Towards a Different Knowledge: the Knjiženstvo Database and the Digitisation of Materials

The first part of this paper introduces the concept of digital humanities and the phases that some researchers note in the development of the humanities in new, digital media, as well as the role of digital humanities in the promotion of the marginalised literatures, particularly that written by women. The core example is the digital database Knjiženstvo, certain segments of which contain not only the data on the texts, but the digitised texts as well. In this paper, we pose the question on how databases can be involved in the creation of new knowledge at all educational levels. To this effect, we necessarily expand certain segments of the database to include those publications on which they already contain information. In relation to this, it has been observed that one of the greatest problems is the part of the database dealing with the periodicals – both women and feminist – and therefore, the second part of the paper is dedicated to this topic. We first analyze the terms women and feminist magazines, and afterwards, we consider the ways in which the materials from these periodicals could be gathered, classified and connected

Application of the reactor based on dielectric barrier discharge for the decolorization of reactive textile dyes

Dekolorizacija reaktivnih boja za tekstil Reactive Black 5, Reactive Blue 52, Reactive Yellow 125 i Reactive Green 15 je ispitana pomoću unapređenog oksidacionog procesa u netermalnom plazma reaktoru, koji je baziran na koaksijalnom dielektričnom barijernom pražnjenju (DBD) sa tankim vodenim filmom rastvora koji se tretira i konstantno obnavlja. Početne koncentracije boja u rastvoru su bile 40,00 i 80,00 mg/L. U prvom delu rada ispitan je uticaj različitih polaznih pH vrednosti (9,00; 7,00; 5,00) rastvora boje i dodatak homogenih katalizatora (H2O2, Fe2+, Fe3+ Mn2+ i Cu2+) na efikasnost dekolorizacije tokom uzastopnih recirkulacija rastvora boje kroz DBD reaktor, tj. primenjene gustine energije (45–315 kJ/L).Uticaj vremena stajanja rastvora nakon tretmana plazmom je ispitivan tokom perioda od 24 h. Promena pH vrednosti i uticaj pH podešavanja rastvora boje posle svake recirkulacije na efikasnost dekolorizacije je testirana. Potvrđeno je da početna pH vrednost i pH korekcija rastvora boje posle svake recirkulacije nemaju uticaja na dekolorizaciju. Efikasnost tretmana plazmom se značajno intenzivira sa dodatkom vodonik-peroksida. Najefikasnija dekolorizacija od 97 % je dobijena u prisustvu 10 mM H2O2 u sistemu od 80,00 mg/L boje Reactive Black 5 i pri primenjenoj gustini energije od 45 kJ/L, posle vremena stajanja od 24 h od tretmana plazmom. Takođe, efekat tretmana plazmom može se poboljšati sa dodatkom soli gvožđa(II) ako su uslovi za Fentonovu reakciju ispunjeni. Tokom tretmana, u pražnjenju se generišu azotasta i azotna kiselina koje smanjuju pH vrednost rastvora. Ispitan je uticaj dodatka različitih visokih koncentracija neorganskih soli (NaCl, Na2SO4 i Na2CO3) na stepen dekolorizacije boje Reactive Black 5 (40,0 mg/L). Takođe, ispitana je promena pH vrednosti i provodljivosti rastvora boje posle svake recirkulacije. Rezultati pokazuju da je dekolorizacija značajno ograničena u prisustvu soli. Sa povećanjem koncentracije neorganskih soli, smanjuje se efikasnost dekolorizacije boje, a stepen inhibicije zavisi od soli koja se koristi. Najefikasnija dekolorizacija od 90 % je dobijena u prisustvu 50 g/L NaCl pri primenjenoj gustini energije od 135 kJ/L posle vremena stajanja od 24 h nakon tretmana plazmom. Povećanje dekolorizacije u prisustvu 50 g/L NaCl je objašnjeno formiranjem hipohlorita iz hlorida tokom tretmana plazmom. Dekolorizacija rastvora koji sadrže neorganske soli Na2SO4 i Na2CO3 je bila manja nego kod rastvora bez dodatka soli. U drugom delu rada ispitana je efikasnosti dekolorizacije i degradacije pri visokim koncentracijama boje Reactive Black 5 (40, 80, 200, 500 i 1000 mg/L). Efikasnost degradacije i mogući putevi degradacije praćeni su merenjem HPK vrednosti, jonskom hromatografijom (IC) i HPLC tehnikom. Pored toga, u okviru ovog rada, značajno je unapređena i optimizovana metoda za merenje HPK vrednosti pomoću kontrolisanog mikrotalasnog tretmana. Toksičnost je ispitana pomoću Artemia salina test organizama. Toksikološki testovi, izvedeni pomoću A. salina, pokazuju da je toksičnost rastvora boje smanjena ili je ostala nepromenjena nakon tretmana, sa izuzetkom za boju Reactive Green 15, gde je detektovan blagi porast toksičnosti samo za jednu vrednost koncentracije.Decolorization of reactive textile dyes Reactive Black 5, Reactive Blue 52, Reactive Yellow 125 and Reactive Green 15 was studied using advanced oxidation processes (AOPs) in a non-thermal plasma reactor, based on coaxial water falling film dielectric barrier discharge (DBD). Used initial dye concentrations in the solution were 40.0 and 80.0 mg/L. The effects of different initial pH (9.00; 7.00; 5.00) of dye solutions, and addition of homogeneous catalysts (H2O2, Fe2+, Fe3+ Mn2+ and Cu2+) on the decolorization during subsequent recirculation of dye solution through the DBD reactor, i.e. applied energy density (45–315 kJ/L) were studied. Influence of residence time was investigated over a period of 24 h. Change of pH values and effect of pH adjustments of dye solution after each recirculation on the decolorization was also tested. It was found that the initial pH of dye solutions and pH adjustments of dye solution after each recirculation did not influence the decolorization. The effect of plasma treatment can be significantly intensified with addition of hydrogen peroxide. The most effective decolorization of 97% was obtained with addition of 10 mM H2O2 in a system of 80.0 mg/L Reactive Black 5 with applied energy density of 45 kJ/L, after residence time of 24 h from plasma treatment. Also, the effect of plasma treatment can be enhanced with addition of iron(II) salts if the conditions for Fenton reactions are fulfilled. During the treatment, the discharge generates other species like nitrous and nitric acids which decrease the pH values of solutions. The effects of addition of inorganic salt different high concentrations (NaCl, Na2SO4 and Na2CO3) on the degree of decolorization of dye Reactive Black 5 (40.0 mg/L) were studied. Changes of pH values and the conductivity of dye solution after each recirculation were tested. The results indicated that decolorization of the dyes was significantly limited in the presence of salts. The increase of concentrations of inorganic salts in water reduced the efficiency of decolorization of dyes, in a varying degree depending of the salt used. The most effective decolorization of over 90 % was obtained with the addition of NaCl (50 g/L), applied energy density of 135 kJ/L and after residence time of 24 hours of plasma treatment. The increased decolorizatin with addition 50 g/L NaCl was explained by forming of hypochlorite from chloride during the plasma treatment. Decolorization of solutions containing inorganic salts Na2SO4 and Na2CO3 were lower than for the solution without salt. In the second part the effectivenes of decolorization and degradation of high concentrations dye Reactive Black 5 (40, 80, 200, 500 and 1000 mg/L) was examined. Efficiency degradation and possible degradation pathways were monitored by measuring the COD value, ion chromatography (IC) and HPLC technique. In addition, as part of this work, has significantly improved and optimized method for measuring the COD value by controlled microwave treatment. Toxicity was evaluated using the brine shrimp Artemia salina as a test organism. Toxicity tests, performed using A. salina, have shown that toxicity of dye solutions was reduced or maintained at the same level after the treatment, except for Reactive Green 15 where slight increase of toxicity was detected for only one concentration value

Nanoscale metal oxides as materials used for modification of carbon-based electrodes in electrochemical sensors

Nanostructured metal oxides used as modifiers of various carbon-based working electrodes serve as the basis for designing sensitive electrochemical sensors to detect desired analytes. The sensors we develop are distinguished by low detection limit (LOD), high analyte selectivity, sensitivity, and versatile real-world sample use case. In this work we present the design of two based on metal oxides as modifiers of carbon paste working electrode (CPE) and their applications in the electrochemical determination of levodopa and adrenaline. The physicochemical properties of designed materials were analyzed by complementary experimental technics (XRPD, TEM, SEM, EDS, electrochemical measurements) to determine their (micro)structural properties and correlate them with electroanalytical performance. Europium has been considered a significant lanthanide element with higher redox reaction behavior. We conducted a hydrothermal synthesis of Eu2O3@Cr2O3 and used them for CPE modification. The proposed Eu2O3@Cr2O3/CPE electrode was used to develop an analytical procedure quantifying L-Dopa in a wide micromolar linear range (1-100 µM), high sensitivity of 1.38 µA µM−1 cm−2 and a low detection limit (LOD = 0.72 µM). On the other side, we investigated the physicochemical properties of the gallium/bismuth mixed oxides and studied the influence of different Ga2O3:Bi2O3 ratios on the electrochemical detection of adrenaline. Square wave voltammetry was optimized, and the best electrode showed a wide linear working range of 7-100 μM, under optimized conditions. The LOD for the proposed sensor was calculated to be 1.9 μM, with a low limit of quantification (LOQ = 5.8 μM). The total performance of the sensors, particularly their performance on real-world samples and their potential for commercialization, had to be carefully evaluated during the sensor construction. Our team is devoted to developing highly selective electrochemical sensors based on nanomaterials to be potentially used as the basis for the fabrication of high-performance miniature devices with exceptional sensitivity to specific analytes, like adrenaline and L-Dopa, in this research

Биосорпција јона никла на тканинама од јуте: кинетичка и изотермска испитивања

Raw jute fabric was chemically modified with 1 % NaOH for 30 min, 17.5 % NaOH for 5 min or with 0.7 % NaClO2 for 30 and 60 min to study the influence of changes in the chemical composition of the fabrics and quantity of carboxyl groups on the biosorption capacity of the fabrics for nickel ions. The effects of contact time and initial concentration of nickel ions on the biosorp- tion capacity of the fabrics were also investigated. The obtained results rev- ealed that the biosorption of nickel ions can be explained by the pseudo-sec- ond-order kinetic model, while the experimental isotherm data fit better with the Langmuir model. The calculated ratios between maximal biosorption cap- acity (6.30–12.06 mg g-1) of the jute fabrics and carboxyl group quantity indi- cated that approximately half of the carboxyl groups of the fabrics’ would be involved in binding nickel ions during biosorption. Therefore, the quantity of carboxyl groups can be used to predict the maximal biosorption capacity of jute fabrics toward nickel ions. In the case of oxidized jute fabrics, the lignin rem- oval, and consequently increased content of cellulose and hemicelluloses, also contributed to a higher biosorption capacity.Сирова тканина од јуте је хемијски модификована 1 % NaOH у току 30 min, 17,5 % NaOH у току 5 min или 0,7 % NaClO2 у току 30 и 60 min у циљу испитивања утицаја промена хемијског састава и садржаја карбоксилних група на биосорпциони капацитет тканина према јонима никла. Такође, испитиван је и утицај времена контакта тканина са раствором NiSO4 и почетне концентрације раствора никла на биосорпциони капацитет тканина од јуте. Добијени резултати указују на то да се процес биосорпције никла може описати кинетичким моделом псеудо-другог реда, а равнотежне вредности добијене за сорпцију никла се боље слажу са Langmuir адсорпционом изотермом. Израчунати однос између максималних биосорпционих капацитета тканина од јуте (6,30–12,06 mg g-1) и садржаја карбоксилних група указују на то да ће приближно половина карбоксилних група учествовати у везивању јона никла током биосорпције. Према томе, садржај карбоксилних група се може користити као индикатор максималног биосорпционог капацитета тканина од јуте према јонима никла. Код оксидисане тканине, уклањање лигнина које је праћено са повећањем садржаја целулозе и хемицелулоза је такође допринело већем биосорпционом капацитету

Preliminary study of copper(II) ions removal from wastewater using solid residue obtained by co-pyrolysis of lignite and high density polyethylene mixture

In this study the solid residue obtained by the co-pyrolysis of low quality, mineral-rich lignite taken from the Kostolac Basin, Serbia (45.36% of ash; 33.42% of total organic carbon; net calorific value of 9.5 MJ/kg) and high density polyethylene, HDPE (mass ratio, 1:1) at 500 oC was tested as a sorbent for Cu2+ ions, considering that as a coaly-based material, simultaneously enriched in clays, it may have good adsorption properties. Sorption experiments of were performed using 0.5 g of solid co-pyrolysis lignite/HDPE product, as sorbent which was treated with 5 cm3 of model solutions containing ~ 200 times higher concentration of Cu2+ ions (242.60 mg/dm3), in relationship to its maximal allowed content in surface water of bad quality. Model solutions were prepared using corresponding nitrates dissolved in distilled water. Two model solutions were prepared. The first model solution contained individual Cu2+ ions, whereas the second one contained mixture of Cu2+, Pb2+, Co2+ and Cd2+ ions. Concentration of each ion in latter was also ~ 200 times higher than its maximal allowed content in surface water of bad quality. Treatment with distilled water was used as a blank. Concentrations of heavy metal ions in initial model solutions and supernatants obtained after sorption experiments were measured using inductively coupled plasma – optical emission spectrometry. The obtained results indicated very efficient sorption of Cu2+ ions from its individual model solution, attaining 99.96%. The efficiency of Cu2+ ions sorption was also high (99.95%) from model solution, which contained mixture of metal ions. It is important to mention that sorption of other metal ions from model solution mixture was also effective (99.99%, 80.70% and 71.04% for Pb2, Cd2+ and Co2+, respectively). The preliminary results showed promising sorption properties of solid residue obtained by the co-pyrolysis of lignite and HDPE against Cu2+, but also possibly for other heavy metals, particularly, Pb2+ ions.Abstracts and Field guides: [https://opac.geologie.ac.at/wwwopacx/wwwopac.ashx?command=getcontent&server=images&value=Pangeo_Austria_2022.pdf

Arsenic removal from aqueous solutions by sorption onto zirconium- and titanium-modified sorbents

Arsenic reduction in drinking water can include treatment by adsorption, switching to alternative water sources, or blending with water that has a lower arsenic concentration. Commercial sorbents MTM, Greensand and BIRM (Clack Corporation) were modified with zirconium and titanium after activation. The modifications were performed with titanium tetrachloride and zirconium tetrachloride. The modified sorbents were dried at different temperatures. The sorption of arsenate and arsenite dissolved in drinking water (200μg L-1) onto the sorbents were tested using a batch procedure. After removal of the sorbent, the concentration of arsenic was determined by HG-AAS. Zirconium-modified BIRM showed the best performance for the removal of both arsenite and arsenate. Modification of the greensand did not affect arsenic sorption ability. Zirconium-modified BIRM diminished the concentration of total As to below 5 μg L-1

Ternary flower-structured nanoferrites with polyvalent cations for potential applications in electrochemical sensors and magnetic hyperthermia

Nanoferrites have been intensively studied because of the possibility of their use in the fields such as medicine, sensors, environmental, agriculture, weather, battery, etc. Often, they are used as modal systems in fundamental science to study physical and chemical phenomena at the nanoscale. Various pathways were applied for the synthesis of nanoferrites with the same composition were led to different microstructure and structure properties, which further influenced magnetic, electric, catalytic and other properties. Consequently, with a controlled synthesis, it is possible to tune the properties of nanoferrites important for applications. On the other side, properties can be controlled by changing chemical composition. In ternary nanoferrites often deviation of stoichiometry accompanied with cation polyvalence was found [1]. The main idea of our work was the application of the polyol-modified method developed for the synthesis of flower-structured iron oxides nanoparticles in the preparation of ternary ZnxMnyFezO4 samples to seek a correlation among chemical composition and microstructure with magnetic hyperthermia efficiency and electrochemical properties. A series of the samples ZnxMnyFezO4 was prepared by polyol process using a slightly modified procedure described in ref [2]. By elemental analysis performed using the ICP technique, the content of cations in the formula unit was determined as follow: Zn0.640Fe2.360O4, Zn0.394Mn0.138Fe2.468O4, Zn0.309Mn0.240Fe2.451O4, Zn0.182Mn0.344Fe2.474O4, Zn0.098Mn0.447Fe2.455O4, Mn0.624Fe2.376O4. The ICP results pointed to the presence of multivalent cations, Mn2+/Mn3+ and Fe3+/Fe2+. Zn has stable valence +2, while the oxidation state of +4 for Mn couldn’t be excluded. Different oxidation states of Mn and Fe and possible deviation of stoichiometry, can create physical effects [3] and make ZnxMnyFezO4 suitable material in practical applications, used for modification of working electrodesin electrochemical sensors. Consequently, we have performed basic electrochemical characterisation of nanoferrites. Cyclic voltammetry of 5 mM K3[Fe(CN)]6/K4[Fe(CN)]6 (1:1) in 0.1 M KCl at bare SPCE and ZnxMnyFezO4-modified SPCE showed that the highest peak current (Ip) was achieved using a Zn0.098Mn0.447Fe2.455O4/SPCE. The Ip was about 22% higher than the bare electrode. X-ray diffraction pattern showed the samples were single-phase crystallising in spinel structure type. Morphology and particle size of the samples were analysed from TEM micrographs. Particles (or crystallites) were agglomerated in a flower-like structure (Figure 1). The diameter of the flowers was around 50-60 nm. Superparamagnetic behaviour of the samples was found from magnetization versus field measurements (hysteresis loops). Prepared samples were in the form of stable colloids with hydrodynamic diameter in the range of 50-120 nm. The heating properties of the samples were analysed from the data of specific absorption rate (SAR), Figure 1b. The highest SAR value was found for Zn0.098Mn0.447Fe2.455O4. The best heating efficiency and electrochemical properties had the same sample. To correlate ZnxMnyFezO4 different efficiency in magnetic hyperthermia and electrochemical sensor applications with parameters like cation distribution in two non-equivalent spinel crystallographic sites (space group, Fd-3m), local distortion on cationic sites, crystallite size and defects, an integrated study of samples structure and microstructure is in progress

Tailoring IONP shape and designing nanocomposite IONS@GN toward modification of SPCE to enhance electrochemical degradation of organic dye

Iron oxide nanoparticles (IONP) with different distinctive morphologies (spherical, cubic, flower-like and needles) were utilized for modification of screen-printed carbon electrodes (SPCE) to be used for synthetic organic dye degradation by an electrochemical approach. This platform was implemented for removal of the synthetic organic dye, Reactive Black 5 (RB5) in aqueous solution. Modified SPCE with spherically shaped IONP (IONS) had the highest dye removal efficiency. Thus, IONS were then used for surface decoration of the most common carbon-based materials (graphene, graphene oxide, carboxylated graphene, graphene nanoribbons, graphene nanoplatelets, single- and multi-wall carbon nanotubes), and the nanocomposites formed were deposited on the electrode surfaces. Using IONS/graphene composite (IONS@GN) for electrode modification resulted in the best effect. Removal of RB5 with this electrode was 51% better in comparison with bare SPCE, reducing the time required for complete dye degradation from 61 to 30 min Using IONS-modified SPCE, total RB5 removal occurred in 51 min, improving the performance by 16% over that of bare SPCE. The effects determined, i.e., the best IONP morphology and best type of carbon-based material for nanocomposite formation to enhance RB5 removal will provide guidelines for further modifications of SPCE with nanomaterials and nanocomposites, for application of this electrochemical approach in the degradation of organic pollutants

Synthesis, Surface Modification and Magnetic Properties Analysis of Heat-Generating Cobalt-Substituted Magnetite Nanoparticles

Here, we present the results of the synthesis, surface modification, and properties analysis of magnetite-based nanoparticles, specifically Co0.047Fe2.953O4 (S1) and Co0.086Fe2.914O4 (S2). These nanoparticles were synthesized using the co-precipitation method at 80 ◦C for 2 h. They exhibit a single-phase nature and crystallize in a spinel-type structure (space group Fd3m). Transmission electron microscopy analysis reveals that the particles are quasi-spherical in shape and approximately 11 nm in size. An observed increase in saturation magnetization, coercivity, remanence, and blocking temperature in S2 compared to S1 can be attributed to an increase in magnetocrystalline anisotropy due to the incorporation of Co ions in the crystal lattice of the parent compound (Fe3O4). The heating efficiency of the samples was determined by fitting the Box-Lucas equation to the acquired temperature curves. The calculated Specific Loss Power (SLP) values were 46 W/g and 23 W/g (under HAC = 200 Oe and f = 252 kHz) for S1 and S2, respectively. Additionally, sample S1 was coated with citric acid (Co0.047Fe2.953O4@CA) and poly(acrylic acid) (Co0.047Fe2.953O4@PAA) to obtain stable colloids for further tests for magnetic hyperthermia applications in cancer therapy. Fits of the Box-Lucas equation provided SLP values of 21 W/g and 34 W/g for CA- and PAA-coated samples, respectively. On the other hand, X-ray photoelectron spectroscopy analysis points to the catalytically active centers Fe2+/Fe3+ and Co2+/Co3+ on the particle surface, suggesting possible applications of the samples as heterogeneous self-heating catalysts in advanced oxidation processes under an AC magnetic field

Multicore flower-like magnetite for potential application in cancer nanomedicine

Nanomaterials are intensively researched both from the fundamental aspect due to new properties at the nanoscale, as well as the aspect of their application in many areas of technology. Magnetic nanoparticles (MNPs) are being tested for use in the diagnosis and therapy of diseases. A new field of medicine, Magnetic nanomedicine is primarily based on the application of MNPs as drug carriers, diagnostic agents in Magnetic Resonance Imaging (MRI) and heat generators in magnetic hyperthermia. Among nanoparticles, magnetic nanoplatforms based on iron oxides for cancer diagnosis and therapy (Cancer nanomedicine) are the most researched and clinically tested. This study presents the results of research into the physicochemical properties of iron oxide nanoparticles prepared by the polyol route, as well as their testing for potential applications as agents in magnetic hyperthermia (MH) and radionuclide carriers (vectors) for the diagnosis and therapy of malignant diseases. Multicore iron oxide structures synthesized by the "polyol" method represent clusters of single-core nanoparticles or crystallites. The dimensions of the single core particles are \textasciitilde13.5 nm, while the nanoflowers formed by clustering are \textasciitilde25 nm, depending on the applied synthesis parameters. For targeted medical applications, nanoflowers are coated with different ligands in order to increase colloidal stability and biocompatibility. The best results were by coating MNPs with polyacrylic acid (PAA). The multifunctionality of nanoflowers was investigated by measuring their hyperthermic efficiency for applications in magnetic hyperthermia and radiolabeling with diagnostic (99mTc) and therapeutic radionuclides (177Lu, 90Y). In addition to traditional methods of cancer therapy (surgery, radiotherapy, and chemotherapy), new ways of therapy such as MH are constantly being developed. MH is a therapy based on the property of MNPs that when placed in an alternating (AC) magnetic field, transform the electromagnetic energy of the field into heat. When located inside a tumor, MNPs can locally generate a temperature of 42-46 °C and destroy cancer cells by heat. The hyperthermic efficiency of MNPs is expressed through the Intrinsic Loss Power (ILP) parameter. The measured ILP was 7.3 nHm2/kg which is considered one of the higher reported values found in the literature for iron oxides. Nanoflowers were radiolabeled with 99mTc, 177Lu, and 90Y radionuclides. The in vitro stability of radiolabeling was investigated. Good in vitro stability indicates that the formed radioactive particles can be used simultaneously for bi-modal cancer therapy (MH and radionuclide therapy) or for MH therapy and diagnostics (theranostics), in the case of labeling with 99mTc