Amanova Ltd.

Ljubljana, Slovenia

Amanova Ltd.

Ljubljana, Slovenia
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Grabec I.,Amanova Ltd
Physics Letters, Section A: General, Atomic and Solid State Physics | Year: 2017

Drifting of sand particles bouncing on a vibrating membrane of a Chladni experiment is characterized statistically. Records of trajectories reveal that bounces are circularly distributed and random. The mean length of their horizontal displacement is approximately proportional to the vibration amplitude above the critical level and amounts about one fourth of the corresponding bounce height. For the description of horizontal drifting of particles a model of vibration driven random walk is proposed that yields a good agreement between experimental and numerically simulated data. © 2016 Elsevier B.V.

Grabec I.,Amanova Ltd | Svegl F.,Amanova Ltd
Nonlinear Phenomena in Complex Systems | Year: 2017

Instability of traffic flow on high-ways leads to non-linear development of jams with detrimental consequences. In order to avoid them we try to formulate an optimal control law by which the flow could be stabilized. For this purpose we describe the influence of speed limit on the stable regime by a new fundamental law that is formulated based upon experimental data of traffic flow. The corresponding non-linear relation indicates how the speed limit has to be adapted to the traffic density in order to provide conditions for a stable flow. © 2017, Education and Upbringing Publishing. All rights reserved.

Mihelcic M.,Slovenian National Institute of Chemistry | Jerman I.,Slovenian National Institute of Chemistry | Svegl F.,Amanova Ltd | Surca Vuk A.,Slovenian National Institute of Chemistry | And 4 more authors.
Solar Energy Materials and Solar Cells | Year: 2012

Novel nickel oxide coatings (100-600 nm in thickness) with low surface roughness (<20 nm) and haze levels down to 6 were deposited at a temperature not higher than 150 °C on FTO glass and conducting plastic films. The coatings were deposited on the substrates from water dispersions made of Ni 1-xO pigment synthesized via the peroxo route by reaction of a H 2O 2/urea mixture with Ni-acetate precursor. The bunsenite Ni 1-xO pigment was obtained after thermal treatment of xerogels at 400 °C for 24 h. Processing common for paint manufacturing was applied for the preparation of water dispersions of the Ni 1-xO pigment, i.e., intensive milling of the pigment with dispersant. Dispersant (NiO xH y) was prepared by colloidal precipitation technique from Ni-sulfate precipitated with sodium hypochlorite. The materials (Ni 1-xO pigment, NiO xH y precipitate, coatings) were investigated using various analytical techniques (TG, DSC, SEM, TEM, IR and optical spectroscopy), while the electrochromic properties were determined by means of in situ spectroelectrochemical measurements, applying standard electrochemical techniques (cyclic voltammetry, chronocoulometry). The results revealed a convenient, simple, and robust technique for making electrochromic paint coatings from pre-prepared Ni 1-xO pigment. They demonstrate the potential of the described electrochromic coatings for manufacturing plastic film based electrochromic devices providing transmissive light modulation. © 2012 Elsevier B.V. All rights reserved.

Likon M.,Insol Ltd. | Remskar M.,Jozef Stefan Institute | Ducman V.,Slovenian National Building And Civil Engineering Institute | Svegl F.,Amanova Ltd.
Journal of Environmental Management | Year: 2013

The genus Populus, which includes poplars, cottonwoods and aspen trees, represents a huge natural source of fibers with exceptional physical properties. In this study, the oil absorption properties of poplar seed hair fibers obtained from Populus nigra italica when tested with high-density motor oil and diesel fuel are reported. Poplar seed hair fibers are hollow hydrophobic microtubes with an external diameter between 3 and 12μm, an average length of 4±1mm and average tube wall thickness of 400±100nm. The solid skeleton of the hollow fibers consists of lignocellulosic material coated by a hydrophobic waxy coating. The exceptional chemical, physical and microstructural properties of poplar seed hair fibers enable super-absorbent behavior with high absorption capacity for heavy motor oil and diesel fuel. The absorption values of 182-211g heavy oil/g fiber and 55-60g heavy oil/g fiber for packing densities of 0.005g/cm3 and 0.02g/cm3, respectively, surpass all known natural absorbents. Thus, poplar seed hair fibers obtained from Populus nigra italica and other trees of the genus Populus are an extremely promising natural source for the production of oil super absorbents. © 2012 Elsevier Ltd.

Mihelcc M.,Slovenian National Institute of Chemistry | Vuk A.S.,Slovenian National Institute of Chemistry | Vuk A.S.,CO NOT | Vrhovsek D.,Cinkarna d.d. | And 4 more authors.
Acta Chimica Slovenica | Year: 2014

Thin electrochromic coatings were obtained by co-grinding the mTiA particle aggregates (300 nm in size) with open-corner heptaisobutyl trisilanol POSS (T8IB7(OH)3POSS) acting as dispersant. After the addition of titanium tetraisopropoxide (3-5%) the mTiA pigment dispersion was deposited on FTO glass and plastic ITO PET foils and coatings were obtained by thermal treatment at 150 °C. Optical transmittance and luminous haze from 2 to 6% of the coatings were determined from the corresponding UV-Vis spectra. The achieved electrochromic effect was evaluated by electrochemical charging/discharging in 1 M LiClO4/PC electrolyte. Results revealed that the colouring/bleaching changes depended on the extent of grinding and the size of the milling zirconia beads, enabling to distinguish between the surface charging of the mTiA grains and the filling and emptying of the anatase density of states. mTiA pigment coatings deposited on plastic foil were used in combination with Ni1-xO pigment coatings for construction of foil-based electrochromic device employing novel gel electrolyte with ionic liquid co-solvent. © 2014 Acta Chim. Slov.

Mihelcic M.,Slovenian National Institute of Chemistry | Surca Vuk A.,Slovenian National Institute of Chemistry | Jerman I.,Slovenian National Institute of Chemistry | Orel B.,Slovenian National Institute of Chemistry | And 5 more authors.
Solar Energy Materials and Solar Cells | Year: 2014

Electrochromic nickel oxide (Ni1-xO) pigment powder which was made from nickel acetate reacting with H2O2/urea solution followed by heat treatment of xerogels at 400 C (24 h) was milled with zirconia beads in pure water or water with added nickel oxyhydroxy precipitate acting simultaneously as the dispersant and the coating binder. The corresponding pigment particle suspensions were spin coated on FTO glass and flexible ITO-PET foils, respectively, and cured at 150 C. The optical properties of the deposited pigment coatings on FTO glass substrates were determined with an UV VIS spectrometer, providing total direct transmittance (TT), total diffuse transmittance (DT) and haze (in %). Haze increased with the coating thickness but did not exceed 4%. SEM micrographs of the deposited pigment coatings revealed that they consisted of agglomerated Ni1-xO pigment with voids. Potential cycling of Ni1-xO pigment coatings and Ni 1-xO thin films was performed in 1 M LiClO4/PC and 0.1 M TBA+ triflate/PC electrolytes, revealing that the pigment coatings exhibited electrochemical and electrochromic activity also in lithium free (aprotic) electrolyte, while variations of the oxidation and reduction reaction peaks at various scan rates confirmed the presence of surface electrochemical reactions. The near-grazing incidence angle reflection-absorption spectroscopic technique (IR RA) was employed for identifying surface and inner-grain Ni-O stretching modes, the former being responsible for observed electrochemical properties, which was also demonstrated from the ex situ IR RA measurements performed for coatings charged/discharged in 1 M LiClO4/PC and 0.1 M TBA+ triflate/PC electrolytes. The results disclosed in this study suggest that the electrochromic effect was not in direct correlation with the de-insertion/insertion of small ions into the NiO (bunsenite) grains but rather the pigment coatings behave similarly to nickel oxide electrochemical capacitors. The electrochromic response of a flexible EC devices made either of PEDOT (self-standing foil) or WO3 and Ni1-xO pigment coatings glued with PMMA based electrolytes without and with lithium salt were recorded for the demonstration of the possible practical application of wet deposited Ni1-xO pigment coatings made as "electrochromic" paints. © 2013 Elsevier B.V.

Moulki H.,CNRS Laboratory of Condensed Matter Chemistry, Bordeaux | Faure C.,CNRS Laboratory of Condensed Matter Chemistry, Bordeaux | Mihelcic M.,Slovenian National Institute of Chemistry | Vuk A.S.,Slovenian National Institute of Chemistry | And 7 more authors.
Thin Solid Films | Year: 2014

Electrochromic (EC) performances of Ni3 + containing NiO thin films, called modified NiO thin films, prepared either by pulsed laser deposition or by chemical route are reported. When cycled in lithium based electrolyte, the comparison of the EC behavior of nonstoichiometric NiO thin films points out a larger optical contrast for the films synthesized by chemical route with the absence of an activation period on early electrochemical cycling due in particular to a larger porosity. Herein we demonstrate faster kinetics for modified NiO thin films cycled in lithium ion free electrolyte. Finally, X-ray absorption spectroscopy is used for a preliminary understanding of the mechanism involved in this original EC behavior linked to the film characteristics including their disorder character, the presence of Ni 3 + and their porous morphology. © 2013 Elsevier B.V. All rights reserved.

Svegl F.,Amanova Ltd. | Surca Vuk A.,Slovenian National Institute of Chemistry | Hajzeri M.,Slovenian National Institute of Chemistry | Slemenik Perse L.,Slovenian National Institute of Chemistry | Orel B.,Slovenian National Institute of Chemistry
Solar Energy Materials and Solar Cells | Year: 2012

Electrochromic nickel oxide (Ni (1-x)O) thin films and composite nickel oxidepolyaniline (Ni (1-x)OPANI) thin films were prepared by a new peroxo soft chemistry route based on a nickel acetate ionic solution precursor. The ionic solution was synthesized from nickel acetate, urea and hydrogen peroxide. The deep green colloidal solution for the preparation of nickel oxide films was prepared by digestion of ionic solution with ethanol. The polyaniline, PANI, was in-situ polymerized from aniline molecular precursor in the second step and then added to the colloidal nickel oxide sol to obtain a deep greenbrown colloidal solution appropriate for deposition of composite Ni (1-x)OPANI films. Thin xerogel films were deposited by a dip-coating technique on FTO glass substrates and heat treated at 300 °C. Nano-crystalline non-stoichiometric Ni (1-x)O and composite Ni (1-x)OPANI films were formed. The as-deposited Ni (1-x)O films exhibited a grayblack color, whereas the composite Ni (1-x)OPANI films were almost transparent. The electrical, optical and electrochromic properties of all films were examined. The results showed that composite Ni (1-x)OPANI films exhibit superior properties over plain Ni (1-x)O films. This confirmed the role of PANI, which was selected to improve the electrical and optical properties of nickel oxide films. The electrochromic properties of grayblack Ni (1-x)O and almost transparent composite Ni (1-x)OPANI films were tested in a 1 M LiClO 4/propylene carbonate electrolyte. Spectroelectrochemical measurements showed charge capacities above 15 mC/cm 2 and coloring/bleaching changes from grayblack to transparent of more than 70%. Such changes are sufficient to enable the preparation of efficient electrochromic cells consisting of an anodic nickel oxide based counter electrode and cathodic WO 3 electrochromic layer. © 2011 Elsevier B.V. All rights reserved.

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