165 research outputs found

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

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    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)

    Investigation on the effect of inorganic acid attack on composite prepared with MK-based geopolymer and waste cork dust

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    The chemical, microstructural and mechanical characterization of novel lightweight composites produced by adding waste cork dust to a metakaolin-based geopolymeric matrix prepared by alkaline activation is presented. The alkaline activator solutions used for the reticulation of the 3D aluminosilicate network at room temperature are composed of NaOH and sodium silicate to maintain a low cost of the final composite. In this line, the research of the highest addition of waste, e.g. cork dust, is pursued starting from 1 and reaching a maximum content of 10 wt% over metakaolin. The chemical stability is evaluated in water as well as in HNO3 or in H2SO4 0.5 and 2.5 N solutions. The addition of cork does not affect the reticulation of the geopolymeric binder used as matrix, as is demonstrated by FT-IR and XRD analyses. The modification of the dense geopolymeric microstructure with the introduction of cork dust weakens the hardened composites that become more permeable to water and acid solutions increasing the weight loss after immersion and decreasing the mechanical resistance to compression. The mechanical performance of the hardened composite with 10 wt% of cork dust still seems to be sufficient for application as self-supporting thermal insulation panels

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

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    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

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

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    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

    Electrochemical synthesis of nanowire anodes from spent lithium ion batteries

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    A novel process is proposed to produce nanostructured batteries anodes from spent lithium-ion batteries. The electrodic powder recovered by the mechanical treatment of spent batteries was leached and the dissolved metals were precipitated as cobalt carbonates. Two different precipitation routes were separately tested producing cobalt carbonates with different Cu and Fe contents. Nanowire anodes were produced by electrodeposition into nanoporous alumina templates from the electrolytic baths prepared by dissolution of the precipitated carbonates. The electrochemical performances of the produced anodes were evaluated as compared to nanowire anodes produced with the same electrodeposition method but using a synthetic cobalt bath. The application of the carbonates produced by directly precipitating all the leached metals gave nanowires with capacity about halved as compared to the nanowires electrodeposited from the synthetic bath. Selectively removing Cu and Fe prior cobalt carbonate precipitation yielded, in contrast, nanowires with capacity initially larger and then gradually approaching that attained by the nanowire electrodeposited from the synthetic bath. A detailed analysis is presented describing the role of metallic impurities in determining the capacity of the produced nanowires. The impact of the illustrated results for the development of sustainable recycling processes of lithium-ion batteries is discussed

    Comparative life cycle analysis between commercial porcelain stoneware and new ones designed by using volcanic scraps

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    : To achieve carbon neutrality by 2050, many companies have started implementing sustainability policies. The aim of this work, as result of collaboration between Universities and companies, is to assess the environmental impacts associated with the production of alternative formulations of porcelain stoneware. The proposed formulations contain extraction scraps and chamotte and have promising technological properties. A comparative analysis of the life cycle in three different scenarios was carried out to assess the environmental footprint of the final products. The analyzed scenarios were a glazed porcelain stoneware (which was taken as a reference and is commercially available), a porcelain stoneware containing pumice scraps, and one containing volcanic lapillus scraps. It was observed that the transportation of raw materials has the largest environmental impact, followed by the production and extraction of the raw materials themselves. From the performed analysis, it was possible to observe that by replacing the currently used materials by the ones hereby studied, environmental benefits can be obtained. In particular, depending on the considered pollutant, the environmental impact can be reduced between a minimum of about 8 % (Freshwater Aquatic Ecotoxicity category) to a maximum of 48 % (Acidification category). In a time when raw materials supply is difficult, the use of scraps, which would otherwise be disposed of, is particularly interesting and can lead to the production of an environmentally friendly product

    Improvement in insulin sensitivity, but without changes in liver enzymes in obese women after 12 weeks of a walking exercise program with self-selected intensity

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    Background: Obesity is related to negative changes in insulin resistance and liver enzymes and is associated with the risk factor for the development of type II diabetes mellitus and nonalcoholic fatty liver disease. A number of studies have demonstrated that aerobic exercise shows promise for disease prevention and treatment in this population. Aim: The objective of the present study was to evaluate the effect of a walking exercise program with self-selected intensity on insulin resistance and liver enzymes in obese women. Methods: Forty-eight obese women (47.8 ± 8.4 years; 88.1 ± 12.0 kg; 158.0 ± 0.1 cm) were divided into two groups: control group (CG; n = 23) and self-selected walking group (SSWG; n = 25). Before and after the exercise program, all subjects underwent anthropometric measurements and blood samples were collected. The intervention consisted of a walking exercise program with self-selected intensity for 12 weeks (3 times/week, totalizing 36 sessions). Results: After the exercise program, fasting glucose, fasting insulin, and HOMA improved only in the SSWG (p 0.05). In addition, there were no differences in liver enzymes after the intervention in both groups (p > 0.05). Conclusions: The results support that a walking exercise program with self-selected intensity improved insulin resistance in obese women. Thus, exercise programs with self-selected intensity seem to be an interesting alternative for improving health and preventing diseases

    Detection of EGFR-Activating and T790M Mutations Using Liquid Biopsy in Patients With EGFR-Mutated Non–Small-Cell Lung Cancer Whose Disease Has Progressed During Treatment With First- and Second-Generation Tyrosine Kinase Inhibitors: A Multicenter Real-Life Retrospective Study

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    Epidermal growth factor receptor T790M detection using liquid biopsy was evaluated in a real-life setting in 120 advanced non–small-cell lung cancer patients whose disease had progressed during first- or second-generation tyrosine kinase inhibitors. The T790M detection rate was 25.8% using liquid biopsy and 49.2% after tissue rebiopsy. Liquid biopsies performed before disease progression according to Response Evaluation Criteria In Solid Tumors were all negative for T790M and T790M positivity was higher in cases of extrathoracic metastatic sites

    Non-small cell lung cancer testing on reference specimens: an italian multicenter experience

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    Introduction: Biomarker testing is mandatory for the clinical management of patients with advanced non-small cell lung cancer (NSCLC). Myriads of technical platforms are now available for biomarker analysis with differences in terms of multiplexing capability, analytical sensitivity, and turnaround time (TAT). We evaluated the technical performance of the diagnostic workflows of 24 representative Italian institutions performing molecular tests on a series of artificial reference specimens built to mimic routine diagnostic samples. Methods: Sample sets of eight slides from cell blocks of artificial reference specimens harboring exon 19 EGFR (epidermal growth factor receptor) p.E746_AT50del, exon 2 KRAS (Kirsten rat sarcoma viral oncogene homologue) p.G12C, ROS1 (c-ros oncogene 1)-unknown gene fusion, and MET (MET proto-oncogene, receptor tyrosine kinase) Δ exon 14 skipping were distributed to each participating institution. Two independent cell block specimens were validated by the University of Naples Federico II before shipment. Methodological and molecular data from reference specimens were annotated. Results: Overall, a median DNA concentration of 3.3 ng/μL (range 0.1–10.0 ng/μL) and 13.4 ng/μL (range 2.0–45.8 ng/μL) were obtained with automated and manual technical procedures, respectively. RNA concentrations of 5.7 ng/μL (range 0.2–11.9 ng/μL) and 9.3 ng/μL (range 0.5–18.0 ng/μL) were also detected. KRAS exon 2 p.G12C, EGFR exon 19 p.E736_A750del hotspot mutations, and ROS1 aberrant transcripts were identified in all tested cases, whereas 15 out of 16 (93.7%) centers detected MET exon 14 skipping mutation. Conclusions: Optimized technical workflows are crucial in the decision-making strategy of patients with NSCLC. Artificial reference specimens enable optimization of diagnostic workflows for predictive molecular analysis in routine clinical practice
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