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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
71

Hålrumsvariationer vid asfalttillverkning : En fallstudie vid Skanska enligt DMAIC avseende förbättringsmöjligheter vid kalltillsatt asfaltåtervinning / Void volume variations in asphalt manufacturing : A case study at Skanska based on DMAIC regarding opportunities for improvement when using cold RAP

Johansson, Paulina January 2018 (has links)
Att optimera hålrumshalten i färdig beläggning är essentiellt bland annat för att en vägkonstruktion inte ska få sprickor, spårbildning eller andra deformationer vid temperaturväxlingar  (Monismith, 1992). Eftersom både återvunnen och jungfrulig asfaltmassa består av stenmaterial, bitumen och tillsatsmedel är återvunnen asfalt värd den jungfruliga massans vikt ton för ton vid utbyte i ett arbetsrecept (Brock & Richmonds, 2007). I takt med att asfaltåtervinning blivit vanligare ökar dock komplexiteten, då återvunnet material är betydligt svårare än jungfruligt att karaktärisera (Karlsson & Isacsson, 2006). Eftersom användningen av återvunnet material förväntas öka samtidigt som lite forskning gjorts i ämnet är det därför av vikt att undersöka hålrumshalter vid kalltillsatt asfaltåtervinning. För studien undersöktes asfaltmassan ABT11 160/220 vid kalltillsättning av upp till 25 % asfaltåtervinning. Sex Sigmas problemlösningsmetodik DMAIC, vilket står för ett projektbaserat förhållningssätt i de fem faserna define, measure, analyze, improve och control, användes för att få en djupgående förståelse för hålrumsproblematiken. I metodiken användes i sin tur statistisk processtyrning och försöksplanering för att svara på studiens syfte, vilket var att granska och utvärdera orsakerna till varför hålrumshalter under asfalttillverkning varierar vid tillsättning av kallt asfaltgranulat samt ge rekommendationer för en förbättrad produktion med avseende på hålrumshalt. Efter granskning av historiska data, beräkningar, intervjuer och observationer ansågs de viktigaste orsakerna till hålrumsvariationer uppkomma från de fem källorna datahantering, kommunikation, resurshantering, materialkunskap och organisationskultur, där de två sistnämnda ansågs vara rotorsaker. På grund av examensarbetets avgränsning granskades endast materialkunskapen mer djupgående. För att fördjupa materialkunskapen valdes faktorerna asfaltåtervinning, jungfruligt bitumen, jungfruligt filler samt tillverknings- och instampningstemperatur ut för fortsatta studier genom två experiment. I det första experimentet granskades hur hålrumshalten påverkades av olika instampningstemperaturer genom en OFAT-studie och i det andra experimentet ansattes ett 24-1 faktorförsök enligt Splitplot där hålrummet mättes vid vanlig instampningstemperatur (135 ˚C) samt genom en vägsimulering. Resultatet från det första experimentet uppvisade ett förhållande enligt ett tredjegradspolynom mellan hålrum och instampningstemperatur med stora hålrumsförändringar under 125 ˚C och över 145 ˚C. Detta medför att det är av än större vikt att kontrollera temperaturen för lågtempererad massa och massa med mycket återvinning för att uppnå godkända hålrum vid utläggning. Det andra experimentet visade att även bitumen och återvinning är signifikanta effekter för hålrummet, där minskade bitumenhalter och ökade återvinningshalter medför högre hålrumshalter samt att återvinningshalter över 15 % medför oönskad ökning av hålrumshalter vid utläggning på väg. För att avhjälpa orsakerna till hålrumsvariationerna rekommenderas att data samlas, utvärderas, kommuniceras och följs upp i större utsträckning genom användning av statistisk processtyrning, värdeflödesanalyser och fortsatta materialstudier. Organisationskulturen bör förändras för att skapa en förståelse för vikten av rekommenderade metoder. Kan rekommendationerna följas innebär det en uppskattad ekonomisk besparing på 11 520 000kr/år, samtidigt som det skulle innebära miljömässiga fördelar i form av bland annat ett minskat uttag av ändliga resurser och minskade CO2-utsläpp. / Optimizing void volumes are essential for the serviceability of asphalt concrete pavements, as fatigue cracking, rutting and other permanent deformations can be caused by e.g. temperature changes (Monismith, 1992). Since both reclaimed asphalt pavement (RAP) and virgin asphalt concrete consist of mineral aggregate, bitumen and additives, RAP is worth the virgin material it replaces ton for ton (Brock & Richmonds, 2007). As the use of RAP becomes more and more popular, the complexity of asphalt manufacturing increases (Karlsson & Isacsson, 2006). This, because the recycled material is harder to characterize than virgin material. Since the usage of RAP is expected to increase in hot-mix asphalt (HMA), while little research has been made in the field of cold feed RAP, it is of great importance to investigate the void volumes with this method. During this study, ABT11 160/220 with the addition of up to 25% cold feed RAP was therefore investigated. Six Sigma’s project improvement methodology DMAIC, acronym for the five phases define, measure, analyze, improve and control, were used to get an in depth understanding for the variations in void volumes. In this method, Statistical Process Control and Design of Experiments were used to answer the research purpose, which was to investigate and evaluate the reasons to why void volumes during asphalt manufacturing varies when adding cold RAP and give recommendations for an improved production regarding void volumes. After an investigation of historic data, calculations, interviews and observations, the most important causes for variations in void volumes came from data collection, communication, resource management, material knowledge and organizational culture, where the last two are seen as root causes. Because of the research delimitations, only the material knowledge was looked into further. To extend the knowledge of the material, the factors RAP, virgin bitumen, virgin filler, manufacturing temperature and temperature for Marshall testing were analyzed through two experiments. In the first experiment, the relationship between void volumes and the temperature for Marshall testing were investigated through an OFAT study, and the second experiment was made through a 24-1 factorial design according to Split plot, in which the void volumes were measured through the normal Marshall testing temperature (135 ˚C) and through a road simulation.  The OFAT result showed that a third degree linear relationship is present between the void volumes and the Marshall testing temperature, with large changes for temperatures lower than 125 ˚C and greater than 145 ˚C. This entails an increased importance of controlling the temperature for warm-mix asphalt (WMA) and asphalt with increased volumes of RAP. The Split plot experiment showed that also bitumen and RAP are significant effects for the void volume, where decreased volumes of bitumen and increased volumes of RAP entails higher void volumes in the pavement. Over 15 % RAP also entails greater void volumes. To decrease the causes for variations in void volumes, the recommendation is to collect, evaluate, communicate and follow up data at a higher extent through implementation of statistical process control, value flow analysis and continued material studies. The organizational culture ought to be changed to create an understanding of the recommended methods. If the recommendations are followed, estimated economic savings of 11 520 000kr/year can be a reality, as well as environmental benefits of e.g. a decreased use of finite resources and reduced CO2 emissions.
72

“REENACTING” THE PLOT

Grahl, Till 31 March 2014 (has links) (PDF)
Das Phänomen Remake ist so alt, wie die Geschichte des Films selbst. Dennoch wird der Begriff immer wieder leichtfertig benutzt, weshalb sich die Arbeit zunächst um die Entwicklung einer praktikablen Arbeitsdefinition bemüht, welche Remakes im engeren Sinne von anderen Formen der Neuinszenierung abgrenzt, bevor in einem nächsten Schritt ausgewählte Original-Remake-Paare einer ausführlichen strukturellen Analyse unterzogen werden: Dazu werden die jeweiligen Filme in ihre einzelnen Szenen aufgegliedert und mit einem Plotschema - dem sogenannten Paradigma nach Syd Field und Hans-Ulrich Mohr - unterlegt, welches neben der allgemeinen Struktur des Films auch für die Handlung besonders relevante Szenen offenlegt und strukturelle Veränderungen offensichtlich macht, aus welchen Änderungen des Inhalts, der Handlungsrichtung und des Genres resultieren. Dazu werden die Neuverfilmungen ihren filmischen Vorgängern in direkter Weise gegenübergestellt, wodurch stilistische Mittel und inszenatorische Elemente sowie historische und kulturelle Zusammenhänge und strukturelle Unterschiede sauber ausgearbeitet und sichtbar gemacht werden können. Damit leistet diese Arbeit einen Beitrag sowohl zum noch spärlich ergründeten Feld der Remakeforschung als auch zur Debatte um die Existenz und Funktionsweise von Filmstrukturen.
73

“REENACTING” THE PLOT: Narrative Muster von Remakes und deren Originalen

Grahl, Till 09 April 2013 (has links)
Das Phänomen Remake ist so alt, wie die Geschichte des Films selbst. Dennoch wird der Begriff immer wieder leichtfertig benutzt, weshalb sich die Arbeit zunächst um die Entwicklung einer praktikablen Arbeitsdefinition bemüht, welche Remakes im engeren Sinne von anderen Formen der Neuinszenierung abgrenzt, bevor in einem nächsten Schritt ausgewählte Original-Remake-Paare einer ausführlichen strukturellen Analyse unterzogen werden: Dazu werden die jeweiligen Filme in ihre einzelnen Szenen aufgegliedert und mit einem Plotschema - dem sogenannten Paradigma nach Syd Field und Hans-Ulrich Mohr - unterlegt, welches neben der allgemeinen Struktur des Films auch für die Handlung besonders relevante Szenen offenlegt und strukturelle Veränderungen offensichtlich macht, aus welchen Änderungen des Inhalts, der Handlungsrichtung und des Genres resultieren. Dazu werden die Neuverfilmungen ihren filmischen Vorgängern in direkter Weise gegenübergestellt, wodurch stilistische Mittel und inszenatorische Elemente sowie historische und kulturelle Zusammenhänge und strukturelle Unterschiede sauber ausgearbeitet und sichtbar gemacht werden können. Damit leistet diese Arbeit einen Beitrag sowohl zum noch spärlich ergründeten Feld der Remakeforschung als auch zur Debatte um die Existenz und Funktionsweise von Filmstrukturen.
74

The exploration of neurophysiological spike train data using visual analytics

Somerville, Jared January 2011 (has links)
Neuroscientists are increasingly overwhelmed by new recordings of the nervous system. These recordings are significantly increasing in size due to new electrophysiological techniques, such as multi-electrode arrays. These techniques can simultaneously record the electrical activity (or spike trains) from thousands of neurons. These new datasets are larger than the traditional datasets recorded from single electrodes where fewer than ten spike trains are usually recorded. Consequently, new tools are now required to effectively analyse these new datasets. This thesis describes how techniques from the field of Visual Analytics can be applied to detect specific patterns in spike train data. These techniques are realised in a software tool called Neurigma. Neurigma is a collection of visual representations of spike train data that are unified to provide a coordinated representation of the data. The visual representations within Neurigma include: an interactive raster plot, an improved correlation grid, a novel representation called the correlation plot (which includes a novel coupling estimation algorithm), and a novel network diagram. These views provide insight into spike train data, and particularly, they identify correlated patterns, called functional connectivity. Within this thesis Neurigma is used to analyse synthetically generated datasets and experimental recordings. Three main findings are presented. First, propagating spiral patterns are identified within recordings from the neonatal mouse retina. Second, functional connectivity is identified within the cat visual cortex. Finally, the functional connectivity of a large synthetic dataset, of 1000 spike trains, is accurately classified into direct, indirect and common input coupling.
75

"Believe me, past a certain age, a man without a family can be a bad thing!" : En narrativ analys av maskuliniteter i första säsongen av tv-serien True Detective

Hurtig, Michael, Arvidsson, Alexander January 2018 (has links)
This thesis aims at identifying, through Will Wright methods of narrative analysis, how the different masculinities are represented in the first season of the TV-series True Detective via the protagonists Rust Cohle and Marty Hart. Theories about hegemonic masculinity and Will Wright's theories for narrative analysis are further applied to see how these similarities and differences are formed by what Wright calls “the professional plot". Through 32 chosen scenes from the first season, this study examines the narrative of True Detective and the relationship between the main characters Rust Cohle and Marty Hart from a point of view that will highlight their hierarchic positions in the hegemonic masculinity, using Raewyn Connell’s studies as a theory. We have found that there are two separate hegemonic spheres, one within the relationship between the main characters, and one within the society as a whole. In the latter, Marty Hart is displayed as a member of the hegemonic masculinity up to the point where he loses his family while Rust Cohle constantly belongs to the subordinate masculinity. This is due to him being in constant clash with the traditional cultural values of Louisiana where the series takes place. Regarding the hegemony within their relationship, Rust Cohle goes through a hegemonic transformation, from the subordinate masculinity to the hegemonic while Marty Hart makes the journey from occupying the hegemonic masculinity to serve as the participating dito.
76

Gráficos de recorrência e de poincaré na análise da quantidade de internações por diferentes grupos nosológicos, ocorridas ao longo de uma década, em um hospital de ensino.

Baptista, Margarete ártico 07 October 2011 (has links)
Made available in DSpace on 2016-01-26T12:51:30Z (GMT). No. of bitstreams: 1 margaretearticobaptista_tese.pdf: 3014770 bytes, checksum: a4b4de19204259991aae1ec3ae61a0aa (MD5) Previous issue date: 2011-10-07 / In the last 30 years, the increasing health care expenditures resulted in an outburst of studies aimed at new proposals on the methodological evaluation of health services. With the aid of computing, several studies have been developed with the purpose of analyzing nonlinear and complex systems. The most outstanding among those methods was the Recurrence Plot, first described by Erickman et al. (1987).Objectives: To analyze the temporal behavior of the weekly amount of admissions by some nosologic groups (Appendix Diseases, Bacterial Diseases, Neoplastic Disease, and Acute Coronary Syndrome), which has occurred over a decade, through Recurrence Plots and Poincaré Recurrence Plots, as well as checking whether the systems are presenting a periodic, chaotic, or random behavior pattern. Material and Methods: The database containing all hospitalizations recorded at the Hospital de Base Regional Medical School Foundation (FUNFARME) of Sao Jose do Rio Preto, a teaching hospital, from January 1, 1998 to December 31, 2007 was peered into a microscope. As a reference to classify all these admissions, the International Statistical Classification of Diseases and Related Health Problems, 10th Revision (ICD-10) was used. The Microsoft Office Excel 2003® was the software used to arrange the data into columns. The admissions were systematically set to the right array, such as day, month, and year. They were arranged into columns according to the uniform criteria of identification of the epidemiological weeks. The recurrence graphs and the respective quantitative analyses of recurrence were developed with the aid of the Visual Recurrence Analysis (VRA) software, which is freely available on the Internet. To perform the comparison among the behavior patterns, mathematical models of time series for random behavior pattern, series time for chaotic behavior pattern, series times for periodic behavior pattern, and series time for linear behavior pattern were constructed. And it has also been performed a comparison between the Recurrence Plots and the Quantitative Analysis of Recurrence with clinical cases of specific groups (young, adult, child, premature newborn, and brain death).Results: It has become clear that the number of weekly admissions for diseases of the appendix has had a tendency over the years from a random behavior pattern. In hospitalizations due to bacterial diseases, there was a chaotic behavior pattern and the neoplastic diseases showed a chaotic behavior pattern tending to a linear behavior pattern. Hospitalizations because of Acute Coronary Syndrome presented a predominantly linear behavior pattern. Conclusions: The visual aspects of Recurrence Plot and Poincaré Recurrence plot exhibited different patterns when comparing quantities of admissions of certain nosologic groups over a decade. The quantitative analysis of recurrence that was useful in classifying the behavior pattern of the quantities of admissions is likely to constitute a useful tool of evaluation and decision making regarding hospital administration. / Nos últimos trinta anos, o crescimento dos gastos com a atenção médica resultou numa expansão dos estudos voltados para novas propostas metodológicas sobre avaliação dos serviços de saúde. Com a utilização da informática, vários estudos têm sido desenvolvidos para análise de sistemas complexos e não lineares, destacando-se, entre esses métodos, os gráficos de recorrência, descritos pela primeira vez por Erickman et al. (1987). Objetivos: Analisar o comportamento temporal da quantidade semanal de internações por alguns grupos nosológicos (Doenças do Apêndice, Doenças Bacterianas, Doenças Neoplásicas e por Síndrome Coronária Aguda) ocorridas ao longo de uma década, por meio de Gráficos de Recorrência e Gráficos de Poincaré e verificar se são sistemas que apresentam comportamentos periódicos, aleatórios ou caóticos. Material e Método: Foi avaliado o banco de dados contendo todas as internações no Hospital de Base da Fundação Faculdade Regional de Medicina de São José do Rio Preto, no período de 01 de janeiro de 1998 a 31 de dezembro de 2007. Como referência para classificação dessas internações, utilizou-se a Décima Revisão da Classificação Internacional de Doenças e de Problemas Relacionados à Saúde (CID 10). Foi utilizado o programa Microsoft Office Excel 2003 para a tabulação dos dados. As internações foram ordenadas em dia, mês, ano e tabuladas, seguindo o critério uniforme de identificação das semanas epidemiológicas. Os gráficos de recorrência e respectiva análise quantitativa foram construídos com o auxílio do software Visual Recurrence Analysis (VRA), disponível gratuitamente na Internet. Para realizar a comparação de padrões de comportamentos foram construídos modelos matemáticos de séries temporais aleatória, caótica, periódica e linear. E também foi realizada comparação entre Gráficos de Recorrência e Análise Quantitativa da Recorrência com casos clínicos de grupos específicos (jovem adulto, criança, Recém- nascido prematuro e morte cerebral). Resultados: Evidenciou-se que a quantidade de internações semanal por doenças do apêndice tiveram uma tendência ao longo dos anos de comportamento aleatório. Nas internações por doenças bacterianas houve comportamento caótico e as internações por doenças neoplásicas apresentaram um comportamento caótico tendendo a linear. As internações por Síndrome Coronária Aguda apresentaram predominantemente comportamento linear, Conclusões: Os aspectos visuais dos Gráficos de Recorrência e de Poincaré exibiram padrões diferentes na comparação entre quantidades de internações de determinados grupos nosológicos ao longo de uma década. A análise quantitativa da recorrência que auxiliou na classificação do comportamento das quantidades de internações e pode constituir-se em ferramenta útil de avaliação e tomada de decisão em administração hospitalar.
77

Isotropic nanocrystalline (Nd,Pr)(Fe,Co)B permanent magnets / Isotropen nanokristallinen (Nd,Pr)(Fe,Co)B-Permanentmagneten

Bollero Real, Alberto 18 November 2003 (has links) (PDF)
Nanokristalline Permanentmagnete zeigen ungewöhnliche magnetische Eigenschaften aufgrund von Oberflächen- und Grenzflächeneffekten, die verschieden von denen massiver oder mikrokristalliner Materialien sind. Diese Arbeit zeigt Ergebnisse einer systematischen Untersuchung der Beziehung zwischen Mikrostruktur und magnetischen Eigenschaften von isotropen nanokristallinen (Nd,Pr)(Fe,Co)B-Permanentmagneten. Hochkoerzitive Magnete vom Typ (Nd,Pr)FeB wurden durch hochenergetisches Mahlen in der Kugelmühle oder Rascherstarrung hergestellt. Der Einfluss geringer Mengen von Zusätzen wie Dy und Zr und die Substitution von Nd durch Pr auf die magnetischen Eigenschaften wird dargestellt. Weiterhin wurde eine Einschätzung des Warmumformverhaltens dieser Materialien durchgeführt. Hochenergetisches Kugelmahlen einer Legierung mit der Anfangszusammensetzung Pr9Nd3Dy1Fe72Co8B6.9Zr0.1 führte, nach Glühbehandlung, zu fast einphasigem Magnetpulver mit einem maximalen Energieprodukt von (BH)max~140 kJm-3. Das hochenergetische Kugelmahlen wurde zu einer sehr vielseitigen Technik zur Herstellung hochleistungsfähiger Nanokompositmagnete weiterentwickelt. Das Zulegieren unterschiedlicher Anteile von weichmagnetischem alpha-Fe ist damit sehr effektiv möglich. Der Zusatz von 25 Gew.-% alpha-Fe führt zu einem hohen (BH)max=178kJm-3. Dies wird auf eine sehr effektive Austauschkopplung zwischen den hart- und weichmagnetischen Phasen zurückgeführt. Die Natur der intergranularen Wechselwirkungen kann durch die Wohlfarth´sche Remanenzanalyse (?deltaJ-plot¡§) beschrieben werden. Im speziellen wurden deltaJ-Diagramme für verschiedene (i) alpha-Fe Gehalte, (ii) Korngrößen und (iii) Austauschlängen erstellt. Es konnte gezeigt werden, dass in den Nanokompositmagneten auf Pr-Basis keine Spinumorientierung auftritt. Abschließend zeigt die Arbeit die Möglichkeit der Nutzung einer mechanisch aktivierten Gas-Festkörper-Reaktion auf, mit der eine sehr feinkörnige Mikrostruktur erhalten wird. Die Untersuchungen wurden mit stöchiometrischen Nd2(Fe1-xCox)14B-Legierungen begonnen (x=0-1). Die Verbindungen wurden unter höheren Wasserstoffdrücken und Temperaturen gemahlen, wodurch sie zu NdH2+delta und krz-(Fe,Co) (x=0-0.75) oder kfz-Co (x=1) entmischt wurden. Die Korngrößen des rekombinierten Nd2(Co,Fe)14B-Materials liegen im Bereich von 40-50 nm. / Nanocrystalline permanent magnets present unusual magnetic properties because of surface/interface effects different from those of bulk or microcrystalline materials. This work presents results of a systematic investigation of the relationship between microstructure and magnetic properties in isotropic nanocrystalline (Nd,Pr)(Fe,Co)B permanent magnets. Highly coercive (Nd,Pr)FeB-type magnets have been produced using high energy ball milling and melt-spinning. The influence of small amounts of additives, Dy and Zr, and the substitution of Nd by Pr on the microstructural and magnetic properties are shown. An assessment of the hot deformation behaviour has been carried out. Intensive milling of an alloy with starting composition Pr9Nd3Dy1Fe72Co8B6.9Zr0.1 yields, after annealing treatment, nearly single-phase magnet powders with a maximum energy product (BH)max?î140kJm-3. Co has a beneficial effect on the intrinsic magnetic properties but also on the microstructure, with a mean grain size of 20nm. Intensive milling is used to produce high-performance nanocomposite magnets by blending this latter alloy with different fractions of soft magnetic alfa-Fe. Addition of 25wt.% alfa-Fe leads to a high (BH)max=178 kJm-3 due to an effective exchange-coupling between the hard and the soft magnetic phases. The intergrain interactions between the crystallites of the nanocomposite structure are analysed. Demagnetisation recoil loops of the nanocomposite magnets show relatively open minor loops due to the exchange-spring mechanism. Information about the intergrain interactions during demagnetisation are obtained by plotting the deviation of the demagnetising remanence from the Wohlfarth-model (¡§deltaJ-plot¡¨). Exchange-coupling phenomena are studied by analysing the evolution of the corresponding deltaJ values when varying (i) the alfa-Fe content, (ii) the annealing temperature, i.e. the grain size and (iii) the measurement temperature. Low temperature measurements do not reveal any sign of spin reorientation for these Pr-based nanocomposite magnets. The work concludes showing the possibility of using a mechanically activated gas-solid reaction to obtain an effective grain refined microstructure starting from stoichiometric Nd2(Fe1-xCox)14B alloys (x=0-1). These compounds were milled under enhanced hydrogen pressure and temperature leading to their disproportionation into NdH2+delta and bcc-(Fe,Co) (x=0-0.75) or fcc-Co (x=1). Grain sizes of recombined Nd2(Fe,Co)14B materials were found to be 40-50nm.
78

Spectroscopic data and multivariate analysis : tools to study genetic perturbations in poplar trees

Wiklund, Susanne January 2007 (has links)
In our society in the 21st century one of the greatest challenges is to provide raw materials to the industry in a sustainable way. This requires increased use of renewable raw materials such as wood. Wood is widely used in pulp, paper and textile industries and ongoing research efforts aim to extend the use of wood in e.g. liquid biofuels and green chemicals. At Umeå Plant Science Center (UPSC) poplar trees are used as model systems to study wood formation. The objective is to understand the function of the genes underlying the wood forming process. This knowledge could result in improved chemical and physical wood properties suitable for different industrial processes. This will in turn meet the demands for a sustainable development. This thesis presents tools and strategies to unravel information regarding genetic perturbations in poplar trees by the use of nuclear magnetic resonance (NMR) spectroscopy and multivariate analysis (MVA). Furthermore, gas chromatography/mass spectrometry (GC/MS) is briefly discussed in this context. Multivariate methods to find patterns and trends in NMR data have been used for more than 30 years. In the beginning MVA was applied in pattern recognition studies in order to characterize chemical structures with different ligands and in different solvents. Today, the multivariate methods have developed and the research have changed focus towards the study of biofluids from plant extracts, urine, blood plasma, saliva etc. NMR spectra of biofluids can contain thousands of resonances, originating from hundreds of different compounds. This type of complex data can be hard to summarize and interpret without appropriate tools and require sophisticated strategies for data evaluation. Related fields of research are rapidly growing and are here referred to as metabolomics. Five different research projects are presented which includes analysis of poplar samples where macromolecules such as pectin and also small molecules such as metabolites were analysed by high resolution magic angle spinning (HR/MAS) NMR spectroscopy, 1H-13C HSQC NMR and GC/MS. The discussion topics include modelling of metabolomic time dependencies in combination with genetic variation, validation of orthogonal projections to latent structures (OPLS) models, selection of putative biomarkers related to genetic modification from OPLS-discriminant analysis (DA) models, measuring one of the main components found in the primary cell-walls of poplar i.e. pectin, the use of Fourier transformed two-dimensional (2D) NMR data in OPLS modelling and model complexity in a PLS model.
79

Proportional slowing in old adults is modulated by episodic memory demands : an investigation of age-related slowing using compatible and arbitrary stimulus-response mappings / Proportional slowing in old adults is modulated by episodic memory demands : an investigation of age-related slowing using compatible and arbitrary stimulus-response mappings

Laubrock, Jochen January 2004 (has links)
Das dominante Datenmuster im Bereich des kognitiven Alterns ist der Alters-x-Komplexitätseffekt. Die vorliegende Studie untersucht, ob das Muster statt durch einen üblicherweise postulierten unspezifischen durch einen spezifischen Mechanismus erklärt werden kann: die mit dem Alter abnehmende Reliabilität episodischer Akkumulatoren. In sechs Reaktionszeit-Experimenten wurden junge und ältere Erwachsene verglichen, dabei wurden frühe kognitive (Stroop-Bedingung) und episodische Schwierigkeit (Reiz-Reaktions-Zuordnung) orthogonal manipuliert. Die vorhergesagte Dreifachinteraktion der beiden Faktoren mit dem Alter zeigte sich über die Experimente hinweg relativ konsistent. Eine modifizierte Brinley-Analyse ergibt deutlich unterschiedliche Steigungen der Regressionsgeraden im Alt-Jung-Raum für niedrige und hohe episodische Schwierigkeit. Als methodischer Beitrag wird im Anhang ein zur modifizierten Brinley-Analyse passendes Regressionsmodell entwickelt, das aus einigen einfachen Verarbeitungsannahmen folgt. Es wird gezeigt, dass in einer klassischen Brinley Metaanalyse die Steigung neben der theoretisch interessierenden Varianz von theoretisch uninteressanter Zwischen-Experiment-Varianz beeinflusst wird. / The age-by-complexity effect is the dominant empirical pattern in cognitive aging. The current report investigates whether a specific high-level mechanism---an age-related decrease in the reliability of episodic accumulators---can account for the age-by-complexity-effect, which is commonly assumed to be caused by an unspecific, low-level deficit. Groups of younger and older adults are compared in six reaction time experiments, using orthogonal manipulations of early cognitive difficulty (e.g., Stroop condition) and episodic demands (e.g., stimulus-response mapping). The predicted three-way interaction of age and the two factors was observed fairly consistently across experiments. A modified Brinley analysis shows that different regression slopes in old-young-space are required for conditions with low and high episodic difficulty. As a methodological contribution, a Brinley regression model following from certain simple processing assumptions is developed. It is shown that in contrast to a standard Brinley meta-analysis, the regression slopes in this model are not influenced by theoretically un-interesting between-experiment variance.
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The isotopic composition of CO2 and H2Ov fluxes in a managed beech forest - Instrument tests and ecological application of two laser-based absorption spectrometers / Die Isotopenkomposition von CO2 und H2Ov Flüssen in einem bewirtschafteten Buchenwald - Instrumententests und ökologische Anwendung zweier laserbasierter Absorptionsspektrometer

Braden-Behrens, Jelka 05 June 2018 (has links)
No description available.

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