cssi/SciSciGPT-SciSciNet huggingface dataset:
The Political Legacy of American Slavery

We show that contemporary differences in political attitudes across counties in the American South in part trace their origins to slavery’s prevalence more than 150 years ago. Whites who currently live in Southern counties that had high shares of slaves in 1860 are more likely to identify as a Republican, oppose affirmative action, and express racial resentment and colder feelings toward blacks. We show that these results cannot be explained by existing theories, including the theory of contemporary racial threat. To explain the results, we offer evidence for a new theory involving the historical persistence of political attitudes. Following the Civil War, Southern whites faced political and economic incentives to reinforce existing racist norms and institutions to maintain control over the newly freed African American population. This amplified local differences in racially conservative political attitudes, which in turn have been passed down locally across generations.
The ideal-cipher model, revisited: an uninstantiable blockcipher-based hash function

The Ideal-Cipher Model of a blockcipher is a well-known and widely-used model dating back to Shannon [25] and has seen frequent use in proving the security of various cryptographic objects and protocols. But very little discussion has transpired regarding the meaning of proofs conducted in this model or regarding the model’s validity. In this paper, we briefly discuss the implications of proofs done in the ideal-cipher model, then show some limitations of the model analogous to recent work regarding the Random-Oracle Model [2]. In particular, we extend work by Canetti, Goldreich and Halevi [5], and a recent simplification by Maurer, Renner, and Holenstein [15], to exhibit a blockcipher-based hash function that is provably-secure in the ideal-cipher model but trivially insecure when instantiated by any blockcipher.
Fast algorithms for online stochastic convex programming

We introduce the online stochastic Convex Programming (CP) problem, a very general version of stochastic online problems which allows arbitrary concave objectives and convex feasibility constraints. Many well-studied problems like online stochastic packing and covering, online stochastic matching with concave returns, etc. form a special case of online stochastic CP. We present fast algorithms for these problems, which achieve near-optimal regret guarantees for both the i.i.d. and the random permutation models of stochastic inputs. When applied to the special case online packing, our ideas yield a simpler and faster primal-dual algorithm for this well studied problem, which achieves the optimal competitive ratio. Our techniques make explicit the connection of primal-dual paradigm and online learning to online stochastic CP.
Investigation of Attic Insulation Effectiveness by Using Actual Energy Consumption Data

Quantitative estimates of attic insulation effectiveness are typically based on a system component analysis approach (i.e., summation of R or U values, from tables, for the individual components making up the subject system). This approach neglects degradation of insulation effectiveness due to the effects of air infiltration, convection currents, densification, moisture content, or any other factors normally present in the attic insulation working environment. Consequently, valid questions may be raised regarding the true effectiveness level of attic insulation which can be resolved only through analysis of field data. In this study, investigators determined the effectiveness of attic insulation using actual energy consumption and weather data for 34 single family residences in the Knoxville, Tennessee area. For each residence, linear regression techniques were used to determine the actual winter energy consumption rates for 2 years before and 3 years after the installation of attic insulation. Comparison of the pre and post installation energy consumption rates confirmed, in all but a few cases, the effectiveness of attic insulation. The agreement between predicted and actual consumption rates is also addressed.
Supernovae versus Neutron Star Mergers as the Major r-Process Sources

I show that recent observations of r-process abundances in metal-poor stars are difficult to explain if neutron star mergers (NSMs) are the major r-process sources. In contrast, such observations and meteoritic data on 182Hf and 129I in the early solar system support a self-consistent picture of r-process enrichment by supernovae (SNe). While further theoretical studies of r-process production and enrichment are needed for both SNe and NSMs, I emphasize two possible direct observational tests of the SN r-process model: gamma rays from the decay of r-process nuclei in SN remnants and surface contamination of the companion by SN r-process ejecta in binaries.
Systematic distillation of composite Fibonacci anyons using one mobile quasiparticle

A topological quantum computer should allow intrinsically fault-tolerant quantum computation, but there remains uncertainty about how such a computer can be implemented. It is known that topological quantum computation can be implemented with limited quasiparticle braiding capabilities, in fact using only a single mobile quasiparticle, if the system can be properly initialized by measurements. It is also known that measurements alone suffice without any braiding, provided that the measurement devices can be dynamically created and modified. We study a model in which both measurement and braiding capabilities are limited. Given the ability to pull nontrivial Fibonacci anyon pairs from the vacuum with a certain success probability, we show how to simulate universal quantum computation by braiding one quasiparticle and with only one measurement, to read out the result. The difficulty lies in initializing the system. We give a systematic construction of a family of braid sequences that initialize to arbitrary accuracy nontrivial composite anyons. Instead of using the Solovay-Kitaev theorem, the sequences are based on a quantum algorithm for convergent search.
Synchrotron infrared spectroscopy of OH-chondrodite and OH-clinohumite at high pressure

High-pressure synchrotron infrared (IR) absorption spectra were collected at ambient temperature for OH-chondrodite and OH-clinohumite up to 38 and 29 GPa, respectively, using argon as the pressure-transmitting medium. The crystal structures of both clinohumite and chondrodite are preserved up to the maximum pressure. However, disordering of the silicate framework appears to become more pronounced at high pressure based on significant broadening of the IR bands with increasing pressure. All three OH bands in both structures shift linearly to higher frequency with pressure up to 18 GPa. Above 18 GPa, the variation of OH frequency with pressure remains linear; however, the slopes for the three OH bands are significantly different as a result of different degrees of hydrogen bonding. The IR results are compared to those from recent Raman studies in which water was used as the pressure-transmitting medium.
An Integrated Model of Multiple-Condition ChIP-Seq Data Reveals Predeterminants of Cdx2 Binding

Regulatory proteins can bind to different sets of genomic targets in various cell types or conditions. To reliably characterize such condition-specific regulatory binding we introduce MultiGPS, an integrated machine learning approach for the analysis of multiple related ChIP-seq experiments. MultiGPS is based on a generalized Expectation Maximization framework that shares information across multiple experiments for binding event discovery. We demonstrate that our framework enables the simultaneous modeling of sparse condition-specific binding changes, sequence dependence, and replicate-specific noise sources. MultiGPS encourages consistency in reported binding event locations across multiple-condition ChIP-seq datasets and provides accurate estimation of ChIP enrichment levels at each event. MultiGPS's multi-experiment modeling approach thus provides a reliable platform for detecting differential binding enrichment across experimental conditions. We demonstrate the advantages of MultiGPS with an analysis of Cdx2 binding in three distinct developmental contexts. By accurately characterizing condition-specific Cdx2 binding, MultiGPS enables novel insight into the mechanistic basis of Cdx2 site selectivity. Specifically, the condition-specific Cdx2 sites characterized by MultiGPS are highly associated with pre-existing genomic context, suggesting that such sites are pre-determined by cell-specific regulatory architecture. However, MultiGPS-defined condition-independent sites are not predicted by pre-existing regulatory signals, suggesting that Cdx2 can bind to a subset of locations regardless of genomic environment. A summary of this paper appears in the proceedings of the RECOMB 2014 conference, April 2–5.
LOWER CENTRAL SERIES AND FREE RESOLUTIONS OF HYPERPLANE ARRANGEMENTS

If M is the complement of a hyperplane arrangement, and A = H ∗ (M, k) is the cohomology ring of M over a field of characteristic 0, then the ranks, �k, of the lower central series quotients of �1(M) can be computed from the Betti numbers, bii = dimTor A (k, k)i, of the linear strand in a minimal free resolution of k over A. We use the Cartan-Eilenberg change of rings spectral sequence to relate these numbers to the graded Betti numbers, b ' = dimTor E (A, k)j, of a minimal resolution of A over the exterior algebra E. From this analysis, we recover a formula of Falk for �3, and obtain a new formula for �4. The exact sequence of low degree terms in the spectral sequence allows us to answer a question of Falk on graphic arrangements, and also shows that for these arrangements, the algebra A is Koszul if and only if the arrangement is supersolvable. We also give combinatorial lower bounds on the Betti numbers, b'+1 , of the linear strand of the free resolution of A over E; if the lower bound is attained for i = 2, then it is attained for all i� 2. For such arrangements, we compute the entire linear strand of the resolution, and we prove that all components of the first resonance variety of A are local. For graphic arrangements (which do not attain the lower bound, unless they have no braid sub-arrangements), we show that b '+1 is determined by the number of triangles and K4 subgraphs in the graph.
The galaxy stellar mass-star formation rate relation: evidence for an evolving stellar initial mass function?

The evolution of the galaxy stellar mass-star formation rate relationship (M*-SFR) provides key constraints on the stellar mass assembly histories of galaxies. For star-forming galaxies, M*-SFR is observed to be fairly tight with a slope close to unity from z ∼ 0 → 2, and it evolves downwards roughly independently of M*. Simulations of galaxy formation reproduce these trends, broadly independent of modelling details, owing to the generic dominance of smooth and steady cold accretion in these systems. In contrast, the observed amplitude of the M*-SFR relation evolves markedly differently than in models, indicating either that stellar mass assembly is poorly understood or that observations have been misinterpreted. Stated in terms of a star formation activity parameter α sf ≡ (M* /SFR)/(t Hubble -1 Gyr), models predict a constant α sf ∼ 1 out to redshifts z ∼ 4+, while the observed M*-SFR relation indicates that α sf increases by approximately three times from z ∼ 2 until today. The low α sf (i.e. rapid star formation) at high z not only conflicts with models, but also difficult to reconcile with other observations of high-z galaxies, such as the small scatter in M*-SFR, the slow evolution of star-forming galaxies at z ∼ 2-4 and the modest passive fractions in mass-selected samples. Systematic biases could significantly affect measurements of M* and SFR, but detailed considerations suggest that none are obvious candidates to reconcile the discrepancy. A speculative solution is considered in which the stellar initial mass function (IMF) evolves towards more high-mass star formation at earlier epochs. Following Larson, a model is investigated in which the characteristic mass M where the IMF turns over increases with redshift. Population synthesis models are used to show that the observed and predicted M*-SFR evolution may be brought into broad agreement if M = 0.5 (1 + z) 2 M ⊙ out to z ∼ 2. Such IMF evolution matches recent observations of cosmic stellar mass growth, and the resulting z = 0 cumulative IMF is similar to the 'paunchy' IMF favoured by Fardal et al. to reconcile the observed cosmic star formation history with present-day fossil light measures.
The Elbs and Boyland-Sims peroxydisulfate oxidations

The Elbs and Boyland-Sims oxidations are shown in Scheme ​Scheme11: Scheme 1 The Elbs and Boyland-Sims Oxidations. Both of these reactions, last reviewed in 1988 [1], are nucleophilic displacements on a peroxide oxygen of the peroxydisulfate ion. In the Elbs oxidation, the nucleophile is a phenolate anion (or a tautomer) and in the Boyland-Sims oxidation, it is a neutral aromatic amine. There is no radical involvement in either case (except in side reactions, see below). The products are aromatic sulfates whose orientation relative to the phenolic group is preferentially para in the Elbs oxidation and ortho in the Boyland-Sims case. These sulfates are useful in synthesis themselves or may be hydrolyzed in acid to the dihydric phenols (or aminophenols). The yields of products are typically low to moderate, but the simplicity of the reactions frequently recommends their use. Reactions are usually carried out by dissolving the phenol or amine in an alkaline aqueous medium, sometimes with the addition of a co-solvent such as pyridine, and then adding a peroxydisulfate salt. The ammonium and sodium salts are much more soluble than the potassium salt. This low solubility may be used to advantage to ensure slow addition of the peroxydisulfate as it is established that higher yields are achieved when the phenol(amine)-peroxydisulfate ratio is large. Isolation of the product usually takes advantage of the high water solubility of the intermediate sulfate ester; acidification of the reaction mixture is followed by extraction of the unreacted starting material (in the case of phenols) by an appropriate organic solvent. The sulfate ester remains in the aqueous phase. Hydrolysis of the sulfate ester in aqueous acid produces the (usually) organic-soluble dihydric phenol. Reactions are usually run at room temperature or below to reduce the incursion of free radical reactions. The rates are rather slow with typical second-order rate constants (at room temperature) in the range 0.1–20 L mol-1 min-1. [1]
Microlensing of broad absorption line quasars

The physical nature of the material responsible for the high-velocity broad absorption line (BAL) features seen in a small fraction of quasar spectra has been the subject of debate since their discovery. This has been especially compounded by the lack of observational probes of the absorbing region. In this paper we examine the role of ‘microlenses’ in external galaxies in the observed variability in the profiles of BALs in multiply imaged quasars. Utilizing realistic models for both the BAL region and the action of an ensemble of microlensing masses, we demonstrate that stars at cosmological distances can provide an important probe of the physical state and structure of material at the heart of these complex systems. Applying these results to the macrolensed BAL quasar system H1413+117, the observed spectral variations are readily reproduced, but without the fine-tuning requirements of earlier studies which employ more simplistic models.
End-to-end integration of a Convolutional Network, Deformable Parts Model and non-maximum suppression

Deformable Parts Models and Convolutional Networks each have achieved notable performance in object detection. Yet these two approaches find their strengths in complementary areas: DPMs are well-versed in object composition, modeling fine-grained spatial relationships between parts; likewise, ConvNets are adept at producing powerful image features, having been discriminatively trained directly on the pixels. In this paper, we propose a new model that combines these two approaches, obtaining the advantages of each. We train this model using a new structured loss function that considers all bounding boxes within an image, rather than isolated object instances. This enables the non-maximal suppression (NMS) operation, previously treated as a separate post-processing stage, to be integrated into the model. This allows for discriminative training of our combined Convnet + DPM + NMS model in end-to-end fashion. We evaluate our system on PASCAL VOC 2007 and 2011 datasets, achieving competitive results on both benchmarks.
Of Word Grenades and Impermeable Walls: Imperial Scholarship Then and Now

This article begins by discussing past and present battles over what history and science should be presented in the high school curriculum. Some states would prefer that young students not learn about subjects like slavery, conquest, or evolution. Accordingly, such states ban these subjects from the curriculum, claiming that they favor particular ethnic groups and reflect “ideological bias.” However, a whitewashed curriculum that intentionally cultivates traditional patriotism is not neutral: it privileges White people by presenting only positive aspects of their history and by pretending that only positives exist. There is no position of objectivity. Every curricular choice represents an ideological bias of some sort. Much scholarship in constitutional law reflects a similar unwillingness to engage seriously with the history of race and racism. This article discusses the epistemic limitations of imperial scholarship. Coined by Richard Delgado, “imperial scholarship” is civil rights scholarship produced mostly by White scholars that does not engage the insights or history produced by critical race scholarship. Most constitutional law scholars fail to address meaningfully the proslavery Constitution, despite the conclusion of a majority of historians that the document was proslavery. Scholarly attempts to ignore this fact marginalize the importance of race and racism before and at the founding of the nation. This article questions how much longer it will take before constitutional law scholars give serious consideration of how the proslavery Constitution, its politics, and its implementation continue to shape contemporary racism.
Bringing inequality back in: The economic inequality footprint of management and organizational practices

In this article, I argue for ‘bringing inequality back in’ to organizational research in order to investigate the role of management and organizational practices in macro-level economic inequality. To set an agenda in this area, I suggest considering three loci where the links between organizations and inequality may be observed: the organizational locus comprising the producer/employee, investor and consumer dimensions; the interorganizational locus to help disentangle issues related to the distribution of economic rewards across value chains, large financial versus non-financial organizations, and across occupations and organizations in general; and socio-political system as a locus where issues related to social change, political influence and the institutional system may be unpacked. In addition, I suggest considering the link between organizations and inequality from other important vantage points: elites, demographics, global inequality and debt. I also briefly highlight issues related to data and analyses. Throughout, I discuss the contributions of the five articles in the special issue and how they push us towards this agenda. Finally, I suggest that it may be helpful to think of an ‘inequality footprint’ of management and organizational practices, potentially leading organizations to reduce and reverse this footprint and ensure that economic benefits reach wider society.
Development of a cost-effective design for the Fusion Ignition Research Experiment

The Fusion Ignition Research Experiment (FIRE) is one of the components of a US Next Step Options (NSO) study which is considering what major experiments might be undertaken in a restructured US Fusion Sciences Program. FIRE is designed for a plasma current of /spl sim/6.5 MA, a burn time of at least 10 s, and a Q in the range of 5 to 10. FIRE has a major radius of 2.0 m, a minor radius of 0.525 m, and a field on axis of 10 T. All of the coils are inertially cooled by liquid nitrogen. FIRE will operate primarily in a double null configuration with an x-point triangularity of 0.8 and an x-point elongation of 2.2. In addition to these technical requirements, a major goal for the FIRE project is for a total project cost of approximately /spl Aring/ (in FY 99 dollars). This paper describes the process and rationale for the engineering design chosen for FIRE, taking into account both the performance and cost goals.
Transport as a consequence of state-dependent diffusion

Overdamped particles subject to a drift in a force field with sinusoidal space dependence and also a sinusoidally modulated space-dependent diffusion, with the same period as the drift, experience a net driving force. The resulting current depends on the amplitude of the modulation of the diffusion and is a periodic function of the phase difference between the sinusoidal drift and the sinusoidal modulation of the diffusion. For small modulation amplitudes a particle subject to state-dependent noise behaves the same way as a particle subject to thermal noise but with a drift which, in addition to the sinusoidal term, contains a net force term [M. Buttiker,Z. Phys. B68:161 (1987)]. A specific example of this behavior [N. G. van Kampen,IBM J. Res. Dev.32:107 (1988); R. Landauer,J. Stat. Phys.53:233 (1988).] is the motion of overdamped particles in a ring subject to a nonuniform temperature field. When the drift and the temperature, which are periodic with a period equal to the ring circumference, are not in phase a noise-induced circulating current results.
Network Structure and Airline Scheduling

This paper provides a simple analysis of the effects of network structure on the scheduling, traffic, and aircraft size choices of a monopoly airline. The analysis shows that switching to a hub-and-spoke network leads to increases in both flight frequency and aircraft size, while stimulating local traffic in and out of the hub. In addition, HS networks are shown to be preferred by the airline when travel demand is low, when flights are expensive to operate, and when passengers place a high value on flight frequency but are not excessively inconvenienced by the extra travel time required for a connecting trip. The welfare analysis shows that the flight frequency, traffic volumes, and aircraft size chosen by the monopolist are all inefficiently low under both network types. Moreover, in the most plausible case, the monopolist's network choice exhibits an inefficient bias toward the HS network, apparently reflecting an excessive desire to economize on the number of flights.
Search for Mixing and CP violation in charm decays

Standard model Mixing and CP violation are expected to be small in the charm sector. Some argue that only in the presence of new physics do we currently expect to observe these effects. Fermilab experiment E791 has the largest sample of reconstructed charm decays recorded to date. We have made an exhaustive search for D 0 D 0 Mixing and CP violation in this data. We present the charm mixing limits on the mixing parameter r mix using hadronic and semileptonic decays, and also present preliminary limits on the CP asymmetry parameter, A CP , for Cabibbo suppressed decays.
Gender Discrimination in the Allocation of Migrant Household Resources.

This paper considers the relationship between international migration and gender discrimination through the lens of decision-making power over intrahousehold resource allocation. The endogeneity of migration is addressed with a difference-in-differences style identification strategy and a model with household fixed effects. The results suggest that while a migrant household head is away, a greater share of resources is spent on girls relative to boys and his spouse commands greater decision-making power. Once the head returns home, however, a greater share of resources goes to boys, and there is suggestive evidence of greater authority for the head of household.
Physicochemical properties and toxicities of hydrophobic piperidinium and pyrrolidinium ionic liquids

Some properties are reported for hydrophobic ionic liquids (IL) containing 1-methyl-1-propyl pyrrolidinium [MPPyrro]{sup +}, 1-methyl-1-butyl pyrrolidinium [MBPyrro]{sup +}, 1-methyl-1-propyl piperidinium [MPPip]{sup +}, 1-methyl-1-butyl piperidinium [MBPip]{sup +}, 1-methyl-1-octylpyrrolidinium [MOPyrro]{sup +} and 1-methyl-1-octylpiperidinium [MOPip]{sup +} cations. These liquids provide new alternatives to pyridinium and imidazolium ILs. High thermal stability of an ionic liquid increases safety in applications like rechargeable lithium-ion batteries and other electrochemical devices. Thermal properties, ionic conductivities, viscosities, and mutual solubilities with water are reported. In addition, toxicities of selected ionic liquids have been measured using a human cancer cell-line. The ILs studied here are sparingly soluble in water but hygroscopic. We show some structure-property relationships that may help to design green solvents for specific applications. While ionic liquids are claimed to be environmentally-benign solvents, as yet few data have been published to support these claims.
Ideology, Attitude Change, and Deliberation in Small Face-to-Face Groups

Previous research has found that face-to-face deliberation can result in aggregate shifts in participants' political views. What is less well known is how such attitude changes vary depending on individual attributes and the nature of a group's deliberation. The present study extends prior research by exploring the relationship between participant ideology and attitude change in small, face-to-face groups. To test a set of hypotheses and research questions, 57 zero-history groups discussed three different public problems for 30–60 minutes, and each participant completed pre- and postdiscussion questionnaires. Participant ideology had a clear association with changes on specific discussion-related issues, but participants from every ideological group experienced increased differentiation between ideologically distinct attitudes. Within-group variance in attitude change was positively correlated with average group scores on self-reported measures of deliberation, extraversion, and conscientiousness. The con...
OFDM for Next-Generation Optical Access Networks

In this tutorial overview, the principles, advantages, challenges, and practical requirements of optical orthogonal frequency division multiplexing (OFDM)-based optical access are presented, with an emphasis on orthogonal frequency division multiple access (OFDMA) for application in next-generation passive optical networks (PON). General OFDM principles, including orthogonality, cyclic prefix use, frequency-domain equalization, and multiuser OFDMA are summarized, followed by an overview of various optical OFDM(A) transceiver architectures for next-generation PON. Functional requirements are outlined for high-speed digital signal processors (DSP) and data converters in OFDMA-PON. A techno-economic outlook for such a “software-defined,” DSP-based optical access platform is also provided.
Phase transition analysis of the dynamic instability of microtubules

This paper provides the phase transition analysis of a reaction diffusion equations system modelling the dynamic instability of microtubules (MTs). For this purpose, we have generalized the macroscopic model studied by Mour?o et al (2011 Comput. Biol. Chem. 35 269?81). This model investigates the interaction between the MT nucleation, the essential dynamics parameters and extinction, and their impact on the stability of the system. The considered framework encompasses a system of partial differential equations for the elongation and shortening of MTs, where the rates of elongation as well as the lifetimes of the elongating shortening phases are linear functions of GTP-tubulin concentration. In a novel way, this paper investigates the stability analysis and provides a bifurcation analysis for the dynamic instability of MTs in the presence of diffusion and all of the fundamental dynamics parameters. Our stability analysis introduces the phase transition method as a new mathematical tool in the study of MT dynamics. The mathematical tools introduced to handle the problem should be of general use.
Reducing collective quantum state rotation errors with reversible dephasing

We demonstrate that reversible dephasing via inhomogeneous broadening can greatly reduce collective quantum state rotation errors, and observe the suppression of rotation errors by more than 21 dB in the context of collective population measurements of the spin states of an ensemble of 2.1×105 laser cooled and trapped 87Rb atoms. The large reduction in rotation noise enables direct resolution of spin state populations 13(1) dB below the fundamental quantum projection noise limit. Further, the spin state measurement projects the system into an entangled state with 9.5(5) dB of directly observed spectroscopic enhancement (squeezing) relative to the standard quantum limit, whereas no enhancement would have been obtained without the suppression of rotation errors.
Autoignition of gasoline surrogates at low temperature combustion conditions

Abstract Understanding the autoignition characteristics of gasoline is essential for the development and design of advanced combustion engines based on low temperature combustion (LTC) technology. Formulation of an appropriate gasoline surrogate and advances in its comprehensive chemical kinetic model are required to model autoignition of gasoline under LTC conditions. Ignition delays of two surrogates proposed in literature for a research grade gasoline (RD387), including a three-component mixture of iso -octane, n -heptane, and toluene and a four-component mixture with the addition of an olefin (2-pentene), were measured in this study using a rapid compression machine (RCM). The present RCM experiments focused on two fuel lean conditions in air corresponding to equivalence ratios of ϕ = 0.3 and 0.5, at two compressed pressures of P C = 20 bar and 40 bar in the compressed temperature range of T C = 665–950 K. Comparison of the measured ignition delays of two gasoline surrogates with those of RD387 reported in our previous study shows that the four-component surrogate performs better in emulating the autoignition characteristics of RD387. In addition, numerical simulations were carried out to assess the comprehensiveness of the corresponding gasoline surrogate model from Lawrence Livermore National Laboratory. The performance of the chemical kinetic model was noted to be pressure dependent, and the agreement between the experimental and simulated results was found to depend on the operating conditions. A good agreement was observed at a compressed pressure of 20 bar, while a reduced reactivity was predicted by the chemical kinetic model at 40 bar. Brute force sensitivity analysis was also conducted at varying pressures, temperatures, and equivalence ratios to identify the reactions that influence simulated ignition delay times. Finally, further studies for improving the surrogate kinetic model were discussed and suggested.
Weight-balanced trees

It is now recognized that binary search trees are structures which can be used efficiently for the organization of files and directories. The ease of insertion and deletion of nodes makes trees very appealing for directories which are often modified. By comparison with a sequential table organization, some additional memory is required for the links between nodes. From a cost-effective viewpoint, this is generally more than compensated for by the savings in searching (for a linear table) and inserting (for an ordered table).
Modular invariant formulation of multi-gaugino and matter condensation☆

Abstract Using the linear multiplet formulation for the dilaton superfield, we construct an effective Lagrangian for hidden sector gaugino condensation in string effective field theories with arbitrary gauge groups and matter. Non-perturbative string corrections to the Kahler potential are invoked to stabilize the dilaton at a supersymmetry breaking minimum of the potential. When the cosmological constant is tuned to zero the moduli are stabilized at their self-dual points, and the vevs of their F -component superpartners vanish. Numerical analyses of one- and two-condensate examples with massless chiral matter show considerable enhancement of the gauge hierarchy with respect to the E 8 case. The non-perturbative string effects required for dilaton stabilization may have implications for gauge coupling unification. As a comparison, we also consider a parallel approach based on the commonly used chiral formulation.
Direct current glow discharges in atmospheric air

A microhollow cathode discharge was used as plasma cathode to sustain a stable direct current glow discharge in atmospheric pressure air. The length of the glow discharge column was varied from 1 mm to 2 cm, with the sustaining voltage increasing linearly with length. For glow discharges with currents on the order of 10 mA, the electron density in the air plasmas exceeded 10/sup 11/ cm/sup -3/, with highest values of almost 10/sup 13/ cm/sup -3/ close to the plasma cathode. When two 8.5-mA discharges were operated in parallel, at a distance of 0.4 cm, the discharge plasmas were found to merge for electrode gaps exceeding 0.5 cm, an effect that can be used to generate large volume, homogenous air plasmas.
Regioselective Inverse Electron Demand Diels-Alder Reactions of N-Acyl 6-Amino-3-(methylthio)-1,2,4,5-tetrazines.

The regioselective inverse electron demand Diels−Alder reactions of 6-[(tert-butyloxycarbonyl)amino]-3-(methylthio)-1,2,4,5-tetrazine (2), 6-(acetylamino)-3-(methylthio)-1,2,4,5-tetrazine (3), and ...
Hydrogen-assisted fracture in single-phase nickel alloys

Abstract The results of this study, which showed greater hydrogen-induced ductility losses for 625 than for 600, are consistent with the slip planarity correlation for hydrogen embrittlement (1–6), since there are good reasons to expect the SFE of 625 to be significantly lower than for 600. Moreover, the established relation (for R
Image processing plume fluence for superconducting thin-film depositions

Abstract Process control is a crucial element in all deposition techniques. It is especially elusive in the versatile and efficient deposition technique known as pulsed-laser-deposition (PLD). PLD produces a plume of highly energetic components which is directed onto a suitable substrate for growing required films. Image processed plume emissions from a YBa 2 Cu 3 O 7 − x target are in situ monitored at 553.5 nm to determine two-dimensional spatial information about the plume. Simultaneously, time-of-flight (TOF) information also at 553.5 nm is gathered from two positions along the plume path. Manual and fuzzy-logic based regulation of laser beam energy based on this TOF feedback has resulted in improved film quality and reproducibility. Imaging of the plume under various deposition conditions, both with and without process control, will help to improve the understanding of changing environmental conditions on the plume characteristics growth and quality.
Three-Dimensional Large Amplitude Body Motions in Waves

Three-dimensional, time-domain, wave-body interactions are studied in this paper for cases with and without forward speed. In the present approach, an exact body boundary condition and linearized free surface boundary conditions are used. By distributing desingularized sources above the calm water surface and using constant-strength flat panels on the exact wetted body surface, the boundary integral equations are numerically solved at each time step. Once the fluid velocities on the free surface are computed, the free surface elevation and potential are updated by integrating the free surface boundary conditions. After each time step, the body surface and free surface are regrided due to the instantaneous wetted body geometry. The desingularized method applied on the free surface produces nonsingular kernels in the integral equations by moving the fundamental singularities a small distance outside of the fluid domain. Constant-strength flat panels are used for bodies with any arbitrary shape. Extensive results are presented to validate the efficiency of the present method. These results include the added mass and damping computations for a hemisphere. The calm water wave resistance for a submerged spheroid and a Wigley hull are also presented. All the computations with forward speed are started from rest and proceeded until a steady state is reached. Finally, the time-domain forced motion results for a modified Wigley hull with forward speed are shown and compared to the experiments for both linear computations and body-exact computations.
The measurement of waste with nonconvex technology

The measurement of waste problem is reconsidered with the generalization that nonconvex production technologies are allowed. A general equilibrium measure of waste allowing for nonconvexity in production is derived by extending the contributions by Debreu (1954) and Diewert (1981, 1985).
Liquid chromatographic determination of florfenicol in the plasma of multiple species of fish

A simple method was developed for determining florfenicol concentration in a small volume (250 micro l) of plasma from five phylogenetically diverse species of freshwater fish. Florfenicol was isolated from the plasma matrix through C(18) solid-phase extraction and quantified by reversed-phase high-performance liquid chromatography with UV detection. The accuracy (84-104%), precision (%RSD<or=8), and sensitivity (quantitation limit <30 ng/ml) of the method indicate its usefulness for conducting pharmacokinetic studies on a variety of freshwater fish.
Deployment repeatability of a space telescope reflector petal

An experimental investigation of the deployment repeatability of a reflector petal intended for a 3-m-diam space telescope is presented. The petal incorporates second-generation precision joint and hinge mechanisms that were designed for optical-level stability and hysteresis. The objective of the experiments was to determine the role of mechanism repeatability and structural kinematics in structural deployment repeatability. The deployment tests were performed in a thermally and mechanically isolated test chamber. A high-precision videometry system was used to measure the position of the petal tip in the two relevant degrees of freedom. The position of the petal for a total of 12 stow-and-deploy measurements are reported, from which the statistics of the petal position for any initial deployment are determined. The 95% confidence region for the deployed position is an ellipse 8.6 μm tall in the deploy/latch direction and 0.8 μm wide in the direction parallel to the hinge axis. The accuracy of the telescope petal's deployment is compared to that of a previously tested truss, and the telescope petal is found to have better repeatability in the hinge direction but less repeatability in the deploy/latch direction. The repeatability of the latch mechanism was found to account for fully the repeatability of the test article when projected through the kinematics of the structure. Indeed, the use of simple kinematics was conservative because it over-predicted the repeatability of the structure by 224%.
Generic and chiral extensions of the supersymmetric standard model

We construct extensions of the Standard Model in which the gauge symmetries and supersymmetry prevent the dangerously large effects that may potentially be induced in a supersymmetric standard model by Planck scale physics. These include baryon number violation, flavor-changing neutral currents, the μ-term, and masses for singlet or vector-like fields under the Standard Model gauge group. For this purpose we introduce an extra non-anomalous U(1)μ gauge group. Dynamical supersymmetry breaking in a secluded sector triggers the breaking of the U(1)μ and generates soft masses for the superpartners via gauge mediation, with the scalars possibly receiving sizable contributions from the U(1)μ D-term. We find several classes of complete and calculable models, in which the messengers do not present cosmological problems and neutrino masses can also be accommodated. We derive the sparticle spectrum in these models and study the phenomenological consequences. We give an exhaustive list of the potential experimental signatures and discuss their observability in the upcoming Tevatron runs. One class of models exhibits interesting new discovery channels, namely WWT, WγT and WZT, which arise when the next-to-lightest supersymmetric particle is a short-lived SU(2)w neutralino.
Weakly Hyperbolic Actions of Kazhdan Groups on Tori

We study the ergodic and rigidity properties of weakly hyperbolic actions. First, we establish ergodicity for C2 volume preserving weakly hyperbolic group actions on closed manifolds. For the integral action generated by a single Anosov diffeomorphism this theorem is classical and originally due to Anosov. Motivated by the Franks/Manning classification of Anosov diffeomorphisms on tori, we restrict our attention to weakly hyperbolic actions on the torus. When the acting group is a lattice subgroup of a semisimple Lie group with no compact factors and all (almost) simple factors of real rank at least two, we show that weak hyperbolicity in the original action implies weak hyperbolicity for the induced action on the fundamental group. As a corollary, we obtain that any such action on the torus is continuously semiconjugate to the affine action coming from the fundamental group via a map unique in the homotopy class of the identity. Under the additional assumption that some partially hyperbolic group element has quasi-isometrically embedded lifts of unstable leaves to the universal cover, we obtain a conjugacy, resulting in a continuous classification for these actions.
Fabrication of high resolution n-type 4H-SiC epitaxial layer alpha particle detectors, defect characterization and electronic noise analysis

In the present work high-resolution alpha particle detectors have been fabricated on high quality 20 μm thick n-type 4H-SiC epitaxial layers. Schottky barrier detectors have been fabricated by depositing 10 nm thick nickel contacts on the Si face of the epilayers. The detectors were characterized using current-voltage (I-V), capacitance-voltage (CV), alpha spectroscopic measurements, and deep level transient spectroscopy (DLTS). I-V measurements revealed a barrier height of ~1.6 eV, diode ideality factor of 1.09, and leakage current of the order of 14 pA at an operating bias of 110 V. C-V measurements revealed low effective doping concentrations of 3.1 × 1014 cm-3 in the epilayers. A micropipe density lower than 1 cm-2 was evaluated in the epilayers. Pulse-height spectroscopy exhibited energy resolution as high as 0.37 % for 5.48 MeV alpha particles with a detector active area of 11 mm2. A diffusion length of ~13.2 μm for holes has been determined in these detectors following a calculation based on a drift-diffusion model. Detailed electronic noise analysis in terms of equivalent noise charge (ENC) was carried out to study the effect of various noise components that contribute to the total electronic noise in the detection system. The noise analysis revealed that the white series noise due to the detector capacitance has substantial effect on the detector’s overall performance. DLTS measurements have revealed the presence of at least four majority (electron) carrier trap levels that can act as recombination/generation or trapping centers.
Microgravity bubble migration in rotating flows

The NASA KC-135 microgravity-environment aircraft was used to gather experimental data on the migration of bubbles in rotating liquid fields under reduced gravity conditions. The data thus obtained were compared to those of an analysis for the prediction of fluid particle trajectories in the presence of both gravitational and rotational fields at the limit of quasi-steady creeping flow. Reasonable agreement with experimental results was achieved, despite the large size of the bubbles, their close proximity to a bounding surface over significant portions of their migration time, and their rather nonspherical geometry.
The topology of tokamak orbits

Guiding-centre orbits in non-circular axisymmetric tokamak plasmas are studied in the constants of motion (COM) space of (v, ζ, ψm. Here, v is the particle speed, ζ is the pitch angle with respect to the parallel equilibrium current, J||, at the point in the orbit where ψ = ψm, and ψm is the maximum value of the poloidal flux function (increasing from the magnetic axis) along the guiding-centre orbit. Two D-shaped equilibria in a flux-conserving tokamak having values of 1.3% and 7.7% are used as examples. In this space, each confined orbit corresponds to one and only one point, and different types of orbit (e.g. circulating, trapped, stagnation and pinch orbits) are represented by separate regions or surfaces in the space. It is also shown that the existence of an absolute minimum B in the higher- (7.7%) equilibrium results in an orbit topology dramatically different from that of the lower- case. The differences indicate the confinement of additional high-energy (v → c, within the guiding-centre approximation), trapped, co- and counter-circulating particles, with an orbit ψm falling within the absolute B-well.
Conversion of nitrosobenzenes to isoxazolidines: an efficient cascade process utilizing reactive nitrone intermediates

Reactive nitrones can be generated directly in situ by an unusual reaction of nitrosobenzene with styrene.
The ACTS multibeam antenna

The Advanced Communication Technology Satellite (ACTS), to be launched in 1993, is introduced briefly, and then the Ka-band multibeam antenna, consisting of electrically similar 30 GHz receive and 20 GHz transmit offset Cassegrain systems utilizing orthogonal linear polarizations, is described. Dual polarization is achieved by using one feed assembly for each polarization in conjunction with nested front and back subreflectors, the gridded front subreflector acting as a window for one polarization and a reflector for the other. The antennas produce spot beams with approximately 0.3 degrees beam width and gains of approximately 50 dBi. High surface accuracy and high edge taper produce low sidelobe levels and high cross-polarization isolation. A brief description is given of several Ka-band components fabricated for ACTS. These include multiflare antenna feedhorns, beamforming networks utilizing latching ferrite waveguide switches, a 30 GHz HEMT low-noise amplifier, and a 20 GHz TWT power amplifier. >