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255. THE INCIDENCE OF NEW ECOSYSTEMS (EE – EMERGING ECOSYSTEMS) IN THE KARST BIOSPHERE RESERVE : GROUP PROJECT, FINAL REPORTKlemen Cotič, Matej Pogorelc, Matjaž Reya, Barbara Šavli, Nika Feigina, Merisa Kapić, Ӧzkan Karaçam, Mariya Perepelytsya, 2017, druge monografije in druga zaključena dela Opis: The need of wood for building and heating, the extensive grazing and population growth in the 18th and 19th centuries led to turning the Karst area in Slovenia into a bare land. In the 19th century organised reforestation started which was successfully performed with Black pine (Pinus nigra J. F. Arnold). Later on, the reforestation was replaced by the process of spontaneous afforestation. The successfulness of reforestation with Black pine also made it possible for the native tree species to grow. The abandoning of the use of agricultural land also contributes to the spontaneous afforestation. In this project we determined the changes in forest cover through time. We used aerial photographs from the years 1957, 1975, 1985 and 2015. By drawing polygons on the maps in the QGIS programme on the areas that are covered with forests, are overgrown or are used for agricultural purpose we compared the areas from the maps of different years. We found out that the area covered with forest had increased by more than 50 % from the year 1957 to 2015. The increase in the area of forest cover due to afforestation provides new habitats for fauna and flora to live in.
Ključne besede: Karst, afforestation, new habitat, Black pine, human impact
Objavljeno v RUNG: 07.11.2017; Ogledov: 5052; Prenosov: 0
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256. ANALIZA EKSPLOZIVNOSTI IN DOLOČITEV VARNOSTNIH UKREPOV PRI PROIZVODNJI ALUMINIJEVEGA PRAHUJanez Balantič, 2017, magistrsko delo Opis: Magistrsko delo obravnava stanje na področju prašnih eksplozij v svetu. Na začetku so opisani prvi znanstveni pristopi k tej problematiki z navedbo statističnih podatkov, ki jim sledi opis znanstvenih teorij nastanka eksplozije. Zatem sledi predstavitev teoretičnih in zakonodajnih načinov za preprečitev eksplozije. Prikazana so doslej znana dejstva in različne teorije o vplivih aluminija na okolje in človeško telo. Pojasnjena je nevarnost eksplozije aluminijevih prahov ter podani napotki za varno in zdravo delo v eksplozijsko roženih prostorih.
V eksperimentalnem delu smo določili osnovne karakteristike in lastnosti izbranih treh vzorcev Al prahu (dva prahova in zdrob), ki se proizvajajo. Vzorcem smo določili velikost in porazdelitev velikosti delcev, specifično površino delcev in termične lastnosti s termično analizo (TG/DTA). Obliko delcev vzorcev Al prahu smo določili z vrstično elektronsko mikroskopijo (SEM). Sledila je določitev minimalne vžigne energije MVE in maksimalnega eksplozijskega tlaka (pmax), maksimalne hitrosti rasti tlaka pri eksploziji (Δp/Δt)max ter izračun deflagracijskega indeksa prahu (Kst). Iz rezultatov analiz smo potrdili hipotezo, da so manjši delci eksplozijsko bolj občutljivi in popolneje izgorevajo ter kot taki pomenijo večje tveganje za nastanek prašne eksplozije. Ugotovili smo tudi, da so Al prahu z manjšimi delci dodani dodatki za zmanjšanje občutljivosti. Za konec smo dobljene rezultate primerjali z dostopnimi literaturnimi navedbami in ugotovili, da so odstopanja prevelika za varno uporabo. Zato je zaradi zagotavljanja zadostne varnosti pred načrtovanjem in delom priporočljivo določiti vsaj velikost in porazdelitev velikosti prašnih delcev. Ta podatek nam namreč omogoči, da v večini literature med kopico podatkov najdemo približno ustrezen vzorec. Seveda pa je potrebno za večjo verjetnost še bolje okarakterizirati vzorce in izvesti še več preizkusov, kar smo v našem primeru tudi izvedli.
Vsaka eksplozija poleg takojšnjih vplivov na ljudeh in okolju pusti tudi dolgotrajne posledice, ki jih z današnjim stanjem tehnike in meritvami niti ne opazujemo in reguliramo. Zato velja, da je najboljši način preprečitve negativnih vplivov eksplozije onemogočanje pogojev za njen nastanek.
Ključne besede: aluminijev prah, prašna eksplozija, eksplozijski parametri, varnostni ukrepi pri proizvodnji aluminijevega prahu, vpliv aluminija na okolje in človeka
Objavljeno v RUNG: 04.09.2017; Ogledov: 6015; Prenosov: 357
 Celotno besedilo (7,48 MB)
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257. Cortisol claws concentrations in dogs from birth to 60 days of ageJasmine Fusi, Tanja Peric, Barbara Bolis, Alessandro Rota, Antonella Comin, Maria Cristina Veronesi, 2017, objavljeni povzetek znanstvenega prispevka na konferenci Opis: During the last fetal stage of development and in the neonatal period, the hypothalamic- pituitary- adrenal (HPA) axis secretes cortisol (C), responsible for several physiologic processes. The claws were recently proved to be a useful, non- invasive matrix for long time- frame retrospective C levels analysis also in puppies (Veronesi et al. 2015, Theriogenology 84:791–796). Because of the scarce knowledge on canine perinatology, this study was aimed to assess the C concentrations in claws of newborn puppies collected at birth, 30 and 60 days of age, and to evaluate the possible influence of age, gender and type
of birth on C claws accumulation. The study was performed on 58
large purebred, normal, healthy puppies, born by spontaneous or cesarean parturition. The mean C claws concentrations significantly decrease from birth (26 ± 16.39 pg/mg) to 30 (10 ± 4.53 pg/mg) and 60 (6 ± 3.12 pg/mg) days of age (p < 0.0001); a decrease was also seen from 30 to 60 days of age (p < 0.05). No influence of newborn gender and type of birth was found. This trend of decrease is in agreement with data reported by (Veronesi et al. 2015, Theriogenology 84:791–796) in dead puppies, and suggests the important role of C around the time of birth. However the exact source of the C accumulated in claws of puppies at birth must be clarified, while the source of C accumulated at 30, and even more at 60 days, can be supposed to be addressed to the newborn itself.
Ključne besede: Cortisol, claws, dog
Objavljeno v RUNG: 01.09.2017; Ogledov: 4655; Prenosov: 0
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258. Electrochemical dissolution of iridium and iridium oxide particles in acidic media : transmission electron microscopy, electrochemical flow cell coupled to inductively coupled plasma mass spectrometry and X-ray absorption spectroscopy studyPrimož Jovanovič, Nejc Hodnik, Francisco Ruiz-Zepeda, Iztok Arčon, Barbara Jozinović, Milena Zorko, Marjan Bele, Martin Šala, Vid Simon Šelih, Samo B. Hočevar, Miran Gaberšček, 2017, izvirni znanstveni članek Opis: Iridium based particles as the most promising proton exchange membrane electrolyser electrocatalysts were investigated
by transmission electron microscopy (TEM), and by coupling of electrochemical flow cell (EFC) with online inductively
coupled plasma mass spectrometer (ICP-MS). Additionally, a thin-film rotating disc electrode (RDE), an identical location transmission
and scanning electron microscopy (IL-TEM and IL-SEM) as well as an X-ray absorption spectroscopy (XAS) studies have
been performed. Extremely sensitive online time-and potential-resolved electrochemical dissolution profiles revealed that iridium
particles dissolved already well below oxygen evolution reaction (OER) potentials, presumably induced by iridium surface oxidation
and reduction processes, also referred to as transient dissolution. Overall, thermally prepared rutile type IrO2 particles (T-IrO2)
are substantially more stable and less active in comparison to as prepared metallic (A-Ir) and electrochemically pretreated (E-Ir)
analogues. Interestingly, under OER relevant conditions E-Ir particles exhibit superior stability and activity owing to the altered
corrosion mechanism where the formation of unstable Ir(>IV) species is hindered. Due to the enhanced and lasting OER performance,
electrochemically pre-oxidized E-Ir particles may be considered as the electrocatalyst of choice for an improved low temperature
electrochemical hydrogen production device, namely a proton exchange membrane electrolyser.
Ključne besede: Iridium Oxide Par-ticles, Electrochemical Dissolution of Iridium, Ir L3-edge XANES
Objavljeno v RUNG: 23.08.2017; Ogledov: 3931; Prenosov: 0
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259. DEHYDROEPIANDROSTERONE SULFATE CLAWS CONCENTRATIONS IN DOGS FROM BIRTH TO 30 DAYS OF AGE: PRELIMINARY RESULTS.Jasmine Fusi, Marta Montillo, Barbara Bolis, Alessandro Rota, Tanja Peric, Maria Cristina Veronesi, 2017, objavljeni povzetek znanstvenega prispevka na konferenci Opis: Similarly to all other species, also in the dog improvements in the knowledge on perinatology are mandatory for a better management of newborns, mainly aimed to reduce the impact of perinatal mortality. However, until recently, the study of canine perinatology was limited mainly because of the invasiveness of many investigation procedures, such as repeated blood sampling. In recent times, the claws/nails were proved to be a useful, non invasive, matrix for long time-frame retrospective hormone concentrations analysis also in babies and puppies [1,2], providing a suitable matrix for perinatal long-term hormonal changes studies. The last intrauterine foetal stage of development and the neonatal period represent the most challenging phases for the mammals offspring. It was demonstrated that the activation of the fetal hypothalamic-pituitary-adrenal (HPA) axis leads to dehydroepiandrosterone (DHEA) and DHEA sulfate (DHEA-S) secretion, the major fetal steroids. Thus, DHEA-S measured at birth in newborns could be considered as a marker of offspring HPA axis activity, under the maternal influence. This study was aimed to assess the DHEA-S concentrations in newborn puppies claws, collected at birth and at 30 days of age, and to evaluate the possible influence of age, gender and type of birth on DHEA-S claws accumulation. The study was performed on 58 large purebred, normal, healthy, viable (Apgar≥7) puppies, 31 males and 27 females, born by vaginal spontaneous (N=22) or caesarean (N=36) parturition. DHEA-S was analysed by RIA. The mean ± SD DHEA-S claws concentration significantly (p<0.01) decreased from birth (210±152.00 pg/mg) to 30 days (91±72.63 pg/mg), evidencing the higher fetal DHEA-S secretion in the last fetal stage of pregnancy in comparison to the first postnatal month of age. According to the type of parturition, higher (p<0.001) DHEA-S claws concentrations were found at birth in puppies born by spontaneous than caesarean parturition (300±167.05 vs 154±112.23 pg/mg, respectively); this finding deserves further investigations. No influence of newborn gender was found. Claws DHEA-S values at birth were a bit higher, but with a lower SD, in comparison to data reported for babies 1-3 weeks old [1]. The trend of decrease is in agreement with data reported for cortisol [2] in dead puppies, and suggests, beside the role of cortisol, the important effects of DHEA-S around the time of birth, also in puppies, as reported for babies [1].
[1] Tegethoff et al. Dehydroepindrosterone in nails of infants: a potential biomarker of intrauterine responses to maternal stress. Biological psychology, 87: 414-420, 2011. [2] Veronesi et al. Coat and claws as new matrices for noninvasive long-term cortisol assessment in dogs from birth up to 30 days of age. Theriogenology, 84: 791-796, 2015.
Ključne besede: DHEA-S, claw, dog
Objavljeno v RUNG: 22.08.2017; Ogledov: 4228; Prenosov: 0
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