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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

The Gas Light Company of Baltimore a study of natural monopoly,

Brown, George Thomas, January 1936 (has links)
Thesis (Ph. D.)--Johns Hopkins University, 1934. / Vita. "Reprinted from [Johns Hopkins University] Studies in Historical and Political Science, series liv, no. 2."
2

The Gas Light Company of Baltimore a study of natural monopoly,

Brown, George Thomas, January 1936 (has links)
Thesis (Ph. D.)--Johns Hopkins University, 1934. / Vita. "Reprinted from [Johns Hopkins University] Studies in Historical and Political Science, series liv, no. 2."
3

Avaliação da eficiência energética em sistemasde iluminação predial = estudo de casos em dois hipermercados na cidade de Campo Grande - MS / Evaluation of the energy efficiency of lighting systems in comercial buildings : a case study in two hipermarkets in the city of Campo Grande-MS, Brazil

Mangiapelo, Leonardo Bruno Santos 20 August 2018 (has links)
Orientador: Alberto Luiz Francato / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo. / Made available in DSpace on 2018-08-20T02:27:34Z (GMT). No. of bitstreams: 1 Mangiapelo_LeonardoBrunoSantos_M.pdf: 36586082 bytes, checksum: 8113b13216e191e2b209d281e23af5bc (MD5) Previous issue date: 2012 / Resumo: No Brasil, as edificações são responsáveis por 45% do consumo de toda energia elétrica produzida no país, sendo 14,6% representado pelo setor comercial. Neste setor, os sistemas de iluminação artificial representam em média 22% do consumo de energia, apresentando grandes possibilidades para ações de eficiência energética. Estudos mostram que é possível reduzir 61% do custo com energia elétrica com ações de eficiência energética em sistemas de iluminação. Levantamentos realizados pelo Procel indicam que nos hipermercados 66,7% possuem potência instalada em iluminação acima de 100 kW, oferecendo grandes oportunidades para ações de eficiência energética no setor de iluminação. A integração da iluminação artificial com a natural possibilita grandes reduções nos custos com energia elétrica, além de proporcionar ambientes mais agradáveis e saudáveis para seus usuários. Ainda, estudos ressaltam que nos projetos luminotécnicos em geral, a eficiência energética do conjunto de equipamentos luminária-lâmpada-reator não costuma ser considerada, sendo comum a adoção de lâmpadas eficientes com luminárias ou reatores pouco eficientes. Neste trabalho, foram analisados dois hipermercados localizados na cidade de Campo Grande - MS. O hipermercado B possui um sistema de aberturas zenitais que possibilita o aproveitamento da iluminação natural e um conjunto de luminárias com refletores brancos e lâmpadas fluorescentes tubulares T8, enquanto o hipermercado A possui um sistema de fechamento com forro e um conjunto de luminárias com refletores metálicos e lâmpadas fluorescentes tubulares T5. Para realizar uma avaliação visando à eficiência energética de ambos os sistemas de iluminação destes hipermercados foram realizados levantamentos em campo, medições do consumo de energia elétrica nos circuitos de iluminação e também medições da distribuição dos níveis internos de iluminâncias. O estudo conclui que o aproveitamento da iluminação natural, associada ao correto dimensionamento do conjunto lâmpada luminária- reator e uso de sistemas automatizados oferecem grandes potenciais para a eficiência energética / Abstract: Buildings in Brazil are responsible for 45% of the whole electrical energy consumption, where 14,6% are performed in commercial buildings. In this sector, artificial lighting represent about 22% share of their energy consumption. Studies show that it is possible to reduce over 50% of the energy cost by implementing energy efficiency actions in lighting systems. According to PROCEL, the installed power with lighting in hypermarkets is greater than 100 kW in over 60% of the cases, thus representing an important type of building in the commercial sector. Additionally, studies show that the group efficiency of the lamp-ballast-luminary if often forgotten, yielding in inefficient lighting projects. The use of natural lighting integrated to the artificial lighting can offer not only potential to reduce energy consumption but also a more pleasant and healthy environment. This work describes a field study that was conducted in two different hypermarkets in the city of Campo Grande - MS in Brazil, with different artificial and natural lighting systems. The lighting system in hypermarket A consists of fluorescent T5 lamps in luminaries with reflexive components and no natural lighting openings while in hypermarket B, it consists of fluorescent T8 lamps in luminaries with no reflexive components and 12 openings for natural lighting. To evaluate and compare the energy efficiency of both lighting systems field research, energy consumption and lighting distribution measurements were carried out. The authors concluded that the use of natural lighting, associated with an efficient combination of lamp-luminary-ballast and automation systems offer great potential for energy efficiency / Mestrado / Recursos Hidricos, Energeticos e Ambientais / Mestre em Engenharia Civil
4

Optimization of Electrified Transport in Route Planning System / Optimering av elektrifierad transport i ruttplaneringssystem

Bergström, Jimmie, Fronda, Alex January 2024 (has links)
The adoption of electric vehicles in the transportation industry has increased significantly in recent years, driven by international and national environmental goals. However, this shift poses challenges for transportation companies as they adjust their fleets to accommodate electric vehicles. The range of electrified transport, which is shorter than conventional transport due to current battery technology, is influenced by various factors such as temperature, air density, topography, available charging infrastructure, loading weight, and other climate-related aspects. Electric vehicles also depend on a functional and accessible charging infrastructure, which is currently considered underdeveloped and inadequate given the growing number of electric vehicles. In addition to this, other important aspects are energy mapping, investment analysis and risk management. This study focuses on enhancing Nordic Routings route optimization system by identifying key parameters that improve route efficiency and optimization. To address the challenges of electrification and its impact on route optimization systems, this study presents a comprehensive analysis comparing conventional and electrified transport within a routing problem. The results showed that factors such as temperature, topography, loading weight, driver behavior and available charging infrastructure significantly impact range and range anxiety. These factors were analyzed through various scenarios based on scientific literature, interviews and modeling in Nordic Routings route optimization system. Furthermore, the study emphasizes the importance of meticulous pre-planning, investment analysis, route planning adjustments and accompanying risk management, summarized in a four-step model. This study also points out recommendations that are provided for managing temperature, weather condition, energy mapping, dynamic planning of charging, integrating live data on charging infrastructure and consideration of topology and loading weight. Implementation of these recommended actions within the route optimization system is essential to facilitate efficient routing for electrified transport, while also considering the current state of battery technology and charging infrastructure. / Elektrifieringen inom transportbranschen har ökat markant senaste åren till följd av internationella och nationella målsättningar för att minska den negativa miljöpåverkan. Den ökade elektrifieringen av transporter innebär dock skillnader i användning, planering och investering jämfört med konventionell transport, vilket medför en omställning för transportföretag som byter ut delar av eller hela fordonsflottan mot elektrifierade alternativ. Räckvidden för elektrifierad transport, som är kortare än konventionell transport på grund av nuvarande batteriteknik, varierar kraftigt av faktorer som temperatur- och väderförhållanden, topografi, tillgänglig laddningsinfrastruktur, lastvikt och andra fordons- eller klimatkopplade aspekter. Fortsättningsvis är elektrifierade fordon beroende av en fungerande och tillgänglig laddningsinfrastruktur, som i dagsläget anses vara underutvecklad och bristfällig utifrån den växande andelen elektrifierade fordon. Utöver detta återfinns andra faktorer som energikartläggning, investeringsanalys och riskhantering som är viktiga aspekter i planeringen av elektrifieringen. Studien som riktades mot Nordic Routings ruttoptimeringssystem utgjorde grunden för att identifiera nyckelparametrar som vidare kan implementeras och utvecklas i deras ruttoptimeringssystem. För att adressera problematiken kring elektrifieringen och hur elektrifierade transporter påverkas i ruttoptimeringssystem, presenterar denna studie en djupgående analys där konventionell och elektrifierad transport jämförs i ett ruttplaneringsproblem. Resultaten visade att faktorer som temperaturer, topologi, lastvikt, förarbeteende och tillgänglig laddningsinfrastruktur har en betydande påverkan på räckvidd och räckviddsångest. Dessa faktorer analyserades utifrån flera scenarier baserat på vetenskaplig litereratur, intervjuer och modellering i Nordic Routing ruttoptimeringssystem. Vidare belyser studien vikten av noggrann förplanering, investeringsanalys, anpassning av ruttplaneringen och den tillhörande riskhanteringen, vilket sammanfattas i en fyrstegsmodell. Slutligen presenterar studien rekommenderade åtgärder såsom hantering av temperatur- och väderförhållanden, energikartläggning och direktuppkopplade data mot laddningsinfrastrukturen, dynamisk planering av laddningsstationer samt beaktande av topologi och lastvikt. Dessa rekommenderade åtgärder behöver implementeras i ruttoptimeringssystemet för att möjliggöra effektiv ruttoptimering med elektrifierad transport, med hänsyn till dagens batteriteknik och laddningsinfrastruktur.
5

Im Zwielicht | Großstadt, Kino, Schützengraben

Simon, Anna 06 April 2022 (has links)
Thema dieser Dissertation ist die Frage, wie sich Licht und Sehen im Zuge der Elektrifizierung veränderten, und zwar aus Sicht literarischer Erzähltexte, die zwischen 1900 und 1933 publiziert wurden. Ausgangslage der Untersuchung ist erstens die These, dass durch den Einsatz des elektrischen Lichts eine Reihe neuer Wahrnehmungsdispositive entstanden, wo trotz der Lichtstärke elektrischer Leuchtmittel zwielichtige Licht- und prekäre Sichtverhältnisse herrschten. An drei besonders markanten Zwielichtszenarien der ästhetisch-technischen Moderne – Großstadt, Kino und Schützengraben – werden anhand einer breiten Quellenbasis aus Literatur, Technik, Wissenschaft, Philosophie und Ästhetik aufgezeigt, wie die Ausdifferenzierung der lichttechnischen Infrastruktur neue Blickregime und ästhetische Weltanschauungen produzierte, die ihrerseits veränderte Techniken des Sehens evozierten. Eine weitere zentrale These lautet, dass sich angesichts der prekären Licht- und Sichtverhältnisse auch die kulturelle Semantik des Lichts veränderte: die Art und Weise, wie Licht, und damit ebenso die Vorstellungen von Wahrnehmung, Wahrheit und Wirklichkeit, vor- und dargestellt wurden. Die neuen Lichtphänomene erforderten neben aisthetischen (die sinnliche Wahrnehmung betreffende) Anpassungsleistungen auch ästhetische Bewältigungsstrategien: neue Darstellungsweisen und symbolisch-metaphorische Zuschreibungen, die das zeitgenössische Wissen über Licht und Sehen gehörig in Bewegung brachte. Es entstanden virulente neue Korrelationen ‚moderner Wahrnehmung‘ zwischen technisch erzeugtem Zwielicht, epistemischer Irritation und narrativ erzeugter Visualität. Ich hoffe, mit meiner Arbeit neue Perspektiven auf die nach wie vor relevante Frage ‚moderner Wahrnehmung‘ zu werfen, die sich seit der ‚elektrischen Moderne‘ sukzessive als immer ausgeklügelteres Zusammenspiel von (Licht-)technik, aisthesis und Ästhetik neuformiert. / This dissertation focuses on how light(ing) and seeing/ perception changed in the course of electrification, from the perspective of German literature, published between 1900 and 1933. My first claim is, that the use of electric light created a series of new perceptual dispositifs, where dubious light and precarious visual conditions prevailed despite the luminous intensity of electric lighting. Three particularly striking twilight scenarios, that play a significant role in technology and aesthetics in the early 20th century, – namely the City, the Cinema, and the Trenches of WWI – are gripping settings to demonstrate, how disruptive lighting infrastructure produced new scopic regimes and innovative aesthetic perspectives (Weltanschauungen) that changed the techniques of visual perception. Drawing from a broad base of sources from literature, technology, science, philosophy, and aesthetics, I argue that the disruptive lighting technologies did not only change light phenomena, visual conditions and perception, but also transformed the cultural semantics of light substantially. Closely tied to concepts of truth, perception and reality, the rhetoric of light and lighting are dense metaphors and symbols, deeply interconnected with the history of knowledge. The new light phenomena required aisthetic (sensory perception-related) adaptations, as well as aesthetic coping strategies, like new modes of representation and symbolic-metaphorical attributions that troubled contemporary knowledge about light and visuality. My research zooms in on the visual dispositifs of ‘electric modernity’ and thus on the new correlations between technically generated twilight, epistemic irritation, and narrative visuality. By analysing the interplay of lighting and visual technology, aisthesis, and literary aesthetics in early 20th century, I hope to shed new light on the intriguing question of ‘modern perception’ that remains relevant from the beginning of the electric age until now.

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