61 research outputs found
Język ciała we frazeologii polskiej i rosyjskiej
The article addresses the issue of a body language as a semiotic code and its reflection in systems of natural languages, in their phraseological resources. The material for analysis is phraseological units of contemporary Polish and Russian languages. The basis for comparison is the phraseological concept by Weronika N. Telia (В.Н. Телия) and linguistic works by Grigorij E. Krejdlin (Г.Е. Крейдлин). First and foremost, three types of signs of the body language are verbalised in subsystems under analysis: bodily symptoms, symptomatic and communicative gestures and a body position.The article addresses the issue of a body language as a semiotic code and its reflection in systems of natural languages, in their phraseological resources. The material for analysis is phraseological units of contemporary Polish and Russian languages. The basis for comparison is the phraseological concept by Weronika N. Telia (В.Н. Телия) and linguistic works by Grigorij E. Krejdlin (Г.Е. Крейдлин). First and foremost, three types of signs of the body language are verbalised in subsystems under analysis: bodily symptoms, symptomatic and communicative gestures and a body position
The Russian Expression не судьба and Its Polish Equivalents
The subject of the article is a comparative analysis of the Russian expression не судьба кому-л. and its Polish equivalents. In the ethno-cultural aspect, it describes one of the Russian key ideas – the concept of SUD’BA. The special status of the discussed unit is evidenced by: the synthetic form and the inability to express its content in the same simple way in another language, the non-assertive type of meaning and informality. The analysis of lexicographic and corpus sources shows that the closest synonyms of the Russian predicate are Polish sentence phrases, coś nie było sądzone komuś and taki los that shows semantic and pragmatic differences. The devaluation of the importance of the Russian unit observed in recent uses consists in changing the attitude of regret towards unfavourable events into a sense of relief and its relation to “light” and ordinary events. This meaning corresponds to Polish – taka już czyjaś uroda.The subject of the article is a comparative analysis of the Russian expression не судьба кому-л. and its Polish equivalents. In the ethno-cultural aspect, it describes one of the Russian key ideas – the concept of SUD’BA. The special status of the discussed unit is evidenced by: the synthetic form and the inability to express its content in the same simple way in another language, the non-assertive type of meaning and informality. The analysis of lexicographic and corpus sources shows that the closest synonyms of the Russian predicate are Polish sentence phrases, coś nie było sądzone komuś and taki los that shows semantic and pragmatic differences. The devaluation of the importance of the Russian unit observed in recent uses consists in changing the attitude of regret towards unfavourable events into a sense of relief and its relation to “light” and ordinary events. This meaning corresponds to Polish – taka już czyjaś uroda
Photothermal conversion efficiency of nanofluids: An experimental and numerical study
This work investigated experimentally the photothermal conversion efficiency (PTE) of gold nanofluids in a cylindrical tube under natural solar irradiation conditions, which was also compared with a developed 3-D numerical model. The PTE of gold nanofluids was found to be much higher than that of pure water, and increased non-linearly with the nanoparticle concentration, reaching 76.0% at a concentration of 5.8 ppm. Significant non-uniform temperature distribution was identified both experimentally and numerically, and a large uncertainty can be produced in the PTE calculation by using only one-point temperature measurement. A mathematical model was also established to calculate the solar absorption efficiency without knowing the temperature field within the nanofluids, which can be used to predict the theoretical PTE for nanofluids based on their optical properties only
Analytical approach for entropy generation and heat transfer in CNT-nanofluid dynamics through a ciliated porous medium
The transportation of biological and industrial nanofluids by natural propulsion like cilia movement and self-generated contraction-relaxation of flexible walls has significant applications in numerous emerging technologies. Inspired by multi-disciplinary progress and innovation in this direction, a thermo-fluid mechanical model is proposed to study the entropy generation and convective heat transfer of nanofluids fabricated by the dispersion of single-wall carbon nanotubes (SWCNT) nanoparticles in water as the base fluid. The regime studied comprises heat transfer and steady, viscous, incompressible flow, induced by metachronal wave propulsion due to beating cilia, through a cylindrical tube containing a sparse (i.e. high permeability) homogenous porous medium. The flow is of the creeping type and is restricted under the low Reynolds number and long wavelength approximations. Slip effects at the wall are incorporated and the generalized Darcy drag-force model is utilized to mimic porous media effects. Cilia boundary conditions for velocity components are employed to determine analytical solutions to the resulting non-dimensionalized boundary value problem. The influence of pertinent physical parameters on temperature, axial velocity, pressure rise and pressure gradient, entropy generation function, Bejan number and stream-line distributions are computed numerically. A comparative study between SWCNT nanofluids and pure water is also computed. The computations demonstrate that axial flow is accelerated with increasing slip parameter and Darcy number and is greater for SWCNT- nanofluids than for pure water. Furthermore the size of the bolus for SWCNT-nanofluids is larger than that of the pure water. The study is applicable in designing and fabricating nanoscale and microfluidics devices, artificial cilia and biomimetic micro-pump
Experimental study of photothermal conversion using gold/water and MWCNT/water nanofluids.
This work experimentally investigated photothermal conversion behavior of Gold/water and MWCNT/water nanofluids at different volumetric concentrations (0.0001–0.004% and 0.0001–0.03%, respectively) in a direct absorption solar collector (DASC). The experiments were conducted for ~10 h outdoor on each test day, without interruptions. The results show that the tested nanofluids have excellent photothermal conversion capability even under very low concentrations. Specific absorption rate (SAR) presented an exponential decay with increasing volumetric concentration of nanoparticles in the sample while both the total energy stored by the fluid sample during the heating period and the stored energy ratio (SER) increased with the increase in nanoparticles concentration. The results indicate the existence of an “optimal” volumetric concentration, above which further nanoparticle addition becomes indifferent or infeasible. This optimal nanoparticle volumetric concentration was found to be 0.002% for the gold nanofluid and 0.001% for the MWCNT samples for the setup used in this work
Impact of clinical phenotypes on management and outcomes in European atrial fibrillation patients: a report from the ESC-EHRA EURObservational Research Programme in AF (EORP-AF) General Long-Term Registry
Background: Epidemiological studies in atrial fibrillation (AF) illustrate that clinical complexity increase the risk of major adverse outcomes. We aimed to describe European AF patients\u2019 clinical phenotypes and analyse the differential clinical course. Methods: We performed a hierarchical cluster analysis based on Ward\u2019s Method and Squared Euclidean Distance using 22 clinical binary variables, identifying the optimal number of clusters. We investigated differences in clinical management, use of healthcare resources and outcomes in a cohort of European AF patients from a Europe-wide observational registry. Results: A total of 9363 were available for this analysis. We identified three clusters: Cluster 1 (n = 3634; 38.8%) characterized by older patients and prevalent non-cardiac comorbidities; Cluster 2 (n = 2774; 29.6%) characterized by younger patients with low prevalence of comorbidities; Cluster 3 (n = 2955;31.6%) characterized by patients\u2019 prevalent cardiovascular risk factors/comorbidities. Over a mean follow-up of 22.5 months, Cluster 3 had the highest rate of cardiovascular events, all-cause death, and the composite outcome (combining the previous two) compared to Cluster 1 and Cluster 2 (all P <.001). An adjusted Cox regression showed that compared to Cluster 2, Cluster 3 (hazard ratio (HR) 2.87, 95% confidence interval (CI) 2.27\u20133.62; HR 3.42, 95%CI 2.72\u20134.31; HR 2.79, 95%CI 2.32\u20133.35), and Cluster 1 (HR 1.88, 95%CI 1.48\u20132.38; HR 2.50, 95%CI 1.98\u20133.15; HR 2.09, 95%CI 1.74\u20132.51) reported a higher risk for the three outcomes respectively. Conclusions: In European AF patients, three main clusters were identified, differentiated by differential presence of comorbidities. Both non-cardiac and cardiac comorbidities clusters were found to be associated with an increased risk of major adverse outcomes
Translator’s Notes in a Russian Translation of Olga Tokarczuk’s Bieguni Novel
The article addresses the issue of translator’s notes in a Russian translation of Olga Tokarczuk’s “Bieguni” novel by Irina Adelʹgejm. The main text of the original, despite its abundance in borrowings, interjections and quotations in languages other than Polish, was not provided with explanatory notes by the author. The translator, however, provided the translation with 149 notes. They are notesexplaining terms, proper names, names of realities and others translated in the main text as well as notes explaining fragments formulated in the novel’s text in languages other than the language of the narration. On the basis of the undertaken analysis it is stated that the strategy of forming paratexts adopted by the translator is inconsistent. The secondary text designates an additional way of reading “Bieguni” novel, but it does not impose it as using the notes is just a possibility and depends on the reader’s choice
Direct growth of carbon nanotubes from stainless steel grids and plasma functionalization for poly(vinyl alcohol) composite production
Over the past 20 years carbon nanotubes (CNTs) have received a great deal of attention in the scientific community due to their extraordinary properties. Although much work has been done to increase the quality of CNT while lowing the cost of production, their high cost is still a major obstacle in preventing their use in everyday life. This issue is especially significant in composite research where a high volume of CNTs is needed. This work presents a simple, inexpensive and scalable method to grow CNTs directly from stainless steel (SS) mesh, without any pretreatment or the use of external catalyst. In addition, the growth substrate is shown to be recyclable for multiple uses. The effect of carbon input on the density, morphology and removal of CNTs was examined. It was found that increased carbon input leads to the growth of larger diameter multi-walled CNTs with stronger adhesion to the surface. The study on the growth of CNTs was done in parallel with a study on the use of CNTs as filler material in poly vinyl alcohol (PVA) composites. However, due to their high surface energies, CNTs often agglomerate together when introduced into polymers and solvents. Surface functionalization of the CNTs via a C2H6/O2 capacitively-coupled RF plasma discharge was used to overcome the issue of agglomeration. The aqueous nanofluids that were created by removal of the CNTs from the substrate through ultrasonication were found to remain stable after boiling and after extended periods of time (> 6 months). The PVA/CNT composites produced were homogenous with good dispersion of the CNTs. Thermally, the composites exhibited a small increase in glass transition and melting point temperatures, as well as a retardation in the degradation of the polymer. Mechanically, the 0.3 wt.% Functionalized-CNT composite showed 28% and 41% increases in tensile strength and modulus, respectively, over the neat polymer.Au cours des vingt dernières années, les nanotubes de carbone (NTCs) ont reçu énormément d'attention au sein de la communauté scientifique en raison de leurs propriétés extraordinaires. Bien que beaucoup de travaux ont été réalisés afin d'améliorer la qualité des NTCs tout en essayant de diminuer leur coût de production, ce coût demeure un obstacle majeur quant à leur utilisation dans la vie quotidienne. Ce problème est particulièrement important dans le contexte des matériaux nanocomposites à base de polymère où des volumes importants de NTCs sont nécessaires. Ce projet de maîtrise avait pour objectif le développement d'une méthode de synthèse simple, peu coûteuse et pouvant facilement être mise à l'échelle. Dans ce contexte, nous avons eu recours à la croissance directe de NTCs sur de l'acier inoxydable, sans utiliser de prétraitement ou catalyseur externe. Nous avons démontré que le substrat de croissance est recyclable pour des usages multiples. Nous avons étudiés l'effet de l'apport de carbone lors de la croissance sur la densité et la morphologie des NTCs, ainsi que sur l'adhésion des tubes à l'acier inoxydable. Nous avons constaté que l'augmentation de l'apport en carbone mène à l'augmentation de nombre de parois de NTCs et à une plus forte adhésion à la surface. L'étude portant sur la croissance des nanotubes de carbone a été effectuée en parallèle avec une étude sur l'utilisation des NTCs comme matériau de remplissage dans les composites à base de polyalcool vinylique (PVA). Il est bien connu qu'en raison de leur énergie de surface élevée, les NTCs ont tendance à s'agglomérer lorsqu'ils sont introduits dans les polymères et les solvants. La fonctionnalisation de surface des NTCs dans une décharge électroluminescente entretenue par couplage capacitif radio fréquentiel (RF) dans un mélange de gaz Ar/C2H6/O2 a été utilisée pour surmonter les problèmes d'agglomération. Cette fonctionnalisation introduit des liens covalents à la surface des NTCs avec des groupes polaires. Des nanofluides NTC/eau distillé créés à partir des NTC fonctionnalisés demeurent stables sur de longues périodes de temps (> 6 mois) et ce, même après chauffage jusqu'au point d'ébullition. Les composites PVA/NTC produits sont homogènes et montrent une bonne dispersion des NTCs. Du point de vue thermique, les composites montrent une légère augmentation de la température de transition vitreuse ainsi que du point de fusion, ainsi qu'un retard dans la dégradation du polymère. Du point de vue mécanique, les composites formés avec une très faible charge massique (0,3 % en masse) montrent des hausses de 28% et 41% dans leur résistance à la traction et module de Young par rapport au polymère pur
Plasma functionalized carbon nanotubes suspensions for high temperature direct absorption thermal energy harvesting
In this PhD thesis, stable carbon nanotube (CNT) colloidal suspensions, known as CNT nanofluids, were synthesized and studied for use in solar thermal energy harvesting applications. The production of a CNT nanofluid that is capable of remaining stable over long periods of time and at the high solar heating temperatures involves a multi-step process, which was developed, characterized and optimized in this thesis. An inexpensive and scalable thermal chemical vapour deposition (t-CVD) process was used to produce CNTs directly from stainless steel mesh. It was found that the acetylene concentration within the t-CVD reactor during growth could be used as a way of controlling the average CNT diameter, with smaller diameter nanotubes being easier to break and remove from the substrate for nanofluid production. In addition this growth method generates an open porous network of CNTs that can then be easily surface-treated using a glow discharge plasma. Functionalization using an argon/oxygen/ethane gas mixture was found to graft oxygen-containing moieties (primarily carboxylic groups) to the surface of the CNTs, mostly likely through a sidewall defect-bonding process.Nanofluids produced with the functionalized-CNTs were quantitatively shown to remain stable in a number of polar base fluids, including water, alcohols and glycols. In particular, the CNT nanofluids using denatured alcohol and glycols as base fluids are stable over extended periods of time (currently tested up to 10 months at 20 °C), at high temperatures (up to 170 °C in glycols for 1 hour), and after repeated evaporation/condensation cycling (using denatured alcohol as base fluid). Optical absorbance measurements of the CNT nanofluids showed that for short collection depths (cm) only small amounts of CNTs (on the order of mg L-1) are required to obtain close to 100 % absorption of solar radiation (assuming no scattering). The unmatched stability of the CNT nanofluids, coupled with their strong broadband electromagnetic absorption properties make them ideal candidates for volumetric solar energy harvesting, and open the door to other interesting potential applications.Cette thèse de doctorat porte sur la synthèse et la caractérisation approfondie de suspensions colloïdales stables contenant des nanotubes de carbone (NTC) – des nanofluides de NTC – et de leur usage potentiel comme fluides absorbeurs et caloporteurs de l'énergie solaire. La synthèse d'un nanofluide de NTC qui reste stable sous les conditions opératoires typiques des panneaux solaires thermiques, c.-à.-d. sur de longues périodes et à hautes températures, nécessitait le développement d'un nouveau procédé. Ce procédé intégré est décrit, caractérisé et optimizé dans cette thèse. Un procédé de dépôt chimique en phase vapeur a été développé pour la synthèse directe de NTC sur des grillages fins d'acier inoxydable. Ce procédé s'avère économique et peut être mis à l'échelle. Il a été observé que la concentration du gaz d'acétylène présent dans le réacteur lors de la croissance des NTC peut être utilisée comme levier pour contrôler leur diamètre moyen; les plus petits NTC étant plus facilement cassés de la surface de croissance, ceux-ci sont donc préférés pour la synthèse de nanofluides. Cette technique de synthèse donne également lieu à des réseaux ouverts et poreux de NTC sur la surface du grillage et ainsi, à une fonctionnalisation chimique de surface aisée avec l'aide d'un plasma produit par une décharge électroluminescente. Des traitements par plasma soutenus dans des mélanges argon/oxygène/éthane donnent lieu à l'ajout sur la surface de NTC de fractions chimiques contenant de l'oxygène - des groupes fonctionnels carboxyles en majorité – fort probablement par l'intermédiaire de liaisons latérales sur les défauts des NTCs.Il a été démontré que les nanofluides de NTCs produits avec le nouveau procédé demeurent stables dans plusieurs liquides polaires (eau, glycols, alcools). En particulier, les nanofluides utilisant l'alcohol dénaturé et les glycols comme liquide de base demeurent stables sur de longues périodes (plus de 10 mois à 20 oC, jusqu'à présent), à haute température (jusqu'à 170 °C avec le glycol comme liquide de base et pour une heure), et même à la suite de nombreux cycles d'évaporation/condensation du fluide de base (alcool dénaturé). Les mesures d'absorbance optique des nanofluides de NTC ont montré qu'une absorption presque complète du spectre solaire (i.e. 100 %, en négligeant la diffusion de la lumière) peut être obtenue sur une courte distance (1 cm) avec une faible quantité de NTC (environ 1 mg L-1). La grande stabilité ainsi que la capacité à absorber les ondes électromagnétiques sur une plage large du spectre font des nanofluides de NTC des candidats idéaux à titre de fluides absorbeurs et caloporteurs pour les capteurs solaires thermiques, et pour bien d'autres applications potentielles
A Stable Carbon Nanotube Nanofluid for Latent Heat-Driven Volumetric Absorption Solar Heating Applications
Recently, direct solar collection through the use of broadly absorbing nanoparticle suspensions (known as nanofluids) has been shown as a promising method to improve efficiencies in solar thermal devices. By utilizing a volatile base fluid, this concept could also be applied to the development of a direct absorption heat pipe for an evacuated tube solar collector. However, for this to happen or for any other light-induced vapor production applications, the nanofluid must remain stable over extended periods of time at high temperatures and throughout repetitive evaporation/condensation cycles. In this work, we report for the first time a nanofluid consisting of plasma-functionalized multiwalled carbon nanotubes (MWCNTs) suspended in denatured alcohol, which achieves this required stability. In addition, optical characterization of the nanofluid demonstrates that close to 100% of solar irradiation can be absorbed over a relatively small nanofluid thickness
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