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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.
31

Analysis of Single Echelon Logistics Model for Delivering Temperature Sensitive E-groceries in Cities using Electric Vehicle

Narayanasamy, Harivignesh January 2022 (has links)
With the increase in the growth of the e-commerce sector since the past decade, the pressure has been progressively more applied to the operations and supply chain. As the pandemic has pushed the companies to provide services at the customer doorstep due to the difficulties in accessing services from brick-and-mortar stores, the logistical operation of the companies is continuously put under pressure. Though the performance aspect of the supply chain operations is achieved as per company’s objectives, the sustainability part is always overlooked. For any logistics provider, the last mile is considered as one of the main deterrents in their supply chain operations. Some of the main factors include performance of the distribution process, delivery time window, level of service, congestion in the urban area, etc. The above and some other factors make it extremely difficult for the logistics provider to be sustainable in their operations.  There is a growing interest among the logistics provider to use electric vehicles in urban logistics. In particular, light electric vehicles are considered to be a valid alternate for fossil fuel powered sprinters or vans. The purpose of the study is to identify the logistical, technological and infrastructural challenges associated with implementing electric vehicles with refrigeration system in delivering e-groceries in cities. The thesis follows the methodology of collecting data from developed electric vehicle and analysing the data to identify the feasibility of implementing electromobility in last mile delivery. In order to identify the commercial application of electromobility, the collected data is applied in the developed simulation model. The scenario-based analysis has been used in the data collection and in simulation modelling experimentation. The scenario analysis has been used to have an in-depth understanding of all the possible outcomes. The results from the test observations provided data for further studies while the results from simulation modeling presented evidence for the effective application of electric vehicles in delivering e-groceries in last-mile. The comparison of electric vehicle (EV) with fossil fuel powered vehicle provided the strong performance of EV’s in terms of environmental, operational, and socio-economic aspects. The thesis provides new knowledge in the area of electromobility in last-mile research and also proposes potential future work which will be assisting the forthcoming research in advancing the boundary of the research topic. / Med den ökade tillväxten inom e-handelssektorn sedan det senaste decenniet har trycket successivt applicerats mer på verksamheten och leveranskedjan. Eftersom pandemin har drivit företagen att tillhandahålla tjänster utanför kunddörren på grund av svårigheterna att få tillgång till tjänster från tegelbutiker, sätts företagens logistiska drift kontinuerligt under press. Även om prestandaaspekten av leveranskedjans verksamhet uppnås enligt företagetsmål, förbises alltid hållbarhetsdelen. För alla logistikleverantörer betraktas den sista milen som en av de främsta avskräckningarna i deras leveranskedja. Några av huvudfaktorerna inkluderar distributionsprocessens prestanda, leveranstidsfönster, servicenivå, trängsel i tätorten etc. Ovanstående och några andra faktorer gör det extremt svårt för logistikleverantören att vara hållbar i sin verksamhet.  Det finns ett växande intresse bland logistikleverantören att använda elfordon i stadslogistik. I synnerhet anses lätta elfordon vara ett giltigt alternativ för sprinter eller skåpbilar som drivs med fossila bränslen. Syftet med studien är att identifiera de logistiska, tekniska och infrastrukturella utmaningarna i samband med att implementera elfordon med kylsystem för att leverera e-livsmedel i städer. Avhandlingen följer metodiken för att samla in data från utvecklade elfordon och analysera data för att identifiera genomförbarheten av att implementera elektromobilitet i sista mils leverans. För att identifiera den kommersiella tillämpningen av elektromobilitet, tillämpas den insamlade informationen i den utvecklade simuleringsmodellen. Den scenariobaserade analysen har använts i datainsamlingen och i simuleringsmodellexperiment. Scenarioanalysen har använts för att få en fördjupad förståelse av alla möjliga utfall. Resultaten från testobservationerna gav data för ytterligare studier medan resultaten från simuleringsmodellering presenterade bevis för den effektiva tillämpningen av elfordon för att leverera e-livsmedel på sista milen. Jämförelsen av elfordon (EV) med fossilbränsledrivna fordon gav elbilarnas starka prestanda när det gäller miljömässiga, driftsmässiga och socioekonomiska aspekter. Avhandlingen ger ny kunskap inom området elektromobilitet inom forskning på sista milen och föreslår även potentiellt framtida arbete som kommer att hjälpa den kommande forskningen att flytta fram gränsen förforskningsämnet.
32

Policy Tools for the Decarbonisation of Urban Freight Transport in Brazil

Mandana, Raghav Somayya January 2021 (has links)
There has been an increase in the carbon dioxide (CO2) emissions in the last 3 decades. A large share of these emissions is produced by the transport sector. In 2010 alone, global transport accounted for 7 GtCO2 eq and approximately 23% of total energy-related CO2 emissions. In order for the decarbonisation of the transport sector, one of the most important strategies is to reduce the use of fossil fuels. Fossil fuel consumption can be reduced by rolling out more battery electric vehicles (BEVs) on public roads. This is one of the methods by which the concept of electromobility is promoted. In order to increase the share of EVs, many countries have implemented different policies that promote the electrification of the transport sector. With respect to freight transport, electric commercial vans are one of the feasible choices.  This Master thesis involves a quantitative study which focus on the “total cost of ownership” (TCO) of light commercial vehicles (LCVs). Two diesel vans currently used in Curitiba, Brazil were selected - the Sprinter van by Mercedes-Benz and the Master van by Renault. In addition, their electric counterparts were also chosen; in conjunction, a sensitivity analysis with respect to fuel prices and annual distance driven was conducted. The results showed that the TCO of the electric LCVs is around 1.6 to 1.7 times higher than their diesel versions. As far as the two van model types were concerned, the Mercedes-Benz Sprinter had a higher TCO than the Renault Master over the chosen vehicle lifetime for both the diesel and electric versions, with the difference around 7.5% for the diesel versions and approximately 13% for the electric versions.  Based on the results of the TCO study, possible economic policies and fiscal instruments were recommended with regards to light commercial freight transport for Curitiba. / Det har skett en ökning av koldioxidutsläppen (CO2) under de senaste 3 decennierna. En stor del av dessa utsläpp produceras av transportsektorn. Bara 2010 svarade, global transport för 7 GtCO2 ekvivalenter och cirka 23% av de totala energirelaterade koldioxidutsläppen. För att avkolning av transportsektorn är en av de viktigaste strategierna att minska användningen av fossila bränslen. Fossil bränsleförbrukning kan minskas genom att rulla ut fler elektriska fordon (EF) på allmänna vägar när det gäller transportsektorn i allmänhet. Detta är en av metoderna som begreppet elektromobilitet främjas. För att öka andelen elbilar har många länder genomfört olika policyer som främjar elektrifiering av transportsektorn. När det gäller godstransport, är elektriska kommersiella lastbilar och skåpbilar två av de möjliga valen.  Detta examensarbete involverar en kvantitativ studie som fokuserar på “totala ägandekostnaderna” (TÄK) för lätta nyttofordon. Två dieselbilar som för närvarande används i Curitiba, Brasilien valdes - Sprinter-skåpbilen från Mercedes-Benz och Master-skåpbilen av Renault. Dessutom valdes deras elektriska motsvarigheter; i samband med detta genomfördes en känslighetsanalys avseende bränslepriser och årlig körd distans. Resultaten visade att T för elektriska LCV är cirka 1.6 till 1.7 gånger högre än deras dieselversioner. När det gäller de två typerna av skåpbilar hade Mercedes-Benz Sprinter en högre TCO än Renault Master under den valda fordonstiden för både diesel - och elektriska versioner, med skillnaden cirka 7.5% för dieselversionerna och cirka 13% för de elektriska versionerna.  Baserat på resultaten av TCO-studien rekommenderades möjlig ekonomisk politik och finanspolitiska instrument när det gäller lätt kommersiell godstransport för Curitiba.
33

Kallikrein Gene Regulation in Hormone-Dependent Cancer Cell Lines

Myers, Stephen Anthony January 2003 (has links)
Hormone-dependent cancers (HDCs), such as those of the prostate, ovary, breast and endometrium, share characteristics that indicate similar underlying mechanisms of carcinogenesis. Through steroid hormone signalling on "down-stream" target genes, the growth, development and progression of HDCs are regulated. One such family of target genes, highly expressed in HDCs and regulated by steroid hormones, are the tissue kallikreins (KLKs). The KLKs are a multigene family of serine proteases involved in physiological processes such as blood pressure regulation, inflammation, and tumour development and progression via the hydrolysis of specific substrates. Although the KLK gene family is clearly implicated in tumourigenesis, the precise roles played by these genes are largely unknown. Additionally, except for the androgen-responsive genes, KLK2 and KLK3, the mechanisms underlying their hormonal regulation in HDCs are yet to be identified. The initial focus of this thesis was to examine the regulation of the kallikreins, KLK1 and KLK4, by estradiol and progesterone in endometrial and breast cancer cell lines. From these studies, progesterone clearly regulated KLK4 expression in T47D cells and therefore, the focus of the remaining studies was to further examine this regulation at the transcriptional level. An overview of the results obtained is detailed below. Human K1 and hK4 protein levels were increased by 10 nmol/L estradiol benzoate, progesterone, or a combination of the two, over 48 hours in the endometrial cancer cell line, KLE. However, these same treatments resulted in no change in KLK1 gene or hK1 protein levels in the endometrial cancer cell lines, HEC1A or HEC1B (only hK1 analysed). Progesterone treatment (0-100 nmol/L) over 24 hours resulted in a clear increase in KLK4 mRNA at the 10 nmol/L dose in the breast cancer cell line, T47D. Additionally, treatment of T47D cells with 10 nmol/L progesterone over 0-48 hr, resulted in the rapid expression of the hK4 protein at 2 hr which was sustained for 24 hr. Further analysis of this latter progesterone regulation with the antiprogesterone, RU486, over 24 hours, resulted in an observable decrease in hK4 levels at 1 µmol/L RU486. Although the estrogen and progesterone regulation of the hK1 protein was not further analysed, the data obtained for hK4 regulation in T47D cell lines, supported the premise that this gene was progesterone-responsive. The rapid expression of hK4 protein by progesterone at two hours suggests that KLK4 transcription is directly coupled to progesterone regulation, perhaps through progesterone receptor (PR) binding to progesterone-responsive regions within the KLK4 promoter or far "up-stream" regions. Thus, the following further studies were performed. To test this hypothesis, the transcription initiation site (TIS) and 5' flanking regions of the KLK4 gene in T47D cells were interrogated. Primer extension and 5' RACE identified the TIS 78 bp 5' of the putative ATG site for translation as identified by Korkmaz et al. (2001). This KLK4 gene transcript consists of only four exons, and thus excludes the pre/pro signal peptide. Although a TATA-box is not present within -25 to -30 bp 5' of the identified TIS, a number of consensus binding motifs for Sp1 and estrogen receptor half-sites were identified. It is possible that the Sp1 sites are involved in the basal levels of transcription for this gene. Additionally, a putative progesterone response element (PRE) was identified in the far "up-stream" regions of the KLK4 gene. Basal levels of transcription were observed within the KLK4 proximal promoter region when coupled to a luciferase reporter gene and transfected into T47D cell lines. Additionally, the KLK4 proximal promoter region did not induce the luciferase reporter gene expression when progesterone was added to the system, however, estradiol was inhibitory for luciferase gene expression. This suggests that the proximal promoter region of the KLK4 gene could contain functional EREs but not PREs. In keeping with this hypothesis, some ER half-sites were identified, but PR sites were not obvious within this region. The identified PRE in the far "up-stream" region of the KLK4 gene assembled the progesterone receptor in vitro, and in vivo, as assessed by electromobility shift assays and chromatin immunoprecipitation assays (EMSAs and ChIPs), respectively. The binding of the PR to the KLK4 PRE was successfully competed out by a PR antibody and not by an androgen receptor antibody, and thus confirms the specificity of the KLK4 PRE-PR complex. Additionally, the PR was recruited and assembled onto and off the progesterone-responsive KLK4 region in a cyclic fashion. Thus, these data strongly suggest that the PR represents one of the core components of a transcription complex for the KLK4 gene, and presumably also contributes to the expression of this gene. Moreover, these data suggest a functional coordination between the PR and the KLK4 progesterone-responsive region in T47D cells, and thus, provide a model system to further study these events in vivo.
34

Alternativní zdroje energie a jejich integrace do konceptu Smart Grids / Alternative Energy Sources and Their Integration into the Concept of Smart Grids

Kopička, Marek January 2012 (has links)
This work deals mainly with electrical energy. In the first part is focused on alternative energy sources, and describes structure of consumption and production of electricity over the past few years, during which is focuses on renewable energy sources. In this context, assesses the conditions for alternative energy sources in the Czech Republic from the perspective of the legislative, as well as current status and potential of alternative energy sources and tries to predict the development of these issues. The next section describes the Smart Grids as a means to achieve these goals. There are presented the basic features of this system, its goals and challenges, a description of the integration of Smart Grids with other sources of electricity and the benefits of using Smart Grids both from the perspective of user and from the perspective of system. Other parts are focused on distributed control systems in the energy sector, its development and principle. The last part is devoted to consideration of the role of alternative energy sources and distributed generation in Smart Grids.
35

Ökonomisch-ökologischer Nettoeffekt der Elektromobilität im öffentlichen Personennahverkehr

Rieckhof, Ramona, May, Nadine, Scope, Christoph, Guenther, Edeltraud 26 August 2021 (has links)
Im Rahmen einer Elektromobilitäts-Fallstudie kombinieren wir zwei lebenszyklusbasierte Methoden und veranschaulichen die Ergebnisse zur Kommunikations- und Entscheidungsunterstützung mittels der Methode des ökonomisch-ökologischen Nettoeffekts. Die Ergebnisse zeigen, dass Elektrofahrzeuge im Vergleich zur EURO6-Dieselfahrzeugen erst in langer Frist ökonomisch und ökologisch wettbewerbsfähig sind. / Building on a case study on electric mobility, we integrate two life cycle methods and visualize the results for communication and decision-support using the economic environmental trade-off. Results suggest that in comparison to EURO6 diesel vehicles electric vehicles are only in the long run economically and environmentally competitive.

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