Detection, Identification and Size distribution of micro-plastic particles

Pollution by micro-plastic in ecosystems is one of the major problems we are facing now, especially in marine environment. Many studies are going on the detection of different micro substances that pollute our environment. Micro-plastics are among the more frequent pollutants of the sort in aquatic ecosystems. There have been some studies earlier on methodologies to detect and identify micro-plastic particles, in the order of one micrometer in environmental samples. Raman spectroscopy in combination with Raman spectral imaging is one of these methodologies. In theory, it is proven that the Raman spectral imaging can be used for the analysis of micro-plastic, but the applicability of this method has yet to be demonstrated. The aim of this project is to find the application of Raman microscopy in combination with Raman spectral imaging for the detection and identification of micro-plastic particles in ecosystems. In Raman spectroscopy, the sample often will produce unwanted fluorescence excited by the laser producing the Raman spectrum. Hence, more research is necessary to find the optimum laser wavelength for a compromise between suppressed fluorescence and low signal intensity for assessments of micro-plastics in environmental samples

Fluorescent marking of roads in high-north

The project objective is to investigate into luminescent coating materials that can be used in marking the roads in high-north. The idea of the project is not entirely new, and efforts have been worldwide to find an energy efficient solution to the street lights. Earlier work conducted in the Netherlands showed quite promising results. However, the challenges include weatherproofing the coat such that it can withstand the harsher conditions such as rain, temperature changes, UV exposure from sunlight. The conditions will be even more stringent in the high north since the roads are exposed to snow, ice, and traffic with studded-wheels. In this work, we are proposing to use polyurethane-based coating materials with added luminescent materials. The work will be carried out by appropriately mixing the materials to obtain the desired luminescent as well as physical properties. The polyurethane-based coats are known for their durable performance and hence used in industries such as aviation, automobiles, etc

Modelled and observed sea-spray icing in Arctic-Norwegian waters

Link to publishers version: http://dx.doi.org/10.1016/j.coldregions.2016.11.002Hazardous marine icing is a major concern for ships operating in Arctic waters during freezing conditions. Sea spray generated by the interaction between a ship and ocean waves is the most important water source in these dangerous icing events. Although there exist several data sets with observations of ice accretion in conjunction with meteorological and oceanographic parameters, these data sets often have shortcomings and only a few are obtained in Arctic-Norwegian waters. In this study, icing rates from a large coast-guard vessel type, the KV Nordkapp class, are used for verification of a newly proposed Marine-Icing Model for the Norwegian COast Guard (MINCOG). Ship observations, NOrwegian ReAnalysis 10km data (NORA10), and wave data based on empirical statistical relationships between wind and waves are all applied in MINCOG and the results are compared. The model includes two different empirically-derived formulations of spray flux. It is found that in general the best results for different verification scores are obtained by using a combination of observed atmosphere and ocean-wave parameters from the ships, and wave period and direction from NORA10, regardless of the spray-flux formulation applied. Furthermore, the results illuminate that wave parameters derived from formulas based on empirical relationships between the local wind speed and significant wave height and wave period, compared to those obtained from observations or NORA10, considerably worsen icing-rate predictions in Arctic-Norwegian waters when applied in MINCOG

Spray Icing on ONEGA Vessel- A Comparison of Liquid Water Content Expressions

The hazards associated with ice accretion primarily due to impinging freezing sea spray on ship structures are considered among serious safety concerns for ships operating in the colder regions. An accurate sea-spray icing-estimation model to evaluate the ice accumulation during operations in these regions can make marine operations safer. The accuracy of the present icing models for estimating icing on ships is substantially dependent on the incoming spray flux generated by the wave-ship interaction. In order to illustrate this, the vessel icing incident of the fishing vessel ONEGA is considered, which capsized after encountering heavy icing. In this study, the ONEGA vessel is modeled using a stability-calculation program. Then assuming the vessel to maintain minimum stability criteria prior to icing, the minimum likely amount of ice accumulation in the exposed locations that destabilized the vessel is estimated. This estimation is compared against another method used to evaluate ice thickness over the period ONEGA was accreting ice. The latter method utilizes the operational weather forecasting model used by MET Norway — “Marine-Icing model for the Norwegian COast Guard (MINCOG)”. The MINCOG model uses spray-flux estimations based on past empirical observations mainly obtained from fishing trawlers. The spray-flux consists of important elements like the liquid-water content (lwc) and the spray-generation frequency. An analysis is carried out applying different formulations for these two elements proposed by different researchers to see the variation in evaluating the total ice accumulation. After noticing the difference in results in total ice thickness from the stability and the icing-model methods used in this study, it is concluded that more investigation and field measurements are needed concerning the neglecting of the contribution of wind-generated spray in the spray flux formula used in MINCOG. Accordingly, multiple real-time spray measurements to develop a more suitable spray-flux formulation may improve the ice accumulation estimation over a longer time period

Sea-spray measurement tools and technique employed in marine icing field expeditions: A critical literature review and assessment using CFD simulations

Sea-spray icing resulting from sea spray droplets accreting on exposed surfaces poses a significant safety concern for vessels and marine structures operating in cold climate regions. One of the key parameters determining the amount of ice accretion is the quantity of incoming sea spray, which eventually comes in contact with the structure in the presence of brine film freezing temperature. Hence, to develop marine icing estimation models, researchers have been inclined towards conducting field measurements to acquire data on sea spray and its key characteristics, such as liquid water content (LWC, mass of spray water per unit volume of air), spray frequency and duration, and droplet size distribution. This paper provides a critical review of various techniques used by researchers for sea spray field measurements. By employing Computational Fluid Dynamics (CFD) simulation, this paper also evaluates the performance of instruments for measuring sea-spray flux employed in such field campaigns. Design issues and potential areas for improvement are identified and discussed, based on which further recommendations for improvement of sea spray data collection are provided. The study provides valuable insights for researchers planning field measurement expeditions and exploring viable options to design an efficient system for collecting sea spray data

Forces on simplified offshore structures according to different wave models.

Master's thesis in Offshore structural engineeringThe reason for creating this thesis was because of the new and revised version of NORSOK N-003 standard. Therefore a comparison between the old and the revised version of NORSOK N-003 standard has been performed. This thesis have been divided in to three main parts. The first part describe how to estimate the 10−2 annual probability crest height, c0.01 and wave height ℎ0.01. (100-years wave) with the metocean contour lines method. Which resulted in: ℎ0.01. = 28.61m and c0.01 = 17.87m by using ℎs = 14.9m and tp = 15.8s The second part revolves around regular waves. A comparison between the old and new method of calculating the ULS design wave have been discussed. The old method uses a Stokes wave profile defined by the 10−2 annual probability wave height, ℎ0.01 with an unfavorable period. Where the new method uses the 10−2 annual probability crest height, c0.01 with a mean wave period to define the ULS design wave. With the same defined wave profiles as the new and old recommendation, one have also compared the Stokes wave with a first order approach. By obtaining the kinematics from all approaches and compared them, one may see that a linear approach has the ability to obtain very close kinematics as the Stokes wave. This depends on the amplitude used and which approximation above mean surface level used. After words, the base shear and overturning moment where calculated by Morison equation. Those results shows that the new method using Stokes wave with c0.01 as the amplitude, results in a larger base share and overturning moment for drag and non-dominated forces but a lower overturning moment for a mass dominated case comparing to the old method using a wave height equal to, ℎ0.01. The conclusion for this part is that the new N-003 standard is more efficient with time and describe the waves in a more accurate manner. For the third and last part one have chosen to discuss irregular wave, where the old N-003 standard suggests a first order process to obtain the corresponding kinematics of a time simulation. Where the revised N-003 standard in other hand require a second order process to describe the surface process and a second order theory to obtain the kinematics of the time history. Matlab has been used to create those simulations and calculated all the data for this thesis. By comparing the two different processes, one found out that the: - Formula used to create the first order irregular surface process follows a Rayleigh distribution for crest heights and the second order surface process follows a Weibull distribution for crest heights. - Wheeler stretching for a first order process underestimates the kinematics, but a constant value above mean surface level is a very good approximation to a second order process using Standsbergs approached. - First order process underestimates the crest heights but overestimates the kinematics, which achieves almost the same result as second order process

The development and use of a new tool for estimating individual sun induced vitamin D in epidemiological surveys

The papers of this thesis are not available in Munin: 1. Kåre Edvardsen, Magritt Brustad, Ola Engelsen and Lage Aksnes: 'The solar UV radiation level needed for cutaneous production of vitamin D3 in the face. A study conducted among subjects living at a high latitude (68° N)', Photochemical & Photobiological Sciences (2007) 6, 57-62. Available at http://dx.doi.org/10.1039/b613263d 2. Magritt Brustad, Kåre Edvardsen, Tom Wilsgaard, Ola Engelsen, Lage Aksnes and Eiliv Lund: 'Seasonality of UV-radiation and vitamin D status at 69 degrees north', Photochemical & Photobiological Sciences (2007) 6, 903-908. Available at http://dx.doi.org/10.1039/b702947k 3. Kåre Edvardsen, Ola Engelsen and Magritt Brustad: 'Duration of vitamin D synthesis from weather model data for use in prospective epidemiological studies', International journal of biometerology (2008) vol. 53, no. 5, 451-459. Available at http://dx.doi.org/10.1007/s00484-009-0231-6 4. Kåre Edvardsen, Marit B. Veierød, Magritt Brustad, Tonje Braaten, Ola Engelsen and Eiliv Lund: 'Vitamin D-effective solar UV radiation, dietary vitamin D and breast cancer risk', International Journal of Cancer (2010) vol. 128, Issue 6, pages 1425–1433. Available at http://dx.doi.org/10.1002/ijc.25463</a

Detection, Identification and Size distribution of micro-plastic particles

Pollution by micro-plastic in ecosystems is one of the major problems we are facing now, especially in marine environment. Many studies are going on the detection of different micro substances that pollute our environment. Micro-plastics are among the more frequent pollutants of the sort in aquatic ecosystems. There have been some studies earlier on methodologies to detect and identify micro-plastic particles, in the order of one micrometer in environmental samples. Raman spectroscopy in combination with Raman spectral imaging is one of these methodologies. In theory, it is proven that the Raman spectral imaging can be used for the analysis of micro-plastic, but the applicability of this method has yet to be demonstrated. The aim of this project is to find the application of Raman microscopy in combination with Raman spectral imaging for the detection and identification of micro-plastic particles in ecosystems. In Raman spectroscopy, the sample often will produce unwanted fluorescence excited by the laser producing the Raman spectrum. Hence, more research is necessary to find the optimum laser wavelength for a compromise between suppressed fluorescence and low signal intensity for assessments of micro-plastics in environmental samples