cssi/SciSciGPT-SciSciNet huggingface dataset:
Nanoporous membrane tube condensing heat transfer enhancement study

Abstract A Transport Membrane Condenser (TMC), made from nanoporous membrane tube bundles, was developed to recover the water vapor and its significant amount of latent heat from boiler flue gases to improve boiler efficiency and save water. Experiments have been carried out to study the phenomena for both a nanoporous membrane tube bundle and an impermeable stainless steel tube bundle with the same characteristic dimensions. Flue gas streams with water vapor mass fraction 11.3%, temperature range from 65 °C to 95 °C are used for the experimental study, which covers the typical TMC waste heat recovery application parameter ranges. Results show convection Nusselt numbers of the membrane tube bundle are 50–80% higher than that of the impermeable stainless steel tube bundle at typical condensation heat transfer conditions. The parametric study has been done by varying cooling water inlet flow rate, water inlet temperature, flue gas inlet flow rate, inlet temperature, and inlet dew point. The condensing heat transfer enhancement effect gives a good perspective for using nanoporous membrane surface to design high efficiency condensing heat exchangers to recover both water vapor and its latent heat from high moisture content low grade waste heat streams.
THE ROAD NOT TAKEN: WHAT IS THE “APPROPRIATE” PATH TO DEVELOPMENT WHEN GROWTH IS UNBALANCED?

This paper develops a model that endogenizes both directed technologies and demography. Potential innovators decide which technologies to develop after considering available factors of production, and individuals decide the quality and quantity of their children after considering available technologies. This interaction allows us to evaluate potentially divergent development paths. We find that unskilled laborâ€“biased technological growth can induce higher fertility and lower education, exerting downward pressure on growth in per-person income. Despite this, for most plausible developing-country scenarios, unskilled intensive growth produces more per-person income than skill-intensive growth. This result is robust to a variety of growth modeling assumptions.
On finite arithmetic simplicial complexes

We compute the Euler-Poincare characteristic of quotients of the Bruhat-Tits building of PGL(n) under the action of arithmetic groups arising from central division algebras over rational function fields of positive characteristic. We use this result to determine the structure of the quotient simplicial complex in certain cases.
Semi-permeable vesicles composed of natural clay

We report a simple route to form robust, inorganic, semi-permeable compartments composed of montmorillonite, a natural plate-like clay mineral that occurs widely in the environment. Mechanical forces due to shear in a narrow gap assemble clay nanoplates from an aqueous suspension onto air bubbles. Translucent vesicles suspended in a single-phase liquid are produced when the clay-covered air bubbles are exposed to a variety of water-miscible organic liquids and water-soluble surfactants. These vesicles of clay are mechanically robust and are stable in water and other liquids. We find that the wetting of organic liquids on clay explains the formation of clay vesicles from clay armored bubbles. Clay vesicles are microporous, exhibit size-selective permeability, and support spontaneous compartmentalization of self-assembling molecules in aqueous environments. The results we report here expand our understanding of potential paths to micro-compartmentalization in natural settings and are of relevance to theories of colloidal aggregation, mineral cycles, and the origins of life.
Current Source Rectifiers in Discontinuous Conduction Modes of Operation

Although the operation of a three-phase current source rectifier (CSR) for ac-to-dc conversion using phase control or low-frequency pulse control is well established in a wide variety of applications, CSR realization using high-frequency pulsewidth-modulation control has been recently studied as a potentially competitive alternative to a voltage source rectifier. In the CSR, reverse blocking gate turn-off switches are realized using series-connected diodes, which prevent any reversal of the dc-link current. A significant consequence of this limitation occurs at light load conditions. The dc-link inductor current enters the discontinuous mode of operation and leads to the loss of the control of the output voltage and a highly distorted input current, which compromise the potential advantages of the approach. This paper characterizes the CSR while operating in the discontinuous conduction mode and proposes a modulation strategy that restores the control of the output voltage and ensures a nearly sinusoidal current at light loads. Simulation and hardware results are provided for a 3-kW laboratory-scale prototype system.
A CD‐Spectroscopic Alternative to Methylation Analysis of Oligosaccharides: Reference Spectra for Identification of Chromophoric Glycopyranoside Derivatives

A microscale method for identifying the monosaccharide units and their linkages in oligosaccharides is presented. Sugar components are identified by UV and CD spectroscopy of chromophoric degradation products. CD spectral data for approximately 150 different glycopyranoside components are provided for use as reference spectra in the identification of unknown derivatives. Procedures for the conversion of oligosaccharides to monosaccharide subunits bearing 4-bromobenzoate and 4-methoxycinnamate chromophores have been developed based on acetolysis/bromination reactions for glycosidic cleavage of per (bromobenzoylated) oligosaccharides. The method offers an alternative means to conventional methylation analysis of oligosaccharides.
High reflectance III-Nitride Bragg reflectors grown by molecular beam epitaxy

Distributed Bragg reflector (DBR) structures based on AlN/GaN have been grown on (0001) sapphire by electron-cyclotron-resonance plasma-assisted molecular-beam epitaxy (ECR-MBE). The design of the structures was predetermined by simulations using the transmission matrix method. A number of structures have been grown with 20.5–25.5 periods showing peak reflectance ranging from the near-UV to the green wavelength regions. For the best sample, peak reflectance up to 99% was observed centered at 467 nm with a bandwidth of 45 nm. The experimental reflectance data were compared with the simulations and show excellent agreement with respect to peak reflectance, bandwidth of high reflectance and the locations of the sidelobes.
Probability of detection of internal voids in structural ceramics using microfocus radiography

The reliability of microfocus x-radiography for detecting subsurface voids in structural ceramic test specimens was statistically evaluated. The microfocus system was operated in the projection mode using low X-ray photon energies (20 keV) and a 10 micro m focal spot. The statistics were developed for implanted subsurface voids in green and sintered silicon carbide and silicon nitride test specimens. These statistics were compared with previously-obtained statistics for implanted surface voids in similar specimens. Problems associated with void implantation are discussed. Statistical results are given as probability-of-detection curves at a 95 percent confidence level for voids ranging in size from 20 to 528 micro m in diameter.
Energy transfer in Rayleigh-Taylor instability.

The spatial structure and energy budget for Rayleigh-Taylor instability are examined using results from a $512\ifmmode\times\else\texttimes\fi{}512\ifmmode\times\else\texttimes\fi{}2040$ point direct numerical simulation. The outer-scale Reynolds number of the flow follows a rough ${t}^{3}$ power law and reaches a final value of about 5500. Taylor microscales and Reynolds numbers are plotted to characterize anisotropy in the flow and document progress towards the mixing transition. A mixing parameter is defined which characterizes the relative rates of entrainment and mixing in the flow. The spectrum of each term in the kinetic energy equation is plotted, at regular time intervals, as a function of the inhomogeneous direction and the two-dimensional wave number for the homogeneous directions. The energy spectrum manifests the beginning of an inertial range by the latter stages of the simulation. The production and dissipation spectra become increasingly opposite and separate in wave space as the flow evolves. The transfer spectrum depends strongly on the inhomogeneous direction, with the net transfer being from large to small scales. Energy transfer at the bubble/spike fronts is strictly positive. Extensive cancellation occurs between the pressure and advection terms. The dilatation term produces negligible energy transfer, but its overall effect is to move energy from high to low density regions.
Cell-specific regulation of the CD21 gene

The Complement Receptor Type 2 (Cr2-145,CR2, CD21) is an important receptor in the innate and acquired immune response. CD21 is produced by B cells and follicular dendritic cells, where it binds cleavage products of the C3 complement protein. CD21 facilitates internalization of immune complexes by B cells to enhance antigen presentation. CD21, in association with CD19/CD81, also serves as a coaccessory activation complex with the B-cell antigen receptor, permitting a lower antigen concentration to achieve maximal B-cell activation. CD21 traps immune complexes on the surface of follicular dendritic cells and displays them to activated B cells in germinal centers. Much work has been conducted to determine the transcriptional control mechanisms dictating CD21 expression. Appropriate transcriptional control of the CD21 gene evidently requires the CD21 promoter, as well as intronic sequences with enhancer and suppressor functions. Chromatin structure has been implicated in regulating the coordination of CD21 promoter and intronic control sequences by regulating access to them by putative transcription factors. This review assesses the past and current research into CD21 transcriptional regulation and offers insight into future experimental directions.
Design of a Thermocapillary Flow Experiment in Reduced Gravity

Detailed considerations for the design of a low-gravity thermocapillary flow experiment are presented. The basic configuration is one in which a fluid contained in a circular dish is subjected to an imposed surface heat flux. Specific consideration is given to the imposed thermal signature, thermal boundary conditions, free-surface deformations, and g-jitter effects. Numerical analysis and ground-based and drop-tower tests are utilized to ensure that reasonable flows are obtained in which measurements can be made relatively easily. The configuration chosen is of further importance because it differs from others in which oscillations were observed.
Current Methods of Laboratory Diagnosis of Chlamydia Trachomatis Infections

Infections caused by Chlamydia trachomatis are probably the most common sexually transmitted diseases in the United States. Commonly unrecognized and often inadequately treated, chlamydial infections can ascend the reproductive tract and cause pelvic inflammatory disease, which often results in the devastating consequences of infertility, ectopic pregnancy, or chronic pelvic pain. C. trachomatis infections are also known to increase the risk for human immunodeficiency virus infection. The obligate intracellular life cycle of C. trachomatis has traditionally required laboratory diagnostic tests that are technically demanding, labor-intensive, expensive, and difficult to access. In spite of these historical challenges, however, laboratory diagnosis of C. trachomatis has been a rapidly advancing area in which there is presently a wide array of commercial diagnostic technologies, costs, manufacturers. This review describes and compares the diagnostic methods for C. trachomatis infection that are currently approved for use in the United States, including the newest DNA amplification technologies which are yet to be licensed for commercial use. Issues to consider in selecting a test for purposes of screening versus diagnosis based on prevalence, performance, legal, social, and cost issues are also discussed.
Correlation-length bounds, and estimates for intermittent islands in parabolic SPDEs

We consider the nonlinear stochastic heat equation in one dimension. Under some conditions on the nonlinearity, we show that the "peaks" of the solution are rare, almost fractal like. We also provide an upper bound on the length of the "islands", the regions of large values. These results are obtained by analyzing the correlation length of the solution.
TRADE SIZE AND INFORMED TRADING: WHICH TRADES ARE “BIG”?

We find adverse-selection spread components increase sharply in the ratio of trade size to quoted depth, and spike when trade size equals quoted depth. We find that two previously documented and prominent indicators of informed trading, raw trade size and high-trading volume half-hours, offer almost no explanatory power for informed trading measures beyond trade size to quoted depth, and a third indicator, time of day, offers no explanatory power among trades with high trade size to quoted depth. Our results suggest trade size to quoted depth is perhaps the single most important indicator that a trade is informed.
Band gaps of InN and group III nitride alloys

Abstract We review the fundamental band gaps of wurtzite InN and group III nitride ternary alloys in the light of the recent discovery of the narrow band gap of InN. The results on the composition, temperature and hydrostatic pressure dependence of the band gaps of these alloys are summarized and discussed. The role of the Burstein–Moss shift for the accurate determination of the band gap is emphasized. The impact of the narrow band gap of InN on new device applications of group III nitrides is briefly discussed.
Design and evaluation of haptic effects for use in a computer desktop for the physically disabled

The human–computer interface remains a mostly visual environment with little or no haptic interaction. While haptics is finding inroads in specialized areas such as surgery, gaming, and robotics, there has been little work to bring haptics to the computer desktop, which is largely dominated today by the GUI/mouse relationship. The mouse as an input device, however, poses many challenges for users with physical disabilities, and it is believed that a haptically enhanced interface could have significant impact assisting in target selection. This paper presents a study intended to evaluate haptic effects used with a force feedback mouse on a computer desktop and a prediction algorithm designed to focus those effects on the desired target. Results of the experiment were partially successful and indicated future directions for improvement. The paper introduces the proposed framework and presents experimental results from targeting tasks using differing haptic effects with a group of physically disabled users.
Xeroderma pigmentosum variant cells are resistant to immortalization

Xeroderma pigmentosum (XP) is a human repair-deficient disorder that is caused by mutations in any of eight genes (A-G, V). The genes for complementation groups A-G have been cloned fully or in part, but the gene for the XP variant (XPV) has yet to be cloned. The lack of progress with XPV is in large part due to the rarity of stably transformed cell lines. We have attempted to immortalize fibroblasts from several XPV patients to obtain cell lines with which to characterize this disease and clone the appropriate gene. We have found, as have other investigators, that this XP group is very difficult to immortalize. We used a variety of approaches, including transfection with pSV ori- (a plasmid containing the simian virus (SV) 40 large T antigen) followed by spontaneous transformation, which provided stable immortal lines from Cockayne syndrome A and B, but not from XPV; transfection with pSV ori- and exposure to 3 Gy of X-rays; transfection with pSV ori-, exposure to 2 Gy of X-rays, and treatment with 1 mM ethyl methanesulfonate; transfection with human papilloma virus-16; and infection with SV40. Even though we used as many as 2 x 10(8) cells in some experiments, we were able to immortalize only one of our lines, XP30RO. Because the biochemical defect in XPV cell lines involves the capacity to replicate damaged DNA templates, perhaps the XPV gene product could be a replication factor that interacts with SV40 T antigen, and whose absence from XPV cell lines presents difficulties for the immortalization process to proceed.
Control of Charge Dilution in Turbocharged Diesel Engines via Exhaust Valve Timing

In this paper we extend an existing crank angle resolved dynamic nonlinear model of a six-cylinder 12 l turbocharged (TC) Diesel engine with exhaust valve closing (EVC) variability. Early EVC achieves a high level of internal exhaust gas recirculation (iEGR) or charge dilution in Diesel engines, and thus reduces generated oxides of nitrogen (NOx). This model is validated in steady-state conventional (fixed EVC) engine operating points. It is expected to capture the transient interactions between EVC actuation, the turbocharger dynamics, and the cylinder-to-cylinder breathing characteristics, although this has not been explicitly validated due to lack of hardware implementation. A nominal low order linear multi-input multi-output model is then identified using cycle-sampled or cycle-averaged data from the higher order nonlinear simulation model. Various low-order controllers that vary EVC to maximize the steady-state iEGR under air-to-fuel ratio (AFR) constraints during transient fueling demands are suggested based on different sensor sets. The difficulty in the control tuning arises from the fact that the EVC affects both the AFR and engine torque requiring coordination of fueling and EVC. Simulation results are shown on the full order model.
Estimation of vehicular emissions by capturing traffic variations

Increase in traffic volumes and changes in travel-related characteristics increase vehicular emissions significantly. It is difficult, however, to accurately estimate emissions with current practice because of the reliance on travel forecasting models that are based on steady state hourly averages and, thus, are incapable of capturing the effects of traffic variations in the transportation network. This paper proposes an intermediate model component that can provide better estimates of link speeds by considering a set of Emission Specific Characteristics (ESC) for each link. The intermediate model is developed using multiple linear regression; it is then calibrated, validated, and evaluated using a microscopic traffic simulation model. The improved link speed data can then be used to provide better estimates of emissions. The evaluation results show that the proposed emission estimation method performs better than current practice and is capable of estimating time-dependent emissions if traffic sensor data are available as model input.
Synthesis and Properties of Metallic Glasses That Contain Aluminum

The synthesis and properties of a class of metallic glasses containing up to 90 atomic percent aluminum are reported. The unusual formability of the glasses and their structural features are pointed out. Mechanical properties including tensile fracture strength and Young's modulus are reported along with crystallization temperatures. The unusually high strengths of the aluminum glasses can be of significant importance in obtaining high-strength low-density materials.
From biological pathways to regulatory networks

This paper presents a general theoretical framework for generating Boolean networks whose state transitions realize a set of given biological pathways or minor variations thereof. This ill-posed inverse problem, which is of crucial importance across practically all areas of biology, is solved by using Karnaugh maps which are classical tools for digital system design. It is shown that the incorporation of prior knowledge, presented in the form of biological pathways, can bring about a dramatic reduction in the cardinality of the network search space. Constraining the connectivity of the network, the number and relative importance of the attractors, and concordance with observed time-course data are additional factors that can be used to further reduce the cardinality of the search space. The networks produced by the approaches developed here should facilitate the understanding of multivariate biological phenomena and the subsequent design of intervention approaches that are more likely to be successful in practice. As an example, the results of this paper are applied to the widely studied p53 pathway and it is shown that the resulting network exhibits dynamic behavior consistent with experimental observations from the published literature.
Stereochemistry and mechanism of the [2 + 2] and [4 + 2] photocycloaddition of alkenes and dienes to pummerer's ketone

Abstract Irradiation of Pummerer's ketone (PK) in furan gave the trans -fused [4 + 2] cycloadducts 2 and 3, whose structures were determined by their 1H NMR spectra and confirmed by X-ray crystallography. Irradiation of PK in the presence of tetramethylethylene (TME) gave cycloadduct 4 and with 1,1-dimethoxyethylene (DME) gave [2 + 2] cycloadducts 5,6 and 7, respectively. The X-ray crystal structures of 4—7 show that the four- and six-membered rings of 4 and 7 are trans-fused, and 5 and 6 are cis-fused, respectively. Differential quenching of the formation of cycloadducts 2–5 and 7 by the free radical TEMPO was observed. Formation of cycloadducts 2–4 was also quenched differentially by O2. A short lived (15 nsec) transient observed on nanosecond flash photolysis of PK is suggested to be a highly twisted triplet excited state, which is the likely precursor of both [4 + 2] and [2 + 2] adducts. It is proposed that stepwise addition of furan and alkenes to PK triplets gives triplet biradicals, which can be intercepted by TEMPO and O2 , and that these reactions probably do not involve a ground state trans-cyclohexenone intermediate.
Coherent acoustic phonon generation in exciton self-trapping

The coupled electronic and vibrational dynamics of exciton self-trapping are studied in the quasi-one-dimensional material $[\text{Pt}{(\text{en})}_{2}][\text{Pt}{(\text{en})}_{2}{\text{Br}}_{2}]\ensuremath{\cdot}{({\text{PF}}_{6})}_{4}$ ($\text{en}=\text{ethylenediamine}$) using femtosecond impulsive excitation techniques. We report transient absorption measurements at 77 K that are modulated by a large amplitude, strongly damped oscillatory component at a frequency of $11\text{ }{\text{cm}}^{\ensuremath{-}1}$ in addition to the $110\text{ }{\text{cm}}^{\ensuremath{-}1}$ excited-state optical-phonon wave-packet oscillation previously observed at room temperature. We find that the characteristics of the low-frequency oscillatory response are consistent with the theoretically predicted generation of a propagating coherent acoustic wave accompanying the formation of the localized lattice deformation that stabilizes the self-trapped state. The observed low-frequency oscillation, interpreted in the context of theoretical models for polaron formation via coupling to acoustic phonons, provides an estimate of the spatial extent of the resulting localized state of $\ensuremath{\sim}5$ unit cells of the PtBr chain structure. This value is in good agreement with the localization length predicted by previous extended Peierls-Hubbard calculations.
Induced Grid Noise and Noise Factor

IT is easily shown that for any type of internal structure the power-frequency spectrum sg(ƒ) of the current fluctuations appearing at the control grid of a triode valve is related to the spectrum sa(ƒ) of the anode current fluctuations by where Yg(ƒ) is the increase, from the ‘cut off’ to the working conditions, of input admittance at the grid with the anode effectively earthed; gm is the high-frequency mutual conductance of the triode. In the case of the ‘induced’ (transit-time) grid noise, and for moderate angles, the relevant component of grid admittance is largely susceptive, being where Ct is the value of the ‘space-charge capacitance’ measured on the valve. Thus, setting The modifications to (2) introduced by distribution of electron velocities and trajectories are discussed elsewhere1, and direct experimental verification is also described.
Why Don't the Poor Save More? Evidence from Health Savings Experiments

Using data from a field experiment in Kenya, we document that providing individuals with simple informal savings technologies can substantially increase investment in preventative health and reduce vulnerability to health shocks. Simply providing a safe place to keep money was sufficient to increase health savings by 66 percent. Adding an earmarking feature was only helpful when funds were put toward emergencies, or for individuals that are frequently taxed by friends and relatives. Group-based savings and credit schemes had very large effects.
Analysis of airship lateral maneuverability

EQUATIONS of motion have been derived and used to investigate analytically lateral and directional maneuverability characteristics of an advanced airship configuration consisting of auxiliary aerodynamic and powered yaw control augmentation. Theoretical expressions for turning radius, sideslip angle, roll angle, and the corresponding rudder deflection or auxiliary control needed in a steady turn have been obtained in terms of vehicle geometry, stability, control, and flight parameters. These theoretical results are also analyzed and shown to agree with experimental observations of the past. Potential for improving vehicle maneuverability either by relaxing its inherent static stability or by use of auxiliary yaw controls is discussed and illustrated with an example 2.8million ft3 airship.
When and why did FSLIC resolve insolvent thrifts

Abstract This paper develops an optimal resolution triage strategy for a deposit-insurance regulator. The regulator seeks to maximize the market value of the deposit insurance enterprise, subject to budget, personal, bureaucratic, political, informational and legal restraints. Testable hypotheses are derived concerning the timing of insolvency resolutions. The paper tests these hypotheses using a two-step hazards model and a data set of thrift resolutions during 1985–1989. The tests focus on the relative roles of value maximization and constraint pressures in decisions to grant capital forbearance. The results suggest that regulators seldom conformed to the benchmark resolution-timing strategy that an “unconflicted” agent would follow under only a budget constraint. Instead, the evidence shows that the resolution timing decision was distorted by personal, political, informational, and legal constraints.
Topological doping of correlated insulators

Abstract A material which is an insulator entirely because of interaction effects is called a correlated insulator. Examples are trans -polyacetylene and the cuprate high-temperature superconductors. Whereas doping of a band insulator results in a shift of the chemical potential into the conduction or valence band, doping of a correlated insulator produces fundamental changes in the electronic density of states itself. We have found that a general feature of doping a correlated insulator is the generation of topological defects; solitons in one-dimension and anti-phase domain walls in higher dimensions. We review the well-known features of this process in polyacetylene, and describe the experimental evidence that the analogous features are seen in the cuprate superconductors. We also distinguish the case in which the doping-induced features can be viewed as a Fermi surface instability, as in polyacetylene. and the more usual case in which they are a consequence of a Coulomb frustrated electronic tendency to phase separation.
Greedy facility location algorithms analyzed using dual fitting with factor-revealing LP

In this article, we will formalize the method of dual fitting and the idea of factor-revealing LP. This combination is used to design and analyze two greedy algorithms for the metric uncapacitated facility location problem. Their approximation factors are 1.861 and 1.61, with running times of O(m log m) and O(n3), respectively, where n is the total number of vertices and m is the number of edges in the underlying complete bipartite graph between cities and facilities. The algorithms are used to improve recent results for several variants of the problem.
Synthesis of angularly substituted trans-fused hydroindanes by convergent coupling of acyclic precursors.

Angularly substituted trans-fused hydroindanes are now accessible by the direct and convergent union of trimethylsilyl (TMS)-alkynes with 4-hydroxy-1,6-enynes by a process that forges three C–C bonds, one C–H bond, and two new stereocenters. The annulation is proposed to proceed by initial formation of a Ti–alkyne complex (with a TMS-alkyne) followed by regioselective alkoxide-directed coupling with the enyne, stereoselective intramolecular cycloaddition, elimination of phenoxide, 1,3-metallotropic shift, and stereoselective protonation of the penultimate allylic organometallic intermediate. Several examples are given to demonstrate the compatibility of this reaction with substrates bearing aromatic and aliphatic substituents, and an empirical model is presented to accompany the stereochemical observations.
Advantage men: The sex pay gap in professional tennis:

Much of the literature on gender inequality in sport is devoted to media bias and conceptualizations of masculinity and femininity. In comparison, there is a paucity of empirical research on the sex pay gap. Our case study uses publically accessible data for professional tennis players ranked in the top 100 at the end of the 2009 season to determine to what extent a pay gap exists between men and women. We find that median earnings – both in 2009 and over a player’s career – are substantially higher for men than women in the sample. Net of various productivity measures, the average female player earned less than her male counterpart for every singles tournament won in 2009. We also find that while prize money for men and women is equal in prestigious tournaments such as Grand Slam events, women’s prize money is considerably lower in many of the less publicized tournaments. We submit that the sex pay gap among professional tennis players can be explained in part by productivity in 2009, as well as differen...
GALAXIES AT THE DETECTION LIMITS OF DEEP X-RAY SURVEYS

The great sensitivities of the Chandra X-ray Observatory and XMM-Newton are allowing us to explore the X-ray emission from galaxies at moderate to high redshift. By using the stacking method, we show that we can detect the ensemble emission from normal elliptical, spiral and irregular galaxies out to redshifts approaching one. The average X-ray luminosity can then be compared with the results of models of the evolution in the numbers of X-ray binaries and can possibly be used to constrain models of star formation.
Toward Standardization of Benefit-Cost Analyses of Early Childhood Interventions

Attempts to delineate a set of standards for conducting benefit-cost analyses of early childhood programs.
Extension of a Helicoidal Vortex Model to Account for Blade Flexibility and Tower Interference

The unsteady vortex method has been extended to account for blade flexibility and tower interference. These are two potential sources of unsteadiness of the flow past a wind turbine blade. The cases presented correspond to an incoming flow speed V=5 m/s and low yaw angles and V=8, 10, and 12 m/s and zero yaw. Comparisons of the root flap bending moments predicted by the model with the National Renewable Energy Laboratory (NREL) experimental data indicate that the NREL blades designed for the wind tunnel campaigns are quite rigid and that the tower interference is responsible for unsteadiness that is well captured by the model for zero yaw as well as for yaw of 5, 10 and 20 deg.
Nonconservative Stability of a Friction Loaded Disk

This paper investigates the vibration of an annular disk that is subjected to rotation and in-plane frictional traction distributed over a sector of the disk's two faces. Technical applications include noise, vibration, and harshness in automotive and aircraft disk brakes, clutches, transmissions, and other rotating machine components. To the degree that the rotor-to-stator friction in such cases is directed along the disk's deformable surface, it is treated here as a nonconservative follower-type load. The vibration model incorporates membrane stiffness which derives both from rotation, and from the stresses established as a result of friction. The plane stress state is determined in closed form as a Fourier series, and that solution is compared with the companion, but computationally intensive, results from finite element analysis. For the cases of sector-shaped and full annular loading, the vibration model predicts the critical mode, which is defined as the one that becomes dynamically unstable at the lowest friction level. Vibration modes and propagating waves that fall into opposite symmetry classes are shown to have opposite stability characteristics in the presence of frictional loading.
In search of optimum ‘relative unanimity’

This paper formulates a simple mathematical framework for the selection of an optimum "relative unanimity” collective decision rule. The approach is first to identify the benefits of moving from a rule of simple majority towards a rule of full unanimity. Then, the costs of moving from simple majority rule towards unanimity are identified. Finally, the issue of an optimal decision rule is mathematically solved.
The fundamental manifold of spheroids

We present a unifying empirical description of the structural and kinematic properties of all spheroids embedded in dark matter halos. We find that the intracluster stellar spheroidal components of galaxy clusters, which we call cluster spheroids (CSphs) and which are typically 100 times the size of normal elliptical galaxies, lie on a "fundamental plane" as tight as that defined by elliptical galaxies (rms in effective radius of ~0.07) but having a different slope. The slope, as measured by the coefficient of the log σ term, declines significantly and systematically between the fundamental planes of ellipticals, brightest cluster galaxies (BCGs), and CSphs. We attribute this decline primarily to a continuous change in Me/Le, the mass-to-light ratio within the effective radius re, with spheroid scale. The magnitude of the slope change requires that it arise principally from differences in the relative distributions of luminous and dark matter, rather than from stellar population differences such as in age and metallicity. By expressing the Me/Le term as a function of σ in the simple derivation of the fundamental plane and requiring the behavior of that term to mimic the observed nonlinear relationship between log Me/Le and log σ, we simultaneously fit a two-dimensional manifold to the measured properties of dwarf elliptical and elliptical galaxies, BCGs, and CSphs. The combined data have an rms scatter in log re of 0.114 (0.099 for the combination of ellipticals, BCGs, and CSphs), which is modestly larger than each fundamental plane has alone, but which includes the scatter introduced by merging different studies done in different filters by different investigators. This "fundamental manifold" fits the structural and kinematic properties of spheroids that span a factor of 100 in σ and 1000 in re. While our mathematical form is neither unique nor derived from physical principles, the tightness of the fit leaves little room for improvement by other unification schemes over the range of observed spheroids.
An efficient [4 + 2 + 1] entry to seven-membered rings

A new nickel-catalyzed procedure for the [4 + 2 + 1] cycloaddition of trimethylsilyl diazomethane with alkynes tethered to dienes has been developed. A broad range of unsaturated substrates participate in the sequence, and stereoselectivities are generally excellent. Three possible mechanisms are proposed, and each involves the generation of a transient nickel carbene species.
Trade Implications of the Trans-Pacific Partnership for ASEAN and Other Asian Countries

The Trans-Pacific Partnership (TPP) aspires to become a state-of-the-art trade agreement linking 12 countries on both sides of the Pacific. In addition to establishing a free trade agreement (FTA) ...
Application of Fracture Mechanics to Space-Shuttle Windows

The fracture properties of an ultralow-expansion glass intended for use in windows for the Space Shuttle were characterized by strength and fracture-mechanics techniques to provide reliable design data. Proof-test diagrams for predicting minimum times-to-failure under specified service loads were developed from measurements of subcritical crack growth in water and air. Failure predictions were confirmed from strength measurements in water. In vacuum (<10−4 torr), the fracture behavior was similar to that of other high-SiO2 glasses, as evidenced by the absence of subcritical crack growth and by insensitivity of the critical stress intensity factor to temperature.
Randomized interpolative decomposition of separated representations

We introduce an algorithm to compute tensor interpolative decomposition (dubbed CTD-ID) for the reduction of the separation rank of Canonical Tensor Decompositions (CTDs). Tensor ID selects, for a user-defined accuracy ?, a near optimal subset of terms of a CTD to represent the remaining terms via a linear combination of the selected terms. CTD-ID can be used as an alternative to or in combination with the Alternating Least Squares (ALS) algorithm. We present examples of its use within a convergent iteration to compute inverse operators in high dimensions. We also briefly discuss the spectral norm as a computational alternative to the Frobenius norm in estimating approximation errors of tensor ID.We reduce the problem of finding tensor IDs to that of constructing interpolative decompositions of certain matrices. These matrices are generated via randomized projection of the terms of the given tensor. We provide cost estimates and several examples of the new approach to the reduction of separation rank.
An investigation of the damping effects of various gas environments on a vibratory MEMS device

An experimental investigation of the damping effects in several different gas chemistries on a vibrating micromachined structure was conducted. A corresponding numerical study using an analytical model was also performed and the results correlated with the experimental observations. The analytical model is based on the compressible Reynolds equation. The theoretical and experimental quality factor show reasonable agreement for different gases. As expected, the quality factor decreases as the gas pressure increases. Both experiments and numerical predictions suggest that these various gases may not affect the mechanical behavior significantly, and could be used for their unique electrical properties, such as permittivities.
Full-Pupil Line-Scanning Confocal Microscope for Imaging Weakly Scattering Tissues: Comparison to Divided-Pupil

Confocal reflectance full-pupil and divided-pupil line-scanning microscopes provide optical sectioning of 1-2?m and image nuclear detail in skin. Line-scanning with linear detectors is a simpler alternative to point-scanning for imaging weakly scattering epithelial tissues.
Limits on Enhanced Radio Wave Scattering by Supernova Remnants

We report multifrequency observations with the NRAO Very Long Baseline Array (VLBA) of the compact radio sources J0128+6306 and J0547+2721, which are viewed through the supernova remnants G127.1+0.5 and S147, respectively. Observations were made at frequencies of 1.427, 1.667, 2.271, and 4.987 GHz. The lines of sight to these sources pass through the shock wave and upstream and downstream turbulent layers of their respective supernova remnants and thus might detect cosmic-ray-generated turbulence produced during the Fermi acceleration process. For both sources, we detect interstellar scattering, characterized by a component of the angular size that scales as the square of the observing wavelength. The magnitude of the scattering is characterized by an effective scattering angular size ?S0 at a frequency of 1 GHz of 13.2 ? 2.6 mas for J0128+6306 and 6.7 ? 2.2 mas for J0547+2721. These angular sizes are consistent with the incidental scattering for any line of sight out of the galaxy at similar Galactic latitudes and longitudes. There is therefore no evidence for enhanced turbulence at these supernova remnants. We establish upper limits to the supernova remnant-associated scattering measures of 8.1-14.8 m-20/3 pc for J0128+6306 and 3.0 m-20/3 pc for J0547+2721.
An electronic clock for correlated noise corrections

Abstract An inexpensive and portable approach is presented to measure the time of occurrence of an experimental event as measured by a specific electronic clock. The clock resets in active synchronization with the experimental AC-power cycle. This allows an efficient and complete correction for correlated noise contributions to pulse area and time measurements of detector channels equipped with PhotoMultiplier Tubes. The electronic board that was developed will be described. The performance for the treatment of correlated noise in experimental data taken at the BNL-AGS facility, and analyses of spectral decompositions of this noise, will also be described.
Frequency Clusters in the Spectrum of Annular Cylinders

As the length of a traction-free annular cylinder is increased, distinct members within any family of radial or longitudinal shear modes have natural frequencies that asymptotically approach a common nonzero value. Such modes, potentially having significantly different numbers of nodes along the cylinder's generator, can have natural frequencies that are indistinguishable from one another within the resolution of test equipment or numerical simulation. The three-dimensional vibration model discussed here predicts the formation of narrow frequency clusters with the cylinder's increasing length, the converged value of which bounds from below the frequencies of all modes within a particular family. In addition to these spectral characteristics, frequency clusters have implications for the forced response of annular cylinders. For the particular families of modes that are of interest here, the steady-state harmonic response at frequencies near a cluster can be spatially confined with displacements that decay rapidly away from the point of maximum response. At other driving frequencies, the response is distributed more uniformly along the length of the cylinder. The derived analytical model is compared with results from laboratory measurements, and from the predictions of wave propagation theory in the limit of infinite cylinder length.
Local expression languages for probabilistic dependence

Abstract A Bayesian belief net is a factored representation for a joint probability distribution over a set of variables. This factoring is made possible by the conditional independence relationships among variables made evident in the sparseness of the graphical level of the net. There is, however, another source of factoring available which cannot be directly represented in this graphical structure. This source is the microstructure within an individual marginal or conditional distribution. We present a representation capable of making this intradistribution structure explicit, and an extension to the SPI algorithm capable of utilizing this structural information to improve the efficiency of inference. We discuss the expressivity of the local expression language, and present early experimental results showing the efficacy of the approach.
Muon Collider/Neutrino Factory: Status and prospects

During the 1990s an international collaboration has been studying the possibility of constructing and operating a high-energy high-luminosity {mu}{sup +}{mu}{sup {minus}} collider. Such a machine could be the approach of choice to extend the discovery reach beyond that of the LHC. More recently, a growing collaboration is exploring the potential of a stored-muon-beam neutrino factory to elucidate neutrino oscillations. A neutrino factory could be an attractive stepping-stone to a muon collider. Its construction, possibly feasible within the coming decade, could have substantial impact on neutrino physics.
Rhodium-Catalyzed Activation and Functionalization of the C−C Bond of Biphenylene

Biphenylene reacts with the rhodium(I) dimer [(dtbpm)RhCl]2 (1) (dtbpm = bis(di-tert-butylphosphino)methane) to yield (dtbpm)Rh(2,2‘-biphenyl)Cl (2). Lewis bases react with compound 2 at room temperature, displacing the chelating phosphine. A new five-coordinate complex, (PPh3)2Rh(2,2‘-biphenyl)Cl (3), is formed when the base is triphenylphosphine. Fluorenone and fluorenimine are formed when the base used is carbon monoxide and isonitrile, respectively. The dimer 1 and compound 2 are catalysts for coupling reactions of biphenylene with unsaturated organic substrates. Substituted phenanthrenes and benzenes are formed using alkynes with simple alkyl or aryl substituents. Substituted phenanthrenes and fluorenes are produced using alkynes with trimethylsilyl substituents. Olefinic substrates yield vinylbiphenyls. The production of vinylbiphenyls is hindered by steric substitution on the olefin. α-Olefins with substituents that block double-bond migration yield the cleanest product ratios.
Multiway cut, pairwise realizable distributions, and descending thresholds

We design new approximation algorithms for the Multiway Cut problem, improving the previously known factor of 1.32388 [Buchbinder et al., 2013]. We proceed in three steps. First, we analyze the rounding scheme of Buchbinder et al. [2013] and design a modification that improves the approximation to [EQUATION]. We also present a tight example showing that this is the best approximation one can achieve with the type of cuts considered by Buchbinder et al. [2013]: (1) partitioning by exponential clocks, and (2) single-coordinate cuts with equal thresholds. Then, we prove that this factor can be improved by introducing a new rounding scheme: (3) single-coordinate cuts with descending thresholds. By combining these three schemes, we design an algorithm that achieves a factor of [EQUATION]. This is the best approximation factor that we are able to verify by hand. Finally, we show that by combining these three rounding schemes with the scheme of independent thresholds from Karger et al. [2004], the approximation factor can be further improved to 1.2965. This approximation factor has been verified only by computer.
Explicit Maximally Recoverable Codes With Locality

Consider a systematic linear code where some (local) parity symbols depend on few prescribed symbols, whereas other (heavy) parity symbols may depend on all data symbols. Such codes have been studied recently in the context of erasure coding for data storage, where the local parities facilitate fast recovery of any single symbol when it is erased, whereas the heavy parities provide tolerance to a large number of simultaneous erasures. A code as above is maximally recoverable, if it corrects all erasure patterns, which are information theoretically correctable given the prescribed dependence relations between data symbols and parity symbols. In this paper, we present explicit families of maximally recoverable codes with locality. We also initiate the general study of the tradeoff between maximal recoverability and alphabet size.
Modelling energy-economic interactions in developing countries: a linear-programming approach

Abstract This paper describes the energy-economic assessment model recently developed at Brookhaven National Laboratory for application to energy assessments in developing countries. This model was designed to be directly applicable to these countries, and as such particular emphasis was given to a simple, yet comprehensive treatment of the energy sector. The discussion stresses the treatment of the electric, refinery and industrial end use sectors, and the linkages with conventional macroeconomic planning models.