cssi/SciSciGPT-SciSciNet huggingface dataset:
Thermal conductivity enhancement of solid-solid phase-change materials for thermal storage

0.6 Nc = 4.0 Frankel, J. I., and Wang, 1\ P., "Radiative Exchange Between Gray Fins Using a Coupled Integral Equation Formulation," Journal of Thermophysics and Heat Transfer, Vol. 2, No. 4, Oct. 1988, pp. 296-302. Frankel, J. I., "Green's Function Solution to Heat Transfer of a Transparent Gas through a Tube," Numerical Heat Transfer, Part B, No. 2, 1989, pp. 231-244. Frankel, J. I., NASA-Marshall Spaceflight Center, Progress Rept. NAG8-109, Jan. 12, 1988. Stakgold, I., Green's Functions and Boundary Value Problems, Wiley, New York, 1979, pp. 86-184.
Use of a combined analog-digital system for re-entry vehicle flight simulation

Simulation of the re-entry phase of space flight for a vehicle on a satellite or lunar mission is being done at General Dynamics/Astronautics on its combined analog-digital system. Vehicle dynamics are simulated in real time on a large general-purpose analog computer, while an on-board digital guidance computer is simulated by digital program on a high-speed digital computer. An unusual feature of the closed loop operation is the facility for breaking the loop and inserting a pilot with manual over-ride capabilities. Problems of computer system control, check-out procedures, synchronization, sources of error, and results of the simulation are presented.
Applications of rule-base coverage measures to expert system evaluation

Often a rule-based system is tested by checking its performance on a number of test cases with known solutions, modifying the system until it gives the correct results for all or a sufficiently high proportion of the test cases. This method cannot guarantee that the rule-base has been adequately or completely covered during the testing process. We introduce an approach to testing of rule-based systems, which uses coverage measures to guide and evaluate the testing process. In addition, the coverage measures can be used to assist rule-base pruning and identification of class dependencies, and serve as the foundation for a set of test data selection heuristics. We also introduce a complexity metric for rule-bases.
Detecting the Dusty Debris of Terrestrial Planet Formation

We use a multiannulus accretion code to investigate debris disks in the terrestrial zone at 0.7-1.3 AU around a 1 M☉ star. Terrestrial planet formation produces a bright dusty ring of debris with a lifetime of 106 yr. The early phases of terrestrial planet formation are observable with current facilities; the late stages require more advanced instruments with adaptive optics.
Deep convolutional networks for pancreas segmentation in CT imaging

Automatic organ segmentation is an important prerequisite for many computer-aided diagnosis systems. The high anatomical variability of organs in the abdomen, such as the pancreas, prevents many segmentation methods from achieving high accuracies when compared to state-of-the-art segmentation of organs like the liver, heart or kidneys. Recently, the availability of large annotated training sets and the accessibility of affordable parallel computing resources via GPUs have made it feasible for "deep learning" methods such as convolutional networks (ConvNets) to succeed in image classification tasks. These methods have the advantage that used classification features are trained directly from the imaging data. We present a fully-automated bottom-up method for pancreas segmentation in computed tomography (CT) images of the abdomen. The method is based on hierarchical coarse-to-fine classification of local image regions (superpixels). Superpixels are extracted from the abdominal region using Simple Linear Iterative Clustering (SLIC). An initial probability response map is generated, using patch-level confidences and a two-level cascade of random forest classifiers, from which superpixel regions with probabilities larger 0.5 are retained. These retained superpixels serve as a highly sensitive initial input of the pancreas and its surroundings to a ConvNet that samples a bounding box around each superpixel at different scales (and random non-rigid deformations at training time) in order to assign a more distinct probability of each superpixel region being pancreas or not. We evaluate our method on CT images of 82 patients (60 for training, 2 for validation, and 20 for testing). Using ConvNets we achieve maximum Dice scores of an average 68% ± 10% (range, 43-80%) in testing. This shows promise for accurate pancreas segmentation, using a deep learning approach and compares favorably to state-of-the-art methods.
Solar neutrino oscillations

The special properties of solar neutrinos that render this flux so uniquely important in searches for neutrino masses and flavor mixing are reviewed. The effects of matter, including density fluctuations and turbulence, on solar neutrino oscillations are explained through analogies with more familiar atomic physics phenomena.
Structure theorems for embedded disks with mean curvature bounded in $L^p$

After appropriate normalizations an embedded disk whose second fundamental form has large norm contains a multi-valued graph, provided the L^P norm of the mean curvature is sufficiently small. This generalizes to non-minimal surfaces a well known result of Colding and Minicozzi.
Vacuum vertices and the ghost-dilaton

Abstract We complete the proof of the ghost-dilaton theorem in string theory by showing that the coupling constant dependence of the vacuum vertices appearing in the closed string action is given correctly by one-point functions of the ghost-dilaton. To prove this at genus one we develop the formalism required to evaluate off-shell amplitudes on tori.
A DIRECT LITHIATION ROUTE TO 2-ACYL-1-(PHENYLSULFONYL)INDOLES

ABSTRACT 2-Acyl-1-(phenylsulfonyl)indoles (3, 7–9) are prepared in 75–84% yield from 1-(phenylsulfonyl)indoles (1, 5) in one operation by treatment of the latter with s-butyllithium followed by inverse quenching of the C-2 lithioindoles with carboxylic acid anhydrides (6).
QUANTUM MECHANICS AND FIELD THEORY WITH MOMENTUM DEFINED ON AN ANTI-DE SITTER SPACE

Relativistic dynamics with energy and momentum restricted to an anti-de Sitter space is presented. Coordinate operators conjugate to such momenta are introduced. Definition of functions of these operators, their differentiation and integration, all necessary for the development of dynamics is presented. The resulting algebra differs from the standard Heisenberg one, notably in that the space–time coordinates do not commute among each other. The resulting time variable is discrete and the limit to continuous time presents difficulties. A parallel approach, in which an overlap function, between position and momentum states, is obtained from solutions of wave equations on this curved space are also investigated. This approach, likewise, has problems in the that high energy behavior of these overlap functions precludes a space–time definition of action functionals.
Tidal Effects in Clusters of Galaxies

High-redshift clusters of galaxies show an overabundance of spirals by a factor of 2-3 and the corresponding underabundance of S0 galaxies, relative to the nearby clusters. This morphological evolution can be explained by tidal interactions with neighboring galaxies and with the hierarchically growing cluster halo. The efficiency of tidal interactions depends on the size and structure of the cluster, as well as on the epoch of its formation. I simulate the formation and evolution of Virgo-type clusters in three cosmologies: a critical density model Ω0 = 1, an open model Ω0 = 0.4, and a flat model Ω0 = 0.4 with a cosmological constant. The orbits of identified halos are traced with a high temporal resolution (~107 yr). Halos with low relative velocities merge only shortly after entering the cluster; after virialization mergers are suppressed. The dynamical evolution of galaxies is determined by the tidal field along their trajectories. The maxima of the tidal force do not always correspond to closest approach to the cluster center. They are produced to a large extent by the local density structures, such as the massive galaxies and the unvirialized remnants of infalling groups of galaxies. Collisions of galaxies are intensified by the substructure, with about 10 encounters within 10 kpc per galaxy in the Hubble time. These very close encounters add an important amount (10%-50%) of the total heating rate. The integrated effect of tidal interactions is insufficient to transform a spiral galaxy into an elliptical but can produce an S0 galaxy. Overall, tidal heating is stronger in the low-Ω0 clusters.
The IRAS 1 Jy Survey of Ultraluminous Infrared Galaxies. I. The Sample and Luminosity Function

A complete flux-limited sample of 118 ultraluminous infrared galaxies (ULIGs) has been identified from the IRAS Faint Source Catalog (FSC). The selection criteria were a 60 ?m flux density greater than 1 Jy in a region of the sky ? > -40?, |b| > 30?. All sources were subsequently reprocessed using co-added IRAS maps in order to obtain the best available flux estimates in all four IRAS wavelength bands. The maximum observed infrared luminosity is Lir = 1012.90 L?, and the maximum redshift is z = 0.268. The luminosity function for ULIGs over the decade luminosity range Lir = 1012-1013 L? can be approximated by a power law ?(L) L-2.35[Mpc-3 mag-1]. In the local universe (z 0.1), the space density of ULIGs appears to be comparable to or slightly larger than that of optically selected QSOs at comparable bolometric luminosities. A maximum likelihood test suggests strong evolution for our sample; assuming density evolution proportional to (1 + z)? we find ? = 7.6 ? 3.2. Examination of the two-point correlation function shows a barely significant level of clustering, ?(r) = 1.6 ? 1.2, on size scales r ~ 22 h-1 Mpc.
Extensive air showers and accelerator data — the NEEDS workshop

Abstract Very high energy cosmic rays are typically studied by measuring extensive air showers formed by secondary particles produced in collisions with air nuclei. The indirect character of the measurement makes the physics interpretation of cosmic ray data strongly dependent on simulations of multiparticle production in showers. In April 2002 about 50 physicists met in Karlsruhe to discuss various aspects of hadronic multiparticle production with the aim of intensifying the interaction between high energy physics and cosmic ray groups. Current and upcoming possibilities at accelerators for measuring features of hadronic interactions of relevance to air showers were the focus of the workshop. This article is a review of the discussions and conclusions.
Pubovaginal Fascial Sling for the Treatment of all Types of Stress Urinary Incontinence: Surgical Technique and Long-term Outcome

This article provides an update on the surgical technique and long-term outcome of the full-length autologous rectus fascial sling in the treatment of women with sphincteric incontinence. The autologous fascial puovaginal sling remains the gold standard against which other surgeries for treating sphincteric incontinence should be compared. The authors have demonstrated that this procedure can be performed in a reproducible fashion with minimal morbidity.
Heterogeneous preferences and location choice with multi-product firms

Abstract We investigate whether the principle of minimum differentiation extends to location choices by multi-product firms of different sizes supplying differentiated goods to consumers with heterogeneous tastes. Our analysis allows for location equilibria to be asymmetric and compares multi-product equilibria with location configurations that would arise if each outlet were operated by a single-product firm. Multi-product firms disperse their products if consumer heterogeneity is low or distance between markets is high. They adopt more dispersed locations than single-product firms to limit business stealing from their own outlets. Asymmetry is shown to characterize location configurations of both multi- and single-product firms.
The Freely Expanding Ring Test—A Test to Determine Material Strength at High Strain Rates

Essai de conception simple pour etudier le comportement de materiaux en grande deformation pour de grandes vitesses de deformation. Mode operatoire. Comparaison avec les donnees obtenues a la barre d'Hopkinson, par tests effectues sur des anneaux de cuivre desoxygene de qualite electronique
An anisotropic metamaterial leaky waveguide

We propose a leaky optical waveguide achieved with a uniaxially anisotropic metamaterial that supports both forward and backward leaky waves. The backward leaky nature is exploited in a sub-diffraction imaging system.
Modification of the Aerospace Environment by Large Space Vehicles

Space Shuttle-type transportation systems will be a source of repetitive modifications to the Earth's plasma environment due to the large amount of rocket exhaust that will be introduced on a routine basis into the ionosphere. The source of the perturbation lies in rapid ionospheric chemistry that leads to a large-scale "ionospheric hole." In this paper, it is shown that the number of ion-electron pairs removed due to rocket exhaust chemistry does not scale simply with the number of molecules contained in the plume. A perturbation source efficiency factor is defined to demonstrate how effects may be maximized or minimized depending on the rocket launch and/or orbital profile. Sample calculations are made for NASA's Space Shuttle and for the proposed heavy-lift launch vehicle envisioned for carrying solar power satellite components into low Earth orbit.
Structure of Abrikosov vortices in SU(2) lattice gauge theory

Abstract We calculate the electric flux and magnetic monopole current distribution in the presence of a static quark-antiquark pair of SU(2) lattice gauge theory in the maximal Abelian gauge. The current distribution confines the flux in a dual Abrikosov vortex whose core size is comparable to the flux penetration depth. The observed structure is described by a dual Ginzburg-Landau model.
Evolution of O Abundance Relative to Fe

We present a three-component mixing model for the evolution of O abundance relative to Fe, taking into account the contributions of the first very massive stars (with masses of ≳100 M_☉) formed from Big Bang debris. We show that the observations of O and Fe abundances in metal-poor stars in the Galaxy by Israelian et al. in 1998 and by Boesgaard et al. in 1999 can be well represented both qualitatively and quantitatively by this model. We use the representation of the number ratios (O/Fe) versus 1/(Fe/H). In this representation, if there is only a single source with a fixed production ratio of O to Fe beyond a certain point, the subsequent evolution of (O/Fe) is along a straight line segment. Under the assumption of an initial Fe ([Fe/H] ~ -3) and O inventory caused by the prompt production by the first very massive stars, the data of Israelian et al. and Boesgaard et al. at -3≾[Fe/H]≾-1 are interpreted to result from the addition of O and Fe only from Type II supernovae (SNII) to the prompt inventory. At [Fe/H] ≳-1, SNII still contribute O while both SNII and Type Ia supernovae contribute Fe. During this later stage, (O/Fe) sharply drops off to an asymptotic value of ~0.8 (O/Fe)_☉. The value of (O/Fe) for the prompt inventory at [Fe/H] ~ -3 is found to be (O/Fe) ~ 20 (O/Fe)_☉. This result suggests that protogalaxies with low "metallicities" should exhibit high values of (O/Fe). The C/O ratio produced by the first very massive stars is expected to be « 1 so that all the C should be tied up as CO and that C dust and hydrocarbon compounds should be quite rare at epochs corresponding to [Fe/H] ≾ -3.
Public Provision and Protection of Natural Resources: Groundwater Irrigation in Rural India

This paper evaluates the effects of a public groundwater provision program on water tables in Northern India. I theorize that public provision leads to sustainable use of groundwater when the fixed costs for private well provision are high. I use village-level longitudinal data on aquifers and wells, and exploit the physical and technological limitations of surface pumps that generate a cost difference at a specific water depth to test this model. My findings suggest that public provision can be used as an alternative in scenarios where prohibitive monitoring costs might preclude the use of other regulatory approaches to prevent over-extraction. (JEL O13, O18, Q15, Q25, Q28, Q53, Q58)
Composable communication constraint-based control

We describe a framework for multi-vehicle control which explicitly incorporates the state of the communication network and the constraints imposed by specifications on the quality of the communications links available to each robot. In a multi-robot adhoc setting, the need for guaranteed communications is essential for cooperative behavior. We propose a control methodology that ensures local connectivity in multi-robot navigation. Specifically, given an initial and final configuration of robots in which the quality of each communication link is above some specified threshold, we synthesize controllers that guarantee each robot goes to its goal destination while maintaining the quality of the communication links above the given threshold. For the sake of simplicity, we assume each robot has a pre-assigned "base unit" with which the robot tries to maintain connectivity while performing the assigned task. The proposed control methodology allows the robot's velocity to align with the tangent of a critical communication surface such that it might be possible for the robot to move on the surface. No assumptions are made regarding the critical surface, which might be arbitrarily complex for cluttered urban environments. The stability of such technique is shown and three-dimensional simulations with a small team of robots are presented. The paper demonstrates the performance of the control scheme in various three-dimensional settings with proofs of guarantees in simple scenarios.
Jetmax: Scalable max-min congestion control for high-speed heterogeneous networks

Recent surge of interest towards congestion control that relies on single-link feedback (e.g., XCP, RCP, MaxNet, EMKC, VCP), suggests that such systems may offer certain benefits over traditional models of additive packet loss. Besides topology-independent stability and faster convergence to efficiency/fairness, it was recently shown that any stable single-link system with a symmetric Jacobian tolerates arbitrary fixed, as well as time-varying, feedback delays. Although delay-independence is an appealing characteristic, the EMKC system developed in exhibits undesirable equilibrium properties and slow convergence behavior. To overcome these drawbacks, we propose a new method called JetMax and show that it admits a low-overhead implementation inside routers (three additions per packet), overshoot-free transient and steady state, tunable link utilization, and delay-insensitive flow dynamics. The proposed framework also provides capacity-independent convergence time, where fairness and utilization are reached in the same number of RTT steps for a link of any bandwidth. Given a 1mb/s, 10gb/s, or googol (10^1^0^0) bps link, the method converges to within 1% of the stationary state in six RTTs. We finish the paper by comparing JetMax's performance to that of existing methods in ns2 simulations and discussing its Linux implementation.
Optimal Computation of Symmetric Boolean Functions in Collocated Networks

We consider collocated wireless sensor networks, where each node's transmissions can be heard by every other node. Each node has a Boolean measurement and the goal of the network is to compute a given Boolean function of these measurements. We first consider the worst case setting and study optimal block computation strategies for computing symmetric Boolean functions. We study three classes of functions: threshold functions, delta functions and interval functions. We provide optimal strategies for the first two classes, and a scaling law order-optimal strategy with optimal preconstant for interval functions. We extend the results to the case of integer measurements and certain integer-valued functions. Next, we address the problem of minimizing the expected total number of bits that are transmitted when node measurements are random and drawn from independent Bernoulli distributions. In the case of computing a single instance of a Boolean threshold function, the problem reduces to one of determining the optimal order in which the nodes should transmit. We show that the optimal order of transmissions depends in an extremely simple way on the values of previously transmitted bits and the ordering of the marginal probabilities of the Boolean variables according to the k-th least likely rule: At any transmission, the node that transmits is the one that has the k-th least likely value of its Boolean variable, where k reduces by one whenever a node transmits a one. Initially the value of k is (n +1 - Threshold). Interestingly, the order of transmissions does not depend on the exact values of the probabilities of the Boolean variables. In the case of identically distributed measurements, we further show that the average-case complexity of block computation of a Boolean threshold function is O(θ), where θ is the threshold. We further show how to generalize to a pulse model of communication. One can also consider the related problem of approximate computation given a fixed number of bits. For the special case of the parity function, we show that the greedy strategy is optimal.
Interactive Multimedia-Based E-Learning: A Study of Effectiveness

The author conducted two experiments to assess effectiveness of interactive e-learning. Students in a fully interactive multimedia-based e-learning environment achieved better performance and higher levels of satisfaction than those in a traditional classroom and those in a less interactive e-learning environment.
Nanosatellites for earth environmental monitoring: The MicroMAS project

The Micro-sized Microwave Atmospheric Satellite (MicroMAS) is a 3U cubesat (34×10×10 cm, 4.5 kg) hosting a passive microwave spectrometer operating near the 118.75-GHz oxygen absorption line. The focus of the first MicroMAS mission (hereafter, MicroMAS-1) is to observe convective thunderstorms, tropical cyclones, and hurricanes from a near-equatorial orbit at approximately 500-km altitude. A MicroMAS flight unit is currently being developed in anticipation of a 2014 launch. A parabolic reflector is mechanically rotated as the spacecraft orbits the earth, thus directing a cross-track scanned beam with FWHM beamwidth of 2.4-degrees, yielding an approximately 20-km diameter footprint at nadir incidence from a nominal altitude of 500 km. Radiometric calibration is carried out using observations of cold space, the earth's limb, and an internal noise diode that is weakly coupled through the RF front-end electronics. A key technology feature is the development of an ultra-compact intermediate frequency processor module for channelization, detection, and A-to-D conversion. The antenna system and RF front-end electronics are highly integrated and miniaturized. A MicroMAS-2 mission is currently being planned using a multi-band spectrometer operating near 118 and 183 GHz in a sun-synchronous orbit of approximately 800-km altitude. A HyMAS-1 (Hyperspectral Microwave Atmospheric Satellite) mission with approximately 50 channels near 118 and 183 GHz is also being planned. In this paper, the mission concept of operations will be discussed, the radiometer payload will be described, and the spacecraft subsystems (avionics, power, communications, attitude determination and control, and mechanical structures) will be summarized.
Congenital cytomegalovirus infection and disease

Almost 100 years after its initial description, congenital cytomegalovirus infection remains common, and the disease continues to leave thousands of infants with permanent developmental disabilities, including vision and hearing loss, cognitive delays, and motor abnormalities. This article reviews current knowledge about the epidemiology, clinical characteristics, diagnosis, management, and prevention of congenital cytomegalovirus infection and disease.
Dimethyldioxirane epoxidation of polycyclic fluoranthene hydrocarbons.

Direct epoxidation of polycyclic fluoranthenes with dimethyldioxirane provides several new mono- and di-oxide derivatives.
Star Formation in the Radio Galaxy NGC 4410A

The NGC 4410 group of galaxies provides us with a rare opportunity to study a nearby (97 h Mpc) example of a radio galaxy (NGC 4410A) embedded in an extended X-ray source, with evidence for star formation that can be readily spatially distinguished from regions dominated by the active galactic nucleus and shocks. We present broadband and narrowband optical images, along with optical and IUE ultraviolet spectroscopy, for the radio galaxy NGC 4410A and its companion, NGC 4410B. Our Hα + [N II] images reveal six luminous H II regions (LHα ~ 1040 ergs s-1) distributed in an arc near NGC 4410A. Partially completing the ring is a prominent stellar loop containing diffuse ionized gas. This filamentary gas, in contrast to the H II regions, shows spectroscopic signatures of shock ionization. The star formation in this system may have been triggered by a collision or interaction between the two galaxies, perhaps by an expanding density wave, as in classical models of ring galaxies. Alternatively, the star formation may have been induced by the impact of a radio jet on the interstellar matter. Extended Lyα is detected in the ultraviolet IUE spectrum. The ultraviolet continuum, which is presumably radiated by the nucleus of NGC 4410A, is not extended. NGC 4410A appears to be interacting with its neighbors in the NGC 4410 group and could be an example of a spiral galaxy transforming into an elliptical.
On braid words and irreflexivity

A left-distributive algebra is a set B equipped with a binary operation (here written as concatenation) such that a(bc) = (ab)(ac) for all a, b, c ∈ B. The free left-distributive algebra on n letters is denoted An, and we write A for A1 If P,Q ∈ B write P <L Q iff one can write P as a strict prefix of Q, i.e., Q = ((PQ1) . . .)Qk for some Q1, . . . , Qk, k ≥ 1. Then a proof that <L is irreflexive (that is, that P 6= ((PQ1) . . .)Qk for all P,Q1, . . . , Qk ∈ A) on A was found by R. Laver ([Lav 92]), under large cardinal assumptions, as part of a theorem that A is isomorphic to a certain algebra of elementary embeddings from set theory. It was also proved in [Lav 92] that <L linearly orders A, the part that for all P,Q ∈ A at least one of P <L Q,P = Q,Q <L P holds being proved independently and by a different method by P. Dehornoy ([Deh 89a, Deh 89b]). The linear ordering of A gives left cancellation, the solvability of the word problem, and other consequences. Left open was whether irreflexivity, and hence the linear ordering, can be proved in ZFC. Recently, Dehornoy ([Deh 92]) has found such a proof, involving an extension of the infinite braid group but without invoking axioms extending ZFC. The purpose of this note is to prove the result without the additional machinery of this extended group, and at shorter length.
Analytic and Reidemeister torsion for representations in finite type Hilbert modules

For a closed Riemannian manifold (M, g) we extend the definition of analytic and Reidemeister torsion associated to a unitary representation of π1 (M) on a finite dimensional vector space to a representation on aA-Hilbert moduleW of finite type whereA is a finite von Neumann algebra. If (M,W) is of determinant class we prove, generalizing the Cheeger-Muller theorem, that the analytic and Reidemeister torsion are equal. In particular, this proves the conjecture that for closed Riemannian manifolds with positive Novikov-Shubin invariants, theL 2-analytic andL 2-Reidemeister torsions are equal.
Clinicians as effective researchers

Abstract This article addresses the commonly asked question—Can clinicians—be effective researchers? The author draws on historical discoveries by inquisitive physicians and his own experience which involved extensive clinical research in various aspects of pulmonary medicine in USA and his more recent experience of overseeing the development of research at King Fahd Medical City in Riyadh, a major tertiary care center in Saudi Arabia. From this experience the author draws some conclusions as to the key ingredients required for successful research, which include—the inquisitiveness, patience, perseverance on the part of the clinician––along with a nurturing and supportive environment, with appropriate institutional financial, emotional and administrative support. The importance of collaboration and finally the need for appropriate data collection and following the Belmont principles need to be emphasized. The author strongly believes that the answer to the question: Can Clinicians be effective researchers is a most definitive yes.
How today’s college students use Wikipedia for course-related research

Findings are reported from student focus groups and a large-scale survey about how and why students (enrolled at six different U.S. colleges) use Wikipedia during the course-related research process. A majority of respondents frequently used Wikipedia for background information, but less often than they used other common resources, such as course readings and Google. Architecture, engineering, and science majors were more likely to use Wikipedia for course-related research than respondents in other majors. The findings suggest Wikipedia is used in combination with other information resources. Wikipedia meets the needs of college students because it offers a mixture of coverage, currency, convenience, and comprehensibility in a world where credibility is less of a given or an expectation from today’s students.
Experimental Study of a Self-Pumping Boiling Collector Solar Hot Water System

Results of an experimental study of a full-scale passive solar hot water heating system utilizing a boiling collector are presented. The self-pumping system alternates between two modes of operation. During the run cycle, vapor pressure drives the evaporated refrigerant downward from the collector to the condenser. Once a present quantity of refrigerant is condensed, vapor pressure is again used to force the return of the condensate to the collector during the pump cycle. In order to assess the thermal penalty of self-pumping operation, the system is also operated with a mechanical pump. Daily operating characteristics and seasonal performance are discussed. Performance of the self-pumping system is strongly influenced by the duration of the pump cycle.
Particle flux measurements with pump limiters

Abstract The pressure buildup in pump limiters is a function of the incident particle flux, the pump limiter geometry, particle-surface interactions, and effects due to interactions of the neutral gas with the incoming plasma. At sufficiently low density and for a short pump limiter throat, the pressure observed in the pump limiter chamber is a direct measure of the particle flux at the limiter slot. This paper discusses a simple model for the correlation between particle flux and pump limiter pressure in ISX-B. In addition, some estimates are presented on the thermalizaton of fast neutrals in the pump limiter duct and its implications for “enhanced particle collection.”.
Electron emission and ion desorption spectroscopy of clean and oxidized Ti(0001)

Abstract The electronic structure of Ti(0001) has been investigated by energy loss spectroscopy (ELS), Auger electron spectroscopy (AES), ultraviolet photoemission spectroscopy (UPS) using synchrotron radiation and electron stimulated desorption (ESD). Resonant electron emission due to a direct recombination process involving an atomic 3p-3d interaction has been observed. Surface oxidation results in the formation of a thin protective TiO2 layer which is stable to 250 ° C. In the oxide, the direct recombination process following 3p excitation gives rise to resonantly enhanced emission from the oxide valence band. The cross section for electron and photon stimulated O+ desorption is shown to be dominated by these atomic resonance effects as well.
Theory of photoinduced charge transfer in weakly coupled donor-acceptor conjugated polymers: application to an MEH-PPV: CN-PPV pair

Abstract In a pair of coupled donor-acceptor conjugated polymer chains, it is possible for an exciton photoexcited on either polymer to decay into a hole in the donor polymer's valence band and an electron in the conduction band of the acceptor polymer. We calculate the corresponding exciton decay rate and its dependence on inter-polymer distance. For a pair of derivatives of poly(phenylene vinylene), PPV, specifically poly[2-methoxy, 5-(2′-ethyl-hexyloxy)-1,4 PPV], MEH-PPV, and poly(2,5-hexyloxy p -phenylene cyanovinylene), CN-PPV, at a separation of 6 A the characteristic decay time is 2.2 ps, whereas at 4 A it is ∼ 50 fs.
Use of Hindered Silyl Ethers as Protecting Groups for the Non-aldol Aldol Process

[reaction: see text] Bulky epoxy bis-silyl ethers, e.g., 15, derived from 5-trialkylsilyloxy-2-alken-1-ols by epoxidation and silylation were treated with TMSOTf to afford non-aldol aldol rearrangement products, the 3,5-bis(silyloxy)alkanals, e.g., 16, with little to none of the corresponding tetrahydrofurans.
Policy requirements for inter Administrative Domain routing

The purpose of this memo is to focus discussion on particular problems in the Internet and possible methods of solution. No proposed solutions in this document are intended as standards for the Internet. Rather, it is hoped that a general consensus will emerge as to the appropriate solution to such problems, leading eventually to the development and adoption of standards.
When do differences matter? On-line feature extraction through cognitive economy

For an intelligent agent to be truly autonomous, it must be able to adapt its representation to the requirements of its task as it interacts with the world. Most current approaches to on-line feature extraction are ad hoc; in contrast, this paper derives principled criteria for representational adequacy by applying the psychological principle of cognitive economy to reinforcement learning. The criteria are principled because they are based on an analysis of the amount of reward the agent forfeits when it generalizes over states. This analysis shows that action-value errors are sometimes irrelevant, and that the agent may optimize its performance with limited cognitive resources by grouping together states whose differences do not matter in its task. The paper presents an algorithm based on this analysis, incorporating an active form of Q-learning and partitioning continuous state-spaces by merging and splitting Voronoi regions. The experiments illustrate a new methodology for testing and comparing representations by means of learning curves. Results from the puck-on-a-hill task demonstrate the algorithm's ability to learn effective representations, superior to those produced by some other, well-known, methods.
Synthesis of β-hydroxy sulfones via opening of hydrophilic epoxides with zinc sulfinates in aqueous media

Abstract Reaction of hydrophilic epoxides (ethylene oxide and propylene oxide) with readily accessible zinc sulfinates in aqueous solution under essentially neutral conditions afforded β-hydroxy sulfones in good yields. This method avoids the need for organic solvents and produces ZnO as the only major reaction byproduct. 2-(Methylsulfonyl)ethanol, a common reagent for the protection of various functional groups, was obtained by this methodology from ethylene oxide in 78% yield. Reaction of various simple zinc alkane- and benzenesulfinates with propylene oxide proceeded regioselectively in 63–67% yield. The corresponding opening of these epoxides with zinc 1,3-butadiene-1-sulfinate afforded 1-butadienyl β-hydroxyalkyl sulfones in 30% yield. Mechanistic studies revealed that the yields of these products were limited by their consumption in competing intra- and intermolecular Michael addition processes.
The 12-Hour Work Day: Differing Employee Reactions.

This field study examined the reactions of non-exempt employees (N=671) to utilizing a “compressed word schedule” (i.e., 12-hour shifts) for staffing a continuous process plant which operated 24-hours per day/seven days per week. The 12-hour shifts were fixed with shifts changing at noon and at midnight. Based upon previous research, it was hypothesized that employees who had actually worked the 12-hour schedule would be more positive towards it than would employees who had never worked it. This was found to be the case. For example, those who had worked the 12-hour schedule saw the compressed schedule as being less fatiguing, saving on commuting cost and time, providing a more regular sleep pattern, and providing more usable time off. A second hypothesis concerned only those working the 12-hour shift. It was hypothesized that those employees working the 12 PM to 12 AM shift would be “less out of phase” with physiological and social rhythms and, thus, react more positively to the 12-hour shift than employees working the 12 AM to 12 PM shift. This hypothesis was strongly supported.
Hydrothermal processing — An emerging technology

Abstract Hydrothermal processing involves the chemistry of hot water under pressure to carry out leaching and precipitation reactions. These reactions are usually conducted at temperatures ranging from 100 to 350°C and pressures in the range from a few to 3000 psig. The reaction medium may be water alone or in combination with inorganic and/or organic acids and bases. The chemistry of this technology permits selective dissolution (leaching) or selective precipitation of metal species to be achieved leading to potentially novel treatment methods using a wide variety of ores and raw materials to produce high quality inorganic products. Thus, hydrothermal technology offers alternate or new approaches which can be technically superior to conventional processing for producing a wide variety of high technology inorganic oxides for specific applications, recovery of valuable components from low grade ores, and converting waste material to marketable products. Furthermore, because of short reaction times, simplicity of the reactor and recycle of reagents, the application of hydrothermal technology frequently leads to processes which can be less energy intensive, less pollutant and/or less capital intensive. Hydrothermal technology has already been used in many successful commercial processes. Now, with the combination of feedstock shortages, rising energy costs, more restrictive pollution abatement regulations, inflationary pressures, need for higher quality products and a better understanding of the chemistry of hot water, this technology is emerging as a viable alternative to more conventional high temperature processing. The technology is expected to impact on several industrial areas, including primary and secondary ferrous and non-ferrous metals, ceramics, electronics, pigments, petroleum, utilities, refractories and inorganic chemicals.
Optimal Allocation of Interconnecting Links in Cyber-Physical Systems: Interdependence, Cascading Failures, and Robustness

We consider a cyber-physical system consisting of two interacting networks, i.e., a cyber network overlaying a physical network. It is envisioned that these systems are more vulnerable to attacks since node failures in one network may result in (due to the interdependence) failures in the other network, causing a cascade of failures that would potentially lead to the collapse of the entire infrastructure. The robustness of interdependent systems against this sort of catastrophic failure hinges heavily on the allocation of the (interconnecting) links that connect nodes in one network to nodes in the other network. In this paper, we characterize the optimum inter-link allocation strategy against random attacks in the case where the topology of each individual network is unknown. In particular, we analyze the “regular” allocation strategy that allots exactly the same number of bidirectional internetwork links to all nodes in the system. We show, both analytically and experimentally, that this strategy yields better performance (from a network resilience perspective) compared to all possible strategies, including strategies using random allocation, unidirectional interlinks, etc.
Enzymatic-isotopic micromethods for the measurement of biogenic amines in brain tissue and body fluids

Publisher Summary This chapter discusses enzymatic-isotopic micromethods for the measurement of biogenic amines in brain tissue and body fluids. Several enzymatic isotopic micromethods are now available. These methods are based on the incubation of the amines with methyltransferase enzymes together with the donor of radioactive methyl groups, S-adenosylmethionine. The radioactive methyl derivatives formed are then separated by means of solvent extraction and the radioactivity counted. The enzymatic-isotopic methods have several advantages: they are fairly simple to perform, relatively inexpensive, do not require sophisticated equipment, and are more sensitive than most of the other assays available today. About 50–100 assays can be done by one person in a day. These assays are potentially very useful to study the levels and metabolism of several biogenic amines in small areas of the brain.
A curious moment: the proposal to certify nurse anesthetists by the american board of anesthesiology

During the 1930s, many different practitioners gave anesthetics to patients. Qualifications were not necessary, and economics often drove the choice of anesthetic administrator. Both physicians and nurse specialists in anesthesia understood the need for specialty certification. For individual physicians, the American Board of Anesthesiology (ABA) was created as a sub-board of the American Board of Surgery (ABS) with the sanction of the American Medical Association and the American Society of Anesthetists. The nurse anesthetists worked toward program rather than individual certification. For one curious moment, the ABS asked the ABA to certify nurse anesthetists. Neither the nurses nor the physician anesthetists were overwhelmingly in favor of the proposal. However, had the proposal succeeded, the face of American anesthesiology would have been quite different.
Alternatives to antibiotics: bacteriocins, antimicrobial peptides and bacteriophages

Bacteriocins, antimicrobial peptides, and bacteriophage have attracted attention as potential substitutes for, or as additions to, currently used antimicrobial compounds. This publication will review research on the potential application of these alternative antimicrobial agents to poultry production and processing. Bacteriocins are proteinaceous compounds of bacterial origin that are lethal to bacteria other than the producing strain. It is assumed that some of the bacteria in the intestinal tract produce bacteriocins as a means to achieve a competitive advantage, and bacteriocin-producing bacteria might be a desirable part of competitive exclusion preparations. Purified or partially purified bacteriocins could be used as preservatives or for the reduction or elimination of certain pathogens. Currently only nisin, produced by certain strains of Lactococcus lactis subsp. lactis, has regulatory approval for use in certain foods, and its use for poultry products has been studied extensively. Exploration of the application of antimicrobial peptides from sources other than bacteria to poultry has not yet commenced to a significant extent. Evidence for the ability of chickens to produce such antimicrobial peptides has been provided, and it is likely that these peptides play an important role in the defense against various pathogens. Bacteriophages have received renewed attention as possible agents against infecting bacteria. Evidence from several trials indicates that phage therapy can be effective under certain circumstances. Numerous obstacles for the use of phage as antimicrobials for poultry or poultry products remain. Chiefly among them are the narrow host range of many phages, the issue of phage resistance, and the possibility of phage-mediated transfer of genetic material to bacterial hosts. Regulatory issues and the high cost of producing such alternative antimicrobial agents are also factors that might prevent application of these agents in the near future.
Stochastic Path Model of Polaroid Polarizer for Bell's Theorem and Triphoton Experiments

Depending on the outcome of the triphoton experiment now underway, it is possible that the new local realistic Markov Random Field (MRF) models will be the only models now available to correctly predict both that experiment and Bell's theorem experiments. The MRF models represent the experiments as graphs of discrete events over space-time. This paper extends the MRF approach to continuous time, by defining a new class of realistic model, the stochastic path model, and showing how it can be applied to ideal polaroid type polarizers in such experiments. The final section discusses possibilities for future research, ranging from uses in other experiments or novel quantum communication systems, to extensions involving stochastic paths in the space of functions over continuous space. As part of this, it derives a new Boltzmann-like density operator over Fock space, which predicts the emergent statistical equilibria of nonlinear Hamiltonian field theories, based on our previous work of extending the Glauber–Sudarshan P mapping from the case of classical systems described by a complex state variable α to the case of classical continuous fields. This extension may explain the stochastic aspects of quantum theory as the emergent outcome of nonlinear PDE in a time-symmetric universe.
Trajectory, Development, and Temperature of Spark Kernels Exiting into Quiescent Air

Measurements of the trajectory, temporal development, and temperature of spark kernels are needed for understanding the ignition process in spark ignition and gas turbine engines. Motivated by this, an infrared camera was used to obtain narrowband radiation intensity measurements of spark kernels exiting into quiescent air. An inverse deconvolution technique was implemented to estimate the temperature and sensible energy of the kernels. This technique is evaluated by a sensitivity analysis and comparisons to measurements of a well characterized flame. Infrared images show that the kernels develop into a toroidal shape after exiting from the igniter. The statistical distribution of the spark kernel trajectory is symmetric. Buoyancy forces are negligible. Regions of high and low radiation intensity are observed in the kernels, indicating temperature gradients within the gases. The radiation intensity emitted by the kernels decreases by more than an order of magnitude after exiting the igniter. Average temperature values decrease by less than 30% over 2 cm of the spark trajectory. Over that same distance the sensible energy of the kernels decreases by 80%.
Complexity analysis of Reed-Solomon decoding over GF(2 m ) without using syndromes

There has been renewed interest in decoding Reed-Solomon (RS) codes without using syndromes recently. In this paper, we investigate the complexity of syndromeless decoding, and compare it to that of syndrome-based decoding. Aiming to provide guidelines to practical applications, our complexity analysis focuses on RS codes over characteristic-2 fields, for which some multiplicative FFT techniques are not applicable. Due to moderate block lengths of RS codes in practice, our analysis is complete, without big O notation. In addition to fast implementation using additive FFT techniques, we also consider direct implementation, which is still relevant for RS codes with moderate lengths. For high-rate RS codes, when compared to syndrome-based decoding algorithms, not only syndromeless decoding algorithms require more field operations regardless of implementation, but also decoder architectures based on their direct implementations have higher hardware costs and lower throughput. We also derive tighter bounds on the complexities of fast polynomial multiplications based on Cantor's approach and the fast extended Euclidean algorithm.