cssi/SciSciGPT-SciSciNet huggingface dataset:
Carbon Nanotubes in Biology and Medicine: In vitro and in vivo Detection, Imaging and Drug Delivery

Carbon nanotubes exhibit many unique intrinsic physical and chemical properties and have been intensively explored for biological and biomedical applications in the past few years. In this comprehensive review, we summarize the main results from our and other groups in this field and clarify that surface functionalization is critical to the behavior of carbon nanotubes in biological systems. Ultrasensitive detection of biological species with carbon nanotubes can be realized after surface passivation to inhibit the non-specific binding of biomolecules on the hydrophobic nanotube surface. Electrical nanosensors based on nanotubes provide a label-free approach to biological detection. Surface-enhanced Raman spectroscopy of carbon nanotubes opens up a method of protein microarray with detection sensitivity down to 1 fmol/L. In vitro and in vivo toxicity studies reveal that highly water soluble and serum stable nanotubes are biocompatible, nontoxic, and potentially useful for biomedical applications. In vivo biodistributions vary with the functionalization and possibly also size of nanotubes, with a tendency to accumulate in the reticuloendothelial system (RES), including the liver and spleen, after intravenous administration. If well functionalized, nanotubes may be excreted mainly through the biliary pathway in feces. Carbon nanotube-based drug delivery has shown promise in various In vitro and in vivo experiments including delivery of small interfering RNA (siRNA), paclitaxel and doxorubicin. Moreover, single-walled carbon nanotubes with various interesting intrinsic optical properties have been used as novel photoluminescence, Raman, and photoacoustic contrast agents for imaging of cells and animals. Further multidisciplinary explorations in this field may bring new opportunities in the realm of biomedicine.
Arytenoid adduction as an adjunct to type I thyroplasty for unilateral vocal cord paralysis

Background Surgical management of unilateral vocal cord paralysis has evolved over the last three decades. The recent use of type I thyroplasty has resulted in improvements in voice, swallowing, and respiration. The study was performed to evaluate our experience in 28 patients undergoing arytenoid adduction as part of their surgical rehabilitation of unilateral vocal cord paralysis. Methods Patients undergoing arytenoid adduction with or without silastic medialization for unilateral vocal cord paralysis were entered into a prospective data base. Evaluation included symptomatic improvement in hoarseness, aspiration, dysphagia, dyspnea, and the radiographic documentation of pneumonia. Objective evaluation included mean phonatory air flow and acoustic analysis. Complications associated with surgery were recorded. Results A satisfactory result was obtained in 27 of 28 (96%) patients. By symptom, improvement in hoarseness was evident in 96%, dyspnea 80%, dysphagia 94%, and aspiration 84%. Improvements in phonatory flow rate (p < .001), estimated mean laryngeal airway resistance (p < .001), and maximally prolonged phonation (p < .01) were identified. Complications occurred in 18% and consisted of local wound sepsis (n= 1), hematoma (n = 1), seroma (n = 1), and transient airway edema (n = 2). There were no episodes of airway obstruction requiring tracheostomy or implant extrusion. Conclusions Arytenoid adduction as part of type I thyroplasty is a safe and effective procedure. Subjective analysis confirms marked improvement in laryngeal function in the form of speech, swallowing, and respiration. Objective analysis confirms improvement in voice parameters. Future directions will focus on determination of those patients best served by arytenoid adduction. © 1999 John Wiley & Sons, Inc. Head Neck 21: 52–59, 1999.
Synthesis, Crystal Structures and Properties of the Zintl Phases Sr2ZnP2, Sr2ZnAs2, A2ZnSb2 and A2ZnBi2 (A = Sr and Eu)

The new intermetallic compounds Sr2ZnP2, Sr2 ZnAs2, A2ZnSb2 and A2ZnBi2 (A = Sr, Eu) have been synthesized from the corresponding elements through high-temperature reactions using the flux-growth method. Their structures have been established by singlecrystal and powder X-ray diffraction. In all cases, the X-ray diffraction patterns can be successfully indexed based on hexagonal cells in the space group P63/mmc (no. 194) with lattice parameters in the range a = 4.31 4.73 and c = 7.9 8.55 . The average structure can be described in the ZrBeSi type (Pearson symbol hP6; 3 unique positions) with defects on the zinc site structure refinements indicate that every second zinc position is vacant, i.e., their formula unit is AZn1 xPn with x = 0.5 (A = Sr, Eu; Pn = P, As, Sb, Bi). No stoichiometry breadth was observed, which could imply that a super-structure with a long-range order of the zinc vacancies is plausible and evidence for such was sought using electron diffraction. The results from these experiments, as well as magnetic susceptibility measurements and band structure calculations using the LMTO code are also discussed.
Surveying pseudomoduli: the good, the bad and the incalculable

We classify possible types of pseudomoduli which arise when supersymmetry is dynamically broken in infrared-free low-energy theories. We show that, even if the pseudomoduli potential is generated only at higher loops, there is a regime where the potential can be simply determined from a combination of one-loop running data. In this regime, we compute whether the potential for the various types of pseudomoduli is safe, has a dangerous runaway to the UV cutoff of the low-energy theory, or is incalculable. Our results are applicable to building new models of supersymmetry breaking. We apply the results to survey large classes of models.
The Evolution of Early-Type Galaxies in Distant Clusters*

We present results from an optical-infrared photometric study of early-type (E+S0) galaxies in 19 galaxy clusters out to z = 0.9. The galaxy sample is selected on the basis of morphologies determined from Hubble Space Telescope (HST) WFPC2 images and is photometrically defined in the K band in order to minimize redshift-dependent selection biases. Using new ground-based photometry in five optical and infrared bands for each cluster, we examine the evolution of the color-magnitude relation for early-type cluster galaxies, considering its slope, intercept, and color scatter around the mean relation. New multiwavelength photometry of galaxies in the Coma Cluster is used to provide a baseline sample at z ≈ 0 with which to compare the distant clusters. The optical-IR colors of the early-type cluster galaxies become bluer with increasing redshift in a manner consistent with the passive evolution of an old stellar population formed at an early cosmic epoch. The degree of color evolution is similar for clusters at similar redshift and does not depend strongly on the optical richness or X-ray luminosity of the cluster, which suggests that the history of early-type galaxies is relatively insensitive to environment, at least above a certain density threshold. The slope of the color-magnitude relationship shows no significant change out to z = 0.9, which provides evidence that it arises from a correlation between galaxy mass and metallicity, not age. Finally, the intrinsic scatter in the optical-IR colors of the galaxies is small and nearly constant with redshift, which indicates that the majority of giant, early-type galaxies in clusters share a common star formation history, with little perturbation due to uncorrelated episodes of later star formation. Taken together, our results are consistent with models in which most early-type galaxies in rich clusters are old, formed the majority of their stars at high redshift in a well-synchronized fashion, and evolved quiescently thereafter. We consider several possible effects that may be introduced by the choice of morphologically recognizable elliptical and S0 galaxies in dense environments as a subject for study. In particular, the inclusion of S0 galaxies, which might be undergoing morphological transformation in clusters as part of the Butcher-Oemler effect, may influence the results of our investigation.
Performance of the binary nonlinear joint transform correlators in the presence of the Fourier plane quantization

Abstract The quantization effects of the joint power spectrum on the performance of both binary joint transform correlator (JTC) and the conventional linear JTC are investigated. Computer simulation is used to determine the correlation peak intensity, peak to sidelobe ratio, and the correlation width for various quantization levels. We show that in binary JTC, a capture effect for the number of the quantization levels exists. No correlation signal is produced when the joint power spectrum is quantized below a certain number of quantization levels. For the quantization levels of the joint power spectrum above this capture level, the correlation performance is comparable to that of the unquantized JTC. For conventional linear JTC, the effects of the quantization is to deteriorate the correlation performance steadily.
Licensing of microcomputer software

Microcomputer software is often packaged with a shrink-wrapped license agreement ill-suited to the educational setting. Licenses which restrict use to a single, unique microcomputer, or require a specific diskette or hardware plug to enable the program, inhibit the educational process and discourage the use of certain excellent software products.This presentation will attempt to define the characteristics of appropriate licenses — site, bulk, and individual — that are most appropriate for schools and colleges with micro labs and teaching clusters. Examples of successful licensing arrangements will be given.The presentation will include a report on current software protection schemes and their impact on site licensing.
APPLICATIONS OF ARTIFICIAL NEURAL NETS IN STRUCTURAL MECHANICS

A brief introduction to the fundamentals of Neural Nets is given first, followed by two applications in structural optimization. In the first case the feasibility of simulating with neural nets the many structural analyses performed during optimization iterations was studied. In the second case the concept of using neural nets to capture design expertese was investigated.
SIMULATION OF HOMOLOGOUS AND CANNIBALISTIC CORONAL MASS EJECTIONS PRODUCED BY THE EMERGENCE OF A TWISTED FLUX ROPE INTO THE SOLAR CORONA

We report the first results of a magnetohydrodynamic simulation of the development of a homologous sequence of three coronal mass ejections (CMEs) and demonstrate their so-called cannibalistic behavior. These CMEs originate from the repeated formations and partial eruptions of kink unstable flux ropes as a result of continued emergence of a twisted flux rope across the lower boundary into a pre-existing coronal potential arcade field. The simulation shows that a CME erupting into the open magnetic field created by a preceding CME has a higher speed. The second of the three successive CMEs is cannibalistic, catching up and merging with the first into a single fast CME before exiting the domain. All the CMEs including the leading merged CME, attained speeds of about 1000 km s–1 as they exit the domain. The reformation of a twisted flux rope after each CME eruption during the sustained flux emergence can naturally explain the X-ray observations of repeated reformations of sigmoids and "sigmoid-under-cusp" configurations at a low-coronal source of homologous CMEs.
DISCOVERY OF 5000 ACTIVE GALACTIC NUCLEI BEHIND THE MAGELLANIC CLOUDS

We show that using mid-IR color selection to find active galactic nuclei (AGNs) is as effective in dense stellar fields such as the Magellanic Clouds as it is in extragalactic fields with low stellar densities using comparisons between the Spitzer Deep Wide Field Survey data for the NOAO Deep Wide Field Survey Bootes region and the SAGE Survey of the Large Magellanic Cloud. We use this to build high-purity catalogs of ~5000 AGN candidates behind the Magellanic Clouds. Once confirmed, these quasars will expand the available astrometric reference sources for the Clouds and the numbers of quasars with densely sampled, long-term (>decade) monitoring light curves by well over an order of magnitude and potentially identify sufficiently bright quasars for absorption line studies of the interstellar medium of the Clouds.
Bargaining Outcomes as the Result of Coordinated Expectations An Experimental Study Of Sequential Bargaining

Experimental studies of two-person sequential bargaining demonstrate that the concept of subgame perfection is not a reliable predictor of actual behavior. Alternative explanations argue that fairness influences outcomes and that bargainer expectations matter and are likely not to be coordinated at the outset. This study examines the process by which bargainers in dyads coordinate their expectations on a bargaining convention and how this convention is supported by the seemingly empty threat of rejecting positive but small subgame perfect offers. To organize the data from this experiment, a Markov model of adaptive expectations and bounded rationality is developed. The model predicts actual behavior quite closely.
Chiral Rings and Anomalies in Supersymmetric Gauge Theory

Motivated by recent work of Dijkgraaf and Vafa, we study anomalies and the chiral ring structure in a supersymmetric U(N) gauge theory with an adjoint chiral superfield and an arbitrary superpotential. A certain generalization of the Konishi anomaly leads to an equation which is identical to the loop equation of a bosonic matrix model. This allows us to solve for the expectation values of the chiral operators as functions of a finite number of ``integration constants.'' From this, we can derive the Dijkgraaf-Vafa relation of the effective superpotential to a matrix model. Some of our results are applicable to more general theories. For example, we determine the classical relations and quantum deformations of the chiral ring of = 1 super Yang-Mills theory with SU(N) gauge group, showing, as one consequence, that all supersymmetric vacua of this theory have a nonzero chiral condensate.
The calculation of monocyclic molecular structures using MINDO/3

A comparison is made of the experimentally determined structures for some 4, 5, and 6 membered monocyclic rings and the MINDO/3 calculated structures. Among several systematic deficiencies the calculated ring structures are found to be too flat. This is attributed to the fact that MINDO/3 underestimates 1,4-eclipsing interactions.
Effects of signal duration and masker duration on detectability under diotic and dichotic listening conditions

The detectability of a 500-Hz tone of either 32- or 256-msec duration in a broad-band 50-dB spectrum level noise was measured as a function of the duration of the noise. The noise was continuous or was gated 0, 125, or 250 msec before the onset of the signal. For the gated noise conditions the noise was terminated approximately 5 msec after termination of the signal. With a homophasic condition (NO SO), the three noise conditions led to approximately the same detectability as did the continuous masker. In an antiphasic condition (NO Sπ), detectability was poorest when signal and masker began together and improved as the delay between noise onset and signal onset increased. The difference between the simultaneous onset and the continuous noise condition was about 9 dB for the 32-msec signal and about 2 dB for the 256-msec signal. These results are compared to those reported by McFadden (1966).
The Spectrum of $BPS$ Branes on a Noncompact Calabi-Yau

We begin the study of the spectrum of BPS branes and its variation on lines of marginal stability on 2(?3), a Calabi-Yau ALE space asymptotic to 3/3. We show how to get the complete spectrum near the large volume limit and near the orbifold point, and find a striking similarity between the descriptions of holomorphic bundles and BPS branes in these two limits. We use these results to develop a general picture of the spectrum. We also suggest a generalization of some of the ideas to the quintic Calabi-Yau.
Sex steroid hormones during multiphase pubertal developments.

Abstract Somatic changes during adolescence were related in this study to the breast or genitalia maturational ratings described by Tanner [1]. Urinary androsterone excretion in boys as well as in girls paralleled more the development of skeletal age as a maturational parameter than the chronological age of the adolescent individuals. Sex differences became obvious in relating the androsterone excretion in boys or girls to the skeletal maturity. A similar relationship between girls and boys to the skeletal development was encountered measuring testosterone excretion values. Plasma estradiol and estrone concentrations in girls and plasma testosterone and dihydrotestosterone levels in boys exhibited close correlations to the pubertal developmental stages. Estradiol levels in boys were highly correlated to testosterone concentrations, indicating that perhaps a significant portion of the estrogen is derived from circulating androgens. 5α-androstane-3α, 17β-diol showed a rise during the maturational stages in boys. Changes in the relationship between dihydrotestosterone/testosterone and androstanediol/testosterone indicate that there is an increment of 5α-reductase activity at the beginning of puberty. Longitudinal studies revealed parallelism between testosterone excretion in the urine and the plasma testosterone concentrations, showing the most marked increments between ages 12 and 14 years. In the rat it was found that plasma testosterone levels rose dramatically after the 25th day of life, the surge in dihydrotestosterone occurred at the 26th day of life, but the peak is reached later. These changes were compared to LH and FSH levels. The rate of increment in plasma FSH concentrations is greatest between 16 and 20 days of age and followed by a spurt in the LH concentration after day 20 of age. The abrupt rise in plasma testosterone seen after day 26 is perhaps mediated by the sudden rise in the two gonadotropins. Changes due to castration and cryptorchidism are discussed.
Twisted-Eguchi-Kawai model: A reduced model for large-N lattice gauge theory

We study the large-$N$ reduced model recently proposed by the present authors. This model is a modified version of the Eguchi-Kawai model incorporating twisted boundary conditions. It is shown that the Schwinger-Dyson equations of our model are the same as in the infinite-lattice theory provided ${[\mathrm{U}(1)]}^{4}$ symmetry is not spontaneously broken. We study the model at strong coupling, weak coupling, and intermediate coupling using analytical and Monte Carlo techniques. At weak coupling, it is shown that for a particular choice of twist, ${[\mathrm{U}(1)]}^{4}$ symmetry is not broken and we prove how one recovers usual planar perturbation theory. Monte Carlo data for $\ensuremath{\chi}$ ratios show striking agreement with Wilson-theory results.
Bakers' Yeast Reductions of Alkyl Levulinates: Synthesis of (R)-(+) and (S)-(-)4-methylbutyrolactones

Abstract The bakers' yeast reduction of a number of alkyl levulinates occurs in good to moderate yields to give the corresponding (S) alcohols in > 98% ee. The (S) alcohol la has been converted to synthetically useful (S)- or (R)-4- methylbutyro-lactone and (S)-(+)-l,4-pentanediol in good yields.
Skin perfusion assessed by contrast ultrasound predicts tissue survival in a free flap model

The purpose of this study was to assess perfusion in a free skin flap model using contrast-enhanced ultrasound (CEU), and to determine if the extent of perfusion early after venous occlusion predicted long-term flap survival. Perfusion was assessed in an autologous abdominal skin flap and adjacent healthy skin in rats using CEU imaging before venous occlusion and following reflow. Perfusion assessment was possible in all flaps and quantitative measurements of microvascular blood volume (BV) and blood velocity were expressed as a ratio to that in the healthy skin. Proximal flap BV 18 h after venous occlusion was significantly greater in those that survived (n = 4) vs. those that became necrotic (n = 6) (BV ratio 0.8 +/- 0.1 vs. 0.2 +/- 0.1, p = 0.0001). A BV ratio of 0.5 predicted graft viability with a sensitivity and specificity of 100%. Microvascular blood velocity at 18 h was similar in grafts that survived and those that became necrotic. Qualitative assessment of perfusion by a "blinded" observer correlated well with quantitative data and predicted flap outcome in all cases. We conclude that skin perfusion can be assessed with CEU. Perfusion 18 h following a secondary ischemic insult in a free flap accurately predicts subsequent tissue survival in this model.
The Impact of AIDS on the Botswana Civil Service: A Case Study of the Police and Prison Services

That HIV/AIDS has had an enormous impact on southern Africa in general, and in Botswana in particular, is not in doubt. Numerous studies have documented certain aspects of the problem—high HIV prevalence rates, increasing numbers of orphans and vulnerable children, declining average life expectancy, and a high number of deaths among adults during their most productive years. Scholars have engaged in speculation about the possible impacts that this disease might have on social relationships, economic growth and development, and governance in both the near and the long terms. But these studies are only forecasts of possible futures, not data driven analyses. This study closely examines data available from two agencies in the Botswana civil service, the police and prisons services in an effort to assess, albeit indirectly, any impact that the HIV/AIDS crisis may have had on the workforce. Although the AIDS epidemic in the country as a whole was reflected in the experience of these services, neither agency su...
Carbon dioxide fixation in lobster nerve.

Aspartic, glutamic, malic, and citric (isocitric) acids were isolated by chromatographic methods from lobster nerves incubated with Ringer9s solution containing C 14 -bicarbonate. All the compounds were labeled; the bulk of the radioactivity appeared in the aspartic acid. The findings suggest the operation in lobster nerves of the citric acid cycle including CO 2 fixation.
FASTRUN - A High Performance Computing Device for Molecular Mechanics Using a Pipeline Architecture

A deep, synchronous pipeline architecture has been selected for a computing device with a power of 500 Million floating point operations per second (MFlops). The device calculates the forces and energy due to pair-wise interactions of many objects in a system. Considerations relating to application specific high-performance computer architectures are addressed. In addition, topics specifically relating to very deep, synchronous unidirectional pipelines are discussed. A key element of the device, a quadratic interpolator based on a lookup table, has been developed and tested. Five of these interpolators with a total computing power of 280 Mflops will be employed in the device.
Catalytic enantioselective Grignard Nozaki–Hiyama methallylation from the alcohol oxidation level: chloride compensates for π-complex instability

Methallyl chloride serves as an efficient allyl donor in highly enantioselective Grignard Nozaki–Hiyama methallylations from the alcohol or aldehyde oxidation level viairidium catalyzed transfer hydrogenation. Under identical conditions, methallyl acetate does not react efficiently. Double methallylation of 1,3-propanediol provides the C2-symmetric adduct as a single enantiomer, as determined by HPLC analysis.
Raman scattering of neat and mixed crystals of IrF6 : the Jahn-Teller interaction in the ground state

Raman scattering data for neat and mixed crystal IrF6 samples at 77 K are reported. It is found that v 2(eg ) both evidence v5(t 2g ) both evidence non-vanishing Jahn-Teller interactions for the Γ8g (4 A 2g ) ground state. The linear Jahn-Teller parameters for these modes are D 2⩽0.·001 and D 5=0·02. The v 5 Jahn-Teller interaction is large enough to quench an expected exciton splitting of ∼20 cm-1 almost completely. The v 2 Jahn-Teller interaction is small enough so that exciton interactions predominate; however, normal v 2 k=0 sharp line exciton structure is not observed. Anomalous phonon behaviour is observed and discussed with respect to other hexafluoride phonon data. The non-Jahn-Teller active modes v 1, v 3, v 4, v 6 are found to behave in a fashion consistent with other members of this series.
Vibrational modes of carbon nanotubes; Spectroscopy and theory

Abstract Experimental and theoretical studies of the vibrational modes of carbon nanotubes are reviewed. The closing of a 2D graphene sheet into a tubule is found to lead to several new infrared (IR)- and Ramanactive modes. The number of these modes is found to depend on the tubule symmetry and not on the diameter. Their diameter-dependent frequencies are calculated using a zone-folding model. Results of Raman scattering studies on arc-derived carbons containing nested or single-wall nanotubes are discussed. They are compared to theory and to that observed for other sp 2 carbons also present in the sample.
Hemodynamic observations in severe preeclampsia complicated by pulmonary edema.

Ten patients with severe preeclampsia complicated by pulmonary edema were studied with invasive hemodynamic monitoring. Eight of 10 patients developed pulmonary edema during the postpartum period. Five patients had alterations in the colloid osmotic pressure-pulmonary artery wedge pressure gradient related to elevations in the pulmonary artery wedge pressure and a reduction in the colloid osmotic pressure. Three patients had hemodynamic findings consistent with pulmonary capillary leak. Two patients had evidence of left ventricular failure. In three of the patients, the central venous pressure was significantly lower than the simultaneously determined pulmonary artery wedge pressure during the acute phase of the pulmonary edema.
Precession interpretation of the isolated pulsar psr b1828-11

Pulse timing of the isolated pulsar PSR B1828-11 shows strong Fourier power at periods 1000, 500, and 250 days, correlated with changes in the pulse profile (Stairs, Lyne, & Shemar). We study the extent to which these data can be explained by precession of the star's rigid crust coupled to the magnetic dipole torque. We find that the correlated changes in the pulse duration and spin period derivative can be explained as precession at a period of 500 days with a wobble angle of 3° if the star's dipole moment is nearly orthogonal to its symmetry axis. The dipole torque produces a harmonic at ~250 days. Comparison of the predicted spin dynamics with the observed pulse durations requires the radio beam to have a nonstandard "hourglass" shape. We make predictions of variations in beam polarization and pulse profile with which to test this interpretation. The precession interpretation of PSR B1828-11 seriously challenges the current understanding of the liquid interior of the neutron star. In particular, if the internal liquid is in a superfluid state, its rotational vortices cannot be significantly pinned to the crust.
Out-going Muon Flux from Neutralino Annihilation in the Sun and the Earth in Supergravity Unification

Predictions for the out-going muon fluxes from the annihilation of neutralinos in the center of the sun and the earth in mSUGRA models are given. Effects of uncertainties of the input data on the local wimp density and on the rms wimp velocity are analyzed. It is shown that the out-going muon flux measurements from the sun and the earth are complementary, with the earth providing a larger flux for low values of fine tuning and the Sun providing a larger flux for high values of fine-tuning. It is further shown that a combination of the out-going muon flux measurements from both the earth and the sun can compete favorably with the direct detection measurements. The mSUGRA predictions are compared with the recent limits from BAIKAL NT-96, MACRO, and BAKSAN.
Muon capture at PSI

Abstract Measuring the rate of muon capture in hydrogen provides one of the most direct ways to study the axial current of the nucleon. The MuCap experiment uses a negative muon beam stopped in a time projection chamber operated with ultra-pure hydrogen gas. Surrounded by a decay electron detector, the lifetime of muons in hydrogen can be measured to determine the singlet capture rate ΛS to a final precision of 1%. The capture rate determines the nucleon's pseudoscalar form factor gP. A first result, gP = 7.3 ± 1.1, has been published [1] and the final analysis of the full statistics will reduce the error by a factor of up to 3. Muon capture on the deuteron probes the weak axial current in the two-nucleon system. Within the framework of effective field theories the calculation of such two-nucleon processes involving the axial current requires the knowledge of one additional low energy constant which can be extracted from the doublet capture rate Λd. The same constant then allows to model-independently calculate related processes such as solar pp-fusion or _d scattering. The MuSun experiment will deduce ΛS to better than 1.5%. The experiment uses the MuCap detection setup with a new time projection chamber operated with deuterium at 30K and several hardware upgrades. The system is currently fully commissioned and the main physics data taking will start in 2011.
Coherent Structure Identification in a Lobed Mixer

The influence of large scale structures on the flow in a lobed mixer (a device utilized to enhance streamwise vorticity for increased mixing) is examined by a pseudo flow visualization method (v. Delville et al. 1988), and the Proper Orthogonal Decomposition (POD) (v. Lumley 1967). The pseudo flow visualization method utilizes specially designed hot wire rakes with high spatial resolution to provide the capability of plotting instantaneous velocity profiles. In this work, a rake of 15 hot wires is used to provide these profiles for a velocity ratio of 2:1, at several positions downstream of the lobed mixer. From these profiles a detailed description of the flow field is achieved. In particular, from this information, an idea of the spatial extent and shedding frequency of the large scale structures is determined. The shedding frequencies found are consistent with those found from spectral measurements. A one-dimensional version of the POD is then applied, which utilizes the measured streamwise velocity two-point correlation tensor. The pseudo flow visualization technique is then used to view the contribution from each proper orthogonal mode to the instantaneous signal and comparisons made to the full signal.Copyright © 1991 by ASME
Possible Alternative Transformation Tougheners to Zirconia: Crystallographic Aspects

Several new potential alternative transformation tougheners to zirconia have been identified on the basis of crystallographic considerations and experimental observations. Examples can be found in ceramics, minerals, and components of glass and of cement. The displacive transformations exhibit martensitic characteristics of dusting or self-disintegration, and a critical particle size effect operates. Large positive volume changes (< 12%) accompany the transformations on cooling, in the lanthanide sesquioxides (Ln2O3), dicalcium silicate (Ca2SiO4), and nickel sulfide (NiS). High Ms temperatures (<2000°C) in the Ln2O3 compounds also suggest the possibility of high-temperature transformation toughening. Detrimental negative volume changes are seen in composites with enstatite (MgO · SiO2) and the lanthanide borates (LnBO3). The relative effects of volume change, X-ray unit-cell shape change, and the (martensitic) macroscopic shape change on the mechanical properties of a composite ceramic can thus be investigated.
What the Null Energy Condition (and When It May Be Violated) Tells Us about Gravitational Wave Frequencies in/for Relic Cosmology?

We introduce a criterion as to the range of HFGW generated by early universe conditions. The 1 to 10 Giga Hertz range is constructed initially starting with what Grupen writes as far as what to expect of GW frequencies which can be detected assuming a sensitivity of 7×h~10-27 . From there we examine the implications of an earlier Hubble parameter at the start of inflation, and a phase transition treatment of pre to post Planckian inflation physics via use of inflatons. We close with an analysis of how gravitational constant G may vary with time, the tie in with the NEC condition and how to select a range of relic GW frequencies. The gravitational frequencies in turn may enable resolving a mis match between the datum that the entropy of the center of the galaxy black hole is greater than the entropy of the present four dimensional universe as we can infer and measure.
Extended superspace, higher derivatives and SL (2, Z) duality

We consider the low-energy effective action for the Coulomb phase of an N = 2 supersymmetric gauge theory with a rank one gauge group. The N = 2 superspace formalism is naturally invariant under an SL(2,Z) group of duality transformations, regardless of the form of the action. The leading and next to leading terms in the long distance expansion of the action are given by the holomorphic prepotential and a real analytic function respectively. The latter is shown to be modular invariant with respect to SL(2,Z).
Force Measurements in Hypervelocity Flows with an Acceleration Compensated Strain Gage Balance

Force and moment measurements are performed on a 6-inch Apollo shaped capsule in the LENS I and 48-Inch reflected shock tunnels at CUBRC in cold hypersonic nitrogen flows and for high enthalpy flows (10 MJ/kg) of air, nitrogen, pure oxygen and a 50%-50% oxygen-argon mixture. Measurements with an acceleration compensated flexured strain gage force balance are compared with non-equilibrium Navier-Stokes computations. For the low enthalpy nitrogen runs, axial and normal force coefficients are within 2% of the numerical predictions whereas the pitching moment is under-predicted by 10%. Excellent agreement within 0.5% for the lift-to-drag ratio is achieved. For the first time, the effect of thermodynamic and chemical non-equilibrium on the force and moment coefficients is measured on a reentry capsule in a reflected shock tunnel and compared with state of the art numerical simulations. Both computations and experiments show an increase in the axial force, normal force and pitching moment coefficients and a decrease in the lift-to-drag ratio.
Eigenmode analysis in unsteady aerodynamics - Reduced-order models

A conceptually novel and computationally efficient technique for computing unsteady flow about isolated airfoils, wings, and turbomachinery cascades is presented. Starting with either a time-domain or frequency-domain computational fluid dynamics analysis of unsteady aerodynamic or aeroacoustic flows, a large, sparse eigenvalue problem is solved using the Lanczos algorithm. Then, using just a few of the resulting eigenmodes, a reduced-order model of the unsteady flow is constructed. With this model, one can rapidly and accurately predict the unsteady aerodynamic response of the system over a wide range of reduced frequencies. Moreover, the eigenmode information provides important insights into the physics of unsteady flows.
Implications of Two Type Ia Supernova Populations for Cosmological Measurements

Recent work suggests that Type Ia supernovae (SNe) are composed of two distinct populations: prompt and delayed. By explicitly incorporating properties of host galaxies, it may be possible to target and eliminate systematic differences between these two putative populations. However, any resulting post-calibration shift in luminosity between the components will cause a redshift-dependent systematic shift in the Hubble diagram. Utilizing an existing sample of 192 SNe Ia, we find that the average luminosity difference between prompt and delayed SNe is constrained to be (4.5 ± 8.9)%. If the absolute difference between the two populations is 0.025 mag, and this is ignored when fitting for cosmological parameters, then the dark energy equation of state (EOS) determined from a sample of 2300 SNe Ia is biased at ~1 σ. By incorporating the possibility of a two-population systematic, this bias can be eliminated. However, assuming no prior on the strength of the two-population effect, the uncertainty in the best-fit EOS is increased by a factor of 2.5, when compared to the equivalent sample with no underlying two-population systematic. To avoid introducing a bias in the EOS parameters, or significantly degrading the measurement accuracy, it is necessary to control the postcalibration luminosity difference between prompt and delayed SN populations to better than 0.025 mag.
Spreadsheet Design: Role of Introductory Documentation in Creating Spreadsheets

“Documentation”—that which is incorporated into the spreadsheet file, in contrast to manuals that come with the software per se—seems to be acknowledged more in theory than in practice. Documentation appears in the first section of the spreadsheet, for it introduces the reader to the model and enables the reader to “get his/her bearings.” Necessary elements include a title line, a purpose statement, directions on how the model is to be used, references to sources and ideas, and a table of contents.
X-Ray Hardness Variations as an Internal/External Shock Diagnostic

The early, highly time-variable X-ray emission immediately following gamma-ray bursts (GRBs) exhibits strong spectral variations that are unlike the temporally smoother emission that dominates after t ~ 103 s. The ratio of hard-channel (1.3-10.0 keV) to soft-channel (0.3-1.3 keV) counts in the Swift X-ray telescope provides a new measure delineating the end time of this emission. We define TH as the time at which this transition takes place and measure for 59 events a range of transition times that spans 10 2 to 104 s, on average 5 times longer than the prompt T90 duration observed in the gamma-ray band. It is very likely that the mysterious light-curve plateau phase and the later power-law temporal evolution, both of which typically occur at times greater than TH and hence exhibit very little hardness ratio evolution, are both produced by external shocking of the surrounding medium and not by the internal shocks thought responsible for the earlier emission. We use the apparent lack of spectral evolution to discriminate among proposed models for the plateau phase emission. We favor energy injection scenarios with a roughly linearly increasing input energy versus time for six well-sampled events with nearly flat light curves at t ≈ 103-104 s. Also, using the transition time TH as the delineation between the GRB and afterglow emission, we calculate that the kinetic energy in the afterglow shock is typically a factor of 10 lower than that released in the GRB. Three very bright events suggest that this presents a missing X-ray flux problem rather than an efficiency problem for the conversion of kinetic energy into the GRB. Lack of hardness variations in these three events may be due to a very highly relativistic outflow or due to a very dense circumburst medium. There are a handful of rare cases of very late time t > 104 s hardness evolution, which may point to residual central engine activity at very late time.
Ghost-free superconformal action for multiple M2-branes

The Bagger-Lambert construction of Script N = 8 superconformal field theories (SCFT) in three dimensions is based on 3-algebras. Three groups of researchers recently realized that an arbitrary semisimple Lie algebra can be incorporated by using a suitable Lorentzian signature 3-algebra. The SU(N) case is a candidate for the SCFT describing coincident M2-branes. However, these theories contain ghost degrees of freedom, which is unsatisfactory. We modify them by gauging certain global symmetries. This eliminates the ghosts from these theories while preserving all of their desirable properties. The resulting theories turn out to be precisely equivalent to Script N = 8 super Yang-Mills theories.
Metallization and insulization during impact

Abstract It is pointed out that the large strains produced by hypervelocity impacts can be expected to produce dramatic changes in the chemical bonding (electronic structures) of materials. This will change the mechanical behavior towards increased ductility when a semi-conductor is compressed until it becomes metallic; and towards increased brittleness when a transition metal is expanded so as to localize its d-band electrons. Both isotropic compression (expansion) and shear strains can cause these transformations. Critical deformation criteria are given based on the observed cubic to tetragonal transformations in compressed semiconductors.
Differential Posets and Smith Normal Forms

We conjecture a strong property for the up and down maps U and D in an r-differential poset: DU + tI and UD + tI have Smith normal forms over \({\mathbb Z}[t]\). In particular, this would determine the integral structure of the maps U, D, UD, DU, including their ranks in any characteristic. As evidence, we prove the conjecture for the Young-Fibonacci lattice YF studied by Okada and its r-differential generalizations Z(r), as well as verifying many of its consequences for Young’s lattice Y and the r-differential Cartesian products Yr.
Force-detected magnetic resonance without field gradients

A novel method of nuclear magnetic resonance (NMR) is described which promises to be preferable to known general methods at sample length scales below approximately 100 microm. Its advantages stem from the seemingly paradoxical combination of a homogeneous static magnetic field and detection of a mechanical force between a spin-bearing sample and a magnet assembly. In contrast to other methods of force-detected nuclear magnetic resonance (FDNMR), the method is characterized by better observation of magnetization, enhanced resolution, and no gradient (BOOMERANG), and it is generally applicable with respect to sample composition, pulse sequence, and magnetic field strength. Further advantages of portability and low cost stem from the small instrument volume and mass and promise to extend the use of NMR to new applications and environments. A sensitivity analysis, relevant to spectroscopy or imaging, quantifies the advantage of BOOMERANG relative to magnetic induction using microcoils and to FDNMR methods that rely on large gradients of the magnetic field at the sample.
Meerwein arylation with 3-fluorobutenone

Abstract 3-Fluorobutenone ( 7 ) reacts with aryl triazenes in the presence of zinc iodide to give 4-aryl-3-fluoro-3-iodo-2-butanones ( 9a – 9f ) in moderate yields. The products arise from a free radical process that terminated by iodination of an alkyl radical. The process yields unusual geminal iodo-fluoro compounds.
Corruption, decentralization and yardstick competition

Several empirical studies have found a negative relationship between corruption and the decentralization of the powers to tax and spend. In this paper we explain this phenomenon using a model of Yardstick Competition. Using data on federal corruption-related convictions in U.S. states, we also provide new evidence that points to the existence of a spatial autoregressive component to explaining corruption. We interpret this as consistent with the theoretical findings.
Local Externalities, Convex Adjustment Costs, and Sunspot Equilibria

We study the possibility of random changes in the allocation of resources among regions/sectors in the presence of local productive externalities, in an environment without intrinsic uncertainty. We show that "positive" externalities over some range of activity are a necessary condition for existence of such sunspot equilibria. For the two-state sunspot case, we derive sufficient conditions for existence of sunspot equilibria, in terms of the properties of adjustment costs, private technologies, and externalities. Journal of Economic Literature Classification Numbers: E32, R13.
Synthesis of tetraphenylporphyrins under very mild conditions

Abstract Reaction of pyrrole and an aromatic aldehyde at room temperature affords the corresponding tetraarylporphyrinogen in high yield at thermodynamic equilibrium. Oxidation yields the porphyrin. The reaction conditions are of broad scope.
A Two-Stage Iterative Process for the Synthesis of Poly-oxazoles

[reaction: see text]. Methodology has been developed to prepare bis-oxazoles via a two-stage iterative process. The sequence begins with C(2)-chlorination of a lithiated oxazole using hexachloroethane. Generation of the C(2)-C(4)(') bond by S(N)Ar substitution with TosMIC anion, followed by conversion to the heterocycle in a one-pot reaction with glyoxylic acid monohydrate, affords the desired bis-oxazole in good yield and purity. The two-stage process allows for efficient synthesis of a tris-oxazole and the first iterative preparation of a tetra-oxazole.
The 1,3-migration of phosphorus from oxygen to carbon: a new synthesis of β-ketophosphonates from enol phosphates

Abstract Enol phosphates, readily prepared from ketone enolates and dialkyl phosphorochloridate, can be converted to the analogous β-ketophosphonates by treatment with strong base.
Permeability and effective pore radius measurements for heat pipe and fuel cell applications

Permeability and effective pore radius of sintered metal powder and carbon paper samples, with specific application to fuel cells and heat pipes, were measured using the rate-of-rise test. The performance of wicks in heat pipes is characterized by effective pore radius and permeability, while the permeability measurement by itself is useful for modeling in-plane phenomena of gas diffusion layers in fuel cells. The rate-of-rise measurement technique is characterized by its simplicity and non-intrusiveness, but previous results have been considered inaccurate. In this study, the amount of liquid in the samples was measured by sight for some samples but also by weight change for other samples, which is a new adaptation of the rate-of-rise test. Data is analyzed using an equation resulting from a simple model of the rising meniscus. Knowing the behavior of the equation is important when reducing data in order to obtain more accurate results. The methods used in experimentation and data reduction demonstrate the wider use and increased accuracy of the rate-of-rise test.
An Instability Index Theory for Quadratic Pencils and Applications

Primarily motivated by the stability analysis of nonlinear waves in second-order in time Hamiltonian systems, in this paper we develop an instability index theory for quadratic operator pencils acting on a Hilbert space. In an extension of the known theory for linear pencils, explicit connections are made between the number of eigenvalues of a given quadratic operator pencil with positive real parts to spectral information about the individual operators comprising the coefficients of the spectral parameter in the pencil. As an application, we apply the general theory developed here to yield spectral and nonlinear stability/instability results for abstract second-order in time wave equations. More specifically, we consider the problem of the existence and stability of spatially periodic waves for the “good” Boussinesq equation. In the analysis our instability index theory provides an explicit, and somewhat surprising, connection between the stability of a given periodic traveling wave solution of the “good” Boussinesq equation and the stability of the same periodic profile, but with different wavespeed, in the nonlinear dynamics of a related generalized Korteweg–de Vries equation.