cssi/SciSciGPT-SciSciNet huggingface dataset:
AirSync: enabling distributed multiuser MIMO with full spatial multiplexing

The enormous success of advanced wireless devices is pushing the demand for higher wireless data rates. Denser spectrum reuse through the deployment of more access points (APs) per square mile has the potential to successfully meet such demand. In principle, distributed multiuser multiple-input-multiple-output (MU-MIMO) provides the best approach to infrastructure density increase since several access points are connected to a central server and operate as a large distributed multiantenna access point. This ensures that all transmitted signal power serves the purpose of data transmission, rather than creating interference. In practice, however, a number of implementation difficulties must be addressed, the most significant of which is aligning the phases of all jointly coordinated APs. In this paper, we propose AirSync, a novel scheme that provides timing and phase synchronization accurate enough to enable distributed MU-MIMO. AirSync detects the slot boundary such that all APs are time-synchronous within a cyclic prefix (CP) of the orthogonal frequency-division multiplexing (OFDM) modulation and predicts the instantaneous carrier phase correction along the transmit slot such that all transmitters maintain their coherence, which is necessary for multiuser beamforming. We have implemented AirSync as a digital circuit in the field programmable gate array (FPGA) of the WARP radio platform. Our experimental testbed, comprising four APs and four clients, shows that AirSync is able to achieve timing synchronization within the OFDM CP and carrier phase coherence within a few degrees. For the purpose of demonstration, we have implemented two MU-MIMO precoding schemes, Zero-Forcing Beamforming (ZFBF) and Tomlinson-Harashima Precoding (THP). In both cases, our system approaches the theoretical optimal multiplexing gains. We also discuss aspects related to the MAC and multiuser scheduling design, in relation to the distributed MU-MIMO architecture. To the best of our knowledge, AirSync offers the first realization of the full distributed MU-MIMO multiplexing gain, namely the ability to increase the number of active wireless clients per time-frequency slot linearly with the number of jointly coordinated APs, without reducing the per client rate.
Parametric Instability of a Rotating Circular Ring With Moving, Time-Varying Springs

Parametric instabilities of in-plane bending vibrations of a rotating ring coupled to multiple, discrete, rotating, time-varying stiffness spring-sets of general geometric description are investigated in this work. Instability boundaries are identified analytically using perturbation analysis and given as closed-form expressions in the system parameters. Ring rotation and time-varying stiffness significantly affect instability regions. Different configurations with a rotating and nonrotating ring, and rotating spring-sets are examined. Simple relations governing the occurrence and suppression of instabilities are discussed for special cases with symmetric circumferential spacing of spring-sets. These results are applied to identify possible conditions of ring gear instability in example planetary gears.
Pseudocraters on Mars

In the Cydonia region of southern Acidalium Planitia are small, low-relief, apparently volcanic domelike structures, whose size, morphology, and general occurrence suggest they are martian analogs of terrestrial pseudocraters, a type of phreatic eruption. Average base diameters are about 800 m, which is somewhat larger than typical Icelandic examples. All the domes have summit pits; elongate domes generally have elongate summit pits or, in extreme cases, double pits. The greatest concentration of these domes is in a region of subdued fractured plains which may be old volcanic flows. Pseudocraters on the earth are produced when lava flows over water-logged ground. On Mars surface or subsurface ice was the likley medium that produced the steam eruptions resulting in cratered domelike structures on the lava surfaces.
Carrier Frequency Offset Estimation for OFDM Systems with Null Subcarriers

An accurate estimation of carrier frequency offset (CFO) is a crucial task for orthogonal frequency-division multiplexing (OFDM) systems but should be performed with affordable computational complexity for practicality. In this paper, the authors derive two new estimation algorithms (one for the integer part and the other for the fractional part of CFO), each of which utilizes only one OFDM block with null subcarriers but offers improved accuracy and reduced complexity. The proposed estimator for fractional CFOs operates iteratively and is insensitive to the initial CFO. The other proposed estimator for integer CFOs employs a pseudonoise binary random sequence to assist in subcarrier arrangement and accurate estimation of the integer CFO. To demonstrate the efficiency of the proposed methods, numerical results are provided from computer simulation and analysis, and comparisons are made with other existing methods in the literature
A k-Omega Turbulence Model for Quasi-Three-Dimensional Turbomachinery Flows

A two-equation k-omega turbulence model has been developed and applied to a quasi-three-dimensional viscous analysis code for blade-to-blade flows in turbomachinery. the code includes the effects of rotation, radius change, and variable stream sheet thickness. The flow equations are given and the explicit runge-Kutta solution scheme is described. the k-omega model equations are also given and the upwind implicit approximate-factorization solution scheme is described. Three cases were calculated: transitional flow over a flat plate, a transonic compressor rotor, and transonic turbine vane with heat transfer. Results were compared to theory, experimental data, and to results using the Baldwin-Lomax turbulence model. The two models compared reasonably well with the data and surprisingly well with each other. Although the k-omega model behaves well numerically and simulates effects of transition, freestream turbulence, and wall roughness, it was not decisively better than the Baldwin-Lomax model for the cases considered here.
Acoustical characterization of exploding hydrogen-oxygen balloons

Exploding hydrogen-oxygen balloons are popular chemistry demonstrations. Although initial research experimentally quantified potential hearing risk via analysis of peak levels [K. L. Gee et al., J. Chem. Educ. 87, 1039–1044 (2010)], further waveform and spectral analyses have been conducted to more fully characterize these impulsive noise sources. While hydrogen-only balloons produce inconsistent reactions and relatively low, variable levels, stoichiometrically mixed hydrogen-oxygen balloons produce consistent high-amplitude noise waveforms. Preliminary consideration is also given to the potential use of these exploding balloons in architectural acoustics applications.
Three-flavor QCD at high density: Color-flavor locking and chiral symmetry breaking

Abstract We propose a symmetry breaking scheme for QCD with three massless quarks at high baryon density wherein the color and flavor SU(3) color × SU(3) L × SU(3) R symmetries are broken down to the diagonal subgroup SU(3) color+ L + R by the formation of a condensate of quark Cooper pairs. We discuss general properties that follow from this hypothesis, including the existence of gaps for quark and gluon excitations, the existence of Nambu-Goldstone bosons which are excitations of the diquark condensate, and the existence of a modified electromagnetic gauge interaction which is unbroken and which assigns integral charge to the elementary excitations. We present mean-field results for a Hamiltonian in which the interaction between quarks is modelled by that induced by single-gluon exchange. We find gaps of order 10–100 MeV for plausible values of the coupling. We discuss the effects of nonzero temperature, nonzero quark masses and instanton-induced interactions on our results.
Simulation of Double-Null Divertor Plasmas with the UEDGE Code

We describe recent modifications to the UEDGE code for simulation of full double-null magnetic configurations. We present simulation results for magnetically balanced double nulls, with and without asymmetries due to divertor recycling and cross-field drifts. Up/down electron temperature asymmetries due to recycling are weak for attached plasmas. Cross-field drifts due to radial electric fields produce strong ion particle fluxes through the private flux regions that drive up/down plasma asymmetries. Electrical currents through grounded divertor plates are sensitive to both recycling-driven and drift-driven asymmetries.
ISOCAM Mid-Infrared Imaging of the Quiescent Spiral Galaxy NGC 7331*

Using the mid-infrared camera (ISOCAM) on the Infrared Space Observatory (ISO), the Sb LINER galaxy NGC 7331 has been imaged in two broadband and four narrowband filters between 6.75 and 15 μm. These maps show a prominent circumnuclear ring of radius 025 × 075 (1.1 × 3.3 kpc) encircling an extended central source. The 7.7 and 11.3 μm dust emission features are strong in this galaxy, contributing approximately one-third of the total IRAS 12 μm broadband flux. In contrast to starburst galaxies, the 15 μm continuum is weak in NGC 7331. The mid-infrared spectrum does not vary dramatically with position in this quiescent galaxy, showing neither large-scale destruction of the carriers of the emission bands nor a large increase in the 15 μm continuum in the star-forming ring. In the bulge there is some enhancement of the LW2 (6.75 μm) flux, probably because of contributions from photospheric light; however, the 11.3 μm dust feature is also seen, showing additional emission from interstellar or circumstellar dust.
Gravitational analog of Faraday’s law via torsion and a metric with an antisymmetric part

In this paper we show that in the presence of torsion and a metric with an antisymmetric part one can construct a gravitational analog of Faraday’s law of electromagnetism.
Coherent substructure of turbulence near the stagnation zone of a bluff body

Abstract An experimental investigation of the evolution of freestream turbulence in crossflow about a circular cylinder was conducted in order to identify the existence of a coherent substructure near the stagnation zone of a bluff body. This coherent substructure is the outcome of the amplification of freestream turbulence by the stretching mechanism in flow diverging about a bluff body. Smoke-visualization of the flow events clearly revealed the selective stretching of cross-vortex tubes and the emergence of an organized turbulent flow pattern near the cylinder stagnation zone. Significant amplification of the total turbulence energy of the streamwise fluctuating velocity was consistently monitored. Realization of selective amplification at scales larger than the neutral scale of the stagnation flow was indicated by the variation of the discrete streamwise turbulence energy. A most amplified scale, characteristics of the energy-containing eddies within the coherent substructure and commensurate with the boundary-layer thickness, was detected. Penetration of the amplified turbulence into the cylinder boundary-layer led to the retardation of separation and to a concurrent decrease in the drag coefficient at subcritical cylinder-diameter Reynolds numbers. The major role played by the amplified turbulence concentrated within the coherent substructure in determining the pressure fluctuations on the upwind face of a bluff body is indicated by the variations of the energy spectra of both incident turbulence and wall-pressure fluctuations.
Sarcomas of the breast.

The term, sarcoma of the breast, without any further qualifications can be misleading because it has been applied to a miscellaneous spectrum of lesions which vary not only in their histologic characteristics but also in clinical behavior. For instance, if in a survey of "sarcoma" of the breast, one should include all cases diagnosed as cystosarcoma phyllodes he would find that (1) the overall incidence of mammary sarcomas becomes quite high, and (2) their overall clinical malignancy is conversely quite low, since the majority of lesions labeled with that term behave as local, relatively harmless conditions. To give another example, in the older age group some relatively slow-growing carcinomas of the breast may exhibit areas of spindle cell, cartilagenous, or osseous metaplasia. To classify these tumors as fibrosarcoma or osteogenic or chondrosarcoma leads only to confusion and consequently to improper treatment since they behave not as sarcomas, but as low-grade
Effect of Coriolis forces in a rotating channel with dimples and protrusions

Abstract Large-eddy simulations are used to investigate the effect of Coriolis forces and dimple depth on heat transfer and friction in a channel with dimples and protrusions on either side. Two geometries with two different dimple–protrusion depths, δ = 0.2 and 0.3 of channel height are investigated over a wide range of rotation numbers, Ro b = −0.77 to 1.10 based on mean velocity and channel height. It is found that the dimple side of the channel is much more sensitive to destabilizing rotational Coriolis forces than the protrusion side of the channel, although both dimples and protrusions react to the stabilizing effects of Coriolis forces on the leading side. The dimpled surface on the trailing side experiences a large increase in heat transfer coefficient from an augmentation ratio of 1.9 for stationary flow to 3.5 at Ro b = 0.77 for δ = 0.2, and from 2.3 to a maximum of 3.8 for δ = 0.3. Placing protrusion on the trailing side, however, only increases the augmentation ratio to between 3.25 and 3.7 from the stationary values of 3.0 and 3.4 for δ = 0.2 and 0.3, respectively. The dimpled leading side experiences a large drop in heat transfer to between augmentation ratios of 1.1 and 1.4 for the two dimple depths. The protrusion surface on the leading side also experiences a large drop in augmentation from 3.0 for a stationary channel to 1.3 at Ro b = 0.77 for δ = 0.2 and from 3.4 to 1.8 at Ro b = 1.1 for δ = 0.3. The results lead to the conclusion that for low rotation numbers | Ro b | Ro b | > 0.2, dimples on the trailing side of the duct give better overall performance. Between the two depths, the deeper dimple/protrusion ( δ = 0.3) gives higher heat transfer augmentation at the price of more frictional losses ranging from 6 to 10 versus 3 to 5 for depth δ = 0.2.
A corollary of the b-function lemma

Let X be an algebraic variety, f a regular function, $${j:U\hookrightarrow X}$$ the complement to the locus of vanishing of f, and M a holonomic D-module on U. Consider the D U [s]-module $${M\otimes ``{f^{s}}''}$$ . The goal of this note is to describe all D X [s] submodules $${N\hookrightarrow j_*(M\otimes ``{f^{s}}'')}$$ such that $${j^*(N)\simeq M\otimes ``{f^{s}}''}$$ .
X;Y translocation in a female with streak gonads, H-Y- phenotype, and some features of turner's syndrome

In women X;Y translocations usually arise as Xp-Yq exchanges. We describe a 17-year-old female with streak gonads, some minor features of Turner's syndrome, and an X;Y translocation involving an exchange between Xq and Yq. Histological examination of the gonads revealed a fibrous stroma with prominent hilar cells. Cultured fibroblasts and peripheral lymphocytes were typed H-Y-. Examination of a buccal smear revealed a single intranuclear structure with the appearance of both a Barr body and a fluorescent Y body. This finding was consistent with the results of BrdU studies showing that the translocation X chromosome had been inactivated in all cells analyzed.
Cis- and trans-1,7,9-trioxadispiro[5.1.5.3]hexadecane: Stability studies and solution structures

Abstract The stability of cis- and trans-1,7,9-trioxadispiro[5.1.5.3]hexadecanes was examined through equilibration studies with the result that the trans-isomer was more stable by 0.3–0.7 kcal/mol, depending upon the solvent. NMR studies indicate that the central ring of these compounds is in a twist-boat conformation in solution which allows these isomers to best accommodate conflicting steric and electronic effects on their stability.
Towards extracting explicit proofs from totality checking in twelf

The Edinburgh Logical Framework (LF) is a dependently type lambda calculus that can be used to encode formal systems. The versatility of LF allows specifications to be constructed also about the encoded systems. The Twelf system exploits the correspondence between formulas and types to give specifications in LF a logic programming interpretation. By interpreting particular arguments as input and others as output, specifications can be seen as describing non-deterministic functions. We can then prove meta-theorems about the encoded systems by showing particular such functions to be total. Twelf provides tools for establishing totality. However, the resulting proofs of meta-theorems are implicit in that they do not yield a certificate that can be given to a proof checker. We begin the process here of making these proofs explicit. We treat the restricted situation in Twelf where context definitions (regular worlds), mutually recursive definitions and lemmas are not used. In this setting we describe and prove correct a translation of the steps in totality checking into an actual proof in the companion logic M2.
Infra-red fixed points at the boundary

Gauged supergravities (in four and five dimensions) with eight supercharges and with vector supermultiplets have a unique ultra-violet (UV) fixed point on a given physical domain Script M of the space of the scalar fields. We show that in these models the infra-red (IR) fixed points are located on the boundary of Script M, where the space-time metric becomes singular.
Mind Out of Time: Wordsworth and Neurophenomenology

If literary art evokes extraordinary forms of cognition in principled ways, then theories and distinctive practices of poetics should prove illuminating for cognitive science. The question is, how to operationalize such theories and practices for controlled experimental study? This paper proposes an answer in terms of the neurophenomenological paradigm developed by Francisco Varela and his students, which seeks to correlate first-person (subjective, introspective) accounts of cognitive experience with third-person (objective, neurophysiological) measures. Given striking correspondences between the neurophenomenological theory of cognitive “transparency” and “breakdown” and the Romantic poetics of defamiliarization, I adopt the Wordsworthian “spot of time” as a test case and use standing literary-critical description to formulate specific neurophenomenological predictions about its defamiliarizing effects.
The relativistic transport model description of subthreshold kaon production in heavy-ion collisions

Abstract The relativistic transport model, in which the nucleon effective mass is connected to the scalar field while its energy is shifted by the vector potential, is extended to include the kaon degree of freedom. We further take into account the medium modification of the kaon mass due to explicit chiral symmetry breaking. Both the propagation of kaons in the mean-field potential and the kaon-baryon elastic scattering are explicitly treated in our study. We find that the attractive kaon scalar mean-field potential in the dense matter leads to an enhanced kaon yield in heavy-ion collisions at energies of about 1 GeV/nucleon that are below the threshold for kaon production from the nucleon-nucleon interaction in free space. The final-state kaon-baryon scattering is seen to affect significantly the kaon momentum spectra, leading to an enhanced yield of kaons with large momenta or at large laboratory angles. With a soft nuclear equation of state and including the attractive kaon scalar potential, the calculated kaon energy spectra agree with the preliminary data on subthreshold kaon production from the heavy-ion synchrotron at GSI.
A Specialist's Quoted Depth and the Limit Order Book

By partitioning quoted depth into the specialist's contribution and the limit order book's contribution, the paper investigates whether specialists manage quoted depth to reduce adverse selection risk. The results show that both specialists and limit order traders reduce depth around information events, thereby reducing their exposure to adverse selection costs. Moreover, specialists' quotes may reflect only the limit order book on the side (or sides) of the market where they believe there is a chance of informed trading. Changes in quoted depth are consistent with specialists managing their inventory as well as having knowledge of the stock's future value.
Diagnosis of deep vein thrombosis and pulmonary embolism

Traditional approaches to diagnosis of deep vein thrombosis and pulmonary embolism are primarily based on the results of compression ultrasonography and the ventilation/perfusion lung scan (V/Q). Spiral computed tomographic imaging may replace the V/Q scan, and the D-Dimer assay may guide evaluation.
One-Pot Preparation of 2,5-Dichloro-4′-phenyloxybenzophenone

Friedel–Crafts-type acylation of phenyl ether with 2,5-dichlorobenzoic acid could be accomplished in a single step using trifluoroacetic anhydride and phosphoric acid. The method gave a greater yield (78%) than the conventional two-step process (71%) of acid chloride generation followed by aluminum trichloride–mediated acylation.
Localization of g-modules on the affine Grassmannian

We consider the category of modules over the affine Kac-Moody algebra ĝ of critical level with regular central character. In our previous paper we conjectured that this category is equivalent to the category of Hecke eigen-D-modules on the affine Grassmannian G((t))/G[[t]]. This conjecture was motivated by our proposal for a local geometric Langlands correspondence. In this paper we prove this conjecture for the corresponding I 0 equivariant categories, where I 0 is the radical of the Iwahori subgroup of G((t)). Our result may be viewed as an affine analogue of the equivalence of categories of g-modules and D-modules on the flag variety G/B, due to Beilinson-Bernstein and Brylinski-Kashiwara.
Radioimmunologic detection of proctolin in arthropods

Abstract 1. Antisera to the insect pentapeptide proctolin (Arg-Tyr-Leu-Pro-Thr) have been prepared and used to quantify proctolin radioimmunoassay (RIA) activity in the central nervous system (CNS) of three orthopterous insects and one crustacean. 2. RIA activity was found throughout the CNS of the orthopterous insects with the 6th abdominal. thoracic and supraesophageal (brain) ganglia being enriched in the peptide relative to the remaining abdominal ganglia. 3. No activity was found in the larval or adult CNS of a Lepidopteran ( Manduca sexta ). 4. RIA activity was also found throughout the crustacean CNS.
Improved Synthesis of Dialkylaminopyrrolines

Abstract The literature synthesis of 5-dialkylamino-3,4-dihydro-2H-pyrroles from 5-methoxy-3,4-dihydro-2H-pyrrole has been much improved. In initial assays, the pyrrolinium salts obtained on alkylation of the dibutylaminoamidine are excellent “naked halide” catalysts.
Correlated Orienteering Problem and its application to informative path planning for persistent monitoring tasks

We propose a novel non-linear extension to the Orienteering Problem (OP), called the Correlated Orienteering Problem (COP). We use COP to plan informative tours (cyclic paths) for persistent monitoring of an environment with spatial correlations, where the tours are constrained to a fixed length or time budget. The main feature of COP is a quadratic utility function that captures spatial correlations among points of interest that are close to each other. COP may be solved using mixed integer quadratic programming (MIQP) that can plan multiple disjoint tours that maximize the quadratic utility function. We perform extensive characterization of our method to verify its correctness, as well as its applicability to the estimation of a realistic, time-varying, and spatially correlated scalar field.
A novel synthesis of N1-(substituted)-pyrimido[5,4-e]-1,2,4-triazine-5,7(1H,6H)-diones

A new synthesis of N1-(substituted)-pyrimido[5,4-e]-1,2,4-triazine-5,7(1H,6H)-diones, which are analogues of the natural product toxoflavin, is reported. Condensation of preformed alkyl or aryl hydrazones with 6-chloro-3-methyl-5-nitrouracil efficiently provides pyrimidotriazinediones in a three-step process that broadens the scope of R1 substituents.
On some aspects of survival under production uncertainty

In recent years there has emerged a considerable volume of literature which analyzes the possibility of a certain performance index staying above a minimum level over time for an agent who operates in a given stochastic dynamic environment. Thus, one may be interested in the potential ability of an agent to meet a minimum positive "subsistence" consumption level over time or of firms being able to pay out a minimum level of dividend to shareholders or to meet a minimal level of debt service in order to avoid bankruptcy. For a renewable resource which is exploited over time at a rate determined by the market or by the optimal policy of its owner, one can examine the circumstances under which the resource does not become extinct over time. The literature on exhaustible resources has focused on the difficulties of maintaining a positive steady level of consumption in an economy which relies on an exhaustible resource as an essential input in production [see Solow (1974), Cass and Mitra (1991)]. In a model of renewable resource with stochastic and concave production function, where the resource is depleted every time period according to market equilibrium, Mirman and Spulber (1984) derived results on chances of survival for the resource. Majumdar and Radner (1991,1992) consider a dynamic model ?f consumption and investment with production uncertainty, where the agent is required to meet a certain strictly positive consumption level every time period in order to survive. They consider cases where the production function is of the canonical neoclassical type and also the case where it is linear. This framework is close to the classical gambler's ruin problem in probability theory (see Feller (1957), Billingsley (1979)). In a similar framework, Ray (1984) analyzed the survival problem of economic agents who had the option of borrowing and lending over time.
Decuplet contributions to hyperon axial vector form factors

Abstract We consider the predictions of chiral perturbation theory for SU (3) breaking in the axial vector form factor g1 measured in semileptonic hyperon decays. Including only octet baryon intermediate states, the non-analytic correlations are ∼ 100%. These corrections are dominated by an SU (3)-symmetric wavefunction renormalization, which explains the fact that the “corrected” predictions still fit the data well. We argue that the large corrections are nonetheless strong evidence that the chiral expansion is breaking down. We theninclude decuplet baryon intermediate states. We find that the effects of a non-zero octet-decuplet mass difference, Δ, significantly changes the pattern of corrections from the Δ = 0 case. The decuplet corrections can cancel the large octet contributions in a non-trivial way, but the corrections no longer favor the SU (6) values of the axial couplings. We also argue the D and F axial couplings cannot be reliably extracted from calculations which keep only the non-analytic corrections.
Structuring information for a computer-based communications medium

Several years ago Prof. Charles E. Osgood suggested that it might be possible to develop a program for a computer-based education system which would eventually allow the public, possibly at a world's fair, to "explore the future." Such an "exploration" would be useful both for education and for social science research. This paper is a progress report on the continuing development of that "exploration of alternative futures" using the PLATO system (see Figure 1).
Selenazolidines as Novel Organoselenium Delivery Agents

Two new classes of selenazolidine-4(R)-carboxylic acids (2-oxo and 2-methyl-SCAs) were synthesized and characterized. Both were designed as latent forms of selenocysteine, intended to provide a chemically superior delivery form for selenium. The prodrugs may be clinically useful when selenium supplementation at supranutritional levels is indicated, such as in cancer chemoprevention.
Matching 3d N=2 Vortices and Monopole Operators

In earlier work with N. Seiberg, we explored connections between monopole operators, the Coulomb branch modulus, and vortices for 3d, $$ \mathcal{N} $$ =2 supersymmetric, U(1) k Chern-Simons matter theories. We here extend the monopole / vortex matching analysis, to theories with general matter electric charges. We verify, for general matter content, that the spin and other quantum numbers of the chiral monopole operators match those of corresponding BPS vortex states, at the top and bottom of the tower associated with quantizing the vortices’ Fermion zero modes. There are associated subtleties from non-normalizable Fermi zero modes, which contribute non-trivially to the BPS vortex spectrum and monopole operator matching; a proposed interpretation is further discussed here.
Growth and some properties of Cr11Ge19

Abstract Cr 11 Ge 19 belongs to a large family of materials known as the Nowotny chimney-ladder compounds, some of which were recently proposed as advanced thermoelectric materials, particularly because of their low thermal conductivity related to their relatively complex crystal structure. In order to assess the potential of the compound Cr 11 Ge 19 for thermoelectric applications, we grew large single crystals of this peritectic compound by a vertical gradient freeze technique and measured the thermoelectric properties of the crystals. Cr 11 Ge 19 forms peritectically at 1201 K and crystals were grown from Ge-rich solutions. The conditions and the results of the crystal growth experiments are presented. The crystals were characterized by X-ray diffractometry, Laue technique, and electron probe microanalysis. The results of the thermoelectric property measurements suggest that Cr 11 Ge 19 has a metallic behavior and therefore presents little interest for thermoelectric applications.
Metabolic Response to Burn Injury: Nutritional Implications

The response to critical illness involves alterations in all aspects of metabolic control, favoring catabolism of stored energy substrates and protein. Glucose production is accelerated, due principally to a chronic elevation in glucagon. Whereas glucose is available at increased rates, the muscle tissue is less responsive than normal to the stimulatory effect of insulin on glucose uptake. Stored triglyceride is also catabolized at a high rate, predominantly due to enhanced adrenergic activity. This causes the release of free fatty acids at a rate well in excess of their requirement for oxidation, leading to a high rate of reesterification and triglyceride transport in plasma. Protein metabolism is characterized by accelerated catabolism that is not balanced by a corresponding increase in synthesis. Whereas the mechanism for this response is not known, peripheral insulin resistance does not appear to be responsible.
ROBUST DESIGN FOR IMPROVED VEHICLE HANDLING UNDER A RANGE OF MANEUVER CONDITIONS

In this article, a robust design procedure is applied to achieve improved vehicle handling performance as an integral part of simulation-based vehicle design. Recent developments in the field of robust design optimization and the techniques for creating global approximations of design behaviors are applied to improve the computational efficiency of robust vehicle design built upon sophisticated vehicle dynamic simulations. The approach is applied to the design of a M916A1 6-wheel tractor/M870A2 3-axle semi-trailer. The results illustrate that the proposed procedure is effective for preventing the rollover of ground vehicles as well as for identifying a design that is not only optimal against the worst maneuver condition but is also robust with respect to a range of maneuver inputs. Furthermore, a comparison is made between a statistical approach and a bi-level optimization approach in terms of their effectiveness in solving robust design problems
Intraepithelial Lesions of the Urinary Bladder With a Discussion of the Histogenesis of Urothelial Neoplasia

Bladder neoplasia of the transitional cell type progresses by two distinct, but occasionally interrelated, pathways characterized morphologically by a papillary or nonpapillary configuration. In this review, the authors discuss intraepithelial lesions of the urinary bladder, le, those lesions confined within the basement membrane of the urothelium. The emphasis is on histogenesis of bladder neoplasia, its putative precursor lesions, and its noninvasive forms. Areas of controversies are highlighted, and the pertinent clinical features, histological findings, and biological potential of these lesions examined.
Low-energy electron microscopy

Low-energy electron microscopy (LEEM) is a relatively new microscopy technique, capable of high-resolution (5 nm) video-rate imaging of surfaces and interfaces. This opens up the possibility of studying dynamic processes at surfaces, such as thin-film growth, strain relief, etching and adsorption, and phase transitions in real time, in situ, as they occur. The resulting video movies contain an unprecedented amount of information that is amenable to detailed, quantitative analysis. In this paper we discuss the principles of LEEM and its application to problems in science and technology.
Impact damage resistance of several laminated material systems

The impact damage resistance of several laminated materials systems (AS4/3501-6, IM7G/X8553-50, and A3705H/3501-6 graphite/epoxy, and wet layup glass/epoxy) was studied by conducting impact tests, measuring the force-time response, and determining the damage caused by different impactor velocities. Various laminate configurations were utilized to better understand the role of stacking sequence and fiber orientation. The results indicate that force is a key parameter in the assessment of impact damage resistance, particularly the force needed to cause incipient damage. Incipient damage is generally in the form of matrix cracks in laminates made from unidirectional tape. This is followed by delamination at the interface with the cracked ply. This damage mode does not change when the material system is changed, although the force at which the damage occurs is affected. Furthermore, ply angle does not change the damage modes that occur, although it does affect the extent of the damage. However, the form of the material, that is, fabric vs unidirectional ply, does affect the damage that occurs. By its woven nature, fabric naturally inhibits the formation of long matrix cracks. This also restricts the amount of delamination that occurs. This in turn results in fiber breaks occurring as the energy dissipated by delamination in other configurations must be dissipated by another mechanism, fiber breakage, in this case. A discussion of the results in terms of the assessment of damage resistance is provided. Needs to provide better understanding are identified.
Study of the behavior of MR fluids in squeeze, torsional and valve modes

In order to understand the effectiveness of MR fluids in some applications, such as bearings, this work focuses on the properties of MR fluids under squeeze mode, torsional mode and squeeze combined with torsional mode. A special device was designed and fabricated to perform these experiments, which were carried out on an Instron Multiaxial Testing Machine. The hysteresis loops of the MR fluids were studied for different intensities of electric current, frequency, strain amplitude and angle amplitude. The results showed that the damping force and the area of the hysteresis loop of MR fluids increase with the current and strain amplitude. Changes on the frequency did not influence the stress values significantly, within the range of frequencies used in these experiments. In order to evaluate the performance of a squeeze film damper (SFD), measurements were made using a MR damper manufactured by Lord Corporation (RD1005), which operates in valve mode. The results of the SFD were compared to the ones obtained with the RD1005 damper. The shape of the hysteresis loop curves and the MR effect were found to be different for the squeeze film damper and the RD1005 damper.
On the Filling Invariants at Infinity of Hadamard Manifolds

We study the filling invariants at infinity divk for Hadamard manifolds defined by Brady and Farb [ Trans. Am. Math. Soc. 350(8) (1998), 3393–3405]. Among other results, we give a positive answer to the question they posed: whether these invariants can be used to detect the rank of a symmetric space of noncompact type.
The Geometry of Barotropic Flow

In this paper we construct a new noninvariant Riemannian metric on the semidirect product of the diffeomorphism group of a manifold and the space of positive functions on that manifold, which has the property that certain geodesics give the equations of barotropic fluid mechanics. We compute a formula for its curvature, analyze the sign of the curvature, and determine directly the growth of Jacobi fields in a few special cases.
Fraunhofer Filters To Reduce Solar Background For Optical Communications

A wavelength that lies within a Fraunhofer line (a spectral interval of reduced solar emission) can carry optical communications in the atmosphere and space with reduced interference from direct or reflected background sunlight. Suitable Fraunhofer lines are located within the tuning range of good candidate laser sources. The laser should be tunable dynamically to track Doppler shifts in the sunlight incident on any solar system body that may appear in the background as viewed by the receiver, or in earthlight for ground-based daylight reception. The Fraunhofer filter used with a direct-detection receiver should be tuned to match the Doppler shifts of the source. The required tuning is calculated here for various situations. A typical Saturn-to-Earth data link can reduce its source power requirement from 8.8 W to 2 W of laser output by employing a Fraunhofer filter instead of a conventional multilayer dielectric filter.
The Persistence of the Radiation Excited in Mercury Vapor

A photographic method was used. Light from an intermittent mercury arc passed through a quartz cell containing Hg vapor at 40\ifmmode^\circ\else\textdegree\fi{} to 100\ifmmode^\circ\else\textdegree\fi{}C, and then together with the excited radiation through a hole in a rotating sector into a spectrograph. The sector was mounted on the shaft of the commutator which operated the arc. Thus for $\ensuremath{\lambda}2537$ a trace was obtained on the plate, whose length depended on the time of persistence of the radiation, the time scale being determined by the speed of rotation. Measurements of the blackening showed that the decay was exponential. The time to decrease to intensity $\frac{1}{e}$ came out 4.0\ifmmode\times\else\texttimes\fi{}${10}^{\ensuremath{-}5}$ and 6.8\ifmmode\times\else\texttimes\fi{}${10}^{\ensuremath{-}5}$ sec. for cells of length 1.6 and 3.2 cm respectively. For the arc alone in a tube of 0.9 cm radius the constant was 0.6\ifmmode\times\else\texttimes\fi{}${10}^{\ensuremath{-}5}$ sec, while for the arc at the center of a bulb of 3 cm radius the constant was 5.5\ifmmode\times\else\texttimes\fi{}${10}^{\ensuremath{-}5}$ sec, The decay was found to be independent of the vapor pressure from.006 to.27 mm for the cell and from.05 to 1.7 mm for the bulb. No persistence was observed when the cell did not contain distilling mercury or when it was sealed off from the pump. Fresh mercury seems to be necessary and also the absence of impurity. It is interesting to note that the time constants are of the order of magnitude of the times required for atoms at the temperatures involved to go without impact from the center to the wall of the cell.
Strategies of Product and Process Innovation: A Loglinear Analysis

Utterback and Abernathy (1975) developed a dynamic innovation model to explain the patterns of product and process innovation and to show which types of innovation would be most strategically appropriate for firms with particular objectives. In this paper the relation-ships between type and/or source of innovation and a number of firm-characteristic variables are examined. Loglinear regression is employed to determine the extent of the postulated relationships in a set of actual industry data on product innovation. The loglinear model provided results which were highly consistent with predictions made on the basis of previous research into product and process innovation.
The Search for Stellar Companions to Exoplanet Host Stars Using the CHARA Array

Most exoplanets have been discovered via radial velocity studies, which are inherently insensitive to orbital inclination. Interferometric observations will show evidence of a stellar companion if it is sufficiently bright, regardless of the inclination. Using the CHARA Array, we observed 22 exoplanet host stars to search for stellar companions in low-inclination orbits that may be masquerading as planetary systems. While no definitive stellar companions were discovered, it was possible to rule out certain secondary spectral types for each exoplanet system observed by studying the errors in the diameter fit to calibrated visibilities and by searching for separated fringe packets.
Curvilinearly T-Stiffened Panel-Optimization Framework Under Multiple Load Cases Using Parallel Processing

Future aerospace vehicles like hybrid wing/body, truss-braced wing, and “double bubble” would have pressurized noncircular fuselage structures and complex wing geometry. Traditional aircraft designs have led to the confidence and experience of designing such structures using the knowledge base built over the years and the resulting rules of thumb. However, there is a lack of experience of load calculations and design of complex, multifunctional, aircraft structural concepts for future aerospace vehicles. Designing such structures will require a physics-based optimization framework. Therefore, a new optimization framework, EBF3PanelOpt, is being developed. Commercial software MD-PATRAN (geometry modeling and mesh generation) and MD-NASTRAN (finite-element analysis) are integrated in EBF3PanelOpt framework using the Python programming environment to design stiffened panels with curvilinear stiffeners. Currently, EBF3PanelOpt optimizes the stiffened panel with curvilinear blade stiffeners, where the loads ar...
A REGION VOID OF IRREGULAR SATELLITES AROUND JUPITER

An interesting feature of the giant planets of our solar system is the existence of regions around these objects where no irregular satellites are observed. Surveys have shown that, around Jupiter, such a region extends from the outermost regular satellite Callisto to the vicinity of Themisto, the innermost irregular satellite. To understand the reason for the existence of such a satellite-void region, we have studied the dynamical evolution of Jovian irregulars by numerically integrating the orbits of several hundred test particles, distributed in a region between 30 and 80 Jupiter-radii, for different values of their semimajor axes, orbital eccentricities, and inclinations. As expected, our simulations indicate that objects in or close to the influence zones of the Galilean satellites become unstable because of interactions with Ganymede and Callisto. However, these perturbations cannot account for the lack of irregular satellites in the entire region between Callisto and Themisto. It is suggested that at distances between 60 and 80 Jupiter-radii, Ganymede and Callisto may have long-term perturbative effects, which may require the integrations to be extended to times much longer than 10 Myr. The interactions of irregular satellites with protosatellites of Jupiter at the time of the formation of Jovian regulars may also be a destabilizing mechanism in this region. We present the results of our numerical simulations and discuss their applicability to similar satellite void-regions around other giant planets.
Solar filaments as tracers of subsurface processes

Solar filaments are discussed in terms of two contrasting paradigms. The standard paradigm is that filaments are formed by condensation of coronal plasma into magnetic fields that are twisted or dimpled as a consequence of motions of the fields&#x2019; sources in the photosphere. According to a new paradigm, filaments form in rising, twisted flux ropes and are a necessary intermediate stage in the transfer to interplanetary space of dynamo-generated magnetic flux. It is argued that the accumulation of magnetic helicity in filaments and their coronal surroundings leads to filament eruptions and coronal mass ejections. These ejections relieve the Sun of the flux generated by the dynamo and make way for the flux of the next cycle.
Chemical Redox Agents for Organometallic Chemistry

1. Advantages of Chemical Redox Agents 878 2. Disadvantages of Chemical Redox Agents 879 C. Potentials in Nonaqueous Solvents 879 D. Reversible vs Irreversible ET Reagents 879 E. Categorization of Reagent Strength 881 II. Oxidants 881 A. Inorganic 881 1. Metal and Metal Complex Oxidants 881 2. Main Group Oxidants 887 B. Organic 891 1. Radical Cations 891 2. Carbocations 893 3. Cyanocarbons and Related Electron-Rich Compounds 894
Weak bisimilarity and regularity of context-free processes is EXPTIME-hard

We show that checking weak bisimulation equivalence of two context-free processes (also called BPA-processes) is EXPTIME-hard, even under the condition that the processes are normed. Furthermore, checking weak regularity (finiteness up to weak bisimilarity) for context-free processes is EXPTIME-hard as well. Adding a finite control of the minimal non-trivial size of 2 to the BPA process already makes weak bisimilarity undecidable.
Convergent Synthesis of Stereodefined exo-Alkylidene-γ-Lactams from β-Halo Allylic Alcohols

A convergent process for the assembly of stereodefined mono- and bicyclic exo-alkylidene-γ-lactams is described that proceeds through the union of β-halo allylic alcohols, aromatic imines, and CO. Overall, regio- and stereoselective Ti-mediated reductive cross-coupling, followed by Pd-catalyzed carbonylation, can be performed in a one- or two-pot procedure, defining a highly selective three-component coupling process for heterocycle synthesis.
HEDGING INFLATION AND INCOME RISKS

This paper describes markets for long-term inflation risk and shows the relationship such markets would have to other potential new markets, markets for long-term claims on income aggregates. The paper presents advantages of indexed long-term bonds and advocates as well the establishment of markets for long-term futures in a consumer price index. The potential use for such long-term inflation risk markets is put into perspective here by comparing the long-term risks to the real value of nominal claims to the long-term risks to national products and dividend incomes using data on fifty-four countries for 1950-90. Copyright 1995 by Blackwell Publishers Ltd and The Victoria University of Manchester
Spectra of Regular Quantum Graphs

We consider a class of simple quasi-one-dimensional classically nonintegrable systems that capture the essence of the periodic orbit structure of general hyperbolic nonintegrable dynamical systems. Their behavior is sufficiently simple to allow a detailed investigation of both classical and quantum regimes. Despite their classical chaoticity, these systems exhibit a “nonintegrable analogue” of the Einstein-Brillouin-Keller quantization formula that provides their spectra explicitly, state by state, by means of convergent periodic orbit expansions.