Comparative study of technological behavior of German ball clay and Italian kaolinitic clay in unconventional porcelain stoneware body

This work focused on obtaining a porcelain stoneware body containing only Italian raw materials. The starting mixtures differed in the feldspathic fraction, one pumice-based and one lapillus-based. German ball clay was gradually replaced by Italian kaolinitic clay. The influence of Italian kaolinitic clay on the technical and aesthetic properties of the final product was analyzed by comparing it with the references. The work was carried out in collaboration with a ceramic company which allowed the tile production process to be simulated in the laboratory and fired in an industrial kiln using the production cycle (48 min, 1210 °C). Ceramic bodies were characterized in order to evaluate technological performance by measuring efflux time and density of slip, flexural strength on green, linear shrinkage and water absorption in vacuum on fired samples. Mineralogical, microstructural (ESEM) and colorimetric analyses were also performed on the fired samples. Efflux time and density are processing parameters; these were in line with the reference in the lapillus-based bodies with kaolinitic clay replacement rates of 100%; in the case of the pumice-based bodies, they were considered acceptable only for replacements of 25%. The lapillus-based body showed a microstructure similar to that of porcelain stoneware. Vacuum water absorption values were better in lapillus-based formulations than in pumice-based formulations but showed higher linear shrinkage values for 100% replacements. According to UNI EN 14411 ISO 13006, some of the products obtained can be classified as porcelain stoneware (group BIa)

Characterization of Volcano-Sedimentary Rocks and Related Scraps for Design of Sustainable Materials

This work started as a joint academia and company research project with the aim of finding new applications for domestically sourced volcanic products and related waste (pumice, lapillus, zeolitic tuff and volcanic debris from Tessennano and Arlena quarry) by creating a database of secondary volcanic raw materials and their intrinsic characteristics to help industry replace virgin materials and enhance circularity. In this context, accurate chemical, mineralogical, morphological, granulometric and thermal characterizations were performed. Based on the results presented, it can be concluded that due to their lightness, these materials can be used in the design and preparation of lightweight aggregates for agronomic purposes or in the construction field. Furthermore, due to their aluminosilicate nature and amorphous fraction, pumice and lapillus can play the role of precursor or activator for geopolymer preparation. With its porous nature, zeolitic tuff can be exploited for flue gas treatment. Due to the presence of feldspathic phase (sanidine), these materials can be used in tile production as a fluxing component, and with their pozzolanic activity and calcium content, they have application in the binder field as supplementary cementitious material or as aggregates

Placement of IoT Microservices in Fog Computing Systems: A Comparison of Heuristics

In the last few years, fog computing has been recognized as a promising approach to support modern IoT applications based on microservices. The main characteristic of this application involve the presence of geographically distributed sensors or mobile end users acting as sources of data. Relying on a cloud computing approach may not represent the most suitable solution in these scenario due to the non-negligible latency between data sources and distant cloud data centers, which may represent an issue in cases involving real-time and latency-sensitive IoT applications. Placing certain tasks, such as preprocessing or data aggregation, in a layer of fog nodes close to sensors or end users may help to decrease the response time of IoT applications as well as the traffic towards the cloud data centers. However, the fog scenario is characterized by a much more complex and heterogeneous infrastructure compared to a cloud data center, where the computing nodes and the inter-node connecting are more homogeneous. As a consequence, the the problem of efficiently placing microservices over distributed fog nodes requires novel and efficient solutions. In this paper, we address this issue by proposing and comparing different heuristics for placing the application microservices over the nodes of a fog infrastructure. We test the performance of the proposed heuristics and their ability to minimize application response times and satisfy the Service Level Agreement across a wide set of operating conditions in order to understand which approach is performs the best depending on the IoT application scenario

Pumice and lapillus scraps: New national environmental-friendly chance for the production of ceramic tiles

Italian pumice and volcanic lapillus scraps have been used in different percentages as alternative raw materials to foreign feldspars in porcelain stoneware mixtures. The aim of this work was to create naturally colored support to limit the use of artificial dyes while maintaining the technical properties of the reference product. For this purpose, the significant presence of chromophores (Fe and Ti in particular) in by-products from extraction of Italian volcanic pumice and lapillus was exploited. The work was carried out in collaboration with a company: the products were made on a laboratory scale and then they were glazed and fired within the industrial production cycle (48 min, 1210 ◦C). The resulting slip and the fired samples were characterized by measuring the efflux time, density, linear shrinkage, water absorption and tensile strength to evaluate the technological performance. In addition, thermogravimetric analysis (TG), differential thermal analysis (DTA), and optical and mechanical dilatometry were performed to study the thermal behavior of the formulations. The obtained products could be classified as porcelain stoneware and belong to the BIa group (WA 0.5%, B. S.>35 MPa) in accordance with UNI EN 14411 ISO 13006

Performance Comparison of Technological Solutions for Spark Applications in AWS

Cloud computing is providing a pay-as-you-go in-frastructure for the deployment of complex applications, with auto-scaling support and the ability to manage and process huge amount of data. However, due to the underlying complexity of the cloud infrastructure, it is not trivial to evaluate the setup providing the best performance of such scenario. To this aim the present paper proposes a thorough performance evaluation of a real application in a Cloud platform, measuring the impact of several design choices and technological solution. The experimental results, based on a real application and on realistic data can provide a significant insight that can integrate the traditional approach of cloud performance evaluation based on synthetic benchmarks

Intrapancreatic accessory spleen false positive to 68Ga-Dotatoc: case report and literature review

Background: Intrapancreatic accessory spleen (IPAS) is an uncommon finding of pancreatic mass. Differential diagnosis with pancreatic tumor, especially with non-functional neuroendocrine tumor (NF-NET), may be very hard and sometimes it entails unnecessary surgery. A combination of CT scan, MRI, and nuclear medicine can confirm the diagnosis of IPAS. 68-Ga-Dotatoc PET/CT is the gold standard in NET diagnosis and it can allow to distinguish between IPAS and NET. Case presentation: A 69-year-old man was admitted to our hospital for an incidental nodule in the tail of the pancreas with focal uptake of 68-Ga-dotatate at PET/CT. NET was suspected and open distal splenopancreatectomy was performed. Pathologic examination revealed an IPAS. Conclusion: This is the second IPAS case in which a positive 68Ga-Dotatoc uptake led to a false diagnosis of pancreatic NET. Here is a proposal of a literature review

Physical-chemical characterization of a galvanic sludge and its inertization by vitrification using container glass

Several industrial processes produce large amounts of heavy metals-rich wastes, which could be considered as "trash-can raw materials". The incorporation in ceramic systems can be regarded as a key process to permanently incorporate hazardous heavy metals in stable matrixes. In particular the aim of this work is to prepare and evaluate environmental risk assessment of coloured glass and glass-ceramic with the addition of chromium(III) galvanic sludge having a high content of Cr2O3 (15.91 wt%). Trivalent chromium compounds generally have low toxicity while hexavalent chromium is recognized by the International Agency for Research on Cancer and by the US Toxicology Program as a pulmonary carcinogen. The sludge has been characterized by ICP -AES chemical analysis, powder XRD diffraction, DTA, SEM, leaching test after different thermal treatments ranging from 400°C to 1200°C. Batch compositions were prepared by mixing this sludge with glass containers. The glass container composition is rich in SiO2 (69.89 wt%), Na 2O (12.32 wt%) and CaO (11.03 wt%), while the sludge has a high amount of CaO (42.90 wt%) and Cr2O3 (15.91 wt%). The vitrification was carried out at 1450°C in an electrical melting furnace for 2 h followed by quenching in water or on graphite mould. Chromium incorporation mechanisms, vitrification processability, effect of initial Cr oxidation state, and product performance were investigated. In particular toxic characterization by leaching procedure and chemical durability studies of the glasses and glass-ceramics were used to evaluate the leaching of heavy metals (in particular of Cr). The results indicate that all the glasses obtained were inert and the heavy metals were immobilized

FIGARO: reinForcement learnInG mAnagement acRoss the computing cOntinuum

The widespread adoption of Artificial Intelligence applications to analyze data generated by Internet of Things sensors leads to the development of the edge computing paradigm. Deploying applications at the periphery of the network effectively addresses cost and latency concerns associated with cloud computing. However, it generates a highly distributed environment with heterogeneous devices, opening the challenges of how to select resources and place application components. Starting from a state-of-the-art design-time tool, we present in this paper a novel framework based on Reinforcement Learning, named FIGARO (reinForcement learnInG mAnagement acRoss the computing cOntinuum). It handles the runtime adaptation of a computing continuum environment, dealing with the variability of the incoming load and service times. To reduce the training time, we exploit the design-time knowledge, achieving a significant reduction in the violations of the response time constraint