improve the yields of a process for preparing a pharmacologically relevant anti-HIV intermediate by nearly 10 fold.
Advances in the Aeronomy of Venus and Mars

Abstract We review here advances in the aeronomy of Earth's nearest neighbors, Venus and Mars, including ion and neutral chemistry, airglow, temperature structures, wave activity and the effects of the newly discovered areas of remnant magnetization. We discuss the results of recent modeling and measurements, both ground based and from satellites, with emphasis on progress of the last 3–5 years.
The Existence Problem for Steiner Networks in Strictly Convex Domains

We consider the existence problem for ‘Steiner networks’ (trivalent graphs with 2π/3 angles at each junction) in strictly convex domains, with ‘Neumann’ boundary conditions. For each of the three possible combinatorial possibilities, sufficient conditions on the domain are derived for existence. In addition, in each case explicit examples of nonexistence are given.
Low-noise CMOS signal processing IC for interpolating cathode strip chambers

A CMOS circuit for obtaining precision amplitude and timing information from the cathodes of a proportional chamber with interpolating cathode strips has been developed. The chip performs charge amplification, shaping, analog storage and multiplexing, and generates a prompt timing pulse which can be used for trigger purposes. Novel features of the IC include: preamplifier optimized for large (40-250 pF) detector capacitance, digitally programmable gain and bandwidth of the fourth-order shaper, and an array of on-chip capacitors and switches for injecting charge for calibration. Noise is less than 1500 RMS electrons with an input capacitance of 100 pF using bipolar 550 nsec shaping. Linearity is better than 0.8% over a dynamic range of 1500:1. The constant fraction discriminator has a time walk of /spl plusmn/2.5 nsec over the range 10-500 fC. Power dissipation is 50 mW per channel. >
Diamond-a new high thermal conductivity substrate for multichip modules and hybrid circuits

Sandia National Laboratories is developing diamond substrate technology to meet the requirements of high thermal conductivity. Thin-film processes were developed and characterized to delineate conductor-resistor networks on free-standing diamond substrates having fine line gold conductors and low and high sheet resistivity resistors. Thin-film hybrid circuit technology was developed on CVD (chemical vapor deposition)-processed, polycrystalline diamond substrates having as-deposited surface finishes as well as those with polished surfaces. Conductors were defined by pattern plating gold and resistors were processed from sputtered tantalum nitride films which were deposited to sheet resistivities of 5 and/or 100 ohms per square. Resistor films on diamond substrates were evaluated for temperature coefficient of resistance (TCR), stability with time and temperature, and trimmability using YAG laser processing. Plated gold conductors were patterned on diamond to feature sizes of 25 microns and successfully tested for adhesion and bondability. Advanced YAG laser trimming techniques were developed to allow resistor trims on both low and high value resistors to within 1% of design value while maintaining required resistor stability. >
Alkenylation of allylic alcohols using alkenylboron dihalides: a formal transition-metal free Suzuki reaction

Carbon-carbon bond formation via substitution of an allylic hydroxide with stereodefined alkenyl groups using alkenylboron dihalides in the absence of transition metals.
Service Delivery and Legitimacy in Fragile and Conflict-Affected States: Evidence from water services in Iraq

Abstract In fragile and conflict-affected states (FCS), governments must rebuild three core governance functions: provision of security, service delivery and political participation. We unpack the connection between service delivery and legitimacy, using a staged model of legitimation, in which progress on the governance functions forms the basis for value-based legitimacy; behavioural legitimacy may, but does not necessarily, follow. With data from Iraq, we explore the role of water services in laying the groundwork for legitimacy. The analysis underscores the complex, non-linear relationship between service delivery and increases in trust and legitimacy, and the process's sensitivity to starting points. Nascent governments can build legitimacy by improving service delivery; however, gains are contingent and often fragile.
An Adaptively Pipelined Mixed Synchronous-Asynchronous Digital FIR Filter Chip Operating at 1.3 Gigahertz

A high-throughput low-latency digital finite impulse response (FIR) filter has been designed for use in partial-response maximum-likelihood (PRML) read channels of modern disk drives. The filter is a hybrid synchronous-asynchronous design. The speed-critical portion of the filter is designed as a high-performance asynchronous pipeline sandwiched between synchronous input and output portions, making it possible for the entire filter to be embedded within a clocked system. A novel feature of the filter is that the degree of pipelining is dynamically variable, depending upon the input data rate. This feature is critical in obtaining a very low filter latency throughout the range of operating frequencies. The filter is a ten-tap six-bit FIR filter, fabricated in a 0.18-μm CMOS process. Resulting chips were fully functional over a wide range of supply voltages, and exhibited throughputs of over 1.3 giga-items/s, and latencies of 2-5 clock cycles. Interestingly, the filter throughput was limited by the synchronous portion of the chip; the internal asynchronous pipeline was estimated to be capable of significantly higher throughputs, around 1.8 giga-items/s. More importantly though, the adaptively pipelined nature of the filter allows it to offer a worst-case latency of only 10 ns, which is half the worst-case latency of the best previously reported comparable fully-synchronous implementation by Rylov et al.
Frequency Domain Method for Real-Time Detection of Oscillations

Because of the growing interest in real-time stability monitoring, there is a need for online methods that can detect off-nominal behavior in control systems. Therefore, we present a realtime frequency domain method for detecting oscillations in control systems. The method uses recursive Fourier transform for representing the measured time domain signal in frequency domain. Oscillations are then detected by monitoring the norm of the Fourier coefficients over a time window of pre-specified size across a range of frequencies that represent off-nominal behavior for the plant. This method is computationally efficient and requires limited memory, hence it can be used for onboard health monitoring of Unmanned Aerial Systems (UAS). Consequently, we demonstrate the feasibility of using this method for real-time detection of oscillation on the Georgia Tech GT Twinstar (UAS).
Crust–core coupling and r‐mode damping in neutron stars: a toy model

R-modes in neutron stars with crusts are damped by viscous friction at the crust-core boundary. The magnitude of this damping, evaluated by Bildsten and Ushomirsky (BU) under the assumption of a perfectly rigid crust, sets the maximum spin frequency for a neutron star spun up by accretion in a Low-Mass X-ray binary (LMXB). In this paper we explore the mechanical coupling between the core r-modes and the elastic crust, using a toy model of a constant density neutron star with a constant shear modulus crust. We find that, at spin frequencies in excess of ≈ 50 Hz, the r-modes strongly penetrate the crust. This reduces the relative motion (slippage) between the crust and the core compared to the rigid crust limit. We therefore revise down, by as much as a factor of 10 − 10, the damping rate computed by BU, significantly reducing the maximal possible spin frequency of neutron star with a solid crust. The dependence of the crust-core slippage on the spin frequency is complicated, and is very sensitive to the physical thickness of the crust. If the crust is sufficiently thick, the curve of the critical spin frequency for the onset of the r-mode instability becomes multi-valued for some temperatures; this is related to the avoided crossings between the r-mode and the higher-order torsional modes in the crust. The critical frequencies are comparable to the observed spins of neutron stars in LMXBs and millisecond pulsars.
Competing Concepts of Inequality in the Globalization Debate

Differing value judgments in measuring inequality underlie the conflicting factual claims about how much poor people have shared in the economic gains from globalization. Opponents in the debate differ in the extent to which they care about relative inequality versus absolute inequality, vertical inequalities versus horizontal inequalities, and whether they are consistently individualistic in assessing the extent of inequality. The value judgments on these issues made by both sides need greater scrutiny if the globalization debate is to move forward.
THE CURIOUS ADVENTURE OF THE ULTRAHIGH ENERGY COSMIC RAYS

I will discuss the mysteries involving the production and extragalactic propagation of ultrahigh energy cosmic rays and suggested possible solutions.
An introduction to data grid management systems

We describe a “grid” as a coordinated infrastructure, formed by combining resources that might be owned by distributed and autonomous administrative domains. A data grid infrastructure facilitates a logical view of distributed resources that are shared between autonomous administrative domains. An emerging data storage problem is the management of unstructured data storage resources for inter/intra/multi-enterprise collaborative efforts. A new paradigm in data management systems, apart from traditional file systems and database systems is required. Data grids are being built around the world for coordinated sharing and management of unstructured data storage resources that are distributed at collaborating teams from the same or different enterprises. Data Grid Management System (DGMS) middleware will soon become part of the software infrastructure in many enterprises.
Valuing Private and Public Greenspace Using Remotely Sensed Vegetation Indices

In a typical metropolitan area, greenspace varies substantially in its quality and extent. Remotely sensed vegetation index data is used to characterize the heterogeneity in private and public greenspace (riparian corridors) in metropolitan Tucson, Arizona. This data set enables the researcher to test if: (1) greenness is a significant determinant of house price variation in this desert city; and (2) whether there is an interaction between public and private greenspace. Private greenspace amenities can be endogenously improved by homeowners as a complement or substitute for the greenspace that is publicly provided, whereas public greenspace might be exogenous or endogenous depending on households ability to pressure the local government to protect or restore public greenspace. The results of a Hausman test indicate that endogeneity is a problem in the dataset and therefore an instrumental variable two stage least squares estimation is used. The results of this analysis indicate that homebuyers in the study area have preferences for both greener lots and greener riparian corridors and that private and public greenspace appear to be substitutes. Results are robust across multiple identification strategies designed to address potential endogeneity. The study results could have fundamental implications for the efficient use of limited water supplies in this semi-arid metropolitan area.
Global Static Testing and Model Validation of Stiffened Thin Film Polyimide Panels

Stiff, thermal-formed polyimide panels are examples of next generation space structures that address some of the issues of membrane-dominated ultra-lightweight structures while maintaining their low mass and low stowage volume characteristics. The research presented here involved statically characterizing and modeling two of these panels both 0.0625 m, one with a mass of 38 g and one with a mass of 25 g – to develop validated computer models which can be used to determine the effects of changing manufacturing parameters and scalability. Static bending tests showed linear full-panel behavior over a range of applied loads for two different polyimide film thicknesses. These data were replicated by simple, coarsely-meshed shell element finite element models that are substantially smaller than three-dimensional models that faithfully represent the detailed internal geometry of the stiffened panels.
A pipelined adaptive differential vector quantizer for low-power speech coding applications

A fine-grain pipelined adaptive differential vector quantizer architecture is proposed for low-power speech coding applications. The pipelined architecture is developed by employing the relaxed look-ahead technique. The hardware overhead due to pipelining is only the pipelining latches. Simulations with speech sampled at 8 kHz show that, for a vector dimension of 8, the degradation in the signal-to-noise ratio (SNR) due to pipelining is negligible. Furthermore, this degradation is independent of the level of pipelining. Thus the proposed architecture is attractive from an integrated circuit (IC) implementation point of view. >
SELF-CORRECTING MULTIGRID SOLVER

A new multigrid algorithm based on the method of self-correction for the solution of elliptic problems is described. The method exploits information contained in the residual to dynamically modify the source term (right-hand side) of the elliptic problem. It has shown that the self-correcting solver is more efficient at damping the short wavelength modes of the algebraic error than its standard equivalent. When used in conjunction with a multigrid method, the resulting solver displays an improved convergence rate with no additional computational work.
Estimation of Hurricane Winds From SeaWinds at Ultrahigh Resolution

Although the SeaWinds scatterometer was not specifically designed to observe tropical cyclones, new high-resolution wind products resolve much of the horizontal structure of these storms. However, these higher resolution products (2.5 km) are inherently noisier than the standard 25-km near-surface wind products. These noise levels combined with rain contamination complicate high-resolution wind estimation-particularly in tropical cyclones. Fortunately, tropical cyclones have structures that can be exploited by using a wind field model. This paper develops a new procedure for hurricane wind field estimation from the SeaWinds instrument at ultrahigh resolution. A simplified hurricane model is developed to provide prior information to be used in maximum a posteriori probability estimation of ocean winds. Using the hurricane model ameliorates the effects of rain and noise and provides useful hurricane parameters such as the eye center location. The model also improves ambiguity selection. The new method reduces the variability of the wind speed and direction estimates, although high wind speeds still tend to be underestimated. The method also greatly improves wind direction estimates in hurricanes-even in rain-contaminated portions of the storm.
Does the Confucius institute impact international travel to China? A panel data analysis.

This article examines the impact of Confucius Institutes on inbound travel to China. We estimate a panel gravity model of inbound tourism flows to China between 2004 and 2010. We use a Poisson pseudo-maximum likelihood estimator to control for heteroscedasticity endemic in gravity models (Santos Silva and Tenreyro, 2006). We find that the presence of Confucius Institute(s) in the source country increases overall tourism in general and business and worker tourists in particular.