The Reduction of Storm Surge by Vegetation Canopies: Three-Dimensional Simulations

Significant buffering of storm surges by vegetation canopies has been suggested by limited observations and simple numerical studies, particularly following recent Hurricanes Katrina, Rita, and Wilma. Here we simulate storm surge and inundation over idealized topographies using a three-dimensional vegetation-resolving storm surge model coupled to a shallow water wave model and show that a sufficiently wide and tall vegetation canopy reduces inundation on land by 5 to 40 percent, depending upon various storm and canopy parameters. Effectiveness of the vegetation in dissipating storm surge and inundation depends on the intensity and forward speed of the hurricane, as well as the density, height, and width of the vegetation canopy. Reducing the threat to coastal vegetation from development, sea level rise, and other anthropogenic factors would help to protect many coastal regions against storm surges

Zeolite Supported Ionic Liquid Catalysts for the Hydrochlorination of Acetylene

An efficient and stable heterogeneous Zeolite Supported Ionic Liquid Catalyst (IL/CaX) has been explored in acetylene hydrochlorination reaction. The IL/CaX catalyst exhibits excellent space time yields of vinyl chloride (VCM), when compared to the benchmark of Au/C systems. Through characterization and kinetic studies, the reaction follows a two-site mechanism, which is described as the adsorbed hydrogen chloride on the Ca2+ in zeolite, reacting with the adsorbed acetylene on the cation of ionic liquid to form vinyl chloride. The catalytic reaction takes place at the IL/CaX interface, whilst the upper interphase IL/CaX is not active. The deactivation of the catalyst is caused by the dissolving byproducts in the ionic liquid layer, which can be reactivated by a simple vacuum procedure. It is of great significance to study and develop green non-mercury catalysts, in acetylene hydrochlorination

Applications of in vivo SPME based on mass spectrometry for environmental pollutants analysis and non-target metabolomics: A review

In vivo analysis of environmental organic pollutants and endogenous metabolites has great impacts on understanding their environmental behavior and exposure risks. This calls for the development of convenient and reliable analytical methods with either high specificity or wide coverage of target compounds in complex matrixes. Different from traditional solvent extraction, solid-phase microextraction (SPME) has emerged as an integrated sample preparation technique by combining sampling, extraction, and cleanup into one step, which exerts great potential on in vivo sampling due to its high sensitivity and low invasiveness. In this view, the design principles of SPME fibers for in vivo sampling, novel SPME fibers, and devices over recent years are summarized for the guidance of SPME fiber design. The applications of in vivo SPME on monitoring uptake, translocation, and degradation of environmental organic pollutants in organisms, as well as non-target metabolomics in environmental toxicology and clinical analysis based on mass spectrometry, are described. SPME fiber directly coupled with mass spectrometry for in vivo analysis has been introduced. The practical limitations and prospects of further research are also discussed. We conceive that in vivo SPME will promote the development of environmental analysis and toxicity assessment in a high-efficiency and high-throughput manner

Highly Active AuCu-Based Catalysts for Acetylene Hydrochlorination Prepared Using Organic Aqua Regia

Development of a sustainable process for designing and synthesising an active and stable catalyst for hydrochlorination of acetylene is challenging, yet crucial, for industrial vinyl chloride monomer (VCM) production. Herein, direct synthesis of bimetallic AuCu catalysts using organic aqua regia (OAR) preparation methods was investigated. In comparison with conventional aqua regia (AR), bimetallic AuCu catalysts synthesised from OAR exhibit enhanced activity and stability. After careful characterisation of the catalyst samples using X-ray diffraction patterns (XRD), Scanning transmission electron microscopy (STEM), X-ray photoelectron spectroscopy (XPS), and Temperature-programmed desorption (TPD), this observation was justified for the following reasons: 1) the existence of sulphur and nitrogen atoms stabilised the cationic Au active sites, and 2) OAR helped to sustain the function of the Cu promotor by stabilising it. Advanced understanding on the importance of promoter stability has unveiled new perspectives for this research area