In this paper, the consensus tracking control problem of second-order multiagent systems with unknown nonlinear dynamics, immeasurable states, and disturbances is investigated. The nonlinear dynamics ...in multiagent systems do not satisfy the matched condition. In this paper, fuzzy logic system is introduced to approximate the unknown nonlinear dynamics, and adaptive high-gain observer is designed to estimate the unmeasured states. Based on backstepping approach and Lyapunov theory, a new adaptive fuzzy distributed controller is proposed for each agent only using the information of itself and its neighbors. Then the consensus tracking is achieved under the designed distributed controller. Moreover, it is proved that all the signals in the multiagent systems are semiglobally uniformly ultimately bounded, and the consensus tracking error converges to a small neighborhood of the origin that can be designed as small as possible. Finally, the simulation result illustrates the effectiveness of the designed controller.
CO2 sequestration by the aqueous carbonation of steel-making slag under various operational conditions was investigated in this study. The effects of the operational conditions, including type of ...steel-making slag, reaction time, reaction temperature, and CO2 flow rate, on the performance of the carbonation process were evaluated. The results indicated that the BOF slag had the highest carbonation conversion, approximately 72%, at a reaction time of 1h, an operating pressure of 101kPa and a temperature of 60°C due to its higher BET surface area of BOF slag compared to UF, FA, and BHC slags. The major factors affecting the carbonation conversion are reaction time and temperature. The reaction kinetics of the carbonation conversion can be expressed by the shrinking-core model. The measurements of the carbonated material by the SEM and XRD instruments provide evidence indicating the suitability of using the shrinking-core model in this investigation. Comparison of the results with other studies suggests that aqueous carbonation by slurry reactor is viable due to its higher mass transfer rate.
Carbon dioxide (CO₂) sequestration experiments using the accelerated carbonation of three types of steelmaking slags, i.e., ultra-fine (UF) slag, fly-ash (FA) slag, and blended hydraulic slag cement ...(BHC), were performed in an autoclave reactor. The effects of reaction time, liquid-to-solid ratio (L/S), temperature, CO₂ pressure, and initial pH on CO₂ sequestration were evaluated. Two different CO₂ pressures were chosen: the normal condition (700psig) and the supercritical condition (1300psig). The carbonation conversion was determined quantitatively by using thermo-gravimetric analysis (TGA). The major factors that affected the conversion were reaction time (5min to 12h) and temperature (40–160°C). The BHC was found to have the highest carbonation conversion of approximately 68%, corresponding to a capacity of 0.283kgCO₂/kgBHC, in 12h at 700psig and 160°C. In addition, the carbonation products were confirmed to be mainly in CaCO₃, which was determined by using scanning electron microscopy (SEM) and X-ray powder diffraction (XRD) to analyze samples before and after carbonation. Furthermore, reaction kinetics were expressed with a surface coverage model, and the carbon footprint of the developed technology in this investigation was calculated by a life cycle assessment (LCA).
Although there is anecdotal evidence of ageism occurring at both the structural level (in which societal institutions reinforce systematic bias against older persons) and individual level (in which ...older persons take in the negative views of aging of their culture), previous systematic reviews have not examined how both levels simultaneously influence health. Thus, the impact of ageism may be underestimated. We hypothesized that a comprehensive systematic review would reveal that these ageism levels adversely impact the health of older persons across geography, health outcomes, and time.
A literature search was performed using 14 databases with no restrictions on region, language, and publication type. The systematic search yielded 13,691 papers for screening, 638 for full review, and 422 studies for analyses. Sensitivity analyses that adjusted for sample size and study quality were conducted using standardized tools. The study protocol is registered (PROSPERO CRD42018090857).
Ageism led to significantly worse health outcomes in 95.5% of the studies and 74.0% of the 1,159 ageism-health associations examined. The studies reported ageism effects in all 45 countries, 11 health domains, and 25 years studied, with the prevalence of significant findings increasing over time (p < .0001). A greater prevalence of significant ageism-health findings was found in less-developed countries than more-developed countries (p = .0002). Older persons who were less educated were particularly likely to experience adverse health effects of ageism. Evidence of ageism was found across the age, sex, and race/ethnicity of the targeters (i.e., persons perpetrating ageism).
The current analysis which included over 7 million participants is the most comprehensive review of health consequences of ageism to date. Considering that the analysis revealed that the detrimental impact of ageism on older persons' health has been occurring simultaneously at the structural and individual level in five continents, our systematic review demonstrates the pernicious reach of ageism.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
2D transition metal carbides and nitrides, named MXenes, are attracting increasing attentions and showing competitive performance in energy storage devices including electrochemical capacitors, ...lithium‐ and sodium‐ion batteries, and lithium–sulfur batteries. However, similar to other 2D materials, MXene nanosheets are inclined to stack together, limiting the device performance. In order to fully utilize MXenes' electrochemical energy storage capability, here, processing of 2D MXene flakes into hollow spheres and 3D architectures via a template method is reported. The MXene hollow spheres are stable and can be easily dispersed in solvents such as water and ethanol, demonstrating their potential applications in environmental and biomedical fields as well. The 3D macroporous MXene films are free‐standing, flexible, and highly conductive due to good contacts between spheres and metallic conductivity of MXenes. When used as anodes for sodium‐ion storage, these 3D MXene films exhibit much improved performances compared to multilayer MXenes and MXene/carbon nanotube hybrid architectures in terms of capacity, rate capability, and cycling stability. This work demonstrates the importance of MXene electrode architecture on the electrochemical performance and can guide future work on designing high‐performance MXene‐based materials for energy storage, catalysis, environmental, and biomedical applications.
Hollow Ti3C2Tx spheres and 3D macroporous MXene films are fabricated using a sacrificial template approach. The 3D MXene films are free‐standing, flexible, and highly conductive. They can serve directly as electrodes for Na‐ion storage and exhibit high capacities accompanied with excellent stabilities and rate performance.
This Colloquium describes a new paradigm for creating strong quantum interactions of light and matter by way of single atoms and photons in nanoscopic lattices. Beyond the possibilities for ...quantitative improvements for familiar phenomena in atomic physics and quantum optics, there is a growing research community that is exploring novel quantum phases and phenomena that arise from atom-photon interactions in one- and two-dimensional nanophotonic lattices. Nanophotonic structures offer the intriguing possibility to control atom-photon interactions by engineering the medium properties through which they interact. An important aspect of these new research lines is that they have become possible only by pushing the state-of-the-art capabilities in nanophotonic device fabrication and by the integration of these capabilities into the realm of ultracold atoms. This Colloquium attempts to inform a broad physics community of the emerging opportunities in this new field on both theoretical and experimental fronts. The research is inherently multidisciplinary, spanning the fields of nanophotonics, atomic physics, quantum optics, and condensed matter physics.
To simultaneously solve the dilemma of energy demand, waste management, and greenhouse gas emission for communities globally, the waste-to-energy (WTE) supply chain as district energy system should ...be a viable method towards circular industrial economy. Several essential state-of-the-art WTE technologies including combustion, gasification and anaerobic digestion were evaluated. Portfolio options of technologies for different types of WTE supply chains were illustrated for achieving circular economy system. Since policy makers have to address the public concerns prior to promulgate and implement relating regulations, the strategies on implementation of WTE supply chain were proposed to overcome the challenging barriers from the aspects of technology, finance, institution and regulation. A total of eight key task-forces were also proposed for effectively executing the strategies. Furthermore, several successful lessons on WTE supply chains such as green fuel pellet for heating supply and co-digestion of organic wastes for bio-gas production around the world were reviewed and illustrated.
•Essential WTE technologies for applying in industry were reviewed and illustrated.•Portfolio options of WTE technologies were illustrated for circular economy system.•Challenging barriers for building WTE supply chain around the world were reviewed.•Integrated policies and strategies for establishing WTE supply chain were proposed.•Successful business models of WTE supply chains around the world were evaluated.
This study aims to explore the current status, potential applications, and future directions of blockchain technology in supply chain management. A literature survey, along with an analytical review, ...of blockchain-based supply chain research was conducted to better understand the trajectory of related research and shed light on the benefits, issues, and challenges in the blockchain-supply-chain paradigm. A selected corpus comprising 106 review articles was analyzed to provide an overview of the use of blockchain and smart contracts in supply chain management. The diverse industrial applications of these technologies in various sectors have increasingly received attention by researchers, engineers, and practitioners. Four major issues: traceability and transparency, stakeholder involvement and collaboration, supply chain integration and digitalization, and common frameworks on blockchain-based platforms, are critical for future orientation. Traditional supply chain activities involve several intermediaries, trust, and performance issues. The potential of blockchain can be leveraged to disrupt supply chain operations for better performance, distributed governance, and process automation. This study contributes to the comprehension of blockchain applications in supply chain management and provides a blueprint for these applications from the perspective of literature analysis. Future efforts regarding technical adoption/diffusion, block-supply chain integration, and their social impacts were highlighted to enrich the research scope.
•Kinetics of BOFS carbonation reaction was well expressed by surface coverage model.•The model was validated by SEM images which indicate the BOFS was covered by CaCO3.•Carbonation conversion of BOFS ...with CRW was higher than that in pure-water system.•Reaction rate in RPB was greater than that in both autoclave and slurry reactors.•The maximum conversion was determined by kinetic model and response surface method.
The reaction kinetics of carbon dioxide (CO2) capture by the accelerated carbonation of basic oxygen furnace slag (BOFS) in a rotating packed bed (RPB) was evaluated using the surface coverage model. Experimental data were utilized to determine the reaction rate constants and maximum carbonation conversion of BOFS based on the surface coverage model. The results indicate that the carbonation of BOFS in an RPB can be well-expressed by the surface coverage model, with R2 values from 0.98 to 0.99. In addition, the results of reaction kinetics could be validated by observation of SEM and XEDS before and after carbonation, which indicates that the reacted BOFS was surrounded by the CaCO3 product. On the other hand, the reaction kinetics of steelmaking slag in an RPB was compared with that in various types of reactors, i.e., autoclave and slurry reactors. The overall rate of carbonation in an RPB (i.e., 0.299min−1) was greater than that in both a slurry reactor (i.e., 0.227min−1) and an autoclave reactor (i.e., 0.033min−1). Furthermore, the maximum carbonation conversion of BOFS was initially determined by the results of the surface coverage model and then confirmed statistically by the response surface methodology (RSM). It was thus concluded that accelerated carbonation of BOFS in the RPB is a viable method due to its faster reaction kinetics under relatively milder reaction conditions. Accelerated carbonation of BOFS in the RPB is a promising process for CO2 capture due to its relatively higher carbonation conversion of BOFS within a shorter reaction time.
PDF
