cssi/SciSciGPT-SciSciNet huggingface dataset:
Multiple Benefits of Carbon-Friendly Agricultural Practices: Empirical Assessment of Conservation Tillage

This study empirically estimates the multiple benefits of a subsidy policy that would offer payments to farmers in return for the adoption of conservation tillage, and compares the outcomes of alternative targeting designs for such a policy. The least-cost incentive payment policy schemes are simulated for the State of Iowa by using the data for roughly 12,000 National Resource Inventory (NRI) points. We use an economic conservation tillage adoption model to evaluate the costs of adoption and a physical process simulation model (EPIC) to estimate the environmental benefits due to adoption at each of the NRI points.Two targeting options are considered. We assess the costs and environmental consequences of a practice-based policy instrument (which maximizes the acres of land in conservation tillage, regardless of its level of environmental benefits) and contrast it to a performance-based instrument (which yields the highest amount of environmental benefits per dollar spent). Carbon sequestration in agricultural soils, reduction of soil erosion by wind and water, and the reduction in nitrogen runoff are considered as possible targets for the performance-based instruments. We find that the practice-based instrument provides high proportions of the four benefits relative to the policies that target the benefits directly, especially at the higher policy budget levels. Similarly, we estimate that targeting one of the four benefits individually provides high percentages of the other benefits as compared with the amounts of the benefits obtainable if they were targeted directly.
Systematic Center-To-Limb Variation in Measured Helioseismic Travel Times and Its Effect on Inferences of Solar Interior Meridional Flows

We report on a systematic center-to-limb variation in measured helioseismic travel times, which must be taken into account for an accurate determination of solar interior meridional flows. The systematic variation, found in time-distance helioseismology analysis using SDO/HMI and SDO/AIA observations, is different in both travel-time magnitude and variation trend for different observables. It is not clear what causes this systematic effect. Subtracting the longitude-dependent east-west travel times, obtained along the equatorial area, from the latitude-dependent north-south travel times, obtained along the central meridian area, gives remarkably similar results for different observables. We suggest this as an effective procedure for removing the systematic center-to-limb variation. The subsurface meridional flows obtained from inversion of the corrected travel times are approximately 10 m s−1 slower than those obtained without removing the systematic effect. The detected center-to-limb variation may have important implications in the derivation of meridional flows in the deep interior and needs to be better understood.
“I like that you can hit a guy and not really get in trouble”: Young ice hockey players' experiences with body checking

Intense debate surrounds the optimal age to integrate body checking in youth ice hockey. While extensive research suggests body checking is associated with heightened injury rates, little research has focused on the psychological and social risks of body checking among youth players. The purpose of this study was to understand young hockey players' initial experiences with body checking, through the lens of psychosocial development. Thirty-four male Peewee (age 11-12) hockey players from nine competitive (representative) teams in southern Ontario, Canada engaged in semi-structured interviews at the beginning and conclusion of their 2011-2012 season. A phenomenological approach was used in the collection and analysis of data offering textural and structural descriptions of how participants experienced body checking. Results emerged in four key categories: (a) new reality of injury; (b) aggression, power, invincibility, and fear (c) coaches' roles; and (d) parents' influences. Findings are discussed in the ...
THERMODYNAMIC VS. KINETIC CONTROL IN THE DIELS-ALDER CYCLOADDITION OF CYCLOPENTADIENE TO 2,3-DICYANO-P-BENZOQUINONE : KINETIC CONTROL REVISITED

Abstract Diels-Alder cycloaddition of cyclopentadiene (1) to 2,3-dicyano-p-benzoquinone (2), when performed in methanol solvent at ambient temperature (kinetic control), gave 3b. Reduction of 3b, carried out under mild conditions by using CeCl3−NaBH4, proceeded stereospecifically to afford diol 5. Subsequently, 5 was converted into the corresponding bis(O-acetyl) derivative, 6, whose structure was established unequivocally via application of X-ray crystallographic methods. An earlier suggestion that 3a results via kinetic control of Diels-Alder cycloaddition of 1 to 2 is thereby shown to be erroneous.
Orbital currents and cheap vortices in underdoped cuprates

Abstract In the past several years, we have developed a theory for the underdoped cuprates in collaboration with Wen, based on an SU(2) formulation of the t – J model. In this formulation, the staggered flux state plays a central role as the progenitor of the Neel state at half-filling and a close competitor to the d-wave superconductor with small doping where it is characterized by staggered orbital currents. We found support for this point of view when we discovered fluctuating orbital currents in the Gutzwiller projected BCS wave function. We shall argue that low-energy vortices, where the staggered flux state is stabilized in the core, are needed to explain many of the unusual properties of underdoped cuprates. Proposed experiments to look for these orbital currents will be discussed.
Small Unsteady Perturbations in Transonic Flows

The effects of very small, low-frequency perturbations on steady transonic flows, in the context of twodimensional flows described by the small perturbation equation, are investigated. Previous time-linearized studies failed to account for the shock wave motions that are known to occur. A method is provided that allows one to correctly account for shock wave motions due to arbitrary but small unsteady changes in the boundary conditions. Consequently, both harmonic and indicia! responses may be determined. Time-linearized results for the transonic flow past an NACA 64A006 airfoil experiencing harmonic motions in one of several modes are presented. Selected results are compared with those obtained from nonlinear calculations using a shock-fitting algorithm.
Standard promotion practices versus up‐or‐out contracts

This article develops a theory concerning the choice between standard promotion practices and up-or-out contracts. Our theory is based on asymmetric learning and promotion incentives. We find that firms employ up-or-out contracts when firm-specific human capital is low and standard promotion practices when it is high. We also find that, if commitment to a wage floor is feasible and effort provision is important, up-or-out is employed when low- and high-level jobs are similar. These results are consistent with many of the settings in which up-or-out is typically observed, such as law firms and academia.
Thermal degradation and electrical properties of random and block piperazine copolyamides

Abstract The thermal degradation of random and block copolymers of terephthaloyl trans-2,5-dimethylpiperazine/isophthaloyl trans-2,5-dimethylpiperazine were investigated in terms of rates, activation energies, degradation products, and electrical properties. The rates of degradation and the nature of the volatile degradation products indicate that both random and block copolymers follow a nearly random free-radical type of cleavage in vacuum with activation energies between 59 and 61 kcal/mole. In the temperature range 390=440°C, the block copolymers are significantly more stable in a vacuum (the rates of degradation are two to four times slower) than the random copolymers. In contrast to the random copolymers, the block copolymers showed only slight frequency dependence of their dielectric constants and dissipation factors between 0.1 and 100 kcps.
Gravity Field of the Jovian System from Pioneer and Voyager Tracking Data

Data sets from the Voyager and Pioneer flybys of Jupiter and the Galilean satellites are employed to characterize the Jovian magnetic field and the effects of the Io torus on transmissions. Both optical and Doppler radio data are considered, except for periods when the Jovian radiation environment disturbed the oscillator stability of the radio transmitters. Account is taken of small accelerations of the spacecraft by tidal forces of a single rising satellite, density differences in the Great Red Spot producing a columnar gravitational change, and three unknown objects in the inner Jovian system. Correction parameters are developed for the effects on the S-band data induced by the Jovian plasmasphere inwards from the Io torus. Calculations are then made of the planet and satellite masses, gravity harmonic coefficients, and orientation of the rotational pole. Large reductions in the uncertainties in previous mass estimates are obtained.
The Discovery of a Second Luminous Low Mass X-Ray Binary in the Globular Cluster M15

We report an observation by the Chandra X-Ray Observatory of 4U 2127+119, the X-ray source identified with the globular cluster M15. The Chandra observation reveals that 4U 2127+119 is in fact two bright sources, separated by 2.7 arcsec. One source is associated with AC 211, the previously identified optical counterpart to 4U 2127+119, a low-mass X-ray binary (LMXB). The second source, M15 X-2, is coincident with a 19th U magnitude blue star that is 3.3 arcsec from the cluster core. The Chandra count rate of M15 X-2 is 2.5 times higher than that of AC 211. Prior to the 0.5 arcsec imaging capability of Chandra, the presence of two so closely separated bright sources would not have been resolved. The optical counterpart, X-ray luminosity, and spectrum of M15 X-2 are consistent with it also being an LMXB system. This is the first time that two LMXBs have been seen to be simultaneously active in a globular cluster. The discovery of a second active LMXB in M15 solves a long-standing puzzle where the properties of AC 211 appear consistent with it being dominated by an extended accretion disk corona, and yet 4U 2127+119 also shows luminous X-ray bursts requiring that the neutron star be directly visible. The resolution of 4U 2127+119 into two sources suggests that the X-ray bursts did not come from AC 211 but rather from M15 X-2. We discuss the implications of this discovery for understanding the origin and evolution of LMXBs in globular clusters as well as X-ray observations of globular clusters in nearby galaxies.
RAPIDITY GAP OF WEAKLY COUPLED LEPTOQUARK PRODUCTION IN ep COLLIDER

We show that the current bounds on the leptoquark couplings imply that if leptoquarks are produced in ep collisions, a significant fraction of them could form a leptoquark–quark bound state. The decay of the bound state has a distinct event shape with rapidity gap. A possible application of this observation in the leptoquark search at HERA is discussed.
Synthesis of the perhydroindole nucleus by a Pummerer/Mannich induced cyclization cascade

Abstract The silicon-induced Pummerer reaction of several amido sulfoxides possessing tethered π-bonds proceeds by way of a thionium N- acyliminium ion cascade to provide various azabicyclic ring systems. This cascade sequence was applied toward the synthesis of a member of the protoberberine alkaloid family.
Alkynylation of 4-Bromo-3-phenylsydnone with Aryl Acetylenes

Various 4-arylethynyl sydnones 2 can be prepared in good yields by reaction of 4-bromo-3-phenylsydnone (1) with aryl acetylenes under palladium catalysis.
Kinematics of rendezvous maneuvers

Mathematical expressions are obtained that solve the rendezvous problem with evasive and passive objects. Two simple rendezvous guidance schemes are imposed on the kinematic equations of motion. Complementary solutions to the resulting differential equations are solutions for rendezvous with passive objects, and particular solutions represent rendezvous with an evasive object. The solutions depend on a nondimensional guidance effectiveness parameter. Effective evasive maneuvers are discussed and analytical results are compared with numerically computed solutions to example rendezvous cases.
A New Short Proof of the Local Index Formula and Some of Its Applications

We give a new short proof of the index formula of Atiyah and Singer based on combining Getzler’s rescaling with Greiner’s approach of the heat kernel asymptotics. As an application we can easily compute the CM cyclic cocycle of even and odd Dirac spectral triples, and then recover the Atiyah-Singer index formula (even case) and the Atiyah-Patodi-Singer spectral flow formula (odd case).
Signal processing for an optical wide band data transmission system

The signal processing for an optical wideband transmission system using gallium arsenide (GaAs) digital integrated circuits and optical fibers has been investigated. Multiplexing, coding, synchronization, demultiplexing, and error checking at 780 Mb/s data rates are described. Data storage in memory for linking to a computer is also considered. The design uses available GaAs and silicon components. The reliability of GaAs components is discussed as well as the layout and thermal considerations required for a high-speed system. >
Mega-Events and Housing Costs: Raising the Rent while Raising the Roof?

This paper examines the relationship between hosting mega-events such as the Super Bowl, Olympics, and World Cup and rental housing prices in host cities. If mega-events are amenities for local residents, then rental housing prices can serve as a proxy for estimating residents’ willingness to pay for these amenities. An analysis of rental prices in a panel of American cities from 1993 to 2005 fails to find a consistent impact of mega-events on rental prices. When controls are placed on the regression models to account for nationwide annual fluctuations in rental prices, mega-events generally exhibit little impact on rental prices in cities as a whole and are as likely to reduce rental prices as increase them. On the other hand, Somewhat stronger evidence exists, however, that mega-events tend to affect rental prices outside of the center city in a fundamentally different manner than in the city core. Atlanta experienced lower rental prices in the central city compared the suburbs both before and after the 1996 Summer Olympics while Salt Lake City witnessed an increase in rental prices in its central city compared to its suburbs before and after the 2002 Winter Olympics.
On the Dynamics of Rotating Fluids and Planetary Atmospheres: A Summary of some Recent Work

An outline is given of some recent and current research in the Geophysical Fluid Dynamics Laboratory of the UK Meteorological Office, on the dynamics of rotating fluids and planetary atmospheres. Many of these investigations bear on the problem of creating a theoretical framework for atmospheric predictability studies.
Non-abelian statistics in the interference noise of the Moore–Read quantum Hall state

We propose noise oscillation measurements in a double point contact, accessible with current technology, to seek for a signature of the non-abelian nature of the ν = 5/2 quantum Hall state. Calculating the voltage and temperature dependence of the current and noise oscillations, we predict the non-abelian nature to materialize through a multiplicity of the possible outcomes: two qualitatively different frequency dependences of the nonzero interference noise. Comparison between our predictions for the Moore–Read state with experiments on ν = 5/2 will serve as a much needed test for the nature of the ν = 5/2 quantum Hall state.
Nonlinear multigrid for electrical impedance tomography

We propose a nonlinear multigrid approach for imaging the electrical conductivity of a body, given simultaneous measurements of d.c. electric currents and voltages at the boundary. The implementation is done for an output least squares formulation of the electrical impedance tomography problem. Extensions to a stronger, variational approach are discussed, as well.
A convenient synthesis of racemic 2′-deoxy carbocyclic thymidines lacking the 5′-methylene group

Abstract A convenient synthesis of racemic 2′-deoxy carbocyclic thymidines lacking the 5′-methylene group is reported. Thus, appropriately protected nucleic acid bases are coupled to 3-cyclopentenol, 1 , via the Mitsunobu reaction. Epoxidation of the protected thymine substituted cyclopentene gives the corresponding syn and anti-epoxides in a 4:1 ratio. Ring opening of the syn-epoxide by a variety of nucleophiles leads to the racemic 2′-deoxy carbocyclic thymidines lacking the 5′-methylene group.
Vision in two sympatric species of pullosquilla (stomatopoda, lysiosquilloidea) living in different depth ranges

We examined the visual systems of two species of the lysiosquilloid stomatopod crustacean genus Pullosquilla living sympatrically in waters around the island of Moorea, French Polynesia. P. litoralis lives in bright, shallow environments to a maximum depth of less than 2 m, while P. thomassini occupies depths to at least 37m. By occupying different environments in the same geographic regions, the closely related species pair affords a rare opportunity to examine the effect of photic environment on visual evolutionary adaptation. We quantified retinal anatomy, determined the spectral diversity of visual pigments, and measured the absorption spectra of intrarhabdomal filters in retinas of both species to compare their complements of spectral receptors. The two species were similar in most respects, but the visual pigment in the main retina of P. thomassini had λmax at 467 nm, compared to 509 nm in the corresponding retinal region of P. litoralis. The absorption of visual pigments in Row 3 of the midband, th...
A new approach to the maximum-flow problem

All previously known efficient maximum-flow algorithms work by finding augmenting paths, either one path at a time (as in the original Ford and Fulkerson algorithm) or all shortest-length augmenting paths at once (using the layered network approach of Dinic). An alternative method based on the preflow concept of Karzanov is introduced. A preflow is like a flow, except that the total amount flowing into a vertex is allowed to exceed the total amount flowing out. The method maintains a preflow in the original network and pushes local flow excess toward the sink along what are estimated to be shortest paths. The algorithm and its analysis are simple and intuitive, yet the algorithm runs as fast as any other known method on dense graphs, achieving an O(n3) time bound on an n-vertex graph. By incorporating the dynamic tree data structure of Sleator and Tarjan, we obtain a version of the algorithm running in O(nm log(n2/m)) time on an n-vertex, m-edge graph. This is as fast as any known method for any graph density and faster on graphs of moderate density. The algorithm also admits efficient distributed and parallel implementations. A parallel implementation running in O(n2log n) time using n processors and O(m) space is obtained. This time bound matches that of the Shiloach-Vishkin algorithm, which also uses n processors but requires O(n2) space.
Control of the discrete vortices from a delta wing

L'ecoulement est perturbe par injection ou aspiration d'un fluide secondaire par une fente le long du bord d'attaque d'une aile delta. Essais en tunnel hydrodynamique et en soufflerie. Etude par visualisations et mesures de vitesse des effets de la perturbation sur le champ d'ecoulement. Calcul de diverses quantites statistiques du champ de vitesse aleatoire
A formula for a quartic integral: a survey of old proofs and some new ones

We discuss several existing proofs of the value of a quartic integral and present a new proof that evolved from rational Landen transformations. We include our personal renditions as related to the history of these particular computations.
Reinganum's trading strategies revisited: Structuring profitable strategies based on updated filters

Purpose – The purpose of this paper is to reexamine the value, momentum and size factors employed in the trading strategy originally proposed by Reinganum. Also to enhance our understanding of the impact of these factors over time; to evaluate the effectiveness of these factors; to develop new strategies through a framework presented by Chan et al.; and to investigate the possibility of limiting the number of filters to allow for a larger universe of eligible stocks without hurting performance for both long and short strategies.Design/methodology/approach – Using data from 1970 to 1983, Reinganum developed a profitable trading strategy based on four (or nine) variables to select stocks. First this paper shows why it is increasingly difficult to implement his original trading strategy, then tests his strategy on 23 additional years of data through 2006, and compares it to similar strategies that incorporate straightforward modifications to his filters. The analysis is further extended to a long/short tradi...
Standards for electrical measurement

At the National Bureau of Standards most precise methods are used for measuring and determining exact values of electrical units. The testing and calibration work of the Bureau is available for an appropriate fee to anyone who needs this high-accuracy service.
Interaction between parallel cracks in layered composites

The plane strain problem of a multi-layered composite with parallel cracks is considered. The main objective is to study the interaction between parallel and collinear cracks. The problem is formulated in terms of a set of simultaneous singular integral equations which are solved numerically. The effect of material properties on the interaction between cracks is also demonstrated.
Residual thermal and moisture influences on the free-edge delamination of laminated composites

A simple delamination analysis method is developed. It is based on a shear-type deformation theory and includes hygrothermal effects. The method is applied to mixed-mode edge delamination specimens made of T300/5208 graphite/epoxy. It is found that residual thermal influences were alleviated when moisture stresses were included. Thermal effects on the interlaminar shear stress and total energy release rate were totally alleviated for the same specific moisture content. Moreover, this value of moisture content was not significantly affected by the stacking sequence for the laminates considered.
Limits to Ice on Asteroids (24) Themis and (65) Cybele

We present optical spectra of (24) Themis and (65) Cybele, two large main-belt asteroids on which exposed water ice has recently been reported. No emission lines, expected from resonance fluorescence in gas sublimated from the ice, were detected. Derived limits to the production rates of water are 400 kg s–1 (5σ) for each object, assuming a cometary H2O/CN ratio. We rule out models in which a large fraction of the surface is occupied by high-albedo ("fresh") water ice because the measured albedos of Themis and Cybele are low (~0.05-0.07). We also rule out models in which a large fraction of the surface is occupied by low-albedo ("dirty") water ice because dirty ice would be warm and would sublimate strongly enough for gaseous products to have been detected. If ice exists on these bodies it must be relatively clean (albedo 0.3) and confined to a fraction of the Earth-facing surface 10%. By analogy with impacted asteroid (596) Scheila, we propose an impact excavation scenario, in which 10 m scale projectiles have exposed buried ice. If the ice is even more reflective (albedo 0.6), then the timescale for sublimation of an optically thick layer can rival the ~103 yr interval between impacts with bodies this size. In this sense, exposure by impact may be a quasi steady-state feature of ice-containing asteroids at 3 AU.
Large Kerr nonlinearities on cavity-atom polaritons

I analyze a scheme that is capable of producing large Kerr nonlinearities on cavity-atom polaritons in a cavity quantum electrodynamics system consisting of multiple three-level atoms confined in a cavity mode. A weak control laser coupled to the atoms from free space induces destructive quantum interference in the polariton excitation of the coupled cavity-atom system and creates large Kerr nonlinearities on the intra-cavity light field. The scheme can be used for optical switching or cross-phase modulation of the cavity-atom polariton at ultralow light levels.
Interactive real time simulation for scheduling and monitoring of STOL aircraft in the terminal area.

1 Alexander, B. (chairman), "Report of Department of Transportation Air Traffic Advisory Committee," Vols. 1 and 2, Dept. of Transportation, Washington, D.C., Dec. 1969. Blumstein, A., "The Landing Capacity of a Runway," Operations Research, Vol. 7, No. 6,1959, pp. 752-763. FAA, "The National Aviation System Plan, Ten Year Plan 1972-1981," (71-01686), March 1971, FAA, Washington, D.C. FAA, "The National Aviation System Policy Summary 1971," (7-10686), March 1971, FAA, Washington, D.C. Lister, S. F. and Raisbeck, G., "Approach to the Establishment of Practical Air Traffic Control Safety Goals," Contract No. FA70WA-2141, Little, Cambridge, Mass., May 1971. Raisbeck, G., Koopman, B. O., et al., "Air Traffic Control System Capacity," Contract No. DOT-FA70WA-2141, Little, Cambridge, Mass., Aug. 1970. Schriever, B. A. and Seifert, W. W., Air Transportation 1975 and Beyond: A Systems Approach, The MIT Press, Cambridge, Mass., 1968. Simpson, R., "Evaluation of Air Traffic Control Models and Simulations," Contract No. DOT-TSC-77, June 1971, MIT, Cambridge, Mass. Wilhelm, W. E., "Following Theory With Applications," Ph.D. dissertation, 1972, Virginia Polytechnic Inst. and State Univ., Blacksburg, Va.
Fluxless solder joining using alkane

Abstract Electronics products are becoming smaller these days. Thus the technology to connect fine pitch electrodes is very important. We developed a new soldering method without applying any flux, which deteriorates the insulation property between electrodes. In the ordinary soldering method, flux is used to dissolve the oxide film. In the new method, we have introduced alkane to remove oxide film by physical reaction. When heat is applied and alkane is boiled, volume expansion energy breaks the oxide film and the desirable clean solder surface is obtained. As a result, the connections become as strong as using the ordinary method.
A Theory of the A Priori

Good evidence is clearly required for the sort of knowledge sought in science, logic, mathematics, and philosophy. This suggests the idea of approaching the a priori through the topic of "evidence" (or reasons). The paper begins with a discussion of our use of "intuitions" as evidence (reasons) in the a priori disciplines (logic, mathematics, philosophy) and an argument showing that omitting intuitions from one's body of evidence leads to epistemic self-defeat. This is followed by an explanation of why intuitions are evidence. The explanation is provided by "modal reliabilism" - the doctrine that there is a certain kind of qualified modal tie between intuitions and the truth. Finally, this tie to the truth is explained by the theory of "concept posses- sion": it is a direct consequence of what it is, by definition, to possess - to understand - the concepts involved in our intuitions. The resulting picture is then shown to imply a qualified autonomy of each of the a priori disciplines vis-a-vis empirical science.
High-Dimensional Shape Fitting in Linear Time

Let $P$ be a set of $n$ points in $\Re^d$. The {\em radius} of a $k$-dimensional flat ${\cal F}$ with respect to $P$, which we denote by ${\cal RD}({\cal F},P)$, is defined to be $\max_{p \in P} \mathop{\rm dist}({\cal F},p)$, where $\mathop{\rm dist}({\cal F},p)$ denotes the Euclidean distance between $p$ and its projection onto ${\cal F}$. The $k$-flat radius of $P$, which we denote by ${R^{\rm opt}_k}(P)$, is the minimum, over all $k$-dimensional flats ${\cal F}$, of ${\cal RD}({\cal F},P)$. We consider the problem of computing ${R^{\rm opt}_k}(P)$ for a given set of points $P$. We are interested in the high-dimensional case where $d$ is a part of the input and not a constant. This problem is NP-hard even for $k = 1$. We present an algorithm that, given $P$ and a parameter $0 < \eps \leq 1$, returns a $k$-flat ${\cal F}$ such that ${\cal RD}({\cal F},P) \leq (1 + \eps) {R^{\rm opt}_k}(P)$. The algorithm runs in $O(nd C_{\eps,k})$ time, where $C_{\eps,k}$ is a constant that depends only on $\eps$ and $k$. Thus the algorithm runs in time linear in the size of the point set and is a substantial improvement over previous known algorithms, whose running time is of the order of $d n^{O(k/\eps^c)}$, where $c$ is an appropriate constant.
Simulating the evolution of soot mixing state with a particle-resolved aerosol model

[1] The mixing state of soot particles in the atmosphere is of crucial importance for assessing their climatic impact, since it governs their chemical reactivity, cloud condensation nuclei activity, and radiative properties. To improve the mixing state representation in models, we present a new approach, the stochastic particle-resolved model PartMC-MOSAIC, which explicitly resolves the composition of individual particles in a given population of different types of aerosol particles. This approach tracks the evolution of the mixing state of particles due to emission, dilution, condensation, and coagulation. To make this direct stochastic particle-based method practical, we implemented a new multiscale stochastic coagulation method. With this method we achieved high computational efficiency for situations when the coagulation kernel is highly nonuniform, as is the case for many realistic applications. PartMC-MOSAIC was applied to an idealized urban plume case representative of a large urban area to simulate the evolution of carbonaceous aerosols of different types due to coagulation and condensation. For this urban plume scenario we quantified the individual processes that contributed to the aging of the aerosol distribution, illustrating the capabilities of our modeling approach. The results showed for the first time the multidimensional structure of particle composition, which is usually lost in sectional or modal aerosol models.
Design for manufacturability and yield

Abstract This paper focuses on the design strategies for VLSI circuits that are aimed at achieving manufacturable, high-yielding chips. The current status of statistical design methodologies is reviewed based upon statistically valid modeling and process characterization approaches. Both parametric and functional yield maximization strategies are covered. This paper argues that by providing a better starting point for manufacturing, the profitability and competitiveness can be significantly improved.
Competition studies in alkyne electrophilic cyclization reactions.

The relative reactivity of various functional groups toward alkyne electrophilic cyclization reactions has been studied. The required diarylalkynes have been prepared by consecutive Sonogashira reactions of appropriately substituted aryl halides and competitive cyclizations have been performed using I2, ICl, NBS and PhSeCl as electrophiles. The results indicate that the nucleophilicity of the competing functional groups, polarization of the alkyne triple bond, and the cationic nature of the intermediate are the most important factors in determining the outcome of these reactions.
Silylcupration of acetylenes

Abstract Several organosilylcuprates have been prepared and their reactions with acetylenes examined. It has been shown that LiCu[Si(SiMe3)3]2 adds to acetylenes in only one manner, i.e. with cis addition and the Si(SiMe3)3 group in the least hindered cite as shown in the equation below. Similarly the sterically hindered LiCu(SiMePh2)2 LiCu[Si(SiMe3)2]2·LiI + RCCH → H+,H2O → trans-RHCCHSi(SiMe3)3 adds only in this fashion. If the less sterically hindered lithium compound, LiSiMe2Ph, is used to prepare the copper reagent, then, when the Li/Cu ratio is reduced to 1 1 a mixture of products, A and B (SiR3 = SiMe2Ph; R′ = n=Bu) is obtained in a ratio of 2 1 , but only one product, A (SiR3 = SiMe2Ph; R′ = n-Bu, t-Bu, Ph), is obtained when the ratio of Li/Cu is 2 1 . Only A is obtained when either diphenylmethylsilyllithium or tris(trimethylsilyl)silyllithium (SiR3 = SiMePh2, Si(SiMe3)3; R′ = n-Bu, t-Bu, Ph) is used regardless of the Li to Cu ratio.
THE S1 SHELL AND INTERSTELLAR MAGNETIC FIELD AND GAS NEAR THE HELIOSPHERE

Many studies of the Loop I magnetic superbubble place the Sun at the edges of the bubble. One recent study models the polarized radio continuum of Loop I as two magnetic shells with the Sun embedded in the rim of the 'S1' shell. If the Sun is in such a shell, it should be apparent in both the local interstellar magnetic field and the distribution of nearby interstellar material. The properties of these subshells are compared to the interstellar magnetic field and the distribution of interstellar Fe{sup +} and Ca{sup +} within {approx}55 pc of the Sun. Although the results are not conclusive, the interstellar magnetic field direction obtained from polarized stars within {approx}30 pc is consistent with the interstellar magnetic field direction of the S1 shell. The distribution of nearby interstellar Fe{sup +} with log N(Fe{sup +}) 12.5 cm{sup -2}) tend to be better described by the path length of the sightline through the S1 and S2 subshells. Column densities of the recombinant ion Ca{sup +} are found to increase with themore » strength of the interstellar radiation field, rather than with star distance or total pathlength through the two magnetic subshells. The ion Ca{sup +} cannot be used to trace the distribution of local interstellar gas unless the spatial variations in the radiation field are included in the calculation of the ionization balance, in addition to possible abundance variations. The result is that a model of Loop I as composed of two spherical magnetic subshells remains a viable description of the distribution of nearby low density interstellar medium, but is not yet proven.« less
The missing piece syndrome in peer-to-peer communication

Typical protocols for peer-to-peer file sharing over the Internet divide files to be shared into pieces. New peers strive to obtain a complete collection of pieces from other peers and from a seed. In this paper we identify a problem that can occur if the seeding rate is not large enough. The problem is that, even if the statistics of the system are symmetric in the pieces, there can be symmetry breaking, with one piece becoming very rare. If peers depart after obtaining a complete collection, they can tend to leave before helping other peers receive the rare piece. 1
Trust games: A meta-analysis

Abstract We collect data from 162 replications of the Berg, Dickhaut, and McCabe Investment game (the “trust” game) involving more than 23,000 participants. We conduct a meta-analysis of these games in order to identify the effect of experimental protocols and geographic variation on this popular behavioral measure of trust and trustworthiness. Our findings indicate that the amount sent in the game is significantly affected by whether payment is random, and whether play is with a simulated counterpart. Trustworthiness is significantly affected by the amount by which the experimenter multiplies the amount sent, whether subjects play both roles in the experiment, and whether the subjects are students. We find robust evidence that subjects send less in trust games conducted in Africa than those in North America.
Studies of liquid metal surfaces using Auger spectroscopy

The surface composition of liquid gallium-tin alloys has been studied in an Auger electron spectrometer (AES) as a function of bulk composition and temperature. The sessile drop samples were cleaned by argon ion bombardment sputtering of the liquid. This technique produced surfaces that were entirely free of impurities within the sensitivity of AES and remained so for many days. Tin was found to be strongly adsorbed at the liquid-vacuum interface. Surface concentrations based on Auger measurements are in reasonably good agreement with values calculated from surface tension measurements interpreted in terms of a monolayer depth distribution model for the adsorbed tin.
Multipath scattering model for LMDS

A model for multipath interference that more accurately depicts scattering mechanisms at frequencies allotted for local multipoint distribution service (LMDS) is proposed. The LMDS system addressed uses orthogonal frequency division multiplexing (OFDM). The proposed model is not statistical as is normally the case in most LMDS studies but relies on the geometrical theory of diffraction (GTD) that uses ray tracing techniques to model multipath scattering behavior in the low-to-mid GHz frequency range. Our study shows that the GTD multipath scattering model provides significant insight into the performance of LMDS systems operating in the GHz range. It is shown that OFDM performance may degrade significantly depending on the number and geometric features of the sources of multipath scattering. This work provides some insight into where it is appropriate to house or locate LMDS systems.
Conditional lambda-theories and the verification of static properties of programs

Abstract We present a proof that a simple compiler correctly uses the static properties in its symbol table. We do this by regarding the target code produced by the compiler as a syntactic variant of a λ-term. In general, this λ-term C may not be equal to the semantics S of the source program: they need be equal only when information in the symbol table is valid. We formulate this relation as a conditional λ-judgment Γ ⊃ S = C, where Γ is a formula that represents the invariants implicit in symbol table Γ. We present rules of inference for conditional λ-judgements and prove their soundness. We then use these rules to prove the correctness of a simple compiler that relies on a symbol table. The form of the proof suggests that such proofs may be largely mechanizable.
Income distribution, political instability, and investment

Abstract This paper successfully tests on a sample of 71 countries for the period 1960–85 the following hypotheses. Income inequality, by fuelling social discontent, increases sociopolitical instability. The latter, by creating uncertainty in the politico-economic environment, reduces investment. As a consequence, income inequality and investment are inversely related. Since investment is a primary engine of growth, this paper identifies a channel for an inverse relationship between income inequality and growth. We measure socio-political instability with indices which capture the occurrence of more or less violent phenomena of political unrest and we test our hypotheses by estimating a two-equation model in which the endogenous variables are investment and an index of socio-political instability. Our results are robust to sensitivity analysis on the specification of the model and the measure of political instability, and are unchanged when the model is estimated using robust regression techniques.
Reduced complexity Sphere Decoding

In Multiple-Input Multiple-Output (MIMO) systems, Sphere Decoding (SD) can achieve performance equivalent to full search Maximum Likelihood (ML) decoding with reduced complexity. Several researchers reported techniques that reduce the complexity of SD further. In this paper, a new technique is introduced which decreases the computational complexity of SD substantially, without sacrificing performance. The reduction is accomplished by deconstructing the decoding metric to decrease the number of computations and exploiting the structure of a lattice representation. Simulation results show that this approach achieves substantial gains for the average number of real multiplications and real additions needed to decode one transmitted vector symbol. As an example, for a 4 × 4 MIMO system, the gains in the number of multiplications are 85% with 4-QAM and 90% with 64-QAM, at low SNR.
Interactive 3D fluid jet painting

We present an interactive system which allows users to create abstract paintings in the style of Jackson Pollock using three dimensional viscous fluid jets. Pollock's paintings were created by using streams of household paint to make guided, semi-random patterns on his canvas. Our fluid jet model consists of two coupled simulations: a Navier-Stokes solver for an axis-symmetric fluid column and a linked-mass system for tracking the three dimensional motion of the jet's axis line. The paint trails left by the jets are represented using implicit surfaces. Our system also includes an algorithm for generating the splatter patterns created by the impacts of a highspeed fluid drops. We allow users to analyze the fractal properties of the images they create, comparing them to those known to exist in Pollock's own paintings.
Solvent Effects in the Nucleophilic Substitutions of Tetrahydropyran Acetals Promoted by Trimethylsilyl Trifluoromethanesulfonate: Trichloroethylene as Solvent for Stereoselective C- and O-Glycosylations

The selectivities of nucleophilic substitution reactions of tetrahydropyran acetals promoted by trimethylsilyl trifluoromethanesulfonate depend upon the reaction solvent. Polar solvents favor the formation of SN1 products, while nonpolar solvents favor SN2 products. Trichloroethylene was identified as the solvent most likely to give SN2 products in both C- and O-glycosylation reactions.
Ceramic Composite Attachments for Transmission of High-Torque Loads

The use of fiber-reinforced ceramic matrix composites (FRCMC) for advanced turbopump (T/P) hot-section components offers a number of potential advantages relative to the use of ‘conventional’ materials. Among these advantages are reduced weight, enhanced life with reduced maintenance and improved performance achievable by increasing the turbine inlet temperature. FRCMC are, however, emerging materials, and their design and analysis present unique challenges. These composites have relatively low thermal expansion coefficients and low strain-to-failure characteristics, and they have nonlinear, anisotropic properties. These characteristics particularly complicate the design of attachments to mating metallic components within a T/P.In an ongoing program*, an FRCMC stator and rotor for a rocket engine T/P are being developed for eventual ground test demonstration. The rotor attachment is designed to transmit high torque loads and provides an example of a design methodology which is compatible with current analytical capabilities. The approach used and described herein applies an empirically derived materials properties data base in combination with macromechanical analysis to reach a solution to this design challenge. This example demonstrates both the capabilities and the limitations of current design and analysis practices and provides direction for future development. A curvic coupling was chosen to meet the specific design goals and will be fabricated and tested to verify the design.Copyright © 1993 by ASME
MAGNITUDE, DOSE-REQUIREMENT AND MODE OF DEVELOPMENT OF TACHYPHYLAXIS TO SUXAMETHONIUM IN MAN

Tachyphylaxis to suxamethonium infused at a constant rate was studied in 15 surgical patients under enflurane—nitrous oxide—oxygen anaesthesia. The compound electromyographic response of the adductor pollicis muscle to stimulation of the ulnar nerve was monitored. A short-lasting and a long-lasting nearly steady state were observed in Phase I and in Phase II, respectively, during both of which a constant infusion resulted in a constant block. Tachyphylaxis occurred during the transition of phases, beginning after infusion of 1.4 ±0.6 (SD) mg kg−1 of suxamethonium, and 36±14(SD) minutes of exposure. Tachyphylaxis peaked after 2.6±1.3 (SD) mg kg−1, and 72±38 (SD) minutes of exposure. The maximum gain in neuromuscular transmission from the initial maintenance level of block as the result of tachyphylaxis was 53±24 (SD) % of the control. The results are thought to reconcile previously reported conflicting clinical observations on tachyphylaxis.
A Sparsity-Based Model of Bounded Rationality*

This article defines and analyzes a “sparse max” operator, which is a less than fully attentive and rational version of the traditional max operator. The agent builds (as economists do) a simplified model of the world which is sparse, considering only the variables of first-order importance. His stylized model and his resulting choices both derive from constrained optimization. Still, the sparse max remains tractable to compute. Moreover, the induced outcomes reflect basic psychological forces governing limited attention. The sparse max yields a behavioral version of basic chapters of the microeconomics textbook: consumer demand and competitive equilibrium. I obtain a behavioral version of Marshallian and Hicksian demand, Arrow-Debreu competitive equilibrium, the Slutsky matrix, the Edgeworth box, Roy’s identity, and so on. The Slutsky matrix is no longer symmetric: nonsalient prices are associated with anomalously small demand elasticities. Because the consumer exhibits nominal illusion, in the Edgeworth box, the offer curve is a two-dimensional surface rather than a one-dimensional curve. As a result, different aggregate price levels correspond to materially distinct competitive equilibria, in a similar spirit to a Phillips curve. The Arrow-Debreu welfare theorems typically do not hold. This framework provides a way to assess which parts of basic microeconomics are robust, and which are not, to the assumption of perfect maximization. JEL Codes: D01, D03, D11, D51.
How small should an economy's fiscal deficit be? - a monetary programming approach

A spreadsheet planning model to help determine the government deficit consistent with a specified vector of country macroeconomic objectives. Beckerman describes a spreadsheet planning model to help determine the government deficit consistent with a policymaker's vector of principal macroeconomic objectives (including real GDP growth, inflation, exchange rate, and international reserve accumulation). The model focuses on the monetary accounts, applying balance-of-payments forecasts formulated separately but based on the same macroeconomic objectives. The model is a consistency exercise, intended as part of a broader consistency exercise for a given macroeconomy. It offers one more perspective on the question of how large a government deficit should be - a perspective that can be used in conjunction with others. For each forecast period, the model determines consistent period-end and period-average stocks for the economy's outstanding central bank assets and liabilities and government obligations. It applies forecasting assumptions about interest rates to forecast central bank profit-and-loss flows, and takes account of these in determining the overall flow of resources that would be available to finance the government deficit. An annex describes a (purely illustrative) simulation carried out during 1999 for Ecuador. This paper - a product of the Poverty Reduction and Economic Management Sector Unit, Latin America and the Caribbean Region - is part of a larger effort in the region to strengthen the tools for macroeconomic policy analysis and planning in the region's economies.
BEGGING THE QUESTION WITH STYLE: ANARCHY, STATE, AND UTOPIA AT THIRTY YEARS

At 30 years' distance, it is safe to say that Nozick's Anarchy, State and Utopia has achieved the status of a classic. It is not only the central text for all contemporary academic discussions of libertarianism; with Rawls's A Theory of Justice, it arguably frames the landscape of academic political philosophy in second half of 20th century. Many factors, obviously account for the prominence of the book. This paper considers one: the book's use of rhetoric to charm and disarm its readers, simultaneously establishing Nozick's credibility with readers, turning them on his ideological opponents, and helping his argument over some of its more serious substantive difficulties.