1. Orography‐induced atmospheric small‐scale waves during Bora using lidar observations and numerical simulationsLonglong Wang, Marija Bervida, Samo Stanič, Luca Patruno, Wenjun Dong, Daru Chen, 2025, original scientific article Abstract: Atmospheric flow of cold air over mountain barriers in the Alpine region often gives a rise to
strong and gusty downslope wind, Bora. Such flows are often accompanied by atmospheric waves, generated by
the flow passing an elevated barrier. Such phenomenon can only rarely be observed visually and can generally
not be reliably reproduced by simplified numerical models. Orography‐induced atmospheric small‐scale waves
were experimentally observed on 25 January 2019 during a Bora outbreak in the Vipava valley, Slovenia. A
vertical scanning lidar, positioned at the lee side of the Trnovski gozd mountain and a fixed direction lidar, 5 km
apart in the Vipava valley, were used to characterize the density field. The flow exhibited a stationary jump after
the mountain ridge and, superimposed, an oscillatory flow pattern. High‐resolution numerical simulations
complemented the observations and supported experimental results on the flow periodicity but also on the wave
structures and propagation characteristics.
Keywords: Bora, wind, lidar, numerical simulation, Vipava valley, atmospheric waves
Published in RUNG: 18.02.2025; Views: 615; Downloads: 6
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2. Gaia22dkvLb : a microlensing planet potentially accessible to radial-velocity characterizationZexuan Wu, Subo Dong, Tuan Yi, Zhuokai Liu, Kareem El-Badry, Andrew Gould, Łukasz Wyrzykowski, K. A. Rybicki, Mateusz Bronikowski, 2024, original scientific article Abstract: We report discovering an exoplanet from following up a microlensing event alerted by Gaia. The event Gaia22dkv is toward a disk source rather than the traditional bulge microlensing fields. Our primary analysis yields a Jovian planet with M_p = 0.59 (+0.15, -0.05) M_J at a projected orbital separation r_perpendicular = 1.4 (+0.8, -0.3) au, and the host is a ∼1.1 M⊙ turnoff star at ∼1.3 kpc. At r' ~= 14, the host is far brighter than any previously discovered microlensing planet host, opening up the opportunity to test the microlensing model with radial velocity (RV) observations. RV data can be used to measure the planet's orbital period and eccentricity, and they also enable searching for inner planets of the microlensing cold Jupiter, as expected from the "inner–outer correlation" inferred from Kepler and RV discoveries. Furthermore, we show that Gaia astrometric microlensing will not only allow precise measurements of its angular Einstein radius θ_E but also directly measure the microlens parallax vector and unambiguously break a geometric light-curve degeneracy, leading to the definitive characterization of the lens system.
Keywords: gravitational microlensing exoplanet detection, planetary astrophysics, astrophysics of galaxies, instrumentation astrophysics, methods for astrophysics, solar astrophysics, stellar astrophysics
Published in RUNG: 23.08.2024; Views: 1446; Downloads: 10
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4. Photoexcited charge mobility in quasi two-dimensional polyacetyleneNadiia Pastukhova, Kejun Liu, Renhao Dong, Gvido Bratina, Xinliang Feng, Egon Pavlica, 1894, published scientific conference contribution abstract Abstract: Two-dimensional conjugated polymers (2DCPs) have been described and recognised as crystalline, one- to two-layer polymer nanosheets prepared by 2D covalent polymerization exhibiting strong in-plane π-electron delocalization with two orthogonal directions and weak out-of-plane π-π stacking.[1,2] The extension of polymer dimensionality into two dimensions improves the alignment of individual polymer sheets and overcomes the limitations associated with charge carrier hopping between polymer chains in one-dimensional and crosslinked polymers.[3] Compared to other two-dimensional materials such as graphene or transition metal dichalcogenides, 2DCPs offer a high degree of flexibility in chemical design and are compatible with liquid-based processing methods. Various 2DCPs have been synthesised by surfactant monolayer-assisted interfacial synthesis (SMAIS).[5]
Of particular interest is the photoresponse of these materials due to their tunable properties, such as bandgap and associated wavelength-dependent photoexcitation, which enables a wide range of applications in optoelectronic devices. Using time-of-flight photoconductivity (TOF-PC) measurements [4], we investigate the charge transport properties of 2D polyacetylene prepared by SMAIS method. We preform TOF-PC measurement of 2D polyacetylene using a focused nanosecond pulse laser at 325 nm and electrode separation of 250 µm. From the bias polarity and time duration of the photocurrent, we can determine the polarity, velocity and mobility of photoexcited charge carriers as a function of applied bias voltage and excitation wavelength. Using excitation at 325 m, we observed an electron mobility in the range of 150 cm2 V-1 s-1, which is in the realm of most advances small-molecule single-crystal organic semiconductors and almost an order of magnitude higher than linear polymeric semiconductors.
Keywords: Two-dimensional conjugated polymers, 2DCPs, 2Dpolymers, charge mobility, time-of-flight photoconductivity
Published in RUNG: 29.11.2022; Views: 2634; Downloads: 0
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5. Plasma-enhanced atomic layer deposition of amorphous Ga2O3 for solar-blind photodetectionZe-Yu Fan, Min-Ji Yang, Bo-Yu Fan, Andraž Mavrič, Nadiia Pastukhova, Matjaž Valant, Bo-Lin Li, Kuang Feng, Dong-Liang Liu, Guang-Wei Deng, Qiang Zhou, Yan-Bo Li, 2022, original scientific article Abstract: Wide-bandgap gallium oxide (Ga2O3) is one of the most promising semiconductor materials for solar-blind (200 nm–280 nm) photodetection. In its amorphous form, a-Ga2O3 maintains its intrinsic optoelectronic properties while can be prepared at a low growth temperature, thus is compatible with Si integrated circuits (ICs) technology. Herein, the a-Ga2O3 film is directly deposited on pre-fabricated Au interdigital electrodes by plasma enhanced atomic layer deposition (PE-ALD) at a growth temperature of 250 °C. The stoichiometric a-Ga2O3 thin film with a low defect density is achieved owing to the mild PE-ALD condition. As a result, the fabricated Au/a-Ga2O3/Au photodetector shows a fast time response, high responsivity, and excellent wavelength selectivity for solar-blind photodetection. Furthermore, an ultra-thin MgO layer is deposited by PE-ALD to passivate the Au/a-Ga2O3/Au interface, resulting in the responsivity of 788 A/W (under 254 nm at 10 V), a 250-nm-to-400-nm rejection ratio of 9.2×103, and the rise time and the decay time of 32 ms and 6 ms, respectively. These results demonstrate that the a-Ga2O3 film grown by PE-ALD is a promising candidate for high-performance solar-blind photodetection and potentially can be integrated with Si ICs for commercial production.
Keywords: Amorphous gallium oxide, Passivation layer, Plasma enhanced atomic layer deposition, Responsivity, Solar-blind photodetector
Published in RUNG: 25.10.2022; Views: 2444; Downloads: 0
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6. Chitosan and their derivatives: Antibiofilm drugs against pathogenic bacteriaFazlurrahman Khan, Dong Pham, Sandra Oloketuyi, Panchanathan Manivasagan, Junghwan Oh, Young-Mog Kim, 2020, review article Abstract: Biofilm formed by several pathogenic bacteria results in the development of resistance against antimicrobial compounds. The polymeric materials present in the biofilm architecture hinder the entry of antimicrobial compounds through the surface of bacterial cells which are embedded as well as enclosed beneath the biofilm matrix. Recent and past studies explored the alternative approaches to inhibit the formation of biofilm by different agents isolated from plants, animals, and microbes. Among these agents, chitosan and its derivatives have got more attention due to their properties such as biodegradability, biocompatibility, non-allergenic and non-toxicity. Recent researches have focused on employing chitosan and its derivatives as effective agents to inhibit biofilm formation and attenuate virulence properties by various pathogenic bacteria. Such antibiofilm activity of chitosan and its derivatives can be further enhanced by conjugation with a wide range of bioactive compounds. The present review describes the antibiofilm properties of chitosan and its derivatives against the pathogenic bacteria. This review also summarizes the mechanisms of biofilm inhibition exhibited by these molecules. The knowledge of the antibiofilm activities of chitosan and its derivatives as well as their underlying mechanisms provides essential insights for widening their applications in the future.
Keywords: Antibiofilm, Biofilm inhibition, Chitosan, Chitosan derivatives, Pathogenic bacteria
Published in RUNG: 14.01.2021; Views: 4056; Downloads: 0
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7. Immobilization of Redox-Responsive Switches Into Calixarene-Based Covalent Organic Polymers for Environmental ApplicationsTina Skorjanc, Dinesh Shetty, Sudhir Kumar Sharma, Jesus Raya, Dong Suk Han, Ramesh Jagannathan, Ali Trabolsi, 2017, unpublished conference contribution Keywords: calixarene, redox switches, dye adsorption
Published in RUNG: 03.09.2020; Views: 3717; Downloads: 0
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8. Morphological diversity in nanoporous covalent organic materials derived from viologen and pyreneGobinda Das, Tina Škorjanc, Sudhir Kumar Sharma, Thirumurugan Prakasam, Carlos Platas-Iglesias, Dong Suk Han, Jesus Raya, John-Carl Olsen, Ramesh Jagannathan, Ali Trabolsi, original scientific article Keywords: covalent organic polymers, hollow tube, polymers, porous materials, iodine capture
Published in RUNG: 02.09.2020; Views: 4064; Downloads: 0
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10. Flexible organic/inorganic hybrid solar cells based on conjugated polymer and ZnO nanorod arrayFei Tong, Kyusang Kim, Daniel Martinez, Resham Thapa, Ayayi Ahyi, John Williams, Dong-Joo Kim, Sungkoo Lee, Eunhee Lim, Kyeong K Lee, Minseo ParK, 2012, original scientific article Keywords: organic/inorganic hybrid solar cells, conjugated polymer, ZnO nanorod array
Published in RUNG: 16.01.2017; Views: 6101; Downloads: 0
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