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• KCl and CaCl 2 were extracted using pure water and HCl solutions at various concentrations, respectively, from industrial cement kiln dust. • For the membrane electrolysis, higher anolyte/lower catholyte concentrations, and higher temperature are appropriate for KOH production. • The CO 2 capture-mineralization was tested by measurement of CO 2 removal efficiency depending on the Ca/CO 2 ratio and gas retention time. Due to the significant amount of CO 2 released from the cement industry, a CO 2 sequestration process suitable for cement-manufacturing plants is required to reduce greenhouse gas emission and to mitigate global warming. In the present study, a new overall process of CO 2 treatment is proposed for the cement industry that includes the extraction of KCl and CaCl 2 from the cement by-products, KCl membrane electrolysis for KOH formation, and CO 2 capture-mineralization using the extracted KOH and CaCl 2. For this three-step process, various experiments were conducted to determine how the results varied in relation to experimental conditions and to find the most suitable conditions for process operation. The KCl and CaCl 2 were extracted using pure water and HCl solutions at various concentrations, respectively, from industrial cement kiln dust. KCl membrane electrolysis was carried out to measure the electrochemical performance in relation to the KCl or KOH concentration, temperature, and applied current density. The single process of CO 2 capture-mineralization was tested by measurement of the CO 2 removal efficiency in relation to variation of the Ca/CO 2 ratio and gas retention time. In addition, the purity of the CaCO 3 produced was evaluated in relation to the Ca/CO 2 ratio, and the CO 2 removal efficiency was examined over time on stream. [ABSTRACT FROM AUTHOR]

Copper-based electrocatalysts have been widely used to generate C 2+ products via the electrocatalytic carbon dioxide reduction reaction (CO 2 RR) because the catalysts possess unique properties for C-C coupling. Tandem catalysis is an attractive concept for C 2+ production, enhancing selectivity and activity by combining CO-generating catalysts with Cu-based catalysts. Herein, the ability of Ag decoration to improve the selectivity of the Cu 2 O catalysts for C 2+ production was investigated. The Ag/Cu 2 O catalyst with 10 wt% Ag content on the Cu 2 O surface (10 Ag/Cu 2 O) exhibited high Faradaic efficiency (FE) of 48% for C 2+ products at –0.99 V (vs. RHE). Moreover, the partial current density of C 2+ products on the 10 Ag/Cu 2 O was improved by 33% compared to the bare Cu 2 O catalyst. The intermediate (CO) generated on the Ag surface migrates by diffusion and/or sequential desorption-re-adsorption from Ag to Cu at the Ag-Cu interface of the Ag/Cu 2 O, increasing CO coverage on the Cu surface. The increase in CO coverage on the Cu surface of the Ag/Cu 2 O catalysts after decoration with Ag effectively reduces the hydrogen evolution reaction (HER), enhancing C-C coupling to generate C 2+ products on the Ag/Cu 2 O. In addition, density functional theory (DFT) calculation results also revealed that Ag provides more CO 2 activation sites, increasing CO coverage and reducing hydrogen adsorption energy, thus suppressing HER and improving the selectivity of CO 2 RR toward C 2+ production. [Display omitted] • The effect of Ag decoration was investigated to improve the C 2+ selectivity of Cu 2 O. • Ag/Cu 2 O catalysts exhibited enhanced C 2+ selectivity and activity than bare Cu 2 O. • The decorated Ag increases CO coverage for C-C coupling and suppresses HER. [ABSTRACT FROM AUTHOR]

This study investigated the synthesis of hierarchically porous heteroatom-doped (B and N) carbon materials from CO 2 or flue gas by CO 2 conversion using NaBH 4 as a reducing agent and their applications as supercapacitors. The resultant carbon materials exhibited a high specific capacitance of 210 F/g at 1 A/g, which is higher than that found in a typical activated carbon. This is because their hierarchical micro-mesoporous structure causes ions to diffuse into the carbon pores with low resistance. In particular, the process synthesizing B/N dual-doped carbon from flue gas reduces the capital/operating cost because the process does not involve an energy-intensive separation process of CO 2 from flue gas. Therefore, the direct conversion of flue gas into B/N dual-doped carbon can lead to a sustainable practice of CO 2 utilization. [ABSTRACT FROM AUTHOR]

This study investigates the effect of boron/nitrogen (B/N) dual doping on the electrocatalytic activity for oxygen reduction reaction (ORR) of carbon materials that are derived from gaseous carbon dioxide (CO 2 ) at 1 atm. In the presence of NaBH 4 , CO 2 was converted to a B-doped carbon material which was further treated with urea at 850 °C for N-doping. Through RDE and RRDE measurements, the enhanced ORR activity of the B/N dual-doped carbon was confirmed in terms of both early onset potentials and large current densities. This arose from the existence of B-N related bond and pyridinic N in the carbon network. As the amount of N content increased, the carbon material became more crystalline and the B/N dual doping led to an increase in the electron transfer number of the carbon materials, implying that the ORR occurred through a dominant four-electron transfer pathway. By utilizing the abundant greenhouse gas as a carbon source, this study provides a facile means by which to synthesize B/N dual-doped carbon for enhanced electrocatalysis. [ABSTRACT FROM AUTHOR]

Abstract: Although electrochemical stability is an essential factor in relation to the potential applications of ionic clathrate hydrates to solid electrolytes, most studies regarding the proton conductors have focused on their ionic conductivity and thermal stability. Solid electrolytes in various electrochemical devices have to endure the applied potentials; thus, we examined the linear sweep voltammograms of various tetraalkylammonium hydroxide hydrates in order to shed light on the trend of electrochemical stability depending on the hydrate structure. We revealed that the electrochemical stability of Me4NOH hydrates is mainly affected by both their ionic concentration and cage occupancy. In particular, the true clathrate structures of β-Me4NOH hydrates are more electrochemically stable than their α-forms that possess partially broken hydrogen bonds. We also observed that the binary THF–Pr4NOH and pure Bu4NOH clathrate hydrates exhibit greater electrochemical stability than those of pure Me4NOH hydrates having lower or similar ionic concentrations. These results are considered to arise from the fact that each of the Pr4N+ and Bu4N+ ions occupies an extended space comprising four cages, which leads to stabilization of the larger unit, whereas a Me4N+ ion is completely included only in one cage. [Copyright &y& Elsevier]

In recent years, unmanned surface vehicles (USVs) have been widely used in various applications. To fulfill target missions, USVs must be able to plan their path to the destination. Although many path-planning methods have been developed, most are inappropriate for application in complex marine environments. In this study, we propose a novel path-planning algorithm, which combines the merits of quadtree representation and visibility graphs, for efficient path planning of USVs in complex marine environments. Quadtree representation reduced the computation time and memory consumption. Additionally, the wind and wave data were considered to shorten the voyage time from the departure to destination points. Furthermore, the Dijkstra algorithm was applied to the quadtree to determine the suboptimal path. We then constructed a visibility graph with path waypoints using an improved line-of-sight algorithm to perform path planning on the visibility graph. The proposed algorithm not only facilitates path planning with minimum voyage time but also maintains the USV clearance distance from the coastline. To verify the performance, the proposed algorithm was compared with other methods for South Korean case studies. Overall, the proposed algorithm was able to generate a high-quality suboptimal path for the USV within a short time span. [ABSTRACT FROM AUTHOR]

Although partial meniscectomy is a common treatment for the tears in the avascular region of the meniscus, mechanical alterations following meniscectomy are known to initiate mechanically-induced osteoarthritis. We aimed to measure the articular cartilage contact pressure distributions in the knees with surgically repaired and partially resected menisci in the avascular region. A pneumatic loading device was developed to apply a 1000 N compressive load on the cadaveric porcine knee samples at the flexion angles of 20, 35, 50, and 65°. We simulated longitudinal meniscal tears in the avascular inner 1/3 portion and the well-vascularized middle 1/3 portion of the meniscus. Articular cartilage contact pressures for the knees with intact, torn, repaired, and resected menisci were compared. For the tears in well-vascularized regions, meniscal repairs restored articular cartilage contact pressures to the levels in intact joints. However, partial meniscectomy significantly increases the maximum contact pressures and the average contact pressures in highly compressed areas. However, partial meniscectomy in the avascular region did not alter the maximum articular cartilage contact pressures and the average contact pressures in highly compressed areas. Stabilities in knee samples were not significantly altered following partial meniscectomy in both inner and middle regions. Although repair surgeries are beneficial for the tears in well-vascularized areas because the articular cartilage contact mechanics are reconstructed, partial meniscectomy may be a viable alternative treatment for the tears in avascular regions without introducing significant mechanical alterations. • Meniscal repair effectively restored articular cartilage contact pressures. • Meniscectomy in avascular regions did not altered cartilage contact pressures. • Meniscectomy could be a viable treatment for the tears in avascular regions. [ABSTRACT FROM AUTHOR]

In the present study, the hydrate anti-agglomerant (AA) performance of three biodegradable emulsifiers (Span 80, lecithin, and lanolin) was evaluated in oil-dominated systems using high-pressure rheological tests. The viscosity variations of the fluid systems were examined depending on the concentration of the emulsifiers and water cut during the entire hydrate formation process. The biodegradable emulsifying AAs prevented the drastic increase in the viscosity of the CH 4 hydrate slurry in mineral oil and significant hydrate agglomeration. The AA performance decreased in the following order: Span 80, lecithin, and lanolin. These biodegradable AAs create W/O (water-in-oil) emulsions, namely, small water droplets in mineral oil, by which more water is converted to hydrate that is well dispersed in the oil phase than in the cases without the AAs. The hydrate aggregates formed in the absence of the AAs contain more unconverted water that acts as a capillary bridge for hydrate aggregation or that is confined at the core of the hydrate particles by the partial conversion of water. The density of the dispersed hydrate particles in the AA tests is lower than that of the hydrate aggregates formed in the absence of the AAs. This is due to the unconverted water confined in the aggregates. Therefore, the AAs not only prevent hydrate agglomeration but also reduce the hydrate bedding risk by increasing the conversion of water to hydrate. Image 1 • Performance of a biodegradable emulsifier was evaluated for gas hydrate inhibition. • Viscosity and pressure variations of oil-dominated fluid systems were examined. • Emulsifier makes hydrates dispersed well in oil phase. • Hydrate agglomeration was prevented and reduce hydrate bedding risk reduced. [ABSTRACT FROM AUTHOR]

Abstract: We used the electrostatic deposition (ESD) method to prepare the protein microarray for observation of the stem cell responses to pattern size, space and shapes. The ESD method allows a reduction in spot size, high efficiency of substance transfer, and high rate in fabrication as a result of ability to simultaneously deposit thousands of identical spots. Typical electrospraying conditions for the deposition of proteins were a voltage of 3.5–4.5keV and the humidity under 40%. The patterns of masks have a variety of shapes, spaces, and hole sizes from 10 to 300μm. Collagen is deposited on conducting polymer in a dry state, preserving the functional activity of proteins. The surface morphology of deposited spots was observed using an atomic force microscope and a scanning electron microscope. Human mesenchymal stem cells were cultured on each extracelluar protein patterned sample and cellular morphology was observed by light microscopy. Cell attachment and spreading on the surface are dependent on the deposition conditions by ESD. Protein deposition with short time is effective on the cell culture. However, collagen pattern size, space and shapes in micrometer size seemed to have little effect on cellular response in our design. [Copyright &y& Elsevier]

• Expression of AFPs on E. coli using cell surface display strategy was investigated. • Kinetic inhibition performance of AFPs was tested. • Monomer to hexamers of AFPs were displayed on surface of bacterial cells. • AFPs exhibited higher KHI effectiveness with increasing number of attached peptides. • KHI performance of AFPs is achieved with higher dosages of the cultures. The expression of anti-freeze proteins (AFPs) on the Escherichia coli using the cell surface display (CSD) strategy was investigated to determine the feasibility of the method as a potential application of kinetic hydrate inhibitors. Monomers to hexamers of type II and III AFPs were displayed on the surfaces of bacterial cells. The kinetic inhibition performance of the AFPs on the synthetic natural gas hydrate formation was tested. The displayed AFPs exhibited higher KHI effectiveness with the increase in the number of peptides attached to the cells. In addition, best KHI performance of the AFPs could be achieved with higher dosages of the cultures when the concentration of the inducer is optimized, regardless of AFP type. Only a small portion of AFPs in the cell cultures exhibited considerable KHI performance, which implies that the CSD could be an effective strategy, reducing the cost for the production and purification of the AFPs. [ABSTRACT FROM AUTHOR]

Estrogens have previously been shown to protect the brain against acute ischemic insults, by potentially augmenting cerebrovascular function after ischemic stroke. The current study hypothesized that treatment with sustained release of high-dose 17β-estradiol (E2) at the time of reperfusion from middle cerebral artery occlusion (MCAO) in rats would attenuate reperfusion injury, augment post-stroke angiogenesis and cerebral blood flow, and attenuate lesion volume. Female Wistar rats underwent ovariectomy, followed two weeks later by transient, two-hour right MCAO (tMCAO) and treatment with E2 ( n =13) or placebo (P; n =12) pellets starting at reperfusion. E2 treatment resulted in significantly smaller total lesion volume, smaller lesions within striatal and cortical brain regions, and less atrophy of the ipsilateral hemisphere after six weeks of recovery. E2-treated animals exhibited accelerated recovery of contralateral forelimb sensorimotor function in the cylinder test. Magnetic resonance imaging (MRI) showed that E2 treatment reduced the formation of lesion cysts, decreased lesion volume, and increased lesional cerebral blood flow (CBF). K trans , a measure of vascular permeability, was increased in the lesions. This finding, which represents lesion neovascularization, was not altered by E2 treatment. Ischemic stroke-related angiogenesis and vessel formation was confirmed with immunolabeling of brain tissue and was not altered with E2 treatment. In summary, E2 treatment administered immediately following reperfusion significantly reduced lesion size, cyst formation, and brain atrophy while improving lesional CBF and accelerating recovery of functional deficits in a rat model of ischemic stroke. [ABSTRACT FROM AUTHOR]

Abstract: A new optical technique based on the heterodyne polarimetry is developed for fast inspection of uniformity of lithography masks in semiconductor industry. Sub-wavelength periodical structure of a sample acts as a wire-grid polarizer, making both the amplitude and phase of the reflected laser beam dependent on geometrical dimensions and optical properties of the mask pattern. The heterodyne technology based on the cross-polarized two-frequency Zeeman laser is used to simultaneously measure the amplitude and the phase of the reflected laser beam. A two-dimensional map of spatial variations can be obtained via point-by-point scanning of the sample. The technique is applicable not only to exact periodical structures like diffraction gratings, but also to double-periodical patterns consisting of large number of periodically distributed small areas of sub-wavelength gratings. Theoretical background, simulation, and experimental results are presented. [Copyright &y& Elsevier]

Abstract: Plasma-enhanced chemical vapor deposition (CVD) has the advantages of low temperature and vertical growth in synthesizing carbon nanotubes (CNTs), but has generally produced stubby CNTs, probably due to an ion bombardment effect. To suppress the ion bombardment, a metal mesh with the same electrical potential as that of the cathode was placed just above the substrate on the cathode. The anode was electrically grounded while the cathode and the mesh were both negatively biased, causing no plasma to occur below the mesh. The substrate was therefore separated from the plasma by the mesh so that the ion bombardment was suppressed. CNTs were grown on a 2nm-thick Invar catalyst with different DC plasma powers of 0–112W at 500°C, 3.3torr for 10min, using C2H2 (28sccm) and NH3 (172sccm). Compared to CNTs grown with no mesh, these CNTs showed smaller diameters and greater lengths. As the plasma power decreased, the CNTs grown with mesh were thinner and longer and resembled those grown at a higher temperature by thermal CVD. Etching these CNTs by N2 plasma reduced their population density and considerably improved their field emission characteristics. [Copyright &y& Elsevier]

A polymer-ZnO colloidal solution was prepared as the organic-inorganic composite electron transport layer of inverted polymer solar cells (i-PSCs) by successive modification of ZnO particles with organic dispersant and polyethyleneimine (PEI), which offers an alternative to previously used complicated processes such as high temperature annealing or multi-layer coatings. The modification of ZnO surfaces with 2-(2-methoxyethoxy) acetic acid (MEA) provides colloidal stability and prevents aggregation of ZnO particles after adding PEI into the ZnO colloidal solution. The amount of incorporated PEI was increased to ~10 wt%, and the cell performance parameters of Jsc and fill factor (FF) were enhanced proportional to PEI content because of its contribution in decreasing the work function of ZnO ETL. By fabrication of i-PSCs with the modified ZnO ETL, the power conversion efficiency (PCE) was increased by ~40% from 5.10% to 7.51% in the ITO/ETL/PV-D4610:PC 60 BM/MoO 3 /Ag structure. The multi-functionalized ZnO ETL provides a more facile process for preparation of an organic-inorganic composite ETL to improve the performance of i-PSCs. Image 1 • Stable PEI-ZnO composite colloidal solution was prepared for electron transport layer in polymer solar cell. • Successive surface modification of ZnO with MEA and PEI yielded stable composite colloid. • The 40% of enhancement in PCE was obtained by using composite colloid. [ABSTRACT FROM AUTHOR]

Microfluidic lenses that have been fabricated using PDMS have serious limitations due to the high gas permeability of the material, which leads to evaporation of the filling liquid and air bubble formation. We report a fast and reliable method of fabricating flexible, thin-film parylene microfluidic devices, and their application in tunable microfluidic lens arrays. A parylene microfluidic lens was built by molding and bonding 1.4-μm-thick parylene layers using nano-adhesivelayers deposited by initiated chemical vapor deposition (iCVD). The focal length of the lens could be tuned by changing the radius of curvature of the lens and/or changing the refractive indices of the filling liquids. The parylene microfluidic lens showed a large range of focal length tuning, and high reproducibility over hundreds of cycles. Image 1 • A flexible, thin-film polyer microfluidic lens array was developed to address issues of highly gas pearmeable PDMS. • Parylene microfluidics was built by bonding chemically inert parylene layers using nano-adhesive layer deposited by iCVD. • Focal length of the lens could be tuned by the radius of curvature and the refractive index of filling liquids. • Repeatibility of the lens operation was tested over hundreds of cycles. [ABSTRACT FROM AUTHOR]