Concentration ratios for chemical analogues of key nuclides for different vegetation types at the Olkiluoto site

Olkiluoto Island on the western coast of Finland has been selected as a repository site for spent nuclear fuel in Finland. This study aimed at identifying differences in concentration ratios (CR), and their distributions, for the elements analysed on soil and vegetation samples taken on the island (Al, B, Ca, Cd, Cr, Cu, Fe, K, Mg, Mn, Ni, P, S, Zn). Many of the elements can be considered to be chemically analogous to radionuclides that, potentially, can be released from the repository. Differences between the soil and vegetation in different tree age, tree species and site fertility classes typical of the forest ecosystems in Olkiluoto were investigated. Lognormal distributions were fitted to the different groupings of the CR data calculated on the basis of the results from 94 sampling plots. In most cases no significant differences were found between the different groupings for a specific element when the 95% confidence intervals were applied. According to the results based on real site data for CRs in forest ecosystems on Olkiluoto, it appears that the current CR-based approach to radionuclide modelling in forest ecosystems is problematic due to the large variation in parameter values and in their practical definition

Reinforcement learning of adaptive online rescheduling timing and computing time allocation

Mathematical optimization methods have been developed to a vast variety of complex problems in the field of process systems engineering (e.g., the scheduling of chemical batch processes). However, the use of these methods in online scheduling is hindered by the stochastic nature of the processes and prohibitively long solution times when optimized over long time horizons. The following questions are raised: When to trigger a rescheduling, how much computing resources to allocate, what optimization strategy to use, and how far ahead to schedule? We propose an approach where a reinforcement learning agent is trained to make the first two decisions (i.e., rescheduling timing and computing time allocation). Using neuroevolution of augmenting topologies (NEAT) as the reinforcement learning algorithm, the approach yields, on average, better closed-loop solutions than conventional rescheduling methods on three out of four studied routing problems. We also reflect on expanding the agent's decision-making to all four decisions. (C) 2020 Elsevier Ltd. All rights reserved.Peer reviewe

Surrogate-based optimization of a periodic rescheduling algorithm

Periodic rescheduling is an iterative method for real-time decision-making on industrial process operations. The design of such methods involves high-level when-to-schedule and how-to-schedule decisions, the optimal choices of which depend on the operating environment. The evaluation of the choices typically requires computationally costly simulation of the process, which-if not sufficiently efficient-may result in a failure to deploy the system in practice. We propose the continuous control parameter choices, such as the re-optimization frequency and horizon length, to be determined using surrogate-based optimization. We demonstrate the method on real-time rebalancing of a bike sharing system. Our results on three test cases indicate that the method is useful in reducing the computational cost of optimizing an online algorithm in comparison to the full factorial sampling.Peer reviewe

Konenäkö automaatiojärjestelmässä

Tiivistelmä. Kandidaatintyön tavoitteena on tutustua kuvankäsittelyyn, erilaisten kuvankäsittelyn sovellutuksiin, sekä niiden mahdollisuuksiin TwinCAT Vision-järjestelmässä. Työssä testataan ja dokumentoidaan Vision-ohjelman ominaisuuksia. Samalla myös pohditaan järjestelmän suorituskykyä.Machine vision in automation system. Abstract. Bachelor’s thesis was to familiarize with the subject of image processing, different image processing applications and their possibilities in TwinCAT Vision system. In thesis Vision software functions are tested and documented. Also, performance of the system is evaluated

Noise of a single electron transistor on a Si3N4 membrane

We have investigated the influence of electron-beam writing on the creation of charge trapping centers which cause 1/f noise in single electron transistors (SET). Two Al/AlOx/Al devices were compared: one where the SET is on a {100} silicon wafer covered by a 120-nm-thick layer of Si3N4, and another one in which the Si was etched away from below the nitride membrane before patterning the SET. The background charge noise was found to be 1×10 exp −3 e/√Hz at 10 Hz in both devices, independent of the substrate thickness.Peer reviewe

Effects of intensified silviculture on timber production and its economic profitability in boreal Norway spruce and Scots pine stands under changing climatic conditions

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Minor Changes in the Hemagglutinin of Influenza A(H1N1)2009 Virus Alter Its Antigenic Properties

BACKGROUND: The influenza A(H1N1)2009 virus has been the dominant type of influenza A virus in Finland during the 2009-2010 and 2010-2011 epidemic seasons. We analyzed the antigenic characteristics of several influenza A(H1N1)2009 viruses isolated during the two influenza seasons by analyzing the amino acid sequences of the hemagglutinin (HA), modeling the amino acid changes in the HA structure and measuring antibody responses induced by natural infection or influenza vaccination. METHODS/RESULTS: Based on the HA sequences of influenza A(H1N1)2009 viruses we selected 13 different strains for antigenic characterization. The analysis included the vaccine virus, A/California/07/2009 and multiple California-like isolates from 2009-2010 and 2010-2011 epidemic seasons. These viruses had two to five amino acid changes in their HA1 molecule. The mutation(s) were located in antigenic sites Sa, Ca1, Ca2 and Cb region. Analysis of the antibody levels by hemagglutination inhibition test (HI) indicated that vaccinated individuals and people who had experienced a natural influenza A(H1N1)2009 virus infection showed good immune responses against the vaccine virus and most of the wild-type viruses. However, one to two amino acid changes in the antigenic site Sa dramatically affected the ability of antibodies to recognize these viruses. In contrast, the tested viruses were indistinguishable in regard to antibody recognition by the sera from elderly individuals who had been exposed to the Spanish influenza or its descendant viruses during the early 20(th) century. CONCLUSIONS: According to our results, one to two amino acid changes (N125D and/or N156K) in the major antigenic sites of the hemagglutinin of influenza A(H1N1)2009 virus may lead to significant reduction in the ability of patient and vaccine sera to recognize A(H1N1)2009 viruses

Europium-based high-temperature superconductors studied by x-ray diffraction and 151Eu Mössbauer spectroscopy

Isotropic powders and magnetically aligned crystallites of EuBa2Cu3O7−δ (1:2:3) and europium-doped Bi2Sr2CaCu2O8 (2:2:1:2) were studied by means of x-ray diffraction and Eu151 Mössbauer spectroscopy. The degree of crystallite orientation of the samples and the values of the lattice constants were determined by x-ray diffraction. The Mössbauer spectra were analyzed considering the full hyperfine Hamiltonian of the nuclear states of the 21.5-keV γ transition. The Mössbauer hyperfine parameters obtained from the superconducting and semiconducting phases are presented. A small change is seen in the Eu151 isomer shift when the oxygen deficiency δ of the 1:2:3 compound is varied. The shift can be explained by a decrease in the s-electron density due to lattice expansion. The changes in the oxidation state of the copper atoms with varying δ were determined from the Mössbauer data: The Cu(2) atoms retain their oxidation state, whereas the Cu(1) atoms adjust their valence according to the value of δ. In the 2:2:1:2 samples, the Eu concentration clearly affected the value of the electric-field gradient at the Eu nucleus. Using a standard procedure, magnetically aligned 2:2:1:2 samples were prepared. The preferred direction of the crystal c axis changed from parallel to perpendicular alignment with the external magnetic field, when the Eu concentration exceeded 20% of the Ca atoms.Peer reviewe