Tesi sul tema "Processability"
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1
Zhang, Fangzhu. "The genetic basis of salad leaf processability". Thesis, University of Southampton, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.436976.
Testo completo
2
Zhu, Xiaojing. "Processability of Nickel-Boron Nanolayer Coated Boron Carbide". Diss., Virginia Tech, 2008. http://hdl.handle.net/10919/28633.
Testo completoAbstract (sommario):
This dissertation work focuses on the processability improvement of B4C, especially the compaction and sintering improvement of B4C by applying a Ni-B nanolayer coating on individual B4C particles.
A modified electroless coating procedure was proposed and employed to coat nanometer Ni-B layer onto micron-sized B4C particles. The thickness was able to be tuned and controlled below 100 nm. Key parameters, including the amount of nickel source, the amount of the surface activation agent (PdCl2), the amount of the complexing agent (C2H8N2), and the addition rate of the reducing agent (NaBH4) were studied. When the targeted thickness was 5 nm, a continuous and uniform nanolayer coating was obtained with the optimal condition of individual parameter combined.
Reduction of the as-coated B4C powder in a H2-Ar atmosphere was studied between 400-900ºC to reduce the surface oxidesâ Ni2O3 and B2O3. Reduction at 800ºC in hydrogen atmosphere was found to be the most effective condition to remove oxygen in the coating layer, with Ni2B as the reduction product.
Compaction of the as-received, separated and uncoated, and separated with Ni-B coating B4C powders using uniaxial die compaction and combustion driven compaction (CDC) techniques was studied. CDC technique showed the advantage over the traditional uniaxial die compaction by yielding much higher green density and green strength (73% vs. 53.8% green density for the Ni-B coated B4C). Among compacts obtained from the same technique, Ni-B coated B4C compact yielded the densest packing with crack-free compact surface and the highest strength, demonstrating more bonding between B4C particles provided by Ni-B surface coating.
Sintering of the Ni-B coated B4C in an Ar atmosphere between 1150 - 1600ºC with soaking time of 2 hrs and 10 hrs was studied. Liquid phase was found to form during the sintering process. Density measurement showed that the liquid phase Ni-B formed greatly facilitated B4C densification. Considerable density increase and inter-granular connection was achieved when sintered at 1600ºC for 10 hrs. The density enhancement by Ni-B coating was supported by transmission electron microscopy-energy dispersive spectroscopy (TEM-EDS) examination which showed that there was B4C species diffusion into liquid Ni-B phase. This liquid phase enhanced the diffusion of B4C species and formed strong bonding between B4C grains by dissolving small B4C particles and sharp edge and corners of B4C particles. Strength test demonstrated that the Ni-B coating dramatically improved the strength of B4C compacts by yielding a much higher strength of the Ni-B coated samples than the uncoated samples (13.97 vs. 1.79 MPa for the uinaxial die compacted samples, 27.03 vs. 2.21 MPa for the CDC samples). Electrical conductivity Ni-B coated B4C samples was also shown to be improved with the electrical resistivity being reduced from infinite for pure B4C samples to 1.8à 10-3 Ω⠢m for the Ni-B coated samples.
This research work has shown that with the Ni-B coating, B4C densification can start at a temperature as low as 1600ºC via a liquid phase sintering process.Ph. D.
3
Lin-Gibson, Sheng. "Cresol Novolac/Epoxy Networks: Synthesis, Properties, and Processability". Diss., Virginia Tech, 2001. http://hdl.handle.net/10919/27296.
Testo completoAbstract (sommario):
Void-free phenolic networks have been prepared by the reaction of phenolic novolac resins with various diepoxides. The stoichiometric ratio can be adjusted to achieve networks with good mechanical properties while maintaining excellent flame retardance. A series of linear, controlled molecular weight, 2,6-dimethylphenol endcapped cresol novolac resins have been synthesized and characterized. The molecular weight control was achieved by adjusting the stoichiometric ratio of cresol to 2,6-dimethylphenol and using an excess of formaldehyde. A dynamic equilibrium reaction was proposed to occur which allowed the targeted molecular weight to be obtained.
A 2000 g/mol ortho-cresol novolac resin was crosslinked by a diepoxide oligomer and by an epoxidized phenolic oligomer in defined weight ratios and the structure-property relationships were investigated. The networks comprised of 60 or 70 weight percent cresol novolac exhibited improved fracture toughness, high glass transition temperatures, low water uptake, and good flame retardance. The molecular weights between crosslinks were also determined for these networks. The stress relaxation moduli were measured as a function of temperature near the glass transition temperatures. Crosslink densities as well as the ability to hydrogen bond affect the glassy moduli of these networks. Rheological measurements indicated that cresol novolac/epoxy mixtures have an increased processing window compared to phenolic novolac/epoxy mixtures.
Maleimide functionalities were incorporated into cresol novolac oligomers, and these were crosslinked with bisphenol-A epoxy. The processability of oligomers containing thermally labile maleimides were limited to lower temperatures. However, sufficiently high molecular weight oligomers were necessary to obtain good network mechanical properties. Networks prepared from 1250 g/mol cresol novolac containing maleimide functionilities and epoxy exhibited good network properties and could be processed easily.
Latent triphenylphosphine catalysts which are inert at processing temperatures (~140°C) but possess significant catalytic activity at cure temperatures 180-220°C were necessary for efficient composite fabrication using phenolic novolac/epoxy matrix resins. Both sequestered catalyst particles and sizings were investigated for this purpose. Phenolic novolac/epoxy mixtures containing sequestered catalysts exhibited significantly longer processing time windows than those containing free catalysts. The resins also showed accelerated reaction rates in the presence of sequestered catalysts at cure temperatures. Trihexylamine salt of a poly(amic acid) was sized onto reinforcing carbon fibers and the composite properties indicated that fast phenolic novolac/epoxy cure could be achieved in its presence.Ph. D.
4
Jin, Lin. "Applications of Polybenzoxazines for Improvement in Processability and Property". Cleveland, Ohio : Case Western Reserve University, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=case1264103508.
Testo completoAbstract (sommario):
Thesis (Doctor of Philosophy)--Case Western Reserve University, 2010Department of Macromolecular Science and Engineering Title from PDF (viewed on 2010-05-25) Includes abstract Includes bibliographical references and appendices Available online via the OhioLINK ETD Center
5
Dimassi, Ossama Khalil. "Yield, composition and processability of Dahlem cashmere goats' milk". Beuren Stuttgart Grauer, 2005. http://d-nb.info/989886174/04.
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6
Clarkson, Graham John Joseph. "The diagnosis and manipulation of baby salad leaf processability". Thesis, University of Southampton, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.402403.
Testo completo
7
Bayram, Fatih. "Acquisition of Turkish by heritage speakers : a processability approach". Thesis, University of Newcastle upon Tyne, 2013. http://hdl.handle.net/10443/1905.
Testo completoAbstract (sommario):
This study presents the findings of cross-sectional psycholinguistic research investigating the first-language acquisition of Turkish among heritage speakers in Germany. Studies in heritage language acquisition in the last decades have provided increasing evidence that heritage speakers do not always converge on the grammars of native speakers, which is predominantly explained in relation to estimates of reduced input and output conditions. Nonetheless, Montrul (2010) underlines the fact that estimates of input cannot be used as measurements and addresses the need for a well-established theoretical framework that will account for the development of heritage speakers’ linguistic system to explain why heritage speakers succeed - or fail - in language acquisition in the ways that they do. This study aims to fill this gap by looking at the phenomena from a developmental perspective within the formalisms of Processability Theory (Pienemann, 1998, 2005), a well-established crosslinguistic approach to acquisition based on the architecture of the human language processor, but which has not previously been applied to Turkish. This study investigated the grammatical competence of twenty-four young heritage speakers of Turkish in Germany by testing their online processing of various Turkish grammatical structures, focusing on passives and subject relative clauses. The results demonstrate that the language acquisition of Turkish heritage speakers is developmentally constrained by availability of processing mechanisms. The participants displayed a clear hierarchy in their development, with competence in the processing of basic grammatical structures that are canonically mapped, but with gaps in the processing of complex structures such as passives and subject relative clauses that are non-canonically mapped and involve long-distance dependencies. This study thus contributes important insights both to theoretical accounts of acquisition of Turkish, and to the wider study of heritage language acquisition.
8
Rudbratt, Filip, e Martin Wretlind. "Production and processability for future square shank tool holders". Thesis, Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-69147.
Testo completoAbstract (sommario):
The square shank tool holder is one of Sandvik Coromants most common products. The tool holder has been manufactured the same way for 25 years without changing tolerances. However, it is predicted that tighter tolerances will be required in the future to maintain competitiveness. The purpose of the thesis was to study how today's square shank tool holders can be made straighter and to what price it can be done. The tolerances allow too much convexity and concavity which might lead to unstable products. To find where in the current production flow the greatest impact occurs, the production flow was studied and then a common square shank tool holder with high production volume was followed through the production flow. The tool holders were measured with a CMM after each station and analysis showed that the hardening station has the largest impact on the tolerances. This lead to six experiments using different manufacturing methods and the results were compared to see what production flow that allowed the best tolerances and lowest cost. The results lead to two optional ways of manufacturing since they showed better results with a production economic perspective. Option 1 includes manufacturing in hardened material and Option 2 includes a grinding process. The production flow for Option 1 is to first harden the blank followed by the manufacturing processes. By moving the hardening processes to the beginning of the production flow, the shape changing is prevented and the final product becomes straighter and obtains a smooth and aesthetic surface since the hardening process creates a rough surface. The production time is increased by CON% and the production cost is increased by CON%. The bottom side flatness tolerance of the final product is reduced by CON%. The production flow for Option 2 is to first manufacture the shank followed by hardening. After the hardening process the tools get surface grounded on the bottom side and the outside. By grinding the tool holder, it becomes straight and the surface flatness obtains a tolerance of CON mm. The production time is increased by CON% and the production cost is increased by CON%. The bottom surface flatness tolerance of the final product is reduced by CON%. The advantages of Option 1 are that the final product becomes better and it is easy to apply in the current production flow. The advantages of Option 2 the surface becomes very flat and the tool holder is more competitive. By choosing any of these two options, Sandvik Coromant will achieve a straighter and more competitive final product.
9
Tyberg, Christy Sensenich. "Void-Free Flame Retardant Phenolic Networks: Properties and Processability". Diss., Virginia Tech, 2000. http://hdl.handle.net/10919/26554.
Testo completoAbstract (sommario):
Phenolic resins are important components of the composite industry because of their excellent flame retardance and cost effectiveness. However, the common procedure for curing phenolic novolac resins uses hexamethylenetetramine (HMTA) and releases volatiles during the cure, which produce networks with numerous voids. This results in materials that lack the toughness necessary for structural applications. An alternative to curing with HMTA is to crosslink the pendant phenolic groups in the novolac resin with epoxy reagents. This reaction proceeds by nucleophilic addition without the release of any volatiles, thereby creating a void-free network. Flame retardance can be achieved by using an excess of the phenolic component. Network densities can also be controlled to maximize both toughness and stiffness by tailoring the stoichiometry of the reagents.
Structure-property relationships of phenolic/epoxy networks have been investigated. Glass transitions decreased, and toughness increased, as the phenolic content in the network was increased. Both results could be correlated to the decrease in network densities along this series, which was investigated by measuring the rubbery moduli well above Tg. Fracture toughness of phenolic/epoxy networks measured by K1c reached 1.03 MPa-m1/2, compared with an epoxy control with K1c = 0.62 MPa-m1/2 and phenolic control with K1c = 0.16 MPa-m1/2. In addition, an increase in novolac content improves flame retardance rather dramatically. The peak heat release rate (PHRR) dropped from 1230 kW/m²⁺ for the epoxy control to 260 kW/m²⁺ for the phenolic/epoxy networks, which approached that of a phenolic resol (PHRR = 116 kW/m²⁺). Phenolic/epoxy composite flame retardance also showed significant improvement when compared to epoxy composites.
Melt processability of phenolic/epoxy composites has been achieved through the use of latent nucleophilic initiators. Kinetics of the phenolic/epoxy cure reactions with latent initiators demonstrated that monomeric phosphine initiators yielded faster cure reactions as compared to polymeric initiators. These latent initiators allow composite melt processing, such as prepregging or pultrusion, without premature curing. In addition, cure cycles can be reduced from 4 hours to less than 30 minutes. Composites prepared using these latent initiators had toughness exceeding that of epoxy composites and fatigue limits significantly higher than those of vinyl ester composites.
Vita removed, June 10, 2013, per author's request. GMcPh. D.
10
Wang, Xiaojing. "Grammatical development among Chinese L2 learners : from a processability account". Thesis, University of Newcastle Upon Tyne, 2011. http://hdl.handle.net/10443/1301.
Testo completoAbstract (sommario):
This study is to investigate the second language acquisition of Chinese grammatical structures by eight Chinese L2 learners. Adopting the theoretical framework of Professor Manfred Pienemann’s Processability Theory (PT), this study focuses on the confirmation and extension of the developmental sequence of the grammatical items found by Zhang (2001 and 2008) and Gao (2005). In essence, this study employed a longitudinal and cross-sectional design. Eight Chinese L2 students from the undergraduate Chinese programme at Newcastle University have been voluntarily selected to join my study. These eight students have a variety of language learning experience and backgrounds, but most importantly (different from other PT-based studies), they have been taught using a completely different textbook and curriculum when compared with the PT-driven developmental sequence. The interviews (elicitation tasks and free talk) were carried out on a regular basis over one academic year. Data was then transcribed and grammatical features tagged. Data analysis was performed through distributional analysis which detailed the linguistic environment of each grammatical item across the PT stages. Emergence criterion has been stipulated and applied to locate the acquisition point of each form. At the same time, a further textbook analysis has been conducted to identify the relationship between the instructions and natural acquisition stages. The results have shown that the overall grammatical progression in the subjects’ interlanguage was compatible with the processing hierarchy hypothesized in the PT, regardless of the learners’ first language and language learning experience. Moreover, the acquisition patterns are never altered by the teaching instruction; instead, the acquisition speed has been somehow influenced by the teaching instruction and other factors. One issue which should be addressed is the exceptional cases identified in the study, which require further work in this area. Apart from that, the research has also shown that the adequate tasks are required in language teaching and grammatical structure elicitation. Therefore, four tasks have been designed and tested across the proposed Chinese processing hierarchy for the benefit of Chinese L2 learners.
11
Niu, Wenhui, Junzhi Liu, Yiyong Mai, Klaus Müllen e Xinliang Feng. "Synthetic Engineering of Graphene Nanoribbons with Excellent Liquid-Phase Processability". Elsevier, 2019. https://tud.qucosa.de/id/qucosa%3A74089.
Testo completoAbstract (sommario):
Over the past decade, the bottom-up synthesis of structurally defined graphene nanoribbons (GNRs) with various topologies has attracted significant attention due to the extraordinary optical, electronic, and magnetic properties of GNRs, rendering them suitable for a wide range of potential applications (e.g., nanoelectronics, spintronics, photodetectors, and hydrothermal conversion). Remarkable achievements have been made in GNR synthesis with tunable widths, edge structures, and tailor-made functional substitutions. In particular, GNRs with liquid-phase dispersibility have been achieved through the decoration of various functional substituents at the edges, providing opportunities for revealing unknown GNR physiochemical properties. Because of the promise of liquid-phase dispersible GNRs, this mini-review highlights recent advances in their synthetic strategies, physiochemical properties, and potential applications. In particular, deep insights into the dvantages and challenges of their syntheses and chemical methodologies are provided to encourage future endeavors and developments.
12
Axtell, Frederick H. "A study of the flow properties and processability of thermoplastic polyesters". Thesis, Loughborough University, 1987. https://dspace.lboro.ac.uk/2134/27045.
Testo completoAbstract (sommario):
Poly(ethylene terephthalate) (PET) has recently gained vast new markets through its ability to be biaxially oriented and/or crystallised rapidly, by 'novel' processing techniques. This investigation aims to provide information enabling theories on these processes to be further developed.
13
Rozenbaoum, Evgueni E. "Rheology and processability of Teflon(RTM) FEP resins for wire coating". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://hdl.handle.net/2429/9589.
Testo completoAbstract (sommario):
Experiments were carried out in both parallel plate and capillary rheometers for a
variety of tetrafluoroethylene/hexafluoropropylene (TFE/HFP) copolymers and
TFE/HFP/per-fluoro(alkyl vinyl ether) (TFE/HFP/PAVE) terpolymers, also known as
Teflon® FEP polymers, having different molecular weights and compositions (HFP and
PAVE content). The critical conditions for the onset of melt fracture and the influence of
temperature, molecular weight, and composition of the resins are determined. The critical
molecular weight for the onset of entanglements was found to be about 100,000, a value
much higher than those previously reported. The relationships between the processability
of the wire coating Teflon® FEP resins and their composition, viscosity, ability to
crystallize, and melt elasticity were established. The experimental data were used for a
thorough rheological modeling of the behavior of these resins. The latter includes
calculation of their linear relaxation time spectra and nonlinear parameters using a multimode
Phan-Thien and Tanner (PTT) constitutive equation.
A new data analysis procedure based on a mathematical model for the
nonisothermal capillary flow of polymer melts coupled with heat transfer is developed.
The computer simulations proposed can be used to provide detailed velocity,
temperature, and pressure distributions and to recover the parameters of the employed
slip velocity model corrected for the effect of viscous heating. Finally, the effect of
various processing aids on the processability of fluoropolymers and polyolefins during
extrusion and wire coating was studied. It was found that polyethylene works as a
processing aid in the extrusion of Teflon® FEP resins in the same way as fluoropolymers
do in the extrusion of polyolefins. Finally, the processing additive based on a boron
nitride (BN) composition was found to eliminate sharkskin melt fracture and postpone
gross melt fracture to significantly higher shear rates for a variety of polymers.
14
Jamieson, J. "Investigation of methods of predicting the processability of polypropylenes used in thermoforming". Thesis, Queen's University Belfast, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.431593.
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Buttkewitz, Pascal Simon [Verfasser]. "Acquiring english as a third language : a processability perspective / Pascal Simon Buttkewitz". Paderborn : Universitätsbibliothek, 2018. http://d-nb.info/1165650053/34.
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Alt, Milan [Verfasser], e U. [Akademischer Betreuer] Lemmer. "Performance and processability of organic field effect transistors / Milan Alt. Betreuer: U. Lemmer". Karlsruhe : KIT-Bibliothek, 2015. http://d-nb.info/1080246312/34.
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Campos, García Antonio. "Influence of organic semiconductors morphology, structure and processability on organic field-effect transistors performance". Doctoral thesis, Universitat Autònoma de Barcelona, 2018. http://hdl.handle.net/10803/666648.
Testo completoAbstract (sommario):
En esta tesis hemos estudiado como la manera de procesar los semiconductores orgánicos puede afectar a su morfología y estructure cristalina. Semiconductores orgánicos de tipo p y n han sido empleados como capas activas en transistores orgánicos de efecto campo (OFETs). Más concretamente, hemos realizado estudios con diferentes semiconductores orgánicos y hemos fabricado transistores con estos semiconductores procesados por solución, con las técnicas de deposición drop casting and bar-assisted meniscus shearing (BAMS), y por evaporación. El propósito de este trabajo ha sido encontrar la correlación entre la estructura molecular, la organización cristalina de las moléculas y la morfología de la capa delgada con las propiedades eléctricas del semiconductor orgánico. También, buscando la mejora del rendimiento y la estabilidad de los dispositivos, los semiconductores orgánicos en esta tesis se han mezclado íntimamente con polímeros aislantes. Además, se ha estudiado en detalle el rol del polímero aislante en la mezcla comparando OFETs basados en películas delgadas constituidas por sólo el semiconductor orgánico con películas delgadas fabricadas a partir de la mezcla de semiconductor y polímero. Por último, la técnica de deposición por spray ha sido estudiada como técnica para depositar contactos orgánicos basados en el metal orgánico tetratiafulvaleno-tetracianoquinodimetano (TTF-TCNQ) y también para la formación de monocristales de semiconductores orgánicos.In this thesis we have studied how the processing of organic semiconductors can affect their morphology and crystal structure. p-Type and n-type organic semiconductors have been employed as active layers in Organic Field-Effect Transistors (OFETs). More in detail, we have performed studies with different organic semiconductors and fabricated transistors based on them by solution (drop casting and bar-assisted meniscus shearing) and by evaporation. The purpose of the work carried out has been elucidating the correlation of the molecular structure, crystal packing and thin film morphology with the electrical properties of the organic semiconductor. Further, aiming at enhancing the performance and stability of the devices, the organic semiconductors used in this thesis were blended with polymer binders. In addition, the effect of the polymer binder has been studied in detail by comparing OFETs based on thin-films of the pristine semiconductor with OFETs based on thin-films of the semiconductor blended with polymers. Finally, spray printing has been explored as technique for depositing organic contacts based on the organic metal tetrathiafulvalene-tetracyanoquinodimethane (TTF-TCNQ) and also for forming single crystals of organic semiconductors.
18
Ishigami, Judith Preston. "Examining the reliability of processability theory-based procedure for use in Japanese SLA assessment". 名古屋大学言語文化研究会, 2009. http://hdl.handle.net/2237/14657.
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Iuras, Andreea. "Processability and performance predictions from surface analysis of small amounts of drug and excipients". Thesis, University of Nottingham, 2015. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.742536.
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Lin, Yue. "Effect of nanoparticulate incorporation on processability, chemistry and thermal properties of high temperature resin systems". Thesis, Loughborough University, 2012. https://dspace.lboro.ac.uk/2134/11759.
Testo completoAbstract (sommario):
Processability, curing dynamics, network formation, and thermal stability of cyanate ester resin (CY) nanocomposites with triSilanolphenyl polyhedral oligomeric silsesquioxane (POSS), natural montmorillonite clay (Na+), MT2EtOH (methyl, tallow, bis-2-hydroxyethyl, ternary ammonium) modified clay (30B), 2M2HT (dimethyl, dihydrogenatedtallow, quaternary ammonium) modified clay (20A), carbon nanotubes (CNTs) were studied by means of differential scanning calorimetry (DSC), modulated temperature differential scanning calorimetry (MTDSC), X-ray diffraction (XRD), field emission gun scanning electron microscopy (FEG-SEM), transmission electron microscopy (TEM), Fourier transform infrared (FTIR) and Raman spectroscopies. For comparison, the influence of the nanofillers on processability, curing dynamics, network formation, and thermal stability of a benzoxazine resin (BEN) were studied as well.
21
Flynn, John J. "Optimizing the Discovery and Processability of Biologically Derived Molecular Glass Host Materials for Photonic Applications". University of Dayton / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1588192751503223.
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22
Nishitani, Atsuko. "A Hierarchy of Grammatical Difficulty for Japanese EFL Learners: Multiple-Choice Items and Processability Theory". Diss., Temple University Libraries, 2012. http://cdm16002.contentdm.oclc.org/cdm/ref/collection/p245801coll10/id/176422.
Testo completoAbstract (sommario):
CITE/Language ArtsEd.D.
This study investigated the difficulty order of 38 grammar structures obtained from an analysis of multiple-choice items using a Rasch analysis. The order was compared with the order predicted by processability theory and the order in which the structures appear in junior and senior high school textbooks in Japan. Because processability theory is based on natural speech data, a sentence repetition test was also conducted in order to compare the result with the order obtained from the multiple-choice tests and the order predicted by processability theory. The participants were 872 Japanese university students, whose TOEIC scores ranged from 200 to 875. The difficulty order of the 38 structures was displayed according to their Rasch difficulty estimates: The most difficult structure was subjunctive and the easiest one was present perfect with since in the sentence. The order was not in accord with the order predicted by processability theory, and the difficulty order derived from the sentence repetition test was not accounted for by processability theory either. In other words, the results suggest that processability theory only accounts for natural speech data, and not elicited data. Although the order derived from the repetition test differed from the order derived from the written tests, they correlated strongly when the repetition test used ungrammatical sentences. This study tentatively concluded that the students could have used their implicit knowledge when answering the written tests, but it is also possible that students used their explicit knowledge when correcting ungrammatical sentences in the repetition test. The difficulty order of grammatical structures derived from this study was not in accord with the order in which the structures appear in junior and senior high school textbooks in Japan. Their correlation was extremely low, which suggests that there is no empirical basis for textbook makers'/writers' policy regarding the ordering of grammar items. This study also demonstrated the difficulty of writing items testing the knowledge of the same grammar point that show similar Rasch difficulty estimates. Even though the vocabulary and the sentence positions were carefully controlled and the two items looked parallel to teachers, they often displayed very different difficulty estimates. A questionnaire was administered concerning such items, and the students' responses suggested that they seemed to look at the items differently than teachers and what they notice and how they interpret what they notice strongly influences item difficulty. Teachers or test-writers should be aware that it is difficult to write items that produce similar difficulty estimates and their own intuition or experience might not be the best guide for writing effective grammar test items. It is recommended to pilot test items to get statistical information about item functioning and qualitative data from students using a think-aloud protocol, interviews, or a questionnaire.
Temple University--Theses
23
Walker, Liv, e Karin Essén. "The applicability of agricultural fibres in industrial cleaning cloths : in the aspects of processability and sustainability". Thesis, Högskolan i Borås, Akademin för textil, teknik och ekonomi, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:hb:diva-23799.
Testo completoAbstract (sommario):
This study has its background in the EU directive, the ‘Single-Use Plastics Directive’. The directive was initiated due to the environmental impacts that the oceans suffer due to plastic waste. The directive presents the most common single-use products found as waste in the oceans, including wipes and cloths. In collaboration with Essity, a global hygiene and health company, this study aims to find a replacement fibre for the currently used polyester fibre in Essity’s industrial cleaning cloths. To this end, we have evaluated the applicability of an agricultural fibre in the aspects of processability and sustainability. A theoretical part including a literature study of agricultural fibres is combined with a practical experimental part to evaluate a manufactured prototype. The theoretical part includes a compilation of the relevant parameters per fibre and the experimental part consists of laboratory tests and a panel test. On this basis, it was concluded that the first agricultural fibre, hemp, did not function adequately in the process due to the variations in fibre length and coarseness. A solution to this problem may be pre-treatments of the fibres. The second fibre, flax, functioned well in the process and may then be considered applicable in the aspect of process. The applicability of an agricultural fibre is possible in industrial cleaning cloths, but the geographical location of cultivation, transport, the chemicals used and irrigation should also be taken into account in the aspects of sustainability.Bakgrunden till denna studie är EU-direktivet, ‘Single-Use Plastics Directive’. Direktivet har sitt ursprung i de miljöproblem som våra hav lider av på grund av nedskräpningen medplastavfall. Direktivet redovisar de engångsartiklar som återfinns allra mest i haven idag, däribland rengöringsdukar. På förekommen anledningen ska därför denna studie i samarbete med Essity, ett globalt hygien- och hälsoföretag, undersöka möjligheten att ersätta den befintliga polyesterfibern i deras industriella rengöringsdukar. Studien har utvärderat möjligheten att använda en naturlig fiber med avseende på tillverkningsprocess och hållbarhet. För att möjliggöra en utvärdering av en tillverkad prototyp, så har en teoretisk del med en litteraturstudie i kombination med en praktisk experimentell del genomförts. Den teoretiska delen består av en sammanställning av relevanta parametrar för varje fiber och den experimentella delen består av laboratorietester och ett paneltest. Slutsatserna från ett förstaförsök var att hampafibrer inte fungerade i processen på grund av variationer i hampansfiberlängd och grovlek. Att göra en förbehandling skulle kunna vara lösningen. I det andraförsöket med linfibrer, visade det sig att linfibrer fungerar i processen och därför kan vara applicerbar med avseende på tillverkningsprocess. En naturlig fiber kan användas i industriella rengöringsdukar, ur ett hållbarhetsperspektiv är det viktigt att beakta den geografiska platsen för odling, transporter, användning av kemikalier och konstbevattning.
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Gonzalez-Ibarra, Alvaro. "The effects of polymeric binders on the processability and properties of composites made by suspension prepregging". Thesis, This resource online, 1993. http://scholar.lib.vt.edu/theses/available/etd-09192009-040513/.
Testo completo
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Adegoke, Olutayo. "Processability of Laser Powder Bed Fusion of Alloy 247LC : Influence of process parameters on microstructure and defects". Licentiate thesis, Högskolan Väst, Avdelningen för avverkande och additativa tillverkningsprocesser (AAT), 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:hv:diva-16114.
Testo completoAbstract (sommario):
This thesis is about laser powder bed fusion (L-PBF) of the nickel-based superalloy: Alloy 247LC. Alloy 247LC is used mainly in gas turbine blades and processing the blades with L-PBF confers performance advantage over the blades manufactured with conventional methods. This is mainly because L-PBF is more suitable, than conventional methods, for manufacturing the complex cooling holes in the blades. The research was motivated by the need for academia and industry to gain knowledge about the processability of the alloy using L-PBF. The knowledge is essential in order to eventually solve the problem of cracking which is a major problem when manufacturing the alloy. In addition, dense parts with low void content should be manufactured and the parts should meet the required performance. Thus, the thesis answered some of the important questions related to process parameter-microstructure-defect relationships. The thesis presented an introduction in chapter 1. A literature review was made in chapter 2 to 4. In chapter 2, the topic of additive manufacturing was introduced followed by an overview of laser powder bed fusion. Chapter 3 focused on superalloys. Here, a review was made from the broader perspective of superalloys but was eventually narrowed down to the characteristics of nickelbased superalloys and finally Alloy 247LC. Chapter 4 reviewed the main research on L-PBF of Alloy 247LC. The methodology applied in the thesis was discussed in chapter 5. The thesis applied statistical design of experiments to show the influence of process parameters on the defects and microstructure, so a detail description of the method was warranted. This was given at the beginning of chapter 5 and followed by the description of the L-PBF manufacturing and the characterization methods. The main results and discussions, in chapter 6, included a preliminary investigation on how the process parameters influenced the amount of discontinuity in single track samples. This was followed by the results and discussions on the investigation of voids, cracks and microhardness in cube samples (detail presentation was given in the attached paper B). Finally, the thesis presented results of the microstructure obtainable in L-PBF manufactured Alloy 247LC. The initial results of the microstructure investigation were presented in paper A.
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Danesh, Ehsan. "Novel polyaniline-based ammonia sensors on plastic substrates". Thesis, University of Manchester, 2014. https://www.research.manchester.ac.uk/portal/en/theses/novel-polyanilinebased-ammonia-sensors-on-plastic-substrates(2c9f641e-fc69-49ea-886f-fdd888dc076c).html.
Testo completoAbstract (sommario):
This thesis describes the development of high performing low-cost and low-power ammonia sensors on plastic substrates using solution processing techniques. As a part of the Marie Curie Initial Training Networks, FlexSmell project aimed at the realisation of such sensors as elements of a sensing system on flexible tags for wireless compatible applications. Ammonia was selected as the target analyte due to its importance in many application fields including food industry, air and water quality monitoring. Polyaniline, a conjugated polymer, was used as the sensing layer for chemiresistive detection of ammonia because of its well-known gas sensing properties. Two distinctive strategies were adapted to tackle doped polyaniline’s lack of solution processablity. Firstly, dopant engineering was utilised to prepare doped polyaniline formulations in aprotic solvents such as n-methyl-2-pyrrolidone. Hybrid composites were then prepared by simply mixing the polyaniline solutions and carbon nanoparticles. Sensors made by spin coating the polyaniline hybrid composites on plastic substrates operating at ~80 °C showed sensitivities more than 6 times higher than that of a commercial metal oxide sensor when exposed to sub-ppm concentrations of ammonia in air. The incompatibility of the multifunctional dopants used in this method with printed electronics, as well as the high boiling point and toxicity of the solvent led to the second approach. A two-step vapour-phase deposition polymerisation method was exploited to in-situ polymerise different polymeric acid-doped polyaniline thin films on plastic substrates. Polyaniline sensors doped with poly(4-styrenesulphonic acid), demonstrated sensitive response to sub-ppm concentrations of ammonia vapour under both dry and humid conditions. These sensors showed enhanced recovery and repeatability when operated at elevated temperatures. Moreover, room temperature ammonia sensors were realised using Nafion as the dopant. Finally, ammonia sensors were made on small (~1 mm^2) printed polymeric micro-hotplates using a vapour-phase deposited polyaniline sensing layer in order to allow reliable operation at ~95 °C with power consumptions as low as 35 mW. Such low-cost, low-power, sensitive and selective ammonia chemiresistors may be incorporated in smart RFID tags for food, air and water quality monitoring.
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Gijswijt, Katrijn. "Processing Dutch : A study on the acquisition of Dutch as a second language using Processability Theory as a framework". Thesis, Stockholms universitet, Centrum för tvåspråkighetsforskning, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-105696.
Testo completoAbstract (sommario):
An ongoing debate within the field of Second Language Acquisition (SLA) discusses the possibility of universal developmental stages in the interlanguage of second language learners. Processability Theory (PT) is one of the theories that enhances this way of thinking about second language acquisition. The belief is that learners go through the same stages of development when learning a new language. An ongoing process in PT is the construction of these developmental stages for individual languages, but today there is still much work needed in this area. The purpose of this thesis is to construct the developmental stages for Dutch, based on an error analysis of second language learners’ interlanguage. The data was collected from Swedish students learning Dutch on a university level. The students were interviewed once per month, and three times in total, so that no developments in their interlanguage could be missed. The data is processed according to the emergence criterion, resulting in developmental tables of the learners’ progress. The result of these interviews provides for the outline on how one acquires Dutch, and together with a grammatical analysis of Dutch word order procedures and morphology, a developmental hierarchy for the acquisition of Dutch according to PT is constructed.I den här studien undersökas den nederländska språkinlärningsprocessen inom ramen av Processbarhetsteorin (PT). PT antar att inlärningsprocessen sker genom universella stadier. Dessa har skapats och forskats för flera olika sprak, men inte för nederländska. I den här uppsatsen kommer den nederländska morfologin och ordföljden att analyseras enligt PT’s stadier, och skapas en hierarki för nederländska. Samtidigt blir hierarkin testad genom en longitudenell studie av inlärningsprocessen av svenska studenter som lär sig nederländska. Dessutom diskuteras frågan om möjlig transfer från både det första och andra språket. Sen debatteras frågan om emergence criterion och procentsatser, och därmed skillnaden mellan språkinlärning och språkbehärskning. Resultatet är en granskning av den egna skapade hierarkin, och möjliga förklarningar för deras inlärningsprocess.
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IWASAKI, Junko, e junkoi@student ecu edu au. "The acquisition of Japanese as a second language and Processability Theory: A longitudinal study of a naturalistic child learner". Edith Cowan University. Community Services, Education And Social Sciences: School Of International, Cultural And Community Studies, 2006. http://adt.ecu.edu.au/adt-public/adt-ECU2006.0022.html.
Testo completoAbstract (sommario):
The aim of this study was to investigate longitudinally how a child learner acquired verbal morpho-syntax in Japanese in a naturalistic second language (L2) context. Specifically the points of emergence for three verbal morpho-syntactic structures, namely verbal inflection, the V-te V structure and the passive/causative structure, were investigated within a framework of Processability Theory (PT) (Pienemann, 1998b). The subsequent development of these structures was also examined. Unlike earlier research about morpheme orders and developmental sequences in language acquisition which was criticised because of its apparent lack of theoretical underpinnings, Pienemann's Processability Theory (PT)(1998b) connects the processability of morpho-syntactic structure to linguistic theories. Pienemann also claims that this theory can be used to explain the acquisition of a wide range of morpho-syntactic structures and that it is typologically plausible and applicable to any language. In recent times PT has been extensively tested in a range of languages acquired as an L2, including German, English and Swedish (Pienemann, 1998b; Pienemann & Hakansson, 1999) and Italian and Japanese (Di Biase & Kawaguchi, 2002). The findings from these studies support this theory.
29
Zhang, Duyao. "Thermodynamic characterisation of semi-solid processability in alloys based on Al-Si, Al-Cu and Al-Mg binary systems". Thesis, University of Leicester, 2015. http://hdl.handle.net/2381/32538.
Testo completoAbstract (sommario):
The processing window is important for the semisolid processability of alloys. Applications of semi-solid metal (SSM) processing, especially aluminium alloys have been expanding for their excellent mechanical properties. However, the alloys well suited and commercially used for SSM processing today are limited in types. The main purpose of this Ph.D. project is to understand what makes an alloy suitable for SSM processing on both aspects of thermodynamics and kinetics. This research started with a fundamental study of binary alloys based on Al-Si, Al-Cu and Al-Mg systems (wt%): Al-1Si, Al-5Si, Al-12Si and Al-17Si; Al-1Cu, Al-2Cu and Al-5Cu; Al-0.5Mg, Al-3Mg and Al-5.5Mg. These are representative of Si, Cu and Mg contents in commercial alloys used for SSM processing. The Single-Pan Scanning Calorimeter (SPSC) and Differential Scanning Calorimeter (DSC) were used to investigate the liquid fraction changes during heating and cooling of these binary alloys. Thermo-Calc and DICTRA (DIffusion-Controlled TRAnsformations) software have been used to predict the fraction liquid versus temperature taking into account both thermodynamics and kinetics. Comparison of the predictions with experimental data revealed that the simulation results show the same pattern with experimental results in the fraction liquid-temperature relationship. However, the SPSC results are closer to the prediction than DSC curves are, even with the relatively large sample size associated with SPSC. This is potentially a significant result as predicting the liquid fraction versus temperature for the heating of a billet for semi-solid processing remains one of the challenges. The results also suggest that the fraction liquid sensitivity to time should be identified as a critical parameter of the process window for semi-solid processing in addition to the fraction liquid sensitivity to temperature. For microstructure investigation, microanalysis techniques, including Scanning Electron Microscopy (SEM) and micro-indentation testing, have been used on polished sections, and compared to theoretical predictions. In addition, some parts of this project are in cooperation with General Research Institute for Nonferrous Metals (GRINM), which aims to design and develop high performance semi-solid alloys. Thermodynamic analysis (both predictions and experiments) were carried out on thixoformed 319s (2.95Cu, 6.10Si, 0.37Mg, wt%) and 201 (4.80Cu, 0.7Ag, wt%) aluminium alloys. SEM techniques and Transmission Electron Microscopy (TEM) were used for the microstructural characterisation. The results showed that the DSC curves were sensitive to microsegregation in SSM alloys and resulted in a lower liquid fraction than the cast alloys calculated through the integration method from the DSC results. Al2Cu phase in SSM alloys 319s and 201 can be dissolved into matrix up to 0.4 % before melting temperature under 3K/min heating rate when compared with 10K/min heating rate. The DSC scan rate should be carefully selected as higher heating rate can inhibit dissolution of the intermetallic phases during heating leading to less accurate liquid fractions predictions.
30
Iwasaki, Junko. "The Acquisition of Japanese as a Second Language and Processability Theory: A Longitudinal Study of a Naturalistic Child Learner". Thesis, Edith Cowan University, Research Online, Perth, Western Australia, 2006. https://ro.ecu.edu.au/theses/73.
Testo completoAbstract (sommario):
The aim of this study was to investigate longitudinally how a child learner acquired verbal morpho-syntax in Japanese in a naturalistic second language (L2) context. Specifically the points of emergence for three verbal morpho-syntactic structures, namely verbal inflection, the V-te V structure and the passive/causative structure, were investigated within a framework of Processability Theory (PT) (Pienemann, 1998b). The subsequent development of these structures was also examined. Unlike earlier research about morpheme orders and developmental sequences in language acquisition which was criticised because of its apparent lack of theoretical underpinnings, Pienemann’s Processability Theory (PT)(1998b) connects the processability of morpho-syntactic structure to linguistic theories. Pienemann also claims that this theory can be used to explain the acquisition of a wide range of morpho-syntactic structures and that it is typologically plausible and applicable to any language. In recent times PT has been extensively tested in a range of languages acquired as an L2, including German, English and Swedish (Pienemann, 1998b; Pienemann & Håkansson, 1999) and Italian and Japanese (Di Biase & Kawaguchi, 2002). The findings from these studies support this theory. Following the acquisition criteria proposed by Pienemann (1998b), the current study analyses the points of emergence of verbal morpho-syntactic structures by a seven year old Australian boy who was acquiring Japanese as a second language (JSL) naturalistically. Data were collected through audio taping approximately 90 minute interactions between the child and other Japanese speakers at each of the 26 sessions over a one-year and nine month period. The task-based elicitation method was used to create as spontaneous interaction as possible between the child and his interlocutors.
31
Hellström, Sara. "Viscose production : Impact from alkali resistance (R18) and hemicellulose content in dissolving cellulose on the processability and quality of viscose". Thesis, Umeå universitet, Kemiska institutionen, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-55055.
Testo completoAbstract (sommario):
In this study the influence of variations in alkali resistance (R18) of cellulose on the quality of the viscose product in terms of carbohydrate content have been examined. The dissolution pattern of hemicellulose in the first steps of the viscose process with different running parameters has been determined. Furthermore the correlation between R18 and hemicellulose content has been studied. Mercerization and pressing was performed in a viscose micro plant at MoRe Research with varying process settings using samples with different R18 and known carbohydrate content. The carbohydrate content was thereafter determined in both the deducted lye and in the alkali cellulose in order to study the dissolution pattern of hemicellulose. A comparison was made in terms of carbohydrate content between speciality celluloses with varying R18 for determining the correlation between the variables. The study showed a clear influence from R18 on the amount of hemicellulose continuing in the viscose process after the pressing. Variations in NaOHconcentration in the mercerization and the press factor in pressing have also a significant effect on the dissolution of hemicellulose while the temperature in mercerization did not have a distinguishable impact. Finally the study also indicated a linear relationship between R18 and the hemicellulose content in speciality cellulose from Domsjö Fabriker.
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Ellingson, Jordan M. "Starch Resin Moisture Level Effect on Injection Molding Processability and Molded Part Mechanical Properties with Pure Starch Resin and Polymer Blends". BYU ScholarsArchive, 2013. https://scholarsarchive.byu.edu/etd/3782.
Testo completoAbstract (sommario):
The current and forecasted global consumption of plastic packaging and products through the 21st century combined with the already reported and growing negative impact of plastics on the environment due to plastics being synthesized from nonrenewable resources that do not biodegrade is of serious concern. However, recent advances in starch technology including the development of thermoplastic starch (TPS) materials —polymers that are both renewable and biodegradable—have brought hope to reducing this impact. The mechanical properties of thermoplastic starch have often been improved by blending with synthetic polymers. One issue that arises with blending is volatilization of the melt from moisture in the TPS materials. Ecostarch™ a proprietary, pelletized thermoplastic starch resin formulated from potato starch, was processed and tested to observe injection molding processability at various moisture levels, in pure TPS as well as various blend ratios with high-density polyethylene (HDPE) and polypropylene (PP). This study evaluated and analyzed the effects of the TPS pellet moisture content on void formation in the plastic pre-injection melt and subsequent molded part mechanical properties. Statistical analysis of the test results showed that moisture had a significant effect on void formation in the plastic melt. In TPS/HDPE blends, voids percent (as measured by cross section area) increased by 300-350% from 0.6% to 1.4% moisture levels. In unblended TPS, void percent increased by 150% from 0.4% to 1.4% moisture levels. In the unblended TPS parts, impact strength (energy in ft-lb) was decreased by 1% from 0.6% to 1.4% moisture level. In the TPS/HDPE and TPS/PP blends, there was no significant effect on impact strength due to the moisture percent levels of the TPS. Modulus decreased by 25% from 0.4% to 1.4% moisture level in unblended TPS parts. From 0.6% to 1.4% change in TPS moisture content, the modulus of the TPS/HDPE blend decreased by 9% at a 30% TPS/70% HDPE blend and decreased by 14% at a 70% TPS/30% HDPE blend. Though the moisture of TPS did not have a significant impact on the tensile strength of TPS/HDPE blends, the tensile strength of TPS/PP blend samples were significantly affected: a change from 0.6% to 1.4% moisture increased tensile strength 34% at a 70% TPS/30% PP blend and increased tensile strength by 22% at a 30% TPS/70% PP blend. Thus the results of this study highlight the relationships between moisture, voids, and mechanical performance of TPS and TPS/Polymer blends.
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Håkansson, Ramberg Maria. "Was bewerten Lehrer? : Die Bedeutung grammatischer und lexikalischer Faktoren bei der Benotung von Schülertexten im Fach Deutsch als Fremdsprache". Licentiate thesis, Linnéuniversitetet, Institutionen för språk (SPR), 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-58056.
Testo completo
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Mondschein, Ryan Joseph. "Structure-Property Relationships of Polyester Regioisomers and Pendant Functionalized Polyetherimides". Diss., Virginia Tech, 2019. http://hdl.handle.net/10919/101706.
Testo completoAbstract (sommario):
Step-growth polymerization enabled the synthesis of novel polyester regioisomers and pendant functionalized polyetherimides (PEI)s. Novel monomers incorporated at targeted mol % produced series of polyesters and PEIs, suitable for systematic analysis of key polymer properties. Subsequent compositional, thermal, mechanical, and rheological characterization forged structure-property relationships to further understand the influence of composition on performance. Altering regiochemistry is a subtle way to maintain the same polymer composition but tune desired properties. Similarly, introducing functional pendant groups expands the property profile of common industrial polymers and installs a handle for secondary chemistry after synthesizing the main polymer. Both altering regiochemistry and adding pendant groups alters polymer properties without the need for large changes in synthetic requirements or reaction conditions, ideal for industrial adoption.
Incorporation of a kinked bibenzoate (BB)-based diester monomers into the commonly utilized linear regioisomer afforded processable amorphous and semi-aromatic (co)polyesters. BB-(co)polyesters with ethylene glycol (EG) possessed improved barrier performance compared to poly(ethylene terephthalate) (PET) while improving on mechanical properties, including tensile and flexural modulus/strength, rivaling bisphenol-A polycarbonate (BPA-PC). Replacement of EG with 1,4-cyclohexanedimethanol (CHDM) improved thermal properties closer to BPA-PC, while enabling melt rheological analysis due to its amorphous morphology. Time-temperature superposition (TTS) analysis produced master curves provided insight into the entanglement molecular weight (Me) and entanglement density. More kinked structures possessed a lower Me and more entanglements.
Introducing kinked monomers posed the question of cyclic speices generation during polymerization, common in step-growth reactions. Thus, systematic incorporation of meta-substituted hydroxyethylresorcinol and para-substituted hydroxyethylhydroquinone regioisomers into PET analogues enabled the characterization of cyclic formation due to monomer regioisomers. Increased meta substitution produced increased amounts of cylic species, analyzed by size exclusion chromatography (SEC).
Adding functionality to high performance polyetherimides (PEI)s is difficult due to the high temperatures required for processing. The lack of thermal stability for commonly utilized H-bonding/reactive groups limits viable moieties. Utilizing the high temperture processing, PEIs incorporating pendant carboxylic acids reacted in the melt to form branched PEIs. These branched PEIs exhibited steeper shear thinning as well as improved flame resistance, limited in thin film commercial PEIs.Doctor of Philosophy
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Pisipati, Padmapriya. "Synthesis and Characterization of Solution and Melt Processible Poly(acrylonitrile-co-methylacrylate) statistical copolymers". Diss., Virginia Tech, 2015. http://hdl.handle.net/10919/73150.
Testo completoAbstract (sommario):
Polyacrylonitrile (PAN) and its copolymers are used in a wide variety of applications ranging from textiles to purification membranes, packaging material and carbon fiber precursors. High performance polyacrylonitrile copolymer fiber is the most dominant precursor for carbon fibers. Synthesis of very high molecular weight poly(acrylonitrile-co-methyl acrylate) copolymers with weight average molecular weights of at least 1.7 million g/mole were synthesized on a laboratory scale using low temperature, emulsion copolymerization in a closed pressure reactor. Single filaments were spun via hybrid dry-jet gel solution spinning. These very high molecular weight copolymers produced precursor fibers with tensile strengths averaging 954 MPa with an elastic modulus of 15.9 GPa (N = 296). The small filament diameters were approximately 5 'm. Results indicated that the low filament diameter that was achieved with a high draw ratio, combined with the hybrid dry-jet gel spinning process lead to an exponential enhancement of the tensile properties of these fibers.
Carbon fibers for polymer matrix composites are currently derived from polyacrylonitrile copolymer fiber precursors where solution spinning accounts for ~40 % of the total fiber production cost. To expand carbon fiber applications into the automotive industry, the cost of the carbon fiber needs to be reduced from $8 to ~$3-5. In order to develop an alternative melt processing route several benign plasticizers have been investigated. A low temperature, persulfate-metabisulfite initiated emulsion copolymerization was developed to synthesize poly(acrylonitrile-co-methyl acrylate) copolymers with acrylonitrile contents between 91-96 wt% with a molecular weight range of 100-200 kg/mol. This method was designed for a potential industrial scale up. Furthermore, water was investigated as a potential melting point depressant for these copolymers. Twenty-five wt% water lead to a decrease in the Tm of a 93/7 wt/wt % poly(acrylonitrile-co-methyl acrylate) of Mw = 200 kg/mol to 160 0C as measured via DSC.
Glycerin, ethylene glycol and glycerin/water combinations were investigated as potential plasticizers for high molecular weight (~200,000 g/mol), high acrylonitrile (93-96 mole:mole %) content poly(acrylonitrile–co-methyl acrylate) statistical copolymers. Pure glycerin (25 wt %) induced crystallization followed by a reduced "Tm" of about 213 °C via DSC. However this composition did not melt process well. A lower MW (~35 kg/mol) copolymer did extrude with no apparent degradation. Our hypothesis is that the hydroxyl groups in glycerin (or water) disrupt the strong dipole-dipole interactions between the chains enabling the copolymer endothermic transition (Tm) to be reduced and enable melting before the onset of degradation. Additionally high molecular weight (Mw = 200-230 kg/mol) poly(acrylonitrile–co-methyl acrylate) copolymers with lower acrylonitrile content (82-85 wt %) were synthesized via emulsion copolymerization and successfully melt pressed. These materials will be further investigated for their utility in packaging applications.Ph. D.
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Пестунов, В. М., В. В. Свяцкий, Л. П. Свяцкая, V. Pestunov, V. Sviatskyi e L. Sviatska. "Разработка привода по условиям оптимальной стойкости инструмента и производительности процесса глубокого сверления". Thesis, „Бял ГРАД - БГ” ООД, 2008. http://dspace.kntu.kr.ua/jspui/handle/123456789/6495.
Testo completoAbstract (sommario):
Разработан привод исходя из условий оптимальной стойкости инструмента и производительности процесса глубокого сверления.The drive based on the conditions of optimum tool stability and the performance of the deep drilling process is designed.
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Schönström, Krister. "Tvåspråkighet hos döva skolelever : Processbarhet i svenska och narrativ struktur i svenska och svenskt teckenspråk". Doctoral thesis, Stockholms universitet, Institutionen för lingvistik, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-39917.
Testo completoAbstract (sommario):
This dissertation examines the language proficiency of school-aged deaf pupils from a bilingual perspective. The first aim of the study is to investigate the Swedish L2 skills of the pupils. This includes testing the validity of the Processability Theory on deaf learners of Swedish as an L2. The second aim is to investigate whether there is a correlation between proficiency in Swedish and Swedish Sign Language (SSL) as suggested in earlier research on deaf bilingualism. This study is cross-sectional and contains data from 38 pupils (grades 5 and 10) from a school for deaf and hearing-impaired pupils in Sweden. The data consists of retellings of a cartoon in written Swedish and of free stories in SSL. For the first part of the study, the Swedish data has been analyzed according to Processability Theory (PT). For the second part of the study, narrative structure in both the Swedish and SSL data has been analyzed. As a theoretical framework, Labov’s narrative model is applied. The results show that there is an implicational order in the informants’ development of Swedish following the predicted grammatical learning order described by PT. The results therefore suggest that PT is a valid theory also for deaf learners of L2 Swedish. The conclusions regarding SSL proficiency suggest that more research about sign language as such is needed to get a deeper understanding of SSL proficiency. The results show that one narrative component of Labov’s model - Evaluation - is an important component in SSL proficiency. The results from the comparative analysis show that there is a positive statistical correlation between some Swedish and SSL variables used in this study, suggesting that skills in Swedish correlate with skills in SSL. This means that a well-developed sign language is important for the deaf to learn any written language as a second language.
38
Hansson, Frida. "Processbarhetsteorin tillämpad på elevers skriftliga produktion : En studie baserad på nyanländas elevtexter i högstadiet". Thesis, Linnéuniversitetet, Institutionen för svenska språket (SV), 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-80213.
Testo completoAbstract (sommario):
Det är vanligt att elever befinner sig på olika kunskapsnivåer i en undervisningsgrupp och för att ta reda på vilka nivåer de befinner sig på går det att tillämpa Processbarhetsteorin. Det är en teori utformad av Manfred Pienemann för att studera hur inlärare processar grammatiska strukturer. Uppsatsen är främst byggd på en kvalitativ ansats på grund av de kvalitativa analyserna men även på en kvantitativ ansats då elevernas texter som är analyserade har räknats i procent och presenterats i fördelningar med hjälp av tabeller. Den deltagande gruppen bestod av 15 elever i en förberedelseklass med blandade åldrar från årskurs 7-9. Analyserna baserades på Processbarhetsteorin enligt Flyman Mattssons och Håkanssons analysmodell (2010, s. 66-75). Resultaten visade att eleverna i undervisningsgruppen, vars texter analyserades, befann sig på olika PT-nivåer och det förekom även olika typer av grammatiska strukturer bland eleverna. Majoriteten av eleverna processade grammatiska strukturer för PT-nivå 2 och/eller PT-nivå 3 i uppgift 1 och/eller uppgift 2. De olika resultaten kan bero på faktorer såsom startålder för språkinlärning då alla elever kom till den svenska skolan vid olika tillfällen men den främsta slutsatsen kan vara att de flesta elever i skolan är på olika kunskapsnivåer eftersom det visade sig genom de olika resultaten hos eleverna.
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Duval, Thomas. "Développement de nouveaux alliages thermoplastiques pour l'aéronautique". Thesis, Montpellier 2, 2012. http://www.theses.fr/2012MON20254.
Testo completoAbstract (sommario):
L'objectif de cette thèse est de créer de nouveaux mélanges thermoplastiques présentant une processabilité accrue comparée à des matrices thermoplastiques hautes performances utilisées dans l'industrie aéronautique. Ces matériaux ont vocation à être intégrés en atmosphère avionique pressurisée. Afin de combler le cahier des charges imposé par le domaine aéronautique, le choix des matériaux s'est porté sur un mélange incompatible de polyétheréthercétone PEEK et de polymères à cristaux liquides LCP présentant une morphologie fibrillaire développée grâce à des conditions particulières d'écoulement lors de la mise en oeuvre.Dans un premier temps, les propriétés rhéologiques des matériaux sont caractérisées de manière à confirmer le respect des spécifications relatives à leur processabilité. La compréhension des phénomènes régissant la baisse de viscosité du mélange permet d'assurer la répétabilité et la reproductibilité des performances rhéologiques en vue d'un transfert industriel. L'étude se concentre ensuite sur les propriétés de cristallinité des mélanges, qui permettent de déterminer que la présence de deux matériaux semi-cristallins au sein d'une même structure ne perturbe pas leurs propriétés de cristallinité garantes de leurs performances thermomécaniques.Enfin, une campagne de caractérisation complète est effectuée afin de dresser une fiche matière et de la comparer aux spécifications exigées par l'industrie aéronautiqueThe aim of this thesis is to create new thermoplastic blends exhibiting improved processability incomparison with high performance aeronautical thermoplastics. These materials are dedicated tointegrating pressurized avionic structures.To reach the specific aeronautical specifications, an incompatible polymer blend made ofpolyetheretherketone PEEK and liquid crystalline polymers LCP is chosen. The particular flow conditionsset for the compounding ensure the blend a fibrillar morphology.First, the material rheological properties are characterized so as to confirm that the processabilityspecifications are met. The viscosity drop causes are explained and grant the maintaining of therheological performances in any processing configuration.The study then focuses on the blend crystallinity properties in order to determine whether two interlinkedsemi-crystalline structures do not impede the thermomechanical performances.At last, a characterization campaign is led to compare the blend performances with the demandedaeronautical specifications
40
Lecocq, Eva. "Caractérisation et mise en œuvre de systèmes réactifs polyamide et polyépoxyde formulés pour le rotomoulage de liners de stockage hyperbare". Phd thesis, INSA de Lyon, 2012. http://tel.archives-ouvertes.fr/tel-01015615.
Testo completoAbstract (sommario):
Ce travail s'inscrit dans le développement de formulations performantes et processables pour les liners de réservoirs de stockage hyperbare. Une large gamme de formulations à base polyamide et polyépoxyde a ainsi été synthétisée en conditions contrôlées, représentatives du procédé de rotomoulage. Les systèmes polyamide ont été modifiés par copolymérisation statistique et les polyépoxydes par une phase dispersée micro- ou nano-structurée avec des thermoplastiques de haute Tg ou des copolymères blocs. Les propriétés morphologiques, thermiques, mécaniques et barrière de chaque formulation ont été caractérisées et confrontées au cahier des charges du matériau. En parallèle, l'influence des conditions opératoires et de la formulation sur les rhéocinétiques de polymérisation, de cristallisation, de gélification et/ou de séparation de phase a ainsi été établie. L'ensemble de ces résultats a été mis à profit afin d'identifier des relations structures - propriétés - processabilité en vue de l'application. Afin de valider le potentiel des formulations retenues, ces dernières ont été rotomoulées en conditions opératoires variables avec un suivi in situ de l'écoulement et ex situ de la viscosité. Ce travail a permis d'établir les fenêtres de processabilité de chaque formulation et de comprendre l'origine des défauts d'écoulement.
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Пестунов, В. М., В. В. Свяцкий, Л. П. Свяцкая, V. Pestunov, V. Sviatskyi e L. Sviatska. "Элементы системы СПИД, ограничивающие выходные характеристики процесса глубокого сверления". Thesis, Nauka i studia, 2008. http://dspace.kntu.kr.ua/jspui/handle/123456789/6496.
Testo completoAbstract (sommario):
Рассмотрены элементы системы СПИД, ограничивающие выходные характеристики процесса глубокого сверления. Предложен механизм подачи с изменяемой величиной вылета инструмента, позволяющий повысить ефективность обработки глубоких отверстий. Elements of the machine-fixture-tool-workpiece system that limit the output characteristics of the deep hole drilling process are considered. A feed mechanism with variable tool discharge size is proposed, which makes it possible to improve the efficiency of processing deep holes.
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Eklund, Heinonen Maria. "Processbarhet på prov : Bedömning av muntlig språkfärdighet hos vuxna andraspråksinlärare". Doctoral thesis, Uppsala universitet, Institutionen för nordiska språk, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-9524.
Testo completoAbstract (sommario):
This dissertation concerns oral language tests from a grammatical perspective. Tests today are usually assessed based on a communicative approach to language, so it is interesting to see how great a significance the level of grammatical development of test takers has for their communicative competence in general. The data in the investigation consist of recorded test conversations from a Swedish national language proficiency test, Tisus (test in Swedish for university and university college studies). The general aim of the study is to investigate whether there is a difference between the test takers who passed and those who failed in terms of their level of grammatical development. This is investigated in one main study and two smaller follow-up studies. The theoretical basis for this work is comprised of theories on second language learning and theories on language testing. For the grammatical analysis, Pienemann’s processability theory (PT) is applied. This theory posits that learners acquire certain morpho-syntactic structures in a particular order, something that produces a hierarchy consisting of five levels. In the main study, a quantitative analysis is made of the test takers’ level of grammatical development relative to their TISUS results. The results show a clear correlation between grammatical level and test results. There also seems to be a kind of watershed at level 4, given that most of the test takers who passed have command of this level in the PT hierarchy, whereas those who failed, as a rule, only make it to level 3. The first follow-up study is more qualitative in nature and is focused on the test takers who deviate from the general pattern of results in the main study: those who failed despite their high grammatical level and those who passed despite their low grammatical level. One result of this follow-up study is that, in these cases, it appears communicative competence was critical. Being able to orient oneself to the special conversational situation represented by the test conversation is considered to be particularly important. In a second follow-up study, the problems of applying PT to morphology and syntax are examined. The results of the dissertation suggest that there is a correlation between grammatical competence and communicative competence in general. This means that the grammatical levels in the PT hierarchy may constitute a useful basis of analysis in oral assessments, as a complement to other assessment tools.
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Stål, Eva-Lena. "Skriftspråklig kompetens hos andraspråksinlärare : Analys av godkända texter från Tisustest och Nationella prov i Svenska som andraspråk B". Thesis, Karlstads universitet, Estetisk-filosofiska fakulteten, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-13993.
Testo completoAbstract (sommario):
Denna studie bygger på andraspråksinlärares skriftliga kompetens kopplad till syntaktiska och kommunikativa nivåer. I synnerhet är syftet att studera språkliga syntaktiska nivåer i texter skrivna av andraspråksinlärare som har behörighet att studera vid universitet. Ytterligare ett syfte är att studera om innehållet i texter kan förmedlas på ett kommunikativt och idiomatisk sätt. Den teoretiska ramen för att mäta syntaktiska nivåer som informanter i denna studie har uppnått bygger på processbarhetsteorin (Pienneman, 1998/ Pienneman & Håkansson, 1999). Studien visar att godkända texter i Svenska som andraspråk B och Tisustest uppnår nivå 4 och 5 på syntaktisk nivå. Studien visar också på variation av kommunikativ kompetens utifrån förmågan att förmedla ett central innehåll. Informanterna uppnår delvis målspråksnormen och delvis avviker från målspråksnormen i varierad grad vilket påverkar den kommunikativa kompetensen. Det mesta av resultatet pekar på individuella skillnader. Vad som kan förklara skillnader mellan informanterna kan delvis kopplas till varierad kognitiv svårighetsgrad i texterna. Studien visar att processbarhetsteorin kan vara ett fördelaktigt verktyg för att mäta syntaktiska nivåer i texter. Dock pekar studien på att det är av vikt att också genomföra en mer omfattande bedömning av kommunikativa språkkunskaper för att kunna göra en helhetsbedömning av skriftlig språkkompetens av andraspråksinlärare.The present study concerns second language learners' syntactic and communicative competence in writing. The aim is to study syntactic performances in texts written by learners of Swedish as a second language permitted to study at university. Another aim is to discuss the communicative and idiomatic performances of the informants. The theoretical framework used for assessment of achieved syntactic levels is the Processability Theory (Pienneman, 1998/Pienneman & Håkansson, 1999). The results reveal that the students who´s texts in Svenska som andraspråk B[1]and the Tisustest[2]have passed the exam have achieved either syntactic level 4 or 5 according to Processability Theory. The study also reveals the variety of communicative and idiomatic competence based on the ability to convey a core content. The informants partly achieve and partly do not achieve the Swedish language norms, in various degrees, which effects the level of communicative competence which they are able to express. The results point to more or less individual differences. There are small differences between the group of informants in Svenska som andraspråk B and in the Tisustest. Possible causes for these differences may partly be connected to the varying degree of cognitive difficulty in producing the different texts. The study shows that the use of Processability Theory may be a beneficial tool to measure levels of syntactic proficiency levels in second language learner texts. However, it appears that it also is important to establish a comprehensive assessment of communicative language skills in order to make an overall assessment of written language skills of second language learners. [1]Swedish as a second language, level B [2]Tisus - Test in Swedish for university studies.
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Czaholi, Attila. "Morphosyntactic competence of adult learners of English in Sweden : The impact of L2 exposure outside school and highest completed education on morphosyntactic development". Thesis, Linnéuniversitetet, Institutionen för språk (SPR), 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-81307.
Testo completoAbstract (sommario):
The aim of this study was to investigate the morphosyntactic development of Grundvux learners (adult learners who study school subjects at elementary school levels in Sweden) of English with the aid of Processability theory, or PT, and to investigate the potential influence of exposure to English outside school and the participants' highest completed formal education on the participants' morphosyntactic levels. The participants of this study were Grundvux learners who studied English either on National Course 2, 3, or 4. This study also investigated how similar or different Course 2, 3 and 4 participants were when it comes to their highest attained PT-levels. The participants described a picture series and answered questions about their highest completed education from their home countries and how much they tend to be exposed to English on a weekly basis outside school. The results show that Course 2, 3 and 4 participants have both similarities and differences regarding their highest attained PT-levels. The results also show that there could be a possible connection between educational background and morphosyntactic development, i.e. that educational background can have a solid influence on morphosyntactic development. Furthermore, this study shows that a connection between exposure to English outisde school and morphosyntactic development is not likely. Yet, more research with more participants and tasks with different instructions are needed to draw definitie conclusions about the effects of exposure to English outside school and highest completed education on learners' morphosyntactic development. Lastly, this study provides some information to in-service teachers about what morphosyntactic structures to teach and when based on the learners' highest attained PT-levels.
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Nordborg, Martin. "Målspråksriktig svenska : - en studie kring betydelsen av fri och bunden ordföljd". Thesis, Karlstads universitet, Institutionen för språk, litteratur och interkultur, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-45819.
Testo completoAbstract (sommario):
Syftet med denna studie har varit att undersöka hur olika ordföljdsprinciper i ett förstaspråk påverkar inlärningen av ordföljden i andraspråket svenska. Två grupper jämfördes där den ena hade ett förstaspråk med en bunden ordföljd baserad på den grammatiska principen och den andra ett förstaspråk med en fri ordföljd baserad på tema-rema-principen. Respondenterna bestod av elever inom den kommunala vuxenutbildningen i en västsvensk kommun som gick och läste på Sfi och SAS Grund. Varje respondent fick i uppgift att fritt skriva en kort uppsats. Texterna analyserades därefter ingående för att kunna identifiera vilka sats- och textgrammatiska ordföljdsfel som hade gjorts. Resultatet visade att de båda grupperna gjorde ungefär samma typ av satsgrammatiska fel men att gruppen med ett förstaspråk med fri ordföljd gjorde något fler textgrammatiska fel. Medan flera andra studier lyfter fram övergeneralisering av tema-rema-principen som det största problemet ur textgrammatisk synvinkel för denna senare grupp, fann jag att det snarare var underanvändning av tema-rema-principen som var problematiskt.The purpose of this study was to examine how different word order principles in a first language influence the learning of word order in Swedish as second language. Two groups were compared in which one had a first language with a bound word order based on the grammatical principle and the other a first language with a free word order based on the topic-comment-principle. Respondents consisted of students in municipal adult education in a western Swedish municipality who studied at SFI and SAS Basic. Each respondent were asked to freely write a short essay. The texts were then analyzed in detail to identify which batch- and text grammatical word order inaccuracy that had been made. The results showed that both groups did about the same type of grammatical errors, but that the group with a first language with free word order did some more text grammatical errors. While several other studies highlight the generalization of the topic-comment-principle as the biggest problem for this latter group, I found that it was rather the lack of use of the topic-comment-principle that was problematic.
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Беспалий, В. О. "Удосконалення технологічного процесу виготовлення втулки 252.014.00.04 шляхом застосування високопродуктивних інструментів та оснастки". Master's thesis, Сумський державний університет, 2020. https://essuir.sumdu.edu.ua/handle/123456789/81332.
Testo completoAbstract (sommario):
Записка: 106 с., 21 рис., 11 табл., 9 додатків, 59 посилань.
Об'єкт розробки – деталь «Втулка 252.014.00.04», що входить до складу газоперекачувального агрегата.
В даному дипломному проекті за освітним рівнем магістра проаналізували службове призначення виробу - газоперекачувального агрегата, вузла та деталі «Втулка», крім того технічні вимоги з показниками технологічності конструкцій деталі. Було обгрунтувано вибір методу отримання заготовки поковкою, були розраховані припуски на діаметральний розмір.
Також для операцій 025, 030 и 035 було проведено аналіз з обгрунтуванням схем базування деталі; обгрунтовано вибір металорізального устаткування, верстатного пристрою, різальних та вимірювальних інструментів; було проведено розрахунки режимів різання та нормування розглянутих операцій.
Спроектовано спеціальний верстатний пристрій для фрезерної з ЧПК операції. Досліджено напруги та деформації в системі фрезерного верстата. Проведено комп'ютерне моделювання деформацій, переміщень і напружень елементів верстата.
Оформлено карти технологічного процесу обробки деталі «Втулка 252.014.00.04».Записка: 106 с., 21 рис., 11 табл., 9 приложений, 59 ссылок. Объект разработки - деталь «Втулка 252.014.00.04», входящая в состав газоперекачивающего агрегата. В данном дипломном проекте по образовательным уровнем магистра проанализировали служебное назначение изделия - газоперекачивающего агрегата, узла и детали «Втулка», кроме того технические требования по показателям технологичности конструкций детали. Было обгрунтувано выбор метода получения заготовки поковки, были рассчитаны припуски на диаметральный размер. Также для операций 025, 030 и 035 был проведен анализ с обоснованием схем базирования детали; обоснованный выбор металлорежущего оборудования, станочного устройства, режущих и измерительных инструментов; было проведено расчеты режимов резания и нормирования рассмотренных операций. Спроектировано специальное станочный устройство для фрезерной с ЧПУ операции. Исследована напряжения и деформации в системе фрезерного станка. Проведено компьютерное моделирование деформаций, перемещений и напряжений элементов станка. Оформлено карты технологического процесса обработки детали "Втулка 252.014.00.04».
Report: 106 pages, 14 tables, 24 pictures, 9 additions, 59 sources. The object of researching is part «Sleeve 252.014.00.04», which is part of the gas pumping unit. In the given diploma project on the educational and qualification level of the master, the official purpose of the product- gas pumping unit and part «Sleeve», as well as technical requirements and technological indicators of the part design are analyzed. The choice of the method of obtaining the initial blank by stamping was justified, machining allowances for diametral dimension were calculated. For operations 025, 030 and 035 an analysis and justification of the workpiece basing scheme were carried out; the choice of metal-cutting machines, tools, cutting and measuring tools is justified; the cutting conditions were calculated and operations were normalized. A special fixture for CNC milling operation has been designed. The stresses and deformations in the milling machine system are investigated. Computer simulation of deformations, displacements and stresses of machine elements has been carried out. The cards of the manufacturing process of the «Sleeve 252.014.00.04» are issued.
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Ferri, Dino <1968>. "Correlazioni tra proprietá reologiche, struttura e processabilitá di blend di LLDPE/LDPE". Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2010. http://amsdottorato.unibo.it/2396/.
Testo completoAbstract (sommario):
Polymer blends constitute a valuable way to produce relatively low cost new materials. A still open question concerns the miscibility of polyethylene blends. Deviations from the log-additivity rule of the newtonian viscosity are often taken as a signature of immiscibility of the two components. The aim of this thesis is to characterize the rheological behavior in shear and elongation of five series of LLDPE/LDPE blends whose parent polymers have been chosen with different viscosity and SCB content and length. Synergistic effects have been measured for both zero shear viscosity and melt strength. Both SCB length and viscosity ratio between the components have been found to be key parameters for the miscibility of the pure polymers. In particular the miscibility increases with increasing SCB length and with decreasing the LDPE molecular weight and viscosity.
This rheological behavior has significant effects on the processability window of these blends when the uni or biaxial elongational flows are involved. The film blowing is one of the processes for which the synergistic effects above mentioned can be crucial. Small scale experiments of film blowing performed for one of the series of blends has demonstrated that the positive deviation of the melt strength enlarges the processability window. In particular, the bubble stability was found to improve or disappear when the melt strength of the samples increased.
The blending of LDPE and LLDPE can even reduce undesired melt flow instability phenomena widening, as a consequence, the processability window in extrusion. One of the series of blends has been characterized by means of capillary rheometry in order to allow a careful morphological analysis of the surface of the extruded polymer jets by means of Scanning Electron Microscopy (SEM) with the aim to detect the very early stages of the small scale melt instabilty at low shear rates (sharksin) and to follow its subsequent evolution as long as the shear rate was increased. With this experimental procedure it was possible to evaluate the shear rate ranges corresponding to different flow regions: smooth extrudate surface (absence of instability), sharkskin (small scale instability produced at the capillary exit), stick-slip transition (instability involving the whole capillary wall) and gross melt fracture (i.e. a large scale "upstream" instability originating from the entrance region of the capillary). A quantitative map was finally worked out using which an assessment of the flow type for a given shear rate and blend composition can be predicted.
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Håkansson, Gloria. "Att testa flerspråkiga elevers språkförmåga : ett specialpedagogiskt perspektiv". Thesis, Högskolan Kristianstad, Fakulteten för lärarutbildning, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:hkr:diva-19049.
Testo completoAbstract (sommario):
Barn och elever som inte utvecklar det svenska språket som förväntat utreds med olika språktester. I denna studie undersöker jag ett vanligt förekommande testmaterial, som används för att kartlägga barns och elevers språkutveckling. Flerspråkiga elever som har språkliga svårigheter måste visa svårigheter på samtliga sina språk för att kunna diagnostiseras med språkstörning eller med läs- och skrivsvårigheter. Eleverna testas med bland andra Trog-2, ett språktest för bedömning av receptiva grammatiska färdigheter, men som inte är normerat för flerspråkiga elever. Syftet med studien är att undersöka om det nämnda testmaterialet, Trog-2, kan fånga de olika språkstrukturer som det avser att mäta när man översätter testets begrepp och grammatiska strukturer till modern standardarabiska (MSA) och libanesisk dialekt. Trog-2 analyseras med hjälp av min egenutvecklade modell, S T O. Denna modell anger tre nivåer av överensstämmelse när det gäller begrepp och grammatiska strukturer när test översätts från ett språk till ett annat. Resultatet visar att i Trog-2 finns grammatiska strukturer som helt saknas i MSA och i libanesisk dialekt, eller att de är svåra eller omöjliga att översätta utan att de går förlorade i översättningen. Det finns också strukturer som det fungerar bra att översätta med bibehållen grammatisk struktur.Pupils who do not develop their Swedish language as expected are investigated with several language tests. In this thesis I translate a part of a commonly used test, which is used to assess children’s language acquisition. Multilingual pupils who have language difficulties have to show difficulties in all their languages to make the conclusion that they have a language impairment. The pupils are tested with among others Trog-2, Test for reception of grammar and it is not standardized for this group. In this thesis I study what happens with grammar constructions in Trog-2 when they are translated to Modern Standard Arabic (MSA) and the Lebanese vernacular. This test is used on multilingual pupils with the assistance of an interpreter. Trog-2 was been analysed using my model, which I call S T O. This model specifies three levels of grades of differences in grammatical structures and concepts when translated from one language to another. The results show that there are a number of grammatical structures that are completely missing in translation or that are difficult to translate while maintaining the grammatical structures. However, there are structures which can be translated while maintaining the grammatical structures.
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Gai, Jing-Gang. "Etudes théoriques et expérimentales de la processabilité du polyéthylène à ultra-haute masse molaire". Thesis, Vandoeuvre-les-Nancy, INPL, 2009. http://www.theses.fr/2009INPL039N/document.
Testo completoAbstract (sommario):
Aujourd’hui le développement de nouveaux matériaux polymères ayant de bonnes propriétés repose de plus en plus sur des procédés de mélange ou de compoundage de polymères au lieu de recourir à la synthèse de nouvelles molécules. L’action du mélange peut fortement influer sur la morphologie des matériaux polymères multi-constituants. Les extrudeuses bi-vis (TSE) sont souvent utilisées comme mélangeurs/réacteurs pour des procédés de mélange, de compoundage et d’extrusion réactive. Cependant, l’étude sur la qualité du mélange dans les TSE demeure un grand défi en raison de la complexité géométrique et du caractère transitoire de l’écoulement. Cette thèse a pour objet de développer un nouvel instrument en line pour mesurer en temps réel la distribution des temps de séjour (DTS) qui caractérise la performance du mélange axial et la capacité de convoyage de différents types d’éléments de vis basées sur l’analyse de l’écoulement transitoire et l’évaluation systématique de la théorie de mélange dans les TSE. Le mélange distributif des polymères fondus est caractérisé par la génération de l’aire des interfaces, un paramètre difficile à mesurer expérimentalement. Alors on fait appel à des simulations numériques de type CFDThe development of new materials with improved properties seems to rely nowadays more on blending and compounding than on the synthesis of chemically new polymers. Mixing may have a great effect on the morphology and structure of multi-component polymer materials. Twin-screw extruders (TSE) are widely used as mixers/reactors for blending, compounding, and reactive processing. This work aimed at developing a new instrument to measure in real time the residence time distribution (RTD) which characterizes the axial mixing and transport abilities of different screw elements based on the analysis of the transient flow pattern and systematic evaluation of mixing theory in TSE. Distributive mixing of polymer melts is characterized by the generation of interfacial area, which is experimentally much more difficult to measure. This 3D numerical simulation based on CFD is adopted
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Philipsson, Anders. "Interrogative Clauses and Verb Morphology in L2 Swedish : Theoretical Interpretations of Grammatical Development and Effects of Different Elicitation Techniques". Doctoral thesis, Stockholm : Centre for Research on Bilingualism, Stockholm University, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-6847.
Testo completo