Browsing by Subject "oil"

Oil spillages represent a serious environmental hazard for flora and fauna of marine and coastal ecosystems. Though marine oil spills have decreased since the 1970s, the increasing production of petroleum goods remains a potential source of pollution due to its use and transportation. When aquatic organisms, including fish, are exposed to toxic oil compounds, this can cause sublethal morphological changes and increase mortality. In this context, herring have been frequently studied, and results suggest that particularly herrings eggs and larvae are highly susceptible to oil toxicity. In this thesis, a Bayesian meta-analysis was conducted to investigate the effects of crude and fuel oil on the mortality of herring eggs from the genus Clupea. Observations from laboratory studies, collected during a literature review, served as input for the statistical analysis. To this end, Bayesian inference modeling was applied to generate posterior probability distributions for additional mortality caused by exposure to oil mixtures. Also, oil concentration, oil type, exposure time, and temperature were analyzed to study possible correlations with mortality impacts. The results of this study suggest that acute mortality of exposed herring eggs is similar to mortality observed for individuals exposed to only small concentrations or none at all. Of all evaluated oil types, medium grade crude oil caused the most significant change in instantaneous mortality with increasing oil concentration. Generally, distinct oil types had a greater influence on mortality outcomes than temperatures at the given concentrations. For the lowest temperatures, some correlations for increased mortality were found. Overall, the unexplained variability between the reviewed studies has a relatively small influence on mortality outcomes. In conclusion, the mortality of exposed herrings eggs is most likely delayed due to sublethal effects, rather than immediate, at the modeled concentrations. Altogether, uncertainty amongst the posterior probability distributions is high, indicating a wide possibility range for the monitored parameters' actual values. The reasons for elevated uncertainty likely stem from diverse experimental setups, biological differences between tested species, relatively small sample sizes, and model-related issues. Thus, future research could consider additional variables, information from observational studies and other fish species to reduce uncertainty in mortality outcomes.

Andean lupin (Lupinus mutabilis Sweet) is a potential oilseed crop, with a very high protein content (40–45%) and 15–20% oil content. It is valued as an alternative protein source for both human and animal consumption, and like several other lupin species, has a potential role in phytoremediation. Previous experience in central and southern Europe has shown the crop to have low and unstable yields with high sensitivity to heat and drought during the grain–filling stage. The species may therefore be more suitable for cool–temperate climates, as it comes from similar altitudes and latitudes as potato. Therefore, an experiment was set out to quantify the responses of Andean lupin to heat stress, using both gradually and suddenly rising temperatures during grain filling. In preliminary tests 60 accessions from 4 germplasm banks were screened for time to flowering and daylength sensitivity. For this experiment, 3 accessions were chosen, 478435, 457972, 457977, with vegetative phase durations of 44, 53, 64 days from sowing to first flower, respectively. Forty two plants of each accession were sown and reduced to 30 on the basis of uniformity. Plants were grown in a glasshouse with 22 °C, 18 h days and 18 °C, 6 h nights until about 25 days after flowering. Ten plants of each accession were subjected to one of the following treatments: control (continuing in the same glasshouse conditions), sudden heat stress (transferred to a growth chamber and subjected to 38 °C from 11:00 to 15:00) or gradual heat stress (transferred to a growth chamber and subjected to temperature increases of 4 °C day temperature and 2 °C night temperature, with the final two days at 38 °C from 11:00 to 15:00). The plants were returned to the glasshouse and when mature, the seeds were harvested and pooled into 3 replicates per accession and treatment for quality analysis. Seed protein, oil, soluble sugar, ash and moisture content were determined. Data were calculated on the basis of percentage of overall seed mass and also on a milligrams per seed basis in order to reflect the seed physiology at grain–filling stage. Sudden heat stress had greater effects on seed composition than gradual heat stress. When compared with control, sudden heat stress resulted in more loss of every component than gradual heat stress, on a per–seed basis, in all 3 accessions and the responses of the accessions to the sudden stress were not statistically different. Under sudden heat stress, mean seed weight declined by 70%, protein content by 70%, oil content by 85%, ash content by 50%, and soluble sugar content by 75%. The accessions responded differently, however, to the gradual heat stress. Accession 478435 experienced significantly greater reduction in seed weight, protein and ash content than accessions 457972 and 457977. Oil content per seed and soluble sugar content per seed were also lower in 478435 than in the other two cultivars, but the difference was not significant. On the flour basis, sudden heat stress increased ash content and decreased oil content and soluble sugar content significantly in all accessions. Accession 478435 had highest value in ash content at significant level. Under gradual stress, protein and ash content were increased while oil mass and soluble sugar mass were decreased. 478435 had significantly higher protein mass and ash mass in flour with respectively 57% and 5.1%, 457977 had significantly higher soluble sugar content with 112 mg/g. The results showed that heat stress can have a significant effect on the quantity and quality of seed yield in Andean lupin. While all tested accessions were severely susceptible to sudden heat stress, gradual stress identified differences between accessions, with one being much more susceptible than the other two. The most susceptible accession was the earliest to flower. Gradual heat stress allows better resolution than sudden heat stress when screening germplasm for heat tolerance.

Uganda’s recent oil discoveries have been described as one of the largest onshore findings in Africa within the past 20 years. It has been estimated that there are 6.5 billion barrels of oil in the Albertine Graben, of which about 1.4 are recoverable. Since the foreign and national stakeholders have launched their oil investment projects, concerns around human and environmental rights violations have been raised internally and internationally. Whereas much scientific work has been produced on oil in Africa, most of this can be placed under the concise umbrella of resource blessing and resource curse. The approach of ‘extractivism’ has come to challenge this simplistic dichotomy, but most of the work about extractivism focuses on Latin America. This thesis, thus, contributes to this growing body of literature. It does so by investigating the discourses that the Ugandan state and the transnational corporation TotalEnergies utilize to promote extractivism in Uganda. More specifically, this thesis aims to answer two questions, namely, what justification methods does the Ugandan state use to legitimate oil extractivism in the Lake Albertine region, and how does the oil corporation Total reproduce narratives of extractivist mindset in legitimizing its operations in the Albertine Graben? Data were collected from policy documents, newspaper articles, and website material. The methods of critical discourse analysis and content analysis and the approaches of extractivism and postcolonialism are applied. The findings show that the Ugandan state legitimates oil through five discourses, namely: economic arguments, employment and social arguments, no substantial ecological effects arguments; statements for energy poverty, energy security, and just transition; and stigmatizing critics arguments. Total uses three distinct discourses, namely, self-regulation and best practice, social and developmental arguments, and no substantial ecological effects arguments. These discourses, while reproducing the extractivist mindset, should be taken seriously as they have severe implications for the wider world.

Crude ol is the most traded commodity in the world. Oil and oil products are very important mediums of trade, and therefore these mediums are also traded in the derivative markets. The value of derivatives and “paper oil” markets is nowadays many times higher than the value of the physical crude oil market. Oil refineries, the end-users of oil products and investors plus speculators have all a significant impact on the market, and together they create the balance of price level. In this thesis, the difference between present spot prices and future forward prices was researched. The results show whether the oil refinery could make a profit by using forwards instead of spot prices for purchasing crude oil and for selling the refined oil products. A general hypothesis is that, on average, forwards are not profitable. This hypothesis holds only if the markets are efficient and all the participants have equivalent information at their disposal. If this is not the case, the markets do not work efficiently, or the balance of supply and demand is not stable. In this thesis, both realized prices and forward prices are examined for the period between 2010 and 2016. The prices and forwards are European market prices, and they are based on the Brent crude oil and Brent-based products. Monthly averages for prices, calculated by daily prices, are used in all the tests and the analysis. The maturities of forwards varied from 1 month to 12 months. The results show that the refiner would have made extra profit by selling especially jet and diesel by using long-run (12 months) forwards. The error term of spot and forward prices was systematic and statistically significant. Hedging the sales of heavy fuel oil (HSFO) by using forwards would also have been, on average, profitable. Nevertheless, the fundament of HSFO is not as clear as jet and diesel. Jet, diesel and HSFO constitute about 2/3 parts of the total production capacity (by volume) of Company X. By hedging the jet, diesel and HSFO, the company could have increased the gross margin by approximately 18 % between 3/2012-12/2016. This means that the gross marging would have increased by about 2 USD/bbl (11.3 vs 13.3 USD/bbl). The results clearly state that the demand for specific forwards (and products) exceeded the supply side in the period studied. This was evident in the higher forward prices compared to realized spot prices. The reason for these findings might be the fact that the end users of jet, diesel and HSFO typically want to secure the level of costs in advance. Airline companies, for example, have to know their cost of fuel to be able to set the price of flight tickets up to one year beforehand. In addition, it is important to notice that Europe is dependent on imported jet and diesel. On the oher hand, the results can be interpreted in a way that the refiners do not want to sell their production in advance. In general, this can be seen in the way that the producers are always waiting for a sudden unexpected shock in the demand side, and therefore the pricing position is kept open. Based on the findings, the supply of crude oil was not profitable. Many estimations of the price of crude oil have been made based on different data sets, and based on the literature, forecasting is very difficult. In addition, hedging gasoline or naphtha production by forwards was not, on average, profitable. Nevertheless, by short run maturities (3–4 months), and in certain conditions, hedging the gasoline would have been profitable. The time period investigated in this thesis saw extreme fluctuation in crude oil pricing. Brent price varied from 35 USD/bbl to 125 USD/bbl. In addition, the time period included both extreme increases and decreases in price. The results might be partly explained by the fluctuations and relatively high level of the price of crude oil. Brent crude oil as an explanatory variable for the price of oil products was also tested in this research. The price of crude oil has explanatory power for the forward values of jet, diesel and HSFO. However, the Brent price could not be used as an explanatory variable for the profitabily of hedging those above-mentioned cracks. Other products (gasoline, naphtha and DFL) did not depend on the price of crude oil as much. In this case, it can be assumed that hedging jet, diesel (and gasoil) and HSFO would be profitable in the near future as well. Then again, many global, political and economical aspects certainly have an effect on the oil markets. Analyzing these aspects is considered to be nearly impossible, and this causes some uncertainty to the forecasting process.