cssi/SciSciGPT-SciSciNet huggingface dataset:
A form verification system for the conceptual design of complex mechanical systems

This paper presents a summary of research into the development and implementation of a domain-independent, computer-based model for the conceptual design of complex mechanical systems [1]. The creation of such a design model includes the integration of four major concepts: (1) the use of a graphical display for visualizing the conceptual design attributes: (2) the proper representation of the complex data and diverse knowledge reguired to design the system; (3) the integration of quality design methods into the conceptual design: (4) the modeling of the conceptual design process as a mapping between functions and forms. Using the design of an automobile as a case study, a design environment was created which consisted of a distributed problem-solving paradigm and a parametric graphical display. The requirements of the design problem with respect to data representation and design processing were evaluated and a process model was specified. The resulting vehicle design system consists of a tight integration between a blackboard system and a parametric design system. The completed system allows a designer to view graphical representations of the candidate conceptual designs that the blackhoard system generates.
Bounded rationality, cognitive maps, and trial and error learning

Abstract The term “bounded rationality” is used here to connote the reasoning capabilities of an actor who, on the one hand, has a goal to achieve and an at least partially formed theory as to how to achieve it, and on the other hand, that the theory is somewhat crude, likely will be revised in the course of the effort, and that success is far from assured. This article presents a theory of how trial and error learning interact with theory modification in the course of problem solving under bounded rationality. The empirical focus is on efforts to advance a technology, especially medical practice, but the analysis is quite general. A central question explored is what makes progress in a field hard or easy.
Implementing Educational Innovations at Scale: Transforming Researchers Into Continuous Improvement Scientists

There is growing concern among researchers and governmental officials that knowing what works in education is important, but not enough for school improvement. Sound evidence alone is not sufficien...
Language directed computer design

It is an accident that digital computers are organized like desk calculators--with somewhat worse luck we might have taken the Turing machine as our model. And someone would have been unenlightened enough to prove that, under certain (actually untrue) assumptions, it made no difference. All general purpose machines can compute the same functions, given sufficient time.
Frontier Equity Markets: Risk Parity Lessons for Asset Allocation

Are frontier markets the next emerging markets? And if so, should global equity investors include them in their portfolios? From a risk parity perspective, investors can benefit from a frontier markets allocation well in excess of the market weight of the asset class. A risk parity portfolio tends to outperform a market-cap-weighted portfolio during periods of positive equity returns, while delivering comparable returns during crisis periods. Historical data shows that even if portfolio managers cannot follow a risk parity asset allocation strategy due to benchmark tracking considerations, overweighting frontier markets can help them outperform their benchmarks during upside periods without increasing downside risks significantly.
A Bayesian approach to calibrating period-luminosity relations of RR Lyrae stars in the mid-infrared

A Bayesian approach to calibrating period-luminosity (PL) relations has substantial benefits over generic least-squares fits. In particular, the Bayesian approach takes into account the full prior distribution of the model parameters, such as the a priori distances, and refits these parameters as part of the process of settling on the most highly-constrained final fit. Additionally, the Bayesian approach can naturally ingest data from multiple wavebands and simultaneously fit the parameters of PL relations for each waveband in a procedure that constrains the parameter posterior distributions so as to minimize the scatter of the final fits appropriately in all wavebands. Here we describe the generalized approach to Bayesian model fitting and then specialize to a detailed description of applying Bayesian linear model fitting to the mid-infrared PL relations of RR Lyrae variable stars. For this example application we quantify the improvement afforded by using a Bayesian model fit. We also compare distances previously predicted in our example application to recently published parallax distances measured with the Hubble Space Telescope and find their agreement to be a vindication of our methodology. Our intent with this article is to spread awareness of the benefits and applicability of this Bayesian approach and encourage future PL relation investigations to consider employing this powerful analysis method.
Rapid construction of the tetracyclic nucleus of cerorubenic acid-III by oxyanionic cope chemistry

Abstract Ketone 3 , produced directly by anionic oxy-Cope rearrangement of 4 , was crafted into silyloxydiene 8 , Diels-Alder condensation of which with methyl acrylate under high pressure permitted arrival at 2 , a tetracyclic precursor to cerorubenic acid-III.
Comparison of Test Results for Flat-Plate, Transpired Flat-Plate, Corrugated, and Transpired Corrugated Solar Air Heaters

Five selective-black-metal-plate experimental air heaters with and without transpiration were designed, fabricated, and tested to compare their technical merits. All were 61 cm x 61 cm (2ft x 2ft), double-glazed with low-iron glass, and those with transpiration contained an additional Teflon film to form a plenum above the absorber plate. The configurations were a reference collector with flow on back only, a transpired slotted plate, a transpired micro-perforated plate, a corrugated plate with flow on back, and a transpired slotted corrugated plate. The results show the magnitude of technical improvement that can be obtained through the slotting, perforating, and corrugating strategems.
Coherent vector meson production in ultra-peripheral heavy-ion collisions at STAR

We report the first observation of coherent rho0 production (AuAu->AuAu rho0) and rho0 production accompanied by mutual nuclear Coulomb excitation (AuAu->Au*Au*rho0),and the observation of coherent e+e- pair production (AuAu->Au*Au*e+e-) in ultra-peripheral relativistic heavy-ion collisions (UPCs). We give transverse momentum, mass, and rapidity distributions. The cross sections for coherent rho0 production at sqrt{s_NN}=130 and 200 GeV are in agreement with theoretical predictions, which treat rho^0 production and nuclear excitation as independent processes.
Diffusion tensor imaging of deep gray matter brain structures: Effects of age and iron concentration

Diffusion tensor imaging (DTI) of the brain has become a mainstay in the study of normal aging of white matter, and only recently has attention turned to the use of DTI to examine aging effects in gray matter structures. Of the many changes in the brain that occur with advancing age is increased presence of iron, notable in selective deep gray matter structures. In vivo detection and measurement of iron deposition is possible with magnetic resonance imaging (MRI) because of iron's effect on signal intensity. In the process of a DTI study, a series of diffusion-weighted images (DWI) is collected, and while not normally considered as a major dependent variable in research studies, they are used clinically and they reveal striking conspicuity of the globus pallidus and putamen caused by signal loss in these structures, presumably due to iron accumulation with age. These iron deposits may in turn influence DTI metrics, especially of deep gray matter structures. The combined imaging modality approach has not been previously used in the study of normal aging. The present study used legacy DTI data collected in 10 younger (22-37 years) and 10 older (65-79 years) men and women at 3.0T and fast spin-echo (FSE) data collected at 1.5T and 3.0T to derive an estimate of the field-dependent relaxation rate increase (the "FDRI estimate") in the putamen, caudate nucleus, globus pallidus, thalamus, and a frontal white matter sample comparison region. The effect of age on the diffusion measures in the deep gray matter structures was distinctly different from that reported in white matter. In contrast to lower anisotropy and higher diffusivity typical in white matter of older relative to younger adults observed with DTI, both anisotropy and diffusivity were higher in the older than younger group in the caudate nucleus and putamen; the thalamus showed little effect of age on anisotropy or diffusivity. Signal intensity measured with DWI was lower in the putamen of elderly than young adults, whereas the opposite was observed for the white matter region and thalamus. As a retrospective study based on legacy data, the FDRI estimates were based on FSE sequences, which underestimated the classical FDRI index of brain iron. Nonetheless, the differential effects of age on DTI metrics in subcortical gray matter structures compared with white matter tracts appears to be related, at least in part, to local iron content, which in the elderly of the present study was prominent in the FDRI estimate of the putamen and visibly striking in the diffusion-weighted image of the basal ganglia structures.
A simple volcano potential with an analytic, zero-energy, ground state

Abstract We describe a simple volcano potential, which is supersymmetric and has an analytic, zero-energy, ground state. (The KK modes are also analytic.) It is an interior harmonic oscillator potential properly matched to an exterior angular momentum-like tail. Special cases are given to elucidate the physics, which may be intuitively useful in studies of higher-dimensional gravity.
Space-time communication for OFDM with implicit channel feedback

We consider wideband communication (e.g., using orthogonal frequency-division multiplexed (OFDM) systems) over a typical cellular "downlink," in which both the base station and the mobile may have multiple antennas, but the number of antennas at the mobile is assumed to be small. Implicit channel feedback can play a powerful role in such systems, especially for outdoor channels, which typically exhibit narrow spatial spreads. A summary of our findings is as follows: a) Implicit channel feedback regarding the covariance matrix for the downlink space-time channel can be obtained, without any power or bandwidth overhead, by suitably averaging uplink channel measurements across frequency. Since this approach relies on statistical reciprocity, it applies to both time-division duplex (TDD) and frequency-division duplex (FDD) systems. Using such covariance feedback yields significantly better performance at lower complexity than conventional space-time or space-frequency codes, which do not employ feedback; b) We provide guidelines for optimizing antenna spacing in systems with covariance feedback. Theoretical investigation of a hypothetical system with completely controllable channel eigenvalues shows that the optimal number of channel eigenmodes is roughly matched to the (small) number of receive antenna elements. Thus, while antenna elements in conventional systems without feedback should be spaced far apart in order to ensure uncorrelated responses, the optimal antenna spacing with covariance feedback is much smaller, thereby concentrating the channel energy into a small number of eigenmodes.
Design of RF MEMS switches without pull-in instability

Micro-electro-mechanical systems (MEMS) switches for radio-frequency (RF) signals have certain advantages over solid-state switches, such as lower insertion loss, higher isolation, and lower static power dissipation. Mechanical dynamics can be a determining factor for the reliability of RF MEMS. The RF MEMS ohmic switch discussed in this paper consists of a plate suspended over an actuation pad by four double-cantilever springs. Closing the switch with a simple step actuation voltage typically causes the plate to rebound from its electrical contacts. The rebound interrupts the signal continuity and degrades the performance, reliability and durability of the switch. The switching dynamics are complicated by a nonlinear, electrostatic pull-in instability that causes high accelerations. Slow actuation and tailored voltage control signals can mitigate switch bouncing and effects of the pull-in instability; however, slow switching speed and overly-complex input signals can significantly penalize overall system-level performance. Examination of a balanced and optimized alternative switching solution is sought. A step toward one solution is to consider a pull-in-free switch design. In this paper, determine how simple RC-circuit drive signals and particular structural properties influence the mechanical dynamics of an RF MEMS switch designed without a pull-in instability. The approach is to develop a validated modeling capability and subsequently study switch behavior for variable drive signals and switch design parameters. In support of project development, specifiable design parameters and constraints will be provided. Moreover, transient data of RF MEMS switches from laser Doppler velocimetry will be provided for model validation tasks. Analysis showed that a RF MEMS switch could feasibly be designed with a single pulse waveform and no pull-in instability and achieve comparable results to previous waveform designs. The switch design could reliably close in a timely manner, with small contact velocity, usually with little to no rebound even when considering manufacturing variability.
Jets from young stars

Most stars produce spectacular jets during their formation. There are thousands of young stars within 500 pc of the Sun and many power jets. Thus, protostellar jets may be the most common type of collimated astrophysical outflow. Shocks powered by outflows excite emission lines throughout the spectrum, exhibit a rich variety of structure, and motions with velocities ranging from less than 20 to over 500 km s−1. Due to their relative proximity, proper motions and structural changes can be observed in less than a year. I review the properties of classical Herbig-Haro objects, irradiated jets, and outflows emerging from the nearest massive star forming regions. Protostellar outflows are ideal laboratories for the exploration of the jet physics.
A NOTE ON OFF-LINE PERMUTATION ROUTING ON A MESH-CONNECTED PROCESSOR ARRAY

We show how to off-line route any permutation of an n×n mesh-connected processor array in 2.5n steps with at most two packets per processor per time step and in 2.25n+3 steps with at most four packets per processor per time step.
Meat Demand under Rational Habit Persistence

The objective of this paper is to explore the theoretical implications of a meat demand model with rational habit formation. The impact of food safety information on meat consumption is systematically analyzed. Important differences between myopic habits and rational habits are underscored. Both the adjustment path to the new equilibrium and new level of consumption are affected by consumers’ perceptions of changes in meat quality. The analysis has implications for empirical demand estimation by incorporating consumers’ expectations and use of event dummy variables rather than index measures of food safety. Le pr´
The Propensity of Multinational Companies to Expand Through Acquisitions

Multinational enterprises may choose to invest internationally through a newly formed subsidiary or by acquiring an existing company. In an attempt to isolate factors which might indicate a propensity to acquire rather than form subsidiaries, this study examined the characteristics of firms which have invested abroad. The results showed that firms with a higher percentage of investments through acquisitions did have some common characteristics. In addition, the nationality of the parent was found to be related to the propensity to acquire.
Where do people draw lines

This paper presents the results of a study in which artists made line drawings intended to convey specific 3D shapes. The study was designed so that drawings could be registered with rendered images of 3D models, supporting an analysis of how well the locations of the artists' lines correlate with other artists', with current computer graphics (CG) line definitions, and with the underlying differential properties of the 3D surface. Lines drawn by artists in this study largely overlapped one another, particularly along the occluding contours of the object. Most lines that do not overlap contours overlap large gradients of the image intensity and correlate strongly with predictions made by recent line-drawing algorithms in CG. A few were not well described by any of the local properties considered in this study. The result of our work is a publicly available data set of aligned drawings, an analysis of where lines appear in that data set based on local properties of 3D models, and algorithms to predict where artists will draw lines for new scenes.
High-pressure chemistry of hydrogen in metals: in situ study of iron hydride.

Optical observations and x-ray diffraction measurements of the reaction between iron and hydrogen at high pressure to form iron hydride are described. The reaction is associated with a sudden pressure-induced expansion at 3.5 gigapascals of iron samples immersed in fluid hydrogen. Synchrotron x-ray diffraction measurements carried out to 62 gigapascals demonstrate that iron hydride has a double hexagonal close-packed structure, a cell volume up to 17% larger than pure iron, and a stoichiometry close to FeH. These results greatly extend the pressure range over which the technologically important iron-hydrogen phase diagram has been characterized and have implications for problems ranging from hydrogen degradation and embrittlement of ferrous metals to the presence of hydrogen in Earth9s metallic core.
Fabrication of biomolecular devices via supramolecular contact-based approaches

This tutorial review provides an outlook on contact-based fabrication methods suitable for biomolecular platforms. Contact-based methods have emerged in response to serial and expensive fabrication techniques that built devices in a serial way, typically point by point or region by region. The review surveys the biological applications of microcontact printing and affinity contact printing. There is a special focus on DNA printing methods harnessing the supramolecular interactions between two complementary DNA strands.
Combined Effects of Wind-Driven Upwelling and Internal Tide on the Continental Shelf

Abstract Internal tides on the continental shelf can be intermittent as a result of changing hydrographic conditions associated with wind-driven upwelling. In turn, the internal tide can affect transports associated with upwelling. To study these processes, simulations in an idealized, alongshore uniform setup are performed utilizing the hydrostatic Regional Ocean Modeling System (ROMS) with conditions corresponding, as closely as possible, to the central Oregon shelf. “Wind only” (WO), “tide only” (TO), and “tide and wind” (TW) solutions are compared, utilizing cases with constant upwelling-favorable wind stress as well as with time-variable observed stress. The tide is forced by applying cross-shore barotropic flow at the offshore boundary with intensity sufficient to generate an internal tide with horizontal velocity amplitudes near 0.15 m s−1, corresponding to observed levels. The internal tide affects the subinertial circulation, mostly through the changes in the bottom boundary layer variability, re...
Morse functions on the 2‐sphere

I produce a generating function for the number of Morse functions on the 2‐sphere with a fixed number of saddle points, and the use it to answer a question of V.I. Arnold.
The AGN source population in the Chandra Deep Field-North Survey: Constraints from X-ray spectroscopy and variability

With the 0.5-10.0 keV background nearly resolved (e.g., Giacconi et al. 2000; Cowie et al. 2002), the emphasis has shifted towards understanding the nature of the faint X-ray population — a clear necessity if we wish to understand the formation and evolution of active galactic nuclei (AGN). Here we report on preliminary spectral and temporal Xray studies of AGN in the 2 Ms Chandra Deep Field-North Survey (CDF-N; D.M. Alexander et al. in prep). Our sample is comprised of 136 CDF-N sources with > 200 net counts (∼30% of the total CDF-N sample), spanning (0.014– 2)× 10 ergs cm s; 72 sources have known redshifts.
KNOWLEDGE TRANSFER IN DEEP CONVOLUTIONAL NEURAL NETS

Knowledge transfer is widely held to be a primary mechanism that enables humans to quickly learn new complex concepts when given only small training sets. In this paper, we apply knowledge transfer to deep convolutional neural nets, which we argue are particularly well suited for knowledge transfer. Our initial results demonstrate that components of a trained deep convolutional neural net can constructively transfer information to another such net. Furthermore, this transfer is completed in such a way that one can envision creating a net that could learn new concepts throughout its lifetime. The experiments we performed involved training a Deep Convolutional Neural Net (DCNN) on a large training set containing 20 different classes of handwritten characters from the NIST Special Database 19. This net was then used as a foundation for training a new net on a set of 20 different character classes from the NIST Special Database 19. The new net would keep the bottom layers of the old net (i.e. those nearest to the input) and only allow the top layers to train on the new character classes. We purposely used small training sets for the new net to force it to rely as much as possible upon transferred knowledge as opposed to a large and varied training set to learn the new set of hand written characters. Our results show a clear advantage in relying upon transferred knowledge to learn new tasks when given small training sets, if the new tasks are sufficiently similar to the previously mastered one. However, this advantage decreases as training sets increase in size.
Nonmonetary Effects of the Financial Crisis in the Great Depression

The credit hypothesis maintains that nonmonetary factors worsen declines in output during severe economic contractions, which has been a prominent rationale for stringent bank regulation. We apply recent advances in time series analysis to re-examine the role of U.S. bank failures in the Great Depression. In brief, month-by-month decompositions of output, prices, money supply, the liabilities of failed firms, and the deposits of failed banks indicate that bank failures did not initiate the fall in output and prices. However, chronic bank failure over at least a two-year period, in combination with a surge in failures in the latter part of this period of banking industry distress, had large negative effects on all of the variables under study. We conclude that chronic bank failures coupled with subsequent threshold failure effects can have deep and pervasive influences on the economy, which justify government intervention at such times. © 1999 Elsevier Science Inc.
The Effects of Food Stamps on Obesity.

Poverty has historically been associated with a decrease in food consumption. This at least partially changed in 1964 when the Food Stamp Act began guaranteeing food for those in poverty. Since the act's passage, the prevalence of obesity has increased dramatically, particularly among those with low incomes. This article examines the effects of the Food Stamp Program on the prevalence of obesity using 1979 National Longitudinal Survey of Youth data. Results indicate that food stamps have significant positive effects on obesity and the obesity gap for females, but these effects are relatively small, and consequently, such benefits are approximated to have played a minor role in increasing obesity at the aggregate level.
Screening CT colonography

CT colonography has become a part of the controversy surrounding total body CT screening. In this article, the current techniques for colonic preparation and distention, the optimum CT protocol, and the recommended use ofimage displays for time-efficient interpretation are discussed. The results of the larger and newer studies and some of the current clinical uses of CT colonography are presented. Issues specific to the use of CT colonography as a screening test are also discussed.
Characterization of CCD-based imaging X-ray detectors for diffraction experiments

Abstract High-resolution CCD-based imaging detectors are successfully used in X-ray diffraction experiments. Some detectors are commercially available, others have been developed by research groups around the world. Reliable comparison of the performance must be based on thorough testing of all relevant characteristics of these detectors. We describe methods of measurements of detector parameters such as conversion gain, linearity, uniformity, point spread function, geometrical uniformity, dark current, and detective quantum efficiency. As an example for the characterization, test results of a single module fiberoptic taper/CCD X-ray detector will be presented. The projected performance of a large area, array detector consisting of 9 CCDs and fiberoptic taper modules, will be given. This new detector (the “Gold” detector) will be installed on Beamline X8C at the National Synchrotron Light Source at Brookhaven National Laboratory.
Cross-coupling of mesylated phenol derivatives with potassium ammonio- and amidomethyltrifluoroborates.

A large array of aryl and heteroaryl mesylates have been successfully employed as electrophiles in a Csp2−Csp3 Suzuki−Miyaura cross-coupling with potassium ammonio- and amidomethyltrifluoroborates to afford the corresponding products in high yields.
Effective potentials for 6-coordinated boron: Structural geometry approach

We have built a database of ab initio total energies for elemental boron in over 60 hypothetical crystal structures of varying coordination Z, such that every atom is equivalent. Fitting to each subset with a particular Z, we extract a classical effective potential, written as a sum over coordination shells and dominated by three-atom (bond angle dependent) terms. In the case Z = 6 (lowest in energy and most relevant), the classical potential has a typical error of 0.1 eV/atom, and favors the inverted-umbrella environment seen in real boron.
Total Synthesis of Callipeltoside A

A convergent total synthesis of cytotoxic marine macrolide callipeltoside A is described. The synthesis highlights two stereoselective [4 + 2] annulations for the preparation of associated pyran rings.
A system for priming a clinical knowledge base

Priming refers to the stocking of a knowledge base with inference rules derived from expert physicians. One approach to priming is demonstrated by KAMM, a program that accepts rules from an expert at a CRT, and integrates them into the systemic memory of a medical consultation system called MEDICO. Decomposition of inference rules, and storage in a relational database, provides for great flexibility. Easy reorganization of the knowledge base is facilitated by RAIN, a Relational Algebraic INterpreter which is available both to the designer and to KAMM. Verification of systems of inference rules, i.e., inference nets, is performed while the rules are still in decomposed form in the relational database. Systemic memory is generated subsequently by KAMM, from the verified network implicit in the relational database. A hashed index on an encyclopedia of propositions helps speed MEDICO's access to groups of inference rules during consultation sessions.
Novel strategies for capturing health-protective mango phytochemicals in shelf stable food matrices

Cost-effective methods for concentration and stabilization of otherwise perishable mango fruit phytoactives into shelf stable high protein ingredients were developed to combat stunting (malnutrition) in rural Africa. Mango juices complexed with sunflower oil and protein-rich legume flours yielded carotenoid-enriched oils and pelleted polyphenol-enriched flour matrices. Carotenoids from juices were concentrated 9-10 times in the fortified sunflower oil. Protein-rich soy and peanut flours captured 2.2-3.2 mg/g polyphenols from the juices. Alternatively, mango juice was sorbed and co-dried with flours, which stably bound the polyphenols, carotenoids, and natural sugars in soy or peanut protein-rich matrices. The concentration of provitamin A carotenoids was almost doubled and total polyphenols were enriched 4-5 times higher in the matrices compared to fresh pureed juice. Both strategies require minimal instrumentation, are compatible with rural village dietary practices; and capture the benefits of otherwise perishable seasonal resources by complexing healthful proteins together with phytoactive compounds.
Spectroscopic Detection of a Stellar-like Photosphere in an Accreting Protostar

We present high-resolution (R is approximately equal to 18,000), high signal-to-noise 2 micron spectra of two luminous, X-ray flaring Class I protostars in the rho Ophiuchi cloud acquired with the NIRSPEC (near infrared spectrograph) of the Keck II telescope. We present the first spectrum of a highly veiled, strongly accreting protostar which shows photospheric absorption features and demonstrates the stellar nature of its central core. We find the spectrum of the luminous (L (sub bol) = 10 solar luminosity) protostellar source, YLW 15, to be stellar-like with numerous atomic and molecular absorption features, indicative of a K5 IV/V spectral type and a continuum veiling r(sub k) = 3.0. Its derived stellar luminosity (3 stellar luminosity) and stellar radius (3.1 solar radius) are consistent with those of a 0.5 solar mass pre-main-sequence star. However, 70% of its bolometric luminosity is due to mass accretion, whose rate we estimate to be 1.7 x 10(exp -6) solar masses yr(exp -1). We determine that excess infrared emission produced by the circumstellar accretion disk, the inner infalling envelope, and accretion shocks at the surface of the stellar core of YLW 15 all contribute significantly to its near-IR (infrared) continuum veiling. Its rotational velocity v sin i = 50 km s(exp -1) is comparable to those of flat-spectrum protostars but considerably higher than those of classical T Tauri stars in the rho Oph cloud. The protostar may be magnetically coupled to its circumstellar disk at a radius of 2 - 3 R(sub *). It is also plausible that this protostar can shed over half its angular momentum and evolve into a more slowly rotating classical T Tauri star by remaining coupled to its circumstellar disk (at increasing radius) as its accretion rate drops by an order of magnitude during the rapid transition between the Class I and Class II phases of evolution. The spectrum of WL 6 does not show any photospheric absorption features, and we estimate that its continuum veiling is r(sub k) is greater than or equal to 4.6. Its low luminosity (2 solar masses) and high veiling dictate that its central protostar is very low mass, M is approx. 0.1 solar masses. We also evaluate multi-epoch X ray data along with these spectra and conclude that the X ray variabilities of these sources are not directly related to their protostellar rotation velocities.
Empirics for economic growth and convergence

The convergence hypothesis has generated a huge empirical literature: this paper critically reviews some of the earlier key findings, clarifies their implications, and relates them to more recent results. Particular attention is devoted to interpreting convergence empirics. The main findings are: (1) The much-heralded uniform 2% rate of convergence could arise for reasons unrelated to the dynamics of economic growth. (2) Usual empirical analyses — cross-section (conditional) convergence regressions, time-series modelling, panel data analysis — can be misleading for understanding convergence; a model of polarization in economic growth clarifies those difficulties. (3) The data, more revealingly modelled, show persistence and immobility across countries: some evidence supports Baumol's idea of ‘convergence clubs’: some evidence shows the poor getting poorer, and the rich richer, with the middle class vanishing. (4) Convergence, unambiguous up to sampling error, is observed across US states.
Manufacture and use of chloroprene monomer

There are only six manufacturers of chloroprene (CD) located outside of the former Communist Bloc countries. Five of these manufacture chloroprene from butadiene via a two step process consisting of chlorination and subsequent dehydrochlorination. The sixth dimerizes acetylene and then hydrochlorinates the dimer to produce CD. Both the acetylene and butadiene-based manufacturing processes are conducted within sealed systems. Therefore, the only potential exposure during manufacture is sampling for product quality, strainer/filter changing and accidental leaks or spills. All six manufacturers produce CD only for the production of polymer. Manufacturers convert CD into polychloroprene polymer (PCP) via emulsion polymerization. A solution of CD and other ingredients is mixed with an aqueous caustic solution to produce an emulsion. Free radicals initiate polymerization and free radical scavengers are added to stop the reaction at the desired conversion. After unreacted monomer is removed, PCP can be sold as a latex (colloid) or isolated and dried to produce solid product. The PCP manufacturing process is also designed to be a closed system. However, the extreme reactivity of CD and the inherent stickiness of PCP polymer, makes it necessary to 'open' the process to remove polymer. This results in potential for operator exposure, in addition to the items mentioned for CD manufacture. With the use of appropriate engineering controls, work practices and personal protective equipment for activities with exposure potential, actual workplace exposures are controlled below the occupational exposure limits (2-10 ppm). The solid PCP products, which comprise approximately 92% of the total amount of polymer manufactured, contain <1 ppm CD. Most PCP latexes contain <0.1% residual CD. So, the potential for CD industrial exposure is limited to CD and PCP manufacture.
Design and synthesis of water-soluble bioconjugatable trans-AB-porphyrins.

Abstract Three free base porphyrins have been prepared that bear a polar and facially encumbering 2,4,6-tris-(carboxymethoxy)phenyl motif at one meso (5-) position. The only other substituent (15-position) comprises phenyl, formyl, or p-aminophenyl. The porphyrins exhibit solubility in water (or aqueous buffer solutions) at pH ≥7 and concentrations >1 mM at room temperature. The concise syntheses, water solubility, and bioconjugatable handle make these porphyrin constructs suitable for biological applications.
Dynamic jamming of iceberg-choked fjords

We investigate the dynamics of ice melange by analyzing rapid motion recorded by a time-lapse camera and terrestrial radar during several calving events that occurred at Jakobshavn Isbrae, Greenland. During calving events (1) the kinetic energy of the ice melange is 2 orders of magnitude smaller than the total energy released during the events, (2) a jamming front propagates through the ice melange at a rate that is an order of magnitude faster than the motion of individual icebergs, (3) the ice melange undergoes initial compaction followed by slow relaxation and extension, and (4) motion of the ice melange gradually decays before coming to an abrupt halt. These observations indicate that the ice melange experiences widespread jamming during calving events and is always close to being in a jammed state during periods of terminus quiescence. We therefore suspect that local jamming influences longer timescale ice melange dynamics and stress transmission.
Power output and efficiency of sound production by crickets

Male crickets produce calling songs that function to attract mates. Sound is produced when membranes of the wings are caused to vibrate during stridulation. Sound fields were measured for three species of crickets. Two species of mole crickets, Scapteriscus acletus and s. vicinus, call from within burrows constructed in the soil. Sound fields of the mole crickets were hemispherical and the power output averaged 4 μW (N = 22, range 2–22 μW). Power output was dependent upon male size and moisture content of soil surrounding the burrow. Efficiency of sound production was estimated to be less than 0.2%. Sound fields of a species of tree crickets, Oecanthus quadripunctatus, approximated that of a doublet source. Power output ranged from 2–17 μW (N = 6) and efficiency was estimated at about 1%.
Orderings for term-rewriting systems☆

Abstract Methods of proving that a term-rewriting system terminates are presented. They are based on the intuitive notion of ‘simplification orderings’, orderings in which any term that is syntactically simpler than another is smaller than the other. As a consequence of Kruskal's Tree Theorem, any nonterminating system must be self-embedding in the sense that it allows for the derivation of some term from a simpler one; thus termination is guaranteed if every rule in the system is a reduction in some simplification ordering. Most of the orderings that have been used for proving termination are indeed simplication orderings; using this notion often allows for much easier proofs. A particularly useful class of simplification orderings, the ‘recursive path orderings’, is defined. Examples of the use of simplication orderings in termination proofs are given.
Efficient Mechanisms for Bilateral Trading

We consider bargaining problems between one buyer and one seller for a single object. The seller’s valuation and the buyer’s valuation for the object are assumed to be independent random variables, and each individual’s valuation is unknown to the other. We characterize the set of allocation mechanisms that are Bayesian incentive compatible and individually rational, and show the general impossibility of ex post efficient mechanisms without outside subsidies. For a wide class of problems we show how to compute mechanisms that maximize expected total gains from trade, and mechanisms that can maximize a broker’s expected profit. Journal of Economic Literature Classification Number: 026.
ASYMPTOTIC STABILITY I: COMPLETELY POSITIVE MAPS

We show that for every "locally finite" unit-preserving completely positive map P acting on a C*, there is a corresponding *-automorphism α of another unital C*-algebra such that the two sequences P, P2, P3, … and α, α2, α3, … have the same asymptotic behavior. The automorphism α is uniquely determined by P up to conjugacy. Similar results hold for normal completely positive maps on von Neumann algebras, as well as for one-parameter semigroups. These results are operator algebraic counterparts of the classical theory of Perron and Frobenius on the structure of square matrices with nonnegative entries.
The Role of Ocean-Atmosphere Interactions in the CO2 Climate Problem

Abstract The climate sensitivity question is examined from the viewpoint of surface energy balance considerations. This approach clarifies the role of ocean-atmosphere interactions in determining the surface warming to an increase in CO2. The study uses a one-dimensional, 17-layer, coupled ocean-atmosphere model. The primary contribution to the surface warming is from the enhanced tropospheric IR emission, which is an order of magnitude greater than the direct CO2 radiative heating at the surface. The source for this enhancement is the increased H2O evaporation from the warmer oceans in the CO2 rich atmosphere and, hence, ocean-atmosphere interactions play a crucial role in determining the magnitude of the surface warming as well as its transient response. This ocean-atmosphere feedback is implicitly included in model studies, but past analysts of model results have not highlighted this aspect of the problem. Consequently, published empirical approaches based on surface energy balance considerations (unaw...
Native Chemical Ligation: A Boon to Peptide Chemistry

The use of chemical ligation within the realm of peptide chemistry has opened various opportunities to expand the applications of peptides/proteins in biological sciences. Expansion and refinement of ligation chemistry has made it possible for the entry of peptides into the world of viable oral therapeutic drugs through peptide backbone cyclization. This progression has been a journey of chemical exploration and transition, leading to the dominance of native chemical ligation in the present advances of peptide/protein applications. Here we illustrate and explore the historical and current nature of peptide ligation, providing a clear indication to the possibilities and use of these novel methods to take peptides outside their typically defined boundaries.
Blade Excitation by Elliptical Whirling in Viscous-Damped Jet Engines

An extension of the author’s earlier method of analyzing multi-shaft jet engine dynamics accounting for flexibility of bladed disks is outlined to calculate the first whirl harmonic for given nonlinear characteristics of squeeze-film dampers. A second whirl harmonic, of which experimental verification is found in Campbell’s paper of 1924, is shown induced by orbit ellipticity. The possibility that this harmonic, especially due to backward whirling, may be a source of blade excitation at higher frequencies than currently recognized from linear analysis is discussed by relating some engine experience.Copyright © 1980 by ASME
Polycarbonyl cations of Cu(I), Ag(I), and Au(I): [M(CO)n]+

Abstract Recently published data for polycarbonyl complexes of monovalent copper, silver, and gold are reviewed and discussed within the context of metal-ligand bonding. For the dicarbonyl complexes [M(CO) 2 ] + the data indicate that (i) metalcarbonyl σ bonding is strongest for M + Au + and weakest for M + Ag + , and (ii) metal-carbonyl π bonding is strongest for M + Cu + and negligible for M + Ag + and Au + . These variations in MCO σ- and π-bond strengths are explained in terms of the ionization energies and the electronic excited state energies of the three gaseous M + cations.
Staged Microgravity Deployment of a Pressurizing Scale-Model Spacecraft

The experiments described were conducted with the goal of obtaining quantitative pressure and motion data for deployment of an inflatable scale-model spacecraft structure in an environment free of gravity. The experiments included a series of staged deployments of two identical unfolding, inflating scale-model solar concentrators, each consisting of three struts and a torus. The experiments were conducted aboard NASA’s KC-135 aircraft. Internal pressure was simultaneously measured at six locations in the deploying structure at the bottom and top of each strut. Deployment motions were tracked using two video cameras and were compared to measured pressures. Consistent trends in pressurization and motion were seen in 11 staged deployments, including nearly constant pressure as the internal volume increased and increasing pressure as volume remained constant. Pressure equalization was observed to occur at different times for different struts, and motion analysis showed varied directions of deployment correlating to these differing pressure equalization times.
Spatially Resolved Millimeter Spectroscopy of the Gravitational Lens PKS 1830-211

This paper presents data from the BIMA interferometer showing spatially resolved absorption spectra of the gravitationally lensed quasar PKS 1830-211. High-resolution (1.2 km s-1) spectra were taken in two spectral windows centered on the redshifted frequencies of the HCO+(2 ← 1) and HCN(2 ← 1) molecular transitions. There is no molecular absorption in the northeast image, but the southwest image reveals optically thick absorbing gas at these transition frequencies. Further analyses conclude that the spectra are consistent with completely saturated absorption in the southwest image, and the line profiles suggest that the absorbing medium is complex, perhaps containing multiple components and small-scale structure. The absorption occurs along a pencil beam through the lensing galaxy which is thought to be a late-type spiral oriented almost face-on. However, the spectra show absorption spanning more than 60 km s-1, which is difficult to explain for this scenario.
Monk's rule and Giambelli's formula for Peterson varieties of all Lie types

A Peterson variety is a subvariety of the flag variety $$G/B$$G/B which appears in the construction of the quantum cohomology of partial flag varieties. Each Peterson variety has a one-dimensional torus $$S^1$$S1 acting on it. We give a basis of Peterson Schubert classes for $$H_{S^1}^*(Pet)$$HS1?(Pet) and identify the ring generators. In type $$A$$A, Harada---Tymoczko gave a positive Monk formula (arXiv:0908.3517, 2009), and Bayegan---Harada gave Giambelli's formula (arXiv:1012.4053, 2010) for multiplication in the cohomology ring. This paper gives Monk's rule and Giambelli's formula for all Lie types.
Amination by lithium alkylamide reagents of ketimines derived from 2-(trifluoromethyl)anilines and methyl halophenyl ketones and their cyclization products 2-(halophenyl)quinolin-4-amines

Abstract The title ketimines containing a fluorine atom at position 2 of the phenyl group are efficiently cyclized under mild conditions to N -[2-(dimethylamino)ethyl]-2-(2-fluorophenyl)quinolin-4-amines by the reaction with a lithium reagent derived from N , N -dimethylethylenediamine. The facile regioselective displacement of C2-F in the presence of another fluorine atom at the phenyl group by the same reagent or N -lithio- N ′-methylpiperazide at a higher temperature is explained in terms of a complex induced proximity effect (CIPE) process. The CIPE process is operative in amination of the 2-fluorophenyl ketimines by the more reactive piperazide reagent prior cyclization to quinolines. The 2-chlorophenyl derivatives are much less reactive in the CIPE assisted amination.
Suppression of electron spin decoherence in a quantum dot

The dominant source of decoherence for an electron spin in a quantum dot is the hyperfine interaction with the surrounding bath of nuclear spins. The decoherence process may be slowed down by subjecting the electron spin to suitable sequences of external control pulses. We investigate the performance of a variety of dynamical decoupling protocols using exact numerical simulation. Emphasis is given to realistic pulse delays and the long-time limit, beyond the domain where available analytical approaches are guaranteed to work. Our results show that both deterministic and randomized protocols are capable to significantly prolong the electron coherence time, even when using control pulse separations substantially larger than what expected from the upper cutoff frequency of the coupling spectrum between the electron and the nuclear spins. In a realistic parameter range, the total width of such a coupling spectrum appears to be the physically relevant frequency scale affecting the overall quality of the decoup...
Physiological principles for the design of hepatic contrast agents.

The general requirements for design of a clinically useful contrast agent for magnetic resonance imaging (MRI) are: (a) magnetic activity which alters image signal intensity; (b) biodistribution to normal tissue and exclusion by diseased tissue (or the reverse); and (c) low toxicity or a high margin of safety for the effective dose.