1,022 research outputs found
Fault detection and fault-tolerant control for nonlinear systems
No full textLinlin Li addresses the analysis and design issues of observer-based FD and FTC for nonlinear systems. The author analyses the existence conditions for the nonlinear observer-based FD systems to gain a deeper insight into the construction of FD systems. Aided by the T-S fuzzy technique, she recommends different design schemes, among them the L_inf/L_2 type of FD systems. The derived FD and FTC approaches are verified by two benchmark processes. Contents Overview of FD and FTC Technology Configuration of Nonlinear Observer-Based FD Systems Design of L2 nonlinear Observer-Based FD Systems Design of Weighted Fuzzy Observer-Based FD Systems FTC Configurations for Nonlinear Systems< Application to Benchmark Processes Target Groups Researchers and students in the field of engineering with a focus on fault diagnosis and fault-tolerant control fields The Author Dr. Linlin Li completed her dissertation under the supervision of Prof. Steven X. Ding at the Faculty of Engineering, University of Duisburg-Essen, Germany
Litter quality modulates changes in bacterial and fungal communities during the gut transit of earthworm species of different ecological groups
No full textAbstract Earthworms are keystone animals stimulating litter decomposition and nutrient cycling. However, earthworms comprise diverse species which live in different soil layers and consume different types of food. Microorganisms in the gut of earthworms are likely to contribute significantly to their ability to digest organic matter, but this may vary among earthworm species. Here, we analyse the effect of food (litter) quality on gut microbiota and their changes during the gut passage (from foregut to hindgut) of earthworms of different ecological groups. The endogeic (soil living) species Aporrectodea caliginosa and the anecic (litter feeding) species Lumbricus terrestris were fed with high- (rape leaves) and low-quality litter (wheat straw) in a microcosm experiment for 18 weeks. Irrespective of earthworm species, alpha diversity of bacterial and fungal communities changed little during the gut passage, with the composition and diversity of microbial communities in the gut generally resembling those in soil more than in litter. In addition, the low-quality litter supported higher alpha diversity and more complex communities than high-quality litter. Further, gut microbial communities of the anecic L. terrestris changed less during gut passage than those of the endogeic A. caliginosa, especially when fed low-quality litter. Our findings indicate that earthworm gut microbial communities are predominantly shaped by the soil they ingest, but are modulated by the quality of litter they feed on and earthworm ecological group. Overall, the results suggest that earthworms primarily influence soil microbiota by mixing and spreading microorganisms from different microhabitats through bioturbation rather than by digesting microorganisms.Open-Access-Publikationsfonds 202
Supplemental Material - Development and Validation of Knowledge Assessment Scales for Dementia and Urinary Incontinence in Community Older People
No full textSupplemental Material for Development and Validation of Knowledge Assessment Scales for Dementia and Urinary Incontinence in Community Older People by Hui Sun, Wenqi Liu, Xuemei Sun, Yinyan Gao, Yancong Chen, Yali Lin, Jinlu Song, Zixuan Zhang, Betty H Wang, Lingqi Li, Hui Feng, Hongzhuan Tan, Qiong Chen, Linlin Peng, Wenjie Dai, and Irene XY Wu in Journal of Applied Gerontology</p
The dominance of big teams in china’s scientific output
No full textModern science is dominated by scientific productions from teams. A recent finding shows that teams of both large and small sizes are essential in research, prompting us to analyze the extent to which a country’s scientific work is carried out by big or small teams. Here, using over 26 million publications from Web of Science, we find that China’s research output is more dominated by big teams than the rest of the world, which is particularly the case in fields of natural science. Despite the global trend that more papers are written by big teams, China’s drop in small team output is much steeper. As teams in China shift from small to large size, the team diversity that is essential for innovative work does not increase as much as that in other countries. Using the national average as the baseline, we find that the National Natural Science Foundation of China (NSFC) supports fewer small teams than the National Science Foundation (NSF) of the United States does, implying that big teams are preferred by grant agencies in China. Our finding provides new insights into the concern of originality and innovation in China, which indicates a need to balance small and big teams. © 2020 Linlin Liu, Jianfei Yu, Junming Huang, Feng Xia, and Tao Jia. Published under a Creative Commons Attribution 4.0 International (CC BY 4.0) license
Synthesis of highly stable UiO-66-NH2 membranes with high ions rejection for seawater desalination
No full textCompact and phase-pure UiO-66-NH2 membranes were synthesized on the 3-aminopropy-ltriethoxysilane (APTES) modified macroporous Al2O3 tubes through a repeated synthesis strategy. APTES acts as a molecular linker for anchoring the metal ions onto the support surface to promote the nucleation and the crystallization of UiO-66-NH2 membrane. Therefore, well-intergrown UiO-66-NH2 membranes could be prepared through a repeated synthesis method on the APIES-modified macroporous Al2O3 tubes. The developed UiO-66-NH2 membranes were evaluated for seawater desalination by pervaporation. It is found that the UiO-66-NH2 membranes show high desalination performances attributing to the narrow pore size which is exactly in between the size of water molecules and hydrated ions. With increasing the feed temperature from 318 to 363 K, the water fluxes increase from 1.5 to 12.1 kg m(-2) h(-1), with ions rejections of above 99.7%. Further, the UiO-66-NH2 membranes display high stability for a long time in seawater desalination, which is very promising for seawater desalination. (C) 2017 Elsevier Inc. All rights reserved
Mycotoxin Biodegradation by Bacillus Bacteria—A Review
No full textMycotoxins are toxic secondary metabolites produced by various types of fungi that are known to contaminate various food products; their presence in the food chain poses significant risks to human and animal health and leads to enormous economic losses in the food and feed industry worldwide. Ensuring food safety and quality by detoxifying mycotoxin is therefore of paramount importance. Several procedures to control fungal toxins have been extensively investigated, such as preventive measures, physical and chemical methods, and biological strategies. In recent years, microbial degradation of mycotoxins has attracted much attention due to its reliability, efficiency, and cost-effectiveness. Notably, bacterial species from the Bacillus genus have emerged as promising candidates for mycotoxin decontamination owing to their diverse metabolic capabilities and resilience in harsh environmental conditions. This review manuscript aims to provide a summary of recent studies on the biodegradation of fungal toxins by Bacillus bacteria, thereby illustrating their potential applications in the development of mycotoxin-degrading products
Structure and function of the thermoTRP channel pore
No full textTemperature-sensitive transient receptor potential (TRP) channels are structurally similar to other tetrameric cation channels, but can be potently activated by heat. Recent studies suggest that the pore-forming region directly participates in activation gating. In this chapter, we summarize major findings from both structural and functional studies concerning the gating role of the pore region, focusing in particular on TRPV1. The emerging picture is that the peripheral S1–S4 region of TRPV1 is rigid and plays a supporting role for the pore to undergo conformational rearrangements. This places the pore region in the center of activation gating
A novel hybrid technique for short-term electricity price forecasting in deregulated electricity markets
No full textThis thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.Short-term electricity price forecasting is now crucial practice in deregulated electricity markets, as it forms the basis for maximizing the profits of the market participants. In this thesis, short-term electricity prices are forecast using three different predictor schemes, Artificial Neural Networks (ANNs), Support Vector Machine (SVM) and a hybrid scheme, respectively.
ANNs are the very popular and successful tools for practical forecasting. In this thesis, a hidden-layered feed-forward neural network with back-propagation has been adopted for detailed comparison with other forecasting models. SVM is a newly developed technique that has many attractive features and good performance in terms of prediction. In order to overcome the limitations of individual forecasting models, a hybrid technique that combines Fuzzy-C-Means (FCM) clustering and SVM regression algorithms is proposed to forecast the half-hour electricity prices in the UK electricity markets. According to the value of their power prices, thousands of the training data are classified by the unsupervised learning method of FCM clustering. SVM regression model is then applied to each cluster by taking advantage of the aggregated data information, which reduces the noise for each training program.
In order to demonstrate the predictive capability of the proposed model, ANNs and SVM models are presented and compared with the hybrid technique based on the same training and testing data sets in the case studies by using real electricity market data. The data was obtained upon request from APX Power UK for the year 2007.
Mean Absolute Percentage Error (MAPE) is used to analyze the forecasting errors of
different models and the results presented clearly show that the proposed hybrid
technique considerably improves the electricity price forecasting
Is There Any Difference in the Effect of Different R and D Sources on Carbon Intensity in China?
No full textIn recent decades, climate change, mostly caused by CO2 emissions, has become a critical issue of concern to people worldwide. It is necessary for countries all around the world to reduce carbon emissions. China, as the world’s largest carbon emitter, is under great pressure to implement carbon-reduction strategies. Technological progress plays a crucial role in balancing environmental and economic development. The main objective of this work is to empirically compare the effects of government and enterprise research and development (R and D) on carbon-emission reduction using the panel data of 30 Chinese provinces from 2009 to 2016. The effects of both government and enterprise R and D investment on carbon intensity are compared in detail through a linear model and a threshold-regression model. Linear-regression results shows that both government and enterprise R and D decrease carbon intensity, while enterprise investment tends to be more instant. Further threshold-regression results indicate that the effects of government and enterprise R and D on carbon intensity are different in different urbanization stages. Guiding enterprises to invest in R and D in medium-developing areas, and increasing government support and subsidies for R and D activities in underdeveloped areas should be an important goal of the government policies
Performance Evaluation of Unit Trusts in UK Market
No full textAbstract
Because of the low risk and professional management, mutual funds have become one of the most popular types of investments for individuals. Since the 1960s, the evaluation of mutual fund performance has aroused great interests in academic researches. However, previous studies have shown that mutual funds often underperform. Therefore, in this dissertation, the situation in the UK market is selected to examine whether unit trusts can ‘beat’ the market in the past five-year period from December 2003 to December 2008. This study employs Jensen’s alpha, Sharpe’s ratio, and Treynor’s ratio to analyse the selectivity abilities of unit trusts. The results suggest that the UK unit trusts cannot beat the market and that the actively managed unit trusts do not have a superior performance to the passively managed ones. Consequently, based on previous researches, two main reasons are determined relating to why unit trusts underperform: liquidity risk and poor managerial investment choices
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