Highly accurate special quadrature methods for Stokesian particle suspensions in confined geometries

Boundary integral methods are highly suited for problems with complicated geometries, but require special quadrature methods to accurately compute the singular and nearly singular layer potentials that appear in them. This paper presents a boundary integral method that can be used to study the motion of rigid particles in three-dimensional periodic Stokes flow with confining walls. A centrepiece of our method is the highly accurate special quadrature method, which is based on a combination of upsampled quadrature and quadrature by expansion (QBX), accelerated using a precomputation scheme. The method is demonstrated for rodlike and spheroidal particles, with the confining geometry given by a pipe or a pair of flat walls. A parameter selection strategy for the special quadrature method is presented and tested. Periodic interactions are computed using the Spectral Ewald (SE) fast summation method, which allows our method to run in O(n log n) time for n grid points, assuming the number of geometrical objects grows while the grid point concentration is kept fixed.Comment: 46 pages, 41 figure

Finnish water mites (Acari: Hydrachnidia, Halacaroidea),

The species of Finnish watermites (Acari, Hydrachidia and Halacaroidea) are listed, and their occurrence in the biogeographical provinces shown. The list is based on publications, on unpublished data known by the authors, and on a private collection (of Pauli Bagge). The list consists of 139 Hydrachnidia and 9 Halacaroidea species, which are mainly limnetic or lotic. Brackish waters and the family Halacaridae have remained little studied

Fast Ewald summation for electrostatic potentials with arbitrary periodicity

A unified treatment for fast and spectrally accurate evaluation of electrostatic potentials subject to periodic boundary conditions in any or none of the three space dimensions is presented. Ewald decomposition is used to split the problem into a real space and a Fourier space part, and the FFT based Spectral Ewald (SE) method is used to accelerate the computation of the latter. A key component in the unified treatment is an FFT based solution technique for the free-space Poisson problem in three, two or one dimensions, depending on the number of non-periodic directions. The cost of calculations is furthermore reduced by employing an adaptive FFT for the doubly and singly periodic cases, allowing for different local upsampling rates. The SE method will always be most efficient for the triply periodic case as the cost for computing FFTs will be the smallest, whereas the computational cost for the rest of the algorithm is essentially independent of the periodicity. We show that the cost of removing periodic boundary conditions from one or two directions out of three will only marginally increase the total run time. Our comparisons also show that the computational cost of the SE method for the free-space case is typically about four times more expensive as compared to the triply periodic case. The Gaussian window function previously used in the SE method, is here compared to an approximation of the Kaiser-Bessel window function, recently introduced. With a carefully tuned shape parameter that is selected based on an error estimate for this new window function, runtimes for the SE method can be further reduced. Keywords: Fast Ewald summation, Fast Fourier transform, Arbitrary periodicity, Coulomb potentials, Adaptive FFT, Fourier integral, Spectral accuracy.Comment: 21 pages, 11 figure

Hygiene aspects of the biogas process with emphasis on spore-forming bacteria

Biogas is a renewable source of energy which can be obtained from processing of biowaste. The digested residues can be used as fertiliser. Biowaste intended for biogas production contains pathogenic micro-organisms. A pre-pasteurisation step at 70°C for 60 min before anaerobic digestion reduces non spore-forming bacteria such as Salmonella spp. To maintain the standard of the digested residues it must be handled in a strictly hygienic manner to avoid recontamination and re-growth of bacteria. The risk of contamination is particularly high when digested residues are transported in the same vehicles as the raw material. However, heat treatment at 70°C for 60 min will not reduce spore-forming bacteria such as Bacillus spp. and Clostridium spp. Spore-forming bacteria, including those that cause serious diseases, can be present in substrate intended for biogas production. The number of species and the quantity of Bacillus spp. and Clostridium spp. in manure, slaughterhouse waste and in samples from different stages during the biogas process were investigated. The number of species of clostridia seemed to decrease following digestion, likewise the quantity. However, Bacillus spp. seemed to pass unaffected through the biogas process. In laboratory-scale experiments the effects on clostridia during pasteurisation and digestion were investigated. Pathogenic clostridia were inoculated in substrates from homogenisation tanks and digester tanks. The inoculated clostridia remained after pasteurisation, but the impacts of digestion differ between different species. Culture followed by identification of C. chauvoei by PCR in samples from cattle died from blackleg, is faster and safer than culture followed by biochemical identification of C. chauvoei. However, for environmental samples the PCR method is not practically applicable for detection of C. chauvoei. To avoid spreading of diseases via biogas plants when digested residues are spread on arable land, a pasteurisation stage at 70°C for 60 min before anaerobic digestion gives adequate reduction of most non spore-forming bacteria, such as salmonella. However, caution should be exercised before digested residues are spread in areas without endemic problems of pathogenic spore-forming bacteria. In Sweden, official recommendation is that digested residues from biogas plants only should be applied on arable land, and not on grasslands for animal pasture

Building Performance - Methods for Improved Prediction and Verification of Energy Use and Indoor Climate

Reducing CO2 emissions is one of the most important goals in Europe as well as the rest of the world. To reach that goal, the use of energy must be reduced. Thus, the building industry is facing a great challenge. Not only energy efficiency but also sustainability is desirable in the building stock. This thesis presents and suggests methods that can be used to improve prediction and verification of building performance regarding energy use and indoor climate. Predictions of energy use and indoor climate generally do not agree with results from measurements in buildings during operation. These discrepancies are counter-productive to the implementation of energy-efficiency and sustainability measures. This thesis addresses these issues and suggests viable partial-solutions to the problems encountered. This research project has measured several energy use and indoor climate related parameters in multi-family buildings in Sweden. The monitoring was frequent, at least once per hour, and the measurements lasted at least one year, which makes it possible to present reference data for the measured parameters and their variations on different time scales and during different conditions. Based on the analysis of the measurements, several methods offering partial-solutions on different levels to the addressed problems have been developed. Examples of these methods are: • A method to assess useful solar heat gains in actual buildings during operation. • A method to assess window airing and air leakage in actual buildings during operation. • A method to assess occupancy level in actual buildings during operation. • Methods to generate hourly input data on hygrothermal conditions that take into account both outdoor conditions and user behaviour. • A method to make meteorological corrections to energy use that takes into account several outdoor climate parameters and the characteristics of the building concerned. The methods aim to describe reality more accurately and can be applied to predictions and verifications. The methods are fully developed and ready to use in practice. These methods together with the discussion and argumentation in this thesis provide the building sector with useful and positivistic recommendations. If these are used, it is believed that it will be possible to increase the quality of predictions and verifications, and agreement between them, as well as to provide buildings displaying increased sustainability, with low energy use and good indoor climate

Gameality – Building a gamer / viewer experience In TV series The heroes of the Baltic Sea

Maisterin opinnäytteessään Pietari tutkii Ylessä kehitetyn "uuden" tv-formaatin, gamealityn lavastamista Heroes of the Baltic Sea -sarjan tekoprosessin kautta. Hän pohtii, miten kyseisen tv-sarjan realitypeliin osallistujat yleisesti kokivat pelitilanteet, ja minkälainen suhde lavastuksella oli pelillisiin tapahtumiin. Analysoimalla keräämänsä haastattelumateriaalia ja tukiaineistoa Pietari pohtii, millä keinoin gamealityn lavastaja voi tukea pelaajan kokemusta ja etenkin uppoutumista peliin. Millainen sopimus syntyi The Heroes of the Baltic Sean pelaajien, itse pelin ja katsojan välille? Miten The Heroes of the Baltic Sean kaltaisen gamealityn vaatimukset lavastukselle eroavat perinteisen draamaelokuvan/-tv-sarjan vaatimuksista? Opinnäytteessään Pietari tutkii uudella tavalla nimettyä tv-sarjan lajityyppiä, gamealityä, ja mitä erityispiirteitä sen lavastukselta vaaditaan verrattuna normaaliin elokuva- ja televisiotyöskentelyyn omien kokemustensa, sekä työryhmä- ja pelaajahaastatteluiden pohjalta. Lisäksi Pietari pohtii jonkin verran sitä, mitä annettavaa gamealityn lavastamiselle on sen “sukulaislajeilla”, kuten pakohuoneilla, tietokonepeleillä ja perinteisemmillä tosi-tv-ohjelmilla.In his MA-thesis, Pietari Bagge is discovering “gameality”, a new form in reality genre and how such a TV show should be designed, through the making process of the series The Heroes of the Baltic Sea. Pietari also ponders upon questions such as: How do the players feel about the gaming situations? In what kind of relation the scenography is to the events in the game? By analysing interviews and selected support sources of information Pietari examines by what means can a production designer help the player to get immersed in to the game. Pietari also tries to find out what kind of unwritten agreement the player makes with the game and how staging such show as The Heroes of the Baltic Sea differs from a more traditionall TV show. Based in his experience and on the interview material of both makers and players, in his thesis, Pietari is researchin this newly named reality TV subgenre, gameality and what special needs it has compared to normal TV and cinema work. Pietari also compares gameality to its relatives, such as escape rooms and computer games, in order to find something usefull in case the subgenre of gameality is visited again

Emergence and upstream flight of lotic mayflies and caddisflies (Ephemeroptera and Trichoptera) in a lake outlet, central Finland

Temporal and spatial occurrence and upstream flight of lotic mayflies and caddisflies were studied by means of kick netting, slit traps and floating emergence traps in Lake Konnevesi and its outlet stream (Siikakoski), mainly in 1983. Twenty species of mayflies and 78 species of caddisflies were recorded. Clearly lotic mayflies in the material were Baetis subalpinus, Heptagenia sulphurea and Ephemerella mucronata, which occurred only in the stream samples. Females of lotic Baetis rhodani had a long distance upstream flight in the area and occurred frequently in the floating emergence traps especially in sandy littoral habitats of L. Konnevesi. Procloeon bifidum and Nixe joernensis, which in some regions occur mainly in streams, were frequently found in the stony littoral belt of L. Konnevesi. Most of the mayflies recorded in the area were univoltine, but Baetis rhodani and Centroptilum luteolum at least had two generations in 1983. Strictly lotic species among caddisflies were Ceratopsyche nevae, Hydropsyche saxonica, Halesus digitatus, Ceraclea perplexa, Ylodes detruncatus, Athripsodes commutatus and Hydroptila forcipata. These were mainly found in stream samples. A short distance upstream flight of females (c. 0.1-0.4 km) was observed in the populations of H. siltalai, Psychomyia pusilla and Oxyethira frici and a moderate distance flight (at least 0.6 km) by females of Hydropsyche pellucidula, Cheumatopsyche lepida and Polycentropus irroratus. The most abundant caddisflies of the stream Siikakoski (Brachycentrus subnubilus, Neureclipsis bimaculata, Rhyacophila nubila, Agapetus ochripes, Micrasema setiferum and Hydroptila cornuta) were frequently found also in floating emergence traps in the lake (3. 7 km from the rapids). Females of Brachycentrus, Neureclipsis and Rhyacophila favoured traps on sandy substrata while females of Hydroptila were usually found in the stony belt. In the trap material of Agapetus ochripes, males were more abundant than females. According to emergence data, all caddisflies recorded in the area were univoltine though the emerging period of several species such as Rhyacophila nubila and Neureclipsis bimaculata was long. Maximum emergence was observed in early June when brachycentrids were swarming and another peak in August when limnephilids and leptocerids were abundant

Donor Age Effects on the Proliferative and Chondrogenic/Osteogenic Differentiation Performance of Equine Bone Marrow- and Adipose Tissue Derived Mesenchymal Stem Cells in Culture

Orthopedic injuries are a major cause of lameness and morbidity in horses. Bone marrow (BM)- and adipose tissue (AT) derived mesenchymal stem cells (MSCs) have shown potential to facilitate the repair of orthopedic injuries and are being used increasingly in veterinary clinics. Presently, the use of MSCs as a therapy for equine patients is most commonly applied as autologous transplants, using BM- and AT-MSCs harvested from the patient shortly after the time of injury. Cell-based therapies are therefore delayed to enable primary cell numbers to be expanded in culture. Of concern, however, are human and rodent studies that have shown a sharp decline in MSC quantity and quality with increasing donor age. This may be problematic for the important equine demographic of older orthopedic patients due to current recommendations that often call for 10-100 million MSCs in treatment protocols. This thesis, therefore, examines the critical gap of knowledge on the relationship between donor age and MSC parameters in horses and tests the hypothesis that increasing donor age is a major variable in equine BM- and AT-MSC proliferation and chondrogenic/osteogenic differentiation with decreasing capacities following non-linear kinetics. To this end, BM- and AT-MSCs and dermal fibroblasts (biological negative control) were harvested immediately post mortem from horses in 5 different age groups, with 4 horses in each age group. The age groups were newborn (0 days), yearling (1-2 years), adult (5-8 years), middle-aged (12-18 years), and geriatric (≥ 22 years) horses. In the first part of the study, the cellular proliferation of the cells was tested using an EdU incorporation assay and by targeted gene expression analysis of proliferation, aging and senescent biomarkers. The results showed that the cellular proliferation of equine MSCs declined with increasing donor age, but interestingly there were no significant difference in pairwise comparisons between age groups other than the geriatric horses. The cellular proliferation of the two MSC types was equally affected by donor age. Tumor suppressor gene expression was up-regulated with increasing donor age. In the second part of the study, the same cells were grown in culture and stimulated separately to differentiate into both chondrocytes and osteocytes. The chondrogenic differentiation potential of the cells was compared quantitatively by measuring pellet size, matrix proteoglycan, and gene expression of articular cartilage biomarkers. The osteogenic differentiation potential of the cells was assessed quantitatively by measuring alkaline phosphatase activity, calcium deposition, and gene expression of subchondral bone biomarkers. Overall, the data showed that the chondrogenic and osteogenic differentiation potential of equine MSCs decline with increasing donor age. The data further indicated that BM-MSCs have a larger chondrogenic pellet size and proteoglycan content, and a higher alkaline phosphatase activity compared to AT-MSCs, and that BM-MSCs calcium deposition was affected earlier by donor age. The chondrogenic and osteogenic differentiation performance of BM-MSCs declined already between newborn and yearlings. AT-MSCs showed minimal chondrogenic differentiation performance in all age groups. Gene expression of growth factors, chondrogenic and osteogenic biomarkers were down-regulated with increasing donor age. Together, these results support the hypothesis that equine BM- and AT-MSCs proliferation and chondrogenic/osteogenic differentiation decline with increasing donor age following non-linear kinetics. Hence, the study highlights the importance of donor age considerations and MSC selection for autologous treatment of orthopedic injuries. This new knowledge has the potential to optimize autologous stem cell therapies of cartilage and bone injuries in horses, and will help advice owners on when to harvest and potentially cryopreserve the cells

Three-dimensional numerical modelling of static and transient Coulomb stress changes on intra-continental dip-slip faults

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