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1. Simulated Diurnal Pulses in Hurricane Dorian (2019)

   https://doi.org/10.1175/MWR-D-23-0049.1  

   Piersante, Jeremiah O. ; Corbosiero, Kristen L. ; Fovell, Robert G. ( November 2023 , Monthly Weather Review)

   Radially outward-propagating, diurnal pulses in tropical cyclones (TCs) are associated with TC intensity and structural changes. The pulses are observed to feature either cloud-top cooling or warming, so-called cooling pulses (CPs) or warming pulses (WPs), respectively, with CPs posing a greater risk for hazardous weather because they often assume characteristics of tropical squall lines. The current study evaluates the characteristics and origins of simulated CPs using various convection-permitting Weather Research and Forecasting (WRF) Model simulations of Hurricane Dorian (2019), which featured several CPs and WPs over the tropical Atlantic Ocean. CP evolution is tested against choice of microphysics parameterization, whereby the Thompson and Morrison schemes present distinct mechanisms for CP creation and propagation. Specifically, the Thompson CP is convectively coupled and propagates outward with a rainband within 100–300 km of the storm center. The Morrison CP is restricted to the cirrus canopy and propagates radially outward in the upper-level outflow layer, unassociated with any rainband, within 200–600 km of the storm center. The Thompson simulation better represents the observations of this particular event, but it is speculated that CPs in nature can resemble characteristics from either MP scheme. It is, therefore, necessary to evaluate pulses beyond just brightness temperature (e.g., reflectivity, rain rate), especially within simulations where full fields are available.

   Tropical cyclone size and structure are influenced by the time of day. Identifying and predicting such characteristics is critical for evaluating hazardous weather risk of storms close to land. While satellite observations are valuable for recognizing daily fluctuations of tropical cyclone clouds as seen from space, they do not reliably capture what occurs at the surface. To investigate the relationship between upper-level cloud oscillations and rainbands, this study analyzes simulations of a major hurricane along the coast of Florida. The results show that rainbands are not always tied to changes in cloud tops, suggesting multiple pathways toward the daily oscillation of upper-level tropical cyclone clouds.

    

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2. Photoluminescence of Cis-Polyacetylene Semiconductor Material

   https://doi.org/10.3390/app12062830  

   Keya, Kamrun N. ; Jabed, Mohammed A. ; Xia, Wenjie ; Kilin, Dmitri ( March 2022 , Applied Sciences)

   Photoluminescence (PL) is one of the key experimental characterizations of optoelectronic materials, including conjugated polymers (CPs). In this study, a simplified model of an undoped cis-polyacetylene (cis-PA) oligomer was selected and used to explain the mechanism of photoluminescence (PL) of the CPs. Using a combination of the ab initio electronic structure and a time-dependent density matrix methodology, the photo-induced time-dependent excited state dynamics were computed. We explored the phonon-induced relaxation of the photoexcited state for a single oligomer of cis-PA. Here, the dissipative Redfield equation of the motion was used to compute the dissipative excited state dynamics of electronic degrees of freedom. This equation used the nonadiabatic couplings as parameters. The computed excited state dynamics showed that the relaxation rate of the electron is faster than the relaxation rate of the hole. The dissipative excited-state dynamics were combined with radiative recombination channels to predict the PL spectrum. The simulated results showed that the absorption and emission spectra both have a similar transition. The main result is that the computed PL spectrum demonstrates two mechanisms of light emission originating from (i) the inter-band transitions, corresponding to the same range of transition energies as the absorption spectrum and (ii) intra-band transitions not available in the absorption spectra. However, the dissipative Redfield equation of the motion was used to compute the electronic degrees of freedom of the nonadiabatic couplings, which helped to process the time propagation of the excited dynamic state. This excited dynamic state shows that the relaxation rate of the electron is faster than the relaxation rate of the hole, which can be used for improving organic semiconductor materials for photovoltaic and LED applications. 

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3. Uneven crystallization of lead halide perovskite in the carbon-electrode based, low-temperature mesoscopic perovskite solar cells

   https://doi.org/10.1063/5.0120065  

   Rong, Qing ; Guo, De’en ; Ma, Jiao ; Lin, Siyuan ; Huang, Han ; Kong, Deming ; Gao, Yongli ; Zhou, Conghua ( November 2022 , Journal of Applied Physics)

   Crystallization of perovskite is monitored in carbon-electrode based, low-temperature, mesoscopic perovskite solar cells. Crystallographic and morphological properties of the perovskite are examined through changes in the film thickness of carbon-electrode or the volume of perovskite precursor. It is observed that, when a relatively thin carbon-electrode or large volume of perovskite precursor is used, perovskite crystallites mainly form on the device surface, leaving the bottom part of the device un-wetted. However, if a thicker carbon-electrode or less perovskite precursor is used, crystallization could be seen in the whole porous skeleton, and relative uniform distribution of perovskite crystallites is achieved. As such, uneven crystallization is observed. Such behavior is due to solvent evaporation on the surface, which facilitates nucleation processes on the surface, while retards crystallization on the bottom due to the Ostwald ripening effect. Charge transfer/recombination processes and photo-to-electric power conversion properties are studied. As expected, uneven crystallization results in retarded charge transfer and increased risk of recombination, and poor power conversion efficiency, for example, ∼3%. In contrast, uniform crystallization accelerates charge transfer and reduces recombination risk, and increases the efficiency to higher than 11% (AM1.5G, 100 mW/cm2). 

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4. HISDAC-ES: historical settlement data compilation for Spain (1900–2020)

   https://doi.org/10.5194/essd-15-4713-2023  

   Uhl, Johannes H. ; Royé, Dominic ; Burghardt, Keith ; Aldrey Vázquez, José A. ; Borobio Sanchiz, Manuel ; Leyk, Stefan ( January 2023 , Earth System Science Data)

   Abstract. Multi-temporal measurements quantifying the changes to the Earth's surface are critical for understanding many natural, anthropogenic, and social processes. Researchers typically use remotely sensed Earth observation data to quantify and characterize such changes in land use and land cover (LULC). However, such data sources are limited in their availability prior to the 1980s. While an observational window of 40 to 50 years is sufficient to study most recent LULC changes, processes such as urbanization, land development, and the evolution of urban and coupled nature–human systems often operate over longer time periods covering several decades or even centuries. Thus, to quantify and better understand such processes, alternative historical–geospatial data sources are required that extend farther back in time. However, such data are rare, and processing is labor-intensive, often involving manual work. To overcome the resulting lack in quantitative knowledge of urban systems and the built environment prior to the 1980s, we leverage cadastral data with rich thematic property attribution, such as building usage and construction year. We scraped, harmonized, and processed over 12 000 000 building footprints including construction years to create a multi-faceted series of gridded surfaces, describing the evolution of human settlements in Spain from 1900 to 2020, at 100 m spatial and 5-year temporal resolution. These surfaces include measures of building density, built-up intensity, and built-up land use. We evaluated our data against a variety of data sources including remotely sensed human settlement data and land cover data, model-based historical land use depictions, and historical maps and historical aerial imagery and find high levels of agreement. This new data product, the Historical Settlement Data Compilation for Spain (HISDAC-ES), is publicly available (https://doi.org/10.6084/m9.figshare.22009643, Uhl et al., 2023a) and represents a rich source for quantitative, long-term analyses of the built environment and related processes over large spatial and temporal extents and at fine resolutions.

    

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5. Real-time mapping of nanopore raw signals

   https://doi.org/10.1093/bioinformatics/btab264  

   Zhang, Haowen ; Li, Haoran ; Jain, Chirag ; Cheng, Haoyu ; Au, Kin Fai ; Li, Heng ; Aluru, Srinivas ( July 2021 , Bioinformatics)

   Abstract Motivation Oxford Nanopore Technologies sequencing devices support adaptive sequencing, in which undesired reads can be ejected from a pore in real time. This feature allows targeted sequencing aided by computational methods for mapping partial reads, rather than complex library preparation protocols. However, existing mapping methods either require a computationally expensive base-calling procedure before using aligners to map partial reads or work well only on small genomes. Results In this work, we present a new streaming method that can map nanopore raw signals for real-time selective sequencing. Rather than converting read signals to bases, we propose to convert reference genomes to signals and fully operate in the signal space. Our method features a new way to index reference genomes using k-d trees, a novel seed selection strategy and a seed chaining algorithm tailored toward the current signal characteristics. We implemented the method as a tool Sigmap. Then we evaluated it on both simulated and real data and compared it to the state-of-the-art nanopore raw signal mapper Uncalled. Our results show that Sigmap yields comparable performance on mapping yeast simulated raw signals, and better mapping accuracy on mapping yeast real raw signals with a 4.4× speedup. Moreover, our method performed well on mapping raw signals to genomes of size >100 Mbp and correctly mapped 11.49% more real raw signals of green algae, which leads to a significantly higher F1-score (0.9354 versus 0.8660). Availability and implementation Sigmap code is accessible at https://github.com/haowenz/sigmap. Supplementary information Supplementary data are available at Bioinformatics online. 

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