LNG-fueled vessels in the Norwegian short-sea market : a cost-effective response to environmental regulation

The objective of this thesis is to assess the environmental and economic advantages of using LNG as fuel for ships. Air emissions from ships are an increasing environmental concern. Since the shipping sector can expect to face more stringent environmental regulations in the future, LNG’s potential as a response to these regulations is analyzed. This study offers an overview of present environmental regulations as well as a description of the properties of LNG. The aim of the final analysis is to identify the cost position of LNG-fueled vessels within different sectors of the Norwegian short-sea shipping market. Net present value (NPV) analysis sets the technical framework for the economic evaluation. The analysis comes to the conclusion that using LNG as fuel for ships offers the potential for significant environmental improvement, regarding both air quality and climate protection, in all sectors subject to the analysis. Economically, LNG as fuel can compete with conventional marine fuel (MGO), at oil prices around approximately 60 $/bbl. Hence, the results of this study indicate that from both an environmental- and economic perspective the investment in LNG powered ships is strongly recommendable. The study also presents some potential barriers with regards to commercial viability and technological feasibility that need to be overcome before LNG becomes fully competitive with other fuels

An Experiential Introduction to Aerospace Engineering

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/77054/1/AIAA-2007-296-801.pd

Evaluation of absolute quantitation by nonlinear regression in probe-based real-time PCR

BACKGROUND: In real-time PCR data analysis, the cycle threshold (CT) method is currently the gold standard. This method is based on an assumption of equal PCR efficiency in all reactions, and precision may suffer if this condition is not met. Nonlinear regression analysis (NLR) or curve fitting has therefore been suggested as an alternative to the cycle threshold method for absolute quantitation. The advantages of NLR are that the individual sample efficiency is simulated by the model and that absolute quantitation is possible without a standard curve, releasing reaction wells for unknown samples. However, the calculation method has not been evaluated systematically and has not previously been applied to a TaqMan platform. Aim: To develop and evaluate an automated NLR algorithm capable of generating batch production regression analysis. RESULTS: Total RNA samples extracted from human gastric mucosa were reverse transcribed and analysed for TNFA, IL18 and ACTB by TaqMan real-time PCR. Fluorescence data were analysed by the regular CT method with a standard curve, and by NLR with a positive control for conversion of fluorescence intensity to copy number, and for this purpose an automated algorithm was written in SPSS syntax. Eleven separate regression models were tested, and the output data was subjected to Altman-Bland analysis. The Altman-Bland analysis showed that the best regression model yielded quantitative data with an intra-assay variation of 58% vs. 24% for the CT derived copy numbers, and with a mean inter-method deviation of × 0.8. CONCLUSION: NLR can be automated for batch production analysis, but the CT method is more precise for absolute quantitation in the present setting. The observed inter-method deviation is an indication that assessment of the fluorescence conversion factor used in the regression method can be improved. However, the versatility depends on the level of precision required, and in some settings the increased cost effectiveness of NLR may justify the lower precision

In vitro intestinal digestion of lipids from the marine diatom Porosira glacialis compared to commercial LC n-3 PUFA products

Marine sources of long chain omega-3 polyunsaturated fatty acids (LC n-3 PUFA) are in high demand for use in health supplements. Mass cultivated marine microalgae is a promising and sustainable source of LC n-3 PUFA, which relieves pressure on natural fish stocks. The lipid class profile from cultivated photosynthetic algae differ from the marine organisms currently used for the production of LC n-3 PUFA. The objective of this study was to compare in vitro intestinal digestion of oil extracted from the cold-adapted marine diatom Porosira glacialis with commercially available LC n-3 PUFA supplements; cod liver oil, krill oil, ethyl ester concentrate, and oil from the copepod Calanus finmarchicus (Calanus® oil). The changes in the free fatty acids and neutral and polar lipids during the enzymatic hydrolysis were characterized by liquid and gas chromatography. In Calanus® oil and the Ethyl ester concentrate, the free fatty acids increased very little (4.0 and 4.6%, respectively) during digestion. In comparison, free fatty acids in Krill oil and P. glacialis oil increased by 14.7 and 17.0%, respectively. Cod liver oil had the highest increase (28.2%) in free fatty acids during the digestion. Monounsaturated and saturated fatty acids were more easily released than polyunsaturated fatty acids in all five oils

Cod at drift in the North Sea

There has been a large-scale geographical re-distribution of the North Sea cod stock over the past century, and recent surveys indicate a north-eastern modal distribution. Here we assess the consequences of the contemporary distribution of North Sea cod (Gadus morhua) spawning biomass to inter-ocean recruitment potential. By simulations of drifting cod eggs and larvae spawned in the northern North Sea over 16 spawning seasons (in the period 1995–2016), we show that a large portion of the North Sea produced pelagic juveniles most likely settle along the Norwegian Sea shelf. For example during the early 2000s when the North Sea cod spawning biomass was at its lowest, 20% to 27% of larvae produced in the northern North Sea most likely settled along the Norwegian Sea shelf, while as few as 8% and 10% were retained within the North Sea in some years. We hypothesise the spillover of North Sea cod into nursery habitat along the Norwegian north-western coast to be beneficial to the stock, as larvae would encounter far higher abundances of their favoured prey, the copepod Calanus finmarchicus. Looking back at a century of overfishing, warming, and variable nursery conditions for cod in the North Sea, getting entrained in the Norwegian coastal current seems like a viable “back-door exit” strategy, allowing the north-eastern spawning cod to thrive even in seemingly adverse climatic periods.publishedVersio

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Avisartikkel i FiskeribladetFiskaren, onsdag 10. juni 2009: s. 6. Gjengitt med tillatelse av FiskeribladetFiskare