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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

A method for calculating the carbon footprint at Volvo Logistics Corporation

Trönnberg Lundin, André, Strömberg Jonzon, Sofie January 2012 (has links)
This thesis handles the need for Volvo Logistics (VLC) to calculate their total carbon footprint of purchased transportations, i.e. the total carbon dioxide emissions by all vehicles employed by VLC to transport the goods of their customers. The purpose of the thesis is therefore to determine a method with which VLC can calculate the total carbon footprint. To be able to decide upon one method that can fulfil the purpose, the authors searched for various methods, both in the academia and within the transportation sector, with which the emissions can be determined. Simultaneously the available input at VLC was studied to determine what type of method would be best suited to the current state of the company. After gathering several methods and determine what input was available and what was not available at VLC, an analysis of the found methods was done. First matching them with the available input to see which were usable as is, and then a more thorough Analytical Hierarchical Process analysis using three main-criterions; credibility, comparability, and simplicity, each with several sub-criterions. The weighting of these criterions was done in a workshop together with VLC employees, particularly the Environmental Manager and an Environmental Analyst, but also with two employees at the Global Logistics Development department at VLC. Using the weighting and the author’s comparisons of the methods within each of the criterions it was possible to obtain the methods with which further analysis should be done. After further analysis was conducted, considering VLC’s situation and possible development, the final methods was decided upon, one for each mode of transport; air, rail, road, and sea. These had to be adapted to better suit VLC and the input that was available; the distances, the weight, and the transport mode, factors which are incorporated in the methods recommended by the authors. The adaptation was then done using expertise at VLC to be able to determine what input VLC could affect as to be able to work towards lowering the total carbon footprint once it was calculated the first time. This also led to a revaluation of the method for sea transportation, forcing a change from the previously chosen one to a more suited method. This meant that three of the four modes; air, road, and sea, was covered by the NTM method, while rail used the Green Cargo method. While adapting the methods; to make them ready to use for VLC, certain changes required to obtain all the input needed was encountered and forwarded to the environmental department, letting them include it in the annual supplier survey. The thesis was concluded by four sets of instructions to be used to calculate the carbon footprint, one two tiered set for each mode of transportation. The instructions are presented in a step by step fashion of how to perform the calculations. The first part; First time usage, depicts those changes needed before the calculations can be attempted, the second part; Annual usage, cover those steps which has to be gone through every time the total carbon footprint for a period is to be calculated.
2

Modeling the Effect of New Commuter Bus Service on Demand and the Impact on GHG Emissions: Application to Greater Boston

Lyman, Christopher 02 July 2019 (has links)
The transportation sector is considered one of the major contributors to greenhouse gas (GHG) emissions in metropolitan areas, and any efforts to reduce these emissions requires strategic management of multiple transportation modes. This paper presents a method to identify opportunities to reduce GHG emissions by expanding commuter bus services and incentives to shift commuters from private cars to transit. The approach uses a nested multinomial logit model for mode choice in a region that includes driving alone, carpooling, walking, cycling, and using four possible transit modes (ferry, commuter rail, rapid transit and bus) by walk access or driving access. A model of existing conditions was calibrated with data from the Boston metropolitan area. Using an emission factor model based on average speeds from the California Air Resources Board (CARB), the net effect of new commuter bus service on GHG emissions from transportation was estimated. Potential GHG reductions are weighed against the capital and operating costs of new transit services to quantify the cost-effectiveness of a new commuter bus service for isolated origin-destination pairs. This modeling framework is used to optimize fares and bus frequency in order to identify the corridors with the most cost-effective potential for GHG reduction. Results are presented for the Boston region, demonstrating the feasibility of implementation and the potential magnitude of benefits for cost-effectively reducing GHG emissions associated with transportation. The method is general and can be applied in other cities around the world.
3

Fatores de controle das emissões de óxido nitroso (N2O) em tanque de aeração de estação de tratamento de esgoto

Brotto, Ariane Coelho 27 April 2017 (has links)
Submitted by Biblioteca de Pós-Graduação em Geoquímica BGQ (bgq@ndc.uff.br) on 2017-04-27T16:58:25Z No. of bitstreams: 1 Dissertação Brotto, A. C.pdf: 1827218 bytes, checksum: d583ce8460c1efc5934c93cec6ef4c3d (MD5) / Made available in DSpace on 2017-04-27T16:58:25Z (GMT). No. of bitstreams: 1 Dissertação Brotto, A. C.pdf: 1827218 bytes, checksum: d583ce8460c1efc5934c93cec6ef4c3d (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico / Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro / Universidade Federal Fluminense. Instituto de Química. Programa de Pós-Graduação em Geociências- Geoquímica Ambiental. Niterói, RJ / O estudo das emissões de óxido nitroso (N2O) em processos de tratamento de esgoto tem se tornado necessário e urgente nos últimos anos visto à sua contribuição às mudanças climáticas globais, já que este gás é responsável por 6% do efeito estufa e tem se tornado a principal substância destruidora do ozônio estratosférico do século XXI. Poucos são os estudos que quantificaram as emissões de N2O diretamente em estações de tratamento de esgoto (ETEs) e a literatura apresenta uma grande variação nos fatores de emissão (FEs) obtidos por eles. As Diretrizes de 2006 do IPCC para Inventários de Gases do Efeito Estufa sugerem o FE de 3,2 (2-8) g N2O pessoa-1 ano-1 para estimativas das emissões de N2O em ETEs, que corresponde a 0,035% do nitrogênio total (NT) emitido como N2O. As emissões de N2O em processo de tratamento de lodos ativados foram determinadas no período de janeiro a julho de 2010 em uma ETE municipal no Estado do Rio de Janeiro que trata aproximadamente 14,7 mil m3 dia-1 com média remoção de DQO para o período de estudo de 73% e carga de NT afluente de 46 mg N L-1. Os principais parâmetros operacionais relacionados às emissões de N2O em ETE foram estudados, a saber, concentração de oxigênio dissolvido (OD), concentração de nitrito (NO2 -), pH e temperatura. As maiores emissões de N2O foram observadas quando a concentração de OD se encontrava entre 1,3 e 3,4 mg L-1, o pH entre 5,9 e 6,5 e temperatura acima de 30oC. Enquanto as menores emissões ocorreram em concentrações de OD abaixo de 1,0 mg L-1 e acima de 4,0 mg L-1, e em pH acima de 6,5. O fluxo de N2O estimado é de 4,1 x 105 g N2O ano-1 e os FEs de N2O per capita, por vazão de esgoto tratado e pela carga NT afluente são 8,1 g N2O pessoa-1 ano-1, 8,0 x 10-5 g N2O L -1 e 0,12%. O FE per capita estimado exclusivamente para o tanque de aeração é aproximadamente 2,5 vezes superior ao proposto pelo IPCC (2006) para inventários de emissões de N2O para países que possuam sistemas centralizados de tratamento de esgoto com avançado controle dos processos de nitrificação e desnitrificação. / The study of nitrous oxide (N2O) emissions from wastewater treatment processes has become necessary and urgent in the last years due to its contribution to global climate change, since this gas is responsible for 6% of the global greenhouse effect and will become the main ozone-depleting substances (ODS) of the 21st century. Few studies have quantified the direct emissions of N2O from wastewater treatment plants (WWTPs) and literature shows a wide variation in the emission factors (EFs) obtained by them. 2006 IPCC Guidelines for National Greenhouse Gas Inventories suggests an EF to estimate N2O emissions from WWTP of 3.2 (2.8) g N2O person-1 yr-1, which corresponds to 0.035% of total nitrogen emitted as N2O. Emissions of N2O from a full-scale activated sludge process was determined from January to July of 2010 during measurement campaign at a municipal WWTP in the State of Rio de Janeiro that treat roughly 14,700 m3 day-1 with an average influent removal COD for the period of study of 73% and total nitrogen load (TN) of 46 mg N L-1. The most important operational parameters leading N2O emissions in WWTP were also studied, namely, dissolved oxygen concentration (DO), nitrite (NO2 -) concentration, pH and temperature. The largest emissions of N2O were observed when DO concentration was between 1.3 and 3.4 mg L-1, pH between 5.9 and 6.5 and temperatures above 30oC. While lower emissions occurred in DO concentrations below 1.0 mg L-1 and above 4.0 mg L-1, and at pH above 6.5. Total estimated annual flux of N2O is 4.1 x 105 g N2O yr-1 and the EF of N2O estimated per capita, wastewater flow and the influent TN load are 8.1 g N2O person-1 yr-1, 8.0 x 10-5 g N2O L(wastewater)-1 and 0.12%. The per capita EF estimated exclusively for the aeration tank is almost 3 times higher than that proposed by the IPCC (2006) for N2O emission inventories for countries that predominantly have advanced centralized WWTPs with nitrification and denitrification steps.

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