78 research outputs found

    Experimentelle Analyse der Stabilisierungseigenschaften von abgehobenen eingeschlossenen nicht-vorgemischten Drallflammen

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    Gegenstand dieser Arbeit war die experimentelle Untersuchung einer eingeschlossenen, abgehobenen, nicht-vorgemischten Drallflamme durch Verwendung einer neuartigen Airblast-Düse. Für die zeitaufge-löste Bestimmung aller drei Geschwindigkeitskomponenten wurde eine Messkampagne unter Verwendung eines kommerziellen 3-D LDA Systems durchgeführt. Konzentrations- und Temperaturmessungen im Feld wurden zum besseren Verständnis der komplexen turbulenten chemischen Interaktion auch durchgeführt

    Sustainability Tools for the Assessment of Construction Materials and Buildings

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    The construction industry, contributing to about 9% of the European Union's GDP, has played a significant influential role in the development of the energy strategy of Europe and is also anticipated to be an important contributor in its successful implementation (EC, 2016). Holistic sustainability assessment tools that are able to evaluate and optimise the environmental performance of construction materials and buildings are considered a key for the development of advanced building designs and use of sustainable building materials and elements and green energy- efficient systems that will raise high the sustainability level of the European built environment. The aim of this work is the thorough explanation of the standardised LCA methodology, and the introduction of the approach of EcoHestia, a comprehensive building sustainability assessment tool. In view of that, the current legislation addressing the construction industry, as well as the state-of-the- art Life Cycle Assessment (LCA) tools that are used for the sustainability assessment and optimisation of construction materials and buildings are also presented. Furthermore, through the employment of EcoHestia, the environmental impact of a case study building is defined, also providing a detailed breakdown of the contribution of each construction material in the overall environmental performance of the building. The analysis of the results has not only determined on the construction materials of the building that are most harmful to the natural resources and the environment, but also showcased the effectiveness and added value of utilizing this approach in moving forward towards a more sustainable green building sector

    Digital Twin for Grey Box modeling of Multistory residential building thermal dynamics

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    Buildings energy efficiency is a widely researched topic, which is rapidly gaining popularity due to rising environmental concerns and the need for energy independence. In Northern Europe heating energy alone accounts for up to 70 percent of the total building energy consumption. Industry 4.0 technologies such as IoT, big data, cloud computing and machine learning, along with the creation of predictive and proactive digital twins, can help to reduce this number. However, buildings thermal dynamics is a very complex process that depends on many variables. As a result, commonly used physics-based white box models are time-consuming and require vast expertise. On the contrary, black box forecasting models, which rely primarily on building energy consumption data, lack fundamental insights and hinder re-use. In this study we propose an architecture to facilitate grey box modelling of building thermal dynamics while integrating real time IoT data with 3D representation of buildings. The architecture is validated in a case study creating a digital twin platform that enables users to define the thermal dynamics of buildings based on physical laws and real data, thus facilitating informed decision making for the best heating energy optimization strategy. Also, the created user interface enables stakeholders such as facility managers, energy providers or governing bodies to analyse, compare and evaluate buildings thermal dynamics without extensive expertise or time resources

    Integration of Building Information Modelling (BIM) and Life Cycle Assessment (LCA) for sustainable constructions

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    The construction industry and the scientific community continue to seek for innovative approaches that can estimate the level of sustainability to be achieved at the end of the project from the early design stages. One of the tools developed for this purpose is Building Information Modelling (BIM), which represents the state- of- the- art tool for bringing together different expertise and achieving optimal designs at an early design stage for the maximisation of their impact. However, the level of the prospect of this tool has not been fully exploited. This paper integrates BIM with an established methodology for assessing a product's or a system's environmental performance- Life Cycle Assessment (LCA)- in an attempt to maximise the benefits from this synergy and achieve the most sustainable constructions. The impact from the integration of these two valuable tools is presented for a water supply system using case studies for a range of different materials. Comparison of a modern Vernetztes Polyethylen (VPE) water supply system against two systems made from traditional materials (steel and copper) was made. The results of this study show that a VPE water supply system performs 87% better than the steel system, and 88% better than a copper water supply system in terms of climate change, while the carbon dioxide emissions released during the production of a VPE system are almost the one tenth of traditional materials water supply systems

    How the quality of urban adaptation plans in Europe has evolved over time: indication of progress? Judgement by way of an assessment framework

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    ABSTRACT: Since the Paris Agreement, there has been an increasing focus on assessing the progress of climate change adaptation across multiple sectors and regions (Lesnikowski et al., 2017; Tompkins et al., 2018; Berrang-Ford et al., 2019). An important question is what ‘progress’ means and how it could be assessed, at the international, national, and local levels. Hitherto, there is a wealth of information on climate responses at sub-national levels (Hale et al., 2021). Cities and urban areas are increasingly recognized as important actors in climate response (Sanchez Rodriguez et al., 2018). In urban adaptation studies, most assessments focus on tracking and analysing policy outputs, such as approved adaptation plans (Castan Broto et al., 2020; Dodman et al., 2022). Analysing plans cannot tell the whole story in terms of actual progress in the collective reduction (or redistribution) of climate risks. However, it can provide information about the quality and relevance of adaptation processes and actions, and help to assess the likelihood that cities’ advance adaptation goals by reducing risks and increasing resilience equitably (Olazabal et al., 2019; Woodruff & Stults, 2016). Scholars have argued that ‘the best method to ensuring robust adaptation is to ensure rigorous adaptation planning processes’ (Preston et al., 2011).N/

    Comparative study on catalytic and non-catalytic pyrolysis of olive mill solid wastes

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    In this study, catalytic and non-catalytic fast pyrolysis of dried olive husk and olive kernels was carried out. A bubbling fluidised bed reactor was used for the non-catalytic processing of the solid olive wastes. In-situ catalytic upgrading of biomass fast pyrolysis vapours was performed in a fixed bed bench-scale reactor at 500 °C, for catalyst screening purposes. A maximum bio-oil yield of 47.35 wt.% (on dry biomass) was obtained from non-catalytic fast pyrolysis at a reaction temperature of 450 °C, while the bio-oil yield was decreased at 37.14 wt.% when the temperature was increased to 500 °C. In the case of the fixed bed unit tests, the highest liquid (52.66 wt.%) and organics (30.99 wt.%) yield was achieved with the use of the non-catalytic silica sand. Depending on the catalytic material, the liquid yield ranged from 47.03 to 43.96 wt.% the organic yield from 21.15 to 16.34 wt.% on dry biomass. Solid products were increased from 28.23 wt.% for the non-catalytic run to 32.81 wt.% on dry biomass, when MgO (5% Co) was used

    Types of Corruption in Small and Micro Enterprises (SMEs) in Ibadan, Nigeria

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    Corruption is a phenomenon that manifests in various types and forms especially among operators of Small and Micro Enterprises (SMEs). Many actions of the operators which constitute corrupt practices often tend to be overlooked in spite of their grave consequences for the success SMEs in Nigeria. The fight against corruption in Nigeria is more concentrated in the formal sector. This study was, therefore, designed to investigate various forms in which corrupt practices are carried out among Small and Micro Enterprises in Ibadan, Nigeria. Business owners, their employees, apprentices and consumers constituted the study population. Primary data were collected using questionnaire administered on 200 business owners, 150 employees and 150 apprentices randomly chosen in five business districts in Ibadan; and the conduct of 10 in-depth interviews with purposively selected participants. Quantitative data were analysed at uni-variate level using simple percentages and frequencies while qualitative data were content analysed. Findings from the study revealed that corrupt practices were rampant among actors in SMEs and the common types of corrupt practices included stealing (60%), deception of customers (78.4%), tax evasion (62%), sale of fake products (76%), sale of expired products (65.2%), tampering with measurement scales (69.6%), bribery (82.4%), and poor service delivery (73%). The study concludes that the level of corruption in SMEs calls for concern and government should extend the fight against corruption to the informal sector in Nigeria
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