Diss. Linköping : Univ., 2005. / Härtill 7 uppsatser.

Diss. (sammanfattning) Linköping : Linköpings universitet, 2007. / Härtill 5 uppsatser.

Magnihill AB har en ambition att ingenting skall gå till spillo, och har begärt att deras mest energikrävande processer skall undersökas, detta för att minska den mängd värmeenergi som används. Magnihill har processer som kräver stora mängder av ånga för att fungera, men även olika källor av överskottsvärme som inte tidigare setts över, som till exempel avgaserna från ångpannan. Fokus lades ned på Magnihills största spillvärme källor, med dessa lösningsförslag, kan Magnihill bli en grönare och mer konkurrenskraftigt företag.

There is always a need to study the properties of complex input–output systems, properties that may be very difficult to determine. Two such properties are the output’s sensitivity to changes in the inputs and the output’s uncertainty if the inputs are uncertain. A system can be formulated as a model—a set of functions, equations and conditions that describe the system. We ultimately want to study and learn about the real system, but with a model that approximates the system well, we can study the model instead, which is usually easier. It is often easier to build a model as a set of combined sub-models, but good knowledge of each sub-model does not immediately lead to good knowledge of the entire model. Often, the most attractive approach to model studies is to write the model as computer software and study datasets generated by that software. Methods for sensitivity analysis (SA) and uncertainty analysis (UA) cannot be expected to be exactly the same for all models. In this thesis, we want to determine suitable SA and UA methods for a road traffic emission model, methods that can also be applied to any other model of similar structure. We examine parts of a well-known emission model and suggest a powerful data-generating tool. By studying generated datasets, we can examine properties in the model, suggest SA and UA methods and discuss the properties of these methods. We also present some of the results of applying the methods to the generated datasets. / Det finns alltid behov av att studera egenskaper hos komplexa input-output-system, egenskaper som kan vara mycket svåra att få fram. Två sådana egenskaper är ut fallets känslighet mot förändringar i ingångsvärdena och utfallets osäkerhet om ingångsvärdena har osäkerhet. Ett system kan formuleras som en modell-en mängd funktioner, ekvationer och betingelser som tillsammans liknar systemet. Vi vill egentligen studera och lära oss det verkliga systemet, men med en modell som approximerar det verkliga systemet bra kan man studera modellen istället, vilket i de flesta fall är enklare. Det är oftast enklare att bygga en modell som en mängd kombinerade delmodeller, men bra kunskap om varje delmodell leder inte omedelbart till bra kunskap om hela modellen. Det enklaste tillvägagångssättet för modellstudier är oftast att studera datamängder som genererats av modellen genom ett datorprogram. Metoder för känslighetsanalys (SA) och osäkerhetsanalys (UA) kan inte förväntas vara likadana för varje modell. I den här avhandlingen ska vi studera SA- och UA-metoder och resultat för en emissionsmodell för vägtrafik, men metoderna kan även användas för andra modeller av liknande struktur. Vi undersöker en välkänd emissionsmodell och föreslår ett kraftfullt verktyg för att generera data. Genom att studera genererade datamängder kan vi undersöka egenskaper i modellen, föreslå SA- och VA-metoder och diskutera metodernas egenskaper. Vi visar också några resultat när man tillämpar metoderna på de genererade datamängderna.

Background: The negative effects of air pollution on morbidity and mortality have been known since the mid 20th century. The two most well known examples are the Meuse Valley disaster in the 1930’ies and the London black fog in December 1952. Whilst there are numerous epidemiological studies, in which associations between morbidity and mortality and high levels of pollutants have been reported, the underlying mechanisms are not clear. Two of the main air pollutants are particulate matter (PM) mostly emanating from diesel exhaust (DE), and ozone, both of which are highly oxidative. Exposure to DE has resulted in adverse effects both in the respiratory tract and in the cardiovascular system. High ozone levels have also been shown to be associated with increased admissions to hospital for respiratory as well as cardiovascular conditions. The main aim of this thesis was to investigate the respiratory and cardiovascular effects of a combination of exposures to ozone and DE. DE generated during the urban part of the standardized European Transient Cycle (ETC) was compared to DE generated by an idling engine. It was also evaluated whether an acute exposure to ozone would have any effects on the cardiovascular system as assessed by venous occlusion forearm plethysmography and heart rate variability (HRV). In addition, fraction of exhaled nitric oxide (FENO) was evaluated as a potential marker for acute exposure to ozone or DE. Methods: Four double-blind randomized cross-over exposure studies were conducted to investigate the effects of ozone and DE on both the respiratory tract and the vascular function in healthy volunteers. All of the exposures were performed in purposely built “walk-in” chambers with strictly controlled exposures. In the first study, the volunteers were exposed to DE (300µg/m3) generated by an idling engine or to air, for one hour in the morning and to ozone (200 ppb) for two hours in the afternoon. A bronchoscopy with bronchial wash (BW) and bronchoalveolar lavage (BAL) was performed 24 hours after the initial exposure. In study II and III, an assessment of vascular function using venous occlusion forearm plethysmography was performed after an exposure to DE (250 µg/m3) generated under transient running conditions, compared to air exposure (study II) and ozone and air exposure (study III). HRV was assessed under a 24 hour period starting before each exposure (study III). In study IV, FENO measurements were conducted after DE and ozone exposures to investigate whether the previously established airway inflammation would be detectable by this non-invasive method. Results: DE exposure enhanced the established ozone-induced airway inflammation in terms of a pronounced neutrophilia in BW. DE generated under transient running conditions, impaired vascular function in healthy volunteers, whereas exposure to ozone did not. HRV were not altered by exposure to ozone. Exposure to DE caused a significant increase in FENO at the 10  (FENO10) and 50 (FENO50) mL/s flow rates at 6 hours post-exposure, but ozone exposure did not affect FENO at any flow rate or time point. Conclusion: We have tried to mimic real-life exposure to air pollutants. In the first study, an exposure to DE followed by an exposure to ozone in the afternoon resulted in an enhanced airway inflammation, suggesting an additive or synergistic effect, supporting the epidemiological findings of unfavorable effects of the combination of these two air pollutants. DE generated by an engine running at the urban part of the standardized European Transient Cycle impaired two important and complementary aspects of vascular function, the regulation of vascular tone and endogenous fibrinolysis. This has previously been shown with DE generated at idling conditions. This suggests that the mechanisms behind the adverse effects can be found in the properties of the particles and not in the gaseous components. In these studies, exposure to ozone did not impair vascular function in healthy subjects, or cause any alterations in HRV. This suggests that the epidemiological evidence for an increased risk of cardiovascular mortality following acute exposure to ozone might not be totally accurate. Previous controlled exposure studies with ozone have not shown an airway inflammation affecting the endothelium, at least not in the same time-frame as following DE exposure. FENO could possibly be a useful tool for assessing airway inflammation caused by DE, whereas the powerful oxidant ozone did not affect FENO. This suggests that the airway inflammatory effects caused by these two pollutants are regulated via different mechanisms.

Global climate change is already having a noticeable impact on the environment that threatens the future of all species including humans. Unfortunately, it is currently accelerating and global temperatures will continue to rise in the coming decades mainly due to greenhouse gases produced by human activities in daily life. One of the biggest contributors is emissions from the transport sector which accounts for 32% of Swedish total CO2 emissions. Within the transport sector, freight transportation is more disruptive to traffic flow than personal vehicles because they take up more space on the road and their speed cannot be controlled as nimble as personal vehicles which causes congestion, waste of fuel and greater emissions. Based on the forecast that freight transportation will grow at a faster rate in the next few years, there is a need to manage them more intelligently while keeping up the demand for daily transport. The concept of OHD with the purpose of traffic distribution has recently been proposed and discussed in some academic and pilot projects. By shifting freight transportation from peak hours to off-peak hours, traffic can be alleviated, thus reducing emission from fuel consumption and reducing the timethey and that parts of traffic operate during the day spent on the road.This thesis presents a more comprehensive assessment of the impact of sustainability on theconcept from multiple perspectives and applies the results to the external logistics of Swedish recycling companies. An empirical study was conducted through fourteen semi-structured interviews with researchers, experts within relevant fields and companies with OHD experience. The combination of the empirical and theoretical study concludes that the opportunities and challenges coexist when the industrial companies implement OHD. The most noticeable opportunity provided by the transition is to get rid of congestion which leads to efficiency improvements, fuel savings and reductions in emissions. However, the concept also has a damaging impact as it exposes residents in the surrounding to noise pollution at the time when they need quiet rest. In addition, another challenge in implementing OHD is getting customers’ cooperation which involves the issue of access. / Klimatförändringar har en märkbar inverkan på miljön och hotar framtiden av alla jordens arter. Dessvärre ökar klimatförändringar och de globala temperaturerna kommer att fortsätta stiga under de kommande decennierna, främst på grund av växthusgaser som produceras av dagliga mänskliga aktiviteter. Transportsektorn ansvarar för 32% av den totala svenskakoldioxid utsläppen och är därav den sektorn med mest utsläpp. Inom transportsektorn orsakar godstransporterna fler hinder i trafikflödet än personbilar eftersom de tar mer plats på vägen och har inte den tekniska möjligheten att accelerera, bromsa eller bibehålla hastigheter i samma mån som personbilar. Därav orsakar de trängsel, slöseri av bränsle samt bidrar till ökat utsläpp av koldioxid. Trafikprognoser förutspår att godstransporter kommer att växa i snabbare mån än andra transportmedel under de kommande åren. Därav finns det ett behov av att hantera godstransporten mer effektivt. Konceptet OHD vars syfte är trafikfördelning av trafiken har nyligen erhållit mycket uppmärksamhet både akademiskt i forskning samt praktiskt i pilotprojekt. Genom att flytta godstransporter från högtrafikerade tider till lågtrafikerade tider kan trafiken fördelas, vilket minskar utsläppen, bränsleförbrukning samt ökar trafik effektivitet.Denna avhandling presenterar en omfattande bedömning av hållbarhetens inverkan av OHDkonceptet från flera perspektiv. Det tillämpar resultaten på externa logistikavdelningen av ett återvinningsföretag. En empirisk fallstudie innehållande fjorton semistrukturerade intervjuer med forskare, experter inom relevanta områden samt företag med erfarenhet av konceptet har genomförts. Studien erhöll slutsatserna att återvinningsindustrin kan erhålla flerfaldiga möjligheter och utmaningar orsakad av implementeringen av OHD i deras verksamhet. Där möjligheterna kan sammanställas till effektivitetsförbättringar, bränslebesparingar och minskade utsläpp, utmaningarna kommer vara ljudföroreningar samt övertygande av alla berörande nödvändiga för dess implementering.