A Resilient Multi-factor Framework for Low Carbon Cities: An International Perspective

The roles of cities in low carbon transition and sustainable development strategies have never been so important. This paper focuses on the transition, while considering the current situations of city carbon emissions in the world. The management practice of city low carbon transformation is analyzed and expounded. We then discuss the low carbon resilience of cities, and establish a mathematical and logical model. The paper illustrates relevant scenarios of the measurement factors, and the meanings of the resilience coefficient. Furthermore, we propose and refine a framework for analyzing the resilience, in combination with emission accounting tools and various aspects of city development

Catalase Enhances Viability of Human Chondrocytes in Culture by Reducing Reactive Oxygen Species and Counteracting Tumor Necrosis Factor-α-Induced Apoptosis

Background/Aims: Both physiologic remodeling and pathologic regeneration of cartilage tissue rely upon chondrocyte functions and are benefited from factors that promote viability and inhibit apoptosis of the cell, and associated mechanisms. High level of reactive oxygen species (ROS) and proinflammatory cytokines activate apoptosis signaling and initiate cell death, which can be attenuated by antioxidants. This study examined the effect of catalase (CAT) on ROS and tumor necrosis factor-α (TNF-α)-induced apoptosis in human C28/I2 chondrocytes cultured in monolayer. Methods: Chondrocytes were treated with diluted CAT in the presence or absence of TNF-α and compared to untreated cells. Levels of hydrogen peroxide (H2O2) and mitochondrial membrane potential (Δψm) were measured using fluorescent labeling, cell apoptosis was assayed by flow cytometry using Annexin V/propidium iodide (PI) staining, gene expression was detected by quantitative real time polymerase chain reaction (qRT-PCR) and the proteins were investigated by Western blotting. Results: CAT effectively reduced the intracellular ROS caused by the monolayer culture system, enhanced the Δψm depending on the presence of TNF-α and promoted morphological features at sub-cellular level. CAT also attenuated the TNF-α-upregulated expression of factors/mediators of extrinsic cell death cascade and apoptotic caspases, ultimately resulted in promoted cellular viability. Conclusion: The anti-apoptotic effect of CAT on chondrocytes via scavenging ROS and suppressing TNF-α-induced cell apoptosis by TNF/TNF receptor (TNFR) mediated death signaling pathway and potentiate CAT as a complementary agent beneficial to cartilage remodeling and regeneration in vivo, and cell-based therapies of cartilage repair demanding viable cells expanded ex vivo

An Ensemble Extreme Learning Machine for Data Stream Classification

Extreme learning machine (ELM) is a single hidden layer feedforward neural network (SLFN). Because ELM has a fast speed for classification, it is widely applied in data stream classification tasks. In this paper, a new ensemble extreme learning machine is presented. Different from traditional ELM methods, a concept drift detection method is embedded; it uses online sequence learning strategy to handle gradual concept drift and uses updating classifier to deal with abrupt concept drift, so both gradual concept drift and abrupt concept drift can be detected in this paper. The experimental results showed the new ELM algorithm not only can improve the accuracy of classification result, but also can adapt to new concept in a short time

A Resilient Multi-factor Framework for Low Carbon Cities: An International Perspective

The roles of cities in low carbon transition and sustainable development strategies have never been so important. This paper focuses on the transition, while considering the current situations of city carbon emissions in the world. The management practice of city low carbon transformation is analyzed and expounded. We then discuss the low carbon resilience of cities, and establish a mathematical and logical model. The paper illustrates relevant scenarios of the measurement factors, and the meanings of the resilience coefficient. Furthermore, we propose and refine a framework for analyzing the resilience, in combination with emission accounting tools and various aspects of city development

Study on Release and Migration of Radionuclides under the Small Break Loss of Coolant Accident in a Marine Reactor

Using severe accident analysis program MELCOR, the small break loss of coolant accident (SBLOCA) analysis model was established for a marine reactor. The release and migration of radionuclides were analyzed during a severe accident induced by SBLOCA. The analysis of the hydrogen source term release showed that the maximum hydrogen release amount was 248.567 kg, and the hydrogen release amount accounted for less than 4% of the air volume. So, there would be no danger of hydrogen explosion accidents. The research mainly focused on the behaviors of the release, the transport, the retention, and the final distribution of inert gases represented by Xe, volatile gases represented by CsI, and nonvolatile nuclides represented by Ba. The results showed that the reactor core exposed completely with a lagging by 510 s and the initial release time of nuclides was lagged by 1916 s. The release shares of Xe in the primary circuit system, the containment, and the environment were 0.013%, 0.06%, and 32.71%, respectively. Also, Ba shared 0.016%, 0.0032%, and 3.28%, respectively, and CsI shared 0.0145%, 0.0012%, and 2.845%, respectively

Green synthesis and evaluation of an iron-based metal-organic framework MIL-88B for efficient decontamination of arsenate from water

International audienceIron-containing metal-organic frameworks (MOFs) have gradually emerged as environmentally benign alternatives for reducing the levels of environmental contamination because of their advantages, such as readily obtained raw materials with low cost, nontoxic metal source with good biocompatibility, and distinguished physicochemical features e.g., high porosity, framework flexibility, and semiconductor properties. In this study, we reported an innovative strategy for synthesizing an iron-based MOF, MIL-88B, at room temperature. The novelty of this strategy was the use of ethanol as solvent and the pretreatment of dry milling with neither the bulk use of a toxic organic solvent nor the addition of extremely dangerous hydrofluoric acid or strong alkali. The synthesized MIL-88B(Fe) was evaluated as a sorbent for removing arsenate in water and it exhibited high adsorption capacity (156.7 mg g(-1)) at a low dosage. The removal capacity of trace arsenate on MIL-88B(Fe) was 32.3 mg g(-1) at a low equilibrium concentration (6.4 mu g L-1), which satisfied the arsenic threshold for drinking water. The results of Fourier transform infrared and X-ray photoelectron spectroscopy indicated that the As(V) molecules bonded with the oxygen molecules, which were coordinated with FeO clusters in the framework. This work presented the potential use of the up-scaled MIL-88B as an excellent sorbent for purifying arsenate-contaminated water

Mg-doped VO2@ZrO2 core-shell nanoflakes for thermochromic smart windows with enhanced performance

The VO2-based smart windows can dynamically and reversibly adjust the indoor solar irradiation to reduce the energy consumption for building glasses. The paper reports the first successful preparation of Mg-doped VO2@ZrO2 core-shell nanocrystals with promoted thermochromic performance as well as tunable appearance and wettability. To our knowledge, the achieved combination of Tlum of 52.4% and ∆Tsol of 7.1% is comparable to the best-reported results of VO2-based core-shell rod structures. The thickness of ZrO2 shell is tunable between 3-14 nm, resulting in a slightly hydrophobic surface and a slight color change toward blue-green and brighter produced films. The preparation method based on hydrothermal and UV-curing methods is facile. The work may inspire future development of VO2 synthesis, their structure-property, and the application the thermochromic films for energy-saving purposes in buildings or automobiles.National Research Foundation (NRF)Accepted versionZuohao Wen and Yujie Ke contributed equally to this work. X. Liu acknowledges the study is supported by the financial support of this work by NSAF (Grant No. 51776143. The use of SEM, XPS, TEM, and AFM was funded by the Open Subsidies for large-scale Equipment of Wuhan University (Grant No. LF20181061). Y. Long thanks to the funding support by the National Research Foundation, Prime Minister’s Office, Singapore under its Campus for Research Excellence and Technological Enterprise (CREATE) programme and Sino-Singapore International Joint Research Institute for funding support