Search results for "Aquinas"
showing 10 items of 86 documents
Triblock SEBS/DVB crosslinked and sulfonated membranes: Fuel cell performance and conductivity
2021
[EN] A set of styrene-ethylene-butylene-styrene triblock copolymer (SEBS) membranes with 10 or 25 wt.% divinyl-benzene (DVB) as a crosslinking agent were prepared and validated. Physicochemical characterization revealed suitable hydrolytic and thermal stability of photo-crosslinked membranes containing 25%wt. DVB and post-sulfonated. These compositions were evaluated in H2/O2 single cells, and electrical and proton conductivities were furtherly assessed. The membranes with the milder post-sulfonation showed greater proton conductivity than those with excessive sulfonation. In terms of electrical conductivity, a universal power law was applied, and the values obtained were low enough for bei…
Effect of the dissolution time into an acid hydrolytic solvent to tailor electrospun nanofibrous polycaprolactone scaffolds
2017
[EN] The hydrolysis of the polycaprolactone (PCL) as a function of the dissolution time in a formic/acetic acid mixture was considered as a method for tailoring the morphology of nanofibrous PCL scaffolds. Hence the aim of this research was to establish a correlation between the dissolution time of the polymer in the acid solvent with the physicochemical properties of the electrospun nanofibrous scaffolds and their further service life behaviour. The physico-chemical properties of the scaffolds were assessed in terms of fibre morphology molar mass and thermal behaviour. A reduction of the molar mass and the lamellar thickness as well as an increase of the crystallinity degree were observed …
Influence of substrate and temperature on the biodegradation of polyester-based materials: Polylactide and poly(3-hydroxybutyrate-co-3-hydroxyhexanoa…
2020
[EN] The extended use of polymers from renewable resources such as aliphatic polyesters or polyhydroxyalkanoates boosted the necessity to understand their behaviour in an end-of-life scenario. Although they can be degraded in reasonable shorter times than traditional polymers, understanding the degradation mechanisms under dissimilar conditions will contribute to further developments in this field. This work aimed to study the effect of temperature and substrate in the degradation of polylactide (PLA) and poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBH) in a simulated laboratory scale to ascertain their contribution, separately or in combination. For this purpose, nine parallel degradat…
Poly (lactic acid)/D-limonene/ZnO bio-nanocomposites with antimicrobial properties
2022
[EN] Antimicrobial films of poly (lactic acid) (PLA)/D-limonene/zinc oxide (ZnO)-based bio-nanocomposites were prepared via melt compounding and subsequent thermocompression. D-limonene was incorporated at concentrations of 10 or 20 wt%, and ZnO pure nanoparticles and those organically modified with oleic acid (O-ZnO), with an average diameter of 13.5 nm, were included at concentrations of 3, 5, and 8 wt%. The plasticizing effect of D-Limonene was corroborated by a decrease in the glass transition temperature compared to pure PLA. The presence of ZnO and O-ZnO in the PLA matrix promoted a slight increase in the degree of crystallinity due to its nucleant performance. Although ZnO and O-ZnO …
Assessing the MALDI-TOF MS sample preparation procedure to analyze the influence of thermo-oxidative ageing and thermo-mechanical degradation on poly…
2011
[EN] Multiple processing by means of successive injection cycles was used to simulate the thermo-mechanical degradation effects on the oligomeric distribution of PLA under mechanical recycling. Likewise, an accelerated thermal ageing over PLA glass transition was performed in order to simulate its service life. MALDI-TOF MS was used for the analysis and the sample preparation procedure was assessed by means of a statistical Design of Experiments (DoE). The quality effects in use for the analysis were signal-to-noise ratio and Resolution. Different matrixes, analyte/matrix proportions and the use of NaTFA as cationization agent were considered. A deep inspection of the statistical results pr…
„Kantor Chrystusa eucharystycznego” – św. Tomasz z Akwinu w przepowiadaniu do dzieci z okazji uroczystości Pierwszej Komunii Świętej
2021
Jan Paweł II w encyklice Ecclesia de Eucharistia wspomina św. Tomasza z Akwinu jako doskonałego teologa i zarazem gorliwego „kantora Chrystusa eucharystycznego”. Określenie „kantor” poetycko, przenośnie oddaje całą pobożność eucharystyczną Tomasza z Akwinu. Na tę jego pobożność eucharystyczną składają się: świadectwo życia eucharystycznego, Traktat o Eucharystii zawarty w Sumie teologicznej, słowa pieśni eucharystycznych i modlitwy związane z Eucharystią. Od wielu lat w parafii św. Józefa Robotnika w Opolu-Wrzoskach realizuje się projekt, w którym tradycyjna uroczystość Pierwszej Komunii Świętej jest proponowana w nowej formie. Tematykę uroczystości przede wszystkim wyznacza historia Euchar…
Water absorption and hydrothermal performance of PHBV/sisal biocomposites
2014
[EN] The performance of biocomposites of poly(hydroxybutyrate-co-valerate) (PHBV) and sisal fibre subjected to hydrothermal tests at different temperatures above the glass transition of PHBV (TH ¿ 26, 36 and 46 C) was evaluated in this study. The influences of both the fibre content and presence of coupling agent were focused. The water absorption capability and water diffusion rate were considered for a statistical factorial analysis. Afterwards, the physico-chemical properties of water-saturated biocomposites were assessed by Fourier-Transform Infrared Analysis, Size Exclusion Chromatography, Differential Scanning Calorimetry and Scanning Electron Microscopy. It was found that the water d…
L'Analogie chez Aristote
2021
Revue de philosophie dont l’objet est de montrer, d’interroger ou d’évaluer les comparaisons effectives dans les différents champs disciplinaires, Analogia est une publication scientifique annuelle de l’IPC.Chaque numéro réunit un conseil scientifique nouveau chargé de sélectionner les contributions en double aveugle.L’Analogie chez Aristote.Sous la direction d’Emmanuel Brochier.Conseil scientifique :- Katerina Ierodiakonou (Genève – Athènes)- André Laks (Paris)- Benjamin C. Morison (Princeton)- Jean-Luc Solère (Boston)Sommaire :- Présentation, par Emmanuel Brochier, p. 5 ;- Christof Rapp : "Spotting similarities between disparate items" Observations on the use of analogy in Aristotle’s met…
Biomaterials coated by dental pulp cells as substrate for neural stem cell differentiation
2011
[EN] This study is focused on the development of an in vitro hybrid system, consisting in a polymeric biomaterial covered by a dental pulp cellular stroma that acts as a scaffold offering a neurotrophic support for the subsequent survival and differentiation of neural stem Cells. In the first place, the behavior of dental pulp stroma on the polymeric biomaterial based on ethyl acrylate and hydroxy ethyl acrylate copolymer was studied. For this purpose, cells from normal human third molars were grown onto 0.5-mm-diameter biomaterial discs. After cell culture, quantification of neurotrophic factors generated by the stromal cells was performed by means of an ELISA assay. In the second place, s…
Effect of perspiration on skin temperature measurements by infrared thermography and contact thermometry during aerobic cycling
2015
[EN] The aim of the present study was to compare infrared thermography and thermal contact sensors for measuring skin temperature during cycling in a moderate environment. Fourteen cyclists performed a 45-mM cycling test at 50% of peak power output. Skin temperatures were simultaneously recorded by infrared thermography and thermal contact sensors before and immediately after cycling activity as well as after 10 min cooling-down, representing different skin wetness and blood perfusion states. Additionally, surface temperature during well controlled dry and wet heat exchange (avoiding thermoregulatory responses) using a hot plate system was assessed by infrared thermography and thermal conta…