| 1. |
- Li, Hailong, 1976-, et al.
(author)
-
Feasibility study about using a stand-alone wind power driven heat pump for space heating
- 2018
-
In: Applied Energy. - : Elsevier Ltd. - 0306-2619 .- 1872-9118. ; 228, s. 1486-1498
-
Journal article (peer-reviewed)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.
|
|
| 2. |
- Nookuea, Worrada, et al.
(author)
-
Viscosity Data of Aqueous MDEA-[Bmim][BF4] Solutions Within Carbon Capture Operating Conditions
- 2017
-
In: 8th International Conference on Applied Energy, ICAE2016, 8-11 October 2016, Beijing, China. - : Elsevier. ; 105, s. 4581-4586
-
Conference paper (peer-reviewed)abstract
- Post-combustion capture with chemical absorption shows higher potential for commercial scale application compared with other technologies. To capture CO2 from the industrial and power plant's flue gases, aqueous alkanolamine solutions are widely used. However, several drawbacks from utilizing the aqueous alkanolamines such as MEA still need to be solved. For example, alkanolamine solutions require intensive energy for regeneration and cause severe corrosion to the equipment though they have high reactivity in capturing CO2. Ionic liquids have been of interest in the recent development of chemical absorption according to their unique characteristics including wide liquid range, negligible volatility and thermal stability. However, due to their high price, high viscosity and low absorption capacity compared to alkanolamines, ionic liquids are still non-desirable for industrial applications. One possible solution to improve the performance of ionic liquids is to use mixtures of ionic liquids and alkanolamines. For a better understanding of the absorption using the mixture of aqueous alkanolamines and ionic liquids, the knowledge of thermo-physical properties of the solutions, especially the viscosity and density are of importance. This paper reports the measured viscosity of MDEA-[Bmim][BF4] aqueous mixtures at various temperatures and concentrations. It was found that the viscosity increase with an increase in [Bmim][BF4] concentration, but decrease with an increase in temperature. Moreover, the impact of temperature on the viscosity is more significant at low temperature range.
|
|
| 3. |
- Yu, Wenjin, et al.
(author)
-
Deep Learning-Based Classification of Cancer Cell in Leptomeningeal Metastasis on Cytomorphologic Features of Cerebrospinal Fluid
- 2022
-
In: Frontiers in Oncology. - : Frontiers Media SA. - 2234-943X. ; 12, s. 1-11
-
Journal article (peer-reviewed)abstract
- Background: It is a critical challenge to diagnose leptomeningeal metastasis (LM), given its technical difficulty and the lack of typical symptoms. The existing gold standard of diagnosing LM is to use positive cerebrospinal fluid (CSF) cytology, which consumes significantly more time to classify cells under a microscope.Objective: This study aims to establish a deep learning model to classify cancer cells in CSF, thus facilitating doctors to achieve an accurate and fast diagnosis of LM in an early stage.Method: The cerebrospinal fluid laboratory of Xijing Hospital provides 53,255 cells from 90 LM patients in the research. We used two deep convolutional neural networks (CNN) models to classify cells in the CSF. A five-way cell classification model (CNN1) consists of lymphocytes, monocytes, neutrophils, erythrocytes, and cancer cells. A four-way cancer cell classification model (CNN2) consists of lung cancer cells, gastric cancer cells, breast cancer cells, and pancreatic cancer cells. Here, the CNN models were constructed by Resnet-inception-V2. We evaluated the performance of the proposed models on two external datasets and compared them with the results from 42 doctors of various levels of experience in the human-machine tests. Furthermore, we develop a computer-aided diagnosis (CAD) software to generate cytology diagnosis reports in the research rapidly.Results: With respect to the validation set, the mean average precision (mAP) of CNN1 is over 95% and that of CNN2 is close to 80%. Hence, the proposed deep learning model effectively classifies cells in CSF to facilitate the screening of cancer cells. In the human-machine tests, the accuracy of CNN1 is similar to the results from experts, with higher accuracy than doctors in other levels. Moreover, the overall accuracy of CNN2 is 10% higher than that of experts, with a time consumption of only one-third of that consumed by an expert. Using the CAD software saves 90% working time of cytologists.Conclusion: A deep learning method has been developed to assist the LM diagnosis with high accuracy and low time consumption effectively. Thanks to labeled data and step-by-step training, our proposed method can successfully classify cancer cells in the CSF to assist LM diagnosis early. In addition, this unique research can predict cancer’s primary source of LM, which relies on cytomorphologic features without immunohistochemistry. Our results show that deep learning can be widely used in medical images to classify cerebrospinal fluid cells. For complex cancer classification tasks, the accuracy of the proposed method is significantly higher than that of specialist doctors, and its performance is better than that of junior doctors and interns. The application of CNNs and CAD software may ultimately aid in expediting the diagnosis and overcoming the shortage of experienced cytologists, thereby facilitating earlier treatment and improving the prognosis of LM.
|
|
| 4. |
- Abolfathi, Bela, et al.
(author)
-
The Fourteenth Data Release of the Sloan Digital Sky Survey : First Spectroscopic Data from the Extended Baryon Oscillation Spectroscopic Survey and from the Second Phase of the Apache Point Observatory Galactic Evolution Experiment
- 2018
-
In: Astrophysical Journal Supplement Series. - : IOP Publishing Ltd. - 0067-0049 .- 1538-4365. ; 235:2
-
Journal article (peer-reviewed)abstract
- The fourth generation of the Sloan Digital Sky Survey (SDSS-IV) has been in operation since 2014 July. This paper describes the second data release from this phase, and the 14th from SDSS overall (making this Data Release Fourteen or DR14). This release makes the data taken by SDSS-IV in its first two years of operation (2014-2016 July) public. Like all previous SDSS releases, DR14 is cumulative, including the most recent reductions and calibrations of all data taken by SDSS since the first phase began operations in 2000. New in DR14 is the first public release of data from the extended Baryon Oscillation Spectroscopic Survey; the first data from the second phase of the Apache Point Observatory (APO) Galactic Evolution Experiment (APOGEE-2), including stellar parameter estimates from an innovative data-driven machine-learning algorithm known as "The Cannon"; and almost twice as many data cubes from the Mapping Nearby Galaxies at APO (MaNGA) survey as were in the previous release (N = 2812 in total). This paper describes the location and format of the publicly available data from the SDSS-IV surveys. We provide references to the important technical papers describing how these data have been taken (both targeting and observation details) and processed for scientific use. The SDSS web site (www.sdss.org) has been updated for this release and provides links to data downloads, as well as tutorials and examples of data use. SDSS-IV is planning to continue to collect astronomical data until 2020 and will be followed by SDSS-V.
|
|
| 5. |
- Blanton, Michael R., et al.
(author)
-
Sloan Digital Sky Survey IV : Mapping the Milky Way, Nearby Galaxies, and the Distant Universe
- 2017
-
In: Astronomical Journal. - : IOP Publishing Ltd. - 0004-6256 .- 1538-3881. ; 154:1
-
Journal article (peer-reviewed)abstract
- We describe the Sloan Digital Sky Survey IV (SDSS-IV), a project encompassing three major spectroscopic programs. The Apache Point Observatory Galactic Evolution Experiment 2 (APOGEE-2) is observing hundreds of thousands of Milky Way stars at high resolution and. high signal-to-noise ratios in the near-infrared. The Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey is obtaining spatially resolved spectroscopy for thousands of nearby galaxies (median z similar to 0.03). The extended Baryon Oscillation Spectroscopic Survey (eBOSS) is mapping the galaxy, quasar, and neutral gas distributions between z similar to 0.6 and 3.5 to constrain cosmology using baryon acoustic oscillations, redshift space distortions, and the shape of the power spectrum. Within eBOSS, we are conducting two major subprograms: the SPectroscopic IDentification of eROSITA Sources (SPIDERS), investigating X-ray AGNs. and galaxies in X-ray clusters, and the Time Domain Spectroscopic Survey (TDSS), obtaining spectra of variable sources. All programs use the 2.5 m Sloan Foundation Telescope at the. Apache Point Observatory; observations there began in Summer 2014. APOGEE-2 also operates a second near-infrared spectrograph at the 2.5 m du Pont Telescope at Las Campanas Observatory, with observations beginning in early 2017. Observations at both facilities are scheduled to continue through 2020. In keeping with previous SDSS policy, SDSS-IV provides regularly scheduled public data releases; the first one, Data Release 13, was made available in 2016 July.
|
|
| 6. |
- Campana, Pietro Elia, et al.
(author)
-
Optimization and assessment of floating and floating-tracking PV systems integrated in on- and off-grid hybrid energy systems
- 2019
-
In: Solar Energy. - : PERGAMON-ELSEVIER SCIENCE LTD. - 0038-092X .- 1471-1257. ; 177, s. 782-795
-
Journal article (peer-reviewed)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.
|
|
| 7. |
- Firmansyah, Husni, et al.
(author)
-
Power and methanol production from biomass combined with solar and wind energy : analysis and comparison
- 2018
-
In: RENEWABLE ENERGY INTEGRATION WITH MINI/MICROGRID. - : ELSEVIER SCIENCE BV. ; , s. 576-581
-
Conference paper (peer-reviewed)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.
|
|
| 8. |
- Jiang, Sheng, et al.
(author)
-
Constructing Chromium Multioxide Hole-Selective Heterojunction for High-Performance Perovskite Solar Cells
- 2022
-
In: Advanced Science. - : Wiley. - 2198-3844. ; 9:30
-
Journal article (peer-reviewed)abstract
- Perovskite solar cells (PSCs) suffer from significant nonradiative recombination at perovskite/charge transport layer heterojunction, seriously limiting their power conversion efficiencies. Herein, solution-processed chromium multioxide (CrOx) is judiciously selected to construct a MAPbI(3)/CrOx/Spiro-OMeTAD hole-selective heterojunction. It is demonstrated that the inserted CrOx not only effectively reduces defect sites via redox shuttle at perovskite contact, but also decreases valence band maximum (VBM)-HOMO offset between perovskite and Spiro-OMeTAD. This will diminish thermionic losses for collecting holes and thus promote charge transport across the heterojunction, suppressing both defect-assisted recombination and interface carrier recombination. As a result, a remarkable improvement of 21.21% efficiency with excellent device stability is achieved compared to 18.46% of the control device, which is among the highest efficiencies for polycrystalline MAPbI(3) based n-i-p planar PSCs reported to date. These findings of this work provide new insights into novel charge-selective heterojunctions for further enhancing efficiency and stability of PSCs.
|
|
| 9. |
- Li, Hailong, 1976-, et al.
(author)
-
Capturing CO2 from Biogas Plants
- 2017
-
In: Energy Procedia. - : Elsevier Ltd. - 1876-6102. ; , s. 6030-6035, s. 6030-6035
-
Conference paper (peer-reviewed)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.
|
|
| 10. |
- Li, Hailong, et al.
(author)
-
Dynamic performance of the standalone wind power driven heat pump
- 2016
-
In: PROCEEDINGS OF RENEWABLE ENERGY INTEGRATION WITH MINI/MICROGRID (REM2016). - : ELSEVIER SCIENCE BV. ; 103, s. 40-45
-
Conference paper (peer-reviewed)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.
|
|
