Dissertations / Theses on the topic 'LENGTH VARIATION'
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1
Bell, S. R. "Mitochondrial DNA length variation in the mussel Mytilus." Thesis, Swansea University, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.636073.
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Three types of mitochondrial DNA length variation in Mytilus were examined. For the purposes of this study, the three variations were termed "macro-length-variation", "micro-length-variation" and "trossulus-length variation". Macro-length-variation was observed at a frequency of 25% at the hybrid M.galloprovincialis/M. edulis population at Mevagissey on the south Cornish coast, southwest England, Mitochondrial DNA (mtDNA) was extracted and digested with a diagnostic enzyme, EcoRI. Positive results with F-genome specific PCR primers and probes indicate that the macro-length-variant is F-genome mtDNA. The normal length for Mytilus mtDNA is approx. 17.4 kb. Macro-length-variants showed mtDNA of lengths between 21.2 and 31.2 kb with an incremental increase of approx. 2.08 kb. Micro-length-variation was observed during polyacrylamide gel electrophoresis of PCR product. Sequence directed bending of the DNA helix is proposed as the cause of the electrophoretic mobility variability. Trossulus-length-variation was studied in five M. trossulus mussels taken from the Gulf of Gdansk in the Baltic Sea. PCR primers flanking the putative control region revealed incremental length increase of approx. 200 bp. PCR product from a normal-length individual and a length-increased individual was cloned and sequenced revealing a single tandem repeat of 190 bp at the extreme 3' end of the putative control region. The repeat junction aligns with a flanking tRNA (tyr) gene. RFLP analysis at a separate PCR locus revealed close similarity between the M. trossulus samples and common M. edulis haplotypes, confirming the findings of previous studies.
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Sagit, Rauan. "Variation in length of proteins by repeats and disorder regions." Doctoral thesis, Stockholms universitet, Institutionen för biokemi och biofysik, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-88553.
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Protein-coding genes evolve together with their genome and acquire changes, some of which affect the length of their protein products. This explains why equivalent proteins from different species can exhibit length differences. Variation in length of proteins during evolution arguably presents a large number of possibilities for improvement and innovation of protein structure and function. In order to contribute to an increased understanding of this process, we have studied variation caused by tandem domain duplications and insertions or deletions of intrinsically disordered residues. The study of two proteins, Nebulin and Filamin, together with a broader study of long repeat proteins (>10 domain repeats), began by confirming that tandem domains evolve by internal duplications. Next, we show that vertebrate Nebulins evolved by duplications of a seven-domain unit, yet the most recent duplications utilized different gene parts as duplication units. However, Filamin exhibits a checkered duplication pattern, indicating that duplications were followed by similarity erosions that were hindered at particular domains due to the presence of equivalent binding motifs. For long repeat proteins, we found that human segmental duplications are over-represented in long repeat genes. Additionally, domains that have formed long repeats achieved this primarily by duplications of two or more domains at a time. The study of homologous protein pairs from the well-characterized eukaryotes nematode, fruit fly and several fungi, demonstrated a link between variation in length and variation in the number of intrinsically disordered residues. Next, insertions and deletions (indels) estimated from HMM-HMM pairwise alignments showed that disordered residues are clearly more frequent among indel than non-indel residues. Additionally, a study of raw length differences showed that more than half of the variation in fungi proteins is composed of disordered residues. Finally, a model of indels and their immediate surroundings suggested that disordered indels occur in already disordered regions rather than in ordered regions.At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 2: In press. Paper 4: Manuscript.
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李玉嫻 and Yuk-han Li. "Telomere length variation and lineage chimerism in bone marrow transplantation." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2002. http://hub.hku.hk/bib/B31227594.
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Mateos, Mariana, and Therese Markow. "Ribosomal intergenic spacer (IGS) length variation across the Drosophilinae (Diptera: Drosophilidae)." BioMed Central, 2005. http://hdl.handle.net/10150/610372.
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BACKGROUND:The intergenic spacer of the ribosomal genes in eukaryotes (IGS) contains duplications of the core transcription promoter. The number of these duplicated promoters, as measured by the IGS length, appears to be correlated with growth rate and development time in several distantly related taxa. In the present study, we examined IGS length variation across a number of species of Drosophila to determine the amount of variation in this trait across different evolutionary time scales. Furthermore, we compared the usefulness of two methods commonly used to determine IGS length: Southern Blot Hybridization (SB) and Polymerase Chain Reaction (PCR).RESULTS:Our results show broad variation in IGS length across the genus Drosophila, but closely related species had similar IGS lengths. Our results also suggest that PCR tends to underestimate the true IGS size when the size is greater than 5 kb, and that this degree of underestimation is greater as the IGS size increases.CONCLUSION:Broad variation in IGS length occurs across large evolutionary divergences in the subfamily Drosophilinae. Although average IGS length has been shown to evolve rapidly under artificial selection, closely related taxa generally have similar average IGS lengths. Our comparison of methods suggests that without previous knowledge of the DNA sequence of the IGS and flanking regions, both methods be used to accurately measure IGS length.
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Quadri, Asima. "Assessment of genetic diversity in Asarum canadense L. using amplified fragment length polymorphism (AFLP)." Virtual Press, 2007. http://liblink.bsu.edu/uhtbin/catkey/1371851.
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Forest fragmentation poses a serious danger to population diversity in plants and animals by increasing species isolation, thus reducing the population size and genetic diversity. However, little information is available concerning how fragmentation impacts plant diversity. AFLP fingerprinting was used to assess genetic diversity within and between populations of Asarum canadense L. (Canadian Wild Ginger) across 11 different populations in East-Central Indiana. AFLP fingerprints using two primer pairs generated 51 distinct bands with an average of 25.5 bands per primer. Forty-eight low molecular weight distinct polymorphic bands were observed (50-200 bp range). The percentage of polymorphism was low (0-25%) indicating low levels of genetic diversity within each population studied. NTSYSpc Numerical Taxonomy Analysis Software generated aphenogram that revealed high levels of homologies within populations (75-100%), with individuals from the same population typically clustered. The genetic diversity between populations ranged from 10-50%. The populations from Jay, Randolph and Henry Counties clustered together exhibiting -54% homology, while populations from Mien, Madison, and Huntington counties shared approximately 64% homology. The populations from Adams, Blackford, Delaware, and Grant counties shared approximately 66% homology. However, within this last group Blackford and Delaware counties shared 90% homology. There were no apparent effects of the size of the forest fragments on the observed diversity measures. A possible relationship between genetic diversity and spatial distance was observed between populations moving from east to west. Possible reasons for this observation may be due to forest types, age of forests, climatic factors, soil types, and/or anthropogenic activities. Overall, the low level of average diversity within the populations strongly suggests that the individuals inhabiting isolated forests primarily propagate by asexual means.Ball State UniversityMuncie, IN 47306Department of Biology
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Achouri, Ali. "Cartes de contrôle pour le coefficient de variation." Nantes, 2014. http://archive.bu.univ-nantes.fr/pollux/show.action?id=7658d471-1a91-4022-9493-9f85b2a06a86.
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La Maîtrise Statistique des Procédés (MSP) est une méthode de suivi de la production basée sur les statistiques. Elle se base essentiellement sur les cartes de contrôle. Une hypothèse indispensable pour le développement des cartes de contrôle est que les paramètres μ0 et 0 du procédé sous-contrôle soient supposés constants. Mais, dans la pratique, il existe de nombreux procédés pour lesquels ces paramètres peuvent être variables. Dans cette optique, le recours au coefficient de variation est une alternative intéressante. Dans cette thèse, nous avons essayé de systématiquement proposer de nouvelles cartes de contrôle pour le coefficient de variation qui n’ont pas encore été traitées jusqu’à présent dans la littérature. Des cartes de contrôle avec règles supplémentaires, des cartes VSI, VSS sont proposées pour le coefficient de variation lorsque les paramètres sont connus. De plus, une carte de type Shewhart pour le coefficient de variation avec paramètres estimés est aussi proposée. Les performances de chacune des cartes ont été évaluées et les paramètres optimaux ont été systématiquement calculés. Une validation empirique des résultats a été élaborée dans des processus industriels existantsThe Statistical Process Control (SPC) is an effective method based on statistics and used to monitor production. Control charts are the most important and primary tools of SPC. An indispensable assumption for the development of control charts is that the process parameters μ0 and 0 are assumed constant. In practice, the process parameters are often variables and the use of the coefficient of variation seems to be an interesting alternative. In this thesis, we will investigate the properties (in terms of the Run Length) of some control charts for the coefficient of variation in the case of known parameters, which have not been researched till now, such as Run Rules Chart, VSI Chart and VSS Chart. In addition, a Shewhart control chart for the coefficient of variation with estimated parameters is proposed. The performance of each control chart has been evaluated and the optimal parameters were systematically computed. An empirical validation of the results has been developed for real industrial processes
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Malan, Roxanne. "Syllabic tone variation by Sepedi speakers with dysarthia." Diss., University of Pretoria, 2016. http://hdl.handle.net/2263/60384.
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Background: Speech production in Bantu languages places great demands on
neuromotor control, because unique speech motor behaviours such as syllabic tone
variation and the aspiration of speech sounds require an additional level of vocal fold
control compared to speech production in Germanic languages. As these motor
behaviours play an important role in differentiating the meaning of words (Van der
Merwe & Le Roux, 2014a), neuromotor speech disorders such as dysarthria may have
a greater impact on communication in Bantu languages than in Germanic languages.
The focus of this study was on syllabic tone variation in Bantu language speakers with
dysarthria compared to typical speakers. Sepedi was the Bantu language investigated.
Syllabic tone variation refers to pitch level changes for every syllable of words in a
tone language (Zerbian & Barnard, 2008a) and requires manipulation of vocal fold
length and mass over and above the voicing or devoicing of sounds within words.
These pitch changes convey the lexical and grammatical meaning of words and may
differentiate between the meanings of two orthographically identical words (Zerbian &
Barnard, 2008a). Studies on lexical tone variation in speakers with dysarthria to date
have focused mostly on the tone languages of Asia and Scandinavia (Kadyamusuma,
De Blesser, & Mayer, 2011). No studies of tone variation in Bantu language speakers
with dysarthria were found. Furthermore, past research only regarded tone variation
in monosyllabic words, with no reference to how tone would be affected across
bisyllabic words and within each of the two syllables of these words. No inquiries were
made into the tone variation ability of speakers with dysarthria when producing short
utterances compared to longer utterances and mostly speakers with congenital
dysarthria were used as research participants. These shortcomings needed to be
addressed to gain a more holistic and accurate view of the extent to which tone
variation is a challenge for Bantu language speakers with dysarthria.
Aims: The first aim of the study was to determine whether a difference exists between
typical Sepedi speakers and Sepedi speakers with dysarthria, in their ability to vary
tone across CVCV words with a HL tone pattern. The second aim of the study was to
determine whether a difference in tone variation exists between short and longer
utterances in typical Sepedi speakers and Sepedi speakers with dysarthria. Method: A quasi-experimental, between-group comparison was used in the study.
Speech samples were obtained from a control group of five typical Sepedi speakers
and from an experimental group of four Sepedi speakers with dysarthria. These
speech samples consisted of 20 consonant-vowel-consonant-vowel (CVCV) words
with high-low (HL) tone variation produced in three- and also in six- /seven-syllable
utterances (resulting in a total of 40 words). The speech samples were analysed
acoustically using Praat software. To achieve the first aim, the following acoustic
measures were obtained from the 40 words produced by participants: (1) Mean
fundamental frequency (F0) of syllable 1 (S1) and syllable 2 (S2), (2) Change in F0
across words from the highest F0 point of S1 to the lowest F0 point of S2, (3) Intrasyllabic
change in F0 within S1 and S2. To achieve the second aim of the study, the
change in F0 across words in short utterances was compared to the change in F0
across words in longer utterances for the typical speakers and speakers with
dysarthria.
Results: Wilcoxon rank tests were used for statistical analyses. Descriptive statistics
were performed and median values were used to achieve research aims. All of the
control participants and participants with dysarthria produced S1 with a higher mean
F0 than S2, as was appropriate for the HL tone pattern ascribed to the target words.
For most of the individuals from both groups, the mean F0 of S1 was significantly
higher than the mean F0 of S2. However, one participant from each group produced
an insignificant difference between the mean F0 values of the two syllables. The control
group produced slightly greater median F0 changes across the words and within S1
than the dysarthria group, but the differences between the speaker groups for the
change in F0 across words and the change in F0 within S1 were insignificant. In
contrast to this, the control group produced a significantly smaller median change in
F0 within S2 than the dysarthria group. Individual speakers from both groups produced
unique patterns of F0 changes for all aspects of tone variation (change in F0 across
words and changes in F0 within S1 and S2). Both speaker groups produced a
significantly greater median change in F0 across words in short utterances compared
to long utterances. The difference in the change in F0 across words between short and
long utterances was significantly greater for the control group than for the dysarthria
group. Conclusions: The speakers with dysarthria in the study maintained the ability to vary
tone across bisyllabic words with an HL tone pattern. The dysarthria group only
differed significantly from the control group with regard to the extent of tone reduction
in the second syllable. This finding may point to possible difficulties in the required
graded relaxation of the vocal folds. Individual differences in F0 changes were found
for both typical speakers and speakers with dysarthria, indicating that unique tone
variation patterns may normally exist for all speakers. For both control and dysarthria
groups, greater tone variation was observed in short compared to longer utterances.
The role of increased utterance length in decreased F0 variation was greater for the
typical speakers than for the individuals with dysarthria.Dissertation (M Communication Pathology)--University of Pretoria, 2016.
Speech-Language Pathology and Audiology
M Communication Pathology
Unrestricted
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Niklison, Alina Maria. "INFLUENCE OF EMBRYONIC METABOLIC RATE AND INCUBATION TEMPERATURE ON INCUBATION LENGTH VARIATION IN NEOTROPICAL PASSERINES." The University of Montana, 2008. http://etd.lib.umt.edu/theses/available/etd-12212007-143823/.
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Variation in embryonic developmental periods influences fitness, but causes of interspecific variation are poorly understood. Allometry, for example, does not explain variation in incubation periods among neotropical passerines. Incubation temperature can explain some variation in developmental periods, but substantial variation remains unexplained. Here we examine two previously untested alternatives. Adult metabolic rates differ among species and similar differences among embryos may explain some variation in embryonic development rates; higher metabolism may allow faster cellular proliferation. Alternatively, metabolic rates are temperature dependent, and metabolic rates might respond differentially to temperature among species and compensate for differing incubation temperatures. These alternatives are untested across any taxa. Therefore, we examined them in tropical Venezuela by measuring embryonic metabolism at four temperatures in 15 passerine species with incubation periods ranging from 12 to 27 days. Embryonic metabolic rates responses to temperature were different among species even at constant embryonic age. Furthermore, species with lower average daily incubation temperature are less sensitive to changes in temperature than species with higher average incubation temperatures. Differences in embryonic mass specific metabolic rate among species explained a significant amount of variation in incubation periods after correcting for incubation temperature. Thus, differences in the rate of living as manifested through metabolism can influence developmental trajectories and deserve greater attention.
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Chakraborty, Ranjay. "Diurnal variation of ocular biometrics under natural and defocused conditions." Thesis, Queensland University of Technology, 2013. https://eprints.qut.edu.au/61093/1/Ranjay_Chakraborty_Thesis.pdf.
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It is well known that a broad range of ocular anatomical and physiological parameters undergo significant diurnal variation. However, the natural diurnal variations that occur in the length of the human eye (axial length) and their underlying causes have been less well studied. Improvements in optical methods for the measurement of ocular biometrics now allow more precise and comprehensive measurements of axial length to be performed than has previously been possible. Research from animal models also suggests a link between diurnal axial length variations and longer term myopic eye growth, and that retinal image defocus can disrupt these diurnal rhythms in axial length. This research programme has examined the diurnal variations in axial length in young normal eyes, the contributing components and the influence of optical stimuli on these changes.
In the first experiment, the normal pattern and consistency of the diurnal variations in axial length were examined at 10 different times (5 measurements each day, at ~ 3-hour intervals from ~ 9 am to ~ 9 pm) over 2 consecutive days on 30 young adult subjects (15 myopes, 15 emmetropes). Additionally, variations in a range of other ocular biometric measurements such as choroidal thickness, intraocular pressure, and other ocular biometrics were also explored as potential factors that may be associated with the observed variations in axial length. To investigate the potential influence of refractive error on diurnal axial length variations, the differences in the magnitude and pattern of diurnal variations in axial length between the myopic and emmetropic subjects were examined. Axial length underwent significant diurnal variation that was consistently observed over the 2 consecutive days of measurements, with the longest axial length typically occurring during the day, and the shortest at night. Significant diurnal variations were also observed in choroidal thickness, IOP and other ocular biometrics (such as central corneal thickness, anterior chamber depth and vitreous chamber depth) of the eye. Diurnal variations in vitreous chamber depth, IOP (positive associations) and choroidal thickness (negative association) were all significantly correlated with the diurnal changes in axial length. Choroidal thickness was found to fluctuate approximately in antiphase to the axial length changes, with the average timing of the longest axial length coinciding with the thinnest choroid and vice versa. There were no significant differences in the ocular diurnal variations associated with refractive error.
Given that the diurnal changes in axial length could be associated with the changes in the eye’s optical quality, whether the optical quality of the eye also undergoes diurnal variation in the same cohort of young adult myopes and emmetropes over 2 consecutive days was also examined. Significant diurnal variations were observed only in the best sphere refraction (power vector M) and in the spherical aberration of the eye over two consecutive days of testing. The changes in the eyes lower and higher order ocular optics were not significantly associated with the diurnal variations in axial length and the other measured ocular biometric parameters. No significant differences were observed in the magnitude and timing of diurnal variations in lower-order and higher-order optics associated with refractive error. Since the small natural fluctuations in the eye’s optical quality did not appear to be sufficient to influence the natural diurnal fluctuations in ocular biometric parameters, in the next experiment, the influence of monocular myopic defocus (+1.50 DS) upon the normal diurnal variations in axial length and choroidal thickness of young adult emmetropic human subjects (n=13) imposed over a 12 hour period was examined. A series of axial length and choroidal thickness measurements (collected at ~3 hourly intervals, with the first measurement at ~9 am and the final measurement at ~9 pm) were obtained over three consecutive days. The natural diurnal rhythms (Day 1, no defocus), diurnal rhythms with monocular myopic defocus (Day 2, +1.50 DS spectacle lens over the right eye), and the recovery from any defocus induced changes (Day 3, no defocus) were examined. Significant diurnal variations over the course of the day were observed in both axial length and choroidal thickness on each of the three measurement days. The introduction of monocular myopic defocus led to significant reductions in the mean amplitude of diurnal change, and phase shifts in the peak timing of the diurnal rhythms in axial length and choroidal thickness. These defocus induced changes were found to be transient in nature and returned to normal the day following removal of the defocus.
To further investigate the influence of optical stimuli on human diurnal rhythms, in the final experiment, the influence of monocular hyperopic defocus on the normal diurnal rhythms in axial length and choroidal thickness was examined in young adult emmetropic subjects (n=15). Similar to the previous experiment, the natural diurnal rhythms (Day 1, no defocus), diurnal rhythms with monocular hyperopic defocus (Day 2, -2.00 DS spectacle lens over the right eye), and the recovery from any defocus induced changes (Day 3, no defocus) were examined over three consecutive days. Both axial length and choroidal thickness underwent significant diurnal variations on each of the three days. The introduction of monocular hyperopic defocus resulted in a significant increase in the amplitude of diurnal change, but no change in the peak timing of diurnal rhythms in both parameters. The ocular changes associated with hyperopic defocus returned to normal, the day following removal of the defocus.
This research has shown that axial length undergoes significant diurnal variation in young adult human eyes, and has shown that the natural diurnal variations in choroidal thickness and IOP are significantly associated, and may underlie these diurnal fluctuations in axial length. This work also demonstrated for the first time that exposing young human eyes to monocular myopic and hyperopic defocus leads to a significant disruption in the normal diurnal rhythms of axial length and choroidal thickness. These changes in axial length with defocus may reflect underlying mechanisms in the human eye that are involved in the regulation of longer term eye growth.
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Amdouni, Asma. "Surveillance statistique du coefficient de variation dans un contexte de petites séries." Nantes, 2015. http://archive.bu.univ-nantes.fr/pollux/show.action?id=dcf36868-32b2-41d6-916b-f9533ee12902.
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La maîtrise statistique des procédés (MSP) est une méthode de contrôle de la qualité basée sur les statistiques. La surveillance du coefficient de variation est une approche efficace à la MSP lorsque la moyenne du processus µ et son écart type σ ne sont pas constants mais leur rapport est constant. Jusqu’à présent, les études portant sur la surveillance du coefficient de variation se sont limitées au cas d’une production avec un horizon infini. Cette thèse présente de nouvelles cartes de contrôle pour surveiller le coefficient de variation dans le contexte fini lorsque les paramètres sont connus : des cartes de contrôle séparées de type Shewhart, des cartes avec des règles supplémentaires et des cartes VSI et VSS. Les paramètres optimaux ont été systématiquement calculés et les performances de chacune de ces cartes ont été également évaluées en développant de nouvelles mesures statistique de performance appropriées dans un contexte de production à horizon fini. Une validation empirique des résultats a été élaborée pour des procédés industriels existantsStatistical Process Control (SPC) is a method of quality control based on statistics and used to monitor production. Monitoring the coefficient of variation is an effective approach to SPC when the process mean µ and standard deviation σ are not constant but their ratio is constant. Until now, research has not investigated the monitoring of the coefficient of variation for short production runs. Viewed under this perspective, in this thesis, we will propose new methods to monitor the coefficient of variation for a finite horizon production, we will investigate the properties (in terms of the Truncated Run Length) of some control charts for the coefficient of variation in a Short Run context in the case of known parameters, such as the one-sided Shewhart Chart, the Run Rules Chart, the VSI and VSS Charts. The performance of each control chart has been evaluated by developing statistical measures of performance appropriate in a Short Run context and the optimal parameters were systematically computed. An empirical validation of the results has been developed for real industrial processes
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Silletta, Thomas. "The effects of pole length variation on the skiing performance of elite cross-country skiers using V-skating techniques /." Thesis, McGill University, 1987. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=66130.
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Mutava, Raymond Ngao. "Evaluation of sorghum genotypes for variation in canopy temperature and drought tolerance." Diss., Kansas State University, 2012. http://hdl.handle.net/2097/14506.
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Doctor of PhilosophyDepartment of Agronomy
P.V. Vara Prasad
Sorghum (Sorghum bicolor L. Moench) is the fifth most economically important cereal crop grown worldwide and adapted to a wide range of climatic conditions. Drought stress has been ranked as one of the most significant causes of crop yield loss with its effects on yield and yield components. Conservative water use by plants is one of the strategies that can be used as a drought coping mechanism. The slow wilting trait has been associated with conservative water use and has been found in some sorghum genotypes. The purpose of this study was to use canopy temperature to screen for drought tolerance in sorghum, evaluate water use efficiency for slow wilting sorghum genotypes and determine variability in root morphology and response to drought among sorghum genotypes. Canopy temperature studies were conducted under field conditions using infrared (IR) sensors while water use efficiency and root studies were conducted under greenhouse conditions. Our results showed a distinct separation in canopy temperature among genotypes under field conditions at 2:00 pm to 6:00 pm. Midday canopy temperature depression (CTD) was positively correlated to yield (R2 = 0.19) and harvest index (R2 = 0.11). CTD was also stable for all the genotypes during the period from 1:00 pm to 7:00 pm. There was a negative correlation between CTD and crop water stress index (CWSI) (R2 = 0.34) and a positive one between canopy temperature and CWSI (R2 = 0.50). Evaluation of genotypes for water use efficiency revealed significant variability among sorghum genotypes in the amount of water used (10.48 – 13.52 kg) and transpiration efficiency (TE) (2.64 – 7.11 g kg-1) among genotypes. Slow wilting genotypes were high in TE. Rooting depth increased for some genotypes under drought stress with genotype SC1124 recording the largest increase (180%). Total root length for some genotypes increased by 11 – 113% with genotypes SC224 and SC1019 recording the greatest increase. There was a positive correlation between water used and root length (R2 = 0.21). These results show that there is potential for selection of drought tolerance in sorghum and that genotypes with the slow wilting traits are efficient in water use.
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Roberts, Robert Richard. "The use, length, and source of narrative material in the sermons of Concordia pulpit a study of their variation with time and occasion /." Theological Research Exchange Network (TREN), 1992. http://www.tren.com.
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Hannrup, Björn. "Genetic parameters of wood properties in Pinus sylvestris (L.) /." Uppsala : Swedish Univ. of Agricultural Sciences (Sveriges lantbruksuniv.), 1999. http://epsilon.slu.se/avh/1999/91-576-5628-2.pdf.
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Faghiri, Pegah. "La variation de l'ordre des constituants dans le domaine préverbal en persan : approche empirique." Thesis, Sorbonne Paris Cité, 2016. http://www.theses.fr/2016USPCA161.
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Cette thèse propose une étude quantitative de la variation de l'ordre des constituants en persan avec un intérêt particulier pour l'ordre relatif entre le COD et le COI étant donné son rôle crucial dans les analyses de la structure du SV. Afin de remédier à une lacune empirique dont souffre l’étude de la syntaxe du persan, notre premier objectif est d’évaluer, à partir de données empiriques robustes, l’hypothèse largement admise selon laquelle il existe un ordre relatif canonique dichotomique entre les compléments verbaux, dépendant du marquage différentiel de l'objet (MDO). Notre second objectif, relatif à la linguistique générale et à la typologie, est de contribuer aux débats controversés sur les préférences translinguistiques de l'ordre des mots en étudiant, dans une langue SOV à structure mixte, les effets des facteurs tels que le poids (ou la longueur relative). Les résultats de nos études de corpus et de nos expériences montrent l’inadéquation du critère MDO pour expliquer l’ordre relatif entre le COD et le COI. Cette conclusion nous conduit à réfuter également l’hypothèse de la position syntaxique double de l’objet au profit d’une structure plate pour le SV. De plus, nos données révèlent une préférence « long-avant-court » subordonnée aux facteurs contribuant à la saillance, tels que la définitude, l'animéité et le rôle grammatical. Nous arguons que cette préférence échappe, en partie ou totalement, aux modèles du traitement se fondant sur la distance entre la tête et ses dépendants, alors qu’elle est compatible avec l'hypothèse selon laquelle dans les langues SOV l'accessibilité conceptuelle des constituants longs favorise leur production plus en amont dans la phraseThis thesis proposes a quantitative study of word order variations in Persian, focusing on the relative order between the direct object (DO) and the indirect object (IO). The latter plays a crucial role in the theoretical analyses of the VP, which in the absence of quantitative studies lack solid empirical underpinning. My first goal is to contribute to the study of Persian syntax by providing reliable data in order to evaluate the prevailing hypothesis according to which there exists a dual canonical relative order between the two objects triggered by the Differential Object marking (DOM). My second goal is to contribute to the ongoing debates on word order preferences in general linguistics and typology by bringing in data on an SOV language with mixed head-direction. To this end, I study the effect of factors such as grammatical weight (or relative length), which are claimed to influence the linear order across languages. First, the results of our corpus and experimental studies show that the DOM account of the relative order between the DO and the IO is flawed. Based on this conclusion, I also reject the two object positions hypothesis and plead for a flat structure view of the VP. Second, our data reveal a “long-before-short” preference, which is shown to depend on the effect of salience-enhancing factors such as definiteness, animacy and the grammatical role. I argue that while this preference is, either totally or partially, incompatible with the predictions of processing-oriented dependency-based models, it can be accounted for by production models assuming that the greater conceptual accessibility of longer constituents favors their early position in SOV languages
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Mendelson, Neil, Patrick Shipman, Darshan Roy, Liling Chen, and John Thwaites. "The dynamic behavior of bacterial macrofibers growing with one end prevented from rotating: variation in shaft rotation along the fiber's length, and supercoil movement on a solid surface toward the constrained end." BioMed Central, 2003. http://hdl.handle.net/10150/610048.
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BACKGROUND:Bacterial macrofibers twist as they grow, writhe, supercoil and wind up into plectonemic structures (helical forms the individual filaments of which cannot be taken apart without unwinding) that eventually carry loops at both of their ends. Terminal loops rotate about the axis of a fiber's shaft in contrary directions at increasing rate as the shaft elongates. Theory suggests that rotation rates should vary linearly along the length of a fiber ranging from maxima at the loop ends to zero at an intermediate point. Blocking rotation at one end of a fiber should lead to a single gradient: zero at the blocked end to maximum at the free end. We tested this conclusion by measuring directly the rotation at various distances along fiber length from the blocked end. The movement of supercoils over a solid surface was also measured in tethered macrofibers.RESULTS:Macrofibers that hung down from a floating wire inserted through a terminal loop grew vertically and produced small plectonemic structures by supercoiling along their length. Using these as markers for shaft rotation we observed a uniform gradient of initial rotation rates with slopes of 25.6degrees/min. mm. and 36.2degrees/min. mm. in two different fibers. Measurements of the distal tip rotation in a third fiber as a function of length showed increases proportional to increases in length with constant of proportionality 79.2 rad/mm. Another fiber tethered to the floor grew horizontally with a length-doubling time of 74 min, made contact periodically with the floor and supercoiled repeatedly. The supercoils moved over the floor toward the tether at approximately 0.06 mm/min, 4 times faster than the fiber growth rate. Over a period of 800 minutes the fiber grew to 23 mm in length and was entirely retracted back to the tether by a process involving 29 supercoils.CONCLUSIONS:The rate at which growing bacterial macrofibers rotated about the axis of the fiber shaft measured at various locations along fibers in structures prevented from rotating at one end reveal that the rate varied linearly from zero at the blocked end to maximum at the distal end. The increasing number of twisting cells in growing fibers caused the distal end to continuously rotate faster. When the free end was intermittently prevented from rotating a torque developed which was relieved by supercoiling. On a solid surface the supercoils moved toward the end permanently blocked from rotating as a result of supercoil rolling over the surface and the formation of new supercoils that reduced fiber length between the initial supercoil and the wire tether. All of the motions are ramifications of cell growth with twist and the highly ordered multicellular state of macrofibers.
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Talaisys, Jonas Lemos. "Conteúdo harmônico e estimativa da variação de comprimento de arcos elétricos gerados artificialmente em linhas de transmissão = Harmonic content and estimation of length variation of artificially generated electrical arc in transmission lines." [s.n.], 2012. http://repositorio.unicamp.br/jspui/handle/REPOSIP/259600.
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Orientador: Maria Cristina Dias TavaresDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação
Made available in DSpace on 2018-08-21T16:31:47Z (GMT). No. of bitstreams: 1 Talaisys_JonasLemos_M.pdf: 12385917 bytes, checksum: 5619a3284121ab56d2a0a337ef2456b4 (MD5) Previous issue date: 2012
Resumo: Este trabalho apresenta resultados do estudo do conteúdo harmônico e da variação do comprimento de arcos elétricos longos, com comprimento inicial superior a 4 m. Os resultados decorreram da análise de uma grande quantidade de dados obtidos de 647 ensaios realizados em ambiente não confinado em um trecho experimental de linha de transmissão aérea de 500 kV. Diversos níveis de corrente de arco foram abrangidos, desde 15 Aef até 10.000 Aef. O conteúdo harmônico da tensão e da corrente dos arcos foi analisado através da Trans-formada de Fourier Discreta em Tempo Reduzido. Mediante um tratamento estatístico, este conteúdo harmônico possibilitou a consolidação da assinatura harmônica dos arcos estudados. Uma contribuição importante da pesquisa consiste na verificação de que o conteúdo harmônico do arco pode ser utilizado para identificar o momento a partir do qual o arco elétrico se encontra com suas características elétricas estabilizadas. A partir deste instante os parâmetros elétricos do arco podem ser utilizados para obtenção de um modelo matemático. Utilizando-se do conteúdo harmônico e de registros visuais, a variação de comprimento foi obtida para 69 arcos. Esta análise inicial permite que se tenha uma noção da velocidade de alongamento destes arcos em relação ao seu nível de corrente. Permitiu também a obtenção de um gradiente de tensão mais preciso dos arcos, considerando-se tanto o alongamento quanto a estabilidade destes. Por fim, este trabalho tem por objetivo apresentar resultados que forneçam características e informações relevantes à obtenção de um modelo matemático de arco elétrico secundário adequado para o estudo da Manobra de Abertura e Religamento Monopolar. O conteúdo harmônico é identificado como uma ferramenta eficaz para caracterização da estabilidade destes arcos e o alongamento é um dos principais fatores relacionados com a extinção e duração do arco secundário
Abstract: This document presents results related to harmonic content and length variation of long electrical arcs in air, with initial length of 4 m. The results are based in the analysis of a data-base containing 647 experiments in non-confined environment of an experimental aerial 500 kV transmission line. The current range analyzed lies between 15 Arms and 10,000 Arms. The harmonic contents of voltage and current of electrical arcs were analyzed by the Short Time Discrete Fourier Transform. Using a statistic treatment this harmonic content allowed to consolidate the harmonic signature of the arcs in study. Furthermore, in the present work it was proposed that the harmonic content of an electrical arc defines the moment when the electric arc has its electrical characteristics stabilized. This instant is crucial to obtain the correct arc electrical parameters that will used to represent the arc. Using the harmonic content and visual data, the variation in length was obtained for 69 arcs. This initial analysis lead to arc elongation velocity regarding the current level and permit-ted to obtaining a more precise arc voltage gradient, considering both elongation as its stability. Finally, this work aims to supply relevant characteristics and information to obtaining a secondary arc model useful to the Single-Phase Autoreclosing Maneuver study. The harmonic content is an efficient way to characterize these arcs and the arc elongation is one of the main factors related to the duration and self-extinction of the secondary arc
Mestrado
Energia Eletrica
Mestre em Engenharia Elétrica
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Serter, Ahmet Volkan. "Implementation And Comparison Of The Advanced Encryption Standard Finalist Algorithms On Tms320c54x." Master's thesis, METU, 2005. http://etd.lib.metu.edu.tr/upload/2/12606839/index.pdf.
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Implementation aspects of Advanced Encryption Standard (AES) Contest finalist algorithms (MARS, RC6, RIJNDAEL, SERPENT and TWOFISH) are studied on TMS320C54X processor. The C codes written by Brian Gladman in 1999 are adapted to TMS320C54X and the speed and memory usage values are compared with the adaptation of Karol Gorski and Michal Skalski&rsquos implementation in 1999. The effects of implementation environment are investigated by comparing the two implementations. The sensitivities of the finalist algorithms to plaintext, key and key length variations together with the possible reasons are studied and scrutinized. Three of the algorithms, MARS, RC6 and RIJNDAEL, are implemented on the same platform by using the assembler language. The results show that assembler implementations are improved with respect to C implementations 13% for MARS, 16-20% for RIJNDAEL and 21-28% for RC6.
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Kinnunen, T. (Tuija). "Keuhkoahtaumataudin sairaalahoito Suomessa: hoitoajan pituus ja sen yhteys ennusteeseen." Doctoral thesis, University of Oulu, 2007. http://urn.fi/urn:isbn:9789514283864.
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Abstract The purpose of this work was to determine on the basis of the national hospital discharge register and cause-of-death statistics the extent of the hospital treatment required for chronic obstructive pulmonary disease (COPD) in Finland over the period 1972–2001, i.e. the use made of hospital services, factors affecting the length of stay in hospital and the correlation of length of stay with the prognosis. Different intervals within this period were taken for study according to the themes of the individual papers. The results suggest that the length of stay in hospital varies both geographically and seasonally in Finland, the shortest times being recorded in Northern Finland in summer. The main explanations for this would appear to lie in regional differences in health care resources and treatment practises and in climatic variations. The mean length of stay in hospital in the total material in 1987–1998 was nine days. The longest periods applied to cases with concurrent pneumonia or a cerebrovascular disorder. The duration of treatment for the exacerbation stage of COPD decreased by two days between 1993 and 2001, with the longest periods of treatment observed in the case of elderly women. One week of treatment with current modalities may be regarded as optimal, as this was associated with the longest interval before the next exacerbation, just over six months. About 3% of all emergency admissions ended in death, most commonly on a Friday in winter or spring. Patients admitted at a weekend died within the first 24 hours more frequently than did those admitted on a weekday. The mean duration of treatment and frequency of hospitalization increased towards the terminal stage. About one fourth of the patients had died within a year of the first admission for COPD and about a half within five years. Hospital treatment for COPD intensified in Finland during the 1990s as the numbers of hospital beds decreased. Treatment times became shorter and deaths in hospital during exacerbation became less frequent. It will be necessary from now onwards, however, to anticipate the ageing of the population and to develop treatment modalities to replace hospitalization, in order to reduce the costs accruing from this disease. Early diagnosis and outpatient rehabilitation should be developed, and special attention should be paid to appropriate treatment at the terminal stageTiivistelmä Tutkimuksen tarkoituksena oli selvittää valtakunnallisen hoitoilmoitusrekisterin ja kuolemansyytilaston avulla keuhkoahtaumataudista (KAT) aiheutunutta sairaalahoitoa Suomessa 1972–2001: sairaalapalvelujen käyttöä, hoitojakson pituuteen vaikuttavia tekijöitä sekä hoitoajan yhteyttä ennusteeseen. Lähdeaineistosta valittiin erilaisia ajanjaksoja tutkimusasetelman mukaan. Tulokset viittaavat siihen, että hoitoajan pituus vaihtelee Suomessa maantieteellisesti ja vuodenaikojen mukaan: lyhyin hoitoaika on Pohjois-Suomessa kesällä. Ilmiötä selittänevät pääosin terveydenhuollon resurssien ja hoitokäytäntöjen alueelliset erot sekä ilmasto-olosuhteiden vaihtelu. Vuosina 1987–1998 keskimääräinen hoitoaika koko aineistossa oli yhdeksän vuorokautta. Jos potilaalla oli samanaikaisina sairauksina keuhkokuume tai aivoverenkiertohäiriö, nämä johtivat pisimpiin hoitoaikoihin. KAT:n pahenemisvaiheen hoitoaika lyheni kaksi vuorokautta vuodesta 1993 vuoteen 2001. Iäkkäitten naisten hoitoajat olivat pisimmät. Viikon pituinen hoitoaika nykyisillä hoitomuodoilla oli optimaalinen, sillä tällöin aika seuraavan pahenemisvaiheen hoitojakson alkuun oli pisin: vähän yli puoli vuotta. Kaikista päivystyshoitojaksoista potilaan kuolemaan päättyi kolmisen prosenttia. Yleisimmin tällainen hoitojakso päättyi potilaan kuolemaan perjantaisin ja todennäköisimmin talvella tai keväällä. Viikonloppuna sairaalaan tulleista potilaista kuoli ensimmäisen vuorokauden aikana enemmän kuin arkipäivinä tulleista. Keskimääräinen hoitoaika oli pisin ja sairaalahoito runsainta sairauden loppuvaiheessa kuoleman lähestyessä. Ensimmäisen KAT:n aiheuttaman hoitojakson jälkeen noin neljännes potilaista oli kuollut vuoden sisällä ja viiden vuoden kuluessa noin puolet. Keuhkoahtaumataudin sairaalahoito on tehostunut Suomessa 1990-luvulla sairaansijojen vähentyessä. Hoitoajat ovat lyhentyneet ja pahenemisvaiheiden sairaalakuolleisuus on vähäistä. Väestön ikääntyminen on kuitenkin ennakoitava ja sairaalaa korvaavia hoitomuotoja kehitettävä taudista aiheutuneiden kustannusten hillitsemiseksi. Varhaisdiagnostiikkaa ja avokuntoutusta on kehitettävä ja erityinen huomio kiinnitettävä sairauden loppuvaiheen asianmukaiseen hoitoon
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Butcher, Daniel S. A. "Influence of asymmetric valve timing strategy on in-cylinder flow of the internal combustion engine." Thesis, Loughborough University, 2016. https://dspace.lboro.ac.uk/2134/23327.
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Variable Valve Timing (VVT) presents a powerful tool in the relentless pursuit of efficiency improvements in the internal combustion engine. As the valves have such ultimate control over the gas exchange processes, extensive research effort in this area has shown how valve event timing can be manipulated to reduce engine pumping losses, fuel consumption and engine out emissions. Pumping losses may be significantly reduced by use of throttleless strategies, making use of intake valve duration for load control, while alternative cycles such as the Miller cycle allow modification of the effective compression ratio. More recently, the value of single valve operation in part load conditions is exploited, bringing with it the concept of asymmetric valve lifts. Work in this area found the side effect of asymmetric valve operation is a significant change in the behaviour of the in-cylinder flow structures, velocities and turbulence intensity. Work presented in this thesis exploits asymmetric valve strategies to modify the in-cylinder flow conditions. The Proper Orthogonal Decomposition (POD) is a method employed in the fluids dynamics field to facilitate the separation of coherent motion structures from the turbulence. In the presented work, the application of POD to in-cylinder flow analysis is further developed by the introduction of a novel method for identifying the POD modes representative of coherent motion and those representative of the turbulence. A POD mode correlation based technique is introduced and developed, with the resulting fields showing evidence of coherence and turbulence respectively. Experimental tests are carried out using a full length optically accessible, single cylinder research engine equipped with a fully variable valve train (FVVT) to allow full control of both valve timing and lift. In-cylinder flow is measured through the use of Particle Image Velocimetry (PIV) at several crank angle timings during the intake stroke whilst the engine is operated under a range of asymmetric valve strategies. The exhaust valves and one intake valve have their respective schedules fixed, while the second intake valve schedule is adjusted to 80\%, 60\%, 40\%, 20\%, 0\% lift. The resulting PIV fields are separated into coherent motion and turbulence using the developed technique, allowing for analysis of each constituent independently. The coherent element gives insight to large scale flows, often of the order of magnitude of the cylinder. These structures not only give a clear indication of the overall motion and allow assessment of flow characteristics such as swirl and tumble ratio, but the variation in the spatial location of these structures provides additional insight to the cyclic to cycle variation (CCV) of the flow, which would not otherwise be possible due to the inclusion of the turbulent data. Similarly, with the cyclic variation removed from the turbulent velocity field, a true account of the fluctuating velocity, u' and derived values such as the Turbulent Kinetic Energy (TKE) may be gained. Results show how manipulation of a one intake valve timing can influence both the large scale motions and the turbulence intensity. By the reduction of lift, the swirl ratio is increased almost linearly as the typical counter-rotating vortex pair becomes asymmetric, before a single vortex structure is observed in the lowest lift cases. A switching mechanism between the two is identified and found to be responsible for increased levels of CCV. With the reduction in lift, TKE is observed not only to increase, but change the spatial distribution of turbulence. Of course, the reduction in valve lift comes with the penalty of a reduced valve curtain area. However, it was identified both in literature and throughout this study that the reduction in lift did not negatively influence the engine breathing as the same trapped mass was achieved under all cases with no adjustment of manifold pressure. While literature shows both bulk motion and turbulence are key in liquid fuel break-up during the intake stroke, the mixing effects under port-injected natural gas were investigated experimentally using Laser Induced Fluorescence (LIF). The valve strategy was found to have no significant effect on the mixture distribution at the time of spark.
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Nyström, Catharina. "Gymnasisters skrivande : En studie av genre, textstruktur och sammanhang." Doctoral thesis, Uppsala universitet, Institutionen för nordiska språk, 2000. http://urn.kb.se/resolve?urn=urn:nbn:se:du-11019.
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Students in upper secondary school write in a number of different genres, and do this in school contexts as well as in their spare time. The study presented here is an overview of this activity and the genres concerned. The theoretical framework of the study is that of genre theory whereby genre is understood as a socially situated concept. The study is based on 2 000 texts gathered from students on different study programmes all over Sweden in the school year of 1996-97. The texts were written in different situations. The most important distinction made here is between test texts (i.e. texts from national tests) and self-chosen texts, which may come from schoolwriting or spare-time writing. The texts are categorized according to genre. This text inventory shows a repertoire of 33 different genres in the text material. A small number of genres, such as story, book-review and expository essay dominate the school writing. The test genres differ from this pattern in that they clearly imitate texts with a genuine communicative intent. The most frequent genres are studied further and each of them is demonstrated by an interpretative reading. This reading shows that the genres differ considerably with respect to genre character and stability of text structure. A quantitative study of text length and variation in vocabulary further shows that texts written by two categories of students, those on vocationally oriented programmes and those on programmes preparing for higher education, differ significantly. Reference cohesion is studied in a smaller sample of the texts. This lexico-semantic mechanism of cohesion proves to exhibit an interrelation with variation in vocabulary as well as with text type. One particular cohesive tie, inference, shows different patterns in texts written by the two categories of students mentioned above.
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Gardner, Michael D. "Scan-Based Near-Field Acoustical Holography on Partially Correlated Sources." Diss., CLICK HERE for online access, 2009. http://contentdm.lib.byu.edu/ETD/image/etd3167.pdf.
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Buterakos, Lewis A. "Bond length and bonded radii variations in nitride molecules and crystals." Thesis, This resource online, 1990. http://scholar.lib.vt.edu/theses/available/etd-03122009-040653/.
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Sun, Bin, and Wipawat Uppatumwichian. "A Study of Factors Which Influence QoD of HTTP Video Streaming Based on Adobe Flash Technology." Thesis, Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-2488.
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Recently, there has been a significant rise in the Hyper-Text Transfer Protocol (HTTP) video streaming usage worldwide. However, the knowledge of performance of HTTP video streaming is still limited, especially in the aspect of factors which affect video quality. The reason is that HTTP video streaming has different characteristics from other video streaming systems. In this thesis, we show how the delivered quality of a Flash video playback is affected by different factors from diverse layers of the video delivery system, including congestion control algorithm, delay variation, playout buffer length, video bitrate and so on. We introduce Quality of Delivery Degradation (QoDD) then we use it to measure how much the Quality of Delivery (QoD) is degraded in terms of QoDD. The study is processed in a dedicated controlled environment, where we could alter the influential factors and then measure what is happening. After that, we use statistic method to analyze the data and find the relationships between influential factors and quality of video delivery which are expressed by mathematic models. The results show that the status and choices of factors have a significant impact on the QoD. By proper control of the factors, the quality of delivery could be improved. The improvements are approximately 24% by TCP memory size, 63% by congestion control algorithm, 30% by delay variation, 97% by delay when considering delay variation, 5% by loss and 92% by video bitrate.
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Corniquel, Béatrice. "Construction de banques d'ADNc de palmier dattier (Phoenix dactylifera L. ). Différenciation de cultivars par RFLP à l'aide des ADNc : isolement et caractérisation d'un ADNc polymorphe. Isolement et caractérisation d'un ADNc codant pour la glutamine synthetase cytosolique." Angers, 1994. http://www.theses.fr/1994ANGE0014.
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La caractérisation des cultivars de palmier dattier a été réalisée par des analyses RFLP et RAPD à partir des feuilles internes des rejets. Des sondes ont été isolées d'une banque d’ADNc construite à partir d'ARNM extraits de cals organogènes du cultivar bou sthammi noire. La sonde ADNc 1 a permis d'obtenir neuf profils d'hybridation distincts pour chacun des neuf cultivars étudiés. Des profils d'amplification distincts pour trois cultivars ont été obtenus par RAPD avec des amorces oligonucléotidiques. Des analyses RFLP ont été aussi réalisées sur du matériel maintenu in vitro ou issu de culture tissulaire afin de déterminer si d'éventuelles variations induites par la culture in vitro affectaient le génome du palmier dattier. L'analyse moléculaire de la sonde ADNc 1 a été abordée. Le transcrit qui comprend 2400 nucléotides est exprimé dans les feuilles et les cals organogènes. Sa séquence partielle a été établie, l'absence d'homologie entre cette séquence de 1456 nucléotides et les séquences enregistrées dans les banques de données suggère que nous avons isole un ADNc codant pour une nouvelle protéine. Un ADNc codant pour la glutamine synthétase a été isolé. L'absence au niveau de la séquence des aminoacides de cet ADNc de l'extension c-terminale qui caractérise la structure primaire des séquences des sous-unités chloroplastiques montre que l’ADNc isole code pour la sous-unité cytosolique de la glutamine synthétase.
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Schreibman, Ken L. "Spectral analysis of cardiac cycle length variations in sinus and ventricular rhythms." Case Western Reserve University School of Graduate Studies / OhioLINK, 1990. http://rave.ohiolink.edu/etdc/view?acc_num=case1054827875.
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Rocha, Kelvin Raymond. "A variational approach for viewpoint-based visibility maximization." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/24816.
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Thesis (Ph.D.)--Electrical and Computer Engineering, Georgia Institute of Technology, 2008.Committee Chair: Allen R. Tannenbaum; Committee Member: Anthony J. Yezzi; Committee Member: Gregory Turk; Committee Member: Joel R. Jackson; Committee Member: Patricio A. Vela
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Nicoll, Jeffrey Scott. "Systematics of bond length and radii variations in flouride and silicate molecules and crystals." Thesis, This resource online, 1993. http://scholar.lib.vt.edu/theses/available/etd-08042009-040412/.
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Bartelmehs, Kurt Lane. "Bond length and bonded radii variations in sulfide molecules and crystals containing main group elements." Thesis, Virginia Polytechnic Institute and State University, 1987. http://hdl.handle.net/10919/91160.
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Molecular orbital calculations on 18 hydrosulfide molecules containing selected main group X-cations yield minimum energy bond lengths, Rt(XS), that reproduce those observed in chemically similar sulfide crystals. A least-squares analysis shows that Rt(XS) can be estimated by the equation R = l.83(s/r)-0.21, where s is the Pauling bond strength and r is the row number of the X-cation in the periodic table, with 98% of the variation of Rt(XS) being explained in terms of a linear dependence on R. In addition, R serves to rank observed XS bond lengths in sulfide crystals for main group X-cations for rows 1 through 5 of the periodic table to within 0.12Å on average, with R accounting for 96% of the variation in the observed bond lengths.
Bonded radii obtained from electron density maps calculated for the molecules show that the radii of both the X-cations and S atom increase with Rt(XS). A similar trend has been found to hold for the bonded radii and the Rt(XO) bond lengths calculated for hydroxyacid molecules (Finger and Gibbs 1985). The radius of S is smaller (1.16Å) when bonded to highly electronegative atoms like 4-coordinate As and larger (1.67Å) when bonded to a considerably less electronegative atoms like 4-coordinate Li but is smaller than Shannon's (1.70Å) crystal radius and Pauling's ionic crystal radius (1.84Å).M.S.
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MACRI', CARMELO NICODEMO. "Adaptations of plant species to environmental changes." Doctoral thesis, Università degli studi di Genova, 2020. http://hdl.handle.net/11567/1003150.
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The future climate change represents the biggest challenge for plant and animal species. The scenarios forecasted by the IPCC predict a global increase in temperatures and regional changes in rainfall during this century. Therefore, studying the relationship between climate and several traits of species is crucial in our understanding of the effects that future changes may have on plants. Species growing along a wide environmental gradient are a suitable study model to verify the relationship between intraspecific variability and both current and future climate. The aim of my PhD project is to analyse the relationship between environmental variability and variation in morphological traits, germination capacity and genetic structure of Lilium pomponium, using a multidisciplinary approach. The results of this study may enhance our understanding about the possible responses of this threatened species to environmental changes. Lilium pomponium is an endemism of the Ligurian and Maritime Alps spanning along a wide altitudinal gradient (100 and 2000 m a.s.l.), ranging from a Mediterranean to a subalpine climate. Our results show that the populations exposed to different environmental pressures have variations in floral characteristics, these variations likely play an important role in reducing among-populations variability in reproductive output. Germination tests show that the increase in temperature may negatively affect seeds germination capacity. Nevertheless, projections of thermal requirement for seed germination under future climatic conditions suggest that populations will probably respond to future temperature increase shifting their germination phenology. Moreover, in the future the species may find suitable ecological conditions for seed germination in new areas at higher altitudes. Finally, genetic analysis suggests that there is no clear pattern of diversity and differentiation between populations, which may be related to the topographic complexity of the areas and to the biogeographical history of the species. Overall, the results obtained suggest that high among-populations variability found in L. pomponium may be a bet-hedging strategy to cope with unpredictable environmental conditions occurring in Mediterranean climate and that it might also represent a successful strategy to face the future environmental change.
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Ulaganathan, Sekar. "The influence of light exposure and seasonal changes on short-term and longer-term changes in axial length of the human eye." Thesis, Queensland University of Technology, 2018. https://eprints.qut.edu.au/115840/1/Sekar_Ulaganathan_Thesis.pdf.
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Myopia (short-sightedness) is a common eye condition that is increasing in prevalence in the population. This research involved a longitudinal study examining the potential role of outdoor light exposure (and its seasonal variations) in the increased eye growth underlying myopia in young adults. Individuals spending less time in bright outdoor light were found to exhibit higher magnitude short-term daily fluctuations in eye length, as well as more rapid eye growth over 12-months. Seasonal variations in light exposure also appeared to impact upon eye growth. This research supports an important role for outdoor light exposure in myopia development in young adults.
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Vallicotti, Daniel [Verfasser], and Marc-André [Akademischer Betreuer] Keip. "Magneto-electro-mechanical coupling phenomena across multiple length scales : variational framework and stability analysis / Daniel Vallicotti ; Betreuer: Marc-André Keip." Stuttgart : Universitätsbibliothek der Universität Stuttgart, 2019. http://d-nb.info/1189662361/34.
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Jiborn, Catherine. "Actitudes lingüísticas hacia las variedadesdialectales del español : Un estudio sociolingüístico con profesores de españolcomo lengua extranjera (ELE) en Suecia." Thesis, Högskolan Dalarna, Spanska, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:du-28056.
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El propósito de este estudio es investigar las actitudes lingüísticas de tres grupos de profesores procedentes de España, Suecia y América Latina, hacia las variedades lingüísticas del español en la enseñanza del español como lengua extranjera (ELE) en Suecia.Los resultados, basados en un cuestionario con un grupo de informantes relativamente limitado, muestran que una clara mayoría opina que se debe enseñar tanto el español de Europa y de América Latina. Ninguno de los informantes tiene preferencia hacia el español de América Latina, mientras que una minoría considerable se inclina por un español de España. Esta actitud positiva hacia la variedad peninsular es más marcada entre profesores de origen español y entre los profesores que enseñan en el nivel primario en las escuelas suecas.En el cuestionario también se ha comparado la incorporación de aspectos gramaticales, lexicales y fonológicos. Se ha considerado que el grupo de informantes no es suficiente amplio como para poder generalizar los resultados.The purpose of this study is to investigate three groups of teachers from Spain, Sweden and Latin America regarding their attitudes towards the varieties of Spanish in the teaching of Spanish as a foreign language (ELE) in Sweden.The results, based on a questionnaire with a relatively limited group of informants, show that a big majority of informants believe that both the Spanish of Spain and Latin American Spanish should be taught. None of the informants had the preference for teaching Latin American Spanish, while a considerable minority was inclined towards Spanish from Spain. This positive attitude towards the peninsular variety is more recognized among teachers of Spanish origin and among the teachers who teaches at the primary school level in Sweden.Grammatical, lexical and phonological aspects have also been compared in the questionnaire but the number of informants in each group was too small for the results to be generalized.
34
Pecheniuk, Natalie Maria. "DNA analysis of common genetic variations which predispose to thrombophilia." Thesis, Queensland University of Technology, 2000.
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Olsson, Jens. "Interplay Between Environment and Genes on Morphological Variation in Perch – Implications for Resource Polymorphisms." Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-7212.
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Maubant, Louise. "Séismes lents et variations du couplage intersismique : le cas de la subduction Mexicaine vue par géodésie spatiale." Thesis, Université Grenoble Alpes, 2020. http://www.theses.fr/2020GRALU026.
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La multiplication depuis 20 ans d'observations de déformations transitoires au cours du cycle sismique a mis en avant la question de l'impact de ces déformations dans l'estimation de l'aléa sismique. Ainsi, dans les zones de subduction, le rôle des séismes lents sur la variabilité spatiale et temporelle du couplage intersismique et sur l'existence de lacunes sismiques est une question de première importance. Nous avons abordé cette problématique par l'analyse d'observations géodésiques et par la modélisation numérique, en se focalisant sur la subduction mexicaine. Cette zone est une cible pertinente pour étudier ces questions en raison de la présence de séismes lents qui font partie des plus grands observés au monde. La géométrie de cette subduction est également favorable aux observations géodésiques. Un premier volet de cette thèse a été consacré à l’étude du séisme lent de 2017-2018 qui a duré plusieurs mois dans la région de Guerrero. Pour cela, de nouvelles observations ont été faites par interférométrie radar satellitaires (InSAR) utilisant les données Sentinel-1, combinées aux données du réseau GPS permanent. Les données InSAR ont permis d’améliorer significativement la couverture et la résolution spatiale des mesures de déformation du sol par rapport aux études précédentes. La fréquence d’acquisition de ces données est de 6 à 12 jours. Un travail méthodologique sur l’extraction du signal tectonique inclus dans les séries temporelles InSAR a été nécessaire en raison de la grande superficie de la zone d’étude où sont présents de fort gradients topographiques. Deux méthodes de séparation de sources ont été employées. La première approche est une décomposition paramétrique, dans laquelle la forme fonctionnelle des signaux de déformation est imposée, et les signaux atmosphériques sont décrits en utilisant comme contrainte des séries temporelles de délais troposphériques zénithaux issus du GPS. La seconde approche utilise l’analyse en composantes indépendantes (ICA) des séries temporelles InSAR, ne nécessitant pas d’à priori sur le signal recherché. Les deux méthodes fournissent des résultats cohérents et permettent de séparer le signal atmosphérique, sans corrections préalables, du signal tectonique. A partir des cartes de séries temporelles de déplacements validées par les mesures GPS, le glissement du séisme lent sur l’interface de subduction est inversé. La distribution spatiale du glissement est cohérente avec celle des évènements précédents et confirme une localisation à la limite de la zone sismique. L’influence de séismes distants sur la cinématique de ce type d’évènement est également confirmée par ces observations.Dans une seconde partie, les déformations intersismiques sur une zone couvrant environ 1000 km de la subduction mexicaine de Jalisco à Oaxaca sont également analysées à partir de mesures InSAR et GPS. Les variations latérales de couplage le long de la subduction entre 2016 et 2019 sont établies pour la première fois de façon homogène sur l’ensemble de cette zone. Entre Michaocan et Jalisco, où de grands séismes ont eu lieu, on retrouve une zone à fort couplage. L’analyse montre bien l’importance que peuvent avoir à l’échelle de temps de quelques années les signaux transitoires comme les séismes lents sur la variabilité du couplage mesurée par géodésie spatiale. La dernière partie de cette thèse, aborde ce problème par une modélisation numérique du cycle sismique sur un plan de faille en 3D, basée sur des lois de friction de type « rate and state ». Cette modélisation permet de reproduire certaines caractéristiques de subduction mexicaine et de replacer les 20 ans d’observations géodésiques à l’échelle de plusieurs cycles sismiques. Les résultats préliminaires donnent des pistes de réflexions intéressantes sur la question de la possibilité qu’un séisme puisse se produire dans la lacune sismique de Guerrero et sur le rôle des séismes lents sur le faible couplage observé dans cette régionOver the last 20 years, the increasing number of transient deformation observations taking place during the seismic cycle has raised the question of their impact in estimating seismic hazard. Thus, in subduction zones, the role of slow slip events on spatial and temporal inter-seismic coupling variability and on the existence of seismic gaps is a matter of primary importance. We approached this problem by analyzing new geodetic observations and numerical modeling, focusing on the case of Mexican subduction. This area is a relevant target to study these issues thanks to the presence of slow slip events, which are among the largest observed in the world. The geometry of this subduction zone is also very favorable for geodetic measurements. The first part of this thesis is devoted to the study of the slow slip event of 2017-2018, which lasted several months in the Guerrero region. To achieve this, new observations have been made using satellite radar interferometry (InSAR) from Sentinel-1 data, in combination with data from the permanent GPS network. InSAR data have significantly improved the coverage and spatial resolution of ground deformation measurements compared to previous studies. The data acquisition frequency is between 6 and 12 days. Methodological developments were necessary to allow the extraction of tectonic signals included in the InSAR time series, due to the large extent of the study area, its strong topographic gradients, and the strong atmospheric perturbations that polluted the signal. Two source separation methods were used. The first approach consists of a parametric decomposition: the deformation signals' functional shapes are imposed, and the atmospheric signal is described using time series of zenithal tropospheric delays extracted from GPS as a constraint. The second approach uses Independent Component Analysis (ICA) of the InSAR time series, which does not require any a priori on the desired signal. Both methods provide consistent results and allow separating the atmospheric signal from the tectonic signal without prior corrections. Using time-series displacement maps validated by GPS measurements, the slow slip event on the subduction interface is inverted. The slip's spatial distribution is consistent with that of previous events and confirms a localization at the edge of the seismic zone. These observations also confirm the influence of distant earthquakes on this type of event's kinematics.The second part of this study analyzes the interseismic deformations in an area covering about 1000 km of the Mexican subduction from Jalisco to Oaxaca using InSAR and GPS measurements. Lateral coupling variations along the subduction between 2016 and 2019 are determined for the first time homogeneously over this zone. Between Michoacan and Jalisco, where large earthquakes took place, we find a zone with strong coupling. The analysis demonstrates the importance of transient signals such as slow slip events over a few years on the variability of the coupling measured by spatial geodesy. The last part of this thesis addresses this problem using numerical modeling of the seismic cycle along a 3D fault plane, based on "rate and state" type friction laws. This modeling allows us to reproduce specific characteristics of Mexican subduction and place the 20 years of geodetic observations at the scale of several seismic cycles. The preliminary results provide interesting insights into the possibility that an earthquake could occur in the Guerrero seismic gap and the role of slow slip events on the weak coupling observed in this region
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Walter, Claudia. "Simulationen hydrologischer Massenvariationen und deren Einfluss auf die Erdrotation." Doctoral thesis, [S.l. : s.n.], 2008. http://nbn-resolving.de/urn:nbn:de:bsz:14-ds-1205946097808-36130.
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Ricci, Monia. "Analisi del segnale elettroencefalografico acquisito durante movimenti lenti e veloci dell'arto superiore." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2020. http://amslaurea.unibo.it/19910/.
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Questo lavoro di tesi ha riguardato l’acquisizione e l’elaborazione di segnali elettroencefalografici (EEG) registrati su 18 volontari mentre veniva loro chiesto di eseguire uno specifico task motorio, ovvero flesso-estensione dell’arto superiore destro a due diverse velocità, per indagare possibili differenze nei segnali EEG associate alla velocità di esecuzione del movimento. Il protocollo sperimentale è stato strutturato in tre blocchi intervallati da una breve pausa di riposo. Ogni blocco consta di 90 trial: si susseguono in maniera random 30 comandi ‘slow’ (il soggetto deve muoversi lentamente), 30 comandi ‘fast’ (il soggetto deve muoversi velocemente), 30 comandi ‘rest’ (il soggetto deve restare fermo). Ogni trial inizia con 1 s di rilassamento; segue il primo segnale (‘cue’ una scritta con l’indicazione del task da eseguire); in corrispondenza alla sua scomparsa si presenta il secondo segnale (‘go’ un beep di 10 ms che indica al soggetto di eseguire il task); infine sono concessi al soggetto 5 s durante i quali eseguire il task. Le elaborazioni sono state condotte sui 16 segnali EEG e su un segnale accelerometrico, acquisiti rispettivamente mediante elettrodi premontati su cuffia e sensore inerziale fissato sul dorso della mano destra. Sono stati analizzati i seguenti correlati neurali del movimento: contingent negative variation, un potenziale di anticipazione motoria identificato nel dominio del tempo tra ‘cue’ e ‘go’; event-related de/synchronization, un incremento/decremento di potenza, osservabile in specifiche bande di frequenza (alpha e beta) e in specifici intervalli nelle mappe tempo-frequenza. Per valutare infine la significatività dei risultati ottenuti si è condotta un’analisi statistica (t-test). Sebbene i risultati ottenuti non evidenzino differenze significative nelle caratteristiche del segnale EEG tra i movimenti ‘slow’ e i movimenti ‘fast’, lo studio si pone come importante punto di partenza per investigazioni future.
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Glane, Sebastian [Verfasser], Wolfgang H. [Akademischer Betreuer] Müller, Wolfgang H. [Gutachter] Müller, and Kolumban [Gutachter] Hutter. "Variations in the length of day of the earth due to topographic core-mantle coupling in a stratified layer / Sebastian Glane ; Gutachter: Wolfgang H. Müller, Kolumban Hutter ; Betreuer: Wolfgang H. Müller." Berlin : Technische Universität Berlin, 2021. http://d-nb.info/1224965914/34.
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Walter, Claudia. "Simulationen hydrologischer Massenvariationen und deren Einfluss auf die Erdrotation." Doctoral thesis, Technische Universität Dresden, 2007. https://tud.qucosa.de/id/qucosa%3A24143.
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Die gestiegene Messgenauigkeit der Erdrotationsparameter ermöglicht inzwischen eine Berücksichtigung von Sekundäreffekten, wie Einflüssen hydrologischer Massenvariationen. Variationen der Erdrotation durch hydrologische Massenvariationen sind bisher weniger gut als atmosphärische und ozeanische Beiträge erforscht. Zur Interpretation, Analyse und Zuordnung von Signalen in den Erdrotationsparamtern wurden mit einem Landoberflächenschema und einem lateralen Abflussmodell langjährige hydrologische Simulationen unter Antrieb aus verschiedenen globalen Atmosphärenmodellen durchgeführt. Diese Simulationen erlaubten die Durchführung von Sensitivitätsstudien über die Abhängigkeit simulierter hydrologischer Beiträge zur Erdrotation von den atmosphärischen Antrieben und der Modellphysik. Alle relevanten hydrologischen Größen wurden auf Plausibilität mit Beobachtungsdaten oder anderen Simulationsergebnissen validiert. Neben dem Beitrag der vertikalen Wasserbilanz wurde auch der Beitrag des lateralen Wassertransportes auf die Erdrotation explizit untersucht. Erstmalig konnte der hydrologische Bewegungsterm quantifiziert werden. Die simulierten hydrologischen Drehimpulsfunktionen wurden schließlich im Kontext des globalen Wasserkreislaufes den beobachteten Erdrotationsparametern gegenübergestellt. Es ergab sich eine besonders gute Übereinstimmung für die hydrologische [chi2]-Komponente mit Residuen aus Beobachtungen und simulierten atmosphärischen und ozeanischen Variationen der Erdrotation.The increasing accuracy of observation of the Earth's rotation allows the consideration of so called secondary effects like the influence of hydrological mass redistributions. Variations of the Earth's rotation due to hydrological influences are yet less investigated than atmospheric and oceanic contributions. In order to analyse, interprete and associate signals in the parameters of the Earth's rotation, longtime hydrologic simulations were performed by forcing a land-surface scheme and a lateral discharge model with data of various global atmospheric models. By these simulations, the dependency of simulated hydrologic contributions to the variations of the Earth's rotation on atmospheric forcing and on the model physics was studied. All relevant hydrologic quantities were validated against observed or modelled values to evaluate their plausibility. In addition to the contribution of the vertical water balance to the variations of the Earth's rotation also the contribution of lateral water transport was explicitely investigated. For the first time the hydrologic motion term was quantified. Eventually, the simulated hydrological angular momentum functions were compared in the context of the global water cycle against observed parameters of the Earth's rotation. The hydrological component of [chi2] did show a very good agreement with residuals of observations and simulated atmospheric and oceanic variations of the Earth's rotation.
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Vaxelaire, Béatrice. "Etude comparee des effets des variations de debit - lent, rapide- surles parametres articulatoires, a partir de la cineradiographie (sujets francais)." Université Marc Bloch (Strasbourg) (1971-2008), 1993. http://www.theses.fr/1993STR20055.
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Ce travail porte sur la comparaison de deux debits articulatoires -lent, rapide pour la realisation des consonnes (p,t,k,b,d,s) du francais, en position inaccentuee intervocalique et en groupes de consonnes, pour 14 parametres articulatoires. La methode d'analyse se fonde sur l'exploitation de films radiologiques avec synchronisation image son. Le debit en tant que duree d'emission peut faire devier une realisation articulatoire de sa trajectoire "habituelle". En effet, il ne resulte pas une simple compression lineaire d'une acceleration de debit. La consideration spatio-temporelle montre que les articulaters sont plus ou moins resistants et operants. Les articulateurs font preuve d'adaptation a la vitesse du geste, en realisant des modifications de leurs mouvements, telles que reduction, assimilation, optimisation etn renforcement articulatoire. Le debit rapide necessite une reorganisation articulatoire. Dans les cas d'anticipation, une nouvelle strategie des articulateurs se met en place. Le debit rapide et des manifestations articulatoires illustrent un fait d'organisation motrice, et les modifications des mouvements des articulateurs s'inscrivent dans une dynamique globale du geste articulatoireThe aim of this thesis is the study of the effects of variations of sheech rates - slow, fast- on the articulatory parameters. This work is to evaluate with the technique of cinemradiography the comparative articulatory beghavior of stop consonants (d, t, k, b, d, g) used in case of french speech production, in unstresed intervolsatic positions and in consonant clusters for 14 parameters. Presented in this study is and examination ascross rates conditions and consequences on the behavior of the articulators. We show that fast rate implies a fow reduction of the articulatory gestures and some compensatory interarticulator gestures. Thers is an adaptation of the articulators to the spedd of the movement through new movements and new anticipatory gestures. A nex strategy of movements emerges with undershoot and overlapping in the dynamical gesture
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Colot, Olivier. "Apprentissage et détection automatique de changements de modèles : application aux signaux électroencéphalographiques." Rouen, 1993. http://www.theses.fr/1993ROUES012.
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La thèse présentée traite du problème de la détection de changements de modèles dans des signaux vectoriels lentement variables. L'étude s'articule autour de deux thèmes: modélisation vectorielle, détection de changements de modèles. Le premier thème est traité sous l'angle d'une technique récursive de modélisation linéaire, tirant profit des propriétés de stationnarité locale des signaux étudiés dans un contexte vectoriel. Dans une seconde partie, le problème de la détection de changements de modèles est étudié. Deux approches sont proposées et testées: la première s'appuie sur un critère d'énergie d'erreurs issues de la modélisation, la seconde est fondée sur la comparaison d'histogrammes approchant des lois de probabilité, les histogrammes étant construits à l'aide d'un critère de type Akaike. La détection de changements de modèles, synonymes de changements de lois, est effectuée à l'aide de mesure de dissemblance. La validation de ces méthodes est réalisée sur des signaux biomédicaux: les signaux électroencéphalographiques
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Sadat, Hamou. "Une nouvelle méthode de modélisation des transferts thermiques en régime graduellement varié." Poitiers, 1988. http://www.theses.fr/1988POIT2349.
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Methode de modelisation orginale, pouvant permettre une representation d'ordre reduit de systemes thermiques instationnaires, notamment a evolution lente, par un developpement en serie obtenu a partir de la solution de l'etat permanent perturbe par le terme de derivee temporelle. Application a la resolution de l'equation de la chaleur, validee sur des exemples de conduction unidimensionnelle. Application au cas des ponts thermiques du batiment en regime variable
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Muñoz, Claudio. "Dynamique et collision de solitons pour quelques équations dispersives nonlinéaires." Phd thesis, Université de Versailles-Saint Quentin en Yvelines, 2010. http://tel.archives-ouvertes.fr/tel-00497710.
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Dans cette thèse, nous étudions quelques propriétés dynamiques des solutions de type soliton de quelques équations dispersives nonlinéaires généralisées. La première partie de ce travail est consacrée à l'étude de l'existence, de l'unicité et du comportement global de solitons pour des équations de KdV généralisées, à variation lente. On donnera une description détaillée de la dynamique pour tout temps et on montrera la non-existence de solitons purs, ce qui est une très grande différence avec l'équation gKdV standard. Dans une deuxième partie, on étudiera le cas de l'équation de Schrödinger nonlinéaire. Pour cette équation, nous allons améliorer tous les résultats précédents en donnant une description précise pour tout temps de la dynamique du soliton dans le régime à variation lente. En plus, sous des hypothèses générales, on montrera ce résultat dans le cas 2-D. Finalement, on considère le problème de collision de deux solitons pour l'équation de KdV généralisée. Complétant les résultats récents de Martel et Merle, concernant le cas quartique, nous montrons que la seule possibilité d'avoir une collision de type élastique est donnée par les cas intégrables. La preuve de tous ces résultats sont des développements et des améliorations de la théorie de Martel et Merle pour la collision de deux solitons des équations gKdV sous différents régimes asymptotiques.
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Bacques, Guillaume. "Étude de variations spatio-temporelles de glissements asismiques le long de failles majeures par Interférométrie RADAR Différentielle satellitaire : Cas du séisme lent de 2009-2010 de Guerrero (Mexique) : Cas de la déformation postsismique suite au séisme de Parkfield (2004, Mw6, Californie)." Thesis, Grenoble, 2013. http://www.theses.fr/2013GRENU044/document.
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La caractérisation des distributions spatio-temporelles des déformations transitoires le long de failles actives constitue actuellement l’un des axes privilégiés de recherches visant la compréhension des processus contrôlant le cycle sismique. Dans ce contexte, nous nous intéressons à deux sites d’études aux caractéristiques comportementales distinctes: la lacune sismique de Guerrero, siège de 4 séismes lents depuis 1997 (zone de subduction, d’une longueur de 100 km à l’ouest d’Acapulco au Mexique, dernière rupture en 1911, temps de récurrence ~4 ans) et le segment de Parkfield (segment de 20-30 km le long de la faille de San Andreas, Californie, 7 ruptures successives -Mw6- depuis 1857, temps de récurrence de ~22 ans). Dans le cas du Mexique, nous portons notre attention sur le séisme lent de 2009-2010 survenu au niveau de la lacune sismique et, dans le cas du segment de Parkfield, nous décrivons la déformation post-sismique suite au séisme du 28 septembre 2004, dernière rupture en date de ce segment, sur la période 2005-2010. Nous utilisons l’interférométrie radar différentiel satellitaire (DINSAR), complété de données GPS, pour estimer les faibles déformations (centimétriques) générées en surface par ces types de déformations. À l’issue de ce travail, dans le cas de la lacune sismique de Guerrero, nos mesures semblent montrer que le séisme lent de 2009-2010 affecte la partie sismogène de la lacune tout en affectant une portion de la subduction qui dépasse les limites géographiques de celle-ci. Dans le cas de Parkfield, nous parvenons à mettre en avant une prolongation temporelle jusqu’en 2010 du glissement post-sismique en plus d’une extension spatiale de ce glissement qui dépasse les limites de la rupture de 2004. Ces nouveaux éléments permettent de discuter plus en avant l’impact de ces déformations transitoires sur le comportement de ces systèmes de failles situés tout deux, sur des sites d’intérêts scientifiques majeursCharacterizing the spacio-temporal evolution of transient deformations along active faults is, by now, one of the most promising ways to better understand the mechanisms that drive the seismic cycle. In this context, we focused our attention on two areas that exhibit different characteristic behaviour types: the Guerrero seismic gap, a location of 4 consecutive slow slip events since 1997 (subduction zone, 100 km long westward from Acapulco, Mexico, last ruptured in 1911, repeating time ~4 years) and the Parkfield segment (20-30 km long segment, San Andreas fault, California, 7 successive breaks -Mw6- since 1857, repeating time ~22 years). In the case of Mexico, we particularly focused our attention on the 2009-2010 slow slip event that occurred at the gap location. In the case of Parkfield, we described the post-seismic deformation related to the 28th September 2004 Mw6 event (last recorded break) from 2005 to 2010. We used space-based differential radar interferometry (DINSAR) in addition to GPS data, to assess surface displacements at centimeter scale that are in relation with those two phenomena. As an outcome of the work, in the Guerrero seismic gap case, our measurements indicate that the 2009-2010 slow slip event has affected the seismogenic part of the gap and extents outside the spatial limits of it. In the case of Parkfield, our measurements indicate that the Parkfield segment has a post-seismic behaviour that lasts until 2010 at least and spatially extends outside the edge the 2004 coseismic trace along the fault line. These elements allow us to discuss the implication of such transient deformations in the two particular cases of the Guerrero seismic gap and the Parkfield segment, both of first scientific interest
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Cárcamo, García Marina. "Las actitudes y creencias de aprendientes brasileños de ELE hacia las variedades diatópicas del español : El caso de las formas de tratamiento." Thesis, Stockholms universitet, Romanska och klassiska institutionen, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-131069.
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En Brasil, la variación lingüística diatópica adquiere relevancia en la enseñanza de español como lengua extranjera, debido a la situación geográfica del país entre Hispanoaméricana y a causa de sus relaciones económicas y culturales, por una parte, con los demás países latinoamericanos, cuya lengua oficial es el español, y por otra, con España. El presente trabajo se centra en el estudio de las actitudes y creencias lingüísticas hacia las variedades diatópicas del español por parte de estudiantes universitarios brasileños de ELE, ya que dichas actitudes y creencias desempeñan un importante papel en la motivación que tienen por aprender, y por ende, en su grado de adquisición de la lengua extranjera. Además de estudiar sistemáticamente las percepciones y las actitudes en relación con las variedades del español, este estudio busca investigar concretamente las actitudes hacia las formas de tratamiento en español (tú, vos, usted, vosotros y ustedes), ya que suponen realizaciones lingüísticas ciertamente variables, tanto geográfica como estilísticamente. Asimismo, contemplamos analizar si existen relaciones entre la proficiencia lingüística de los encuestados, su perfil académico y el contacto que tienen con hablantes de variedades de español y las actitudes generales que declaran tener hacia tales variedades. En base a datos empíricos, consideramos las implicaciones que tienen los resultados para la enseñanza de ELE en un contexto en el que el español se concibe como una lengua pluricéntrica. Para investigar estas variables, utilizamos un cuestionario, que suministramos a 60 estudiantes que cursan español en el Centro de Ensino de Línguas de la Universidade Estadual de Campinas y que, además, realizan sus estudios en esta misma universidad. A través de técnicas de observación de actitudes tanto directas como indirectas, y mediante el estudio cuantitativo y cualitativo de las variables que analizamos, concluimos que existe una prevalencia por las variedades latinoamericanas con respecto a la variedad peninsular por parte de los estudiantes brasileños de ELE, lo cual supone un contraste con investigaciones previas realizadas en este ámbito. En el caso de las actitudes hacia las formas de tratamiento, los resultados de la investigación muestran que no existe una correspondencia de estas actitudes con las actitudes generales hacia las variedades diatópicas, puesto que la forma vos, característica exclusivamente de variedades latinoamericanas, se concibe como una de las menos utilizadas y una de las más innecesarias en el uso de la lengua española.In Brazil, diatopic language variation gains importance in the teaching of Spanish as a foreign language, due to the geographic situation of Brazil between Spanish America and as a result of its economic and cultural relations, on the one hand, with the other Latin American countries, whose official language is Spanish, and on the other hand, with Spain. This paper focuses on the study of attitudes and linguistic beliefs towards diatopic varieties of Spanish by Brazilian students of Spanish as a Foreign Language (SFL), since such attitudes and beliefs play an important role in motivating students to learn, and therefore, in their acquisition level of the foreign language. Apart from systematically studying the perceptions and attitudes regarding the diatopic varieties of Spanish, this study seeks to specifically investigate attitudes towards the forms of address in Spanish (tú, vos, usted, vosotros and ustedes), because it is a variable linguistic topic, both geographically and stylistically. Furthermore, it studies the relationship between language proficiency of the students, their academic profile and their contact with speakers of varieties of Spanish as well as the general attitudes that they have towards Hispanic varieties. Based on empirical data, the discussion considers implications for teaching of SFL in a context where Spanish is conceived as a pluricentric language. To investigate all these variables, a questionnaire was distributed to 60 Brazilian students enrolled in the Spanish courses of the Language Learning Centre at the University of Campinas, who also follow their undergraduate and posgraduate studies at the same university. Using both direct and indirect observation techniques regarding attitudes, and quantitative and qualitative analysis, the paper concludes that there is a preference for the Latin American varieties compared to the Peninsular varieties amongst Brazilian students of Spanish. These results are different from the ones presented in previous research in this area. In the case of attitudes towards the forms of address in Spanish, the results show that there is no correspondence of these attitudes with the general attitudes towards diatopic varieties, since vos, which is exclusively characteristic of the Latin American varieties, is conceived as one of the least used and most unnecessary forms in Spanish.
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Niraula, Dipesh. "Physics and applications of conductive filaments in electronic structures: from metal whiskers to solid state memory." University of Toledo / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1561471348406944.
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Castellà, Josep M. "La Complexitat lingüística en el discurs oral i escrit: densitat lèxica, composició oracional i connexió textual." Doctoral thesis, Universitat Pompeu Fabra, 2002. http://hdl.handle.net/10803/7486.
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La present tesi consisteix en una anàlisi compativa de tres gèneres de discurs ?conversa informal (llengua oral prototípica), classe magistral (gènere intermedi) i prosa acadèmica (llengua escrita prototípica)? en català, en tres aspectes de l'estructuració i la complexitat lingüística: la densitat lèxica, la composició oracional i la connexió textual (total: 90 trets lèxics, gramaticals i textuals analitzats). Els objectius principals són a/ dotar la lingüística catalana d'una descripció detallada, fins ara inexistent, del contrast lingüístic entre oralitat i escriptura, i b/ fer una aportació a la recerca internacional sobre el tema per intervenir, d'una banda, en el debat originat sobre la complexitat sintàctica i, especialment, sobre la presència d'oracions subordinades en els dos modes de discurs i, de l'altra, per ampliar aquesta mena d'investigació a l'àmbit del discurs, com han reclamat alguns tractadistes.La presente tesis consiste en un análisis comparativo de tres géneros de discurso ?conversación informal (lengua oral prototípica), clase magistral (género intermedio) y prosa académica (lengua escrita prototípica)? en catalán, en tres aspectos de la estructuración y la complejidad lingüística: la densidad léxica, la composición oracional y la conexión textual (total: 90 rasgos léxicos, gramaticales y textuales analizados). Los objetivos principales son a/ dotar la lingüística catalana de una descripción detallada, hasta ahora inexistente, del contraste lingüístico entre oralidad y escritura, y b/ hacer una aportación a la investigación internacional sobre el tema para intervenir, por un lado, en el debate originado sobre la complejidad sintáctica y, especialmente, sobre la presencia de oraciones subordinadas en los dos modos de discurso y, por otro lado, para ampliar este tipo de investigación al ámbito del discurso, como han reclamado algunos tratadistas.
The present work consists of a comparative analysis of three discourse genres --informal conversation (prototypical oral language), academic lecture (intermediate genre), and academic prose (prototypical written language)-- in Catalan, focusing on three aspects of linguistic structure and complexity: lexical density, sentence composition, and textual connexion (total: 90 lexical, grammatical, and textual features analysed). The main purposes are: (a) to provide Catalan linguistics with a detailed description --non-available so far-- of the linguistic opposition between literacy and speech; and (b) to make a contribution to the international research in this field in order to, on the one hand, participate in the discussion about the syntactic complexity, and, especially, about the presence of subordinated clauses in the two modes of discourse, and, on the other, extend this kind of research to the discourse level, as some researchers have claimed.
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BHATI, PRIYANKA. "SIMULATION AND ANALYSIS OF CONTACT LENGTH VARIATION IN TOP CONTACT AND BOTTOM CONTACT ORGANIC FIELD EFFECT TRANSISTOR." Thesis, 2016. http://dspace.dtu.ac.in:8080/jspui/handle/repository/14569.
Full textAbstract:
Research into organic eld e ect transistors (OFETs) has made signi cant advances both scienti -
cally and technologically during the last decade, and the rst products will soon enter the market.
Printed electronic circuits using organic resistors, diodes and transistors may become cheap alterna-
tives to silicon-based systems, especially in large-area applications.
In OFET organic semiconductor used in the simulation is pentacene which is a p-type semicon-
ductor. It works in the accumulation mode. When gate voltage and drain voltage is applied. This
simulation is done with ATLAS. ATLAS is simulation software.
In this thesis work variation in the contact length is observed. How small contact can be obtained.
Contact material used in OFET source and drain is Au (Gold). We can reduce the cost by using less
amount of Au. If contact length is reduced the cost is reduced. By reducing the contact length we
can reduce the geometry of the device. This can be used in the nano organic device.
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"Variation in Telomere Length Control, Senescence and Genetic Instability in Saccharomyces yeast." Tesis, Universidad de las Américas Puebla, 2005. http://catarina.udlap.mx/u_dl_a/tales/documentos/lbi/guzman_b_nd/.
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