3D Modeling of the Magnetization of Superconducting Rectangular-Based Bulks and Tape Stacks

In recent years, numerical models have become popular and powerful tools to investigate the electromagnetic behavior of superconductors. One domain where this advances are most necessary is the 3D modeling of the electromagnetic behavior of superconductors. For this purpose, a benchmark problem consisting of superconducting cube subjected to an AC magnetic field perpendicular to one of its faces has been recently defined and successfully solved. In this work, a situation more relevant for applications is investigated: a superconducting parallelepiped bulk with the magnetic field parallel to two of its faces and making an angle with the other one without and with a further constraint on the possible directions of the current. The latter constraint can be used to model the magnetization of a stack of high-temperature superconductor tapes, which are electrically insulated in one direction. For the present study three different numerical approaches are used: the Minimum Electro-Magnetic Entropy Production (MEMEP) method, the $H$-formulation of Maxwell's equations and the Volume Integral Method (VIM) for 3D eddy currents computation. The results in terms of current density profiles and energy dissipation are compared, and the differences in the two situations of unconstrained and constrained current flow are pointed out. In addition, various technical issues related to the 3D modeling of superconductors are discussed and information about the computational effort required by each model is provided. This works constitutes a concrete result of the collaborative effort taking place within the HTS numerical modeling community and will hopefully serve as a stepping stone for future joint investigations

Il paese di Cuccagna nelle letterature europee tra Due e Trecento

Il contributo prende in esame le prime tre testimonianze letterarie del paese di Cuccagna che ci siano giunte dal Medioevo europeo (Li fabliaus de Cocagne, il poema in medio Inglese The Land of Cokaygne e la terza novella dell’ottava giornata del Decameron), per esaminare il diverso ruolo svolto e la diversa forma assunta dal meraviglioso paese in ciascun testo. Strumento per mantenere lo status quo (Li fabliaus de Cocagne), elemento parodico e satirico del mondo monastico (The Land of Cokaygne) o bugia rivolta ai più ingenui e creduloni (Decameron, VIII, 3), questa fantasia alimentare assume caratteri diversi anche in relazione alla cultura alimentare che lo scrivente intende rappresentare, in funzione dei suoi scopi e del suo pubblico. Nel racconto di Maso del Saggio, al centro del paese svetta una montagna di Parmigiano grattugiato da cui rotolano ravioli, concreta rappresentazione delle aspirazioni alimentari di un povero pittore fiorentino come Calandrino; nel poema inglese il cibo, tra cui uccelli arrosto e costose spezie, appare più elitario e adatto a satireggiare l’alimentazione dei monaci, ricca e abbondante a dispetto della loro regola; nel fabliau francese, il cui messaggio deve apparire valido per tutti gli strati sociali, tra i cibi raffigurati non appaiono gli elementi più poveri e quotidiani (pane, legumi, vegetali), ma nemmeno quelli più ricchi e raffinati (spezie, cacciagione di piuma, vini orientali), e Cocagne costituisce pertanto la raffigurazione eterna e sovrabbondante della tavola quotidiana dei ricchi, ma anche degli strati poveri nei momenti di festa o particolare abbondanza

Teoria classica dei campi e propagazione di particelle

In questa tesi si vuole introdurre lo studio della propagazione di particelle, secondo la teoria classica dei campi e la meccanica quantistica. Introducendo il formalismo lagrangiano per le teorie di campo, vengono discussi i vari tipi di trasformazioni che si possono effettuare sull'azione, ponendo in rilievo il legame tra trasformazioni di riferimento, simmetrie dell'azione e grandezze conservate. Si dimostra il teorema di Noether e lo si applica allo studio delle simmetrie del campo elettromagnetico. Si introduce poi il campo di Klein--Gordon, con l'obiettivo di formulare le basi per la descrizione della propagazione di particelle scalari. Le funzioni di Green permettono di interpretare l'interazione tra le sorgenti e il campo in termini di propagazione di particelle reali e virtuali, e vengono calcolate usando il metodo distribuzionale generale. Si tratta infine la propagazione libera delle particelle, esaminando in particolare il caso non relativistico. Il propagatore quantistico libero permette di interpretare l'esperimento della doppia fenditura effettuato con una singola particella non relativistica, ricavando una possibile espressione per l'intensità della figura d'interferenza

Determinação de compostos fenólicos por cromatografia líquida de alta eficiência isocrática durante estacionamento da erva-mate

Different phenolic compound, 5- caffeoylquinic acid (5-CQA), caffeic acid (AC) and rutin (Ru) contents of yerba-mate (Ilex paraguariensis) Brazilian samples of 06 different regions of São Mateus - Paraná, during natural and accelerated industrial storage, were evaluated. For quantification, a reverse phase HPLC isocratic method was developed and validated using methanol:water (35:65 v/v) acidified with 0.5% acetic acid as mobile phase and a photodiode array detector. The six sample global average contents were (34.90 and 36.10 mg g-1) for 5-CQA, (0.18 mg g-1 and 0.23 mg g-1) for AC and (7.12 and 7.18 mg g-1) for Ru, respectively, for the natural and accelerated storage systems. The results showed that the 5-CQA and Ru content are kept constant during the storage while AC content increase only during accelerated storage

Honey Environmental DNA Can Be Used to Detect and Monitor Honey Bee Pests: Development of Methods Useful to Identify Aethina tumida and Galleria mellonella Infestations

Environmental DNA (eDNA) contained in honey derives from the organisms that directly and indirectly have been involved in the production process of this matrix and that have played a role in the hive ecosystems where the honey has been produced. In this study we set up PCR-based assays to detect the presence of DNA traces left in the honey by two damaging honey bee pests: the small hive beetle (Aethina tumida) and the greater wax moth (Galleria mellonella). DNA was extracted from 82 honey samples produced in Italy and amplified using two specific primer pairs that target the mitochondrial gene cytochrome oxidase I (COI) of A. tumida and two specific primer pairs that target the same gene in G. mellonella. The limit of detection was tested using sequential dilutions of the pest DNA. Only one honey sample produced in Calabria was positive for A. tumida whereas about 66% of all samples were positively amplified for G. mellonella. The use of honey eDNA could be important to establish early and effective measures to contain at the local (e.g., apiary) or regional scales these two damaging pests and, particularly for the small hive beetle, to prevent its widespread diffusion

Towards the Development of Nutrigenetic Concepts in Pigs by Merging Genomics, Transcriptomics and Metabolomics

In a context of system biology concepts applied to livestock, animal nutrition can be considered as the netwotk interconnecting metabolic, physiologic and genetic aspects. The aim of this Thesis was to detect markers associated with productive traits and metabolic pathways in pigs, merging analyses on pig genome, transcriptome and metabolome. Several approaches of target metabolomics, target re-sequencing of pig genome portions and RNA-seq have been performed, adding classical lab validations. Analysis of the variability in pig genes related to metabolism like bitter taste receptors genes (TAS2R), fatty acids receptors genes (GPR120), KMO and others have been carried out in different pig populations, including commercial breeds (Large White, Duroc, Landrace, Pietran, Meishan) and Italian local pig breeds (Mora Romagnola, Nero Siciliano, Apulo-Calabrese, Casertana and Cinta Senese) as well as wild boars. Moreover, genome wide association analyses based on metabolites and, for most metabotypes, significant SNPs were close or within genes directly involved in the catabolic or anabolic pathways of the targeted metabolites. A few of these markers were associated (P nominal value <0.01) with production and carcass traits. According to our results, the development of precision feeding strategies focused on specific amino acid needs of the animals according to their genotype in genes involved in the amino acid metabolism pathways would be one of the envisaged perspectives of application in pig nutrigenetics and, more generally, in livestock nutrition

Shotgun sequencing of honey DNA can describe honey bee derived environmental signatures and the honey bee hologenome complexity

Honey bees are large-scale monitoring tools due to their extensive environmental exploration. In their activities and from the hive ecosystem complex, they get in close contact with many organisms whose traces can be transferred into the honey, which can represent an interesting reservoir of environmental DNA (eDNA) signatures and information useful to analyse the honey bee hologenome complexity. In this study, we tested a deep shotgun sequencing approach of honey DNA coupled with a specifically adapted bioinformatic pipeline. This methodology was applied to a few honey samples pointing out DNA sequences from 191 organisms spanning different kingdoms or phyla (viruses, bacteria, plants, fungi, protozoans, arthropods, mammals). Bacteria included the largest number of species. These multi-kingdom signatures listed common hive and honey bee gut microorganisms, honey bee pathogens, parasites and pests, which resembled a complex interplay that might provide a general picture of the honey bee pathosphere. Based on the Apis mellifera filamentous virus genome diversity (the most abundant detected DNA source) we obtained information that could define the origin of the honey at the apiary level. Mining Apis mellifera sequences made it possible to identify the honey bee subspecies both at the mitochondrial and nuclear genome levels

Numerical Investigation on the Thermo-Mechanical Behavior of HTS Tapes and Experimental Testing on Their Critical Current

This work extends to second generation Rare-Earth Barium-Copper-Oxide ((Re)BCO) tapes an experimental proce- dure previously developed to analyze the impact of double bending at room temperature on the performance of Bismuth-Strontium- Calcium-Copper-Oxide (BSCCO) tapes. The modified procedure is applied to measure the critical current of a commercial (Re)BCO tape subjected to bending around a cylindrical mandrel first on one side, then on the other side, followed by the cooldown to cryogenic temperature. In the bending phase, mandrels of decreasing diame- ter are used to identify the minimum curvature leading to a signif- icant reduction of the tape critical current. Furthermore, a novel finite element model is developed to complement the experimental results. The model simulates the double bending at room tempera- ture, the following straightening of the sample, and its cooldown to cryogenic conditions. The coupled thermo-mechanical numerical model together with the temperature-dependent mechanical prop- erties allow investigating the combination of thermal contraction effects and bending loads in the whole domain of the problem. The experimental and numerical results obtained help to give a better insight in the distribution of the strain and stress components inside the (Re)BCO tape and to evaluate their impact on the conductor electrical performance in relevant operating condition

Distribution of the Main Apis mellifera Mitochondrial DNA Lineages in Italy Assessed Using an Environmental DNA Approach

Simple Summary The conservation of the genetic diversity of the native honey bee subspecies is a hot topic in many European countries. Mitochondrial DNA (mtDNA) analyses can provide some information that is useful to monitor the genetic integrity of Apis mellifera populations. A preliminary distribution of the main honey bee mitotypes in Italy was obtained more than 20 years ago. In this study we obtained an updated and more detailed distribution map of the main groups of honey bee mitotypes using an unconventional method that exploits the information derived from the environmental DNA contained in the honey. The results were quite different from the picture taken two decades ago. The African mtDNA lineage was spread all over Italy and not only in Sicily, where it is mainly attached to the A. m. siciliana subspecies, and where it was identified in the previous investigation. A reduction in the frequency of the M lineage was also evident, and, on the other hand, a counterbalanced increase in the C mitotypes was observed in regions all over. The obtained results provided an updated distribution map of the A, C and M groups of mitotypes in Italy, which could be a starting point to design appropriate conservation programs for native honey bee subspecies. Growing interest has been emerging on the need to monitor the genetic integrity of the European Apis mellifera subspecies that could be threatened by the human-mediated dispersion of non-native populations and lines. Mitochondrial DNA (mtDNA) lineages can provide useful information for this purpose. In this study, we took advantage of the environmental DNA (eDNA) contained in the honey, which can be analyzed to detect the main groups of mitotypes of the honey bees that produced it. In this study, we applied this eDNA to produce a distribution map all over the Italian peninsula and the two major islands (Sicily and Sardinia) of the following three honey bee mtDNA lineages: A, C and M. A total of 607 georeferenced honey samples, produced in all Italian regions, was analyzed to detect these lineages. The A lineage was widespread in Sicily, as expected, considering that A. m. siciliana carries the African lineage. Surprisingly, this lineage was also reported in about 14% of all other samples produced in almost all continental regions, and in Sardinia. The applied method obtained an updated distribution map of honey bee mtDNA lineages that could be useful to design policies for the conservation of Italian honey bee genetic resources