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A dry sorbent post-combustion CO 2 capture process using a circulating fluidized bed (CFB) was developed to a 10 MWe scale. Particle attrition is a major challenge for many CFBs owing to the loss of particles and increased operating costs. Furthermore, predicting and alleviating the rate of particle attrition in an entire CFB is difficult owing to limited information on attrition in the riser and cyclone. This study experimentally investigated particle attrition in risers and cyclones and the effect of system scale-up using CO 2 adsorbent particles used in a 10 MWe scale CFB. Experiments were conducted in two types of CFBs to measure the attrition rate in the riser and cyclone for 22 and 12 h for each experimental condition. To verify the scaled-up effect, internals were added to the riser to measure the effect of the surface-area-to-volume ratio. Correlations for the attrition rate of CO 2 adsorbent particles in riser and cyclone were proposed, and a model for the scale-up effect was suggested. In the 10 MWe scale system, particle attrition mainly occurred in the cyclone (58.0 %) and riser (37.3 %) according to the calculation, and the calculated overall attrition rate reasonably matched the operational data. Figure: (a) Calculated attrition rate of CO 2 adsorbent particles in the circulating fluidized bed of 10 MWe scale CO 2 capturing process, and (b) effect of cyclone inlet gas velocity on the particle attrition rate in cyclone. [Display omitted] • Particle attrition mainly occur in the cyclone and riser of a CFB. • Attrition rate in cyclone was proportional to the square of the gas velocity. • The top size of fines formed by attrition in riser increased with gas velocity. • Attrition rate in the riser increases by increasing surface area. • Correlation for particle attrition rate in the riser and cyclone are proposed. [ABSTRACT FROM AUTHOR]

Attrition rate R a,j versus new stirring factor α new. • The new stirring factor α new was a key factor for jet attrition. • The α new fit well the effect of bed height on jet attrition. • The top size of fines formed by attrition increased with α new. • The attrition rate increased linearly with α new. Particle attrition is a major challenge when handling bulk solid materials with fluidized beds due to its ability to cause particle loss. Herein, the particle attrition induced by the gas jets on a perforated plate distributor in a bubbling fluidized bed was investigated for CO 2 adsorbent particles. An attrition tube, which used air as the fluidizing gas, was used as the fluidized bed. At a constant fluidizing velocity, the initial static bed height and orifice gas velocity were considered as variables. It was confirmed that abrasion dominated the particle attrition. The trend indicating the change in the maximum size of the particles (d pm,a) formed by attrition followed that of the attrition rate (i.e., the formation rate of fine particles via attrition). A new stirring factor that combined the model developed by Werther and Xi with the original stirring factor adequately explained the effect of the static bed height on both the attrition rate and d pm,a when the initial static bed height was greater than the length of the orifice gas jet that penetrated the bed. The attrition rate increased linearly with the new stirring factor. However, d pm,a increased exponentially with the new stirring factor. Relationships were successfully proposed to enable the estimation of the attrition rate and d pm,a for the CO 2 adsorbent particles. This study provided the evidence indicating the significance of the effect of bed height on particle attrition induced by the gas jet on the distributor. Moreover, proper models for correlating the attrition rate and the maximum size of the fine particles formed by attrition in the bubbling fluidized bed were provided. [ABSTRACT FROM AUTHOR]

This study aimed to provide a design and operational approach for a loop-seal, which is the heart of a circulating fluidized bed (CFB). Thousands of CFB systems use this non-mechanical valve to optimize performance by controlling the solids circulation rate while preventing gas mixing between reactors. Nevertheless, its design and operating guidance remains unclear because of its intricate flow characteristics, causing confusion in design and operation of the entire CFB. This study experimentally investigated the three most important elements while designing and operating loop-seal: conditions for initiating solids flow, the maximum obtainable solids flow rate, and quantitative control of solids flow rate. Experiments were conducted in a CFB, which simulated 3 MWth chemical looping combustion (CLC) system that is currently being developed. The onset of solids flow occurs when the gas drag force in horizontal passage overcomes the resistance force generated by the bed of particles. The maximum solids circulation rate was determined by solids height in the supply chamber and pressure around CFB loop. A correlation for quantitative control of solids flow in loop-seal was proposed by the relationship between the gas drag force and particle velocity. Finally, operational conditions for the loop-seal in 3 MWth CLC were proposed. Operating conditions of the loop-seal in 3 MWth chemical looping combustion system derived in this study. [Display omitted] • Flow characteristics in loop-seal was analyzed and design factors were confirmed. • Solid flow started after overcoming resistance force by solid in horizontal path. • Particle velocity in horizontal path increased linearly by drag force of gas. • Solid height in standpipe determined the maximum solid circulation rate. • 3 Nm3/hr of Q sup,in was required for solid circulation of 15 kg/s in 3 MWth CLC. [ABSTRACT FROM AUTHOR]

In this paper, we show the energy decay rate for a von Karman system with a boundary nonlinear delay term. This work is devoted to investigate the influence of kernel function g and the effect of the boundary nonlinear term μ 1 | u t ( t ) | m − 1 u t ( t ) , a boundary nonlinear time delay term μ 2 | u t ( t − τ ) | m − 1 u t ( t − τ ) and prove energy decay rates of solutions when g do not necessarily decay exponentially and the boundary condition has a time delay. [ABSTRACT FROM AUTHOR]

Emojis are increasingly adopted in various platforms, such as text messages, social media, or blogs, as part of other digital communications. Recently, emojis have been used in brand-related user-generated content (UGC) as a strategic communication tool to promote positive outcomes. In spite of their increasing importance, little is known about the impact of incorporating emojis in brand-related UGC on consumer reactions. In particular, few research studies have investigated the joint effect of emojis with texts, which is the most important context where emojis function, and the contextual conditions that affect the influence of emojis on consumer reactions. To fill this research gap, we study brand-related UGC, focusing on the effect of emojis and the contextual conditions (e.g., texts). Using large-scale brand-related social media posts from Instagram, we find that, overall, the presence of emojis is positively associated with consumer engagement. Economically, the presence of emojis increases the average number of likes by 72% and the average number of comments by 70% in comparison to posts without any emojis. The interaction effects between emojis and texts reveal that emotional emojis have a positive and significant relationship with consumer engagement only when the texts in brand-related UGC are being skewed toward positive sentiments. However, informational emojis are negatively related with consumer engagement in the similar context. Additionally, the investigations regarding the contextual conditions show that using more emotional emojis has a positive influence on consumer engagement in commercial posts but a negative influence in general posts. • The study examines the effect of emojis and the contextual conditions in UGC. • Having emojis is likely to increase consumer engagement (CE) in brand-related UGC. • A greater use of emojis may not be beneficial in CE in brand-related UGC. • Emotional emojis increase CE in the posts where texts are being positively skewed. • Emotional emojis positively impact on CE in commercial posts, not in general posts. [ABSTRACT FROM AUTHOR]

3 MWth scale chemical looping combustion (CLC) system using circulating fluidized bed (CFB) is being developed as a liquidized natural gas power generation technology to reduce CO 2 emissions. Dipleg, considered a blood vessel of CFB, conveys solids captured by cyclone to the fluidized bed while preventing gas mixing. This vertical passage plays key role in solids circulation and cyclone performance in thousands of CFB systems, yet only a limited information is available on its design and operation. This study experimentally investigated the flow characteristics in dipleg to verify design and operating conditions for smooth solid flow while predicting the amount of gas mixing. When solid circulation rate increased, both upward and downward gas flowrates in dipleg increased. It was found that the sum of two flowrates were equal to the volumetric flowrate of solids in the dipleg. Unstable operation occurred when 1) the gas-solid relative velocity in the dipleg became higher than the minimum slugging velocity, and 2) bubble diameter in bubbling bed became larger than the dipleg diameter. Finally, models for operation range and the amount of gas mixing in dipleg were proposed, and the design and operation range of the dipleg in 3 MWth scale CLC was suggested. Gas flows and design range of a dipleg in 3 MWth chemical looping combustor derived in this study. [Display omitted] • Applicability of dipleg in CFB was investigated and design factors were confirmed. • The amount of up- and down-stream gas was measured within dipleg. • Almost same amount of gas was exchanged with the down-stream particles. • Slugging in dipleg interfered the solid flow. • Bubble, larger than dipleg diameter, prevents the solid flow within dipleg. [ABSTRACT FROM AUTHOR]

Highlights: [•] A novel energy-efficient carbon capture process with multi-stages is proposed. [•] K2CO3, Na2CO3 promoted MgO, and Li4SiO3 were used as the sorbents for each stage. [•] A flow-sheet simulator based on a mathematical model was developed. [•] The heating demand for three-stage process was estimated to be1.73GJ/ton-CO2. [•] The net electrical efficiency loss of the retrofitted coal power plant was 9.5%. [Copyright &y& Elsevier]

Abstract: In this paper, we consider a semi-linear wave equation with damping and source terms. Using a potential well method, we prove the existence and uniqueness of global solutions of the wave equation and investigate uniform decay rates of solutions. Moreover, an example is given to illustrate our results. [Copyright &y& Elsevier]

Abstract: In this study, we investigate a pine wilt transmission model with nonlinear incidence rates. The stability of the system is analyzed for disease-free and endemic equilibria. It is proved that the global dynamics are completely by the basic reproduction number . If is less than one, the disease-free equilibrium is globally asymptotically stable, and in such a case, the endemic equilibrium does not exist. If is greater than one, the disease persists and the unique endemic equilibrium is globally asymptotically stable. [Copyright &y& Elsevier]

Abstract: The first objective of this paper is to make the mathematical model for vibration suppression of an axially moving heterogeneous string. In order to describe the geometrical nonlinearity due to finite transverse deformation, the exact expression of the strain is used. The mathematical modeling is derived first by using Hamilton’s principle and variational lemma and the derived nonlinear PDE system is the Kirchhoff type equation with boundary feedback control. Next, we show the existence and uniqueness of strong solutions of the PDE system via techniques of functional analysis, mainly a theorem of compactness for the analysis of the approximation of the Faedo–Galerkin method and estimate a decay rate for the energy. The theoretical results are assured by numerical results of the solution’s shape and asymptotic behavior for the system. [Copyright &y& Elsevier]

Abstract: In this paper, we consider the initial-boundary value problem for a nonlinear Kirchhoff type equation with the damping term and spring boundary conditions. We establish the global existence and uniqueness of solutions to this problem in time, and give an example and simulation to illustrate our results. For the proof, we use the Faedo–Galerkin approximate method. Finally, we study the asymptotic behavior of solutions and some of its simulation results. Results of this paper are able to apply industrial parts such as a typical model widely used to represent threads, wires, magnetic tapes, belts, band saws, and so on. [Copyright &y& Elsevier]

Abstract: The purpose of this paper is to derive a sharp energy decay estimate for a quasi-linear wave equation with localized strong dissipation of the type in a domain of , where is a nonnegative function supported only on a part of the boundary . We note that the index of algebraic decay depends on dimension and no geometrical condition is imposed on the boundary . [Copyright &y& Elsevier]

• Most simple, stable, robust lateral shearing interferometer using a polarization grating compared to other interferometers. • Based on the balanced achromatic scheme between two shearing wavefronts, any kinds of optical source, even broadband light sources such as white light can be available. • Thoroughly new concept to estimate the surface roughness. • Snapshot roughness capability opposed to other optical techniques and valuable measurement results. A compact optical roughness measurement sensor based on lateral shearing interferometry is theoretically described and experimentally verified. By adopting the advanced surface roughness parameter extraction methods based on statistical machine learning technique and the partial integration approach, the sensor using a polarization grating and a polarization camera can instantaneously obtain a surface gradient map and provide reliable surface roughness parameters. To verify the operation and the performance of the sensor, a flat mirror and roughness standard specimens were measured, and the results were compared with those of a white light scanning interferometer as the reference values. As a result, the roughness parameters were very close to the reference values with <5 nm accuracy and <0.1 nm repeatability. [ABSTRACT FROM AUTHOR]

Abstract: The purpose of this study was to examine the effects of perceived efficacy, perceived risk, communication quality, and trust on social acceptance of nuclear power plants (NPPs) in South Korea. The results of this study indicated that perceived efficacy was most strongly related to social acceptance of NPPs. In addition, communication quality and trust mediated relationships among perceived efficacy, perceived risk, and social acceptance of NPPs. These results also provided practical implications for managing risk communication in South Korea. [Copyright &y& Elsevier]

[Display omitted] • Solids flow rate in riser exit F s depended on riser solids amount M s. • F s depended on elutriation rate constant. • F s for circulating fluidized bed is similar with that for batch riser. • F s decreased with increasing riser diameter D. • M s increased with D. This study was conducted to provide improved relationships on the external solids circulation rate and solids inventory in the riser of the circulating fluidized bed (CFB) through increasing the basic understanding on how the solids flow rate in the riser exit establishes. The relation between the solids inventory in the riser and the solids flow rate in the riser exit was investigated in batch elutriation and CFBs, using air as fluidizing gas at atmospheric pressure and temperature. A batchwise riser (0.1 m-i.d., 2.75 m-height) and the riser of a CFB system (0.1 m-i.d., 2.5 m-height) were used to measure the relation for different gas velocities (1.5–2.4 m/s) and groups of solids (0.064–0.201 mm in diameter, 2045–4080 kg/m3 in apparent density). The batch elutriation indicated that the amount of solids inventory in the riser determined the solids flow rate in the riser exit, increasing with the amount of the solids inventory in the riser. The solids flow rate in the exit of the riser strongly depended on the elutriation rate constant combined with the amount of the solids inventory in the riser. When the riser was same in size, the relationship on the solids flow rate in the riser exit, derived in the batch elutriation, was valid in the CFB. Relationships on the external solids circulation rate and solids inventory in the riser of the CFB were proposed based on the data from this study and the literature. It was found that the external solids circulation rate per cross-sectional area of the riser decreased with increasing the riser diameter, however, the static bed height of solids in the riser (h st,c) increased with the riser diameter. The dependency of h st,c on riser diameter was greater in the fast bed than in the bed of pneumatic conveying. [ABSTRACT FROM AUTHOR]

This paper proposed a sustainable strategy for converting plastic waste into energy over pyrolysis to address the dual crises of environment and energy. A fluidized-bed reactor was designed for processing three different plastic waste (PP, LDPE and ABS). A product yield and properties from a fluidized bed system were comprehensively analyzed and compared with those from a fixed-bed system. The fluidized-bed reactor well converted ABS and PP wastes into pyrolysis fuel, exhibiting higher medium and low fraction (C 5 ∼ C 22 of 89.17 % for ABS) as compared to the amount from a fixed bed reactor (84.7 %) whereas LDPE and PP resulted in the similar product yields in the range of C 5 ∼ C 22 from both reactors. In case of LDPE, the given pyrolysis temperature (520 °C) was not feasible to properly process them into fuels so that dominant heavy oil (∼67.4 %) were produced regardless of the reactor type. GCMS analysis indicated that ABS pyrolysis oil is mainly composed of aromatics, aromatic-N and olefins whereas PP pyrolysis oil mainly includes olefins, paraffins and oxygenated compounds. From the current study, a potential use of a fluidized-bed reactor for pyrolysis was evaluated to overcome the major limitations of conventional pyrolysis process. [Display omitted] • Pyrolysis with fluidized bed and fixed bed reactors were carried out for plastic waste. • Fluidized-bed reactor produces 26–38 % more light chemicals (C5–C10) than fixed-bed. • LDPE requires severer pyrolysis conditions (>520 °C) for a complete pyrolysis reaction. • ABS oil is mainly composed of aromatics (72 %) whereas PP includes paraffins and olefins. • Fluidized-bed reactor enhances C1–C2 gas yield (8.6–38.1 % more) over fixed-bed. [ABSTRACT FROM AUTHOR]

Phase measuring deflectometry has been applied for free-form specular surface metrology, but its measured slope results are sensitive to the depth of sample positioning, which is also called the height-slope ambiguity. The objective of this work is to tackle this height-slope ambiguity problem. The main idea is to introduce collimated camera rays using a telecentric imaging lens and collimated structured-light illumination with a Fourier lens. This setup makes the fringe phases become only sensitive to the surface slopes and insensitive to the depth of the sample positioning. In this way, the slope calculation is theoretically independent of the sample depth. We call this new deflectometry technique Collimated Phase Measuring Deflectometry (CPMD). With our developed CPMD experimental setup, the measurement is insensitive to the depth of sample positioning, e.g. , the measured height dispersion is less than 30 nm RMS within a 10 mm depth range when measuring a 50-mm-diameter spherical mirror with a 200 mm radius of curvature. The merits and limitations of the proposed CPMD technique are discussed, revealing its prospects in practical metrology applications and potential future investigations. • We proposed Collimated Phase Measuring Deflectometry (CPMD) for optical metrology. • The CPMD theoretically eliminates the height-slope ambiguity in deflectometry. • Collimated camera rays and illuminations relax the tolerance for sample positioning. • This feature opens new potential metrology applications by using CPMD. • It allows for more practical measurements, such as the inspection of freeform optics. [ABSTRACT FROM AUTHOR]

The drag reduction of commercial vehicles is the principal challenge to improving fuel saving and decreasing air pollution. Accordingly, several flow control devices, including gap fairing, cab roof fairing, boat tail, and side skirt were introduced to reduce the aerodynamic drag exerted on heavy vehicles. Although such devices have exhibited good drag reduction performance, their aerodynamic performance can be improved further. Moreover, a comprehensive and systematic research is required, including drag force measurement, flow field analysis and real-scale proving ground test, to evaluate the fuel consumption of heavy vehicles. In this study, the drag reduction effect of the aero full package (AFP) of a tractor–trailer, which integrated gap fairing, flap-type side skirt and lower inclined air deflector boat tail, was investigated through wind tunnel experiments and proving ground test. On the basis of the results of drag and PIV measurement, the integrated AFP was found to significantly modify the flow structure around the vehicle, thereby leading to a 26.5% reduction in drag coefficient compared with the reference tractor-trailer model (C D = 0.693). Furthermore, the proving ground test using real tractor–trailer verified that the integrated AFP provides 13.4% fuel saving. The present results will provide practical information for improving the aerodynamic performance and fuel efficiency of heavy vehicles. • The aero full package for tractor-trailer consist of gap fairing, flap-type side skirt and LIAD boat tail was newly proposed. • The aero full package reduces drag coefficient up to 26.5% compared with reference tractor-trailer. • The flow structures around tractor-trailer model is revealed through PIV experiments. • Real-scale proving ground test confirmed 13.4% fuel saving with the aero full package. [ABSTRACT FROM AUTHOR]

• A functionalized magnetic nanocomposites-based nanoabrasive has been prepared via a simple and modified hydrothermal route. • The polishing performance of the nanoabrasive is investigated at different pH of the slurry and at different polishing time. • BK-7 and Fused silica glasses have been explored for the polishing using the developed nanoabrasive-based slurry. • The reduced surface roughness (Ra) are noted as 2 Å and 1 Å for BK-7 and Fused silica glasses, respectively. • The superparamagnetic nature of the nanocomposites made the prepared nanoabrasives recyclable and reusable for polishing. Optical instruments such as X-ray optics, high-power laser systems, synchrotron beamlines, lithography, and laser-based sensors, require a superfine optical surface to meet their tight optical performance tolerances. This study describes the development of a nanocomposite-based nanoabrasive that can provide a superfinish optical surface via optical polishing. The Malic acid as an organic surface modifier is functionalized with the superparamagnetic iron oxide nanoparticles (SPION). Strong chemical attachment between SPION nanoparticles and the Malic acid is verified through fourier transform infrared spectroscopy. A significant enhancement in the surface area and zeta potential value of SPION nanoparticles is observed when it is functionalized with the Malic Acid. The particle size distribution of the functionalized nanoabrasive is also narrowed down to 8–26 nm. The polishing performance of the functionalized SPION nanoabrasive has been investigated on the BK7 and Fused Silica glasses for precision optical polishing. The polishing results showed superfine surface finishing of the BK7 glass and the Fused silica glass down to the Ra value of 0.23 nm and 0.1 nm, respectively. [ABSTRACT FROM AUTHOR]

Attrition rate versus static bed height. [Display omitted] • The rate of attrition (RA) by bubbles related with RA by gas jets. • An equation on top size of particles (TSP) formed by attrition was proposed. • Bed heights existed for minimum RA and TSP formed by attrition. Particle attrition induced by bubbles in a bubbling fluidized bed was investigated with CO 2 adsorbent particles (0.128 mm in diameter, 1770 kg/m3 in apparent density). The theoretical relationship between the rate of attrition by gas jets on the perforated plate distributor (R a,j) and the rate of attrition by bubbles (R a,b) in the bed was revealed that the rate constant of attrition by bubbles (K a,b) was the product of the rate constant of attrition by gas jets (C a) and dimensionless particle diameter (d pbc). An attrition tube (0.035 m-i.d.) using the perforated-plate distributor designed for reducing the attrition by gas jets was employed as the fluidized bed, and the air as the fluidizing gas. The mode of attrition by bubbles was identified as abrasion. The rate of attrition by bubbles (R a,b) was linearly proportional to the power given to the bed solids by bubbles. The top size of the fine particles formed by attrition (d pm,ab) increased exponentially with an increase of bed mass and gas velocity. The effects of temperature, pressure, and area of internal surface contacting particle bed on the R a,b and d pm,ab were negligible under the tested condition. Empirical relationships on R a,b and d pm,ab were proposed based on the experimental data. When both jet and bubble attrition were significant, there existed the static bed heights that gave respectively the minimum attrition rate and the minimum of the top size of fine particles formed by attrition. Each optimal static bed heights increased with an increase of the orifice jet velocity of the perforated plate distributor. [ABSTRACT FROM AUTHOR]

Highlights: [•] Crisis research, especially as related to strategy or management, began to appear with more frequency in the 90s in Public Relations Review (PRR) and 2000s in Journal of Public Relations Research (JPRR). [•] Relationship research was strong from the 1970s through the 2000s in PRR and became a focus in JPRR in the 2000s. [•] Globalization was the focus of research in the 1990s and 2000s in PRR. [•] Theory has dominated in JPRR throughout the journal's history. [•] PRR seems to often play the role of setting the research agenda, which transfers to JPRR in subsequent time periods. [ABSTRACT FROM AUTHOR]