Transport–diffusion models with nonlinear boundary conditions and solution by generalized collocation methods

AbstractThis paper deals with the derivation of a class of nonlinear transport and diffusion models implemented with nonlinear boundary conditions. Mathematical tools to treat the initial-boundary value problems are developed, based on generalized collocation methods, focused on the treatment of nonlinear boundary conditions in one space dimension. Applications refer to a problem of interest in applied sciences

A new numerical method for a class of Volterra and Fredholm integral equations

In the present work, we introduce a new numerical method based on a strong version of the mean-value theorem for integrals to solve quadratic Volterra integral equations and Fredholm integral equations of the second kind, for which there are theoretical monotonic non-negative solutions. By means of an equality theorem, the integral that appears in the aforementioned equations is transformed into one that enables a more accurate numerical solution with fewer calculations than other previously described methods. Convergence analysis is given

A Next-to-Leading-Order Study of Dihadron Production

The production of pairs of hadrons in hadronic collisions is studied using a next-to-leading-order Monte Carlo program based on the phase space slicing technique. Up-to-date fragmentation functions based on fits to LEP data are employed, together with several versions of current parton distribution functions. Good agreement is found with data for the dihadron mass distribution. A comparison is also made with data for the dihadron angular distribution. The scale dependence of the predictions and the dependence on the choices made for the fragmentation and parton distribution functions are also presented. The good agreement between theory and experiment is contrasted to the case for single $\pi^0$ production where significant deviations between theory and experiment have been observed.Comment: 22 pages, 15 figures; 3 references added, one figure modified for clarit

Age estimation in children by measurement of open apices in teeth: a European formula

The aim of the present paper was to improve and expand research with a larger number of children from various European countries and to provide a common formula useful for all these countries. Orthopantomographs taken from 2,652 European Caucasian children (1,382 boys, 1,270 girls) aged between 4 and 16 years were analyzed. The children came from Croatia, Germany, Kosovo, Italy, Slovenia, Spain, and the UK. Following the pilot study, subjects’ age was modeled as a function of gender (g), morphological variables (predictors)×5 (second premolar), s (sum of normalized open apices) N0, and the first-order interaction between s and N0. The results showed that all these variables contributed significantly to the fit, so that all were included in the regression model, yielding the following linear regression formula: Age=8.387+ 0.282 g−1.692×5+0.835 N0−0.116 s−0.139 s×N0, where g is a variable, 1 for males and 0 for females. The equation explained 86.1% (R2=0.861) of total deviance. The median of the residuals (=observed age minus predicted age) was −0.114 years, with (RefB.2) interquartile range=1.22 years

Selecting Technologies for Sour and Ultra-Sour Gas Treating

As the cleanest fossil fuel, natural gas plays a key role in the path towards renewables. Considering the increasing gas demand, rich CO2 and H2S gas reserves, in the past considered economically unviable, are becoming fruitful. However, the non-conventional nature of this kind of gases, in addition to the potentially higher production cost, raises the need of new strategies for their monetization, bypassing the conventional approaches. Starting from the huge number of novel large-scale projects for the exploitation of rich-H2S gas fields, this paper overviews the current tendencies in sour and ultra-sour natural gas production, focusing on the removal of sulfur-based compounds, together with H2S and CO2. At first, available technologies for ultra-sour gas treatment are discussed. Then, simulations of the absorption processes based on a real case-study are carried out, in order to verify the effectiveness of the proposed alternatives for the removal of mercaptans, as well as CO2 and H2S. Results are critically analyzed, in view of providing a practical guide of industrial interest for the selection of the most suitable method

Prototype gluten-free breads from processed durum wheat: Use of monovarietal flours and implications for gluten detoxification strategies

gluten-free; detoxification strategies; sourdough; celiac disease; epitopes; in-vitro simulated human gastroduodenal digestionIn this investigation, we reported the production of prototype breads from the processed flours of three specific Triticum turgidum wheat genotypes that were selected in our previous investigation for their potential low toxic/immunogenic activity for celiac disease (CD) patients. The flours were subjected to sourdough fermentation with a mixture of selected Lactobacillus strains, and in presence of fungal endoproteases. The breads were characterized by R5 competitive enzyme linked immunosorbent assay in order to quantify the residual gluten, and the differential efficacy in gluten degradation was assessed. In particular, two of them were classified as gluten-free (<20 ppm) and very low-gluten content (<100 ppm) breads, respectively, whereas the third monovarietal prototype retained a gluten content that was well above the safety threshold prescribed for direct consumption by CD patients. In order to investigate such a genotype-dependent efficiency of the detoxification method applied, an advanced proteomic characterization by high-resolution tandem mass spectrometry was performed. Notably, to the best of our knowledge, this is the first proteomic investigation which benefitted, for protein identification, from the full sequencing of the Triticum turgidum ssp. durum genome. The differences of the proteins’ primary structures affecting their susceptibility to hydrolysis were investigated. As a confirmation of the previous immunoassay-based results, two out of the three breads made with the processed flours presented an exhaustive degradation of the epitopic sequences that are relevant for CD immune stimulatory activity. The list of the detected epitopes was analyzed and critically discussed in light of their susceptibility to the detoxification strategy applied. Finally, in-vitro experiments of human gastroduodenal digestion were carried out in order to assess, in-silico, the toxicity risk of the prototype breads under investigation for direct consumption by CD patients. This approach allowed us to confirm the total degradation of the epitopic sequences upon gastro-duodenal digestion

Hardware prototyping and validation of a W-ΔDOR digital signal processor

Microwave tracking, usually performed by on ground processing of the signals coming from a spacecraft, represents a crucial aspect in every deep-space mission. Various noise sources, including receiver noise, affect these signals, limiting the accuracy of the radiometric measurements obtained from the radio link. There are several methods used for spacecraft tracking, including the Delta-Differential One-Way Ranging (ΔDOR) technique. In the past years, European Space Agency (ESA) missions relied on a narrowband ΔDOR system for navigation in the cruise phase. To limit the adverse effect of nonlinearities in the receiving chain, an innovative wideband approach to ΔDOR measurements has recently been proposed. This work presents the hardware implementation of a new version of the ESA X/Ka Deep Space Transponder based on the new tracking technique named Wideband ΔDOR (W-ΔDOR). The architecture of the new transponder guarantees backward compatibility with narrowband ΔDOR

LATTES: a novel detector concept for a gamma-ray experiment in the Southern hemisphere

The Large Array Telescope for Tracking Energetic Sources (LATTES), is a novel concept for an array of hybrid EAS array detectors, composed of a Resistive Plate Counter array coupled to a Water Cherenkov Detector, planned to cover gamma rays from less than 100 GeV up to 100 TeVs. This experiment, to be installed at high altitude in South America, could cover the existing gap in sensitivity between satellite and ground arrays. The low energy threshold, large duty cycle and wide field of view of LATTES makes it a powerful tool to detect transient phenomena and perform long term observations of variable sources. Moreover, given its characteristics, it would be fully complementary to the planned Cherenkov Telescope Array (CTA) as it would be able to issue alerts. In this talk, a description of its main features and capabilities, as well as results on its expected performance, and sensitivity, will be presented.Comment: Proceedings of the 35th International Cosmic Ray Conference (ICRC2017), Busan, South Korea. Presented by R. Concei\c{c}\~{a}o. 8 pages; v2: correct affiliation + journal referenc

On the stochastic mechanics of the free relativistic particle

Given a positive energy solution of the Klein-Gordon equation, the motion of the free, spinless, relativistic particle is described in a fixed Lorentz frame by a Markov diffusion process with non-constant diffusion coefficient. Proper time is an increasing stochastic process and we derive a probabilistic generalization of the equation $(d\tau)^2=-\frac{1}{c^2}dX_{\nu}dX_{\nu}$. A random time-change transformation provides the bridge between the $t$ and the $\tau$ domain. In the $\tau$ domain, we obtain an \M^4-valued Markov process with singular and constant diffusion coefficient. The square modulus of the Klein-Gordon solution is an invariant, non integrable density for this Markov process. It satisfies a relativistically covariant continuity equation