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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.
141

SÃntese e AvaliaÃÃo do potencial de uma meso-Porfirina, derivada do LCC, como desativadora dos metais pesados: cÃdmio, chumbo e nÃquel / Summary and Evaluation of the Potential of a meso-porphyrin, derived from the CNSL, disable heavy metals: cadmium, lead and nickel

FÃtima AndrÃa Lima GirÃo 28 October 2008 (has links)
FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgico / A busca por processos quÃmicos que reduzam ou eliminem o uso e a geraÃÃo de substÃncias tÃxicas tem sido crescente nas Ãltimas dÃcadas. Com este novo direcionamento para reduÃÃo do impacto das atividades industriais, foram propostas alternativas que possam reduzir o impacto ambiental. Neste aspecto, foram sintetizados meso-porfirnas do tipo A4 (meso-5,10,15,20) a partir do LÃquido da Casca da Castanha do Caju - LCC (uma fonte renovÃvel, local, abundante e biodegradÃvel). A meso-porfirina utilizada neste trabalho foi obtida a partir do processo de destilaÃÃo do LCC. O primeiro derivado refere-se à formaÃÃo do composto bromado, seguido da obtenÃÃo do derivado aldeÃdico, finalmente, com o auxÃlio do pirrol, tem-se a formaÃÃo da meso-porfirina. Os compostos foram purificados em coluna cromatogrÃfica e caracterizados por tÃcnicas experimentais de RMN 13C e 1H , GC-EM, IV e UV-VIS, que confirmaram a obtenÃÃo do produto desejado. A porfirina base livre foi submetida aos processos de metalaÃÃo utilizando-se para isto, Ni(C2H3O2).4H2O, Cd(CH3COO)2 e Pb(CH3COO)2, como sal doador do metal e diclorometano como solvente, conforme metodologia usual a reaÃÃo permaneceu em agitaÃÃo constante. A metalaÃÃo foi acompanhada por espectroscopia no UV-VIS e cromatografia de camada delgada
142

AÃÃo antioxidante de derivados do lÃquido da castanha de cajà (LCC) sobre a degradaÃÃo termooxidativa do POLI (1,4-CIS-ISOPRENO) / Antioxidants action of derivatives of the on the Cashew nut shell liquid (CNSL) thermal degradation of POLI (1,4-CIS-ISOPRENO)

Francisco Helder Almeida Rodrigues 11 May 2006 (has links)
CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / O lÃquido da castanha de caju (LCC) à constituÃdo de uma mistura de fenÃis com uma longa cadeia alquilÃca na posiÃÃo meta, possuindo diferentes graus de insaturaÃÃes. O estudo cinÃtico da degradaÃÃo termooxidativa a 140ÂC de filme de poli(1,4-cis-isopreno) sintÃtico (PIS), na ausÃncia e presenÃa do LCC tÃcnico e natural e seus derivados (Ãcido anacÃrdico, cardol, cardanol, cardanol hidrogenado e cardanol hidrogenado e alquilado), foi monitorado por espectroscopia na regiÃo do infravermelho atravÃs do acompanhamento da absorbÃncia relativa das bandas em 3450 cm-1, 1720 cm-1 e 835 cm-1. O tempo de induÃÃo (τi) e as constantes aparentes de velocidade para a formaÃÃo de produtos contendo hidrÃxido (kOH) e carbonila (kC=O) e para o consumo das ligaÃÃes duplas da cadeia (kC=C) foram os parÃmetros utilizados. Todos os materiais estudados apresentaram efeito estabilizante na degradaÃÃo tÃrmica do PIS, evidenciado pelo aumento do tempo de induÃÃo e a diminuiÃÃo das constantes aparentes de velocidade. AnÃlise das variaÃÃes de kOH, kC=O, kC=C e τi indica que o mecanismo de aÃÃo independe dos derivados do LCC. A maior efetividade dos derivados do LCC tÃcnico à prÃxima a 3 % (m/m), com exceÃÃo do cardol e HAlqcardanol. Por outro lado, a maior efetividade dos derivados do LCC natural (cardol e cardanol) à prÃxima a 2 % (m/m), com exceÃÃo do Ãcido anacÃrdico e do prÃprio LCC. A atividade antioxidante dos derivados do LCC depende da quantidade de material polimerizado presentes neles. Baseado nos parÃmetros cinÃticos, a ordem de atividade antioxidante para os derivados do LCC tÃcnico foi: LCC > cardol >> cardanol ≅ cardanol hidrogenado e alquilado > cardanol hidrogenado. Para os derivados do LCC natural a ordem foi: cardol > cardanol >> LCC natural >> Ãcido anacÃrdico. AnÃlise termogravimÃtrica revela que a adiÃÃo de derivados do LCC provoca estabilizaÃÃo do PIS quando degradado tanto em atmosfera de nitrogÃnio, como em ar sintÃtico. Os antioxidantes comerciais testados: IPPD (N-isopropil-N-fenil-p-fenileno-diamina), DPPD (N,Nâ-fenil-p-fenileno-diamina), Banox H (2,2,4-trimetil-1,2-dihidroquinolina-polimerizado) e Banox S (fenol estirenado) apresentaram uma atividade bastante superior, com exceÃÃo do BHT (2,6-di-terc-butil-4-metil-fenol). Dentre os derivados do β-naftol, o AO-3 (1,6-diamino-β-naftol) apresentou uma atividade antioxidante similar ao IPPD, embora com menores valores de constantes aparentes de velocidade. Por outro lado, os derivados AO-1 (6-N-etil, N-etilamino-β-naftol) e AO-2 (6-N-etil,N-dietilamino-β-naftol) apresentaram uma atividade antioxidante um pouco superior que os derivados do LCC, mas inferior ao AO-3. / Cashew nut shell liquid (CNSL) is a mixture of meta-alkyl-phenols which varies on its degree of unsaturation attached to the benzene nucleus. The kinetic study of the thermal degradation at 140ÂC of synthetic cis-1,4-polyisoprene film, in the absence and presence of technical and natural CNSL and some derivatives (anacardic acid, cardol, cardanol, hydrogenated cardanol and alkylated hydrogenated cardanol) was carried out by infrared spectroscopy through the evolution of the relative absorbance of the bands in 3450 cm-1, 1720 cm-1 and 835 cm-1. The amount of hydroxyl and carbonyl group formed and also of carbon double bond consumed during the degradation was determined. All material studied showed antioxidant activity that was verified by an increase in the induction period and a decrease in the apparent rate constants of thermal-oxidation. The antioxidant effectiveness is higher for the addition of 3% (w/w) of technical CNSL derivatives, except for alkylated cardanol. The antioxidant effectiveness is higher for the addition of 2% (w/w) of natural CNSL derivatives, except for anacardic acid and pure. Based on kinetic parameters the order of antioxidant activity for technical CNSL derivative was: CNSL >> cardanol ≅ hydrogenated and alkylated cardanol >> hydrogenated cardanol. For natural CNSL components the order was: cardol > cardanol >> CNSL >> Anacardic acid. Thermogravimetric analyses reveals that the addition of LCC derivatives provide stabilization of PIS in atmosphere of nitrogen, as well as in synthetic air. The commercial antioxidants: IPPD (N-isopropyl-N-phenil-p-phenilene-diamine), DPPD (N,Nâ-phenil-p- phenilene-diamine), Banox H (2,2,4-trimethyl-1,2-dihidroquinoline-polimerizade) and Banox S (phenol styrened) presented a quite superior activity, except for BHT (2,6-di-terc-buthyl-4-methyl-phenol. Among β-naftol derivatives, AO-3 (1,6-diamine-β-naftol) presented a similar antioxidant activity to IPPD, although with smaller values of the apparent rate constants. On the other hand, the derivatives AO-1 (6-N-ethyl, N-ethylamine-β-naftol) and AO-2 (6-N-ethyl,N-diethylamine-β-naftol) presented a quite superior antioxidant activity when compared to LCC derivatives, but inferior to AO-3.
143

Energirenovering av en kulturhistoriskt värdefull byggnad med LCC-optimering : En fallstudie av Skylten i Linköping / Energy Refurbishment of a Culture Historical Building with LCC Optimization : A Case Study of Skylten in Linköping

Tingström, Louise January 2017 (has links)
I dagsläget står bostads- och servicesektorn för cirka 40% av den totala slutliga energianvändningen i Sverige [1], vilket motsvarar utsläpp av cirka 6 miljoner ton koldioxidekvivalenter [2]. Cirka 90% av denna energianvändning har sitt ursprung från hushåll och lokalbyggnader [1]. Eftersom Sveriges nationella klimatmål innefattar att utsläppen år 2020 ska minska med 40% jämfört med år 1990  [3] är det aktuellt att minska energianvändningen i byggnader. Det här examensarbetet har som syfte att ta fram åtgärdsförslag som bör realiseras vid renovering av en ändamålslokal med kulturhistoriskt värde. Åtgärdsförslag har därför tagits fram genom en livscykelkostnadsoptimering i OPERA-MILP. Eftersom det var känt att inomhustemperaturen sommartid ofta översteg normalt sett accepterad maxtemperatur (24°C [4]) har även åtgärdsförslag för ett förbättrat inomhusklimat undersökts. Byggnaden i dagsläget, en planerad renovering samt en livscykelkostnadsoptimerad byggnad har modellerats i IDA-ICE för att simulera energiflöden och inomhusklimat.  Modellen av byggnaden i dagsläget resulterade i ett fjärrvärmebehov på cirka 120 000 kWh under ett år, vilket är en avvikelse med 6% mot historisk fjärrvärmedata. Den planerade renoveringen fick ett ökat behov med cirka 5 000 kWh på grund av att källaren kommer att värmas upp. Livscykelkostnadsoptimeringen i OPERA-MILP gav följande åtgärder: byte till energiglas och vindbjälksisolering på 14 cm. Dessa åtgärder minskade fjärrvärmebehovet med cirka 2 000 kWh jämfört med den planerade renoveringen, vilket innebär att behovet fortfarande är större än i dagsläget. Den specifika energianvändningen minskade dock något då den gick från 114 kWh/(m2, år) till 100 kWh/(m2, år), vilket beror på den ökade tempererade arean och de energibesparande åtgärderna. Vid simulering av modellerna sågs att byggnaderna var överhettade sommartid. Därför undersöktes inre solavskärmning, fjärrkyla, ventilationsstyrning och olika ventilationstyper. Fjärrkyla resulterade i ett behagligt inomhusklimat med en driftskostnad på cirka 4 000 sek årligen. Slutligen simulerades en kombination av olika åtgärder vilket resulterade i ett minskat fjärrvärmebehov med cirka 13 000 kWh jämfört med dagsläget och en specifik energianvändning på 88 kWh/(m2, år). Detta gjordes genom att kombinera de livscykelkostnadsoptimerade åtgärderna med tätning, fjärrkyla samt närvarostyrd ventilation. / As of today, the housing and service sector stands for about 40% of the total net energy use in Sweden [1], which equal emissions of about 60 million tons of carbon dioxide equivalents [2]. About 90% of this energy use originates from households and facilities [1]. Since Sweden's national climate goal includes that the emissions year 2020 should be reduced by 40% in comparison with year 1990 [3] it is up-to-date to reduce the energy use in buildings. This master's thesis aims to develop measure proposals that should be implemented during refurbishment of a facility with a cultural-historical value. Measures has therefore been proposed by a life cycle cost optimization in OPERA-MILP. Since it was known that the indoor temperature during summer reaches over the normally accepted maximum temperature (24°C [4]), indoor climate improving measures has also been investigated. The building of today, the planned refurbished building and the life cycle cost optimized building has been modeled in IDA-ICE to simulate the energy flows and indoor climate. The model of the building of today resulted in a district heating requirement of about 120 000 kWh per year, which is a variation of 6% in comparison to historical district heating data. The planned refurbishment got an increased requirement of about 5 000 kWh due to the fact that the basement will be heated. The life cycle cost optimization in OPERA-MILP gave the following measures: change to energy glas and 14 cm insulation in the attic. These measures decreased the district heating requirement with about 2 000 kWh in comparison with the planned refurbishment, which means that the requirement is still larger than the requirement of the building of today. However, the specific energy use decreased as it went from 114 kWh/(m2, year) to 100 kWh/(m2, year), due to the increased heated area and the energy saving measures. In simulation of the models it was seen that the buildings were overheated during summer. Therefore blinds, district cooling, ventilation controlling and ventilation types were investigated. District cooling resulted in a pleasant indoor climate with an operation cost of about 4 000 sek yearly. Lastly, a combination of different measures were simulated which resulted in a decreased district heating use of about 13 000 kWh compared to the model of today and a specific energy use of 88 kWh/(m2, year). This was done by combining the optimal life cycle cost measures with sealing, district cooling and presence controlled ventilation.
144

LIVSCYKELKOSTNADSANALYS AV FÖRSLAG PÅ ENERGIEFFEKTIVISERINGAR - TVÅ FASTIGHETER BELÄGNA I UMEÅ / Life cycle cost analysis ofproposals for energy efficiencies – Two properties located in Umeå, Sweden

Wahlgren, Victor January 2021 (has links)
This report is a degree project carried out at Rejles AB on behalf of a local real estate company in Umeå, Sweden. The real estate company bought two properties with a total of 95 rental apartments from another company in 2018. The buildings were built in 1991 and have installed new ventilation units in 2015, in other words before the change of ownership. The real estate company has requested confidentiality and therefore the properties will be named Property A and Property B. Property A consists of 59 apartment and Property B consists of 36 apartments. The real estate company thinks that the properties consume a lot of purchased energy compared to other properties that they manage in the same area. Property A purchased energy in the form of district heating and electricity corresponding to an average of 623 MWh per year during the years 2018, 2019 and 2020. The same figure for Property B was 477 MWh per year. Both properties received the grade E in the latest energy declaration (Swedish standard). The rating scale is graded from A to G, where A is the best, C is the requirement for new construction and G is the worst. The project begins with the head of administration describing the buildings, providing information and some floor plans. They contributed with, among other things, data on purchased district heating, electricity, and cold water from the years they were owners. This together provided a basis for field studies of the properties. During the site study, temperature measurements were made, products were documented, and the drawings were supplemented. Thereafter, calculations were made in Excel and simulations of the buildings in IDA ICE. Finally, a life cycle cost analysis was made The conclusion that both properties have the lighting in stairwells and elevators running around the clock, all year round. This could reduce the cost from 9,400 SEK per year to 1,200 SEK per year with sensory control. By lowering the temperature in the auxiliary spaces to 18 °C on Property A, a saving of at least 7,800 SEK per year could be made. The same measure in Property B would result in savings of 2,936 SEK per year. Property B has 36 towel warmers in the rental apartments and 9 towel warmers in different rooms in the property. All 45 towel warmers run on the hot water circulation. The 9 towel warmers in the property were not in use and should be taken out of service. This has the potential to make a saving of a total of 8,900 SEK per year. Replacing the remaining 36 with electric towel rails would provide a saving of SEK 35,000 SEK per year for the property owner. The above measures would make all the buildings to go from classification E to D according to BBR's BFE 2020: 4. / Denna rapport är ett examensarbete utfört på Rejlers AB på uppdrag åt ett lokalt fastighetsbolag i Umeå. Fastighetsbolaget köpte upp två fastigheter med totalt 95 hyreslägenheter från ett annat bolag 2018. Byggnaderna stod färdiga 1991 och har installerat nya ventilationsaggregat 2015, alltså innan ägarbytet. Nuvarande fastighetsbolaget vill att fastigheterna går under sekretess och därför kommer fastigheterna att benämnas som Fastighet A och Fastighet B. Fastighet A har 59 lägenheter och Fastighet B har 36 lägenheter. Fastighetsbolaget tycker att fastigheterna har en hög energianvändning jämfört med andra fastigheter som de förvaltar i samma område. Fastighet Aköper energi i form av fjärrvärme och elektricitet motsvarande ett snitt på 623 MWh per år. Samma siffra för Fastighet B var 477 MWh per år. I den senaste energideklarationen fick båda fastigheterna betyget E. Betygsskalan är graderad från A till G, där A är bäst, C är kravet för nybyggnation och G är sämst. Projektet inleddes med att förvaltningschefen beskrev byggnaderna, tillhandahöll information och ritningar. Fastighetsbolaget bidrog med bland annat data på inköpt fjärrvärme, elektricitet och kallvatten från åren som de varit ägare. Fastighetsbolaget gav även de senaste priserna för fjärrvärme och elektricitet. Detta tillsammans gav ett underlag för platsstudie av fastigheterna. Under platsstudien gjordes temperaturmätningar, produkter dokumenterades och ritningarna kompletterades. Där efter gjordes beräkningar i Excel och simuleringar av byggnaderna i IDA ICE. Till sist gjordes en livscykelkostandsanalys. Resultatet visade att kostnaden för fastighetsel kan gå från 9,4 tkr per år till 1,2 tkr per år genom att ersätta konstant belysning med sensorstyrd belysning. Genom att sänka temperaturen i biutrymmen till 18 °C i Fastighet A, så skulle en besparing på minst 7,8 tkr per år kunna göras. Samma åtgärd i Fastighet B skulle ge besparing på 3,0 tkr per år. Fastighet B hade totalt 45 handdukstorkar kopplade på varmvattencirkulationen, varav 9 av dem fanns i biutrymmen och användes ej. Det går att göra en besparing på 8,9 tkr per år att koppla bort handdukstorkarna belägna i biutrymmen. Med att ersätta resterande 36 med elektriska skulle det ge en besparing på 35,4 tkr per år för fastighetsägaren. Ovanstående förslag till åtgärder skulle göra att alla byggnaderna går från klassificeringen E till D enligt BBR:s BFE 2020:4.
145

Jämförelse av CAV- och VAV-ventilationssystem för Björkhöjdskolan / Comparison of CAV- and VAV-ventilation system of Björkhöjd school

Holgersson, Lisa, Tekle, Yonatan January 2020 (has links)
För att klara klimatmålen i Sverige och som EU-land behövs det genomföras fler energieffektiviseringar. Syftet med detta arbete har därför varit att jämföra två olika ventilationssystem,VAV-system och CAV-system inför en ombyggnation i Björkhöjdskolan som befinner sig i Borås kommun. Jämförelsen omfattas av en energi- och kostnadsanalys på de olika systemen föratt se vilket som drar mest energi och vilket som är mest kostnadseffektivt. Metodiken för att lösa arbetets frågeställningar har varit genom informationssamling från projektets deltagare och beräkningsgång i Microsoft Excel och Google kalkyl. Resultatet visar att VAV-system är den mest energieffektiva valet av ventilationssystem. Den har en årlig energianvändning på 7984 kWh/skolår medan CAV-systemet använder 22 087kWh/skolår. Den ekonomiska analysen visar att VAV-systemet har en högre LCC-kostnad jämfört med CAV-systemet. Den totala LCC-kostnaden för VAV-systemet är 2 128 045 kr och 2 027 494kr för CAV-systemet. Däremot har VAV-systemet en lägre nuvärdeskostnad än CAV-systemet. Om verksamheten hade omfattats av en säker beläggningsgrad skulle det totala luftflödet varit lägre och ett mindre luftbehandlingsaggregat hade kunnat väljas. Om kalkylräntan sjunker någon procent och energiprishöjningen höjs någon procent hade skillnaden i pris mellan systemen varit närmare noll. Förslag på framtida analys kan vara att göra en driftoptimering när en beläggningsgrad finns, då kan det framföras en tydlig motivering till att välja VAV-system som är bäst ur miljösynpunkt. / In order to reach the climate goals in Sweden that the EU has set, energy efficient solutions in buildings are required all around the country. The purpose of this report has therefore been to compere two different ventilations systems, VAV-system (variable air velocity) and CAV(constant air velocity) in a reconstruction of an a school buiding that is located in Borås. The comparison has involved both an energy- and economic analysis of the two different ventilation systems. The method to complete this report has been through gathering information from the project participants and calculations using Microsoft Excel and Google calculation. The result of this study makes it clear that a VAV-system is the best energy efficient choice of ventilation system. The yearly energy use of the VAV-system is 7984 kWh/school year while CAV-system uses 22087 kWh/school year. The economic analysis shows that the VAV-system has a higher LCC-cost due to the high investment sum. The total LCC-cost for VAV-system is 2128 045 SEK and 2 027 494 SEK for the CAV-system, however the present value for the VAVsystemis lower than the CAV-system. If the school could secure an occupancy the total air flow of the air handling unit (AHU) could be reduced. This could potentially lead to a change to a lower sized AHU that gives a lower cost of the AHU and further energy savings. A suggestion is to evaluate this further in a later stage of the project in order to optimize the AHU when the occupancy is given and more certain. In addition this could motivate to choice of the more energy efficient VAV-system.
146

Energi- och kostnadseffektiva klimatskal : För lager-, industri- och kontorsbyggnader

Aderskog, Mikael, Hoff, Christopher January 2013 (has links)
A study to optimize insulation thickness for stock-, industrial- and office-buildings for external walls and roof in an economical perspective has been conducted on behalf of DynaMate. DynaMate’s role is to maintain all Scania’s buildings. Analysis has also included other parts of the building envelope, such as windows, exterior doors and industrial doors. In this thesis, three different types of exterior wall constructions has been investigated, these are a sandwich design consisting of sheet metal and a another one consisting of concrete, as well as a wall of concrete with a coating of plasters. Furthermore, two types of roof structures have been studied, these are TRP-sheets and a concrete structure, both of which are externally isolated. For all types of building envelopes, different standard thicknesses of insulation have been used and the U-value of the windows has been varied. To calculate the energy needed for the different kinds of buildings, the program IDA Indoor Climate and Energy has been used.  Furthermore, a sensitivity analysis of the air tightness has been implemented for the building envelope. Based on the program results LCC (Life-cycle cost) calculations have been carried out for all combinations, thus be able to form an idea of ​​the combination and what kind of structure that is most economically tenable. A thermograph study was conducted in an existing warehouse at Scania. Observations show that the connection between the sandwich material of sheet metal and the foundation wall is flawed as this has a much lower thermal resistance compared to other parts of the building envelope. An alternative connection was developed which reduces the heat loss to one-fifth of the initial connection. An analysis regarding the companies approach to the vapour barrier in roof structures for industrial buildings has been investigated from a moisture standpoint. The analysis shows that without a functioning vapour barrier the moisture content in the construction increases over time, which leads to increased heating costs. The conclusion of this study shows that a reduction of insulation thickness for all types of studied buildings is more economically tenable than increasing the thickness. This is mainly due to the high cost of capital that the company uses for these investments. This means that any savings on cooling and heating costs very quickly is overthrown by the interest rate of the additional cost of the investment.
147

LCC Applications for Bridges and Integration with BMS

Safi, Mohammed January 2012 (has links)
Bridges are vital links in many transport networks and represent a big capital investment for both governments and taxpayers. They have to be managed in a way that ensures society's needs are optimally met. In many countries, bridges are mainly managed using bridge management systems (BMSs). Although many BMSs contain some forms of life-cycle costing (LCC), the use of LCC in bridge engineering is scarce. LCC in many BMSs has mainly been applied within the bridge operation phase, even though it has several useful applications within the bridge entire life, from cradle to grave. This licentiate thesis discusses the need of a BMS with integrated comprehensive LCC tools that can assist decision-makers at all levels and within all phases in selecting the most cost-effective alternative from an array of applicable alternatives. The thesis introduces the Swedish Bridge and Tunnel Management System (BaTMan). Acomprehensive integrated LCC implementation scheme is illustrated, taking into account the bridge investment and management process in Sweden. The basic LCC analytical tools as well as other helpful LCC techniques are addressed. Detailed case studies for real bridges at different investment phases are presented to demonstrate the recent improvement of BaTMan practically in the LCC integration. Cost records for 2,508 bridges extracted from BaTMan inventory data are used as input data in the presented case studies. Considering the same records, the average real and anticipated initial costs of different bridge types in Sweden will schematically be presented. The thesis introduces a bridge LCC program developed over this research named "BaTMan-LCC". The reason for which this program was developed is to combine all possible LCC applications for bridges in one tool and facilitate its implementation. The sensitivity analysis as well as the LCC saving potential highlighted in the presented case studies emphasizes the feasibility and the possibility of developing BaTMan to accommodate the applications of BaTMan-LCC. / QC 20120301 / ETSI
148

The effectiveness of grouted macadam at intersections. : A life-cycle cost analysis

Jacobsen, Sofie January 2012 (has links)
Intersections often experience severe rutting in the asphalt concrete layers due to slow moving, high loads, acceleration, deceleration and turning. This thesis aims to investigate the effectiveness of grouted macadam, open graded asphalt with its voids filled with cement grout, as a pavement material at intersections. This was done by investigating the properties of grouted macadam through a literature review and performing a life-cycle cost analysis comparing grouted macadam and asphalt concrete as pavement materials at an intersection. Grouted macadam is found to be similar to asphalt concrete concerning the relation between stiffness and temperature and frequency as well as fatigue behaviour. The main differences are that grouted macadam is stiffer, stronger and not prone to rutting. Thus it would be suitable to address rutting problems. The main drawbacks are that construction demands extra time and precision and that it is expensive compared to asphalt concrete. The life-cycle cost analysis showed that assuming that the grouted macadam has a service life of twenty years and rehabilitation of the asphalt concrete in the form of mill and refill takes place every fourth year the life-cycle costs are approximately the same. A sensitivity analysis was performed that showed that local variations can have large impact on the life-cycle costs. The main conclusion is that grouted macadam can be effective as a pavement material at intersections that experiences severe rutting and frequently reoccurring rehabilitations.
149

On maintenance management of wind and nuclear power plants

Nilsson, Julia January 2009 (has links)
Electrical production in Sweden today is mainly from nuclear and hydro power. However, there is large increase in renewable energy like wind power and the installed new capacity goals are large. Several electrical production sources are important for the sustainability of the energy system. Maintenance is an approach for keeping a system sustainable. The importance of structured maintenance for reliable electrical production systems triggers the development of qualitative and quantitative maintenance management methods. Examples of these methods are Reliability-Centered Maintenance (RCM) which is a structured qualitative approach that focuses on reliability when planning maintenance, and Reliability Centered Asset Management (RCAM) which is a development of RCM into a quantitative approach with the aim to relate preventive maintenance to total maintenance cost and system reliability. This thesis presents models, as applications of RCAM, based on the methods of Life Cycle Cost (LCC) and mathematical optimization, applied to wind and nuclear power plants. Both deterministic and stochastic approaches have been used and the proposed models are based on the Total Cost model, which summarizes costs for maintenance and production loss, and the Aircraft model, which is an opportunistic maintenance optimization model. Opportunistic maintenance is preventive maintenance performed at opportunities. The wind power applications in this study show on different ways to cover costs of condition monitoring systems (CMS) and further on economic benefits of these when uncertainties of times to failure are included in the model. The nuclear power applications show on that the optimization model is dependent on the discount rate and that a high discount rate gives more motivation for opportunistic replacements. When put into a stochastic framework and compared to other maintenance strategies it is shown that an extended opportunistic maintenance optimization model has a good overall performance, and that it, for high values of the constant cost of performing maintenance, is preferable to perform opportunistic maintenance. The proposed models, applied to wind and nuclear power plants, could be extended and adapted to fit other components and systems. / Reliability and cost centered maintenance methods
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Energieffektivisering och underhållsplanering : Ett samarbete mellan två handlingar

Sundberg, David, Veiksaar, Viktor January 2021 (has links)
In Sweden there are a lot of challenges when it comes to making buildings more energy efficient. In the year of 2018, the construction and housing business in Sweden, accounted for a total energy usage of 105 TWh, which is one third of the country’s total energy usage. In connection with today’s global environmental problems, it is important that all countries take the responsibility to minimize their energy usage as much as possible. Since the middle of the 1990’s the United Nations (UN) has been working on creating mutual goals based on each of its members specific conditions. The Kyoto Protocol and the 2030 Agenda are established agreements that have been made to reduce the members of UNs’ energy consumption and help solve the climate crisis. This thesis has been made in collaboration with Fastighetsstudion i Uppsala AB with the supervisors Sven Detterberg, a certified consultant in the field of energy efficiency and Andreas Andersson, a consultant in the field of maintenance planning. They have noticed that the energy mapping plan and the maintenance plan are made by two different contractors, even though they have a lot of their investment basis in common. A maintenance plan is something a property must have according to law, and the costs to maintain the property are a yearly expenditure that has been considered by the property manager. But when it comes to investing in making the building more energy efficient it can get very costly, and the money to these investments is something that is not accounted for in the yearly expenditure. Many property managers do not go through with investing in recommended energy efficiencies, because they cannot afford it, as it can take decades before the reduced cost in energy consumption pays for the investment by itself. The aim of this study is to synergize the energy mapping plan and the maintenance plan to see how much of the initial cost of the energy efficiency investments can be saved by combining it with planned maintenance costs. A tenant-owned association with four property buildings has been studied in this thesis. The properties have an existing energy mapping plan made in 2019 by Sven Detterberg, and a maintenance plan made in 2016 by Riksbyggen AB. Life cycle costs have been calculated by synergizing the planned maintenance and different energy efficiencies suggested in the energy mapping plan. The goal is to guide the tenant-owned associations on how the plans can be synergized, thus making the suggested energy efficiencies more affordable. This will in the long run help the tenant-owned association by increasing the value of the property, improve its economy and reduce its CO2-emissions. The case studied in this thesis achieved positive results. After combining the cost of the suggested energy efficiencies with the relevant planned maintenance costs it was concluded that all 5 suggestions would be profitable within less than 15 years and four of them in less than 10 years. Before combining the two plans, four of the suggestions would not be profitable within a 15-year period.

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