pinecone/core-2020-05-10-deduplication huggingface dataset:
Voltammetric and DFT Studies on Viloxazine: Analytical Application to Pharmaceuticals and Biological Fluids

The oxidative behavior of viloxazine was studied at a glassy carbon electrode in different buffer systems using cyclic, differential pulse and square-wave voltammetry. The oxidation process was shown to be diffusion-controlled and irreversible over the studied pH. The voltammetric study of the model compounds, 2-ethoxyanisole and morpholine, associated with quantum mechanical (DFT) calculations, allowed to elucidate the oxidation mechanism of viloxazine. An analytical method was developed for the quantification of viloxazine using an acetate pH 5 buffer solution as a supporting electrolyte. A linear response was obtained in the range 7 to 45 muM, with a detection limit of 0.8 muM. Validation parameters such as sensitivity, precision and accuracy were evaluated. The proposed method was successfully applied to the determination of viloxazine in pharmaceutical formulations and in human serum. The results were statistically compared with those obtained through an established high-performance liquid chromatography technique, no significant differences having been found between the two methods.http://dx.doi.org/10.1002/elan.20080420
Quantitation of erythrocyte pentose pathway flux with [2-13C]glucose and 1H NMR analysis of the lactate methyl signal

A simple and sensitive NMR method for quantifying excess 13C-enrichment in positions 2 and 3 of lactate by 1H NMR spectroscopy of the lactate methyl signal is described. The measurement requires neither signal calibrations nor the addition of a standard and accounts for natural abundance 13C-contributions. As a demonstration, the measurement was applied to sim3 mumol of lactate generated by erythrocyte preparations incubated with [2-13C]glucose to determine the fraction of glucose metabolized by the pentose phosphate pathway (PP). PP fluxes were estimated from the ratio of excess 13C-enrichment in lactate carbon 3 relative to carbon 2 in accordance with established metabolic models. Under baseline conditions, PP flux accounted for 7 ± 2% of glucose consumption while in the presence of methylene blue, a classical activator of PP activity, its contribution increased to 27 ± 10% of total glucose consumption (P < 0.01). Magn Reson Med 51:1283-1286, 2004. © 2004 Wiley-Liss, Inc.http://dx.doi.org/10.1002/mrm.2009
Stability Analysis of Difference Methods for Parabolic Initial Value Problems

Abstract  A decomposition of the numerical solution can be defined by the normal mode representation, that generalizes further the spatial eigenmode decomposition of the von Neumann analysis by taking into account the boundary conditions which are not periodic. In this paper we present some new theoretical results on normal mode analysis for a linear and parabolic initial value problem. Furthermore we suggest an algorithm for the calculation of stability regions based on the normal mode theory.http://dx.doi.org/10.1007/s10915-004-4799-
Fatigue design of cast steel nodes in tubular bridge structures

Due to their aesthetic and structural advantages, tubular space truss structures are enjoying increasing popularity in modern bridge construction. The use of cast steel nodes for the joints between the circular hollow section members is also becoming increasingly popular. The fatigue design of such joints, however, requires additional knowledge with respect to their fatigue resistance. Previous experimental investigations showed very clearly that the fatigue behaviour is governed by the welds between the casting stubs and the hollow section members. This paper presents a methodology for the determination of allowable initial sizes of casting defects as a function of the required fatigue resistance of the welds. The relative influence of the main parameters is quantitatively discussed and recommendations for design are given.http://dx.doi.org/10.1016/j.ijfatigue.2007.03.00
Confined brownian ratchets

We analyze the dynamics of Brownian ratchets in a confined environment. The motion of the particles is described by a Fick-Jakobs kinetic equation in which the presence of boundaries is modeled by means of an entropic potential. The cases of a flashing ratchet, a two-state model, and a ratchet under the influence of a temperature gradient are analyzed in detail. We show the emergence of a strong cooperativity between the inherent rectification of the ratchet mechanism and the entropic bias of the fluctuations caused by spatial confinement. Net particle transport may take place in situations where none of those mechanisms leads to rectification when acting individually. The combined rectification mechanisms may lead to bidirectional transport and to new routes to segregation phenomena. Confined Brownian ratchets could be used to control transport in mesostructures and to engineer new and more efficient devices for transport at the nanoscale
Noncyclic geometric phase for neutrino oscillation

We provide explicit formulae for the noncyclic geometric phases or
Pancharatnam phases of neutrino oscillations. Since Pancharatnam phase is a
generalization of the Berry phase, our results generalize the previous findings
for Berry phase in a recent paper [Phys. Lett. B, 466 (1999) 262]. Unlike the
Berry phase, the noncyclic geometric phase offers distinctive advantage in
terms of measurement and prediction. In particular, for three-flavor mixing,
our explicit formula offers an alternative means of determining the
CP-violating phase. Our results can also be extended easily to explore
geometric phase associated with neutron-antineutron oscillations
Levitating spherical particle in a slightly tapered tube at low Reynolds numbers: Application to the low-flow rate rotameters

In this study, a theoretical framework is developed to predict the equilibrium conditions of a non-neutrally buoyant sphere placed in a vertical conical tube as encountered in liquid rotameters. The analysis presented herein is applicable for a sphere heavier than the surrounding fluid, situated on the axis of a slightly tapered tube. The sphere is subject to the laminar flow conditions with the Reynolds numbers ranging between the Stokes type regimes up to values corresponding to slightly inertial regimes. In this work, we assume that the aperture angle of the tube is small and that the drag force is mainly due to the dissipation located in the gap between the tube and the sphere. Under these conditions, it is possible to consider the tube as locally cylindrical and we can use the results previously obtained for the correction factor of the Stokes force on a sphere subject to a Poiseuille flow in a tube of constant cross-section. We obtain an equation relating the flow rate to the vertical position of the sphere in the tube and the validity of this analysis is demonstrated by applying it to a commercially available rotameter. The present study provides a simple but sound theoretical method to calibrate such flowmeters
Reactive Attachment Disorder and Disinhibited Social Engagement Disorder in School-Aged Foster Children - A Confirmatory Approach to Dimensional Measures

This study aimed to investigate the factor structure and external correlates of the constructs Reactive Attachment Disorder (RAD) and Disinhibited Social Engagement Disorder (DSED) from the Diagnostic and Statistical Manual of Mental Disorders (DSM-5). The following were addressed: First, do our data support the DSM-5 conceptualization of RAD/DSED as two separate constructs? Second, are RAD and DSED distinct from other well-established dimensions of child psychopathology? Third, what are the external correlates of RAD/DSED in this sample? The study sample included 122 foster children aged 6–10 years. Foster parents completed the Strengths and Difficulties Questionnaire (SDQ), and the RAD/DSED-scale from the Developmental and Well-Being Assessment. Child protection caseworkers completed a questionnaire regarding exposure to maltreatment and placement history. Confirmatory factor analysis (CFA) of the RAD/DSED items identified a good fit for a model with a two-factor structure, which is congruent with the DSM-5 definition of RAD and DSED. A new CFA model, which included the RAD and DSED factors together with the four problem factors of the SDQ (emotional, conduct, hyperactivity-inattention, and peer problems), also demonstrated a good fit with our data. RAD and DSED were associated with the SDQ Impact scale and help seeking behavior. This was partly explained by the SDQ externalizing and peer problem subscales. Our findings lend support for the DSM-5 conceptualization of RAD and DSED as separate dimensions of child psychopathology. Thus, the assessment of RAD and DSED provides information beyond other mental health problems
Detecting changes in the basin of attraction of a dynamical system: Application to the postural restoring system

A method that provides athree-dimensional representation ofthe basin ofattraction of a dynamical system from experimen tal data was applied tothe problem ofdynamic balance restoration. The method isbased onthe density ofthe data onthe phase space ofthe system under study and makes use ofmodeling and numerical curve fittingtools.For the\ud
dynamical system ofbalance restora tion,the shape and the size of the basin of attraction depend on the dynamics of the postural restoring mechanisms and contain important\ud
information regarding the biomechanical,as well as the neuromuscular condition of the individual. The aim ofthis work was toexamine the ability ofthe method todetect,\ud
through the observed changes inthe shape and/or the size ofthe calculated basins of attraction, (a)the inherent differences between different systems (in the current application, postural restoring systems of different individuals)and (b)induced chan ges in the\ud
same system (thepostural restoring system of an individual).The results ofthe study confirm the validity of the method and furthermore justify its robustness
High isolation series-shunt photoconductive microwave switch

This article presents a wide band compact high isolation photoconductive switch, which is based on the series-shunt switch design with three photoconductive switches made of diced high-resistivity silicon wafer placed over a microstrip gap and activated by 808-nm near-infrared laser diodes. The switch shows an insertion loss of 1.2 dB and an isolation of 44.8 dB at 2 GHz. It is easy to operate and control by light, high-speed, electromagnetically transparent and it does not require any biasing circuits
Four-Band Hamiltonian for fast calculations in\ud
intermediate-band solar cells

The 8-dimensional Luttinger–Kohn–Pikus–Bir Hamiltonian matrix may be made up of four 4-dimensional blocks. A 4-band Hamiltonian is presented, obtained from making the non-diagonal blocks zero. The parameters of the new Hamiltonian are adjusted to fit the calculated effective masses and strained QD bandgap with the measured ones. The 4-dimensional Hamiltonian thus obtained agrees well with measured quantum efficiency of a quantum dot intermediate band solar cell and the full absorption spectrum can be calculated in about two hours using Mathematica© and a notebook. This is a hundred times faster than with the commonly-used 8-band Hamiltonian and is considered suitable for helping design engineers in the development of nanostructured solar cells
Paediatric community-acquired septic shock: results from the REPEM network study

Introduction and purpose of the study With this study we aimed to describe a "true world" picture of severe pae-diatric 'community-acquired' septic shock and establish the feasibility of a future prospective trial on early goal-directed therapy in children. During a 6-month to 1-year retrospective screening period in 16 emergency departments (ED) in 12 different countries, all children with severe sepsis and signs of decreased perfusion were included. Results A 270,461 paediatric ED consultations were screened, and 176 cases were identified. Significant comorbidity was present in 35.8 % of these cases. Intensive care admission was deemed necessary in 65.7 %, mechanical ventilation in 25.9 % and vasoactive medications in 42.9 %. The median amount of fluid given in the first 6 h was 30 ml/kg. The overall mortality in this sample was 4.5 %. Only 1.2 % of the survivors showed a substantial decrease in Paediatric Overall Performance Category (POPC). 'Severe' outcome (death or a decrease ≥2 in POPC) was significantly related (p0.01) to: any desaturation below 90 %, the amount of fluid given in the first 6 h, the need for and length of mechanical ventilation or vasoactive support, the use of dobutamine and a higher lactate or lower base excess but not to any variables of predisposition, infection or host response (as in the PIRO (Predisposition, Infection, Response, Organ dysfunction) concept). Conclusion The outcome in our samplewas very good.Many children received treatment early in their disease course, so avoiding subsequent intensive care. While certain variables predispose children to become septic and shocked, in our sample, only measures of organ dysfunction and concomitant treatment proved to be significantly related with outcome. We argue why future studies should rather be large multinational prospective observational trials and not necessarily randomised controlled trial
Light dark matter candidates in intense laser pulses I: paraphotons and fermionic minicharged particles

Polarimetric experiments driven by the strong field of a circularly polarized laser wave can become a powerful tool to limit the parameter space of not yet detected hidden-photons and minicharged particles associated with extra U(1) gauge symmetries. We show how the absorption and dispersion of probe electromagnetic waves in the vacuum polarized by such a background are modified due to the coupling between the visible U(1)-gauge sector and these hypothetical degrees of freedom. The results of this analysis reveal that the regime close to the two-photon reaction threshold can be a sensititive probe of these hidden particles. Parameters of modern laser systems are used to estimate the projected sensitivities on the corresponding coupling constants in regions where experiments driven by dipole magnets are less constricted. The role played by a paraphoton field is analyzed via a comparison with a model in which the existence of minicharges is assumed only. For both scenarios is found that the most stringent exclusion limit occurs at the lowest threshold mass; this one being determined by a certain combination of the field frequencies and dictated by energy momentum balance of the photo-production of a pair of minicharged particles. The dependencies of the observables on the laser attributes as well as on the unknown particle parameters are also analyzed
On heat properties of AdS black holes in higher dimensions

We investigate the heat properties of AdS Black Holes in higher dimensions. We consider the study of the corresponding thermodynamical properties including the heat capacity explored in the determination of the black hole stability. In particular, we compute the heat latent. To overcome the instability problem, the Maxwell construction, in the ( T, S )-plane, is elaborated. This method is used to modify the the Hawking-Page phase structure by removing the negative heat capacity regions. Then, we discuss the thermodynamic cycle and the heat engines using the way based on the extraction of the work from a black hole solution
Evidence for asymptotic safety from dimensional reduction in causal dynamical triangulations

We calculate the spectral dimension for a nonperturbative lattice approach to quantum gravity, known as causal dynamical triangulations (CDT), showing that the dimension of spacetime smoothly decreases from ∼ 4 on large distance scales to ∼ 3/2 on small distance scales. This novel result may provide a possible resolution to a long-standing argument against the asymptotic safety scenario. A method for determining the relative lattice spacing within the physical phase of the CDT parameter space is also outlined, which might prove useful when studying renormalization group flow in models of lattice quantum gravity
Varying constants quantum cosmology

We discuss minisuperspace models within the framework of varying physical constants theories including Λ-term. In particular, we consider the varying speed of light (VSL) theory and varying gravitational constant theory (VG) using the specific ansätze for the variability of constants: c(a) = c0 an and G(a)=G0 aq. We find that most of the varying c and G minisuperspace potentials are of the tunneling type which allows to use WKB approximation of quantum mechanics. Using this method we show that the probability of tunneling of the universe ``from nothing'' (a=0) to a Friedmann geometry with the scale factor at is large for growing c models and is strongly suppressed for diminishing c models. As for G varying, the probability of tunneling is large for G diminishing, while it is small for G increasing. In general, both varying c and G change the probability of tunneling in comparison to the standard matter content (cosmological term, dust, radiation) universe models
A study of pressure-driven displacement flow of two immiscible liquids using a multiphase lattice Boltzmann approach

The pressure-driven displacement of two immiscible fluids in an inclined channel in the presence of viscosity and density gradients is investigated using a multiphase lattice Boltzmann approach. The effects of viscosity ratio, Atwood number, Froude number, capillary number, and channel inclination are investigated through flow structures, front velocities, and fluid displacement rates. Our results indicate that increasing viscosity ratio between the fluids decreases the displacement rate. We observe that increasing the viscosity ratio has a non-monotonic effect on the velocity of the leading front; however, the velocity of the trailing edge decreases with increasing the viscosity ratio. The displacement rate of the thin-layers formed at the later times of the displacement process increases with increasing the angle of inclination because of the increase in the intensity of the interfacial instabilities. Our results also predict the front velocity of the lock-exchange flow of two immiscible fluids in the exchange flow dominated regime. A linear stability analysis has also been conducted in a three-layer system, and the results are consistent with those obtained by our lattice Boltzmann simulations
Enhanced magnetization and improved insulating character in Eu substituted BiFeO3

The polycrystalline Bi1-xEuxFeO 3 (x=0, 0.05, and 0.1) ceramics were synthesized by conventional solid-state route. X-ray diffraction studies and Raman measurements revealed that the compounds crystallized in rhombohedral structure with R3c space group. In addition, a nominal percentage of orthorhombic phase was observed in 10 mol.% Eu substituted BiFeO3. Appearance of weak ferromagnetism and significant increase in Néel temperature TN in the substituted compounds were discussed on the basis of structural distortions. Enhanced remnant magnetization of 75 memu/g and large coercive field of 6.4kÖe were observed in 10 mol.% Eu substituted BiFeO3. Equivalent circuit model was employed to estimate the grain and grain boundary contributions towards the electrical parameters such as resistance and conductivity. Non-Debye type of relaxation was confirmed from impedance and electric modulus studies. The obtained frequency variation of ac conductivity at different temperature obeys Jonscher's power law and is consistent with the correlated barrier hopping model. Temperature variations of ac conductivity explained that electronic hopping, oxygen vacancies movement, and/or creation of defects contribute to conduction in all the compounds
Dynamics of rising bubble inside a viscosity-stratified medium

The rising bubble dynamics in an unconfined quiescent viscosity-stratified medium\ud
has been numerically investigated. This is frequently encountered in industrial as well\ud
as natural phenomena. In spite of the large number of studies carried out on bubbles\ud
and drops, very few studies have examined the influence of viscosity stratification\ud
on bubble rise dynamics. To the best of our knowledge, none of them have isolated\ud
the e\ud
ff\ud
ects of viscosity-stratification alone, even though it is known to influence the\ud
dynamics extensively, which is the main objective of the present study. By conducting\ud
time-dependent simulations, we present a library of bubble shapes in the Galilei and\ud
the Eötvös numbers plane. Our results demonstrate some counter-intuitive phenom-\ud
ena  for  certain  range  of  parameters  due  to  the  presence  of  viscosity  stratification\ud
in the surrounding fluid. We found that in a linearly increasing viscosity medium,\ud
for certain values of parameters, bubble undergoes large deformation by forming an\ud
elongated skirt, while the skirt tends to physically separate the wake region from the\ud
rest of the surrounding fluid. This peculiar dynamics is attributed to the migration\ud
of less viscous fluid that is carried in the wake of the bubble as it rises, and thereby\ud
creating an increasingly larger viscosity contrast between the fluid occupied in the\ud
wake region and the surrounding fluid, unlike that observed in a constant viscosity\ud
medium. It is also observed that the e\ud
ff\ud
ect of viscosity stratification is qualitatively\ud
di\ud
ff\ud
erent for di\ud
ff\ud
erent regimes of the dimensionless parameters. In future, it will be\ud
interesting to investigate this problem in three-dimensions
Effect of crystal structure and cationic order on phonon modes across ferroelectric phase transformation in Pb(Fe0.5-xScxNb0.5)O3 bulk ceramics

Pb(Fe0.5-xScxNb0.5)O3 [(PFSN) (0 ≤ x ≤ 0.5)] multiferroic relaxors were synthesized and the temperature dependence of phonon modes across ferroelectric to paraelectric transition was studied. With varying Sc content from x = 0 to 0.25 the structure remains monoclinic and with further addition (x = 0.3 - 0.5) the structure transforms into rhombohedral symmetry. Structural refinement studies showed that the change in crystal structure from monoclinic to rhombohedral symmetry involves a volume increment of 34-36%. Associated changes in the tolerance factor (1.024 ≤ t ≤ 0.976) and bond angles were observed. Structure assisted B′-B″ cation ordering was confirmed through the superlattice reflections in selected area electron diffraction (SAED) pattern of Pb(Sc0.5Nb0.5)O3 (x = 0.5). Cation ordering is also evident from the evolution of Pb-O phonon mode in Raman spectra of compositions with rhombohedral symmetry (x ≥ 0.3). The high temperature Raman scattering studies show that the B-localized mode [F1u, ∼250 cm−1] and BO6 octahedral rotational mode [F1g, ∼200 cm−1], both originating from polar nano regions (PNRs) behave like coupled phonon modes in rhombohedral symmetry. However, in monoclinic symmetry they behave independently across the transition. Softening of B localized mode across the transition followed by the hardening for all compositions confirms the diffusive nature of the ferroelectric transformation. The presence of correlation between the B localized and BO6 rotational modes introduces a weak relaxor feature for systems with rhombohedral symmetry in PFSN ceramics, which was confirmed from the macroscopic dielectric studies