| 1. |
- Aamodt, K., et al.
(författare)
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The ALICE experiment at the CERN LHC
- 2008
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Ingår i: Journal of Instrumentation. - 1748-0221. ; 3:S08002
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Forskningsöversikt (refereegranskat)abstract
- ALICE (A Large Ion Collider Experiment) is a general-purpose, heavy-ion detector at the CERN LHC which focuses on QCD, the strong-interaction sector of the Standard Model. It is designed to address the physics of strongly interacting matter and the quark-gluon plasma at extreme values of energy density and temperature in nucleus-nucleus collisions. Besides running with Pb ions, the physics programme includes collisions with lighter ions, lower energy running and dedicated proton-nucleus runs. ALICE will also take data with proton beams at the top LHC energy to collect reference data for the heavy-ion programme and to address several QCD topics for which ALICE is complementary to the other LHC detectors. The ALICE detector has been built by a collaboration including currently over 1000 physicists and engineers from 105 Institutes in 30 countries, Its overall dimensions are 16 x 16 x 26 m(3) with a total weight of approximately 10 000 t. The experiment consists of 18 different detector systems each with its own specific technology choice and design constraints, driven both by the physics requirements and the experimental conditions expected at LHC. The most stringent design constraint is to cope with the extreme particle multiplicity anticipated in central Pb-Pb collisions. The different subsystems were optimized to provide high-momentum resolution as well as excellent Particle Identification (PID) over a broad range in momentum, up to the highest multiplicities predicted for LHC. This will allow for comprehensive studies of hadrons, electrons, muons, and photons produced in the collision of heavy nuclei. Most detector systems are scheduled to be installed and ready for data taking by mid-2008 when the LHC is scheduled to start operation, with the exception of parts of the Photon Spectrometer (PHOS), Transition Radiation Detector (TRD) and Electro Magnetic Calorimeter (EMCal). These detectors will be completed for the high-luminosity ion run expected in 2010. This paper describes in detail the detector components as installed for the first data taking in the summer of 2008.
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| 2. |
- Campana, Pietro Elia, et al.
(författare)
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Optimization and assessment of floating and floating-tracking PV systems integrated in on- and off-grid hybrid energy systems
- 2019
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Ingår i: Solar Energy. - : PERGAMON-ELSEVIER SCIENCE LTD. - 0038-092X .- 1471-1257. ; 177, s. 782-795
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Tidskriftsartikel (refereegranskat)abstract
- Considering the targets of Thailand in terms of renewable energy exploitation and decarbonization of the shrimp farming sector, this work evaluates several scenarios for optimal integration of hybrid renewable energy systems into a representative shrimp farm. In particular, floating and floating-tracking PV systems are considered as alternatives for the exploitation of solar energy to meet the shrimp farm electricity demand. By developing a dynamic techno-economic simulation and optimization model, the following renewable energy systems have been evaluated: PV and wind based hybrid energy systems, off-grid and on-grid PV based hybrid energy systems, ground mounted and floating PV based hybrid energy systems, and floating and floating-tracking PV based hybrid energy systems. From a water-energy nexus viewpoint, floating PV systems have shown significant impacts on the reduction of evaporation losses, even if the energy savings for water pumping are moderate due to the low hydraulic head. Nevertheless, the study on the synergies between water for food and power production has highlighted that the integration of floating PV represents a key solution for reducing the environmental impacts of shrimp farming. For the selected location, the results have shown that PV systems represent the best renewable solution to be integrated into a hybrid energy system due to the abundance of solar energy resources as compared to the moderate wind resources. The integration of PV systems in off-grid configurations allows to reach high renewable reliabilities up to 40% by reducing the levelized cost of electricity. Higher renewable reliabilities can only be achieved by integrating energy storage solutions but leading to higher levelized cost of electricity. Although the floating-tracking PV systems show higher investment costs as compared to the reference floating PV systems, both solutions show similar competiveness for reliabilities up to 45% due to the higher electricity production of the floating-tracking PV systems. The higher electricity production from the floating-tracking PV systems leads to a better competitiveness for reliabilities higher than 90% due to lower capacity requirements for the storage systems.
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| 3. |
- Firmansyah, Husni, et al.
(författare)
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Power and methanol production from biomass combined with solar and wind energy : analysis and comparison
- 2018
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Ingår i: RENEWABLE ENERGY INTEGRATION WITH MINI/MICROGRID. - : ELSEVIER SCIENCE BV. ; , s. 576-581
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Konferensbidrag (refereegranskat)abstract
- This study addresses the techno-economic analysis and comparison of systems for power and methanol production from biomass combined with solar and wind energy, from both technical and economic perspectives. Three different systems, based on Integrated Gasification Combined-Cycle (IGCC), Oxy-fuel combustion, and syngas gasification, were evaluated. The hydrogen required for methanol production comes from water electrolysis driven by solar and wind energy. In addition, the effect of location was discussed.
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| 4. |
- He, Haoran, et al.
(författare)
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Deciphering microbiomes dozens of meters under our feet and their edaphoclimatic and spatial drivers
- 2024
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Ingår i: Global Change Biology. - 1354-1013. ; 30:1
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Tidskriftsartikel (refereegranskat)abstract
- Microbes inhabiting deep soil layers are known to be different from their counterpart in topsoil yet remain under investigation in terms of their structure, function, and how their diversity is shaped. The microbiome of deep soils (>1 m) is expected to be relatively stable and highly independent from climatic conditions. Much less is known, however, on how these microbial communities vary along climate gradients. Here, we used amplicon sequencing to investigate bacteria, archaea, and fungi along fifteen 18-m depth profiles at 20–50-cm intervals across contrasting aridity conditions in semi-arid forest ecosystems of China's Loess Plateau. Our results showed that bacterial and fungal α diversity and bacterial and archaeal community similarity declined dramatically in topsoil and remained relatively stable in deep soil. Nevertheless, deep soil microbiome still showed the functional potential of N cycling, plant-derived organic matter degradation, resource exchange, and water coordination. The deep soil microbiome had closer taxa–taxa and bacteria–fungi associations and more influence of dispersal limitation than topsoil microbiome. Geographic distance was more influential in deep soil bacteria and archaea than in topsoil. We further showed that aridity was negatively correlated with deep-soil archaeal and fungal richness, archaeal community similarity, relative abundance of plant saprotroph, and bacteria–fungi associations, but increased the relative abundance of aerobic ammonia oxidation, manganese oxidation, and arbuscular mycorrhizal in the deep soils. Root depth, complexity, soil volumetric moisture, and clay play bridging roles in the indirect effects of aridity on microbes in deep soils. Our work indicates that, even microbial communities and nutrient cycling in deep soil are susceptible to changes in water availability, with consequences for understanding the sustainability of dryland ecosystems and the whole-soil in response to aridification. Moreover, we propose that neglecting soil depth may underestimate the role of soil moisture in dryland ecosystems under future climate scenarios.
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| 5. |
- Li, Hailong, 1976-, et al.
(författare)
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Capturing CO2 from Biogas Plants
- 2017
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Ingår i: Energy Procedia. - : Elsevier Ltd. - 1876-6102. ; , s. 6030-6035, s. 6030-6035
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Konferensbidrag (refereegranskat)abstract
- As a renewable energy, biogas produced from anaerobic digestion and landfill is playing a more and more important role in the energy market. Capturing CO2 from biogas can result in a negative CO2 emission. Depending on how biogas is utilized, there are different routes to capture CO2. A biogas plant that uses raw biogas to produce power and heat can be retrofitted by integrating CO2 capture. In order to identify the best option, three retrofits were compared from both technical and economic perspectives, including SYS-I, which captures CO2 from raw gas and produces biomethane instead of electricity and heat, SYS-II, which captures CO2 using MEA-based chemical absorption after the combustion of raw gas, and SYS-III, which captures CO2 by using oxy-fuel combustion of the raw gas. In general, SYS-I can achieve the highest profit and shortest payback time, mainly due to the high price of biomethane. SYSII and SYS-III are clearly influenced by carbon credit. In order to have positive profits for the retrofits of SYS-II and SYS-III, carbon credit needs to exceed 750SEK (or 100USD)/ton CO2 and 113 SEK (or 15USD)/ton CO2 respectively.
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| 6. |
- Li, Hailong, et al.
(författare)
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Dynamic performance of the standalone wind power driven heat pump
- 2016
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Ingår i: PROCEEDINGS OF RENEWABLE ENERGY INTEGRATION WITH MINI/MICROGRID (REM2016). - : ELSEVIER SCIENCE BV. ; 103, s. 40-45
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Konferensbidrag (refereegranskat)abstract
- Reducing energy consumption and increasing use of renewable energy in the building sector are crucial to the mitigation of climate change. Wind power driven heat pumps have been considered as a sustainable measure to supply heat for detached houses, especially those that even don't have access to the grid. This work is to investigate the dynamic performance of a heat pump system directly driven by a wind turbine. The heat demand of a detached single family house was simulated in details. According to the simulations, the wind turbine is not able to provide the electricity demanded by the heat pump all the time due to the intermittent characteristic of wind power. To solve it, an electric energy storage system was included. Obviously, increasing the size of battery can always reduce the probability of load loss. However, different from the energy storage system, increasing the capacity of wind turbines is not necessary to reduce the probability of load loss instead, due to the different start-up speeds for different capacities of wind turbines. In order to maximize the system benefit, it is of great importance to optimize the capacity of the wind turbine and the size of the energy storage system simultaneously based on dynamic simulations.
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| 7. |
- Li, Hailong, 1976-, et al.
(författare)
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Feasibility study about using a stand-alone wind power driven heat pump for space heating
- 2018
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Ingår i: Applied Energy. - : Elsevier Ltd. - 0306-2619 .- 1872-9118. ; 228, s. 1486-1498
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Tidskriftsartikel (refereegranskat)abstract
- Reducing energy consumption and increasing the use of renewable energy in the building sector are crucial to the mitigation of climate change. Wind power driven heat pumps have been considered as a sustainable measure to supply heat to the detached houses, especially those that even do not have access to the electricity grid. This work is to investigate the dynamic performance of a heat pump system driven by wind turbine through dynamic simulations. In order to understand the influence on the thermal comfort, which is the primary purpose of space heating, the variation of indoor temperature has been simulated in details. Results show that the wind turbine is not able to provide the electricity required by the heat pump during the heating season due to the intermittent characteristic of wind power. To improve the system performance, the influences of the capacity of wind turbine, the size of battery and the setpoint of indoor temperature were assessed. It is found that increasing the capacity of wind turbines is not necessary to reduce the loss of load probability; while on the contrary, increasing the size of battery can always reduce the loss of load probability. The setpoint temperature clearly affects the loss of load probability. A higher setpoint temperature results in a higher loss of thermal comfort probability. In addition, it is also found that the time interval used in the dynamic simulation has significant influence on the result. In order to have more accurate results, it is of great importance to choose a high resolution time step to capture the dynamic behaviour of the heat supply and its effect on the indoor temperature.
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| 8. |
- Nookuea, Worrada, et al.
(författare)
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Comparison of Mass Transfer Models on Rate-Based Simulation of CO2 Absorption and Desorption Processes
- 2017
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Ingår i: Proceedings of the 9th International Conference on Applied Energy. - : Elsevier. ; 142, s. 3747-3752
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Konferensbidrag (refereegranskat)abstract
- The effective technology for capturing CO2 at the low concentration is chemical absorption, due to the high reactivity between CO2 and aqueous amine solutions. To capture CO2, the process involves complex reactive separations. The accurate calculation of hydrodynamic properties, and mass and energy transfer are of importance for the design of the absorber and desorber columns. This paper performs the rate-based simulations of CO2 absorption by Monoethanolamine in Aspen Plus. In the calculation of the mass transfer coefficients, different mass transfer models were implemented. In comparison with the desorber, the impacts of mass transfer models were more significant in the simulation of the absorber. For both columns, the impacts of the mass transfer models on the concentration profiles were more significant than those on the temperature profiles. For the absorber, the maximum deviations occur at the bottom of the column for both the concentration and the temperature profiles. Different from the absorber, for the desorber, the maximum deviations occur close to the top of the column.
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| 9. |
- Nookuea, Worrada, et al.
(författare)
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Impacts of thermo-physical properties of gas and liquid phases on design of absorber for CO2 capture using monoethanolamine
- 2016
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Ingår i: International Journal of Greenhouse Gas Control. - : Elsevier BV. - 1750-5836 .- 1878-0148. ; 52, s. 190-200
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Tidskriftsartikel (refereegranskat)abstract
- Absorption of CO2 with aqueous amines in post-combustion capture is characterized as a heat and mass transfer processes with chemical reaction, which is sensitively affected by the thermo-physical properties of fluids. In order to optimize the design of the absorber of CO2 capture process, in this paper, the impacts of thermo-physical properties on the column design were investigated. Furthermore, the property impacts on the capital cost of the absorber unit were also identified and analyzed. Results show that the gas phase density has the most significant effect on the column diameter. Underestimation of the gas phase density of 10% may result in an increase of about 6% of the column diameter. For the packing height, the liquid phase density has the most significant effect. 10% underestimation of the liquid phase density may result in an increase of 8% of the packing height. Moreover, the effect from the liquid phase viscosity is also significant. For the annual capital cost, the liquid phase density also shows the most significant effect. Underestimation of the liquid phase density of 10% leads to the cost overestimation of $1.4 million for the absorption column for a 400 MW coal-fired power plant. Therefore, the development of the flue gas density model and liquid phase density and viscosity models of the aqueous amine solution with CO2 loading should be prioritized.
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| 10. |
- Nookuea, Worrada, et al.
(författare)
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Sensitivity study of thermo-physical properties of gas phase on absorber design for CO2 capture using monoethanolamine
- 2015
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Ingår i: CLEAN, EFFICIENT AND AFFORDABLE ENERGY FOR A SUSTAINABLE FUTURE. - : Elsevier BV. ; 75, s. 2305-2310
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Konferensbidrag (refereegranskat)abstract
- Absorption of CO2 with aqueous amines in post-combustion capture is characterized as mass transfer process with chemical reaction. Hydrodynamics and mass transfer in gas and liquid phases in a packed column have significant influences on absorber design especially for the design of packing height. In this paper, the sensitivity study has been conducted to investigate the impacts of gas phase density, viscosity and diffusivity on the hydrodynamics and mass transfer and further the total packing height of a countercurrent flow with random packing column, using reactive absorption process and integral rate-based models. Results show that density and diffusivity have opposite effect to viscosity. Amongst various properties, diffusivity has the most significant effect on the packing height compared to density and viscosity. Overestimation of diffusivity of 5% may result in decrease of 3.2% of packing height. Moreover, developing more accurate diffusivity model should be prioritized for more accurate absorber design. (C) 2015 The Authors. Published by Elsevier Ltd.
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