1. Morphological diversity in nanoporous covalent organic materials derived from viologen and pyreneAli Trabolsi, Ramesh Jagannathan, John-Carl Olsen, Jesus Raya, Dong Suk Han, Carlos Platas-Iglesias, Thirumurugan Prakasam, Sudhir Kumar Sharma, Tina Škorjanc, Gobinda Das, izvirni znanstveni članek Najdeno v: osebi
Ključne besede: covalent organic polymers, hollow tube, polymers, porous materials, iodine capture
Objavljeno: 02.09.2020; Ogledov: 1832; Prenosov: 0
 Polno besedilo (2,00 MB) |
2. Remarkably efficient removal of toxic bromate from drinking water with a porphyrin–viologen covalent organic frameworkAli Trabolsi, Mark Anthony Olson, Gobinda Das, Jesus Raya, Liaqat Ali, Felipe Gandara, Dinesh Shetty, Tina Skorjanc, 2020, izvirni znanstveni članek Najdeno v: osebi
Ključne besede: bromate, covalent organic frameworks, Zincke reaction, porphyrin, water purification, viologen
Objavljeno: 02.09.2020; Ogledov: 1829; Prenosov: 0
Polno besedilo (777,01 KB) |
3. Fast and efficient removal of paraquat in water by porous polycalix [n] arenes (n= 4, 6, and 8)Ali Trabolsi, Jesus Raya, Zouhair Asfari, Bikash Garai, Tina Škorjanc, Sandra Boutros, Dinesh Shetty, 2020, izvirni znanstveni članek Najdeno v: osebi
Ključne besede: paraquat, adsorption, calixarene, covalent polymers, water purification
Objavljeno: 02.09.2020; Ogledov: 1761; Prenosov: 0
Polno besedilo (1,35 MB) |
4. Rapid and Efficient Removal of Perfluorooctanoic Acid from Water with Fluorine-Rich Calixarene-Based Porous PolymersAli Trabolsi, Ozgur Yazaydin, Serdal Kirmizialntin, Mark Anthony Olson, Zouhair Asfari, Jesus Raya, Liaqat Ali, Turan Selman Erkal, Tina Škorjanc, Ilma Jahovic, Dinesh Shetty, 2020, izvirni znanstveni članek Najdeno v: osebi
Ključne besede: Perfluorooctanoic acid, calixarene, adsorption, covalent polymers
Objavljeno: 02.09.2020; Ogledov: 1788; Prenosov: 0
Polno besedilo (16,88 MB) |
5. Immobilization of Redox-Responsive Switches Into Calixarene-Based Covalent Organic Polymers for Environmental ApplicationsAli Trabolsi, Ramesh Jagannathan, Dong Suk Han, Jesus Raya, Sudhir Kumar Sharma, Dinesh Shetty, Tina Skorjanc, 2017, prispevek na konferenci brez natisa Najdeno v: osebi
Ključne besede: calixarene, redox switches, dye adsorption
Objavljeno: 03.09.2020; Ogledov: 1695; Prenosov: 0
Polno besedilo (7,64 MB) |
6. Aircraft vertical profiles during summertime regional and Saharan dust scenarios over the north-western Mediterranean basin: aerosol optical and physical propertiesJesus Yus-Díez, Marina Ealo, Marco Pandolfi, Noemi Perez, Gloria Titos, Griša Močnik, Xavier Querol, A. Alastuey, 2021, izvirni znanstveni članek Opis: Accurate measurements of the horizontal and vertical distribution of atmospheric aerosol particle optical properties are key for a better understanding of their impact on the climate. Here we present the results of a measurement campaign based on instrumented flights over north-eastern Spain. We measured vertical profiles of size-segregated atmospheric particulate matter (PM) mass concentrations and multi-wavelength scattering and absorption coefficients in the western Mediterranean basin (WMB). The campaign took place during typical summer conditions, characterized by the development of a vertical multi-layer structure, under both summer regional pollution episodes (REGs) and Saharan dust events (SDEs). REG patterns in the region form under high insolation and scarce precipitation in summer, favouring layering of highly aged fine-PM strata in the lower few kma.s.l.
The REG scenario prevailed during the entire measurement campaign. Additionally, African dust outbreaks and plumes from northern African wildfires influenced the study area. The vertical profiles of climate-relevant intensive optical parameters such as single-scattering albedo (SSA); the asymmetry parameter (g); scattering, absorption and SSA Ångström exponents (SAE, AAE and SSAAE); and PM mass scattering and absorption cross sections (MSC and MAC) were derived from the measurements. Moreover, we compared the aircraft measurements with those performed at two GAW–ACTRIS (Global Atmosphere Watch–Aerosol, Clouds and Trace Gases) surface measurement stations located in north-eastern Spain, namely Montseny (MSY; regional background) and Montsec d'Ares (MSA; remote site).
Airborne in situ measurements and ceilometer ground-based remote measurements identified aerosol air masses at altitudes up to more than 3.5 kma.s.l.
The vertical profiles of the optical properties markedly changed according to the prevailing atmospheric scenarios. During SDE the SAE was low along the profiles, reaching values < 1.0 in the dust layers. Correspondingly, SSAAE was negative, and AAE reached values up to 2.0–2.5, as a consequence of the UV absorption increased by the presence of the coarse dust particles. During REG, the SAE increased to > 2.0, and the asymmetry parameter g was rather low (0.5–0.6) due to the prevalence of fine PM, which was characterized by an AAE close to 1.0, suggesting a fossil fuel combustion origin. During REG, some of the layers featured larger AAE (> 1.5), relatively low SSA at 525 nm (< 0.85) and high MSC (> 9 m2 g−1) and were associated with the influence of PM from wildfires. Overall, the SSA and MSC near the ground ranged around 0.85 and 3 m2 g−1, respectively, and increased at higher altitudes, reaching values above 0.95 and up to 9 m2 g−1. The PM, MSC and MAC were on average larger during REG compared to SDE due to the larger scattering and absorption efficiency of fine PM compared with dust. The SSA and MSC had quite similar vertical profiles and often both increased with height indicating the progressive shift toward PM with a larger scattering efficiency with altitude.
This study contributes to our understanding of regional-aerosol vertical distribution and optical properties in the WMB, and the results will be useful for improving future climate projections and remote sensing or satellite retrieval algorithms.
Najdeno v: osebi
Ključne besede: aerosol, climate change, Saharan dust, black carbon, aerosol absorption, aerosol scattering
Objavljeno: 14.01.2021; Ogledov: 1663; Prenosov: 0
Polno besedilo (10,82 MB) |
7. Determination of the multiple-scattering correction factor and its cross-sensitivity to scattering and wavelength dependence for different AE33 Aethalometer filter tapesAndres Alastuey, Griša Močnik, Vera Bernardoni, Jesús Yus-Díez, Davide Ciniglia, Matic Ivančič, Xavier Querol, Noemí Perez, Cristina Reche, Martin Rigler, Roberta Vecchi, Sara Valentini, Marco Pandolfi, 2021, izvirni znanstveni članek Opis: Providing reliable observations of aerosol particles' absorption properties at spatial and temporal resolutions suited to climate models is of utter importance to better understand the effects that atmospheric particles have on climate. Nowadays, one of the instruments most widely used in international monitoring networks for in situ surface measurements of light absorption properties of atmospheric aerosol particles is the multi-wavelength dual-spot Aethalometer, AE33. The AE33 derives the absorption coefficients of aerosol particles at seven different wavelengths from the measurements of the optical attenuation of light through a filter where particles are continuously collected. An accurate determination of the absorption coefficients from the AE33 instrument relies on the quantification of the non-linear processes related to the sample collection on the filter. The multiple-scattering correction factor (C), which depends on the filter tape used and on the optical properties of the collected particles, is the parameter with both the greatest uncertainty and the greatest impact on the absorption coefficients derived from the AE33 measurements.
Here we present an in-depth analysis of the AE33 multiple-scattering correction factor C and its wavelength dependence for two different and widely used filter tapes, namely the old, and most referenced, TFE-coated glass, or M8020, filter tape and the currently, and most widely used, M8060 filter tape. For performing this analysis, we compared the attenuation measurements from AE33 with the absorption coefficients measured with different filter-based techniques. On-line co-located multi-angle absorption photometer (MAAP) measurements and off-line PP_UniMI polar photometer measurements were employed as reference absorption measurements for this work. To this aim, we used data from three different measurement stations located in the north-east of Spain, namely an urban background station (Barcelona, BCN), a regional background station (Montseny, MSY) and a mountaintop station (Montsec d'Ares, MSA). The median C values (at 637 nm) measured at the three stations ranged between 2.29 (at BCN and MSY, lowest 5th percentile of 1.97 and highest 95th percentile of 2.68) and 2.51 (at MSA, lowest 5th percentile of 2.06 and highest 95th percentile of 3.06). The analysis of the cross-sensitivity to scattering, for the two filter tapes considered here, revealed a large increase in the C factor when the single-scattering albedo (SSA) of the collected particles was above a given threshold, up to a 3-fold increase above the average C values. The SSA threshold appeared to be site dependent and ranged between 0.90 to 0.95 for the stations considered in the study. The results of the cross-sensitivity to scattering displayed a fitted constant multiple-scattering parameter, Cf, of 2.21 and 1.96, and a cross-sensitivity factor, ms, of 1.8 % and 3.4 % for the MSY and MSA stations, respectively, for the TFE-coated glass filter tape. For the M8060 filter tape, Cf values of 2.50, 1.96 and 1.82 and ms values of 1.6 %, 3.0 % and 4.9 % for the BCN, MSY and MSA stations, respectively, were obtained. SSA variations also influenced the spectral dependence of C, which showed an increase with wavelength when SSA was above the site-dependent threshold. Below the SSA threshold, no statistically significant dependence of C on the wavelength was observed. For the measurement stations considered here, the wavelength dependence of C was to some extent driven by the presence of dust particles during Saharan dust outbreaks that had the potential to increase the SSA above the average values. At the mountaintop station, an omission of the wavelength dependence of the C factor led to an underestimation of the absorption Ångström exponent (AAE) by up to 12 %. Differences in the absorption coefficient determined from AE33 measurements at BCN, MSY and MSA of around 35 %–40 % can be expected when using the site-dependent experimentally obtained C value instead of the nominal C value. Due to the fundamental role that the SSA of the particles collected on the filter tape has in the multiple-scattering parameter C, we present a methodology that allows the recognition of the conditions upon which the use of a constant and wavelength-independent C is feasible.
Najdeno v: osebi
Ključne besede: black carbon, aerosol absorption, filter photometer, artifact
Objavljeno: 01.10.2021; Ogledov: 1168; Prenosov: 0
Polno besedilo (1,76 MB) |
8. Detection of mineral dust concentration in Mediterranean and Central Europe by measuring optical absorption of dust particlesIrena Ježek, Matic Ivančič, Martin Rigler, Asta Gregorič, Balint Alfoldy, Luka Drinovec, JEAN SCIARE, MICHAEL PIKRIDAS, FLORIN UNGA, Andres Alastuey, Marco Pandolfi, Jesus Yus Diez, Griša Močnik, 2020, prispevek na konferenci brez natisa Najdeno v: osebi
Ključne besede: mineral dust, optical absorption, virtual impactor
Objavljeno: 22.11.2021; Ogledov: 1083; Prenosov: 0
Polno besedilo (4,15 MB) |
9. Covalent Organic Framework Based on Azacalix[4]arene for the Efficient Capture of Dialysis Waste ProductsSerdal Kirmizialtin, Jesus Raya, Abdul Khayum Mohammed, Liaqat Ali, Salma Abubakar, Nawavi Naleem, Pascal Simon, Felipe Gándara, Dinesh Shetty, Tina Škorjanc, 2022, izvirni znanstveni članek Najdeno v: osebi
Ključne besede: azacalixarene, covalent organic frameworks, dialysis, uric acid, creatinine, adsorption
Objavljeno: 08.09.2022; Ogledov: 539; Prenosov: 0
Polno besedilo (3,14 MB) |
