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The new instrument using a TC–BC (total carbon–black carbon) method for the online measurement of carbonaceous aerosols
Martin Rigler, Luka Drinovec, Gašper Lavrič, Anastasia Vlachou, André S. H. Prévôt, Jean-Luc Jaffrezo, IASONAS STAVROULAS, Jean Sciare, Judita Burger, Irena Krajnc, Janja Turšič, Anthony D. A. Hansen, Griša Močnik, 2020, original scientific article

Abstract: We present a newly developed total carbon analyzer (TCA08) and a method for online speciation of carbonaceous aerosol with a high time resolution. The total carbon content is determined by flash heating of a sample collected on a quartz-fiber filter with a time base between 20 min and 24 h. The limit of detection is approximately 0.3 µg C, which corresponds to a concentration of 0.3 µg C m−3 at a sample flow rate of 16.7 L min−1 and a 1 h sampling time base. The concentration of particulate equivalent organic carbon (OC) is determined by subtracting black carbon concentration, concurrently measured optically by an Aethalometer®, from the total carbon concentration measured by the TCA08. The combination of the TCA08 and Aethalometer (AE33) is an easy-to-deploy and low-maintenance continuous measurement technique for the high-time-resolution determination of equivalent organic and elemental carbon (EC) in different particulate matter size fractions, which avoids pyrolytic correction and the need for high-purity compressed gases. The performance of this online method relative to the standardized off-line thermo-optical OC–EC method and respective instruments was evaluated during a winter field campaign at an urban background location in Ljubljana, Slovenia. The organic-matter-to-organic-carbon ratio obtained from the comparison with an aerosol chemical speciation monitor (ACSM) was OM/OC=1.8, in the expected range.
Found in: osebi
Keywords: total carbon, aeroosl, black carbon, carbonaceous matter
Published: 17.08.2020; Views: 2007; Downloads: 67
.pdf Fulltext (226,45 KB)

Short-range urban dispersion experiments using fixed and moving sources
Stephen E Belcher, Alison S Tomlin, James Tate, Marina K Neophytou, Rex E Britter, Fredrik Petterson, Iain R White, Graham Nickless, Catheryn S Price, Damien Martin, Dudley E. Shallcross, Janet F Barlow, Alan Robins, 2009, original scientific article

Abstract: Four perfluorocarbon tracer dispersion experiments were carried out in central London, United Kingdom in 2004. These experiments were supplementary to the dispersion of air pollution and penetration into the local environment (DAPPLE) campaign and consisted of ground level releases, roof level releases and mobile releases; the latter are believed to be the first such experiments to be undertaken. A detailed description of the experiments including release, sampling, analysis and wind observations is given. The characteristics of dispersion from the fixed and mobile sources are discussed and contrasted, in particular, the decay in concentration levels away from the source location and the additional variability that results from the non-uniformity of vehicle speed.
Found in: osebi
Keywords: dapple, perfluorocarbon, tracer, mobile source
Published: 18.07.2019; Views: 2189; Downloads: 0
.pdf Fulltext (265,68 KB)

Application of beam deflection spectrometry for the determination of iron species in passive samplers exposed to Southern Ocean ice
Hanna Budasheva, Arne Bratkič, Martin Šala, Dorota Korte, Mladen Franko, 2021, unpublished conference contribution

Found in: osebi
Published: 02.12.2021; Views: 913; Downloads: 9
.pdf Fulltext (1,52 MB)
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Anaerobic Co-Digestion of Ligno-Cellulosic degradation products - Wood Resin Residue from Tannin Production
Gregor Draago Zupančič, Mario Panjicko, Domagoj Eršek, Goran Lukić, Žiga Velišček, Martin Gojun, 2018, published scientific conference contribution

Abstract: Tannin is a very versatile industrial material used for many applications. During tannin production, a residue is produced, which consists of 10 – 15 % sodium acetate solution with up to 10 % water-soluble wood resins by mass. Since it contains a high portion of acetate, it can be useful for anaerobic digestion to produce biomethane, whereas wood resins may exhibit inhibitory effects. In order to test the biodegradability of wood resin residue, several batch tests were performed with two approaches. In the first approach, co-digestion with corn-silage and animal waste was performed utilizing suspended biomass inoculum. In the second approach, co-digestion with pulp and paper wastewater was performed utilizing granular biomass inoculum. In the first approach, the results showed partial inhibition of degradation using mixtures of 25.6 % and total inhibition using 100.0 % of wood resin. Maximum biodegradability achieved was 83.4 %. In the second approach, the results showed partial inhibition of degradation using mixtures of 1.7 and 3.3 % of wood resin. Maximum biodegradability achieved was 64.3 %. Because the second approach enabled us to process larger quantities of wood resin (larger COD load), a pilot experiment of anaerobic co-digestion with pulp and paper wastewater was performed, utilising similar conditions to the considered full-scale treatment. The results showed COD degradation between 70.1 and 81.7 % and a potential increase in total produced biomethane of 36 – 39 %, with no significant adverse effects. Wood resin residue yielded 45 – 50 m3 of biomethane per tonne, which exhibits a good potential for biomethane production. If used for biomethane production in pulp and paper wastewater treatment, the valorisation value of the wood resin residue is between 54,500 € and 94,000 €, which makes the presented treatment also an economically viable option.
Found in: osebi
Keywords: Anaerobic digestion, biomethane production, wood resin residue
Published: 11.03.2020; Views: 2442; Downloads: 0
.pdf Fulltext (666,01 KB)

Prenova montažnega procesa v podjetju Agromehanika Kranj
Martin Hočevar, 2020, undergraduate thesis

Abstract: Podjetje Agromehanika v celoti prenavlja poslovne procese, v diplomskem delu pa smo se v okviru prenove proizvodnih procesov omejili na prenovo montažnega procesa. Podjetje se občasno srečuje s problemom predolgih dobavnih rokov, zato smo si zastavili ambiciozen cilj: skrajšati čas montaže za 30 %. Proučili smo teoretična dognanja, nato pa naredili analizo obstoječega stanja: izmerili in narisali velikost montažne delavnice, popisali potrebno opremo ter ugotovili razpoložljivo število montažnih delavcev pri obstoječem načinu montaže. Pridobili smo kosovnico za izbrani izdelek, potem pa merili čase posameznih operacij ter narisali in opisali zaporedje izvajanja le-teh. Sledilo je načrtovanje prenove montažnega procesa za izbrani proizvod. Projekt prenove montažnega procesa smo vodili s precedenčnim diagramom. Za oskrbo z vijačnim materialom smo uvedli sistem KANBAN. Ločili smo logistično in montažno funkcijo. Odločili smo se za ravno linijsko postavitev in uvedli izboljšave v procesu montaže. Rezultat prenove montažnega procesa za izbrani proizvod je bil znižanje časa montaže za 41,57 % v pilotni liniji brez dodatnih investicij in 64,25 % v predvideni liniji z dodatnimi investicijami. Prihranek časa pri delu montažnih delavcev smo ovrednotili tudi finančno. Prenova montažnega procesa podjetju zagotavlja končne proizvode, razpoložljive v krajšem času kot doslej. S tem je skrajšan dobavni rok, ki je kupcem ključnega pomena v času, ko pridobijo državne subvencije za razvoj kmetijstva, ki jih morajo črpati v predvidenem roku. Zato ima prenova montažnega procesa za podjetje multiplikativen pozitiven učinek, s katerim obdrži obstoječe stranke, s krajšimi dobavnimi časi pa morda pridobi tudi nove.
Found in: osebi
Keywords: prenova, poslovni proces, proizvodni proces, montažni proces, vitka proizvodnja, sistem KANBAN, »ravno pravočasno«, linija, operacija, precedenčni diagram
Published: 28.10.2020; Views: 2120; Downloads: 85
.pdf Fulltext (1,42 MB)

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