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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
331

Konverze prezentací mezi platformou LaTeX a Microsoft Power Point / LaTeX and Microsoft Power Point Presentations Convertor

Černý, Lukáš January 2011 (has links)
This work deals with theoretical and practical basis for the creation of converter between LaTeX and Microsoft PowerPoint presentations. It discusses the use of LaTeX and the Beamer class for presentations, programmatic creation of PowerPoint documents using PowerPoint Primary Interop Assemblies and PresentationML. It outlines the use of the scanners and parsers generators GPLEX and GPPG respectively. It deals with the characteristics of today's tools for document conversion. And finally deals with the particular pitfalls of the design, implementation and testing of the application for conversion of documents between LaTeX platform and Microsoft PowerPoint.
332

XML bei der Herstellung von Lehrmaterial

Huebsch, Chris 27 April 2000 (has links)
Gemeinsamer Workshop von Universitaetsrechenzentrum und Professur Rechnernetze und verteilte Systeme (Fakultaet fuer Informatik) der TU Chemnitz. Workshop-Thema: Infrastruktur der ¨Digitalen Universitaet¨ Dieser Beitrag befasst sich mit einer Anwendung von XML fuer die Erstellung von Lehrmaterialien. Das darauf basierende Werkzeug ist in der Lage, sowohl eine Online-Version in HTML als auch eine weiterverarbeitbare (und damit letztendlich ausdruckbare) Latex-Version zu generieren.
333

BibTeX-Frontends unter Unix

Sontag, Ralph 22 February 2001 (has links)
BibTeX gilt als leistungsfähiges Literaturverwaltungsprogramm für LaTeX. In der praktischen Anwendung erweist es sich jedoch als recht spröde und unhandlich. Verschiedene Ansätze versuchen, einige seiner Kanten abzuschleifen. In diesem Vortrag werden einige Tools erwähnt und vorgestellt, die das Leben mit BibTeX unter Unix, speziell Linux, erleichtern sollen.
334

HTML und PDF - Konkurrenz oder Ergänzung?

Sontag, Ralph 27 April 2001 (has links)
Gemeinsamer Workshop von Universitaetsrechenzentrum und Professur "Rechnernetze und verteilte Systeme" der Fakultaet fuer Informatik der TU Chemnitz. Workshop-Thema: Mobilitaet Eine Vielzahl von Browsern und anderen Werkzeugen analysiert, verarbeitet, manipuliert oder erzeugt mehr oder weniger erfolgreich HTML-Dateien. Doch browserspezifische Erweiterungen machen den Nutzern das Leben schwer. Die Übertragung wird dank Firewalls, Filterfunktionen und browserspezifischen Erweiterungen instabil. Lokal gespeicherte Dateien vermeiden dies, erfüllen jedoch andere Wünsche des modernen, mobilen Lerners nicht. Der Einsatz von HTML als Zielformat in der Lehre mit neuen Medien muß gelegentlich überdacht werden. Ein weiterer denkbarer Kandidat ist das PDF-Format, das durch die Einbindung von Hyperlinks, Inhaltsverzeichnissen, Stichwortregistern und sogar Formularen viele Anforderungen an multimediale Lehrmaterialien erfüllt.
335

\LaTeX \today

Riedel, Wolfgang 08 May 2002 (has links)
Gemeinsamer Workshop von Universitaetsrechenzentrum und Professur Rechnernetze und verteilte Systeme der Fakultaet fuer Informatik der TU Chemnitz. Darstellung des aktuellen Standes von LaTeX, ausgehend von konkreten (veralteten) Beispieldokumenten Betrachtung von Dokumentklasse (KOMA-Script), Layout, PDF-Erzeugung
336

Modification of a commercial poly (VDF-co-HFP) copolymer latex

Naidoo, Sarnia January 2019 (has links)
Fluorinated polymers are niche macromolecules that play an essential role in modern life. The special properties of fluorine, including among others, a large electronegativity (ca 3.98), low polarisability, small van der Waal’s radius (135 pm) and the strong C-F bond (ca 485 kJ · mol−1), impart unique properties to organofluorine compounds. Flu-oropolymers exhibit a combination of desirable traits, including high thermal stability, low coefficient of friction, chemical inertness, oleo- and hydrophobicity, and low surface tension. Among the fluoropolymers, polyvinylidene fluoride (PVDF), and copolymers of vinylidene fluoride (VDF) and hexafluoropropylene (HFP), have found applications in the coatings industry as the binder in exterior coatings. The chemical inertness of poly(VDF-co-HFP) copolymer, however, prevents disper-sion of pigments into the coating and also inhibits adhesion of the coating onto substrates. An acrylic modifier polymer is typically added to the poly(VDF-co-HFP) copolymer to improve the dispersion of pigments and the adhesion of the coating. This acrylic copoly-mer is physically blended with the poly(VDF-co-HFP) copolymer on a macromolecular scale (i.e. it forms a thermodynamically miscible blend). The loading of acrylic copolymer in commercial PVDF coatings is often in the range of 20 to 30 % by weight of polymer solids. Typically, copolymers of methyl methacrylate, ethyl acrylate and methacrylic esters are employed. Alternative strategies to overcome the adhesion problem include, among others, chem-ical modification of the surface of the fluoropolymer film. This can be achieved by graft copolymerisation or core shell emulsion polymerisation. These methods are used to funcionalise the polymer chains, while maintaining the desirable properties of the parent polymer. Due to environmental regulations, industry focus has shifted towards develop-ing coatings with a low volatile organic compound (VOC) content. Aqueous, low VOC, air-drying coatings can be formulated directly from the acrylic modified fluoropolymer (AMF) latex and have superior properties to solvent based, high VOC, air-dry coatings. Their advantages include low viscosities, reduced flammability, reduced odour and easy application using conventional equipment. A large portion of the aqueous coatings are sold into the architectural market with over 70 % of architectural paints used in the United States being classified as aqueous. Arkema Inc. has developed a commercial aqueous fluoropolymer latex using the method of seeded emulsion polymerisation. VDF and HFP monomers are randomly copolymerised via emulsion polymerisation. This poly(VDF-co-HFP) copolymer may be used as the seed material in a core-shell polymerisation using acrylic monomers. Kato et al. [49] discloses the preparation of an AMF formulation for poly(VDF-co-HFP) copoly-mer. Preliminary testing of membrane textiles coated with such formulations showed that the AMF coatings degrade under UV irradiation more rapidly than is is expected for poly(VDF-co-HFP) copolymer. The patent indicates that the nature of the product formed by the emulsion polymerisation is not well understood and the product my be either a graft copolymer of a core-shell system. The aim of this research reported in this dissertation was to shed light on the nature of the final product, and to verify the claims made in the above-mentioned patent. Various acrylic monomers were copolymerised via seeded emulsion polymerisation us-ing commercial poly(VDF-co-HFP) copolymer as the seed material. The concentration and the ratios of the monomers were varied according to the formulation guidelines in Kato et al.[49]. ATR-FTIR spectroscopy and19F NMR spectroscopy was used to de-termine the microstructure of the resultant latexes. ATR-FTIR spectra confirmed the presence of C=C and C=O bonds in latexes. This indicates that unreacted acrylic com-ponents are present. The ATR-FTIR spectra of the films indicated the disappearance of the C=C bonds from the latex, which indicates that the monomers are evaporated easily from the latexes during film formation. The 19F NMR spectra confirmed that no modi-fication of the poly(VDF-co-HFP) copolymer backbone took place during the reactions. The particle size distribution graphs showed an increase particle sizes and this suggested that some self polymerisation of the monomer occurred. The viscosity of the latexes were lower compared to the due to the experiments being conducted under dilution. The flow characteristics of the poly(VDF-co-HFP) copolymer was also influenced with some reactions yielding shear thickening latexes as compared to the shear thinning poly(VDF-co-HFP) copolymerc. The reactions also yielded latexes which displayed lower and higher surface tensions than the poly(VDF-co-HFP) copolymer. Therefore, the conclusion may be drawn from this work that core-shell formation occurred during the emulsion copolymerisation, as opposed to grafting of the monomer onto the poly(VDF-co-HFP) copolymer backbone. The claims made in the literature could not be substantiated; in particluar, the reported improvements in film forming ability were not realised. No commercially useful advantage exists for the emulsion copolymerisation of poly(VDF-co-HFP) copolymer with acrylic monomers over the solution blending of poly(VDF-co-HFP) copolymer with acrylic copolymers. / Dissertation (MEng)--University of Pretoria, 2019. / Chemical Engineering / MEng / Unrestricted
337

Filtration Performance of a NIOSH-Approved N95 Filtering Facepiece Respirator With Stapled Head Straps

Medina, Daniel E 11 December 2009 (has links)
Certain models of NIOSH-approved filtering facepiece air purifying respirators are manufactured with stapled head straps. Depending on the manufacturer, these head straps may be stapled to the filter media itself. This may cause leakage through the filter media of the respirator, potentially exposing the user to an unacceptable level of contaminant. In this study, monodisperse polystyrene latex (PSL) spheres were generated to challenge four replicates of a N95 single use respirator model made by the same manufacturer. Nominal particle sizes of the PSL spheres used to challenge the respirators were 0.5, 1, and 2 micrometers in diameter. All respirators were sealed onto a custom built testing assembly and tested in a sealed chamber. Particle sizes of interest were generated using a nebulizer, and passed through a diffusion dryer and a Krypton-85 radioactive source prior to entering the test chamber. The dryer reduces the humidity of the aerosol generating by the nebulizer, while the radioactive source neutralizes the charge of the aerosol cloud. The test chamber was constructed using a glass aquarium measuring 32 x 53 x 122 centimeters. Three stainless steel air diffusers were placed above the testing compartment to evenly distribute the aerosol in the chamber. An exhaust manifold was placed at the lower part of the chamber beneath another stainless steel diffuser below the area where test respirators were placed. The respirators were challenged as received from the manufacturer with 0.5, 1 and 2 micrometer-sized (PSL) spheres. The same procedure was repeated for each respirator after sealing the areas where the head straps were stapled with silicon rubber. Testing was conducted at a flow rate of 85 liters per minute, as specified in the NIOSH respirator testing protocol. A laser particle counter was used to measure the concentration inside and outside of the respirator. The results showed unsealed efficiencies for particle sizes 0.5, 1, and 2 micrometers of 96.68%, 99.72%, 99.88% and sealed efficiencies of 97.35%, 99.82%, 99.93% respectively. There were no differences for particle size or sealing at 1.0 and 2.0 micrometers. A significant drop in efficiency was observed when testing with 0.5 micrometer PSL spheres. The drops in efficiency are not sufficient to reduce the integrity of the respirator for N95 certification. However, the leakages detected will have a cumulative effect when added to other sources of single use respirator leakage in the field.
338

Filtration Efficiency of Surgical Masks

Sanchez, Erin 18 February 2010 (has links)
Surgical masks are intended to be used to prevent transmission of disease from a health care worker to a patient. Often times, they are relied upon by health care workers for their own protection. In light of recent developments regarding preparation for health care worker response to global infectious diseases such as H1N1 Influenza, health care workers may experience a false sense of security when wearing surgical masks. The goal of this study was to evaluate the filtration efficiency of a double strap tie-on surgical mask. The manufacturer asserts a >95% efficiency with a 0.1 um challenge aerosol under FDA testing procedures. The NIOSH Title 42 CFR Part 84 certification criteria call for testing at a rate of 85 lpm representing a human moderate to heavy work load breathing rate. Three sizes of monodispersed aerosols (polystyrene latex beads: 0.5 um, 1.0 um, 2.0 um) were used. The specific aims were to measure the collection efficiencies of this mask for the various particle sizes. Two tests were performed. In the first, masks were affixed to a dummy head and the edges of the mask were not sealed. In the second, the edges of the masks were sealed to the head using silicone sealant, so all penetration was through the filtering material of the mask. Differences in upstream and downstream particle concentrations were measured. Thus, penetration by leakage around the mask and through the filtering material was measured. The experimental set up involved passing the aerosol from the nebulizer through a diffusion dryer and Kr-85 charge equilibrator ensuring a dry charge neutralized aerosol cloud for detection by a LASAIR particle counter. The analysis revealed that the filtration efficiency for 0.5 um particles ranged from 3% to 43% for the unsealed masks and 42% to 51% for the sealed. For 1.0 um particles, the efficiency was 58% to 75% for unsealed and 71% to 84% for sealed masks. For 2.0 um, the efficiency was 58% to 79% for unsealed masks and 69% to 85% for the sealed masks. The data were statistically significant and indicated that surgical masks were associated with very low filtration efficiency. This suggests that they may be inadequate against airborne viruses and bacteria.
339

Manufatura aditiva de scaffolds estruturados recobertos com látex para regeneração óssea /

Marcatto, Vinícius Assis January 2020 (has links)
Orientador: Gustavo Franco Barbosa / Resumo: O desempenho de tecidos e órgãos de todo organismo vivo, fica naturalmente comprometido com o passar dos anos, e se faz necessário intervenções médicas para eventuais reconstituições ou reparações de tecidos acometidos e danificados por doenças ou lesões. Neste contexto, a Engenharia Tecidual tem trabalhado de maneira interdisciplinar nos campos das Engenharias, Biologia e Medicina, e tem trazido grandes evoluções e opções aos já difundidos transplantes e enxertos ósseos. Nesse âmbito, impulsionado pelas recentes aplicações da tecnologia da manufatura aditiva, novos polímeros termoplásticos biodegradáveis têm sido utilizados com sucesso. Dessa forma, este trabalho de pesquisa tem como propósito principal desenvolver scaffolds 3D mimetizando o osso trabecular, aliando as propriedades de biocompatibilidade e biodegradabilidade do já difundido e certificado PLA (ácido polilático). Assim, os scaffolds 3D de PLA em sua versão comercial, são recobertos com látex natural extraído da Hevea brasiliensis por meio da técnica dip-coating, afim de otimizar a biocompatibilidade, promovendo condições para a angiogênese e proporcionando condições para a migração, diferenciação e proliferação de tecido ósseo, características estas que foram detectadas em estudos recentes deste material com resultados promissores. Com auxílio de softwares CAD, foi possível desenvolver geometrias com interconectividade estruturada, seguidos de definição de parâmetros de processamento e fabricação utilizando a t... (Resumo completo, clicar acesso eletrônico abaixo) / Mestre
340

The Effect of Fatty Acid Unsaturation on Properties and Performance of Monomers and Latex Polymers from Plant Oils

Demchuk, Zoriana January 2020 (has links)
The interest in renewable natural resources, including plant oils, has become increasingly appealing due to the oil abundance, availability, and wide range of applications for polymers and polymeric materials thereof. In this dissertation, a library of plant oil-based acrylic monomers (POBMs) with a broad range of unsaturation was synthesized using a one-step transesterification. It is demonstrated that the unsaturation degree of plant oil remains preserved during the synthesis and determines the structure and properties of POBMs. The life cycle assessment (LCA) was conducted in this study to evaluate the environmental impact of soybean oil-based acrylic monomer (SBM) production. LCA was applied to provide guidance for SBM synthesis optimization, including the type of catalyst, the ratio between reactants, renewable sources (soybean oil/biodiesel), and solvent recycling. The performed LCA shows the positive effect of the inclusion of the solvent recycling step in the SBM synthesis. This study shows that POBMs behave as conventional vinyl monomers in free radical polymerization and copolymerization. The monomer unsaturation impacts polymerization rate and molecular weight of resulted polymers decreasing as follows: poly(OVM) > poly(SFM) > poly(SBM) > poly(LSM), due allylic termination presented during polymerization. A series of stable POBM-based latexes with high solid content (40-45 %) and monomer conversion (95-97 %) were synthesized using miniemulsion process. The incorporation of POBMs fragments provides the plasticizing effect on the resulting latex polymers, as seen by a noticeable decrease in their glass transition temperature (Tg). The crosslink density of POBM-based latex films follows the linear dependence vs. monomer feed unsaturation, providing a tool for controlling latex mechanical properties, including hardness, toughness, Young's modulus, etc. Besides, the presence of highly hydrophobic POBM fragments enhances water resistivity of latex coatings and films. Following the "greener" vector of research, a variety of stable latexes from high oleic soybean oil-based monomer (HOSBM) and cardanol, eugenol, and guaiacol derivatives were synthesized in miniemulsion. Resulting polymeric materials advantageously combine flexibility provided by HOSBM fragments with strength facilitated by aromatic biobased units.

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