• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 36
  • 23
  • 5
  • 3
  • 1
  • 1
  • Tagged with
  • 73
  • 73
  • 26
  • 17
  • 16
  • 16
  • 15
  • 14
  • 13
  • 13
  • 13
  • 12
  • 11
  • 11
  • 10
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

GraalVM’s Ahead-of-Time Compilation: Benefits and Challenges in Production

Evaldsson, Tom, Bardakani, Mohamad Yazan January 2024 (has links)
The widespread adoption of containerization for application deployment emphasizes the need for improved performance and efficiency, particularly in Java Virtual Machine (JVM)-based applications. Traditional JVMs often struggle with resource efficiency and long startup times, leading to increased operational costs and a larger environmental footprint. This is especially significant in microservices architectures where resource optimization is crucial for sustainability and cost-effectiveness. This thesis aims to evaluate the effectiveness of GraalVM’s Ahead-of-Time (AOT)compilation and native image support in enhancing the performance of JVM-based applications within a microservices architecture. The focus is reducing startup times, improving resource utilization, and overall operational efficiency at Ericsson, contributing to a greener economy. The research involved migrating a JVM-based program to run on GraalVM. Systematic performance tests measured key metrics such as startup time, memory usage, and performance. Semi-structured interviews with industry professionals were also utilized to gather qualitative insights into the migration challenges and benefits. The results indicated that native images significantly reduced startup times and memory usage compared to standard JVMs. Profile Guided Optimization (PGO)massively increased performance but at the cost of compilation time, memory usage, and build size. Interviews revealed that developers are cautiously optimistic about the benefits of AOT compilation with GraalVM but also revealed major concerns about complexity and compatibility. GraalVM’s AOT benefits make it a viable option for both microservice and serverless architectures. However, the decision to adopt GraalVM requires careful consideration of the trade-offs. These include larger build sizes, longer compilation times, and the need for specialized knowledge to maintain stability. Future work should focus on case studies in real-world environments to further validate and explore the benefits and drawbacks of AOT compilation..
22

Briquetting and Reduction of DRI/HBI Fines for Next-Generation Iron and Steel Making Technology

NITUNGA, Eddy-Nestor January 2024 (has links)
The current transition from Blast Furnace (BF) to Hydrogen-Direct Reduction (H-DR) is an initiative to reduce the carbon footprint in Iron and Steel production. The shift from traditional coke-based Iron and Steel making to a green H-DR requires new innovative technologies, underscoring the importance of collective efforts in this field. The production of DRI/HBI fines, which account for 1-2% wt. of DR production, poses a significant challenge for the iron and steel industries. These fines, rich in iron, are generated inside the plant during the handling, production, and transportation process. Their recycling in the DR process is difficult without proper agglomeration. Here, briquetting emerges as a promising solution to this challenge. This research work is dedicated to exploring the use of innovative binders in briquetting the DRI/HBI fines. It aims to understand the H2 -based reduction behaviour of the briquettes and the role of embedded biocarbon in enhancing resource efficiency. The study also investigates the impact of binders on the mechanical strength, moisture content, and compaction pressure of the briquettes. The optimized briquettes are then subjected to H2-based reduction using a thermogravimetric technique (TGA) followed by characterization by XRF, XRD, and LECO analysis, and mechanically evaluated to assess their potential in the next-generation H2-based Iron and Steel Making. Keywords: DRI/HBI Fines, Organic binders, Briquetting, H2 Reduction, Biocarbon, Recycling, Resource Efficiency
23

Återbruk inom byggindustrin - en dold resurs? : En studie om återbrukets potential inom den svenska byggindustrin / Reuse within the construction industry – a hidden resource?

Mathias, Fernqvist, Douglas, Ulfshagen, Eric, Bullat January 2024 (has links)
The construction industry today accounts for a significant portion of the world's resource consumption and waste production, which greatly impacts the environment. This study examines the opportunities and challenges associated with the reuse of materials within the Swedish construction industry, particularly in large infrastructure and construction projects. The aim is to investigate current practices regarding reuse, identify obstacles and opportunities, and propose improvements to promote circularity in the construction sector. Through an interview study and a field study of an ongoing construction project, the research provides an in-depth understanding of how reuse is handled in practice and the challenges involved.  The results show that despite a great interest in reuse, there are significant obstacles such as regulations, economic factors, and a lack of coordination. Many companies and authorities view reuse as a necessary measure to reduce environmental impact, but face challenges such as costs and complex regulations. However, opportunities exist through digital solutions and better coordination, which can make reuse both economically and environmentally beneficial. Projects with the proper conditions show that reuse can be both profitable and environmentally friendly. The study suggests that to increase reuse in the construction industry, policy adjustments, better economic incentives, and further development of digital platforms for coordination and efficient management of reused materials are required. By introducing clearer regulations and creating economic incentives, companies can be motivated to choose reuse over virgin materials. With the right measures, the environmental impact of the construction industry can be significantly reduced, contributing to a more sustainable future.
24

Resurseffektivisering : På ICA Sverige AB:s centrallager / Resource efficiency : At ICA Sverige AB:s central warehouse

Gillmén, Martin January 2016 (has links)
Logistik är den del av ett företag som påverkar företagets resultat på ett mycket betydande sätt. Kunden ställer krav på att få sin produkt levererad på en viss tidpunkt och om produkten då inte levereras på utsatt datum kan detta leda till en förlorad kund och därmed förlorade framtida inkomster. För att lyckas leverera till kund på utsatt tid krävs det att många processer fungerar väl ihop och att ett välplanerat system är implementerat. Denna rapport är skriven på ICA Sverige ABs centrallager i Kungälv och handlar om effektivisering. Mer specifik effektivisering av användningen av truckar. Genom att förkorta körsträckor och eliminera icke-värdeskapande körsträckor kan man få ett mer effektivt lager. Jag har samlat in relevant data så som genomsnittlig sträcka per order samt information om vilka lagergångar som är mest trafikerade för att veta vart i lagret som problemet finns och varför det uppstått. Zon-indelning är en metod som är känd för att minska körsträckor på ett lager. En implementering av metoden underlättas också av att ICA i dagsläget har sorterat artiklarna på ett sådant sätt att de första tio lagergångarna är fyllda med SRS-backar. Det är en metod som inte bara förkortar körsträckor utan och effektiviserar materialhantering. Teoridelen av arbetet görs för att får en större insikt i ämnen logistik samt för att hitta och benämna de metoder som påverkar logistiken i ett företag. Olika typer av materialhanteringsmetoder, lagringsmetoder, artikelplaceringsmetoder är exempel på vad som beskrivs djupare. Analysen har gjort för att analysera och koppla samman de teorier som använts till de problem som behandlas i rapporten men även reflektioner och tankar kring varför teorierna har använts. Rapporten har skrivits på ICA Sverige ABs centrallager i Kungälv och har koncentrerats till färskvaruavdelningen där problemet med långa körsträckor har uppkommit. / Logistics is that part of a company that affects the company’s efficiency in a considerable way. The customer has demands on the product to have it delivered on a specific date and if the product isn’t delivered on that date the consequences may result in a loss of a customer and therefore a loss of income. To be able to deliver the product on the specific date to the customer there’s a couple of processes that need to work flawlessly together and that a well worked out system is implemented. This report is written at ICA Sverige AB’s central warehouse is Kungälv, Sweden. It surrounds the subject of efficiency in warehousing and usage of lift trucks. Thru minimizing the driving distance of the lift trucks and eliminating not-value processes you can create a more efficient warehouse. I’ve gathered information regarding average distance per completed order and information regarding which of the warehouse aisles is the busiest to get an insight in where the problem is and why it has occurred. Zone-picking is a method that is known to minimize lift truck distances in a warehouse. An implementation of this method at ICA is facilitated by the fact that the articles already are sorted in a way that the first ten aisles are filled with plastic crates. It’s a method that not only minimizes the lift truck distances but also make the material handling more efficient. The theory part of the report is done to get a bigger insight in the subject of logistics but also to find and mention methods that affect the logistics in a company. Different types of material handling methods, storage methods and article placement methods are examples of methods describe. The analyzing part of the report has been done to connect mentioned theories to main problems that the report is surrounding but also includes reflections and thoughts about why the theories have been used. The report has been written at ICA Sverige AB’s central warehouse in Kungälv and has been focused on the fresh food compartment of the warehouse where problems with long distances for the lift trucks has occurred.
25

Material flow analysis and CO2 footprint in lumber from managed Brazilian Amazon rainforests. / Análise de fluxo de massa e pegada de CO2 em madeira serrada de florestas manejadas na Amazônia brasileira.

Numazawa, Camila Thiemy Dias 29 October 2018 (has links)
Using wood produced under forest management in the Amazon has been proposed as a way of preserving the ecosystem, generating jobs and to aid in climate change mitigation by using wood products as carbon stock and through CO2 uptake from the atmosphere during forest regrowth. However, the scarcity of research based on primary data of Amazonian lumber incorporated into construction can unknowingly lead to incorrect forest management and consequently forest destruction. Besides, it is necessary to verify the real environmental impacts. Two approaches were applied in this research to evaluate the wood product chain: material flow analysis and CO2 footprint calculation of managed Amazonian lumber. The research quantified the resource efficiency and CO2 footprint based on residue generation during the raw extraction in 5 forest plots in State of Pará, followed by the lumber production and the end-of-life phases, giving the CO2 balance between the emissions from residue decomposition and the CO2 uptake during forest regrowth, disregarding the energy consumption. Results indicated that the large quantities of logging residues are the main source of CO2 emissions in the material flow from selective logging, ranging from 9% to 36% of the initial forest biomass, while timber logs represented between 4% and 11%. Logging residues ranged from 2.9 t t-1 to 3.1 t t-1 per tonne of log. Combined with an average sawmill lumber yield of 54%, wastage rate values increased to between 5.7 t t-1 and 6.6 t t-1, resulting in a CO2 footprint of managed Amazonian lumber ranging between -6.6 tCO2 t-1 for reduced impact logging as carbon stock, to emissions of 6.1 tCO2 t-1 from cradle-to-gate for conventional logging. From cradle-to-grave the total CO2 footprint of lumber is estimated to range from neutral to 7.5 tCO2 t-1. Resource efficiency ranged from 13% to 15%. In this study, only the forest under reduced impact logging was able to fully recover its initial aboveground biomass, showing that in most cases regulations in the New Forest Code for Amazon forest management may not ensure sustainable logging, leading to forest destruction. Policies need to be improved and integrated with results from empirical research based on primary data to achieve sustainable exploitation of the Amazon forest. / O processo seletivo de utilização da madeira de manejo florestal na Amazônia tem sido proposto como forma de conservação e preservação do ecossistema, associada a geração de empregos e à mitigação de mudanças climáticas, pelo estoque de carbono dada a absorção de CO2 da atmosfera durante o crescimento da floresta. No entanto, a limitação de pesquisas baseadas em dados primários sobre madeiras amazônicas incorporadas na construção civil pode levar, inconscientemente, ao manejo florestal incorreto e, consequentemente, à destruição da floresta no contexto original e de reais impactos ambientais provocadas por ações inadequadas. Duas abordagens foram aplicadas nesta pesquisa para avaliar a cadeia de produtos de madeira: análise de fluxo de material e cálculo da pegada de CO2 da madeira manejada na Amazônia. A pesquisa analisou a eficiência dos recursos e a pegada de CO2 com base na geração de resíduos durante a extração em 5 florestas no Estado do Pará, produção madeireira e o fim de vida, proporcionando o balanço de CO2 entre as emissões da decomposição de resíduos e a absorção do CO2 durante a recomposição florestal, desconsiderando a energia consumida. Os resultados indicaram que o expressivo volume de resíduos florestais é a principal fonte de emissões de CO2 no fluxo de material proveniente da extração seletiva, variando de 9% a 36% da biomassa florestal inicial, enquanto os troncos de madeira representam entre 4% e 11%. Os resíduos de exploração florestal variaram de 2,9 a 3,1 t de resíduos por tonelada de tora. Combinado com um rendimento médio de madeira de serraria de 54%, os valores da taxa de desperdício aumentaram para entre 5,7 t e 6,6 t de resíduos por tonelada de tora e madeira serrada, resultando em uma pegada de CO2 variando entre -6,6 tCO2 t-1 (exploração de impacto reduzido) considerado estoque de carbono e as emissões de 6,1 tCO2 t-1 do berço à porta. No final da vida útil, estima-se que a pegada total de CO2 da madeira entre o berço e o túmulo é de neutra (exploração de impacto reduzido) a 7,5 tCO2 t-1, com uma eficiência de recursos variando de 13% a 15%. Neste estudo, apenas a floresta sob prática de extração de impacto reduzido foi capaz de recuperar totalmente sua biomassa inicial acima do solo, mostrando que as regulamentações do Novo Código Florestal para o manejo da florestal amazônica pode não garantir a sustentabilidade de uso do recurso florestal para aquela exploração que não esteja alicerçada dentro desse contexto de conservação da floresta original. As políticas precisam ser melhoradas, integradas e dinâmicas com base em resultados derivados de pesquisas empíricas baseadas em dados primários garantindo a exploração sustentável na Amazônia.
26

Site-level resource efficiency analysis

Gonzalez Hernandez, Ana January 2018 (has links)
To achieve agreed targets for reducing global carbon emissions, industry must become more resource-efficient. To this end, two viable strategies exist: energy efficiency and material efficiency. Despite their inherent interdependence, industry continues to treat these two strategies as isolated pursuits, providing in the process only a partial insight into the potential of resource efficiency. To resolve this disconnect, this thesis attempts to develop and apply tools that help integrate industrial energy and material efficiency analyses. Three areas of research are explored. The first is concerned with a fundamental component of industrial performance: efficiency benchmarks. No agreed-upon metric exists to measure the efficiency with which the sector trans- forms both energy and materials - that is, how resource-efficient they are. This thesis applies exergy - a well-established method to consolidate energy and materials into a single metric - to a case study of the global steel industry in 2010. Results show that this exergy-based metric provides a suitable proxy to capture the interactions between energy and materials. By comparing energy and material efficiency options on an equal footing, this metric encourages the recovery of material by-products - an intervention excluded from traditional energy efficiency metrics. To realise resource efficiency opportunities, individual industry firms must be able to identify them at actionable time-frames and scopes. Doing this hinges on understanding resources flows through entire systems, the most detailed knowledge of which resides in control data. No academic study was found to exploit control data to construct an integrated picture of resources that is representative of real operations. In the second research area, control data is extracted to track the resource flows and efficiency of a basic oxygen steel-making plant from TataSteel. This second case study highlights the plant's material efficiency options during operations. It does so by building close-to-real-time Sankey diagrams of resource flows (measured in units of exergy) for the entire plant and its constituent processes. Without the support of effective policies the new exergy approach is unlikely to be widely adopted in industry. By collating evidence from interviews and policy documents, the third area explores why the European Union's industrial energy and emissions policies do not incentivise material efficiency. Results suggest several contributing factors, including: the inadequacy of monitored indicators; an imposed policy lock-in; and the lack of a designated industry lobby and high-level political buy-in. Policy interventions are then proposed to help integrate material efficiency into energy and climate agendas. The European Union's limited agency stresses the need for Member States and industry to drive the move to a low-carbon industry in the short-term.
27

Application of Quantitative and Qualitative Methods for Building a Case for Industrial Pollution Prevention: Case Study of a Dairy Processing Facility

Aikenhead, Graham Smith 11 January 2013 (has links)
This thesis investigates the use of a combined set of quantitative and qualitative tools to help address known barriers associated with adopting and sustaining pollution prevention (P2) in an industrial manufacturing setting. The research was conducted at an Ontario dairy processing facility in the form of a case study. P2 is an alternative approach to traditional pollution control or abatement techniques. P2 is a preferred method for pollution management, both environmentally and economically, as it focuses on the efficient use of resources to prevent pollution at the source. The tools used in this research included: wastewater treatability testing, hierarchical process mapping, employee interviews, and causal loop diagrams (CLDs). The application of these tools assisted the participating facility in better characterizing its existing environmental problems, uncovering concrete resource saving opportunities within its processes, and providing more adaptive visual approaches of documenting and conveying P2 concepts. / OMAFRA Agri-Food and Rural Link KTT Funding Program
28

Storage and aggregation for fast analytics systems

Amur, Hrishikesh 13 January 2014 (has links)
Computing in the last decade has been characterized by the rise of data- intensive scalable computing (DISC) systems. In particular, recent years have wit- nessed a rapid growth in the popularity of fast analytics systems. These systems exemplify a trend where queries that previously involved batch-processing (e.g., run- ning a MapReduce job) on a massive amount of data, are increasingly expected to be answered in near real-time with low latency. This dissertation addresses the problem that existing designs for various components used in the software stack for DISC sys- tems do not meet the requirements demanded by fast analytics applications. In this work, we focus specifically on two components: 1. Key-value storage: Recent work has focused primarily on supporting reads with high throughput and low latency. However, fast analytics applications require that new data entering the system (e.g., new web-pages crawled, currently trend- ing topics) be quickly made available to queries and analysis codes. This means that along with supporting reads efficiently, these systems must also support writes with high throughput, which current systems fail to do. In the first part of this work, we solve this problem by proposing a new key-value storage system – called the WriteBuffer (WB) Tree – that provides up to 30× higher write per- formance and similar read performance compared to current high-performance systems. 2. GroupBy-Aggregate: Fast analytics systems require support for fast, incre- mental aggregation of data for with low-latency access to results. Existing techniques are memory-inefficient and do not support incremental aggregation efficiently when aggregate data overflows to disk. In the second part of this dis- sertation, we propose a new data structure called the Compressed Buffer Tree (CBT) to implement memory-efficient in-memory aggregation. We also show how the WB Tree can be modified to support efficient disk-based aggregation.
29

From Food to Fuel: The Swedish Resource Efficiency Dilemma.

Lundgren, Monia January 2014 (has links)
The EU has embarked on a resource efficiency trajectory in order to solve resource scarcity and general sustainability issues. The conversion of food waste into fuel is considered resource efficient as it makes use of resources that would otherwise be discarded. On the other hand, the food sector affects the environment substantially as it is inherently resource intensive and excessive. The purpose of the study was to assess how resource efficient the food waste substrate (feedstock for energy production) is from a life-cycle perspective. The study also aimed to determine if associated Swedish incentives and current market signals promote resource efficiency in Sweden. The food waste substrate has a complex life-cycle and current analyses neglect crucial life-cycle impacts. This makes resource efficiency difficult to determine in absolute terms. The first resource efficiency principle, that promotes the use of fewer inputs, becomes questionable as the food waste substrate has twice as many input stages in comparison to the food crop substrate. The second principle, stating that the food waste substrate should contribute to a low-carbon economy, also falls short due to a calculation method that neglects crucial emission stages. Due to the absent life-cycle perspective, crucial environmental impacts associated with food production are neglected. This affects the achievement of the Swedish Generation Goal and environmental quality objectives. The study concludes that the food waste substrate should undergo a thorough life-cycle analysis. Furthermore, it should be compared to other biofuel options in order to determine degree of resource efficiency. Only then can an appropriate set of EU and national policy measures be instated to safeguard scarce resources and promote a sustainable agriculture and energy sector.
30

Reducing fabric consumption : by improving marker efficiency

Widanalage, Varuna Lasantha Kumara, Kizilirmak, Serkan January 2020 (has links)
Resource degradation is a significant problem in the world, which is directly related to the textile and fashion industry. Efficient use of the material has been identified as an essential aspect to be addressed seriously. It is a critical topic that has attracted the attention of people and companies in recent years and has become a fundamental issue of sustainability. This research study was based on UN sustainable development goals number 12 and 8, which focuses on resource efficiency. The research is designed in considering fabric consumption, which has a significant impact on the textile and clothing industry to contribute to a brighter future and a more sustainable life. The purpose of this study is to reduce the fabric consumption through improving marker efficiency. The research focuses on investigating the behaviour of marker efficiency concerning usable fabric widths, markers with different sizes and marker with style combinations to reduce fabric consumption. The improvements of the existing markers lead to reduce fabric wastage during the cutting process while improving resource efficiency in consumption and production. In this study, the explanatory sequential design of mixed research method is employed with carrying out experiments to collect and analyze quantitative data, explained and elaborated with qualitative findings through expert interviews to get insights into the quantitative findings in a deductive approach. The marker efficiency significantly varies according to the combination of sizes and style and usable fabric width. The improvements of the marker efficiency, reduce the fabric consumption per garment and increase resource efficiency while preventing waste generation. A saving of 1% of a material which consumed millions of tons per year, significantly affect on reducing resource depletion and environmental pollution. This study is limited to five usable fabric widths, four size marker combinations and two style combinations. Moreover, it is focused on material efficiency, and cost efficiency is not considered. There are possibilities for clothing manufactures’ to improve resource efficiency by improving marker efficiency while planning the demand, considering multi-size and multi-style markers. They can concern usable fabric widths, which provide higher marker efficiencies during material purchasing.

Page generated in 0.0671 seconds