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This review focuses on the occurrence and interactions of engineered nanoparticles (ENPs) and brominated flame retardants (BFRs) such as polybrominated diphenyl ethers (PBDEs) in water systems and the generation of highly complex compounds in the environment. The release of ENPs and BFRs (e.g. PBDEs) to aquatic environments during their usage and disposal are summarised together with their key interaction mechanisms. The major interaction mechanisms including electrostatic, van der Waals, hydrophobic, molecular bridging and steric, hydrogen and π-bonding, cation bridging and ligand exchange were identified. The presence of ENPs could influence the fate and behaviour of PBDEs through the interactions as well as induced reactions under certain conditions which increases the formation of complex compounds. The interaction leads to alteration of behaviour for PBDEs and their toxic effects to ecological receptors. The intermingled compound (ENPs-BFRs) would show different behaviour from the parental ENPs or BFRs, which are currently lack of investigation. This review provided insights on the interactions of ENPs and BFRs in artificial, environmental water systems and wastewater treatment plants (WWTPs), which are important for a comprehensive risk assessment.

Development of polymeric magnetic adsorbents is a promising approach to obtain efficient treatment of contaminated water. However, the synthesis of magnetic composites involving multiple components frequently involves tedious preparation steps. In the present study, a magnetic chitosan-palygorskite (MCP) nanocomposite was prepared through a straight-forward one pot synthesis approach to evaluate its lead (Pb2+) removal capacity from aqueous solution. The nano-architectural and physicochemical properties of the newly-developed MCP composite were described via micro- and nano-morphological analyses, and crystallinity, surface porosity and magnetic susceptibility measurements. The MCP nanocomposite was capable to remove up to 58.5 mg Pb2+ g−1 of MCP from water with a good agreement of experimental data to the Langmuir isotherm model (R2 = 0.98). The Pb2+ adsorption process on MCP was a multistep diffusion-controlled phenomenon evidenced by the well-fitting of kinetic adsorption data to the intra-particle diffusion model (R2 = 0.96). Thermodynamic analysis suggested that the adsorption process at low Pb2+ concentration was controlled by chemisorption, whereas that at high Pb2+ concentration was dominated by physical adsorption. X-ray photoelectron and Fourier transform infrared spectroscopy results suggested that the Pb adsorption on MCP was governed by surface complexation and chemical reduction mechanisms. During regeneration, the MCP retained 82% Pb2+ adsorption capacity following four adsorption–desorption cycles with ease to recover the adsorbent using its strong magnetic property. These findings highlight the enhanced structural properties of the easily-prepared nanocomposite which holds outstanding potential to be used as an inexpensive and green adsorbent for remediating Pb2+ contaminated water. Refereed/Peer-reviewed

This work analyzes and discusses the influence of human activities on the meteorological conditions related to winter haze events in Beijing, Tianjin, and Hebei (i.e., the Jing–Jin–Ji region) during 1961–2016, using the results of two numerical simulation experiments based on the Community Atmosphere Model version 5.1.1 (http://www.cesm.ucar.edu/models/cesm1.0/cam/docs/ug5_1_1/book1.html) used in the international Climate Variability and Predictability Programme (CLIVAR) Climate of the 20th Century. Detection and Attribution Project (C20C+ D&A). The results show that, under the influence of human activities, the changes in dynamical and thermal meteorological conditions related to winter haze events in the Jing–Jin–Ji region are conducive to the formation and accumulation of haze, and prevent the diffusion of pollutants. The dynamical conditions mainly include the obvious weakening of the East Asian winter monsoon (EAWM) and the enhancement of the near-surface anomalous southerly wind. The thermal conditions include the obvious increase in surface temperature, and the enhancement of water vapor transport and near-surface inversion. The relative contribution of dynamical and thermal conditions to the variation of haze days in the Jing–Jin–Ji region is analyzed using statistical methods. The results show that the contribution of human activities to the increase of haze days in the Jing–Jin–Ji region is greater than that of natural forcing for the study period. To be specific, the dynamical meteorological factors contribute more to the haze days than the thermal meteorological factors. The contribution of thermal meteorological factors is basically the same in both scenarios.

PM2.5 and its main chemical components have been investigated during six air pollution periods across four seasons from Jun. 16, 2016 to Jun. 15, 2017 at a suburban site in Beijing, China. Daily PM2.5 mass concentrations were measured with associated ions, OC, EC, 16 PAHs and seven heavy metals. Mass closure analyses were conducted using measured and reconstructed chemical components. Chemical ratios were used to identify possible pollution sources, while principal component analysis (PCA) coupled with multiple linear regression (MLR) method was used to estimate the source contribution to PM2.5 mass. The annual mean PM2.5 concentration (96.7 μg m−3) is about 2.8 times the national level-2 standard limit, with apparent seasonal variation of daily exceedances as winter > spring > autumn > summer. Generally, higher levels are observed in winter and autumn than in spring and summer for NO3−, SO42−, NH4+, Cl−, K+, OC, EC, PAHs and metals Zn, As, Cu, Pb, along with higher concentrations of NOx, CO and SO2. Secondary ions and carbon fractions are most abundant over all seasons, except levels of dust related species Ca2+, Mg2+, Ca, Fe and Mn are also high in spring. The reconstructed results show that PM2.5 consists of mostly organic compounds (26–38%) and ammonium salts (NH4NO3 + (NH4)2SO4) (43–53%) in winter and autumn, while summer is dominated mainly by ammonium salts (81%). In spring, very high PM2.5 episodes are occasionally composed of large amount of soil/road dust and gypsum particles (23–55%) due to floating dust events with drier weather conditions and human activities. Fuel combustions and secondary sources are responsible for ~70% of PM2.5 mass while mobile source is mostly a regional origin.

In this study, an experiment of macroscopic spray performance of stabilized nanofuels under high injection and ambient pressure is conducted on a Common rail direct fuel injection. The tested nanofuels have been prepared by DE20 (20% ethanol, 80% diesel by volume) blends with nano-CeO2 at 25 ppm(DE20Ce25), 50 ppm(DE20Ce50),100 ppm(DE20Ce100) respectively. Furthermore, appropriate amount of CTAB whose weight is equal to CeO2 and 2%vol 1-decanol were added as surfactant additive. All tested fuels were ultrasonically oscillated at a frequency of 40 khz for 45min in order to enhance their stability. The macroscopic spray characteristics of diesel-ethanol with dispersed cerium nanoparticles have been measured using the optical diagnostic techniques of shadowgraph. Comparing with those the pure diesel(D100), the spray penetration of DE20, DE20Ce25, DE20Ce50, DE20Ce100 increased by −3%, −1.8%, −0.3% and 9.5%, while the spray cone angle increased by −3%,4%,2.8% and 12.5% as well as spray area increased by −3%,-1.3%,0.6% and 31% respectively. The addition of nanoparticles also enhances the instability of fuel and shortens the crucial breakup time. In addition, the influence caused by increasing viscosity and surface tension are balanced by the disturbance. Furthermore, the macroscopic spray characteristics of DE20Ce50 show little difference with the pure diesel which means it can be a promising alternative fuel for CI engine with no required modification.

The production and use of Engineered Nanoparticles (ENPs) or materials containing ENPs has increased astonishingly, leading to increased exposure to workers and consumers. The invention and applications of new materials either create new opportunities or pose new risks and uncertainties. The uncertainties concerning application of ENPs are posing disturbances to the ecosystem and human health. This review first addresses in vitro and in vivo studies conducted on the toxicity of ENPs to animals and humans. Ethical justifications are provided specially with reference to Intergenerational Justice (IRG-J) and Ecological Justice (EC-J). The social benefits and burdens of ENPs are identified for present and future generations. Some mitigation approaches for combating the potential risks posed by ENPs are proposed. Finally, suggestions for the safe handling of ENPs in future are proposed in the review.

3D printing of conductive polymer nanocomposites, which combines the electrical conductivity of nanofillers with customer-designed geometries, is promising for various sensors. However, the single shape of sensors restricts their environmental adaptability if the detecting environment changes. Herein, 3D and 4D printing of poly (D,L-lactide-co-trimethylene carbonate) (PLMC)/CNT nanocomposites with electro-responsive shape-changing capability was achieved by direct ink writing (DIW). The rheological and solvent evaporation capabilities of PLMC/CNT ink were modulated to make it printable. Electrical, mechanical, thermal and shape memory properties were investigated and various structures from micro to macro were constructed. The printed structure showed excellent shape-changing behavior under 25 V within 16 s. Then UV photoinitiators were introduced to trigger hydrogen abstraction reaction to make PLMC chains form cross-linking networks. The modified composite ink was printed into shape-changing liquid sensors. The influence of three solvents and layer thickness on liquid sensitivity was compared. The shape-changing capability helped the sensor maintain a high precision for liquid detection. The sensor in its original, deformed and recovered shape showed similar changing trend of resistance and exhibited excellent repeatability. We envision wide environmental adaptability of using the shape-changing sensor for detecting leakage of various solvents in varying environment.

In this study, spray characteristics of biodiesel blending with di-n-butyl ether (DBE15, DBE30) were investigated by experiment and analysis and compared with diesel. Spray characteristics parameters including spray tip penetration, spray cone angle, maximum spray width and spray tip velocity were used to compare under different injection pressures and ambient pressures. The spray images were analyzed according to light intensity level, while the gas entrainment mass and equivalent ratio were analyzed by empirical model. The results showed that the spray tip penetration of biodiesel added with DBE was reduced and the spray cone angle and maximum spray width were increased. The range of light intensity level of biodiesel was the narrowest, while the light intensity level of biodiesel-DBE blends was similar to that of diesel. Empirical models showed that biodiesel shows poor gas-fuel mixing. DBE30 had a larger gas entrainment mass and a lower equivalence ratio, similar to diesel. It was proved that the biodiesel added with DBE enhanced the gas-fuel mixing.

In this assay, a new polyethyleneinmine-gold nanoparticles-protoporphyrin cobalt (II) (PEI-AuNPs-CoPP) nanocomposite was synthesized by a simple method under mild conditions, and it was used to fabricate an electrochemical sensor for the detection of hydrogen peroxide (H2O2). The structures of nanomaterials were characterized by fourier transform infrared (FTIR) spectroscopy and ultraviolet visible spectrometry (UV–vis). Under the optimum condition, the current intensity was linearly related to H2O2 concentration in the range of 50–280 aM (R2 = 0.9932). It's worth mentioning that a lower detection limit of 7.26 aM was obtained at a signal-to-noise rate of 3. In addition, the experiments showed that ascorbic acid (AA), uric acid (UA) and glucose (Glu) had little effect on the determination of H2O2. The sensor had a good analytical performance for the determination of H2O2 in human serum samples. These results suggested that the proposed PEI-AuNPs-CoPP nanocomposites had practical application prospect in biological sample analysis and clinical diagnosis.

In the structural health monitoring or nondestructive examination system based on the Lamb wave technology, the accurate and valid characteristics of wave packet extracted from the signal are critical factors to evaluate damage. However, the dispersion effect and the multi-mode characteristic in the elastic wave make the data extraction difficult and degrade the resolution, and therefore further prevent the effectiveness of Lamb wave for damage detection. In this study, we proposed a model-based approach for extracting effective characteristics from the noisy signals. By taking the narrow band Gabor pulse as the incident pulse and considering the general non-linear frequency dispersion (quadratic dispersion), we developed a model with five parameters to model the dispersive wave packet and obtained the parameter vector of each wave packet by the expectation-maximization (EM) algorithm. The parameters in the model present the characteristics of signals, which can be further applied to locate and evaluate the structure’s damage. To study the convergence property, synthetic signals with different sampling rates and noise intensities were considered. Furthermore the developed approach is also verified by the experimental data from an isotropic aluminum plate.

The thermo-mechanical properties of unidirectional carbon fiber reinforced epoxy-based shape memory polymer (SMP) composites with fiber mass fractions of 16%, 23%, 30%, 37% are evaluated by using three-point bending tests. The SMP composites show temperature-dependent flexural modulus and strength, with one order of magnitude difference between 120 °C and 20 °C. The composites show good shape recovery capability, with measured recovery ratios of more than 93% at 120 °C and 100% after 20 min at that temperature. The recovery stresses increase nonlinearly during reheating; the maximum recovery stress is approximately proportional to the fiber mass fraction. The composites show recovery capability under external loads, with the recovery ratio being inversely proportional to the partial load level. The composites feature good shape memory properties during cyclic loading and unloading at 120 °C. Their loss factors and stiffness losses decrease significantly during the first three cycles, and then stabilize after ten cycles.

Cardiac troponin I (cTnI) is considered to be the most valuable biomarker for the diagnosis of acute myocardial infarction (AMI). The sensitive and efficient determination of cTnI is essential for the early diagnosis and prognostic assessment of AMI. In this paper, we designed for the first time an electrochemical immunosensor based on the ring-opening polymerization (ROP) reaction as a signal amplification strategy for the highly sensitive detection of cTnI. Briefly, 3-mercaptopropionic acid (MPA) was used as a cross-linking agent to immobilize Ab

Compared with short-duration events, long-lasting regional extreme low-temperature events (RELTEs) often have more severe impacts on human societies due to the induced persistence and large geographic area of related weather and climate disaster. Accordingly, an improved objective technique was applied to identify all long-lasting RELTEs in Eurasia from the winter of 1948/1949 to 2017/2018, followed by an in-depth discussion of its variation in terms of the annual frequency, duration, impacted area, mean intensity, maximum intensity, and a comprehensive index. The RELTE lasting for 52 d in the winter of 2007/2008 exhibited the longest duration, largest impacted area, and a greatest comprehensive index, which induced extremely low temperatures for more than 20 d in Western Asia, Central Asia, and China. During the past 70 winters, the frequency of long-lasting RELTEs decreased, especially after the late 1960s. Nevertheless, the mean and maximum intensities and comprehensive index exhibited distinctly increasing trends. All indicators of winter long-lasting RELTEs had a similar inter-decadal fluctuation featured by two noticeable peaks occurring around 1970 and 2007, and a remarkable recovery was discovered in the period of late 1990s to mid-2010s, especially for the occurrence of super long-lasting events. Significantly, winter long-lasting RELTEs in Eurasia showed distinct trends under various decadal climate backgrounds, i.e., a strong negative or weak positive trend in the accelerated warming period and conversely, a strong positive or weak negative trend in the warming slowdown stage. These findings indicate that we should be alert of the similar future recovery of winter long-lasting RELTEs in Eurasia, which are likely to occur in the slowdown period of global warming.