cssi/SciSciGPT-SciSciNet huggingface dataset:
Discussion and Analysis of Flue Gas Utilization in a Phosphoric Acid Fuel Cell Engine During Idle Operation

Fuel cell technology has in recent years won the favor of all major car manufacturers as a likely future replacement of the internal combustion engine. This has been driven by the potential for high efficiency and low emissions. Still, fuel cell engines must overcome major hurdles before being introduced into the market. One such hurdle is systems integration; in particular, with fuel cell engines that do not use hydrogen as their primary fuel. In these engines, fuels, such as methanol, are employed instead of hydrogen because of their high-energy density and ease of storage. However, these benefits are counterbalanced by the need to reform these fuels on-board the fuel cell vehicle, thus substantially increasing the complexity of the fuel cell engine. Through the course of operating a 30 ft methanol-fueled phosphoric acid fuel cell bus, repeated overheating of the steam-reformer catalyst bed at low engine power outputs was noted. For the purpose of better understanding these overheating events, relevant data was obtained from the bus. Bus operation at low-power outputs was found to have low hydrogen consumption (∼40% to ∼60% of the stack's incoming hydrogen) due to low electrical demands and reformate flow rate constraints. In the bus, the anode flue gas is burned in the reformer burner, which provides the heat required for the endothermic methanol steam reforming reaction (see Fig. 1 later). At low engine power, the flue gas is the reformer burner's only fuel, but the energy carried by the flue gas is much greater than the energy required for the reforming reaction and consequently causes reformer overheating at low power. This case serves as an example of how appropriate fuel cell system integration is crucial in order to harness fuel cell benefits. To study such system integration problems, a steady-state model of the fuel cell bus engine was developed. Using this model the bus reformer overheating problem was understood and several possible improvements for utilization of the flue gas were conceited.
Prospective Analysis of a Rapid Trauma Ultrasound Examination Performed by Emergency Physicians

The objective of this prospective study was to determine the sensitivity, specificity, and accuracy of the rapid trauma ultrasound examination, performed by emergency physicians, for detecting free peritoneal and thoracic fluid in patients presenting to a level I trauma center with major blunt or penetrating torso trauma. Emergency medicine residents and faculty were trained to perform an ultrasound examination of the torso evaluating for free intraperitoneal, retroperitoneal, pleural, and pericardial fluid. In the 245 study patients, emergency physicians examined 975 intracavitary spaces and demonstrated 64 positive findings for free fluid as documented by computed tomography scan, diagnostic peritoneal lavage, exploratory laparotomy, chest radiography, tube thoracostomy, or formal two-dimensional echocardiography. The rapid trauma ultrasound examination was 90% sensitive, 99% specific, and 99% accurate. Ultrasonography can serve as an accurate diagnostic adjunct in detecting free peritoneal and thoracic fluid in trauma patients. Appropriately trained emergency physicians can accurately perform and interpret these trauma ultrasound examinations.
Modeling the Ignitability of a Pilot Injection for a Diesel Primary Reference Fuel: Impact of Injection Pressure, Ambient Temperature and Injected Mass

In this paper, we studied the accuracy of computational modeling of the ignition of a pilot injection in the Sandia National Laboratories (SNL) light-duty optical engine facility, using the physical properties of a cetane/iso-cetane Diesel Primary Reference Fuel (DPRF) mixture and the reaction kinetics of a well-validated mechanism for primary reference fuels. Local fuel-air equivalence ratio measurements from fuel tracer based planar laser-induced fluorescence (PLIF) experiments were used to compare the mixture formation predictions with KIVA-ERC-based simulations. The effects of variations in injection mass from 1 mg to 4 mg, in-cylinder swirl ratio, and near-TDC temperatures on non-combusting mixture preparation were analyzed, to assess the accuracy of the model in capturing average jet behavior, despite its inability to model the nonnegligible jet-by-jet variations seen in the experiments. Fired simulations were able to capture well the measured ignitability trends at the different injection conditions tested, but showed some deviations in the minimum temperature needed for robust ignition, pointing out the need for further work to focus on achieving fully comprehensive modeling with detailed chemical kinetics of the DPRF58 mixture and a full engine geometry representation.
Intramolecular chiral relay at stereogenic nitrogen: oxazolidine catalysts derived from Ephedra alkaloids

Abstract A series of oxazolidines have been prepared by reaction of either (1 R ,2 S )-ephedrine or (1 S ,2 S )-pseudoephedrine with salicylaldehyde derivatives. The resultant oxazolidines were used as catalytic ligands in the addition of diethylzinc to a variety of aromatic and aliphatic aldehydes. It was determined that the (1 R ,2 S )-ephedrine based oxazolidine derivative 9 gave the highest enantioselectivities.
Atmospheric neutrinos in the context of muon and neutrino radiography

Using the atmospheric neutrinos to probe the density profile of the Earth depends on knowing the angular distribution of the neutrinos at production and the neutrino cross section. This paper reviews the essential features of the angular distribution with emphasis on the relative contributions of pions, kaons and charm.
Metallicity Gradients in the Intracluster Gas of Abell 496

Analysis of spatially resolved ASCA spectra of the intracluster gas in Abell 496 confirms there are mild metal abundance enhancements near the center, as previously found in a joint analysis of spectra from Ginga Large Area Counter and Einstein solid state spectrometer. Simultaneous analysis of spectra from all ASCA instruments (SIS + GIS) shows that the iron abundance is 0.36 ± 0.03 solar 3'-12' from the center of the cluster and rises ~50% to 0.53 ± 0.04 solar within the central 2'. The F-test shows that this abundance gradient is significant at the more than 99.99% level. Nickel and sulfur abundances are also centrally enhanced. We use a variety of elemental abundance ratios to assess the relative contribution of Type Ia supernovae (SNe Ia) and Type II supernovae (SNe II) to the metal enrichment of the intracluster gas. We find spatial gradients in several abundance ratios, indicating that the fraction of iron from SNe Ia increases toward the cluster center, with SNe Ia accounting for ~50% of the iron mass 3'-12' from the center and ~70% within 2'. The increased proportion of SN Ia ejecta at the center is such that the central iron abundance enhancement can be attributed wholly to SNe Ia; we find no significant gradient in SN II ejecta. These spatial gradients in the proportion of SN Ia/II ejecta imply that the dominant metal enrichment mechanism near the center is different than in the outer parts of the cluster. We show that the central abundance enhancement is unlikely to be due to ram pressure stripping of gas from cluster galaxies or to secularly accumulated stellar mass loss within the central cD. We suggest that the additional SN Ia ejecta near the center is the vestige of a secondary SN Ia-driven wind from the cD (following a more energetic protogalactic SN II-driven wind phase), which was partially smothered in the cD due to its location at the cluster center.
The Differential Impact of Accurate Product Cost Information in Imperfectly Competitive Markets: A Theoretical and Empirical Investigation*

Many researchers claim that costing systems that provide materially more accurate or precise cost reports have a strict value-enhancing effect on decisions (i.e., Cooper 1988, 1995; Cooper and Kaplan 1991; Christensen and Sharp 1994; Rogers. Comstock. and Pritz 1994; Swenson 1995; Gupta and King 1997). However, this study provides theoretical and empirical evidence that the value of more accurate cost information may be dependent upon the firm's competitive market structure, as well as the firm's product market strategy. We extend the theoretical work of Gal-Or 1986 to incorporate an endogenous imprecise cost signal in two imperfect market structures: Cournot competition and Bertrand competition with imperfectly substitutable products. In addition, we theoretically link market structure to product market strategy. To examine product market strategy, we employ a laboratory markets design that allows for strategic reaction by a rival firm in each of these markets, because the competitive position of a firm is determined by its capacity to produce at low cost, or to differentiate its product from other products (Porter 1985). Consistent with our theoretical work, we argue that firms that compete on the basis of cost leadership (which we demonstrate may be characterized as Cournot competition), benefit through increased profits from increased product cost accuracy, whereas firms that compete on the basis of product differentiation (which we demonstrate may be characterized as Benrand competition) do not benefit from such increased product cost accuracy. Our results are consistent with this contention. That is, profit is higher in the experimental cost leadership markets (operationalized as Cournot markets) when subjects know their true cost, while profit is higher in the experimental product differentiation markets (operationalized as Bertrand markets) when subjects receive uninformative cost reports and make their decisions based on expected costs. These results suggest that the value of more accurate cost reports may be dependent upon the firm's competitive market structure strategy and product market strategy.
15-cm Multipole Gas Ion Thruster

A 15-cm multipole thruster was operated on argon and xenon. The multipole approach used has been shown to be capable of low discharge losses and flat ion beam profiles with a minimum of redesign. This approach employs low magnetic field strengths and flat or cylindrical sheet-metal parts and hence is suited to rapid op. timization and scaling. Only refractory metal cathodes were used in this investigation.
Volcano impacts on climate and biogeochemistry in a coupled carbon–climate model

Abstract. Volcanic eruptions induce a dynamical response in the climate system characterized by short-term global reductions in both surface temperature and precipitation, as well as a response in biogeochemistry. The available observations of these responses to volcanic eruptions, such as to Pinatubo, provide a valuable method to compare against model simulations. Here, the Community Climate System Model Version 3 (CCSM3) reproduces the physical climate response to volcanic eruptions in a realistic way, as compared to direct observations from the 1991 eruption of Mount Pinatubo. The model's biogeochemical response to eruptions is smaller in magnitude than observed, but because of the lack of observations, it is not clear why or where the modeled carbon response is not strong enough. Comparison to other models suggests that this model response is much weaker over tropical land; however, the precipitation response in other models is not accurate, suggesting that other models could be getting the right response for the wrong reason. The underestimated carbon response in the model compared to observations could also be due to the ash and lava input of biogeochemically important species to the ocean, which are not included in the simulation. A statistically significant reduction in the simulated carbon dioxide growth rate is seen at the 90% level in the average of 12 large eruptions over the period 1870–2000, and the net uptake of carbon is primarily concentrated in the tropics, with large spatial variability. In addition, a method for computing the volcanic response in model output without using a control ensemble is tested against a traditional methodology using two separate ensembles of runs; the method is found to produce similar results in the global average. These results suggest that not only is simulating volcanoes a good test of coupled carbon–climate models, but also that this test can be performed without a control simulation in cases where it is not practical to run separate ensembles with and without volcanic eruptions.
Reliable Design and Development Techniques

Mechanical concepts must be applied to modify electronic circuit design in order that large scale computer equipment can attain practical levels of reliability. This paper cites some specific mechanical design problems with regard to the reliability of a particular computer system, the AN/FSQ-7.
HOW DOES A SYSTEM RESPOND WHEN DRIVEN AWAY FROM THERMAL EQUILIBRIUM

It is widely appreciated that our understanding of nonequilibrium phenomena has not kept pace with its equilibrium counterpart. In recent years, however, consideration of the above question, posed at the microscopic level of statistical mechanics, has yielded some intriguing theoretical results distinguished by two common features. First, the results remain valid far from equilibrium, that is, even if the system is disturbed violently from its initial equilibrium state. Second, they incorporate information about the history of the system over some span of time; effectively, these results are statistical predictions about what we would see if we could watch a movie of the system filmed at the atomic level, rather than predictions about individual snapshots.
Doubling Property for BiLipschitz Homogeneous Geodesic Surfaces

In this paper we discuss general properties of geodesic surfaces that are locally biLipschitz homogeneous. In particular, we prove that they are locally doubling and that there exists a special doubling measure analogous to the Haar measure for locally compact groups.
Synthetic approaches to novel isomeric dideoxynucleosides containing a chiral furanethanol carbohydrate moiety

Abstract Synthetic approaches to novel chiral dideoxynucleosides containing a furanethanol carbohydrate moiety have been developed. The key steps in these syntheses were the stereoselective preparation of the trans -allylbutyrolactone 5 , its conversion to the deoxygenated allyl sugar 8 , and its facile base-catalyzed isomerization to the cis -allylbutyrolactone 6 . These synthetic developments allow access to chiral isomeric dideoxynucleosides of both the purine and pyrimidine families.
An analysis of the liquidity benefits provided by secondary markets

Abstract Listing shares in liquid secondary markets either to facilitate acquisitions or to diversify owner’s personal wealth are among the most important reasons for firms to go public [Brau, J.C., Fawcett, S.E., 2006. Initial public offerings: An analysis of theory and practice. Journal of Finance 61, 399–436]. We contend that the expected benefits derived from the liquidity provided by secondary markets are relevant for understanding important decisions made in preparation for an IPO. We hypothesize that the potential losses caused by an IPO failure induce firms that benefit more from going public to hire more reputable underwriters and to adopt more conservative pricing policies. We use several proxies for the benefits firms derive from post-IPO liquidity. The results indicate that firms that benefited more from liquidity were taken public by more prestigious underwriters and exhibited substantially larger levels of price revisions and underpricing. Post-IPO liquidity is also important for understanding the decision to retain the lead underwriter in subsequent SEOs.
Palladium-Catalyzed 1,1-Aryloxygenation of Terminal Olefins

This paper describes the 1,1-arylacetoxylation of diverse α-olefins using organostannanes and hypervalent iodine oxidants. The reaction provides a convergent approach for generating a C−C and a C−O bond as well as a new stereocenter in a single catalytic transformation.
Theory of dendritic growth—II. Instabilities in the limit of vanishing surface tension☆

Abstract We present a linear stability analysis of the Ivantsov needle crystal in the limit of zero capillarity and vanishingly small Peclet number. If we make a quasi-stationary approximation for the diffusion field, the stability eigenvalue problem turns out to be exactly solvable. The result is that the paraboloidal steady-state solution is completely unstable. The instabilities are spatially oscillating modes localized at the tip.
Coal-CO2 Slurry Feed for Pressurized Gasifiers: Slurry Preparation System Characterization and Economics

Abstract Gasification-based plants with coal-CO 2 slurry feed are predicted to be more efficient than those with coal-water slurry feed. This is particularly true for high moisture, low rank coal such as lignite. Nevertheless, preparation of the CO 2 slurry is challenging and the losses associated with this process have not been accounted for in previous analyses. This work introduces the Phase Inversion-based Coal-CO 2 Slurry (PHICCOS) feeding system, in which coal-CO 2 slurry is prepared at ambient temperature via coal-water slurry. Steady-state process simulation is used to estimate the performance of the proposed slurry preparation and feeding system for bituminous coal and lignite. An Integrated Gasification Combined Cycle (IGCC) power plant with carbon capture is used here as a potential application, but this concept is applicable to any high-pressure coal feeding process. The economic attractiveness of the PHICCOS feeding system is assessed through calculation of its capital costs and resulting levelized cost of electricity, relative to competing commercial technologies. The findings of this work show that the PHICCOS feeding system offers a good tradeoff between overall process performance and costs. It is the most cost-effective method for feeding lignite and the second most attractive for bituminous coal, for which the competing technology is marginally cheaper. The PHICCOS feeding system is hence the only feeding system which is consistently cost-effective across the entire coal rank spectrum and is increasingly so for high-moisture and high-ash coal.
Microdeletions in the Y Chromosome of Infertile Men

Background Some infertile men with azoospermia or severe oligospermia have small deletions in regions of the Y chromosome. However, the frequency of such microdeletions among men with infertility in general is unknown. We sought to determine the prevalence of Y-chromosome microdeletions among infertile men and to correlate the clinical presentation of the men with specific deletions. Methods We studied 200 consecutive infertile men. Each man was evaluated comprehensively for known causes of infertility, and Y-chromosome microdeletions were studied with use of the polymerase chain reaction to amplify specific regions of the chromosome. The Y chromosomes of 200 normal men were also analyzed. Results Fourteen infertile men (7 percent) and four normal men (2 percent) had microdeletions of the Y chromosome. Nine of the infertile men had azoospermia or severe oligospermia (sperm concentration, <5 million per milliliter), four had oligospermia (sperm concentration, 5 million to <20 million per milliliter), and o...
Doubly periodic self-translating surfaces for the mean curvature flow

We construct new examples of self-translating surfaces for the mean curvature flow from a periodic configuration with finitely many grim reaper cylinders in each period. Because this work is an extension of the author’s article on the desingularization of a finite family of grim reaper cylinders, we simply discuss the ideas of the construction and here prove only that the periodic configuration has the necessary flexibility. These examples show that self-translating surfaces do not necessarily have quadratic volume growth rate in contrast to self-shrinking surfaces.
Tunisia's women: partners in revolution

This paper examines gender politics of the Tunisian revolution and the transitional period from 14 January 2011 to the elections on 23 October 2011 within the theoretical framework of revolutionary ‘restoration’. The broader arc of the revolution saw a radical change in Tunisia's gender politics from ‘state-feminist’ ideology of the pre-revolution period to decentralised ‘gender activisms’ of the post-revolutionary period. Revolution, however, also moves towards restorations of social and gender dynamics of the previous political order. The post-revolutionary ‘gender activisms’ sought to restore the justice of foundational moral principles: ‘secular human rights’ or ‘Islamist principles’. The transitional government also restored the gendered hierarchies reminiscent of the nationalist period. The restoration of the foundational principles of the Tunisian state and Third World nationalist discourse signalled the persistence of a gender paradox where Tunisian women's social struggles coexisted within the ma...
Antidepressant Overdose–induced Seizures

Treating patients with psychiatric problems can present numerous challenges for clinicians. The deliberate self-ingestion of antidepressants is one such challenge frequently encountered in hospitals throughout the United States. This review focuses on 1) the classes of antidepressants, their pharmacologic properties, and some of the proposed mechanism(s) for antidepressant overdose-induced seizures; 2) the evidence for seizures caused by antidepressants in overdose; 3) management strategies for patients who have intentionally or unintentionally overdosed on an antidepressant, or who have experienced an antidepressant overdose-induced seizure.
Structural and Electronic Properties of La@C82

The structural and electronic properties of the La@C82 fullerene have been investigated by means of the Car-Parrinello method, which is based on the local density approximation of the density functional theory. The topological arrangement of the C82 cage was assumed to be a C3v symmetry isomer. Three configurations were considered, one with the lanthanum atom at the center of the cluster, one with it along the threefold axis, and one with it at a low-symmetry, highly coordinated site. The structure was fully relaxed and it was found that the last of these configurations is energetically preferred. In this position, the lanthanum atom is nearly in a La3+ state and the unpaired electron is somewhat delocalized on the cage, in agreement with available experimental data. This arrangement suggests that the chemical shifts of the 5s and 5p lanthanum states can be used as a structural probe and as a way of further validating this picture. It is argued that this conclusion is not affected by the assumed fullerene structure.
Analytical study of the primer vector and orbit transfer switching function

This work focuses on investigating the behavior of the orbit transfer switching function for the two-body problem. Recent work indicated that use of an analytical expression for the switching function could significantly reduce the computational time required to determine when to end coast arcs during trajectory optimization. This analysis of the switching function begins by showing how the primer vector and switching function in various coordinate systems are related, and two representative systems are considered for the remaining analysis. Given that multiple harmonics are manifest simultaneously in the switching function during coast arcs, some possible behaviors of such functions are considered relative to finding bounds containing the desired coast-terminating zero. It is seen that the method proposed in recent work can fail. A relatively simple improvement involving the slope of the switching function at the sampled points is used to make the method more robust and enable the production of example optimal solutions that would not have been possible with the earlier method. In terms of the two chosen systems, analytical expressions for the switching function and its derivative during coasting as well as transformation matrices that relate the systems to each other are therefore presented in Appendices A, B, and C.
On a problem of rota

Abstract Let S ( n , k ) denote Stirling numbers of the second kind; for each n , let K n be such that S ( n , K n ) ⩾ S ( n , k ) for all k . Also, let P ( n ) denote the lattice of partitions of an n -element set. Say that a collection of partitions from P ( n ) is incomparable if no two are related by refinement. Rota has asked if for all n , the largest possible incomparable collection in P ( n ) contains S ( n , K n ) partitions. In this paper, we construct for all n sufficiently large an incomparable collection in P ( n ) containing strictly more than S ( n , K n ) partitions. We also estimate how large n must be for this construction to work.
Optimization in gradient networks

Gradient networks can be used to model the dominant structure of complex networks. Previous work has focused on random gradient networks. Here we study gradient networks that minimize jamming on substrate networks with scale-free and Erdős-Renyi structure. We introduce structural correlations and strongly reduce congestion occurring on the network by using a Monte Carlo optimization scheme. This optimization alters the degree distribution and other structural properties of the resulting gradient networks. These results are expected to be relevant for transport and other dynamical processes in real network systems.
Intramolecular endo-dig hydrosilylation catalyzed by ruthenium: evidence for a new mechanistic pathway.

The ruthenium catalyst [Cp*Ru(MeCN)3]PF6 effects a novel intramolecular hydrosilylation of homo- and bis-homopropargylic alcohols, producing products of unique regioselectivity under very mild conditions with excellent selectivity. The reaction is compatible with a wide range of functional groups and tolerates substantial steric bulk. In addition to producing valuable synthetic intermediates thus far obtainable only in circuitous fashion, the results imply the necessity for a reexamination of the mechanism surrounding trans-hydrosilylation reactions, at least for ruthenium catalysts. At the very least, a simple cis addition/isomerization mechanism almost certainly cannot be active in this case. A silicon−ruthenium transposition could potentially provide a rationalization. However, the evidence for any products of syn addition with nonhydrido ruthenium catalysts is very scarce. Alternatively, a direct trans addition to orthogonal p-systems is also a possibility.
Finiteness theorems and algorithms for permutation invariant chains of Laurent lattice ideals

We study chains of lattice ideals that are invariant under a symmetric group action. In our setting, the ambient rings for these ideals are polynomial rings which are increasing in (Krull) dimension. Thus, these chains will fail to stabilize in the traditional commutative algebra sense. However, we prove a theorem which says that ''up to the action of the group'', these chains locally stabilize. We also give an algorithm, which we have implemented in software, for explicitly constructing these stabilization generators for a family of Laurent toric ideals involved in applications to algebraic statistics. We close with several open problems and conjectures arising from our theoretical and computational investigations.
Pd-catalyzed Kumada-Corriu cross-coupling reactions at low temperatures allow the use of Knochel-type Grignard reagents.

A catalyst system able to operate at temperatures as low as −65 °C for the Pd-catalyzed Kumada−Corriu cross-coupling reaction is described. This unprecedented level of activity allows the use of highly functionalized (Knochel-type) Grignard reagents. Additionally, the tolerance of the protocol toward a wide variety of functional groups allows for the synthesis of valuable compounds, including heterocyclic or polyfluoro biaryls.
anti-Diastereo- and enantioselective carbonyl (hydroxymethyl)allylation from the alcohol or aldehyde oxidation level: allyl carbonates as allylmetal surrogates.

Enantioselective transfer hydrogenation of carbonate 1a in the presence of aromatic, allylic, or aliphatic alcohols 2a−2i employing a cyclometalated iridium C,O-benzoate derived from allyl acetate, 4-cyano-3-nitrobenzoic acid and (S)-SEGPHOS delivers products of (hydroxymethyl)allylation 4a−4i in good isolated yields (60−74%), good anti-diastereoselectivities (5:1−10:1 dr) and exceptional levels of enantiocontrol (93−99% ee). Under identical reaction conditions, but in the presence of isopropanol, aldehydes 3a−3i are converted to an equivalent set of adducts 4a−4i in good isolated yields (58−74%), good anti-diastereoselectivities (4:1−14:1 dr), and exceptional levels of enantiocontrol (95−99% ee). Thus, identical sets of adducts 4a−4i are produced with equal facility from the alcohol or aldehyde oxidation level. These studies represent the first general method for enantioselective carbonyl (hydroxymethyl)allylation, a process that has no highly stereoselective counterpart in conventional allylmetal chemistry.
Broadband shock associated noise from supersonic jets measured by a ground observer

The theory of broadband shock associated noise from supersonic jets in flight previously developed in the nozzle-fixed coordinates is extended to the coordinate system of a stationary ground observer.
Scanning Tunneling Microscopy and Infrared Spectroscopy as Combined In- Situ Probes of Electrochemical Adlayer Structure: Cyanide on PT(111)

Abstract The spatial structure of irreversibly adsorbed cyanide adlayers on a Pt(111) electrode is deduced by means of in situ scanning tunneling microscopy (STM) combined with infrared reflection—absorption spectroscopy (IRAS). The latter data suggests atop-like PtCN coordination. The STM images display a (2 ×2 )R30°−7CN structure, with cyanides bound in symmetric atop sites surrounded by hexagonal “clusters”, of CN, likely bound in near-atop sites. This arrangement, stable over the applied potential range −0.5 to 0 V versus SCE, gives way to a (2×2) structure and disordered adlayers at lower potentials. These findings are compared with previous structural information deduced from ex situ electron diffraction.
Exact Solutions of Low-Dimensional Reaction-Diffusion Systems

We briefly review some common diffusion-limited reactions with emphasis on results for two-species reactions with anisotropic hopping. Our review also covers single-species reactions. The scope is that of providing reference and general discussion rather than details of methods and results. Recent exact results for a two-species model with anisotropic hopping and with 'sticky' interaction of like particles, obtained by a novel method which allows exact solution of certain single-species and two-species reactions, are discussed.
Conformational and vibrational analysis of 2-pentyne and 2-hexyne

Abstract Normal-coordinate calculations were repeated for 2-pentyne and 3-hexyne, and the resulting force constants were used to interpret infrared and Raman spectra that were obtained for 2-hexyne. This compound exists as a mixture of two rotational isomers in the liquid and vapor states. The conformer with all carbons coplanar is the only one present in the solid state. Molecular-mechanics calculations show the two conformers to be approximately equal in energy.
Useful electrophilic trifluoromethylating agents; S-, Se- and Te-(trifluoromethyl)dibenzo-thio-, -seleno- and -telluro-phenium-3-sulfonates

Abstract Se, Se- and Te -(Trifluoromethyl)dibenzo-thio-. -seleno- and -telluro-phenium-3-sulfonates and their dimethyl and nitro derivatives have been synthesized in good yield by sulfonation of the corresponding (trifluoromethyl) dibenzocyclic chalcogen salts with fuming sulfuric acid or by sulfonation followed by nitration. The practical use of these power-variable trifluoromethylating agents has been demonstrated. Thus, they provide good yields of trifluoromethylated products, and the by-product (a salt of dibenzothiophene-3-sulfonic acid or an analog) was easily removed from the products by filtration or by washing with water. S -(Perfluoro-ethyl, -n-butyl- and -n-octyl) dibenzothiophenium-3-sulfonates have also been synthesized and a similar perfluoroalkylation using one of them has been accomplished.
Scalable and efficient broadcasting algorithms for very large internetworks

Broadcast is a special case of routing in which a packet is to be delivered to a set that includes all the network nodes. While dynamic and distributed broadcast techniques have been proposed and used in the Internet, unfortunately they suffer from scalability problems, i.e. they are not efficient with respect to the tremendous size of today's networks. Moreover, it has been observed that the cost of routing and the broadcast time are two conflicting performance measures as far as optimization is concerned, especially in large networks. Also, many of the current techniques are not robust enough and give low performance under events of link failure. First, we show that in order to achieve universal reachability, internets have naturally acquired a multi-level hierarchical structure. Second, utilizing this existing hierarchy, we propose scalable broadcasting protocols which achieve near-optimal cost and time measures. Because of the hierarchy, our proposed algorithm only maintains information of links connected to direct neighbors, thereby making it scalable to future growth in size of the network. We show that time-optimal broadcast in point-to-point networks can be achieved by formulating the problem as finding maximum marching in bipartite graphs. Several heuristics based on matchings are presented. Performance bounds are derived along with numerical and simulation results obtained that prove the validity and feasibility of the scheme.
Adjoint trapping: a new phenomenon at strong 't Hooft coupling

Adding matter of mass m, in the fundamental representation of SU(N), to = 4 supersymmetric Yang-Mills theory, we study ``generalized quarkonium'' containing a (s)quark, an anti(s)quark, and J massless (or very light) adjoint particles. At large 't Hooft coupling λ >> 1, the states of spin ≤ 1 are surprisingly light (Kruczenski et al., [1]) and small ([2]) with a J-independent size of order λ1/2/m. This ``trapping'' of adjoint matter in a region small compared with its Compton wavelength and compared to any confinement scale in the theory is an unfamiliar phenomenon, as it does not occur at small λ. We explore adjoint trapping further by considering the limit of large J. In particular, for J >> λ1/2 >> 1, we expect the trapping phenomenon to become unstable. Using Wilson loop methods, we show that a sharp transition, in which the generalized quarkonium states become unbound (for massless adjoints) occurs at J 0.22λ1/2. If the adjoint scalars of = 4 are massive and the theory is confining (as, for instance, in * = 1 theories) then the transition becomes a cross-over, across which the size of the states changes rapidly from ~ λ1/2/m to something of order the confinement scale ~ Λ−1.
A Coupled Model To Predict Interformation Flow Through an Abandoned Well

This paper presents a novel approach for predicting flow between two formations coupled by an abandoned well. A steady-state, abandoned-well model is derived analytically and applied with a "series of steady states" to create the transient flow response. The model is verified by comparison to the results of a transient, analytical, interformation well model for a single injector given by Avci. This model is the first to include true pressure losses in the abandoned wellbore calculated from established equations for turbulent or laminar pipe flow, plugs, and a casing perforation. The model can also predict flow behind pipe through an open or plugged annulus or a fracture in the annular plug. Finally, the model is the first to incorporate the effect of pressure variations on well flow caused by production or injection in the overlying formation. Application of the model in a single-phase simulation demonstrates the impact of location and condition, rock and fluid properties, initial pressures, and well operations in the coupled formations on the abandoned-well flow. Evolving pressure distributions in the coupled formations may move flow up or down the hole. Pressure losses in the wellbore or behind pipe (through plugs) are shown to preclude flow. The model is also applied to a field case to demonstrate its use as a prediction tool for abandoned-well flow. As opposed to the limited analytical solutions or complex numerical-simulation methods currently available, the new abandoned-well model provides a simple means to determine flow for realistic field conditions.
The MECO experiment: a search for lepton flavor violation in muonic atoms

Abstract MECO will search for direct evidence of muon and electron flavor violation in the decay of muons in Coulomb bound states via coherent recoil of the nucleus and decay electron. The expected sensitivity to the μ − N→e − +N branching fraction relative to muon capture μ − N (A, Z)→ ν μ + N (A, Z−1) is R μe −17 at 90% confidence level, roughly 3–4 orders of magnitude lower than current limits. This article provides an overview of the experiment.
Invisible Flow Watermarks for Channels With Dependent Substitution, Deletion, and Bursty Insertion Errors

Flow watermarks efficiently link packet flows in a network in order to thwart various attacks such as stepping stones. We study the problem of designing good flow watermarks. Earlier flow watermarking schemes mostly considered substitution errors, neglecting the effects of packet insertions and deletions that commonly happen within a network. More recent schemes considered packet deletions but often at the expense of the watermark visibility. We present an invisible flow watermarking scheme capable of enduring a large number of packet losses and insertions. To maintain invisibility, our scheme uses quantization-index-modulation (QIM) to embed the watermark into interpacket delays, as opposed to time intervals including many packets. As the watermark is injected within individual packets, packet losses and insertions may lead to watermark desynchronization and substitution errors. To address this issue, we add a layer of error-correction coding to our scheme. Experimental results on both synthetic and real network traces demonstrate that our scheme is robust to network jitter, packet drops, and splits, while remaining invisible to an attacker.
Ages and metallicities of five intermediate-age star clusters projected towards the Small Magellanic Cloud

Colour–magnitude diagrams are presented for the first time for L32, L38, K28 (L43), K44 (L68) and L116, which are clusters projected on to the outer parts of the Small Magellanic Cloud (SMC). The photometry was carried out in the Washington system C and T1 filters, allowing the determination of ages by means of the magnitude difference between the red giant clump and the main-sequence turn-off, and metallicities from the red giant branch locus. The clusters have ages in the range 2–6 Gyr, and metallicities in the range −1.65<[Fe/H]<−1.10, increasing the sample of intermediate-age clusters in the SMC. L116, the outermost cluster projected on to the SMC, is a foreground cluster, and somewhat closer to us than the Large Magellanic Cloud. Our results, combined with those for other clusters in the literature, show epochs of sudden chemical enrichment in the age–metallicity plane, which favour a bursting star formation history as opposed to a continuous one for the SMC.
Locality of the strange sea in the nucleon

Abstract We introduce the concept of “locality” for the strange sea in the nucleon, which measures the proximity of the strange and anti-strange quarks in the momentum and coordinate spaces. The CCFR data for the strange and anti-strange distributions imply a “local” strange sea in momentum space, which is unexpected in QCD and is at variance with the simple meson-cloud model where the strangeness is generated from the virtual transition of the nucleon to a hyperon plus a kaon. We present a simple model to interpret the CCFR data and to correlate momentum and coordinate space locality, yielding an upper bound of 0.005 fm 2 on the strange radius. We also discuss the significance of locality for other charge-conjugation-odd observables.
Solving the hierarchy problem with brane crystals

Abstract The brane world scenario advocated by Arkani-Hamed et al. transmutes the hierarchy problem into explaining why extra dimensions have sizes much larger than the fundamental scale. In this Letter we discuss possible solutions to this problem by considering the compactified dimensions to be populated by a large number of branes in a crystal lattice. The experimental consequences of this scenario are described, including the presence of large energy gaps in the spectrum of Kaluza–Klein modes.
Symplectic fillings of Seifert fibered spaces

We give finiteness results and some classifications up to diffeomorphism of minimal strong symplectic fillings of Seifert fibered spaces over S^2 satisfying certain conditions, with a fixed natural contact structure. In some cases we can prove that all symplectic fillings are obtained by rational blow-downs of a plumbing of spheres. In other cases, we produce new manifolds with convex symplectic boundary, thus yielding new cut-and-paste operations on symplectic manifolds containing certain configurations of symplectic spheres.
Surface Temperature in Oscillating Sliding Interfaces

A model is developed to predict the behavior of two sliding bodies undergoing oscilla motion. A set of four dimensionless groups is introduced to characterize the transient dimensionless surface temperature rise. They are: the Peclet number P e , the Biot number B i , the amplitude of oscillation A, and the Hertzian semi-contact width α. Also considered in the analysis is the effect of the ratio β=A/α of the amplitude to the semi-contact width. The results of a series of simulations, covering a range of these independent parameters, are presented, and examples are provided to illuminate the utility of the model.
Voltammetry of zinc tetraphenylporphyrin in solution and in polymer films: The effect of axial ligands

Abstract Cyclic voltammetry at Pt electrodes is presented for the title compound in solution with added pyridine or polyvinylpyridine and (C6H5)3P and (C6H5)3As as the well, and in films formed on the electrode from polyvinylpyridine with the porphyrin incorporated by axial ligation. The axial ligands have only a small effect on the one electron reversible oxidaton of the porphyrin but after the second oxidation step, a slow reaction leads to a peripheral nucleophilic substitution whihc is reversed only at much more cathodic voltages (−0.1 V). The substituted form also displays a quasi-reversible reaction at a quite anodic potential (1.0 V) which is rendered unobservable by excess pyridine ligand.
Heterogeneity in the stereochemistry of mycolactones isolated from M. marinum: toxins produced by fresh vs. saltwater fish pathogens

A novel mycolactone has been identified from Mycobacterium marinum infecting freshwater fish.
A Simple Characterization of the Minimal Obstruction Sets for Three-State Perfect Phylogenies

Abstract We give a characterization of the minimal obstruction sets for the existence of a perfect phylogeny for a set of three-state characters that can be inferred by testing each pair of characters. This leads to a O ( m 2 n + p ) time algorithm for outputting all p minimal obstruction sets for a set of m three-state characters over a set of n taxa.
The Intermediate Higgs

Two paradigms for the origin of electroweak superconductivity are a weakly coupled scalar condensate, and a strongly coupled fermion condensate. The former suffers from a finetuning problem unless there are cancelations to radiative corrections, while the latter presents potential discrepancies with precision electroweak physics. Here we present a framework for electroweak symmetry breaking which interpolates between these two paradigms, and mitigates their faults. As in Little Higgs theories, the Higgs is a pseudo-Nambu Goldstone boson, potentially composite. The cutoff sensitivity of the one loop top quark contribution to the effective potential is canceled by contributions from additional vector-like quarks, and the cutoff can naturally be higher than in the minimal Standard Model. Unlike the Little Higgs models, the cutoff sensitivity from one loop gauge contributions is not canceled. However, such gauge contributions are naturally small as long as the cutoff is below 6 TeV. Precision electroweak corrections are suppressed relative to those of Technicolor or generic Little Higgs theories. In some versions of the intermediate scenario, the Higgs mass is computable in terms of the masses of these additional fermions and the Nambu-Goldstone Boson decay constant. In addition to the Higgs, new scalar and pseudoscalar particles are typically present at the weak scale.
I am a sensor, and I approve this message

Despite the popularity of adding sensors to mobile devices, the readings provided by these sensors cannot be trusted. Users can fabricate sensor readings with relatively little effort. This lack of trust discourages the emergence of applications where users have an incentive to lie about their sensor readings, such as falsifying a location or altering a photo taken by the camera.This paper presents a broad range of applications that would benefit from the deployment of trusted sensors, from participatory sensing to monitoring energy consumption. We present two design alternatives for making sensor readings trustworthy. Although both designs rely on the presence of a trusted platform module (TPM), they trade-off security guarantees for hardware requirements. While our first design is less secure, it requires no additional hardware beyond a TPM, unlike our second design. Finally, we present the privacy issues arising from the deployment of trusted sensors and we discuss protocols that can overcome them.
Tandem application of C-C bond-forming reactions with reductive ozonolysis

Several variants of reductive ozonolysis, defined here as the in situ generation of aldehydes or ketones during ozonolytic cleavage of alkenes, are demonstrated to work effectively in tandem with a number of C-C bond-forming reactions. For reactions involving basic nucleophiles (1,2-addition of Grignard reagents, Wittig or Horner-Emmons olefinations, and directed aldol reactions of lithium enolates), the one-pot process offers a rapid and high-yielding alternative to traditional two-step protocols.
The effect of sucralfate on the growth of cariogenic streptococci

Sucralfate, an aluminum salt of sucrose octasulfate, has been shown to be effective in reducing the discomfort of radiation therapy-induced oral mucositis. This study was done to determine whether sucralfate could be used as a nutritional source for dental caries-producing organisms. Three Streptococcus strains were cultured in a defined medium. Sucralfate powder was evaluated for its ability to be used as a carbohydrate food source by these organisms. The addition of sucralfate alone did not stimulate the organism's growth. The addition of sucralfate and glucose resulted in less growth than the addition of glucose alone. Increasing the sucrlfate concentration from 1% to 10% in the glucose-containing cultures resulted in statistically significant growth inhibition (p
A Review of the Effects of Algal Blooms on Shellfish and Aquaculture

Toxic algal blooms occur worldwide and in some areas they are a common and seasonal occurrence. Historically, attention has been focused on blooms of toxic dinoflagellates (e.g., Protogonyaulax tamarensis). More recently, attention has been turned to other species (e.g., Dinophysis, Aureococcus, Gymnodininum). These blooms often present problems with respect to optimal utilization of the shellfish resources, and the magnitude of economic losses can be catastrophic. Nevertheless, successful culture facilities and commercial harvests persist in areas prone to toxic algal blooms. This paper reviews the literature available on occurrences of toxic algal blooms, discusses the means by which harvesters, managers, and industry cope with the problems associated with toxic algal blooms, and makes recommendations for the most efficient and successful utilization of resources in the face of environmental instability.