Friction Stir Welding of Copper Canisters Using Power and Temperature Control

This thesis presents the development to reliably seal 50 mm thick copper canisters containing the Swedish nuclear waste using friction stir welding. To avoid defects and welding tool fractures, it is important to control the tool temperature within a process window of approximately 790 to 910°C. The welding procedure requires variable power input throughout the 45 minute long weld cycle to keep the tool temperature within its process window. This is due to variable thermal boundary conditions throughout the weld cycle. The tool rotation rate is the input parameter used to control the power input and tool temperature, since studies have shown that it is the most influential parameter, which makes sense since the product of tool rotation rate and spindle torque is power input. In addition to the derived control method, the reliability of the welding procedure was optimized by other improvements. The weld cycle starts in the lid above the joint line between the lid and the canister to be able to abort a weld during the initial phase without rejecting the canister. The tool shoulder geometry was modified to a convex scroll design that has shown a self-stabilizing effect on the power input. The use of argon shielding gas reduced power input fluctuations i.e. process disturbances, and the tool probe was strengthened against fracture by adding surface treatment and reducing stress concentrations through geometry adjustments. In the study, a clear relationship was shown between power input and tool temperature. This relationship can be used to more accurately control the process within the process window, not only for this application but for other applications where a slow responding tool temperature needs to be kept within a specified range. Similarly, the potential of the convex scroll shoulder geometry in force-controlled welding mode for use in applications with other metals and thicknesses is evident. The variable thermal boundary conditions throughout the weld cycle, together with the risk of fast disturbances in the spindle torque, requires control of both the power input and the tool temperature to achieve a stable, robust and repeatable process. A cascade controller is used to efficiently suppress fast power input disturbances reducing their impact on the tool temperature. The controller is tuned using a recently presented method for robust PID control. Results show that the controller keeps the temperature within ±10°C of the desired value during the 360º long joint line sequence. Apart from the cascaded control structure, good process knowledge and control strategies adapted to different weld sequences i.e. different thermal boundary conditions have contributed to the successful results

Translating United States congressional speeches : functionalist and discourse-analytical perspectives

This thesis seeks to highlight problems and strategies relevant to translating United States congressional speeches for a European readership. The analyzed material comprises ten as-yet untranslated speeches held in the House of Representatives and the Senate by members of both main parties, Democrats and Republicans. The material was delimited by time frame and subject matter: the speeches coincide with Donald Trump’s presidency and concern the United States’ commitment to NATO. The method of analysis involves a merger of functionalist translation approaches and political discourse analysis. Political source texts and their translations have been discussed by Christina Schäffner, upon whose genre-specific analyses of political speeches this thesis relies. Discourse analysis was chosen as a supplementary perspective due to the instruments it offers for the socio-cultural contextualization of texts beyond their linguistic units, thus adding to the generalizability of the analysis across potential target language communities. The discourse-analytical models employed in the thesis are derived from Muntigl (2002) and van Dijk (2002). Muntigl examines how political issues are politicized and depoliticized through specific linguistic resources, while van Dijk discusses discourse structures and how they reflect the wider context of discourse production, including a “cultural Common Ground” between interactants. The speeches are first analyzed under these two models, whereafter parallels are drawn between the results of the discourse analysis and Schäffner’s functionalist framework, so as to establish what implications the material poses for translation. The analysis found notable overlap between Schäffner’s functionalist approaches and the Muntigl and van Dijk models. The translational problems identified concern chiefly metaphor (including path semantic structures by which issues are politicized and depoliticized), genre conventions, contrastive meanings, deixis and, lastly, implicit information resulting from the speakers’ beliefs and the knowledge they assume of primary addressees. In light of these observations, further research on the translation of United States congressional speeches is encouraged

Developing student teachers’ PCK for teaching technology with a sustainability edge in primary school

In Swedish primary schools, technology teaching may appear different depending on what educational setting the pupils meet. Many pupils experience the subject of technology as taking part in practical making-activities without recognizing the technological knowledge involved, and many teachers feel uncertain of what and how to teach technology, especially concerning sustainability. Thus, it is necessary to pinpoint these issues within teacher education. This paper presents the first iteration of a Design-Based Implementation Research (DBIR) study on a teaching module that provides student teachers with theoretical and practical knowledge in technology education. The purpose of the study is to capture and understand how student teachers transform acquired knowledge and skills into Pedagogical Content Knowledge (PCK) for teaching technology in primary school. Special attention is on how student teachers evolve relations between technology education and sustainable development. The study is designed and implemented in line with DBIR based on principles of collaboration and has strong connections between practice and theory (Fishman & Penuel, 2018). The participating researchers, also the teacher educators, have together with teachers at a municipal technological resource facility jointly identified underlying premises such as policy document statements; topics and content of value for all participants; potential participating schools; and reviews of previous research. The study includes 12 student teachers enrolled in a science and technology course. Data is collected in several steps including student teachers’ written individual reflections, their project assignments, their lesson plans, and focus group interviews. Based on qualitative content analysis, components of PCK are traced to elucidate the transformation of student teachers’ PCK for teaching technology with a sustainability edge. The results contribute to knowledge of what efforts, such as teaching module design features and connections to sustainability, should be made to develop student teachers’ PCK for teaching technology in primary school

Matrix proteinases in lung injury in the preterm infant

During inflammation, excess production and release of matrix proteinases, including matrix metalloproteinases (MMPs) and serine proteinases, may result in dysregulated extracellular proteolysis leading to development of tissue damage. Pulmonary inflammation may play an important role in the pathogenesis of lung injury in the preterm infant. The aims of this study were to evaluate involvement of MMPs and serine proteinase trypsin in acute and chronic lung injury in preterm infants and to study the role of these enzymes in acute lung injury by means of an animal model of hyperoxic lung injury. Molecular forms and levels of MMP-2, -8, and -9, and their specific inhibitor, tissue inhibitor of metalloproteinases (TIMP)-2, as well as trypsin were studied in tracheal aspirate fluid (TAF) samples collected from preterm infants with respiratory distress. Expression and distribution of trypsin-2 and proteinase-activated receptor 2 (PAR2) was examined in autopsy lung specimens from fetuses, from preterm infants with respiratory distress syndrome (RDS) or bronchopulmonary dysplasia (BPD), and from newborn infants without lung injury. We detected higher MMP-8 and trypsin-2 and lower TIMP-2 in TAF from preterm infants with more severe acute respiratory distress. Infants subsequently developing BPD had higher levels of MMP-8 and trypsin-2 early postnatally than did those who survived without this chronic lung injury. Immunohistochemically, trypsin-2 was mainly detectable in bronchial epithelium, but also in alveolar epithelium, and its expression was strongest in prolonged RDS. Since trypsin-2 is potent activator of PAR2, a G-protein coupled receptor involved in inflammation, we studied PAR2 expression in the lung. PAR2 co-localized with trypsin-2 in bronchoalveolar epithelium and its expression was significantly higher in bronchoalveolar epithelium in preterm infants with prolonged RDS than in newborn controls. In the experimental study, rats were exposed to >95% oxygen for 24, 48, and 60 hours, or room air. At 48 hours of hyperoxia, MMP-8 and trypsin levels sharply increased in bronchoalveolar lavage fluid, and expression of trypsin appeared in alveolar epithelium, and MMP-8 predominantly in macrophages. In conclusion, high pulmonary MMP-8 and trypsin-2 early postnatally are associated with severity of acute lung injury and subsequent development of BPD in preterm infants. In the injured preterm lung, trypsin-2 co-localizes with PAR2 in bronchoalveolar epithelium, suggesting that PAR2 activated by high levels of trypsin-2 is involved in lung inflammation associated with development of BPD. Marked increase in MMP-8 and trypsin early in the course of experimental hyperoxic lung injury suggests that these enzymes play a role in the pathogenesis of acute lung injury. Further exploration of the roles of trypsin and MMP-8 in lung injury may offer new targets for therapeutic intervention.Bronkopulmonaalinen dysplasia (BPD) on pienen keskosen krooninen keuhkosairaus, joka kehittyy arviolta joka neljännelle syntyessään alle 1500 g painavista vauvoista. Sairaus on tavallisin niillä keskosilla, jotka ovat olleet happi- ja hengityskonehoidossa syntymänsä jälkeen keuhkojen kypsymättömyydestä johtuvan hengitysvaikeus-oireyhtymän eli RDS-taudin vuoksi. Keuhkojen varhaisella tulehduksellisella reaktiolla uskotaan olevan merkittävä osuus BPD:n synnyssä. Tulehduksen kroonistuessa keuhkorakkularakenteet vaurioituvat ja keuhkoihin alkaa muodostua arpikudosta ja samalla kudoksen normaali kasvu ja kehitys häiriintyvät. Matriksin metalloproteinaasit (MMP:t) ovat solunulkoista ainesta pilkkovia entsyymejä, joiden aktiivisuutta säädellään tarkasti. Niillä on tärkeä rooli kudosten kasvuun liittyvässä solunulkoisen aineksen uudelleenmuotoilussa, mutta niiden liikatuotanto esim. tulehduksen yhteydessä voi johtaa kudosvaurion syntyyn. Trypsiini on haiman ruuansulatusentsyymi, jonka on viime vuosina osoitettu esiintyvän laajalti ihmisen muissakin kudoksissa, myös keuhkoissa. Trypsiinin biologinen merkitys ruuansulatuskanavan ulkopuolella on kuitenkin yhä epäselvä. Tiedetään, että se kykenee hajoittamaan solunulkoista ainesta ja aktivoimaan MMP-entsyymejä ja proteinaasi-aktivoituva reseptori 2:ta (PAR2), jolla on useissa kudoksissa osoitettu olevan tulehdusta ja arpikudoksen muodostumista edistävä vaikutus. Tässä väitöskirjatyössä selvitettiin MMP:ien ja trypsiinin osuutta keskosen akuutin (RDS-tauti) ja kroonisen keuhkovaurion (BPD) synnyssä. Tutkimuksessamme havaitsimme, että RDS-tautia sairastavien keskosten henkitorven huuhtelunäytteissä MMP-8:n ja trypsiinin pitoisuudet olivat korkeammat, ja toisaalta MMP-estäjä TIMP-2:n matalammat niillä keskosilla, joilla RDS-tauti oli vaikeampi. Jo ensimmäisellä elinviikolla MMP-8:n ja trypsiinin pitoisuudet olivat merkittävästi korkeammat niillä keskosilla, joille sittemmin kehittyi BPD kuin niillä, jotka selvisivät ilman kroonista keuhkovauriota. Tutkimme myös trypsiinin ja PAR2:n ilmaantumista keuhkorakenteissa ruumiinavausaineistossa. RDS- ja BPD-tautiin menehtyneillä keskosilla trypsiinin ja PAR2 ilmaantuivat erityisesti keuhkoputkien ja myös keuhkorakkuloiden epiteelissä. Pitkittyneeseen RDS-tautiin tai BPD-tautiin kuolleilla PAR2 ilmaantui myös keuhkorakkuloiden seinämien sidekudosta tuottavissa soluissa. Kokeellisessa rotan hyperoksisessa (altistus yli 95-%:lle hapelle) keuhkovammassa osoitimme MMP-8:n ja trypsiinin pitoisuuksien keuhkoissa lisääntyivät vahvasti jo keuhkovaurion synnyn varhaisessa vaiheessa. Vaikka selvää syy-yhteyttä emme tulostemme perusteella voi osoittaa, MMP-8:n ja trypsiinin voimakas esiintyminen keuhkoissa yhdessä vaurioiden kanssa viittaa siihen, että näillä proteinaasientsyymeillä voi olla merkitystä keskosen akuutin ja kroonisen keuhkovaurion synnyssä. Jatkotukimuksia tarvitaan selvittämään, voisiko näitä proteinaaseja estämällä ehkäistä keuhkovaurion syntyä

Composite UHPC-AAC/CLC facade elements with modified interior plaster for new buildings and refurbishment. Materials and production technology

The awareness of the environmental impact of the building sector is increasing. Steel reinforced concrete is the most commonly used construction material, though with a high-embodied energy and carbon footprint. Large environmental gains may arise if an alternative to steel reinforced concrete is developed. In this context, ultra-high performance concrete (UHPC) materials are shown to be promising alternatives with advantages such as lower embodied energy and reduced environmental impact. Predictions suggest that UHPC composite elements for building envelopes could have other benefits such as an increased service life, optimised use of building area due to thinner elements and minimised maintenance due to the absence of reinforcement or use of non-corrosive reinforcing materials such as carbon fibres. In the framework of the H-HOUSE project funded by the European Commission, composite elements are developed. The aim is to create facade panels combining an autoclaved aerated concrete or cellular lightweight concrete insulation layer with an external UHPC supporting layer. To enhance occupant comfort and health, hygroscopic materials that are capable to buffer indoor air humidity shall be applied to the inside of such elements. Indoor air humidity levels are expected to be more stable, which shall subsequently improve the indoor climate and minimise potential decay to the construction

Early Elevation of Matrix Metalloproteinase-8 and -9 in Pediatric ARDS Is Associated with an Increased Risk of Prolonged Mechanical Ventilation

BACKGROUND: Matrix metalloproteinases (MMP) -8 and -9 may play key roles in the modulation of neutrophilic lung inflammation seen in pediatric Acute Respiratory Distress Syndrome (ARDS). We aimed to perform a comprehensive analysis of MMP-8 and MMP-9 activity in tracheal aspirates of pediatric ARDS patients compared with non-ARDS controls, testing whether increased MMP-8 and -9 activities were associated with clinical outcomes. METHODS: Tracheal aspirates were collected from 33 pediatric ARDS patients and 21 non-ARDS controls at 48 hours of intubation, and serially for those who remained intubated greater than five days. MMPs, tissue inhibitor of metalloproteinases (TIMPs), human neutrophil elastase (HNE) and myeloperoxidase (MPO) activity were measured by ELISA, and correlated with clinical indicators of disease severity such as PRISM (Pediatric Risk of Mortality) scores, oxygen index (OI), multi-organ system failure (MOSF) and clinical outcome measures including length of intubation, ventilator-free days (VFDs) and mortality in the Pediatric Intensive Care Unit (PICU). RESULTS: Active MMP-9 was elevated early in pediatric ARDS subjects compared to non-ARDS controls. Higher MMP-8 and active MMP-9 levels at 48 hours correlated with a longer course of mechanical ventilation (r = 0.41, p = 0.018 and r = 0.75, p<0.001; respectively) and fewer number of VFDs (r = -0.43, p = 0.013 and r = -0.76, p<0.001; respectively), independent of age, gender and severity of illness. Patients with the highest number of ventilator days had the highest levels of active MMP-9. MMP-9 and to a lesser extent MMP-8 activities in tracheal aspirates from ARDS subjects were sensitive to blockade by small molecule inhibitors. CONCLUSIONS: Higher MMP-8 and active MMP-9 levels at 48 hours of disease onset are associated with a longer duration of mechanical ventilation and fewer ventilator-free days among pediatric patients with ARDS. Together, these results identify early biomarkers predictive of disease course and potential therapeutic targets for this life threatening disease

Capillary Regeneration in Scleroderma: Stem Cell Therapy Reverses Phenotype?

BACKGROUND. Scleroderma is an autoimmune disease with a characteristic vascular pathology. The vasculopathy associated with scleroderma is one of the major contributors to the clinical manifestations of the disease. METHODOLOGY/PRINCIPAL FINDINGS. We used immunohistochemical and mRNA in situ hybridization techniques to characterize this vasculopathy and showed with morphometry that scleroderma has true capillary rarefaction. We compared skin biopsies from 23 scleroderma patients and 24 normal controls and 7 scleroderma patients who had undergone high dose immunosuppressive therapy followed by autologous hematopoietic cell transplant. Along with the loss of capillaries there was a dramatic change in endothelial phenotype in the residual vessels. The molecules defining this phenotype are: vascular endothelial cadherin, a supposedly universal endothelial marker required for tube formation (lost in the scleroderma tissue), antiangiogenic interferon α (overexpressed in the scleroderma dermis) and RGS5, a signaling molecule whose expression coincides with the end of branching morphogenesis during development and tumor angiogenesis (also overexpressed in scleroderma skin. Following high dose immunosuppressive therapy, patients experienced clinical improvement and 5 of the 7 patients with scleroderma had increased capillary counts. It was also observed in the same 5 patients, that the interferon α and vascular endothelial cadherin had returned to normal as other clinical signs in the skin regressed, and in all 7 patients, RGS5 had returned to normal. CONCLUSION/SIGNIFICANCE. These data provide the first objective evidence for loss of vessels in scleroderma and show that this phenomenon is reversible. Coordinate changes in expression of three molecules already implicated in angiogenesis or anti-angiogenesis suggest that control of expression of these three molecules may be the underlying mechanism for at least the vascular component of this disease. Since rarefaction has been little studied, these data may have implications for other diseases characterized by loss of capillaries including hypertension, congestive heart failure and scar formation.Scleroderma Research Foundatio