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431.
432.
THE ROLE OF SPECT/CT SCINTIGRAPHY IN LOCALIZATION OF PARATHYROID ADENOMAS
Sebastijan Rep, 2016, master's thesis

Abstract: Parathyroid scintigraphy is based on the different accumulation and distribution of radiopharmaceutical 99mTc-MIBI (MIBI) in parathyroid and adjacent tissues. Different scintigraphic techniques can be used: subtraction scintigraphy is a combination of MIBI and 99mTc-pertehnetate (pertehnetate) scintigraphy; SPECT can be performed after intravenous injection of MIBI or in the combination with low-dose computerized tomography (SPECT/CT) which allows precise anatomical localization of enlarged parathyroid glands (EPG). The objectives of our study were: to assess diagnostic performance of preoperative localization of EPG (adenomas and hyperplasia) of the early, delayed and combined SPECT/CT and of subtraction scintigraphy in patients with biochemically proven primary hyperparathyroidism (PHP); to determine whether size of EPG, serum parathyroid hormone (PTH), calcium (Ca) and phosphate (P) correlate with successful localization; to assess radiation exposure of patients with early and late SPECT/CT and subtraction scintigraphy The study included 41 patients in whom early, delay SPECT/CT and subtraction scintigraphy were performed. For all scintigraphic methods sensitivity, specificity, positive predictive value, negative predictive value and accuracy were calculated. Receiver Operating Characteristic analysis was used to express relationship between scintigraphy results and size of the EPG and serum Ca, P and PTH levels. ImPACT CT Patient Dosimetry Calculator and weighting factors for radiopharmaceuticals (MIBI and pertechnetate) were used for calculating patient expose dose. Sensitivity and specificity were 51.1% and 98.3 for subtraction scintigraphy, 65.1% and 97.5% for early SPECT/CT and 65.1% and 95.5% for delay SPECT/CT. In combined early and delay SPECT/CT sensitivity and specificity were 74.4% and 95.1%.Only size of the EPG correlated with successful localization in our study (AUC of 0.791-0.810). The highest average ED per patient had subtraction scintigraphy (7.37±0.40 mSv), which was statistically significant higher in comparison to combined early and delayed SPECT/CT (6.81±0.44 mSv). The most sensitive and most accurate method of preoperative localization of EPG in patients with PHP is combined early and delayed SPECT/CT. Only size of the EPG correlates with successful localization. The highest radiation exposure is after subtraction scintigraphy.
Keywords: Enlarged parathyroid glands, early SPECT/CT, delayed SPECT/CT, combined SPECT/CT, subtraction scintigraphy, 99mTc-MIBI, 99mTc-pertechnetate, effective dose, serum parathyroid hormone, calcium, phosphate
Published in RUNG: 03.10.2016; Views: 6420; Downloads: 252
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433.
FLOODPLAIN FORESTS OF SOČA RIVER BETWEEN KOBARID AND CONFLUENCE WITH RIVER TOLMINKA: CURRENT SITUATION AND DEVELOPMENT
Janez Pagon, 2016, master's thesis

Abstract: In its upper course the Soča River is one of the best preserved Alpine rivers. Despite that, there have been few studies of its riverine forests, which are an integral part of the river. The research in this thesis encompasses part of the river basin between the towns of Kobarid and the confluence with the Tolminka River. It was found that the riverine forests in the study area are not a homogeneous habitat. Rather, they consist of numerous phytosociological communities with a syn-dynamic connection. The majority of riverine forests in the study area is younger than 50 years old and were established either by the overgrowing of agricultural land or from degraded forests. Accordingly, the forest structure is characterised mainly by uneven-aged stands or younger structural stages, which are frequently returned to their earlier stages due to human impacts. The majority of these forests have low quality prospects. Based on their vegetation and stand characteristics, the riverine forests under study were classified into six stand types. A comparison of the functions and characteristics of particular forest types revealed similarities between the stand types of initial willow, white willow and grey alder. Forests in this cluster are under the influence of soil water and high floodwaters. Their most pronounced function is ecological. In their growing stock, there is a large share of deciduous softwood. Forests in this cluster cover 62% of all riverine forests in the study area. Silvicultural measures are rare in these forests and are less important for the existence of the stands than environmental features like a high level of soil water and minimised human impact on their habitat and the river course. An important characteristic of the second cluster, which consists of pioneer forest on higher-lying river terraces and the riparian corridor stand type is a lack of contact with soil water. In the tree layer of the growing stock in this cluster, species appearing on drier riverine-forest sites prevail (European ash, small-leaved lime, European hornbeam, sessile oak). These forest stands have a greater timber industry potential; therefore, modest measures and limited human impact (especially that which leads to a change in land use like forest grazing and clearing) are recommended. The stands in this cluster cover 30% of the analysed riverine forest area. The third cluster of riverine forests consists of anthropogenic riverine forest stands where the human impact is so significant that they mainly perform a social function. The stand type of this cluster represents 8% of the riverine forests in the study area, and it is suggested that they should be managed as parkland and not as forest areas. Directing visitors to these areas would unburden other, more preserved stand types from the pressures created by human activities (tourism, recreation, construction work). Growth and increment analyses of the most common tree species in the riverine forests in the study area show that mainly olive and white willow, followed by grey alder, have substantial current height (both willow types up to 1.14 m/year), diametric (willow up to 1.4 cm/year) and volumetric increments. However, their rapid growth makes these subjects prone to rapid ageing. The region of northern Primorska was inhabited early in history. Accordingly, there was great pressure imposed on riverine forests already in the past. The analysis of old maps revealed that up to the beginning of the 20th century, the riverine forest area within the scope of analysis was under 50 ha. Within the process of the overgrowing of agricultural land in Slovenia, a process that is currently still underway, the aforementioned riverine forest area increased to 229.16 ha. This thesis shows that the study area is not an unspoiled wilderness. On contrary, just as in the past, it is a crossroads of numerous and frequently conflicting interests. The riverine forest situation on the Soča River in the area b
Keywords: the Soča river, riverine forests, successional stage, forest stand
Published in RUNG: 20.09.2016; Views: 5693; Downloads: 161
.pdf Full text (8,00 MB)

434.
Solar-driven photocatalytic treatment of diclofenac using immobilized TiO2-based zeolite composites
Marin Kovacic, Subhan Salaeh, Hrvoje Kušić, Andraz Suligoj, Marko Kete, Mattia Fanetti, Urška Lavrenčič Štangar, Dionysios D. Dionysiou, Ana Lončarić Božić, 2016, original scientific article

Abstract: The study is aimed at evaluating the potential of immobilized TiO2-based zeolite composite for solar-driven photocatalytic water treatment. In that purpose, TiO2-iron-exchanged zeolite (FeZ) composite was prepared using commercial Aeroxide TiO2 P25 and iron-exchanged zeolite of ZSM5 type, FeZ. The activity of TiO2-FeZ, immobilized on glass support, was evaluated under solar irradiation for removal of diclofenac (DCF) in water. TiO2-FeZ immobilized in a form of thin film was characterized for its morphology, structure, and composition using scanning electron microscopy/energydispersive x-ray spectroscopy (SEM/EDX). Diffuse reflectance spectroscopy (DRS) was used to determine potential changes in band gaps of prepared TiO2-FeZ in comparison to pure TiO2. The influence of pH, concentration of hydrogen peroxide, FeZ wt% within the composite, and photocatalyst dosage on DCF removal and conversion efficiency by solar/ TiO2-FeZ/H2O2 process was investigated. TiO2-FeZ demonstrated higher photocatalytic activity than pure TiO2 under solar irradiation in acidic conditions and presence of H2O2.
Keywords: Photocatalysis, Thin films, TiO2-FeZ, Solar irradiation, Diclofenac, Water Treatment
Published in RUNG: 22.07.2016; Views: 6051; Downloads: 0
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435.
Efficient mineralization of aqueous organic pollutants by photocatalytic ozonation
Urška Lavrenčič Štangar, Marko Kete, invited lecture at foreign university

Abstract: Photocatalytic ozonation process using TiO2 photocatalyst (O3/TiO2/UV – PH-OZ) conducted in acidic water environment often leads to synergistic effect in terms of decomposition and mineralization of aqueous organic contaminants, which makes the process suitable for waste water treatment or pretreatment of drinking water. [1,2] The synergism is among other factors (pH, O3 dose, T,…) greatly influenced by photocatalyst physicochemical properties and pollutant type. In the first part of the study, five different commercial TiO2 photocatalysts (P25, PC500, PC100, PC10 and JRC-TiO-6) were used in O2/TiO2/UV, O3/TiO2 and O3/TiO2/UV advanced oxidation systems for degradation of two pollutants (dichloroacetic acid - DCAA and thiacloprid – neonicotinoid pesticide), simultaneously present in water solution. [3] Results of PH-OZ (O3/TiO2/UV) experiments showed that in contrast to DCAA which adsorbs on TiO2 surface, synergistic effect is much more expressed in the case of thiacloprid which doesn’t adsorb. The influence of BET surface area of the photocatalyst and its dispersivity will be discussed. In the second part of this study, selected catalysts were immobilized on a proper support to avoid post-filtration step in the process of greywater treatment. A good adhesion of a catalyst on various supports was successfully achieved by immobilization of commercial TiO2 powders (P25, P90, PC500) with the help of a sol-gel silica-titania binder [4]. For the purpose of simulated greywater treatment, special compact reactor was designed and developed, utilizing Al2O3 porous reticulated monolith foams as TiO2 carriers and UVA-lamps inside (Fig. 1). [5] With degradation of LAS+PBIS and Reactive blue 19 (RB 19) as representatives of surfactants and textile dyes respectively, commonly found in household greywater, and phenol as trace contaminant, an evaluation of PH-OZ and photocatalytic oxidation has been performed (an example in Fig. 2). Synergistic effect of PH-OZ was generally much more expressed in mineralization reactions, showing TOC half lives of less than one hour for the mixture of pollutants in compact reactor. [5] Due to its superior cleaning capacity, PH-OZ process employing efficient photocatalysts is suitable for treating wastewaters also with higher loading of organic pollutants. 1. U. Černigoj, U.Lavrenčič Štangar, J. Jirkovsky, J. Hazard. Mater. (2010) 177:399–406. 2. U. Černigoj, U.Lavrenčič Štangar, P. Trebše, Appl. Catal. B Environ. (2007) 75:229–238. 3. M. Kete, U. Černigoj, U. Lavrenčič Štangar: Photocatalytic ozonation – study of reaction parameters and mechanism, article under submission 4. M. Kete, E. Pavlica, F. Fresno, G. Bratina, U. Lavrenčič Štangar, Environ. Sci. Pollut. Res. (2014) 21:11238–11249. 5. M. Kete: Towards efficient removal of contaminants in water from household appliances by TiO2-photocatalysis: design, optimization and performance studies of the photoreactor with immobilized catalysts, Doctoral dissertation (2015), University of Nova Gorica, Nova Gorica.
Keywords: photocatalysis, ozonation, TiO2, dichloroacetic acid, thiacloprid, mechanisms, LAS+PBIS, Reactive blue 19, phenol
Published in RUNG: 21.07.2016; Views: 6762; Downloads: 0
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436.
THE EFFECTS OF MIXED COMMUNAL WASTE RECYCLING MANAGEMENT IN SLOVENIA - CASE STUDY
Peter Bohinec, 2016, master's thesis

Abstract: With the adjustment of the Slovenian legislation with the European one we have an obligation to increase the reuse and recycling target for municipal solid waste by up to 65% by 2030 and gradual limitation of the landfilling of municipal solid waste to 10% by 2030 (Directive 2008/98 on waste, 2015). This represents a major challenge for municipalities in Slovenia. This study contains a plan for establishing new waste treatment facility in the Municipality of XY. As all new constructions in Slovenia, the presented facility needs to provide all the environmental protective measures predicted by the legislation. Beside the legislation, it is also important to ensure that new waste treatment facilities will have a low or no effect on the environment. Based on the Environmental Protection Act and the Construction Act of Slovenia, measures to ensure long term monitoring of the waste treatment facility as a case study in the Municipality of XY are presented. Before constructing the new facility, the track of “baseline” – a one-year monitoring of the following environmental parameters was crucial: groundwater, air dust deposit, condition of the soil on the area where new facility will operate in the future. The thesis points out the importance of the so-called track “baseline” monitoring of environmental parameters before new waste treatment facility will operate. This will be the basis for the introduction of operating monitoring for the new waste treatment facility in the future. Data for the analysis of presence of pollutants were acquired from groundwater, air dust deposit, soil sampling and containment of chemical pollutants. The following methods of analysis were employed in the acquisition of laboratory results of specific physical and chemical parameters: ion chromatography, gas chromatography, spectrophotometry, titration, inductive coupled plasma – mass detector, measurement with an electrode. It was determined that in the period between 2011 and 2012, the groundwater samples taken from three drilled wells containing pollutants as for example in the P-2 well there were adsorbable organic halogens - AOX, boron and mineral oils found. The results of the dust deposit show increased value of lead and zinc. More concerning are analysis of the soil samples where the quantity of copper at the MM2 measuring point were 530mg/kg, on 20 April 2012 the present critical level was 300 mg/kg. At the same measuring point (MM2) on the same day, the value of zinc was 650 mg/kg and almost reached the critical level of 720 mg/kg. The levels of heavy metals as cadmium, copper, lead and zinc in the soil samples taken at the MM2 and MM3 measuring points were at the warning level. All the detected parameters were evaluated and present a good basis for future operational monitoring of the environment in the area of the new waste treatment facility in the future. This case study has shown that planned steps in the improvement of the waste management in the Municipality of XY are crucial to protect the environment. The analysis and interpretation present an important basis for planning and monitoring a new waste treatment facility which will help to improve our goals and reduce landfilling to 10% and increace recycling by up to 65% by 2030 as predicted by the Directive on waste (Directive 2008/98 on waste, 2015).
Keywords: odpadki, krožno gospodarjenje z odpadki, podtalnica, zemljine, prašni delci v zraku, spremljanje stanja okolja.
Published in RUNG: 20.07.2016; Views: 4550; Downloads: 308
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437.
Study of Li-S batteries by S K-edge RIXS spectroscopy
Matjaž Kavčič, Matjaž Žitnik, Klemen Bučar, Marko Petrič, Iztok Arčon, Robert Dominko, Alen Vižintin, 2016, published scientific conference contribution abstract

Abstract: Li-S batteries are considered as one of the most promising candidates for future batteries in applications where high energy density is required [1]. Despite that the general principle of operation is known for a long time [2], the lack of detailed understanding of relevant operation mechanisms has so far prevented their extensive use. A Li-S battery is composed of a lithium metal anode and a sulfur based cathode, separated by a porous separator wetted with electrolyte. During the battery cycle the reduction and oxidation of S to Li2S and back proceeds through a complicated equilibrium mixture of compounds that are typically dissolved in the electrolyte in the form of long and short chain polysulfides. In order to improve our understanding of polysulfide formation and its interactions within electrode, which are essential to achieve the long term cycling stability, development and application of new analytical tools is required. In this work sulfur K-edge resonant X-ray emission (RXES) measurements were performed on the Li-S battery in operando mode. The experiment was performed at the ID26 beamline at ESRF using the Johansson type tender x-ray emission spectrometer [3]. Full K-L RIXS maps were recorded on a set of chemically prepared Li2Sx sample standards characterized by different Li:S stoichiometric ratio, followed by the operando measurements on Li-S battery. Using the spectra recorded on Li2Sx standards two excitation energies were chosen and RXES spectra from the back of the battery cathode were sequentially acquired during one discharge cycle (C20). The relative amounts of each sulfur compound in the cathode during the discharge cycle were determined from the linear combination fit using measured reference standard spectra. Because of resonant excitation conditions the sensitivity for the polysulfide detection was significantly enhanced. Our work sets up S K-edge RIXS spectroscopy as an important analytical tool to study the mechanism of Li-polysulfide formation in the cathode and their interaction with the host matrix and electrolyte.
Keywords: RIXS, RXES, Li-S battery, operando, Sulphur K-edge XANES, Lithium polysulphides, Li2S
Published in RUNG: 28.06.2016; Views: 5582; Downloads: 0
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