| 1. |
- Beal, Jacob, et al.
(författare)
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Robust estimation of bacterial cell count from optical density
- 2020
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Ingår i: Communications Biology. - : Springer Science and Business Media LLC. - 2399-3642. ; 3:1
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Tidskriftsartikel (refereegranskat)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. |
- Shao, Xue-Feng, et al.
(författare)
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Polyvinylpyrrolidone (PVP)-enabled significant suppression of supercooling of erythritol for medium-temperature thermal energy storage
- 2022
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Ingår i: Journal of Energy Storage. - : Elsevier BV. - 2352-152X .- 2352-1538. ; 46, s. 103915-
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Tidskriftsartikel (refereegranskat)abstract
- The supercooling effect is deemed to be a crucial issue for thermal energy storage using phase change materials (PCMs). The exploration of promising additives plays a decisive role in effective suppression efforts for suppressing the supercooling effect of a PCM. The present work proposed a potential additive, polyvinylpyrrolidone (PVP), to reduce the supercooling of erythritol, which is the most promising polyol PCM candidate for medium temperature range. PVP with various loadings was dispersed in erythritol to make composites for the proof-of-concept tests. It was shown that the degree of supercooling of erythritol can be reduced significantly from over 64 ? to about 21 ? in the presence of only 1.0 wt.% PVP. Along with the mitigated supercooling effect, the addition of PVP also leads to an increase of the retrievable latent heat during crystallization, from ~187 J/g to ~224 J/g at the same minute PVP loading of 1.0 wt.%, by increasing the crystallinity of erythritol. The PVP-loaded erythritol composites exhibit little sacrifice in latent heat of fusion, i.e., only ~15% loss when the PVP loading reaches 6.0 wt.%. In addition, multiple tests confirmed that PVP can be dissolved in erythritol, thus desirable compatibility was obtained and the composites would have long-term reliability. This proposed additive enables an efficient and cost-effective way for improving the crystallization behaviors of erythritol (and other polyol PCMs) towards real-world applications.
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| 3. |
- Zhang, Zhixin, et al.
(författare)
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Vectorized rooftop area data for 90 cities in China
- 2022
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Ingår i: Scientific Data. - : Springer Nature. - 2052-4463. ; 9:1
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Tidskriftsartikel (refereegranskat)abstract
- Reliable information on building rooftops is crucial for utilizing limited urban space effectively. In recent decades, the demand for accurate and up-to-date data on the areas of rooftops on a large-scale is increasing. However, obtaining these data is challenging due to the limited capability of conventional computer vision methods and the high cost of 3D modeling involving aerial photogrammetry. In this study, a geospatial artificial intelligence framework is presented to obtain data for rooftops using high-resolution open-access remote sensing imagery. This framework is used to generate vectorized data for rooftops in 90 cities in China. The data was validated on test samples of 180 km(2) across different regions with spatial resolution, overall accuracy, and F1 score of 1 m, 97.95%, and 83.11%, respectively. In addition, the generated rooftop area conforms to the urban morphological characteristics and reflects urbanization level. These results demonstrate that the generated dataset can be used for data support and decision-making that can facilitate sustainable urban development effectively.
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