Analyzing the Impact of RDF Graph Structure on Dataset Search: A Case Study with ACORDAR

openNel mondo del Semantic Web, RDF si pone come elemento cardine per la modellazione precisa dei dati e dei loro legami. L'obiettivo centrale di questo lavoro è esplorare le dinamiche dei grafi RDF, mettendo in luce le principali problematiche e potenzialità nell'ambito della ricerca di dataset. Il caso studio di ACORDAR viene esaminato per illustrare l'effetto delle strutture a grafo sull'organizzazione dei dati. Vengono analizzate le tecniche di serializzazione in RDF, sottolineando la centralità di elementi quali gli URI e le capacità avanzate offerte da SPARQL. Si affronta il tema della riproducibilità di ACORDAR, mettendo in risalto l'importanza dei metadati nella fase di ricerca dei dataset. In conclusione, si delineano prospettive future per ottimizzare la ricerca di dataset, arricchendo l'analisi con informazioni tratte dalle strutture a grafo e avvalendosi delle tecnologie emergenti.RDF plays a central role in the era of the Semantic Web, enabling a structured representation of datasets and their relationships. The complex nature of RDF graph structures significantly influences the retrieval of datasets, offering a blend of both challenges and possibilities. Delving deeply into the ACORDAR case study, the work unveils how graph structures influence dataset retrieval and the organization of data. Furthermore, it introduces serialization methods within RDF, emphasizing the importance of URI and the capabilities of the SPARQL. Presenting the ACORDAR reproducibility, the research underscores the significance of metadata in dataset search. Exploring potential avenues for future research in dataset search, the investigation integrates graph structures and harnesses emerging technologies from the Semantic Web era

Investigation of Electroplastic Effect on Four Grades of Duplex Stainless Steels

Since the late 1950s, an effect of electrical current in addition to joule heating on the deformation of metals called the Electroplastic Effect (EPE) has been known. It is used nowadays in the so-called Electrically Assisted Forming (EAF) processes, but the understanding of the phenomenon is not very clear yet. It has been found that EPE increases the formability of high stacking fault energy (SFE) materials, while low SFE materials reach fracture prematurely. Since Duplex Stainless Steels (DSSs) possess a microstructure consisting of two phases with very different SFE (low SFE austenite and high SFE ferrite) and they are widely used in industry, we investigated EPE on those alloys. Tensile tests at 5 A/mm2, 10 A/mm2 and 15 A/mm2 current densities along with thermal counterparts were conducted on UNS S32101, UNS S32205, UNS S32304 and UNS S32750. The DSS grades were characterized by means of optical microscopy, X-ray diffraction and their mechanical properties (ultimate tensile strength, total elongation, uniform elongation and yield stress). An increase in uniform elongation for the electrical tests compared to the thermal counterparts as well as an increase in total elongation was found. No differences were observed on the yield stress and on the ultimate tensile strength. Un uneven distribution of the current because of the different resistivity and work hardening of the two phases has been hypothesized as the explanation for the positive effect of EPE

Permanent Magnet Heater for a Precise Control of Temperature in Aluminum Billets before Extrusion

Abstract Aluminum billets are heated at a prescribed temperature before hot working in gas or induction or resistance furnaces. Temperature distribution variable along the billet axis, or 'taper profile' with the initial section hotter than the final part of the billet, improves the extrusion process (isothermal extrusion). Taper temperature distribution is typically realized in induction heater thanks to the accurate control that this technology allows in thermal processing. Permanent Magnet Heaters, PMH, have been recently proposed as a high efficiency solution for the heating of electrically conductive materials. The optimal design of a Permanent Magnet Heater is presented with reference to a real industrial case. The design has been carried out by means of transient magnetic and thermal 2D and 3D Finite Element Models coupled with multiobjective optimization algorithms

Numerical modelling of silicon melt purification in induction directional solidification system

Solar grade silicon production is an energy intensive and harmful to the environment process. Yet 40% of this valuable product material is lost into sawdust (kerf loss) during wafering. The kerf waste from Fixed Abrasive Sawing of PV silicon wafers is pelletized and then remelted in an induction furnace. The furnace has a square cross-section quartz crucible, surrounded by graphite susceptors and heated by an induction coil that enables directional solidification of the new ingot. Top and bottom 'pancake' coils provide additional temperature control. Once melted, silicon becomes electrically conductive and subject to stirring by induction. To recycle the silicon, particulate impurities (due to the sawing, condensed silicon oxides or carbides) need to be removed. Flow control and the electromagnetic Leenov-Kolin force are used to expel particulates, through a novel dual frequency induction scheme. Three-dimensional, multi-physics numerical modelling captures the electromagnetic, fluid-flow and heat-transfer effects in this process. The presented results show it is possible to retain the impurity particles on the sides of the solidified ingot where they can be sliced off and removed

Multi-objective design of a power inductor: a benchmark of inverse induction heating

In the paper, a bi-objective optimization problem characterized by coupled field analysis is investigated. The optimal design of a pancake inductor for the controlled heating of a graphite disk is considered as the benchmark problem. The Pareto front trading off electrical efficiency and thermal uniformity is identified by means of a standard algorithm of evolutionary computing. A mesh-inspired definition of thermal uniformity is proposed

Multi-physics and multi-objective design of a benchmark device: a problem of inverse induction heating

In the paper, a bi-objective optimization problem characterized by a multi-physics field analysis is investigated. The optimal design of a pancake inductor, related to the design of industrial devices for the controlled heating of a graphite disk is considered as the benchmark problem. The expected goal of the optimization process is to improve temperature uniformity in the disk as well as electrical efficiency of the inductor. The optimized device is designed using a multi-physics problem: magnetic problem for electrical efficiency computation and thermal problem for temperature uniformity computation. The solution of the relevant bi-objective optimization problem is based on a modified multi-objective genetic algorithm in the class of Non-dominated Sorting Genetic Algorithm. The proposed algorithm exploits the migration concept to vary the population genetic characteristics during optimization process in order to improve the Pareto front approximation

Phenoloxidase activity and haemolymph cytology in honeybees challenged with a virus suspension (deformed wings virus DWV) or phosphate buffered suspension (PBS)

The innate immune system of honeybees mainly consists in antimicrobial peptides, cellular immunity and melanisation. In order to investigate the immune response of honeybees to immune stressors, three stress degrees were tested. Newly emerged bees naturally DWV-infected were collected from a Varroa mite free apiary and divided into three experimental groups: naturally DWV infected bees. PBS injected bees. and artificially DWV super infected bees. Phenoloxidase activity and haemolymph cellular subtype count were investigated. Phenoloxidase activity was highest (P<0.05) in DWV-superinfected bees. and the haemocyte population differed within the three observed groups. Although. immune responses following DWV infection have still not been completely clarified. this investigation sheds light on the relation between cell immunity and the phenoloxidase activity of DWV naturally infected honeybees exposed to additional stress such as injury and viral superinfection

Detection of replicative Kashmir Bee Virus and Black Queen Cell Virus in Asian hornet Vespa velutina (Lepelieter 1836) in Italy

Information concerning the pathogenic role of honey bee viruses in invasive species are still scarce. The aim of this investigation was to assess the presence of several honey bee viruses, such as Black Queen Cell Virus (BQCV), Kashmir Bee Virus (KBV), Slow Paralysis Virus (SPV), Sac Brood Virus (SBV), Israeli Acute Paralysis Virus (IAPV), Acute Bee Paralysis Virus (ABPV), Chronic Bee Paralysis Virus (CBPV), in Vespa velutina specimens collected in Italy during 2017. Results of this investigation indicate that among pathogens, replicative form of KBV and BQCV were detected, assessing the spillover effect of both these viruses from managed honey bees to hornets

Detection of Hepatitis E Virus Antibodies in Domestic and Wild Animal Species in Central Italy

Hepatitis E virus (HEV) is known for its zoonotic potential. Although several mammalian species have been indicated as possible viral reservoir, the host range of the infection is partially defined. In this work serum samples collected from wild brown hares, red deer, wild rabbits, cattle living in semi-wild state and wild boar-hunting dogs were tested by a multi-species ELISA assay. Only sera from red deer (5.6%), wild rabbit (38.5%) and wild-boar hunting dogs (14.3%) scored positive. The investigation indicated the circulation and the high endemicity of HEV in various animal species in Central Italy, and the importance that these species can play in the epidemiology of infection