| 1. |
- Beal, Jacob, et al.
(author)
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Robust estimation of bacterial cell count from optical density
- 2020
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In: Communications Biology. - : Springer Science and Business Media LLC. - 2399-3642. ; 3:1
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Journal article (peer-reviewed)abstract
- Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data.
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| 2. |
- Garcia, Adriana Alvarado, et al.
(author)
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Fostering HCI Research in, by, and for Latin America
- 2020
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In: Extended Abstracts of the 2020 CHI Conference on Human Factors in Computing Systems, CHI 2020. - New York, NY, USA : Association for Computing Machinery (ACM).
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Conference paper (peer-reviewed)abstract
- Over the last 20 years, the Latin American Human-Computer Interaction (HCI) community has been working to shed light on how the diverse populations in the region are adopting, using, and making sense of computational technologies. Latin America's tense socio-political context, plurality of languages, collectivist culture, and historical relationship with the Global North make it a unique and rich space for HCI research. Considering the growing number of studies about Latin American communities and the emergent efforts to contribute to the HCI literature, we propose to host a SIG meeting at the 2020 ACM CHI conference. Our goal is to consolidate these efforts to better promote HCI research in, by, and for Latin America, by (1) bringing together researchers, practitioners, and students who are interested in engaging with Latin America through their research and practice, (2) envisioning a shared research agenda, and (3) identifying strategies for making its contributions more visible and impactful in the international community.
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| 3. |
- He, Mao Qiang, et al.
(author)
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Phylogenomics, divergence times and notes of orders in Basidiomycota
- 2024
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In: Fungal Diversity. - 1560-2745 .- 1878-9129. ; 126, s. 127-406
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Journal article (peer-reviewed)abstract
- Basidiomycota is one of the major phyla in the fungal tree of life. The outline of Basidiomycota provides essential taxonomic information for researchers and workers in mycology. In this study, we present a time-framed phylogenomic tree with 487 species of Basidiomycota from 127 families, 47 orders, 14 classes and four subphyla; we update the outline of Basidiomycota based on the phylogenomic relationships and the taxonomic studies since 2019; and we provide notes for each order and discuss the history, defining characteristics, evolution, justification of orders, problems, significance, and plates. Our phylogenomic analysis suggests that the subphyla diverged in a time range of 443–490 Myr (million years), classes in a time range of 312–412 Myr, and orders in a time range of 102–361 Myr. Families diverged in a time range of 50–289 Myr, 76–224 Myr, and 62–156 Myr in Agaricomycotina, Pucciniomycotina, and Ustilaginomycotina, respectively. Based on the phylogenomic relationships and divergence times, we propose a new suborder Mycenineae in Agaricales to accommodate Mycenaceae. In the current outline of Basidiomycota, there are four subphyla, 20 classes, 77 orders, 297 families, and 2134 genera accepted. When building a robust taxonomy of Basidiomycota in the genomic era, the generation of molecular phylogenetic data has become relatively easier. Finding phenotypical characters, especially those that can be applied for identification and classification, however, has become increasingly challenging.
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| 4. |
- Huang, Yetian, et al.
(author)
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Free-Space Optics Communications Employing Elliptical-Aperture Multimode Diversity Reception Under Anisotropic Turbulence
- 2022
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In: Journal of Lightwave Technology. - 0733-8724 .- 1558-2213. ; 40:5, s. 1502-1508
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Journal article (peer-reviewed)abstract
- We experimentally demonstrate an elliptical-aperture multimode diversity receiver to mitigate the impairment from anisotropic turbulence, which is emulated by employing an electrically-controlled heater. The anisotropy gradually decreases as the flow-level of the introduced airflow from fans increases. In contrast to circular-aperture reception, the elliptical-aperture multimode diversity receiver can effectively resist beam wander under anisotropic turbulence, reducing outage probability from 14.63% to 0.38% for detecting a dual-polarization 30-Gbaud QPSK signal. Without the aid of an adaptive optics system, this work demonstrates the feasibility of realizing an anisotropic-turbulence-resistant FSO link using multimode and multi-aperture diversity reception employing digital coherent combining techniques.
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| 5. |
- Huang, Yetian, et al.
(author)
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Optical Broadcasting Employing Incoherent And Low-Coherence Spatial Modes for Bi-Directional Optical Wireless Communications
- 2021
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In: Journal of Lightwave Technology. - 0733-8724 .- 1558-2213. ; 39:3, s. 833-838
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Journal article (peer-reviewed)abstract
- We introduce recently developed space division multiplexing (SDM)-associated technologies into optical wireless communications (OWC) and propose to use incoherent and low-coherence spatial modes to realize optical broadcasting with reliable performance by mitigating coherent interference. We experimentally demonstrate reconfigurable optical beam steering using a programmable multi-plane light conversion (MPLC)-based mode multiplexer (MMUX) and realize point-to-multi-point optical wireless communications with low-loss up-link optical beam combining and reach extension using multimode fiber (MMF). Both incoherent and low-coherence spatial modes can be generated employing the cost-efficient components such as multimode vertical cavity surface emitting laser (MM-VCSEL) and broadband amplified spontaneous emission (ASE) noise source.
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| 6. |
- Martinez-Manuel, Leopoldo, et al.
(author)
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A comprehensive analysis of the optical and thermal performance of solar absorber coatings under concentrated flux conditions
- 2022
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In: Solar Energy. - : Elsevier BV. - 0038-092X .- 1471-1257. ; 239, s. 319-336
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Journal article (peer-reviewed)abstract
- Solar Absorber Coatings (SACs) are widely used materials for improving thermal efficiencies of solar receivers. Traditionally, these SACs are investigated using heat treatments to test their optical-thermal properties; however, tests under concentrated flux conditions are still required. In this work, the thermal efficiency of different SACs is experimentally evaluated and compared. The analyzed SACs are: (1) Pyromark®2500, (2) Solkote®, (3) Thurmalox®250, (4) Comex® and (5) a new Soot from Forest Biomass (SFB) based coating. To assess the SACs performance, a High Flux Solar Simulator along with a calorimetric test bench are implemented under a well-controlled indoor environment applying two levels of concentrated irradiance of 100 ± 3 kW/m2 and 415 ± 12 kW/m2 named low and high flux level, respectively. Results show that, for a low flux level, the analyzed coatings present thermal efficiencies in a range from 91.74% to 83.24%, exhibiting a slightly close performance in most of the cases. Correspondingly, for a high flux level, the efficiencies range from 88.69% to 72.69%, with Pyromark®2500 being the most efficient in both cases. In addition, variations in the optical properties are reported for the experimental campaign with the high flux level, observing slight changes in the spectral absorptance and emittance. From these results, Pyromark presents the highest drop in solar absorptance of 1.22%, which is attributed to microcracks observed through the Scanning Electron Microscope (SEM). Thus, the presented approach can provide valuable information about the effects that concentrated flux levels can have in the optical-thermal performance of the analyzed samples.
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| 7. |
- Onate, Angelo, et al.
(author)
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Characterization of Nb-Si-doped low-carbon steel treated by quenching and partitioning : Thermic treatment in two stages supported by computational thermodynamical simulation and controlled sample dimensions
- 2023
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In: Materials Today Communications. - : Elsevier BV. - 2352-4928. ; 34
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Journal article (peer-reviewed)abstract
- Quench and partition steels find wide use in the automotive industry because of their high capability of energy absorption. Industrial demands have prompted the expansion of this research field because of the influence these materials have on components that can absorb high energy of impact to reduce passenger damage, for example. The partition process's difficulties lie mainly in controlling the thermodynamics and the kinetics of the phase transformation. Both affect achieving adequate austenite retention and optimal mechanical properties. Many researchers have attempted to increase these materials' energy absorption efficiency by incorporating micro -alloying elements that control phase transformation during the partitioning process, typically done in three steps. However, no research has been carried out on this topic using Nb and Si microalloying on low-carbon steels in two stages. Therefore, an alloy was designed and modelled with mechanical reinforcement by precipitation and transformation-induced plasticity (TRIP), doping the steel with Nb and Si in a two-stage quenching and parti-tioning process. Then, steel samples were fabricated to validate the model. There were two groups of samples with different dimensions to evaluate the sensitivity of austenite retention concerning the sample thickness. The main results showed that 10.75% of retained austenite allows an energy absorption of 30.55 GPa% with a two -stage quenching and partitioning heat treatment. Sample thickness influences austenite retention due to diffusion kinetics during the partitioning process. Finally, virtual tests quantified the unit strain energy absorption of the retained austenite at 1.9 mJ at 25 degrees C.
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| 8. |
- Oñate, A., et al.
(author)
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Production of Nb-doped super duplex stainless steel based on recycled material : A study of the microstructural characterization, corrosion, and mechanical behavior
- 2023
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In: Materials Chemistry and Physics. - : Elsevier BV. - 0254-0584 .- 1879-3312. ; 308
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Journal article (peer-reviewed)abstract
- The corrosion behavior of a new Nb-doped stainless steel (SDSS-Nb) designed by the CALPHAD method, produced using an open atmosphere process based on recycled materials, was investigated to improve the circular economy. Three heat-treatment conditions were evaluated to assess the sensitization effects of the precipitates and inclusions. XRD and SEM-EDS were used for phase identification, and sensitization was analyzed by cyclic polarization and Scanning Kelvin Probe Force Microscopy (SKPFM). The thermodynamic stability predicted by Thermo-Calc agrees with that observed by SEM-EDS. It was observed by cyclic polarization that the corrosion sensitization was mainly provided by the σ phase, which was deduced from the results obtained by SEM-EDS, XRD, and Thermo-Calc simulations. Furthermore, it was obtained that the sensitization due to Cr2N precipitates and nonmetallic inclusions was low, and the mechanical response is comparable to commercial UNS32750 super duplex stainless steel, which allows a good performance in severe environments and an efficient industrial application. Additionally, it has been obtained by SKPFM that the shear potential between the σ phase and the austenite is between 210 mV and 241 mV and that its value depends on the stability and equilibrium reached by the σ phase during thermal cycling.
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| 9. |
- Roederer, Ian U., et al.
(author)
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The discovery space of ELT-ANDES. Stars and stellar populations
- 2024
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In: Experimental Astronomy. - 0922-6435. ; 57:2
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Journal article (peer-reviewed)abstract
- The ArmazoNes high Dispersion Echelle Spectrograph (ANDES) is the optical and near-infrared high-resolution echelle spectrograph envisioned for the Extremely Large Telescope (ELT). We present a selection of science cases, supported by new calculations and simulations, where ANDES could enable major advances in the fields of stars and stellar populations. We focus on three key areas, including the physics of stellar atmospheres, structure, and evolution; stars of the Milky Way, Local Group, and beyond; and the star-planet connection. The key features of ANDES are its wide wavelength coverage at high spectral resolution and its access to the large collecting area of the ELT. These features position ANDES to address the most compelling questions and potentially transformative advances in stellar astrophysics of the decades ahead, including questions which cannot be anticipated today.
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