Solvent Extraction of Niobium and Tantalum. II. Extraction and Separation of Zirconium and Niobium with Di-n-octyl-methylene- bis-phosphonic Acid

A mehod for separating 95Zr from 1\u275Nb by extraction process with din-n-octyl-methylene-bis-phosphonic acid (DOMPA), of the for mula CH2[PO(OCsH11)0Hh, is \u27 given. Extraction behav iour of both metals under different conditions has been studied and extraction from sulphuric, hydrochloric, hydrofluoric and oxalic acid solutions is described, The influence of these acids and reagent cone. on separation of niobium and zirconium is discussed. It has been found that by extraction with DOMPA a quantitative separation is possible from mixed oxalic and sulphuric acid solutions of metal cone. lower than 10-s, as well as separation of radionuclides from carrier free solutions

Critical edges in Rips complexes and persistence

We consider persistent homology obtained by applying homology to the open Rips filtration of a compact metric space $(X,d)$. We show that each decrease in zero-dimensional persistence and each increase in one-dimensional persistence is induced by local minima of the distance function $d$. When $d$ attains local minimum at only finitely many pairs of points, we prove that each above mentioned change in persistence is induced by a specific critical edge in Rips complexes, which represents a local minimum of $d$. We use this fact to develop a theory (including interpretation) of critical edges of persistence. The obtained results include upper bounds for the rank of one-dimensional persistence and a corresponding reconstruction result. Of potential computational interest is a simple geometric criterion recognizing local minima of $d$ that induce a change in persistence. We conclude with a proof that each locally isolated minimum of $d$ can be detected through persistent homology with selective Rips complexes. The results of this paper offer the first interpretation of critical scales of persistent homology (obtained via Rips complexes) for general compact metric spaces.Comment: 20 pages, 5 figure

Integrated stratigraphy of the Middle-Upper Jurassic of the Krížna Nappe, Tatra Mountains

Middle-Upper Jurassic pelagic carbonates and radiolarites were studied in the Krížna Nappe of the Tatra Mountains (Central Western Carpathians, southern Poland and northern Slovakia). A carbon isotope stra- tigraphy of these deposits was combined with biostratigraphy, based on radiolarians, calcareous dinoflagellates and calpionellids. In the High Tatra and Belianske Tatra Mountains, the Bajocian and part of the Bathonian are represented by a thick succession of spotted limestones and grey nodular limestones, while in the Western Tatra Mountains by relatively thin Bositra-crinoidal limestones. These deposits are referable to a deeper basin and a pelagic carbonate platform, respectively. The various carbonate facies are followed by deep-water biosiliceous facies, namely radiolarites and radiolarian-bearing limestones of Late Bathonian-early Late Kimmeridgian age. These facies pass into Upper Kimmeridgian-Lower Tithonian pelagic carbonates with abundant Saccocoma sp. The bulk-carbonate isotope composition of the carbonate-siliceous deposits shows positive and negative δ13C excursions and shifts in the Early Bajocian, Late Bajocian, Early Bathonian, Late Bathonian, Late Callovian, Middle Oxfordian and Late Kimmeridgian. Additionally, the δ13C curves studied show a pronounced increasing trend in the Callovian and a steadily decreasing trend in the Oxfordian-Early Tithonian. These correlate with the trends known from the Tethyan region. The onset of Late Bathonian radiolarite sedimentation is marked by a decreasing trend in δ13C. Increased δ13C values in the Late Callovian, Middle Oxfordian and Late Kimmeridgian (Moluccana Zone) correspond with enhanced radiolarian production. A significant increase in CaCO_{3} content is recorded just above the Late Callovian δ13C excursion, which coincides with a transition from green to variegated radiolarites

Media Representations of Muslim Women

Magistrsko delo naslavlja problematiko stereotipnega uokvirjanja žensk islamske veroizpovedi v medijih na zahodu. S pomočjo pregleda že obstoječih študij medijskih tekstov oriše najpogostejše medijske okvire žensk islamske veroizpovedi in predstavi ključne značilnosti teh okvirov s pomočjo grafike. K odgovarjanju na raziskovalno vprašanje, kako mediji reprezentirajo ženske islamske veroizpovedi, pristopa s kombinacijo pristopov orientalizma ter teorije predsodkov in stereotipov v povezavi s teorijami medijskega uokvirjanja in premise post-feminizmov. Metodološko se poslužuje predvsem kvalitativne interpretativne analize in kritične analize diskurza. Ukvarja se predvsem s koncepti generalizacije in uniformnosti ter binarnim opredeljevanjem žensk islamske veroizpovedi v primerjavi z ženskami iz zahodnih družb oziroma v odvisni relaciji do moških islamske veroizpovedi. Opredeli najbolj prepoznavne medijske reprezentacije žensk islamske veroizpovedi kot (i) drugačne, (ii) zakrite žrtve, (iii) teroristke in (iv) osvobojene ter v nadaljevanju razpravlja o morebitnih vzrokih za tovrstna medijska uokvirjanja v navezavi na aktualne dogodke, predvsem pojavom islamskih terorističnih napadov po 11. septembru 2001. Osvetli kontekstualno spreminjanje oziroma prilagajanje medijskega uokvirjanja družbeno-političnim interesom in izpostavi pomanjkanje avtentične reprezentacije vseh posameznic islamske veroizpovedi.Master thesis addresses the issue of stereotypical framing of Muslim women in the Western media. By overviewing the already existing studies of media texts it illustrates the most common media frames of Muslim women and presents frames\u27 key characteristics with an infographic. It uses a combination of orientalism, as well as theory of prejudice and stereotypes in relation to media framing theories and post-feminism premises to answer the research question of how media represents Muslim women. Methodologically it adopts especially qualitative interpretative analysis and critical discourse analysis. It mainly deals with concepts of generalization and uniformity, as well as binary definition of Muslim women in relation to the women from Western societies and in relation to Muslim men. It identifies the most notable media representations of Muslim women as (i) different, (ii) covered victims, (iii) terrorists, and (iv) liberated, moreover, it discusses the potential reasons for these media frames related to the current events, especially the Islamic terrorist attacks after 9/11. The thesis illuminates the contextual transformation of media framing in relation to socio-political affairs and highlights the lack of authentic representation of individual members of the Muslim women’s community

A Middle Jurassic Radiolarite-Clastic Succession from the Medvednica Mt. (NW Croatia

On the NW part of Medvednica Mt. radiolarites with carbonate olistoliths, shales and siltites, matrix-supported conglomerates and basic volcanic rocks were investigated. This facies association is informally named the Poljanica unit. Major element geochemical data indicate deposition of radiolarites in the vicinity of the middle oceanic ridge, while sedimentological data indicate deposition in an area closer to the continent. Shales and siltites, as well as matrix-supported conglomerates, were deposited in short periods characterised by increased input of terrigenous material. Matrix-supported polymict conglomerates are composed of silicified shales, lithic graywackes, cherts and metabasalts, and were deposited by debris flow mechanisms as a consequence of synsedimentary tectonic activity. Carbonate olistoliths are composed of biomicrosparite, and jointly with deformed radiolarian cherts compose an olistostrome. Basic volcanic rocks represent high-Ti tholeiitic basalts formed in the MORB realm. Micropalaeontological investigation of radiolarite samples proved the Middle Jurassic (latest Bajocian - early Bathonian to late Bathonian - early Callovian) age of the Poljanica unit. Additionally, a new radiolarian species Theocapsomma medvednicensis n.sp. has been described. Conodont analyses from carbonate olistoliths in radiolarites proved their Triassic age. The investigated radiolarite-clastic succession is the result of subduction processes. Further continuation of this process caused incorporation of these deposits into the accretionary prism, where they were brought in direct contact with Triassic volcanic rocks and radiolarites (in the form of a tectonic mélange). Based on the lithological similarities with the Middle Jurassic turbidite-olistostrome successions in the Western Carpathians and Northern Calcareous Alps, the study area is considered to be part of the Meliata-Hallstatt Ocean

Integrated stratigraphy (radiolarians, calcareous nannofossils, carbon and strontium isotopes) of the Sinemurian–Pliensbachian transition at Mt. Rettenstein, Northern Calcareous Alps, Austria

A 95 m thick succession of grey siliceous limestone and marl on Mount Rettenstein in the Northern Calcareous Alps allowed us to study well-preserved and diverse radiolarian assemblages across the Sinemur- ian–Pliensbachian boundary. The distribution of 31 most characteristic radiolarian species is presented. Am- monites of the Jamesoni Subzone, the topmost subzone of the Jamesoni Zone, have been previously found in the upper part of the section. The radiolarian data are complemented with calcareous nannofossil biostratigraphy, and carbon and strontium isotope analyses of bulk carbonate samples. A negative stable carbon isotope excursion (CIE) occurs in the middle part of the section and is correlated to the supraregional Sinemurian – Pliensbachian Boundary Event. Radiolarian assemblages below the negative CIE belong to the Canutus rockfishensis – Wrangellium thurstonense and Jacus? sandspitensis radiolarian zones. Katroma clara and several other species belonging to the subsequent Canutus tipperi – Katroma clara Radiolarian Zone first occur at the beginning of the negative CIE. The first occurrence of the nannofossil Similiscutum cruciulus, which defines the base of the NJ4 Calcareous Nannofossil Zone, was recognized near the top of the negative CIE, 10 m above the inferred stage boundary. The strontium isotope ratio is due to diagenetic alteration of bulk micrite systematically shifted to higher values, but clearly decreases across the stage boundary. This decrease is compatible with the trend of the standard 87Sr/86Sr curve established in skeletal calcite. This is the first time radiolarian zones across the Sinemurian–Pliensbachian boundary in Europe can be tied to calcareous nannofossil zones and chemostratigraphy and also calibrated to chronostratigraphy. These results contribute to the stability of Lower Jurassic radiolarian zones and will allow the recognition of the Sinemur- ian–Pliensbachian boundary in deep-marine successions where ammonites are absent