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Iskalni niz: "ključne besede" (immobilization) .

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1.
Environmental impacts and immobilization mechanisms of cadmium, lead and zinc in geotechnical composites made from contaminated soil and paper-ash
Marija Đurić, Primož Oprčkal, Vesna Zalar Serjun, Alenka Mauko Pranjić, Janez Ščančar, Radmila Milačič, Ana Mladenovič, 2021, izvirni znanstveni članek

Povzetek: Paper-ash is used for remediation of heavily contaminated soils with metals, but remediation efficiency after longer periods has not been reported. To gain insights into the mechanisms of immobilization of cadmium (Cd), lead (Pb), and znic (Zn), a study was performed in the laboratory experiment in uncontaminated, artificially contaminated, and remediated soils, and these soils treated with sulfate, to mimic conditions in contaminated soil from zinc smelter site. Remediation was performed by mixing contaminated soil with paper-ash to immobilize Cd, Pb, and Zn in the geotechnical composite. Partitioning of Cd, Pb, and Zn was studied over one year in seven-time intervals applying the sequential extraction procedure and complementary X-ray diffraction analyses. This methodological approach enabled us to follow the redistribution of Cd, Pb, and Zn over time, thus, to studying immobilization mechanisms and assessing the remediation efficiency and stability of newly formed mineral phases. Cd, Pb, and Zn were effectively immobilized by precipitation of insoluble hydroxides after the addition of paper-ash and by the carbonization process in insoluble carbonate minerals. After remediation, Cd, Pb, and Zn concentrations in the water-soluble fraction were well below the limiting values for inertness: Cd by 100 times, Pb by 125 times, and Zn by 10 times. Sulfate treatment did not influence the remediation efficiency. Experimental data confirmed the high remediation efficiency and stability of insoluble Cd, Pb, and Zn mineral phases in geotechnical composites.
Ključne besede: cadmium, lead, zinc, contaminated soil, paper ash, immobilization mechanisms
Objavljeno v DiRROS: 04.07.2023; Ogledov: 301; Prenosov: 196
.pdf Celotno besedilo (2,95 MB)
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2.
Environmental acceptability of geotechnical composites from recycled materials : comparative study of laboratory and field investigations
Marija Đurić, Vesna Zalar Serjun, Ana Mladenovič, Alenka Mauko Pranjić, Radmila Milačič, Janez Ščančar, Janko Urbanc, Nina Mali, Alenka Sešek Pavlin, Janez Turk, Primož Oprčkal, 2023, izvirni znanstveni članek

Povzetek: The environmental properties of three geotechnical composites made by recycling wastes were investigated on a laboratory scale and in the field with the use of lysimeters designated for the revitalization of degraded mining sites. Composites were prepared by combining the mine waste with paper-mill sludge and foundry sand (Composite 1), with digestate from municipal waste and paper ash (Composite 2), and with coal ash, foundry slag and waste incineration bottom ash (Composite 3). The results of laboratory leaching tests proved that Composites 1 and 3 are envi- ronmentally acceptable, according to the legislative limits, as the potentially hazardous substances were immobilized, while in Composite 2, the legislative limits were exceeded. In the field lysimeters, the lowest rate of leaching was determined for optimally compacted Composites 1 and 3, while for Composite 2 the leaching of Cu was high. This study proved that optimally installed Composites 1 and 3 are environmentally acceptable for use in construction as an alternative to virgin materials, for the revitalization of degraded mining sites or, along with Composite 2, for closure operations with landfills. In this way, locally available waste streams are valorised and channelized into a beneficial and sustainable recycling practice.
Ključne besede: waste, recycling, lysimeter, potentiali hazardous substances, immobilization, revitalisation, environmental, open access
Objavljeno v DiRROS: 29.05.2023; Ogledov: 289; Prenosov: 224
.pdf Celotno besedilo (3,42 MB)
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3.
A method for the immobilization of chitosan onto urinary catheters
Alenka Vesel, Nina Recek, Rok Zaplotnik, Albert Kurinčič, Katja Kuzmič, Lidija Fras Zemljič, 2022, izvirni znanstveni članek

Povzetek: A method for the immobilization of an antibacterial chitosan coating to polymeric urinary medical catheters is presented. The method comprises a two-step plasma-treatment procedure, followed by the deposition of chitosan from the water solution. In the first plasma step, the urinary catheter is treated with vacuum-ultraviolet radiation to break bonds in the polymer surface film and create dangling bonds, which are occupied by hydrogen atoms. In the second plasma step, polymeric catheters are treated with atomic oxygen to form oxygen-containing surface functional groups acting as binding sites for chitosan. The presence of oxygen functional groups also causes a transformation of the hydrophobic polymer surface to hydrophilic, thus enabling uniform wetting and improved adsorption of the chitosan coating. The wettability was measured by the sessile-drop method, while the surface composition and structure were measured by X-ray photoelectron spectroscopy and Fourier-transform infrared spectroscopy. Non-treated samples did not exhibit successful chitosan immobilization. The effect of plasma treatment on immobilization was explained by noncovalent interactions such as electrostatic interactions and hydrogen bonds.
Ključne besede: polymer, chitosan immobilization, adhesion, plasma-surface modification, biopolymers
Objavljeno v DiRROS: 05.12.2022; Ogledov: 441; Prenosov: 272
.pdf Celotno besedilo (6,47 MB)
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4.
Higher neural demands on stimulus processing after prolonged hospitalization can be mitigated by a cognitively stimulating environment
Uroš Marušič, Rado Pišot, Voyko Kavcic, 2021, izvirni znanstveni članek

Povzetek: Prolonge d periods of complete physical inactivity or bed rest trigger various alterations in the functional and metabolic levels of the human body. However, bed rest-related adaptations of the central nervous system are less known and thoroughly studied. The aim of this study was to investigate brain electrophysiological changes using event-related potentials (ERPs) after 14 days of bed rest and 12 consecutive sessions of computerized cognitive training (CCT). Sixteen older (Mage= 60 years) healthy volunteers were randomly divided into a CCT treatment group and an active control group. All participants performed ERP measurements based on the foveal visual presentation of a circle on a black background before and after bed rest. After 14 days of bed rest, participants in the control group showed increased peak P1 amplitude (p = .012), decreased P1 latency (p = .024), and increased P2 amplitude (p = .036), while the CCT group also showed decreased P1 latency (p = .023) and decreased P2 latency (p = .049). Our results suggest that, even from a central adaptation perspective, prolonged periods of physical inactivity or bed rest trigger additional neural recruitment and should therefore be minimized, and that CCT may serve as a tool to mitigate this. Future research should focus on other aspects of central nervous system adaptation following periods of immobilization/hospitalization to improve our knowledge of infl uence of physical inactivity and its eff ects on cortical activity and to develop appropriate countermeasures to mitigate functional dysregulation.
Ključne besede: aging, physical inactivity, immobilization, electroencephalography, EEG, computerized cognitive training
Objavljeno v DiRROS: 13.05.2021; Ogledov: 1143; Prenosov: 814
.pdf Celotno besedilo (820,21 KB)
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