Repozitorij Univerze v Novi Gorici

Iskanje po repozitoriju
A+ | A- | Pomoč | SLO | ENG

Iskalni niz: išči po
išči po
išči po
išči po
* po starem in bolonjskem študiju

Opcije:
  Ponastavi


1 - 6 / 6
Na začetekNa prejšnjo stran1Na naslednjo stranNa konec
1.
Extraction of Organochlorine Pesticides from Plastic Pellets and Plastic Type Analysis
Špela Koren, Manca Kovač Viršek, Petra Makorič, Maryline Pflieger, 2017, pregledni znanstveni članek

Opis: Plastic resin pellets, categorized as microplastics (≤5 mm in diameter), are small granules that can be unintentionally released to the environment during manufacturing and transport. Because of their environmental persistence, they are widely distributed in the oceans and on beaches all over the world. They can act as a vector of potentially toxic organic compounds (e.g., polychlorinated biphenyls) and might consequently negatively affect marine organisms. Their possible impacts along the food chain are not yet well understood. In order to assess the hazards associated with the occurrence of plastic pellets in the marine environment, it is necessary to develop methodologies that allow for rapid determination of associated organic contaminant levels. The present protocol describes the different steps required for sampling resin pellets, analyzing adsorbed organochlorine pesticides (OCPs) and identifying the plastic type. The focus is on the extraction of OCPs from plastic pellets by means of a pressurized fluid extractor (PFE) and on the polymer chemical analysis applying Fourier Transform-InfraRed (FT-IR) spectroscopy. The developed methodology focuses on 11 OCPs and related compounds, including dichlorodiphenyltrichloroethane (DDT) and its two main metabolites, lindane and two production isomers, as well as the two biologically active isomers of technical endosulfan. This protocol constitutes a simple and rapid alternative to existing methodology for evaluating the concentration of organic contaminants adsorbed on plastic pieces.
Najdeno v: ključnih besedah
Povzetek najdenega: ...on the polymer chemical analysis applying Fourier Transform- InfraRed (FT-IR) spectroscopy. The developed methodology focuses on 11...
Ključne besede: Environmental Sciences, Issue 125, Microplastics, resin pellets, pesticides, persistent organic pollutants, organochlorine pesticides, dichlorodiphenyltrichloroethane, endosulfan, hexachlorocyclohexane, lindane, Fourier transform infrared spectroscopy, pressurized fluid extractor
Objavljeno: 10.07.2017; Ogledov: 1143; Prenosov: 0

2.
VizieR Online Data Catalog: A 1689 HAWK-I J-band image (Petrushevska+, 2016)
Tanja Petrushevska, zaključena znanstvena zbirka podatkov ali korpus

Opis: The NIR data were obtained with the High Acuity Wide field K-band imager mounted on the VLT (Programmes ID 082.A-0431, 0.83.A-0398, 090.A-0492, 091.A-0108, P.I. Goobar). The HAWK-I has an array of four 2048x2048 HgCdTe detectors covering a total area of 7.5'x7.5' with a sampling of 0.106"/pix per pixel. The chips are separated by a 15" gap.
Najdeno v: ključnih besedah
Povzetek najdenega: ...Clusters: galaxy, Infrared sources...
Ključne besede: Clusters: galaxy, Infrared sources
Objavljeno: 23.01.2018; Ogledov: 696; Prenosov: 0
.pdf Polno besedilo (341,31 KB)

3.
VizieR Online Data Catalog: Measured photometry of SN 2014J from HST (Amanullah+, 2014)
R. Amanullah, Tanja Petrushevska, zaključena znanstvena zbirka podatkov ali korpus

Opis: We obtained observations (Program DD-13621; PI: Goobar) of SN 2014J with HST in the four UV broadband filters F218W, F225W, F275W, and F336W for seven epochs using a total of seven HST orbits during Cycle 21. In addition to this we also obtained optical broad-, medium-, and narrowband photometry in filters F467M, F631N, and F845M for visits (1, 3) and optical broadband photometry using F438W, F555W, and F814W for the remaining five visits. All observations were obtained with the Wide-Field Camera-3 (WFC3) using the UVIS aperture UVIS2-C512C-SUB.
Najdeno v: ključnih besedah
Povzetek najdenega: ...Supernovae, Photometry: HST, Photometry: UBVRI, Photometry: infrared, Extinction...
Ključne besede: Supernovae, Photometry: HST, Photometry: UBVRI, Photometry: infrared, Extinction
Objavljeno: 23.01.2018; Ogledov: 540; Prenosov: 0
.pdf Polno besedilo (430,24 KB)

4.
Amorphous nanocomposite of polycarbosilanes and aluminum oxide
Andraž Mavrič, 2018, doktorska disertacija

Opis: This work presents a paradigm for high temperature stabilization of bulk amorphous aluminium oxide. The thermodynamic stabilization is achieved by preparing a nanocomposite, where polymethylsilane dendritic molecules are dispersed in an aluminium hydroxide gel. Upon heat-treatment the gel transforms to the amorphous aluminium oxide that is stable up to 900°C. The dispersion of the macromolecules and their covalent bonding to the alumina matrix induce homogeneously distributed strain fields that keep the alumina amorphous. The first part of the thesis focuses on the synthesis, characterization and solubility properties of the dendritic polymethylsilane. The polymethylsilane is synthetized by electrochemical polymerization from trichloromethylsilane monomer. The polymerization mechanism, involving a single polymerization pathway, is identified. The polymer growth proceeds through reduction of the monomers to the silyl anions and their addition to the growing polymer. The solubility of three chemically related but topologically different polysilanes (linear, dendritic and network) were studied by dynamic light scattering. At room temperature the agglomerates in a range from 500 to 1300 nm are present. They undergo de-agglomeration at slightly elevated temperatures of around 40°C. The de-agglomeration results in formation of stable solutions, where a hydrodynamic diameter of the individual polymer molecules was measured to be in a range from 20 to 40 nm. The obtained diameters of two dendritic polymethylsilane macromolecules, synthesized under different electrolysis conditions, are much larger than the theoretical size estimated for an ideal dendrimer. We determined by 29Si NMR that the reason for this is in a large number of branching irregularities (defects) contained in the molecular structure. Combining the experimental values obtained by DLS and density measurements with a structural model that considers the branching irregularities, it is shown that the inclusion of the defects allows the dendritic polymer to exceed the sterical limitations and form the hyperbranched dendritic structure. The final size depends on a relative amount of the branching defects. In the second part, the synthetized polymethylsilane molecules were successfully used for the nanocomposite formation. The aluminium hydroxide gel with the dispersed polymethylsilane molecules was prepared as a precursor. Upon heat-treatment it gives the amorphous aluminium oxide stable up to 900°C. The dispersed macromolecules induce homogeneously distributed strain fields that keep the aluminium oxide amorphous during the thermal treatment the dispersed macromolecules covalently bind to the matrix, inducing the interface strain. The amorphous state was confirmed by the presence of penta-coordinated aluminium detected by 27Al NMR and a low bandgap measured by UV-vis absorption spectroscopy.
Najdeno v: ključnih besedah
Povzetek najdenega: ...electron microscopy, scanning electron microscopy, X-ray diffraction, infrared spectroscopy, UV-Vis spectroscopy...
Ključne besede: amorphous aluminium oxide, polymethylsilane, nanocomposite, electropolymerization, solubility, agglomeration, de-agglomeration, dendrimer, hyperbranched dendritic structure, dynamic light scattering, thermal analysis, transmission electron microscopy, scanning electron microscopy, X-ray diffraction, infrared spectroscopy, UV-Vis spectroscopy
Objavljeno: 19.07.2018; Ogledov: 1363; Prenosov: 78
.pdf Polno besedilo (5,07 MB)

5.
Medium-range structure of vitreous SiO2 obtained through first-principles investigation of vibrational spectra
Alfredo Pasquarello, Paolo Umari, Luigi Giacomazzi, 2009, izvirni znanstveni članek

Najdeno v: ključnih besedah
Povzetek najdenega: ...silica, Raman, infrared, v-DOS, first-principles, glass...
Ključne besede: silica, Raman, infrared, v-DOS, first-principles, glass
Objavljeno: 15.10.2018; Ogledov: 371; Prenosov: 0
.pdf Polno besedilo (874,77 KB)

6.
First principles vibrational spectra of tetrahedrally-bonded glasses: sio2, geo2 and gese2
Luigi Giacomazzi, 2007, doktorska disertacija

Najdeno v: ključnih besedah
Povzetek najdenega: ...Germania, Chalcogenide Glasses, Vibrational Spectra, Raman Spectroscopy, Infrared, First-principles,...
Ključne besede: Silica, Germania, Chalcogenide Glasses, Vibrational Spectra, Raman Spectroscopy, Infrared, First-principles
Objavljeno: 31.01.2019; Ogledov: 458; Prenosov: 0
.pdf Polno besedilo (2,03 MB)

Iskanje izvedeno v 0 sek.
Na vrh