High-density polyethylene membranes embedded with carboxylated and polyethylene glycol-grafted nanodiamond to be used in membrane bioreactors

In this work, neat and modified nanodiamond (ND) particles were embedded into high-density polyethylene (HDPE) membranes to improve hydrophilicity and antifouling properties. The membranes were prepared via thermally induced phase separation (TIPS) method and used for pharmaceutical wastewater treatment in membrane bioreactors (MBR) system. To prevent the agglomeration of ND, it was modified using two methods: thermal carboxylation (ND-COOH) and grafting with polyethylene glycol (ND-PEG). Membranes with different concentration of ND-COOH and ND-PEG nanoparticles ranging from 0.00 to 1.00 wt % were prepared and characterized using a set of analyses including water contact angle, pure water flux, tensile strength, differential scanning calorimeter, field emission scanning electron microscopy, and energy dispersive X-ray spectroscopy. It was found that the optimum contents of ND-COOH and ND-PEG nanoparticles were 0.50 wt % and 0.75 wt %, respectively. The interfacial interaction between nanoparticles and HDPE matrix was studied based on Pukanzsky model. To examine the performance of membranes, critical flux, filtration experiment in the MBR, and fouling analysis of membranes were carried out. The results showed that among the fabricated membranes, 0.75 wt % HDPE/ND-PEG membrane had the highest water flux and the best antifouling properties. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47914.     

Additive Manufacturing of Hard Magnetic Passive Shims to Increase Field Homogeneity of a Halbach Magnet

Obtaining a highly homogeneous magnetic field is desired for field-controlled applications. For example, the resolution of magnetic analysis methods can be improved by generating a stronger and more homogeneous field over the region of interest (ROI). A set of 3D-printed passive shims is fabricated using additive manufacturing to improve the magnetic field homogeneity of a Halbach magnet assembly. The feedstock is a custom acrylonitrile butadiene styrene (ABS)-hard magnet composite filament filled with 60% wt. isotropic NdFeB. Additionally, a method for investigating the remanence is developed and validated. The result reveals a good agreement between the new method and existing measurement techniques for the remanence of permanent magnets. It is also shown that the additive manufacturing procedure has negligible effects on the magnetic properties. Performing a parametric study over a rectangular ROI, an optimized shim configuration is achieved. In the optimized and 3D-printed configuration, the average norm of the magnetic flux density, B_norm, is increased by 13% and, more importantly, a 43% increase in the magnetic uniformity is obtained. These results highlight the great potential of freeform manufacturing, namely, additive manufacturing, to tailor the properties of magnet structures.     

Synthesis,Corrosion and Bioactivity Evaluation of Gelatin/Silicon and Magnesium Co-Doped Fluorapatite Nanocomposite Coating Applied on AZ31 Mg Alloy

In this study, a nano-composite composed of gelatin as the matrix and Si-Mg-FA nano-particles as an additive was deposited on the AZ31 Mg alloy via dip coating method. In addition, a coating composed of MgO, MgSiO₃ and Mg₂SiO₄ phases was applied on the AZ31 Mg alloy by anodizing process. It was found that the Nano-composite coating with a uniform distribution of nano-particles within the gelatin matrix with the thickness of about 9 µm was dense, crack-free and uniform whereas the surface of anodized layer was relatively coarse due to the presence of flaws and micro-cracks. The surface morphology, EDS analysis and FTIR results revealed the ability of nano-composite coated specimen to form the bone-like apatite. Due to the presence of aforementioned phases and special surface features, the anodized specimen possessed higher and lower corrosion resistance than uncoated and nano-composite coated specimens, respectively. The passive coating resistances (R_CT) of nano-composite, anodized specimen and uncoated samples were 2164, 1449 and 1024 Ω cm², respectively.     

Sonification and interaction design in computer games for visually impaired individuals

Multimedia Tools and Applications - Video games are changing how we interact and communicate with each other. They can provide an authentic and collaborative platform for building new communities...     

Role of Chloride Ion and Dissolved Oxygen in Electrochemical Corrosion of AA5083-H321 Aluminum-Magnesium Alloy in NaCl Solutions under Flow Conditions

Flow-induced corrosion consists electrochemical and mechanical components. The present paper has to assessed the role of chloride ion and dissolved oxygen in the electrochemical component of flow induced corrosion for AA5083-H321 aluminum-magnesium alloy which is extensively used in the construction of high-speed boats, submarines, hovercrafts, and desalination systems, in NaCl solutions. Electrochemical tests were carried out at flow velocities of 0, 2, 5, 7 and 10 m/s, in aerated and deaerated NaCl solutions with different sodium chloride concentrations. The results showed that the high rate of oxygen reduction under hydrodynamic conditions causes an increase in the density of pits on the surface. The increase of chloride ions concentration under flow conditions accelerates the rate of anodic reactions, but have no influence on the cathodic reactions. Thus, in the current work, it was found that under flow conditions, due to the elimination of corrosion products inside the pits, corrosion resistance of the alloy is increased.     

Effect of surface oxidation on corrosion mechanism of Co–20·8Ni–6Al–10Cu–11Fe cobalt alloy in molten cryolite

In this paper, the effect of surface oxidation on corrosion behaviour of Co–20·8Ni–6Al–10Cu–11Fe alloy in molten cryolite is investigated. The samples were produced by casting and then were oxidised at 1000°C for 10, 30 and 70 h respectively. The oxide layers were studied by scanning electron microscope (SEM) and X-ray diffraction (XRD). To determine the corrosion behaviour of the oxidised samples, they were exposed to molten cryolite at 930°C for 20 h. After corrosion, the samples were studied by SEM. The results showed that all the samples corroded, but the sample oxidised for 70 h, was more stable than the other and the other one that oxidised for 10 h, corroded severely.     

Improving the functionality of biodegradable food packaging materials via porous nanomaterials

Non-biodegradability and disposal problems are the major challenges associated with synthetic plastic packaging. This review article discusses a new generation of biodegradable active and smart packaging based on porous nanomaterials (PNMs), which maintains the quality and freshness of food products while meeting biodegradability requirements. PNMs have recently gained significant attention in the field of food packaging due to their large surface area, peculiar structures, functional flexibility, and thermal stability. We present for the first time the recently published literature on the incorporation of various PNMs into renewable materials to develop advanced, environmentally friendly, and high-quality packaging technology. Various emerging packaging technologies are discussed in this review, along with their advantages and disadvantages. Moreover, it provides general information about PNMs, their characterization, and fabrication methods. It also briefly describes the effects of different PNMs on the functionality of biopolymeric films. Furthermore, we examined how smart packaging loaded with PNMs can improve food shelf life and reduce food waste. The results indicate that PNMs play a critical role in improving the antimicrobial, thermal, physicochemical, and mechanical properties of natural packaging materials. These tailor-made materials can simultaneously extend the shelf life of food while reducing plastic usage and food waste.     

The Effect of Pre-oxidation Treatment on Corrosion Behavior of Ni–Cu–Fe–Al Anode in Molten CaCl<Subscript>2</Subscript> Salt

This article presents Ni–Cu–Fe–Al alloy as a novel inert anode used in FFC process (the Fray Farthing Chen) in molten calcium chloride salts for producing titanium. The alloy was prepared by vacuum induction melting; then utilized as anode material in molten CaCl₂ for 16 h at 900 °C. Morphology and the corrosion behavior of the samples were analyzed using scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS). The product on the cathode was analyzed using X-ray diffraction (XRD). After 16 h electrolysis of anodes, EDS and SEM analysis of the samples showed that the corrosion depth of the non-oxidized sample was shorter. Corrosion attacks more severe for the pre-oxidized sample than the non-oxidized sample, which indicated that the corrosion resistance of outer layer is higher on the non-oxidized sample. The XRD results show that the TiO₂ pellets were successfully reduced to the lower oxides using the Ni–Cu–Fe–Al inert anode.     

The effect of tracking technique on the quality of user experience for augmented reality mobile navigation

Augmented reality (AR) technology is changing the way we interact with the world by making the journey seamless and interactive. This is done by layering digital enhancements over an existing reality or real life scenario. However, employing AR technologies in wayfinding and navigation does not automatically bring positive experiences. We argue that tracking techniques are important in mobile AR navigation and fundamentally affect the quality of user experience. In this paper, we propose two different tourist AR applications based on different tracking techniques. In addition to the analysis of the applications, we conducted a user evaluation to study the effect of different AR tracking techniques on the performance of users and the quality of user experience.     

Processing and properties of an ethylene–vinyl acetate blend foam incorporating ethylene–vinyl acetate and polyurethane waste foams

Waste polyurethane foam (w‐PU) and waste ethylene–vinyl acetate foam (w‐EVA) were used as fillers for the production of an ethylene–vinyl acetate (EVA) blend foam. Two different foaming techniques (single‐stage and heat–chill processes) were used for this purpose. The waste foam concentration was varied up to 30 wt % of the original EVA. The physical, mechanical, and morphological properties of the filled foam were studied. The single‐stage process produced blend foams with a lower density and a greater cell size than the foams obtained by the heat–chill process. The density and compression strength of the blend foam increased as the percentage of w‐PU foam increased. However, for the w‐EVA/EVA blend foams, the addition of w‐EVA foam did not significantly affect the density or compression strength compared to the original EVA foams. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44708.