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Insight into the thermodynamic model for reforming of methane over nickel catalyst
Get PDFThe reforming of light hydrocarbons to produce synthesis gas, H2 and CO, is an important intermediate for manufacturing valuable basic chemicals and synthesis fuels. In order to understand these reforming processes better, elementary step reaction mechanisms are developed. In the available literature, the surface reaction mechanisms are usually achieved with the help of reaction kinetic parameters without using the thermochemistry of the species referred to kinetic models due to the unavailability of the thermochemistry of the intermediate species involved in the multi-step reaction mechanism. In this work, investigations are made to obtain the thermochemistry of the intermediate species to establish thermodynamic equilibrium in order to develop thermodynamic model for steam reforming of methane over nickel. The thermochemistry of the surface bound species is taken from different sources available in the literature and after that a detailed sensitivity analysis is performed to match the results with experiments. The simulation set up is adapted from the literature experiments given in [1]. The results produced with the one-dimensional tool using the thermodynamic model developed in the present investigation consisting of 21 reversible reactions are compared with the kinetic scheme with 42 irreversible reactions from reference simulation along with their experimental results. Both the models show some major differences in the reaction pathways which provides a useful insight into the key rate determining steps and needs further investigations
Simulation of distribution system for low temperature district heating in future urban areas – Case study of a planned city district in Gävle
Get PDFIn Europe, the prices of natural gas and electricity reached an all-time high in 2022. A way to mitigate high electricity costs is to expand district heating systems in urban areas, this will reduce electric load as well as increase the power generation possibilities in combined heat and power plants. District heating has been the dominant heat supply technology in urban areas in Sweden since the 1980s. However, as the energy efficiency in buildings increase, district heating distribution losses must be reduced to ensure a cost-efficient heat supply. This has led to the idea of the 4th generation district heating which is characterized by low distribution temperatures. In this study, low-temperature district heating distribution in a planned future city district is simulated using a Python-based tool. Two different low-temperature distribution systems are investigated: 1) 2-pipe low-temperature system, and 2) a cascading 3-pipe low-temperature system. The focus is on simulating the distribution losses, temperature drop, and mass flow in the pipe network. The scope of the analysis also includes an investigation of the effect of lower return temperatures on the central district heating network. The results indicate that the low-temperature distribution system with the 2-pipe system performs better than the cascading system when considering distribution losses and temperature drop. The mass flow depends on the temperature demand in the heating systems in the buildings and is considerably high for both low-temperature distribution systems investigated
Thermodynamics analysis of a novel compressed air energy storage (CAES) system combined with SOFC-MGT and using low grade waste heat as heat source
Get PDFAs modern societies face increasing energy demands and a complex smart grid with multiple inputs of traditional and intermittent renewable energy power generation systems, the need for energy storage systems has become a general trend. Among these systems, compressed air energy storage (CAES) has received extensive attention due to its low cost and high efficiency. This study proposes a novel design framework for a hybrid energy system comprised of CAES system, gas turbine, and high-temperature solid oxide fuel cells, aiming for power generation and energy storage solutions. The overall model of the hybrid power generation system was constructed in Aspen Plus, and the mass balance, energy balance, and thermodynamic properties of the thermal system were simulated and analyzed. The results demonstrate that the hybrid system utilizes the functional complementarity of CAES and solid oxide fuel cells (SOFC), resulting in the cascade utilization of energy, flexible operation mode and increased efficiency. The overall round trip efficiency of the system is 63%, and the overall exergy efficiency is 67%, with a design net power output of 12.5 MW. Additionally, thermodynamic analysis shows that it is advisable to operate the system under higher compressor and turbine isentropic efficiencies, and optimal SOFC/MGT (Micro Gas Turbine) split air flow rates. The results of this article provide guidance for designing innovative hybrid systems and system optimization
Virtuell Simulering för kvalitetssäkring av träning för befäl inom räddningstjänsten
No full textIntresse och behov för att kvalitetssäkra träning av befäl inom räddningstjänst ökar. Idag finns inget krav på certifiering av befäl i Sverige, så som i t.ex. i Storbritannien och Estland, men räddningstjänster uttrycket behov av att systematisera, genomföra och dokumentera befälsträning. Utgångspunkten ligger på att vidareutveckla träningen, fokusera mer explicit på lärandet och utvecklande av feedback, snarare än att ge kritisk bedömning.
Befälsträning innebär uppbyggnad av, såväl tekniska som icke-tekniska färdigheter, så som situationsuppfattning, riskbedömning, förutseendet av händelseförlopp, kommunikation och ledarskap, vilket kräver att den tränande kan agera i hela, realistiska och dynamiska händelser. Att diskutera eller spela rollspel i händelser illustrerade med foton, video eller animationer, används för träning, medan praktiska övningar på fysiska övningsfält ofta ansetts som det mest realistiska övningsformatet. Sådana övningar är resurskrävande och därmed begränsade till antal, men också begränsade utifrån säkerhets- och miljöaspekter, samt variation av övningsobjekt. Ofta används containrar och betonghus som ska representera olika objekt i olika scenarion. En byggnad kan t.ex. representera en mekanisk verkstad på förmiddagen och ett hotell på eftermiddagen, utan att visuellt kunna representera någondera. Bränder är kontrollerade och bränslet begränsat. Dessa förutsättningar påverkar möjligheterna till att visualisera kritiska skadeplatsfaktorer och skapa dynamik i scenarion, vilket i sin tur påverkar befälsträning.
Virtuell simulering möjliggör idag lösningar till ovan nämnda begränsningar för befälsträning, där personer kan agera i befälsrollen fullt ut och t.ex. uppleva konsekvenser av beslut. Många personer kan tränas, resurseffektivt, med samma förutsättningar (scenario, problematik etc.). Det ger möjlighet att kvalitetssäkra träningen och att skapa ett kvalitetssäkringssystem för befäl.
Denna presentation delar erfarenheter från en studie genomförd under införandet av virtuell simulering för kvalitetssäkring av styrkeledare och insatsledare i Nerikes Brandkår under 2021-2022, där såväl virtuell simulering med motspel genomförts och utvärderats, men där också ett system för kvalitetssäkring av befäl testats. Syftet med presentationen är att visa konkreta exempel på utmaningar och möjligheter för kvalitetssäkring av räddningstjänstpersonal i olika ledningsroller, genom att använda virtuell simulering och ett forskningsbaserat kvalitetssäkringssystem
Stoppa blödningen
No full textStop the Bleed är ett utbildnings- och forskningsinitiativ som lanserades av Vita huset och inrikesdepartementet (DHS) i USA under Obama-administrationen 2015. Som svar på bland annat skolskjutningar har Stop the Bleed arbetat för att öka samhällets resiliens vid livshotande blödningar. Lekmän som gått Stop the Bleed-utbildning i USA kan i dag räknas i miljoner. Katastrofmedicinskt centrum (KMC) har på uppdrag av Myndigheten för samhällsskydd och beredskap (MSB) tagit initiativet till Sverige, och utvecklat ett utbildningskoncept anpassat till svenska förhållanden. Stoppa blödningen bygger på train the trainer-principen – huvudinstruktörer erhåller kunskaper och färdigheter inom ett ämnesområde, och utbildar instruktörer. Dessa kan sedan föra kunskaper vidare genom användarutbildningar. I dag erbjuds huvudinstruktörs- och användarutbildningar på KMC. Den första huvudinstruktörsutbildningen genomfördes i januari 2020, då 16 kursdeltagare från bland annat Röda korset och MSB deltog. Fram till mars 2023 har 100 huvudinstruktörer utbildats i KMC:s regi. Användarutbildningar har hållits runt om i landet sedan lansering av Stoppa blödningen, och huvudinstruktörer och intstruktlrer som sprider utbildningen vidare återfinns brett inom räddningstjänst och ambulans, och bland annat inom olika myndigheter och civilförsvarsförbundet.
Andra initiativ med utbildning riktad till allmänheten inom första hjälpen och blödningskontroll finns t.ex. i Norge, Israel, Storbritannien och USA. Norska Helsedirektoratets nationella första hjälpen-strategi ”Sammen redder vi liv” strävar efter att första hjälpen-utbildning och träning ska ingå i ett livslångt lärande för alla i Norge. Israeliska MDA ger kursen ”First seven minutes” som förbereder civila på masskadehändelser, och vad man kan göra för att rädda liv under de allra första minuterna efter en händelse. I Storbritannien finns initiativet ”Citizen Aid”, där allmänheten kan ladda ner en app som ger instruktioner och råd vid olika typer av händelser, t.ex. knivattack. Den senaste utvecklingen av Stop the Bleed-initiativet i USA är FAST-utbildningen som amerikanska Röda korset erbjuder; FAST står för First Aid in Severe Trauma och riktar sig till alla, men speciellt skolelever. Kursen erbjuds kostnadsfritt till gymnasielärare och elever under 19 år. Nästa steg i utvecklingen av Stoppa blödningen är en bredare implementering för att höja svenska samhällets beredskap när det kommer till att agera vid livshotande blödning.
 
Professionalism & Leadership Development in Ice Hockey: Understanding Social Emotional Learning Experiences of Coaches in Atlantic Canada
Get PDFThis qualitative research study investigated the Social Emotional Learning training experiences of ice hockey coaches in Atlantic Canada. Social Emotional Learning (SEL) and leadership in sport is an emergent field which has been gaining attention on a national level. The purpose of this study was to examine various aspects of SEL within coaching leadership training of Canadian ice hockey coaches in Atlantic Canada. Minor hockey coaches (n=8) were recruited to participate in semi-structured interviews. Five questions pertaining to hockey coaching background, leadership training, communication, and SEL training experiences were posed to participants. Interviews were offered both in person or virtually as an option for convenience. Analysis of data suggested that clear expectations and effective communication with players and guardians were valuable aspects for relationship building. Limited professional development opportunities surrounding aspects of SEL were noted by participants, training provided was outdated in certain aspects, and current topics of inclusion, diversity, and culture. Future recommendations for continued study within the field of SEL within ice hockey are offered
The History and Future of Fluid Power Pumps and Motors
Get PDFPositive displacement pumps have been around for thousands of years, but it was first in the beginning of the 19th century they started to be used for power transmission purposes. At that time, the fluid was water, and the applications were primarily presses. During the century, the technology developed and towards its end, fluid power systems were used to transmit power to hundreds or even thousands of consumers within several cities. However, in the 20th century, these large-scale fluid power transmission systems were outcompeted by the electric grid. But at the same time, the focus for fluid power was shifted towards self-contained, oil-based systems, which were suitable in many mobile applications powered by combustion engines. Once again, fluid power systems are now undergoing a transition. This especially apply to mobile applications, where combustion engines are being replaced by electric motors. This puts new requirements on the hydraulic systems as well as the pumps and motors that are to be used. Electrification means increased focus on energy efficiency, and speed-control becomes more relevant than before. New system designs are therefore highly relevant. Depending on the architecture that is chosen, different requirements will be set on the pumps and motors. Aspects such as multi-mode operation, high- and low-speed performance, and displacement control will be discussed in this paper
Aerial View Localization with Reinforcement Learning: Towards Emulating Search-and-Rescue
Get PDFClimate-induced disasters are and will continue to be on the rise, and thus search-and-rescue (SAR) operations, where the task is to localize and assist one or several people who are missing, become increasingly relevant. In many cases the rough location may be known and a UAV can be deployed to explore a given, confined area to precisely localize the missing people. Due to time and battery constraints it is often critical that localization is performed as efficiently as possible. In this work we approach this type of problem by abstracting it as an aerial view goal localization task in a framework that emulates a SAR-like setup without requiring access to actual UAVs. In this framework, an agent operates on top of an aerial image (proxy for a search area) and is tasked with localizing a goal that is described in terms of visual cues. To further mimic the situation on an actual UAV, the agent is not able to observe the search area in its entirety, not even at low resolution, and thus it has to operate solely based on partial glimpses when navigating towards the goal. To tackle this task, we propose AiRLoc, a reinforcement learning (RL)-based model that decouples exploration (searching for distant goals) and exploitation (localizing nearby goals). Extensive evaluations show that AiRLoc outperforms heuristic search methods as well as alternative learnable approaches, and that it generalizes across datasets, e.g. to disaster-hit areas without seeing a single disaster scenario during training. We also conduct a proof-of-concept study which indicates that the learnable methods outperform humans on average. Code and models have been made publicly available at https://github.com/aleksispi/airloc
Service design as a practice of freedom in collaborative cultural producers
Get PDFService design is strongly linked to practices that maintain workers' dependency on management. Social movements in Brazil eschew hierarchical management, instead seeking self-management based on solidarity, equality, and democracy. In recent years, social movements appropriated digital infrastructures to design and deliver collaborative services. This paper hypothesizes that this could be considered designing services as a practice of freedom. The hypothesis is explored through a descriptive study of the self-management practices of a particular collective associated with the Brazilian Digital Culture movement
An overview of Service Design education in Latin America
Get PDFDespite services being the largest component of the world economy, their importance may still not be recognized in regions such as Latin America. Therefore, this contribution presents exploratory research informed by the steps of a systematic literature review to collect, organise, and analyse educational offerings in Service Design, including graduate and specialisation levels, thematic areas, and specific courses offered under these programs in Latin America. The research results reveal that only eleven institutions ranked as the best in Latin America have Service Design offerings at the aforementioned levels. The findings indicate a lack of educational offerings in Service Design in Latin America