cssi/SciSciGPT-SciSciNet huggingface dataset:
Mach Number Effects on Turbine Blade Transition Length Prediction

The effect of a Mach number correction on a model for predicting the length of transition was investigated. The transition length decreases as the turbulent spot production rate increases. Much of the data for predicting the spot production rate comes from low speed flow experiments. Recent data and analysis showed that the spot production rate is affected by Mach number. The degree of agreement between analysis and data for turbine blade heat transfer without film cooling is strongly dependent of accurately predicting the length of transition. Consequently, turbine blade heat transfer data sets were used to validate a transition length turbulence model. A method for modifying models for the length of transition to account for Mach number effects is presented. The modification was made to two transition length models. The modified models were incorporated into the two-dimensional Navier-Stokes code, RVCQ3D. Comparisons were made between predicted and measured midspan surface heat transfer for stator and rotor turbine blades. The results showed that accounting for Mach number effects significantly improved the agreement with the experimental data.
Speed limit effectiveness in short-term rural interstate work zones

Average speed and speed variance are two characteristics of traffic flow that affect accident rates and severity near work zones. Operationally, work zones account for approximately 24% of the non-recurring delay. A policy for work zone speed limits has to delicately balance the safety and the efficiency impacts. If speeds are set too low, then avoidable congestion and speed violations might result. If speeds are set too high then, again, safety may be compromised. In this paper, results from field studies conducted on three Interstate 70 maintenance short-term work zones in rural Missouri are presented for three different speed limit scenarios: no posted speed limit reduction, 10 mph posted speed limit reduction, and 20 mph posted speed limit reduction. The 85th percentile speeds and standard deviation of speed were found to be 81 and 10 mph; 62 and 8 mph; and 48 and 6 mph, respectively for the three scenarios. The differences in 85th percentile speed and standard deviation of speed among all three scena...
General and Stereospecific Route to 9-Substituted, 8,9-Disubstituted, and 9,10-Disubstituted Analogues of Benzolactam-V8

Nitration of the l-tyrosine derivative 9 provides the 3-nitro compound 13, which is converted into amide 15 by reduction and protection. Nitration of 15 either ortho or para to the acetamido group ...
Scalable high-definition video coding

A new source coding algorithm is proposed which delivers an encoded bit stream that is scalable in both spatial resolution and frame rate. Motion compensated temporal filtering is combined with a spatial subband/wavelet pyramid to provide an efficient 3D multiresolution representation that yields perceptually acceptable low frame rate sequences. Error feedback hierarchical coding is used to eliminate the propagation of coding errors between spatio temporal resolutions in order to achieve near optimal results for each subvideo. The proposed order in of refinement addressees the non-commutative property of motion compensated temporal filtering and spatial subband/wavelet analysis. A new algorithm based on adaptive conditional arithmetic coding of quantizer significance maps is introduced and is shown to increase coding efficiency. Experimental results demonstrate a significant improvement in performance over other published algorithms. The algorithm is found to be more robust with respect to variations in the type of motion present in video data. The code-and-refine nature of the hierarchical algorithm makes it possible to use the algorithm as a scalable extension to other source coding algorithms. Finally, the complexity of the algorithm is modest and is well suited to a parallel implementation.© (1998) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
FT-IR and XPS study of copper(II) complexes of imidazole and benzimidazole

Abstract Several Cu(II) complexes coordinated to imidazole (IMDAH) and benzimidazole (BIMDAH) ligands have been isolated as powdered solids. Compounds prepared are Cu(BIMDAH)4Cl2, Cu(IMDAH)4Cl2, Cu(BIMDAH)2Cl2, Cu(IMDAH)2Cl2 and Cu(BIMDA)2 (BIMDA = deprotonated form of BIMDAH ligand). These compounds have been characterized by elemental analysis, and by diffuse reflectance Fourier Transform and X-ray photoelectron spectroscopy. The results show that Cu(BIMDAH)4Cl2 and Cu(IMDAH)4Cl2 are formed as discrete mononuclear complexes in which the ligands are coordinated in a monodentate fashion. In contrast, the Cu- (BIMDAH)2Cl2 and Cu(IMDAH)2Cl2 complexes are formed as polymeric species. The Cu(BIMDA)2 complex also forms a polymeric structure with the ligands coordinated in a bidentate manner. X-ray photoelectron data illustrates that the surface composition of each of these complexes closely resembles that of the bulk material.
On orthogonal and symplectic matrix ensembles

The focus of this paper is on the probability,Eβ(O;J), that a setJ consisting of a finite union of intervals contains no eigenvalues for the finiteN Gaussian Orthogonal (β=1) and Gaussian Symplectic (β=4) Ensembles and their respective scaling limits both in the bulk and at the edge of the spectrum. We show how these probabilities can be expressed in terms of quantities arising in the corresponding unitary (β=2) ensembles. Our most explicit new results concern the distribution of the largest eigenvalue in each of these ensembles. In the edge scaling limit we show that these largest eigenvalue distributions are given in terms of a particular Painleve II function.
Heat kernel and moduli spaces II

In this paper we describe a proof of the formulas of Witten [W1], [W2] about the symplectic volumes and the intersection numbers of the moduli spaces of principal bundles on a compact Riemann surface. It is known that these formulas give all the information needed for the Verlinde formula. The main idea of the proof is to use the heat kernel on compact Lie groups, in a way very similar to the heat kernel proof of the Atiyah-Singer index formula and the Atiyah-Bott fixed point formula. The Reidemeister torsion comes into the picture, through a beautiful observation of Witten, as the symplectic volume of the moduli space. It plays the role similar to that played by the Ray-Singer torsion in the path-integral computations on the space of connections. The basic idea is as follows. Consider a smooth map between two compact smooth manifolds f : M → N . Let H(t, x, x0) be the heat kernel of the Laplace-Beltrami operator on N with x0 a fixed regular value of f . Because of the basic properties of the heat kernel, we know that for any continuous function a(y) on M , when t goes to zero, ∫
Unexpected fragmentations leading to quinanes and hydrindanes mediated by a silyl radical

Abstract Useful bicyclic ring systems are obtained by tris -trimethylsilylsilyl radical (TMS 3 Si·) mediated fragmentation of strained alkene precursors.
Heteroatom-Heteroatom-Bond Forming Reactions

Recent progress on the use of hypervalent iodine reagents for the construction of heteroatom-heteroatom bonds is reviewed. Reactions of aryl-λ 3-iodanes with heteroatom substrates derived from third-row elements and beyond are considered first, and an unusual example of heteroatom-heteroatom bond formation with diaryliodonium salts is then discussed. Finally, the use of sulfonylimino(aryl)iodanes for imidations of phosphorus, sulfur, selenium, and arsenic compounds, including enantioselective transformations (S,Se), and alternate hypervalent iodine approaches to N-sulfonylsulfilimines and N-sulfonylarsinimines are summarized.
Detrital remanent magnetization in the solar nebula

[1] We introduce the theoretical basis of a new form of remanent magnetization that likely formed on primitive bodies in the solar system. Accretional detrital remanent magnetization (ADRM) operates via “compass needle”-type alignment of ferromagnetic solids with locally uniform background fields in the solar nebula. Accretion of coherently aligned magnetic particles should have formed aggregates up to centimeters in size with significant net magnetic moment. We quantify several processes that constrain the likelihood of ADRM formation, finding that rotational gas damping and background field intensities expected for the solar nebula are sufficient to mutually align magnetic particles with diameters between ∼30 μm and several cm. The lower bound is dictated by Brownian motion or radiative torque while the upper bound is set by aerodynamic torque on non-spherical particles. Processes important for interstellar dust dynamics such as Larmor-type precession and Purcell torque are less significant in the solar nebula. ADRM can be potentially observed as zones of coherent magnetization in primitive chondrites and may be detected by spacecraft magnetic field observations on the surfaces of small bodies. Observational identification and characterization of ADRM would constrain the strength and geometry of magnetic fields in the early solar system, the accretion process of sub-meter sized objects, the formation regions of chondrite parent bodies, and the alteration history of chondritic components.
Physics development of web-based tools for use in hardware clusters doing lattice physics

Jefferson Lab and MIT are developing a set of web-based tools within the Lattice Hadron Physics Collaboration to allow lattice QCD theorists to treat the computational facilities located at the two sites as a single meta-facility. The prototype Lattice Portal provides researchers the ability to submit jobs to the cluster, browse data caches, and transfer files between cache and off-line storage. The user can view the configuration of the PBS servers and to monitor both the status of all batch queues as well as the jobs in each queue. Work is starting on expanding the present system to include job submissions at the meta-facility level (shared queue), as well as multi-site file transfers and enhanced policy-based data management capabilities.
A model of chemical releases leading to upper-atmospheric chemi-ion formation.

Upper atmospheric formation of electron cloud produced by chemiionization reactions of chemical release agents
Territorial Stigmatization in the Age of Advanced Marginality

The comparative sociology of the structure, dynamics, and experience of urban relegation in the United States and the European Union during the past three decades reveals the emergence of a new regime of marginality. This regime generates forms of poverty that are neither residual, nor cyclical or transitional, but inscribed in the future of contemporary societies insofar as they are fed by the ongoing fragmentation of the wage labour relationship, the functional disconnection of dispossessed neighbourhoods from the national and global economies, and the reconfiguration of the welfare state in the polarizing city. Based on a methodical comparison between the black American ghetto and the French working-class banlieue at century's turn, this article spotlights three distinctive spatial properties of `advanced marginality' — territorial fixation and stigmatization, spatial alienation and the dissolution of `place', and the loss of a hinterland — and draws out their implications for the formation of the `pre...
New developments in the organometallic chemistry of calcium, strontium and barium

Cet article presente differentes procedures de preparation de complexes d'alcolinoterreux metalloceniques. Caracterisation structurale par diffraction RX
PROBING COSMIC DUST OF THE EARLY UNIVERSE THROUGH HIGH-REDSHIFT GAMMA-RAY BURSTS

We explore the extinction properties of the dust in the distant universe through the afterglows of high-redshifted gamma-ray bursts (GRBs) based on the Drude model which, unlike previous studies, does not require a prior assumption of template extinction laws. We select GRB 070802 at z 2.45 (which shows clear evidence for the 2175 A extinction bump) and GRB 050904 at z 6.29, the second most distant GRB observed to date. We fit their afterglow spectra to determine the extinction of their host galaxies. We find that (1) their extinction curves differ substantially from that of the Milky Way and the Small and Large Magellanic Clouds (which were widely adopted as template extinction laws in the literature); (2) the 2175 A extinction feature appears to be also present in GRB 050904 at z 6.29; and (3) there does not appear to be strong evidence for the dependence of dust extinction on redshifts. The inferred extinction curves are closely reproduced in terms of a mixture of amorphous silicate and graphite, both of which are expected supernova condensates and have been identified in primitive meteorites as presolar grains originating from supernovae (which are considered as the main source of dust at high-z).
Transit Vehicles as Traffic Probe Sensors

New algorithms are presented that use transit vehicles as probes for determining traffic speeds and travel times along freeways and other primary arterials. A mass transit tracking system based on automatic vehicle location data and a Kalman filter used to estimate vehicle position and speed are described. A system of virtual probe sensors that measure transit vehicle speeds by using the track data is also described. Examples showing the correlation between probe data and inductance loop speed-trap data are presented. Also presented is a method that uses probe sensor data to define vehicle speed along an arbitrary roadway as a function of space and time, a speed function. This speed function is used to estimate travel time given an arbitrary starting time. Finally, a graphical application is introduced for viewing real-time speed measurements from a set of virtual sensors that can be located throughout King County, Washington, on arterials and freeways.
The Use of Aryl Hydrazide Linkers for the Solid Phase Synthesis of Chemically Modified Peptides

Since Merrifield introduced the concept of solid phase synthesis in 1963 for the rapid preparation of peptides, a large variety of different supports and resin-linkers have been developed that improve the efficiency of peptide assembly and expand the myriad of synthetically feasible peptides. The aryl hydrazide is one of the most useful resin-linkers for the synthesis of chemically modified peptides. This linker is completely stable during Boc- and Fmoc-based solid phase synthesis and yet it can be cleaved under very mild oxidative conditions. The present article reviews the use of this valuable linker for the rapid and efficient synthesis of C-terminal modified peptides, head-to-tail cyclic peptides and lipidated peptides.
Synthesis of Deoxyribonucleoside Phosphorodithioate Dimers by a Triester Method

Abstract Modified oligodeoxynucleotides have recently received much attention due to their therapeutic applications. Among the more promising are phosphorodithioates where both nonbridging oxygen atoms in the phosphate diesters are replced by sulfur. Deoxynucleoside phosphorodithioate dimers have been prepared in several ways, using H-phosphonate, phosphordiamidite, phosphoramidite, and thiophosphoramidite methods. Reports have also appeared on the synthesis of oligonucleotides with alternating phosphodiester and dithiophosphodiester linkages, as well as one on ribonucleoside dimers. Of the above methods, the thiophosphoramidite method has been applied successfully for the preparation of mixed base oligonucleotides containing contiguous phosphorodithioate linkages. However, this method gives products which contain varying amounts of phosphorothioate linkages (2 − 10%) due to factors associated with the involvement of trivalent thiophosphorus compounds. In addition, the thiophosphoramidite synthons are dif...
The stability of free electron lasers against filamentation

Abstract We estimate the growth rate of the filamentation instability in a relativistic electron beam travelling parallel to an intense laser beam. We further estimate how the altered index of refraction in a high power FEL will affect the growth rate. We find that due to the finite emittance, FELs will be stable against filamentation.
A self-dual poset on objects counted by the Catalan numbers and a type-B analogue

Abstract We introduce two partially ordered sets, P n A and P n B , of the same cardinalities as the type-A and type-B noncrossing partition lattices. The ground sets of P n A and P n B are subsets of the symmetric and the hyperoctahedral groups, consisting of permutations which avoid certain patterns. The order relation is given by (strict) containment of the descent sets. In each case, by means of an explicit order-preserving bijection, we show that the poset of restricted permutations is an extension of the refinement order on noncrossing partitions. Several structural properties of these permutation posets follow, including self-duality and the strong Sperner property. We also discuss posets Q n A and Q n B similarly associated with noncrossing partitions, defined by means of the excedance sets of suitable pattern-avoiding subsets of the symmetric and hyperoctahedral groups.
A COMPLETELY DIASTEREOSELECTIVE ELECTROPHILIC FLUORINATION OF A CHIRAL, NONCARBOHYDRATE SUGAR RING PRECURSOR : APPLICATION TO THE SYNTHESIS OF SEVERAL NOVEL 2'-FLUORONUCLEOSIDES

A new and completely diastereoselective method for the introduction of fluorine into a noncarbohydrate sugar ring precursor has been developed. The use of N-fluorodibenzenesulfonimide (5) for the electrophilic fluorination of chiral lactone 4, which is derived from l-glutamic acid, yields the key intermediate 6. This is transformed into an anomeric acetate 8 and is used for the synthesis of a number of novel α-2‘-fluoronucleosides. Since glutamic acid is used as the synthetic starting material, the l enantiomer may also be synthesized simply by using d-glutamic acid. The incorporation of fluorine into the 2‘ position of the nucleoside provides several advantages including acid stability of the anomeric bond and general resistance to oxidative metabolism. Further, fluorine is a close mimic of hydroxyl groups in size and polarity and in its ability to act as a hydrogen bond acceptor. This may aid in the recognition of these nucleosides by the enzymes involved in nucleoside activation.
Climbing nitrogenase: Toward a mechanism of enzymatic nitrogen fixation

“Nitrogen fixation”, the reduction of dinitrogen (N2) to two ammonia (NH3) molecules, by the Mo-dependent nitrogenase is essential for all life. Despite four decades of research, a daunting number of unanswered questions about the mechanism of nitrogenase activity make it the “Everest of enzymes”. This Account describes our efforts to climb one “face” of this mountain by meeting two interdependent challenges central to determining the mechanism of biological N2 reduction. The first challenge is to determine the reaction pathway: the composition and structure of each of the substrate-derived moieties bound to the catalytic FeMo cofactor (FeMo-co) of the molybdenum−iron (MoFe) protein of nitrogenase. To overcome this challenge, it is necessary to discriminate between the two classes of potential reaction pathways: (1) a “distal” (D) pathway, in which H atoms add sequentially at a single N or (2) an “alternating” (A) pathway, in which H atoms add alternately to the two N atoms of N2. Second, it is necessary ...
A survey of smart data pricing: Past proposals, current plans, and future trends

Traditionally, network operators have used simple flat-rate broadband data plans for both wired and wireless network access. But today, with the popularity of mobile devices and exponential growth of apps, videos, and clouds, service providers are gradually moving toward more sophisticated pricing schemes. This decade will therefore likely witness a major change in the ways in which network resources are managed, and the role of economics in allocating these resources. This survey reviews some of the well-known past broadband pricing proposals (both static and dynamic), including their current realizations in various consumer data plans around the world, and discusses several research problems and open questions. By exploring the benefits and challenges of pricing data, this article attempts to facilitate both the industrial and the academic communities' efforts in understanding the existing literature, recognizing new trends, and shaping an appropriate and timely research agenda.
Pharmacophore-based discovery of 3,4-disubstituted pyrrolidines as a novel class of monoamine transporter inhibitors.

Abstract 3,4-Disubstituted pyrrolidines were discovered as a novel class of monoamine transporter inhibitors through 3-D database pharmacophore searching using a new pharmacophore model. The most potent analogue 12 has Ki values of 0.084 μM in [3H]mazindol binding, 0.20, 0.23, and 0.031 μM in inhibition of dopamine (DA), serotonin (SER), and norepinephrine (NE) reuptake, respectively. Functional antagonism testing in vitro showed that 11 and 12 are weak cocaine antagonists.
Prostaglandin E2 enhances long-term repopulation but does not permanently alter inherent stem cell competitiveness

Hematopoietic stem cell (HSC) transplantation is a lifesaving therapy for malignant and nonmalignant hematologic diseases and metabolic disorders. Although successful, hematopoietic transplantation can be hindered by inadequate stem cell number or poor engrafting efficiency. To overcome these deficits, we and others have previously reported the HSC-enhancing ability of a short-term exposure of prostaglandin E2 (PGE2); this strategy has now progressed to phase 1 clinical trials in double cord blood transplantation. To further analyze the short- and long-term effects of HSC exposure to PGE2, we followed the repopulation kinetics of PGE2-treated hematopoietic grafts through 5 serial transplantations and compared inherent long-term competitiveness in a HSC head-to-head secondary transplantation model. Treatment with PGE2 did not result in a long-term increase in HSC competitiveness, lineage bias, or enhanced proliferative potential, demonstrating that pulse exposure to PGE2 results in transient increases in HSC homing and engraftment potential.
Imaging caries lesions and lesion progression with polarization sensitive optical coherence tomography

New diagnostic tools are needed for the characterization of dental caries in the early stages of development. If carious lesions are detected early enough, they can be arrested without the need for surgical intervention. The objective of this study was to demonstrate that polarization sensitive optical coherence tomography (PS-OCT) can be used for the imaging of early caries lesions and for the monitoring of lesion progression over time. High-resolution polarization resolved images were acquired of natural caries lesions and simulated caries lesions of varying severity created over time periods of 1 to 14 days. Linearly polarized light was incident on the tooth samples and the reflected intensity in both orthogonal polarizations was measured. PS-OCT was invaluable for removing the confounding influence of surface reflections and native birefringence necessary for the enhanced resolution of the surface structure of caries lesions. This study demonstrated that PS-OCT is well suited for the imaging of interproximal and occlusal caries, early root caries, and for imaging decay under composite fillings. Longitudinal measurements of the reflected light intensity in the orthogonal polarization state from the area of simulated caries lesions linearly correlated with the square root of time of demineralization indicating that PS-OCT is well suited for monitoring changes in enamel mineralization over time.
Duration of debt overhang with two lender banks

Abstract This paper discusses the duration of the debt overhang with two lender banks. We model the problem as an infinite horizon game with two banks as players. In every period, each bank decides either to sell its loan exposure to the debtor country at the present secondary market price, or to wait and keep its exposure to the next period. Under the assumptions of homogeneous price function and short length of periods, we show that the equilibrium expected duration is quite long.
TWO SUBCLASSES OF PROTO-PLANETARY NEBULAE: MODEL CALCULATIONS

We use detailed radiative transfer models to investigate the differences between the star-obvious low-level elongated proto-planetary nebulae (SOLE PPNs) and dust-prominent longitudinally extended proto-planetary nebulae (DUPLEX PPNs), which are two subclasses of PPNs suggested by Ueta, Meixner, & Bobrowsky. We select one SOLE PPN, HD 161796, and one DUPLEX PPN, IRAS 17150-3224, both of which are well studied and representative of their PPN classes. Using an axisymmetric dust shell radiative transfer code, we model these two sources in detail and constrain their mass-loss histories, inclination angles, and dust composition. The physical parameters derived for HD 161796 and IRAS 17150-3224 demonstrate that they are physically quite different and that their observed differences cannot be attributed to inclination-angle effects. Both HD 161796 and IRAS 17150-3224 are viewed nearly edge-on. However, the more intensive axisymmetric superwind mass loss experienced by IRAS 17150-3224 (8.5 × 10-3 M☉ yr-1 and an equator/pole = 160) has created a high optical depth dust torus (AV = 37) that obscures its central star. In contrast, HD 161796, which underwent a lower rate superwind ( = 1.2 × 10-4 M☉ yr-1 and an equator/pole = 9), has an optically thinner dust shell that allows the penetration of direct starlight. Based on our analysis of the dust composition, which is constrained by dust optical constants derived from laboratory measurements, both objects contain oxygen-rich dust, mainly amorphous silicates, but with some significant differences. IRAS 17150-3224 contains only amorphous silicates with sizes ranging from 0.001 to larger than ~200 μm. HD 161796 contains amorphous silicates, crystalline silicates (enstatite and forsterite), and crystalline water ice with sizes ranging from 0.2 to larger than ~10 μm. If these calculations reflect a more general truth about SOLE versus DUPLEX PPNs, then these two subclasses of PPNs are physically distinct, with the SOLE PPNs derived from low-mass progenitors and DUPLEX PPNs derived from high-mass progenitors.
Subdirect decompositions of transformation graphs

A transformation graph is a finite directed graph with exactly one edge issuing from each vertex. A graph is subdirectly decomposed into two factor graphs, if it is isomorphic to a subgraph of their direct (Cartesian) product. The decomposition is A -optimal, if the maximal order (i.e., number of vertices) of the factor graphs is minimal. It is B -optimal, if the sum of the orders is minimal. This paper describes techniques for obtaining optimal decompositions of a given connected transformation graph. To achieve this objective, computationally convenient expressions are introduced for the isomorphism classes of transition graphs, i.e., finite, directed graphs with at most one edge issuing from each vertex. Then, formulas are derived for computing the expression of the direct (Cartesian) product of given transition graphs. The decomposition techniques are based on these expressions and formulas. The results obtained are directly applicable to the synthesis of autonomous sequential networks by means of parallel-connected smaller networks.
Do analysts generate trade for their firms? Evidence from the Toronto stock exchange

Abstract It has generally been assumed that the potential commission revenue is an important determinant of a sell-side analyst's decision of what firms to cover and what information to publicly release. However, because stock volume has not been disaggregated on a brokerage-firm level, uncertainty remains regarding the economic importance of the relation between analyst coverage and brokerage-firm volume. Using a unique data set that identifies the broker(s) involved in each trade, I find that brokerage volume is significantly higher in covered stocks than in uncovered stocks. On average, brokers increase their market share in covered stocks by 3.8% relative to uncovered stocks.
General and practical conversion of aldehydes to homologated carboxylic acids.

The reaction of aldehydes with trichloromethide followed by sodium borohydride or sodium phenylseleno(triethyl)borate under basic conditions affords homologated carboxylic acids in high yields. This operationally simple procedure provides a practical, efficient alternative to other homologation protocols. The approach is compatible with sensitive aldehydes including enals and enolizable aldehydes. It also offers convenient access to α-monodeuterated carboxylic acids.
New oxides of the filled-Ti2Ni type structure

Abstract The metal atom ordering and oxygen occupancy of four compounds of the filled-Ti2Ni type structure have been determined by single-crystal X-ray diffraction studies. Three additional phases have been identified and indexed from powder X-ray diffraction data. All the phases crystallize in space group Fd 3 m with the following compositions: Zr4Ni2O ( a = 12.1970(9) A ), ZΓ6Ni4Ti2O0.6 ( a = 12.0299(9) A ), Nb6Ni6O ( a = 11.2117(5) A ), and Nb6Ni4Ta2O2 ( a = 11.5813(3) A ). Phases identified using powder data are Nb4Ni2O ( a = 11.5933(3) A ), Zr4Cu2O ( a = 12.2659(7) A ), and Zr6Co4Ti2O ( a = 11.8649(9) A ). A comparison of the structures and oxygen occupancies is presented, as well as tentative explanations based on results of extended Huckel calculations. The role of interstitial oxygen as an electron acceptor and its effect on metal-metal bonding are considered.
Explaining and forecasting interannual variability in the flow of the Nile River

This study analyzes extensive data sets collected during the twentieth century and defines four modes of natural variability in the flow of the Nile River, identifying a new significant potential for improving predictability of floods and droughts. Previous studies have identified a significant teleconnection between the Nile flow and the eastern Pacific Ocean. El Nino–Southern Oscillation (ENSO) explains about 25% of the interannual variability in the Nile flow. Here, this study identifies a region in the southern Indian Ocean, with a similarly strong teleconnection to the Nile flow. Sea surface temperature (SST) in the region (50–80° E and 25–35° S) explains 28% of the interannual variability in the flow of the Nile River and, when combined with the ENSO index, the explained variability of the flow of the Nile River increases to 44%. In addition, during those years with anomalous SST conditions in both oceans, this study estimates that indices of the SSTs in the Pacific and Indian oceans can collectively explain up to 84% of the interannual variability in the flow of the Nile. Building on these findings, this study uses the classical Bayesian theorem to develop a new hybrid forecasting algorithm that predicts the Nile flow based on global model predictions of indices of the SST in the eastern Pacific and southern Indian oceans.
The Term Structure of Interest Rates and Monetary Policy during a Zero Interest Rate Period

This paper empirically evaluates the validity of the term structure of interest rates in a low interest rate environment using high-frequency Japanese data. Allowing for the time-varying term premium, we obtain evidence that when interest rates are low and the short end of the term structure is studied, there is no evidence to support the term-structure relationship. This poor performance is attributed to little information in the interest rate spread that can be used to predict future economic activity and/or to the absence of the persistent term premium. In contrast, some evidence for the term-structure relationship is found when the long end of the term-structure data is considered during a relatively high interest rate period.
Metal–insulator transition in a low-mobility two-dimensional electron system

Abstract We have varied the disorder in a two-dimensional electron system in silicon by applying substrate bias. When the disorder becomes sufficiently low, we observe the emergence of the metallic phase, and find evidence for a metal–insulator transition (MIT): the single-parameter scaling of conductivity with temperature near a critical electron density. We obtain the scaling function β , which determines the length (or temperature) dependence of the conductance. β is smooth and monotonic, and linear in the logarithm of the conductance near the MIT, in agreement with the scaling theory for interacting systems.
The Role of Firm-Specific Incentives and Country Factors in Explaining Voluntary IAS Adoptions: Evidence from Private Firms

Abstract This paper investigates voluntary adoptions of International Accounting Standards (IAS) by private enterprises, and builds on prior research which posits that higher quality financial reports through IAS adoption can reduce information asymmetry and facilitate contracting with external parties. Specifically, we pursue the following questions. First, do firm-specific incentives matter in the IAS adoption decision after controlling for country-level institutional factors? Second, does the relative importance of firm vs. country factors vary across institutional settings? Using a sample of 3,722 small and medium-sized private enterprises from 56 countries, we report two primary findings. First, both firm and country factors matter in the voluntary IAS adoption decision. Second, when we focus on sub-samples of countries partitioned by the level of economic development, we find that firm factors dominate country factors in more developed countries, while in less developed countries, country factors do...
Frobenius modules and de Jong's theorem

Let k be a field of characteristic p>0. A theorem of de Jong shows that morphisms of modules over W(k)[[t]] with Frobenius and connection structure descend from the completion of W(k)((t)). A careful reading of de Jong's proof suggests the possibility that an analogous theorem holds for modules with only a Frobenius structure. We show that this analogue holds in one weak formulation and fails in a second stronger formulation.
Car accidents and number of stopped cars due to road blockage on a one-lane highway

Within the framework of a simple model of car traffic on a one-lane highway, we study the probability of the occurrence of car accidents when drivers do not respect the safety distance between cars, and, as a result of the blockage during the time T necessary to clear the road, we determine the number of stopped cars as a function of car density. We give a simple theory in good agreement with our numerical simulations.
CoSaMP: iterative signal recovery from incomplete and inaccurate samples

Compressive sampling (CoSa) is a new paradigm for developing data sampling technologies. It is based on the principle that many types of vector-space data are compressible, which is a term of art in mathematical signal processing. The key ideas are that randomized dimension reduction preserves the information in a compressible signal and that it is possible to develop hardware devices that implement this dimension reduction efficiently. The main computational challenge in CoSa is to reconstruct a compressible signal from the reduced representation acquired by the sampling device. This extended abstract describes a recent algorithm, called, CoSaMP, that accomplishes the data recovery task. It was the first known method to offer near-optimal guarantees on resource usage.
In situ auger electron spectroscopy applied to the study of chemisorption and diffusion during reactive implantation of titanium into iron

Abstract Auger electron spectroscopy (AES) has been used to monitor the composition of Fe and FeTi surfaces, in situ, during Ti, Fe and Ar ion implantation in the presence of CO, C 2 H 2 , CH 4 , N 2 and NH 3 gases at pressures of approximately 10 -6 Torr. Implantation-induced subsurface carburization was observed for Ti + implantation into Fe in CO and C 2 H 2 and for Ar + implantation into an FeTi alloy in CO. In these cases, Ti carbide-like bonding of carbon at the surface preceded the subsurface carburization. Carburization was not observed when CH 4 gas was present during Ti implantation of Fe nor was it observed when CO gas was present during Fe self-implantation. Subsurface nitridation, similar to but not exactly analogous to the carburization, occurred during Ti + implantation of Fe with NH 3 gas present. Nitridation did not occur with N 2 gas present even though some nitrogen was adsorbed. The influences of surface chemical reactions are considered, along with other chemical and physical arguments, in proposing an interpretation of these results.
Beam energy dependence of azimuthal anisotropy at RHIC-PHENIX

Recent PHENIX measurements of the elliptic (υ 2) and hexadecapole (υ 4) Fourier flow coefficients for charged hadrons as a function of transverse momentum (p T ), collision centrality and particle species are presented and compared with results from the PHOBOS and STAR Collaborations respectively. The status of extensions to future PHENIX measurements at lower beam energies is also discussed.
Dynamical and chemical characteristics of tropospheric intrusions observed during START08

[1] Intrusions of air from the tropical upper troposphere into the extratropical stratosphere above the subtropical jet potentially have a significant impact on the composition of the lowermost stratosphere (the stratospheric part of the “middle world”). We present an analysis of tropospheric intrusion events observed during the Stratosphere-Troposphere Analyses of Regional Transport 2008 (START08) experiment using kinematic and chemical diagnostics. The transport processes operating during each event are discussed using high-resolution model analyses and backward trajectory calculations. Each intrusion observed during START08 can be related to a Rossby wavebreaking event over the Pacific Ocean. Trajectory analysis shows that the intruding air masses can be traced back to the tropical upper troposphere and lower stratosphere. In situ chemical observations of the tropospheric intrusions are used to estimate the mixing time scales of the observed intrusions through use of a simple box model and trace species with different photochemical lifetimes. We estimate that the time scale for an intrusion to mix with the background stratospheric air is 5 to 6 days. Detailed analysis of small-scale features with tropospheric characteristics observed in the stratosphere suggests frequent irreversible transport associated with tropospheric intrusions. Trace gas distributions and correlations are consistent with the dynamics of the high-resolution NCEP GFS analyses, suggesting that these features are captured by the GFS assimilation and forecast system. A global analysis of intrusion events observed during the START08 time period (April–June 2008) is also given.
Diversity of MMSE MIMO Receivers

In most multiple-input multiple-output (MIMO) systems, the family of waterfall error curves, calculated at different spectral efficiencies, are asymptotically parallel at high signal-to-noise ratio. In other words, most MIMO systems exhibit a single diversity value for all fixed rates. The MIMO minimum mean square error (MMSE) receiver does not follow this pattern and exhibits a varying diversity in its family of error curves. This paper analyzes this interesting behavior of the MMSE MIMO receiver and produces the MMSE MIMO diversity at all rates. The diversity of the quasi-static flat-fading MIMO channel consisting of any arbitrary number of transmit and receive antennas is fully characterized, showing that full spatial diversity is possible if and only if the rate is within a certain bound which is a function of the number of antennas. For other rates, the available diversity is fully characterized. At sufficiently low rates, the MMSE receiver has a diversity similar to the maximum likelihood receiver (maximal diversity), while at high rates, it performs similarly to the zero-forcing receiver (minimal diversity). Linear receivers are also studied in the context of the MIMO multiple-access channel. Then, the quasi-static frequency selective MIMO channel is analyzed under zero-padding and cyclic-prefix (CP) block transmissions and MMSE reception, and lower and upper bounds on diversity are derived. For the special case of SIMO under CP, it is shown that the aforementioned bounds are tight.
Numerical approximation of (n-1)-dimensional stable manifolds in large systems such as the power system

Abstract This paper discusses a direct method for numerical computation of the local quadratic approximations of ( n − 1)-dimensional stable manifolds for the unstable equilibria on the stability boundary in large systems. The algorithm proposed here does not require time-consuming normal form or symbolic computations. The numerical procedure is illustrated on transient stability problems in simple power system models. © 1997 Elsevier Science Ltd.
A discussion with Richard Nelson on the contributions of Alfred Chandler

David Teece discusses with Richard R. Nelson the contributions of Alfred D. Chandler Jr to a variety of areas in business history, economics, and management. Topics include Chandler's understanding of organizational capabilities, management leadership, technology, strategy, and the theory of the business firm. The discussion also reviews Chandler's role as a historian and as a theorist. It concludes with reflections on the future importance of Chandler's work. Copyright 2010 The Author 2010. Published by Oxford University Press on behalf of Associazione ICC. All rights reserved., Oxford University Press.
Maximizing conservation and in-kind cost share: Applying Goal Programming to forest protection

Abstract This research evaluates the potential gains in benefits from using Goal Programming to preserve forestland. Two- and three-dimensional Goal Programming models are developed and applied to data from applicants to the U.S. Forest Service's Forest Legacy Program, the largest forest protection program in the United States. Results suggest that not only do these model yield substantial increases in benefits, but by being able to account for both environmental benefits and in-kind partner cost share, Goal Programming may be flexible enough to facilitate adoption by program managers needing to account for both ecological and political factors.
Hypersonic Flow Past an Axisymmetric Body with Small Longitudinal Curvature

The problem of steady supersonic flow past an axisymmetric body with small longitudinal curvature is solved by means of a perturbation technique. Assuming a slender body within the framework of hypersonic smalldisturbance theory, the resulting differential equations are solved explicitly in closed form using the weak polar crossflow approximation. The perturbation quantities are expressed as series expansions involving powers of the radial distance from the nose of the body and functions of a single angular variable 0. The various flowfield quantities including the surface pressure coefficient have been calculated explicitly in terms of the series. The present analytical results compare favorably with available experimental data and Van Dyke's numerical calculations for hypersonic flow past an ogival-shaped slender body.
Finding low-scale technicolor at hadron colliders

In multiscale and topcolor-assisted models of walking technicolor, relatively light spin-one technihadrons ρT and ωT exist and are expected to decay as ρT → W πT, ZπT and ωT → γπT. For MρT ≃ 200GeV and MπT ≃ 100GeV, these processes have cross sections in the picobarn range in ¯ pp colisions at the Tevatron and about 10 times larger at the Large Hadron Collider. We demonstrate their detectability with simulations appropriate to Run II conditions at the Tevatron.
On the super-replicating approach when trading a derivative is limited

We extend the theory of super-replicating a European option by relaxing its two main assumptions: we take into account the constraints on trading the option and allow it to be traded inter-temporally. The first extension has a dramatic effect on the price of a portfolio hedging the option, while the second has a dramatic effect on finding arbitrage opportunities in the market. We introduce a new approach for identifying the best arbitrage opportunities in the market with friction.
Second malignant neoplasms in patients treated for Hodgkin's disease with radiotherapy or radiotherapy and chemotherapy

The incidence of second malignant neoplasms (SMN) was assessed in 248 patient with Hodgkin's disease (HD) treated by radiotherapy alone (XRT) or in combination with chemotherapy (XRT + C) between January/1960 and June/1977. Radiation therapy was categorized as less than extended field (less than EF), extended field (EF) or total nodal irradiation (TNI). Chemotherapy was scored as single agent (SAC) or multiagent (MAC). MAC consisted primarily of either nitrogen mustard, vincristine, prednisone and procarbazine (MOPP) or cyclophosphamide, vinblastine, procarbazine and prednisone (CVPP). Ten metachronous malignancies occurred 1-21 years (median 10 years) after the diagnosis of HD. With a median follow-up of 6 years the observed-to-expected ratio (O/E) was 4.2 for XRT alone and 7.6 for XRT + MAC. For 46 patients with greater than or equal to 10 years follow-up (median 13 years) the O/E ratio was 16.1 for XRT and 26.5 for XRT + MAC. All SMN occurred in patients who had not had a splenectomy at or prior to the time of HD diagnosis. Only four of nine solid SMN were within treatment portals or near portal margins. The diagnosis of another malignant neoplasm was made prior to or simultaneous with the diagnosis of HD in four additional patients. This observation, and the occurrence of five of six SMN outside of the treatment field in the XRT alone group, suggest that there may be factor(s) associated with the incidence of SMN in HD in addition to treatment itself.
HYPERGEOMETRIC ZETA FUNCTIONS

This paper investigates a new family of special functions referred to as hypergeometric zeta functions. Derived from the integral representation of the classical Riemann zeta function, hypergeometric zeta functions exhibit many properties analogous to their classical counterpart, including the intimate connection to Bernoulli numbers. These new properties are treated in detail and are used to demonstrate a functional inequality satisfied by second-order hypergeometric zeta functions.
The Impact of Trader Type on the Futures Volatility-Volume Relation

We examine the volatility-volume relation in futures markets using volume data categorized by type of trader. We find that the positive volatility-volume relation is driven by the general public, a group of traders who are distant from the trading floor and therefore without precise information on order flow. Clearing members and floor traders who observe order flow often decrease volatility. Our findings are consistent with Shalen's (1993) hypothesis that uninformed traders who cannot differentiate liquidity demand from fundamental value change increase volatility. IN THEIR 1993 STUDY, Bessembinder and Seguin suggest that the volatilityvolume relation in financial markets may depend on the type of trader. We investigate whether specific types of futures market traders, which we distinguish by the information they possess, actually have different effects on the positive volatility-volume relation. We use the Liquidity Data Bank (LDB) to test this information effect. The LDB is a database that separates futures volume by four types of traders: market makers, clearing members (such as financial institutions) trading for their own accounts, floor traders trading for other exchange members, and the general public (individual speculators, managed funds, and small