26 resultados para Glutaraldéhyde (GA)
Resumo:
Denna studie syftar till att via utformandet av en teoretisk modell nå ökad förståelse för hur människan erfar lidandet. Studien, som har en hermeneutisk ansats, fokuserar lidandet som drama och kamp, vilka beskrivs som lidandets form och substans. Data insamlades genom samtal med informanter från två kontext. Den ena informantgruppen som utgjordes av nio personer med drogrelaterade problem valdes med utgångspunkt i ett antagande om att missbruket härrör från ett livslidande. De övriga informanterna (nio stycken) söktes inom ett till det yttre kontrasterande kontext, de hjärtopererade patienternas. De texter dessa samtal genererade tolkades sedan med utgångspunkt i en hermeneutisk ansats, som hämtat metodologisk inspiration av Ricoeur och Helenius. Tolkningen ägde rum i flera steg och det meningsbärande söktes genom naiv tolkning, analys av textens struktur samt genom ett sökande efter alternativa tolkningar. Tolkningsprocessen resulterade en uppsättning teser vilka relaterades till undersökningens teoretiska perspektiv samt till en begreppsanalys av ’kamp’. Den teoretiska modellen tar fasta på lidandets kamp som en kamp mellan värdighet och skam, lust och olust. Denna kamp kan gestaltas i lidandets drama där människan på olika sätt söker lindring i lidandet. Detta kan ske genom att man försöker besegra lidandet, avtäcka det eller försonas med det. Ytterligare ett sätt att söka lindring är att ge upp lidandets kamp och resignera. I den teoretiska modellen gestaltas även hur människan kan förhålla sig till kampen på olika sätt beroende på vilket perspektiv hon har inför framtiden. Då människan uppfattar att framtiden präglas av ett hot om avskurenhet och död förhåller hon sig till livet på ett sådant sätt att lidandet dominerar. Om uppfattningen om framtiden präglas av liv och gemenskap kan hon förhålla sig till kampen som hälsa. När lidandet blir outhärdligt förlorar människan sin förankring i tiden. I och med att människan isoleras i nuet kan lidandet bemästras och begränsas till en konkret situation. För att en rörelse i hälsoprocesserna skall äga rum måste människan emellertid relatera till tiden. Relationen till en annan människa och skapandet av en lidandeberättelse innebär en möjlighet till förankring i tiden och därmed också till helande.
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In this work mathematical programming models for structural and operational optimisation of energy systems are developed and applied to a selection of energy technology problems. The studied cases are taken from industrial processes and from large regional energy distribution systems. The models are based on Mixed Integer Linear Programming (MILP), Mixed Integer Non-Linear Programming (MINLP) and on a hybrid approach of a combination of Non-Linear Programming (NLP) and Genetic Algorithms (GA). The optimisation of the structure and operation of energy systems in urban regions is treated in the work. Firstly, distributed energy systems (DES) with different energy conversion units and annual variations of consumer heating and electricity demands are considered. Secondly, district cooling systems (DCS) with cooling demands for a large number of consumers are studied, with respect to a long term planning perspective regarding to given predictions of the consumer cooling demand development in a region. The work comprises also the development of applications for heat recovery systems (HRS), where paper machine dryer section HRS is taken as an illustrative example. The heat sources in these systems are moist air streams. Models are developed for different types of equipment price functions. The approach is based on partitioning of the overall temperature range of the system into a number of temperature intervals in order to take into account the strong nonlinearities due to condensation in the heat recovery exchangers. The influence of parameter variations on the solutions of heat recovery systems is analysed firstly by varying cost factors and secondly by varying process parameters. Point-optimal solutions by a fixed parameter approach are compared to robust solutions with given parameter variation ranges. In the work enhanced utilisation of excess heat in heat recovery systems with impingement drying, electricity generation with low grade excess heat and the use of absorption heat transformers to elevate a stream temperature above the excess heat temperature are also studied.
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Wastes and side streams in the mining industry and different anthropogenic wastes often contain valuable metals in such concentrations their recovery may be economically viable. These raw materials are collectively called secondary raw materials. The recovery of metals from these materials is also environmentally favorable, since many of the metals, for example heavy metals, are hazardous to the environment. This has been noticed in legislative bodies, and strict regulations for handling both mining and anthropogenic wastes have been developed, mainly in the last decade. In the mining and metallurgy industry, important secondary raw materials include, for example, steelmaking dusts (recoverable metals e.g. Zn and Mo), zinc plant residues (Ag, Au, Ga, Ge, In) and waste slurry from Bayer process alumina production (Ga, REE, Ti, V). From anthropogenic wastes, waste electrical and electronic equipment (WEEE), among them LCD screens and fluorescent lamps, are clearly the most important from a metals recovery point of view. Metals that are commonly recovered from WEEE include, for example, Ag, Au, Cu, Pd and Pt. In LCD screens indium, and in fluorescent lamps, REEs, are possible target metals. Hydrometallurgical processing routes are highly suitable for the treatment of complex and/or low grade raw materials, as secondary raw materials often are. These solid or liquid raw materials often contain large amounts of base metals, for example. Thus, in order to recover valuable metals, with small concentrations, highly selective separation methods, such as hydrometallurgical routes, are needed. In addition, hydrometallurgical processes are also seen as more environmental friendly, and they have lower energy consumption, when compared to pyrometallurgical processes. In this thesis, solvent extraction and ion exchange are the most important hydrometallurgical separation methods studied. Solvent extraction is a mainstream unit operation in the metallurgical industry for all kinds of metals, but for ion exchange, practical applications are not as widespread. However, ion exchange is known to be particularly suitable for dilute feed solutions and complex separation tasks, which makes it a viable option, especially for processing secondary raw materials. Recovering valuable metals was studied with five different raw materials, which included liquid and solid side streams from metallurgical industries and WEEE. Recovery of high purity (99.7%) In, from LCD screens, was achieved by leaching with H2SO4, extracting In and Sn to D2EHPA, and selectively stripping In to HCl. In was also concentrated in the solvent extraction stage from 44 mg/L to 6.5 g/L. Ge was recovered as a side product from two different base metal process liquors with Nmethylglucamine functional chelating ion exchange resin (IRA-743). Based on equilibrium and dynamic modeling, a mechanism for this moderately complex adsorption process was suggested. Eu and Y were leached with high yields (91 and 83%) by 2 M H2SO4 from a fluorescent lamp precipitate of waste treatment plant. The waste also contained significant amounts of other REEs such as Gd and Tb, but these were not leached with common mineral acids in ambient conditions. Zn was selectively leached over Fe from steelmaking dusts with a controlled acidic leaching method, in which the pH did not go below, but was held close as possible to, 3. Mo was also present in the other studied dust, and was leached with pure water more effectively than with the acidic methods. Good yield and selectivity in the solvent extraction of Zn was achieved by D2EHPA. However, Fe needs to be eliminated in advance, either by the controlled leaching method or, for example, by precipitation. 100% Pure Mo/Cr product was achieved with quaternary ammonium salt (Aliquat 336) directly from the water leachate, without pH adjustment (pH 13.7). A Mo/Cr mixture was also obtained from H2SO4 leachates with hydroxyoxime LIX 84-I and trioctylamine (TOA), but the purities were 70% at most. However with Aliquat 336, again an over 99% pure mixture was obtained. High selectivity for Mo over Cr was not achieved with any of the studied reagents. Ag-NaCl solution was purified from divalent impurity metals by aminomethylphosphonium functional Lewatit TP-260 ion exchange resin. A novel preconditioning method, named controlled partial neutralization, with conjugate bases of weak organic acids, was used to control the pH in the column to avoid capacity losses or precipitations. Counter-current SMB was shown to be a better process configuration than either batch column operation or the cross-current operation conventionally used in the metallurgical industry. The raw materials used in this thesis were also evaluated from an economic point of view, and the precipitate from a waste fluorescent lamp treatment process was clearly shown to be the most promising.
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Initially identified as stress activated protein kinases (SAPKs), the c-Jun Nterminal kinases (JNKs) are currently accepted as potent regulators of various physiologically important cellular events. Named after their competence to phosphorylate transcription factor c-Jun in response to UVtreatment, JNKs play a key role in cell proliferation, cell death or cell migration. Interestingly, these functions are crucial for proper brain formation. The family consists of three JNK isoforms, JNK1, JNK2 and JNK3. Unlike brain specific JNK3 isoform, JNK1 and JNK2 are ubiquitously expressed. It is estimated that ten splice variants exist. However, the detailed cellular functions of these remain undetermined. In addition, physiological conditions keep the activities of JNK2 and JNK3 low in comparison with JNK1, whereas cellular stress raises the activity of these isoforms dramatically. Importantly, JNK1 activity is constitutively high in neurons, yet it does not stimulate cell death. This suggests a valuable role for JNK1 in brain development, but also as an important mediator of cell wellbeing. The aim of this thesis was to characterize the functional relationship between JNK1 and SCG10. We found that SCG10 is a bona fide target for JNK. By employing differential centrifugation we showed that SCG10 co-localized with active JNK, MKK7 and JIP1 in a fraction containing endosomes and Golgi vesicles. Investigation of JNK knockout tissues using phosphospecific antibodies recognizing JNK-specific phosphorylation sites on SCG10 (Ser 62/Ser 73) showed that phosphorylation of endogenous SCG10 was dramatically decreased in Jnk1-/- brains. Moreover, we found that JNK and SCG10 co-express during early embryonic days in brain regions that undergo extensive neuronal migration. Our study revealed that selective inhibition of JNK in the cytoplasm significantly increased both the frequency of exit from the multipolar stage and radial migration rate. However, as a consequence, it led to ill-defined cellular organization. Furthermore, we found that multipolar exit and radial migration in Jnk1 deficient mice can be connected to changes in phosphorylation state of SCG10. Also, the expression of a pseudo-phosphorylated mutant form of SCG10, mimicking the JNK1- phopshorylated form, brings migration rate back to normal in Jnk1 knockout mouse embryos. Furthermore, we investigated the role of SCG10 and JNK in regulation of Golgi apparatus (GA) biogenesis and whether pathological JNK action could be discernible by its deregulation. We found that SCG10 maintains GA integrity as with the absence of SCG10 neurons present more compact fragmented GA structure, as shown by the knockdown approach. Interestingly, neurons isolated from Jnk1-/- mice show similar characteristics. Block of ER to GA is believed to be involved in development of Parkinson's disease. Hence, by using a pharmacological approach (Brefeldin A treatment), we showed that GA recovery is delayed upon removal of the drug in Jnk1-/- neurons to an extent similar to the shRNA SCG10-treated cells. Finally, we investigated the role of the JNK1-SCG10 duo in the maintenance of GA biogenesis following excitotoxic insult. Although the GA underwent fragmentation in response to NMDA treatment, we observed a substantial delay in GA disintegration in neurons lacking either JNK1 or SCG10.
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Kirjallisuusarvostelu
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Defects in semiconductor crystals and at their interfaces usually impair the properties and the performance of devices. These defects include, for example, vacancies (i.e., missing crystal atoms), interstitials (i.e., extra atoms between the host crystal sites), and impurities such as oxygen atoms. The defects can decrease (i) the rate of the radiative electron transition from the conduction band to the valence band, (ii) the amount of charge carriers, and (iii) the mobility of the electrons in the conduction band. It is a common situation that the presence of crystal defects can be readily concluded as a decrease in the luminescence intensity or in the current flow for example. However, the identification of the harmful defects is not straightforward at all because it is challenging to characterize local defects with atomic resolution and identification. Such atomic-scale knowledge is however essential to find methods for reducing the amount of defects in energy-efficient semiconductor devices. The defects formed in thin interface layers of semiconductors are particularly difficult to characterize due to their buried and amorphous structures. Characterization methods which are sensitive to defects often require well-defined samples with long range order. Photoelectron spectroscopy (PES) combined with photoluminescence (PL) or electrical measurements is a potential approach to elucidate the structure and defects of the interface. It is essential to combine the PES with complementary measurements of similar samples to relate the PES changes to changes in the interface defect density. Understanding of the nature of defects related to III-V materials is relevant to developing for example field-effect transistors which include a III-V channel, but research is still far from complete. In this thesis, PES measurements are utilized in studies of various III-V compound semiconductor materials. PES is combined with photoluminescence measurements to study the SiO2/GaAs, SiNx/GaAs and BaO/GaAs interfaces. Also the formation of novel materials InN and photoluminescent GaAs nanoparticles are studied. Finally, the formation of Ga interstitial defects in GaAsN is elucidated by combining calculational results with PES measurements.
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Kartta kuuluu A. E. Nordenskiöldin kokoelmaan
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Kartta kuuluu A. E. Nordenskiöldin kokoelmaan
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The bedrock of old crystalline cratons is characteristically saturated with brittle structures formed during successive superimposed episodes of deformation and under varying stress regimes. As a result, the crust effectively deforms through the reactivation of pre-existing structures rather than by through the activation, or generation, of new ones, and is said to be in a state of 'structural maturity'. By combining data from Olkiluoto Island, southwestern Finland, which has been investigated as the potential site of a deep geological repository for high-level nuclear waste, with observations from southern Sweden, it can be concluded that the southern part of the Svecofennian shield had already attained structural maturity during the Mesoproterozoic era. This indicates that the phase of activation of the crust, i.e. the time interval during which new fractures were generated, was brief in comparison to the subsequent reactivation phase. Structural maturity of the bedrock was also attained relatively rapidly in Namaqualand, western South Africa, after the formation of first brittle structures during Neoproterozoic time. Subsequent brittle deformation in Namaqualand was controlled by the reactivation of pre-existing strike-slip faults.In such settings, seismic events are likely to occur through reactivation of pre-existing zones that are favourably oriented with respect to prevailing stresses. In Namaqualand, this is shown for present day seismicity by slip tendency analysis, and at Olkiluoto, for a Neoproterozoic earthquake reactivating a Mesoproterozoic fault. By combining detailed field observations with the results of paleostress inversions and relative and absolute time constraints, seven distinctm superimposed paleostress regimes have been recognized in the Olkiluoto region. From oldest to youngest these are: (1) NW-SE to NNW-SSE transpression, which prevailed soon after 1.75 Ga, when the crust had sufficiently cooled down to allow brittle deformation to occur. During this phase conjugate NNW-SSE and NE-SW striking strike-slip faults were active simultaneous with reactivation of SE-dipping low-angle shear zones and foliation planes. This was followed by (2) N-S to NE-SW transpression, which caused partial reactivation of structures formed in the first event; (3) NW-SE extension during the Gothian orogeny and at the time of rapakivi magmatism and intrusion of diabase dikes; (4) NE-SW transtension that occurred between 1.60 and 1.30 Ga and which also formed the NW-SE-trending Satakunta graben located some 20 km north of Olkiluoto. Greisen-type veins also formed during this phase. (5) NE-SW compression that postdates both the formation of the 1.56 Ga rapakivi granites and 1.27 Ga olivine diabases of the region; (6) E-W transpression during the early stages of the Mesoproterozoic Sveconorwegian orogeny and which also predated (7) almost coaxial E-W extension attributed to the collapse of the Sveconorwegian orogeny. The kinematic analysis of fracture systems in crystalline bedrock also provides a robust framework for evaluating fluid-rock interaction in the brittle regime; this is essential in assessment of bedrock integrity for numerous geo-engineering applications, including groundwater management, transient or permanent CO2 storage and site investigations for permanent waste disposal. Investigations at Olkiluoto revealed that fluid flow along fractures is coupled with low normal tractions due to in-situ stresses and thus deviates from the generally accepted critically stressed fracture concept, where fluid flow is concentrated on fractures on the verge of failure. The difference is linked to the shallow conditions of Olkiluoto - due to the low differential stresses inherent at shallow depths, fracture activation and fluid flow is controlled by dilation due to low normal tractions. At deeper settings, however, fluid flow is controlled by fracture criticality caused by large differential stress, which drives shear deformation instead of dilation.
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Under september månad 2015 gav sökordet ”kris” dagligen upphov till ett trettiotal träffar i sökmotorn till Frankrikes största dagstidningar. Dagspressen överflödas av kriser och i skrivande stund är den mest omtalade krisen de flyktingströmmar som når Europa som resultat efter flera års krig i Mellanöstern. Pro gradu-avhandlingen studerar flyktingkrisen som en diskursiv händelse, en social konstruktion av en företeelse som tar de aktuella personerna och deras åsikter i beaktande. Avhandlingen är uppbyggd som en linje som inleds med mediestrategier och går till iscensättandet av nyheten, för att sedan analysera de olika åsikterna och personerna som ger upphov till lingvistisk polyfoni och mångtydighet. Syftet med avhandlingen är att studera hur medierna påverkar vår förståelse av en kris. För att få en dynamisk bild av bevakningen av flyktingkrisen studeras rubriker till ett hundratal titlar som publicerats i september 2015 av två stora franska dagstidningar: Le Figaro och Libération. Tidningarnas motsatta politiska orientering står som grund för en heltäckande och varierande genomläsning av medieuppmärksamheten kring flyktingkrisen. Som metod utförs en diskursanalys på materialet för att få reda på hur de båda tidningarna framställer krisen. Skillnader och likheter studeras, såväl som förekommande teman och en karakteristisk vokabulär i anknytning till krisen. Hypotesen är att flyktingarnas egna åsikter kommer i skymundan i medierna. Som resultat har jag noterat element i krisen som tidigare framställts som viktiga ur lingvistisk synvinkel på krisdiskurs av lingvisten Marie Veniard. Utöver det observeras några kompletterande betydelsekomponenter som står i förbindelse med flyktingkrisens komplexa natur. Ett speciellt mönster för att framställa flyktingarna har visat sig vara ofta förekommande i de båda tidningarna. Flyktingarna nämns för att ge rubrikerna ett autentiskt värde men paradoxalt nog möjliggör de även otydlighet i fråga om vem som faktiskt yttrar sig, flyktingarna eller journalisterna?
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The aim of this study was to examine how to support breastfeeding of preterm infants immediately after birth in the delivery ward, during their hospital stay in a neonatal intensive care unit (NICU), and at home after hospital discharge. Specifically, the role of early physical contact, maternal breastfeeding attitude, and an internet-based peer support group were investigated. The delivery ward practices concerning the implementation of early physical contact between a mother and her infant admitted to a NICU were examined by a structured survey in two hospitals. An Internet-based, breastfeeding peer-support intervention for the mothers of preterm infants was developed and tested in a randomized controlled design with one year follow-up. The main outcomes were the duration of exclusive and overall breastfeeding, expressing milk, and maternal attitude. In addition, the perceptions of mothers of preterm infants were investigated by analyzing the peer-support group discussions with a qualitative approach. The implementation of early physical contact was different between the two hospitals studied and was based more on hospital routines than the physiological condition of the infant. Preterm infants, who were born before a gestational age (GA) of 32 weeks, were hardly ever allowed to have early contact with their mothers. Both, a higher GA and early physical contact predicted earlier initiation and increased frequency of breastfeeding in the NICU. A maternal breastfeeding-favorable attitude predicted increased frequency of breastfeeding in the NICU and also a longer duration of overall breastfeeding. The actual duration of breastfeeding was, however, shorter than the mothers intended in advance. The internet-based, peer-support intervention had no effect on the duration of breastfeeding, expressing milk, or maternal attitude. The participating mothers enjoyed the possibility of sharing their experiences of preterm infants with other mothers in similar situations. Some of the mothers also experienced being given useful advice for breastfeeding. Based on the mothers’ discussions, a process of breastfeeding preterm infants was created. This included some paradoxical elements in the NICU where, for example, breast milk was emphasized over breastfeeding and support in the hospital varied. Hospital discharge was a critical point, when the mothers faced breastfeeding in reality. Over time, the mothers assimilated their breastfeeding experience into part of being a mother. The care practices related to early physical contact in delivery wards need to be re-evaluated to allow more infants to have a moment with the mother. Maternal attitude could be screened prenatally and attitude-focused interventions developed. Breastfeeding support in the NICU should be standardized. Internet-based breastfeeding peer-support intervention was feasible but additional research is needed.