The potential for electrical energy storage to both provide services to the electrical grid and help to better integrate renewable energies in the electrical system is promising. This report investigates one type of storage, compressed air energy storage (CAES), where energy is stored by compressing air during hours of low electricity demand and later expanding the air to generate electricity during high demand hours. To this day it exists two large plants, but small facilities have yet to be implemented, raising the question whether it could be viable to use CAES on a smaller scale as well. By creating a model of a CAES system based on the principles of thermodynamics and applying it to a hypothetical group of residences, its ability to balance daily fluctuations in electricity demand is explored. The result show that the system is able to cover some of the demand but there is no economic profit to be gained. The results of this report suggest that a CAES system of this size is not a viable option during current price market for electricity in Sweden but during other circumstances it could be relevant. / Dagens energisystem kräver vissa tjänster för att kunna behålla stabilitet och tillgodose energibehovet. Energilagring är ett sätt att förse systemet med dessa tjänster samtidigt som det också skapar möjlighet att bättre utnyttja förnyelsebara energiresurser, som vind och sol, som annars kan vara för oförutsägbara för att kunna utnyttjas maximalt. I denna studie undersöks komprimerad luft som energilagring (CAES). Sammanfattningsvis används billig elektricitet under timmar då elförbrukningen är låg för att komprimera luft och lagra denna för att sedan expandera luften igen och på så vis generera elektricitet vid behov eller då det finns ekonomisk vinstmöjlighet. CAES systemet kan vara uppbyggt och dimensionerat på flera olika sätt vilket undersöks samt beskrivs i närmare detalj. Möjligheten att använda CAES i liten skala för att tillgodose ett dagligen varierande energibehov undersöks och det utrönas ifall detta är ekonomiskt gynnsamt eller inte. Detta undersöks genom att skapa en modell över ett CAES-system som appliceras på energibehovet för en grupp bostäder. Resultatet visar att systemet kan täcka en del av energibehovet men ekonomisk vinning är inte möjligt. Utifrån dessa resultat konstateras att CAES i liten skala inte är ett ekonomiskt försvarbart alternativ för att täcka toppar i ett varierande energibehov vid det rådande energipriset i Sverige men under andra omständigheter skulle det kunna vara möjligt.

An urgent transformation from fossil fuels to cleaner energy sources to combat climate change has led to the utilization of renewable energies like solar, wind, and tidal power. However, the intermittency of these sources hinders their wider implementation. To address this, large-scale electrical energy storage (EES) systems are needed. These systems store excess energy during periods of surplus and release it during peak demand, enhancing grid reliability. Secondary batteries have been developed as promising EES solutions due to their reliability, independence from weather, and ease of maintenance. While lithium-ion batteries (LIBs) are popular as secondary batteries, their limited lithium supply, and rising costs demand for cost-effective alternatives. This study focuses on developing sodium iron fluorophosphate (Na2FePO4F) as a promising cathode material for SIBs. Because of its iron-based composition, which is generated from sustainable sources, Na2FePO4F offers a potential solution to the cost and supply difficulties related with LIBs. However, challenges exist, including low electronic conductivity and inferior electrochemical performance. To address these challenges, this research explores mechanochemically assisted solid-state synthesis routes as a low-cost and environmentally friendly approach. The characterization and performance evaluation of Na2FePO4F (NFPF) and NFPF/C positive electrode materials for sodium-ion batteries (SIBs) were systematically investigated through a range of analytical techniques, including XRD, TGA, SEM-EDS, FT-IR, and Raman analyses. A single-step solid-state synthesis demonstrates effectiveness in producing NFPF and NFPF/C-positive electrode materials. Moreover, Fe2O3 nanoparticles serve as the primary iron source in the solid-state synthesis of iron-based fluorophosphate Na2FePO4F/C, successfully producing both NFPF pristine phase and NFPF carbon-coated active materials. Finally, a comparison between the two synthesis pathways reveals that the active material from single-step solid-state synthesis exhibits a superior initial discharge specific capacity of 74.24 mAh⋅g−1 at 0.005 C, outperforming the double-step solid-state synthesis. These findings can contribute to the development of affordable and sustainable energy storage solutions, offering alternatives to traditional LIBs. / En akut omvandling från fossila bränslen till renare energikällor för att bekämpa klimatförändringarna har lett till ett utnyttjande av förnybar energi som sol-, vind- och tidvattenkraft. Emellertid hindrar dessa källors intermittenser deras bredare genomförande. För att komma till rätta med detta behövs storskaliga system för lagring av elektrisk energi (EES). Dessa system lagrar överskottsenergi under perioder med överskott och släpper ut den under toppbelastning, vilket förbättrar nätets tillförlitlighet. Sekundära batterier har utvecklats som lovande EES-lösningar på grund av deras tillförlitlighet, väderberoende och enkla underhåll. Medan litiumjonbatterier (LIB) är populära som sekundära batterier, kräver deras begränsade litiumtillgång och stigande kostnader kostnadseffektiva alternativ. Denna studie fokuserar på att utveckla natriumjärnfluorfosfat (Na2FePO4F) som ett lovande katodmaterial för SIB. På grund av sin järnbaserade sammansättning, som genereras från hållbara källor, erbjuder Na2FePO4F en potentiell lösning på kostnads- och försörjningssvårigheter relaterade till LIB. Men det finns utmaningar, inklusive låg elektronisk konduktivitet och sämre elektrokemisk prestanda. För att möta dessa utmaningar undersöker denna forskning mekanokemiskt assisterade syntesvägar i fast tillstånd som ett billigt och miljövänligt tillvägagångssätt. Karakteriseringen och prestandautvärderingen av Na2FePO4F (NFPF) och NFPF/C positiva elektrodmaterial för natriumjonbatterier (SIB) undersöktes systematiskt genom en rad analytiska tekniker, inklusive XRD, TGA, SEM-EDS, FT-IR och Raman analyser. En enstegs solid state-syntes visar effektivitet vid framställning av NFPF och NFPF/C-positiva elektrodmaterial. Dessutom tjänar Fe2O3-nanopartiklar som den primära järnkällan i solid state-syntesen av järnbaserat fluorfosfat Na2FePO4F/C, vilket framgångsrikt producerar både NFPF orörd fas och NFPF kolbelagda aktiva material. Slutligen avslöjar en jämförelse mellan de två syntesvägarna att det aktiva materialet från enstegs-solid-state-syntes uppvisar en överlägsen initial urladdningsspecifik kapacitet på 74,24 mAh⋅g−1 vid 0,005 C, vilket överträffar dubbelstegs-solid-state-syntesen. Dessa resultat kan bidra till utvecklingen av prisvärda och hållbara energilagringslösningar, som erbjuder alternativ till traditionella LIB.

This study explores the application of micro-CCHP systems that utilize a 30 kW gas microturbine and an absorption chiller. Engineering Equation Solver (EES) is used to model a novel single-effect and double-effect water-lithium bromide absorption chiller that integrates the heat recovery unit and cooling tower of a conventional CCHP system into the chiller’s design, reducing the cost and footprint of the system. The results of the EES model are used to perform heat and material balances for the micro-CCHP systems employing the novel integrated chillers, and energy budgets for these systems are developed. While the thermal performance of existing CCHP systems range from 50-70%, the resulting thermal performance of the new systems in this study can double those previously documented. The size of the new system can be significantly reduced to less than one third the size of the existing system.

The purpose of this study was to serve as a starting point in gaining understanding and experience of simulating a typical Pool Type Research Reactor with the thermal hydraulic software code Flownex®. During the study the following evaluations of Flownex® were done: * Assessment of the simplifying assumptions and possible shortcomings built into the software. * Definition of the applicable modelling methodology and further simplifying assumptions that have to be made by the user. * Evaluation of the accuracy and compatibility with the Pool Type Research Reactor. * Comparing the results of this study with similar studies found in the open literature. For the study the IAEA MTR 10 MW benchmark reactor (IAEA, 1992a) was used. A steady state simulation using Flownex® was done on a single fuel assembly, and this was compared with a model that was developed using the software package EES (Engineering Equation Solver). The results have shown good agreement between the different packages. After this verification, a steady state simulation of the entire core was done to obtain the characteristics of the reactor operating under normal condition. Finally, transient simulations were done on various LOFAs (Loss of Flow Accidents). The results of the various LOFAs were compared with studies that were previously done on the IAEA MTR 10 MW reactor. / Thesis (M.Ing. (Nuclear Engineering))--North-West University, Potchefstroom Campus, 2012.

The purpose of this study was to serve as a starting point in gaining understanding and experience of simulating a typical Pool Type Research Reactor with the thermal hydraulic software code Flownex®. During the study the following evaluations of Flownex® were done: * Assessment of the simplifying assumptions and possible shortcomings built into the software. * Definition of the applicable modelling methodology and further simplifying assumptions that have to be made by the user. * Evaluation of the accuracy and compatibility with the Pool Type Research Reactor. * Comparing the results of this study with similar studies found in the open literature. For the study the IAEA MTR 10 MW benchmark reactor (IAEA, 1992a) was used. A steady state simulation using Flownex® was done on a single fuel assembly, and this was compared with a model that was developed using the software package EES (Engineering Equation Solver). The results have shown good agreement between the different packages. After this verification, a steady state simulation of the entire core was done to obtain the characteristics of the reactor operating under normal condition. Finally, transient simulations were done on various LOFAs (Loss of Flow Accidents). The results of the various LOFAs were compared with studies that were previously done on the IAEA MTR 10 MW reactor. / Thesis (M.Ing. (Nuclear Engineering))--North-West University, Potchefstroom Campus, 2012.

Made available in DSpace on 2015-04-11T13:52:44Z (GMT). No. of bitstreams: 1 Dissertacao Luiz Eduardo Nistal Final.pdf: 903691 bytes, checksum: f069c2eae913ceca0fc6d31175805730 (MD5) Previous issue date: 2009-02-20 / FAPEAM - Fundação de Amparo à Pesquisa do Estado do Amazonas / This study assessed the Economic Solidarity Enterprises (ESEs) as an alternative to generate employment and income in the state of Amazonas in the first decade of the XXI century. The research aimed to assess general (and discuss) the attached Economic Enterprises (ESEs) as an alternative to generate employment and income in the state of Amazonas in the first decade of the XXI century. The implementation of this objective is the general response of the following specific objectives: a) Draw the profile of solidarity Economic Enterprises (ESEs) in Brazil b) Draw the profile of solidarity Economic Enterprises (ESEs) in Amazonas, c) evaluate an example of business Economic Solidarity in greater concentration in the city of Amazonas. Defined as a dialectic relationship between the various empirical studies, literature and the exercise of reflection, trying to approach them, and thus seize the object of study, focused on the contribution of the United Economic Enterprises (UEEs) in the generation of employment and income in the city of Manaus, in the first decade of the XXI century. The ESE found in the Amazon are characterized rather as an economic alternative to unemployment imposed by the dynamics of the capitalist system, and is, before the economy, the People's Economy, and allows people to 35,777 jobs, which is important to their welfare, then its development. / Este trabalho avaliou os Empreendimentos Econômicos Solidários (EES) como alternativos na geração de ocupação e renda no Estado do Amazonas na primeira década do século XXI. A pesquisa teve como objetivo geral avaliar (e discutir) os Empreendimentos Econômicos Solidários (EES) como alternativa de geração de ocupação e renda no Estado do Amazonas na primeira década do século XXI. A execução desse objetivo geral passa pela resposta dos seguintes objetivos específicos: a) Traçar o perfil dos Empreendimentos Econômicos Solidários (EES) no Brasil; b) Traçar o perfil dos Empreendimentos Econômicos Solidários (EES) no Amazonas; c) Avaliar um exemplo de Empreendimento Econômico Solidário na cidade de maior concentração no Amazonas. Definido como uma relação dialética entre as diversas investigações empíricas, bibliográfico e o exercício de reflexão, buscando a aproximação entre eles, e assim apreender o objeto de estudo, centrado na contribuição dos Empreendimentos Econômicos Solidário (EES) na geração de ocupação e renda na cidade de Manaus, na primeira década do século XXI. Os EES encontrados no Amazonas se caracterizam sim como alternativa econômica ao desemprego imposta pela dinâmica do sistema capitalista, e pertence, antes da Economia Solidária, à Economia Popular, e possibilita ocupação a 35.777 pessoas, contribuindo ao bem-estar social, portanto, ao desenvolvimento.

This master’s thesis presents an overview of the basic forces acting on the vehicle, the basic methods of analysis of accident, collection of data used in the analysis of accidents, an overview of the basic performance criteria and thresholds used in the homologation test of occupant protection in a frontal impact, used crash tests, homologation tests and specifications for these tests. Attention is paid to Euro NCAP crash tests and to homologation tests of vehicles Skoda Octavia with aim to try to compare them with selected accidents in terms of depth and character deformation and evaluate findings comparision.

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Purpose: Environmental and climate issues are constantly on the agenda. At the climatechange conference in Paris, it was decided that the global average temperature shouldnot increase more than 2°C. This means that the energy consumption must be reduced.With the EU's 2020 targets as a basis, national goals have been set, which means thatSweden will achieve a 20 %increase of the energy efficiency by 2020. The public sectorshould act as a role model, therefore the Swedish Energy Agency was handing out asubsidy between 2010 and 2014 as a contribution to local governments for improvingenergy efficiency in its own organization. The goal of this study is to analyze how theenergy efficiency subsidy has helped municipalities in their work to reduce the energyuse in its real estate, and what remains to do to reach the 2020 target.Method: To reach the goal both a qualitative and quantitative study has been made.The data collection methods was interviews, a document analysis and a literaturereview. A case study has been made together with Herrljunga municipality.Findings: The energy efficiency subsidy has several positive effects. The energy usehas been reduced by 8% between 2009 and 2014 for the whole country and the casestudy object has been reduced by 12%. This can be refer to that the municipality hasprioritized the issue of energy higher. Other positive effects include improved indoorclimate and user behavior and that they have better control over energy consumption.The energy work is proceeding in many municipalities after the subsidy, the work willbe financed with own funds. To achieve the goal they should continue the work thatthey began but also complete it with other actions. This may be, for example: replaceheating- and ventilation systems, train the user group and renovate energy smart.Implications: The study shows that the subsidy has provided a push to energy issuesin the municipalities, the subsidy has resulted in a decreased energy use. After thesubsidy stopped many municipalities continued to work when they have seen thebenefits. The study also shows that it is possible for Sweden's municipalities to achievea reduction of energy use by 20% by 2020 in their real estates. To reach this Swedishmunicipalities needs to continue to work actively with energy issues and make newenergy efficiency measures.Limitations: This study has been limited to the municipality's own real estates. Theresult of the study is not valid for all the municipalities that received the subsidy asindependent but it provides an overview of the outcome of the municipalities together. Every municipality can learn from this report. / Syfte: Miljö- och klimatfrågor är ständigt på agendan, vid klimatmötet i Parisbeslutades att höjningen av jordens medeltemperatur inte får överstiga 2°C. Dettainnebär att energianvändning måste minska. Med EU:s 2020-mål som grund har ettnationellt mål satts upp som innebär att Sverige ska öka energieffektiviteten med 20 %till 2020. Den offentliga sektorn ska agera förebild därför delade Energimyndighetenmellan 2010 och 2014 ut ett bidrag till kommuner och landsting förenergieffektivisering i den egna organisationen. Studiens mål är att undersöka hurEnergieffektiviseringsstödet har hjälpt kommunerna i arbete med att minskaenergianvändningen i sitt fastighetsbestånd samt vad som finns kvar att göra för att nå2020-målet.Metod: För att nå målet har både en kvalitativ och kvantitativ studie utförts.Empiriinsamlingen består av intervjuer, en dokumentanalys och en litteraturstudie. Enfallstudie är gjord tillsammans med Herrljunga kommun.Resultat: Energieffektiviseringsstödet har gett positiva effekter i de kommunalalokalerna. Minskningen av energianvändandet har sjunkit med 8 % mellan 2009-2014för hela landet och fallstudieobjektet har minskat med 12 %. Detta kan hänföras till attden kommunala verksamheten har prioriterat energifrågan högre än innan. Andrapositiva effekter är bättre inomhusklimat och brukarbeteende samt att de fått störrekontroll på energianvändningen. I de flesta kommuner fortlöper energiarbetet efterbidragets slut men med egen finansierade medel. För att nå målet bör man fortsättaarbete som påbörjats men även komplettera det med andra åtgärder. Detta kanexempelvis vara: byta värme- och ventilationssystem, utbilda brukargruppen, renoveraenergismart.Konsekvenser: Studien visar att bidraget har gett ökat fokus till energifrågorna ikommunerna har bidraget lett till en att energiförbrukningen minskat. Efter att bidragetslutade delas ut fortsätter många kommuner med arbetet då man sett vilka vinster detger. Studien visar också att det är möjligt för Sveriges kommuner att nå en minskningav energiförbrukningen med 20 % till 2020 i sitt fastighetsbestånd. För att nå hela vägendit behöver Sveriges kommuner fortsätta arbeta aktivt med energifrågorna och göra nyaenergieffektiviseringsåtgärder.Begränsningar: Denna studie är begränsad till kommunens egna fastigheter. Resultatetav studie är inte giltigt för varje kommun som mottagit bidraget men ger en översiktligbild över utfallet för kommunerna gemensamt. Alla kommuner kan lära något av denna studie.

Le concept de développement durable fut promu à la Conférence de Rio de 1992avec l’adoption d’un certain nombre d’instruments juridiques. Le droit africain s’estprobablement adapté aux règles et aux principes inhérents au concept avec, commeconséquence, la refonte ou la révision des codes ou lois de protection del’environnement. Face aux problèmes environnementaux récurrents, à la difficilegestion intégrée des ressources en eau, à l’opérationnalisation critique de la solidaritéà l’eau potable pour tous, à la gouvernance environnementale défaillante, la questionde l’évolution efficiente du droit de l’environnement africain au regard du conceptde développement durable se pose. Il se révèle un insuccès de la saisie du conceptpar le droit africain. Au final, un nouveau modèle de droit de l’environnement, auprofit des pays de l’Afrique de l’Ouest, s’avère nécessaire. / The concept of sustainable development was promoted in the Rio Conference in1992 with the adoption of a number of legal instruments. African law has probablyadapted to the rules and principles inherent to the concept with, as a consequence,consolidation or revision of codes and laws to protect the environment. Facingrecurrent environmental problems, the difficult Integrated water resources, criticaloperationalization of solidarity drinking water for all, the failed environmentalgovernance, the question of the efficient development of the law of the Africanenvironment in relation to the concept of sustainable development arises. It proves afailure in the seizure of the concept by the African law. Finally, a new model ofenvironmental law in favor of the countries of West Africa is necessary.