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Optimization of electricity demand based on electricity prices on day-ahead market
No full textZ naraščajočim deležem obnovljivih virov energije postaja elektroenergetski sistem vse bolj nestanoviten, kar se odraža v povečanih cenovnih nihanjih na trgu z električno energijo. Takšne razmere spodbujajo razvoj metod za prilagajanje porabe, zlasti pri večjih gospodinjskih porabnikih, kot so toplotne črpalke. V magistrskem delu predstavljamo celovit pristop k optimizaciji delovanja ogrevalnega sistema s toplotno črpalko glede na cene električne energije na trgu za dan vnaprej. Razvili smo inovativno metodo za identifikacijo parametrov sistema na podlagi zgodovinskih podatkov obratovanja - brez potrebe po dodatnih meritvah na terenu. Uporabljen model temelji na fizikalnem opisu sistema in se bistveno razlikuje od principa črne škatle, saj je interpretabilen in omogoča razumevanje vedenja sistema. Z njegovo uporabo smo optimizirali stroške delovanja toplotne črpalke, ob tem pa ohranili nespremenjeno raven bivalnega udobja. Toplotno kapaciteto stavbe smo izkoristili za premik porabe električne energije v časovna obdobja z nižjimi cenami, s čimer ogrevalni sistem postane prilagodljiv porabnik v pametnem omrežju. Rešitev smo validirali na podatkih celotne ogrevalne sezone in dosegli prihranke med 15 in 25 %. Predlagani pristop omogoča stroškovno učinkovito in uporabniku prijazno upravljanje energije in je primeren za integracijo v obstoječe krmilne sisteme.With the increasing share of renewable energy sources, the electrical power system is becoming more volatile, resulting in significant price fluctuations in the electricity market. Such conditions encourage the development of demand-side flexibility methods, particularly for large residential consumers such as heat pumps. This master\u27s thesis presents a comprehensive approach to optimize the operation of a heat pump-based heating system in response to day-ahead electricity market prices. An innovative method was developed to identify system parameters solely from the historical operational data, eliminating the need for additional on-site measurements. Unlike black-box models, the employed model is based on a physical representation of the system, offering interpretability and insights into system behavior. Using this model, the operating cost of the heat pump was optimized while maintaining living comfort. By leveraging the building’s thermal capacity, electricity consumption was shifted to periods with lower prices, effectively turning the heating system into a flexible load within a smart grid. Validation with data from an entire heating season showed energy cost savings of between 15 and 25 %. The proposed solution is cost-effective, user-friendly, and well-suited for integration into existing control systems
Potential of the use of peroxynitric acid in combination with cold oxygen gaseous plasma for preventing fungal infection on corn grains
No full textOkužbe zrnja z glivami predstavljajo velik problem v kmetijstvu, saj so odgovorne za večino izgube pridelka, poleg tega pa predstavljajo tudi nevarnost za zdravje ljudi in živali. Trenutno se v svetu ta težava rešuje z uporabo velike količine fungicidov, ki sicer povečajo količino pridelka, ampak ob prekomerni uporabi predstavljajo nevarnost za okolje ter zdravje ljudi in živali. V zadnjih letih se zato išče nove, okolju in ljudem bolj prijazne alternative, med katerimi sta tudi peroksidušikova kislina (PNA) in hladna plazma. V tej magistrski nalogi smo testirali vpliv PNA v kombinaciji s hladno kisikovo plazmo na zaviranje rasti gliv Aspergillus flavus in Fusarium fujikuroi na zrnu koruze (Zea mays). Rezultati so pokazali, da je bila PNA učinkovita pri zmanjšanju rasti A. flavus in F. fujikuroi, saj je bil v obeh primerih že po 30-sekundni obdelavi s 50 mM PNA delež okuženih zrn manjši od 25 %, pri 300-sekundni obdelavi s 100 mM PNA pa rasti gliv na zrnu ni bilo več zaznati. Vpliv na zaviranje glivne okužbe na zrnu koruze v kombinaciji s hladno kisikovo plazmo ni bil statistično značilno večji od obdelave samo s PNA, kljub temu da je trend nakazoval nekoliko manjšo okužbo. PNA tudi ni vplivala na kaljivost zrn. Glede na rezultate ima PNA zelo dober potencial kot alternativa fungicidov. Ker ne vpliva na samo kaljivost, bi jo lahko uporabljali tako pri zrnu, namenjenem za prehrambne namene, kakor tudi na zrnu, namenjenem za nadaljnjo setev.Grain infections by fungi represent a significant issue in agriculture, as they are responsible for the majority of crop loss and pose a health risk to humans and animals. Currently, this problem is addressed globally through the use of large quantities of fungicides, which, although increasing crop yield, pose a new problem with their excessive use as they endanger the health of humans and animals and threaten the safety of ecosystems into which they are released. As a result, in recent years, there has been a search for new alternatives to fungicides that are more environmentally friendly and safer for humans. Among these alternatives are peroxynitric acid (PNA) and cold plasma. In this master\u27s thesis, we tested the effect of PNA in combination with cold oxygen plasma on preventing the growth of Aspergillus flavus and Fusarium fujikuroi on corn grain (Zea mays). The results showed that PNA is effective in reducing the growth of A. flavus and F. fujikuroi, with the infection rate of grain being less than 25 % after a 30-second treatment with 50 mM PNA, and no growth detected after a 300-second treatment with 100 mM PNA. Seed decontamination in combination with cold oxygen plasma was not statistically significantly greater than decontamination with PNA alone, although the trend suggested this direction. PNA also does not affect grain germination. Based on our results, PNA shows great potential as an alternative to fungicides, and since it does not affect germination, it could be used for grain intended for the foods as well as for grain used for sowing
Knafelj scholarship students of mathematics and natural sciences at the University of Vienna between 1872 and 1890
No full textNa podlagi arhivskega gradiva, ki ga hrani Univerzitetni arhiv na Dunaju, je identificiranih petnajst študentov matematike in naravoslovnih smeri, ki so bili v obdobju 1872–1890 Knafljevi štipendisti. Analizirani so biografski podatki študentov, pregled vpisanih predmetov po smereh, prejemanje drugih štipendij ter delna rekonstrukcija njihovega nadaljnjega življenja. Večina obravnavanih Knafljevih štipendistov je poučevala kot gimnazijski učitelji tako na slovenskem ozemlju kakor v drugih deželah avstro-ogrske monarhije. Štirje so bili tudi ravnatelji, in sicer v Ljubljani, Kranju in Kopru. Obravnavani posamezniki so pomembno prispevali k razvoju gimnazijskega izobraževanja in promocije znanosti na področju matematike in naravoslovnih smeri, tudi z izdajanjem učbenikov v slovenskem jeziku, nekateri so bili aktivni tudi na drugih družbenih področjih.According to archival material stored at the Vienna University Archives, fifteen students of mathematics and natural sciences who received the Knafelj scholarship between 1872 and 1890 have been identified. This article analyses students’ biographical data of the students and provides an overview of the subjects they enrolled in, the other scholarships they received, as well as a partial reconstruction of their careers. Most of the Knafelj scholarship recipients later worked as high school teachers, both in Slovenia and in other regions of the Austro-Hungarian Empire. Four of them were also headmasters in Ljubljana, Kranj and Koper. The individuals also made important contributions to the development of secondary education and the promotion of learning in the fields of mathematics and the natural sciences, in particular through the publication of textbooks in Slovenian, while others contributed to wider society in other ways too
Analysis of sugars, amino acids, and phenolic compounds in nectar of selected native melliferous plant species
No full textV raziskavi smo preučevali nektar dvanajstih avtohtonih medovitih rastlinskih vrst. Zanimala nas je količina izločenega nektarja in njegova sestava, predvsem sladkorji, aminokisline ter fenolne spojine. Preučili smo tudi vpliv dela dneva na nektar in vpliv abiotskih dejavnikov, kot so temperatura zraka ter prsti, vlažnosti prsti in zraka ter UVB sevanje. Vzorce nektarja smo pridobili z metodo s kapilarami in pranja cvetov v naravnem okolju v Ljubljani ter okolici. Preverili smo, ali sta obe metodi zbiranja nektarja res zanesljivi in uporabni za globoke ter plitve cvetove in ugotovili, da je metoda s kapilarami bolj zanesljiva, ampak z manjšimi omejitvami pri plitvih cvetovih.In this study, we investigated the nectar of twelve native melliferous plant species. We focused on the quantity of secreted nectar and its composition, particularly sugars, amino acids, and phenolic compounds. We also examined the effect of time of day on nectar as well as the influence of abiotic factors, such as air and soil temperature, soil and air humidity, and UVB radiation. Nectar samples were collected using capillary tubes and by washing flowers in their natural environment in Ljubljana and its surroundings. We evaluated whether both nectar collection methods are reliable and suitable for deep and shallow flowers, and found that the capillary tube method is more reliable, although it has some limitations when used with shallow flowers
Oblikoslovne dvojnice: pomoč ali ovira za jezikovne uporabnike
No full textPrispevek s pragmatičnega vidika obravnava nekatere oblikoslovne dvojnice v sodobnih normativnih priročnikih (pravopisu in enojezičnem slovarju), ki v njih niso vedno poenotene. Preverjene bodo z rabo v oblikoslovnem korpusu in tudi diahrono utemeljene. S sproščeno pisno komunikacijo v sodobni standard vdirajo prvine iz neknjižnih jezikovnih zvrsti, zato pomenijo dvojnice dobrodošlo pomagalo za lažje doseganje jezikovne pravilnosti, če jih jezikovni uporabniki in svetovalci usvojijo.This article applies a pragmatic approach to certain morphological variants in modern normative manuals (the normative guide and a monolingual dictionary), which do not always agree. They are checked by use in a morphological corpus and also justified from a diachronic perspective. Through relaxed written communication, elements from nonstandard language are introduced into the modern standard, and so variants are a welcome help for achieving linguistic correctness if they are acquired by language users and advisers
Development and evaluation of a confocal optical system for 3D surface characterization
No full textNatančna 3D karakterizacija inženirskih površin zahteva brezkontaktne metode z visoko ločljivostjo, ki presegajo omejitve klasične mikroskopije. V okviru magistrskega dela smo razvili in optimizirali modularni konfokalni laserski skenirni mikroskop, ki deluje v odbojnem načinu. Izbrana metodologija temelji na optični zasnovi z laserskim virom valovne dolžine 658 nm, uporabi polarizacijske optike za filtriranje parazitskih odbojev ter optičnem vlaknu v vlogi konfokalne zaslonke. Krmiljenje galvanometrskih zrcal in motorizirane osi z smo izvedli z namenskim komunikacijskim protokolom prek mikrokrmilnika. Z eksperimentalno validacijo na aluminijastem vzorcu smo potrdili ustreznost sistema za rekonstrukcijo topografije. Dosegli smo lateralno ločljivost 1,23 μm in aksialno ločljivost 26,0 μm. Referenčna meritev višine stopnice z digitalnim mikroskopom Keyence VHX-7000 je pokazala dejansko višino 45,57 ± 3,06 μm. Z uporabo 3D Gaussovega filtriranja smo pri posamičnem preseku izmerili višino 44,89 μm (napaka -1,5 %), statistična analiza vseh presekov pa je pokazala mediano 45,00 μm (napaka -1,3 %). Razviti sistem tako dosega relativno točnost boljšo od 2 % za višinske razlike reda 50 μm. S sistemom smo uspešno demonstrirali princip optičnega rezanja in profilometrijo kovinskih površin.Precise 3D characterization of engineering surfaces requires non-contact methods that overcome the limitations of conventional microscopy. In this master\u27s thesis, we developed and optimised a modular confocal laser scanning microscope operating in reflectance mode. The chosen methodology is based on an optical design using a 658 nm wavelength laser source, polarisation optics to filter parasitic reflections, and an optical fibre serving as the confocal pinhole. Control of the galvanometer mirrors and the motorised z-axis was implemented via a custom communication protocol using a microcontroller. Experimental validation on an aluminium sample confirmed the system\u27s suitability for topography reconstruction. We achieved a lateral resolution of 1.23 μm and an axial resolution of 26.0 μm. A reference measurement of the step height using a Keyence VHX-7000 digital microscope yielded an actual height of 45.57 ± 3.06 μm. Using 3D Gaussian filtering, we measured a height of 44.89 μm (error -1.5 %) for a single cross-section, while statistical analysis of all cross-sections yielded a median of 45.00 μm (error -1.3 %). The developed system thus achieves a relative accuracy better than 2 % for height differences of approximately 50 μm. With this system, we successfully demonstrated the principle of optical sectioning and profilometry of metal surfaces
Pravopisne obravnave priimkov s stališča spola
No full textČlanek obravnava priimke od Slovenskega pravopisa iz leta 1899 do pravopisa iz leta 1990. V slovarskih delih pravopisa iz leta 1899 in pravopisa iz leta 1920 za priimke kategorija spola ni navedena, v pravopisu iz leta 1935 pa so priimki označeni kot samostalniki moškega spola ali pa oznake za spol nimajo. Pravopisa iz let 1950 in 1962 uvedeta pregibanje ženskih imen in priimkov kot posebno poglavje. Novost pri obravnavi prinaša šesti pravopis leta 1990, ki v slovarju 2001 za najpogostejše slovenske priimke navaja tudi neknjižne oblike, priimkom znanih ženskih oseb pa pripisuje ženski slovnični spol.This article discusses surnames in editions of the Slovenian normative guide from 1899 to 1990. In the dictionary sections of the 1899 and 1920 normative guides, there is no gender category for surnames, whereas in the 1935 normative guide surnames are marked as masculine nouns or may lack gender indications. The 1950 and 1962 normative guides introduce the declension of female first names and surnames as a separate chapter. An innovation in treatment came with the sixth normative guide in 1990, which, like the 2001 dictionary, also includes non-standard forms for the most common Slovenian surnames and assigns feminine grammatical gender to surnames of well-known women
Do kod (lahko) seže norma v skladnji?
No full textSkladnja kot jezikovna ravnina je hkrati tudi ciljna ravnina vsakega jezikovnega sporočanja in zato je pod vplivom stalnih jezikovnih sprememb. Obravnava s komentiranjem konkretnih primerov znotraj besednozvezne, stavčne, povedne in nadpovedne skladnje predstavlja potencialne (še ne) povsem ustaljene posebnosti v rabi, ki so zato slovnično, pomensko in pragmatično lahko problematični ter zato obsojeni na sprotno in stalno presojo tudi z vidika normativnosti.Syntax as a target linguistic level of communication is under the influence of constant linguistic changes. This discussion with commentary on specific examples within phraselevel, sentence-level, propositional, and supra-propositional syntax presents potential (still not fully established) special features in usage, which can therefore be grammatically, semantically, and pragmatically problematic, and are thus condemned to ongoing and constant evaluation from the perspective of normativity
Prešernov kult v letih po drugi svetovni vojni
No full textŠtevilni politični režimi se v želji po legitimaciji svoje oblasti sklicujejo na kulturno izročilo, pri čemer pogosto prikrojijo sporočila v kanoniziranih delih in biografije znanih ustvarjalcev. Pojav je mogoče analizirati skozi odnos socialistične Jugoslavije do Franceta Prešerna. Pesnika so med drugo svetovno vojno partizani začeli predstavljati kot zgodnjega revolucionarja in preroka osvoboditve Slovencev. Podoba "partizanskega" pesnika je bila razširjena tudi v prvih povojnih letih, ko se je krepila skozi številne zapise, proslave in spominske projekte.In order to legitimize their power, many political regimes invoke cultural tradition, often tailoring the messages of canonized works and the biographies of famous artists. This phenomenon can be analyzed through the attitude of socialist Yugoslavia toward France Prešeren. During the Second World War, the Partisans began to portray the poet as an early revolutionary and a prophet of the liberation of the Slovenians. The image of the "Partisan" poet was also widespread in the first postwar years, when it was strengthened through numerous writings, celebrations, and memorial projects