cssi/SciSciGPT-SciSciNet huggingface dataset:
Designed Chiral Acyl Radical Equivalents. Preparation and Cyclizations of Disymmetrically Substituted 1,3-Dioxabicyclo[4.4.0]decan-2-yl Radicals

The diastereoselectivity of 5-exo-trigonal cyclizations of 2-(4-penten-1-yl)-1,3-dioxolan-2-yl and 2-(4-penten-1-yl)-1,3-dioxan-2-yl radicals is investigated. When dioxolanes or dioxanes derived from C2 symmetrically substituted diols are employed the diastereoselectivity is poor. In the dioxanyl series this is a consequence of the cyclization occurring through a twist-boat conformer. Disymmetrically substituted dioxanyl radicals, derived from the alcohols 21 and 41, are, however, constrained to chairlike conformations and accordingly give rise to highly diastereoselective cyclizations. Conditions are described for the hydrolysis of the resulting spiroacetals and for determination of the ee of the resulting 2-methylcyclopentanones.
Synthesis of the C'D'E'F' domain of maitotoxin.

A devised biomimetic strategy toward the C′D′E′F′ domain (6) of maitotoxin (1) led to hydroxy triepoxide 8 as a postulated polyepoxide precursor. However, all attempts to induce the desired cascade to form the targeted compound through a zip-type reaction under neutral or acidic conditions failed, prompting adoption of a linear stepwise approach to 6. The successful synthetic strategy for the synthesis of the C′D′E′F′ domain of maitotoxin commenced from furfuryl alcohol (11), proceeded through F′ ring building block 15, and involved two regio- and stereoselective intramolecular hydroxy epoxide openings and a stereoselective SmI2-mediated ring closure to forge rings C′, E′, and D′, respectively. 13C NMR spectroscopic analysis of the synthesized domain (6) and comparisons with previous results confirmed the original structural assignment of this region of maitotoxin. X-ray crystallographic analysis of 6 provided unambiguous proof of its structure.
Numerical Study of EHD-Enhanced Forced Convection Using Two-Way Coupling

Numerical results are presented for heat transfer enhancement using electric field in forced convection in a horizontal channel. The main objective of the present study is to verify the assumption that is commonly used in the numerical study of this kind of problem, which assumes that the electric field can modify the flow field but not vice versa (i.e., the so-called one-way coupling). To this end, numerical solutions are obtained for a wide range of governing parameters (V 0 =10, 12.5, 15 and 17.5 kV as well as u i =0.0759 to 1.2144 m/s) using both one-way and two-way couplings
Where, oh where has the r-process gone?

We present a review of the possible sources for r-process nuclei (r-nuclei). It is known that there is as yet no self-consistent mechanism to provide abundant neutrons for a robust r-process in the neutrino-driven winds from nascent neutron stars. We consider that the heavy r-nuclei with mass numbers A>130 (Ba and above) cannot be produced in the neutrino-driven winds. Nonetheless, the r-process and the neutrino-driven winds may be directly or indirectly related by some unknown additional mechanism, which, for example, could provide ejecta with very short dynamic timescales of ≾0.004 s. This undetermined mechanism must supply a neutron source within the same general stellar sites that undergo core collapse to produce the neutron star. Observational data on low-metallicity stars in the Galactic halo show that sites producing the heavy r-nuclei do not produce Fe or any other elements between N and Ge. Insofar as a forming neutron star is key to producing the heavy r-nuclei, then the only possible sources are supernovae resulting from collapse of O–Ne–Mg cores or accretion-induced collapse of white dwarfs, neither of which produce the elements of the Fe group or those of intermediate mass (above C and N). Observational evidence on s and r-nuclei in low-metallicity stars with high C and N abundances shows that the r-process is also active in binary systems. The nuclei with A∼90–110 produced by charged-particle reactions (CPR) in the neutrino-driven winds are in general present in metal-poor stars with high or low abundances of heavy r-nuclei. The CPR nuclei and the heavy r-nuclei are not strongly coupled. Some metal-poor stars show extremely high enrichments of heavy r-nuclei and have established that the abundance patterns of these nuclei are universally close to the solar abundance pattern of heavy r-nuclei. Using a template star with high enrichments of heavy r-nuclei and another with low enrichments we develop a two-component model based on the abundances of Eu (from sources for heavy r-nuclei) and Fe (from Fe core-collapse supernovae). This model gives very good quantitative predictions for the abundances of all the other elements in those metal-poor stars with [Fe/H]≲-1.5 for which the Eu and Fe abundances are known. We attribute the CPR elements such as Sr, Y, and Zr to reactions in the neutrino-driven winds from a nascent neutron star and the heavy r-nuclei to the hypothecated true “r-process”. The CPR nuclei should be produced whenever a neutron star is formed regardless of whether heavy r-nuclei are produced or not. Using the two-component model we estimate the yield of the CPR element Sr to be ∼10^(-6)M_⊙ for a single neutron star formation event. Self-consistent astrophysical models are needed to establish that the CPR nuclei are common to the neutron stars produced in both sources for the heavy r-nuclei and those for Fe. We show that the observational data appear fully consistent with the two-component model. The specific mechanism and site for the production of heavy r-nuclei remains to be found.
Analysis of Sound Signal Generation Due to Flank Wear in Turning

A new concept is introduced to model the main effect of tool wear on system dynamics during stable cutting. Audible sound generated from the cutting process is analyzed as a source for monitoring tool wear during turning, assuming adhesive wear as the predominant wear mechanism. The analysis incorporates the dynamics of the cutting process. In modeling the interaction on the flank surface, the asperities on the surfaces are represented as a trapezoidal series function with normal distribution. The effect of changing asperity height, size, spacing, and the stiffness of the asperity interaction is investigated and compared with experimental data.
UNDERWRITING SPREADS AND REPUTATIONAL CAPITAL: AN ANALYSIS OF NEW CORPORATE SECURITIES

When entering a new security market, investment banks must establish their reputation. This is done through direct experience in the security market or through reputational capital established in existing security markets. I examine the effects of underwriters' market reputation in publicly underwritten offerings in forty-three financial innovations and find more significant entry barriers for less prestigious underwriters. An analysis of underwriting spreads reveals first-issue pricing advantages due to reputational capital. Unlike the more prestigious underwriters, the less prestigious underwriters reduce spreads upon first entry into each new security market to overcome their lack of market reputation.
Along-slope current generation by obliquely incident internal waves

A series of numerical experiments is performed to investigate the breaking of obliquely incident internal waves propagating towards a bottom slope. The case of critical reflection is considered, where the angle between the wave group velocity vector and the horizontal matches the bottom slope angle. The flow evolution is found to be significantly different from the evolution observed previously in simulations of normally incident waves. The divergence of the Reynolds stress in the breaking zone causes a strong along-slope mean current, which changes the flow structure dramatically. The wave does not penetrate the current but breaks down at its upper surface as the result of a critical layer interaction. A continuously broadening mean along-slope current with an approximately constant velocity is produced. We propose a simple model of the process based on the momentum conservation law and the radiation stress concept. The model predictions are verified against the numerical results and are used to evaluate the possible strength of along-slope currents generated by this process in the ocean.
Electroactive polymer based microfluidic pump

Abstract A planar, valveless, microfluidic pump using electrostrictive poly(vinylidene fluoride-trifluoroethylene) [P(VDF-TrFE)] based polymer as the actuator material is presented. P(VDF-TrFE) thick films having a large electrostrictive strain ∼5–7% and high elastic energy density of 1 J/cm 3 have been used in a unimorph diaphragm actuator configuration. The microfluidic pump was realized by integrating a nozzle/diffuser type fluidic mechanical-diode structure with the polymer microactuator. The P(VDF-TrFE) unimorph diaphragm actuator, 80 μm thick and 2.2 mm × 2.2 mm in lateral dimensions, showed an actuation deflection of 80 μm for an applied electric field of 90 MV/m. The microfluidic pump could pump methanol at a flow rate of 25 μl/min at 63 Hz with a backpressure of 350 Pa. The flow rate of this pump could be easily controlled by external electrical field. Two different sizes of nozzle/diffuser elements were studied and the pumping efficiency of these structures is 11 and 16%, respectively.
Nanoshell-Enabled Photothermal Cancer Therapy: Impending Clinical Impact

Much of the current excitement surrounding nanoscience is directly connected to the promise of new nanoscale applications in cancer diagnostics and therapy. Because of their strongly resonant light-absorbing and light-scattering properties that depend on shape, noble metal nanoparticles provide a new and powerful tool for innovative light-based approaches. Nanoshells—spherical, dielectric core, gold shell nanoparticles—have been central to the development of photothermal cancer therapy and diagnostics for the past several years. By manipulating nanoparticle shape, researchers can tune the optical resonance of nanoshells to any wavelength of interest. At wavelengths just beyond the visible spectrum in the near-infrared, blood and tissue are maximally transmissive. When nanoshell resonances are tuned to this region of the spectrum, they become useful contrast agents in the diagnostic imaging of tumors. When illuminated, they can serve as nanoscale heat sources, photothermally inducing cell death and tumor r...
Formation of oxometal complexes by the oxidative decarbonylation of metal carbonyls

Abstract Various metal carbonyls are readily decarbonylated by oxidation with tert-butyl hydroperoxide in benzene or dichloromethane solutions either at ambient temperatures or by slight heating. With the tri-carbonyl complex (dien)Mo(CO) 3 , the oxidative decarbonylation affords the trioxo complex (dien)MoO 3 in high yields. The rhenium tricarbonyl Cp*Re(CO) 3 is analogously converted by tert-butyl hydroperoxide in a one-step procedure to the trioxo complex Cp∗ReO 3 , either by heating a benzene solution to 80°C or by actinic irradiation at 25°C. The products derived from the oxidative decarbonylation of the other metal carbonyls have not been as readily identified since the corresponding oxometal complexes are by and large structurally uncharacterized.
The structure of the core of ideals

The core of an R-ideal I is the intersection of all reductions of I. This object was introduced by D. Rees and J. Sally and later studied by C. Huneke and I. Swanson, who showed in particular its connection to J. Lipman's notion of adjoint of an ideal. Being an a priori infinite intersection of ideals, the core is difficult to describe explicitly. We prove in a broad setting that: core(I) is a finite intersection of minimal reductions; core(I) is a finite intersection of general minimal reductions; core(I) is the contraction to R of a ‘universal’ ideal; core(I) behaves well under flat extensions. The proofs are based on general multiplicity estimates for certain modules.
A Parallel Two Pass MDL Context Tree Algorithm for Universal Source Coding

We present a novel lossless universal source coding algorithm that uses parallel computational units to increase the throughput. The length-N input sequence is partitioned into B blocks. Processing each block independently of the other blocks can accelerate the computation by a factor of B, but degrades the compression quality. Instead, our approach is to first estimate the minimum description length (MDL) source underlying the entire input, and then encode each of the B blocks in parallel based on the MDL source. With this two-pass approach, the compression loss incurred by using more parallel units is insignificant. Our algorithm is work-efficient, i.e., its computational complexity is O(N/B). Its redundancy is approximately B log(N/B) bits above Rissanen’s lower bound on universal coding performance, with respect to any tree source whose maximal depth is at most log(N/B).
SVX3: A deadtimeless readout chip for silicon strip detectors

Abstract A new silicon strip readout chip called the SVX3 has been designed for the 720 000 channel CDF silicon upgrade at Fermilab. SVX3 incorporates an integrator, analog delay pipeline, ADC, and data sparsification for each of 128 identical channels. Many of the operating parameters are programmable via a serial bit stream, which allows the chip to be used under a variety of conditions. Distinct features of SVX3 include use of a backside substrate contact for optimal ground referencing, and the capability of simultaneous signal acquisition and digital readout, allowing deadtimeless operation in the Fermilab Tevatron.
Topochemical synthesis of alkali-metal hydroxide layers within double- and triple-layered perovskites.

The formation of alkali-metal hydroxide layers within lamellar perovskites has been accomplished by a two-step topochemical reaction strategy. Reductive intercalation of ALaNb2O7 with alkali metal (A = K, Rb) and RbCa2Nb3O10 with Rb leads to A2LaNb2O7 and Rb2Ca2Nb3O10, respectively. Oxidative intercalation with stoichiometric amounts of water vapor, produced by the decomposition of calcium oxalate monohydrate in a sealed ampule, allows the insertion hydroxide species. Compounds of the form (A2OH)LaNb2O7 (A = K, Rb) and (Rb2OH)Ca2Nb3O10 are accessible. X-ray diffraction data indicates a clear layer expansion of almost 3 A on the insertion of hydroxide relative to that of the parent. Rietveld refinement of neutron diffraction data collected on deuterated samples of (Rb2OD)LaNb2O7 (P4/mmm space group, a = 3.9348(1) A, c = 14.7950(7) A) finds that both rubidium and oxygen species reside in cubic sites forming a CsCl-like interlayer structure between niobate perovskite blocks. Hydrogens, attached to the interl...
COMPACTION AND DENSITY FLUCTUATIONS IN VIBRATED GRANULAR MEDIA

We report measurements of the density of a vibrated granular material as a function of time or taps. The material studied consists of monodisperse spherical glass beads confined to a long, thin cylindrical tube. Changes in vibration intensity are used to induce transitions between two steady state densities that depend on the intensity of the vibrations. We find a complex time evolution similar to previous work on the irreversible relaxation from a loose state toward a steady state. In addition, frequency dependent third order moments of the density fluctuations are measured. The data indicate a coupling between large variations in density on one time scale and noise power over a broad range of higher-frequency scales.
Diastereoselection in the conjugate additions of organocopper reagents to N-enoyloxazolidinones

Abstract A survey of conjugate additions of Yamamoto organocopper reagents to N-enoyl-4-substituted oxazolidinones is reported. Diastereofacial selectivity is reversed for 4-phenyl and 4-benzyloxazolidinones of the same relative configuration. Alkenylcopper reagents demonstrate superior results in asymmetric additions using the 4-phenyloxazolidinone auxiliary.
Ion traps fabricated in a CMOS foundry

We demonstrate trapping in a surface-electrode ion trap fabricated in a 90-nm CMOS (complementary metal-oxide-semiconductor) foundry process utilizing the top metal layer of the process for the trap electrodes. The process includes doped active regions and metal interconnect layers, allowing for co-fabrication of standard CMOS circuitry as well as devices for optical control and measurement. With one of the interconnect layers defining a ground plane between the trap electrode layer and the p-type doped silicon substrate, ion loading is robust and trapping is stable. We measure a motional heating rate comparable to those seen in surface-electrode traps of similar size. This demonstration of scalable quantum computing hardware utilizing a commercial CMOS process opens the door to integration and co-fabrication of electronics and photonics for large-scale quantum processing in trapped-ion arrays.
Substance Abuse Treatment and Motor Vehicle Fatalities

The danger of alcohol- and drug-impaired driving implies that policies that reduce substance abuse can save lives. We study this issue in small U.S. counties where access to substance abuse treatment can be measured directly through the presence of treatment facilities. We find that placing an additional treatment clinic in a county reduces the number of alcohol-related motor vehicle fatalities by 15%. An additional outpatient clinic, which specializes in treating the local population, reduces the overall number of alcohol-related deaths by 26%. In the counties that we study, this reduction in alcohol-related accidents saves 0.66 lives per county per year.
Do Vacancy Decontrol Provisions Undo Rent Control

Abstract When rent control laws have vacancy decontrol–recontrol provisions, new tenants may offset lower future rent by paying higher current rent. Also when tenants compete for scarce apartments, those with longer durations will predominate in rental sectors that are controlled. New York City's rent stabilization has a vacancy decontrol–recontrol provision. As expected, I find that in 1981 tenants new to New York City's rent-stabilized sector paid higher rent than those who occupied comparable apartments in an uncontrolled sector. However, these same stabilized-sector tenants wound up paying less in 1987, provided that they still occupied the apartments. Furthermore, those who chose the stabilized sector had longer durations than those who chose the uncontrolled sector.
Fault containment in weakly stabilizing systems

Abstract Research on fine tuning stabilization properties has received attention for more than a decade. This paper presents probabilistic algorithms for fault containment. We demonstrate two exercises in fault containment in a weakly stabilizing system, which expedite recovery from single failures, and confine the effect of any single fault to the constant-distance neighborhood of the faulty process. The most significant aspect of the algorithms is that the fault gap, defined as the smallest interval after which the system is ready to handle the next single fault with the same efficiency, is independent of the network size. We argue that a small fault gap increases the availability of the fault-free system.
Longitudinal residual stresses in boron fibers

A technique is proposed for measuring the longitudinal residual stress distribution in commercial CVD (Chemical Vapor Deposition) boron on tungsten fibers of 102, 142, and 203 microns in diameter. The experimental apparatus is so designed that continuous measurements are made of the length changes of a boron fiber specimen as the surface of the fiber is removed by electropolishing. The effects of surface removal on core residual stress and core-initiated fracture are discussed. The three sizes of boron fibers investigated show similar residual stress distributions, i.e., compressive at the surface, tensile near the core, and for the 102-micron fiber compressive again in the core. It is shown that an increase in UTS is due to the increase in the compressive stress at the core produced by fiber contraction during surface removal. An expression is derived for calculating the longitudinal residual stress at a given radius for an as-received fiber of a certain radius from measurements of the axial strain produced by removal of the surface by electropolishing.
THE STABILITY AND DYNAMICS OF PLANETS IN TIGHT BINARY SYSTEMS

Planets have been observed in tight binary systems with separations less than 20 AU. A likely formation scenario for such systems involves a dynamical capture, after which high relative inclinations are likely and may lead to Kozai oscillations. We numerically investigate the fate of an initially coplanar double-planet system in a class of binaries with separation ranging between 12 and 20 AU. Dynamical integrations of representative four-body systems are performed, each including a hot Jupiter and a second planet on a wider orbit. We find that, although such systems can remain stable at low relative inclinations (40°), high relative inclinations are likely to lead to instabilities. This can be avoided if the planets are placed in a Kozai-stable zone within which mutual gravitational perturbations can suppress the Kozai mechanism. We investigate the possibility of inducing Kozai oscillations in the inner orbit by a weak coupling mechanism between the planets in which the coplanarity is broken due to a differential nodal precession. Propagating perturbations from the stellar companion through a planetary system in this manner can have dramatic effects on the dynamical evolution of planetary systems, especially in tight binaries and can offer a reasonable explanation for eccentricity trends among planets observed in binary systems. We find that inducing such oscillations into the orbit of a hot Jupiter is more likely in tight binaries and an upper limit can be set on the binary separation above which these oscillations are not observed.
Impact of the Farm Financial Crisis on Agribusiness Firms and Rural Communities

The high real interest rates and low commodity prices since the early 1980s have created financial problems for many farmers, especially those in highly leveraged positions. Surveys of farmers in the United States and Iowa have indicated that as many as 30% of U.S. farm operators have debt-to-asset ratios greater than 70%. Several farm simulation studies suggest that farmers in this greaterthan 70% debt-to-asset category are likely to become insolvent within two to three years if economic conditions and commodity prices do not improve significantly (Johnson et al., "Progress Report"). Farm asset values have been falling in response to these conditions in agriculture. While farmers are bearing the brunt of the financial difficulties in agriculture, the current crisis has implications for other sectors in the rural economy that interact with the farm economy. The viability of agribusinesses which supply production inputs and marketing services to farmers, the main street merchants who provide consumer and retail services, and the other social institutions such as schools
A new shift-invariant representation for periodic linear systems

Abstract This paper presents a new family of shift-invariant representations for periodic linear discrete-time systems. This representation has the advantages over the standard representation [5] of preserving the time step of the original system, and of preserving causality under arbitrary feedback. The disadvantage is that the realization is not minimal. An application in attitude determination is presented.
A generalization of MacMahon's formula

We generalize the generating formula for plane partitions known as MacMahon's formula as well as its analog for strict plane partitions. We give a 2-parameter generalization of these formulas related to Macdonald's symmetric functions. The formula is especially simple in the Hall-Littlewood case. We also give a bijective proof of the analog of MacMahon's formula for strict plane partitions.
Photometric observations of visual double stars by the area scanning technique

UBV magnitude differences in visual binaries are presented and their accuracy is discussed. Typical observed image profiles of double stars, including sample profiles of Antares, are shown.
Mean Flowfield Structure of a Supersonic Three-Dimensional Base Flow

The mean flowfield structure in the wake region of a circular cylinder at 10 o angle of attack in Mach 2.5 flow is described. Results from the full three-dimensional Reynolds averaged Navier-Stokes equations, supplemented with a compressibility-corrected two-equation turbulence model, are compared with extensive available experimental data. The main elements of the shock pattern, surface oil flow on the afterbody and the base surfaces, velocity vector plots in the symmetry and lateral planes and end-view flow images are reproduced to good accuracy. Based on this success, the computed solution is employed to generate a model for the mean flow. The main feature is a pair of longitudinal vortices, separated by high-speed fluid entrained primarily from the leeward and lateral afterbody boundary layers, and bounded from below by the windward afterbody boundary layer. The three-dimensional wave structure is elucidated and correlated with the streamline structure. Vorticity distribution analysis indicates that in the mean flow description, the vortex cores are two legs of a horseshoe-like structure. The predictive capability of the present RANS approach is baselined for future detached eddy simulations by comparing mesh resolved surface pressures on the afterbody and the base region: these are found to differ by between 10% to 15%.
Economic Linkages between Agriculture and Other Sectors within Rural America

Examines the relationship between agriculture and communities in rural areas in the United States. Link between economics and agriculture; Historical indicators of performance in the farm and nonfarm sectors of midwestern states; Information on agricultural output at the beginning of the 1985 farm bill.
tinyNBI: distilling an API from essential OpenFlow abstractions

If simplicity is a key strategy for success as a network protocol OpenFlow is not winning. At its core OpenFlow presents a simple idea, which is a network switch data plane abstraction along with a control protocol for manipulating that abstraction. The result of this idea has been far from simple: a new version released each year, five active versions, complex feature dependencies, unstable version negotiation, lack of state machine definition, etc. This complexity represents roadblocks for network, software, and hardware engineers. We have distilled the core abstractions present in 5 existing versions of OpenFlow and refactored them into a simple API called tinyNBI. Our work does not provide high level network abstractions (address pools, VPN maps, etc.), instead it focuses on providing a clean low level interface that supports the development of these higher layer abstractions. The goal of tinyNBI is to allow configuration of all existing OpenFlow abstractions without having to deal with the unique personalities of each version of OpenFlow or their level of support in target switches.
Enhanced effects of starlight on the interstellar medium

The photodesorption of molecules and atoms from the surfaces of interstellar grains can be an important source of heating for the interstellar medium and the origin of instabilities which may separate grains and gas. For low densities, the force exerted on the grains is proportional to the gas density and independent of the radiation intensity; for high densities, it is proportional to the radiative flux and independent of the gas density. This force may act differently on grains of different sizes. The photoelectric effect may also be an efficient mechanism for the separation of gas and dust in diffuse clouds.
Realizing degree imbalances in directed graphs

Abstract In a directed graph, the imbalance of a vertex v is b(v)=d + (v)−d − (v) . We characterize the integer lists that can occur as the sequence of imbalances of a simple directed graph. For the realizable sequences, we determine the maximum number of arcs in a realization and provide a greedy algorithm that constructs realizations with the minimum number of arcs.
Post-shock temperatures in minerals

An experimental technique was developed for measuring post-shock temperatures in a wide variety of materials, including those of geophysical interest such as silicates. The technique uses an infrared radiation detector to determine the brightness temperature of samples shocked to pressures in the range 5 to approximately 30 GPa; in these experiments measurements were made in two wavelength ranges (4.5 to 5.75 microns and 7 to 14 microns). Reproducible results, with the temperatures in the two wavelength bands generally in excellent agreement, were obtained for aluminum-2024 (10.5 to 33 GPa, 125 to 260 C), stainless steel-304 (11.5 to 50 GPa, 80 to 350 C), crystalline quartz (5.0 to 21.5 GPa, 80 to 250 C), forsterite (7.5 to 28.0 GPa, approximately 30 to 160 C) and Bamble bronzite (6.0 to 26.0 GPa, approximately 30 to 225 C). It is concluded that release adiabat data should be used, wherever available, for calculations of residual temperature, and that adequate descriptions of the shock and release processes in minerals are more complex than generally assumed.
No Easy Way Out: Dangerous Offenders and Preventive Detention

One of the more vexing problems faced by authorities in the criminal justice system is the existence of individuals who have served their sentences for their previous crimes but seem very likely to commit further, quite serious offenses involving vio lence against their fellow citizens if they are released from prison. Such offenders are especially troubling if we assume that the sentences for their previous crimes were propor tional, they are not eligible for standard forms of involuntary civil commitment, and if, pace R. A. Duff, we imagine what we would say to the future victims (or surviving family members) of their crimes if they ask why some form of pre ventive detention of these dangerous individuals was not undertaken.1 For many, it suffices to respond to the prospect of preventive detention by saying that we currently do not have the means available to identify accurately dangerous offenders in advance of their crimes.2 Even if this is true, we might not be convinced that it fully disposes of the problems posed by such offenders. First, we might get better at identifying the individuals who are
New unifying concepts for modeling smart materials

Material modeling techniques for active materials include a broad number of approaches that are often focused on predicting a specific field-coupled constitutive relation. This field-coupled material behavior may include electro-mechanical, magnetostrictive, thermal or light induced phase transformations, or ionic deformation. Limited work has been conducted on developing a unified theory. Such theories are useful for quantifying underlying field-coupled mechanics concepts that may otherwise be neglected in phenomenological models. The theoretical approach presented here employs nonlinear continuum mechanics coupled to a set of microscale order parameters that describe microstructure evolution and phase changes. Unifying concepts are obtained which illustrate how material constants such as piezoelectric coefficients depend on the choice of the order parameter and mechanical energy function without introducing explicit phenomenological coupling parameters.
Fractional standard map: Riemann-Liouville vs. Caputo

Abstract Properties of the phase space of the standard maps with memory obtained from the differential equations with the Riemann–Liouville and Caputo derivatives are considered. Properties of the attractors which these fractional dynamical systems demonstrate are different from properties of the regular and chaotic attractors of systems without memory: they exist in the asymptotic sense, different types of trajectories may lead to the same attracting points, trajectories may intersect, and chaotic attractors may overlap. Two maps have significant differences in the types of attractors they demonstrate and convergence of trajectories to the attracting points and trajectories. Still existence of the most remarkable new type of attractors, “cascade of bifurcation type trajectories”, is a common feature of both maps.
On the Performance Analysis of Resilient Networked Control Systems Under Replay Attacks

This technical note studies a resilient control problem for discrete-time, linear time-invariant systems subject to state and input constraints. State measurements and control commands are transmitted over a communication network and could be corrupted by adversaries. In particular, we consider the replay attackers who maliciously repeat the messages sent from the operator to the actuator. We propose a variation of the receding-horizon control law to deal with the replay attacks and analyze the resulting system performance degradation. A class of competitive (resp. cooperative) resource allocation problems for resilient networked control systems is also investigated.
Horizontal Gravel-Packing Technique for Slim, Cased Holes in Highly Permeable Zones: A Single-Well Case History

Gravel packing is becoming a common practice for controlling unconsolidated sands in horizontal wellbores. So far horizontal gravel packing has been applied almost exclusively to open holes with screens in them. If a formation has a high permeability, and therefore a high fluid loss rate, placement of a gravel pack may be prevented by premature dehydration and bridging of the gravel pack sand in the wellbore/screen annulus. The usual method of preventing these high fluid losses and the resultant bridging is to damage the formation face prior to gravel packing. The damage mechanism is usually salt, calcium carbonate, or other particles that seal off the formation face. Once gravel packing is completed, the formation damage is (hopefully) remediated using acid or undersaturated brines to restore the completion's productivity. There is, however, a risk that the damage cannot be successfully removed once it is gravel packed against the formation face. Acid diversion is also a problem when attempting to remediate damage in an open-hole gravel packed completion. This paper presents an alternative technique for performing a horizontal gravel pack in a high permeability zone while reducing the risk of permanently damaging the formation's permeability. The technique involves cementing casing through the horizontal completion interval and then shooting perforations in a horizontal orientation. The perforations can then be acidized with better diversion techniques than is possible in an open hole completion. An uncentralized screen is then gravel packed. The horizontally positioned perforations provide a self-diverting gravel pack. The self-diverting nature of thus technique makes it relatively insensitive to fluid loss: whereas, open-hole techniques are very sensitive to fluid loss. The uncentralized liner rests on the bottom of the horizontal to provide maximum standoff from the perforations. The above technique was applied at Thums Long Beach Company to a well with a 560' horizontal completion cased with a 4-1/2 liner (4.052 ID). The technique's acidizing phase, however, was not performed duc to fishing concerns inside the slim liner. This paper presents a case history for gravel packing a 690 long. 2-7/8 slotted liner inside the horizontal 4-1/2 casing. To our knowledge, this is the slimmest horizontal gravel pack ever attempted. The gravel packing was performed successfully even though fluid returns were never established during the job. The lack of fluid returns is duc to excessive fluid loss to the formation. The self-diverting nature of the horizontal perforations was the key to successful gravel packing. Production rates, on the other hand were not as successful since we did not acidize the perforations prior to gravel packing. Comparisons between this well and open-hole horizonlal gravel packs are made.
Electron-ion scattering in dense multi-component plasmas: application to the outer crust of an accreting neutron star

The thermal conductivity of a dense multi-component plasma (MCP) is critical to the modeling of accreting neutron stars. To this end, we perform large-scale molecular dynamics simulations to calculate the static structure factor of the dense MCP in the neutron star crust from near the photosphere-ocean boundary to the vicinity of the neutron drip point. The structure factors are used to validate a microscopic linear mixing rule that is valid for arbitrarily complex plasmas over a wide range of Coulomb couplings. The microscopic mixing rule in turn implies and validates the linear mixing rule (LMR) for the equation of state properties and also the LMR for the electrical and thermal conductivities of dense MCPs. To make our result as useful as possible, for the specific cases of electrical and thermal conductivities, we provide a simple analytic fit that is valid for arbitrarily complex MCPs over a wide range of Coulomb couplings. We compute the thermal conductivity for a representative compositional profile of the outer crust of an accreting neutron star in which hundreds of nuclear species can be present. We utilize our results to re-examine the so-called impurity parameter formalism as used to characterize impure plasmas.
Redshifts from Spitzer Spectra for Optically Faint Radio-selected Infrared Sources

Spectra have been obtained with the Infrared Spectrograph on the Spitzer Space Telescope for 18 optically faint sources (R 23.9 mag) having fν(24 μm) > 1.0 mJy and having radio detections at 20 cm to a limit of 115 μJy. The sources are within the Spitzer First Look Survey. Redshifts are determined for 14 sources from strong silicate absorption features (12 sources) or strong PAH emission features (two sources), with median redshift of 2.1. Results confirm that optically faint sources of ~1 mJy at 24 μm are typically at redshifts z ~ 2, verifying the high efficiency in selecting high-redshift sources based on extreme infrared-to-optical flux ratio, and indicate that 24 μm sources that also have radio counterparts are not systematically different than samples chosen only by their infrared-to-optical flux ratios. Using the parameter q = log[fν(24 μm)/fν(20 cm)], 17 of the 18 sources observed have values of 0 < q < 1, in the range expected for starburst-powered sources, but only a few of these show strong PAH emission as expected from starbursts, with the remainder showing absorbed or power-law spectra consistent with an AGN luminosity source. This confirms previous indications that optically faint Spitzer sources with fν(24 μm) 1.0 mJy are predominately AGNs and represent the upper end of the luminosity function of dusty sources at z ~ 2. Based on the characteristics of the sources observed so far, we predict that the nature of sources selected at 24 μm will change for fν(24 μm) 0.5 mJy to sources dominated primarily by starbursts.
Kinetic studies of ligand substitution rates for the Ru(NH3)5(H2O)2+ ion in Nafion films

Substitution rates have been measured for reaction of a number of pyridines with the Nafion-bound Ru(NH/sub 3/)/sub 5/(H/sub 2/O)/sup 2 +/ complex. Reaction activities have been determined by electrochemical techniques, which also allow for determination of site thermodynamics and heterogeneity during the course of the reaction. Diffusion-coefficient effects are investigated by variation in polymer film thickness, and partition coefficients have been determined under equilibrium conditions by optical absorbance techniques. The partition-coefficient corrected rate law is found to be first order in Nafion-bound (Ru/sup II/) and first order in ligand concentration in the polymer phase. The partition-coefficient corrected bimolecular rate constants for a variety of pyridine ligands are found to vary by a factor of 5, which contrasts with the relatively constant substitution rates observed in aqueous solution. Also, sterically hindered ligands, such as 2-propylpyridine, exhibit surprisingly high substitution rate constants on the Nafion-bound Ru/sup II/ ion. These rate data indicate that pronounced molecular reactivity changes can occur upon electrode modification and have implications with respect to the design of chemically modified electrodes for use in electrocatalysis.
Transient X-ray sources in the field of the unidentified gamma-ray source TeV J2032+4130 in Cygnus

We present an analysis of Chandra ACIS observations of the field of TeV J2032+4130, the first unidentified TeV source, detected serendipitously by HEGRA. This deep (48.7 ks) observation of the field follows up on an earlier 5 ks Chandra director’s discretionary observation. Of the numerous point-like X-ray sources in the field, the brightest are shown to be a mixture of early and late-type stars. We find that several of the X-ray sources are transients, exhibiting rapid increases in count rates by factors 3–10, and similar in nature to the one, hard absorbed transient source located in the earlier Chandra observation of the field. None of these transient sources are likely to correspond to the TeV source. Instead, we identify a region of diffuse X-ray emission within the error circle of the TeV source and consider its plausible association.
Tuning Nanoparticle Catalysis for the Oxygen Reduction Reaction

Advances in chemical syntheses have led to the formation of various kinds of nanoparticles (NPs) with more rational control of size, shape, composition, structure and catalysis. This review highlights recent efforts in the development of Pt and non-Pt based NPs into advanced nanocatalysts for efficient oxygen reduction reaction (ORR) under fuel-cell reaction conditions. It first outlines the shape controlled synthesis of Pt NPs and their shape-dependent ORR. Then it summarizes the studies of alloy and core-shell NPs with controlled electronic (alloying) and strain (geometric) effects for tuning ORR catalysis. It further provides a brief overview of ORR catalytic enhancement with Pt-based NPs supported on graphene and coated with an ionic liquid. The review finally introduces some non-Pt NPs as a new generation of catalysts for ORR. The reported new syntheses with NP parameter-tuning capability should pave the way for future development of highly efficient catalysts for applications in fuel cells, metal-air batteries, and even in other important chemical reactions.
A Chiral Rhodium Complex for Rapid Asymmetric Transfer Hydrogenation of Imines with High Enantioselectivity

A chiral rhodium complex, (R)-Cp*RhCl[(1S,2S)-p-TsNCH(C6H5)CH(C6H5)NH2 ] (1a, (S,S)-Cp*RhClTsDPEN), generated from [Cp*RhCl2]2 and (1S,2S)-N-p-toluenesulfonyl-1,2-diphenylethylenediamine [(S,S)-TsDPEN], and its enantiomer 1b were found to provide superior catalysts for the rapid, high-yielding, asymmetric transfer hydrogenation of some heterocyclic imines, using an HCO2H−Et3N azeotrope as the hydrogen source.
A Model-Free ON–OFF Iterative Adaptive Controller Based on Stochastic Approximation

A model-free on-off iterative adaptive controller is described for application to microscale servo systems performing repeated motions under extremely strict power constraints. The approach is motivated by the needs of piezoelectric actuators in autonomous microrobots, where power consumption in analog circuitry and/or for position sensing may be much larger than that of the actuators themselves. The control algorithm adjusts switching instances between “on” and “off” inputs to the actuator to minimize an objective function using simultaneously perturbed stochastic approximation of the gradient with just a single sensor measurement in each iteration. Convergence conditions for the gradient approximation are shown to apply when the possibility for a range of possible switching times minimizing the objective function is accounted for, while a method is proposed for avoiding local minima for plants with bounded nonlinearities. The algorithm is tested on a prototype piezoelectric microactuator.
What Happened to the NGC 6251 Counterjet

We have used the Very Long Baseline Array to produce a high dynamic range image of the nucleus of NGC 6251 at 1.6 GHz and snapshot images at 5.0, 8.4, and 15.3 GHz to search for emission from a parsec-scale counterjet. Previous VLBI images at 1.6 GHz have set a lower limit for the jet/counterjet brightness ratio near the core at about 80:1, which is larger than expected, given the evidence that the radio axis is fairly close to the plane of the sky. A possible explanation is that the inner few parsecs of the counterjet are hidden by free-free absorption by ionized gas associated with an accretion disk or torus. This would be consistent with the nearly edge-on appearance of the arcsecond-scale dust disk seen in the center of NGC 6251 by Hubble Space Telescope (HST). We detect counterjet emission close to the core at 1.6 GHz, but not at the higher frequencies. Given that the optical depth of free-free absorption falls off more rapidly with increasing frequency than the optically thin synchrotron emission from a typical radio jet, this result implies that the absence of a detectable parsec-scale counterjet at high frequencies is not due to free-free absorption unless the density of ionized gas is extremely high and we have misidentified the core at 1.6 GHz. The most likely alternative is a large jet/counterjet brightness ratio caused by relativistic beaming, which in turn requires the inner radio axis to be closer to our line of sight than the orientation of the HST dust disk would suggest.
A facile synthesis of 2-oxazolidinones via Hofmann rearrangement mediated by bis(trifluoroacetoxy)iodobenzene

Abstract A mild and efficient synthesis of 2-oxazolidinones from β-hydroxypropionamides via Hofmann rearrangement was achieved in 96% to quantitative yield using bis(trifluoroacetoxy)iodobenzene (BTI) in acetonitrile. The method should be useful in both solution- and solid-phase construction of 2-oxazolidinone libraries.
Evidentiary Standards and Information Acquisition in Public Law

This article considers the type of evidence that an overseer (e.g., a court) should require before allowing a government agent to take some proposed action. The court can increase agency research incentives by prohibiting actions unless the agent produces supporting evidence, and/or by permitting action even when the agent uncovers adverse evidence. The court thus faces a trade-off between an evidentiary standard's ex post effects on the agent's policy decision and its ex ante effects on the agent's incentive to do research. An extension allows the court to make research effort a precondition for action, regardless of the evidence produced.
Coronae Around Helium Stars and X-Ray Sources

Calculations of the acoustic energy generation for helium-rich composition show that the maximum acoustic energy generation is located around 12000K at log g = 4 and 15000K at log g = 6. The author’s suggestion in his last paper that a helium star v Sgr may have a corona seems to be justified. X-ray from a corona around a helium star is strongest when the physical parameters of the star are logg ~ 6 and Te ~ 15000K. But the total energy flux is too small to account for the observed X-ray sources.
On pure conjectural equilibrium with non-manipulable information

An information structure in a non-cooperative game determines the signal that each player observes as a function of the strategy profile. Such information structure is called non-manipulable if no player can gain new information by changing his strategy. A Conjectural Equilibrium (CE) (Battigalli in Unpublished undergraduate dissertation, 1987; Battigalli and Guaitoli 1988; Decisions, games and markets, 1997) with respect to a given information structure is a strategy profile in which each player plays a best response to his conjecture about his opponents’ play and his conjecture is not contradicted by the signal he observes. We provide a sufficient condition for the existence of pure CE in games with a non-manipulable information structure. We then apply this condition to prove existence of pure CE in two classes of games when the information that players have is the distribution of strategies in the population.