Raman spectroscopy potentiality in the study of geopolymers reaction degree

AbstractAlkali‐activated materials (AAMs) and "geopolymers" are inorganic polymeric materials obtained by mixing of solid aluminosilicate precursors with an alkaline solution (generally, KOH or NaOH and Na2SiO3 mixed in various ratios). This class of aluminosilicate materials has emerged as a greener alternative to traditional concrete, for large‐scale as well as for niche applications such as conservation and restoration of built heritage. In this work we apply Raman spectroscopy both to aluminosilicate precursors (metakaolin, pumice, volcanic ash, volcanic soils, clayey sediments, ceramic waste) and to the respective AAMs. In the field of vibrational spectroscopy, Raman is much less employed in the literature with respect to Fourier transform infrared (FTIR) to have insights into the alkali activation process from a molecular point of view. The aim of this paper is to investigate the potentiality of a Raman approach to the comparison of the employed raw materials with the respective AAMs. Raman analyses during the first hours of geopolymerization were also carried out on the clayey sediments and ceramic waste‐based products. The results, differentiated according to the employed precursors, exhibit spectra relative to crystalline and amorphous phases that can give an indication about the newly formed aluminosilicate gel

Potentiality of the Use of Pyroclastic Volcanic Residues in the Production of Alkali Activated Material

Volcanic rocks have been used for building activity by the inhabitants of important cities located on the slopes of Mt. Etna, Italy. In this paper, the potential use of volcanic residues (code 20 03 03—“Municipal waste” residues from road cleaning in the European Waste Catalogue (EWC)) for the production of alkali activated material, especially devoted to the restoration of buildings belonging to the Baroque Sicilian architecture, was investigated. In particular, large volcanic pyroclastic deposits of recent eruptions considered waste materials were studied and a volcanic paleo-soil, locally named ghiara, widely used for mortars and plaster production in XVII–XVIII century with good pozzolanic features, was also considered. Both volcanic materials were activated using different mixtures of NaOH and Na2SiO3. Furthermore, formulations with different amount of metakaolin addition (10–25 wt%) were prepared due to low reactivity of volcanic materials and to allow the activation at room temperature. X ray diffraction revealed the formation of small quantities of zeolites as a result of the alkali activation process. The mechanical-physical results evidenced that the mechanical strength is strongly dependent on the metakaolin amount (10–38 MPa); accessible porosity average 25% and an average pore diameter of 0.06 µm; water absorption range 9–15%, eluates conductivity in the range 20–350 µS/m. These results confirm the occurring of alkali activation and the good potential for these pyroclastic wastes for valorization in the restoration field

Deaths in SARS-Cov-2 Positive Patients in Italy: The Influence of Underlying Health Conditions on Lethality

This study aims to underline the clinical characteristics of patients who died after testing positive for SARS-CoV-2 infection in one region of Italian and to evaluate the influence of underlying health conditions on the fatal outcome. A matched case-control study was designed by analyzing the data regarding positive subjects observed up to April 21, 2020. The case fatality rate was 7.9%, with a higher proportion of deaths in men than women. The specific standardized mortality ratio was 0.15—0.13 for males and 0.2 for females, showing that mortality is much lower than expected. Cardiovascular diseases, chronic lung diseases and diabetes mellitus showed a significant association with the outcome. Although the case fatality rate in Sardinia in regard to age and gender patterns seems to be similar to that for Italy as a whole, its quantitative value was far lower than the national one and possible explanations might include the genetic characteristics of the Sardinian population or the immediate closure of its borders as soon as the epidemic started. Our results highlighted that lethality is strongly dependent on the presence of multiple concomitant serious diseases. It is important to have epidemiological strategies for effective guidance on public health actions in order to improve chances of survival

Remission of Pseudotumor Cerebri Syndrome after Initiating Pregnancy and Menarche: The Puzzling Role of Female Sex Hormones

Pseudotumor cerebri syndrome (PTCS) is characterized by increased intracranial pressure with normal cerebrospinal fluid components and no detectable anomalies of the brain parenchyma on magnetic resonance imaging. Presenting signs and symptoms are heterogeneous, but they commonly include headache, visual disturbances (i.e., vision loss and/or double vision), and papilledema. The etiology is uncertain, but several underlying risk factors associated with PTCS have been identified, including obesity, endocrine abnormalities (e.g., hyperaldosteronism, Cushing syndrome, hyperandrogenism, and Addison disease), medications (e.g., tetracycline, recombinant growth hormone therapy), and viral infections (e.g., chickenpox). Patients with postpubertal PTCS are more typically females in their reproductive age, thereby making crucial (although not fully understood) the role of female hormones in the pathophysiology of this condition. We describe two female patients with PTCS who were followed up at our institution. They experienced prompt (and full) remission of headache and visual disturbances during the first trimester of pregnancy and within the first 2 months after the onset of menarche (i.e., at 20 and 11 years of age), respectively. We reviewed the literature searching for similar cases and hypothesized on the pathophysiologic (and still unclear) involvement of female sex hormones in regulating intracranial pressure, making some patients prone to PTCS

Toward Kansei Information Processing in music/dance interactive multimodal environments

Abstract. This paper gives an overview of research projects and of recently developed systems at our Lab on interactive multimodal environments. In particular, we focus on (i) movement and gesture analysis, mainly for non-symbolic, expressive data from human movement and gesture and their relation to music performance; (ii) machine communication to humans, supported by semi-autonomous mobile on-wheels robots technology: how a machine move in the environment can be a further communication channel with humans.