Repository of University of Nova Gorica

Search the repository
A+ | A- | Help | SLO | ENG

Query: search in
search in
search in
search in
* old and bolonia study programme

Options:
  Reset


1 - 10 / 15
First pagePrevious page12Next pageLast page
1.
Harmonic-structured copper
Dmitry Orlov, Kei Ameyama, Choncharoen Sawangrat, Shota Kato, 2014, original scientific article

Found in: ključnih besedah
Keywords: copper, microstructure design, bimodal grain structure, harmonic-structure, metal powder
Published: 16.06.2016; Views: 1797; Downloads: 62
URL Fulltext (0,00 KB)

2.
Oxalic acid adsorption states on the clean Cu(110) surface
Sara Fortuna, 2016, original scientific article

Abstract: Carboxylic acids are known to assume a variety of configurations on metallic surfaces. In particular oxalic acid on the Cu(110) surface has been proposed to assume a number of upright configurations. Here we explore with DFT calculations the possible structures that oxalic acid can form on copper 110 at different protonation states, with particular attention at the possibility of forming structures composed of vertically standing molecules. In its fully protonated form it is capable of anchoring itself on the surface thanks to one of its hydrogen-free oxygens. We show the monodeprotonated upright molecule with two oxygens anchoring it on the surface to be the lowest energy conformation of a single oxalic molecules on the Cu(110) surface. We further show that it is possible for this configuration to form dense hexagonally arranged patterns in the unlikely scenario in which adatoms are not involved.
Found in: ključnih besedah
Summary of found: ...structures that oxalic acid can form on copper 110 at different protonation states, with particular...
Keywords: oxalic acid, oxalate, cu(110), copper, surface, adsorption, density functional theory, DFT
Published: 11.10.2016; Views: 1686; Downloads: 0
.pdf Fulltext (1,21 MB)

3.
Biotransformation of copper oxide nanoparticles by the pathogenic fungus Botrytis cinerea
Katarina Vogel-Mikuš, Darko Makovec, Tamás Papp, Iztok Arčon, Johannes Teun van Elteren, Marjana Regvar, Eva Kovačec, 2017, original scientific article

Abstract: Two plant pathogenic fungi, Botrytis cinerea and Alternaria alternata, isolated from crop plants, were exposed to Cu in ionic (Cu2þ), microparticulate (MP, CuO) or nanoparticulate (NP, Cu or CuO) form, in solid and liquid culturing media in order to test fungal response and toxic effects of the mentioned compounds for the potential use as fungicides. B. cinerea has shown pronounced growth and lower levels of lipid peroxidation compared to A. alternata. Its higher resistance/tolerance is attributed mainly to biotransformation of CuO and Cu NPs and CuO MPs into a blue compound at the fungal/culturing media interface, recognized by Cu K-edge EXAFS analysis as Cu-oxalate complex. The pronounced activity of catechol-type siderophores and organic acid secretion in B. cinerea induce leaching and mobilization of Cu ions from the particles and their further complexation with extracellularly secreted oxalic acid. The ability of pathogenic fungus to biotransform CuO MPs and NPs hampers their use as fungicides. However the results show that B. cinerea has a potential to be used in degradation of Cu(O) nanoparticles in environment, copper extraction and purification techniques.
Found in: ključnih besedah
Keywords: copper, metal oxide nanoparticles, detoxification mechanisms, metal pollution, Cu-oxalate
Published: 23.08.2017; Views: 1446; Downloads: 0
.pdf Fulltext (1,52 MB)

4.
Role of Surface Cu-O-Zr Sites in the Photocatalytic Activity of TiO2 Nanoscale Particles
Nataša Novak Tušar, Iztok Arčon, Urška Lavrenčič Štangar, Olena Pliekhova, 2016, published scientific conference contribution abstract

Found in: ključnih besedah
Summary of found: ...Photocatalysis, Titanium dioxide, Copper, Zirconia, co-doping, EXAFS, XANES...
Keywords: Photocatalysis, Titanium dioxide, Copper, Zirconia, co-doping, EXAFS, XANES
Published: 23.08.2017; Views: 1731; Downloads: 0
.pdf Fulltext (426,28 KB)

5.
Heavy metal analysis with in-situ prepared copper film electrode as a tool for environmental monitoring
Nana Ivana Hrastnik, 2017, master's thesis

Abstract: Monitoring and measuring heavy metals in the environment is of great importance and requires sensitive and reliable analytical techniques capable of detecting trace level concentrations. Nowadays, measurements of heavy metals are usually performed using sophisticated and expensive instrumental techniques, such as atomic absorption spectroscopy (AAS), atomic fluorescence spectroscopy (AFS), inductively coupled plasma mass spectrometry (ICP-MS), inductively coupled plasma optical emission spectroscopy (ICP-OES) etc. In this aspect, advanced electroanalytical (stripping) techniques represent a favourable alternative, facilitating sensitive and selective measurements of various analytes using relatively simple, portable and non-expensive instrumentation. This work is an investigation of novel copper-based electrodes for measuring trace levels of selected heavy metal ions, i.e. mercury(II), lead(II), tin(IV) and nickel(II). The methods of choice were anodic stripping voltammetry (ASV) in combination with the in-situ prepared copper film electrode (CuFE) for measuring low concentrations of mercury(II) and lead(II) (simultaneously) and tin(IV) in the test solutions and adsorptive cathodic stripping voltammetry (AdCSV) for determination of nickel(II). Metal-film electrodes are regularly employed in electrochemical stripping analysis due to their simple fabrication and surface regeneration. The newly developed CuFE appears to be a cheaper alternative to gold-based electrodes with several attractive electroanalytical characteristics, i.e. with low limits of detection (LOD), good repeatability and favourable linear response.
Found in: ključnih besedah
Keywords: Copper film electrode, anodic stripping voltammetry, adsorptive cathodic stripping voltammetry, heavy metals, environment.
Published: 12.09.2017; Views: 2003; Downloads: 137
.pdf Fulltext (1,78 MB)

6.
The effect of Zr loading on photocatalytic activity of Cu modified TiO2
Urška Lavrenčič Štangar, Nataša Novak Tušar, O. L. Pliekhov, Mattia Fanetti, Iztok Arčon, Olena Pliekhova, 2018, published scientific conference contribution

Found in: ključnih besedah
Summary of found: ...Titanium diokside, acidic sites, surface titration, copper, zirconium...
Keywords: Titanium diokside, acidic sites, surface titration, copper, zirconium
Published: 10.09.2018; Views: 964; Downloads: 0
.pdf Fulltext (39,79 MB)

7.
Crystal habit modification of Cu(II) isonicotinate-N-oxide complexes using gel phase crystallisation
Jonathan Steed, Žygimantas Drabavičius, Katja Ferfolja, Dipankar Ghosh, Krishna Kumar Damodaran, 20, original scientific article

Abstract: We report the crystallisation of three forms of copper(II) isonicotinate-N-oxide complex and their phase interconversion via solvent-mediated crystal to crystal transformation. The different forms of copper complex have been isolated and characterised by single crystal X-ray diffraction. Gel phase crystallisation performed in hydrogels, low molecular weight gels and gels of tailored gelator showed crystal habit modification. Crystallisation in aqueous ethanol resulted in concomitant formation of blue (form-I) and green (form-II/IV) crystals while use of low molecular weight gel results in selective crystallization of the blue form-I under identical conditions. Comparison of gel phase and the solution state crystallisation in various solvent compositions reveals that the blue form-I is the thermodynamically stable form under ambient conditions.
Found in: ključnih besedah
Summary of found: ...report the crystallisation of three forms of copper(II) isonicotinate-N-oxide complex and their phase interconversion via...
Keywords: copper(II) complex, gel phase crystallisation, crystal habit modification, isonicotinate-N-oxide, X-ray diffraction
Published: 08.11.2018; Views: 778; Downloads: 0
.pdf Fulltext (968,24 KB)

8.
Zr/Cu-TiO2 CATALYSTS FOR PHOTOCATALYTIC WATER TREATMENT
Olena Pliekhova, doctoral dissertation

Abstract: This work entitled «Zr/Cu-TiO2 catalysts for photocatalytic water treatment» tackles a problem of tons of dyes discharged everyday mainly from textile industries. This is a huge concern because of dyes persistence, toxicity and potential to the bioaccumulation in living organisms. Here, a small contribution to overall problem is presented. The research work consists of three main parts: Theoretical background, Experimental and Results and discussion. In the Theoretical background chapter the overall problem is identified and discussed. The main water treatment techniques are presented briefly with their advantages and drawbacks. Photocatalysis assisted with TiO2 is shown as an alternative additional technique with its own pros and cons. Further, a cursory overview of TiO2 modification techniques is made and advantages in using copper and zirconium oxides for TiO2 modification are presented. The reason and possible positive effect of using of two oxides simultaneously for TiO2 modification is indicated. Additionally, a positive impact of solar light for overall rate of dyes degradation assisted with TiO2 is discussed. Within the framework of photosensitization effect, the problem of using dyes for assessment of photocatalytic properties of materials under the visible light is touched on. Photothermal methods as possible beneficial techniques for this purpose are proposed. In the Experimental chapter, all experimental techniques used in current research work with the technical details specific for the research work are presented. There are methods of materials preparation, photocatalytic tests under different conditions and varying model pollutants, and physico-chemical characterization techniques. The Results and discussion chapter is divided by three subchapters. Each chapter is dedicated to one hypothesis, which was checked and confirmed or disproved. The first hypothesis is about beneficial loading of copper and zirconium oxides to TiO2. After numerous experiments held, it was concluded that the pair of copper and zirconium oxides is beneficial for simultaneous application on TiO2 surface to promote its performance. The second subchapter is about zirconium distribution and its impact on the activity of studied materials towards the antraquinone dye Reactive Blue 19. Different techniques such as XRD, TEM, EXAFS and many others were used in order to characterize the materials and to understand the details of the processes taking place. The existence of upper limit of copper oxide loading for its beneficial effect on TiO2 performance was demonstrated. It was observed that zirconium species loading leads to improvement in performance of materials with higher copper loading, which otherwise lowers activity of TiO2 – this is in case when copper only above its optimal level is present. It was concluded that zirconium oxide containing species occupy rutile surface sites in mixed phase TiO2 and this way beneficially influence the material performance towards the dye removal. The third subchapter is about the visible light TiO2 assisted dye degradation. It is well known that photosensitization mechanism of dye degradation appears under the visible and as a consequence under the solar light irradiation. This leads to the overall enhancement of dyes degradation, which is positive and may be used as a benefit for faster pollutant destruction. However, this fact leads to mishmash in the determination of real photocatalytic activity of materials towards the dye. It was hypothesized that the impact of photosensitization mechanism on the overall material performance against Reactive blue 19 dye (RB19) descends with the dye concentration lowering. Thermal lens spectrometry (TLS) which is sensitive to chemicals at low concentrations was used for hypothesis evaluation. To summarize the research work achievements, the conclusions of the thesis are given at the end.
Found in: ključnih besedah
Summary of found: ...techniques is made and advantages in using copper and zirconium oxides for TiO2 modification are...
Keywords: titanium dioxide, photocatalysis, zirconium/copper, surface modification, water treatment, dyes
Published: 03.12.2019; Views: 694; Downloads: 24
.pdf Fulltext (3,18 MB)

9.
Substrate- to Laterally-Driven Self-Assembly Steered by Cu Nanoclusters: The Case of FePcs on an Ultrathin Alumina Film
Maria Peressi, Nicola Seriani, Giovanni Comelli, Tomas Skala, Zhijing Feng, Fatema Mohamed, Erika Tomsič, Manuel Corva, Erik Vesselli, 2018, original scientific article

Found in: ključnih besedah
Summary of found: ... copper, nanoclusters, alumina, iron phthalocyanine, Ni3Al...
Keywords: copper, nanoclusters, alumina, iron phthalocyanine, Ni3Al
Published: 03.12.2019; Views: 466; Downloads: 0
.pdf Fulltext (9,93 MB)

10.
Capabilities of hydrogen-producing green algae Clamydomonas reinhardtii for copper bioremediation in wastewaters
Urška Žvab, Danijel Stojković, Matjaž Valant, 2019, published scientific conference contribution abstract

Found in: ključnih besedah
Keywords: copper, hydrogen, wastewater, green algae, Clamydomonas reinhardtii
Published: 19.12.2019; Views: 545; Downloads: 0
.pdf Fulltext (18,68 MB)

Search done in 0 sec.
Back to top