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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

LCC jämförelse mellan centralt- och lägenhetsplacerat FTX-system / LCC comparison between centralized- and decentralized mechanical ventilation

Johansson, Linus, Pettersson, Marcus January 2018 (has links)
Purpose: The forthcoming energy requirements that will come into force in 2020, are about more energy-efficient construction and strive to build near-zero energy buildings. In order for the building industry to succeed in producing buildings that meet these demands, it requires more energy-efficient products and installations within the framework of a normal investment. It is the operating cost that is responsible for the largest energy use in buildings, which opens to investigate the energy consumption over a life cycle cost. Choosing the right ventilation system reduces the energy consumption, and then the life cycle cost if the investment makes too much impact. It is generally known in the building industry that the design- and production times are very time limited, which means that companies use previously proven systems that work regardless of whether there are more energy-efficient products. This can lead to reduce the innovative thinking for sustainable development, so that better options for installations do not find out in the global market. The study refers to comparing the two different ventilation systems centralized and decentralized in terms of energy and life cycle costs. To make a decision which of the centralized- and decentralized system is the better option. Method: For the most part, the quantitative method of collecting and analyzing quantifiable data is applied. Document analyzes and own calculations have given rise to the result. Findings: The study´s results indicate that the decentralized ventilation system is both more energy efficient and has less cost over a life cycle. One major reason for the result is the sale of the extra living space that occurs when vertical shafts disappears when installing decentralized ventilation system. It can also be seen in the result that the air unit is cheaper for the centralized ventilation system, while installation and materials are cheaper for the decentralized ventilation system. Implications: As the result shows, the decentralized ventilation system is both more energy efficient and cheaper over a life cycle. Additional energy savings on the decentralized ventilation system can be done if a home-away mode is installed. It means that the airflow decreases when no one is home, which reduces energy consumption. Furthermore, it will be ensured that removal of vertical shaft when installing decentralized ventilation system reduces investment and more saving can be done. Limitations: This study will only analyse a five-storey multifamily house in Jönköping together whit a centralized and decentralized ventilation system. Keywords: Ventilation, HVAC, centralized mechanical ventilation, decentralized mechanical ventilation, Nzeb, LCC.
2

Síntese e caracterização de surfactantes glicosídicos a partir da amilose e alquil fenóis extraídos do LCC. / Synthesis and characterization of glycosidic surfactantes from amylose and alkyl extracted phenols of the LCC.

França, Francisco 30 August 2007 (has links)
FRANÇA F.C.F. Síntese e caracterização de surfactantes glicosídicos a partir da amilose e alquil fenóis extraídos do LCC. 2007. 145 f. Tese (Doutorado em Química Inorgânica) – Centro de Ciências, Universidade Federal do Ceará, Fortaleza, 2007. / Submitted by irlana araujo (irlanaaraujo@gmail.com) on 2011-11-16T19:40:38Z No. of bitstreams: 1 2007_tes_Fran França.pdf: 7682996 bytes, checksum: 7ba0c141ae5431aa23030764cd569dd1 (MD5) / Approved for entry into archive by Aline Nascimento(vieiraaline@yahoo.com.br) on 2011-11-17T11:20:22Z (GMT) No. of bitstreams: 1 2007_tes_Fran França.pdf: 7682996 bytes, checksum: 7ba0c141ae5431aa23030764cd569dd1 (MD5) / Made available in DSpace on 2011-11-17T11:20:22Z (GMT). No. of bitstreams: 1 2007_tes_Fran França.pdf: 7682996 bytes, checksum: 7ba0c141ae5431aa23030764cd569dd1 (MD5) Previous issue date: 2007-08-30 / Nonionic surfactants are synthesised from renewable raw materials such as fat acids and sugars. They are dermatological safe, biodegradable and provide excellent surface active properties, such as good wettability, good foaming production and good cleaning ability. The present work deals with the synthesis and characterization of alkyl polyglycosides where the hydrophilic part is constituted of oligosaccharides derived from the degradation of amylose and the hydrophobic part is constituted from phenolics lipids which constitute the cashew nut shell liquid (CNSL). The condensation reaction between the hydrophilic and hydrophobic parts is the usual Köenig-Knorr reaction with some modifications. The structural characterization of the surfactants was followed by nuclear magnetic ressonance (NMR) together with Fourier transform IR spectroscopy (FT-IR). The two techniques showed evidence of characteristics bands of aromatic rings, glycosides rings, olefin and paraffin. The cross-peak NOESY spectra demonstrated that the preferred conformation of the glycosidic units in the head groups was of 4C1 type with an anomeric  configuration. The thermal behaviour of the surfactants as well as their behaviour in solution (selfassembly) is strongly dependent of its structural characteristics (head group and hydrophobic tail). Measures of surface tension demonstrated that the Critical Micelle Concentration (CMC) values for the surfactants studied were comparable to the values cited for the nonionic surfactants in the literature. The isothermic study of surface tension versus the concentration natural logarithm indicates that the aggregation behaviour of the alkylphenyl glycosides is dependent of its structural characteristics. The values of the area per molecule “A” indicate that cardyl glycosides probably form larger aggregates than cardanyl e anacardyl glycosides. Theoretical considerations about the critical packing parameters (CPP) data showed that the major kinds of aggregates are of vesicles and bilayer types indicating the possibility of nanotubes formation by self-assembly once these structures are intermediaries that anticipate the nanostructure formation in solution / Surfactantes não iônicos são sintetizados a partir de matérias-primas renováveis tais como álcoois graxos e açúcares. Exibem segurança dermatológica, biodegradabilidade e excelentes propriedades de superfície ativa, tal como uma boa molhabilidade, boa produção de espuma e boa habilidade de limpeza. O presente trabalho trata da síntese e caracterização de surfactantes alquil poliglicosídicos cuja parte hidrofílica é constituída de oligossacarídeos derivados da degradação da amilose e a parte hidrofóbica é constituída de lipídios fenólicos que constituem o Líquido da Castanha do Caju (LCC). A reação de condensação entre as partes hidrofílica e hidrofóbica foi realizada através da reação de Köenig-Knorr com algumas modificações. A caracterização estrutural dos surfactantes foi acompanhada por ressonância magnética nuclear (RMN) juntamente com a espectroscopia de absorção na região do infravermelho (IV). As duas técnicas evidenciaram bandas características de anéis aromáticos, anéis glicosídicos, olefinas e parafinas (alifáticos). Os picos cruzados do espectro NOESY mostraram que a conformação preferida das unidades glicosídicas nos grupos cabeça é do tipo 4C1 com uma configuração anomérica. O comportamento térmico dos surfactantes bem como seu comportamento em solução (auto-associação) é fortemente dependente de suas características estruturais (grupo cabeça e cauda hidrofóbica). Medidas de tensão superficial mostraram que os valores da Concentração Micelar Crítica (CMC) para os surfactantes estudados são comparáveis aos valores citados na literatura para surfactantes não iônicos. O estudo da isoterma de tensão superficial versus logaritmo natural da concentração indicou que o comportamento de agregação dos alquilfenil glicosídeos é dependente de suas características estruturais. Os valores de área por molécula “A” indicam que os cardil glicosídeos provavelmente formam agregados menores do que os cardanil e anacardil glicosídeos. Considerações teóricas sobre os dados de parâmetros críticos de empacotamento (PCE) indicam que os principais tipos de agregados são do tipo vesículas e bicamadas, indicando a possibilidade da formação de nanotubos por auto-associação uma vez que estas estruturas são intermediárias e que antecedem a formação de nanoestruturas em solução.
3

LCC-analys av FTX-system : En jämförelse av centralt- och lägenhetsplacerat / LCC-analysis of HRV-systems : A comparison of central units and apartment units

Appelgren, Jörgen, Kjellström, Fredrik January 2011 (has links)
This report is the result of a thesis conducted at the consulting firm Bjerking AB andis the final part of the Bachelor Programme in Construction Engineering at Universityof Uppsala. The work aims to investigate the costs and how the choice of ventilationsystem affects building projects during a long-term period. This report covers costssuch as investment, maintenance and energy but also how they affect residents andbuilders. Building regulations for energy consumption are expected to be tougher;therefore a comparison of two different heat recovery ventilation systems(HRV-system) was made. One system is based on a centrally placed unit that coversthe whole buildings ventilation through vertical shafts. The second system is based onapartment placed unit that only covers the individual apartment’s ventilation. The unitmakes it possible for the individual user to control the ventilation flow.The method used for comparison of the costs was Life Cycle Cost (LCC). It results inthe total cost during a selected calculation period of 20 years, where yearly basedcosts as energy and maintenance is included. Two housing projects in central Uppsalawere chosen as a reference. They were similar in design but with the two differentsystems of ventilation. A questionnaire was handed out to provide experience fromresidents with apartment units. The results were used in the analysis of the systemsand to determine its pros and cons.Information of costs was collected from different companies and resulted intocustomized spreadsheets to determine the cost per apartment. The result shows thatthe difference in investment is not significant between the systems but is big inmaintenance and energy. The biggest difference is maintenance where the apartmentsystems many service points is increasing the cost. Energy consumption for theapartment system leads to higher energy costs than with a central system, even if thecontrol function is used. The explanation is that a central systems fans have lowerpower usage and the heat recovery is more efficient then an apartment system.The conclusion is that a central system has a lower total cost compared to anapartment system during the calculation period. A reason for choosing the apartmentsystem would be if a need to maximize living space is a priority, and the developingphase of the project is well thought thru.Keywords: LCC-analysis, HRV-systems, Central unit, Apartment unit.
4

Isoleringsmaterials påverkan på LCA och LCC i prefabricerade småhus / The impact of insulation materials on LCA and LCC in prefabricated houses

Georges, Steve, Larsson, Oskar January 2020 (has links)
Syfte: Syftet var att undersöka huruvida olika isoleringsmaterial inom byggsektorn påverkar CO2-utsläppen, kostnaden och köldbryggor i småhus. Detta utfördes för att belysa vilka effekter det medföra kortsiktigt och långsiktigt för både byggföretagen samt för klimatet. Metod: Metoderna som användes var litteraturstudie, dokumentanalys och fallstudie. Resultat: Resultaten från empirin visade att isoleringsmaterialet fick relativt stora konsekvenser för de totala energiförlusterna. Detta genom att köldbryggorna och U-värdenas storlek förändras medan areor och längderna på köldbryggorna är konstanta. Skillnaderna blir tydligare ju större area huset har (inklusive antal våningar) och det ger i de flesta fall även upphov till längre köldbryggor. Resultatet visade att cellulosa hade det bästa LCC-värdet medan aerogel hade det sämsta LCC-värde, aerogel var cirka 790% värre än cellulosa. Aerogel hade lägst koldioxidutsläpp vid utsläpp från el som bedriver huset medans mineralull, cellplast, cellulosa släpper ut cirka 10% mer än aerogel. Vid isoleringsmaterialproduktion släpper aerogel mest koldioxid och cellulosan absorberar koldioxid.   Konsekvenser: Isoleringsmaterialet har en stor inverkan på energiförlusterna i småhus. Det främsta skälet till att välja ett bättre isoleringsmaterial är på grund av värmekonduktivitet, då det får miljömässiga och ekonomiska konsekvenser. Lägre energiförbrukning är positivt för miljön. Begränsningar: På grund av examensarbetets omfattning begränsades undersökningen till småhus som är stationerade i Sverige. Det medförde att studien anpassades efter krav som återfinns I BBR (Boverkets Byggregler). Beräkningarna och värden för köldbryggorna är endast utförda teoretiskt, d. v. s ingen uppföljning sker eftersom tiden och resurserna inte är tillräckliga. Nyckelord: Aerogel, cellplast, cellulosa, energiförluster, energitransmission, hållbart byggande isoleringsmaterial, långsiktigt byggande, köldbryggor, mineralull, polyuretan, / Purpose: The purpose was to analyze to which degree different insulation materials affected the, CO2-emissions, cost and thermal bridges in houses. This was due to the fact that we wanted to highlight the effects it brought in the long and short run for both the building companies but also for the environment. Method: The methods used was literature studies, document analysis and case study. Findings: The results from the empiricism showed that the insulations material had relatively large consequences for the total energy losses. This due to the thermal bridges and the U-values size change while the areas and the lengths of the thermal bridges remain constant. The differences become more distinct with larger areas on the houses (including the amount of building floors) and usually result in longer thermal bridges. The results of the empirical study showed that cellulose had the best LCC value while aerogel had the worst LCC value, aerogel was about 790% worse than cellulose. Aerogel had the best carbon dioxide emissions when emitted from electricity while mineral wool, cellular plastic, cellulose emitted about 10% more than aerogel. In insulating material production, aerogel releases most carbon dioxide and the cellulose absorb carbon dioxide. Implications: The insulation material does have a large impact on the energy transmission in houses. There is more than one reason to choose a better insulation material, mainly because of environmental and economic reasons. Less energy consumption is positive for the environment. Limitations: Due to the extent of the examination project this study was limited to houses stationed in Sweden. It resulted in the study being costumed to fit the requirements in Boverket national board of housing, building and planning. The calculations and the values of the thermal bridges are only calculated in theory. Keywords: Aerogel, cellulose, energy loss, insulation material, mineral wool, polyurethane, polystyrene, sustainable building, thermal bridges,
5

Mall för LCC-analys vid kabelkanalisation inom järnväg

Lindblom, Henrik, Velin, Dan January 2016 (has links)
Examensarbetet handlar om Trafikverkets tillämpning av LCC-kalkylering för projektering av kabelkanalisation inom järnväg. Arbetet görs för Rejlers Sverige AB och syftar till att få fram ett verktyg för beräkning av LCC enligt de krav som ställs av Trafikverket, diskussion om huruvida tillämpning av metoden är användbar.
6

LCC på ventilationssystemet på en skola : en undersökning huruvida VAV eller CAV är mest ekonomiskt i längden

Dahlberg, Håkan January 2013 (has links)
Vid projektering idag ställs konstruktören ofta inför valet att projektera för antingen ventilation med konstanta flöden, eller med variabla flöden. Vidare kan även flödena varieras manuellt eller automatiskt. Det konstruktören måste ta hänsyn till är investeringskostnaden, men även potentiella energi- samt kostnadsbesparingar över tid. Många gånger är det svårt att veta hur energianvändningen påverkas av de olika systemvalen varför det är svårt att välja det mest optimala systemet.Detta arbete undersöker livscykelkostnaden, LCC, med nuvärdeskostnaden på en skola i Uppsala med tre olika system, antingen konstant ventilationsflöde, CAV med timer, manuellt styrd variabel ventilation, VAV, eller automatisk VAV med styrning på temperatur och CO2. Huvudanledningen till det är att skolor består av en mängd olika klassrum och lokaler som inte alltid används under skoltiden, risken finns alltså att skolan överventileras med ett traditionellt CAV. Johansson (2005) visade att VAV mycket väl vara ekonomiskt försvarbart just i skolor varför syftet med detta arbete är att se hur det föreligger i detta aktuella fall, och vilken av lösningarna som är mest ekonomisk.Skolan simuleras med programvaran VIP Energy 2.0.8, ett simuleringsprogram för energibalansberäkning, där de tre olika driftsfallen undersöks och hur energibehovet förändras men varierad ventilationsgrad. Även temperaturerna i klassrummen simuleras och beaktas. Kostnaderna för de olika installationerna presenteras där det visar sig mer avancerade system är betydligt dyrare. Den billigaste lösningen kostar 450 000 kr medan den dyraste kostar 680 000 kr. Vidare diskuteras kalkylräntan, energipris och energiprisförändringarna, och där används två olika kalkylräntor, 5 % och 10 %. Ett Sverigepris på energi presenteras, men även ett Europa-anpassat alternativ där elpriset antas dyrare. Realenergipriset antas öka med 3 % per år.Resultatet visar att de energivinster man gör med de mer avancerade variabla systemen som försvinner de på grund av de dyrare investeringskostnaderna. I vissa fall visar det som däremot att en manuell VAV styrning på ventilationen kan vara ekonomisk försvarbar.Ett problem som dock uppstår med sänkt ventilation under sommarhalvåret är innetemperaturer som överstiger de högstanivåer som Socialstyrelsen satt. / When designing today, the building designer is often faced with the choice of planning for either ventilation with constant flow or variable flow. Furthermore the flows can be varied manually or automatically. The building designer has to take into account the cost of the investment, but also potential energy- and cost savings over time. Many times it is difficult to know how energy is affected by the various systems making it difficult to choose the most optimal system.This work investigates the LCC present value at a school in Uppsala with three different systems, either CAV with timer, manually controlled VAV or automatic VAV with is controlled by temperature and CO2. The main reason is that schools consist of a variety of classrooms and facilities that are not always used during school time, the risk is that schools can be over ventilated with a traditional CAV. Johansson (2005) showed that VAV can be financially feasible in schools why the purpose of this thesis is to see how it is in this current case, and which solution is the most economical.The school is simulated with software VIP Energy 2.0.8 where the three different operating conditions are investigated and how energy changes with varied ventilation rate. The temperatures in the classrooms are also simulated and observed. The costs of the various installations are presented where it appears more advanced systems are significantly more expensive. The cheapest solution costs 450 000 SEK while the most expensive costs 680 000 SEK. Furthermore the thesis also discuss the cost of capital, energy price and energy price changes, and where two different discount rates, 5% and 10%, is used. A Sweden Price on energy is presented, but also a Europe-adapted option where electricity price is predictable more expensive. Real energy prices are expected to increase by 3% per year.The results show that the energy savings due to the more advanced variable systems is marginalized because of the expensive investment costs. In some cases it shows that a manual control of ventilation VAV may be economic considerations.A problem arises, however, with reduced ventilation during the summer months as the temperatures exceeds the maximum levels Socialstyrelsen made.
7

Nätplan för fördelningsstationen TT7142 Ånimskog : Vattenfall Eldistribution AB

Aguilar, Ximena, Jason, Daria January 2004 (has links)
No description available.
8

Nätplan för fördelningsstationen TT7142 Ånimskog : Vattenfall Eldistribution AB

Aguilar, Ximena, Jason, Daria January 2004 (has links)
No description available.
9

Síntese e avaliação termo-oxidativa de potenciais biolubrificantes a partir do cardanol / Synthesis and thermo-oxidative evaluation of potential biolubricants from cardanol

Almeida, Mayara Oliveira de January 2017 (has links)
ALMEIDA, Mayara Oliveira de. Síntese e avaliação termo-oxidativa de potenciais biolubrificantes a partir do cardanol. 2017. 75 f. Dissertação (Mestrado em Química)- Universidade Federal do Ceará, Fortaleza, 2017. / Submitted by Celia Sena (celiasena@dqoi.ufc.br) on 2017-09-29T14:30:05Z No. of bitstreams: 1 2017_dis_modealmeida.pdf.pdf: 4126965 bytes, checksum: ef9f56adcff0053c9fb2a5ec76782155 (MD5) / Approved for entry into archive by Jairo Viana (jairo@ufc.br) on 2017-10-09T22:52:50Z (GMT) No. of bitstreams: 1 2017_dis_modealmeida.pdf.pdf: 4126965 bytes, checksum: ef9f56adcff0053c9fb2a5ec76782155 (MD5) / Made available in DSpace on 2017-10-09T22:52:50Z (GMT). No. of bitstreams: 1 2017_dis_modealmeida.pdf.pdf: 4126965 bytes, checksum: ef9f56adcff0053c9fb2a5ec76782155 (MD5) Previous issue date: 2017 / The need to replace petroleum based lubricants with sustainable and environmentally friendly alternatives has encouraged the development of vegetable oil based materials - Biolubricants. Although there are several advantages, the development of biolubricants can compete directly with the agricultural and food sector, making their use unfeasible with respect to economic and social aspects. The present work describes the use of cardanol, a major constituent of an agro-industrial by-product obtained from cashew nut shell liquid (CNSL), as a raw material in the synthesis of new compounds as potential biolubricants. The synthesis of these materials was carried out under solvent free conditions, free of catalyst and/or using microwave irradiation. The biolubricants obtained were structurally characterized by techniques mass spectrometry (GC/MS), infrared (IR) spectroscopy and NMR (1H and 13C). The thermal and oxidative stability of the materials were also evaluated by the thermoanalytical techniques, TGA and DSC. And their viscosities were analyzed by means of rheological studies. The TGA results showed that the chemical modifications in the cardanol led to the obtaining of compounds with high thermo-oxidative stability, which presented values of T (onset) above 220 ° C. The DSC analysis (ASTM E-2009) showed that all products obtained had a much higher initial oxidation temperature (OOT) than cardanol. The rheological studies indicated that the different chemical modifications also influenced the viscosities of the potential biolubricants. / A necessidade de substituir os lubrificantes à base de petróleo por alternativas sustentáveis e favoráveis ao meio ambiente tem incentivado o desenvolvimento de materiais à base de óleo vegetal - Biolubrificantes. Embora existam diversas vantagens, o desenvolvimento de biolubrificantes pode competir diretamente com o setor agrícola e alimentício, tornando o seu uso inviável no que diz respeito aos aspectos econômicos e sociais. O presente trabalho descreve a utilização do cardanol, constituinte majoritário de um subproduto agro-industrial obtido a partir do Líquido da Casca da Castanha de Caju (LCC), como matéria-prima na síntese de novos compostos como potenciais biolubrificantes. A síntese destes materiais foi realizada em condições livres de solvente, livres de catalisador e/ou utilizando irradiação de microondas. Os biolubrificantes obtidos foram caracterizados estruturalmente pelas técnicas espectrometria de massa (CG/EM), espectroscopia no infravermelho (IV) and RMN (1H e 13C). A estabilidade térmica e oxidativa dos materiais também foram avaliadas pelas técnicas termoanalíticas, TGA e DSC. Suas viscosidades foram analisadas por meio de estudos reológicos. Os resultados de TGA destacaram que as modificações químicas no cardanol levaram a obtenção de compostos com elevada estabilidade termo-oxidativa, os quais apresentaram valores de T(onset) acima de 220 °C. As análises de DSC (ASTM E-2009) mostraram que todos os produtos obtidos apresentaram temperatura inicial de oxidação (OOT) muito maior do que o cardanol. Os estudos reológicos indicaram que as diferentes modificações químicas também influenciaram nas viscosidades dos potenciais biolubrificantes.
10

Náklady životního cyklu výrobku

Flíborová, Eva January 2007 (has links)
Prace je zamerena na analyzu zivotniho cyklu vyrobku. Vybranym vyrobkem je automaticka pracka.Soucasti prace je i hodnotova analyza, srovnavajici zjistene naklady se stupnem splneni pozadovanych funkci.

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