cssi/SciSciGPT-SciSciNet huggingface dataset:
Multi-objective OLSR for proactive routing in MANET with delay, energy, and link lifetime predictions

Abstract In this paper, we develop a multi-objective approach for proactive routing in a Mobile Ad Hoc Network (MANET). We consider three routing objectives: minimizing average end-to-end delay, maximizing network energy lifetime, and maximizing packet delivery ratio. Accordingly, we develop three routing metrics: mean queuing delay on each node, energy cost on each node, and link stability on each link. For the proposed multi-objective approach, we develop efficient prediction methods: (a) predicting queuing delay and energy consumption using double exponential smoothing, and (b) predicting residual link lifetime using a heuristic of the distributions of the link lifetimes in MANET. Extensive simulation (by using ns2) is performed for the comparison of this multi-objective OLSR with existing OLSRs. The results show that the multi-objective OLSR is effective in finding optimal routing by tradeoffs among proposed objectives.
Parametric Thermodynamic Analysis of a Solid Oxide Fuel Cell Gas Turbine System Design Space

Author(s): Tarroja, B; Mueller, F; Maclay, J; Brouwer, J | Abstract: A parametric study of a solid oxide fuel cell-gas turbine (SOFC-GT) hybrid system design is conducted with the intention of determining the thermodynamically based design space constrained by modern material and operating limits. The analysis is performed using a thermodynamic model of a generalized SOFC-GT system where the sizing of all components, except the fuel cell, is allowed to vary. Effects of parameters such as pressure ratio, fuel utilization, oxygen utilization, and current density are examined. Operational limits are discussed in terms of maximum combustor exit temperature, maximum heat exchanger effectiveness, limiting current density, maximum hydrogen utilization, and fuel cell temperature rise. It was found that the maximum hydrogen utilization and combustor exit temperature were the most significant constraints on the system design space. The design space includes the use of cathode flow recycling and air preheating via a recuperator (heat exchanger). The effect on system efficiency of exhaust gas recirculation using an ejector versus using a blower is discussed, while both are compared with the base case of using a heat exchanger only. It was found that use of an ejector for exhaust gas recirculation caused the highest efficiency loss, and the base case was found to exhibit the highest overall system efficiency. The use of a cathode recycle blower allowed the largest downsizing of the heat exchanger, although avoiding cathode recycling altogether achieved the highest efficiency. Efficiencies in the range of 50-75% were found for variations in pressure ratio, fuel utilization, oxygen utilization, and current density. The best performing systems that fell within all design constraints were those that used a heat exchanger only to preheat air, moderate pressure ratios, low oxygen utilizations, and high fuel utilizations. Copyright © 2010 by ASME.
The Solar Wind Around Pluto (SWAP) Instrument Aboard New Horizons

The Solar Wind Around Pluto (SWAP) instrument on New Horizons will measure the interaction between the solar wind and ions created by atmospheric loss from Pluto. These measurements provide a characterization of the total loss rate and allow us to examine the complex plasma interactions at Pluto for the first time. Constrained to fit within minimal resources, SWAP is optimized to make plasma-ion measurements at all rotation angles as the New Horizons spacecraft scans to image Pluto and Charon during the flyby. To meet these unique requirements, we combined a cylindrically symmetric retarding potential analyzer with small deflectors, a top-hat analyzer, and a redundant/coincidence detection scheme. This configuration allows for highly sensitive measurements and a controllable energy passband at all scan angles of the spacecraft.
Heavy tails in Calabi-Yau moduli spaces

We study the statistics of the metric on Kahler moduli space in compactifications of string theory on Calabi-Yau hypersurfaces in toric varieties. We find striking hierarchies in the eigenvalues of the metric and of the Riemann curvature contribution to the Hessian matrix: both spectra display heavy tails. The curvature contribution to the Hessian is non-positive, suggesting a reduced probability of metastability compared to cases in which the derivatives of the Kahler potential are uncorrelated. To facilitate our analysis, we have developed a novel triangulation algorithm that allows efficient study of hypersurfaces with h 1,1 as large as 25, which is difficult using algorithms internal to pack-ages such as Sage. Our results serve as input for statistical studies of the vacuum structure in flux compactifications, and of the distribution of axion decay constants in string theory.
Fast convergence of natural bargaining dynamics in exchange networks

Bargaining networks model the behavior of a set of players who need to reach pairwise agreements for making profits. Nash bargaining solutions in this context correspond to solutions which are stable and balanced. Kleinberg and Tardos [19] proved that, if such solutions exist, then they can by calculated in polynomial time. This left open the question: Are there dynamics which can describe the bargaining process of real-world players, and which converge quickly to a Nash bargaining solution? This paper provides an affirmative answer to that question.The contribution of this paper is threefold: (1) We introduce a single-stage local dynamics which models the way in which actual players could bargain. We show that (approximate) fixed points of our dynamics are in one-to-one correspondence with (approximate) Nash bargaining solutions. (2) We prove that our dynamics converges to an e-fixed point in O(1/e2) iterations independent of the network size when the potential earnings (weights) are uniformly bounded. We use this to prove that an approximate Nash bargaining solution is reached in time polynomial in 1/e, the network size and 1/g. Here g is the difference between the weights of the two corners of the matching polytope having largest weights, and controls the behavior of fast message passing algorithms for maximum weight matching (matching naturally arises as a subproblem of Nash bargaining). (3) Our proof introduces a new powerful technique from functional analysis to this set of problems. The technique allows us to extend our results in various directions. We believe the tools introduced here will be useful in many related problems.As a corollary, for bipartite graphs we prove polynomial time convergence to an approximate Nash bargaining solution, with probability close to one under small random perturbations.
The mod 2 cohomology of fixed point sets of anti-symplectic involutions

Abstract Let M be a compact, connected symplectic manifold with a Hamiltonian action of a compact n-dimensional torus G=Tn. Suppose that σ is an anti-symplectic involution compatible with the G-action. The real locus of M is X, the fixed point set of σ. Duistermaat uses Morse theory to give a description of the ordinary cohomology of X in terms of the cohomology of M. There is a residual G R =( Z /2 Z ) n action on X, and we can use Duistermaat's result, as well as some general facts about equivariant cohomology, to prove an equivariant analogue to Duistermaat's theorem. In some cases, we can also extend theorems of Goresky–Kottwitz–MacPherson and Goldin–Holm to the real locus.
ANDERSON LOCALIZATION IN THE SEVENTIES AND BEYOND

Little attention was paid to Anderson's challenging paper on localization for the first ten years, but from 1968 onwards it generated a lot of interest. Around that time a number of important questions were raised by the community, on matters such as the existence of a sharp distinction between localized and extended states, or between conductors and insulators. For some of these questions the answers are unambiguous. There certainly are energy ranges in which states are exponentially localized, in the presence of a static disordered potential. In a weakly disordered one-dimensional potential, all states are localized. There is clear evidence, in three dimensions, for energy ranges in which states are extended, and ranges in which they are diffusive. Magnetic and spin-dependent interactions play an important part in reducing localization effects. For massive particles like electrons and atoms the lowest energy states are localized, but for massless particles like photons and acoustic phonons the lowest en...
Environmental Sustainability Initiatives: A Comparative Analysis of Plant Efficiencies in Europe and the U.S.

The importance of environmental sustainability initiatives (ESI) for engineering and supply chain management practice and research is undeniable. However, despite the widespread attention to this domain, investigations in the effects of ESI on performance have been ambiguous and led to contradicting results, calling for the examination of contingencies influencing the relationship. This study works to bring insight and clarity into this debate by a comparative analysis of ESI among efficient and inefficient plants in Europe and the U.S. Specifically, using a sample of 402 plants located in Europe and the U.S., we study the impact of an explicit set of ESI (recycling, waste reduction, pollution prevention, ISO 14000 certification) on plant efficiency, an important performance measure which is, however, rarely considered. Basing our rationale on the resource-based view of the firm, we suggest that plants more heavily engaged in ESI are also characterized by a greater level of efficiency. We test this contention in both European and U.S. plants. Extending this cross-national comparison, we further study whether the emphasis on ESI differs in the two country groups. Relying on institutional theory, we suggest that the pursuit of ESI is enhanced among European plants, compared to their U.S. counterparts. Our findings and conclusions draw attention to the importance of contingencies to be considered and bring light to the seemingly contradictory findings in prior research. Important implications for engineering and supply chain management practice and research are highlighted.
SN 2006aj and the Nature of Low-Luminosity Gamma-Ray Bursts

We present SMARTS consortium optical/IR light curves of SN 2006aj, associated with GRB 060218. We find that this event is broadly similar to two previously observed events, SN 1998bw/GRB 980425 and SN 2003lw/GRB 031203. In particular, all of these events are greatly underluminous in gamma rays compared with typical long-duration GRBs. We find that the observation by Swift of even one such event implies a large enough true event rate to create difficulties in interpreting these events as typical GRBs observed off-axis. Thus, these events appear to be intrinsically different from and much more common than high-luminosity GRBs, which have been observed in large numbers out to a redshift of at least 6.3. The existence of a range of intrinsic energies of GRBs may present challenges to using GRBs as standard candles.
Pd(II)-catalyzed decarboxylative cross-coupling of oxamic acids with potassium phenyltrifluoroborates under mild conditions

A novel Pd-catalyzed decarboxylative cross-coupling of oxamic acids with potassium phenyltrifluoroborates has been realized under mild reaction conditions. This method provides an efficient access to N-mono- or N,N-disubstituted benzamides and benzoates.
Measurements of particles rebound characteristics on materials used in gas turbines

This paper describes an experimental method used to find the rebound characteristics of small solid particles impacting different materials. Such data are used for particle trajectories and erosion calculations in turbomachinery. The materials which are investigated are: 410 Stainless Steel, 2024 Aluminum, 6A1-4V Titanium, INCO 718, RENE 41, AM355, L605 Cobalt, and Alumina (A12O3). Particle materials are fly ash of 15 p. In addition, erosion rate equation was developed for INCO 718 that predicts the erosion rates at high temperatures very well.
The Joint Airport Weather Studies Project

A block diagram of the joint airport weather studies program is presented. Background leading to the development of the program is reviewed. Basic studies, aircraft performance, and detection and warning techniques used to develop fine scale structure of thunderstorm dynamics and kinematics in the vicinity of a major airport; effect of thunderstorm low level wind shear on aircraft performance; and development of real time testing of flow level wind shear detection and warning techniques and displays are described.
A Simplified Model of a Nine-phase Synchronous Machine Using Vector Space Decomposition

Abstract This article describes the use of vector space decomposition for development of a simplified model of a nine-phase synchronous machine. It is shown that the nine-phase machine can be reduced to the usual d-q equivalent circuit model plus seven additional non-torque-producing circuits. These additional components are shown to provide additional current paths for both zero-sequence components as well as negative-sequence components.
Intraconnectivity and Interconnectivity: When Value Creation May Reduce Profits

This paper analyses firms' decisions to provide connectivity to their customers. We distinguish between intraconnectivity---the ability of one firm's customers to connect to each other---and interconnectivity---the ability of one firm's customers to connect with another firm's customers. The profitability implications of allowing connectivity are not a straightforward consequence of the consumer value of connectivity, because connectivity affects not only the customer value but also the intensity of competition by creating or changing network externality. We find that if sales are driven by brand switching rather than by category expansion, a firm may find it optimal not to provide intraconnectivity even if providing it is not costly and may find it optimal to provide interconnectivity even at a cost exceeding the consumer value of connectivity. On the other hand, if category expansion is possible, providing intraconnectivity may be profitable. In this case, either the equilibrium intraconnectivity provision may be asymmetric or both firms may find it (individually) optimal to provide intraconnectivity. Under certain conditions in the latter case, the firms' choice of intraconnectivity is a prisoner's dilemma game.
The Marinari-Parisi model and collective field theory

We derive the supersymmetric collective field theory for the Marinari-Parisi model. For a specific choice of the superpotential, to leading order we find a one-parameter family of ground states which can be connected via instantons. At this level of analysis the instanton size implied by the underlying matrix model does not appear.
Respiratory fluid mechanics

This article covers several aspects of respiratory fluid mechanics that have been actively investigated by our group over the years. For the most part, the topics involve two-phase flows in the respiratory system with applications to normal and diseased lungs, as well as therapeutic interventions. Specifically, the topics include liquid plug flow in airways and at airway bifurcations as it relates to surfactant, drug, gene, or stem cell delivery into the lung; liquid plug rupture and its damaging effects on underlying airway epithelial cells as well as a source of crackling sounds in the lung; airway closure from “capillary-elastic instabilities,” as well as nonlinear stabilization from oscillatory core flow which we call the “oscillating butter knife;” liquid film, and surfactant dynamics in an oscillating alveolus and the steady streaming, and surfactant spreading on thin viscous films including our discovery of the Grotberg–Borgas–Gaver shock.
Immobilization of chiral catalysts on magnetite nanoparticles for highly enantioselective asymmetric hydrogenation of aromatic ketones

Magnetite nanoparticle (MNP)-supported asymmetric catalysts were synthesized by direct immobilization of a 4,4′-bisphosphonic acid-substituted BINAP-Ru-DPEN complex onto MNPs. The resulting heterogeneous catalyst (7) was highly active for the asymmetric hydrogenation of a wide range of aromatic ketones with remarkably high activity (>99% conversion with 0.1 mol% catalyst) and enantioselectivity (up to 98.1% ee) as a result of the bulky 4,4′-substituents (i.e., phosphonic acid groups) on BINAP. Catalyst 7 could be readily recycled and reused through simple magnetic decantation 9 times without the loss of activity or enantioselectivity. An alternative strategy was also explored to immobilize the [4,4′-(TMS)2-BINAP]-Ru-DPEN complex onto MNPs by first grafting a DPEN derivative onto the MNP surface followed by complexation of [4,4′-(TMS)2-BINAP]-Ru(DMF)2Cl2 to the surface-bound DPEN, but this immobilization strategy did not provide a robust heterogeneous catalyst, presumably due to oxidation of the Ru(II) intermediate by iron oxide nanoparticles.
The effects of sympathetic outflow on upregulation of vanilloid receptors TRPV1 in primary afferent neurons evoked by intradermal capsaicin

The vanilloid receptor TRPV1 is a key nociceptive molecule located in primary afferent nociceptive neurons in dorsal root ganglia (DRG) for initiating neurogenic inflammation and pain. Our recent study demonstrates that up-regulation of TRPV1 receptors by intradermal injection of capsaicin is modulated by activation of the protein kinase C (PKC) cascade. Neurogenic inflammation and pain resulting from capsaicin injection are sympathetically dependent, responding to norepinephrine, adenosine 5′-triphosphate (ATP) and/or neuropeptide Y released from sympathetic efferents. In a rat model of acute neurogenic inflammatory pain produced by capsaicin injection, we used immunofluorescence and Western blots combined with pharmacology and surgical sympathectomies to analyze whether the capsaicin-evoked up-regulation of TRPV1 in DRG neurons is affected by sympathetic outflow by way of activating the PKC cascade. Sympathetic denervation reduced significantly the capsaicin-evoked expressions of TRPV1, calcitonin gene-related peptide and/or phosphorylated PKC and their co-expression. These reductions could be restored by exogenous pretreatment with an analog of ATP, α,β-methylene ATP. Inhibition of PKC with chelerythrine chloride prevented the ATP effect. Consistent results were obtained from experiments in which capsaicin-evoked changes in cutaneous inflammation (vasodilation and edema) were examined after sympathetic denervation, and the effects of the above pharmacological manipulations were evaluated. Our findings suggest that the capsaicin-evoked up-regulation of TRPV1 receptors in DRG neurons is modulated sympathetically by the action of ATP released from sympathetic efferents to activate the PKC cascade. Thus, this study proposes a potential new mechanism of sympathetic modulation of neurogenic inflammation.
Quantum Theory of a Gas Laser

We derive the equation of motion for the quantum-mechanical radiation density matrix of a gas laser to lowest order in the dimensionless coupling constant. Our derivation is fully quantum mechanical and we can calculate the coherence properties from the radiation density matrix. Our model consists of $N$ two-level systems interacting with radiation in a cavity in the presence of dissipation, pumping, and collisions. The method we use is a generalization of the Bogoliubov derivation of the kinetic equation for a small parameter. Our derivation holds for any physically realizable pump power, and near threshold reduces to Lamb's near-threshold theory. With the equation of motion for the radiation density matrix, we obtain solutions both for when the average field is nonzero and for when it is zero. The steady-state electromagnetic density is the same in both cases except for a small spontaneous-emission term. We show that the reason gas lasers do not satisfy rate equations is the existence of zeroth-order correlations between the internal atomic variables and atomic center-of-mass variables. It is these same zeroth-order correlations which are responsible for the Lamb dip. Our derivation includes collisions and reduces the calculations of their effect to quadrature.
Cord Blood (CB) Extends Transplant Access to Racial and Ethnic Minorities: A Prospective Study of 309 Unrelated Searches in Patients with High-Risk Hematologic Malignancies

Strict HLA-match using high resolution typing for HLA-A,B,C,DRB1 improves unrelated volunteer donor (URD) hematopoietic stem cell (HSC) transplant outcome but limits the number of suitable donors. In contrast, CB transplantation (CBT) is associated with a greatly reduced HLA-match requirement which may extend the donor pool. Therefore, we prospectively evaluated donor availability in 309 patients [median age 46 (range 1–71 years)] with high-risk hematologic malignancies between 10/05–5/08 with the hypothesis that CB would extend transplant access. Adequate donor-recipient HLAmatch was ≥/10 HLA-A,B,C,DRB1,DQ alleles for a T cell depleted or ≥9/10 alleles for an unmodified URD graft. Adequate CB units were ≥4/6 HLA-A,B antigen, DRB1 allele matched and ≥1.5 × 107/nucleated cells/kg/unit and double unit grafts were used to augment engraftment. URDs had priority as HSC source; CB was chosen if no suitable URD was available in the required time period. While 28 patients with suitable URDs had no CB search, the results of the 281 patients with both URD and CB formal search/confirmatory typing are shown in Table 1. This combined search group had highly diverse ancestry with only 60 (21%) of northwestern (NW) European origin and 99 (35%) were non-European. 9–10/10 URDs were available for the majority of NW, Eastern and mixed Europeans but not for Southern or non-European patients. Notably, CB extended HSC availability to all and especially Southern European, Asian, African, and Hispanic patients with no Asian patient being without a CB graft. Table 1: Comparison of Formal Search for Both URD and CB by Patient Ancestry The ancestry of the 201 patients who were transplanted and the 15 not transplanted due to lack of suitable graft is shown in Table 2. The remaining 93 patients were not transplanted for other reasons. Table 2: Patient Ancestry if Transplanted or No Graft URD transplant recipients were predominantly (68%) NW, Eastern, or mixed European with Asian, African and Hispanic patients combined accounting for only 18%. In contrast, only 4 (8%) of CBT recipients were NW European. While these patients received CB due to urgency (n=1), patient preference (n=1), or MD preference over mismatched URD (n=2), the remaining 48 (92%) of CBT recipients including 15% Southern Europeans and 49% non-Europeans (13% Asian, 19% African, 15% Hispanic, 2% Middle Eastern) did not have other donor options. Of 15 patients (5% of the 309 total) not transplanted due to lack of any HSC source 10 were non-European including 6 of African ancestry. Notably, the median weight of this “no graft” group [87kg (range 66–151)] was significantly higher than CBT [70kg (range 13–109)] recipients (p
Real Grassmann polylogarithms and Chern classes

In this paper we define real grassmann polylogarithms, which are real single valued analogues of the grassmann polylogarithms (or higher logarithms) defined by Hain and MacPherson. We prove the existence of all such real grassmann polylogs, at least generically. We also prove that the canonical choice of such an m-polylogarithm represents the Beilinson Chern class on the rank m part of the algebraic K-theory of the generic point of every complex algebraic variety. One part of each such grassmann m-polylogarithm is a real, single-valued function defined generically on the grassmannian of m planes in C^{2m}. We prove that this function represents the Borel regulator (up to a factor of 2) on K_{2m-1} of all number fields.
A cancellation theorem for ideals

Abstract We prove cancellation theorems for special ideals in Gorenstein local rings. These theorems take the form that if KI⊆JI, then K⊆J.
An empirical test of the effect of basis risk on cash market positions

Traditional theory holds that hedgers use futures markets to reduce the amount of price risk they bear. In doing so, they trade price risk for basis risk, that is, unexpected movements in the difference between the spot and futures prices. Theoretical work has shown that the presence of basis risk reduces the position in the cash market as well as the relative use of futures as a hedging instrument. This paper empirically measures the effect of basis risk on the cash market position, using data on the storage of corn. Results show that basis risk statistically and economically significantly reduces the level of storage. The implications of basis risk on cash market positions extend beyond commodity storage to any hedging situation, including the use of currency futures to insure against exchange rate risk.
Early Evidence on the Informativeness of the SEC's Market Risk Disclosures: The Case of Commodity Price Risk Exposure of Oil and Gas Producers

The paper provides early evidence on the informativeness of commodity price risk measures required by the Securities and Exchange Commission's new market risk disclosure rules (SEC 1997). I use existing disclosures of oil and gas producers (O&G) to obtain proxies for the tabular and sensitivity analysis disclosures required by the new SEC rules. I find that proxies for the tabular and the sensitivity analysis format are significantly associated with O&G firms' stock return sensitivities to oil and gas price movements. This finding casts doubt on claims that the new market risk disclosures do not reflect firms' risk exposures. The proxies for the tabular format and sensitivity format disclosures are not substitutable explanations of firms' risk exposures. This evidence suggests that disclosures from one disclosure format are not comparable to those from the other reporting format.
A Converse Extrapolation Theorem for Translation-Invariant Operators

Abstract We prove a converse of Yano's extrapolation theorem for translation invariant operators.
Pressure Sores-the Problem

This article first appeared in Bedsore Biomechanics and is reproduced by kind permission of Palgrave Macmillan, Macmillan Publishers Ltd
Common rate maximization in two-layer cellular radio systems

We address the common rate maximization problem in two-layer cellular networks where high-power and low-power base stations are colocated in the same geographical area. Interference becomes a serious problem when two or more layers are considered in the same network. For this purpose, power control in the downlink needs to be used to limit the interference and to fully exploit the benefits of additional layer deployments. We present an analytical framework to the common rate maximization problem both with and without maximum power constraints and propose a heuristic algorithm. We present simulation results for the proposed approaches in a two-layer network setup and observe a significant common rate increase compared to single-layer wireless networks.
Demand Side Management in Smart Grids Using a Repeated Game Framework

Demand-side management (DSM) is a key solution for reducing the peak-time power consumption in smart grids. To provide incentives for consumers to shift their consumption to off-peak times, the utility company charges consumers the differential pricing for using power at different times of the day. Consumers take into account these differential prices when deciding when and how much power to consume daily. Importantly, while consumers enjoy lower billing costs when shifting their power usage to off-peak times, they also incur discomfort costs due to the altering of their power consumption patterns. Existing works propose stationary strategies for the myopic consumers to minimize their short-term billing and discomfort costs. In contrast, we model the interaction emerging among self-interested and foresighted consumers as a repeated energy scheduling game and prove that the stationary strategies are suboptimal in terms of long-term total billing and discomfort costs. Subsequently, we propose a novel framework for determining optimal nonstationary DSM strategies, in which consumers can choose different daily power consumption patterns depending on their preferences, routines, and needs. As a direct consequence of the nonstationary DSM policy, different subsets of consumers are allowed to use power in peak times at a low price. The subset of consumers that are selected daily to have their joint discomfort and billing costs minimized is determined based on the consumers power consumption preferences as well as on the past history of which consumers have shifted their usage previously. Importantly, we show that the proposed strategies are incentive compatible. Simulations confirm that, given the same peak-to-average ratio, the proposed strategy can reduce the total cost (billing and discomfort costs) by up to 50% compared to existing DSM strategies.
The Thermodynamic Limit for Matter Interacting with Coulomb Forces and with the Quantized Electromagnetic Field: I. The Lower Bound

The proof of the existence of the thermodynamic limit for electrons and nuclei interacting via the Coulomb potential, was accomplished decades ago in the framework of non-relativistic quantum mechanics, . This result did not take account of interactions caused by magnetic fields, however, (the spin-spin interaction, in particular) or of the quantized nature of the electromagnetic field. Recent progress has made it possible to undertake such a proof in the context of non-relativistic QED. This paper contains one part of such a proof by giving a lower bound to the free energy that is proportional to the number of particles and which takes account of the fact that the field, unlike the particles, is never confined to a finite volume. In the earlier proof the lower bound was a ‘two line’ corollary of the ‘stability of matter’. In QED the proof is much more complicated.
Thickness-dependent spontaneous dewetting morphology of ultrathin Ag films.

We show here that the morphological pathway of spontaneous dewetting of ultrathin Ag films on SiO2 under nanosecond laser melting is dependent on film thickness. For films with thickness h of 2 nm ≤ h ≤ 9.5 nm, the morphology during the intermediate stages of dewetting consisted of bicontinuous structures. For films with 11.5 nm ≤ h ≤ 20 nm, the intermediate stages consisted of regularly sized holes. Measurement of the characteristic length scales for different stages of dewetting as a function of film thickness showed a systematic increase, which is consistent with the spinodal dewetting instability over the entire thickness range investigated. This change in morphology with thickness is consistent with observations made previously for polymer films (Sharma and Khanna 1998 Phys. Rev. Lett. 81 3463–6; Seemann et al 2001 J. Phys.: Condens. Matter 13 4925–38). Based on the behavior of free energy curvature that incorporates intermolecular forces, we have estimated the morphological transition thickness for the intermolecular forces for Ag on SiO2. The theory predictions agree well with observations for Ag. These results show that it is possible to form a variety of complex Ag nanomorphologies in a consistent manner, which could be useful in optical applications of Ag surfaces, such as in surface enhanced Raman sensing.
Exciplex quenching of photoexcited platinum(II) terpyridines: influence of the orbital parentage

Abstract Quenching studies involving a range of Lewis bases establish that exciplex quenching can affect the lifetime of the emissive charge-transfer state of a platinum(II) terpyridine. The evidence comes from studies of Pt(trpy)SCN + , where trpy denotes 2,2′:6′,2″-terpyridine, and a Pt(4′-XT)Cl + series where 4′-XT denotes a 4′-substituted trpy derivative and X is a CN, SMe or NMe 2 substituent. Thus, in dichloromethane the quenching rate constant increases with the donor number as the quencher varies from a relatively weak base like acetonitrile or acetone to a stronger donor like DMSO or pyridine. For the thiocyanate complex in particular, the quenching rate increases by almost three orders of magnitude. Within the Pt(4′-XT)Cl + series, the rates show a marked variation with the electron-donating ability of the substituent X. Thus, with pyridine as the quencher, the rate constant varies from 3.5×10 8 to 1.0×10 10 M −1 s −1 as X changes from NMe 2 to CN. Variations in the orbital parentage of the excited state account for the trend because the Lewis acidity of the metal center decreases with the delocalization of the hole onto the ligand. When the rate of exciplex formation is slow, an outer-sphere complex accumulates in solution and the kinetic plots show saturation behavior at high quencher concentrations.
Surface-Enhanced Raman Spectroscopy with Gold Nanoring Dimers

Surface-enhanced Raman scattering of benzenethiol on gold nanoring dimers with 20 nm gaps was studied. The localized surface plasmon resonance wavelength was determined using reflection spectroscopy. A SERS enhancement factor of 2.0x10 6 was obtained.
Rhodium Catalyzed Allylic Isomerization in Water

A water-soluble rhodium bis-phosphine complex was used for the aqueous phase isomerization of three allylic alcohols. For the isomerization of cinnamyl alcohol, the catalyst was recycled with slight loss of activity and the optimum phosphine:rhodium ratio was found to be 6:1.
Sequential reactions of trimethylsilyldiazomethane with 4-alkenyl ketones and aldehydes catalyzed by lewis bases

A sequence of a carbonyl addition between 4-alkenyl ketones and aldehydes with trimethylsilyldiazomethane followed by a 1,3-Brook rearrangement and an intramolecular 1,3-dipolar cycloaddition was promoted by Lewis bases tetrabutylammonium triphenyldifluorosilicate (TBAT) or potassium tert-butoxide (KO-t-Bu). Through these concatenated bond-forming processes, a variety of novel bi- and tricyclic Δ1-pyrazolines were synthesized.
A cosmologically motivated description of the dark matter halo profile for the Low Surface Brightness Galaxy, Malin 1

In this paper we derive a possible mass profile for the low surface brightness galaxy, Malin 1, based upon previously published space-based and ground-based photometric properties and kinematics. We use properties of the bulge, normal disk, outer extended disk, and H i mass as inputs into mass profile models. We find that the dark matter halo model of Malin 1 is best described by a halo profile that has undergone adiabatic contraction, inconsistent with the findings for most disk galaxies to date, yet consistent with rotation curve studies of M31. More importantly, we find that Malin 1 is baryon dominated in its central regions out to a radius of ~10 kpc (in the bulge region). Low surface brightness galaxies are often referred to as being dark matter dominated at all radii. If this is the case, then Malin 1 would seem to have characteristics similar to those of normal barred disk galaxies, as suggested by other recent work. We also find that Malin 1 falls on the rotation curve shear versus spiral arm pitch angle relation for normal galaxies, although more LSB galaxies need to be studied to determine if this is typical.
Behavior of triangular shell element stiffness matrices associated with polyhedral deflection distributions.

Invariants of triangular shell element stiffness matrices associated with polyhedral deflection distribution, discussing effect of geometry
FDTD simulation of exposure of biological material to electromagnetic nanopulses.

Ultra-wideband (UWB) electromagnetic pulses of nanosecond duration, or nanopulses, are of considerable interest to the communications industry and are being explored for various applications in biotechnology and medicine. The propagation of a nanopulse through biological matter has been computed using the finite difference-time domain (FDTD) method. The approach required the reparametrization of existing Cole–Cole model-based descriptions of dielectric properties of biological matter in terms of the Debye model without loss of accuracy. Several tissue types have been considered. Results show that the electromagnetic field inside biological tissue depends on incident pulse rise time and width. Rise time dominates pulse behaviour inside tissue as conductivity increases. It has also been found that the amount of energy deposited by 20 kV m−1 nanopulses is insufficient to change the temperature of the exposed material for pulse repetition rates of 1 MHz or less, consistent with recent experimental results.
Nanoporous Noninvasive Cellular Electrical Activity-Based Analysis Devices

In recent years, rapid advancements have been made in the biomedical applications of microtechnology and nanotechnology. While the focus of such technologies have been primarily on in vitro analytical and diagnostic tools, more recently in vivo therapeutic and sensing applications have gained attention. The long-term integration of cells with inorganic materials provides the basis for novel sensing platforms. The work presented here focuses on the ability to maintain cells long-term in nanoporous silicon-based microenvironments. This article describes the creation of nanoporous, biocompatible, alumina membranes as a platform for incorporation into a cell-based device targeted for in situ recording of cellular electrical activity variations due to the changes associated with the surrounding microenvironments. Studies described herein focus on the interaction of nanoporous alumina substrates embedded in silicon patterned with cells of interest. The fidelity of such a system is demonstrated in terms of viability, proliferation, and functionality. The capability of such microfabricated nanoporous membranes, as in vitro for cell-based assays for sensing and drug delivery applications, is also demonstrated. It has potential in vivo application for therapeutic immunoisolation.
Hypersonic Viscous-Inviscid Interaction with Vectored Surface Mass Transfer.

Abstract : A fundamental theoretical study of homogeneous vectored injection and suction in high speed flows with heat transfer and self-induced gradients is described, based on local similarity solutions of the laminar boundary layer equations. The results show the important effects of both injection velocity and vector angle on a variety of physical properties of practical interest such as velocity and temperature profiles, skin friction, heat transfer rate, displacement thickness and induced pressure field. In addition, the existence of a new set of solutions pertaining to upstream-vectored injection is established and investigated. Moreover, it is shown that the frictional heating associated with the tangential injection velocity component can significantly influence the heat transfer characteristics of high speed flows. (Author)
Turbulence measurements for heated gas slot injection in supersonic flow

Spark-Schlieren and Nanosecond Shadowgraph photographs give qualitative and some quantitative descriptions of the resulting flow. The profile measurements were made at four axial stations (x/H=0.25, 4, 10, and 20). Tests were also conducted to study the influence of an oblique wave (P 2 /P 1 ∼1.8) impinging on the shear layer between stations 3 and 4. All of the results are compared with results for unheated injection at the same conditions
Fast inference in generalized linear models via expected log-likelihoods

Generalized linear models play an essential role in a wide variety of statistical applications. This paper discusses an approximation of the likelihood in these models that can greatly facilitate computation. The basic idea is to replace a sum that appears in the exact log-likelihood by an expectation over the model covariates; the resulting "expected log-likelihood" can in many cases be computed significantly faster than the exact log-likelihood. In many neuroscience experiments the distribution over model covariates is controlled by the experimenter and the expected log-likelihood approximation becomes particularly useful; for example, estimators based on maximizing this expected log-likelihood (or a penalized version thereof) can often be obtained with orders of magnitude computational savings compared to the exact maximum likelihood estimators. A risk analysis establishes that these maximum EL estimators often come with little cost in accuracy (and in some cases even improved accuracy) compared to standard maximum likelihood estimates. Finally, we find that these methods can significantly decrease the computation time of marginal likelihood calculations for model selection and of Markov chain Monte Carlo methods for sampling from the posterior parameter distribution. We illustrate our results by applying these methods to a computationally-challenging dataset of neural spike trains obtained via large-scale multi-electrode recordings in the primate retina.
Estrogen attenuates oxidative stress‐induced apoptosis in C6 glial cells

The neuroprotective effects of estrogen have been previously implicated in neurodegenerative diseases. In order to examine whether estrogen protects cells from calpain-mediated death, we investigated the mechanism of estrogen's inhibitory effects of apoptotic death in C6 (rat glioma) cells following exposure to H2O2. Cells were preincubated with 4 μm estrogen for 2 h and then exposed to 100 μm H2O2 or 2 μm ionomycin for 24 h. Intracellular free calcium (Ca2+) was quantified using Fura-2. Levels of cell death were measured by colorometric assay. Bax/Bcl-2 ratio and calpain activity, as measured by calpain-cleaved spectrin degradation, were monitored by Western blot. Apoptosis was evaluated morphologically by Wright staining. Treatment with H2O2 caused significant increases in intracellular [Ca2+] which were attenuated by preincubation with estrogen. H2O2 and ionomycin caused cell death in a dose-dependent manner. Preincubation with estrogen increased viability in cells treated with H2O2 but not in cells treated with ionomycin. Western blotting showed an increase in Bax/Bcl-2 ratio and calpain activity following treatment with H2O2, and estrogen pretreatment decreased levels of both. Cell morphology indicated apoptosis in cells treated with H2O2, and pretreatment with estrogen reduced apoptosis. These results indicate a role for estrogen in preventing apoptosis in C6 glial cells exposed to H2O2. Our results suggest that estrogen may have a protective role in minimizing glial cell death in neurological diseases. Acknowledgements: Supported in part by grants from NIH-NINDS and South Carolina Electric and Gas.
Relaxation-Based Electrical Simulation

Circuit simulation programs have proven to be most important computer-aided design tools for the analysis of the electrical performance of integrated circuits. One of the most common analyses performed by circuit simulators and the most expensive in terms of computer time is nonlinear time-domain transient analysis. Conventional circuit simulators were designed initially for the cost-effective analysis of circuits containing a few hundred transistors or less. Because of the need to verify the performance of larger circuits, many users have successfully simulated circuits containing thousands of transistors despite the cost. Recently, a new class of algorithms has been applied to the electrical IC simulation problem. New simulators using these methods provide accurate waveform information with up to two orders of magnitude speed improvement for large circuits. These programs use relaxation methods for the solution of the set of ordinary differential equations, which describe the circuit under analysis, rather than the direct sparse-matrix methods on which standard circuit simulators are based. In this paper, the techniques used in relaxation-based electrical simulation are presented in a rigorous and unified framework, and the numerical properties of the various methods are explored. Both the advantages and the limitations of these techniques for the analysis of large IC's are described
Intersatellite Optical Heterodyne Communication Systems

High-capacity intersatellite communication crosslinks will allow more efficient and reliable operation of military and commercial satellite systems. High-speed optical crossl inks can serve as a key building element of an interconnected space-based communication systemfor military applications. A network such as this would provide immediate communication among satellites, eliminating the need for ground-based relay stations and expensive worldwide ground tracking networks, which would greatly improve the efficacy and reduce the vulnerability of existing satellite systems. Crosslinks can also provide connectivty for commercial global satellite communication systems and for deep-space applications. Optical heterodyne communicatiol systems using semiconductor lasers offer small-aperture, modest-weight, low-power, point-to-point crosslink packages, characteristics that are suitable for the envisioned applications. System research and development performed at Lincoln Laboratory permits the implementation of an efficient optical crosslink based on readily available, state-of-the-art devices and technology.
Chern–Simons forms on associated bundles, and boundary terms

Let E be a principle bundle over a compact manifold M with compact structural group G. For any G-invariant polynomial P, the transgressive forms $$TP(\omega)$$ defined by Chern and Simons in (Ann. Math. 99:48–69, 1974) are shown to extend to forms $$\Phi P(\omega)$$ on associated bundles B with fiber a quotient F = G/H of the group. These forms satisfy a heterotic formula $$d\Phi P(\omega)=P(\Omega)-P(\Psi),$$ relating the characteristic form $$P(\Omega)$$ to a fiber-curvature characteristic form. For certain natural bundles B, $$P(\Psi)=0$$ , giving a true transgressive form on the associated bundle, which leads to the standard obstruction properties of characteristic classes as well as natural expressions for boundary terms. These forms also yield new secondary characteristic classes giving refined information about the associated bundles B.
Multiple-antenna capacity in correlated Rayleigh fading with channel covariance information

We analyze a mobile multiple input multiple output wireless link with M transmit and N receive antennas operating in a spatially correlated Rayleigh flat fading environment. Only the correlations between the channel coefficients are assumed to be known at the transmitter and the receiver. The channel coefficients are correlated in space and uncorrelated in time from one coherence interval to another. These coefficients remain constant for a coherence interval of T symbol periods after which they change to another independent realization according to the spatial correlation model. For this system we characterize the structure of the input signal that achieves capacity. The capacity achieving transmit signal is expressed as the product of an isotropically distributed unitary matrix, an independent nonnegative diagonal matrix and a unitary matrix whose columns are the eigenvectors of the transmit fade covariance matrix. For the case where the number of transmit antennas M is larger than the channel coherence interval T, we show that the channel capacity is independent of the smallest M-T eigenvalues of the transmit fade covariance matrix. In contrast to the previously reported results for the spatially white fading model where adding more transmit antennas beyond the coherence interval length (M>T) does not increase capacity, we find that additional transmit antennas always increase capacity as long as their channel fading coefficients are spatially correlated with the other antennas. We show that for fast hopping or fast fading systems (T=1) with only channel covariance information available to the transmitter and receiver, transmit fade correlations are beneficial. Mathematically, we prove this by showing that capacity is a Schur-convex function of the vector of eigenvalues of the transmit fade correlation matrix. We also show that the maximum possible capacity gain due to transmitter fade correlations is 10logM dB.