Repozitorij Univerze v Novi Gorici

Iskanje po repozitoriju
A+ | A- | Pomoč | SLO | ENG

Iskalni niz: išči po
išči po
išči po
išči po
* po starem in bolonjskem študiju

Opcije:
  Ponastavi


1 - 10 / 94
Na začetekNa prejšnjo stran12345678910Na naslednjo stranNa konec
1.
Atmospheric black carbon in the metropolitan area of La Paz and El Alto, Bolivia: concentration levels and emission sources
Valeria Mardoñez-Balderrama, Griša Močnik, Marco Pandolfi, Robin L. Modini, Fernando Velarde, Laura Renzi, Angela Marinoni, Jean-Luc Jaffrezo, Isabel Moreno R., Diego Aliaga, 2024, izvirni znanstveni članek

Opis: Abstract. Black carbon (BC) is a major component of submicron particulate matter (PM), with significant health and climate impacts. Many cities in emerging countries lack comprehensive knowledge about BC emissions and exposure levels. This study investigates BC concentration levels, identifies its emission sources, and characterizes the optical properties of BC at urban background sites of the two largest high-altitude Bolivian cities: La Paz (LP) (3600 m above sea level) and El Alto (EA) (4050 m a.s.l.), where atmospheric oxygen levels and intense radiation may affect BC production. The study relies on concurrent measurements of equivalent black carbon (eBC), elemental carbon (EC), and refractory black carbon (rBC) and their comparison with analogous data collected at the nearby Chacaltaya Global Atmosphere Watch Station (5240 m a.s.l). The performance of two independent source apportionment techniques was compared: a bilinear model and a least-squares multilinear regression (MLR). Maximum eBC concentrations were observed during the local dry season (LP: eBC = 1.5 ± 1.6 µg m−3; EA: 1.9±2.0 µg m−3). While eBC concentrations are lower at the mountain station, daily transport from urban areas is evident. Average mass absorption cross sections of 6.6–8.2 m2 g−1 were found in the urban area at 637 nm. Both source apportionment methods exhibited a reasonable level of agreement in the contribution of biomass burning (BB) to absorption. The MLR method allowed the estimation of the contribution and the source-specific optical properties for multiple sources, including open waste burning.
Ključne besede: black carbon, aerosol absorption, source apportionment, mass absorption cross-section
Objavljeno v RUNG: 29.10.2024; Ogledov: 141; Prenosov: 0
.pdf Celotno besedilo (3,35 MB)
Gradivo ima več datotek! Več...

2.
Analiza vpliva izgorevanja lesne biomase na koncentracije onesnaževal v zunanjem zraku : magistrsko delo
Irena Kranjc, 2024, magistrsko delo

Opis: Les je v Sloveniji tradicionalno pomemben obnovljiv vir za ogrevanje v gospodinjstvih. Pri tem nastajajo delci, ki imajo negativen vpliv na zdravje. Z namenom določitve vpliva izgorevanja lesne biomase na raven onesnaženja z delci smo na več lokacijah v obdobju med 2016 in 2021 izvedli vzorčenje delcev PM10 in njihovo kemijsko analizo. Analiza je bila usmerjene v parametre povezane z izgorevanje lesne biomase: levoglukozan, manozan, galaktozan, organski in elementarni ogljik, kalij in benzo [a] piren. V obdobju med 2016 in 2021 so bile v januarju in februarju najvišje koncentracije izmerjene v letu 2017, najnižje pa v letu 2021. Razlike so povezane predvsem z različnimi meteorološkimi razmerami. Koncentracije delcev PM10, kot tudi koncentracije in deleži levoglukozana, kalija in benzo [a] pirena so bile v zimskih mesecih višje, kot v poletnem obdobju. Izjema sta le organski in elementarni ogljik, pri katerih je koncentracija v zimskem času višja, kot v poletnem, njuna deleža v delcih PM10 pa se preko leta bistveno ne spreminjata. Na podlagi razmerja med levoglukozanom in manozanom smo ugotovili, da se v Sloveniji za ogrevanje uporablja tako mehek, kot trd les. Delež delcev, ki jih lahko pripišemo izgorevanju lesne biomase je bil v januarju in februarju v obravnavnem obdobju visok – najvišji je bil v Novem mestu (52 % ± 5 %), najnižji pa v Mariboru (21 % ± 6 %).
Ključne besede: delci PM10, levoglukozan, manozan, izgorevanje lesne biomase, raven onesnaženja z delci, magistrske naloge
Objavljeno v RUNG: 26.09.2024; Ogledov: 406; Prenosov: 7
.pdf Celotno besedilo (2,72 MB)

3.
4.
Dust, convection, winds and waves : the 2022 NASA CPEX-CV campaign
Edward P. Nowottnick, Angela K. Rowe, Amin R. Nehrir, Jonathan A. Zawislak, Aaron J. Piña, Will McCarty, Rory A. Barton-Grimley, Kristopher M. Bedka, J. Ryan Bennett, Griša Močnik, 2024, izvirni znanstveni članek

Opis: The NASA Convective Processes Experiment - Cabo Verde (CPEX-CV) field campaign took place in September 2022 out of Sal Island, Cabo Verde. A unique payload aboard the NASA DC-8 aircraft equipped with advanced remote sensing and in situ instrumentation, in conjunction with radiosonde launches and satellite observations, allowed CPEX-CV to target the coupling between atmospheric dynamics, marine boundary layer properties, convection, and the dust-laden Saharan Air Layer in the data-sparse tropical East Atlantic region. CPEX-CV provided measurements of African Easterly Wave environments, diurnal cycle impacts on convective lifecycle, and several Saharan dust outbreaks, including the highest dust optical depth observed by the DC-8 interacting with what would become Tropical Storm Hermine. Preliminary results from CPEX-CV underscore the positive impact of dedicated tropical East Atlantic observations on downstream forecast skill, including sampling environmental forcings impacting the development of several non-developing and developing convective systems such as Hurricanes Fiona and Ian. Combined airborne radar, lidar, and radiometer measurements uniquely provide near-storm environments associated with convection on various spatiotemporal scales and, with in situ observations, insights into controls on Saharan dust properties with transport. The DC-8 also collaborated with the European Space Agency to perform coordinated validation flights under the Aeolus spaceborne wind lidar and over the Mindelo ground site, highlighting the enhanced sampling potential through partnership opportunities. CPEX-CV engaged in professional development through dedicated team building exercises that equipped the team with a cohesive approach for targeting CPEX-CV science objectives and promoted active participation of scientists across all career stages.
Ključne besede: convective processesž, Saharan dust, aerosol, airborne measurements
Objavljeno v RUNG: 09.09.2024; Ogledov: 400; Prenosov: 5
.pdf Celotno besedilo (6,60 MB)
Gradivo ima več datotek! Več...

5.
6.
7.
8.
On-flight intercomparison of three miniature aerosol absorption sensors using unmanned aerial systems (UASs)
Michael Pikridas, Spiros Bezantakos, Griša Močnik, Christos Keleshis, Fred Brechtel, Iasonas Stavroulas, Gregoris Demetriades, Panayiota Antoniou, Panagiotis Vouterakos, Marios Argyrides, 2019, izvirni znanstveni članek

Opis: The present study investigates and compares the ground and in-flight performance of three miniaturized aerosol absorption sensors integrated on board small-sized Unmanned Aerial Systems (UASs). These sensors were evaluated during two contrasted field campaigns performed at an urban site, impacted mainly by local traffic and domestic wood burning sources (Athens, Greece), and at a remote regional background site, impacted by long-range transported sources including dust (Cyprus Atmospheric Observatory, Agia Marina Xyliatou, Cyprus). The miniaturized sensors were first intercompared at the ground-level against two commercially available instruments used as a reference. The measured signal of the miniaturized sensors was converted into the absorption coefficient and equivalent black carbon concentration (eBC). When applicable, signal saturation corrections were applied, following the suggestions of the manufacturers. The aerosol absorption sensors exhibited similar behavior against the reference instruments during the two campaigns, despite the diversity of the aerosol origin, chemical composition, sources, and concentration levels. The deviation from the reference during both campaigns concerning (eBC) mass was less than 8 %, while for the absorption coefficient it was at least 15 %. This indicates that those sensors that report black carbon mass are tuned and corrected to measure eBC more accurately than the absorption coefficient. The overall potential use of miniature aerosol absorption sensors on board small UASs is also illustrated. UAS-based absorption measurements were used to investigate the vertical distribution of eBC over Athens up to 1 km above sea level during January 2016, exceeding the top of the planetary boundary layer (PBL). Our results reveal a heterogeneous boundary layer concentration of absorbing aerosol within the PBL intensified in the early morning hours due to the concurrent peak traffic emissions at ground-level and the fast development of the boundary layer. After the full development of the PBL, homogenous concentrations are observed from 100 m a.g.l. to the PBL top.
Ključne besede: Unmanned Aerial Systems, Cyprus Atmospheric Observatory, eBC, vertical profiling, microaethalometer
Objavljeno v RUNG: 13.05.2024; Ogledov: 843; Prenosov: 3
URL Povezava na datoteko

9.
A method for quantification of mineral dust in air based on optical absorption of particles concentrated by a virtual impactor and a device performing the said method : SI3783336 (T1), 2024-02-29
Luka Drinovec, Griša Močnik, Iasonas Stavroulas, Spiros Bezantakos, Michael Pikridas, Florin Unga, Jean Sciare, 2024, patent

Opis: The present invention belongs to the field of devices and methods for measurement of particle concentration, more precisely to the field of devices and methods for quantification of particles based on their physical characteristics, especially with the use of optical means. The invention relates to a method for determination of ambient mineral dust concentration based on optical absorption of particles concentrated by a virtual impactor as well as a device performing the said method. The method comprises the following steps:- Sampling air samples with particle size smaller than 1 µm (PM1) and sampling air samples with particle size up to 10 µm;- Concentrating the samples with particle sizes up to 10 µm with a virtual impactor;- Measuring optical absorption of collected samples at least one wavelength from UV to IR spectre, preferably from 370 to 950 nm, most preferably at 370 nm;- Subtracting the absorption of the samples with particle size smaller than 1 µm from the absorption of the sample concentrated by the virtual impactor.
Ključne besede: dust, black carbon, aerosols
Objavljeno v RUNG: 24.04.2024; Ogledov: 1622; Prenosov: 7
URL Povezava na datoteko
Gradivo ima več datotek! Več...

10.
Zakaj Slovenije ne zanimajo polarne raziskave? : Vroči mikrofon
2024, radijska ali televizijska oddaja, podkast, intervju, novinarska konferenca

Ključne besede: Antarktični sporazum, polarne raziskave, podnebne spremembe, raziskovalci
Objavljeno v RUNG: 24.04.2024; Ogledov: 1673; Prenosov: 4
URL Povezava na datoteko

Iskanje izvedeno v 0.04 sek.
Na vrh