pinecone/core-2020-05-10-deduplication huggingface dataset:
Control of Discrete Event Systems with Respect to Strict Duration: Supervision of an Industrial Manufacturing Plant

26 pagesInternational audienceIn this paper, we propose a (max,+)-based method for the supervi- sion of discrete event systems subject to tight time constraints. Systems under consideration are those modelled as timed event graphs and repre- sented with linear (max,+) state equations. The supervision is addressed by looking for solutions of constrained state equations associated with timed event graph models. These constrained state equations are derived by reducing duration constraints to elementary constraints whose con- tributions are injected in the system's state equations. An example for supervisor synthesis is given for an industrial manufacturing plant subject to a strict temporal constraint, the thermal treatment of rubber parts for the automotive industries. Supervisors are calculated and classified ac- cording to their performance, considering their impact on the production throughput
Bismuth-coated mesoporous platinum microelectrodes as sensors for formic acid detection

Mesoporous platinum microeletrodes (MPtEs) modified by sub-monolayers of irreversibly adsorbed bismuth (Bi-MPtE) were investigated for their potential use as sensors for the detection of formic acid in direct formic acid fuel cells. The mesoporous platinum films were prepared by electrodeposition of platinum on Pt microdisks substrates 25 m diameter, from hexachloroplatinic acid dissolved in the aqueous domain of the lyotropic liquid crystalline phase of octaethylene glycol monohexadecyl ether. The roughness factor (RF) of the MPtEs was about two orders of magnitude greater than those of the corresponding polished microelectrodes. Bismuth ad-atoms onto the platinum surface were deposited by under potential deposition from 1 mM Bi3+ ions in 0.5 M H2SO4 solutions. The catalytic activity of a series of Bi-MPtEs, characterized by different roughness and fractional bismuth coverage (Bi), towards the oxidation of HCOOH, was investigated by cyclic voltammetry and potential step experiments. Compared to MPtEs, Bi-MPtEs displayed enhanced electrooxidation currents at lower potentials. The stability of irreversibly adsorbed bismuth, and consequently the Bi-MPtEs catalytic activity, was found to depend on the high potential limit employed in the measurements. In general, both electrode stability and electrocatalytic performance were good, provided that the operational potential was kept  0.4 V vs. Ag/AgCl. Bi-MPtEs with Bi > 0.3 provided almost sigmoidal shaped waves with low hysteresis, as those expected for microelectrodes working under steady state. The effect of concentration of HCOOH was investigated over the range 0.01 – 5 M, and linearity between current and concentration depended on both roughness factor and bismuth coverage. A Bi-MPtE characterised by RF = 210 and Bi ≥ 0.6 provided linearity up to 2 M of formic acid. Reproducibility of the sensors was within 2% (r.s.d). The same sensor, under the optimized experimental conditions, could be employed for at least two months with negligible loss of the initial performance
Boolean-like-algebras

Using Vaggione's concept of central element in a double-pointed algebra, we\ud
introduce the notion of \emph{Boolean-like variety} as a generalisation of\ud
Boolean algebras to an arbitrary similarity type. Appropriately relaxing the\ud
requirement that every element be central in any member of the variety, we\ud
obtain the more general class of \emph{semi-Boolean-like varieties}, which\ud
still retain many of the pleasing properties of Boolean algebras. We prove\ud
that a double-pointed variety is discriminator iff it is semi-Boolean-like,\ud
idempotent, and $0$-regular. This theorem yields a new Maltsev-style\ud
characterisation of double-pointed discriminator varieties
Numerical resolution of a mono-disperse model of bubble growth in magmas

International audienceGrowth of gas bubbles in magmas may be modeled by a system of differential equations that account for the evolution of bubble radius and internal pressure and that are coupled with an advection-diffusion equation defining the gas flux going from magma to bubble. This system of equations is characterized by two relaxation parameters linked to the viscosity of the magma and to the diffusivity of the dissolved gas, respectively. Here, we propose a numerical scheme preserving, by construction, the total mass of water of the system. We also study the asymptotic behavior of the system of equations by letting the relaxation parameters vary from 0 to infinity, and show the numerical convergence of the solutions obtained by means of the general numerical scheme to the simplified asymptotic limits. Finally, we validate and compare our numerical results with those obtained in experiments
Hydrogen radiolytic release from zeolite 4A/water systems under γ irradiations

International audienceWe irradiated samples of zeolites 4A which contained different quantities of water. We measured the quantity of hydrogen released. Hydrogen radiolytic yields, present two maxima, for two water loading ratios. Hydrogen release is enhanced by the strength of the zeolite/water interaction. Hydrogen release is enhanced by the quantity of water interacting with the zeolite. a b s t r a c t Although the radiolysis of bulk water is well known, some questions remain in the case of adsorbed or confined water, especially in the case of zeolites 4A, which are used to store tritiated water. An en-hancement of the production of hydrogen is described in the literature for higher porous structures, but the phenomenon stays unexplained. We have studied the radiolysis of zeolites 4A containing different quantities of water under 137 Cs gamma radiation. We focused on the influence of the water loading ratio. The enhancement of hydrogen production compared with bulk water radiolysis has been attributed to the energy transfer from the zeolite to the water, and to the influence of the water structure organization in the zeolite. Both were observed separately, with a maximum efficiency for energy transfer at a loading ratio of about 13%, and a maximum impact of structuration of water at a loading ratio of about 4%
Stable-isotope dilution measurement of isovalerylglycine by tandem mass spectrometry in newborn screening for isovaleric acidemia

Background: Recent neonatal screening for isovaleric acidemia by tandem mass spectrometry based on dried blood spot levels of C5-acylcarnitines, including isovalerylcarnitine and its isomer, pivaloylcarnitine, which is derived from pivalate-generating antibiotics, has caused many false-positive results. We have developed a method to overcome this interference.
Methods: The amounts of isovalerylglycine were determined by a stable-isotope dilution electrospray tandem mass spectrometric analysis, using multiple reaction monitoring with product ions of m/z 132, which were generated predominantly from quasi-molecular ions of isovalerylglycine butylester but apparently not from those of pivaloylglycine butylester. 
Results: Isovalerylglycine concentrations in dried blood spots of control newborns were 0.17 ± 0.03 nmol/ml, and those of patients with isovaleric acidemia ranged from 1.3 to 80.0 nmol/ml. Those of the newborns treated with antibiotics, which caused high C5-acylcarnitine levels (1.9 ± 1.7 nmol/ml) in dried blood spots, were 0.22 ± 0.05 nmol/ml. 
Conclusions: Our data showed that the present method is useful in eliminating the false-positive results due to antibiotics use in newborn screening for isovaleric acidemia
Formation of graphene oxide nano-disks by electrochemical oxidation of HOPG

When HOPG (highly oriented pyrolytic graphite) was electrochemically oxidized in alkali
solution, STM observation showed that graphite oxide with homo-sized disks 15 nm in diameter and
0.5 nm in thickness was formed dispersively on the HOPG surface. With an increase in the anodic
charge, the number of the disks enhanced, and covered finally the HOPG surface without overlap at the
maximum coverage,70%. The projected area of the disks was proportional to the anodic charge when
the charge was small. The disks were hydrophilic. The double layer capacitance of the oxidized HOPG
increased slightly with the anodic charge, implying that the disks should be an electrical insulator. The
fully disk-coated HOPG did not block the diffusion-controlled current of the redox species. The layer of
the disks must be porous for ions or solutions. The formation of the uniform size may be ascribed to
the difference between the density of graphite oxide and that of the basal plane of graphite. The
formation of nano-disks and their properties are inconsistent with such an image of intercalation that
ions are inserted into layers of graphenes of HOPG
T-type Ca2+ channels in non-vascular smooth muscles

T-type Ca2+ current has been recorded in smooth muscle myocytes, and associated interstitial cells, from smooth muscle cells isolated from the gastro-intestinal tract, urinary bladder, urethra, prostate gland, myometrium, vas deferens, lymphatic vessels and airways smooth muscle. By contrast, current through such channels has not been recorded from other tissues, such as the ureter. Whilst the properties of this Ca2+ current are similar in most of these cells, with respect to their voltage-dependence, ion selectivity and response to channel modulators, some differences have been recorded, most notably in the gastro-intestinal tract, and may demand a reappraisal of how a T-type Ca2+ current is characterised. The functions of such a current in different tissues remains uncertain. In most of smooth muscles discussed in this review, it is hypothesised that it underlies rhythmic or spontaneous electrical activity, especially in concert with other current-carrying systems, such as Ca2+-activated outward currents. Of equal interest is that the T-type Ca2+ channel may be a target for agents that modulate tissue function, especially in pathological conditions, or are the site of secondary effects of agents used in clinical medicine. For example, T-type Ca2+ channel modulators have been proposed to reduce overactive muscular activity in the gastro-intestinal or urinary tract, or function as tocolytic agents: and the action of volatile anaesthetics on them in airways smooth muscle requires consideration in their overall action
Analytic behavior of the QED polarizability function at finite temperature

We revisit the analytical properties of the static quasi-photon polarizability function for an electron gas at finite temperature, in connection with the existence of Friedel oscillations in the potential created by an impurity. In contrast with the zero temperature case, where the polarizability is an analytical function, except for the two branch cuts which are responsible for Friedel oscillations, at finite temperature the corresponding function is not analytical, in spite of becoming continuous everywhere on the complex plane. This effect produces, as a result, the survival of the oscillatory behavior of the potential. We calculate the potential at large distances, and relate the calculation to the non-analytical properties of the polarizability
On the relation between battery size and PV power ramp rate limitation

PV power fluctuations caused by clouds are leading operators of grids with high renewable energy penetration rates to impose ramp rate limitations. Costly battery energy storage systems are used for fulfilling these regulations but the question of the power and energy requirements for accomplishing them has not been fully answered. This work analyses the effects of reducing the size of a battery designed to absorb every fluctuation by taking into consideration, both, the fluctuation occurrence and the penalties in case of non-compliance of a given prescribed ramp-rate limitation. A theoretical analysis was carried out in order to assess the relation between size reduction and ramp rate compliance, obtaining as result a model for predicting the probability of non-compliances with a reduced battery. Additionally, the battery size reduction analysis was applied to the particular grid code currently proposed for Puerto Rico, creating new tools for selecting a battery with reduced power and energy capacity
Major agricultural changes required to mitigate phosphorus losses under climate change

Phosphorus losses from land to water will be impacted by climate change and land management for food production, with detrimental impacts on aquatic ecosystems. Here we use a unique combination of methods to evaluate the impact of projected climate change on future phosphorus transfers, and to assess what scale of agricultural change would be needed to mitigate these transfers. We combine novel high-frequency phosphorus flux data from three representative catchments across the UK, a new high-spatial resolution climate model, uncertainty estimates from an ensemble of future climate simulations, two phosphorus transfer models of contrasting complexity and a simplified representation of the potential intensification of agriculture based on expert elicitation from land managers. We show that the effect of climate change on average winter phosphorus loads (predicted increase up to 30% by 2050s) will be limited only by large-scale agricultural changes (e.g., 20–80% reduction in phosphorus inputs)
Entanglement of hard-core bose gas in degenerate levels under local noise

Quantum entanglement properties of the pseudo-spin representation of the BCS model is investigated. In case of degenerate energy levels, where wave functions take a particularly simple form, spontaneous breaking of exchange symmetry under local noise is studied. Even if the Hamiltonian has the same symmetry, it is shown that there is a non-zero probability to end up with a non-symmetric final state. For small systems, total probability for symmetry breaking is found to be inversely proportional to the system size
Curves with rational chord-length parametrization

It has been recently proved that rational quadratic circles in standard Bezier form are parameterized by chord-length. If we consider that standard circles coincide with the isoparametric curves in a system of bipolar coordinates, this property comes as a straightforward consequence. General curves with chord-length parametrization are simply the analogue in bipolar coordinates of nonparametric curves. This interpretation furnishes a compact explicit expression for all planar curves with rational chord-length parametrization. In addition to straight lines and circles in standard form, they include remarkable curves, such as the equilateral hyperbola, Lemniscate of Bernoulli and Limacon of Pascal. The extension to 3D rational curves is also tackled
Spatially Resolved Luminescence Spectroscopy of Single GaN/(Al,Ga)N Quantum Disks

The dependence of the optical transition energy Et of GaN quantum disks (Qdisks) embedded within (Al,Ga)N nanocolumns grown on a (111) Si substrate on disk thickness, disk diameter, barrier thickness, and barrier composition has been investigated by both spatially resolved cathodoluminescence spectroscopy and applying a theoretical model. Results of Et on the disk and barrier thickness, as well as barrier composition resemble those of corresponding quantum wells, whereas results on the disk diameter are essentially determined by the lateral strain distribution of the Qdisks
Provision of artificial warrens as a means to enhance native wild rabbit populations: what type of warren and where should they be sited?

In Spain, wild rabbits are essential for some highly endangered species, and, therefore, many actions have been undertaken to increase their populations. In the present study, artificial warrens are provided as a means to increase shelter for native wild rabbit populations in a given area. We evaluate the use of three types of warrens by rabbits and the effect on that use of five habitat characteristics at two spatial scales (500 × 500-m grids and 25-m plots). To evaluate that use, we identified pre-established signs at the entrances to each warren, and based on this, we calculated occupancy rate and activity. Our results indicate that rabbit abundance within a grid is the only variable which simultaneously explains both the greater occupancy and the higher activity in the artificial warrens located in that grid. Some 73.2% of the grids showed signs of rabbit use at the time of the evaluation. However, the pre-existing rabbit populations within the grids were not quantified and, hence, we cannot state that the warrens contributed to an increase in the rabbit abundance. Regarding the habitat, our results reveal that warrens should be situated in grids with food coverage of less than 50%, while the use of each individual refuge is greater where food availability in the immediate surroundings is at least 20% and shelter at least 50%. The tube warrens showed significantly greater rabbit use than the other types while there was little difference between the stone and pallet warrens in terms of use
Abstraction-carrying code: a model for mobile code safety

Proof-Carrying Code (PCC) is a general approach to mobile\ud
code safety in which programs are augmented with a certificate (or proof).\ud
The intended benefit is that the program consumer can locally validate the\ud
certificate w.r.t. the "untrustcd" program by means of a certificate checker a\ud
process which should be much simpler, efficient, and automatic than generating\ud
the original proof. The practical uptake of PCC greatly depends on the\ud
existence of a variety of enabling technologies which allow both proving programs\ud
correct and replacing a costly verification process by an efficient checking\ud
proceduri on th( consumer side. In this work we propose Abstraction-\ud
Carrying Code (ACC), a novel approach which uses abstract interpretation\ud
as enabling technology. We argue that the large body of applications of abstract\ud
interpretation to program verification is amenable to the overall PCC\ud
scheme. In particular, we rely on an expressive class of safely policies which\ud
can be defined over different abstract domains. We use an abstraction (or\ud
abstract model) of the program computed by standard static analyzers as a\ud
certificate. The validity of the abstraction on ihe consumer side is checked\ud
in a single pass by a very efficient and specialized abstract-interpreter. We\ud
believe that ACC brings the expressiveness, flexibility and automation which\ud
is inherent in abstract interpretation techniques to the area of mobile code\ud
safety
Ruthenacycles and Iridacycles as Catalysts for Asymmetric Transfer Hydrogenation and Racemisation

Ruthenacycles, which are easily prepared in a single step by reaction between enantiopure aromatic amines and [Ru(arene)Cl2]2 in the presence of NaOH and KPF6, are very good asymmetric transfer hydrogenation catalysts. A range of aromatic ketones were reduced using isopropanol in good yields with ee’s up to 98%. Iridacycles, which are prepared in similar fashion from [IrCp*Cl2]2 are excellent catalysts for the racemisation of secondary alcohols and chlorohydrins at room temperature. This allowed the development of a new dynamic kinetic resolution of chlorohydrins to the enantiopure epoxides in up to 90% yield and 98% enantiomeric excess (ee) using a mutant of the enzyme Haloalcohol dehalogenase C and an iridacycle as racemisation catalyst.
Retrieving Biko: a Black Consciousness critique of whiteness

There is an important history often neglected by genealogies of ‘critical whiteness studies’: Steve Biko's Black Consciousness critique of white liberalism. What would it mean to retrieve this criticism in the context of white anti-racism in the post-apartheid era? Said's (2003) contrapuntal method proves useful here as a juxtaposing device whereby the writings of a past figure can be critically harnessed, travelling across temporal and ideological boundaries to interrogate the present. Four interlinked modes of disingenuous white anti-racism can thus be identified: (1) a fetishistic preoccupation with disproving one's racism; (2) ostentatious forms of anti-racism that function as means of self-promotion, as paradoxical means of white self-love; (3) the consolidation and extension of agency through redemptive gestures of ‘heroic white anti-racism’; (4) ‘charitable anti-racism’ which fixes tolerance within a model of charity, as an act of generosity and that reiterates the status and role of an anti-racist benefactor
Volume changes in a filled elastomer studied via digital image correlation

Volumetric strains in a filled SBR specimen subjected to cyclic uniaxial tension with increasing extensions are studied. Digital image correlation is used to follow the kinematics of two orthogonal free faces. A volume expansion is observed past a critical elongation, which can be interpreted as the onset of cavitation. Under unloading, the volume returns to its original value and remains constant upon reloading. Increasing the elongation to higher values than the previous cycle leads again to a volumetric expansion
An experimental study on the effects of lubrication in form tapping

This paper presents the results of a study of lubrication in form tapping and aims
at a better understanding of its effect. It appears that lubrication is of paramount
importance. Oil with efficient high pressure additives can reduce considerably the torque
necessary to form the thread. Lubricants reduce the tool / work material friction during the
forming process and, as a consequence, the resulting strain distribution and the strain
hardening of the thread are affected. This investigation includes an analysis on the effects of
additives in lubricants on the temperature during tapping, enabling correlation with the
appearance of chemical elements of the oil which react with the thread material and
contribute to lubrication.These AMN
these CIFR
Modeling the deformation textures and microstructural evolutions of a Fe–Mn–C TWIP steel during tensile and shear testing

The high manganese austenitic steels with low stacking fault energy (SFE) present outstanding mechanical properties due to the occurrence of two strain mechanisms: dislocation glide and twinning. Both mechanisms are anisotropic. In this paper, we analyzed the effect of monotonous loading path on the texture, the deformation twinning and the stress–strain response of polycrystalline high Mn TWIP steel. Experimental data were compared to predicted results obtained by two polycrystalline models. These two models are based on the same single crystal constitutive equations but differ from the homogenization scheme. The good agreement between experiments and calculations suggest that the texture plays a key role in twinning activity and kinetics with regard to the intergranular stress heterogeneities. Rolling direction simple shear induces single twinning while rolling and transverse direction uniaxial tensions induce multi-twinning leading to lower twin volume fractions due to twin–twin interactions
Dynamics and kinetics of the S + HO2 reaction: A theoretical study

We report a quasi-classical trajectory study of the S + HO2 reaction using a previously reported global potential energy surface for the ground electronic state of HSO2. Zero-point energy leakage is approximately accounted for by using the vibrational energy quantum mechanical threshold method. Calculations are carried out both for specific ro-vibrational states of the reactants and thermalized ones, with rate constants being reported as a function of temperature. The results suggest that the title reaction is capture type, with OH and SO showing as the most favorable products. The internal energy distribution of such products and the reaction mechanism are also investigated. © 2008 Wiley Periodicals, Inc. Int J Chem Kinet 40: 533-540, 2008http://dx.doi.org/10.1002/kin.2034