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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Establishment Methods of Arundinaria Species for Restoration Purposes

Russell, David Pierce 11 August 2012 (has links)
Rivercane, Arundinaria gigantea, is the native woody evergreen grass that has exhibited rapid population decline since European colonization of North America. Agriculture and urban expansion have reduced this important ecosystem type to remnant populations. This poses challenges to current restoration efforts by minimizing genetic diversity and limiting healthy host sites for propagation. Objectives of this research were to test four methods of establishment that would promote the greatest survivability and growth of propagules. Non-irrigated field studies indicated greatest rivercane growth response when planted in increased shade (60 - 85% light reduction). Monthly plantings indicated that February offered the greatest probability of survival. Application of slow release 19-6-12 fertilizer (33.3 g) enhanced growth, but fertilizer applications are not recommended without adequate soil moisture. Halosulfuron (72.6 g a.i./ha) applications for weed control showed no damage to rivercane plants compared to control.
2

Index selection in terminal sire sheep: implications for genetic improvement in a crossbreeding system

Marquez Betz, Gabriela Carolina 30 December 2013 (has links)
Using terminal sires for crossbreeding is standard practice in the UK sheep industry, where over 70% of market lambs have terminal sire breeding. Thus, selection focusing on terminal sires will translate to changes in the entire industry. Consumers perceive lamb meat as fatty and demand for it has decreased. A lean growth index was developed for terminal sire breeds to increase carcass lean content while keeping fat constant at a constant age end point. The purposes of this study were: to evaluate the effects of index selection of terminal sires on their crossbred offspring up to harvest; to evaluate the effectiveness of the index within the terminal sire breeds; to evaluate the presence and consequences of heterogeneous environmental variances and genetics by environment interactions (GxE) on genetic evaluation. The most widely used breeds of terminal sires in the UK are Charollais, Suffolk, and Texel. These breeds participated in sire referencing schemes from the early 1990s by sharing rams selected on the lean growth index. From 1999 to 2002 approximately 15 high and 15 low lean growth index score rams per breed were selected from their sire referencing schemes and mated to Welsh and Scottish Mule ewes. Their crossbred offspring were reared on 3 farms in the UK under commercial conditions. In total, 6,515 lambs were born between 2000 and 2003. Lambs were weighed at birth (BWT), 5 weeks (5WT), and 10 weeks (10WT). The average daily gain (ADG) from birth to 10 weeks was calculated. Lambs were finished to an estimated 11% subcutaneous fat by visual examination. At harvest, they were weighed (HWT), ultrasonically scanned for muscle (UMD) and fat (UFD) depth, and assessed for condition score and conformation. Lambs sired by high index rams were on average, across breeds, heavier at all ages (P < 0.01) with 0.07 ± 0.03, 0.3 ± 0.1, 0.4 ± 0.1, and 1.2 ± 0.2 kg greater BWT, 5WT, 10WT, and HWT respectively. Their ADG was 5.1 ± 1.9 g/d greater than low index sired lambs. They had thicker UMD (0.7 ± 0.2 mm) and thinner UFD (0.08 ± 0.01 mm). High vs. low index sired lambs took the same amount of days to reach harvest fatness. Suffolk-sired lambs were on average heavier, with greater ADG, whereas Charollais-sired lambs were lightest with smallest ADG. Texel-sired lambs had thicker UMD than Charollais (0.7 ± 0.2 mm; P < 0.001) but were not different than Suffolk. Charollais-sired lambs had greater UFD than both Texel- (0.098 ± 0.016 mm) and Suffolk- (0.061 ± 0.017 mm) sired lambs (P < 0.001). Texel-sired lambs reached harvest condition faster than the other breeds (P < 0.01). Index selection produced heavier and leaner lambs at finishing. Producers have flexibility in choosing the terminal sire that best fits their production system. Heteroscedascity and GxE were found to be more important for ultrasonic traits than weight traits. Fitting a farm by sire random interaction component improved model fit, but only accounted for less than 2% of the variation in weight traits. For ultrasonic traits, it accounted for at least 10% of the variation. When fitting traits as separate but correlated by farm, genetic correlations among traits were mostly above 0.8, indicating no GxE. Reactions norms for sires were fitted. For weight traits and UMD, sires had positive slopes (were environmentally sensitive) that were similar in value, thus performance improved with improving environments. For UFD, reaction norm slopes varied form negative to positive, indicating GxE. Consequences of heteroscedasticity are not large for these data, and any consequence of GxE on breeding goals should be evaluated before explicitly modeling it in genetic evaluation. There was evidence of genetic variation in sensitivity of sires; therefore, they could be selected to be more or less sensitive depending on economic considerations. / Ph. D.
3

The relationship between the TeacherInsight™ interview scores and student performance as measured by the Texas Growth Index.

Koerner, Robert Jacob 08 1900 (has links)
In their efforts to make the selection and hiring process more efficient, school administrators utilize teacher selection instruments such as the Web-based TeacherInsight™ assessment tool (The Gallup Organization, Princeton, NJ). Tools such as these instruments are now used regularly by school systems across the nation to assess teachers regarding their knowledge, talents, skills, attitudes, and values. According to Gallup, the TeacherInsight is a predictor of teacher talent and is based on 12 themes. This study utilized 132 elementary and secondary teachers and approximately 4,500 students currently enrolled in Grades 3 through 11 to determine if the TeacherInsight is a predictor of student achievement. This study considered: (1) the relationship between the TeacherInsight and student achievement as measured by the Texas Growth Index (TGI); (2) the relationship between teacher characteristics (years of experience, level [primary or secondary], gender, age, degree) and the TeacherInsight instrument; (3) the relationship between teacher characteristics (years of experience, level [primary or secondary], gender, age, degree) and student achievement as measured by the TGI; and (4) the relationship between student classifications (limited English proficient, economically disadvantaged, at-risk) and student achievement as measured by the TGI. The analyses found a very weak positive relationship between the TeacherInsight and student achievement using the TGI in the subjects of English/ reading and math. Additional analysis based on levels (primary and secondary) between TeacherInsight scores and TGI values were not significant. Teacher characteristics were poor predictors of scores on the TeacherInsight. Of the characteristics, years of teaching experience was the strongest predictor of scores on the TeacherInsight. Although the overall analyses indicated significant relationships, they were very weak for both English/reading and math. Teacher characteristics were also poor predictors of student achievement. Again, the overall analysis indicated a significant but weak relationship for both English/reading and math. When considering the relationship between student classifications of LEP, economically disadvantaged, and at-risk, only at-risk had a weak relationship to student achievement. The findings provide little support to the validity of TeacherInsight in terms of its ability to predict student achievement scores and its usefulness as a tool for the selection of teachers by school systems. Until more extensive research is completed on the TeacherInsight and its impact on student achievement, no definitive answers for school systems can be made. Suggestions and recommendations for future studies are provided in the discussion section.
4

PROGRESIVNÍ VÝROBNÍ POSTUPY A MODELOVÁNÍ STRUKTUR A VLASTNOSTÍ LITIN S KULIČKOVÝM GRAFITEM / PROGRESSIVE PRODUCTION PROCESSES AND SIMULATION OF STRUCTURES AND PROPERTIES OF SPHEROIDAL GRAPHITE CAST IRON

Musilová, Iveta January 2010 (has links)
The thesis is concerned with relationships between progressive technological processes of spheroidal graphite cast iron’s production and their structural properties. The aim of the work is to explain causal relationship between parameters of the proposed manufacturing technology of the iron type given (involving selected variants of modification and inoculation of melt and the parameters of melt crystallization, solidification and cooling down in a mould), their structure and even chemical heterogeneity of elements in this structure. For close specification of presented relationships three-dimensional model of spheroidal graphite growth was used, which was developed at the Brno University of Technology, Faculty of Mechanical Engineering. Its usability in praxis has been verified on the basisis of the application of this model on experimentally acquired data. The U GRAFIT 20 model of the authors Stránský and Million counting segregation in the frame of eutectic cell has not still been used for prediction of segregation in real condition in greater extent. On the basis of the above mentioned model microsegregation within “on average” of the cell has been discovered during experimental melts. Microsegregation has been described by segregation and heterogeneity indexes. Calculated values of segregation and heterogeneity indexes have been compared with experimentally verified values. On the basis of comparison of calculated and measured values the possibility of further usage of the mentioned model in praxis has been explored.
5

Evaluation of moisture safety in cold attic and external wall designs commonly used in the building sector

Saleh, Yad January 2020 (has links)
Kontinuerligt försvårade och mer krävande energikrav utlyst från den Europeiska unionen ochsvenska myndigheter har lett till en förändring av hur konstruktionsdetaljer och lösningar somanvänds inom nyproduktionssektorn utformas. Förändringarna har skapat en osäkerhet ur enfuktsäkerhetssynpunkt. Uttökade krav och förbättrad energiprestanda låter som ett problemfrittideal att sträva efter, dock har det i många fall lett till oförutsägbara konsekvenser i olika delar avbyggnaden. Två av de byggnadskomponenter som påverkats har varit ytterväggar och kallvindarsom har varit utformade utefter nya energikrav i nyproducerade hus.Den största utmaningen med utformningen av nyare kallvindar har varit balansgången mellanhög energiprestanda genom ökad isoleringstjocklek och fuktsäkerhet. Ökad isoleringstjocklekkombinerat med minimerad värmeförlust från ventilationsaggregat, inomhus och skorstenar harlett till, i överlag, kallare vindutrymmen med ökad risk för kondensation av fukt på kallare ytor ijämförelse med äldre byggnader. En lösning på detta har varit inkluderingen av uteluftsventileringi utformningen av vinden. Detta har lett till en återkommande fråga angående den optimalaluftomsättningen som krävs för utökad fuktsäkerhet, och i vissa fall, om uteluftsventilering ensär nödvändig.En annan stor utmaning har varit att säkerhetsställa fuktsäkerheten i väggar som är isolerade ien högre grad. Det finns en potentiell risk för kondens i kalla, yttre ytor om isoleringen utökas.Utöver detta så existerar det en hel del lösningar som har fungerat i det förflutna men som lärleda till ökad risk för skada när det kombineras med nya utformade lösningar som uppfyllerenergikraven.Detta arbete har fördjupat sig i dessa två komponenter, ytterväggar och kallvindar, för atthitta kritiska designval som har en stor påverkan på fuktsäkerheten. Arbetet har skett medsimuleringsprogrammen IDA ICE och WUFI 6. Båda programmen har kombinerats för attuttnyttja deras styrkor i simuleringsprocessen.Resultatet visar att en låg luftomsättning är optimal. Ingen ventilering alls lär leda till ökadfukthalt och ökad luftomsättning lär leda till en betydligt högre risk för mögel på råsponten ivinden. Placeringen av ett litet isoleringslager ovanpå råsponten leder till en minskad risk förmögel.Ytterväggar med tjockare isolering är mer benägna att skadas i jämförelse med mindre isoleradeväggar. Dock är det visat att en uttökad isoleringstjocklek även kan vara till fördel för att minskamögelrisken om isoleringslagret som uttökas är det yttersta isoleringslagret. Ett annat krav är attdet yttersta lagret bör ha dränerande egenskaper, exempelvis mineralull. Beräkningarna har ävenpåvisat ett antal andra faktorer som påverkar fuktsäkerheten i dess helhet.
6

Explorer la physique de l'accélération cosmique / Exploring the physics of cosmic acceleration

Steigerwald, Heinrich Maria 02 March 2015 (has links)
L'expansion accélérée de l'univers est devenu un fait établi que personne ne pouvait prévoir il y a encore une vingtaine d'années. Pour expliquer l'accélération cosmique, l'univers doit être composé de $75%$ d'énergie noire, une matière hypothétique à pression négative. Une alternative aussi vertigineuse consiste à modifier la relativité générale d'Einstein à l'échelle cosmique.Mes travaux de thèse portent sur la contrainte des modèles d'énergie noire et de gravité modifiée avec les données observationnelles provenant de la croissance linéaire des structures cosmologiques. Une méthode basée sur une nouvelle paramétrisation de l'index de croissance des perturbations linéaires cosmologiques permet d'analyser un grand nombre de modèles "accélératoires" en même temps. Nous avons évalué et validé cette méthode par une analyse systématique de sa précision et de sa performance. Mes résultats montrent que le modèle standard de la cosmologie (le modèle $Lambda$CDM) reste en accord avec les données actuelles. Dans une étude approfondie, nous simulons les contraintes possibles avec les futures sondes cosmologiques de "précision" comme Euclid. Pour analyser encore plus de modèles en même temps, nous introduisons la théorie effective des champs de l'énergie noire (EFT) dans le formalisme développé auparavant. La EFT est un formalisme prometteur qui permet d'explorer d'une manière complète tous les modèles gravitationnels non-standards résultant de l'addition d'un degré de liberté supplémentaire dans l'équation d'Einstein. Nous proposons une paramétrisation de cette théorie que nous confrontons avec les données actuelles et futures. / The accelerated expansion of the universe has become an established fact that nobody could foresee until twenty years ago. To explain the cosmic acceleration, the universe must be composed by $75%$ of dark energy, a hypothetical form of matter with negative pressure. Alternatively, Einstein's field equation must be modified on cosmic scales. During my thesis I have worked on the constraint of dark energy and modified gravity models with data coming from the observed growth rate of cosmic structures. We have introduced a method based on a new parametrization of the growth index of linear cosmological perturbations. An advantage is the possibility of a concurrent analysis of multiple accelerating models. We have evaluated and validated the method in a systematic precision and performance check. My results show that the standard model of cosmology (the $Lambda$CDM model) remains consistent with current data. In an ongoing study, we have simulated future constraints for upcoming cosmological 'precision' probes like Euclid.In a second step, we introduce the effective field theory of dark energy (EFT) into our formalism. The EFT is a promising framework that allows to explore in a complete way all non-standard gravitational models that result from adding one degree of freedom in Einstein's field equation. Another advantage is its neat split of background and perturbation observables. We propose a parametrization of the EFT that we confront with current and simulated future constraints.
7

Optimalizace návrhu moderních nízkoenergetických dřevostaveb / Optimizing the design of modern low-energy wooden houses

Vahalová, Eva January 2017 (has links)
The main aim of the thesis was focused on hygrothermal simulation of critical details of two prefabricated wooden buildings - especially connections of the perimeter wall to monolithic foundations, respectively with waterproofing layer. The composition of the external walls of these selected buildings has quite different compositions and thus different potentials of drying integrated moisture from the components. Practical measurement of moisture weight-content was applied to the wooden bottom plate, which is in direct contact with the concrete slab structures. The influence of different design solutions on hygrothermal characteristics of the wooden plate was examined with regards to the risk of mould growth, analysis of mass loss due to the decay fungi and with the aim to estimate the durability of the studied details of prefabricated wooden houses. The subsequent research focused on the differences in physical and mechanical properties of natural spruce wood (Untreated, (-), A) and impregnated spruce (Treated, (+), B) using supercritical CO2 and its possible impact on wood protection for mould growth. Samples of identical Untreated and Treated spruce were collected in the laboratory and subjected to thermal and hygrothermal experiments. The comparison of the resulting values of the individual experiments is presented. Required values needed for numerical calculations were obtained from these experiments. In conclusion, the summary of founded comparison is presented. The mould growth analysis and its influence on the durability of wooden structures offer a view of the behaviour of the structures. Relevant findings and recommendations for the future praxis are mentioned.
8

Post-traumatic Spiritual Growth in the LGBTQ+ Community in the Midwestern US After Experienced Religious Trauma

Allen, Ryan Joseph 16 December 2022 (has links)
No description available.

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