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Students who are deaf and use sign language frequently have language delays that affect their literacy skills. Students who use American Sign Language (ASL) often lack fluent language models in both the home and school settings, delaying both the development of a first language and the development of literacy in printed English. Mediated and scaffolded instruction presented by a More Knowledgeable Other (MKO; Vygotsky, 1978, 1994) may facilitate acquisition of a first foundational language. Repeated viewings of fluent ASL models on DVDs paired with adult mediation has resulted in increases in vocabulary skills for DHH students who used ASL (Cannon, Fredrick, & Easterbrooks, 2010; Golos, 2010; Mueller & Hurtig, 2010). Classifiers are a syntactic sub-category of ASL vocabulary that provides a critical link between ASL and the meaning of English phrases. The purpose of this study was to investigate the effects of teacher-mediated repeated viewings of ASL stories on DHH students’ classifier production during narrative retells. This study included 10 student participants in second, third, and fourth grades and three teacher participants from an urban day school for students who are DHH. The researcher used a multiple baseline across participants design followed by visual analysis and calculation of the percentage of non-overlapping data (PND; Scruggs, Mastropieri, & Casto, 1987) to examine the effects of the intervention. All students increased their classifier production during narrative retells following a combination of teacher mediation paired with repeated viewings of ASL models.

The aim with this study was to investigate the effects a change of manufacturing process would have on the mechanical properties of drill bits made of a WC/Co composite used for stone cutting. The method used today is sintering, where the material is heated in a conventional sintering oven. The other method was microwave sintering, where the material is heated by radiation in the microwave region. Also an investigation of the manufacturing cost were made. The main difference between the two heating methods is that the conventional way is a rather slow process and the microwave method is very fast. The material is also heated homogeniously in the method with mirowaves, aposed to the case with the conventional sintering where the material is heated from the outside in. This makes the material harder and more wear resistent. Another positive effect is that the pysical properties of the drill bits is easier to controll, because of the very small grain growth due to the short process time.The cost of manufacturing these drill bits by microwave sintering does not exceed the cost of the conventionall sintering.

Thin polyurethane films have been widely used as erosion-resistant coatings on helicopter rotor blades. Published research has mainly focused on empirical studies that relate the mechanical properties such as rebound resilience and hardness of polyurethane to solid particle erosion resistance. However polyurethane possesses phase mixing at multiple scales and thus sand particle erosion resistance depends also on the micro structure and the phase mixing. Hence, it is very important to carry out detailed and systematic investigations to understand the step-by-step mechanism of erosion and how it relates to the polyurethane micro, meso, and macrostructure. Thermal transitions of the pristine films have been studied through Differential Scanning Calorimetry (DSC) and Dynamic Mechanical Analysis (DMA) yielding micro-scale information such as glass transition temperatures of the hard and soft segments and melting temperature of the soft segment. The next stage of our study involved sand particle erosion tests carried out at 500 mph, at an impact angle of 30 degrees. Test specimens were exposed to two different sand media at different mass loadings ranging from 0.1 to 20 g/cm^2. The tools of characterization used on the pristine polyurethane are once again used on the eroded specimens, with the goal to compare pre- and post- erosion results. The comparison of FTIR results on pre-eroded and eroded films reveal the removal of macromolecular bonds corresponding to soft segments in the micro scale. The reduction of the crystalline portion of the soft segment observed from DSC results supports the FTIR findings. Scanning electron microscopy (SEM) images of the eroded specimens are used to correlate the sequence of the damage due to erosion. The observations revealed that after initial ductile deformation of the soft segments on the surface, brittle cracks are formed on the hard segments. The increased exposure to sand particles leads to formation of fragments containing mainly soft segments with cracks in the hard segments propagating in a brittle manner. As exposure increases, cracks intersect and material on the surface gets removed which mainly contains the soft segments as revealed by the FTIR and DSC results.

NP-hard problems have numerous applications in various fields such as networks, computer systems, circuit design, etc. However, no efficient algorithms have been found for NP-hard problems. It has been commonly believed that no efficient algorithms for NP-hard problems exist, i.e., that P6=NP. Recently, it has been observed that there are parameters much smaller than input sizes in many instances of NP-hard problems in the real world. In the last twenty years, researchers have been interested in developing efficient algorithms, i.e., fixed-parameter tractable algorithms, for those instances with small parameters. Fixed-parameter tractable algorithms can practically find exact solutions to problem instances with small parameters, though those problems are considered intractable in traditional computational theory. In this dissertation, we propose a new approach of algorithm design and analysis: discovering better measures for problems. In particular we use two measures instead of the traditional single measure?input size to design algorithms and analyze their time complexity. For several classical NP-hard problems, we present improved algorithms designed and analyzed with this new approach, First we show that the new approach is extremely powerful for designing fixedparameter tractable algorithms by presenting improved fixed-parameter tractable algorithms for the 3D-matching and 3D-packing problems, the multiway cut problem, the feedback vertex set problems on both directed and undirected graph and the max-leaf problems on both directed and undirected graphs. Most of our algorithms are practical for problem instances with small parameters. Moreover, we show that this new approach is also good for designing exact algorithms (with no parameters) for NP-hard problems by presenting an improved exact algorithm for the well-known satisfiability problem. Our results demonstrate the power of this new approach to algorithm design and analysis for NP-hard problems. In the end, we discuss possible future directions on this new approach and other approaches to algorithm design and analysis.

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We prepared a seties of tridentate amido diphosphine ligands, including symmetrical [N(o-C6H4PR2)2]- ([R-PNP]- ; R = Ph, iPr, Cy) and unsymmetrical [N(o-C6H4PPh2) (o-C6H4PiPr2)]-. Deprotonation of neutral ligands, H[R-PNP] ( R = Ph, iPr, Cy) or H[Ph-PNP-iPr], with n-BuLi in ether solutions at -35oC produced the lithium complexes, [R-PNP]Li(solv)n ( R = Ph, iPr, Cy; solv = THF, OEt2; n = 1,2) or [Ph-PNP-iPr]Li(solv)n (solv = THF, OEt2; n = 1,2), respectively. The reactions of the lithium complexes or neutral ligands with NiCl2(DME) in THF solutions generated nickel(II) chloride complexes, [R-PNP]NiCl ( R = Ph, iPr, Cy) or [Ph-PNP-iPr]NiCl, which was then reacted with a variety of Grignard reagents to afford the corresponding hydrocarbyl complexes. Of particular interest among the compounds isolated are alkyl complexes that contain £]−hydrogen atoms. The metathetical reactions of nickel(II) chloride complexes with LiNHPh, NaOPh, NaSPh, or NaOtBu, respectively, produced the correspounding nickel anilide, nickel phenolate, nickel thiophenolate and nickel tert-butoxide derivatives. Protonolysis studies of nickel(II)-heteroatom complexes revealed the basic reactivity of these £k-donor ligands. The basicity follows the order OtBu > NHPh > OPh > SPh. Treatment of Ni(COD)2 (COD = cycloocta-1,5-diene) with neutral ligands produced the correspounding four-corrdinate nickel hydride complexes, [R-PNP]NiH (R = Ph, iPr, Cy) or [Ph-PNP-iPr]NiH. The olefin insertion reactions of [iPr-PNP]NiH or [Ph-PNP-iPr]NiH with ethylene, 1-hexene, and norbornene, respectively, generated the corresponding ethyl, n-hexyl, and 2-norbornyl complexes. The formation of [iPr-PNP]Ni(n-hexyl) or [Ph-PNP-iPr]Ni(n-hexyl) is indicative of exclusive 1,2-insertion of 1-hexene. In contrast, styrene inserts into the Ni-H bond of [Ph-PNP-iPr]NiH in an exclusively 2,1-manner to afford [Ph-PNP-iPr]NiCH(Me)Ph. The selective 2,1-insertion products [R-PNP]NiCH(Me)CO2Me (R = Ph, iPr, Cy) or [Ph-PNP-iPr]NiCH(Me)CO2Me were also isolated from the reactions of methyl acrylate with the corresponding nickel hydride complexes. The effects of the phosphorus and olefin substituent on the reactivity and regioselectivity of the olefin insertion reactions are discussed. We also prepared nickel acyl complexes and nickel complexes catalyzed C-N bond formation. In addition to solution NMR spectroscopic data for all new compounds. X-ray diffraction revealed solid structures. A series of five-coordinate aluminum complexes supported by o-phenylene - derived amido diphosphine ligands have been prepared and structurally characterized. Alkane elimination reactions of trialkylaluminum with neutral ligands, H[R-PNP] ( R = Ph, iPr) and H[Ph-PNP-iPr] in toluene solution at -35oC respectively produced the corresponding dialkyl complexes [iPr-PNP]AlR'2, [Ph-PNP]AlR'2 and [iPr-PNP-Ph]AlR'2 (R' = Me, Et, iBu) in high isolated yield. The dihydride complexes [iPr-PNP] AlH2, [Ph-PNP]AlH2 and [iPr-PNP-Ph]AlH2 prepared in one-pot reactions of in situ prepared dichloride precursors with LiAlH4 in THF at room temperature. X-ray diffraction studies revealed a distorted trigonal-bipyramidal structure for these molecules in which the two phosphorus donors are mutually trans. The solution structures of these complexes were all characterized by 1H, 13C, and 31P NMR spectroscopy. The NMR data are indicative of solution C2 symmetry for [iPr-PNP]- and [Ph-PNP]- complexes, whereas they are indicative of C1 for [iPr-PNP-Ph]- derivatives. The 1H NMR spectra of [iPr-PNP]AlR'2, [Ph-PNP]AlR'2 and [iPr-PNP-Ph]AlR'2 (R' = Et, iBu) revealed diastereotopy for the £\-hydrogen atoms in these molecules.

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<p>Detta examensarbete har utförts vid Linköpings universitet i samarbete med Scania Transmission i Södertälje och behandlar kravsättning av ytstrukturer samt processer för hårdbearbetning av kugghjul och axlar. Aktuella artikelritningar innefattar endast krav för Ra-värde, den aritmetiska medelavvikelsen för ytjämnhetsprofilen (R-profilen). Förslag på nya parametrar enligt av Scania tillämpade SS-EN ISO standards har tagits fram, detta för att ge en noggrannare beskrivning av vilken ytstruktur som skall uppnås. Resultatet är generellt tillämpningsbart men fokuseras mot kugghjulens hål, plan och diametrar. Vidare presenteras en jämförelse mellan metoder så att transmissionsverkstäderna kan tillverka kugghjul/axlar på ett kostnadseffektivare sätt. Arbetet grundas på en litteraturstudie av handböcker och standards kompletterat med kartläggning av nuläget genom insamling av mätdata. En omvärldsanalys och några bearbetningsprover med hårdsvarvning har också utförts. Till skillnad från nuläget föreslås en övergång från att ange Ra-värde på ritningarna till att ange en övre gräns för Rz-värde som en begränsning av amplituden. Ytor i relativ rörelse och ytor som ingår i pressförband föreslås kompletteras med en undre gräns för Rz-värde samt en undre gräns för relativ bärighet. Med införandet av ett bärighetskrav ges även en specifikation för profilens fördelning. Angivelse av bearbetningsmetod och eventuellt bearbetningsmönster föreslås att anges i klartext på ritningen då parametrar som beskriver karakteristiska drag för olika bearbetningsmetoder visat sig väldigt variationsbenägna i nulägesanalysen. Jämförelse av hårdbearbetningsmetoder har visat att det i kombinationsmaskiner, hårdsvarvning och slipning, vore intressant att enbart hårdsvarva kugghjulens glidlagerytor, något som enligt bearbetningsprover och omvärldsanalys verkar rimligt. Detta bör efter godkännda riggprover anammas som ett första optimeringssteg. Fler intressanta koncept för framtida bearbetningsalternativ finns att studera i rapportens resultat och diskussionskapitel.</p> / <p>This master thesis report was performed at Linköpings University in cooperation with Scania Transmission in Södertälje and deals with specification of surface textures and processes for hard part machining of cogwheels and shafts. Present blueprints only include requirements for Ra-values, arithmetic mean deviation of the roughness profile (R-profile). Suggestions of new parameters according to SS-EN ISO standards used by Scania have been compiled with the aim of providing a more accurate description of the surface texture that is to be achieved. The result can be applied in general but are focused towards holes of cogwheels, planes and diameters. Furthermore a comparison between different methods is presented so that the transmission workshops can manufacture cogwheels and shafts in a costefficient manner. The work is based on a comparative literature study of handbooks and standards with complementary documentation of the present situation through collecting of measurements. A reference analysis and a few manufacturing tests of hard turning have also been performed. In difference from the present situation a transition from providing Ra-values on the blueprints to specify an upper limit for Rz-value to restrict the amplitude is recommended. Surfaces in relative motion and surfaces in heavy force fit are suggested to be complemented with a lower limit for Rz-values and a lower limit for relative material ratio. With an introduction of material ratio requirements the profiles distribution are also specified. Denunciation of manufacturing method and surface lay if any is suggested to be stated en clair on the blueprint being so that parameters describing characteristic features for different manufacturing methods have shown a wide range of distribution in the present state analysis. Comparison of hard part machining methods have shown that in combination machines, hard turning and grinding, solely hard turning of the cogwheels slide bearing surfaces would be interesting, which also seems plausible due to manufacturing samples and the reference analysis. After approved rigg tests this method can be adopted as a first step of optimization. More interesting concepts for future manufacturing alternatives are provided in the reports result and discussion chapters.</p>

Tez (Doktora) - Süleyman Demirel Üniversitesi, Fen Bilimleri Enstitüsü, Makina Mühendisliği Anabilim Dalı, 2009. / Kaynakça var.