• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 1481
  • 1124
  • 553
  • 524
  • 210
  • 153
  • 120
  • 113
  • 56
  • 39
  • 37
  • 34
  • 33
  • 21
  • 20
  • Tagged with
  • 5034
  • 1048
  • 954
  • 948
  • 546
  • 518
  • 351
  • 338
  • 326
  • 323
  • 226
  • 203
  • 188
  • 182
  • 159
  • 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.
331

The transfer of training and skills by Texas State 4-H Council members: A qualitative study

Bruce, Jacklyn Antoinette 30 September 2004 (has links)
This study examined the elements that affect the transfer of training and skills by Texas State 4-H Council members. It described the patterns of motivation and learning styles of former State 4-H Council members, as well as the demonstration of leadership life skills. This study also described the leadership experiences of former State 4-H Council members after their council year concludes. The researcher used a purposive sampling technique to identify former members of the Texas State 4-H Council who were willing to discuss their experiences. A snowball sampling technique was used in which the members of the first group identified the remainder of the sample. There were fifteen individuals interviewed. Traditional qualitative research methodologies were used to collect and triangulate data. These methods included interviews, participant observation, and document analysis. The researcher used documented methods of dependability (dependability audit and reflexive journaling), transferability (thick description, purposive sample, and reflexive journaling), confirmability (confirmability audit and the reflexive journal), and credibility (persistent observation, triangulation, peer debriefing, member checking, and reflexive journaling) to establish trustworthiness. The major findings of the study were as follows: 1) State 4-H Council members tend to be extrinsically motivated individuals that follow self-determining pattern of motivational needs including the needs for a sense of competence, inter-relatedness, and autonomy; 2) Eight of the State 4-H Council members demonstrated a mix of social learning theory and experiential learning theory during the years of preparation prior to attaining their State 4-H Council positions; 3) State 4-H Council members demonstrated a command of the seven leadership life skill categories; and 4) The transfer of skills and knowledge by State 4-H Council members is affected both positively and negatively by the elements of training transfer. Recommendations include implementation of a needs assessment to determine training content and greater experiential training opportunities. The addition of personality types, gender and sensitivity training, and positive conflict resolution should be added to training agendas. State 4-H Council members should be afforded greater decision-making power, beyond that of deciding themes for state events.
332

Amidate complexes of the group 4 metals : sythesis, reactivity, and hydroamination catalysis

Thomson, Robert Kenneth 05 1900 (has links)
A series of bidentate amidate ligands with variable groups R' and R" abbreviated by [R"(NO)R'] and adamantyl substituted tetradentate amidate ligands abbreviated by Ad[0₂N₂] were utilized as ancillaries for Ti, Zr, and Hf. Protonolysis routes into homoleptic amidate complexes, tris(amidate) mono(amido), bis(amidate) bis(amido), and bis(amidate) dibenzyl complexes are high yielding when performed with tetrakis(amido) and tetrabenzyl group 4 starting materials. Many of these complexes have been characterized in both the solid-state and in the solution phase, where in the latter case these complexes are fluxional and undergo exchange processes. Multiple geometric isomers are possible with the mixed N,0 chelate provided by the amidate ligands, and geometric isomerization of bis(amidate) bis(amido) complexes has been examined through X-ray crystallographic and density functional theory (DFT) calculations. Isomerization is dictated largely by the steric bulk present at the N of the amidate ligands, and is proposed to proceed through a K²-K¹-K² ligand isomerization mechanism, which is supported by crystallographic evidence of K¹-bound amidate ligands. The amidate ligand system binds to these metals in a largely electrostatic fashion, with poor orbital overlap, generating highly electrophilic metal centers. The bis(amidate) dibenzyl complexes of Zr and Hf are reactive towards insertion, abstraction, and protonolysis. Insertion of isocyanides into the Zr-C bonds of [DMP(NO) tBu]₂Zr(CH₂Ph₂ results in the formation of ƞ₂-iminoacyl complexes, which can either undergo thermally induced C=C coupling to generate an enediamido complex (aryl isocyanides), or rearrange to generate a bis(amidate) bis(vinylamido) complex (alkyl isocyanides). Benzyl abstraction to generate cationic Zr bis(amidate) benzyl complexes is also possible through reaction with [Ph₃C][B(C₆F₅)4] or B(C₆F₅)₃ Terminal imido complexes with novel pyramidal geometries are generated through protonolysis of bis(amidate) bis(amido) Ti and Zr complexes with primary aryl amines. DFT calculations demonstrate the existence of a Zr⁻₌N triple bond for these complexes. Dimeric imido complexes have been characterized in the solid state, but are not maintained in solution. Cycloaddition reactions of the terminal Zr imido complexes with C=0 bonds result in the formation of proposed oxo complexes and organic metathesis products. Catalytic aminoalkene cyclohydroamination has also been realized with these complexes, generating N-heterocyclic products. A series of kinetic and labeling studies support an imido-cycloaddition mechanism for catalytic cyclohydroamination of primary aminoalkenes with neutral bis(amidate) Ti and Zr precatalysts. The intermediate Ti imido complex, K²-[Dipp(NO)tBu-K¹_[DiPP(No) tBu]Ti=NCH₂CPh₂CH₂CH=CH₂(NHMe₂), has been isolated and characterized in the solid-state and in solution. Amine stabilized imido complexes of this type are invoked as the resting state for the catalytic reaction, and solution phase data support a chair-like geometry, where the alkene is coordinated to the metal center. A diastereoselectivity study supports this proposed solution structure. Eyring and Arrhenius parameters, as well as isolation of a 7-coordinate model imido complex, support a seven-coordinate transition state for the rate-determining metallacycle protonolysis reaction. In contrast, secondary aminoalkene hydroamination catalysis with cationic Zr benzyl complexes is proposed to proceed through a σ-bond insertion mechanism. Proton loss from cationic Zr amido complexes to generate imido species is proposed with primary aminoalkenes, and the resultant neutral imido complexes can catalyze the cyclization of these substrates by the aforementioned imido-cycloaddition mechanism. The ability of the amidate ligand system to promote both mechanisms is unique in the field of alkene hydroamination catalysis.
333

Plate-forme ouverte pour contenus et traitements multimédias en ligne

Le Bonhomme, Benoît 14 December 2009 (has links) (PDF)
L'émergence des contenus multimédias sur Internet, l'accès aux contenus multimédias et leurs enrichissements constituent un vaste domaine de recherche. Cette thèse s'inscrit dans ce contexte, et présente la réalisation complète et opérationnelle d'une plate-forme de diffusion multimédia interopérable et ouverte. Après avoir spécifié l'architecture de la plate-forme en introduisant le support de tous types de médias, l'indexation efficace, la recherche de contenus et leurs visualisations en ligne, la première contribution de cette thèse est une extension de la norme MPEG 7 permettant d'assurer la gestion des contenus graphiques 3D, ainsi que des informations liées à un système multimédia. Cette extension a permis le développement d'une plate-forme de diffusion gérant tous types de contenus, appelée MyMultimédiaWorld.com, entièrement normalisée à l'aide de MPEG 7 et MPEG 4. La deuxième contribution porte sur les facilités d'accès à la plate-forme multimédia. D'une part, nous avons développé une solution simple et originale d'API d'accès aux contenus multimédia par de applications tierces. D'autre part, nous proposons une solution basée sur le principe d'API pour intégrer dans une plate-forme des algorithmes multimédias. Cette solution permet la création de nouveaux services à partir d'algorithmes externes. A partir des deux APIs, nous proposons une nouvelle approche pour l'évaluation automatique d'algorithmes multimédias. Les aspects clés de cette approche sont l'évaluation en ligne, des conditions identiques pour l'exécution des algorithmes et la mise à jour automatique des résultats. L'approche développée est démontrée à l'aide de deux benchmarks différents, le premier pour l'évaluation des algorithmes de compression de maillage 3D et le second pour le benchmark des descripteurs de formes 3D développé dans le cadre des projets FAME2 et POPS du pôle de compétitivité System@tic. Les avantages de cette approche ont été reconnus récemment par le comité de normalisation MPEG avec sa décision d'adopter www.MyMultimédiaWorld.com pour l'évaluation des algorithmes de compression de maillage 3D.
334

Active Shape Model Segmentation of Brain Structures in MR Images of Subjects with Fetal Alcohol Spectrum Disorder

Eicher, Anton 01 December 2010 (has links)
Fetal Alcohol Spectrum Disorder (FASD) is the most common form of preventable mental retardation worldwide. This condition affects children whose mothers excessively consume alcohol whilst pregnant. FASD can be identied by physical and mental defects, such as stunted growth, facial deformities, cognitive impairment, and behavioural abnormalities. Magnetic Resonance Imaging provides a non-invasive means to study the neural correlates of FASD. One such approach aims to detect brain abnormalities through an assessment of volume and shape of sub-cortical structures on high-resolution MR images. Two brain structures of interest are the Caudate Nucleus and Hippocampus. Manual segmentation of these structures is time-consuming and subjective. We therefore present a method for automatically segmenting the Caudate Nucleus and Hippocampus from high-resolution MR images captured as part of an ongoing study into the neural correlates of FASD. Our method incorporates an Active Shape Model (ASM), which is used to learn shape variation from manually segmented training data. A discrete Geometrically Deformable Model (GDM) is rst deformed to t the relevant structure in each training set. The vertices belonging to each GDM are then used as 3D landmark points - effectively generating point correspondence between training models. An ASM is then created from the landmark points. This ASM is only able to deform to t structures with similar shape to those found in the training data. There are many variations of the standard ASM technique - each suited to the segmentation of data with particular characteristics. Experiments were conducted on the image search phase of ASM segmentation, in order to find the technique best suited to segmentation of the research data. Various popular image search techniques were tested, including an edge detection method and a method based on grey prole Mahalanobis distance measurement. A heuristic image search method, especially designed to target Caudate Nuclei and Hippocampi, was also developed and tested. This method was extended to include multisampling of voxel proles. ASM segmentation quality was evaluated according to various quantitative metrics, including: overlap, false positives, false negatives, mean squared distance and Hausdorff distance. Results show that ASMs that use the heuristic image search technique, without multisampling, produce the most accurate segmentations. Mean overlap for segmentation of the various target structures ranged from 0.76 to 0.82. Mean squared distance ranged from 0.72 to 0.76 - indicating sub-1mm accuracy, on average. Mean Hausdorff distance ranged from 2:7mm to 3:1mm. An ASM constructed using our heuristic technique will enable researchers to quickly, reliably, and automatically segment test data for use in the FASD study - thereby facilitating a better understanding of the eects of this unfortunate condition.
335

Music of numbers [printed music] : nine pieces for two players and pianoforte.

Solomon, Ian Bernard. January 1981 (has links)
No abstract available. / Thesis (M.Mus.)-University of Natal, Durban, 1981.
336

Revision och Kreditbetyg : Vilken betydelse har revision för kreditbetyget?

Gallo Jonsson, Caroline, Gydell, Sofie January 2014 (has links)
No description available.
337

Efter Energiutmaningen : Vad hände med undervisningen i fysik?

Nilsson, Amanda January 2013 (has links)
The purpose of this thesis is to try to find out what effect subject oriented projects like Energiutmaningen has on the teachers, with a focus on teachers’ physics education. What was the experience for the teachers who participated and what effects did the project have on them. Four teachers were interviewed through qualitative interviews. From the result it showed that the most experienced teachers, who have been teaching physics for many years, gained a new perspective of their teaching, through their participation a development showed in their education. Before Energiutmaningen the practical teaching mostly consisted of strict laboratory exercises. The main reason was due to the time allotted that held back a more stimulating education. Today, the teachers are utilizing more open-ended laboratory exercises, instead of the more strict, and are developing their education with aspect to the students. Instead of just trying to capture the students’ interest, they are today more focused on challenging and trying to raise the students to a higher level. The teachers achieved this by including more open- ended laboratory exercises and by having more focus on the communication in physics as a subject.  The project has also contributed to give the least experienced teacher a higher sense of security, since she doesn’t have as much experience as the others in teaching physics. For the least experienced teacher the development was focused on a higher sense of security in teaching physics. Before the project she didn’t have much self-confident in her teaching, due to her limited knowledge. The results after the project shows that she now has a bigger sense of security in her teaching, but this is not something she can put to use due to her not teaching physics today.
338

The perceived role of the youth agent as viewed by 4-H adult and junior leaders

Caldwell, William E. January 1973 (has links)
The major purpose of the study was to analyze perceptions of Area Extension Agents - Youth held by local 4-H adult leaders and junior leaders. In general, the study was designed to ascertain whether differences in perception between the two groups, categorized by age do, in fact, occur. More specifically, the hypotheses and sub-hypotheses were used to analyze differences in perceptions of 4-H adult leaders and junior leaders on; (1) ''real'' and ''ideal'' behavior of the youth agent, and (2) initiating structure and consideration dimensions of leadership behavior.The population for the study was defined as all 4-H adult leaders and junior leaders in Indiana during the year of 1972. Twenty counties were randomly selected from the total 92 Indiana counties for participation in the study. The Area Extension Agents Youth of the sample counties were requested to submit a list of 4-H adult leaders and junior leaders. The list was used to randomly select a sample of fifty 4-H adult leaders and fifty junior leaders for data collection. The LBDQ instrument which measures two dimensions of leadership, initiating structure and consideration, was used to collect data needed for the analysis. Four-H adult leaders and junior leaders were randomly assigned to the 'ideal' and 'real" forms of the questionnaire to maintain unbiased predictions of the population. Instruments completed by the individual respondents were coded by age group and by county.A 2 x 2 factorial analysis of variance design, accompanied by subsequent individual mean comparisons, was employed for analysis of the data. The F test for significance was applied for decision with regard to four major hypotheses and eight sub-hypotheses with an alpha of .05.The following conclusions were supported by the findings of the study: 1. The level of expectations for initiating structure-leadership with respect to clearly delineated relationships between the youth leader and the group, well-defined patterns of organization, channels of communication, and ways of getting the job done--is higher among Indiana 4-H adult leaders than the younger junior leader counterparts. Four-H adult leaders desire a more structured form of leadership.2. Expecations of 4-H adult leaders are the same as expectations of junior leaders with regard to youth agent consideration-leadership behavior indicative of friendship, mutual trust, respect, and warmth. Both groups have high levels of expectations.3. Junior leaders are better satisfied with the leadership of youth agents than are adult leaders with regard to both leadership dimensions, initiating structure and consideration.4. Youth leaders are not meeting the ideal expectations either group, the junior leaders or the adult leaders.
339

Naturen som läromästare : En studie av några pojkars och flickors aktivitet vid utomhusundervisning / Nature as a teacher -a study of some boys and girls activity in outdoor education

Henriksson, Maria January 2013 (has links)
Studiens syftevaratt undersöka flickorsoch pojkars aktiviteter utomhus och hur de eventuellt skiljde sig åt.Teoretiska utgångspunktervar skilda perspektiv på lärandeutifrån utomhuspedagogisk forskning och klassrumsforskning med genusperspektiv. Som metodvaldes observation utifrån ett observationsschema samt kontinuerliga dagboksanteckningar om elevernas sätt att använda sina sinnen, deras rörelsemönster och verbala kommunikation samt förekomsten av gruppkonstellationer och deras engagemang. Resultatet av observationerna presenterasutifrån varje skolas förutsättningar för utomhusundervisning, organisation och upplägg avaktivitet och det visar att eleverna till stor del var passivt deltagande men aktivt lyssnande. Devar delaktiga i de organiserade aktiviteterna. Den huvudsakliga skillnaden mellan pojkarna och flickorna visade att pojkarna var mer lekfulla, mer aktiva och rörliga. Det var främst desom söktenaturföremål. Flickorna fann sin trygghet ikonstellationer av två och två eller fyra. Pedagogens roll skilde sigåt mellanårskurserna, hur de var aktiva samt på vilket sätt de kommuniceradeverbalt med de deltagande eleverna.
340

New amine-substituted cyclopentadienyl and indenyl ligands

Marsh, Sarah Margaret Beatrice January 1997 (has links)
This thesis concerns the new amine-substituted cyclopentadiene and indene ligands C(_5)H(_5)(CH(_2))(_3)N((^t)Bu)H and C(_9)H(_7)(CH(_2))(_3)N((^t)Bu)H which can co-ordinate to a metal through all five carbon atoms of the five-membered ring (η(^5)) and/ or through the nitrogen (σ). Chapter 1 reviews the recent literature concerning Lewis-base functionalised cyclopentadienyl and indenyl ligands and their compounds with s-, p-, d- and f-block metals. Chapter 2 contains a brief review of possible synthetic routes to amine-substituted cyclopentadienyl and indenyl ligands with some examples from the recent literature, and a detailed account of the synthesis of C(_5)H(_5)(CH(_2))(_3)N((^t)Bu)H and C(_9)H(_7)(CH(_2))(_3)N((^t)Bu)H. The amino alcohol (^t)BuNH(CH(_2))(_3) OH was synthesised by the conjugate addition of (^t)BuNH(_2) to ethyl acrylate and reduction of the product ester (^t)BuNH(CH(_2))(_2)C0(_2)Et using LiAIH(_4). (^t)BuNH(CH(_2))(_3)OH was converted into (^t)BuNH(CH(_2))(_3)Br.HBr and (^t)BuNH(CH(_2)(_3)Cl.HCl by reaction with HBr or SOCI(_2). Reaction between (^t)BuNH(CH(_2))(_3)C1.HC1 and two equivalents of Na(C(_5)H(_5)) gave C(_5)H(_5)(CH(_2))(_3)N((^t)Bu)H in good yield. Treatment of (^1)BuNH(CH(_2))(_3)C1.HC1 with excess NaOH followed by reaction with Li(C(_9)H(_7)) gave C(_9)H(_7)(CH(_2))(_3)N((^t)Bu)H, also in good yield. Chapter 3 describes the synthesis of various main group and iron compounds of C(_5)H(_5)(CH(_2))(_3)N((^t)Bu)H and C(_9)H(_7)(CH(_2))(_3)N((^t)Bu)H. Lithium salts Li[C(_5)H(_4)(CH(_2))(_3)N((^t)Bu)H], Li[C(_5)H(_4)(CH(_2))(_3)N((^t)Bu)]Li, Li[C(_9)H(_6)(CH(_2))(_3)N((^t)Bu)H] and Li[C(_9)H(_6)(CH(_2))(_3)N((^t)Bu)]Li were prepared for use as reactive intermediates and Li[C(_5)H(_4)(CH(_2))(_3)N((^t)Bu)H] was characterised as its THF-adduct by (^t)H NMR spectroscopy. The silyl derivatives (Me(_3)Si)C(_5)H(_4)(CH(_2))(_3)NH(^t)Bu and (Me(_3)Si)C(_5)H(_4)(CH(_2))(_3)N((^t)Bu)SiMe(_3) were synthesised and characterised by NMR spectroscopy, and (Me(_3)Si)C(_9)H(_6)(CH(_6))(_3)N((^t)Bu)H and (Me(_3)Si)C(_9)H(_6)(CH(_2))(_3)N((^t)Bu)(SiMe(_3)) were also synthesised. The anune-substituted ferrocene Fe{η(^5)-C(_5)H(_4)(CH(_2))(_3)N((^t)Bu)H}(_2) was synthesised and oxidised to the corresponding ferricenium ion which was isolated as its PF(_6)(^-) salt. Exploratory work was carried out into the preparation of heterobimetallic species by reaction between Fe{η(^5)-C(_5)H(_4)(CH(_2))(_3)N((^t)Bu)H}(_2) and MX(_2) (M = Co, Ni, X = CI, M = Mn, X = Br). The substituted bis(indenyl) iron(II) complex Fe{η(^5)-C(_9)H(_6)(CH(_2))(_3)N((^t)Bu)H}(_2) was also synthesised. Chapter 4 is an account of the chemistry of {η(^5) :σ-C(_5)H(_4) (CH(_2))(_3)N(^t)Bu}Ti(NMe(-2))(_2) which was synthesised by an aminolysis reaction between C(_5)H(_5)(CH(_2))(_3)NH(^t)Bu and Ti(NMe(_2))(_4) Reaction between this compound and various weak acids gave a range of new compounds including{η(^5):σ-C(_5)H(_4)(CH(_2))(-3)N(^t)Bu} Ti(O(^t)Pr)(_2), {η(^5):σ-C(_5)H(_4)(CH(_2))(_3)N(^t)Bu)(_2), {η(^5):σC, {η(^5):σ-C(_5)H(_4)(CH(_2))(_3)N(^t)Bu}Ti(C(_5)H(_5))(NMe(_2)) , {η(^5):σ-C(_5)H(_4)(CH(_2))(_3)N(^t)Bu}Ti(SnBu(_3))(_z) and the imido-bridged dimer [{η(^5):σ-C(_5)H(_4)(CH(_2))(_3)N(^t)Bu}Ti(NHPh)](_2)(µ-NPh)2, the X-ray structure of which is reported. Chapter 5 describes the experimental procedures used, and chapter 6 gives lists of characterising data for each compound. Appendix A gives details of the methods used for magnetic susceptibility determinations; appendix B lists X-ray crystallographic data for [ {η(^5):σ-C(_5)H(_4)(CH(_2))(_3)N(^t)Bu}Ti(NHPh)](_2)(µ-NPh)(_2) and appendix C lists departmental colloquia attended.

Page generated in 0.0436 seconds