ALBERT

Description: In this study we report on the sintering behavior, microstructure and electrical properties of Al-doped ZnO ceramics containing 0–0.2 wt. % graphene sheets (AZO-GNSs) and processed using spark plasma sintering (SPS). Our results show that the addition of 〈0.25 wt. % GNSs enhances both the relative density and the electrical resistivity of AZO ceramics. In terms of the microstructure, the GNSs are distributed at grain boundaries. In addition, the GNSs are also present between ZnO and secondary phases (e.g., ZnAl2O4) and likely contribute to the measured enhancement of Hall mobility (up to 105.1 cm2·V−1·s−1) in these AZO ceramics. The minimum resistivity of the AZO-GNS composite ceramics is 3.1 × 10−4 Ω·cm which compares favorably to the value of AZO ceramics which typically have a resistivity of 1.7 × 10−3 Ω·cm.

Description: The installation of stationary super-capacitor energy storage system (ESS) in metro systems can recycle the vehicle braking energy and improve the pantograph voltage profile. This paper aims to optimize the energy management, location, and size of stationary super-capacitor ESSes simultaneously and obtain the best economic efficiency and voltage profile of metro systems. Firstly, the simulation platform of an urban rail power supply system, which includes trains and super-capacitor energy storage systems, is established. Then, two evaluation functions from the perspectives of economic efficiency and voltage drop compensation are put forward. Ultimately, a novel optimization method that combines genetic algorithms and a simulation platform of urban rail power supply system is proposed, which can obtain the best energy management strategy, location, and size for ESSes simultaneously. With actual parameters of a Chinese metro line applied in the simulation comparison, certain optimal scheme of ESSes’ energy management strategy, location, and size obtained by a novel optimization method can achieve much better performance of metro systems from the perspectives of two evaluation functions. The simulation result shows that with the increase of weight coefficient, the optimal energy management strategy, locations and size of ESSes appear certain regularities, and the best compromise between economic efficiency and voltage drop compensation can be obtained by a novel optimization method, which can provide a valuable reference to subway company.

Description: The application of a stationary ultra-capacitor energy storage system (ESS) in urban rail transit allows for the recuperation of vehicle braking energy for increasing energy savings as well as for a better vehicle voltage profile. This paper aims to obtain the best energy savings and voltage profile by optimizing the location and size of ultra-capacitors. This paper firstly raises the optimization objective functions from the perspectives of energy savings, regenerative braking cancellation and installation cost, respectively. Then, proper mathematical models of the DC (direct current) traction power supply system are established to simulate the electrical load-flow of the traction supply network, and the optimization objections are evaluated in the example of a Chinese metro line. Ultimately, a methodology for optimal ultra-capacitor energy storage system locating and sizing is put forward based on the improved genetic algorithm. The optimized result shows that certain preferable and compromised schemes of ESSs’ location and size can be obtained, acting as a compromise between satisfying better energy savings, voltage profile and lower installation cost.

Description: Sustainability, Vol. 10, Pages 1459: Domestic Wheat Trade and Its Associated Virtual Cropland Flow in China, 2010–2015 Sustainability doi: 10.3390/su10051459 Authors: Xiaolin Chen Xiaojie Liu Litao Liu Yali Zhang Jinhua Guo Jing Huang Meijun Zhou Yang Zhao Liang Wu Lun Yang Fei Lun How to meet food demands with limited cropland has become a serious problem worldwide, especially in China. Global and national food trade can alleviate regional food unbalance among different countries or regions to some extent. The embedded virtual land also flows with food trade, and reasonable food trade can save global croplands and protect local ecosystems. Therefore, it is of great importance to study how trade influences land use as well as its associated environmental consequences. Recent studies have mainly focused on global food trade and its associated virtual land flow; however, only a few have focused on national food trade and its associated virtual land flow. Thus, this study aims to explore the domestic wheat trade and its associated virtual land flows in China during the period 2010–2015, based on the CHINAGRO model and previous studies. The Huang-Huai-Hai Plain and its surrounding regions were the main producers and consumers of wheat and virtual wheat. Without wheat stocks and international wheat trade, the annual domestic wheat trade accounted for 16.43% of the total national wheat production in China. Anhui was the largest net exporter of wheat, followed by Henan, while the developed areas such as Beijing, Guangdong, and Shanghai were the main net importers. Additionally, as an important transfer region, Jiangsu was the largest exporter and importer of wheat virtual cropland, but it finally presented as a net exporter of wheat cropland. During this period, domestic wheat trade led to a total land savings of 2.62 Mha/a, accounting for 10.80% of Chinese wheat cropland. However, compared with the year 2010, Shandong, Hebei, and Sichuan turned into wheat net importers in 2015, which was due to different reasons such as national agriculture polices and economic development. In addition, the net virtual cropland per capita has been greatly influenced by local economic development.

Description: Sensors, Vol. 17, Pages 2778: A Denoising Method for Randomly Clustered Noise in ICCD Sensing Images Based on Hypergraph Cut and Down Sampling Sensors doi: 10.3390/s17122778 Authors: Meng Yang Fei Wang Yibin Wang Nanning Zheng Intensified charge-coupled device (ICCD) images are captured by ICCD sensors in extremely low-light conditions. They often contains spatially clustered noises and general filtering methods do not work well. We find that the scale of the clustered noise in ICCD sensing images is often much smaller than that of the true structural information. Then the clustered noise can be identified by properly down-sampling and then up-sampling the ICCD sensing image and comparing it to the noisy image. Based on this finding, we present a denoising algorithm to remove the randomly clustered noise in ICCD images. First, we over-segment the ICCD image into a set of flat patches, and each patch contains very little structural information. Second, we classify the patches into noisy patches and noise-free patches based on the hypergraph cut method. Then the noise-free patches are easily recovered by the general block-matching and 3D filtering (BM3D) algorithm, since they often do not contain the clustered noise. The noisy patches are recovered by subtracting the identified clustered noise from the noisy patches. After that, we could get the whole recovered ICCD image. Finally, the quality of the recovered ICCD image is further improved by diminishing the remaining sparse noise with robust principal component analysis. Experiments are conducted on a set of ICCD images and compared with four existing denoising algorithms, which shows that the proposed algorithm removes well the randomly clustered noise and preserves the true textural information in the ICCD sensing images.

Description: Energies, Vol. 11, Pages 752: Optimization of Energy Management Strategy and Sizing in Hybrid Storage System for Tram Energies doi: 10.3390/en11040752 Authors: Yu Wang Zhongping Yang Fei Lin In order to design a well-performing hybrid storage system for trams, optimization of energy management strategy (EMS) and sizing is crucial. This paper proposes an improved EMS with energy interaction between the battery and supercapacitor and makes collaborative optimization on both sizing and EMS parameters to obtain the best working performance of the hybrid storage system. This paper demonstrates the whole process of the improvement of the EMS, the traction calculation, the parameter optimization, and the sizing optimization based on real tram and line conditions. The improved strategy is proven to be superior as it guarantees normal operation and avoids shutdown conditions when the supercapacitor is at a low voltage. Furthermore, the optimized sizing result largely decreases the weight of the storage system and obtains a long battery lifespan.

Description: Sustainability, Vol. 10, Pages 2158: Evaluation of Antimicrobial Activities of Seaweed Resources from Zhejiang Coast, China Sustainability doi: 10.3390/su10072158 Authors: Yong Li Siqi Sun Xiaowei Pu Yuzhe Yang Fei Zhu Shouyu Zhang Nianjun Xu In order to utilize seaweeds as a natural therapeutic agent in aquatic cultures, it is important to evaluate their antimicrobial activities. We analyzed that of the typical seaweeds of the Zhejiang Coast in order to improve their potential utilization. Six species of seaweeds were collected from the Zhejiang coast—Ulva pertusa, Ulva prolifera, Gloiopeltis furcata, Gracilariopsis lemaneiformis, Sargassum fusiforme and Ishige okamurae—and their ethanolic extracts were tested for antibacterial effects as well as antiviral activity against the white spot syndrome virus (WSSV). The seaweed extracts inhibited bacterial growth in vitro, and increased the immune responsiveness and survival of the crab Scylla paramamosain infected with WSSV in a concentration-dependent manner. U. prolifera, G. lemaneiformis, and S. fusiforme showed the most potent antibacterial activities and most significant enhancement of the innate immunity in healthy crabs. In conclusion, our study showed that the seaweed extracts have therapeutic effects and are a potential natural medicine for aquatic animals.

Description: Energies, Vol. 11, Pages 1764: Research on an Intelligent Behavior Evaluation System for Unmanned Ground Vehicles Energies doi: 10.3390/en11071764 Authors: Yang Sun He Yang Fei Meng A scientific and reasonable evaluation system for unmanned ground vehicles (UGVs) is very important. This paper studies the intelligent behavior of UGVs, and also proposes a comprehensive evaluation system for this intelligent behavior. The test and evaluation system includes the test content design, the test environment design, the test methods and the evaluation method. Using a hierarchical design approach, the test content is designed to be stage by stage, moving from simplicity to complexity and from individual modules to the entire vehicle. The hierarchical test environment is established according to the test content levels. The extension analytic hierarchy process (EAHP) has a better advantage than the analytic hierarchy process (AHP) to avoid the problem of the ambiguity of expert experience judgment and the consistency of the judgment matrix in determine the weight of each evaluation index. Using chaos theory to calculate the Lyapunov index, the quality of the trajectory of the UGV is characterized. The grey relational analysis method is used to analyze the correlation between the comparison series and the reference series, and a comprehensive quantitative result of the intelligent behavior of the UGV is obtained. The experiment shows that the intelligent behavior evaluation system of the UGV is scientific and effective.

Description: IJGI, Vol. 7, Pages 287: Utilizing MapReduce to Improve Probe-Car Track Data Mining ISPRS International Journal of Geo-Information doi: 10.3390/ijgi7070287 Authors: Li Zheng Meng Sun Yuejun Luo Xiangbo Song Chaowei Yang Fei Hu Manzhu Yu With the rapidly increasing popularization of the automobile, challenges and greater demands have come to the fore, including traffic congestion, energy crises, traffic safety, and environmental pollution. To address these challenges and demands, enhanced data support and advanced data collection methods are crucial and highly in need. A probe-car serves as an important and effective way to obtain real-time urban road traffic status in the international Intelligent Transportation System (ITS), and probe-car technology provides the corresponding solution through advanced navigation data, offering more possibilities to address the above problems. In addition, massive spatial data-mining technologies associated with probe-car tracking data have emerged. This paper discusses the major problems of spatial data-mining technologies for probe-car tracking data, such as true path restoration and the close correlation of spatial data. To address the road-matching issue in massive probe-car tracking data caused by the strong correlation combining road topology with map matching, this paper presents a MapReduce-based technology in the second spatial data model. The experimental results demonstrate that by implementing the proposed spatial data-mining system on distributed parallel computing, the computational performance was effectively improved by five times and the hardware requirements were significantly reduced.

Description: Lambertian surfaces represent an important assumption when constructing thermal radiance transfer equations for remote sensing observations of ground surface temperatures. We identify the properties of ground surfaces in thermal infrared regions as Lambertian surfaces via field experiments. Because Lambertian surfaces present homogeneous thermal emissions levels in hemispheric directions for a specific ground surface under specific kinetic temperatures and emissions, we conducted a series of field experiments to illustrate the properties of such ground surfaces. Four typical ground surfaces were selected for the experiments to observe thermal emissions: bare soil, grass, water, and concrete. Radiance thermometers were used to observe ground emissions from seven directions: 30°, 45°, 60°, 90°, 120°, 135°, and 150°. Solar zenith angles were considered for the observation of ground emissions. Experiments were conducted in five different regions of China (Beijing, Nanjing, Xilinguole, Yongzhou, and Jiangmen) during both daytime and nighttime. To determine whether different observation angles have significantly different effects on radiance, statistical analyses (ANOVA and Friedman test) were conducted. Post hoc multiple comparison tests and pairwise multiple comparisons were also conducted to examine the various pairings of observation angles and to measure the radiance differences. Roughly half of the radiance groups of all observed sites were tested via an ANOVA, and the remaining groups with unequal variances were subjected to the Friedman test. The results indicate that statistically significant differences in the radiance levels occurred among the seven angles for almost all of the sites (39 of the 40 groups). The results of our experiments indicate that the selected ground surfaces, especially the grass and the bare soil, may not behave with Lambertian properties in the thermal infrared region. This is probably attributed to the roughness of the selected surface, because we found that roughness is an important factor affecting the observed magnitude of thermal emission from different directions of the ground surface under study. Therefore, whether or not a terrestrial surface can be assumed to be a Lambertian surface should be based on their geometric structure. When the surface is relatively smooth, we can say that it is close to the Lambertian property in thermal emission.