cssi/SciSciGPT-SciSciNet huggingface dataset:
Dimensions of Tight Spans

Given a finite metric, one can construct its tight span, a geometric object representing the metric. The dimension of a tight span encodes, among other things, the size of the space of explanatory trees for that metric; for instance, if the metric is a tree metric, the dimension of the tight span is one. We show that the dimension of the tight span of a generic metric is between $$ {\left\lceil {\frac{n} {3}} \right\rceil } $$ and $$ {\left\lfloor {\frac{n} {2}} \right\rfloor } $$ that both bounds are tight.
Microwave spectrum and conformation of isopropyl fluoroformate

Abstract The microwave spectrum of isopropyl fluoroformate is characterized by intense a -type R -branch transitions from one conformational species. The rotational constants of the ground state, A 0 = 4967.0(8) MHz, B 0 = 1704.69(2) MHz, C 0 = 1468.86(1) MHz and κ = −0.8651(2) are consistent with a τ 1 (OCOC) = 0°, τ 2 (COCH) ~35° structure. This structure can be viewed as a combination of the two conformational species found in ethyl fluoroformate. Two vibrational satellites having rotational constants A 0 = 4963(5) MHz, B 0 = 1694.11(7) MHz. C 0 = 1471.43(4) MHz and A 0 =4998(6) MHz, B 0 = 1705.21(7) MHz, C 0 = 1471.10(4) MHz have been assigned.
Non-Fourier dynamic thermoelasticity with temperature-dependent thermal properties

This study numerically investigates the effect of temperature-dependent thermal conductivity, specific heat, and density on coupled, non-Fourier dynamic thermoelastic models involving relaxation times. The thermal response of a semi-infinite slab to both a step change and linear, ramp increase in applied surface temperature is presented. It is observed that a thermal conductivity which decreases with temperature results in reduced temperature gradients, and therefore reduced maximum displacements and stresses. However, decreasing specific heat or density with temperature causes increased temperature gradients, and therefore increased displacements and stresses. In addition to altering the magnitudes of the displacements and stresses, the variable properties also result in phase shifts of the displacement and stress waves. The ramp increase in surface temperature results in displacement and stress waves of lower magnitudes that are spread over a longer time interval compared to the results for the step change in surface temperature. 20 refs.
On Wireless Scheduling With Partial Channel-State Information

A time-slotted queueing system for a wireless downlink with multiple flows and a single server is considered, with exogenous arrivals and time-varying channels. It is assumed that only one user can be serviced in a single time slot. Unlike much recent work on this problem, attention is drawn to the case where the server can obtain only partial information about the instantaneous state of the channel. In each time slot, the server is allowed to specify a single subset of flows from a collection of observable subsets, observe the current service rates for that subset, and subsequently pick a user to serve. The stability region for such a system is provided. An online scheduling algorithm is presented that uses information about marginal distributions to pick the subset and the Max-Weight rule to pick a flow within the subset, and which is provably throughput-optimal. In the case where the observable subsets are all disjoint, or where the subsets and channel statistics are symmetric, it is shown that a simple scheduling algorithm-Max-Sum-Queue-that essentially picks subsets having the largest squared-sum of queues, followed by picking a user using Max-Weight within the subset, is throughput-optimal.
Dynamics of the chiral phase transition from AdS/CFT duality

We use Lorentzian signature AdS/CFT duality to study a first-order phase transition in strongly coupled gauge theories that is akin to the chiral phase transition in QCD. We discuss the relation between the latent heat and the energy (suitably defined) of the component of a D-brane which lies behind the horizon at the critical temperature. A numerical simulation of a dynamical phase transition in an expanding, cooling quark-gluon plasma produced in a relativistic collision is carried out.
Magnetic Reconnection in the Solar Wind at Current Sheets Associated with Extremely Small Field Shear Angles

Using Wind 3 s plasma and magnetic field data, we have identified nine reconnection exhausts within a solar wind disturbance on 1998 October 18-20 driven by a moderately fast interplanetary coronal mass ejection (ICME). Three of the exhausts within the ICME were associated with current sheets having local field shear angles, θ, ranging from 4° to 9°, the smallest reported values of θ yet associated with reconnection exhausts in a space plasma. They were observed in plasma characterized by extremely low (0.02-0.04) plasma β, and very high (281-383 km s–1) Alfven speed, V A. Low β allows reconnection to occur at small θ and high V A leads to exhaust jets that are fast enough relative to the surrounding solar wind to be readily identified. Very small-θ current sheets are common in the solar wind at 1 AU, but typically are not associated with particularly low plasma β or high V A. On the other hand, small-θ current sheets should be common in the lower solar corona, a plasma regime of extremely low β and extremely high V A. Our observations lend credence to models that predict that reconnection at small-θ current sheets is primarily responsible for coronal heating.
Direct chemical dynamics simulations: coupling of classical and quasiclassical trajectories with electronic structure theory

In classical and quasiclassical trajectory chemical dynamics simulations, the atomistic dynamics of collisions, chemical reactions, and energy transfer are studied by solving the classical equations of motion. These equations require the potential energy and its gradient for the chemical system under study, and they may be obtained directly from an electronic structure theory. This article reviews such direct dynamics simulations. The accuracy of classical chemical dynamics is considered, with simulations highlighted for the F− + CH3OOH reaction and of energy transfer in collisions of CO2 with a perfluorinated self-assembled monolayer (F-SAM) surface. Procedures for interfacing chemical dynamics and electronic structure theory computer codes are discussed. A Hessian-based predictor–corrector algorithm and high-accuracy Hessian updating algorithm, for enhancing the efficiency of direct dynamics simulations, are described. In these simulations, an ensemble of trajectories is calculated which represents the experimental and chemical system under study. Algorithms are described for selecting the appropriate initial conditions for bimolecular and unimolecular reactions, gas-surface collisions, and initializing trajectories at transition states and conical intersections. Illustrative direct dynamics simulations are presented for the Cl− + CH3I SN2 reaction, unimolecular decomposition of the epoxy resin constituent CH3NHCHCHCH3 versus temperature, collisions and reactions of N-protonated diglycine with a F-SAM surface that has a reactive head group, and the product energy partitioning for the post-transition state dynamics of C2H5F HF + C2H4 dissociation. © 2012 John Wiley & Sons, Ltd.
On Synchronous Robotic Networks—Part II: Time Complexity of Rendezvous and Deployment Algorithms

This paper analyzes a number of basic coordination algorithms running on synchronous robotic networks. We provide upper and lower bounds on the time complexity of the move-toward-average and circumcenter laws, both achieving rendezvous, and of the centroid law, achieving deployment over a region of interest. The results are derived via novel analysis methods, including a set of results on the convergence rates of linear dynamical systems defined by tridiagonal Toeplitz and circulant matrices.
GIT1 Mediates HDAC5 Activation by Angiotensin II in Vascular Smooth Muscle Cells

Objective— The G protein-coupled receptor (GPCR)-kinase2 interacting protein1 (GIT1) is a scaffold protein involved in angiotensin II (Ang II) signaling. Histone deacetylase-5 (HDAC5) has emerged as an important substrate of calcium/calmodulin-dependent protein kinase II (CamK II) in GPCR signaling. Here we investigated the hypothesis that Ang II-mediated vascular smooth muscle cell (VSMC) gene transcription involves GIT1-CamK II-dependent phosphorylation of HDAC5. Methods and Results— Ang II rapidly stimulated phosphorylation of HDAC5 at Ser498 in VSMCs. Knockdown of GIT1 significantly decreased HDAC5 phosphorylation induced by Ang II. The involvement of Src, phospholipase γ (PLCγ), and CamK II in GIT1-mediated HDAC5 phosphorylation was demonstrated. The association of GIT1 and CamK II was constitutive but increased after stimulation with Ang II. Moreover, the interaction of GIT1 and CamK II through the ARF GTPase-activating protein (ARF-GAP) and coiled-coil domains of GIT1 was essential for the phosphorylation of HDAC5. Finally, knockdown of GIT1 decreased myocyte enhancer factor 2 transcriptional activity induced by Ang II. Conclusions— This study identifies a novel function for GIT1 as a mediator of Ang II-induced VSMC gene transcription via a Src-PLCγ-CamK II-HDAC5 signaling pathway.
QCD evolution equations: Numerical algorithms from the Laguerre expansion

A complete numerical implementation, in both singlet and non-singlet sectors, of a very elegant method to solve the QCD Evolution equations, due to Furmanski and Petronzio, is presented. The algorithm is directly implemented in x-space by a Laguerre expansion of the parton distributions. All the leading-twist distributions are evolved: longitudinally polarized, transversely polarized and unpolarized, to NLO accuracy. The expansion is optimal at finite x, up to reasonably small x-values (x{approx}10{sup {minus}3}), below which the convergence of the expansion slows down. The polarized evolution is smoother, due to the less singular structure of the anomalous dimensions at small-x. In the region of fast convergence, which covers most of the usual perturbative applications, high numerical accuracy is achieved by expanding over a set of approximately 30 polynomials, with a very modest running time.
Efficient approximation concepts using second order information

The primary goal of this paper is to show how second derivative information can be used in an effective way in structural optimization problems. The basic idea is to generate such an information at the expense of only one more ‘virtual load case’ in the sensitivity analysis part of the finite element code. To achieve this goal a primal–dual approach is employed, that can also be interpreted as a sequential quadratic programming method. Another objective is to relate the proposed method to the well known family of approximation concepts techniques, where the primary optimization problem is transformed into a sequence of non-linear explicit subproblems. When restricted to diagonal second derivatives, the new approach can be viewed as a recursive convex programming method, similar to the ‘Convex Linearization’ method (CONLIN), and to its recent generalization, the ‘Method of Moving Asymptotes’ (MMA). This new method has been successfully tested on simple problems that can be solved in closed form, as well as on sizing optimization of trusses. In all cases the method converges faster than CONLIN, MMA or other approximation techniques based on reciprocal variables.
Determination of elliptic curves by their adjoint p-adic L-functions

Fix p an odd prime. Let E be an elliptic curve over QQ with semistable reduction at p. We show that the adjoint p-adic L-function of E evaluated at infinitely many integers prime to p completely determines up to a quadratic twist the isogeny class of E . To do this, we prove a result on the determination of isobaric representations of GL(3,AQ)GL(3,AQ) by certain L-values of p-power twists.
Large grain boundary area superconductors

For many applications of polycrystalline high-Tc superconductors the small critical currents of the grain boundaries pose a severe problem. To solve this problem, we derive novel designs for the microstructure of coated conductors.
Slope Versus Elasticity and the Burden of Taxation

The incidence of the burden of a tax is usually presented as an application of elasticity in introductory economics. A more useful exposition of tax incidence results if slope is used rather than elasticity.
Formally Testing the Present Value Model of Farmland Prices

This paper applies recent statistical developments in the study of stock market price movements to study the plausibility of the constant expected returns version of the present value model as an explanation of farmland prices. Using Iowa farmland price and rent data over the 1921–86 sample period, formal test results indicate that, although farmland price and rent movements are highly correlated, price movements are not consistent with the implications of this model. There appear to be persistent predictable excess positive and/or negative returns in the Iowa farmland market.
Search for neutrinos from the sun

A search was made for solar neutrinos with a detector based upon the reaction ${\mathrm{Cl}}^{37}(\ensuremath{\nu}, {e}^{\ensuremath{-}}){\mathrm{Ar}}^{37}$. The upper limit of the product of the neutrino flux and the cross sections for all sources of neutrinos was 3\ifmmode\times\else\texttimes\fi{}${10}^{\ensuremath{-}36}$ ${\mathrm{sec}}^{\ensuremath{-}1}$ per ${\mathrm{Cl}}^{37}$ atom. It was concluded specifically that the flux of neutrinos from ${\mathrm{B}}^{8}$ decay in the sun was equal to or less than 2\ifmmode\times\else\texttimes\fi{}${10}^{6}$ ${\mathrm{cm}}^{\ensuremath{-}2}$ ${\mathrm{sec}}^{\ensuremath{-}1}$ at the earth, and that less than 9% of the sun's energy is produced by the carbon-nitrogen cycle.
Malnutrition and inflammation-"burning down the house": inflammation as an adaptive physiologic response versus self-destruction?

A summary of my 2014 Rhoads Lecture is presented that explores our progress in understanding the complex interplay of malnutrition and inflammation. A historical perspective is provided that highlights the contributions of some of the key pioneers in the nutrition assessment field. Advances in agriculture, education, public health, healthcare, and living standards have affected traditional settings for malnutrition. The chronic disease, surgery, and injury conditions that are associated with modern healthcare are becoming prevalent settings for malnutrition. One consequence has been a growing appreciation for the contributions of inflammation to malnutrition in these clinical conditions. This recognition has driven a fresh look at how we define and think about malnutrition syndromes. An inflammatory component is included in the definitions suggested by the recent Academy of Nutrition and Dietetics and American Society for Parenteral and Enteral Nutrition consensus report that also describes characteristic...
Steroids and the maturation of rat tissues.

Abstract In normal developing rats there are two periods when glucocorticoids exert important influences upon hepatic chemical differentiation: new enzymes appear in liver after the late fetal and also after the postnatal (2nd week) upsurge of plasma corticosterone. Cortisol, administered prior to the natural increase in endogenous corticosterone, induces these enzymes before the scheduled time. Such interference also causes premature losses in enzymes (in various organs) which appear to be more important to growth per se than to tissue-specific metabolic functions. Current hypotheses about the mechanism of hormone action are inadequate to explain the fact that glucocorticoids, even in the same tissue, induce different enzymes at different stages of development. Several observations suggest that the competence of different synthetic systems to respond to a hormonal trigger develops in distinct steps, under the impact of additional, specific stimuli.
Boron trihalide-promoted addition of aryl aldehydes to styrenes. A new convenient and highly efficient synthesis of 1,3-dihalo-1,3-diarylpropanes

Reactions of aryl aldehydes with styrenes in the presence of boron trichloride in CH2Cl2 at 0°C produce 1,3-dichloro-1,3-diarylpropanes in excellent yields. Reactions carried out using boron tribromide generate the corresponding 1,3-dibromo-1,3-diarylpropane in good yields.
An alternative routing algorithm for the pyramid structures

A pyramid structure of size n has a diameter of log n, which immediately leads to an optimal routing algorithm, using only parent-child links. However, shortest paths between nodes may be unavailable because of the existence of faulty nodes. On the other hand, there exist many other potential communication paths using links in the associated meshes.In this paper, we present an alternative routing algorithm making use of both mesh links and parent-child links, and study a set of bypassing paths associated with this algorithm.
Numerical proof of stability of roll waves in the small-amplitude limit for inclined thin film flow

Abstract We present a rigorous numerical proof based on interval arithmetic computations categorizing the linearized and nonlinear stability of periodic viscous roll waves of the KdV–KS equation modeling weakly unstable flow of a thin fluid film on an incline in the small-amplitude KdV limit. The argument proceeds by verification of a stability condition derived by Bar–Nepomnyashchy and Johnson–Noble–Rodrigues–Zumbrun involving inner products of various elliptic functions arising through the KdV equation. One key point in the analysis is a bootstrap argument balancing the extremely poor sup norm bounds for these functions against the extremely good convergence properties for analytic interpolation in order to obtain a feasible computation time. Another is the way of handling analytic interpolation in several variables by a two-step process carving up the parameter space into manageable pieces for rigorous evaluation. These and other general aspects of the analysis should serve as blueprints for more general analyses of spectral stability.
Gain-Bandwidth Optimal Design for the New Formulation Quantitative Feedback Theory

Recent work in Quantitative Feedback Theory (QFT) has extended the methodology to include a more mathematically tractable formulation which allows consideration of both parametric and non-parametric uncertainty. An issue that remains largely unsolved is that of constructive existence conditions for optimal QFT controllers. The methodology developed in Thompson and Nwokah (1994) was to build upon the classical Bode analysis approach to loop shaping by defining the structure and parameters of an acceptable initial QFT controller a priori; locally optimal controllers of this structure could then be computed via a constrained nonlinear programming algorithm. The primary purpose of this paper is to extend this methodology to the sensitivity-based, “new formulation” QFT bounds. This technique is demonstrated for the nonminimum-phase problem of Nordgren et al. (1994).
Probabilistic Analysis to Quantify Optical Performance and Error Budgets for Next Generation Heliostats

Current heliostats cost ∼$200/m2 of reflective area and are estimated to contribute up to 50% of the total solar power tower plant costs. A drastic overall cost reduction is required in order for concentrated solar thermal power to be economically viable. The Department of Energy has set forth the SunShot initiative targeting a levelized cost of energy (LCOE) of $0.06/kWh by the year 2020. The cost of each heliostat must be brought down to an estimated $75/m2 to achieve this rigorous goal. One of the driving aspects of heliostat design and cost are the heliostat optical errors. At the moment, it is relatively unclear about the amount of error that can be present in the system while still maintaining low cost and high optical accuracy. The optical errors present on heliostat mirror surfaces directly influence the plant LCOE by causing beam spillage. This can result in an increase in the number of heliostats, an increased receiver size, and decreased thermal efficiency. Assuming a fixed heliostat cost of $75/m2, the effects of optical errors on LCOE are evaluated within the software DELSOL. From a probabilistic analysis, beam quality errors (i.e. slope error, alignment errors, etc.) are shown to have more importance on the LCOE than tracking errors. This determination results in a realization that the tracking errors and beam quality errors can be combined into a “bundled” root-sum-square (RSS) error value. A “bundled” error value of 2 mrad results in an LCOE of $0.06/kWh. This “bundled” value is the basis for a new optical error budget and is decomposed into five individual errors. These five errors can be used as design specifications for new generation heliostats.Copyright © 2013 by ASME
Transfer Function Formulation of Constrained Distributed Parameter Systems, Part I: Theory

The distributed system is an assembly of distributed elements. A generalized displacement method is developed to evaluate the free and forced responses
INDUCTION OF OVULATION IN THE HEN BY INJECTION OF PROGESTERONE INTO THE BRAIN

Progesterone in a solution of propylene glycol regularly induced premature ovulation in the hen when injected into certain regions of either the hypothalamus or the caudal ncostriatum but not in other parts of the forebrain. The effective quantity of hormone is estimated to be no more than 5 μg. Progesterone did not induce ovulation when injected into the pituitary. It is thus indicated that the steroid acts upon certain regions of the brain to cause release of ovulation-inducing hormone.
N4‐(dialkylamino)methylene derivatives of 2′‐deoxycytidine and arabinocytidine: Physicochemical studies for potential prodrug applications

The synthesis and physicochemical parameters of a series of N4-(N,N-dialkyl)formamidine derivatives of 2'-deoxycytidine (dCyd, 1) and arabinocytidine (ara-C, 2), as prodrug prototypes, are described. The lipophilicity of the formamidine derivatives compared to that of the parent nucleosides increased 1.26- to 145-fold. The corresponding half-lives of the derivatives in aqueous solution at pH 7.4 and 37 degrees C ranged from 3.7 to 52 h. The analogues most stable to hydrolysis in both series (3 and 4) were the diisopropyl derivatives (3d and 4d). The substitution effects of the sugar OH groups at the 2'- and 3'-positions on the corresponding partition coefficients gave pi-values of -0.16 and -0.55, respectively. These values are significantly more positive than those generally associated with aliphatic hydroxy substituents indicating that sugar OH groups of nucleosides have a decreased tendency to associate with the aqueous phase. The in vitro growth inhibitory activities of the ara-C derivatives (4) against murine lymphocytic leukemia L1210 cells indicate that prodrug to drug conversion readily occurs. The results confirm our previous findings about the versatility of the formamidine modification of nucleosides bearing exocyclic amino groups. The data facilitate optimization of lipophilicities and hydrolytic stabilities and thus contribute to the design and further development of the formamidine type of prodrug derivatives.
Reneging: A Topic to Promote Engaging Discussions About Law and Ethics in a Business Law or Legal Environment Course

A recent study showed only one-third of young adults see any problem with reneging on a job contract. This paper reviews the law and ethics of reneging and suggests options for presenting the reneging issue. It assesses the content of student papers on reneging and reports results of a pre- and post-course survey on student attitudes toward reneging, permitting modest conclusions about the effect of a legal studies course on student thinking.
Periodic states, local effects and coexistence in the BML traffic jam model

Abstract The Biham–Middleton–Levine (BML) model is simple lattice model of traffic flow, self-organization and jamming. Rather than a sharp phase transition between free-flow and jammed, it was recently shown that there is a region where stable intermediate states exist, with details dependent on the aspect ratio of the underlying lattice. Here we investigate square aspect ratios, focusing on the region where random, disordered intermediate (DI) states and conventional global jam (GJ) states coexist, and show that DI states dominate for some densities and timescales. Moreover, we show that periodic intermediate (PI) states can also coexist. PI states converge to periodic limit cycles with short recurrence times and were previously conjectured to arise from idiosyncrasies of relatively prime aspect ratios. The observed coexistence of DI, PI and GJ states shows that global parameters, density together with aspect ratio, are not sufficient to determine the full jamming outcome. We investigate additional features that lead towards jamming and show that a strategic perturbation of a few selected bits can change the nature of the flow, nucleating a global jam.
An object-oriented environment for robot system architectures

The object-oriented Robot Independent Programming Environment (RIPE), which is being used for the rapid design and implementation of a variety of applications, is described. A system architecture based on hierarchies of distributed multiprocessors provides the computing platform for a layered programming structure that models the application as a set of software objects. These objects are designed to support model-based automated planning and programming, real-time sensor-based activity, error handling, and robust communication. The object-oriented paradigm provides mechanisms such as inheritance and polymorphism which allow the implementation of the system to satisfy the goals of software reusability, extensibility, reliability, and portability. Designing a hierarchy of generic parent classes and device-specific subclasses which inherit the same interface allows a Robot Independent Programming Language (RIPL) to be realized. Workcell tasks demonstrating robot cask handling operations for nuclear waste facilities, which are successfully implemented using this object-oriented software environment, are discussed. >
Localization and Gluing of Topological Amplitudes

We develop a gluing algorithm for Gromov-Witten invariants of toric Calabi-Yau threefolds based on localization and gluing graphs. The main building block of this algorithm is a generating function of cubic Hodge integrals of special form. We conjecture a precise relation between this generating function and the topological vertex at fractional framing.
GROUND- AND EXCITED-STATE STRUCTURAL ORIENTATION OF 2-(2'-HYDROXYPHENYL)BENZAZOLES IN CYCLODEXTRINS

The effects of α-, β- , γ-, and 2,6-di-O-methyl-β-cyclodextrins (CDs) on the ground- and excited-state properties of 2-(2‘-hydroxyphenyl)benzoxazole, 2-(2‘-hydroxyphenyl)benzothiazole, and 2-(2‘-hydroxyphenyl)benzimidazole in aqueous media are investigated. Steady-state fluorescence measurements are used to characterize the interaction of CDs with these azoles. Absorbance measurements indicate increased solubility of the azoles in aqueous solutions of CDs. Measurements of acidity constants (pKa) and data from induced circular dichroism indicate increased ground- and excited-state acidities of the phenolic protons of the molecules in the presence of CDs and axial orientation of the molecules within the CD cavity, respectively. The data further suggest a planar stucture for HBO and a twisted confirmation for both HBT and HBI. The association constants of the inclusion complexes have also been estimated. These studies are further supplemented by comparative spectroscopic studies of 2-(2‘-methoxyphenyl)benzot...
Telementoring Facilitates Independent Hand-Assisted Laparoscopic Living Donor Nephrectomy

Laparoscopic living donor nephrectomy is a major advance but a challenging procedure to learn even after laparoscopic training. It requires significant previous training in both laparoscopic and transplant surgery. Telementoring has been shown to reduce the laparoscopic learning curve in other fields. Of six cases of hand-assisted laparoscopic (HAL) living donor nephrectomy at our institution, an on-site mentor supervised the initial two. We present the subsequent four cases as the first documented examples of telementored HAL live donor nephrectomy. Telelink was established with a Comstation (Zydacron, UK) incorporating a Z360 telementoring codec and four ISDN lines (512 kb/s) with time delay of 500 ms for both audio and video. The remote surgeon in Minnesota (USA) could change independently between the laparoscopic and external views. The operating surgeons were able to look at the mentor and converse with him throughout. There were no adverse events in recipients and graft function was excellent. With regards to the telementored group the mean operative time was 240 minutes, the mean warm ischemic time 189 seconds, the mean estimated blood loss 171 mL, and the mean length of hospital stay 3 days. Telementoring for laparoscopic donor nephrectomy is feasible, effective, and likely to aid independent practice by providing continued supervision and reducing the learning period.
Computation of confined turbulent coaxial jet flows

The characteristics of the recirculation zones in confined coaxial turbulent jets are investigated numerically employing the k-epsilon turbulent model. The geometrical arrangement corresponds to the experimental study of Owen (1976) and the investigation is undertaken to provide information for isothermal flow relevant to combustor flows. For the first time, the shape, size, and location of the recirculation zones for the above experimental configuration are correctly predicted. The processes leading to the observed results are explained. Detailed comparisons of the prediction with measurements are made. It is shown that the recirculation zones are very sensitive to the central jet exit configuration and the velocity ratio of the jets.
Deceleration Lengths for Exit Terminals

AbstractGeneral freeway design practice assumes deceleration for a vehicle exiting the freeway occurs between the point when the vehicle clears the through-traffic lane and the point of limiting design speed for the ramp proper. The length provided between these points should be at least as great as the distance needed to accomplish the appropriate deceleration, which is governed by the speed of traffic on the through lane and the speed to be attained on the ramp. The deceleration length values used in design are based on assumed running speed for the limited-access highway and the ramp, along with deceleration rates based on 1930s studies. The need to update the speed assumption for the highway and the ramp curve is clear, although determining appropriate deceleration rates is not as simple. Previous research has demonstrated that drivers select speeds at or above the design speed on horizontal curves, rather than the much lower average running speed that previously had been assumed for several design el...
A melting model for variably depleted and enriched lherzolite in the plagioclase and spinel stability fields

[1] Here we develop a lherzolite melting model and explore the effects of variations in mantle composition, pressure, temperature, and H2O content on melt composition. New experiments and a compilation of experimental liquids saturated with all of the mantle minerals (olivine, orthopyroxene, clinopyroxene, plagioclase and/or spinel) are used to calibrate a model that predicts the temperature and major element composition of a broad spectrum of primary basalt types produced under anhydrous to low H2O-content conditions at upper mantle pressures. The model can also be used to calculate the temperature and pressure at which primary magmas were produced in the mantle, as well as to model both near-fractional adiabatic decompression and batch melting. Our experimental compilation locates the pressure interval of the plagioclase to spinel transition on the solidus and shows that it is narrow (� 0.1 GPa) for melting of natural peridotite compositions. The multiple saturation boundaries determined by our model provide a method for assessing the appropriate mineral assemblage, as well as the extent of the fractional crystallization correction required to return a relatively primitive liquid to equilibrium with the mantle source. We demonstrate that an inaccurate fractionation correction can overestimate temperature and depths of melting by hundreds of degrees and tens of kilometers, respectively. This model is particularly well suited to examining the temperature and pressure of origin for intraplate basaltic volcanism and is used to examine the petrogenesis of a suite of Holocene basaltic lavas from Diamond Crater in Oregon’s High Lava Plains (HLP).
Water pollution control

The ‘Act of 76’ arose out of an inquiry about ‘…how far the present use of rivers or running waters…for the purpose of carrying off the sewage of towns…and the refuse from industrial processes and manufacturers…can be prevented without risk to the public health or serious injury to such processes…and how far such sewage and refuse can be utilized and got rid of otherwise than by discharge into rivers…or rendered harmless before reaching them;…the effect on the drainage of lands and inhabited places of obstructions to the natural flow of rivers or streams caused by mills, weirs, locks, and other navigation works, and into the best means of remedying any evils thence arising.’ With this charge, Victoria, Queen of England, on April 6, 1868, initiated the Royal Commission that brought into being the Rivers Pollution Prevention Act of 1876 [Rivers Pollution Commission, 1870].
Computation of the Statistics of Forced Response of a Mistuned Bladed Disk Assembly via Polynomial Chaos

The method of polynomial chaos has been used to analytically compute the statistics of the forced response of a mistuned bladed disk assembly. The model of the bladed disk assembly considers only one mode of vibration of each blade. Mistuning phenomenon has been simulated by treating the modal stiffness of each blade as a random variable. The validity of the polynomial chaos method has been corroborated by comparison with the results from numerical simulations.
Deriving boundary S matrices

Abstract We show how to derive exact boundary S matrices for integrable quantum field theories in 1 + 1 dimensions using lattice regularization. We do this calculation explicitly for the sine-Gordon model with fixed boundary conditions using the Bethe ansatz for an XXZ-type spin chain in a boundary magnetic field. Our results agree with recent conjectures of Ghoshal and Zamolodchikov, and indicate that the only solutions to the Bethe equations which contribute to the scaling limit are the standard strings.
Toward fullerene-based X-ray contrast agents: design and synthesis of non-ionic, highly-iodinated derivatives of C60

Abstract An X-ray contrast agent precursor based on C 60 has been designed, synthesized, and characterized. The compound is the monoadduct of a malonodiamide containing six iodine atoms and eight acetal-protected alcohols with multiple hindered rotations at ambient temperature.
New Directions in Measuring Racial Isolation in School

This article offers new directions in measuring racial isolation in schools. The most widely used measurement approach is to examine the mean on the distribution of school percentage non-White across non-White students (the isolation rate) or the percentage of non-White students in schools with large shares of non-Whites (e.g., 90% or more) at a single point in time. Using data on New York City public school students, I discuss the complexity that is revealed when school officials and researchers consider the following three dimensions of racial isolation: between classrooms, over time, and among non-White students.
Architectural choices for the Columbia 0.8 Teraflops machine

We discuss the hardware design choices made in our 16K-node 0.8 Teraflops supercomputer project, a machine architecture optimized for full QCD calculations. The efficiency of the conjugate gradient algorithm in terms of balance of floating-point operations, memory handling and utilization, and communication overhead is addressed. We also discuss the technological innovations and software tools that facilitate hardware design and what opportunities these give to the academic community.
A programmable second order oversampling CMOS sigma-delta analog-to-digital converter for low-power sensor interface electronics

A programmable second order oversampling sigma-delta analog-to-digital converter (ADC) is designed and fabricated in 0.5 μm n-well CMOS process for low-power interface electronics of a sensor node in wireless sensor networks. The sigma-delta ADC can be programmed to operate at three different oversampling ratios of 16, 32, and 64 to give three different resolutions of 9, 12 and 14 bits, respectively which impact the power consumption of the sensor module. The major part of power is consumed in the decimator of the ADC by the integrators which operate at the highest sampling rate. Hence, an alternate design is introduced in the integrator stages by inserting sign extension coder circuits and reusing the same integrators for different resolutions and oversampling ratios. The programmable ADC can be interfaced with on or off-chip nanosensors for detection of traces of toxic gases and chemicals.
A Magnetically-Switched, Rotating Black Hole Model for the Production of Extragalactic Radio Jets and the Fanaroff and Riley Class Division

A model is presented in which both Fanaroff and Riley class I and II extragalactic jets are produced by magnetized accretion disk coronae in the ergospheres of rotating black holes.
A PROSTHETIC GROUP FOR THE RAPID INTRODUCTION OF FLUORINE INTO PEPTIDES AND FUNCTIONALIZED DRUGS.

Fluoride ion as the tetrabutylammonium salt displaces bromide in para-substituted benzyl bromides in acetonitrile or dimethylformamide. The p-bromomethyl benzoyl (BMB) group has been coupled to amino groups, including peptide amino groups, via its N-hydroxysuccinimide ester. In a subsequent step, the facile displacement of bromide by fluoride occurred under conditions compatible for use with 18F radiotracers.
The Stratification of Jupiter's Troposphere at the Galileo Probe Entry Site

Galileo Probe Atmospheric Structure Investigation (ASI) pressure and temperature sensor data acquired during the parachute descent phase have been used to derive the static stability structure of Jupiter's troposphere at pressure levels of 0.5–22 bars using three techniques. The first approach utilizes both the p-sensor and T-sensor data, but since the p-sensor's zero offset was significantly affected by the thermal anomaly in the probe, two other approaches using only T-sensor data have also been developed. By making the physically reasonable assumptions of equilibrium descent for the probe and hydrostatic balance of the atmosphere, an algorithm for deriving the background static stability from T-sensor measurements alone is developed. Regions with static stability 0.1–0.2 K km−1 are found at 0.5–1.7 bars, 3–8.5 bars, and 14–20 bars. Between these layers, regions of weaker static stability are present. Mean molecular weight gradients due to the vertical variation of water vapor abundance near the 11-bar pressure level appear to stabilize the atmosphere at this level. Oscillatory structures with vertical wavelength ∼15–30 km and amplitude ∼0.1–0.2 K are observed in the T-sensor data. For pressure <2 bars, these eddies are well above the noise level of the measurements and are consistent with the predictions of linear gravity wave theory for a wave with horizontal phase speed cx=160 m s−1 with respect to System III propagating through the static stability derived from the T-sensor data alone. They provide quantitative confirmation of the static stability derived from T-sensor data in the troposphere where p<2 bars. The observed static stability structure shows an inverse correlation with the regions of wind shear observed by the Doppler Wind Experiment: regions of highest shear in the horizontal wind appear to be associated with regions of lowest static stability. The particulate population detected by other experiments on the probe shows some correlation with the uppermost layer of static stability, suggesting enhanced solar energy deposition at these levels may play a role in producing the positive static stability.
Synthy: A system for end to end composition of web services

The demand for quickly delivering new applications is increasingly becoming a business imperative today. However, application development is often done in an ad hoc manner resulting in poor reuse of software assets and longer time-to-delivery. Web services have received much interest due to their potential in facilitating seamless business-to-business or enterprise application integration. A web service composition system can help automate the process, from specifying business process functionalities, to developing executable workflows that capture non-functional (e.g. Quality of Service (QoS)) requirements, to deploying them on a runtime infrastructure. Intuitively, web services can be viewed as software components and the process of web service composition similar to software synthesis. In addition, service composition needs to address the build-time and runtime issues of the integrated application, thereby making it a more challenging and practical problem than software synthesis. However, current solutions based on business web services (using WSDL, BPEL, SOAP, etc.) or semantic web services (using ontologies, goal-directed reasoning, etc.) are both piecemeal and insufficient. We formulate the web service composition problem and describe the first integrated system for composing web services end to end, i.e., from specification to deployment. The proposed solution is based on a novel two-staged composition approach that addresses the information modeling aspects of web services, provides support for contextual information while composing services, employs efficient decoupling of functional and non-functional requirements, and leads to improved scalability and failure handling. We also present Synthy, a prototype of the service composition system, and demonstrate its effectiveness with the help of an application scenario from the telecom domain.
Formation of aryl-nitrogen, aryl-oxygen, and aryl-carbon bonds using well-defined copper(I)-based catalysts.

We report mild synthetic protocols for the formation of aryl−carbon, aryl−nitrogen, and aryl−oxygen bonds based on soluble, well-defined copper(I) catalysts. These protocols do not require the use of palladium and/or expensive ligands.
THE ATOMIC WEIGHT OF PROTACTINIUM

Up to the present time the atomic weight of not a single member of the actinium series of radioactive elements has been determined by orthodox chemical methods. An opportunity for such a determination was given for the first time in 1927 when protactinium, the longest-lived isotope of element 91, was isolated and obtained in the state of pure compounds. Unfortunately the quantities of the element then available were extremely small. In the following years the political and financial difficulties in obtaining raw material and working it up for larger quantities of pro­tactinium have been overcome and recently over 0.1 gm of pure Pa2O5 were isolated and made available for an atomic weight determination. In the meantime Aston succeeded in determining with his mass-spectrograph the isotopic mass of AcD, the end product of the actinium series, in the mass spectra of leads from different sources. His value of 207 for AcD leads by simple additions to 231 as the atomic weight of protactinium. On the basis of Aston’s data Rutherford estimated the half-period of actino-uranium, the parent of the series, to equal 4·0 × 108 years, a figure which has been fully confirmed by subsequent research.
DNF are teachable in the average case

We study the average number of well-chosen labeled examples that are required for a helpful teacher to uniquely specify a target function within a concept class. This "average teaching dimension" has been studied in learning theory and combinatorics and is an attractive alternative to the "worst-case" teaching dimension of Goldman and Kearns which is exponential for many interesting concept classes. Recently Balbach showed that the classes of 1-decision lists and 2-term DNF each have linear average teaching dimension. As our main result, we extend Balbach's teaching result for 2-term DNF by showing that for any 1?s?2 ?(n), the well-studied concept classes of at-most-s-term DNF and at-most-s-term monotone DNF each have average teaching dimension O(ns). The proofs use detailed analyses of the combinatorial structure of "most" DNF formulas and monotone DNF formulas. We also establish asymptotic separations between the worst-case and average teaching dimension for various other interesting Boolean concept classes such as juntas and sparse GF 2 polynomials.
A unified approach for minimizing composite norms

We propose a first-order augmented Lagrangian algorithm (FALC) to solve the composite norm minimization problem $$\begin{aligned} \begin{array}{ll} \min \limits _{X\in \mathbb{R }^{m\times n}}&\mu _1\Vert \sigma (\mathcal{F }(X)-G)\Vert _\alpha +\mu _2\Vert \mathcal{C }(X)-d\Vert _\beta ,\\ \text{ subject} \text{ to}&\mathcal{A }(X)-b\in \mathcal{Q }, \end{array} \end{aligned}$$where $$\sigma (X)$$ denotes the vector of singular values of $$X \in \mathbb{R }^{m\times n}$$, the matrix norm $$\Vert \sigma (X)\Vert _{\alpha }$$ denotes either the Frobenius, the nuclear, or the $$\ell _2$$-operator norm of $$X$$, the vector norm $$\Vert .\Vert _{\beta }$$ denotes either the $$\ell _1$$-norm, $$\ell _2$$-norm or the $$\ell _{\infty }$$-norm; $$\mathcal{Q }$$ is a closed convex set and $$\mathcal{A }(.)$$, $$\mathcal{C }(.)$$, $$\mathcal{F }(.)$$ are linear operators from $$\mathbb{R }^{m\times n}$$ to vector spaces of appropriate dimensions. Basis pursuit, matrix completion, robust principal component pursuit (PCP), and stable PCP problems are all special cases of the composite norm minimization problem. Thus, FALC is able to solve all these problems in a unified manner. We show that any limit point of FALC iterate sequence is an optimal solution of the composite norm minimization problem. We also show that for all$$\epsilon >0$$, the FALC iterates are $$\epsilon $$-feasible and $$\epsilon $$-optimal after $$\mathcal{O }(\log (\epsilon ^{-1}))$$ iterations, which require $$\mathcal{O }(\epsilon ^{-1})$$ constrained shrinkage operations and Euclidean projection onto the set $$\mathcal{Q }$$. Surprisingly, on the problem sets we tested, FALC required only $$\mathcal{O }(\log (\epsilon ^{-1}))$$ constrained shrinkage, instead of the $$\mathcal{O }(\epsilon ^{-1})$$ worst case bound, to compute an $$\epsilon $$-feasible and $$\epsilon $$-optimal solution. To best of our knowledge, FALC is the first algorithm with a known complexity bound that solves the stable PCP problem.
The MafA transcription factor becomes essential to islet β-cells soon after birth

The large Maf transcription factors, MafA and MafB, are expressed with distinct spatial–temporal patterns in rodent islet cells. Analysis of Mafa−/− and pancreas-specific Mafa∆panc deletion mutant mice demonstrated a primary role for MafA in adult β-cell activity, different from the embryonic importance of MafB. Our interests here were to precisely define when MafA became functionally significant to β-cells, to determine how this was affected by the brief period of postnatal MafB production, and to identify genes regulated by MafA during this period. We found that islet cell organization, β-cell mass, and β-cell function were influenced by 3 weeks of age in MafaΔpanc mice and compromised earlier in MafaΔpanc;Mafb+/− mice. A combination of genome-wide microarray profiling, electron microscopy, and metabolic assays were used to reveal mechanisms of MafA control. For example, β-cell replication was produced by actions on cyclin D2 regulation, while effects on granule docking affected first-phase insulin secretion. Moreover, notable differences in the genes regulated by embryonic MafB and postnatal MafA gene expression were found. These results not only clearly define why MafA is an essential transcriptional regulator of islet β-cells, but also why cell maturation involves coordinated actions with MafB.