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Normirka izvan kanona: Roksanda Njeguš u srpskom književnom sistemu
No full textThis paper will discuss the work of Roksanda Njeguš (1915–2009) in the context of Serbian literature. Roksanda Njeguš was a translator from Slovenian and Italian into Serbo-Croatian, a writer, and a cultural worker. She published a book of literary reportage Normirac u srcu (1949) and the novels Kidanje (1959), Stolice na kiši (1978), and Otpisani iz ružičaste zone (1998). This paper aims to outline one possible line of interpretation of the author’s oeuvre regarding the broader political and cultural context of its creation. The author’s narrative focus is women’s experience during the National Liberation Struggle, and her last novel is dedicated to the breakup of Yugoslavia. Therefore, this work will attempt to view her novels as a literary chronicle of Socialist Yugoslavia through the female experience of struggle. By analysing her novels, this paper will critically reevaluate the author’s marginal position in the canon of the Serbian literary system.Ovaj rad istražuje književne doprinose Roksande Njeguš (1915–2009) u kontekstu srpske književnosti. Roksanda Njeguš je bila prevoditeljka sa slovenačkog i italijanskog na srpskohrvatski jezik, autorka i kulturna radnica, ostavila je značajan pečat u književnom i kulturnom životu Jugoslavije. Iako je objavila četiri knjige: Normirac u srcu (1949), Kidanje (1959), Stolice na kiši (1978) i Otpisani iz Ružičaste zone (1998), njen opus u nekadašnjoj jugoslovenskoj, a današnjoj srpskoj književnosti, nalazi se na marginama naučne i kritičke recepcije. U ovoj studiji će se ponuditi jedna moguća interpretacija autorkinog opusa kroz kontekstualizaciju unutar šireg političkog i kulturnog miljea u kojem je nastao. Centralno mesto njenog narativnog fokusa jeste prikaz ženskih iskustava tokom Narodnooslobodilačke borbe, a njen poslednji roman posvećen je raspadu Jugoslavije. Stoga ovaj rad teži da interpretira romane Roksande Njeguš kao književnu hroniku socijalističke Jugoslavije kroz prizmu ženske borbe i ženskog iskustva. Takođe, kroz temeljnu analizu njenih književnih dela, nastojaće se da se kritički prevrednuje autorkin položaj unutar srpskog književnog sistema. Posmatrajući teme, motive i narativne tehnike koje je koristila autorka, u radu se teži ka objašnjenju značaja njenih doprinosa nekadašnjoj jugoslovenskoj književnosti. Sinteza uvida iz različitih izvora ima za cilj da ponudi obuhvatno razumevanje autorkinog književnog nasleđa
Exploring polymer and surfactant soft-templating in the synthesis of transparent silica monoliths for ▫▫ capture
No full textA potential way to mitigate the increasing amount of CO2, one the main agents related to climate change, is to capture, controllably release, and store it for later use [1]. The today-available CO2 capture substances most often rely on toxic and environmentally problematic polyamine resins. As a sustainable alternative, not-functionalized monoliths made from solid naturally abundant materials such as amorphous silicon dioxide or silica, are being investigated for CO2 capture [2]. In such monoliths, their capability of capturing CO2 is strongly influenced by their specific surface area, as CO2 adsorbs to the silica surface. However, a high degree of porosity reduces the mechanical stability of silica monoliths, leading to embrittlement and breaking during handling. The porosity and mechanical stability can be optimised by incorporating soft-templating agents, such as polymers and surfactants. Furthermore, tuning the internal structure of silica monoliths – particularly their average pore size – allows the synthesis of transparent monoliths [3]. This feature is especially advantageous for photothermal (PT) CO₂ desorption applications, where PT-active nanoparticles are incorporated within the silica matrix. In such systems, the transparency of the monoliths permits uniform illumination of all PT-active particles, ensuring their complete activation and a uniform release of the adsorbed CO₂.
In this study we explored the synthesis of transparent, highly porous silica monoliths using polymers and surfactants, as soft-templating agents, to elucidate their effect on the monolith’s transparency and porosity. The monoliths were synthesized by sol-gel templating and calcination. Several soft-templating agents were studied, including low- and high-molecular-weight polyethylene glycols, polyvinyl pyrrolidones, and polyvinyl alcohols, starch, microcrystalline cellulose, and surfactants sodium dodecylsulfate and hexadecyltrimethylammonium bromide. The prepared monoliths were examined using gas sorption porosimetry, SEM, and compression tests. We prepared optically and visually transparent monoliths (Figure) with high specific surface area (400 – 800 m2/g) and small diameter pores (2 – 8 nm). These findings highlight the high potential of transparent silica monoliths for potential future CO2 capture applications
Analysis of a hyperchaotic system with a hyperbolic sinusoidal nonlinearity and its application to area exploration using multiple autonomous robots
No full textAs applications of chaotic systems span numerous fields in engineering, physics, encryption, communications, and robotics, there is a continuing need to introduce novel chaotic systems and study their applicability in the aforementioned fields. In this chapter, a four-dimensional hyperchaotic system is introduced and analyzed through calculation of bifurcation diagrams and Lyapunov exponents. The system is a modification of the system proposed by Li and Sprott (Int J Bifurcation Chaos 24:1450034, 2014) and a generalization of the system in Moysis et al. ( Int J Dyn Control:1–11, 2020). The system has no rest points and thus belongs to the category of systems with hidden attractors. The system is then applied to the problem of chaotic area exploration. The aim here is to combine the dynamics of the chaotic system with the motion dynamics of an autonomous robot exploring an area. This results into a chaotic and unpredictable motion that nonetheless ensures coverage of the given area. Such a technique can be useful for exploration or patrolling tasks. Numerical simulations are performed to study the coverage achieved with respect to simulation time. The case of multiple robots is also considered
Nickel-decorated ZnO nanoparticles for effective solar reduction of hexavalent chromium and removal of selected pharmaceuticals
Get PDFThe efficient visible light driven photocatalytic reduction of hexavalent chromium, Cr(VI) was demonstrated using ZnO nanoparticles (NPs) decorated with oxo-clusters of transition metals. The ZnO NPs were synthesized by a facile one-pot solvothermal synthesis followed by a fast microwave-assisted (MW) grafting of transition metals on the surface of NPs. Nickel was found to be the most active transition metal for photocatalytic activity as demonstrated by reduction of Cr(VI) to Cr(III). The optimally grafted samples contained 0.5 wt% Ni and increased photocatalytic activity by almost one-fold. The oxo-clusters did not enter the lattice of ZnO but rather resided on the surface and their efficient bonding to the ZnO surface was proved by Raman, TEM and X-Ray absorption techniques. Influence of MW power was studied and shown that excessive power load leads to formation of elongated structures of ZnO which decreases the photocatalytic activity. It was demonstrated by measuring fluorescent radical products that electrons, efficiently transferred via oxygen, were the main active species in combination with the unchanged oxidation power of holes and • OH in the grafted samples. The applicability of the materials was tested in immobilized plug flow photoreactor system degrading five pharmaceuticals simultaneously where their long-term use was shown
Aerosol spectral optical properties in the Paris urban area and its peri-urban and forested surroundings during summer 2022 from ACROSS surface observations
Get PDFAbstract. The complex refractive index (CRIn−ik) and the single scattering albedo (SSA) are key parameters driving the aerosol direct radiative effect. Their spatial, temporal, and spectral variabilities in anthropogenic–biogenic mixed environments are poorly understood. In this study, we retrieve the spectral CRI and SSA (370–950 nm wavelength range) from in situ surface optical measurements and the number size distribution of submicron aerosols at three sites in the greater Paris area, representative of the urban city, as well as its peri-urban and forested rural environments. Measurements were taken as part of the ACROSS (Atmospheric Chemistry of the Suburban Forest) campaign in June–July 2022 under diversified conditions: (1) two heatwaves leading to high aerosol levels, (2) an intermediate period with low aerosol concentrations, and (3) an episode of long-range-transported fire emissions. The retrieved CRI and SSA exhibit an urban-to-rural gradient, whose intensity is modulated by the weather conditions. A full campaign average CRI of 1.41−0.037i (urban), 1.52−0.038i (peri-urban), and 1.50−0.025i (rural) is retrieved. The imaginary part of the CRI (k) increases and the SSA decreases at the peri-urban and forest sites when exposed to the influence of the Paris urban plume. Values of k > 0.1 and SSA < 0.6 at 520 nm are related to a black carbon mass fraction larger than 10 %. Organic aerosols are found to contribute to more than 50 % of the aerosol mass and up to 10 % (urban), 17 % (peri-urban), and 22 % (forest) of the aerosol absorption coefficient at 370 nm. A k value of 0.022 (370 nm) was measured at the urban site for the long-range-transported fire episode