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Sökning: WFRF:(Liu Hailong)

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1.
  • Beal, Jacob, et al. (författare)
  • Robust estimation of bacterial cell count from optical density
  • 2020
  • Ingår i: Communications Biology. - : Springer Science and Business Media LLC. - 2399-3642. ; 3:1
  • 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.
  • Chen, Jinhan, et al. (författare)
  • The effect of hot isostatic pressing on thermal conductivity of additively manufactured pure tungsten
  • 2020
  • Ingår i: International journal of refractory metals & hard materials. - : Elsevier BV. - 0263-4368. ; 87
  • Tidskriftsartikel (refereegranskat)abstract
    • The crack-healing behaviors and microstructure evolution of pure tungsten produced by laser powder bed fusion (LPBF) were studied and compared before and after post hot isostatic pressing (post-HIP) treatment. An average thermal conductivity of 133 W.m(-1).K-1 at room temperature (RT) was obtained after HIP, which was 16% higher than that of as-built sample (115 W.m(-1).K-1). Although the HIP process had little effect on density, it resulted in a large grain size of > 300 mu m accompanied by a decrease in dislocation density and crack healing, which led to a substantial improvement of thermal conductivity of pure tungsten. The positive correlation between relative density and thermal conductivity of as-built tungsten was reported.
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3.
  • Guo, Yangyi, et al. (författare)
  • The use of the general thermal sensation discriminant model based on CNN for room temperature regulation by online brain-computer interface
  • 2023
  • Ingår i: Building and Environment. - : Elsevier Ltd. - 0360-1323 .- 1873-684X. ; 241
  • Tidskriftsartikel (refereegranskat)abstract
    • Brain-computer interface (BCI) technology can realize dynamic room temperature adjustment based on individual real-time thermal sensation, which can provide the basis for future intelligent buildings. However, the generalization ability of previous thermal sensation discrimination model (TSDM) is limited, which is a serious obstacle to the application. In this paper, a general TSDM was developed by using convolutional neural network (CNN), which can be well applied to new subjects. In the study, the CNN-TSDM was established and evaluated based on the offline experimental data, and then the BCI closed-loop online room temperature control experiment was carried out based on this CNN-TSDM to further verify. The offline analysis results show that the recognition performance of CNN-TSDM in new subjects is significantly higher than that of typical shallow learning algorithms, and its area under the ROC curve (AUC) value reaches 0.789. In the online experiments of the two simulated environments, BCI using the CNN-TSDM dynamically controlled the air conditioning to improve the room temperature to the comfortable level according to the subjects' thermal sensation. The subjective score of subjects decreased from 3.1 to 3.0 for the hot uncomfortable to 1.1 and 1.2 for the cool comfortable (p < 0.001, p < 0.001). Moreover, in a hotter simulated experimental environment, BCI automatically controlled the air conditioner for longer cooling to obtain a same degree of thermal comfort. The total cooling time (p < 0.05) and the single cooling time (p < 0.05) of the air conditioner were significantly increased. This further confirmed the effectiveness and robustness of the general CNN-TSDM.
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4.
  • He, Xiaohe, et al. (författare)
  • Real-time regulation of room temperature based on individual thermal sensation using an online brain–computer interface
  • 2022
  • Ingår i: Indoor Air. - : NLM (Medline). - 0905-6947 .- 1600-0668. ; 32:e13106
  • Tidskriftsartikel (refereegranskat)abstract
    • Regulation of indoor temperature based on neurophysiological and psychological signals is one of the most promising technologies for intelligent buildings. In this study, we developed a system for closed-loop control of indoor temperature based on brain-computer interface (BCI) technology for the first time. Electroencephalogram (EEG) signals were collected from subjects for two room temperature categories (cool comfortable and hot uncomfortable) and used to build a thermal-sensation discrimination model (TSDM) with an ensemble learning method. Then, an online BCI system was developed based on the TSDM. In the online room temperature control experiment, when the TSDM detected that the subjects felt hot and uncomfortable, BCI would automatically turn on the air conditioner, and when the TSDM detected that the subjects felt cool and comfortable, BCI would automatically turn off the air conditioner. The results of online experiments in a hot environment showed that a BCI could significantly improve the thermal comfort of subjects (the subjective thermal comfort score decreased from 2.45 (hot uncomfortable) to 0.55 (cool comfortable), p < 0.001). A parallel experiment further showed that if the subjects wore thicker clothes during the experiment, the BCI would turn on the air conditioner for a longer time to ensure the thermal comfort of the subjects. This has further confirmed the effectiveness of TSDM model in evaluating thermal sensation under the dynamic change of room temperature and showed the model's good robustness. This study proposed a new paradigm of human-building interaction, which is expected to play a promising role in the development of human-centered intelligent buildings.
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5.
  • Liu, Kun, et al. (författare)
  • A study of intrinsic amorphous silicon thin film deposited on flexible polymer substrates by magnetron sputtering
  • 2016
  • Ingår i: Journal of Non-Crystalline Solids. - : Elsevier BV. - 0022-3093 .- 1873-4812. ; 449, s. 125-132
  • Tidskriftsartikel (refereegranskat)abstract
    • Amorphous silicon (a-Si) has gained its popularity in thin film Solar cell fabrication for its high absorption coefficient, high applicability on flexible substrates and practical feasibility for low-cost roll-to-roll mass fabrication. Working as the intrinsic layer, the optical-electrical characteristics of amorphous silicon film is crucial to the cell performance. In this work, the amorphous silicon film has been fabricated on PET substrate by magnetron sputtering method. The main optical-electrical characteristics have been systematically investigated under different fabrication conditions (sputtering power, working pressure, working temperature). The results indicate that the deposition rate increases remarkably from 1.88 to 834 nm/min with the sputtering power increasing from 60 W to 120 W, while the light transmission rate decreases from 86% to 46% in the visible spectrum range (390 nm to 780 nm). Theoretical calculations have been carried out, showing a decreasing deposition rate under an increasing working pressure. A rising temperature provides a higher deposition rate and lower trans-mittance in the certain range. The optimized processing parameters in the fabrication of amorphous silicon thin film are obtained for high photoelectric property on flexible substrates.
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6.
  • Liu, Kun, et al. (författare)
  • B-Doped Amorphous Silicon Thin Films Deposited on Flexible PET Substrate by Magnetron Sputtering
  • 2015
  • Ingår i: Journal of Computational and Theoretical Nanoscience. - : American Scientific Publishers. - 1546-1955 .- 1546-1963. ; 12:9, s. 2931-2936
  • Tidskriftsartikel (refereegranskat)abstract
    • Depositing amorphous silicon doped with different elements on flexible substrates offers a large potential for the roll-to-roll processes lowering the manufacturing cost of solar cells. Unique magnetron sputtering method was adopted to deposit B-doped amorphous silicon thin film on flexible PET substrate instead of solid substrate materials like glass, metal and silicon. Effects of different substrates were investigated, as well as the processing parameters including sputtering power and working pressure. The structure and performance of the samples were characterized with SEM, XRD, surface profile meter and UV-spectrophotometer. The comparison between PET and glass shows that the alternative of PET substrate significantly improved the deposition rate. Optimal results were obtained as pressure of 0.2 Pa and RF power of 120 W, which showed the lowest transmittance as well as a minimum optical band gap, both are of great significance to photovoltaic conversion. Theoretical justification and experimental data including the feasible magnetron sputtering way, PET flexible substrate and optimized process parameters to the mass production of cheap and high performance heterojunction thin film solar cells were achieved.
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7.
  • Liu, L., et al. (författare)
  • Forecasting Power Output of Photovoltaic System Using A BP Network Method
  • 2017
  • Ingår i: Energy Procedia. - : Elsevier Ltd. - 1876-6102. ; 142, s. 780-786
  • Tidskriftsartikel (refereegranskat)abstract
    • The characteristics of intermittent and stochastic of solar energy has brought great challenges to power grid system in terms of operation and regulation. Power forecasting is an important factor for optimal schedule of power grid system and assessing the working performance of PV systems. In order to forecast the power output of a PV system located in Ashland at 24-hour-ahead for higher efficiency, a back propagation (BP) neural network model is proposed. Before designing the model, correlation analysis is done to investigate the relationship between power output and solar irradiance and ambient temperature, which are key parameters affecting the power output of PV systems. Based on a correlation analysis, the model admitted the following input parameters: hourly solar radiation intensity, the highest, the lowest daily and the average daily temperature, and hourly power output of the PV system. The output of the model is the forecasted PV power output 24 hours ahead. Based on the datasets, the neural network is trained to improve its accuracy. The best performance is obtained with the BP neural network structure of 28-20-11. The analysis of the error indicator MAPE shows that the proposed model has great accuracy and efficiency for forecasting the power output of photovoltaic systems.
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8.
  • Liu, Linan, et al. (författare)
  • Silicon Effects on Biomass Carbon and Phytolith-Occluded Carbon in Grasslands Under High-Salinity Conditions
  • 2020
  • Ingår i: Frontiers in Plant Science. - : Frontiers Media S.A.. - 1664-462X. ; 11, s. 1-13
  • Tidskriftsartikel (refereegranskat)abstract
    • Changes in climate and land use are causing grasslands to suffer increasingly fromabiotic stresses, including soil salinization. Silicon (Si) amendment has been frequentlyproposed to improve plant resistance to multiple biotic and abiotic stresses and increaseecosystem productivity while controlling the biogeochemical carbon (C) cycle. However,the effects of Si on plant C distribution and accumulation in salt-suffering grasslandsare still unclear. In this study, we investigated how salt ions affected major elementalcomposition in plants and whether Si enhanced biomass C accumulation in grasslandspecies in situ. In samples from the margins of salt lakes, our results showed that thediffering distance away from the shore resulted in distinctive phytocoenosis, includinghalophytes and moderately salt-tolerant grasses, which are closely related to changingsoil properties. Different salinity (NaC/KC, ranging from 0.02 to 11.8) in plants causednegative effects on plant C content that decreased from 53.9 to 29.2% with theincrease in salinity. Plant Si storage [0.02–2.29 g Si m?2 dry weight (dw)] and plantSi content (0.53 to 2.58%) were positively correlated with bioavailable Si in soils(ranging from 94.4 to 192 mg kg?1). Although C contents in plants and phytoliths werenegatively correlated with plant Si content, biomass C accumulation (1.90–83.5 g Cm?2 dw) increased due to the increase of Si storage in plants. Plant phytolith-occludedcarbon (PhytOC) increased from 0.07 to 0.28h of dry mass with the increase of Sicontent in moderately salt-tolerant grasses. This study demonstrates the potential ofSi in mediating plant salinity and C assimilation, providing a reference for potentialmanipulation of long-term C sequestration via PhytOC production and biomass Caccumulation in Si-accumulator dominated grasslands.
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9.
  • Liu, Zhan, et al. (författare)
  • Thermodynamic analysis on the feasibility of a liquid energy storage system using CO2-based mixture as the working fluid
  • 2022
  • Ingår i: Energy. - : Elsevier BV. - 0360-5442 .- 1873-6785. ; 238
  • Tidskriftsartikel (refereegranskat)abstract
    • Pioneering investigation is conducted on the feasibility of designing novel liquid energy storage system by using working fluid blending CO2 with organic fluids to address the condensation problem of subcritical CO2. Organic substances are cautiously screened according to the criteria of environment effect, temperature glide, critical temperature and flammability of working fluid as well as the system performance. Mathematical model of the system is built for thermodynamic examination. An in-house code is developed to complete the system simulations combing with REFPROP subroutine. Results demonstrate that compared to the system with pure CO2, the system with mixture produces an improvement of net power output and energy density and a reduction of charge pressure at an expense of slightly decreasing round trip efficiency. The payment of 6.45 % for round trip efficiency can reduce 55.59 % of charge pressure by taking CO2/R32 as an instance. The system round trip efficiency, energy density and charge pressure decrease with the increase in organic fluid composition. An optimal compression ratio can be identified to reach a maximal round trip efficiency for all mixtures. The cooler outlet temperature is suggested being at the critical temperature of working fluid to reach better system performance. 
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10.
  • Song, Zhaoliang, et al. (författare)
  • High potential of stable carbon sequestration in phytoliths of China's grasslands
  • 2022
  • Ingår i: Global Change Biology. - : John Wiley & Sons. - 1354-1013 .- 1365-2486. ; 28:8, s. 2736-2750
  • Tidskriftsartikel (refereegranskat)abstract
    • Phytolith carbon (C) sequestration plays a key role in mitigating global climate change at a centennial to millennial time scale. However, previous estimates of phytolith-occluded carbon (PhytOC) storage and potential in China's grasslands have large uncertainties mainly due to multiple data sources. This contributes to the uncertainty in predicting long-term C sequestration in terrestrial ecosystems using Earth System Models. In this study, we carried out an intensive field investigation (79 sites, 237 soil profiles [0-100 cm], and 61 vegetation assessments) to quantify PhytOC storage in China's grasslands and to better explore the biogeographical patterns and influencing factors. Generally, PhytOC production flux and soil PhytOC density in both the Tibetan Plateau and the Inner Mongolian Plateau had a decreasing trend from the Northeast to the Southwest. The aboveground PhytOC production rate in China's grassland was 0.48 x 10(6) t CO2 a(-1), and the soil PhytOC storage was 383 x 10(6) t CO2. About 45% of soil PhytOC was stored in the deep soil layers (50-100 cm), highlighting the importance of deep soil layers for C stock assessments. Importantly, the Tibetan Plateau had the greatest contribution (more than 70%) to the PhytOC storage in China's grasslands. The results of multiple regression analysis indicated that altitude and soil texture significantly influenced the spatial distribution of soil PhytOC, explaining 78.1% of the total variation. Soil phytolith turnover time in China's grasslands was mainly controlled by climatic conditions, with the turnover time on the Tibetan Plateau being significantly longer than that on the Inner Mongolian Plateau. Our results offer more accurate estimates of the potential for phytolith C sequestration from ecological restoration projects in degraded grassland ecosystems. These estimates are essential to parameterizing and validating global C models.
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11.
  • Wu, Lele, et al. (författare)
  • Organic matter composition and stability in estuarine wetlands depending on soil salinity
  • 2024
  • Ingår i: Science of the Total Environment. - 0048-9697 .- 1879-1026. ; 945
  • Tidskriftsartikel (refereegranskat)abstract
    • Coastal wetlands are key players in mitigating global climate change by sequestering soil organic matter. Soil organic matter consists of less stable particulate organic matter (POM) and more stable mineral-associated organic matter (MAOM). The distribution and drivers of MAOM and POM in coastal wetlands have received little attention, despite the processes and mechanisms differ from that in the upland soils. We explored the distribution of POM and MAOM, their contributions to SOM, and the controlling factors along a salinity gradient in an estuarine wetland. In the estuarine wetland, POM C and N were influenced by soil depth and vegetation type, whereas MAOM C and N were influenced only by vegetation type. In the estuarine wetland, SOM was predominantly in the form of MAOM (> 70 %) and increased with salinity (70 %–76 %), leading to long-term C sequestration. Both POM and MAOM increased with SOM, and the increase rate of POM was higher than that of MAOM. Aboveground plant biomass decreased with increasing salinity, resulted in a decrease in POM C (46 %–81 %) and N (52 %–82 %) pools. As the mineral amount and activity, and microbial biomass decreased, the MAOM C (2.5 %–64 %) and N pool (8.6 %–59 %) decreased with salinity. When evaluating POM, the most influential factors were microbial biomass carbon (MBC) and dissolved organic carbon (DOC). Key parameters, including MBC, DOC, soil salinity, soil water content, aboveground plant biomass, mineral content and activity, and bulk density, were identified as influencing factors for both MAOM abundance. Soil water content not only directly controlled MAOM, but together with salinity also indirectly regulated POM and MAOM by controlling microbial biomass and aboveground plant biomass. Our findings have important implications for improving the accumulation and increased stability of soil organic matter in coastal wetlands, considering the global sea level rise and increased frequency of inundation.
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12.
  • Xia, Shaopan, et al. (författare)
  • Storage, patterns and influencing factors for soil organic carbon in coastal wetlands of China
  • 2022
  • Ingår i: Global Change Biology. - : John Wiley & Sons. - 1354-1013 .- 1365-2486. ; 28:20, s. 6065-6085
  • Tidskriftsartikel (refereegranskat)abstract
    • Soil organic carbon (SOC) in coastal wetlands, also known as "blue C," is an essential component of the global C cycles. To gain a detailed insight into blue C storage and controlling factors, we studied 142 sites across ca. 5000 km of coastal wetlands, covering temperate, subtropical, and tropical climates in China. The wetlands represented six vegetation types (Phragmites australis, mixed of P. australis and Suaeda, single Suaeda, Spartina alterniflora, mangrove [Kandelia obovata and Avicennia marina], tidal flat) and three vegetation types invaded by S. alterniflora (P. australis, K. obovata, A. marina). Our results revealed large spatial heterogeneity in SOC density of the top 1-m ranging 40-200 Mg C ha(-1), with higher values in mid-latitude regions (25-30 degrees N) compared with those in both low- (20 degrees N) and high-latitude (38-40 degrees N) regions. Vegetation type influenced SOC density, with P. australis and S. alterniflora having the largest SOC density, followed by mangrove, mixed P. australis and Suaeda, single Suaeda and tidal flat. SOC density increased by 6.25 Mg ha(-1) following S. alterniflora invasion into P. australis community but decreased by 28.56 and 8.17 Mg ha(-1) following invasion into K. obovata and A. marina communities. Based on field measurements and published literature, we calculated a total inventory of 57 x 10(6) Mg C in the top 1-m soil across China's coastal wetlands. Edaphic variables controlled SOC content, with soil chemical properties explaining the largest variance in SOC content. Climate did not control SOC content but had a strong interactive effect with edaphic variables. Plant biomass and quality traits were a minor contributor in regulating SOC content, highlighting the importance of quantity and quality of OC inputs and the balance between production and degradation within the coastal wetlands. These findings provide new insights into blue C stabilization mechanisms and sequestration capacity in coastal wetlands.
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14.
  • Campana, Pietro Elia, et al. (författare)
  • Economic optimization of photovoltaic water pumping systems for irrigation
  • 2015
  • Ingår i: Energy Conversion and Management. - : Elsevier BV. - 0196-8904 .- 1879-2227. ; 95, s. 32-41
  • Tidskriftsartikel (refereegranskat)abstract
    • Photovoltaic water pumping technology is considered as a sustainable and economical solution to provide water for irrigation, which can halt grassland degradation and promote farmland conservation in China. The appropriate design and operation significantly depend on the available solar irradiation, crop water demand, water resources and the corresponding benefit from the crop sale. In this work, a novel optimization procedure is proposed, which takes into consideration not only the availability of ground-water resources and the effect of water supply on crop yield, but also the investment cost of photovoltaic water pumping system and the revenue from crop sale. A simulation model, which combines the dynamics of photovoltaic water pumping system, groundwater level, water supply, crop water demand and crop yield, is employed during the optimization. To prove the effectiveness of the new optimization approach, it has been applied to an existing photovoltaic water pumping system. Results show that the optimal configuration can guarantee continuous operations and lead to a substantial reduction of photovoltaic array size and consequently of the investment capital cost and the payback period. Sensitivity studies have been conducted to investigate the impacts of the prices of photovoltaic modules and forage on the optimization. Results show that the water resource is a determinant factor.
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15.
  • Campana, Pietro Elia, et al. (författare)
  • Optimal grassland locations for sustainable photovoltaic water pumping systems in China
  • 2015
  • Ingår i: CLEAN, EFFICIENT AND AFFORDABLE ENERGY FOR A SUSTAINABLE FUTURE. - : Elsevier. ; 75, s. 301-307
  • Konferensbidrag (refereegranskat)abstract
    • Grassland is of strategic importance for food security of China because of the high number of livestock raised in those areas. Grassland degradation due to climate change and overgrazing is thus regarded as severe environmental and economic threat for a sustainable future development of China. Photovoltaic water pumping (PVWP) systems for irrigation can play an important role for the conservation of grassland areas, halting degradation, improving its productivity and farmers' income and living conditions. The aim of this paper is to identify the technically suitable grassland areas for the implementation of PVWP systems by assessing spatial data on land cover and slope, precipitation, potential evapotranspiration and water stress index. Furthermore, the optimal locations for installing PVWP systems have been assessed using a spatially explicit renewable energy systems optimization model based on the minimization of the cost of the whole supply chain. The results indicate that the PVWP-supported grassland areas show high potential in terms of improving forage productivity to contribute to supplying the local demand. Nevertheless, the optimal areas are highly sensitive to several environmental and economic parameters such as ground water depth, forage water requirements, forage price and CO2 emission costs. These parameters need to be carefully considered in the planning process to meet the forage yield potentials. (C) 2015 The Authors. Published by Elsevier Ltd.
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16.
  • Campana, Pietro Elia, et al. (författare)
  • Suitable and optimal locations for implementing photovoltaic water pumping systems for grassland irrigation in China
  • 2017
  • Ingår i: APPLIED ENERGY. - : Elsevier BV. - 0306-2619 .- 1872-9118. ; 185, s. 1879-1889
  • Tidskriftsartikel (refereegranskat)abstract
    • Grassland plays a key role for the food security of China because of the large number of livestock raised in those areas. Thus, grassland degradation due to climate change and overgrazing is considered as one of the most severe environmental and economic threat for the future sustainable development of China. Photovoltaic water pumping systems for irrigation can play a fundamental role for the conservation of grassland areas. This paper investigates the geospatial distribution of the technically suitable grassland locations for the implementation of photovoltaic water pumping systems. The technically suitable grassland areas were taken as starting point to assess the optimal locations. The assessment of the optimal locations was conducted using a spatially explicit optimization model of renewable energy systems based on the cost minimization of the whole forage supply chain. The results indicate that the photovoltaic water pumping systems provide high potential for improving forage productivity, contributing to meet the local demand. The optimal areas are highly sensitive to several environmental and economic parameters such as increased forage potential yield, forage management costs, forage water requirements, ground water depth, forage price and CO2 price. Most of the optimal areas are selected when the market forage price ranges from 300 to 500 $/tonne DM, indicating that the forage produced using PVWP technology for irrigation is already competitive compared to the imported forage.
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17.
  • Dai, B., et al. (författare)
  • Energetic performance of transcritical CO2 refrigeration cycles with mechanical subcooling using zeotropic mixture as refrigerant
  • 2018
  • Ingår i: Energy. - : Elsevier Ltd. - 0360-5442 .- 1873-6785. ; 150, s. 205-221
  • Tidskriftsartikel (refereegranskat)abstract
    • Transcritical CO2 refrigeration cycle integrated with mechanical subcooling (MS) cycle operating with zeotropic mixture is proposed in this study, based on the concept of Lorenz cycle. An energetic model is developed and analyses are conducted in detail. A maximum overall coefficient of performance (COP) is achieved at the optimum discharge pressure and optimum subcooling degree. The maximum overall COP, optimum subcooling degree and discharge pressure are closely related to the temperature glide of the mixtures. The energy efficiency of the transcritical CO2 refrigeration cycle can be efficiently improved, and the high pressure can be reduced when mixtures with proper temperature glide are used as MS cycle refrigerant. Compared with pure R32, the overall COP is enhanced by 4.91%, and the discharge pressure decreases by 0.11 MPa at evaporation temperature of −5 °C and ambient temperature of 35 °C when R32/R1234ze(Z) (55/45) is employed as MS refrigerant. The mixtures with proper temperature glide are recommended. The thermal performance of the overall cycle can be enhanced more significantly for hot and warm climate regions, or relative low evaporation temperature applications, though a high subcooling degree is required to meet the optimum operation condition.
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18.
  • Dai, Baomin, et al. (författare)
  • Environmental and economical analyses of transcritical CO2 heat pump combined with direct dedicated mechanical subcooling (DMS) for space heating in China
  • 2019
  • Ingår i: Energy Conversion and Management. - : PERGAMON-ELSEVIER SCIENCE LTD. - 0196-8904 .- 1879-2227. ; 198
  • Tidskriftsartikel (refereegranskat)abstract
    • An environmental and economical assessment model is developed, in order to evaluate the performances of transcritical CO2 heat pump system with dedicated mechanical subcooling (CO2 HPDMS). Introducing DMS to traditional CO2 HP system is an efficient method to reduce the primary energy consumption, which can be further decreased by using small temperature difference fan-coil unit (STD-FCU) as heating terminal. Using CO2 heat pump system for space heating is an environmentally-friendly heating method. The corresponding pollution emissions are only inferior to those of the wall hanging gas heater. The initial capital cost and operating cost of CO2 HPDMS system are both lower than those of CO2 HPBASE system, and the CO2 compressor cost accounts for about 80% of the overall initial capital cost. In contrast to other traditional heating methods, the payback periods of CO2 HPDMS system are not more than 9 years in most cases. If the CO2 compressor and electricity price are reduced by 20% and 28.79% respectively, the life cycle cost of CO2 HPDMS will be competitive to that of coal-fired boiler. In China, it is a promising way to adopt CO2 HPDMS for space heating in the near future with the assistant of electricity price subsidy and compressor price reduction.
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19.
  • Dai, B., et al. (författare)
  • Evaluation of transcritical CO 2 heat pump system integrated with mechanical subcooling by utilizing energy, exergy and economic methodologies for residential heating
  • 2019
  • Ingår i: Energy Conversion and Management. - : Elsevier Ltd. - 0196-8904 .- 1879-2227. ; 192, s. 202-220
  • Tidskriftsartikel (refereegranskat)abstract
    • A transcritical CO 2 heat pump (HP) system for residential space heating integrated with direct dedicated mechanical subcooling (DMS) is proposed, and mathematical models are developed to study the annual energetic and economic performances considering the influence of frosting. The operation characteristics by adopting different heating terminals used in five typical cities are also assessed. The results show a maximum coefficient of performance (COP) is achieved at the optimum discharge pressure and subcooling degree. The COP is promoted by 24.4% and the discharge pressure is decreased by 2.093 MPa at the ambient temperature of −10 °C and water supply/return temperature of 45/40 °C. The seasonal performance factor (SPF) is enhanced more noticeably for severe cold region. For the case of Harbin using floor-coil radiator (FCR) or normal fan-coil unit (N-FCU) as heating terminal, SPF is improved by 32.0%. The highest SPF is achieved when small temperature difference fan-coil unit (STD-FCU) is employed. The exergy efficiency can also be apparently improved, especially for the cities located in severe cold region and using FCR or N-FCU as heating terminal due to the reduction in throttling loss of CO 2 system. The purchased equipment cost and electricity cost of the CO 2 HP with DMS are both lower than those of traditional CO 2 heat pump system. The CO 2 HP DMS system using STD-FCU as heating terminal shows superior economical efficiency to traditional system, with levelized annual total cost reduced by 7.51–15.27%. 
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20.
  • Fanourgakis, George S., et al. (författare)
  • Evaluation of global simulations of aerosol particle and cloud condensation nuclei number, with implications for cloud droplet formation
  • 2019
  • Ingår i: Atmospheric Chemistry and Physics. - : Copernicus GmbH. - 1680-7316 .- 1680-7324. ; 19:13, s. 8591-8617
  • Tidskriftsartikel (refereegranskat)abstract
    • A total of 16 global chemistry transport models and general circulation models have participated in this study; 14 models have been evaluated with regard to their ability to reproduce the near-surface observed number concentration of aerosol particles and cloud condensation nuclei (CCN), as well as derived cloud droplet number concentration (CDNC). Model results for the period 2011-2015 are compared with aerosol measurements (aerosol particle number, CCN and aerosol particle composition in the submicron fraction) from nine surface stations located in Europe and Japan. The evaluation focuses on the ability of models to simulate the average across time state in diverse environments and on the seasonal and short-term variability in the aerosol properties. There is no single model that systematically performs best across all environments represented by the observations. Models tend to underestimate the observed aerosol particle and CCN number concentrations, with average normalized mean bias (NMB) of all models and for all stations, where data are available, of -24% and -35% for particles with dry diameters >50 and >120nm, as well as -36% and -34% for CCN at supersaturations of 0.2% and 1.0%, respectively. However, they seem to behave differently for particles activating at very low supersaturations (<0.1%) than at higher ones. A total of 15 models have been used to produce ensemble annual median distributions of relevant parameters. The model diversity (defined as the ratio of standard deviation to mean) is up to about 3 for simulated N3 (number concentration of particles with dry diameters larger than 3nm) and up to about 1 for simulated CCN in the extra-polar regions. A global mean reduction of a factor of about 2 is found in the model diversity for CCN at a supersaturation of 0.2% (CCN0.2) compared to that for N3, maximizing over regions where new particle formation is important. An additional model has been used to investigate potential causes of model diversity in CCN and bias compared to the observations by performing a perturbed parameter ensemble (PPE) accounting for uncertainties in 26 aerosol-related model input parameters. This PPE suggests that biogenic secondary organic aerosol formation and the hygroscopic properties of the organic material are likely to be the major sources of CCN uncertainty in summer, with dry deposition and cloud processing being dominant in winter. Models capture the relative amplitude of the seasonal variability of the aerosol particle number concentration for all studied particle sizes with available observations (dry diameters larger than 50, 80 and 120nm). The short-term persistence time (on the order of a few days) of CCN concentrations, which is a measure of aerosol dynamic behavior in the models, is underestimated on average by the models by 40% during winter and 20% in summer. In contrast to the large spread in simulated aerosol particle and CCN number concentrations, the CDNC derived from simulated CCN spectra is less diverse and in better agreement with CDNC estimates consistently derived from the observations (average NMB -13% and -22% for updraft velocities 0.3 and 0.6ms-1, respectively). In addition, simulated CDNC is in slightly better agreement with observationally derived values at lower than at higher updraft velocities (index of agreement 0.64 vs. 0.65). The reduced spread of CDNC compared to that of CCN is attributed to the sublinear response of CDNC to aerosol particle number variations and the negative correlation between the sensitivities of CDNC to aerosol particle number concentration (Nd=Na) and to updraft velocity (Nd=w). Overall, we find that while CCN is controlled by both aerosol particle number and composition, CDNC is sensitive to CCN at low and moderate CCN concentrations and to the updraft velocity when CCN levels are high. Discrepancies are found in sensitivities Nd=Na and Nd=w; models may be predisposed to be too "aerosol sensitive" or "aerosol insensitive" in aerosol-cloud-climate interaction studies, even if they may capture average droplet numbers well. This is a subtle but profound finding that only the sensitivities can clearly reveal and may explain intermodel biases on the aerosol indirect effect.
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21.
  • Galanopoulos, Christos, et al. (författare)
  • Impacts of acidic gas components on combustion of contaminated biomass fuels
  • 2018
  • Ingår i: Biomass and Bioenergy. - : Elsevier. - 0961-9534 .- 1873-2909. ; 111, s. 263-277
  • Tidskriftsartikel (refereegranskat)abstract
    • The formation of high concentrations of acid gases; in combustion with large variations in fuel qualities, represents a major challenge for energy production from contaminated biomass fuels. This paper provides a comprehensive evaluation of the effects of acid gas formation and retention in the combustion of recycled wood fuels. A model has been developed based on the chemical reactions involved and empirical correlations from plant monitoring and testing. The model has been used to study the behaviour of acidic gas components in critical stages of a bubbling fluidised bed boiler process. Results indicate that the variation in type of fuel contamination is the most important issue to deal with in the combustion of recycled wood fuels. Peaks in the flue gas chlorine concentrations cannot be suppressed easily by conventional flue gas cleaning measures. Upon applying ammonium sulphate dosing for the protection of chlorine induced corrosions, it is sometimes difficult to maintain the required S/Cl ratio when large variations of fuel chlorine occur. Moreover, a high level of chlorine in the fuel can also indirectly affect the emission control of sulphur dioxide because it would require an increased level of ammonium sulphate decomposition, which results in a high level of SO2 in flue gas. The study also shows a beneficial effect of the recirculation of quench water from the flue gas condenser to the boiler. It offers opportunities for the optimisation of flue gas cleaning and flue gas condensation, for improving the efficiencies of water and wastewater treatment, as well as for emission reduction with a sustainable way.
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22.
  • Gao, Y., et al. (författare)
  • Cooling pitch cabinets in wind turbines using a pulsating heat pipe : A case study
  • 2023
  • Ingår i: Case Studies in Thermal Engineering. - : Elsevier Ltd. - 2214-157X. ; 50
  • Tidskriftsartikel (refereegranskat)abstract
    • As the electric capacity of wind turbine increases, heat dissipation in pitch cabinets becomes challenging owing to the limited space and rotating conditions. To cool down the pitch cabinet more effectively and allow heat dissipation, we designed and implemented a pulsating heat pipe (PHP) in this study. We designed PHP parameters and conducted performance tests to compare the cooling performance of the fabricated PHP with that of an air-based cooling system in a 1.5 MW wind turbine. The results demonstrated steady PHP operation under rotating conditions (17.3 rpm). At a heat load of 1000 W, the evaporator outlet temperature was only 76.1 °C. However, increasing the ambient temperature adversely affected PHP operation, resulting in higher temperature and thermal resistance. The heat-pipe-based cooling system lowered the insulated gate bipolar transistor (IGBT) temperature by about 20.4 °C in relation to the air-based cooling system, while being suitable under varied conditions. Additionally, the system could successfully operate when the heat load of IGBT was 2350 W, corresponding to a 7 MW electric capacity of the wind turbine. Reducing the manufacturing cost of the heat pipe would further enhance the applicability of this system for pitch cabinet IGBT cooling, such as decreasing payback period. 
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23.
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24.
  • Gong, Xun, et al. (författare)
  • Of Atlantic Meridional Overturning Circulation in the CMIP6 Project
  • 2022
  • Ingår i: Deep-Sea Research Part II: Topical Studies in Oceanography. - : Elsevier BV. - 0967-0645 .- 1879-0100. ; 206
  • Tidskriftsartikel (refereegranskat)abstract
    • The Atlantic Meridional Overturning Circulation (AMOC) upper-cell circulation is widely linked to global oceans and climate. Here, we focus on a statistical overview about the modelled AMOCs on the basis of the historical simulations in the 5th and 6th phase of the Coupled Model Intercomparison Project (CMIP5 and CMIP6), including the modelled AMOC strength, cell structure, long-term trend and the variabilities on interannual, decadal and multi-decadal scales. Our results show that the multi-model averaged AMOC mean state of CMIP5 is insignificantly different from the CMIP6 results, meanwhile the corresponding multi-model averaged AMOC variability is reduced from CMIP5 to CMIP6 results. Moreover, the CMIP6 multi-model averaged AMOC becomes further distinct from the mean state of Rapid Climate Change (RAPID) observations. Overall, 7 out of the 18 CMIP6 models have suggested AMOC strengthening, meanwhile 6 models have indicated declining trends in the AMOC, with the rest 5 models in the variabilities with insignificant trends. Overall, the CMIP6 results have suggested pronounced modelling discrepancies in revealing AMOC trends, distinct from the more commonly weakening trend of the AMOCs in the CMIP5 simulations. Moreover, the multi-model averaged AMOC variabilities are comparable between CMIP5 and CMIP6 simulations, on inter-annual, decadal and multi-decadal time scales, with the discrepancies remaining among models.
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25.
  • Guo, S., et al. (författare)
  • Mobilized thermal energy storage : Materials, containers and economic evaluation
  • 2018
  • Ingår i: Energy Conversion and Management. - : Elsevier Ltd. - 0196-8904 .- 1879-2227. ; 177, s. 315-329
  • Tidskriftsartikel (refereegranskat)abstract
    • The transportation of thermal energy is essential for users who are located far away from heat sources. The networks connecting them achieve the goal in efficient heat delivery and reasonable cost, especially for the users with large heat demands. However, it is difficult to satisfy the heat supply of the detached or emergent users with the existing pipelines. Therefore, a promising alternative, called mobilized thermal energy storage (M-TES), was proposed to deliver the heat flexibly without the restriction of networks. In this paper, a review of studies on M-TES is conducted in terms of materials, containers and economic evaluation. The potential candidates of materials, such as sugar alcohols, hydrated salts, alkalies and zeolite are reviewed and compared based on their thermophysical properties, price, advantages and disadvantages. Various containers, including the shell-and-tube, encapsulated, direct-contact, detachable and sorptive types, are discussed from the aspects of configuration, performance and utilization. Furthermore, the studies on the economic evaluation of M-TES systems are summarized and discussed based on the analysis of the economic indicators, including initial cost, operating cost, revenue, subsidy and energy cost. Finally, the challenges and future perspectives for developing M-TES are presented.
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26.
  • Hailong, Liu, et al. (författare)
  • A simulation study of particles generated from pellet wear contacts during a laboratory test
  • Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
    • In the blast furnace process, material losses occur due to mechanical wear between charged iron ore pellets and are exhausted in the form of dust in the off-gases. A redesigned tribometer combined with a ventilation chamber was developed to identify the dust emission from the mechanical wear contact of pellets. In order to obtain a better understanding of the measurement results, a coupled drift flux with a unified Eulerian deposition model was adopted to investigate particle dispersion and deposition during tests. Two influential factors, namely the air condition (5-20 l/min) and particle size (1-20 µm) were examined. The predicted results were presented by introducing two parameters, namely the measurable fraction and the deposition fraction. For each air condition, the measurable fraction declines while the deposition fraction rises as particle size grows. The critical size of the particles that becomes airborne and captured at the outlet was identified to be around 20 µm. In addition, a high airflow rate supplied at the inlet was observed to be favorable for improving the measurable fraction. Nevertheless, the results show that nearly 50 % of emitted particles (1-20 µm) that failed to be captured during tests. Thus it could be expected that these generated particles would be transported deeply in a blast furnace if they are not efficiently removed from the off-gas. As a consequence, they may influence the quality of the products. Furthermore, the validation of the simulation results against the experimental data was achieved by using the predicted measurable fraction.
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27.
  • Han, Guilin, et al. (författare)
  • Carbon-nitrogen isotope coupling of soil organic matter in a karst region under land use change, Southwest China
  • 2020
  • Ingår i: Agriculture, Ecosystems & Environment. - : Elsevier. - 0167-8809 .- 1873-2305. ; 301, s. 1-11
  • Tidskriftsartikel (refereegranskat)abstract
    • The soil stable carbon (C) and nitrogen (N) isotopes are widely used to indicate C3/C4 vegetation history, N sources and transformation processes, respectively. However, land use change, particularly converting forest into farm land, alters soil organic matter (SOM) sources and processes in soils, resulting in a hard understanding of soil C and N fate. In the present study, soil organic carbon (SOC) and soil organic nitrogen (SON) contents, and their stable isotope compositions (δ13C and δ15N) were determined in the five soil profiles under land use change (i.e., conversion of native forest land into shrub land, grass land, maize field, and paddy land) in Lobo county, Guizhou province, Southwest China. A coupling of 13C and 15N isotope in SOM under land use change was verified whether it could provide more accurate indications of sources and transformation processes.The SOC and SON contents of native forest land at the 0∼20 cm depth were significantly larger than these under other transformed lands. The SOC and SON contents decreased exponentially with increasing soil depth under all land use types, and showed opposite trends with soil pH. The C/N ratios of SOM in the soils under undisturbed native forest decreased from 10 to 7 with increasing soil depth, while an irregular fluctuation along soil profile was shown in other transformed lands. Similarly to the most study in the soils under C3 forest, the δ13C and δ15N values of SOM in the soils under native forest at the 0∼50 cm depth increased with increasing soil depth, with the range of −27.7‰∼−25.7‰ and 6.5‰∼10.0‰, respectively. While decreasing trends of them in the soils below 50 cm depth were attributed to the mixing of 13C and 15N-depleted organic matters from bedrocks. However, the δ13C and δ15N values of SOM along the soil profiles under other transformed lands were intensively irregularly fluctuated between −29.1‰ and −19.0‰, 1.2‰ and 7.9‰, respectively. The single δ13C and δ15N signals in the soil profiles of transformed lands indeed revealed the alterations of historical C3/C4 composition and N transformation processes after land use change, but these indications were not specific. The result of the coupling of 13C and 15N isotope under native forest land reveals a positive relationship between them, which associated with full plant-absorption against 15N-depleted inorganic nitrogen derived from SOM mineralization. This study suggests that the coupling of CN isotope fractionation more likely occurs in the C3 forest ecosystem with high N utilization efficiency. However, the replacement of native forest by farm land or grass land will reduce soil N utilization efficiency.
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28.
  • Hao, Qian, et al. (författare)
  • Holocene carbon accumulation in lakes of the current east Asian monsoonal margin: Implications under a changing climate
  • 2020
  • Ingår i: Science of the Total Environment. - : Elsevier. - 0048-9697 .- 1879-1026. ; 737, s. 1-13
  • Tidskriftsartikel (refereegranskat)abstract
    • Carbon (C) present in lake sediments is an important global sink for CO2; however, an in-depth understanding of the impact of climate variability and the associated changes in vegetation on sediment C dynamics is still lacking. A total of 13 lakes were studied to quantify the influence of climate and vegetation on the reconstructed Holocene C accumulation rate (CAR) in lake sediments of the modern East Asian monsoonal margin. The corresponding paleoclimate information was assessed, including the temperature (30–90°N in the Northern Hemisphere) and precipitation (indicated by the δ18O of the Sanbao, Dongge, and Hulu caves). The Holocene vegetation conditions were inferred by pollen records, including arboreal pollen/non-arboreal pollen and pollen percentages. The results showed that the peak CAR occurred during the mid-Holocene, coinciding with the strongest period of the East Asian summer monsoon and expansion of forests. Lakes in the temperate steppe (TS) regions had a mean CAR of 13.41 ± 0.88 g C m−2 yr−1, which was significantly greater than the CARs of temperate desert (TD) and highland meadow/steppe (HMS; 6.76 ± 0.29 and 7.39 ± 0.73 g C m−2 yr−1, respectively). The major influencing factor for the TS sub-region was vegetation dynamics, especially the proportion of arboreal vegetation, while temperature and vegetation coverage were more important for the HMS. These findings indicate that C accumulation in lake sediments is linked with climate and vegetation changes over long timescales; however, there was notable spatial heterogeneity in the CARs, such as opposing temporal changes and different major influencing factors among the three sub-regions during the mid-Holocene. Aridification and forest loss would decrease C storage. However, prediction of C accumulation remains difficult because of the spatial heterogeneity in CARs and the interaction between the CAR and various factors under future climate change conditions.
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29.
  • Hao, Qian, et al. (författare)
  • Organic blue carbon sequestration in vegetated coastal wetlands: Processes and influencing factors
  • 2024
  • Ingår i: Earth-Science Reviews. - 0012-8252 .- 1872-6828. ; 255, s. 104853-104853
  • Tidskriftsartikel (refereegranskat)abstract
    • Coastal wetlands play a vital role in carbon (C) sequestration, named ‘blue carbon’. The review aims to disentangle the processes and influencing factors, including elevated atmospheric CO2, global climate warming, sea level rise and anthropogenic activities. Firstly, we provided an overview of C processes, including input, output, and deposition, in coastal wetlands. We then summarized the impacts of different factors on C processes by modifying soil physicochemical properties, plant growth, vegetation type, and microbial community composition. Vegetation composition was a major contributor to C inputs, and C outputs was mainly controlled by microbial decomposition. Increased atmospheric CO2 concentration and associated climate warming often enhanced vegetation growth, while climate warming also promoted soil C decomposition. As a result, C storage could increase under mild warming conditions in the short-term, but decrease in the long-term as the severity of warming intensifies. Elevated salinity, caused by sea level rise, can be harmful to plant growth and inhibit organic C decomposition because of the reduced biomass and the weakened metabolic capacity of microorganisms. Most of human activities, such as reclamation, can lead to less C input and more C output, resulting in decreased C storage in coastal wetlands. Additionally, we also illustrate various coastal wetland restoration methods aimed at enhancing C sequestration, including legal frameworks, scientific theories, vegetation management, hydrological restoration, and other relevant constructions. Vegetation management could benefit plant growth and enhance C input effectively, and hydrological restoration can maintain the harmonious development of coastal wetland ecosystems. Other constructions, including breakwater, spillway, and dredged material, could protect coastal wetlands, especially facing sea level rise. This review offers valuable theoretical support and scientific references for the sustainable development and management of coastal wetlands in a changing climate.
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30.
  • He, W., et al. (författare)
  • Optimal Thermal Management Of Server Cooling System Based Cooling Tower Under Different Ambient Temperatures
  • 2022
  • Ingår i: Applied Thermal Engineering. - : Elsevier Ltd. - 1359-4311 .- 1873-5606. ; 207
  • Tidskriftsartikel (refereegranskat)abstract
    • To develop a highly efficient and energy-saving cooling system in a data center, this study investigates the optimal thermal management both on the internal server cooling cycle and external cold source water cycle under different ambient temperatures based on the principle of minimal power consumption. Taking a server cabinet of 4.8 kW as the case, an internal indirect water-cooled heat sink cycle and an external cooling tower cold source cycle are constructed. A hybrid thermal management model combined with a heat dissipation model and a power consumption model was developed with the aid of MATLAB and TRNSYS. Using this model, the relationship between the chip dissipation performance attached to the fin-type heat sink and the energy consumption performance of the cooling system under different water working conditions and ambient temperatures was analyzed. Finally, to achieve minimal system energy consumption, the optimized inlet temperature and water flow rates corresponding to different ambient temperatures were obtained by fitting expressions that can better serve the optimal design of data center cooling systems. Furthermore, when the optimal value was applied using the year-round temperature of Tianjin, China in the case study, a 21.3% reduction in power consumption and a 4.43% decrease in the power usage effectiveness can be achieved compared to the case without optimization. Therefore, significant power can be saved in a data center cooling system through thermal management optimization. 
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31.
  • Heuzé, Céline, 1988, et al. (författare)
  • No Emergence of Deep Convection in the Arctic Ocean Across CMIP6 Models
  • 2024
  • Ingår i: Geophysical Research Letters. - 0094-8276 .- 1944-8007. ; 51
  • Tidskriftsartikel (refereegranskat)abstract
    • As sea ice disappears, the emergence of open ocean deep convection in the Arctic, which would enhance ice loss, has been suggested. Here, using 36 state-of-the-art climate models and up to 50 ensemble members per model, we show that Arctic deep convection is rare under the strongest warming scenario. Only five models have convection by 2100, while 11 have had convection by the middle of the run. For all, the deepest mixed layers are in the eastern Eurasian basin. When that region undergoes a salinification and increasing wind speeds, the models convect; yet most models are freshening. The models that do not convect have the strongest halocline and most stable sea ice, but those that lose their ice earliest -because of their strongly warming Atlantic Water- do not have a persistent deep convection: it shuts down mid-century. Halocline and Atlantic Water changes urgently need to be better constrained in models.
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32.
  • Hu, C., et al. (författare)
  • Different control strategies for MEA based chemical absorption
  • 2021
  • Ingår i: Energy Proceedings. - : Scanditale AB.
  • Konferensbidrag (refereegranskat)abstract
    • When capturing CO2 from biomass fired combined heat and power plants, the dynamic changes in the feedstock and the heat and electricity demands can clearly affect the operation of the boiler, which can further affect the performance of chemical absorption CO2 capture. To handle such dynamic changes, control systems are needed. This work aims to compare the performance of two control strategies that can control the reboiler duty in the stripper to achieve a constant capture rate. Control strategy A uses the reboiler temperature as input based on a PID controller; and control strategy B is a modification of control strategy A by introducing a feedforward compensation based on the flowrate of rich solution when regulating the reboiler duty. Based on dynamic simulations, it is found that control strategy B can reduce the settling time and capture more CO2 with a lower average energy penalty within a certain time length.
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33.
  • Huang, Q., et al. (författare)
  • Dynamic operating characteristics of a compressed CO2 energy storage system
  • 2023
  • Ingår i: Applied Energy. - : Elsevier Ltd. - 0306-2619 .- 1872-9118. ; 341
  • Tidskriftsartikel (refereegranskat)abstract
    • For the first time, the study investigated the dynamic performances of a compressed CO2 energy storage (CCES) system based on a dynamic model, which was validated using experimental data. The dynamic round-trip efficiency (RTE) of a scaled-up CCES system in two typical operation modes was studied, including Mode 1: the basic operation mode, where the inlet pressure of the compressor or the expander is not controlled, and Mode 2: the controlled operation mode, where the capacity for compression or expansion is regulated to remain constant. Dynamic RTE varies in the range 16.7%-56.7% in various operation modes. A new key performance indicator, utilization of tank (UOT), was defined to reflect how much working gas is used in a charging or a discharging process. In general, high charging and high discharging capacities lead to low UOTs and low RTEs. Moreover, the comparison between the dynamic model and its equivalent steady-state model showed a significant difference in system performances. The RTE of the steady-state model reaches 68.5%, which is much higher than the corresponding dynamic RTE of 55.3%. © 2023
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34.
  • Huang, Qingxi, et al. (författare)
  • Integrating compressed CO(2 )energy storage in an oxy-coal combustion power plant with CO2 capture
  • 2022
  • Ingår i: Energy. - : PERGAMON-ELSEVIER SCIENCE LTD. - 0360-5442 .- 1873-6785. ; 254
  • Tidskriftsartikel (refereegranskat)abstract
    • To compensate for the high cost of CO2 capture, this study proposes a novel solution that integrates a compressed CO2 energy storage (CCES) system into an oxy-coal combustion power plant with CO2 capture (Oxy_CCES). The integration of energy storage has the potential to create arbitrage from variations in electricity prices. The proposed Oxy_CCES system can achieve a higher net efficiency of 34.1%, and a higher exergy efficiency of 57.5%, than that of a liquified oxygen storage-integrated oxy-coal combustion power plant (Oxy_O-2). Two scenarios, i.e., retrofitting an existing oxy-coal combustion power plant (S-I) and building a new plant (S-II), were established to compare the Oxy_CCES and Oxy_O-2. In S-I, the payback time of the Oxy_CCES is one year and in the S-II the levelized cost of electricity (LCOE) of the Oxy_CCES increases by 1.8%, which is lower than that of the Oxy_O-2. The sensitivity analysis shows that, when the difference between the peak and the valley electricity prices and the capacities of the energy storage systems increase by 50%, the net present value (NPV) and LCOE of the Oxy_CCES system increase by 113.4% and 1.7% respectively, which are lower than the NPV and LCOE increase of the Oxy_O-2.
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35.
  • Jain, Shubham, et al. (författare)
  • Engineering 3D degradable, pliable scaffolds toward adipose tissue regeneration; optimized printability, simulations and surface modification
  • 2020
  • Ingår i: Journal of Tissue Engineering. - : SAGE Publications. - 2041-7314. ; 11
  • Tidskriftsartikel (refereegranskat)abstract
    • We present a solution to regenerate adipose tissue using degradable, soft, pliable 3D-printed scaffolds made of a medical-grade copolymer coated with polydopamine. The problem today is that while printing, the medical grade copolyesters degrade and the scaffolds become very stiff and brittle, being not optimal for adipose tissue defects. Herein, we have used high molar mass poly(L-lactide-co-trimethylene carbonate) (PLATMC) to engineer scaffolds using a direct extrusion-based 3D printer, the 3D Bioplotter (R). Our approach was first focused on how the printing influences the polymer and scaffold's mechanical properties, then on exploring different printing designs and, in the end, on assessing surface functionalization. Finite element analysis revealed that scaffold's mechanical properties vary according to the gradual degradation of the polymer as a consequence of the molar mass decrease during printing. Considering this, we defined optimal printing parameters to minimize material's degradation and printed scaffolds with different designs. We subsequently functionalized one scaffold design with polydopamine coating and conducted in vitro cell studies. Results showed that polydopamine augmented stem cell proliferation and adipogenic differentiation owing to increased surface hydrophilicity. Thus, the present research show that the medical grade PLATMC based scaffolds are a potential candidate towards the development of implantable, resorbable, medical devices for adipose tissue regeneration.
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36.
  • Katlein, Christian, et al. (författare)
  • Platelet Ice Under Arctic Pack Ice in Winter
  • 2020
  • Ingår i: Geophysical Research Letters. - 0094-8276 .- 1944-8007. ; 47:16
  • Tidskriftsartikel (refereegranskat)abstract
    • The formation of platelet ice is well known to occur under Antarctic sea ice, where subice platelet layers form from supercooled ice shelf water. In the Arctic, however, platelet ice formation has not been extensively observed, and its formation and morphology currently remain enigmatic. Here, we present the first comprehensive, long-term in situ observations of a decimeter thick subice platelet layer under free-drifting pack ice of the Central Arctic in winter. Observations carried out with a remotely operated underwater vehicle (ROV) during the midwinter leg of the MOSAiC drift expedition provide clear evidence of the growth of platelet ice layers from supercooled water present in the ocean mixed layer. This platelet formation takes place under all ice types present during the surveys. Oceanographic data from autonomous observing platforms lead us to the conclusion that platelet ice formation is a widespread but yet overlooked feature of Arctic winter sea ice growth.
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37.
  • Kimel, Alexey, et al. (författare)
  • The 2022 magneto-optics roadmap
  • 2022
  • Ingår i: Journal of Physics D. - : Institute of Physics (IOP). - 0022-3727 .- 1361-6463. ; 55:46
  • Tidskriftsartikel (refereegranskat)abstract
    • Magneto-optical (MO) effects, viz. magnetically induced changes in light intensity or polarization upon reflection from or transmission through a magnetic sample, were discovered over a century and a half ago. Initially they played a crucially relevant role in unveiling the fundamentals of electromagnetism and quantum mechanics. A more broad-based relevance and wide-spread use of MO methods, however, remained quite limited until the 1960s due to a lack of suitable, reliable and easy-to-operate light sources. The advent of Laser technology and the availability of other novel light sources led to an enormous expansion of MO measurement techniques and applications that continues to this day (see section 1). The here-assembled roadmap article is intended to provide a meaningful survey over many of the most relevant recent developments, advances, and emerging research directions in a rather condensed form, so that readers can easily access a significant overview about this very dynamic research field. While light source technology and other experimental developments were crucial in the establishment of today's magneto-optics, progress also relies on an ever-increasing theoretical understanding of MO effects from a quantum mechanical perspective (see section 2), as well as using electromagnetic theory and modelling approaches (see section 3) to enable quantitatively reliable predictions for ever more complex materials, metamaterials, and device geometries. The latest advances in established MO methodologies and especially the utilization of the MO Kerr effect (MOKE) are presented in sections 4 (MOKE spectroscopy), 5 (higher order MOKE effects), 6 (MOKE microscopy), 8 (high sensitivity MOKE), 9 (generalized MO ellipsometry), and 20 (Cotton–Mouton effect in two-dimensional materials). In addition, MO effects are now being investigated and utilized in spectral ranges, to which they originally seemed completely foreign, as those of synchrotron radiation x-rays (see section 14 on three-dimensional magnetic characterization and section 16 on light beams carrying orbital angular momentum) and, very recently, the terahertz (THz) regime (see section 18 on THz MOKE and section 19 on THz ellipsometry for electron paramagnetic resonance detection). Magneto-optics also demonstrates its strength in a unique way when combined with femtosecond laser pulses (see section 10 on ultrafast MOKE and section 15 on magneto-optics using x-ray free electron lasers), facilitating the very active field of time-resolved MO spectroscopy that enables investigations of phenomena like spin relaxation of non-equilibrium photoexcited carriers, transient modifications of ferromagnetic order, and photo-induced dynamic phase transitions, to name a few. Recent progress in nanoscience and nanotechnology, which is intimately linked to the achieved impressive ability to reliably fabricate materials and functional structures at the nanoscale, now enables the exploitation of strongly enhanced MO effects induced by light–matter interaction at the nanoscale (see section 12 on magnetoplasmonics and section 13 on MO metasurfaces). MO effects are also at the very heart of powerful magnetic characterization techniques like Brillouin light scattering and time-resolved pump-probe measurements for the study of spin waves (see section 7), their interactions with acoustic waves (see section 11), and ultra-sensitive magnetic field sensing applications based on nitrogen-vacancy centres in diamond (see section 17). Despite our best attempt to represent the field of magneto-optics accurately and do justice to all its novel developments and its diversity, the research area is so extensive and active that there remains great latitude in deciding what to include in an article of this sort, which in turn means that some areas might not be adequately represented here. However, we feel that the 20 sections that form this 2022 magneto-optics roadmap article, each written by experts in the field and addressing a specific subject on only two pages, provide an accurate snapshot of where this research field stands today. Correspondingly, it should act as a valuable reference point and guideline for emerging research directions in modern magneto-optics, as well as illustrate the directions this research field might take in the foreseeable future.
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38.
  • Li, Qiang, et al. (författare)
  • Microbial Necromass, Lignin, and Glycoproteins for Determining and Optimizing Blue Carbon Formation
  • 2024
  • Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 58, s. 468-479
  • Tidskriftsartikel (refereegranskat)abstract
    • Coastal wetlands contribute to the mitigation of climate change through the sequestration of “blue carbon”. Microbial necromass, lignin, and glycoproteins (i.e., glomalin-related soil proteins (GRSP)), as important components of soil organic carbon (SOC), are sensitive to environmental change. However, their contributions to blue carbon formation and the underlying factors remain largely unresolved. To address this paucity of knowledge, we investigated their contributions to blue carbon formation along a salinity gradient in coastal marshes. Our results revealed decreasing contributions of microbial necromass and lignin to blue carbon as the salinity increased, while GRSP showed an opposite trend. Using random forest models, we showed that their contributions to SOC were dependent on microbial biomass and resource stoichiometry. In N-limited saline soils, contributions of microbial necromass to SOC decreased due to increased N-acquisition enzyme activity. Decreases in lignin contributions were linked to reduced mineral protection offered by short-range-ordered Fe (FeSRO). Partial least-squares path modeling (PLS-PM) further indicated that GRSP could increase microbial necromass and lignin formation by enhancing mineral protection. Our findings have implications for improving the accumulation of refractory and mineral-bound organic matter in coastal wetlands, considering the current scenario of heightened nutrient discharge and sea-level rise.
  •  
39.
  • Li, Xueqiang, et al. (författare)
  • Key factors affecting the performance of the multi-stream heat exchanger for CO2 condensation
  • 2023
  • Ingår i: International journal of thermal sciences. - : Elsevier Masson s.r.l.. - 1290-0729 .- 1778-4166. ; 192
  • Tidskriftsartikel (refereegranskat)abstract
    • The multi-stream heat exchanger (MS-HEX) is an important equipment in CO2 capture processes, especially for CO2 condensation. By now, little attention has been paid to thoroughly investigating its performance. To provide insights for optimizing the design and operation of the MS-HEX, this paper evaluated the impacts of some key factors, such as the flow arrangement and the content of non-condensable (NC) gases, on the performances of the MS-HEX, including the exit vapor fraction, the pressure drop, the heat transfer coefficient (HTC), and the sub-cooling degree. A 3D CFD model was developed and validated. Based on simulations, it was found that the flow arrangement can clearly affect the performance of the MS-HEX, and there existed an optimal one, which can give the highest sub-cooling degree. Moreover, increasing the volume fraction of NC gases can lead to a decrease of the HTC and the sub-cooling degree; and Ar showed the biggest impact, followed by O2 and N2. For instance, compared to condensing a stream containing 5 vol % N2, condensing a stream containing 5 vol % Ar led to a lower HTC and a lower sub-cooling degree, which can be up to 27.3% and 4 K, respectively.
  •  
40.
  • Li, Xueqiang, et al. (författare)
  • Optimizing cooling electronic chips at high altitude with consideration of solar radiation
  • 2023
  • Ingår i: International journal of thermal sciences. - : Elsevier. - 1290-0729 .- 1778-4166. ; 183
  • Tidskriftsartikel (refereegranskat)abstract
    • Maintaining a proper working environment for electronic chips is challenging for airships, as the ambient parameters at high altitude are largely different from those on the ground, which can influence the performance of cooling. This work aims to optimize the finned sink to minimize the weight with the consideration of the impact of solar radiation. By using a validated 3D model, it was found that the ignorance of the solar radiation can lead to a temperature deviation of 4.1 °C for electronic chips at 20 km when the solar radiation intensity was 1400 W/m2 and the wind speed was 10 m/s. Meanwhile, compared to the solar radiation intensity and the emissivity, the direction of solar radiation showed more impacts. In addition, even though the solar radiation doesn't influence the optimal fin height, fin number, and fin thickness, it would clearly affect the optimal heat transfer area ratio. As a result, it can clearly change the optimized weight, which was 5.7% higher if the solar radiation was not considered. © 2022 The Authors
  •  
41.
  • Li, Y., et al. (författare)
  • A life cycle analysis techno-economic assessment framework for evaluating future technology pathways – The residential air-conditioning example
  • 2021
  • Ingår i: Applied Energy. - : Elsevier Ltd. - 0306-2619 .- 1872-9118. ; 291
  • Tidskriftsartikel (refereegranskat)abstract
    • Clarity on cost and environmental benefits of individual technologies evaluated in a systemic and systematic manner is necessary in communicating the results at the policy level so as to enable effective decisions. Yet, the highly complex nature of many energy modelling tools makes it difficult for non-specialists to interpret and make sense of their results. An integrated life cycle analysis and techno-economic assessment framework is proposed in this study, as a first step towards developing an alternative and potentially more intuitive energy systems modelling tool. The residential air-conditioning sector in the Southeast Asian context is used as an example to demonstrate the advantages of the modelling methodology in profiling future technology pathways. The use of best available R32 technology can lead to cumulative savings of 2195 million tonnes of greenhouse gas emissions in the region by 2050; while the best available R407C technology has an average cost of $40.85 per tonne of greenhouse gas abatement. In addition, our modelling tool is capable of profiling energy outlooks for emerging economies and will be further integrated with hourly energy analysis frameworks in the next steps of development. 
  •  
42.
  • Li, Y., et al. (författare)
  • Study on the optimal deployment for Photovoltaic components recycle in China
  • 2019
  • Ingår i: Energy Procedia. - : Elsevier Ltd. - 1876-6102. ; , s. 4298-4303
  • Konferensbidrag (refereegranskat)abstract
    • Photovoltaic (PV) production and installation surge in recent years because of technology development and policy orientation. However, due the deadlines of subsidy set by Chinese government, most of the PV projects are carried out in a hurry and quality issues appear. Some equipment turn out to be inferiors. The demand for subsequent treatment for PV components will surge in the early future. However, the insufficiency of recycle facilities and supporting policies, lack of public focus, make it difficult. For a better planning of PV recycle, an optimization model is applied to study on the optimal deployment of PV recycle centers in China during 2040 to 2045 based on cost minimization. Transportation cost for PV modules, capital cost and operational cost for recycle center in different provinces are taken into consideration of objective functions. The result indicates that the peak of PV components recycle will arrive around 2042. At the early stage, recycle centers will be established in Zhejiang, Guangdong, and Shanxi province, considering the intensive installation and convenient transportation. The discarded PV panels will be transported to those provinces. Then, as the recycle demand surging, recycle centers will be scattered in many provinces, such as Jiangsu, Ningxia, Hebei, Inner Mongolia and so on. Most of the PV components will be recycled within the installed provinces. 
  •  
43.
  • Li, Y., et al. (författare)
  • The impact of dual-credit scheme on the development of the new energy vehicle industry
  • 2019
  • Ingår i: Energy Procedia. - : Elsevier Ltd. - 1876-6102. ; , s. 4311-4317
  • Konferensbidrag (refereegranskat)abstract
    • In order to further promote the development of the new energy vehicle industry, Parallel Management regulation for corporate average fuel consumption and new energy vehicle credits for passenger vehicles (dual-credit scheme) have been proposed by Ministry of Industry and Information Technology in September 2017. This study attempted to investigate the impact of dual-credit scheme on the penetration of new energy vehicles and the short-term strategies of the automotive industry. For this purpose, a market analysis model is proposed based on game theory and the credit market equilibrium to quantify the effects of the credit trading mechanism. Four categories of automakers are considered. The obtained results show that: (i) The dual-credit scheme is indeed an effective policy solution that enables the expansion of the volume of NEV market. (ii) The dual-credit scheme can accelerate the elimination of outdated technologies with lower driving mileage, and it can also promote the adoption of technologies with longer driving mileage. (iii) The dual-credit scheme allows all automakers to achieve their targets in a market efficient manner. 
  •  
44.
  • Lin, H., et al. (författare)
  • The impact of electric vehicle penetration and charging patterns on the management of energy hub : A multi-agent system simulation
  • 2018
  • Ingår i: Applied Energy. - : Elsevier Ltd. - 0306-2619 .- 1872-9118. ; 230, s. 189-206
  • Tidskriftsartikel (refereegranskat)abstract
    • In this paper, a multi-agent system (MAS) was developed to simulate the operation of an energy hub (EH) with different penetration rates (PRs) and various charging patterns of electric vehicle (EV). Three charging patterns, namely uncontrolled charging pattern (UCP), rapid charging pattern (RCP) and smart charging pattern (SCP), together with vehicle to grid (V2G), were simulated in the MAS. The EV penetration rates (EV-PRs), from 10% to 90% with a step of 20%, are considered in this study. Under the UCP, the peak load increases by 3.4–17.1% compared to the case without EVs, which is the reference case in this study. A main part of the increased electricity demand can be supplied by the gas turbine (GT) when the PR is lower, i.e. 71.7% under 10% PR and 37.4% under 50% PR. Under the SCP, the charging load of EVs is shifted to the valley period and thus the energy dispatch of the EH at 07:00–23:00 remain the same as that in the reference case. When V2G is considered, the electricity demand from the grid becomes the largest in all of the cases, e.g. the demand with 50% PR doubles the electricity demand in the reference case. However, the GT output decreases by 2.9–15.7% at 07:00–23:00 due to the effect of V2G. The variations in the EH's operation further raise the changes in energy cost, i.e. the electricity and cooling prices are lowered by 18.3% and 33.8% due to the availability of V2G and the heating and cooling prices increase by 3.5% and 4.3% under the UCP with the PR of 50%. Regarding the V2G capacity, near 39% of the EVs’ battery capacity can be discharged via V2G. In addition, the paper also produced a V2G potential line, which is an effective tool to provide the maximum potential of the EVs for peak shaving at any specific time.
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45.
  • Liu, Chunping, et al. (författare)
  • Genetic Structure and Hierarchical Population Divergence History of Acer mono var. mono in South and Northeast China
  • 2014
  • Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 9:1, s. e87187-
  • Tidskriftsartikel (refereegranskat)abstract
    • Knowledge of the genetic structure and evolutionary history of tree species across their ranges is essential for the development of effective conservation and forest management strategies. Acer mono var. mono, an economically and ecologically important maple species, is extensively distributed in Northeast China (NE), whereas it has a scattered and patchy distribution in South China (SC). In this study, the genetic structure and demographic history of 56 natural populations of A. mono var. mono were evaluated using seven nuclear microsatellite markers. Neighbor-joining tree and STRUCTURE analysis clearly separated populations into NE and SC groups with two admixed-like populations. Allelic richness significantly decreased with increasing latitude within the NE group while both allelic richness and expected heterozygosity showed significant positive correlation with latitude within the SC group. Especially in the NE region, previous studies in Quercus mongolica and Fraxinus mandshurica have also detected reductions in genetic diversity with increases in latitude, suggesting this pattern may be common for tree species in this region, probably due to expansion from single refugium following the last glacial maximum (LGM). Approximate Bayesian Computation-based analysis revealed two major features of hierarchical population divergence in the species' evolutionary history. Recent divergence between the NE group and the admixed-like group corresponded to the LGM period and ancient divergence of SC groups took place during mid-late Pleistocene period. The level of genetic differentiation was moderate (F-ST = 0.073; G(ST)' = 0.278) among all populations, but significantly higher in the SC group than the NE group, mirroring the species' more scattered distribution in SC. Conservation measures for this species are proposed, taking into account the genetic structure and past demographic history identified in this study.
  •  
46.
  • Liu, G., et al. (författare)
  • Numerical analysis of inner heating tube position for improving solid-phase transition in a shell-and-tube heat accumulator
  • 2023
  • Ingår i: Alexandria Engineering Journal. - : Elsevier B.V.. - 1110-0168 .- 2090-2670. ; 65, s. 771-784
  • Tidskriftsartikel (refereegranskat)abstract
    • Latent heat thermal storage (LHTS) system is vital to reduce environment pollution. In the shell-and-tube heat accumulator, the position of the inner heating tube plays a vital role in the thermal storage. To analyze the effect of the inner tube position on the phase transition, a two-dimensional numerical model is developed. The structure has the minimum full melting time of 3480 s when the inner tube is 12 mm (L = 12 mm) from the center. Compared with L = 0 mm, the full melting time at L = 12 mm can be reduced by 13.4%. 
  •  
47.
  • Liu, Hailong, et al. (författare)
  • A pin-on-disc study of airborne wear particles from dry sliding wheel-rail contacts
  • 2016
  • Ingår i: Civil-Comp Proceedings. - : Civil-comp press. - 1759-3433. ; 110
  • Tidskriftsartikel (refereegranskat)abstract
    • Pin-on-disc laboratory tests were carried out to identify the generation of airborne wear particles in wheel-rail contacts under different sliding velocities. The results show that the sliding velocity significantly influences both the number and size distribution of airborne wear particles. A comparison of the contact temperature was obtained during tests. For tests with high sliding velocities (1.2 and 3.4 m/s), the particle number concentration level was related to the elevated contact temperature in selected time intervals. Moreover, morphological and elemental analyses of collected particles and pin worn surfaces were studied by using a scanning electron microscope and field emission-scanning electron microscope. The data suggests that the oxide layers were detected within the pin's worn surfaces and an abundant presence of iron-oxide containing particles was observed. Therefore, it can be concluded that abundant fine and ultrafine airborne particles are more likely to be produced from an oxidative wear process in a wheel-rail contact under high sliding velocities.
  •  
48.
  • Liu, Hailong, et al. (författare)
  • A simulation study of airborne wear particles from laboratory wheel-rail contacts
  • 2016
  • Ingår i: Particuology. - : Elsevier. - 1674-2001 .- 2210-4291.
  • Tidskriftsartikel (refereegranskat)abstract
    • Laboratory measurements of airborne particles from sliding contacts are often performed using a tribometer located in a ventilation chamber. Although knowledge of particle transport behavior inside the chamber is required because it can influence the analysis of measurements, this knowledge is lacking. A numerical model was built based on the same geometry as a pin-on-disc measurement system to explain particle transport behavior inside the chamber and to determine the deviation between real amounts of generated and measured particles at the outlet. The effect of controlled flow conditions on the airflow pattern and particle transport inside the chamber was studied for different experimental conditions. Calculations show that a complex airflow pattern is formed by the spinning disc, and that it differs for each rotational speed. Simulation results reveal that particle transport in the chamber is governed mainly by the airflow pattern. The deposition velocity in the chamber was estimated and the possibility that part of the generated particles would remain in the chamber was studied. This led to an approximate estimation of particle loss rate. A comparison between experimental and simulated results with respect to the particle mass flow rate close to the outlet yields a reference factor of 0.7, which provides an indication of the difference between measured and real values.
  •  
49.
  • Liu, Hailong, et al. (författare)
  • A simulation study of off-gas particles generated from contact between pellets in a laboratory test
  • 2015
  • Ingår i: Proceedings of the 6th International Congress on the Science and Technology of Steelmaking, ICS 2015. - : Chinese Society for Metals. ; , s. 972-976
  • Konferensbidrag (refereegranskat)abstract
    • A pin-on-disc tribometer situated in a sealed cylindrical chamber was redesigned and used to find out the correlation between pellets properties and generated particles. To understand the results, it is important to understand the dust particle transport behavior inside the chamber. This could be achieved by using a simulation method. With the simulation, it is also possible to determine the operational parameters which in turn could be used to obtain good experimental results. Therefore, a model was built based on the same geometry as the particle measurement system. The flow field was firstly solved with the renormalized group (RNG) k-e turbulence model. Thereafter, a simplified drift-flux method was applied to simulate the particle transport inside the test chamber. Two important characteristics, gravitational separation and diffusion are considered in the modelling. Three groups of particles with different diameters (1nm, 1μm and 10μm) were released at the contact area between the pellets. The simulation results show that the influence of gravitational setting on particle transport is noticeable for 10μm particles, while the influence can be neglected for 1nm and 1μm. On the other hand, the diffusion has a lesser effect on particle dispersion for 1nm, 1μm and 10μm particles. Moreover, the particle loss rate was estimated by the ratio between the amount of released and escaped particles in elapsed time. The results show that the measurable portion of large micro-particles can be increased by increasing the inlet air velocity.
  •  
50.
  • Liu, Hailong, et al. (författare)
  • A Simulation Study of Particles Generated from Pellet Wear Contacts during a Laboratory Test
  • 2016
  • Ingår i: ISIJ INTERNATIONAL. - : Iron and Steel Institute of Japan. - 0915-1559. ; 56:11, s. 1910-1919
  • Tidskriftsartikel (refereegranskat)abstract
    • In the blast furnace process, material losses occur due to mechanical wear between charged iron ore pellets and are exhausted in the form of dust in the off-gases. A redesigned tribometer combined with a ventilation chamber was developed to identify the dust emission from the mechanical wear contact of pellets. In order to obtain a better understanding of the measurement results, a coupled drift flux with a unified Eulerian deposition model was adopted to investigate particle dispersion and deposition during tests. Two influential factors, namely the air condition (5-20 L/min) and particle size (1-20 mu m) were examined. The predicted results were presented by introducing two parameters, namely the measurable fraction and the deposition fraction. For each air condition, the measurable fraction declines while the deposition fraction rises as particle size grows. The critical size of the particles that becomes airborne and captured at the outlet was identified to be around 20 mu m. In addition, a high airflow rate supplied at the inlet was observed to be favorable for improving the measurable fraction. Nevertheless, the results show that nearly 50% of emitted particles (1-20 mu m) that failed to be captured during tests. Thus it could be expected that these generated particles would be transported deeply in a blast furnace if they are not efficiently removed from the off-gas. As a consequence, they may influence the quality of the products. Furthermore, the validation of the simulation results against the experimental data was achieved by using the predicted measurable fraction.
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