Global ETD Search

171	Bioinspired Surface for Low Drag, Self-Cleaning, and Antifouling: Shark Skin, Butterfly and Rice Leaf Effects Bixler, Greg January 2013 (has links) No description available. Mechanical Engineering Nanotechnology Fluid Dynamics Shark skin lotus leaf rice and butterfly wing effect drag reduction self-cleaning antifouling embossed film fish scale butterfly wing rice leaf rice leaf inspired
172	Extendable ladder cover solution for swedish fire vehicles Molbeck Blyth, Marco Aurelio, Acosta Vega, María Isabel January 2016 (has links) The following thesis project has been done in direct collaboration with Autokaross i Floby AB Rescue Vehicle Department, in Sweden. The report contains the design development of a protective cover against weather conditions for the extendable ladder in a fire vehicle. The aim of the report has been to develop a functional and low cost solution cover for the FEL on a fire truck, which is allocated on the roof, with the express intention of providing adequate access and protection against weather conditions in Nordic countries, so as to prevent premature deterioration of the FEL unit. The company has set the technical and conceptual boundaries, with the help of the two previous concepts currently used, the BMC and the ACP. The initial requirements laid out by the company were expressed through a number of specific demands which can be categorized in two main points: Cost: Designing a solution keeping in mind cost limits, assembly cost and time, and space optimization. This was done by taking into account the two existing solutions, particularly the BMC, which represents the lowest, cost wise and function wise. Therefore it was used as the basis on which to apply improvements, rather than trying to lower the high cost on the overqualified function of the ACP. Function: Providing the adequate protection and access to the FEL. In this case, the problem was solved by establishing the correct degree of protection relevant to the Nordic weather conditions and FEL needs, and regarding the access, this was assured by fully automating the opening/closing process with the existing extraction operating system of the FEL. The result of this report is a concept solution which meets the company’s demands, obtained by creative detailing, together with an analysis regarding possible considerations that could improve the creative detailing result in this report in the form of future work. The report documents the process that has taken place in exploration, concept generation, concept evaluation, concept selection, and detailed CAD development. Each section shows the requirements and adjustments taken to fulfil the company’s needs. Extendable ladder Cover Weather Conditions Box Manual Cover (BMC) Automatic Cover Panel (ACP) Fire Truck Cabin Creative detailing User Height Automatic Unfolding Procedure Packaging Process Fixed Extendable Ladder (FEL) Transportable Extendable Ladder (TEL) Mock-up ionized aluminium C-box Concept tree Lotus Blossom Low Fidelity Prototyping
173	Protoplast fusion of Lolium perenne and Lotus corniculatus for gene introgression Raikar, S. V. January 2007 (has links) Lolium perenne is one of the most important forage crops globally and in New Zealand. Lotus corniculatus is a dicotyledonous forage that contains valuable traits such as high levels of condensed tannins, increased digestibility, and high nitrogen fixing abilities. However, conventional breeding between these two forage crops is impossible due to their markedly different taxonomic origin. Protoplast fusion (somatic hybridisation) provides an opportunity for gene introgression between these two species. This thesis describes the somatic hybridisation, the regeneration and the molecular analysis of the putative somatic hybrid plants obtained between L. perenne and L. corniculatus. Callus and cell suspensions of different cultivars of L. perenne were established from immature embryos and plants were regenerated from the callus. Of the 10 cultivars screened, cultivars Bronsyn and Canon had the highest percentage of callus induction at 36% each on 5 mg/L 2,4-D. Removal of the palea and lemma which form the seed coat was found to increase callus induction ability of the embryos. Plant regeneration from the callus was achieved when the callus was plated on LS medium supplemented with plant growth regulators at different concentrations. Variable responses to shoot regeneration was observed between the different cultivars with the cv Kingston having the lowest frequency of shoot formation (12%). Different factors affecting the protoplast isolation of L. perenne were investigated. The highest protoplast yield of 10×10⁶ g⁻¹FW was obtained when cell suspensions were used as the tissue source, with enzyme combination 'A' (Cellulase Onozuka RS 2%, Macerozyme R-10 1%, Driselase 0.5%, Pectolyase 0.2%), for 6 h incubation period in 0.6 M mannitol. Development of microcolonies was only achieved when protoplasts were plated on nitrocellulose membrane with a L. perenne feeder layer on PEL medium. All the shoots regenerated from the protoplast-derived calli were albino shoots. The highest protoplast yield (7×10⁶ g⁻¹FW) of L. corniculatus was achieved from cotyledons also with enzyme combination 'A' (Cellulase Onozuka RS 2%, Macerozyme R-10 1%, Driselase 0.5%, Pectolyase 0.2%), for 6 h incubation period in 0.6 M mannitol. The highest plating efficiency for L. corniculatus of 1.57 % was achieved when protoplasts were plated on nitrocellulose membrane with a L. perenne feeder layer on PEL medium. The highest frequency of shoot regeneration (46%) was achieved when calli were plated on LS medium with NAA (0.1 mg/L) and BA (0.1 mg/L). Protoplast fusion between L. perenne and L. corniculatus was performed using the asymmetric somatic hybridisation technique using PEG as the fusogen. L. perenne protoplasts were treated with 0.1 mM IOA for 15 min and L. corniculatus protoplasts were treated with UV at 0.15 J/cm² for 10 min. Various parameters affecting the fusion percentage were investigated. Successful fusions were obtained when the fusions were conducted on a plastic surface with 35% PEG (3350 MW) for 25 min duration, followed by 100 mM calcium chloride treatment for 25 min. A total of 14 putative fusion colonies were recovered. Shoots were regenerated from 8 fusion colonies. Unexpectedly, the regenerated putative hybrid plants resembled L. corniculatus plants. The flow cytometric profile of the putative somatic hybrids resembled that of L. corniculatus. Molecular analysis using SD-AFLP, SCARs and Lolium specific chloroplast microsatellite markers suggest that the putative somatic hybrids could be L. corniculatus escapes from the asymmetric protoplast fusion process. This thesis details a novel Whole Genome Amplification technique for plants using Strand Displacement Amplification technique. Lolium perenne Lotus corniculatus callus cell suspension protoplasts shoot regeneration protoplast fusion polyethylene glycol plant growth regulators putative hybrid colonies whole genome amplification strand displacement amplification
174	LA PLACE D'UNE TECHNOLOGIE D'INFORMATION ET DE COMMUNICATION DANS LE PROCESSUS DE STRUCTURATION D'UNE ORGANISATION : Le cas de l'usage d'une messagerie électronique Fereyre, Florian 01 July 2010 (has links) (PDF) Ce travail de recherche tente d'appréhender la place occupée par une technologie d'information et de communication (TIC) au sein de la théorie de la structuration, développée par Anthony Giddens. Nous avons, dans ce cadre, étudié l'usage d'une messagerie électronique interne Lotus Notes au sein d'une organisation commune à EDF et Gaz de France. Ce travail est fondé sur une analyse de l'usage de cette TIC dans un cadre professionnel, sur l'examen de ses formes de déterminations et sur la caractérisation des logiques dans lesquelles elle s'intègre. Ces phénomènes sont liés aux usages de la messagerie en tant que ressource d'allocation et support pour les ressources d'autorité. Ces activités s'inscrivent dans le processus de contrôle réflexif de l'action des usagers. L'étude de ces phénomènes nous a permis de mettre en évidence l'importance de la messagerie électronique en tant que conteneur d'information, participant à la cueillette, à l'entreposage et au recouvrement d'information, ainsi que la place de ces activités dans le processus de structuration à l'œuvre dans l'organisation considérée. Ces phénomènes traduisent un principe structurel fondé sur le contrôle des échanges et de l'information. Structuration TIC usages pouvoir organisations messagerie électronique EDF Gaz de France Lotus Notes relations au travail contrôle conteneur d'information dualité du structurel contrôle réflexif de l'action ressources d'allocation ressources d'autorité cueillette d'information entreposage d'information recouvrement d'information principe structurel incertitude angoisse micro-actions rationalité technique archivage
175	Stoffübertragung beim Spritzgießen Härtig, Thomas 22 March 2013 (has links) (PDF) Das Fügen mehrerer Komponenten während des Spritzgießprozesses wird bei vielen Spritzgießsonderverfahren angewandt. Diese Arbeit beschäftigt sich mit der Verbundbildung zwischen einem kalten Einlegeteil und der einströmenden Kunststoffschmelze beim Spritzgießen, im Folgenden Stoffübertragung genannt. Ein Großteil der Untersuchungen findet an Zweikomponenten-Zugstäben statt, wobei erste und zweite Komponente aus dem gleichen Thermoplast gefertigt werden. Mögliche Einflussfaktoren auf die Verbundfestigkeit werden zunächst im Theorieteil vorgestellt und diskutiert. Eine Auswahl relevanter Prozess- und Materialparameter wird dann in praktischen Versuchen detailliert analysiert. Es wird nach korrelierenden Tendenzen sowohl zwischen unterschiedlichen Verfahren als auch zwischen verschiedenen Kunststoffen gesucht. Mittels statistischer Versuchsplanung werden die Spritzgießparameterkombinationen nach Größe des Einflusses auf die Verbundfestigkeit sortiert. Dies trägt zum Verständnis der bei der Stoffübertragung ablaufenden Grundmechanismen bei. Weiterhin werden die Einflüsse der Prozessparameter auf das neue Verfahren der In-Mold Oberflächenmodifizierung, bei dem ein funktionaler Modifikator während des Spritzgießprozesses übertragen wird, mit den Ergebnissen der Zweikomponenten-Verbundfestigkeit verglichen. Abschließend wird auf die Besonderheiten bei der selektiven Stoffübertragung eingegangen und das neue Verfahren des In-Mold Printing vorgestellt. / The joining of two components by the process of injection molding is state of the art, although adhesion phenomena are not fully understood yet. The formation of bonds between a cold material, which was inserted or applied onto the surface of the cavity before injection molding, and an injected polymer melt is studied in this work. Providing sufficient bond strength, the material is transferred from the surface of the mold to the injection molded part. Possibly influencing factors on the bond strength are first identified, theoretically discussed, later in experiments varied and finally analyzed. Thereby correlating tendencies between different polymers and different in-mold technologies are observed. The relevant material and processing parameters are put in order by their influence on the bond strength using design of experiments. This helps to understand the mechanisms of the formation of bonds. The majority of the experiments is concerned with two component injection molding by measuring the bond strength of two component tensile bars, produced under varying processing conditions. In each case, first and second components are made of the same thermoplastic polymer. The thermal energy of the melt can be used also to initiate chemical reactions. This permits bonding of a thin layer of a functional polymer, which is applied onto the surface of the mold before injecting the melt, to the surface of the molded part. In this way, process-integrated surface modification during injection molding becomes possible. In a further attempt, patterns of paint are printed onto the surface of the mold by pad printing. During injection molding the paint is transferred completely to the surface of the polymeric part. Using this new technology of In-Mold Printing, fully finished surface decorated parts can be produced by injection molding. Spritzgießen Mehrkomponentenspritzgießen Stoffübertragung In-Mold Printing In-Mold Oberflächenmodifizierung Grenzfläche Grenzschicht Verbundfestigkeit Verbundhaftung Adhäsionsmechanismen Haftung Zweikomponentenspritzgießen Dekoration Kunststoffoberflächen Oberflächenmodifizierung Oberflächenfunktionalisierung two component injection molding multi component injection molding In-Mold Printing In-Mold Surface Modification material transfer interface boundary layer adhesion phenomena bond strength surface functionalization polymer surface decoration ddc:620 Spritzgießen Thermoplast Kunststoff-Metall-Verbund Kunststoff-Metall-Klebeverbindung Kunststoffverpackung Polymerschmelze Kunststoffschweißen Kunststofftechnik Kunststoffverarbeitung Kunststoffindustrie Kunststoffformteil Kunststoffherstellung Kunststoffkleben Kunststoff Kunststoffbauteil Formstoff <Kunststoff> Grenzfläche Grenzflächenphysik Grenzflächenreaktion Korngrenze Grenzschicht Spritzgussform Verbundverhalten Verbund Adhäsion Diffusionsmodell Diffusion Chemische Reaktion Reaktionsdynamik Modifizierung Modifikator Drucken Oberflächenstruktur Oberflächenveredelung Oberfläche <Motiv> Lotus-Effekt Technische Oberfläche Oberflächenprüfung Festkörperoberfläche Flüssigkeitsoberfläche Polymere Spritzgießwerkzeug Farbe <Motiv>
176	Stoffübertragung beim Spritzgießen Härtig, Thomas 28 February 2013 (has links) Das Fügen mehrerer Komponenten während des Spritzgießprozesses wird bei vielen Spritzgießsonderverfahren angewandt. Diese Arbeit beschäftigt sich mit der Verbundbildung zwischen einem kalten Einlegeteil und der einströmenden Kunststoffschmelze beim Spritzgießen, im Folgenden Stoffübertragung genannt. Ein Großteil der Untersuchungen findet an Zweikomponenten-Zugstäben statt, wobei erste und zweite Komponente aus dem gleichen Thermoplast gefertigt werden. Mögliche Einflussfaktoren auf die Verbundfestigkeit werden zunächst im Theorieteil vorgestellt und diskutiert. Eine Auswahl relevanter Prozess- und Materialparameter wird dann in praktischen Versuchen detailliert analysiert. Es wird nach korrelierenden Tendenzen sowohl zwischen unterschiedlichen Verfahren als auch zwischen verschiedenen Kunststoffen gesucht. Mittels statistischer Versuchsplanung werden die Spritzgießparameterkombinationen nach Größe des Einflusses auf die Verbundfestigkeit sortiert. Dies trägt zum Verständnis der bei der Stoffübertragung ablaufenden Grundmechanismen bei. Weiterhin werden die Einflüsse der Prozessparameter auf das neue Verfahren der In-Mold Oberflächenmodifizierung, bei dem ein funktionaler Modifikator während des Spritzgießprozesses übertragen wird, mit den Ergebnissen der Zweikomponenten-Verbundfestigkeit verglichen. Abschließend wird auf die Besonderheiten bei der selektiven Stoffübertragung eingegangen und das neue Verfahren des In-Mold Printing vorgestellt. / The joining of two components by the process of injection molding is state of the art, although adhesion phenomena are not fully understood yet. The formation of bonds between a cold material, which was inserted or applied onto the surface of the cavity before injection molding, and an injected polymer melt is studied in this work. Providing sufficient bond strength, the material is transferred from the surface of the mold to the injection molded part. Possibly influencing factors on the bond strength are first identified, theoretically discussed, later in experiments varied and finally analyzed. Thereby correlating tendencies between different polymers and different in-mold technologies are observed. The relevant material and processing parameters are put in order by their influence on the bond strength using design of experiments. This helps to understand the mechanisms of the formation of bonds. The majority of the experiments is concerned with two component injection molding by measuring the bond strength of two component tensile bars, produced under varying processing conditions. In each case, first and second components are made of the same thermoplastic polymer. The thermal energy of the melt can be used also to initiate chemical reactions. This permits bonding of a thin layer of a functional polymer, which is applied onto the surface of the mold before injecting the melt, to the surface of the molded part. In this way, process-integrated surface modification during injection molding becomes possible. In a further attempt, patterns of paint are printed onto the surface of the mold by pad printing. During injection molding the paint is transferred completely to the surface of the polymeric part. Using this new technology of In-Mold Printing, fully finished surface decorated parts can be produced by injection molding. info:eu-repo/classification/ddc/620 ddc:620

Page generated in 0.0465 seconds