ALBERT

Description: 〈p〉Publication date: 1 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Computer Methods in Applied Mechanics and Engineering, Volume 355〈/p〉 〈p〉Author(s): Jean-Lou Pfister, Olivier Marquet, Marco Carini〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The stability analysis of elastic structures strongly coupled to incompressible viscous flows is investigated in this paper, based on a linearization of the governing equations formulated with the Arbitrary-Lagrangian–Eulerian method. The exact linearized formulation, previously derived to solve the unsteady non-linear equations with implicit temporal schemes, is used here to determine the physical linear stability of steady states. Once discretized with a standard finite-element method based on Lagrange elements, the leading eigenvalues/eigenmodes of the linearized operator are computed for three configurations representative for classical fluid–structure interaction instabilities: the vortex-induced vibrations of an elastic plate clamped to the rear of a rigid cylinder, the flutter instability of a flag immersed in a channel flow and the vortex shedding behind a three-dimensional plate bent by the steady flow. The results are in good agreement with instability thresholds reported in the literature and obtained with time-marching simulations, at a much lower computational cost. To further decrease this computational cost, the equations governing the solid perturbations are projected onto a reduced basis of free-vibration modes. This projection allows to eliminate the extension perturbation, a non-physical variable introduced in the ALE formalism to propagate the infinitesimal displacement of the fluid–solid interface into the fluid domain.〈/p〉〈/div〉

Description: Telescoping path optimization (TPO) of single-cylinder pin-type multisection boom (SPMB) is a practical engineering problem that is valuable to investigate. This article studies the TPO problem and finds the key of TPO is to obtain the maximum retraction backmost combination. A mathematic model on the basis of the quadratic penalty function of a Hopfield neural network (HNN) is constructed. Two strategies are presented to improve the performance of TPO model: one is proportional integral derivative (PID) strategy that adaptively adjusts the parameter λ of the constrained term and the parameter of the optimization objective term by controlling the value of constraint violation and the other is efficiency factor strategy that an efficiency factor is introduced in model for prioritizing the constrained term over the objective term. Data test shows that compared with the path of boom length changing before optimization, both the number of sections that need to be moved and the total travels of cylinder can be reduced by 10%-30% after optimization. Both the PID strategy and the efficiency factor strategy achieve good optimization effects. The efficiency factor strategy is excellent at moderating the conflicts between the constrained term and the objective term; thus the generations of the valid and the optimal solutions get well improved.

Description: A belt drive and a chain drive are the main types of flexible power transmission. In the traditional belt and chain drive design process, engineers need to do a lot of rework to get a design. To solve this problem, taking the Shell Eco-Marathon vehicle as an example, the traditional design and optimization design of the transmission system are carried out. In the optimization design, component optimization and overall optimization design model of the belt and chain drive are first established. Second, the charts in the design manual are converted into formulas by using MATLAB. Finally, an optimization design model is established in Microsoft Excel, and the Excel Solver tool is used to find the optimal design result. The design method proposed in this paper can effectively determine the optimal design of transmission system and provides a new method for the processing of such problems.

Description: This paper proposes a superresolution two-dimensional (2D) direction of arrival (DOA) estimation algorithm for a rectangular array based on the optimization of the atomic norm and a series of relaxation formulations. The atomic norm of the array response describes the minimum number of sources, which is derived from the atomic norm minimization (ANM) problem. However, the resolution is restricted and high computational complexity is incurred by using ANM for 2D angle estimation. Although an improved algorithm named decoupled atomic norm minimization (DAM) has a reduced computational burden, the resolution is still relatively low in terms of angle estimation. To overcome these limitations, we propose the direct minimization of the atomic norm, which is demonstrated to be equivalent to a decoupled rank optimization problem in the positive semidefinite (PSD) form. Our goal is to solve this rank minimization problem and recover two decoupled Toeplitz matrices in which the azimuth-elevation angles of interest are encoded. Since rank minimization is an NP-hard problem, a novel sparse surrogate function is further proposed to effectively approximate the two decoupled rank functions. Then, the new optimization problem obtained through the above relaxation can be implemented via the majorization-minimization (MM) method. The proposed algorithm offers greatly improved resolution while maintaining the same computational complexity as the DAM algorithm. Moreover, it is possible to use a single snapshot for angle estimation without prior information on the number of sources, and the algorithm is robust to noise due to its iterative nature. In addition, the proposed surrogate function can achieve local convergence faster than existing functions.

Description: In this paper, we enrich and develop power-type Aczél-Vasić-Pečarić’s inequalities. First of all, we give some new versions of theorems and corollaries about Aczél-Vasić-Pečarić’s inequalities by quoting some lemmas. Moreover, in combination with Hölder’s inequality, we give some applications of the new version of Aczél-Vasić-Pečarić’s inequality and give its proof process.

Description: 〈p〉Publication date: 15 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials, Volume 380〈/p〉 〈p〉Author(s): Gautam Kumar Sarma, Aslam Khan, Ahmed Mohamed El-Toni, Md. Harunar Rashid〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Herein, we report for the first time, the synthesis of CuO-Nd(OH)〈sub〉3〈/sub〉 nanocomposites via a co-precipitation method coupled with the hydrothermal aging process. Varying the pH of the reaction medium, the shape of the nanocomposites could be controlled which determines their surface areas. These CuO-Nd(OH)〈sub〉3〈/sub〉 nanocomposites exhibit very high adsorption capacity with successful removal of ∼ 97% of brilliant blue G (BBG) from water in 180 min under ambient condition. The adsorption process primarily follows Lagergren pseudo-first-order kinetics. The Langmuir isotherm model fits well with a very high monolayer adsorption capacity of 394.1 mg g〈sup〉−1〈/sup〉 at 30 °C. The mechanistic study supports chemisorption-type adsorption between the dye molecule and the adsorbent. Regeneration of the spent adsorbent makes the whole process cyclic and eco-friendly.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0304389419307915-ga1.jpg" width="297" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials, Volume 380〈/p〉 〈p〉Author(s): Junchao Zhao, Zhitao Yin, Muhammad Usman Shahid, Haoran Xing, Xudong Cheng, Yangyang Fu, Song Lu〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The re-ignition of pool fires is a common hazard phenomenon in fire extinguishing. Dry chemicals with oleophobicity may solve this problem because powders can float on the oil surface and prevent evaporation of fuel pool. In this research, MAPP (modified ammonium polyphosphate) with superhydrophobicity, oleophobicity, and higher chemical activity is prepared which can quickly quench pool fires and provide longer protection. The activation indexes of MAPP for water, diesel, aviation kerosene and gasoline are 98.5%, 87.4%, 98.7% and 98.4%, respectively. Lower activation energy of MAPP means that it will show higher chemical activity in fire. The fire-extinguishing performance of MAPP is much higher than that of Commercial UDCA (ultra-fine dry chemical agent) during fire experiments. After extinguished by MAPP, the fuel pool is hard to be re-ignited. The significance of this study is to propose a new strategy for preventing the re-ignition of pool fires.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0304389419305497-ga1.jpg" width="492" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials, Volume 380〈/p〉 〈p〉Author(s): L. Sbardella, I. Velo-Gala, J. Comas, I. Rodríguez-Roda Layret, A. Fenu, W. Gernjak〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉 〈p〉Ultraviolet radiation (UV)-activated peroxydisulfate (PDS) and peroxymonosulfate (PMS) advanced oxidation processes were examined for their capacity to remove nine pharmaceutically active compounds (PhACs) from secondary effluent. The effect of operational parameters (initial oxidant concentration, UV exposure time, pH, common coexisting anions and effluent organic matter (EfOM)) on UV/PDS and UV/PMS treatment efficiency was investigated in a collimated beam device housing a low-pressure mercury UV lamp emitting light at 253.7 nm.〈/p〉 〈p〉Both AOPs achieved high removals (〉90%) when applied to pure water. Under otherwise similar conditions the removal percentage fell by 20–30% due to the scavenging of effluent organic matter (EfOM) in secondary effluent. Finally, eliminating EfOM but maintaining the inorganic composition, the radical scavenging effect was reduced and 98.3% and 85.6% average removals were obtained by UV/PDS and UV/PMS, respectively.〈/p〉 〈p〉Increasing pH improved degradation of several PhACs containing amine groups. Higher oxidant dosages created only a significant benefit in UV/PDS. The chloride anion produced a negligible effect on both processes, while higher nitrate concentrations increased removal percentage but did not affect degradation rate constants. Finally and surprisingly, the addition of bicarbonate had the strongest positive impact on the degradation kinetics observed, even stronger than the elimination of EfOM from secondary effluent.〈/p〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0304389419308222-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 5 July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Technological Forecasting and Social Change〈/p〉 〈p〉Author(s): Sorin M.S. Krammer, Alfredo Jiménez〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉We posit that the investments in political connections made by a firm in an emerging market will impact differently its propensity to introduce radical and incremental innovations. In addition, we argue that this effect will be moderated by alternate non-market firm strategies, such as bribery. Using a dataset of more than 9000 firms in 30 emerging economies from Eastern Europe and Central Asia we find that political connections increase the probability of radical innovation but have no significant impact on incremental innovation. Moreover, larger bribing reduces the positive impact of political connections on radical innovation. Our results confirm the importance of political connections for firm activities, but also caution firms on their heterogeneous impact on various types of innovations, and their detrimental interplay with other non-market strategies.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: Available online 6 July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 International Journal of Production Economics〈/p〉 〈p〉Author(s): W.W. Nasr, M.Y. Jaber〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Companies have to account for continuously evolving technologies that are driven by the consumer's appetite for new and innovative products, requiring them to modify their production systems to become flexible, where items do not have standard features and specifications. It is normal though that new products and processes would result in a considerable proportion of non-conforming items produced by the supplier and rejected by the buyer (a company). We consider a two-level joint production system that investigates the behavior of the supplier and the buyer's production systems. We assume that the proportion of non-conforming items produced by the supplier is a random variable whose mean and variance reduce due to learning effects. We examine investing in the supplier's process to speed up the learning process and propose a mathematical framework to quantify the effectiveness of an investment. Heuristics are developed to solve those mathematical models. We consider a finite planning horizon since products, today, have short lives, and we present a numerical study to show that the proposed action can be economically beneficial to the system.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: Available online 5 July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 International Journal of Production Economics〈/p〉 〈p〉Author(s): Philipp Wetzel, Erik Hofmann〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this paper, we examine the functional form of the relationship between working capital assets and corporate performance beyond the traditional single-company perspective. In particular, we explore how a focal company's adequate level of working capital is influenced by the presence of limited financial resources along the supply chain. Moreover, we investigate the performance impact of supply chain finance (SCF)-oriented working capital management (WCM) approaches. Based on the SCF-oriented school of thought, we subject propositions regarding the relationship between working capital and corporate performance from prior WCM research to explorative empirical testing. In doing so, we raise awareness of factors that have yet to be tested. We derive methodological implications for conducting interorganizational studies in the field of SCF and outline a future research agenda. The explorative results indicate (i) the existence of a profit-maximizing level of working capital, (ii) superior performance of companies adopting an SCF-oriented WCM approach, (iii) higher profit-maximizing levels of working capital for focal companies facing financially constrained supply chain partners, (iv) a positive performance impact of efficient inventory management, and (v) differentiated payment strategies toward up- and downstream supply chain partners.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 1 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Computer Methods in Applied Mechanics and Engineering, Volume 355〈/p〉 〈p〉Author(s): Zhao Wang, Amit Subhash Shedbale, Sachin Kumar, Leong Hien Poh〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A localizing gradient damage model with micro inertia effect is proposed for the dynamic fracture of quasi-brittle materials. The objective is to achieve mesh independent solutions, and to avoid spurious effects associated with the conventional nonlocal enhancement. The proposed localizing gradient damage model closely resembles the conventional gradient enhancement, albeit with an interaction domain that decreases with damage, complemented by a micro inertia effect. We first consider a classical crack branching problem, where the localizing gradient damage model is shown to resolve the mesh sensitivity issue, as well as to correctly reproduce the crack profile. Moreover, the micro inertia effect is observed to retard the crack velocity. Next, the tensile loading of a Polymethyl Methacrylate plate is considered. It is shown that the proposed model effectively captures the experimentally observed transition of crack profiles as the loading rate increases, i.e. from a straight crack propagation, to sub-branching, and finally to macro branching. Numerical results in terms of crack patterns, crack velocities, and fracture energies are in good agreement with the experimental data. To furthermore demonstrate the superior performance of the localizing gradient damage model, the macro branching problem is solved using the conventional gradient enhancement with micro inertia. It is shown that a spurious damage growth and an erroneous interaction between closely spaced cracks suppress the development of macro branching, even though reasonable values are obtained for the fracture energy and crack velocity. The localizing gradient damage model is able to fully resolve these issues.〈/p〉〈/div〉

Description: 〈p〉Publication date: 1 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Computer Methods in Applied Mechanics and Engineering, Volume 355〈/p〉 〈p〉Author(s): D. Xiao〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A novel error estimation method for the parametric non-intrusive reduced order model (P-NIROM) based on machine learning is presented. This method relies on constructing a set of response functions for the errors between the high fidelity full model solutions and P-NIROM using machine learning method, particularly, Gaussian process regression method. This yields closer solutions agreement with the high fidelity full model. The novelty of this work is that it is the first time to use machine learning method to derive error estimate for the P-NIROM. The capability of the new error estimation method is demonstrated using three numerical simulation examples: flow past a cylinder, dam break and 3D fluvial channel. It is shown that the results are closer to those of the high fidelity full model when considering error terms. In addition, the interface between two phases of dam break case is captured well if the error estimator is involved in the P-NIROM.〈/p〉〈/div〉

Description: 〈p〉Publication date: 1 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Computer Methods in Applied Mechanics and Engineering, Volume 355〈/p〉 〈p〉Author(s): M. Goudarzi, A. Simone〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉We report the results of a comparative analysis of mesh independent discrete inclusion models and point out some shortcomings of classical approaches in the approximation of the strain field across an inclusion (artificial continuity) and the slip profile along an inclusion (oscillatory behavior). We also present novel embedded reinforcement models based on partition of unity enrichment strategies, adaptive 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" altimg="si246.svg"〉〈mi〉h〈/mi〉〈/math〉-refinement, and order/regularity extensions. These novel models are assessed by means of mesh convergence studies and it is shown that they improve the quality of the solution by significantly decreasing local spurious oscillations in the slip profile along an inclusion.〈/p〉〈/div〉

Description: 〈p〉Publication date: 1 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Computer Methods in Applied Mechanics and Engineering, Volume 355〈/p〉 〈p〉Author(s): C. Hermange, G. Oger, Y. Le Chenadec, D. Le Touzé〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A 3D fluid–structure coupling between Smoothed Particle Hydrodynamics (SPH) and Finite Element (FE) methods is proposed in this paper, with its application to complex tire hydroplaning simulations on rough ground. The purpose of this work is to analyze the SPH–FE coupling capabilities for modeling efficiently such a complex phenomenon. On the fluid side, the SPH method is able to handle the three complex interfaces of the hydroplaning phenomenon: free-surface, ground/fluid and fluid/tire interfaces. On the solid side, the FE method is used for its ability to treat tire–ground contact. A new algorithm dedicated to such SPH–FE coupling strategies is proposed to optimize the computational efficiency through the use of differed time steps between fluid and solid solvers. This way, the number of calls to the FE solver is minimized while maintaining the accuracy and stability of the coupling. The ratio between these respective time steps relies on a control procedure based on pressure loading. The present 3D SPH–FE model is first validated with different academic test cases and experimental data before considering the complex problem of the 3D hydroplaning simulations. Hydroplaning simulations are performed and analyzed on 3D configurations involving both smooth and rough grounds.〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Computers & Fluids, Volume 191〈/p〉 〈p〉Author(s): Tibing Xu, Yee-Chung Jin〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉This paper incorporates an improved Laplacian model for the pressure Poisson equation, a stabilization technique and a newly proposed advanced conditional collision force model in a projection-based particle method of the Moving Particle Semi-implicit (MPS) method. The Laplacian model is used to calculate pressure field and is able to predict more accurate results. The stabilization technique is used to eliminate density variation, which is developed from the continuity equation and transport theorem. The conditional collision force model is developed to handle approaching particles in simulations. With the conditional collision force model and the stabilization technique, the density calculation is improved in the dam-breaking flow and the number of separate jumping particles in the flow is greatly reduced due to the stabilization technique. By using the conditional collision force model, the Laplacian model can calculate the rotation of a square fluid patch. The stabilization technique further enhances the calculation, allowing the method to predict the evolution of the fluid patch in long duration. Including the three techniques, the present MPS is able to predict accurate pressure in the dam-breaking flow and rotation of the fluid patch. The energy variation in the impact of two rectangular fluid patches is also reproduced by the implemented techniques.〈/p〉〈/div〉

Description: 〈p〉Publication date: 1 September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Computer Methods in Applied Mechanics and Engineering, Volume 354〈/p〉 〈p〉Author(s): 〈/p〉

Description: 〈p〉Publication date: 15 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials, Volume 380〈/p〉 〈p〉Author(s): Chi Xu, Lirong Gao, Minghui Zheng, Lin Qiao, Lili Cui, Kunran Wang, Di Huang〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Short- and medium-chain chlorinated paraffins (SCCPs and MCCPs) in commercial rubber track products and raw materials (rubber granules and adhesives) were investigated by two-dimensional gas chromatography with electron-capture negative-ionization mass spectrometry (GC × GC-ECNI-MS). The mean SCCP and MCCP concentrations in the rubber track products were 3.64 × 10〈sup〉3〈/sup〉 and 4.14 × 10〈sup〉4〈/sup〉 μg/g, respectively. The mean SCCP concentration in the products was significantly higher than those in the rubber granules (2.78 μg/g), but in the same order of magnitude as those in the adhesives (3.34 × 10〈sup〉3〈/sup〉 μg/g). The SCCP concentrations in almost half of the rubber track products and four fifths of the adhesives exceeded the limit (1.5 g/kg) set in Chinese standard GB 36246-2018. The dominant SCCP and MCCP congeners in the rubber track products were similar to those in the relevant adhesives but different from those in the paired granules. Principal component analysis and contribution calculations indicated that chlorinated paraffins (CPs) in adhesives could be the main sources of CPs in rubber track products. The high CP concentrations found in rubber track products are of special concern because of the relatively high exposures for children and negative effect on human health and environment.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0304389419308076-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials, Volume 380〈/p〉 〈p〉Author(s): Tufan Paul, Dimitra Das, Bikram Kumar Das, Saikat Sarkar, Soumen Maiti, Kalyan Kumar Chattopadhyay〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Photocatalytic activity of low band gap semiconductor largely restrained by high recombination rate of photogenerated charge carriers. To enhance the catalytic performance numerous protocols were adopted amongst which designing of novel hybrid via coupling of semiconductors are very intriguing from modest application point of view. Here, we report facile realization of type II heterojunctions embracing polymeric graphitic carbon nitride (g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉/GCN) and all-inorganic cesium lead halide perovskite (CsPbBrCl〈sub〉2〈/sub〉) for degradation complex organic effluents under visible-light illumination. Synthesized hybrid presented much improved performance in toxic cationic and anionic dyes degradation as compared to individual building units. Signature of favorable staggered gap junction’s formation at interface was confirmed via Mott-Schottky analysis. Such kind of junctions delay the recombination of photogenerated electron holes and facilitates active radical generation at catalyst surface thereby ensures improved photocatalytic performance. Charge transfer process in heterojunction further illustrated via Density functional theory (DFT) based calculations. Several scavenger tests have been performed to examine the impact of different active radicals in the photocatalysis which suggests manifold performance improvement in the presence of very small concentrations of EDTA. A plausible photocatalytic mechanism in accordance with the type II junction has been proposed.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0304389419308088-ga1.jpg" width="311" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials, Volume 380〈/p〉 〈p〉Author(s): Vepika Kandjou, Ana M. Perez-Mas, B. Acevedo, M. Hernaez, Andrew G. Mayes, Sonia Melendi-Espina〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The increasing depletion of freshwater necessitates the re-use and purification of wastewaters. Among the existing separation membrane materials, graphene oxide (GO) is a promising candidate, owing to its tunable physicochemical properties. However, the widening of GO membranes pore gap in aqueous environments is a major limitation. Crosslinking agents can be incorporated to alleviate this problem. This study describes a comparative analysis of uncrosslinked and p-Phenylenediamine (PPD) crosslinked GO membranes’ water purification performance. Dip-coating and dip-assisted layer-by-layer methods were used to fabricate the uncrosslinked and crosslinked membranes respectively. The covalent interaction between GO and PPD was confirmed by Fourier Transform Infra-Red and X-ray Photoelectron Spectroscopy. The excellent membrane topographical continuity and intactness was assessed by means of Scanning Electron Microscopy, while water contact angle measurements were undertaken to evaluate and confirm membrane hydrophilicity. The improvement impact of the crosslinker was manifested on the enhancement of the stability and performance of the membranes during nanofiltration tests of aqueous solutions of methylene blue in a homemade nanofiltration cell operated at 1 bar.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0304389419307939-ga1.jpg" width="452" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials, Volume 380〈/p〉 〈p〉Author(s): Elisabete Luís Afonso, Lina Carvalho, Sara Fateixa, Carlos Oliveira Amorim, Vitor S. Amaral, Carlos Vale, Eduarda Pereira, Carlos Manuel Silva, Tito Trindade, Cláudia Batista Lopes〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Technology critical elements (TCE) are considered the vitamins of nowadays technology. Factors such as high demand, limited sources and geopolitical pressures, mining exploitation and its negative impact, point these elements as new emerging contaminants and highlight the importance for removal and recycling TCE from contaminated waters. This paper reports the synthesis, characterization and application of hybrid nanostructures to remove and recover lanthanides from water, promoting the recycling of these high value elements. The nanocomposite combines the interesting properties of graphite nanoplatelets, with the magnetic properties of magnetite, and exhibits good sorption properties towards La(III), Eu(III) and Tb(III). The sorption process was very sensitive to solution pH, evidencing that electrostatic interactions are the main binding mechanism involved. Removal efficiencies up to 80% were achieved at pH 8, using only 50 mg/L of nanocomposite. In ternary solution, occurred a preferential removal of Eu(III) and Tb(III). The equilibrium evidenced a rare but interesting behaviour, and as a proof-of-concept the recoveries and reutilization rates, at consecutive cycles, highlight the recyclability of the composite without loss of efficiency. This study evidences that surface charge and the number of active sites of the composite controls the removal process, providing new insights on the interactions between lanthanoids and magnetic-graphite-nanoplatelets.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0304389419307988-ga1.jpg" width="406" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials, Volume 380〈/p〉 〈p〉Author(s): Daria Boglaienko, Hilary P. Emerson, Yelena P. Katsenovich, Tatiana G. Levitskaia〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Technetium-99 (Tc) is a long-lived radioactive contaminant present in legacy nuclear waste streams and contaminated plumes of the nuclear waste storage sites worldwide that poses risks for human health and the environment. Pertechnetate (TcO〈sub〉4〈/sub〉〈sup〉−〈/sup〉), the most common chemical form of Tc under oxidative conditions, is of particular concern due to its high aqueous solubility and mobility in the subsurface. One approach to treatment and remediation of TcO〈sub〉4〈/sub〉〈sup〉−〈/sup〉 is reduction of Tc〈sup〉7+〈/sup〉 to less soluble and mobile Tc〈sup〉4+〈/sup〉 and its removal from the contaminated streams such as liquid secondary waste generated during vitrification of the Hanford low activity tank waste. Zero valent iron (ZVI) is a common reactive agent for reductive treatment of environmental contaminants, including reducible heavy metal ions, which can offer a potential solution to this challenge. Here, we present a comparative study of eleven commercial ZVI materials manufactured by different methods that were evaluated for the reductive removal of TcO〈sub〉4〈/sub〉〈sup〉−〈/sup〉 from an aqueous 80 mM NaCl solution at near neutral pH representing low activity waste off-gas condensate. Performance of ZVI materials was analyzed in relation to time-dependent Fe〈sup〉2+〈/sup〉 dissolution as well as pH and ORP profiles of the contact solution. Large variability in the efficiency and kinetics of Tc〈sup〉7+〈/sup〉 reduction by different ZVI materials was contingent on their origin. ZVI materials manufactured by electrolytic method exhibited superior performance, and the kinetics of the Tc〈sup〉7+〈/sup〉 reduction correlated to particle size. ZVI materials manufactured by iron pentacarbonyl reduction with hydrogen were ineffective for Tc〈sup〉7+〈/sup〉 reduction. In general, our results highlight the need for thorough performance analysis of commercial ZVI materials for any contaminant of interest.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0304389419307897-ga1.jpg" width="470" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 3 July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials〈/p〉 〈p〉Author(s): Manzoor Ahmad, Qingsong Yang, Yanying Zhang, Juan Ling, Wasim Sajjad, Shuhua Qi, Weiguo Zhou, Ying Zhang, Xiancheng Lin, Yuhang Zhang, Junde Dong〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Understanding the microbial community succession to polycyclic aromatic hydrocarbons (PAHs) and identification of important degrading microbial groups are crucial for the designing of appropriate bioremediation strategies. In the present study, two distinct phenanthrene enriched bacterial consortia were treated against high molecular weight (Pyrene, Benzo (a) pyrene and Benzo (a) fluoranthene) and the response was studied in term of taxonomic variations by using High Throughput Illumina sequencing and qPCR analysis. Overall, the type of PAHs significantly affected the composition and the relative abundance of bacterial communities while no obvious difference was detected between bacterial communities of benzo (a) pyrene and benzo (a) fluoranthene treatments. Genera, 〈em〉Novosphingobium〈/em〉, 〈em〉Pseudomonas〈/em〉, 〈em〉Flavobacterium〈/em〉, 〈em〉Mycobacterium, Hoeflae,〈/em〉 and 〈em〉Algoriphagus〈/em〉 dominated all PAHs treatment groups indicating that they could be the key PAHs degrading phylotypes. Due to the higher abundance of gram-negative PAH-ring hydroxylating dioxygenase gene than that of gram-positive bacteria in all treated groups, we speculated that gram-negative bacteria may contribute more in the PAH degradation. The studied sediments harbored rich PAHs degrading bacterial assemblages involved in both low and high molecular weight PAHs and these findings provided new insight into the perspective of microbial PAHs bioremediation in the mangrove ecosystem.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0304389419308167-ga1.jpg" width="301" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials, Volume 380〈/p〉 〈p〉Author(s): Zizhen Li, Anthony Ivanenko, Xiangchao Meng, Zisheng Zhang〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Methanol is widely applied in photocatalysis as a scavenger of holes, and is also studied as a model system for heterogeneous photocatalysis for the production of formaldehyde. Compared to commercial processes for formaldehyde production via thermal catalytic methanol oxidation, photocatalytic oxidation of methanol to formaldehyde may be more promising when considering the following aspects: 1) lower reaction temperature and pressure (generally operated at room temperature and ambient pressure); 2) lower cost of the energy source (such as solar light) and 3) easy-to-design reactive system. Photocatalytic methanol oxidation was carried out using four different bismuth-based semiconductors (BBS), Bi〈sub〉2〈/sub〉WO〈sub〉6〈/sub〉, Bi〈sub〉2〈/sub〉MoO〈sub〉6〈/sub〉, BiOBr and BiVO〈sub〉4〈/sub〉, under varying system temperature (5–50 °C), bubbling speed (0.1–1.0 LPM), catalyst dosage (0.2–2.0 g/L), and initial methanol concentration (12.5–250 mM). It was found that the formaldehyde formation rate for all photocatalysts increased as a function of each of these system parameters. Of these four BBS, it was found that Bi〈sub〉2〈/sub〉WO〈sub〉6〈/sub〉 had the highest formaldehyde formation rate (0.081 mM/h). This work provides a new approach to produce formaldehyde using photocatalysis, and future work has also been proposed.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0304389419307757-ga1.jpg" width="341" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials, Volume 380〈/p〉 〈p〉Author(s): Xiaohui Li, Hongxia Xu, Bin Gao, Yuanyuan Sun, Xiaoqing Shi, Jichun Wu〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Laboratory saturated columns packed with granular limestone grains were used to explore the retention and remobilization of functional bacteria FA1 under various physicochemical conditions. The unique surface properties of limestone and FA1 caused some unexpected phenomena. Solution IS, cation type, temperature and surface biological property all affected FA1 retention in the columns. The IS effect was temperature dependent and initial solution pH showed little influence due to the strong buffering ability of limestone. Perturbations of solution IS caused slight release of previously retained bacteria in some columns with NaCl as the background electrolyte, while increase in flow rate caused no release at all. When CaCl〈sub〉2〈/sub〉 was the background, bacterial remobilization only occurred following both cation exchange and IS reduction. DLVO forces incorporating with surface roughness calculation were determined to assist with interpretation of interaction mechanisms. All the experimental evidences suggest the importance of cation bridging, cation exchange, surface roughness, and hydrophobic interaction in controlling bacterium transport in saturated limestone porous media.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0304389419308118-ga1.jpg" width="336" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials, Volume 380〈/p〉 〈p〉Author(s): Lei Qin, Huan Yi, Guangming Zeng, Cui Lai, Danlian Huang, Piao Xu, Yukui Fu, Jiangfan He, Bisheng Li, Chen Zhang, Min Cheng, Han Wang, Xigui Liu〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this study, four kinds of porous carbon materials were used as supports to anchor gold nanoparticles (AuNPs) for catalytic reduction of nitroaromatics and 4-nitrophenol (4-NP) was employed as a model material. Results identified that carbon black (CB) restricted-Au catalyst (Au/CB) provided large specific surface area, small AuNPs size, and low cost, which showed highly catalytic activity for 4-NP reduction. Besides, with the increase of Au loadings, the catalytic activity of Au/CB was enhanced and the 1.2 wt% of Au loading exhibited the best catalytic activity with the high rate of 0.8302 min〈sup〉−1〈/sup〉 and the turnover frequency of 492.50 h〈sup〉−1〈/sup〉. Universality and real water application demonstrated that the as-prepared Au/CB catalyst was promising candidate for other phenols and azo dyes reduction and had great potential for practical application. Furthermore, after ten cycles, Au/CB still retained satisfying stability and activity. These results suggested that the larger specific surface area and smaller particle size attributing to the porosity of CB were conducive to improving the catalytic activity of Au catalysts. This design shows high potential of hierarchical porous carbon materials for highly catalytic reaction in many fields, especially the water purification.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0304389419308179-ga1.jpg" width="249" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials, Volume 380〈/p〉 〈p〉Author(s): Rahul Ram, James Vaughan, Barbara Etschmann, Joël Brugger〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉 〈p〉The longest-lived naturally occurring isotope of polonium is polonium-210, one of the daughters of uranium-238 (138 days half-life). As a daughter radionuclide of radon-222, polonium-210 can become enriched in pore fluids in U-bearing rocks, leading to contents in excess of 100 Bq.g〈sup〉−1〈/sup〉 in some products from the mineral, coal, oil and gas industries (e.g., anode slimes in copper refinement; sludge from the oil and gas industry). Since 2006, IAEA recommendation limits require polonium and other radionuclides from the U- and Th-series decay to be regulated for products and wastes that contain 〉1 Bq.g〈sup〉−1〈/sup〉, which results in the classification of large amounts of industrial products and waste as radioactive.〈/p〉 〈p〉To develop effective methods for polonium removal and/or control, it is necessary to acquire an understanding of its aqueous chemistry. Based on a review of available experimental data, we developed a self-consistent thermochemical model for polonium in inorganic aqueous solutions. Polonium exists mainly in two oxidation states in aqueous solutions: Po(IV) and Po(II). The importance of Po(II) is unique, as Te(II) or Se(II) complexes do not appear to play a significant role in aqueous solution at room temperature. The model is used to discuss polonium speciation in some environmental and process waters.〈/p〉 〈/div〉

Description: 〈p〉Publication date: 15 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials, Volume 380〈/p〉 〈p〉Author(s): Benjamin Tawiah, Bin Yu, Ruichao Wei, Richard K.K. Yuen, Wei Chen, John H. Xin, Bin Fei〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Poly(lactic acid) (PLA) is an important bioplastic polymer with wide engineering applications, but has relatively low tensile strength and high susceptibility to flames. This manuscript reports the synthesis of a new cyclo-phosphorus-nitrogen flame retardant (FR) - hexaphenyl (nitrilotris(ethane-2,1-diyl))tris(phosphoramidate) (HNETP) for concurrent FR and tensile strength enhancement. 〈sup〉1〈/sup〉H, 〈sup〉13〈/sup〉C Nuclear Magnetic Resonance and Fourier Transform Infra-red spectra showed that HNETP was successfully synthesized. The FR properties of PLA/HNETP composites were investigated, and the peak heat release rate (PHRR) reduced by ˜ 51.3%, total heat released (THR) ˜ 43.1%, and carbon monoxide (CO) production by ˜ 46.5% with 3 wt% HNETP loading. The fire performance index increased by ˜ 65.8%, while the fire growth index decreased by ˜ 56.7%. The tensile strength and the Young’s Modulus improved to ˜ 67.4 and ˜ 87.8% respectively. A significant increase in limiting oxygen index (LOI) (32.5%) was attained with a V-0 rating in the vertical burning test. TG-IR study showed considerable reduction in pyrolysis gaseous products by the PLA/HNETP composites compared to PLA. Insignificant changes were observed in the glass transition and the melting temperature of PLA and PLA/HNETP biocomposites.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S030438941930809X-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 10 April 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Technological Forecasting and Social Change〈/p〉 〈p〉Author(s): John Rice, Nigel Martin〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Smart Information and Communications Technology (ICT) is envisaged to provide the capabilities to plan, design, construct, operate and manage Australia's key infrastructure. With over 75% of Australia's population living in cities and accessing public and private goods and services, ICT is positioned as a strategic resource for smart infrastructure developments. In this study, international and domestic stakeholder inputs on the future role of smart ICT in advancing Australia's infrastructure development and operations were crowdsourced for analysis. The study identifies several forms of smart ICT (e.g. building information modelling software) enabled infrastructure that possesses potential to deliver over A$9 billion per annum in domestic economic improvements, with commensurate advancement of communities, regions and urban environments. However, to be effective these smart ICT require enablement through open and interoperable data, sound governance and policy, and government leadership and coordination using dedicated resources. While smart infrastructure development is presently slow and lumbering, the identified smart ICT present as valuable strategic technologies for change and development in domestic communities.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: Available online 24 April 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Technological Forecasting and Social Change〈/p〉 〈p〉Author(s): Rahat Iqbal, Faiyaz Doctor, Brian More, Shahid Mahmud, Usman Yousuf〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Big Data has significant impact in developing functional smart cities and supporting modern societies. In this paper, we investigate the importance of Big Data in modern life and economy, and discuss challenges arising from Big Data utilization. Different computational intelligence techniques have been considered as tools for Big Data analytics. We also explore the powerful combination of Big Data and Computational Intelligence (CI) and identify a number of areas, where novel applications in real world smart city problems can be developed by utilizing these powerful tools and techniques. We present a case study for intelligent transportation in the context of a smart city, and a novel data modelling methodology based on a biologically inspired universal generative modelling approach called Hierarchical Spatial-Temporal State Machine (HSTSM). We further discuss various implications of policy, protection, valuation and commercialization related to Big Data, its applications and deployment.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: Available online 12 April 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Technological Forecasting and Social Change〈/p〉 〈p〉Author(s): F.W. Geels, A. McMeekin, B. Pfluger〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Social acceptance and political feasibility are important issues in low-carbon transitions. Since computer models struggle to address these issues, the paper advances socio-technical scenarios as a novel methodological tool. Contributing to recent dialogue approaches, we develop an eight-step methodological procedure that produces socio-technical scenarios through various interactions between the multi-level perspective and computer models. As a specific contribution, we propose ‘transition bottlenecks’ as a methodological aid to mediate dialogue between qualitative MLP-based analysis of 〈em〉contemporary〈/em〉 dynamics and quantitative, model-generated 〈em〉future〈/em〉 pathways. The transition bottlenecks also guide the articulation of socio-technical storylines that suggest how the social acceptance and political feasibility of particular low-carbon innovations can be improved through social interactions and endogenous changes in discourses, preferences, support coalitions and policies. Drawing on results from the 3-year PATHWAYS project, we demonstrate these contributions for the UK electricity system, developing two low-carbon transition pathways to 2050 commensurate with the 2 °C target, one based on technological substitution (enacted by incumbent actors), and one based on broader system transformation (enacted by new entrants).〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Technological Forecasting and Social Change, Volume 147〈/p〉 〈p〉Author(s): Emrah Karakilic〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The transition from industrial capitalism to cognitive capitalism and the rise of the digital revolution have brought the subject of intellectual property rights to the forefront as a controversial issue. This paper holds that the theoretical apparatus and concepts belonging to the industrial phase of capitalism largely fall short with respect to the repercussions that intellectual property rights regime yields. Embracing the methodological precept that social theory must be moulded in order to address the contours of contemporary social reality, this paper engages in an autonomist Marxist update on the concept of intellectual property rights. It ultimately challenges the “intellectual property rights are a socio-economic need” thesis and speculatively argues that the current system of intellectual property rights, directed politically towards the enclosure of commons, constitutes a structural contradiction by i) forming a basis for a social crisis in terms of the established relations of production, and ii) curtailing a part of the socio-economic opportunities for innovation, profit-making, and growth.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: Available online 9 April 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Technological Forecasting and Social Change〈/p〉 〈p〉Author(s): Daniela Maresch, Johannes Gartner〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Disruptive technological change can contribute to a more abundant world. However, potentially disruptive technologies often struggle to significantly influence practice. One prominent example is additive manufacturing (AM). Although AM is often regarded as the next great technological revolution in waiting, it has not yet established itself on a large scale in many fields of application. We investigate the reasons behind those challenges by looking at the various fields in which AM is applied and relating them to the specific challenges AM faces, as well as the opportunities it offers in those fields. Our findings rely on a multi-perspective technology foresight process that is based on a discourse analytic approach and that comprises data tomography covering the biggest German-language online magazine on AM and qualitative interview data collected from a range of AM stakeholders. The findings provide an empirically well-founded evaluation and explanation of the link between the challenges and opportunities offered by AM and the extent to which this disruptive technology is leveraged in specific fields. The findings prompt recommendations on how new potentially disruptive technologies can foster abundance in traditional, well established market economies based on the example of the well-developed but traditional market economy of Austria.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: Available online 24 April 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Technological Forecasting and Social Change〈/p〉 〈p〉Author(s): Måns Nilsson, Adis Dzebo, Georgia Savvidou, Katarina Axelsson〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Quantitative models of transitions, such as energy systems models and integrated assessment models, do not usually represent social processes, institutions and politics. Their view of societal transitions, along with the governance required to drive them, is therefore limited. Socio-technical systems approaches, in contrast, represent the social side but lack a quantitative view of the future system. This paper addresses this by bridging an energy systems model with socio-technical systems analysis and a local action study, analysing the future transition of the residential heating system in Sweden. The paper focuses on demand-side shifts that would drive a transition to a highly efficient, low-carbon heating system until 2050. A conceptual framework for bridging three approaches is introduced and applied. For example, niche-innovations identified in the socio-technical study are implemented as scenario options in the model. Landscape signals are external drivers of the scenario, and the regime study identifies barriers and governance requirements. The local action study provides insights into community attitudes affecting niches and regime change. Our results indicate that the linking of approaches is meaningful, in that it provides an enriched understanding of future systems change in many dimensions. Further research is required using a variety of models on a variety of domains or sectors to draw more generalizable lessons about bridging modelling and social science-based approaches for transition studies.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: Available online 10 July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of the Franklin Institute〈/p〉 〈p〉Author(s): Yaonan Shan, Kun She, Shouming Zhong, Jun Cheng, Wenyong Wang, Can Zhao〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉This paper investigates the passivity of Markovian jump discrete-time systems (MJDTSs) with channel fading via event-triggered state feedback control. First, the concerned MJDTSs contain infinitely distributed delays and switching rules with partially known transition probability (TP) information. Next, the fading channel, as an unreliable channel, is introduced into MJDTSs to better reflect the engineering practice in networked environment. Due to the present of channel fading, a series of random variables satisfying some certain probability density functions (PDFs) will be obstacles in the process of proof. Then, an event-triggered controller is designed for MJDTSs with channel fading and incomplete transition probability (ITP) for the first time. Thanks to this event-triggered mechanism, the state feedback control could greatly reduce energy consumption during transmission. Subsequently, under the above controller, we obtain some novel sufficient criteria in the form of linear matrix inequalities (LMIs) to ensure the passivity of closed-loop system. Finally, some simulation results are provided to demonstrate the feasibility and effectiveness of the proposed theoretical method.〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 10 July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of the Franklin Institute〈/p〉 〈p〉Author(s): Ahmed Bendib, Aissa Chouder, Kamel Kara, Abdelhammid Kherbachi, Said Barkat, Walid Issa〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In a microgrid (MG) topology, the secondary control is introduced to compensate for the voltage amplitude and frequency deviations, mainly caused by the inherent characteristics of the droop control strategy. This paper proposes an accurate approach to derive small signal models of the frequency and amplitude voltage at the point of common coupling (PCC) of a single-phase MG by analyzing the dynamics of the second-order generalized integrator-based frequency-locked loop (SOGI-FLL). The frequency estimate model is then introduced in the frequency restoration control loop, while the derived model of the amplitude estimate is introduced for the voltage restoration loop. Based on the obtained models, the MG stability analysis and proposed controllers’ parameters tuning are carried out. Also, this study includes the modeling and design of the synchronization control loop that enables a seamless transition from island mode to grid-connected mode operation. Simulation and practical experiments of a hierarchical control scheme, including traditional droop control and the proposed secondary control for two single-phase parallel inverters, are implemented to confirm the effectiveness and the robustness of the proposal under different operating conditions. The obtained results validate the proposed modeling approach to provide the expected transient response and disturbance rejection in the MG.〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials, Volume 379〈/p〉 〈p〉Author(s): Shuyu Jia, Jialu Wu, Lin Ye, Fuzheng Zhao, Tong Li, Xu-Xiang Zhang〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Chlorination can contribute to the enrichment of specific antibiotic resistance genes (ARGs) in drinking water, but the underlying molecular ecological mechanisms remain unknown, which may hinder the assessment and control of the resulting health risks. In this study, metagenomic assembly and Resfams annotation were used to profile the co-occurrence patterns of ARGs, mobile genetic elements (MGEs) and their bacterial hosts, as well as the correlations of potential pathogens with the antibiotic resistome, in a full-scale drinking water treatment and transportation system. Seven ARG types involved in different resistance mechanisms occurred in drinking water and chlorination enhanced the total abundance of the ARGs (〈em〉p〈/em〉 〈  0.05). The ARGs encoding resistance-nodulation-cell division and ATP-binding cassette antibiotic efflux pumps predominated in all the samples and were primarily responsible for the ARG accumulation. After chlorination, the ARGs were primarily carried by predominant 〈em〉Sphingomonas〈/em〉, 〈em〉Polaromonas〈/em〉, 〈em〉Hyphomicrobium〈/em〉, 〈em〉Acidovorax〈/em〉, 〈em〉Pseudomonas〈/em〉 and 〈em〉Fluviicola〈/em〉. Further, enrichment of the bacterial hosts and MGEs greatly contributed to alteration of the antibiotic resistome. 〈em〉Pseudomonas alcaligenes〈/em〉, carrying multiple ARGs, was identified as a potential pathogen in the chlorinated drinking water. These findings provide novel insights into the host-ARG relationship and the mechanism underlying the resistome alteration during drinking water chlorination.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0304389419307940-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 4 July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of the Franklin Institute〈/p〉 〈p〉Author(s): Xi Wang, Shukai Li, Tao Tang〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉With the objective to promote the efficiency of heavy haul transportation, this paper investigates the efficiently intermittent cruise control problem for heavy haul trains. Based on the concept of periodically intermittent control, the closed-loop form of the error dynamic state-space model for heavy haul trains is given considering uncertain parameters, which is different from existing heavy haul train control methods in that the control forces are only provided in part of the running period. To facilitate the controller design, a set of linear matrix inequalities (LMIs) are presented as the sufficient conditions for the existence of the periodically intermittent controller, which guarantees both the speed tracking error and the relative coupler displacements are exponentially stable at the equilibrium state. Simulation results indicate that the proposed control scheme can significantly improve the control efficiency without sacrificing too much on speed tracking performance.〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 4 July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of the Franklin Institute〈/p〉 〈p〉Author(s): Xin Hu, Chi Huang, Jianquan Lu, Jinde Cao〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉This paper studies the stabilization problem of Boolean control networks with stochastic impulses, where stochastic impulses model is described as a series of possible regulatory models with corresponding probabilities. The stochastic impulses model makes the research more realistic. The global stabilization problem is trying to drive all states to reach the predefined target with probability 1. A necessary and sufficient condition is presented to judge whether a given system is globally stabilizable. Meanwhile, an algorithm is proposed to stabilize the given system by designing a state feedback controller and different impulses strategies. As an extension, these results are applied to analyze the global stabilization to a fixed state of probability Boolean control networks with stochastic impulses. Finally, two examples are given to demonstrate the effectiveness of the obtained results.〈/p〉〈/div〉

Description: 〈p〉Publication date: 1 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Computer Methods in Applied Mechanics and Engineering, Volume 355〈/p〉 〈p〉Author(s): Liyang Xu, Zhenzhou Lu, Luyi Li, Yan Shi〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Traditional sensitivity analysis methods for the model with correlated inputs and univariate output fail to provide satisfactory results for multivariate output. In this work, we first establish a reasonable contribution classification for the univariate output with the correlated input. Then the covariance decomposition method is extended to the case of correlated inputs as a reference, and the vector projection sensitivity index is extended to aggregate the correlated and uncorrelated contributions of the input to multiple outputs. The definition of the new sensitivity index is based on the vector projection, which can take into account both uncertainties and correlations among multiple outputs by projecting the conditional variance vector (built by the full marginal variance contributions) on the unconditional variance vector (built by unconditional variance magnitudes and correlation of the multiple outputs). The mathematical properties of the extended vector projection sensitivity index are discussed and its relations with other existing sensitivity indices are highlighted. Two numerical examples and two engineering examples about an aircraft structure are employed to illustrate the validity and potential benefits of the extended vector projection sensitivity index.〈/p〉〈/div〉

Description: Aiming at the problems in which there exists collocation between services and manufacturing tasks, multiobjective cloud manufacturing service composition optimization seldom considers the synergy degree of composite cloud services and the complexity of service composition, so a novel service composition optimization approach, called improved genetic algorithm based on entropy (IGABE), is put forward. First, the mathematical expressions of service collocation degree, composition synergy degree, composition entropy, and their related influence factors of the service composition are analyzed, and their definitions and calculation methods are given. Then, a multiobjective cloud manufacturing service composition optimization mathematical model is established. Moreover, crossover and mutation operators are improved by introducing normal cloud model theory and piecewise function, and improved roulette selection method is used to perform the selection operation. And the fitness function of the proposed IGABE is designed by combining Euclidean deviation with angular deviation. Finally, the manufacturing task of a wheeled cleaning robot is exemplified to verify the correctness of the proposed multiobjective optimization model for cloud manufacturing service composition and the effectiveness of the proposed algorithm, compared with Standard Genetic Algorithm (SGA), Hybrid Genetic Algorithm (HGA), and Cloud-entropy Enhanced Genetic Algorithm (CEGA). The studied results show that IGABE converges faster than SGA and HGA and can analyze and reflect the content difference expressed by the objective functions of service composition scheme and its approximation degree to the corresponding dimensions of the ideal point vector more comprehensively than CEGA. As such, the optimal service composition obtained by IGABE algorithm can better meet the complex needs of users.

Description: The phenomenon of coordinate measuring machines has led to a significant improvement in accuracy, adaptability, and reliability for measurement jobs. The coordinate measuring machines with scanning capabilities provide the alternative to output precise acquisition at a faster rate. However, they are less accurate as compared to discrete probing systems and slower than the noncontact techniques. Therefore, the data acquisition using a scanning touch probe needs improvement, so that it can provide commendable performance both in terms of accuracy and scanning time. The determination of appropriate scanning parameters is crucial to minimize the inaccuracy and time associated with the scanning process. However, it can be demanding as well as unreliable owing to the presence of uncertainty from a multitude of factors that may influence the measurement process. The optimization of data acquisition using a scanning touch probe is a multiresponse process which involves definite uncertainties from various sources. Therefore, multioptimization tools based on grey relational analysis coupled with principal component analysis and fuzzy logic were employed to enhance the utilization of the scanning touch probe. The work described here has the objective to identify the appropriate combination of scanning factors which can simultaneously boost the accuracy and lessen the scanning time. This study demonstrates the capability and effectiveness of the uncertainty theory based optimization methods in coordinate metrology. It also suggests that the uncertainty associated with the parameter optimization can be significantly reduced using these techniques. It has also been noticed that the results from the two techniques are in accord, which corroborates their application in coordinate metrology. The result from this study can be applied to other probing systems and can be broadened to include more experiments and parameters in various scenarios as needed by the specific application.

Description: Dissolved gas-in-oil analysis (DGA) is a powerful method to diagnose and detect transformer faults. It is of profound significance for the accurate and rapid determination of the fault of the transformer and the stability of the power. In different transformer faults, the concentration of dissolved gases in oil is also inconsistent. Commonly used gases include hydrogen (H2), methane (CH4), acetylene (C2H2), ethane (C2H6), and ethylene (C2H4). This paper first combines BP neural network with improved Adaboost algorithm, then combines PNN neural network to form a series diagnosis model for transformer fault, and finally combines dissolved gas-in-oil analysis to diagnose transformer fault. The experimental results show that the accuracy of the series diagnosis model proposed in this paper is greatly improved compared with BP neural network, GA-BP neural network, PNN neural network, and BP-Adaboost.

Description: 〈p〉Publication date: 5 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials, Volume 379〈/p〉 〈p〉Author(s): Ngan Hong Le, Yo-han Han, Hyunsook Jung, Joungmo Cho〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Highly efficient catalytic reaction systems are developed to rapidly and selectively oxidize 2-chloroethyl ethyl sulfide (CEES). In the systems, precursors containing bromide(s) and nitrate anions are chosen for the development of cyclic catalytic loop and the effect of acids on the selective oxidation of CEES are investigated by the addition of several homogeneous acid catalysts. The experimental results reveal that addition of acid results in a higher concentration of tribromide, which is reported as a key component for the observed activity in the catalytic solution. As a consequence, a dramatic improvement in catalytic activity is observed, especially when the molar amount of acid is controlled to be more than twice the initial concentration of tribromide. For the efficient design of a catalytic system, heterogeneous acid catalysts possessing different ratios of Brønsted to Lewis acid sites are also considered. Compared to reaction systems catalysed by homogeneous acids, similar reaction behaviour is observed for the reaction with Amerlyst-15, while those with other heterogeneous catalysts, containing Lewis or mixed acid sites in their structure, exhibits an adverse effect of selective sulfoxidation, mainly due to the adsorption of anions onto Lewis sites and consequential deconstruction of the catalytic loop.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0304389419307836-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials, Volume 379〈/p〉 〈p〉Author(s): Jian Chen, Xinghui Xia, Haotian Wang, Yawei Zhai, Nannan Xi, Hui Lin, Wu Wen〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The partition of polycyclic aromatic hydrocarbons (PAHs) among water-soil-air is temperature-dependent. Thus, we hypothesized that climate warming will affect the accumulation and uptake pathway of PAHs in plants. To test this hypothesis, enclosed soil/water-air-plant microcosm experiments were conducted to investigate the impact of warming on the uptake and accumulation of four PAHs in spinach (〈em〉Spinacia oleracea〈/em〉 L.). The results showed that root uptake was the predominant pathway and its contribution increased with temperature due to the promoted acropetal translocation. Owing to the increase in freely dissolved concentrations of PAHs in soil pore water, the four PAH concentrations in roots increased by 60.8–111.5% when temperature elevated from 15/10 to 21/16 °C. A model was established to describe the relationship between bioconcentration factor of PAHs in root and temperature. Compared with 15/10 °C, the PAH concentrations in leaves at both 18/13 and 21/16 °C elevated due to the increase in PAH concentrations in air, while slightly decreased when temperature elevated from 18/13 to 21/16 °C because the PAH concentrations in air decreased, resulting from accelerated biodegradation of PAHs in topsoil. This study suggests that warming will generally enhance the PAH accumulation in plant, but the effect will differ among different plant tissues.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0304389419307848-ga1.jpg" width="241" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Technological Forecasting and Social Change, Volume 146〈/p〉 〈p〉Author(s): Marco Capasso, Teis Hansen, Jonas Heiberg, Antje Klitkou, Markus Steen〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Governments in countries across the world increasingly adopt the “green growth” discourse to underline their ambition for the greening of their economies. The central tenet of this narrative is the economic opportunities rather than challenges arising from the pursuit of environmental sustainability. Our paper synthesises insights from 113 recent scientific articles, dealing with both environmental issues and economic growth, as well as innovation. Our ambition is exploratory in attempting to take stock of heterogeneous contributions across the spectrum of social science. The articles have been reviewed with a focus on six themes, derived from current discussions in economic geography and transition studies: skills, technology, physical resources, markets, institutions and policies. Four major implications emerge from the review. First, green growth requires competences that allow for handling complex, non-routine situations – in both the private and the public sector. Second, technological progress should be directed towards greener technologies, to avoid investments funds being channelled to brown technologies for short-term returns. Third, our knowledge of the opportunities for achieving green growth must base upon a joint assessment of market failures, structural system failures and transformational system failures. Finally, greater attention should be devoted to the geography of green growth processes at different scales.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 1 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Computer Methods in Applied Mechanics and Engineering, Volume 355〈/p〉 〈p〉Author(s): Yunfei Ma, Jiahuan Cui, Nagabhushana Rao Vadlamani, Paul Tucker〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The Immersed Boundary Method has been used to simulate a range of fundamental flows and turbulence. Such studies have demonstrated the method’s promising applicability for engineering analysis. However, to the authors’ knowledge, flows in coupled components or in scenarios with coupled physics, such as rotor–stator interaction, fan–intake interaction, aeroelastics, aeroacoustics, etc., are still rarely investigated using high-fidelity methods. Due to its high computational costs, the complexity of geometry meshing process and the requirement for moving boundaries limit the investigation of flows in such environments. Previous research suggests that high-fidelity simulations with an acceptable geometry modelling strategy may tackle these issues and provide useful insights. There exists a hierarchy of geometry modelling methods which includes the conventional Directly Mesh Resolving (DMR) method, the Immersed Boundary Method (IBM), and the IBM with Smeared Geometry (IBMsg, or eIBMg). The present research proposes an alternative to these approaches in the form of the Euler IBM with local force (eIBMl) by imposing a distribution function generated from blade configuration. Compared to the eIBMg, this method can include more realistic flow physics within each blade passage without smearing its geometry. This method is applied to the study of fan–intake interaction focusing on the transport of inlet distortion through blade passages and pressure wave propagation.〈/p〉〈/div〉

Description: This paper presents a hybrid metaheuristic that combines estimation of distribution algorithm with tabu search (EDA-TS) for solving the max-mean dispersion problem. The proposed EDA-TS algorithm essentially alternates between an EDA procedure for search diversification and a tabu search procedure for search intensification. The designed EDA procedure maintains an elite set of high quality solutions, based on which a conditional preference probability model is built for generating new diversified solutions. The tabu search procedure uses a fast 1-flip move operator for solution improvement. Experimental results on benchmark instances with variables ranging from 500 to 5000 disclose that our EDA-TS algorithm competes favorably with state-of-the-art algorithms in the literature. Additional analysis on the parameter sensitivity and the merit of the EDA procedure as well as the search balance between intensification and diversification sheds light on the effectiveness of the algorithm.

Description: The measured temperature of a concrete pouring block depends strongly on the position of the buried thermometer. Only when the temperature measured by the thermometer accurately reflects the actual temperature of the concrete pouring block do reasonable temperature-control measures become possible. However, little research has been done on how to determine the proper position of thermometers buried in a concrete pouring block embedded with cooling pipes. To address this situation, we develop herein a method to determine the position of thermometers buried in a concrete pouring block. First, we assume that the design temperature-control process line characterizes the average-temperature history of the concrete pouring block. Under this assumption, we calculate the average-temperature history of the concrete pouring block by using the water-pipe-cooling FEM, following which the temperature history of an arbitrary point in the concrete pouring block is obtained by interpolating the shape function. Based on the average-temperature history of the concrete pouring block and the temperature history of the arbitrary point, we build a mathematical model to optimize the buried position of the thermometer and use the optimization algorithm to determine this position. By using this method, we establish finite-element models of concrete prisms with four typical water-pipe spacing cases for concrete-dam engineering and obtain the geometric position of the thermometers by using the optimization algorithm. By burying thermometers at these positions, the measured temperature should better characterize the average-temperature history of the concrete pouring block, which can provide useful information for regulating the temperature of concrete pouring blocks.

Description: In this paper, we consider a risk averse competitive firm that adopts currency futures and options for hedging purpose. Based on the assumption of unbiased markets of currency futures and options, we propose the optimal hedging model in dynamic setting. By using two-stage optimization method, we prove that it is desirable for the prudent enterprise to buy exchange rate options to hedge currency risk. Furthermore, we derive the closed-form solutions of the multiperiod hedging problem with the quadratic utility function. We investigate an empirical study incorporated into GARCH-t prediction on the efficiency of hedging with currency futures and options. The empirical results demonstrate that hedging with currency futures and options can reduce the silver export firm’s risk exposure. Profits and the effective boundaries are compared in three cases: hedging with futures and options synchronously, only with futures and without any hedge. The results of multiple comparisons among different hedging strategies show that hedging with linear and nonlinear derivatives is advisable for the export firm.

Description: Currently, it is a challenge to effectively assess the seismic performance of the high-speed railway bridge line. To figure it out, this paper discussed the applicability of the Pushover analysis in the seismic fragility of the high-speed railway bridge. As the piers are the core components to resist the earthquakes, a typical high-speed railway bridge line consisting of 22 piers was established by the finite element software OpenSees. The influences of the different pier height and sites on the fragility analysis of the pies were investigated. From the component level, the seismic performance of the high-speed railway bridge line was evaluated by the Pushover analysis. The results show that the seismic responses of the piers by the Pushover analysis are agreeable with those by the incremental dynamical analysis when the peak ground acceleration is less than 0.4g. The high piers have better seismic performance than the lower piers. The high-speed railway bridge line exhibits good seismic performance under the 7-degree design earthquake (0.15g) and the 8-degree low-level earthquake (0.10g) but may be severely damaged under the 9-degree low-level earthquake (0.40g).

Description: As typical thermostatically controlled loads (TCL) driven by constant-speed compressor, constant-speed air-conditioners play important roles in demand-side response for their abilities of energy conversion and storage. Their great potential for load regulation can be incorporated into power system scheduling through demand response. In view of their operating characteristics, a virtual energy storage (VES) model of thermostatically controlled loads with electrical and thermal parameters is established. This model is discretized and linearized to simplify calculation. By analyzing the control function and constraints of the VES model, the control strategy of VES of constant-speed air-conditioners load with virtual charging state priority is proposed. Example analysis shows that this strategy can solve and alleviate power shortage problem of the system by participating in demand response, which provides methodological support for constant-speed compressor temperature-control load to participate in the system operation.

Description: 〈p〉Publication date: 15 January 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials, Volume 382〈/p〉 〈p〉Author(s): Anastasios Chalkidis, Deshetti Jampaiah, Patrick G. Hartley, Ylias M. Sabri, Suresh K. Bhargava〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The role of natural gas in mitigating greenhouse gas emissions and advancing renewable energy resource integration is undoubtedly critical. With the progress of hydrocarbons exploration and production, the target zones become deeper and the possibility of mercury contamination increases. This impacts on the industry from health and safety risks, due to corrosion and contamination of equipment, to catalyst poisoning and toxicity through emissions to the environment. Especially mercury embrittlement, being a significant problem in LNG plants using aluminum cryogenic heat exchangers, has led to catastrophic plant incidents worldwide. The aim of this review is to critically discuss the conventional and alternative materials as well as the processes employed for mercury removal during gas processing. Moreover, comments on studies examining the geological occurrence of mercury species are included, the latest developments regarding the detection, sampling and measurement are presented and updated information with respect to mercury speciation and solubility is displayed. Clean up and passivation techniques as well as disposal methods for mercury-containing waste are also explained. Most importantly, the environmental as well as the health and safety implications are addressed, and areas that require further research are pinpointed.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0304389419309902-ga1.jpg" width="297" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 January 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials, Volume 382〈/p〉 〈p〉Author(s): Amanda Pereira da Costa Araújo, Nathalie Ferreira Silva de Melo, Admilton Gonçalves de Oliveira Junior, Fernando Postalli Rodrigues, Thiago Fernandes, Julya Emmanuela de Andrade Vieira, Thiago Lopes Rocha, Guilherme Malafaia〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Microplastics (MPs) are critical emerging pollutants found in the environment worldwide; however, its toxicity in aquatic in amphibians, is poorly known. Thus, the aim of the present study is to assess the toxicological potential of polyethylene microplastics (PE MPs) in 〈em〉Physalaemus cuvieri〈/em〉 tadpoles. According to the results, tadpoles’ exposure to MP PE at concentration 60 mg/L for 7 days led to mutagenic effects, which were evidenced by the increased number of abnormalities observed in nuclear erythrocytes. The small size of erythrocytes and their nuclei area, perimeter, width, length, and radius, as well as the lower nucleus/cytoplasm ratio observed in tadpoles exposed to PE MPs confirmed its cytotoxicity. External morphological changes observed in the animal models included reduced ratio between total length and mouth-cloaca distance, caudal length, ocular area, mouth area, among others. PE MPs increased the number of melanophores in the skin and pigmentation rate in the assessed areas. Finally, PE MPs were found in gills, gastrointestinal tract, liver, muscle tissues of the tail and in the blood, a fact that confirmed MP accumulation by tadpoles. Therefore, the present study pioneering evidenced how MPs can affect the health of amphibians.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0304389419310209-ga1.jpg" width="248" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 29 August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 International Journal of Production Economics〈/p〉 〈p〉Author(s): Tsan-Ming Choi, Lipan Feng, Rong Li〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In platform operations for rental services, product information disclosure (supported by the blockchain technology) is critical to attract customers. By building a stylized duopoly basic analytical model, we conduct a game-theoretic analysis to explore the product information disclosure game between two rental service platforms. We derive the optimal level of product information disclosure and identify the theoretical conditions in which it is optimal to disclose or not to disclose information, which actually means two different types of supply chains. Under the basic model with the two competing platforms scenario, we uncover that from each platform's perspective, there exists a critical threshold on the proportion of information sensitive consumers in the market with which the platform can decide whether it is optimal to disclose product information or not. If the information auditing cost is sufficiently small, it is optimal for the platform to disclose the product information as much as possible. We find that when the product's rental service profit margin increases, the likelihood that both competing platforms will disclose information (including full information) for their products is higher. We also explore the impacts brought by product information disclosure on consumer surplus and seller benefits, and discuss the roles played by the blockchain technology. To check robustness of the results as well as to examine different supply chain configurations, we extend the analysis to the cases when (i) the platforms are risk averse in decision making, (ii) rather than selling the product, the seller (owner of the product to be shared) consigns the product to the platform and shares a revenue, (iii) there is a common rental service platform which receives and provides rental services for two substitutable products. We find that the core qualitative managerial insights remain valid in the basic and all the extended models. Managerial implications are discussed.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: Available online 29 August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 International Journal of Production Economics〈/p〉 〈p〉Author(s): Kimitoshi Sato, Kenichi Nakashima〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In recent years, pay-per-use (PPU) services have been introduced that involve metered billing based on data collected from sensor devices. Although such a PPU service provides benefits to customers who are not planning to use the product frequently, the company is exposed to uncertainty regarding the amount of revenue that will be generated. This study examines the conditions under which a PPU service will be effective at increasing a firm's profit in the presence of uncertainty regarding customers' expected and actual usage frequencies. We consider two pricing problems. First, we formulate a single-period model for when the selling price of the product is given and derive an optimal PPU fee to maximize the expected profit. Then, we analytically show that the PPU service has higher profits than the case without the service when the actual usage is higher than the expected usage. Second, we formulate a joint pricing model in which the firm determines jointly the PPU fee and the selling price to maximize the expected profit. Then, we numerically show that the firm benefits from the PPU service when both the customers' valuation and the actual usage are high.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: Available online 29 August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of the Franklin Institute〈/p〉 〈p〉Author(s): Quanxin Zhu, S. Vimal Kumar, R. Raja, Fathalla Rihan〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉This paper addresses the issue of reliable feedback control of an uncertain aircraft flight control systems with disturbances via non-fragile sampled-data control approach. In particular, the parameter uncertainties are assumed to be randomly occurring which is described by the Bernoulli distributed sequences. By constructing a suitable Lyapunov-Krasovskii functional together with Wirtinger-based inequality, a new set of sufficient conditions in terms of linear matrix inequalities is obtained to ensure the asymptotic stability and extended dissipativity of the aircraft flight control systems not only when all actuators are operational, but also in case of some actuator failures. Finally, simulation results are conducted to validate the effectiveness of the proposed control design technique.〈/p〉〈/div〉

Description: The buckling loads of shell structures are sensitive to initial geometric imperfections. Conventional methods used to model geometric imperfections cannot determine the accuracy of buckling loads with high computational efficiency. A new computational approach based on particle swarm optimization (PSO) is proposed to obtain the lower bound of the buckling load of shell structures with geometric imperfections. The proposed approach assumes a nodal geometric position using uncertain parameters. The buckling loads of the shell structures are then optimized using the PSO-based approach. Both academic and practical numerical examples have been thoroughly investigated. Thus, the applicability and accuracy of the proposed method is critically validated.

Description: 〈p〉Publication date: 15 January 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials, Volume 382〈/p〉 〈p〉Author(s): Aihua Xu, Yi Wei, Qiancheng Zou, Wenyu Zhang, Yezi Jin, Zeyu Wang, Lizhen Yang, Xiaoxia Li〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Herein, a new peroxymonosulfate (PMS) activation system was proposed employing nonredox metal ions as Lewis acids (LA), which have been widely recognized to play important roles in many biological and chemical oxidations. With Co〈sup〉2+〈/sup〉 ions as model catalysts, it was found that oxidizing power of PMS was enhanced after binding weak LA such as Ca〈sup〉2+〈/sup〉 ions, leading to its easier reduction to active radicals and substantial enhancement of dye degradation. The promoting effect of Ca〈sup〉2+〈/sup〉 was also observed with other cobalt catalysts including CoFe〈sub〉2〈/sub〉O〈sub〉4〈/sub〉 and Co〈sub〉3〈/sub〉O〈sub〉4〈/sub〉. The rate of PMS decomposition in Co〈sup〉2+〈/sup〉+LA/PMS system was correlated with Lewis acidity; while in the presence of strong LA including La〈sup〉3+〈/sup〉 and Y〈sup〉3+〈/sup〉, the dye degradation rate declined. The interactions of LA with PMS were characterized and the detailed mechanism was proposed. The present study provides the first example of the promoting effect of weak LA on PMS activation with cobalt based catalysts.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0304389419310350-ga1.jpg" width="361" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 January 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials, Volume 382〈/p〉 〈p〉Author(s): Zhiwen Lei, Jianwen Feng, Yu Yang, Jinlai Shen, Weide Zhang, Chaoyang Wang〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Zeolitic imidazolate frameworks (ZIFs) possess tremendous potential in various adsorption and catalysis areas for their particular structures. However, the dispersibility and acid stability of ZIFs are important issues hindering their applications. To address these challenges, a transparent polydimethysiloxane (PDMS) coating was constructed to heterogeneously anchor the Cu doped ZIF-67 (Cu/ZIF-67) nanoparticles on melamine sponge surface, achieving a PDMS-coated ZIF three-dimensional composite sponge. Thus PDMS coating could also effectively protect ZIFs from acid damage to prolong the service life of photocatalyticity. It was demonstrated that the composite sponges were able to repeatedly (over 40 cycles) degrade Sudan I dyes with remarkable photocatalytic efficiency (〉97%). More importantly, the ion impenetrability of PDMS coating made the ZIFs based composite a longer term catalytic life than unprotected Cu/ZIF-67 under acid condition. Incidentally, due to the introduction of rough ZIFs and hydrophobic PDMS coating, the obtained sponge also exhibits super-hydrophobicity (158.5°), great compressibility and excellent oil/acid water separation performance. We expect that such a polymer coating strategy could act as a novel inspiration for extending the applications and life span of ZIF-based composites.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉 〈p〉MF-ZIF-67@PDMS sponge shows an efficient photocatalytic activity for lipophilic Sudan I degradation under acid conditions and excellent oil/acidic water separation.〈/p〉 〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0304389419310118-ga1.jpg" width="264" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉 〈/div〉

Description: Online quality prediction helps to identify the web service quality degradation in the near future. While historical web service usage data are used for online prediction in preventive maintenance, the similarities in the usage data from multiple users invoking the same web service are ignored. To improve the service quality prediction accuracy, a multivariate time series model is built considering multiple user invocation processes. After analysing the cross-correlation and similarity of the historical web service quality data from different users, the time series model is estimated using the multivariate LSTM network and used to predict the quality data for the next few time series points. Experiments were conducted to compare the multivariate methods with the univariate methods. The results showed that the multivariate LSTM model outperformed the univariate models in both MAE and RMSE and achieved the best performance in most test cases, which proved the efficiency of our method.

Description: The problem of artificial potential function (APF) safety and obstacle avoidance guidance for autonomous rendezvous and docking of chaser spacecraft with noncooperative spacecraft is studied. The relative motion equation of the chaser and the target is established based on the line-of-sight coordinate system, the reference state is designed, and the corresponding state error is deduced. The attitude motion equation of the noncooperative target spacecraft in space is established. The safety and obstacle avoidance guidance problem of autonomous rendezvous and docking with noncooperative target is transformed into a path planning problem in a dynamic environment. The attractive potential function is designed according to the state error. In order to ensure that the chaser can safely approach the noncooperative target spacecraft, a safe corridor with ellipse cissoid is designed in the final approaching stage of autonomous rendezvous and docking. The obstacle is assumed to be a sphere with a certain radius to avoid its influence in the approach, and the obstacle potential function is designed based on the Gaussian function method. The total potential function of the system is designed according to the attractive potential function, the safe potential function, and the obstacle potential function. The total potential function of the system is modified to ensure that the reference state is the minimum of the total potential function of the system. The stability of the system is proven according to the Lyapunov stability principle, and the conditions for satisfying the monotonic decrease in the total potential function of the system are deduced. Finally, the effectiveness of the proposed method is verified by three sets of numerical simulations.

Description: 〈p〉Publication date: November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Technological Forecasting and Social Change, Volume 148〈/p〉 〈p〉Author(s): Juan A. Martínez-Román, Javier Gamero, María de Loreto Delgado-González, Juan A. Tamayo〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Innovation is essential to the knowledge economy and requires organizations to open to external markets. This paper delves into the influence of product innovation on internationalization in SMEs and elaborates an explanatory model of their innovative behavior. Analysis of the data of 123,395 surveys of firms in 13 European countries demonstrates that product innovation drives the firm's commercial expansion and favors its exportation activity, though with a non-linear relationship and decreasing performances as innovation level increases. It is also demonstrated that, in general terms, risk in geographic market extension does not vary in a relevant way when firms are more innovative. Significant differences were detected between countries in regard to the impact of innovation and its marginal utility, and in the evolution of risk in said market extension with increasing innovation. The comparative analysis reveals differences between more and less technological industries, and, on an aggregate level, between more developed economies in the Western and Eastern European transition economies, with less marked disparities from north to south. Analysis of the model reveals the prominence of internal variables in innovative behavior, as well as a certain disconnect between firms and the institutional context in the set of countries.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 January 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials, Volume 382〈/p〉 〈p〉Author(s): Zhen Zhang, Jing Liu, Fenghua Shen, Yuchen Dong〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The temporal influence of reaction atmosphere and chlorine on arsenic release in combustion, gasification and pyrolysis of sawdust was studied using an on-line analysis system. The arsenic release amount in combustion atmosphere was higher than that in CO〈sub〉2〈/sub〉 gasification and argon pyrolysis. The derived values of activation energy followed the order: combustion 〈 gasification 〈 pyrolysis. Furthermore, the enhancement effect of chlorine species on arsenic release percentage in air combustion was also higher than that in gasification and pyrolysis conditions. The total proportion of arsenic release in combustion with additive chlorine is bigger than the case in gasification and pyrolysis, especially when 20% chlorine is added. According to equilibrium analysis, arsenic oxides were identified as the main gaseous arsenic species and their formation were decreased in the oxygen-deficient environment, mainly accounting for lesser arsenic release proportion in gasification and pyrolysis than combustion. The release of arsenic was promoted to a different extent with additive chlorine, mainly caused by the AsCl〈sub〉3〈/sub〉 (g) formation. By the findings of the experiments and theoretical analyses, the possible reaction pathways and release mechanisms of arsenic species were proposed.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0304389419310015-ga1.jpg" width="479" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 January 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials, Volume 382〈/p〉 〈p〉Author(s): Daniel Ociński, Piotr Mazur〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The hybrid polymer obtained by entrapment of Fe-Mn waste oxides from water deironing into a chitosan matrix was evaluated as an As(III) and As(V) sorbent. Its maximum adsorption capacity determined from a Langmuir isotherm model was 44.17 mg As(III)/g or 26.80 mg As(V)/g and 50.73 mg As(III)/g or 82.99 mg As(V)/g under neutral and acidic conditions, respectively. The pH markedly influenced the efficiency and the rate of As(V) adsorption, whereas its impact on As(III) removal was slight. The sorbent was simply regenerated using NaOH solution, and no drop in adsorption capacity was observed after 6 cycles. The physical form and the durability of the sorbent enabled continuous work in a fixed-bed system without clogging of the bed. Arsenic concentration in the effluent exceeded 0.01 mg As/L only after passing about 2700 bed volumes. Arsenates formed surface complexes with iron oxides and were bounded by the imine groups of cross-linked chitosan. Arsenites were oxidized by MnO〈sub〉2〈/sub〉 before adsorption but, because of the low Mn:Fe ratio, a fraction of them were also directly bound to the iron oxides, especially at neutral pH. The conducted studies confirmed the usability of the examined material as a highly efficient sorbent for arsenic removal from water.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0304389419310167-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 January 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials, Volume 382〈/p〉 〈p〉Author(s): Bor-Shuang Liaw, Ting-Ting Chang, Haw-Kai Chang, Wen-Kuang Liu, Po-Yu Chen〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this study, low-cost and eco-friendly hydroxyapatite (HA) minerals were extracted from scales of Tilapia fish (〈em〉Oreochromis mossambicus〈/em〉). After calcination, fish-scale extracted powder was further confirmed to be HA by X-ray diffraction with mean particle size of 5.96 μm determined by particle size analyzer. The calcined powder was utilized as the raw material and combined with chitosan (CS) to synthesize composite scaffolds by freeze casting and cross-linking. Mercury porosimetry results showed that the scaffolds possessed hierarchical porous structure. Microstructural features characterized by SEM revealed unidirectional channel structures with channel sizes ranged from 10 to 100 μm and 1 to 50  μm for scaffolds freeze-casted at 2 ℃/min and 5 ℃/min cooling rates, respectively. The adsorption kinetics of HA/CS composite scaffolds with varying channel sizes were investigated by both batch and fixed-bed processes with different Pb(П) initial concentrations (100 and 1000 mg/L). The adsorption capability was optimized by tuning the cooling rates and the maximum adsorption amount could reach 75–570 mg/g in batch process and 94 mg/g in fixed bed process. In summary, the HA/CS composite scaffolds showed great capability to remove heavy metal ions from waste water and their tunable channel sizes could be applied in suitable fields under both statistic and flowing conditions.〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 January 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials, Volume 382〈/p〉 〈p〉Author(s): Pyeong-Koo Lee, Min-Ju Kang, Youn-Joong Jeong, Yi Kyun Kwon, Soonyoung Yu〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉As-contaminated soil samples were chosen to identify As sources near a Zn smelter where Zn contamination in soils was found to be of smelter origin. Based on the As concentrations and Pb isotopic compositions, high As levels in soils were originated from the geogenic source. There was no consistent trend in As concentrations with either depth or distance from the smelter, while the Pb isotopic compositions in soils varied regardless of As levels and were quite different from those of smelter origin. Transmission electron microscopy (TEM) and selected area electron diffraction (SAED) suggested that the high As concentrations were due to arsenopyrite and its alteration minerals, which were easily found but heterogeneously distributed within host rocks. A detailed investigation of As levels and Pb isotropic compositions along the predominant wind direction also supported that the As contamination was of geogenic origin unlike the Zn contamination. The atmospheric emissions from the smelter increased the Zn concentrations and decreased the 〈sup〉206〈/sup〉Pb/〈sup〉207〈/sup〉Pb ratios at surface layers, while the As concentrations occasionally exceeded the worrisome level at deep layers. According to the Pb isotropic compositions, about 21% of the As-contaminated soils were impacted by the smelter, in particular at the surface layer.〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 January 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials, Volume 382〈/p〉 〈p〉Author(s): Shouqiang Huang, Liang Li, Nanwen Zhu, Ziyang Lou, Weiqiao Liu, Jiehong Cheng, Haoming Wang, Pengxuan Luo, Hui Wang〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The high concentration of chloride (Cl〈sup〉−〈/sup〉) ions in leachate often has negative effects in their harmless treatments, and the common treatments containing the ion exchange method consume excessive antichlors due to their large particle sizes and unfavorable morphologies. Herein, the antichlors of the Bi(III) containing oxides with quantum dots (QDs) or two-dimensional (2D) structures are first explored for the removal and recovery of Cl〈sup〉−〈/sup〉 ions in concentrated leachate. By using the QDs/2D flakes constructed antichlors of Bi〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 and the magnetite Bi-Ti composite, the maximum Cl〈sup〉−〈/sup〉 removal rates of 61.8% and 66.1% are respectively achieved under the optimum conditions. The higher removal efficiency of the magnetite Bi-Ti composite is contributed by its less stable crystal phases of Bi〈sub〉25〈/sub〉FeO〈sub〉40〈/sub〉/Bi〈sub〉12〈/sub〉TiO〈sub〉20〈/sub〉, which can proceed more deeply in the removal of Cl〈sup〉−〈/sup〉 ions compared with that of Bi〈sub〉2〈/sub〉O〈sub〉3〈/sub〉. The recovered terminal magnetite Bi-Ti precipitate with Bi〈sub〉2〈/sub〉O〈sub〉3〈/sub〉/BiOCl heterostructure exhibits excellent photocatalytic activity in the degradation of the dechlorinated leachate, where a total organic carbon removal rate of 87.2% is achieved under UV–vis-near-infrared irradiation. Therefore, the selection of Bi(III) containing oxides opens a promising and high-value method for the removal and recovery of Cl〈sup〉−〈/sup〉 ions in leachate and other waste waters.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0304389419309951-ga1.jpg" width="261" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 21 August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials〈/p〉 〈p〉Author(s): Jingwen Pan, Baoyu Gao, Wen Song, Xing Xu, Qinyan Yue〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Effective managements of organic solid waste and surface water eutrophication can reuse/reduce solid waste resources, and ensure surface water safety. Herein, an easily-recoverable amine-functionalized biosorbent was developed from biogas residue (BR-N) for nitrate and phosphate removals from surface water. Physicochemical characteristics revealed that BR-N has a cross-staggered structure with abundant quaternary-amine groups to enhance the diffusion and electrostatic attraction of nitrate/phosphate. In batch studies, nitrate/phosphate could be effectively removed by the BR-N within a wide pH range of 5.0-9.0, and the maximum adsorption capacities of BR-N were 64.12 mg/g for nitrate and 34.40 mg P/g for phosphate. After continuous 8 cycles of adsorption-desorption, BR-N still exhibited 〉82% adsorption capacity for nitrate/phosphate removals, implying the high chemical stability and reusability for water treatment. Whereafter, BR-N has real application prospect in water treatment, which could effectively treat ˜380, ˜260 and ˜760 bed volumes (BV) of three actual eutrophic surface water to satisfy the surface water standard of China (GB3838-2002). The cost of BR-N was 2.89 $/kg evaluated by energy-economy assessment, indicating the low-cost production of biogas residue-based adsorbent for treating eutrophic surface water. Overall, this study provides a new idea for high-value utilization of organic solid waste and purification of eutrophic water.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0304389419310271-ga1.jpg" width="301" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 20 August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials〈/p〉 〈p〉Author(s): Yaoping Hu, Zhijin Gao〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Million tons of sewage sludge produced yearly creates a severe pollution problem to environment, and thus needs either to be properly disposed of, or recovered. Here, we demonstrate a value-added utilization of sewage sludge by converting its contained organics into nanosized carbon dots (CDs) with microwave irradiation. This synthetic method, using waste resources as precursors and avoiding the requirement of hazardous reagents and complex procedures, has the great advantage of low cost, environmental friendliness, and easy scalability. The resultant CDs exhibit excellent fluorescence properties with a large quantum yield (QY) of up to 21.7%, higher than the most values of waste-derived CDs. It is found that CDs can serve as a sensitive and selective sensor to detect para-nitrophenol (p-NP), a toxic pollutant, through fluorescence quenching, giving a linear detection range of 0.2–20 μM and a detection limit of as low as 0.069 μM. Systematic investigations suggest that the inner filter effect (IFE) is the dominant sensing mechanism. Moreover, the practical applications of CDs for p-NP assay in real water samples achieve good results.〈/p〉〈/div〉 〈h5〉Graphical Abstract〈/h5〉 〈div〉 〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0304389419310027-ga1.jpg" width="301" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉 〈p〉Sewage sludge as a renewable resource toward highly fluorescent carbon dots for sensing of para-nitrophenol through inner filter effect.〈/p〉 〈/div〉

Description: 〈p〉Publication date: 15 January 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials, Volume 382〈/p〉 〈p〉Author(s): Kun Wu, Dongdong Chen, Shaoyou Lu, Jianzhang Fang, Ximiao Zhu, Fan Yang, Tao Pan, Zhanqiang Fang〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Developing inexpensive and stable photocatalysts without noble metals, yet remarkably enhancing the photocatalytic activities, is highly needed. Here, a novel carbon and cerium co-doped porous g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 (C/Ce-CN) has been successfully prepared through thermal polymerization of the supramolecular aggregation. The morphologies, chemical structures, optical and photoelectrochemical properties of the synthesized photocatalysts were analyzed via a series of characterization measurements. Experimental results indicated that C/Ce-CN showed remarkably enhanced photocatalytic activity of TC and RhB degradation, which is about 2.6 and 2.4 times higher than that of pristine CN, and it also exhibited a good stability. Compared with bare CN, the enhanced performance of C/Ce-CN is mainly attributed to the stronger utilization rate of visible light, the rapider charge transfer rate, the longer lifetime of carriers and the larger surface specific area. The main intermediates in degradation process of antibiotics were tested by the HPLC-MS. Finally, the possible photocatalytic degradation pathways and mechanisms were proposed.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0304389419309811-ga1.jpg" width="286" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 January 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials, Volume 382〈/p〉 〈p〉Author(s): Zhuo Li, Zhenyang Yu, Changzheng Cui, Fangting Ai, Daqiang Yin〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Increasing concerns are earned on the multigenerational hazards of antibiotics due to the connection between their mother-children transfer via cord blood and breast milk and obesity in the children. Currently, 〈em〉Caenorhabditis elegans〈/em〉 was exposed to sulfamethoxazole (SMX) over 11 generations (F0–F10). Indicators of obesogenic effects and gene expressions were measured in each generation and also in T11 to T13 that were the offspring of F10. Biochemical analysis results showed that SMX stimulated fatty acids in most generations including T13. The stimulation was resulted from the balance between enzymes for fatty acid synthesis (e.g., fatty acid synthetase) and those for its consumption (e.g., fatty acid transport protein). Gene expression analysis demonstrated that the obesogenic effects of SMX involved peroxisome proliferator activated receptors (PPARs, e.g., 〈em〉nhr-49〈/em〉) and insulin/insulin-like signaling (IIS) pathways (e.g., 〈em〉ins-1〈/em〉, 〈em〉daf-2〈/em〉 and 〈em〉daf-16〈/em〉). Further epigenetic analysis demonstrated that SMX caused 3-fold more H3K4me3 binding genes than the control in F10 and T13. In F10, the most significantly activated genes were in metabolic and biosynthetic processes of various lipids, nervous system and development. The different gene expressions in T13 from those in F10 involved development, growth, reproduction and responses to chemicals in addition to metabolic processes.〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 21 August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials〈/p〉 〈p〉Author(s): Mingmei Ding, Wei Chen, Hang Xu, Zhen Shen, Tao Lin, Kai Hu, Chun hui Lu, Zongli Xie〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The development of non-cobalt-based heterogeneous catalysts with efficient catalytic activity, good stability and nontoxicity is very important for the application of peroxymonosulfate-based advanced oxidation processes (AOPs) in water treatment. In this work, with two dimensional MXene as the catalyst substrate, a novel α-Fe〈sub〉2〈/sub〉O〈sub〉3〈/sub〉/MXene (FM) nanocomposite was fabricated through a facile solvothermal method. Systematic characterization demonstrated that the MXene substrate could facilitate the size reduction and good dispersion of α-Fe〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 nanoparticles. The FM nanocomposite achieved high efficiency and stability towards activating peroxymonosulfate (PMS) to produce free radicals for the degradation of salicylic acid (SA) in aqueous solution. The operating parameters, including catalyst dosage, PMS dosage, SA concentration and initial pH value, were evaluated and analysed. The co-existence of sulfate radicals (SO〈sub〉4〈/sub〉〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/rad"〉〈sup〉—〈/sup〉) and hydroxyl radicals (〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/rad"〉OH) was confirmed using electron paramagnetic resonance spectroscopy and radical scavenger tests, while SO〈sub〉4〈/sub〉〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/rad"〉〈sup〉—〈/sup〉was identified as the main reactive species in the FM/PMS catalytic system. The possible mechanisms for the electron transfer and radical generation during the process of PMS activation by the FM nanocomposite are further investigated using XPS and in situ Raman analysis. The results provide an avenue for rationally constructing and developing alternative catalysts for the treatment of organics in wastewater.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0304389419310180-ga1.jpg" width="256" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 January 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials, Volume 382〈/p〉 〈p〉Author(s): Long Peng, Lei Li, Qinhao Lin, Mei Li, Guohua Zhang, Xinhui Bi, Xinming Wang, Guoying Sheng〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A single particle aerosol mass spectrometry (SPAMS) was deployed to investigate the mixing state and chemical processing of Pb-rich particles in suburban Beijing. Based on a large dataset of mass spectra, Pb-rich particles were classified into Pb-O-Cl-N-S (55%), Pb-N (17%), Pb-N-S (15%), and Pb-EC (7%). Residual coal combustion, industrial activities, and meteorological conditions were identified as main factors regulating the variations of Pb-rich particles in the atmosphere. The highest abundance of the Pb-rich particles was observed during heating period (HP) primarily due to the increase in coal usage. Pb in Pb-O-Cl-N-S type was identified in forms of PbO, PbCl〈sub〉2,〈/sub〉 and Pb(NO〈sub〉3〈/sub〉)〈sub〉2〈/sub〉. Dominantly presented in the form of Pb(NO〈sub〉3〈/sub〉)〈sub〉2〈/sub〉, Pb-N type represented the completely transformed Pb-rich particles from PbO/PbCl〈sub〉2〈/sub〉 by atmospheric processes. It is found that PbCl〈sub〉2〈/sub〉 and PbO could be transformed to Pb(NO〈sub〉3〈/sub〉)〈sub〉2〈/sub〉, highly dependent on the amount of NO〈sub〉2〈/sub〉 and RH. Significant enhancement of nitrate in Pb-O-Cl-N-S particles was observed when the RH was greater than 60%, emphasizing the importance of heterogeneous hydrolysis of N〈sub〉2〈/sub〉O〈sub〉5〈/sub〉 on the formation of Pb(NO〈sub〉3〈/sub〉)〈sub〉2.〈/sub〉 Compared with non-carcinogenic PbCl〈sub〉2〈/sub〉/PbO and insoluble PbO, soluble and carcinogenic Pb(NO〈sub〉3〈/sub〉)〈sub〉2〈/sub〉 produced by atmospheric processes may significantly enhance negative effects of Pb-rich particles on human health and the ecosystem.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0304389419309689-ga1.jpg" width="481" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 January 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials, Volume 382〈/p〉 〈p〉Author(s): Qiulai He, Jianyang Song, Wei Zhang, Shuxian Gao, Hongyu Wang, Jian Yu〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Aerobic granular sludge-based simultaneous nitrification, denitrification and phosphorus removal (SNDPR) systems were configured for the treatment of low-strength municipal wastewater. Granular characteristics, process performance, and the corresponding microbial ecology dynamics were comprehensively explored with sodium acetate and succinate as mixed carbon source. Results revealed that aerobic granules kept structural and functional resilience, while mixed carbon source largely altered and balanced the growth and competition of phosphorus/glycogen accumulating organisms (PAOs/GAOs). Appropriate ratio of mixed carbon source was vital for superb physiochemical behaviors and reliable removal performance by aerobic granules. Therefore, the aerobic granular SNDPR system could achieve deep-level nutrients removal through enhancing the anaerobic carbon uptake rate and strengthening the carbon usage efficiency. The present work could add some guiding sight into the application of aerobic granular SNDPR system for wastewater treatment.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0304389419309975-ga1.jpg" width="244" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 January 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials, Volume 382〈/p〉 〈p〉Author(s): Ronghua Mu, Yanhui Ao, Tengfei Wu, Chao Wang, Peifang Wang〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Bi〈sub〉4〈/sub〉O〈sub〉5〈/sub〉I〈sub〉2〈/sub〉 loaded anatase-TiO〈sub〉2〈/sub〉 (B) biphase nanowires composite photocatalysts were fabricated by an in situ calcination method and exhibited outstanding photocatalytic activity. The microstructure, optical performance and band structure of the composite photocatalysts were investigated by relevant characterizations. The results demonstrated the successful formation of heterojunction between anatase-TiO〈sub〉2〈/sub〉 (B) biphase nanowires and Bi〈sub〉4〈/sub〉O〈sub〉5〈/sub〉I〈sub〉2〈/sub〉, which integrated the advantages of homojunction and heterojunction. Therefore, it definitely improved separation efficiency of photo-induced electron-holes because of the formation of multi-junctions. In order to test the enhanced photocatalytic activity, acetaminophen was chosen as target pollutant. The sample with 67% Bi〈sub〉4〈/sub〉O〈sub〉5〈/sub〉I〈sub〉2〈/sub〉 (TiO〈sub〉2〈/sub〉-Bi〈sub〉4〈/sub〉O〈sub〉5〈/sub〉I〈sub〉2〈/sub〉-3) presented the highest photocatalytic activity on the degradation of acetaminophen and its reaction apparent rate constant was 10 and 25 times as that of Bi〈sub〉4〈/sub〉O〈sub〉5〈/sub〉I〈sub〉2〈/sub〉 and TiO〈sub〉2〈/sub〉 biphase nanowires, respectively. Through trapping experiments and LC–MS/MS analysis, O〈sup〉〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/rad"〉〈/sup〉H was proved to be the key active specie during the photocatalytic process of acetaminophen degradation〈strong〉. Meanwhile〈/strong〉 a possible degradation pathway was proposed based on the detected intermediate products.〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 January 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials, Volume 382〈/p〉 〈p〉Author(s): Juan Xiao, Chuan Wang, Hong Liu〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Fenton-like degradations of dimethyl phthalate (DMP) and phenolic compounds (phenol, catechol, resorcinol, and hydroquinone) in single and binary systems were investigated by focusing on the Fe(III)/Fe(II) redox cycle during the reaction processes. Quinone-like substances were generated and found to be responsible for the autocatalytic transformation of Fe(III) to Fe(II) in the Fenton-like process with DMP or phenolics. Moreover, phenolic compounds could accelerate the Fenton-like degradation of DMP, with an increased efficiency of H〈sub〉2〈/sub〉O〈sub〉2〈/sub〉 utilization. The effect of phenolic compounds on the degradation of DMP followed the order: catechol ≈ hydroquinone 〉 resorcinol 〉 phenol, which could be attributed to the interaction between quinone-like substances and iron ions. Hydroquinone-like substances accelerated the Fe(III)/(II) redox cycle. The formation of iron complexes between catechol-like substances and iron ions facilitated the release of H〈sup〉+〈/sup〉 and regeneration of Fe(II). In addition, a plausible mechanism for enhanced Fenton-like degradation of DMP by phenolics was proposed.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0304389419309616-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 January 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials, Volume 382〈/p〉 〈p〉Author(s): Min-Hua Cui, Thangavel Sangeetha, Lei Gao, Ai-Jie Wang〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Understanding the electrode configuration is vital for the successful application of bioelectrochemical system (BES) in recalcitrant wastewater treatment. Especially in those traditional anaerobic processes that integrate with BES to construct effective hybrid bioreactors. Hybrid bioreactors employed granular graphite as electrode material achieved 86.62 ± 1.83% decolorization efficiency of azo dye acid orange 7 (AO7) at influent AO7 loading rate of 800 g/(m〈sup〉3〈/sup〉∙d) and it was about 6% higher than that with carbon fiber brush electrodes. Such electrodes were positioned above the anaerobic sludge layer and higher efficiency (8%) than the reactors with electrodes placed beneath the sludge layer was observed. Tracer experiments and modeling of residence time distribution indicated that the fluid pattern in hybrid bioreactors was modified to plug flow pattern and had a better consummate mixing ability compared to the conventional anaerobic reactor. Simulation using computational fluid dynamics technique showcased favorable mass transfer near electrode modules. The hydrodynamics of simulation and experimental results were connected by simplifying electrode module as a porous media model. This study thus proved that hybrid bioreactors can effectively enhance wastewater treatment comprehensively through the analysis of decolorization performance and hydrodynamics.〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 January 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials, Volume 382〈/p〉 〈p〉Author(s): Libing Chu, Dan Chen, Jianlong Wang, Zhilin Yang, Qi Yang, Yunpeng Shen〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In present work, the degradation of antibiotic and inactivation of antibiotic resistance genes (ARGs) in cephalosporin C fermentation (CEPF) residues were performed using ionizing radiation, ozonation and thermal treatment. The results showed that the three treatment methods could degrade cephalosporin C effectively, with the removal efficiency of 85.5% for radiation at dose of 100 kGy, 79.9% for ozonation at dosage of 5.2 g O〈sub〉3〈/sub〉/L, and 71.9% and 87.3% for thermal treatment at 60 °C and 90 °C for 4 h. The cephalosporin resistance gene tolC was detected in the raw CEPF residues, and its abundance was decrease 74.2% by radiation, 64.6% by ozonation and 26.9%–37.1% by thermal treatment respectively. The presence of protein, glucose and acetate in the CEPF residues had inhibitive influence on the degradation of cephalosporin C by ionizing radiation, and the effect was more significant when the antibiotic concentration was lower. The total content of COD, polysaccharides and protein changed slightly after radiation and thermal treatment, while they were decreased greatly by ozonation. The primary techno-economic analysis showed that the operational cost of ionizing radiation by electron beam at 50 kGy ($5.2/m〈sup〉3〈/sup〉) was comparable to thermal treatment ($4.3–7.9/m〈sup〉3〈/sup〉), which was more economical than ozonation ($14.6/m〈sup〉3〈/sup〉).〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S030438941931012X-ga1.jpg" width="336" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 19 August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials〈/p〉 〈p〉Author(s): Jianhua Yuan, Yao Ma, Fei Yu, Yiran Sun, Xiaohu Dai, Jie Ma〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The recovery of nitrogen (N) and phosphorus (P) from wastewater is of great importance in addressing the global nutrient crisis. The limitations of existing methods require the development of effective technology. Here, two different hydrogel adsorbents were fabricated with good separation ability for metal cation (M〈sup〉+〈/sup〉) and metal anion (M-) but showed little removal of nutrients. Based on the materials, a novel three-stage operation system combining adsorption and capacitive deionization (CDI) technology was presented for nutrient recovery and wastewater treatment. In the first two stages, mixed metals in wastewater were successfully separated (Cu〈sup〉2+〈/sup〉: 144.6 mg/g; Cr〈sub〉2〈/sub〉O〈sub〉7〈/sub〉〈sup〉2−〈/sup〉: 167.0 mg/g), and nutrients were retained (N and P 〈 1 mg/g). In the third stage, the residual trace metal ions in the solution were removed (2.0 mg/L to N/A), and the nutrients were enriched through electroadsorption and desorption processes by CDI. Plants using recovered liquid fertilizers revealed similar values for height, root length, and chlorophyll compared with those obtained using actual fertilizers. The results indicated that this novel three-stage operation system (3S A-C system) combining adsorption and CDI is efficient in recovering liquid fertilizers from wastewater and is a promising technology for simultaneously addressing nutrient crises and environmental pollution.〈/p〉〈/div〉 〈h5〉Graphical Abstract〈/h5〉 〈div〉 〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0304389419309938-ga1.jpg" width="301" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉 〈p〉Three-stage operation system (3S A-C system) combining adsorption and CDI is efficient in recovering liquid fertilizers from wastewater and is a promising technology for simultaneously addressing nutrient crises and environmental pollution.〈/p〉 〈/div〉

Description: 〈p〉Publication date: 15 January 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials, Volume 382〈/p〉 〈p〉Author(s): Yating Luo, Binhui Ye, Jien Ye, Jingli Pang, Qiao Xu, Jingxuan Shi, Bibo Long, Jiyan Shi〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Some ions in soils may affect the growth and metabolism of microorganisms and subsequently alter the remediation efficiency of Cr(VI). Here, the effects of different Ca〈sup〉2+〈/sup〉 and SO〈sub〉4〈/sub〉〈sup〉2−〈/sup〉 levels on the reduction of Cr(VI) by 〈em〉Penicillium oxalicum〈/em〉 SL2 were investigated. The results showed that Cr(VI) reduction by 〈em〉P. oxalicum〈/em〉 SL2 in potato dextrose liquid (PDL) medium was accelerated by the presence of exogenous Ca〈sup〉2+〈/sup〉 and SO〈sub〉4〈/sub〉〈sup〉2−〈/sup〉. The Cr(VI) reduction rates were increased by 52.5% (200 mg L〈sup〉−1〈/sup〉 Ca〈sup〉2+〈/sup〉 treated) and 55.9% (2000 mg L〈sup〉−1〈/sup〉 SO〈sub〉4〈/sub〉〈sup〉2−〈/sup〉 treated), respectively. High concentration of Ca〈sup〉2+〈/sup〉 in medium resulted in the production of calcium oxalate crystals, which was contributed to the adsorption of chromium. In addition, X-ray absorption near-edge spectroscopy (XANES) analysis showed that 〈em〉P. oxalicum〈/em〉 SL2 could reduce the toxicity of Cr(VI) by synthesizing cysteine (Cys) and reduced glutathione (GSH). The decrease of thiol compounds (Cys and GSH) in 〈em〉P. oxalicum〈/em〉 SL2 mycelia treated with SO〈sub〉4〈/sub〉〈sup〉2−〈/sup〉 proved the alleviation of oxidative stress. In conclusion, exogenous Ca〈sup〉2+〈/sup〉 could reduce the damage of Cr(VI) to 〈em〉P. oxalicum〈/em〉 SL2 by maintaining the integrity of cell wall, and the addition of SO〈sub〉4〈/sub〉〈sup〉2−〈/sup〉 alleviated the Cr(VI) toxicity to 〈em〉P. oxalicum〈/em〉 SL2, thus accelerating the reduction of Cr(VI).〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S030438941931026X-ga1.jpg" width="479" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 January 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials, Volume 381〈/p〉 〈p〉Author(s): Taher Rahimi-Aghdam, Zahra Shariatinia, Minna Hakkarainen, Vahid Haddadi-Asl〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Nitrogen (N-GQD) as well as nitrogen and phosphorous co-doped (NP-GQD) graphene quantum dots were demonstrated as novel, low cost, green and highly effective flame retardants and smoke suppressants for polyacrylonitrile (PAN) nanocomposites. The N-GQD and NP-GQD samples were synthesized by hydrothermal method with citric acid as the main reactant. For the first time, the flame retardant and smoke suppressant properties of the NP-GQD were studied. The GQDs were introduced into PAN by solvent blending route. Subsequently, thermal stability, flame retardancy, fire behavior, fire hazard and structure of the residual char were investigated by thermogravimetric analysis (TGA), UL-94 vertical burning test, cone calorimetry, FE-SEM, and Raman spectroscopy. Results showed that both PAN/N-GQD and PAN/NP-GQD nanocomposites had higher flame retardancy and smoke suppressant behavior in addition to lower fire hazard properties than neat PAN. Furthermore, the residual chars for the nanocomposite samples were increased in comparison to the neat PAN. The improvements were even more significant in case of the PAN/NP-GQD due to the synergistic effect of nitrogen and phosphorous. The improvements were mainly ascribed to the ability of the N-GQD and NP-GQD to provide stronger and larger protective char barrier layers, which was even more pronounced in case of the NP-GQD.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0304389419309677-ga1.jpg" width="475" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: Target signal extraction has a great potential for applications. To solve the problem of error extraction of target signals in the current constrained independent component analysis (cICA) method, an enhanced independent component analysis with reference (EICA-R) method is proposed. The new algorithm establishes a unified cost function, which combines the negative entropy contrast function and the distance metric function. The EICA-R method transforms the constrained optimization problem into unconstrained optimization problem to overcome the problem of threshold setting of distance metric function in constrained optimization problem. The theoretical analysis and simulation experiment show that the proposed EICA-R algorithm overcomes the problem of the error extraction of the existing algorithm and improves the reliability of the target signal extraction.

Description: A mathematical model is developed to examine the behaviors of a peristalsis flow with nanoparticles in a symmetric channel under the magnetic environment. Here, the nanofluid is electrically conducted through an external magnetic field. Thermal radiation and Joule heating effects are also retained in the present analysis. Under the lubrication approach, the reduced nonlinear systems are obtained. Then, they are solved very efficiently by means of a homotopy analysis method-based package BVPh 2.0. The influences of important physical parameters on the flow behaviors are presented. Analysis of the entropy generation is illustrated. It is found that the Brownian diffusion and the thermophoresis are the two most important nanoparticle slip mechanisms in the Jeffery fluids as well. Besides, the Hartman number, the type of the Jeffery fluid, the Brinkman number, and the thermal radiation parameter play important roles on flow behaviors. Results show that the temperature profile enhanced but the nanoparticles’ volume fraction profiles lowered with increase in the Hartman number. However, using the Jeffery nanofluid induces effect on the velocity distribution that decreases with the increase in the Jeffery fluid parameter. It is also found that the generated total entropy increases with an increase in the Brownian motion parameter but with a decrease in the thermophoresis parameter.

Description: 〈p〉Publication date: 15 January 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials, Volume 382〈/p〉 〈p〉Author(s): Yao Yuan, Wei Wang, Yongqian Shi, Lei Song, Chao Ma, Yuan Hu〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The extensive utilization of rigid polyurethane foam (RPUF) as construction insulation material has brought two main troubles to our society: fire risks and toxic hazards. To reduce the fire hazards of RPUF, a layered MoS〈sub〉2〈/sub〉 decorated with Cu〈sub〉2〈/sub〉O nanoparticles was creativity obtained by hydrothermal technology and facile wet chemical treatment for reducing the toxic product formations of polyurethane nanocomposites during combustion. Due to the low weight ratio of Cu〈sub〉2〈/sub〉O attached onto MoS〈sub〉2〈/sub〉, the resulting Cu〈sub〉2〈/sub〉O-MoS〈sub〉2〈/sub〉 hybrid effectively prevented the MoS〈sub〉2〈/sub〉 nanosheets from restacking. However, the Cu〈sub〉2〈/sub〉O-MoS〈sub〉2〈/sub〉-M hybrid was produced by increasing content of Cu〈sub〉2〈/sub〉O, which has the characteristic stacked layer structure of MoS〈sub〉2〈/sub〉. Reduced harmful organic volatiles and the toxic gases (e.g. a respective decrease of ca. 28% and 53% for CO and NO〈sub〉x〈/sub〉 products) were obtained because of synergistic effect between the physical adsorption of MoS〈sub〉2〈/sub〉 and catalysis action of Cu〈sub〉2〈/sub〉O. Notably, the addition of Cu〈sub〉2〈/sub〉O-MoS〈sub〉2〈/sub〉 hybrids led to high char formation of the RPUF nanocomposite, indicating the effectively catalytic carbonization property. In addition, the N-Gas model for predicting fire smoke toxicity was developed and demonstrated. Furthermore, the research offers direct proofs of the negative influence of the stacked MoS〈sub〉2〈/sub〉 on reducing the smoke toxicity for RPUF nanocomposites.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0304389419309823-ga1.jpg" width="370" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 January 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials, Volume 382〈/p〉 〈p〉Author(s): Guangxue Zhang, Zhenfang Ma, Jian Shen, Kai Zhang, Jinqing Wang, Zuohe Chi〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Acoustic agglomeration is a process in which an intense sound field is applied to promote relative motion and rapid agglomeration among aerosol particles. This technology is able to improve significantly and rapidly the visibility of the smoke in a fire situation, and therefore assists the quick evacuation of evacuees. In this paper, the elimination effect of polystyrene smoke using acoustic agglomeration technology is experimentally investigated. The results show that the smoke transmittance will be increased to 0.75 from the initial value of 0.24 in only 0.5 min, in a 1.5 kHz acoustic field at a sound pressure level of 141 dB. The agglomeration rate is sensitive to acoustic frequency and there is an optimal operation frequency, which indicates that the predominant mechanism is orthokinetic interaction. Under the conditions of our experiments, the optimal frequency for eliminating soot particles is determined to be 1.5 kHz. As an energy consuming process, the agglomeration efficiency increases proportionally with the acoustic power until the corresponding nonlinear acoustic effects become significant. Moreover, it is found that the agglomeration rate of thicker smoke is much higher than thin ones at the early stage of the process, but the discrepancy tends to vanish at the later stage.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S030438941931043X-ga1.jpg" width="261" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 January 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials, Volume 382〈/p〉 〈p〉Author(s): Qiming Liu, Yaoyue Li, Huafeng Chen, Jian Lu, Guangsuo Yu, Maxim Möslang, Yanbo Zhou〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Dyes and heavy-metal ions are common pollutants in printing and dyeing wastewater, and are thus attracting considerable attention. Herein, an eco-friendly straw-based adsorbent, WS-CA-AM, was prepared by grafting with acrylamide (AM) and citric acid (CA) groups to remove representative dyes and heavy metals from aqueous solution. The adsorption capacities of WS-CA-AM for methyl orange (MO) and methylene blue (MB) were 3053.48 and 120.84 mg/g, which were 54 and 3 times those of unmodified straw, respectively. Moreover, the adsorption capacities for MB, MO, Cr〈sub〉2〈/sub〉O〈sub〉7〈/sub〉〈sup〉2−〈/sup〉 and Cu〈sup〉2+〈/sup〉 in the mixed system increased by 210%, 133%, 196% and 151%, respectively, compared with those in the single system. The significant increase in adsorption capacity can be attributed to the collaborative effect through electrostatic attraction. The functional groups and adsorbed pollutants all served as adsorption sites for pollutants. These results indicate that WS-CA-AM is a potential applicant for the removal of dyes and heavy-metal ions from mixed aqueous solution.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S030438941930994X-ga1.jpg" width="280" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 January 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials, Volume 382〈/p〉 〈p〉Author(s): Hongting Xu, Yue Song, Long Cang, Dongmei Zhou〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Electrokinetic 〈em〉in situ〈/em〉 chemical oxidation (EK-ISCO) could be used to remediate inorganic/organic-contaminated soil. Oxidizing agents were effectively delivered to the contaminated zones through electromigration and the electroosmosis. However, the cathode may react with oxidants, which would reduce the oxidative effect and lead to low contaminant removal rates. In this study, ion-exchange membranes (IEMs) enhanced EK-ISCO was used to remediate polycyclic aromatic hydrocarbons (PAHs) in contaminated soil. IEMs were installed between the electrode compartment and the soil compartment. The results showed that the IEMs could effectively control pH and the oxidation-reduction potential (ORP) changes in the soil column. Placing a cation-exchange membrane (CEM) at the cathode prevented the S〈sub〉2〈/sub〉O〈sub〉8〈/sub〉〈sup〉2−〈/sup〉 from contacting the cathode and reduced the oxidative loss effect, which meant that PAH removal efficiency significantly improved (from 33.1% to 87.1%). Furthermore, there were minimal changes to the soil properties. Maintaining the soil at a low pH also improved the PAH removal efficiency (93.1%), but the physicochemical properties of the soil significantly changed and a large amount of power was consumed (2015 kWh t〈sup〉−1〈/sup〉). This study indicated that placing a CEM at the cathode improved remediation efficiency, and reduced power consumption and the adverse effects on soil properties during EK-ISCO.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0304389419309963-ga1.jpg" width="369" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 21 August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials〈/p〉 〈p〉Author(s): Yan Kong, Yuan Zhuang, Baoyou Shi〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Polymer hydrogels usually has limited catalytic activity and stability in catalysis. Here, we presented for the first time the preparation of a novel double-metal-crosslinked alginate hydrogel using graphene oxide to facilitate the Fe(II)/Fe(III) redox cycles. Five multivalent metal cations were used as crosslinkers to prepare different alginate-GO-M (Fe(III), Fe(II), La(III), Ce(III), and Co(II)), and the effects of assisted metal cations (La(III), Ce(III), and Co(II)) on different Fe(II) bimetallic alginate-GO-Fe-M(AG-Fe-M) complexes were investigated. Double-metal-crosslinked alginate-GO hydrogels can degrade tetracycline much faster during the initial 10 min than single-metal-crosslinked hydrogels. In addition, the release of iron from AG-Fe-Ce (10.59 ppm) is less than that from AG-Fe-Co (21.57 ppm) and AG-Fe-La (25.6 ppm) during the Fenton reaction. More importantly, the AG-Fe-Ce does not release TOC and maintains most of the catalytic activity after four reuse cycles, confirming its excellent stability. For the treatment of raw water containing a high proportion of proteinaceous matter and tetracycline, the AG-Fe-Ce significantly reduces the molecular weight of the dissolved organic matter. We deduced that the humic acid and protein show good complexation ability to tetracycline, thereby reducing its bioavailability. This study provides new insights into the synthesis of polymer catalysts for water treatment.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0304389419310143-ga1.jpg" width="301" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 1 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Computer Methods in Applied Mechanics and Engineering, Volume 357〈/p〉 〈p〉Author(s): Delfim Soares〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this work, a simple, stable, non-iterative, uncoupled formulation is proposed for nonlinear pore-dynamic analyses. Here, each phase of the coupled problem is treated separately, uncoupling the governing equations of the porous model. Thus, simpler, smaller and better conditioned systems of equations are obtained, providing a more efficient numerical approach. In addition, in the proposed technique, solution is carried out without considering any iterative computation, even when nonlinear models are regarded, further improving the effectiveness of the method. Incompressible and impermeable media may also be directly analysed by the new formulation, without requiring any special discretization procedure, as it is the case in standard analyses. At the end of the paper, numerical examples are presented, illustrating the effectiveness and potentialities of the new technique.〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 January 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials, Volume 382〈/p〉 〈p〉Author(s): Shengmin Wu, Shenghu Zhang, Yang Gong, Lili Shi, Bingsheng Zhou〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The accurate detection and quantification of nanoparticles (NPs) in aquatic environments are essential for toxicological and ecological risk assessment. Herein, we used single particle inductively coupled mass spectroscopy (SP-ICP-MS) to quantify titanium nanoparticles (Ti-NPs) in the extraction fractions of surface waters, and transmission electron microscopy coupled with an energy dispersive X-ray spectrometer (TEM-EDS) to specifically identify the nanoparticles. By using gold-NPs as reference standard, this approach achieved a Ti-NPs size detection limit in water of 25 nm with a particle number concentration limit of 10〈sup〉2〈/sup〉 particles/ml. We measured Ti-NPs concentrations in surface waters from Lake Taihu, China. The results revealed that the particles concentration was 2.78 × 10〈sup〉5〈/sup〉 particles/ml with the mean size of 67 nm in October 2016, and the particles concentration of 2.28 × 10〈sup〉5〈/sup〉 particles/ml with the mean size of 65 nm in April 2018, respectively. Based on TEM-EDS observation, various shapes of Ti-NPs were further identified, including regular cubes, long rods and flaky. We further measured the total organic carbon (TOC), and found that there was a positive correlation between Ti-NPs and TOC. This method enabled accurate detection and quantification of Ti-NPs concentration in environmental surface waters, which could be hugely useful for environmental risk assessment in aquatic systems.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0304389419309999-ga1.jpg" width="156" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 January 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials, Volume 381〈/p〉 〈p〉Author(s): Xiaolin Cai, Pengfei Wang, Zejiao Li, Yan Li, Naiyi Yin, Huili Du, Yanshan Cui〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Organic matter (OM) was proved to have a high affinity for arsenic (As) in the presence of ferric iron (Fe(III)), the formed ternary complex OM-Fe(III)-As(V) were frequently studied before; however, the mobilization and transformation of As from OM-Fe(III)-As(V) in the presence of As(V)-reducing bacteria remains unclear. Two different strains (〈em〉Desulfitobacterium〈/em〉 sp. DJ-3, 〈em〉Exiguobacterium〈/em〉 sp. DJ-4) were incubated with OM-Fe(III)-As(V) to assess the biotransformation of As and Fe. Results showed that 〈em〉Desulfitobacterium〈/em〉 sp. DJ-3 could substantially stimulate the reduction and release of OM-Fe complexed As(V) and resulted in notable As(III) release (30 mg/L). The linear combination fitting result of 〈em〉k〈sup〉3〈/sup〉〈/em〉-weighted As K-edge EXAFS spectra showed that 56% of OM-Fe-As(V) was transformed to OM-Fe-As(III) after 144 h. Besides, strain DJ-3 could also reduce OM complexed Fe(III), which lead to the decomposition of ternary complex and the release of 11.8 mg/g Fe(II), this microbial Fe(III) reduction process has resulted in 11% more As liberation from OM-Fe(III)-As(V) than without bacteria. In contrast, 〈em〉Exiguobacterium〈/em〉 sp. DJ-4 could only reduce free As(V) but cannot stimulate As release from the complex. Our study provides the first evidence for microbial As reduction and release from ternary complex OM-Fe(III)-As(V), which could be of great importance in As geochemical circulation.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S030438941930929X-ga1.jpg" width="351" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 January 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials, Volume 381〈/p〉 〈p〉Author(s): Lila Otero-González, Sergey V. Mikhalovsky, Miroslava Václavíková, Mikhail V. Trenikhin, Andrew B. Cundy, Irina N. Savina〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Novel macroporous iron oxide nanocomposite cryogels were synthesized and assessed as arsenite (As(III)) adsorbents. The two-step synthesis method, by which a porous nanonetwork of iron oxide is firstly formed, allowed a homogeneous dispersion of the iron oxide in the cryogel reaction mixture, regardless of the nature of the co-polymer forming the cryogel structure. The cryogels showed excellent mechanical properties, especially the acrylamide-based cryogel. This gel showed the highest As(III) adsorption capacity, with the maximum value estimated at 118 mg/g using the Langmuir model. The immobilization of the nanostructured iron oxide gel into the cryogel matrix resulted in slower adsorption kinetics, however the cryogels offer the advantage of a stable three-dimensional structure that impedes the release of the iron oxide nanoparticles into the treated effluent. A preliminary toxicity evaluation of the cryogels did not indicate any apparent inhibition of human hepatic cells activity, which together with their mechanical stability and high adsorption capacity for As(III) make them excellent materials for the development of nanoparticle based adsorption devices for drinking water treatment.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0304389419309501-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Computers in Industry, Volume 112〈/p〉 〈p〉Author(s): Patrick Dallasega, Rafael A. Rojas, Giulia Bruno, Erwin Rauch〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A special characteristic of Engineer-to-Order (ETO) construction supplier companies is that they are composed of an off-site and on-site production part. Often, their synchronization is difficult by using traditional scheduling and monitoring methodologies resulting in excessive lead times, buffer levels and, as a result, additional costs. Real-time data, made available by Industry 4.0 technologies, represent a high potential to sense and react to plan deviations as soon as they appear. The paper presents a decentralized and agile approach for scheduling and control in ETO construction supply chains. The approach was modelled and validated based on a case study of an ETO façade supplier company and a discrete event simulation. It emerged that the agile approach has its main benefits in the reduction of buffer sizes and construction lead-times. The original aspect of the article is the investigation of effects of agile scheduling and control in ETO construction supply chains.〈/p〉〈/div〉

Description: 〈p〉Publication date: November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Computers in Industry, Volume 112〈/p〉 〈p〉Author(s): Juan Jose Rubio, Takahiro Kashiwa, Teera Laiteerapong, Wenlong Deng, Kohei Nagai, Sergio Escalera, Kotaro Nakayama, Yutaka Matsuo, Helmut Prendinger〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Structural Health Monitoring (SHM) has benefited from computer vision and more recently, Deep Learning approaches, to accurately estimate the state of deterioration of infrastructure. In our work, we test Fully Convolutional Networks (FCNs) with a dataset of deck areas of bridges for damage segmentation. We create a dataset for delamination and rebar exposure that has been collected from inspection records of bridges in Niigata Prefecture, Japan. The dataset consists of 734 images with three labels per image, which makes it the largest dataset of images of bridge deck damage. This data allows us to estimate the performance of our method based on regions of agreement, which emulates the uncertainty of in-field inspections. We demonstrate the practicality of FCNs to perform automated semantic segmentation of surface damages. Our model achieves a mean accuracy of 89.7% for delamination and 78.4% for rebar exposure, and a weighted F1 score of 81.9%.〈/p〉〈/div〉

Description: 〈p〉Publication date: 1 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Computer Methods in Applied Mechanics and Engineering, Volume 357〈/p〉 〈p〉Author(s): Byungseong Ahn, Hyuk Lee, Joong Seok Lee, Yoon Young Kim〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A numerical method based on topology optimization is developed for designing a metasurface that anomalously reflects longitudinal elastic waves. While the analysis and design of metasurfaces and metamaterials have received much attention recently, no numerical method to design elastic metasurfaces for anomalous reflection has been explored. Here, we formulate a density-based topology optimization suitable for finding a set of phase-delaying unit cells forming a metasurface that anomalously reflects longitudinal waves impinged upon it. Each unit cell is designed to yield the specific phase delay between the incident and reflected elastic waves. The transfer matrix approach using the averaged finite element results is employed to efficiently and accurately calculate the phase delay while the wave phenomena are analyzed by the finite element analysis. As case studies, metasurfaces converting normally incident longitudinal waves to anomalously reflected longitudinal waves were designed. Various target anomalous reflection angles were considered including the extreme reflection angle of 90°. To investigate the numerical aspect of the developed method, we investigated the effect of the sizes of the unit cells, both along the perpendicular and normal directions to the wave incidence. The mesh dependence issue was also investigated. Finally, we applied the developed topology optimization method to design metasurfaces for wave focusing and trapping in a waveguide.〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 21 August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of the Franklin Institute〈/p〉 〈p〉Author(s): Cheng Tan, Zhongchang Liu, Wing Shing Wong〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉This paper investigates the formation control of interconnected second-order systems. Each agent is assumed to be capable of measuring its own absolute velocity and the relative positions with respect to its neighboring agents, whereas the target formation is described by absolute positions of all agents in a global coordinate. For such formation control problems, no distributed control policy was reported in existing literature. This paper focuses on the string connection structure of the agents and proposes a distributed control policy that takes the form of purely state feedback without incorporating any feed-forward component. The closed-loop system equation is characterized by an oscillation matrix whose entries are the feedback controller gains. Formation control is accomplished by formulating the agents’ target positions as feedback controller gains. Moreover, it is shown that for agent models described by double integrators, each of the agents located at the two endpoints of the string structure should know its own absolute position. For a class of agent models where each agent’s acceleration depends on its own position, the control laws do not need to use the absolute position. For both system models, the target formations that are asymptotically reachable by the proposed control laws are specified explicitly. Numerical simulations have been conducted to illustrate the effectiveness of the theoretical results.〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 January 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials, Volume 381〈/p〉 〈p〉Author(s): Xiao Zhang, Qiqi Shi, Boxiong Shen, Zhenzhong Hu, Xiaoqi Zhang〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A novel magnetic composite catalyst of MnOx loaded on MIL-100(Fe) was prepared for the removal of Hg〈sup〉0〈/sup〉 from flue gas, 〈em〉via〈/em〉 incipient wetness impregnation followed with calcination at 300 °C. The MIL-100(Fe) supported catalyst showed greater capacity of Hg〈sup〉0〈/sup〉 adsorption and oxidation than Fe〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 supported catalyst at all test temperatures, showing Hg〈sup〉0〈/sup〉 removal efficiency of 77.4% at 250 °C with high GHSV of 18,000 h〈sup〉−1〈/sup〉. Besides the merit of high BET surface area and developed porous, the ultra-highly dispersed and homogeneous Fe sites on MIL(Fe) significantly promoted Hg〈sup〉0〈/sup〉 adsorption and oxidation 〈em〉via〈/em〉 the synergy effect with MnOx. Furthermore, the catalyst exhibited magnetic property, which allowed easy separation of the catalyst from fly ash with a recovery of 104%. SO〈sub〉2〈/sub〉, H〈sub〉2〈/sub〉O and NH〈sub〉3〈/sub〉 in flue gas were proved inhibited Hg〈sup〉0〈/sup〉 removal 〈em〉via〈/em〉 different mechanisms. SO〈sub〉2〈/sub〉 and H〈sub〉2〈/sub〉O competed and desorbed Hg〈sup〉2+〈/sup〉 on the surface of catalyst, while NH〈sub〉3〈/sub〉 was more likely to compete adsorption sites with Hg〈sup〉0〈/sup〉.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0304389419309574-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 January 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials, Volume 381〈/p〉 〈p〉Author(s): Qi Wang, Pinghua Chen, Xiong Zeng, Hualin Jiang, Feifan Meng, Xueqin Li, Tao Wang, Guisheng Zeng, Lingling Liu, Hongying Shu, Xubiao Luo〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A nanocomposite of (ZrO〈sub〉2〈/sub〉-Al〈sub〉2〈/sub〉O〈sub〉3〈/sub〉)/GO was successfully synthesized by a simple sonochemical method in this study. A special 3D network was formed in (ZrO〈sub〉2〈/sub〉-Al〈sub〉2〈/sub〉O〈sub〉3〈/sub〉)/GO, which produced a large surface area and good distribution of metal oxide nanoparticles. The as-synthesized (ZrO〈sub〉2〈/sub〉-Al〈sub〉2〈/sub〉O〈sub〉3〈/sub〉)/GO exhibits a maximum fluoride adsorption capacity of 62.2 mg/g, and an adsorption ability of 13.80 mg/g when the F〈sup〉−〈/sup〉 equilibrium concentration is 1 mg/L, both of which are higher than most previously reported defluoridation adsorbents, indicating that it is among the top adsorbents. Large amounts of drinking water contaminated by F〈sup〉−〈/sup〉 can be treated by (ZrO〈sub〉2〈/sub〉-Al〈sub〉2〈/sub〉O〈sub〉3〈/sub〉)/GO to meet the WHO limit, indicating the high potential for practical application of the adsorbent. Based on the experimental analysis, the origin of the high defluoridation performance and the adsorption mechanism were discussed in detail. Due to the simple preparation, easy operation and high performance, the adsorbent and the related sonochemical method are considered to be significant for developing highly effective adsorbents.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0304389419309070-ga1.jpg" width="366" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 January 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hazardous Materials, Volume 381〈/p〉 〈p〉Author(s): Zhe Yang, Changxiang Wang, Danqing Liu, Sen Yang, Yumei Li, Yu Ning, Yangyang Zhang, Ye Tang, Wei Zhang, Yilian Li〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Uranium-enriched coal ash (CA) receives a significant attention as a supplementary nuclear resource also due to its potential environmental risk. Combining with CA, the changing trend of uranium occurrence in synthetic coal ash (SCA) was described at CaO-Al〈sub〉2〈/sub〉O〈sub〉3〈/sub〉-Fe〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 ternary phase diagrams with a fixed SiO〈sub〉2〈/sub〉 (wt. %, 30%, 50% and 70%) and Na〈sub〉2〈/sub〉O (2%) content. This study reveals that the mode of uranium occurrence proposes a three-stage changing process during coal combustion including uranium oxidation, combination and encapsulation. Furthermore, a high frequency of encapsulated uranium resulted from the complicated interactions among major components with a medium SiO〈sub〉2〈/sub〉 content, whereas the degree was higher at a higher SiO〈sub〉2〈/sub〉, resulting in the decrease of uranium mobility. Uranium was encapsulated by Si-Al matrix and Fe-Si depletion if provided the high Al〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 and Fe〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 but low CaO contents. However, with the development of calcium looping and biomass co-firing process, the change of element mobility should be considered in industry owing to the extra-added alkaline metals. As the activation of Ca〈sup〉2+〈/sup〉 induces a significant susceptibility of acid attack, cautions must be paid in CA with a higher Ca/Si ratio to avoid its utilization as constructive materials for the potential environmental risk.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0304389419309318-ga1.jpg" width="314" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉