Synthesis and structural characterization of microporous arsenates and phosphates

Predmet rada i istraživanja ove doktorske disertacije su sinteza i strukturne karakteristike novih kristalnih arsenata i fosfata koji sadrže Mg, K, Ca, Mn, Fe, Co, Ni, Cu, Zn, Sr, Ba i druge katjone. U strukturama arsenata i fosfata, AsO4- i PO4-tetraedri najčešće se vezuju sa tetraedarski ili oktaedarski koordinisanim katjonima prelaznih metala formirajući otvorene strukture (slojeve ili 3D mreže) sa širokim opsegom različitih topologija. U šupljinama ili porama u obliku povezanih ili nepovezanih kanala, tunela, kaveza i međuslojnog prostora mogu se ugraditi različiti vanmrežni joni (obično alkalni i zemnoalkalni katjoni) ili molekuli (najčešće mali organski molekuli), što čini ova jedinjenja veoma interesantnim zbog njihovih fizičkih i hemijskih osobina i potencijalne primene. U okviru ispitivanja sistema T1O–T2O–X2O5–(H2O)–Y, gde je T1 dvovalentni ili jednovalentni (K+, Ca2+, Zn2+, Sr2+, Ba2+), T2 dvovalentni ili trovalentni (Mg2+, Mn2+, Fe2+, Co2+, Ni2+, Cu2+, Zn2+, Fe3+, Co3+), X petovalentni (P5+, As5+) katjon, a Y je vanmrežni katjon H2(C2H8N2)2+ ili NH4 + sintetisana su nova jedinjenja metodom niskotemperaturne hidrotermalne sinteze i određene njihove kristalne strukture. Cilj je bio da se u okviru ovog sistema sintetišu monokristali koji u mikroporama ili međuslojnom prostoru sadrže različite jone i molekule kao što je etilendiamin, C2H4(NH2)2, ili odgovarajuća protonovana forma. Kvalitet dobijenih monokristala proveravan je pomoću optičkog mikroskopa ili binokularne lupe i strukture kristala određene su metodom rendgenske difrakcije na monokristalu. Za morfološku i hemijsku karakterizaciju korišćena je metoda skenirajuće elektronske mikroskopije (SEM) dopunjena energetsko-disperzivnim sistemom (EDS). Kod kristala koji su zahtevali preciznu kvantitativnu hemijsku analizu korišćena je elektronska mikrosonda, a metoda ramanske spektroskopije korišćena je za određivanje prisustva H2O, (OH)−, (NH4)+ i NH3. Pokazano je da četiri sintetisana kristala imaju zeolitski DFT-tip strukture. To su (H2en)[ZnAsO4]2 (ZnAs), (H2en)[Co0,1Zn0,9AsO4]2 (ZnCoAs),...The doctoral dissertation research subjects are the synthesis and structural investigation of new arsenate and phosphate containing Mg, K, Ca, Mn, Fe, Co, Ni, Cu, Zn, Sr, Ba and other cations. In the structures of arsenates and phosphates, AsO4- and PO4-tetrahedra are usually linked with tetrahedrally and octahedrally coordinated cations of transition metals forming open structures (layers or 3D frameworks) with a wide range of different topologies. In the holes, or pores, which are in the form of a connected or unconnected channels, tunnels, cages and the interlayered space, various non-framework ions (usually alkaline and earth alkaline cations) or molecules (usually small organic molecules) can be incorporated. Therefore these compounds are very interesting due to their physical and chemical properties and potential applications. In the course of the investigation of the T1O–T2O–X2O5–(H2O)–Y system, where T1 is a divalent or monovalent (K+, Ca2+, Zn2+, Sr2+, Ba2+), T2 divalent or trivalent (Mg2+, Mn2+, Fe2+, Co2+, Ni2+, Cu2+, Zn2+, Fe3+, Co3+), X pentavalent (P5+, As5+) cation, and Y is non-framework cation H2(C2H8N2)2+ or NH4 +, several novel compounds have been synthesized using the low temperature hydrothermal synthesis method, and their crystal structures have been determined. The aim was to synthesize single crystals with micropores or interlayer space containing different ions and molecules like the ethylenediamine, C2H4(NH2)2, or the corresponding protonated forms. The quality of the obtained single crystals was evaluated using an optical or binocular microscope, and the crystal structure was solved using single-crystal X-ray diffraction data. For the morphological and chemical characterization the scanning electron microscopy (SEM), coupled with energy-dispersive system (EDS) was used. The electron microprobe provide precise quantitative chemical analysis, and the Raman spectroscopy method was used for the determination of the presence of H2O, (OH)−, (NH4)+ and NH3..

The occurence of opaline matter in hydrothermally altered diabase, Debelo brdo, Povlen mountain area

In this paper it is described the occurence of glassy opaline matter lining hydrothermal vent discovered in altered diabase. These diabase rocks represent tectonically emplaced extrusive igneous body within the volcanic-sedimentary ophiolitic assemblage so called diabase-chert formation. At the microscopic scale, an altered mass of diabase is composed of distinct domains of the wavy and reticular fibrous carbonates interlocking the interstitial patches of the amorphous to locally recrystalised opaline matter. It was observed that the opaline matter lined the altered mass as well, and that it occurs either in the form of boitroidal aggregates or as the alternating colorless and translucent milky white band

RESEARCH OF PIG FARM IMPACT ON GROUNDWATER QUALITY

Potrebe za pitkom vodom svakodnevno rastu kao i broj onečišćivača koji onečišćuju kvalitetu podzemne vode. Zbog toga je neophodno utvrditi čim veći broj onečišćivača i kvantificirati njihov utjecaj na okoliš. U radu je analizirana kvaliteta podzemne vode na lokacijama koje su u neposrednoj blizini svinjogojske farme. Sve vrijednosti parametara su uspoređene s maksimalnim zakonom dopuštenim koncentracijama i provedena je statistička obrada podataka i korelacijska analiza. Iz dobivenih rezultata je vidljiva degradacija kvalitete podzemne vode u blizini svinjogojske farme.Needs for drinking water has been increasing but the number of polluters that degrade groundwater quality has been increasing as well. Therefore, it is necessary to define as many polluters as possible and quantify their influence in the environment. In the paper, groundwater quality at locations near a pig farm was analyzed. All parameter values were compared with the maximal permissible concentrations. Statistical analysis of data and correlation analysis were carried out. The obtained results show degradation of the groundwater quality near the pig farm

Possibility to use spent fluid catalytic cracking catalyst as component of Portland cement binders

Fluid cracking catalyst residue (spent FCC) is a by-product from petrol refineries. It primarily consists of zeolite (in used sample - faujasite) and amorphous aluminosilicates. In this study, possibility to use spent FCC as a component of binders with low content of Portland cement (PC) have been investigated. Binders made with high volume of mineral additions are being developed in order to reduce the amount CO2 emitted by PC industry. Fly ash (FA), a by-product of coal combustion in thermal power plants, is one of the most commonly used raw material for these binders. The main shortages of binders with high volume of FA are long setting time and low early strength. In this work, mixtures of PC, FA and spent FCC were prepared. It was found that addition of spent FCC to low PC mixtures significantly shortened setting time and improved early strength of the binders. However, 28-day compressive strength of the ternary binder was lower than the strength of low PC binder synthesized with FA only, which indicated the need for further optimization of the binder composition

Micro- to nanoscale textures of gold in arsenopyrite and scorodite from the As-Au-Bi assemblage of Drenjak locality (Serbia)

Arsenopyrite and pyrite are important carriers of Au that is present in the form of microscopic and “invisible” gold. Such gold can be expected to be released upon the process of oxidation of these sulfides. In studied gold mineralization at Drenjak, related to the granitoids of the Oligocene-Miocene Kopaonik Ore District, the main arsenopyrite-pyrite-(bismuthinite) sulfide assemblage was formed in the quartz bodies and partly replaced by scorodite (FeAsO4·2H2O) and Bi-arsenate. With only up to 5 ppm of gold recorded by LA-ICP-MS, aforementioned sulfide minerals are here practically free from lattice-bound gold. Native gold is present in the mineralization, generally ranging in grain size from 20 µm down to the nanoparticles, as revealed by TEM. It is mainly hosted by arsenopyrite and scorodite. In arsenopyrite, gold is polycrystalline and consists of nanocrystallites 20–30 nm in size. It was deposited after arsenopyrite, healing its cavities and microcracks, often associated with native bismuth and bismuthinite. The abundance of gold and Bi minerals correlates with the presence of scorodite. Two types of gold are present in scorodite and Bi arsenate: i) prevailing relict Au grains retained after arsenopyrite oxidation, ii) colloidal-like gold co-precipitated with the arsenates. Based on our observations, we additionally present and discuss indications of low-temperature hydrothermal origin of scorodite, formerly known only as a weathering produc

Some examples of interactions between certain rare earth elements and soil

The rare earth elements represent an increasingly more and more important industrial resource. The increased use may result in waste generation, and their impact upon the environment quality has not been studied sufficiently. Their interaction with soil has been studied in this paper. The Freundlich adsorption isotherm has been determined for lanthanum, erbium and gadolinium at three different soil types (humus, clay and sand type), whereas the sequential extraction at these soil types has been applied for lanthanum and neodymium. The interaction of certain rare earth elements with soil components has been tested as well as the quantity in which these elements are bound to soil and later on extracted in solutions. The objective was to determine the soil capacity for disposal, first of all, of the electronic waste that contains these elements and to assume their fate in the environment.Supplementary material: [https://cherry.chem.bg.ac.rs/handle/123456789/5139

Poland, Slovenia, the World : Challenges of present-day education

Publikacja recenzowana / Peer-reviewed publicationTransformations of education in changing Europe are multifaceted. One of the latter is the process of strengthening the cooperation among universities in this part of the world. This cooperation is carried out in many fields – from joint projects and researches – to joint analyses, discourses and publications. This monograph – a collection of reflections, thoughts and polemics deriving from theoretical and empirical researches, carried out as a part of a joint research project simultaneously undertaken at both these universities under the name “Problems and challenges of modern education” – constitutes one of the fruits of the cooperation between Andrzej Frycz Modrzewski Cracow University and the University of Ljubljana

Synthesis and structural characterization of microporous arsenates and phosphates

Predmet rada i istraživanja ove doktorske disertacije su sinteza i strukturne karakteristike novih kristalnih arsenata i fosfata koji sadrže Mg, K, Ca, Mn, Fe, Co, Ni, Cu, Zn, Sr, Ba i druge katjone. U strukturama arsenata i fosfata, AsO4- i PO4-tetraedri najčešće se vezuju sa tetraedarski ili oktaedarski koordinisanim katjonima prelaznih metala formirajući otvorene strukture (slojeve ili 3D mreže) sa širokim opsegom različitih topologija. U šupljinama ili porama u obliku povezanih ili nepovezanih kanala, tunela, kaveza i međuslojnog prostora mogu se ugraditi različiti vanmrežni joni (obično alkalni i zemnoalkalni katjoni) ili molekuli (najčešće mali organski molekuli), što čini ova jedinjenja veoma interesantnim zbog njihovih fizičkih i hemijskih osobina i potencijalne primene. U okviru ispitivanja sistema T1O–T2O–X2O5–(H2O)–Y, gde je T1 dvovalentni ili jednovalentni (K+, Ca2+, Zn2+, Sr2+, Ba2+), T2 dvovalentni ili trovalentni (Mg2+, Mn2+, Fe2+, Co2+, Ni2+, Cu2+, Zn2+, Fe3+, Co3+), X petovalentni (P5+, As5+) katjon, a Y je vanmrežni katjon H2(C2H8N2)2+ ili NH4 + sintetisana su nova jedinjenja metodom niskotemperaturne hidrotermalne sinteze i određene njihove kristalne strukture. Cilj je bio da se u okviru ovog sistema sintetišu monokristali koji u mikroporama ili međuslojnom prostoru sadrže različite jone i molekule kao što je etilendiamin, C2H4(NH2)2, ili odgovarajuća protonovana forma. Kvalitet dobijenih monokristala proveravan je pomoću optičkog mikroskopa ili binokularne lupe i strukture kristala određene su metodom rendgenske difrakcije na monokristalu. Za morfološku i hemijsku karakterizaciju korišćena je metoda skenirajuće elektronske mikroskopije (SEM) dopunjena energetsko-disperzivnim sistemom (EDS). Kod kristala koji su zahtevali preciznu kvantitativnu hemijsku analizu korišćena je elektronska mikrosonda, a metoda ramanske spektroskopije korišćena je za određivanje prisustva H2O, (OH)−, (NH4)+ i NH3. Pokazano je da četiri sintetisana kristala imaju zeolitski DFT-tip strukture. To su (H2en)[ZnAsO4]2 (ZnAs), (H2en)[Co0,1Zn0,9AsO4]2 (ZnCoAs),...The doctoral dissertation research subjects are the synthesis and structural investigation of new arsenate and phosphate containing Mg, K, Ca, Mn, Fe, Co, Ni, Cu, Zn, Sr, Ba and other cations. In the structures of arsenates and phosphates, AsO4- and PO4-tetrahedra are usually linked with tetrahedrally and octahedrally coordinated cations of transition metals forming open structures (layers or 3D frameworks) with a wide range of different topologies. In the holes, or pores, which are in the form of a connected or unconnected channels, tunnels, cages and the interlayered space, various non-framework ions (usually alkaline and earth alkaline cations) or molecules (usually small organic molecules) can be incorporated. Therefore these compounds are very interesting due to their physical and chemical properties and potential applications. In the course of the investigation of the T1O–T2O–X2O5–(H2O)–Y system, where T1 is a divalent or monovalent (K+, Ca2+, Zn2+, Sr2+, Ba2+), T2 divalent or trivalent (Mg2+, Mn2+, Fe2+, Co2+, Ni2+, Cu2+, Zn2+, Fe3+, Co3+), X pentavalent (P5+, As5+) cation, and Y is non-framework cation H2(C2H8N2)2+ or NH4 +, several novel compounds have been synthesized using the low temperature hydrothermal synthesis method, and their crystal structures have been determined. The aim was to synthesize single crystals with micropores or interlayer space containing different ions and molecules like the ethylenediamine, C2H4(NH2)2, or the corresponding protonated forms. The quality of the obtained single crystals was evaluated using an optical or binocular microscope, and the crystal structure was solved using single-crystal X-ray diffraction data. For the morphological and chemical characterization the scanning electron microscopy (SEM), coupled with energy-dispersive system (EDS) was used. The electron microprobe provide precise quantitative chemical analysis, and the Raman spectroscopy method was used for the determination of the presence of H2O, (OH)−, (NH4)+ and NH3..

The Role of Spatial Planning in the Investment Process in Poland and Slovenia

This paper is based on the hypothesis that: “Spatial planning should regulate spatial development, taking into account the public and private interests, and enabling the development of public and private investments in construction projects. Investors may be discouraged from construction on account of too small or too excessive a number of spatial implementation conditions (land use guidelines) in particular, where an adequate professional basis has not been provided

Fastness of dye-based ink-jet printing inks in aqueous solution in the presence and absence of oxygen

Photodegradation of the ink-jet prints is a complex process in which many external and internal factors are involved. Nevertheless, the role of colorants and various accompanying substances in the ink is often overlooked. Our research work aimed to determine the fastness of water-based ink-jet inks in aqueous solutions. A printing ink often contains a complex mixture of colorants to achieve optimal optical properties of color and a suitable fastness of the print. Therefore, we investigated the composition and stability of cyan, magenta, yellow, and black inks under the influence of UVC light in the presence of oxygen as well as in an inert environment based on TLC chromatography and spectrophotometric analysis. The process of photodegradation was evaluated based on ink amount and half-life. According to the results, the majority of inks consist of at least two colorants that differ in color and polarity. The results have shown that the presence of oxygen negatively affects the stability of inkstherefore, the inert atmosphere prolongs the durability of ink in water solution