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  • 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.
1

LCA různých konstrukčních systémů obálky budov

Fousek, Jan January 2017 (has links)
Goal of this work is to analyze life cycle assessment of building construction systems. LCA has been made by two different methods. One is based on ISO standards (Athena) and other on works with Ecoindicator (Ecolizer). Subject of comparison has been life cycle stages, materials and construction systems. The best results of constructions recived construction made of brick block and wood based Two by Four difuse-open construction. The worst construction is rebar-concrete one and most difficult was to understand results of construction made of CLT panel.
2

Life Cycle Assessment of Portland Cement and Concrete Bridge : Concrete Bridge vs. Wooden Bridge

Mousavi, Marjan January 2013 (has links)
Today global warming mitigation, natural resource conservation and energy saving are some of the significant concerns of different industries, such as cement and concrete industries. For that reason, a streamlined life cycle assessment (LCA) model of one ton of a Portland cement, CEM I produced in Cementa AB’s Degerhamn plant, has been developed by using the LCA software KCL-ECO. LCA is a tool that identifies in which stages of a product’s life cycle the most environmental burdens occur. The environmental analysis was limited to identify total energy consumption and total carbon dioxide (CO2) emissions per ton of Portland cement. Results show that the most significant energy consumption and CO2 emissions are related to clinker kiln, due to the process of calcination of limestone and fuel combustion in the kiln. Of total CO2 emissions, 52 % and 46 % result from the calcination process and fuel combustion respectively.  One of the applications of CEM I is in construction of concrete bridges. Therefore an LCA model of a concrete bridge located north of Stockholm was developed in KCL-ECO. Environmental indicators calculated are: total CO2 emissions and energy consumption through the entire life cycle of the bridge. CO2 uptake or carbonation of the concrete during the service life of the product and end of life treatment is one of the advantages of concrete products. During the carbonation process, some of the total CO2 released from calcination will be absorbed into the concrete. Results indicate that production of raw materials and transports during the life cycle of the concrete bridge, are main contributors to total CO2 emissions. Among raw materials, cement production has the highest CO2 emissions. Energy consumption is mainly related to concrete and concrete products production. CO2 uptake during the use phase of the bridge is small compared to total CO2 emissions from calcination. Furthermore, the results show that different waste handling practises result in different CO2 uptake behaviours. The total CO2 uptake from crushing and storing of the demolished concrete (scenario 1) and landfilling of the demolished concrete (scenario 2) is 10 % and 5 % of the total CO2 emissions from calcination respectively.  Since comparison of different construction materials from an environmental point of view is always desirable, the LCA tool was used to compare the total energy consumption and the CO2 emissions from a concrete bridge and a wooden bridge. The functional unit was defined as 1 square meter of bridge surface area, since the bridges were of different sizes and shapes. In this comparison the total emissions and energy consumption were much higher for the concrete bridge than for the wooden bridge.  In order to show how different assumptions could affect the results, a virtual concrete bridge with the same shape and size as the wooden bridge was designed and compared with the wooden bridge. The functional unit selected for this case was one bridge. In this case the virtual concrete bridge requires less energy, while the wooden bridge emits less CO2 to the atmosphere. For the wooden bridge, CO2 in growing forests was included, which could be debated. Overall, a comparison of the environmental performance of the wooden bridge and the concrete bridges was more complex than initially expected and great care is recommended in choosing material and application. With concrete, the design (and quantity of material used) seems to be a very sensitive parameter and may result in much larger energy used and CO2 emissions than a wooden bridge. On the other hand, the virtual bridge comparison showed that concrete advantages such as higher durability and lower maintenance may be theoretically combined with a comparable energy and climate performance as a wooden alternative.
3

Evaluating the Environmental Impact of a Product : Partial Life Cycle Assessment / Utvärdering av en produkts miljöpåverkan : Partiell livscykelanalys

Ek, Lina, Ström, Sanna January 2020 (has links)
Purpose – The purpose of this research is to investigate how manufacturing organisations can decrease their environmental impact in the supply chain. To meet the purpose, two research questions were formulated:  1. How can a manufacturing organisation reduce its environmental impact caused by transportation?  2. How can a manufacturing organisation reduce its environmental impact caused by production?  Method – To provide the opportunity to reach a conclusion and to create a basic understanding of the research area, a literature review was conducted, which formed the basis of the theoretical framework. Through a case study at a manufacturing organisation, interviews and document analyses were used as sources for empirical data. In order to develop solutions and recommendations, collected data and theoretical framework were analysed and discussed.  Findings – The research findings indicate that there are several possible measures to implement to reduce an organisation's environmental impact in the supply chain. A decisive factor is creating a holistic and fundamental understanding of sustainability and enabling everyone involved to work according a common view and in the same direction. In addition, a requirement to pursue the same goal is that all stakeholders are involved where a prerequisite is a well-functioning internal communication.  Implications – The research did not contribute to any new theories, but through the research analysis, statements and theories from previous research were strengthened. The research suggests actions that can be used for organisations to reduce their environmental impact, but also to increase the understanding of why actions should be implemented. Society has an important responsibility for motivating and provide conditions for manufacturing organisations to reduce their footprint. This research is considered to lead to an improved environment in the form of lower emission levels where both organisations and the entire community take responsibility for the planet.  Limitations – The case study is designed as a single-case study which, from a validity perspective, is not considered as advantageous as a multiple case study because the results are difficult to generalize. In order to strengthen the study's reliability, several functional units and / or organisations could have been included in the study.
4

The challenges of “cradle-to-cradle” strategy : A case study with Huawei Company

Zhang, Xiaoyu, Huang, Shuai January 2019 (has links)
The cradle to cradle (C2C) is a sustainable business strategy that mimics the natural recycling cycle and waste is reused, the question of when and how to apply the C2C concept successfully in business is still controversial. This thesis takes Huawei, the leading enterprise in the mobile communication industry, as an example, and to investigate the challenges for Chinese mobile communication companies in implementing an effective C2C strategy to achieve a sustainable development. This study used the semi-structured interviews in the qualitative data collection method to interview both Huawei and China Telecommunications’ managers. Data analysis shows that for the electronics industry with low recycling rate and high pollution, Huawei still faces many challenges in adopting the C2C strategy,which includes alloy recycling, recycling of electronic products in consumers' hands, disassembly problems, and recycling of electronic products by value, Another challenge is the mismatch between C2C evaluation mechanism and China's mobile communications industry. Only fully considered cradle to cradle, cradle to Grave, and Life cycle, the sustainable mode of the mobile communications industry would be reached.
5

The quantification of medical waste from the point of generation to the point of disposal: case studies at three private hospitals in Pretoria

Heunis, Louis Barend 11 1900 (has links)
The South African Waste Information System (SAWIS) was developed by the Department of Environmental Affairs and Tourism (DEAT) in 2005. This is a system used by government and industry to capture routine data on the tonnages of waste generated, recycled and disposed of in South Africa on a monthly and annual basis. All waste producers and waste management organisations should contribute to this national waste database and should accurately monitor the types and quantities of waste produced and handled. According to DEAT (2006) the need for Data verification is important. DEAT (2006:59) defined the term Data Verification as: "assessing data accuracy, completeness, consistency, availability and internal control practices that serve to determine the overall reliability of the data collected." The aim of the study is to determine a procedure, as well as the nature and extent of internal and external source documents, which could be used in the reconciliation of medical waste quantities from generation to disposal. The key objectives are to determine whether the selected hospitals keep internal records of the quantities of medical waste generated; to reconcile the waste quantities on the internal records with the external records, such as the collection certificates, invoices and waste incineration certificates; to ascertain whether the quantity of medical waste generated is equal to the quantity of waste incinerated and disposed of to determine the ratio factor between the quantity of medical waste before incineration and the quantity of the residue (ashes) after incineration, and to make recommendations on the reconciliation of waste quantities from the point of generation to the point of disposal. The results of the study indicate that the destruction certificate is the proof that the waste that was on-site collected by the service provider has been disposed /treated. Especially as an internal control measure. The health care risk waste (HCRW) management record keeping of quantities of weight as per Hospital A, Hospital B and Hospital C allows the opportunity to analyse the weight per month and per Hospital and per category and to make comparisons. The weakness or the gap however still exist that the waste is not weighed at the point of origin, but at the point where the waste service provider collects the waste onsite. It is from this point onwards that the service level agreement between the hospital and the waste service provider and the document management system and the tracking receipt and the waste collection documents (WCD) becomes relevant and where the quantities of waste per category are for the first time recorded. The hypothesis as stated in Chapter 1 was proven valid. The study concludes that reconciliation and comparison between the collection certificate and the destruction certificate and the monthly invoice is therefore possible, but the risk of mixing of waste and the understating or overstating of waste quantities is still not overcome. / Environmental Sciences / M. Sc. (Environmental management)

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