Since the identification of carbon nanotubes (CNTs) by Ijima in 1991, this material has become a subject of great interest and effort in science because of the outstanding physical properties it exhibits. CNTs can be thought of as graphene sheets rolled into seamless cylinders of various diameters and in principle infinite length. Depending on the number of concentrically arranged tubes, CNTs are termed single‐walled (SWCNT), double‐walled (DWCNT), and multi‐walled (MWCNT) CNTs. Moreover SWCNTs exist as semiconducting or metallic types, depending on the orientation of the hexagonal lattice relative to the tube axis, as classified by the chiral indices (n, m). Their extraordinary mechanical, electrical, thermal, and optical properties render them very attractive for a wide range of applications including advanced composite materials. However synthesis of CNT‐based composite materials still remains a big challenge. In particular it remains to overcome the difficulties in achieving good nanotubes dispersion within the matrix material. The fact that present synthesis routes produce SWCNTs in a bundled state due to van der Waals intertube interaction is another serious hurdle, as SWCNT bundles do not exhibit the excellent properties of their individual components. Thus special treatment has to be applied in order to break these bundles. In an ideal composite material, the individual SWCNTs would be homogeneously dispersed in the matrix. A second issue is the interaction between the CNTs and the host: to improve the load transfer between host and filler covalent linking between the two components is desirable. One approach to solve these problems is functionalization of the CNT source material prior to its incorporation into the polymer matrix. Optimization is required to maximize the transfer from the polymer to the CNTs but minimize the number of wall defects created by the covalent grafting of the functional groups on the CNT sidewalls. Moreover appropriate functional groups have to be chosen to assure compatibility with the polymer being used. Synthesis of the polymethyl methacrylate (PMMA) composite material used here, based on functionalized SWCNTs, was reported recently and its study revealed inhomogeneities in the CNT distribution within the polymer and associated degradation in the mechanical properties suggested as being attributed to the presence of CNT agglomerates. Since Raman spectroscopy, as a mostly non‐destructive analysis method, has proven to be a powerful tool for studying both pure CNT materials and CNT‐based composites, it was used in this work along with supporting methods (scanning electron microscopy (SEM) and focused ion beam (FIB)) for extended characterization of the composite material, including analysis of the source SWCNT material before and after functionalization. Employment of different laser excitation energies (1.96eV and 2.33eV) allowed to separately probe metallic and semiconducting CNTs in the composite samples. The CNT distribution in the samples was illustrated by Raman spectral mapping of the G+‐ peak intensity as a function of position, thus elucidating the presence of CNT agglomerates of different size and shape. At both photon energies, spectral line scans across the boundary regions were performed revealing a substantial drop in intensity of G+ CNT Raman mode and an increase of the D/G+‐intensity ratio. Examination of the D/G+‐ intensity ratio of the SWCNT material before incorporation into the composite showed a higher value for functionalized than for the raw SWCNTs. Furthermore, the metallic nanotubes exhibited a higher degree of functionalization. Raman spectral imaging revealed some inhomogeneities of the CNT distribution in the composite material: the spectra of the areas with good CNT dispersion in the composite exhibit a higher D/G+‐ intensity ratio than in areas with CNT agglomerates indicating that functionalized CNTs are preferentially dispersed in the polymer matrix while non functionalized ones tend to group together in agglomerates. Furthermore significant laser heating of the SWCNTs in composites has been revealed resulting in a downshift of the G+‐ peak position which was much more pronounced in agglomerates than in the areas with dispersed CNTs and detected at the very lowest laser irradiances. SEM/FIB dual beam technique was employed as a supplementary analysis tool. The composites microstructure in CNT agglomerates as well as in the dispersed area was investigated by acquisition of SEM crossectional images confirming the different local CNT concentrations.

Pea (Pisum sativum L.) is the most cultivated pulse in the temperate zone, economically important with high nutritional value (high protein content of 20-30%) and relatively low cost. Root rot is its predominant disease, it is referred to as root rot complex because it involves many pathogens. The most important pathogens of pea root rot are fungi and oomycetes. The aim of this project is to assess the possibility of using root samples with known disease severity index (DSI) to identify pea root rot causing pathogens using a MinION device from Oxford Nanopore technologies. DNA barcoding is the use of a standardized segment or region of the DNA to identify the organism to species level by comparison with a reference library. The ITS region is the barcode sequence marker of fungi. In this study, extracted DNA from pea plant roots of six naturally infected pea fields were sequenced. Two different primer pairs; ITS1Catta & ITS4ngsUni (fungi targeted) and ITS1OO & ITS4ngs (oomycota targeted) were used for the polymerase chain reaction (PCR) amplification. Taxonomic identification was done using Kraken2 bioinformatics tool and UNITE reference database. Organisms from fungal phyla Ascomycota, Basidiomycota and Oomycota were recovered from all the samples, but none of the pea rot root specific pathogens (Sclerotinia sclerotiorum, Pythium ultimum, Thielaviopsis basicola, Fusarium solani, Fusarium oxysporum, Ascochyta pinodella, Aphanomyces euteiches and Rhizoctonia solani) were identified. This project could not validate the use of nanopore sequencing using a MinIon device for the identification of specific pathogens causing pea root rots.

No description available.

The role of hydroelectricity in the Swedish energy system is increasing rapidly as the share of renewable energy sources in the country grows. Meanwhile, the dams are under current revision as ecology and safety requirements has changed since most of them were built. The need for research regarding the Swedish hydroelectric dams is higher than ever.  Historically, such research has been made through measurements in physical laboratory models – scaled down several times to reasonable sizes. However, these models become problematic in cases of very shallow waters. Distorted scaling allows the flows to keep necessary depths to remain representative for the prototype flows, however, research on such distorted flows are quite limited and moreover limited to models with completely free surface flows.  In this study the effects of distortion upon physical as well as numerical measurements of water depths and velocities are analyzed for a dam with a tunnel outlet at the bottom. Measurements were made in a distorted physical model with a distortion ratio of 3, the values of which were later compared to measurements conducted in an earlier study of the same dam in an undistorted model. Furthermore, results of numerical simulations for both the earlier mentioned scales as well as measurements in two models with distortion ratios of 2 and 4 were added to the comparison.  The purpose of the study is to widen the knowledge of distorted models and flows, as well as the knowledge of which situations CFD can perform satisfactory results and not. Numerically conducted values seem to match physical ones well, whereas the differences increased rapidly following an increased distortion ratio. Initially a goal of the study was to find a suitable distortion-ratio to obtain differences of a maximum of 10%, however, as the study came to show consistently much larger differences than that regarding water depths, the question of why these large differences occur rose to become the more significant one. The leading theory of why the differences increase as the distortion ratio becomes greater is that of the decreased utilization of the cross-sectional tunnel area, which leads to higher velocities and thereby higher tunnel resistance.

In recent decades, spinor-helicity formalism has gained popularity as a useful tool for studyingscattering amplitudes in four dimensions. This formalism has been extended to higher dimensions,but there is still much work to be done around its application. This thesis explores a new approachto extending the spinor-helicity formalism to ten dimensions by breaking the Lorentz symmetryinto two five-dimensional subspaces. We use this approach to express the ten-dimensional dynamical variables in terms of five-dimensional spinor helicities. We divide the polarization vectorsinto a direct sum of two massive polarization vectors, each living in five dimensions. We thenapply this new spinor-helicity formalism in ten dimensions to construct the YM, SYM, and higherderivative amplitudes. The results obtained in this thesis suggest that this approach may providea promising avenue for extending the spinor-helicity formalism relevant to SYM, supergravity, andsuperstring theory.

The use of exhaled breath analysis in assessing the health status of human individuals is an intriguing concept that has attracted more and more attention during recent years. Although detection of species in breath can, to a certain extent, be made by both electrochemical and mass spectrometric techniques, these do not always provide sufficient sensitivity, selectivity and speed. Due to the development of new laser sources in the (MIR) wavelength region, absorption spectrometry (AS) has shown such good performance that MIR-AS techniques start to become more viable alternatives to breath analysis. Of the large number of species exhaled  (major species, which are in %-concentrations, e.g. H2O and CO2, minor species, which exist in ppm concentrations, e.g. CO and CH4, and trace species, which exist in low or sup-ppb concentrations), some are more important than others, such as Carbonyl Sulfide, Ethane, Ethylene and Formaldehyde, since they are important biomarkers for various diseases e.g. chronic respiratory diseases, acute lung transplant rejection, UV-radiation damage of the skin and gastro-esophageal/breast cancer. The present thesis consists of a compilation and analysis of possible transitions primarily in the 3-4 µm region that can be used for detecting such species by MIR-AS techniques.

<p>Godkänd; 1994; 20070410 (ysko)</p>

No description available.

No description available.

The cost of developing new pharmaceuticals has increased, while the number ofpharmaceuticals approved has declined. This highlights the importance for newpharmaceuticals to quickly become successful. The aim of this thesis is to explore thefactors of importance when launching new pharmaceuticals. Initially a literature reviewhas been conducted to explore general factors of importance for a pharmaceutical tobecome a commercial success. Furthermore, eleven in-depth interviews have beenperformed with stakeholders from the Swedish healthcare system to identify significantfactors on a national and regional level in Sweden. A thematic analysis was used tocategorize the data collected in the interviews. The result of the literature review showed that the value creating process is of utmostimportance for a pharmaceutical to become a success. This is affected by a customeroriented focus, the design of the pharmaceutical study and the outcome from the healtheconomic analysis. Additionally, a number of challenges in the pharmaceutical supplychain were identified, which could cause a bottleneck during the launch of newpharmaceuticals. In the empirical part a main theme ‘Trust’ with a total of seven subthemes was identified.The seven subthemes are factors that are essential to gain the trust and create the value,they are: ‘Guidelines and Regulations’, ‘Clinical Efficacy and Clinical Evidence’,‘Marketing’, ‘Information’, ‘Adherence and Compliance’, ‘Health Economics’ and‘Financial Aspect’. The subtheme ‘Guidelines and Regulations’ highlights the connectionbetween guidelines and utilization of pharmaceuticals. The ‘Clinical Efficacy and ClinicalEvidence’ was identified as the utmost important success factor. Furthermore the theme‘Value of Money’, including the subthemes ‘Health Economics’ and ‘Financial Aspect’,highlights the importance of the budget aspect and the increasing use of healtheconomics to evaluate health benefits and costs in healthcare. The subtheme ‘Adherenceand Compliance’ stresses the importance of information to the end user, whereas thesubtheme ‘Information’ highlights the information exchange among differentstakeholders. The subtheme ‘Marketing’ describes the effect of personal relationshipbetween industry and prescribers, and the effect on the pharmaceutical use it can have.