| 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. |
- Shi, Zhi Sheng, et al.
(författare)
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Enrichment of Ni–Mo–V via pyrometallurgical reduction from spent hydrogenation catalysts and the multi-reaction mechanism
- 2023
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Ingår i: Rare Metals. - 1001-0521 .- 1867-7185. ; 42:8, s. 2700-2712
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Tidskriftsartikel (refereegranskat)abstract
- Spent hydrogenation catalysts are important secondary resources due to richness in the valuable metals of Ni, Mo and V. Recovery of valuable metals from spent catalysts has high economic value and environmental benefits since they are hazardous wastes as well. Traditional recycling processes including hydrometallurgical leaching and soda roasting-leaching have disadvantages such as generating large amounts of wastewater, long process, and low recovery efficiency of valuable metals. Thus, this paper proposed synergistic enrichment of Ni, Mo and V via pyrometallurgical reduction at 1400–1500 °C. The melting temperature and viscosity of slag were reduced through slag designing by software FactSage 7.1. The phase diagram of Al2O3-CaO-SiO2-Na2O-B2O3 was drawn, and low-temperature region (≤ 1300 °C) was selected as target slag composition. Ni, Mo, and V can be collaborative captured and recovered through the mutual solubility at molten state. Increasing the melting temperature and the amount of CaO, Na2O and C were conducive to improving the metals recovery rates. The kilogram-scale experiments were carried out, and the recovery efficiencies of Ni, Mo and V were 98.3%, 95.3% and 97.9% under optimized conditions: at 1500 °C, with the basicity of 1.0, 13.1 wt% SiO2, 7.0 wt% B2O3, 7.7 wt% Na2O and 20.0 wt% C. The distribution behavior of valuable metals was clarified by investigating the melting process of slag and the reduction in valuable metals. Ni was preferentially reduced and acted as a capturing agent, which captured other metals to form NiMoV alloys. Graphical abstract: [Figure not available: see fulltext.]
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| 3. |
- Huang, Zi-Nan, et al.
(författare)
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Analysis of the stress field in the reactor vessel of the China Initiative Accelerator Driven System during postulated ULOF and UTOP transients
- 2023
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Ingår i: Annals of Nuclear Energy. - : Elsevier BV. - 0306-4549 .- 1873-2100. ; 194
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Tidskriftsartikel (refereegranskat)abstract
- The China Initiative Accelerator Driven System (CiADS) was proposed by China Academy of Science since 2015. The subcritical reactor in CiADS is a liquid Lead Bismuth Eutectic (LBE) cooled fast reactor. When the reactor core is in operation, the LBE coolant will directly contact and corrode the inner surface of reactor vessel. Due to the high temperature, the corrosion will be more severe. If the stress on the reactor vessel exceeds the limit, the plastic deformation will occur, leading to the generation and expansion of defects and cracks, and the safety of the reactor will be affected. Therefore, evaluating the stress field of the reactor vessel under different operating conditions is a very important research project. In this paper, the finite element analysis software ADINA was applied to analyze the reactor vessel in CiADS, and the ASME Code was used as stress assessment standards. We can preliminarily prove that the stress assessments of the vessel during the postulated Unprotected Loss of Flow (ULOF) accidents satisfy the requirements of ASME Code. The limit reactivity insertion to protect the vessel from plastic deformation is 0.58$ in the postulated Unprotected Transient over Power (UTOP) accidents based on our current results. Therefore, we can preliminarily conclude that the current material selection and structural design of the reactor vessel in CiADS could survive most of the postulated transient accidents considering the stress effect.
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| 4. |
- Ma, Chuanwei, et al.
(författare)
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Global trends in the prevalence of secondhand smoke exposure among adolescents aged 12-16 years from 1999 to 2018 : an analysis of repeated cross-sectional surveys.
- 2021
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Ingår i: The Lancet Global Health. - : Elsevier. - 2214-109X. ; 9:12, s. E1667-E1678
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Secondhand smoke exposure can cause morbidity and premature mortality. However, the global prevalence of, and trends in, secondhand smoke exposure among adolescents are poorly documented. We aimed to assess the prevalence of, and trends in, secondhand smoke exposure among adolescents from 1999 to 2018.METHODS: We did an analysis of the most recent data from the Global Youth Tobacco Survey (GYTS), a nationally representative, self-administered, school-based cross-sectional survey of tobacco use and related factors among adolescents aged 12-16 years worldwide. Data from 142 countries and territories that had done a GYTS between 2010 and 2018, comprising 711 366 participants, were used to assess the prevalence of secondhand smoke exposure. Data from 131 countries and territories that had done two or more surveys between 1999 and 2018, comprising 1 405 458 participants, were used to assess trends in secondhand smoke exposure. The frequency of secondhand smoke exposure at home, in public places, or in any place was defined as follows, based on students' responses: 1 or more days, 3 or more days, 5 or more days, or daily during the past 7 days.FINDINGS: Based on the most recent surveys done in 142 countries between Jan 1, 2010, and Dec 31, 2018, the global prevalence of secondhand smoke exposure in any place was 62·9% (95% CI 61·7-64·1) on 1 or more days, 51·0% (49·8-52·1) on 3 or more days, 40·1% (38·9-41·2) on 5 or more days, and 32·5% (31·5-33·6) daily during the past 7 days. The prevalence of secondhand smoke exposure at home was 33·1% (95% CI 32·1-34·1) on 1 or more days, 20·1% (19·3-20·9) on 3 or more days, 14·9% (14·2-15·7) on 5 or more days, and 12·3% (11·7-13·0) daily during the past 7 days; and in public places the prevalence of secondhand smoke exposure was 57·6% (56·4-58·8) on 1 or more days, 43·4% (42·2-44·6) on 3 or more days, 30·3% (29·2-31·5) on 5 or more days, and 23·5% (22·5-24·5) daily during the past 7 days. Between Jan 1, 1999, and Dec 31, 2018, the prevalence of secondhand smoke exposure (on ≥1 day during the past 7 days) in any place decreased in 57 (43·5%) of 131 countries, increased in 27 (20·6%), and remained unchanged in 47 (35·9%). Although the prevalence of secondhand smoke exposure at home decreased in 86 (65·6%) countries, the prevalence in public places did not change in 46 (35·1%) countries and increased in 40 (30·5%).INTERPRETATION: Secondhand smoke exposure among adolescents remains a serious public health challenge worldwide. Although the prevalence of secondhand smoke exposure at home decreased in most countries, the prevalence in public places increased or remained unchanged in most countries between 1999 and 2018. These findings emphasise the need to strengthen smoke-free policies, especially in public places.FUNDING: Youth Team of Humanistic and Social Science of Shandong University, Jinan, China.TRANSLATION: For the Chinese translation of the abstract see Supplementary Materials section.
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| 5. |
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| 6. |
- Wang, Di-Si, et al.
(författare)
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Analysis of the Accelerator-Driven System Fuel Assembly during the Steam Generator Tube Rupture Accident
- 2021
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Ingår i: Materials. - : MDPI AG. - 1996-1944. ; 14:8
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Tidskriftsartikel (refereegranskat)abstract
- China is developing an ADS (Accelerator-Driven System) research device named the China initiative accelerator-driven system (CiADS). When performing a safety analysis of this new proposed design, the core behavior during the steam generator tube rupture (SGTR) accident has to be investigated. The purpose of our research in this paper is to investigate the impact from different heating conditions and inlet steam contents on steam bubble and coolant temperature distributions in ADS fuel assemblies during a postulated SGTR accident by performing necessary computational fluid dynamics (CFD) simulations. In this research, the open source CFD calculation software OpenFOAM, together with the two-phase VOF (Volume of Fluid) model were used to simulate the steam bubble behavior in heavy liquid metal flow. The model was validated with experimental results published in the open literature. Based on our simulation results, it can be noticed that steam bubbles will accumulate at the periphery region of fuel assemblies, and the maximum temperature in fuel assembly will not overwhelm its working limit during the postulated SGTR accident when the steam content at assembly inlet is less than 15%.
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| 7. |
- Wang, Peng, et al.
(författare)
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Linking Emergence to the Complex Product System
- 2020
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Ingår i: IEEE Access. - : Institute of Electrical and Electronics Engineers (IEEE). - 2169-3536. ; 8, s. 34286-34298
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Tidskriftsartikel (refereegranskat)abstract
- The increasing complexity of product calls for manufacturing integration, while in turn high integration brings the problems of system level complexity. This paper proposes that complex product system (CoPS) should be managed as a dynamical system. The dynamical characteristics of CoPS are discussed from the perspective of emergence. A conceptual model is established to analyze the cause, process and result of the CoPS emergence. The mechanism of inner state emergence in CoPS is interpreted by formal languages to provide a point view of state space. It is concluded that the behavior of CoPS, especially the complexity, exhibits the 'entity is greater than the sum of the parts' phenomena when satisfying given necessary conditions. A novel methodology is then established to evaluate this emergence-based complexity. The feasibility and application of the novel complexity measurement is verified by an example of turbine housing production process. Further discussions are made on how to manage the potential emerging complexity based on the proposed measurement.
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| 8. |
- Xi, Bin, et al.
(författare)
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Influence of TIG and Laser Welding Processes of Fe-10Cr-4Al-RE Alloy Cracks Overlayed on 316L Steel Plate
- 2022
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Ingår i: Materials. - : MDPI AG. - 1996-1944. ; 15:10, s. 3541-
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, the possibility of applying different welding strategies to overlay an FeCrAl layer against corrosion from heavy liquid metal on a plain plate made of 316L austenitic stainless steel was investigated. This technology could be used in manufacturing the main vessel of CiADS, which may be considered as a more economic and feasible solution than production with the corrosion-resistant FeCrAl alloy directly. The main operational parameters of the laser welding process, including laser power, weld wire feeding speed, diameter of the welding wire, etc., were adjusted correspondingly to the optimized mechanical properties of the welded plate. After performing the standard nuclear-grade bending tests, it can be preliminarily confirmed that the low-power pulse laser with specific operational parameters and an enhanced cooling strategy will be suitable to surface an Fe-10Cr-4Al-RE layer with a thickness of approximately 1 mm on a 40 mm-thick 316L stainless steel plate, thanks to the upgraded mechanical properties incurred by refined grains with a maximum size of around 300 mu m in the welded layer.
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| 9. |
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| 10. |
- Yang, Sheng, et al.
(författare)
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Development of a welding process to overlay FeCrAl alloy on a thin wall austenitic stainless steel tube
- 2021
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Ingår i: Nuclear Materials and Energy. - : Elsevier BV. - 2352-1791. ; 27
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, we investigated the possibility of applying the low power pulse laser welding technology to surface a protective layer against heavy liquid metal corrosion in fuel cladding tube made of austenitic 316L stainless steel. Based on results from flaring, flattening, bending tests and metallographic microscope investigations, we can preliminarily confirm the possibility of using low power pulse laser with specific power input to weld Fe-10Cr-4Al-RE alloy on the outer surface of a 316L stainless steel tube with the inner diameter of 11.8 mm and wall thickness of 0.65 mm.
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