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•MnO2/CNF-CNT coaxial cable mat is fabricated by electrospining and thermal treatment.•Specific capacitance of 483.5 F/g is achieved by the MnO2/CNF-CNT.•The energy density is ...209.4 Wh/kg at 1000 W/kg.
Supercapacitors (SCs) are important devices for energy storage because they provide a higher power density as compared to that of batteries. However, SCs with high energy density and good flexibility are still under development. In this study, we fabricated MnO2-coated Carbon nanotube (CNT)-embedded carbon nanofiber (CNF) (referred to as MnO2/CNF-CNT) core–shell cables to investigate pseudo-capacitators, while activated CNF-CNTs obtained by CO2 activation was used for Electrical double-layer capacitors (EDLCs). Owing to the unique structure of the materials and high electrical conductivity of the CNTs on the CNFs, a specific capacitance of 483.5 F/g was achieved using MnO2/CNF-CNT mat with 1 M Na2SO4 aqueous electrolyte at 0.5 A/g. A flexible MnO2/CNF-CNT supercapacitor was assembled, which was binder-free, electrically conductive media-free, and current collector-free. Further an asymmetric supercapacitor was assembled with the MnO2/CNF-CNT mat and activated CNF-CNT mat in an ionic liquid (1-ethyl-3-methylimidazolium bis (trifluoromethylsulfonyl) imide) electrolyte. The maximum specific capacitance of, energy density of and power density of 94.25 F/g, 209.4 Wh/kg and 1000 W/kg can be achieved with the asymmetric supercapacitor at 0.5 A/g and 4.0 V. We believe that these materials have significant potential for use in light-weight and flexible SCs.
In this study, we systematically investigated the plasmonic effects of silver nanoplates (Ag NPLs) embedded in organic and perovskite (PVSK) photovoltaic (PV) cells. Optical properties of the Ag NPLs ...were manipulated by varying their sizes and shapes through controllable wet chemical processes. As the lengths of the edges of the Ag NPLs increased, their surface plasmon resonance bands broadened, with the maximum extinction wavelength extending to as far as 750nm. After embedding various types of Ag NPLs into the PEDOT:PSS poly(3,4-ethylenedioxythiophene)/polystyrenesulfonate layer, the short-circuit photocurrent density increased by 7.6–17.5%, relative to that of the pre-optimized control PVs, with the power conversion efficiency (PCE) increasing by up to 13%. We obtained an optimized PCE of 8.5% for normal PVSK device under simulated AM 1.5G irradiation (100mWcm−2). After the incorporation of Ag NPLs, a much higher PCE of 9.6% was obtained. External quantum efficiencies were increased significantly as a result of the increased plasmonic scattering effect of Ag NPLs.
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•We study the plasmonic effects of silver nanoplates (Ag-NPLs) for PV application.•Properties of the Ag-NPLs can be controlled through wet chemical processes.•Ag-NPLs were embedded in organic and perovskite (PVSK) PV cells.•The performance of Ag-NPLs-embedding PV devices increase by up to 13%.•A PCE of 9.6% was achieved for PVSK PV cell with good stability.
Climate change poses a significant threat to humanity. Achieving net-zero emissions is a key goal in many countries. Among various energy resources, solar power generation is one of the prominent ...renewable energy sources. Previous studies have demonstrated that post-processing techniques such as bias correction can enhance the accuracy of solar power forecasting based on numerical weather prediction (NWP) models. To improve the post-processing technique, this study proposes a new day-ahead forecasting framework that integrates weather research and forecasting solar (WRF-Solar) irradiances and the total solar power generation measurements for five cities in northern, central, and southern Taiwan. The WRF-Solar irradiances generated by the Taiwan Central Weather Bureau (CWB) were first subjected to bias correction using the decaying average (DA) method. Then, the effectiveness of this correction method was verified, which led to an improvement of 22% in the forecasting capability from the WRF-Solar model. Subsequently, the WRF-Solar irradiances after bias correction using the DA method were utilized as inputs into the transformer model to predict the day-ahead total solar power generation. The experimental results demonstrate that the application of bias-corrected WRF-Solar irradiances enhances the accuracy of day-ahead solar power forecasts by 15% compared with experiments conducted without bias correction. These findings highlight the necessity of correcting numerical weather predictions to improve the accuracy of solar power forecasts.
This study proposed a model for deterministic and probabilistic wind power generation forecasting and its corresponding procedures. The main contents include numerical weather prediction (NWP) ...systems, data preprocessing techniques, and forecasting models that use artificial intelligence methods. NWP wind speeds generated by the Central Weather Bureau (CWB) of Taiwan based on three atmospheric models, namely deterministic weather research and forecasting (WRFD), radar weather research and forecasting (RWRF), and WRF-based ensemble prediction system (WEPS), were used as model inputs. In terms of data preprocessing, the NWP wind speeds were corrected based on the height of the wind turbines, and principal components analysis (PCA) and empirical mode decomposition (EMD) were also evaluated for their feature extraction performance. Artificial neural network (ANN), long short-term memory (LSTM), gated recurrent unit (GRU), and eXtreme gradient boosting (XGBoost) were the forecast models used to predict wind power generation. The forecast results demonstrated that the use of the XGBoost model in conjunction with both PCA and EMD data preprocessing achieved the most accurate forecasting. The average forecasting errors (i.e., normalized root mean square error (NRMSE) and mean absolute percentage error (MAPE)) were 5.43% and 3.30% for one-hour-ahead and 9.78% and 6.83% for one-day-ahead, respectively. The empirical data collected at a wind farm in Taiwan verified the accuracy of the proposed method. Thus, the importance of model selection, NWP, and data preprocessing is ultimately self-evident.
We developed a preconcentration method in which aerosol droplets containing enriched perfluorinated sulfonic acids (PFSs) are generated through bubble bursting and collected. The droplets were ...subjected to PFS analysis of perfluorohexane sulfonic acid (PFHxS) and perfluorooctanesulfonic acid (PFOS) through surface‐assisted laser desorption/ionization‐time‐of‐flight mass spectrometry; silver nanoplates (AgNPts) were assisting materials. The method was highly efficient, with an approximately three‐order magnitude enhancement (5 × 10−13 to 1 × 10−11 M). Ultralow PFS concentrations (0.5 ng/L of PFOS; 0.4 ng/L of PFHxS) were detected in preconcentrated tap water containing PFSs. Our method has potential for rapid real‐world PFS detection in water.
Coral reefs are suffering on a global scale due to human impacts, thereby necessitating cryopreservation efforts. The objective of this study was to develop a suitable vitrification and laser warming ...protocol for larvae of the scleractinian coral Seriatopora caliendrum, which inherit their dinoflagellate algal symbionts vertically. Toxicity experiments were conducted with the cryoprotectants (CPAs) ethylene glycol (EG), propylene glycol (PG), dimethyl sulfoxide (DMSO), glycerol (GLY), and methanol (METH; listed in order from least to most toxic), and larvae were subjected to vitrification and laser warming using 2 M EG + 1 M PG and 2 M EG + 1 M DMSO. Vitrification and laser warming (300 V, 10 ms pulse width, 2 mm beam diameter) using a vitrification solution of 2 M EG + 1 M PG, 40% w/v Ficoll, and 10% v/v gold nanobars (GNB) at a final concentration of 1.2 × 10
GNB/mL and a characteristic wavelength of 535 nm resulted in larvae with vitality and settlement percentages of 55 and 9%, respectively. This represents the first successful instance of cryopreservation of coral larvae that proceeded to settle upon warming, and suggests that the vitrification and ultra-fast laser warming approach may be applicable to other threatened marine species.
In recent years, the penetration of photovoltaic (PV) power generation in Taiwan has increased significantly. However, most photovoltaic facilities, especially for small-scale sites, do not include ...relevant monitoring and real-time measurement devices. The invisible power generation from these PV sites would cause a huge challenge on power system scheduling. Therefore, appropriate methods to estimate invisible PV power generation are needed. The main purpose of this paper is to propose an improved fuzzy model for estimating the PV power generation, which includes the clustering processing for PV sites, selection of representative PV sites, and the improvement of the conventional fuzzy model. First, this research uses the K-nearest neighbor (KNN) algorithm to fill in some of the missing data; then, two clustering algorithms are applied to cluster all the photovoltaic sites. Next, the relationship between the power generation of a single PV site and the total generation of all sites at the same cluster is further analyzed to select the representative PV sites. Finally, an improved fuzzy model is implemented to estimate the PV power generation. This research used actual data that were measured from PV sites in Taiwan for the estimation, verification, and comparison study. The numerical results demonstrate that the proposed method can obtain an average estimation error about 7% by using limit measurements from PV sites, highlighting the high efficiency and practicability of the proposed method.
The 5th International Taiwan Symposium on Raman Spectroscopy (TISRS 2017) and Taiwan Association of Raman Spectroscopy (TARS) Summer Camp were held from June 27th to 30th at National Chiayi ...University in Taiwan. Four plenary speakers and 14 invited speakers, from France, Hong Kong, India, Italy, Japan, New Zealand, Taiwan, and United States, presented their research findings in TISRS in front of an audience of more than 200 participants from 12 countries. Thirty‐seven posters in biology and material sciences were exhibited at the symposium. Following TISRS, five experts delivered lectures to students in the summer camp. The mission of this congress was to promote continuous developments and applications of Raman spectroscopy, with a focus this year on surface‐enhanced Raman scattering (SERS), tip‐enhanced Raman spectroscopy (TERS), imaging methods, and their applications to molecular, biological, and nanomaterial sciences. This meeting also served as a platform for junior researchers to exhibit their recent studies. In this report, we highlight novel findings and perspectives in Raman spectroscopy that emerged in this symposium. The topics of lecture given in the summer camp are listed.
The mission of this congress was to promote continuous developments and applications of Raman spectroscopy, with a focus this year on surface‐enhanced Raman scattering (SERS), tip‐enhanced Raman spectroscopy (TERS), imaging methods, and their applications to molecular, biological, and nanomaterial sciences. This meeting also served as a platform for junior researchers to exhibit their recent studies.
The proportion of renewable power generation in the world has been increasing in recent years. However, the fluctuations and uncertainties of renewable power generation bring a considerable challenge ...to future unit scheduling. Therefore, the generation flexibility in power systems becomes more critical as a large amount of renewable generation is integrated into power systems. The use of flexible generators with energy storage systems is one of the most efficient methods of improving power system flexibility. The primary purpose of this study is to explore the effect of generation flexibility on the cost of unit scheduling. A flexibility index is used to evaluate the generation flexibility in the Taiwan power system, and a multi-scenario analysis for renewable power integration is considered. This study also considers various system constraints, such as the unit commitment of actual hydro and thermal units, the scheduling of flexible internal combustion engines (ICEs) and energy storage systems, and possible curtailments of renewable power generation. According to the seasonable characteristics of renewable power generation, this study provides a suitable capacity for flexible ICE units and energy storage systems. Furthermore, this study demonstrates that the cost of unit scheduling is effectively reduced by increasing flexible ICE units and energy storage systems. The results of this study can be used as a reference for power systems in preparing flexible generating units and energy storage systems under the integration of a large amount of renewable power generation in the future.
This study investigates the effects of two salinity treatments (20‰ and 34‰) with seawater on the photocatalytic degradation of sulfonamide antibiotics (SAs). Three SAs, sulfamethoxazole (SMX), ...sulfamonomethoxine (SMM), and sulfadimethoxine (SDM), were respectively added (50 mg L−1) to saline water containing 100 mg L−1 of TiO2, and irradiated with ultraviolet (UV) light. The results revealed that the photocatalytic degradation and mineralization of the SAs decreased with an increasing level of salinity treatments. The residual concentrations of the chemical oxygen demand (COD) and dissolved organic carbon (DOC) in the solutions also revealed that SA mineralization decreased with the salinity treatments. The toxicity of the SA solutions to the bioluminescent bacteria, Vibrio fischeri, in the photocatalytic processes increased with the irradiation times, but decreased with an increasing level of salinity treatments. Further study indicated that the inhibitory effects of cations in seawater were Ca2+ > Mg2+ > K+ > Na+, whereas for anions they were I− > SO42− > Cl− > Br−.
•Salinity treatment reduced both the photolysis and photocatalytic degradation of the SAs.•SA solution toxicity decreased with salinity treatment.•The inhibitory effects of cations were Ca2+ > Mg2+ > K+ > Na+.•The inhibitory effects of anions were I− > SO42− > Cl− > Br−.•Mineralization in the photocatalytic processes of SAs can be inhibited by adding seawater.
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