Prefazione

La speciale attenzione con la quale il mondo delle lingue romanze oggi si riferisce alle questioni degli studi gender nel mondo accademico, affonda le sue radici in una tradizione antica, basata innanzitutto su uno sforzo costante di comprensio e. La letteratura contemporanea è un luogo privilegiato per la ricerca dell’identità sessuale. È, d’altro canto, significativo che una delle fasi più feconde dell’approfondimento dell’argomento si ha nel XXI secolo, in parallelo con lo sviluppo del clima culturale orientato verso la rinascita dell’antropologia

Mot de la Redaction

Si on peut constater que notre monde contemporain est orienté vers le ra-tionalisme, la technologie, la productivité, l’efficacité et la performance, on peut toujours s’interroger sur la place qu’il laisse encore aux manifestations rituelles. En effet, à l’origine de toute capacité de conceptualisation, l’existence des rites fut associée à la religion et, par ailleurs, au sacré. Dans ce contexte, il est utile de se poser la question de savoir si, aujourd’hui, l’espace relevant du sacrum se réduit dans l’ordre social, compte tenu du recul des pratiques religieuses dans les sociétés occidentales et autres (...

Mot de la Redaction

La diversité des opinions concerne tous les domaines de la vie sociale, ce qui engendre irrémédiablement de nombreux conflits entre différents points de vue. Suite à Raymond Williams (KeyworLa diversité des opinions concerne tous les domaines de la vie sociale, ce qui engendre irrémédiablement de nombreux conflits entre différents points de vue. Suite à Raymond Williams (Keywords: A Vocabulary of Culture and Society, 1983), qui disait que la culture était un processus social et historique, il est légitime de considérer cette dernière comme une succession ininterrompue de conflits, ainsi que de tentatives cherchant à les apaiser.ds: A Vocabulary of Culture and Society, 1983), qui disait que la culture était un processus social et historique, il est légitime de considérer cette dernière comme une succession ininterrompue de conflits, ainsi que de tentatives cherchant à les apaise (...

The interplay of oxidative stress and immune dysfunction in Hashimoto’s thyroiditis and polycystic ovary syndrome: a comprehensive review

In recent years, there has been a significant increase in the concomitant incidence of Hashimoto’s thyroiditis (HT) and polycystic ovary syndrome (PCOS), both in terms of incidence, etiology, and clinical consequences. PCOS patients suffering from autoimmune thyroid diseases show insulin resistance, impaired glucose tolerance, weight gain, and metabolic and reproductive complications. Studies have shown that chronic stress and its consequence, i.e. oxidative stress, play an important role in the pathomechanism of both disorders. It has also been shown that long-term exposure to stress triggers biological mechanisms, in particular related to the regulation of the inflammatory cascade, which plays a key role in autoimmune diseases. The paper is a review of the literature on the role of chronic stress, oxidative stress, and immune processes in the pathogenesis of HT and PCOS. In addition, the review is a source of knowledge about the treatment of these diseases, and in particular the use of antioxidants in therapeutic management

Polyurethane foams with 1,3,5-triazine ring and silicon

W wyniku zmieszania oligoeteroli z pierścieniem 1,3,5-triazynowym i atomami krzemu uzyskano poliol nadający się do otrzymywania sztywnej pianki poliuretanowej. Zbadano właściwości fizyczne i użytkowe otrzymanej pianki: gęstość pozorną, chłonność wody, stabilność wymiarów, współczynnik przewodzenia ciepła, odporność termiczną i właściwości ogniowe. Stwierdzono, że charakteryzuje się ona zwiększoną wytrzymałością mechaniczną i odpornością termiczną w stosunku do klasycznych, sztywnych pianek poliuretanowych oraz zmniejszoną szybkością palenia. Podczas długotrwałego wygrzewania w temperaturze 150-200°C następuje wzrost jej wytrzymałości na ściskanie. Pianka poddana ekspozycji w temperaturze 150°C w ciągu miesiąca staje się samogasnąca, a wygrzewana w temperaturze 175°C - niepalna.By mixing oligoetherols with 1,3,5-triazine rings and silicon atoms, polyol suitable for the preparation of rigid foam polyurethanes were obtained. The physical and utility properties of the obtained foam as well as bulk density, water absorption, dimensional stability, thermal conductivity, heat resistance and fire properties were examined. It has been found that it is characterized by improved mechanical strength, heat resistance and a reduced rate of smoking compared with conventional rigid polyurethane foams. During the prolonged heating of the foam at a temperature of 150-200°C its compressive strength increases. The foam subjected to exposure at 150°C and at 175°C during the month becomes self-extinguishing and non-flammable respectively

EXPERIMENTAL INVESTIGATION OF FLOW BOILING IN A VERTICAL NARROW CHANNEL

ABSTRACT Experimental investigations on thermofluid-dynamic phenomena in a vertical narrow rectangular microchannel with the hydraulic diameter d h = 0.27 mm were carried out. The experiments are performed under fluid-inlet subcooling conditions with de-ionised and degassed water for different mass fluxes (50-2000 kg/m 2 s) and heat fluxes (2-150 kW/m 2 ). Moreover, flow visualisation of the two-phase flow patterns along the channel is performed using a digital high-speed video camera. Investigations on pressure drop during single-and twophase flow have been carried out. The present work is concentrated on two-phase heat transfer. The mean heat transfer coefficient and the local heat transfer coefficient at saturated conditions were calculated and the latter ones was compared with available correlations. NOMENCLATURE A heat transfer area, m

Use of a Mixture of Polyols Based on Metasilicic Acid and Recycled PLA for Synthesis of Rigid Polyurethane Foams Susceptible to Biodegradation

Two polyol raw materials were obtained in the conducted research, one based on metasilicic acid (MSA), the other based on poly(lactic acid) (PLA) waste. The obtained polyols were characterized in terms of their applicability for the production of rigid polyurethane foams (RPUFs). Their basic analytical properties (hydroxyl number, acid number, elemental analysis) and physicochemical properties (density, viscosity) were determined. The assumed chemical structure of the obtained new compounds was confirmed by performing FTIR and 1H NMR spectroscopic tests. Formulations for the synthesis of RPUFs were developed on the basis of the obtained research results. A mixture of polyols based on MSA and PLA in a weight ratio of 1:1 was used as the polyol component in the polyurethane formulation. The reference foam in these tests was a foam that was synthesized only on the basis of MSA-polyol. The obtained RPUFs were tested for basic functional properties (apparent density, compressive strength, water absorption, thermal conductivity coefficient etc.). Susceptibility to biodegradation in soil environment was also tested. It was found that the use of mixture of polyols based on MSA and PLA positively affected the properties of the obtained foam. The polyurethane foam based on this polyol mixture showed good thermal resistance and significantly reduced flammability in comparison with the foam based MSA-polyol. Moreover, it showed higher compressive strength, lower thermal conductivity and biodegradability in soil. The results of the conducted tests confirmed that the new foam was characterized by very good performance properties. In addition, this research provides information on new waste management opportunities and fits into the doctrine of sustainable resource management offered by the circular economy

Polyols and Polyurethane Foams Obtained from Mixture of Metasilicic Acid and Cellulose

Hydroxyalkylation of the mixture of metasilicic acid and cellulose with glycidol and ethylene carbonate leads to a polyol suitable to obtain rigid polyurethane foams. The composition, structure, and physical properties of the polyol were studied in detail. The obtained foams have apparent density, water absorption, and polymerization shrinkage, as well as heat conduction coefficients similar to conventional, rigid polyurethane foams. The polyols and foams obtained from environmentally unobtrusive substrates are easily biodegradable. Additionally, the obtained foams have high thermal resistance and are self-extinguishing. Thermal exposure of the foams leads to an increase of the compressive strength of the material and further reduces their flammability, which renders them suitable for use as heat insulating materials