1,721,002 research outputs found
Circular Economy in The Building Sector Toward Climate Change Mitigation And Environmental Sustainability: Players And Effective Measures
No full textThis thesis explores the implementation of the circular economy as a climate change mitigation strategy in the building sector, identifying stakeholders as key drivers of change. It argues that fragmented stakeholder engagement, caused by traditional and conservative socio-organisational dynamics, hinders the circular economy transition. Thus, enhanced collaboration and communication throughout the building life cycle are proposed as a pathway toward effective circular economy implementation.
This thesis places stakeholder dynamics at the centre of its analysis to address the lack of effectiveness in the circular economy transition. Consequently, it aims to suggest strategies and support informed decision-making that facilitates the effective implementation of the circular economy in the building sector, providing a well-constructed and validated roadmap for stakeholders. This roadmap is intended to guide stakeholders in navigating their path toward practical and effective circular economy implementation across the building life cycle, while also validating widely held but previously unformalised assumptions.
The methodological framework of this thesis follows a four-step approach: literature review, recurrence and effectiveness concept, systems thinking concept, and questionnaire. The first three steps supported the development of the roadmap, while the questionnaire served to validate it. Following a comprehensive literature review, a theoretical understanding of stakeholder dynamics was developed using a generic mathematical approach through the recurrence and effectiveness concept. This was followed by the systems thinking concept, implemented via a system dynamics (SD) computer simulation tool. Lastly, the questionnaire assessed whether the theoretical concepts and simulation outcomes aligned with real-world sectoral dynamics.
This thesis provides a comprehensive, literature-supported exploration of the circular economy as a climate change mitigation strategy in the building sector, offering an in-depth understanding, evaluation, and representation of stakeholder dynamics from theoretical, simulation-based, and real-world perspectives. It presents a well-developed and validated roadmap to guide stakeholders in implementing the circular economy effectively across the building life cycle, with a particular focus on the design phase. Additionally, a hypothetical case study illustrates ideal stakeholder relationships within a collaborative network committed to the roadmap, highlighting key interactions essential for enabling the circular transition during the design phase and throughout the entire life cycle.
The innovation of this thesis lies in its focus on stakeholder dynamics as a solution to the challenges of circular economy implementation in the building sector, employing a methodological framework that integrates both quantitative and qualitative approaches. While limitations arise from the complexity of the research problem and specific methodological constraints, the thesis contributes to the literature by mapping intricate stakeholder dynamics and identifying connections that inform strategies for effective circular economy implementation, ultimately supporting climate change mitigation and environmental sustainability
Unravelling complexity toward circularity: a system-dynamics based approach
No full textThis paper employed the System Dynamics (SD) methodological tool to investigate the intricate dynamics of transitioning to the circular economy, as a climate change mitigation strategy, in the building sector while focusing on stakeholder dynamics throughout the building life cycle. This paper's methodological approach used a two-stage approach, encompassing problem articulation and formulation of dynamic hypothesis. In the problem articulation stage, this paper identified the stakeholder dynamics in the building life cycle thanks to a comprehensive critical literature review. This paper then delved deeper into the stakeholder dynamics in the formulation of dynamic hypothesis stage. The results revealed that the stakeholders are interdependent while working together to address common concerns. Furthermore, the results emphasized the importance of stakeholder collaboration and communication in overcoming barriers to the circular economy transition in the building sector. Thus, this paper aims to contribute to the understanding of stakeholder dynamics while streamlining the decision-making process and suggesting potential solutions for the effective implementation of the circular economy in the prevailing linear state of the building sector to pave the way for a collaborative and communicative approach to climate change mitigation. While recognizing the limitations, this paper suggests future research for a more comprehensive analysis of the complex system's dynamics
Empowering Circular Economy Transition in the Building Sector: a Stakeholder-Centric approach in the Design Phase for Climate Change Mitigation
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Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Investigation of the aerodynamic performance of the NACA 2412 airfoil under rain conditions
Get PDFFen Bilimleri Enstitüsü, Makine Mühendisliği Ana Bilim DalıBu tez çalışmasında, ilk olarak kanat profilleri etrafında akışın sayısal çözümleri için sabit sayısal teknik belirlenmiş ve ikinci olarak kanat profilleri etrafında yağmur şartlarının aerodinamik karakteristiklere etkileri incelenmiştir. Sayısal çözümler Ansys-Fluent HAD yazılımı kullanılarak gerçekleştirilmiştir. Sayısal testlerden elde edilen sonuçlar literatürdeki deneysel ve sayısal sonuçlar ile karşılaştırılmış ve sonuçların tek fazlı ve çift fazlı uygulamalar için uyum içerisinde olduğu görülmüştür. Kanat Profili etrafında; havanın bulunması durumuna göre hava+şiddetli yağmur ve hava+hafif yağmur fazlarının bulunması aerodinamik karakteristikleri kötüleştirmektedir. Bir başka deyişle, direnç katsayısı artmakta, kaldırma katsayısı ise azalmaktadır. Bu durum yüksek hücum açılarında daha belirgin hale gelmektedir. Ancak, yine de yüksek Reynolds sayılarında bu kötüleşme ihmal edilebilir seviyede elde edilmiştir. Teorik olarak hafif yağmur (10 g/m3) şartlarında birim hacim (m3) başına kütle (g) artışı nedeniyle özellikle direnç katsayısında yaklaşık %1 seviyesinde, şiddetli yağmur (30 g/m3) şartlarında ise %2.5 kötüleşme beklenmektedir. Bu durumun elde edilen sonuçlara yansımadığı görülmektedir.In this thesis, firstly, a fixed numerical technique was determined for the numerical solutions of the flow around the airfoils, and secondly, the effects of rain conditions on aerodynamic characteristics around the airfoils were investigated. Numerical solutions were performed using Ansys-Fluent HAD software. The results obtained from the numerical tests were compared with the experimental and numerical results in the literature and it was seen that the results were in harmony for single-phase and two-phase applications. Around the Airfoil; According to the presence of air, the presence of air + heavy rain and air + light rain phases worsens aerodynamic characteristics. In other words, the drag coefficient increases and the lift coefficient decreases. This becomes more evident at high angles of attack. However, this deterioration is still negligible at high Reynolds numbers. Theoretically, due to the increase in mass (g) per unit volume (m3) in light rain (10 g/m3) conditions, it is expected to deteriorate especially by 1% in the resistance coefficient and 2.5% in heavy rain (30 g/m3) conditions. It is seen that this situation is not reflected in the results obtained
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Investigation of flow and heat transfer parameters in dual i?mpi?ngi?ng jet flow
No full textBu tez çalışmasında iki farklı lüle geometrisi kullanılarak çarpan jet akışında akış ve ısı transferi karakteristikleri deneysel olarak incelenmiş ve birbirleri ile karşılaştırılması yapılmıştır. Lüle geometrisi olarak iç içe iki dairesel borudan oluşan lüleler kullanılmıştır. Birinci lülede iç boru girdap üreteçle ve dış boru düz iken, ikinci lülede ise her iki boruda düz olarak seçilmiştir. İlk olarak farklı geometrilerde lüleler için farklı çalışma parametreleri altında oluşturulan hava jetlerinin akış karakteristiklerinin incelenmesi yapılmıştır. Akış karakteristikleri deneyi farklı Reynolds sayılarında farklı lüle-levha mesafesinin hidrolik çapa oranlarında H/Dh=0.5,1,2,4,5,6,7,8,9,10 gerçekleştirilmiştir. Sadece içteki lüleden akış olması durumunda, düz jet akışlı lüleden çıkan hız profili parabolik iken, dönen jet akışlı lüleden çıkan hız profili iki tepeli olarak oluşmaktadır. Dönmenin oluşturduğu türbülanslı akışın levha üzeri çarpan jet ısı transferinde daha fazla etkili olması beklenmektedir. Bu yüzden sadece dönen akışlı jet lüleli çarpan jet ısı transferi deneylerinde kullanılmıştır. Isı transferi karakteristikleri 3 iç lüle debisi ve 3 dış lüle debisi için toplam 9 farklı Reynolds sayısı kombinasyonu ve H/Dh =1, 3, 5 oranlarında elde edilmiştir.In this thesis, flow and heat transfer characteristics of impinging jet flow were investigated experimentally and compared with each other using two different nozzle geometries. Nozzles which are consisting of two circular pipes intertwined were used as nozzle geometry. In the first nozzle, the inner pipe was selected with a vortex generator and the outer pipe was straight, while in the second nozzle the all of pipes was selected straight. Firstly, flow characteristics of air jets which are formed under different operational parameters for nozzles of different geometries were investigated. The flow characteristics of the test was carried out for different Reynolds numbers at different ratios between nozzle-plate to hydraulic diameter at H / Dh = 0.5,1; 2; 4; 5; 6; 7; 8; 9; 10. In case of the flow only through the inner nozzle, the velocity profile from the straight jet flow nozzle is parabolic and the velocity profile from the rotating jet flow nozzle consists of two peaks. The turbulent flow which is generated by the rotation is expected to be more effective in impinging jet heat transfer to the plate. Therefore, only rotating flow jet nozzle was used in impinging jet heat transfer experiments. Heat transfer characteristics were obtained with a total combinations of 9 different Reynolds number which is combined 3 inner nozzle flow rates, 3 outer nozzle flow rates and H / Dh = 1, 3, 5
A novel method to determine background concentrations and spatial distributions of heavy metals in soil at large scale using machine learning coupled with remote sensing-terrain attributes
No full textSoil heavy metals are among the most hazardous materials in the environment. Their harmful effects can extend to surrounding systems (air, plants, water), and given the appropriate conditions may ultimately have negative effects on human health. Thus, preventing pollution and protecting pristine soils and preindustrial areas from human activities that lead to the concentration of heavy metals (HMs) is a priority. Here, a novel methodology was proposed to establish background concentrations of eight soil HMs, cobalt (Co), chromium (Cr), copper (Cu), iron (Fe), manganese (Mn), nickel (Ni), lead (Pb), and zinc (Zn), and digitally map their spatial distributions in an area (i.e., harrats region) that has not yet been impacted by industrial activity. The proposed methodology combined measurements of the target HMs and fifty-two environmental covariates (ECOVs) derived from 2017 to 2021 Landsat 8/9 OLI and Shuttle Radar Topography Mission (SRTM)-derived terrain attributes. Random forest and stepwise multiple linear regression models were further used to digitally map the studied HMs. The methodology is important for any future environmental pollution/monitoring studies in the area and can be applied in other similar environments. Machine learning algorithms show great ability to use available environmental variables and investigate the relationships between the factors influencing HMs accumulation under a given soil environment. The proposed methodology was effective for describing HMs spatial variability in the environments investigated. • The proposed method is a novel way to predict soil HMs and their spatial distribution over large areas. • Remote sensing/digital elevation models (DEMs)-derived ECOVs are useful for predicting and digitally mapping soil HMs, thus important for future environmental monitoring studies. • Explainable algorithms (i.e., RF and SMLR) are able to utilize ECOVs for HMs prediction and to establish background concentrations over large areas.Therefore, the combination of machine learning and RS/DEMs-based ECOVs is crucial to overcome the disadvantages of HMs determination via conventional methods
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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