38 research outputs found
Data och kod för "The potential of semiochemical blends to monitor saproxylic beetle communities"
No full textThis folder contains all data and code used in the article "The potential of semiochemical blends to monitor saproxylic beetle communities" by Viktor Gårdman, Bo Aulin, Mikael A. Molander, & Mats Jonsell.
The data stems from sampling of saproxylic beetles using crosstraps baited with one of three different pheromone blends between 2017-2023 (excluding 2022) at three different harbors in southern Sweden: Gothenburg (57.7017° N, 11.9479° E), Mönsterås (57.0416° N, 16.4431° E) and Norrköping (58.5877° N, 16.1924° E). Individual counts of all recorded species of saproxylic weevils (Curculionidae) (including barkbeetles (Scolytinae)), long-horned beetles (Cerambycidae), and jewel beetles (Buprestidae) are provided per month, year, harbor, blend and number of traps used. The data collection has been conducted by the Swedish Board of Agriculture with the aim to survey the potential entry of woodboring pests through timber import to Swedish harbors. Identification of beetles has been done by experts at the Swedish University of Agricultural Sciences. All data files are .csv files. Note that more types of pheromone blends or other attractants have been used in other traps at the same sites, and that more sites have been monitored throughout years. The data here is only from consistently used sites and blends between 2017-2023. For the complete dataset on catches of beetles across all sampling sites and baits, please refer to the Swedish Board of Agriculture (https://jordbruksverket.se/).
The SpeciesMatrix contains raw counts of individuals sampled per species and month, year, harbor, and blend. The number of traps used at each occasion is also given.
Data on tree host preferences (file 'TreeHost') for the sampled species was extracted from the Swedish Species Information Center (SLU ArtDatabanken, https://artfakta.se/).
The GLMM_Species_Modified folder contains individual .csv files of counts for each species deemed suitable for individual analysis per harbor, year, month, and blend. The number of traps used for every occasion is also given. These files have further has modified to remove excess zeros. To avoid zero-inflation, any years, harbors, or baits with zero findings for each species have been removed. These are the files used to run the GLMM models.
The SSOS file contains all records of saproxylic weevils, bark beetles, long-horned beetles, and jewel beetles found in the publicly available records in the Swedish Species Observations System (SSOS = "Artportalen", https://www.artportalen.se/) in a 10x10km square around each harbor between 2017-2023.
All analyses were conducted using R version 4.4.0 and the code is presented through Rmarkdown.Den här mappen innehåller data och kod till artikeln ”The potential of semiochemical blends to monitor saproxylic beetle communities” av Viktor Gårdman, Bo Aulin, Mikael A. Molander & Mats Jonsell.
Rådatan härstammar från jordbruksverkets övervakning av vedlevande skalbaggar vid Sveriges hamnar. Skalbaggarna samlas in med crosstraps betade med en av tre feromonblandningar. Detta har gjorts mellan 2017-2023 (exklusive 2022) vid tre olika hamnar i södra Sverige: Göteborg (57,7017° N, 11,9479° E), Mönsterås (57,0416° N, 16,4431° E) och Norrköping (58,5877° N, 16,1924° E). Alla registrerade arter av vedlevande vivlar (Curculionidae) (inklusive barkborrar (Scolytinae)), långhorningar (Cerambycidae) och praktbaggar (Buprestidae) har räknats till individantal. Datan anger individantal av varje art per månad, år, hamn, feromonblandning och antal fällor som använts. Datainsamlingen har utförts av Jordbruksverket i syfte att kartlägga den potentiella införseln av vedlevande skadegörare genom timmerimport till svenska hamnar. Identifieringen av skalbaggarna har gjorts av experter vid Sveriges lantbruksuniversitet. Alla datafiler är .csv-filer. Observera att fler typer av feromonblandningar eller andra lockmedel har använts i andra fällor på samma platser, och att fler platser har övervakats under åren. Uppgifterna här är endast från konsekvent använda platser och blandningar mellan 2017-2023. För fullständiga uppgifter om fångster av skalbaggar från alla provtagningslokaler och beten, kontakta Jordbruksverket (https://jordbruksverket.se/).
SpeciesMatrix innehåller rådata av individer som provtagits per art och månad, år, hamn och feromonblandning. Antalet fällor som användes vid varje tillfälle anges också.
Data kring vilka trädslag arterna lever av (filen ”TreeHost”) hämtades från ArtDatabanken (SLU ArtDatabanken, https://artfakta.se/).
Mappen GLMM_Species_Modified innehåller individuella .csv filer för varje art som valts ut för individuella analyser med individalantal för varje kombination av år, månad, hamn och bete. Även information om antalet fällor per fångstillfälle anges. Hamnar, år eller beten med noll fynd för varje art har tagits bort. Syftet med detta är att undvika zero-inflation i modellerna. GLMM_Species_Modified innehåller alltså filerna som används för att köra GLMM-modellerna.
SSOS filen innehåller alla vedlevande vivlar, barkborrar, långhorningar och praktbaggar som rapporterats från Artportalen i en 10x10km ruta kring varje hamn mellan 2017-2023 (https://www.artportalen.se/).
Alla analyser är utförda i R version 4.4.0 och presenteras via Rmarkdown
Singlet Exciton Fission and Photochemical Upconversion
No full textThe Sun is the main source of renewable energy on Earth. Our planet receives about 174 PW of solar power. At the same time, global energy consumption from all energy sources is orders of magnitude lower and is equal to approximately 16 TW. Clearly, solar energy has a tremendous potential, as well as numerous advantages over conventional sources of energy. In recent years the photovoltaic industry exhibited significant growth, however the main obstacles that are preventing widespread introduction of solar cells are their still low efficiency and high cost. The major factors contributing to the low efficiency are non-efficient conversion and lack of absorption of sunlight by the active layer material. Sunlight has a broad spectrum spanning over the UV, visible, and NIR optical ranges. Commonly, solar cells are constructed using a single junction, which leads to two fundamental loss mechanisms: i) for photons with a higher energy than the band gap the energy surplus is lost as heat and only the band gap energy harvested, ii) photons with an energy lower than the band gap are not harvested at all. Together, these losses constitute a limitation of the efficiency of a silicon solar cell by half. In the work described in this thesis we have explored ways to decrease these losses by using advanced materials that allow to efficiently down-convert high energy photons, and up-convert low energy photons to the energies close to the band gap energy. Both of these approaches can be achieved in certain classes of organic materials and are known as singlet exciton fission and photochemical upconversion. This thesis combines the results of experimental research of both singlet exciton fission and photochemical upconversion in organic materials by means of laser spectroscopy tools: transient absorption and time resolved luminescence. Singlet exciton fission is a process by which a singlet excited state is converted into a combination two triplet excited states with half the energy. The two triplet together constitute an overall singlet state and hence it is a spin-allowed process that can in principle be very efficient. In this thesis, singlet fission has been studied in a range of perylenediimide (PDI) derivatives in the crystalline state. Substitution at imide nitrogen position allows to obtain different crystal structures in the solid state. In this way the electronic coupling between neighboring molecules in a crystal can be varied without significantly changing the energetics of their singlet and triplet levels. Singlet exciton fission was experimentally detected for a variety of different crystal structures of PDI. The formation of triplet excited states was found to occur on a sub-picosecond time scale. The experimentally detected fission rates and triplet yields were significantly higher than predicted by earlier theoretical calculations and were found to depend only very weakly on the crystal structure. The latter can be explained by intermolecular vibrational modes that could significantly speed up fission in perylenediimides. Photochemical upconversion can be seen as the reverse process of singlet fission. In this case, two triplet excited states, formed through a triplet sensitizer, are combined into a single higher lying singet excited state by triplet-triplet annihilation. Using this approach it is possible to convert low-energy photons that are normally not absorbed in a solar cell into higher energy photons that can be converted efficiently. In this thesis, photochemical upconversion was studied in bi-component mixtures of triplet sensitizer and triplet acceptor in solutions. Metal based porphyrins were used as triplet sensizers, and diphenylanthracene was used as triplet acceptor. The triplet sensitizer produces triplets by fast intersystem crossing due to spin-orbit coupling. The triplets are subsequently transferred to the triplet acceptor by Dexter energy transfer. When two acceptor molecules in the triplet state encounter each other, triplet-triplet annihilation occurs which results in emission from a singlet state. The overall process can be described as conversion of two low energy photons into one high energy photon. In this way, photons that are normally not absorbed by an active material in a solar cell can be converted into photons that can be absorbed, leading to a significant potential enhancement of the overall efficiency. In this work the dependence of the photochemical upconversion process on the metal in triplet sensitizer (porphyrin) was studied. Efficient upconversion was observed for platinum and palladium based porphyrins ( 25-30%) while for the zinc porphyrin the efficiency was considerably less ( 12%). For free base porphyrin, no upconversion was detected. The upconversion process is the result of a series of individual steps outlined above where most steps are the same for all the combinations. The differences in efficiency are traced back to the dependence of energy transfer efficiency on core metal of the porphyrin. Finally, we have made an attempt to achieve upconversion from the near infrared region. For this purpose, we have used porphyrin oligomers consisting of two or four porphyrin rings that have a red-shifted absorption beyond 700 nm. It is shown that using the two-ring oligomer as a sensitizer for a perylene bisimid, it is possible to convert 700 nm light to the 500-600 nm range. For the four-ring oligomer, no noticeable upconversion was observed, possibly because the triplet of the porphyrin oligomer is just below that of the perylene bisimid in this case.ChemE/Chemical EngineeringApplied Science
Upconversion: Kinetics of a model system
No full textPhotochemical upconversion is a process upon which the photons of low energy are converted into photons of higher energy by means of sensitized triplet triplet annihilation. Photochemical upconversion has a potential application in the eld of photovoltaics, where it can signicantly improve the eciency of solar cells by exploiting the energy of near infrared band of solar radiation. In order to design highly ecient chromophores for photochemical upconversion, better understanding of the elementary processes is crucial. Current thesis is an attempt to do so by studying the kinetics and eciency of photochemical upconversion in a model system metal-OEP/DPA utilizing time resolved transient absorption and photoluminescence spectroscopic techniques.Opto-electronic MaterialsChemical EngineeringApplied Science
Gay athlete's experiences in sport and exercise domains in Finland
No full textSport is perceived to be one of the last fortresses of heteronormative and homonegative attitudes that cause psychological and social issues for LGBT (lesbian, gay, bisexual, and transgender) athletes, especially in their self-confidence and self-concept. Furthermore, these negative mindsets challenge LGBT individuals' participation in organized sport and physical activity. To offer effective consulting services, it is vital for sport psychologists to be aware of the issues that LGBT athletes might struggle with throughout their sport careers. Adopting 'queer theory' as a theoretical framework, this study strives to understand a gay male athlete's experiences in sport and physical activity in Finland, and how these experiences reflects in his sexual identity development and management, and relationships to others in sport. Autoethnography, an 'autobiographical genre of writing', and narrative analysis was utilized in this study as it enables the reader to vicariously share author's own experiences in sport and physical activity. Self-observational and self-reflective data was gathered from author's exercise and personal memory logs. Findings are presented in the form of narrative, which is constructed based on the data produced by the author. The story reveals the challenge of sexual identity development in- and outside of sport, and the constant negotiation between social and athletic identities. Interpretations of the findings are discussed with relevant theories of sexual identity development and previous LGBT research in sport. This study shows albeit there are general positive change of attitudes towards LGBT people in Finland, homosexual athletes can still have various difficulties in developing and expressing their sexual identity in organized sport and physical activity. Queer practice has a potential to confront the unequal and oppressive heteronormative constructs in sport and physical activity domains. However, more studies and stories are needed to understand the experiences of LGBT people in sport to develop programs and interventions aimed at increasing athletes' and sport practitioners' openness to LGBT athletes.unknown accessibilityei tietoa saavutettavuudest
The impact of science on economic growth and its cycles: the mathematical dynamics determined by the basic macroeconomic facts
No full textThe author shows that the enormous gap between theory and facts in modern macroeconomics can only be eliminated by nonlinear macroeconomic dynamics with the following special characteristics: First of all, only certain group-theoretical invariants generate the correct growth cycles with irregularly varying lengths, not any stochastic process as usually applied for this purpose. Furthermore, a special extended value function and generalized human capital are needed for a correct representation of scientific and technological innovation. Finally, the correct nonlinear macroeconomic dynamics are not reducible to microeconomics, for both of the above mentioned reasons
Efficient algorithms for calculating Euclidean distance spectra of muliti-user continuous phase modulation systems
No full textThe performance of maximum likelihood detection of a coded modulation scheme over an additive white Gaussian noise channel can be predicted precisely by its Euclidean distance spectrum. In this paper, three algorithms are developed to generate the Euclidean distance spectra. The first algorithm is an exhaustive tree-search algorithm which is simplified by exploiting the correspondence between a code tree and the trellis. This algorithm is then modified to incorporate the A* algorithm and results in two heuristic algorithms. Moreover, the technique of trellis minimization is further developed for the multi user case and employed to reduce the complexity and memory requirements. Numerical results confirm that the proposed algorithms can generate the distance spectra of all systems with lower complexity relative to previous methods and are particularly suited for multi user CPM systems
CNFs from softwood pulp fibers containing hemicellulose and lignin
No full textThe energy demand to produce cellulose nanofibrils, CNFs, is high and additionally the cost of the starting material, the pulp, is substantial as high purity cellulose dissolving pulp is generally used. Pulps aimed for board and paper are produced at higher yield as they contain hemicelluloses and, in the case of unbleached pulp, lignin, and would be a more economical starting material for CNFs. It is of interest to understand how the presence of hemicellulose and lignin affects the fibrillation process and CNF properties. Kraft cooks of softwood were performed as well as kraft cooks with addition of polysulfide to increase the hemicellulose content. Part of the pulps were bleached to remove residual lignin, thus making it possible to compare pulps with and without lignin. Higher amount of hemicellulose had an obstructive effect on the enzymatic pre-treatment whereas lignin had no adverse effect on enzyme accessibility. Increased amount of charged groups improved the accessibility for enzymes. Both hemicellulose and lignin were carboxymethylated when pre-treatment by carboxymethylation was employed. However, carboxymethylation partly dissolved hemicelluloses. The tensile strength of CNF films was independent of the chemical composition of the pulp and the pre-treatment strategy. However, since the enzymatic pre-treatment decreased the cellulose DP more, CNF films from enzymatically pre-treated pulps had generally lower tensile strength. © 2022, The Author(s).</p
Continuous phase modulated orthogonal multiple access scheme
No full textThis paper focuses on the design and performance analysis of continuous phase modulated orthogonal multiple access systems. The multiuser interference is firstly derived in the context of single user detection, which reveals that the interference is determined by the modulation format. Therefore, the interference can be successfully suppressed by carefully chosen modulation parameters. Based on this observation, a class of orthogonal multiple access schemes is proposed. It is shown that the proposed strategy not only facilitates simple detection at the receiver side but also offers improved sum rate
A simplified detector for FDMA-CPM systems
No full textThis paper concerns developing a low complexity detector for spectrally-efficient Frequency-Division-Multiple-Access (FDMA) multiuser systems based on Continuous-Phase-Modulation (CPM). A class of tree-trellis-search based algorithms is proposed for joint/iterative detection and the complexity is further reduced employing a state-reduction technique based on mismatched filters. The proposed detector is evaluated in terms of minimum achievable Euclidean distance. Analytical and simulated results reveal that the proposed detector offers near optimum performance with significantly reduced complexity
Single user detection of continuous phase modulated multiuser systems
No full textThe performance analysis of single user detection of continuous phase modulated multiuser systems is presented in this paper. The discussion is formulated in the context of a mismatched receiver and the performance of single user detection is analyzed in terms of Euclidean distance. Taking the modulation parameters into consideration, a closed-form expression for the performance evaluation is obtained. Principles of designing the transceiver for spectrally-efficient systems are proposed. Numerical and analytical results show that properly designed spectrally efficient multiuser systems can be successfully detected by the presented detector with low complexity
