pinecone/core-2020-05-10-deduplication huggingface dataset:
A comparative framework: how broadly applicable is a 'rigorous' critical junctures framework?

The paper tests Hogan and Doyle's (2007, 2008) framework for examining critical junctures. This framework sought to incorporate the concept of ideational change in understanding critical junctures. Until its development, frameworks utilized in identifying critical junctures were subjective, seeking only to identify crisis, and subsequent policy changes, arguing that one invariably led to the other, as both occurred around the same time. Hogan and Doyle (2007, 2008) hypothesized ideational change as an intermediating variable in their framework, determining if, and when, a crisis leads to radical policy change. Here we test this framework on cases similar to, but different from, those employed in developing the exemplar. This will enable us determine whether the framework's relegation of ideational change to a condition of crisis holds, or, if ideational change has more importance than is ascribed to it by this framework. This will also enable us determined if the framework itself is robust, and fit for the purposes it was designed to perform — identifying the nature of policy change
Vacuum-ultraviolet photoabsorption imaging system for laser plasma plume diagnostics

We describe a recently designed and constructed system based on a 1 m normal incidence vacuum monochromator with corrected (toroidal) optics that produces a wavelength tuneable and collimated vacuum-ultraviolet (VUV) (λ=30–100 nm) beam. The VUV continuum source is a laser-generated gold plasma. The primary function of the system is the measurement of time resolved “images” or spatial distributions of photoabsorption/photoionization in expanding laser plasma plumes. This is achieved by passing the beam through the sample of interest (in our case a second synchronised plasma) and recording the “footprint” of the attenuated beam on a charge coupled device. Using this VUV photoabsorption imaging or “shadowgraphy” technique we track and extract column density distributions in expanding plasma plumes. We can also measure the plume front velocity. We have characterized the system, particularly in relation to spectral and spatial resolution and the experimental results meet very well the expectations from ray tracing done at the design phase. We present first photoabsorption images and column density distributions of laser produced Ca plumes from the system
A Fractal Interaction Model for Winding Paths through Complex Distributions: Application to Soil Drainage Networks

Water interacts with soil through pore channels putting mineral constituents and pollutants into solution. The irregularity of pore boundaries and the heterogeneity of distribution of soil minerals and contaminants are, among others, two factors influencing that interaction and, consequently, the leaching of chemicals and the dispersion of solute throughout the soil. This paper deals with the interaction of irregular winding dragging paths through soil complex distributions. A mathematical modelling of the interplay between multifractal distributions of mineral/pollutants in soil and fractal pore networks is presented. A Ho¨lder path is used as a model of soil pore network and a multifractal measure as a model of soil complex distribution, obtaining a mathematical result which shows that the Ho¨lder exponent of the path and the entropy dimension of the distribution may be used to quantify such interplay. Practical interpretation and potential applications of the above result in the context of soil are discussed. Since estimates of the value of both parameters can be obtained from field and laboratory data, hopefully this mathematical modelling might prove useful in the study of solute dispersion processes in soil
Fractional-order viscoelasticity applied to describe uniaxial stress relaxation of human arteries.

Viscoelastic models can be used to better understand arterial wall mechanics in physiological and pathological conditions. The arterial wall reveals very slow time-dependent decays in uniaxial stress-relaxation experiments, coherent with weak power-law functions. Quasi-linear viscoelastic (QLV) theory was successfully applied to modeling such responses, but an accurate estimation of the reduced relaxation function parameters can be very difficult. In this work, an alternative relaxation function based on fractional calculus theory is proposed to describe stress relaxation experiments in strips cut from healthy human aortas. Stress relaxation (1 h) was registered at three incremental stress levels. The novel relaxation function with three parameters was integrated into the QLV theory to fit experimental data. It was based in a modified Voigt model, including a fractional element of order α, called spring–pot. The stressrelaxation predictionwas accurate and fast. Sensitivity plots for each parameter presented a minimum near their optimal values. Least-squares errors remained below 2%. Values of order α = 0.1–0.3 confirmed a predominant elastic behavior. The other two parameters of the model can be associated to elastic and viscous constants that explain the time course of the observed relaxation function. The fractional-order model integrated into the QLV theory proved to capture the essential features of the arterial wall mechanical response
Multimedia Retrieval by Means of Merge of Results from Textual and Content Based Retrieval Subsystems

The main goal of this paper it is to present our experiments in ImageCLEF 2009 Campaign (photo retrieval task). In 2008 we proved empirically that the Text-based Image Retrieval (TBIR) methods defeats the Content-based Image Retrieval CBIR “quality” of results, so this time we developed several experiments in which the CBIR helps the TBIR. The TBIR System [6] main improvement is the named-entity sub-module. In case of the CBIR system [3] the number of low-level features has been increased from the 68 component used at ImageCLEF 2008 up to 114 components, and only the Mahalanobis distance has been used. We propose an ad-hoc management of the topics delivered, and the generation of XML structures for 0.5 million captions of the photographs (corpus) delivered. Two different merging algorithms were developed and the third one tries to improve our previous cluster level results promoting the diversity. Our best run for precision metrics appeared in position 16th, in the 19th for MAP score, and for diversity value in position 11th, for a total of 84 submitted experiments. Our best and “only textual” experiment was the 6th one over 41
Dynamics of counterpropagating waves in parametrically forced systems

Parametrically driven waves in weakly dissipative systems with one extended dimension are considered. Multiple scale techniques are used to derive amplitude equations describing the interaction between counterpropagating waves. Dissipation, detuning and forcing are all assumed to be weak and any coupling to mean fields (such as large scale flows in fluid systems) is ignored. If the aspect ratio is moderately large the system is described by a pair of nonlocal equations for the (complex) amplitudes of the waves. The dynamics of these equations are studied both in annular and bounded geometries with lateral walls. The equations admit spatially uniform solutions in the form of standing waves and spatially nonuniform solutions with both simple and complex time-dependence. Transitions among these states are investigated as a function of the driving in three particular cases
Formability prediction of thin metal sheets using various localization criteria

The aim of this paper is to give an overview of the theoretical basis of the most significant and commonly used localization criteria reformulated into a unified framework, and to apply these criteria to different materials in order to determine their formability domains. After giving a general material description based on a phenomenological approach, theoretical foundations of localization criteria are presented together with their advantages and drawbacks. These criteria rely on diverse theories: maximum load principle, bifurcation analysis, Marciniak-Kuczynski analysis, and stability analysis by a linear perturbation method. They are then applied to a brass and a Dual Phase steel and the predicted Forming Limit Diagrams (FLD) are discussed
Thermal exchange effects on steel thixoforming processes

Steel thixoforging is an innovative semi-solid forming process. It allows the manufacturing of complex parts and minimises the forming load. This work aims to identify and characterise the main feature zones of a thixoforging part. The material flow and the forging load are dependent on the thixoforging speed, the tool temperature and the initial temperature of the slug. The data are obtained for C38 thixoforging steel. A specific extrusion tool was designed that integrates the heating of the tool and the slug. This tool was set up on a high-speed hydraulic press. This work highlights the effects of heat exchange on the microstructure, the internal flow and the mechanical characteristics of thixoforging material. These heat exchanges depend primarily on the working speed and tool temperature. The internal flow is composed of three distinct zones. Among them, only semisolid zone is observed during working. The microstructures of thixoforming C38 steel consist of ferrite, pearlite and bainite
Processability and characterization of poly(vinyl chloride)-b-poly(n-butyl acrylate)-b-poly(vinyl chloride) prepared by living radical polymerization of vinyl chloride. Comparison with a flexible commercial resin formulation prepared with PVC and dioctyl phthalate

This work reports the synthesis and processing of a new flexible material based on PVC produced by living radical polymerization. The synthesis was carried out in a two-step process. In the first step the macroinitiator alpha, omega-di(iodo)poly(butyl acrylate) [alpha, omega-di(iodo)PBA] was synthesized in water by single electron transfer/degenerative chain transfer mediated living radical polymerization (SET-DTLRP) catalyzed by Na2S2O4. In the second step this macroinitiator was reinitiated by SET-DTLRP of vinyl chloride (VC), thereby leading to the formation of the block copolymer poly(vinyl chloride)-b-poly(butyl acrylate)-b-poly(vinyl chloride) [PVC-b-PBA-b-PVC]. This new material was processed on a laboratory scale. The DMTA traces showed only a single glass transition temperature, thus indicating that no phase segregation was present. The copolymers were studied with regard to their processing, miscibility, and mechanical properties. The first comparison with commercial formulations made with PVC and dioctyl phthalate (DOP) is presented. J. VINYL ADDIT. TECHNOL., 12:156-165, 2006. © 2006 Society of Plastics Engineershttp://dx.doi.org/10.1002/vnl.2008
Novel Asymmetric Wittig Reaction: Synthesis of Chiral Allenic Esters

Wittig reactions between 10-(phenylsulfonyl)isobornyl (triphenylphosphoranylidene)acetates (1 and 6) and ketenes resulted in asymmetric induction, with the selective synthesis of allenes with axial chirality. Use of the (1R)-(-)-10-(phenylsulfonyl)isoborneol unit allows the synthesis of allenes with S configuration, whereas use of the (1S)-(+)-10-(phenylsulfonyl)isoborneol unit produces allenes with R configuration. The structure of (1R)-(-)-10-(phenylsulfonyl)isobornyl (S)-5,5-dimethylhexa-2,3-dienoate (2e) was determined by X-ray crystallography. Chirooptical studies of the allenic esters were carried out, confirming that two sets of enantiomeric derivatives were obtained. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)http://dx.doi.org/10.1002/ejoc.20040041
Unaltered hepatic oxidative phosphorylation and mitochondrial permeability transition in wistar rats treated with nimesulide: Relevance for nimesulide toxicity characterization

Nonsteroidal anti-inflammatory drugs have been associated with hepatotoxicity in susceptible patients. One such example is nimesulide, a preferential cyclooxygenase 2-inhibitor, widely used for the treatment of inflammation and pain. It was suggested that nimesulide could exert its hepatotoxicity by altering hepatic mitochondrial function, which was demonstrated in vitro. The objective of this study was to verify whether liver mitochondria isolated from rats treated with doses of nimesulide well above therapeutic levels possessed decreased calcium tolerance and oxidative phosphorylation, which indicates in vivo nimesulide mitochondrial toxicity. Male and female rats received nimesulide or its vehicle twice daily, for 5 days, and were killed on the seventh day for the isolation of liver mitochondria. Mitochondrial respiration, transmembrane electric potential, and calcium tolerance were characterized in all experimental groups. Nimesulide had no effect on liver mitochondrial function. Indexes of mitochondrial integrity, calcium loading capacity, and oxidative phosphorylation efficiency were unchanged between liver mitochondria from treated and control animals. In the animals tested, no evidence of degraded mitochondrial function due to nimesulide administration could be found. The results corroborate the notion that despite recognized in vitro mitochondrial toxicity, nimesulide does not cause detectable mitochondrial dysfunction in Wistar rats, even when administered in much higher concentrations than those known to have anti-inflammatory effects. © 2007 Wiley Periodicals, Inc. J Biochem Mol Toxicol 21:53-61, 2007; Published online in Wiley InterScience (). DOI 10.1002/jbt.20159http://dx.doi.org/10.1002/jbt.2015
Techniques of intestinal transplantation in rat

Two surgical models of intestinal transplantation in the rat are described. One is the implantation of fetal and newborn intestine as free grafts into the omentum of adult recipients, the other the adult intestine transplantation as an accessory graft using vascular anastomoses. A hundred and sixteen small-bowel transplantations were done; 36 of which were fetal intestine (group I), 40 of newborn intestine (group II), and 40 of adult intestine (group III). In the fetal and newborn intestinal transplantation, we emphasize the practices that allowed us to avoid ischemic and traumatic injury to the graft. In the adult intestine transplantation with vascular anastomoses, we heighten the modifications in the surgical technique that made the operation easier and the strategies used to prevent hypothermia and hypovolemic shock. Once experienced with the two chosen surgical techniques, transplantation using an avascular segment became much easier and quicker than transplantation with vascular anastomoses. © 1998 Wiley-Liss, Inc. MICROSURGERY 18:424-429, 1998http://dx.doi.org/10.1002/(SICI)1098-2752(1998)18:7<424::AID-MICR7>3.0.CO;2-
Mean-filed theories with mixed states and associated boson expansions

A variational derivation of the Liouville-von Neumann equation of quantum-statistical mechanics is presented, in order to formulate mean-field approximations appropriate to mixed states. The Hartree-Fock and the RPA at finite temperatures are particular cases of the general formalism. A thermal boson expansion is defined, which allows us to describe anharmonic motion around a thermal excited state. In a numerical application on the basis of the Lipkin model, temperature-dependent phase transitions are observed
Silica grafted polyethylenimine as heterogeneous catalyst for condensation reactions

Primary amine groups were attached to a silica surface by using α,ω-diamines derivatives
and (3-glycidyloxypropyl)-trimethoxysilane activation. The same activation was used to
graft polyethylenimine, which also contains secondary and tertiary amine groups. These
silica aminated structures were tested as heterogeneous catalysts in nitroaldol
condensation with nitromethane, the derivative with the polyethylenimine moiety being
the more active catalyst. This catalyst also showed efficiency in the Knoevenagel
condensation of benzaldehydes with ethyl cyanoacetate under very mild reaction
conditions and showed much the same efficiency when used in consecutive reaction runs.
A reaction mechanism with participation of the several amine groups of the catalysts is
discussed
Roles of the troponin isoforms during indirect flight muscle development in Drosophila

Troponin proteins in cooperative interaction with tropomyosin are responsible for controlling the contraction of the striated muscles in response to changes in the intracellular calcium concentration. Contractility of the muscle is determined by the constituent protein isoforms, and the isoforms can switch over from one form to another depending on physiological demands and pathological conditions. In Drosophila, a majority of the myofibrillar proteins in the indirect flight muscles (IFMs) undergo post-transcriptional and post-translational isoform changes during pupal to adult metamorphosis to meet the high energy and mechanical demands of flight. Using a newly generated Gal4 strain (UH3-Gal4) which is expressed exclusively in the IFMs, during later stages of development, we have looked at the developmental and functional importance of each of the troponin subunits (troponin-I, troponin-T and troponin-C) and their isoforms. We show that all the troponin subunits are required for normal myofibril assembly and flight, except for the troponin-C isoform 1 (TnC1). Moreover, rescue experiments conducted with troponin-I embryonic isoform in the IFMs, where flies were rendered flightless, show developmental and functional differences of TnI isoforms and importance of maintaining the right isoform
Ab-initio vibrational properties of transition metal chalcopyrite alloys determined as high-efficiency intermediate-band photovoltaic materials

In this work, we present frozen phonon and linear response ab-initio research into the vibrational properties of the CuGaS2 chalcopyrite and transition metal substituted (CuGaS2)M alloys. These systems are potential candidates for developing a novel solar-cell material with enhanced optoelectronic properties based in the implementation of the intermediate-band concept. We have previously carried out ab-initio calculations of the electronic properties of these kinds of chalcopyrite metal alloys showing a narrow transition metal band isolated in the semiconductor band gap. The substitutes used in the present work are the 3d metal elements, Titanium and Chromium. For the theoretical calculations we use standard density functional theory at local density and generalized gradient approximation levels. We found that the optical phonon branches of the transition metal chalcopyrite, are very sensitive to the specific bonding geometry and small changes in the transition metal environment
Space-state robust control of a Buck converter with amorphous core coil and variable load

Pulse-width modulation is widely used to control electronic converters. One of the most frequently used topologies for high DC voltage/low DC voltage conversion is the Buck converter. These converters are described by a second order system with an LC filter between the switching subsystem and the load. The use of a coil with an amorphous magnetic material core rather than an air core permits the design of smaller converters. If high switching frequencies are used to obtain high quality voltage output, then the value of the auto inductance L is reduced over time. Robust controllers are thus needed if the accuracy of the converter response must be preserved under auto inductance and payload variations. This paper presents a robust controller for a Buck converter based on a state space feedback control system combined with an additional virtual space variable which minimizes the effects of the inductance and load variations when a switching frequency that is not too high is applied. The system exhibits a null steady-state average error response for the entire range of parameter variations. Simulation results and a comparison with a standard PID controller are also presented
Two-dimensional mesh optimization in the finite element method

The solution to the problem of finding the optimum mesh design in the finite element method with the restriction of a given number of degrees of freedom, is an interesting problem, particularly in the applications method. At present, the usual procedures introduce new degrees of freedom (remeshing) in a given mesh in order to obtain a more adequate one, from the point of view of the calculation results (errors uniformity). However, from the solution of the optimum mesh problem with a specific number of degrees of freedom some useful recommendations and criteria for the mesh construction may be drawn. For 1-D problems, namely for the simple truss and beam elements, analytical solutions have been found and they are given in this paper. For the more complex 2-D problems (plane stress and plane strain) numerical methods to obtain the optimum mesh, based on optimization procedures have to be used. The objective function, used in the minimization process, has been the total potential energy. Some examples are presented. Finally some conclusions and hints about the possible new developments of these techniques are also given
Irradiation uniformity at the Laser MegaJoule facility in the context of the shock ignition scheme

The use of the Laser MegaJoule facility within the shock ignition scheme has been considered. In the first part of the study, one-dimensional hydrodynamic calculations were performed for an inertial confinement fusion capsule in the context of the shock ignition scheme providing the energy gain and an estimation of the increase of the peak power due to the reduction of the photon penetration expected during the high-intensity spike pulse. In the second part, we considered a Laser MegaJoule configuration consisting of 176 laser beams that have been grouped providing two different irradiation schemes. In this configuration the maximum available energy and power are 1.3 MJ and 440 TW. Optimization of the laser?capsule parameters that minimize the irradiation non-uniformity during the first few ns of the foot pulse has been performed. The calculations take into account the specific elliptical laser intensity profile provided at the Laser MegaJoule and the expected beam uncertainties. A significant improvement of the illumination uniformity provided by the polar direct drive technique has been demonstrated. Three-dimensional hydrodynamic calculations have been performed in order to analyse the magnitude of the azimuthal component of the irradiation that is neglected in twodimensional hydrodynamic simulations
Testing solar panels for small-size satellites: the UPMSAT-2 mission

At present, the development of small-size satellites by universities, companies and research institutions have become a usual practice, which is spread rapidly. In this kind of projects the cost play a significant role. One of the main points are the Assembly, Integration and Test (AIT) plans, which carries out an associated cost for simulating the environmental conditions. For instance, in the power subsystems test and, in particular in the solar panels testing, the irradiance and temperature conditions might be the optimum so the performances of the system are next to real operational conditions.&#13; To reproduce the environmental conditions in terms of irradiance, solar simulators are usually used, which carries an associated increase of cost for testing equipments. The aim of this paper is to present an alternative and unexpenssive way to perform the AIT plans on spacecraft power subsystems, from a testing campaign performed using outdoor clean-sky conditions and an isolation system to protect the panels. A post-process of the measured data is therefore needed, taking into account the conditions in which the test has been accomplished. The I-V characteristics obtained are compared with a theorical 1-diode/2-resistor equivalent electric circuit, achieving enough precision based solely in the manufacturer data