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Elemental associations in stream and alluvial sediments of the Savinja and Voglajna Rivers (Slovenia, EU) as a result of natural processes and anthropogenic activities
Gorazd Žibret, 2022, izvirni znanstveni članek

Povzetek: Stream and alluvial sediments of the Savinja and Voglajna rivers were sampled, and sediment fractions <0.063 and 0.063–0.125 mm were analyzed on the content of 60 of the main and trace elements. The objective was to determine elemental associations and identify possible sources of these associations. Differences of Al/Ti oxides ratio (9.7–26) can be attributed to the variations in the source rocks, while the K/Al oxides ratio indicates erosional or depositional river regime and variation in source rocks. One anthropogenic and three natural associations of elements were identified. The anthropogenic association (Ag, In, Sb, Cu, As, Zn, Pb, Cd, Bi, Mo and Sn) is linked to historic Zn smelting in the Celje area, and the subsequent erosion of the material from inadequately managed pyrometallurgical waste deposit. The second association (Li, Sc, Al, V, Cs and Ga) is linked to clay minerals, the third one (Mg, Ca and Te) to carbonate rocks, and the fourth one (Hf, Zr) to the heavy mineral fraction.
Ključne besede: heavy metals, smelting, weathering, erosion, deposition, farming, waste
Objavljeno v DiRROS: 06.07.2022; Ogledov: 535; Prenosov: 378
.pdf Celotno besedilo (5,57 MB)
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14.
Impact of urbanization and steel mill emissions on elemental composition of street dust and corresponding particle characterization
Klemen Teran, Gorazd Žibret, Mattia Fanetti, 2022, izvirni znanstveni članek

Povzetek: Street Dust (SD) acts as a sink and source of atmospheric particles containing Potentially Toxic Elements (PTEs) and can pose a possible pathway of PTEs to human bodies. Comprehensive SD study, where 249 samples were collected from rural, urban and industrialized areas aimed to increase the understanding between sedimentation of atmospheric dust derived from anthropogenic activities and elemental composition of SD. Elemental composition for 53 elements (ICP-MS, aqua regia digestion) was determined on fraction <0.063 mm. Significantly increased levels of Sn-Cu-Sb-Bi-Ag-Ba-Mo-Pt-Pb and other elements have been detected in urban environments, compared to the rural ones. SEM/EDS investigation identified that main carriers of Ba, Cu and Sn are most likely particles derived from non-exhaust traffic emissions. Areas around steel mills show a strong enrichment with Cr, Mo, Ni and W, which exponentially decreases with the increased distance from the plant, reaching corresponding urban background 15 and 20 km from the source. SEM/EDS inspection identified spherical and melted irregular particles as the main carriers of the above-mentioned elements. City managers shall adapt measures to reduce amount of vehicular traffic and quantity of deposited SD on the public surfaces and encourage green city planning, while industrial emitters are encouraged to reduce their dust emissions.
Ključne besede: ironwork, pollution, potentially toxic elements, Slovenia, traffic
Objavljeno v DiRROS: 10.06.2022; Ogledov: 571; Prenosov: 278
.pdf Celotno besedilo (10,32 MB)

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Building of the Al-Containing secondary raw materials registry for the production of low CO2 mineral binders in South-Eastern European region
Gorazd Žibret, Klemen Teran, Lea Žibret, Katarina Šter, Sabina Dolenec, 2021, izvirni znanstveni članek

Povzetek: The bottleneck in the process for increasing production of low CO2 mineral binders, based on BCSA (belite sulfoaluminate) clinkers, is the availability of Al-rich raw materials. For that purpose, a new registry of Al-containing secondary mineral residues (industrial and mine waste) has been developed and is presented in this paper. The methodology of creating the registry consists of three main steps: Gathering ideas, consolidation of ideas, and implementation. In order to achieve this, the following methodology was adopted: Analysis of similar registries by potential end-users and seeking potential solutions and tools to be used, and conducting 3 rounds of stakeholder consultations via workshops in order to determine crucial parameters and features the registry needs to contain. The key discussion points were about which data the registry needs to contain, who shall be the potential users, and what are the stakeholderʼs expectations from the registryʼs portal. Potential individual registry variables were identified as being relevant/irrelevant or available/unavailable, and potential solutions for the registrys sustainability were explored. Each Al-rich waste/residue data entry is divided into 10 slots, describing legal status, location, quantities, chemical (REE included), mineralogical, physical and radiological properties, life-cycle assessment, additional data, and data relevancy. The registry will act as a matchmaking tool between producers/holders of Al-rich secondary raw materials and potential producers of cement clinkers.
Ključne besede: cement, belite sulfoaluminate clinker, waste, by--product, deležniki
Objavljeno v DiRROS: 10.06.2022; Ogledov: 499; Prenosov: 302
.pdf Celotno besedilo (2,23 MB)
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16.
The valorisation of selected quarry and mine waste for sustainable cement production within the concept of circular economy
Emilija Fidanchevski, Katarina Šter, Maruša Mrak, Ljiljana Kljajević, Gorazd Žibret, Klemen Teran, Bojan Poletanovic, Monika Fidanchevska, Sabina Dolenec, Ildikó Merta, 2022, izvirni znanstveni članek

Povzetek: The cement industry could potentially consume large amounts of solid industrial waste in order to improve its sustainability. The suitability of selected quarry and mine waste as secondary raw materials (SRM) was examined for the sustainable production of cement following the concept of a circular economy. The chemical, mineralogical, and radiological characterization of SRM was conducted in this study. Its potential use in low-carbon and low-energy belite-sulfoaluminate cement was investigated by incorporating the examined SRM into cement clinker. Various characterization methods were used to characterize the cement, including X-ray powder diffraction (XRD), thermal analysis (DTA/TG), and isothermal calorimetry. Depending on the chemical composition of the waste, lower or higher amounts were allowed to be incorporated into the raw clinker mixture for a targeted clinker phase composition. Among the samples, differences were observed in the phase composition of synthesized clinkers, which slightly influenced the reactivity of the cement but did not significantly change the compressive strength of the final product.
Ključne besede: mineralne surovine, rudarski odpadki, rudniki, kamnolomi, cement, klinker, krožno gospodarstvo, BCSA clinker, cement, circular economy, clinker, mine wastes, quarry waste
Objavljeno v DiRROS: 10.06.2022; Ogledov: 576; Prenosov: 299
.pdf Celotno besedilo (3,34 MB)
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Neural bases of age-related sensorimotor slowing in the upper and lower limbs
Uroš Marušič, Manca Peskar, Kevin De Pauw, Nina Omejc, Gorazd Drevenšek, Bojan Rojc, Rado Pišot, Voyko Kavcic, 2022, izvirni znanstveni članek

Povzetek: With advanced age, there is a loss of reaction speed that may contribute to an increased risk of tripping and falling. Avoiding falls and injuries requires awareness of the threat, followed by selection and execution of the appropriate motor response. Using event-related potentials (ERPs) and a simple visual reaction task (RT), the goal of our study was to distinguish sensory and motor processing in the upper- and lower-limbs while attempting to uncover the main cause of age-related behavioral slowing. Strength (amplitudes) as well as timing and speed (latencies) of various stages of stimulus- and motor-related processing were analyzed in 48 healthy individuals (young adults, n = 24, mean age = 34 years; older adults, n = 24, mean age = 67 years). The behavioral results showed a significant age-related slowing, where the younger compared to older adults exhibited shorter RTs for the upper- (222 vs. 255 ms; p = 0.006, respectively) and the lower limb (257 vs. 274 ms; p = 0.048, respectively) as well as lower variability in both modalities (p = 0.001). Using ERP indices, age-related slowing of visual stimulus processing was characterized by overall larger amplitudes with delayed latencies of endogenous potentials in older compared with younger adults. While no differences were found in the P1 component, the later components of recorded potentials for visual stimuli processing were most affected by age. This was characterized by increased N1 and P2 amplitudes and delayed P2 latencies in both upper and lower extremities. The analysis of motor-related cortical potentials (MR) revealed stronger MRCP amplitude for upper- and a non-significant trend for lower limbs in older adults. The MRCP amplitude was smaller and peaked closer to the actual motor response for the upper- than for the lower limb in both age groups. There were longer MRCP onset latencies for lower- compared to upper-limb in younger adults, and a non-significant trend was seen in older adults. Multiple regression analyses showed that the onset of the MRCP peak consistently predicted reaction time across both age groups and limbs tested. However, MRCP rise time and P2 latency were also significant predictors of simple reaction time, but only in older adults and only for the upper limbs. Our study suggests that motor cortical processes contribute most strongly to the slowing of simple reaction time in advanced age. However, late-stage cortical processing related to sensory stimuli also appears to play a role in upper limb responses in the elderly. This process most likely reflects less efficient recruitment of neuronal resources required for the upper and lower extremity response task in older adults.
Ključne besede: aging, sensoriomotor integration, event-related potential, finger and foot responses, motor-related cortical potential
Objavljeno v DiRROS: 04.05.2022; Ogledov: 531; Prenosov: 427
.pdf Celotno besedilo (2,66 MB)
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19.
Distribution of Pb, Zn and Cd in stream and alluvial sediments in the area with past Zn smelting operations
Gorazd Žibret, Barbara Čeplak, 2021, izvirni znanstveni članek

Povzetek: The sources of Zn, Pb and Cd in alluvial and stream sediments have been studied in the area of historical Zn smelting tradition. 30 samples of stream sediments and samples from 4 alluvial sediment profiles were collected. Fractions 0.125–0.063 and < 0.063 mm were analysed by the means of ICP-MS prior 4-acid digestion. The highest levels of Zn, Cd and Pb were detected in the alluvial sediments in the closest vicinity to the abandoned slag and ore roasting residue waste dumps, reaching 96 and 4520 mg/kg, 522 and 26,800 mg/kg and 3.7 and 31 mg/kg for Pb, Zn and Cd in stream and alluvial sediments, respectively. The Voglajna River then transports contamination particles into the Savinja River, which afterwards flows into the Sava River. Consequently, the anomaly can even be detected in the Sava River, more than 30 km downstream. Higher levels of Pb, Zn and Cd have been found in fraction < 0.063 mm compared to 0.125–0.063 mm fraction. Impacts of historically contaminated soil erosion and in particular the wash-out of Zn-smelting waste from the improperly managed waste dump were recognised as the dominant sources of Zn, Cd and Pb in the stream and alluvial sediments.
Ključne besede: onesnaženje okolja, rečni sedimenti, porazdelitev elementov, topilništvo
Objavljeno v DiRROS: 03.03.2022; Ogledov: 587; Prenosov: 215
.pdf Celotno besedilo (1,76 MB)

20.
Temporal changes in the epidemiology, management, and outcome from acute respiratory distress syndrome in European intensive care units : a comparison of two large cohorts
Yasser Sakr, Bruno François, Jordi Solé-Violan, Katarzyna Kotfis, Ulrich Jaschinski, Angel Estella, Marc Leone, Stephan M. Jakob, Xavier Wittebole, Luis E. Fontes, Viktorija Tomič, 2021, izvirni znanstveni članek

Povzetek: Background. Mortality rates for patients with ARDS remain high. We assessed temporal changes in the epidemiology and management of ARDS patients requiring invasive mechanical ventilation in European ICUs. We also investigated the association between ventilatory settings and outcome in these patients. Methods. This was a post hoc analysis of two cohorts of adult ICU patients admitted between May 1–15, 2002 (SOAP study, n = 3147), and May 8–18, 2012 (ICON audit, n = 4601 admitted to ICUs in the same 24 countries as the SOAP study). ARDS was defined retrospectively using the Berlin definitions. Values of tidal volume, PEEP, plateau pressure, and FiO2 corresponding to the most abnormal value of arterial PO2 were recorded prospectively every 24 h. In both studies, patients were followed for outcome until death, hospital discharge or for 60 days. Results. The frequency of ARDS requiring mechanical ventilation during the ICU stay was similar in SOAP and ICON (327[10.4%] vs. 494[10.7%], p = 0.793). The diagnosis of ARDS was established at a median of 3 (IQ: 1–7) days after admission in SOAP and 2 (1–6) days in ICON. Within 24 h of diagnosis, ARDS was mild in 244 (29.7%), moderate in 388 (47.3%), and severe in 189 (23.0%) patients. In patients with ARDS, tidal volumes were lower in the later (ICON) than in the earlier (SOAP) cohort. Plateau and driving pressures were also lower in ICON than in SOAP. ICU (134[41.1%] vs 179[36.9%]) and hospital (151[46.2%] vs 212[44.4%]) mortality rates in patients with ARDS were similar in SOAP and ICON. High plateau pressure (> 29 cmH2O) and driving pressure (> 14 cmH2O) on the first day of mechanical ventilation but not tidal volume (> 8 ml/kg predicted body weight [PBW]) were independently associated with a higher risk of in-hospital death. Conclusion. The frequency of and outcome from ARDS remained relatively stable between 2002 and 2012. Plateau pressure > 29 cmH2O and driving pressure > 14 cmH2O on the first day of mechanical ventilation but not tidal volume > 8 ml/kg PBW were independently associated with a higher risk of death. These data highlight the continued burden of ARDS and provide hypothesis-generating data for the design of future studies.
Ključne besede: respiratory insufficiency, artificial respiration, tidal volume, airway pressures, driving pressure
Objavljeno v DiRROS: 16.06.2021; Ogledov: 1141; Prenosov: 533
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