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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.
61

PAPER WEAR : Investigating an alternative process of making dress byusing paper sheets as material.

Harting Bjerre, Sisse Victoria Karla January 2021 (has links)
Paper material is in some contexts considered basic and unsophisticated, however designers and artists often approach the well-known material and explore the expressional value of paper craft. This work aims to investigate an alternative process of making dress, by using paper as material to interpret wearing in order to highlight the making process in the result, through the diverse properties of paper sheets and binders.  The series of examples in ‘Paper Wear’ suggests an alternative language in form and expression and the investigation has given a further understanding of dress and the importance of experimental design thinking, as well as a deeper understanding of the role of the human body in dress. The outcome of the investigation creates a tension between a well-known material used in the process of making and the finished result, challenging traditional garment conventions and how garments are perceived in relation to material, function and body.
62

MECHANICS OF POLYMER INTERFACES: PRESSURE SENSITIVE ADHESIVE TAPES AND POLYMER MATRIX COMPOSITES

Jared A Gohl (16637397) 07 August 2023 (has links)
<p>The interface between two dissimilar materials often presents a challenge for materials engineers. Mismatches of moduli, coefficients of thermal expansion, surface energies and chemical functionalities can create headaches for engineers seeking to control and understand interfacial bonding. In this work, I am interested in two specific interfacial problems: the adhesion of pressure sensitive adhesive tapes to various substrates and the interface in polymer reinforced composite materials between the reinforcement phase and the matrix.</p> <p>Pressure sensitive adhesive tapes (PSATs) are an important class of materials with applications ranging from medical adhesives to roadway markings. In this work, I present a novel 90° peel fixture to be used in the evaluation of road tapes on roadway surfaces in construction zones. This modular fixture was validated on control surfaces before demonstrating the capability to test pavement marking tapes from road surfaces. Within the context of medical adhesives, I am interested in the deformation of the skin around the PSAT during peeling. By developing a model to predict this deformation, adhesives can be tailored to mitigate skin damage. I present experimental evidence indicating the independence of peeling force to the elastic modulus of the substrate along with deformation measurements of skin analogs during the removal of a medical tape. A new model for predicting the deformation of soft substrates during peel is reported based on the contact mechanics of a rectangular prism indenting an elastic half space.</p> <p>Polymer matrix composites are another category of materials which are increasingly adopted to improve performance or efficiency by reducing the weight of components. These materials offer a high specific strength but often fail catastrophically rather than gradually. Using stress responsive fluorescent molecules called mechanophores, I present a methodology to quantify stresses within the polymeric matrix near the reinforcement phase. By correlating in situ fluorescence intensity measurements during a uniaxial tensile test to stresses predicted from a finite element analysis model, a calibration was developed. This calibration was then applied to increasingly complex composite geometries. Chemically bonding these mechanophores to the interface between two materials allows for the detection of interfacial failures through fluorescence microscopy. I present a technique to synthesize interfacial spirolactam mechanophores on industrially relevant epoxy and silica material systems. I demonstrate the ability of these systems to detect failures in the system through in situ confocal microscopy during deformation.</p>
63

INHIBITORY KINESIO® TAPE APPLICATION TO THE HAMSTRING MUSCLE GROUP: AN INVESTIGATION OF ACTIVE RANGE OF MOTION AND PERCEIVED TIGHTNESS OVER TIME

German, Rachael M. 07 May 2013 (has links)
No description available.
64

A Comparative Performance Analysis Of Pavement Marking Materials

Yu, Conglong 07 August 2004 (has links)
This research provides the evaluation of the technical measurements of pavement marking materials from a two-year data collection on 2002 National Transportation Product Evaluation Program (NTPEP)?s Mississippi Test Deck from June, 2002 to June 2004. The materials studied in this research were divided into permanent and temporary material groups on two different pavement surfaces ---- asphalt and concrete. The retro reflectivity and durability of permanent marking materials among different surfaces, colors and groups were studied. Also the characteristics for temporary tapes, which include internal tape strength, adhesion, tackiness and dicernablity were compared and regressed. This correlation analysis is to see whether these ratings are correlated to each other. The results of this study can be used for estimating service lives of pavement marking materials. They also can be used by states to select appropriate pavement marking materials for different needs.
65

Wind in Her Hair

Wang, Jennifer A. 02 July 2004 (has links)
No description available.
66

The effect of viewing videotapes of a selected sport skill performed by self and others on self-assessment /

DeBacy, Diane Lee January 1969 (has links)
No description available.
67

Experimental use of the video tape recorder as an evaluative instrument and observational tool in supervision of student teachers of physical education /

De Genaro, Arthur Paul, January 1969 (has links)
No description available.
68

The design and manufacturing of scandia-ceria stabilized zirconia ceramics for use as electrolyte material in solid oxide fuel cells

Bean, Glenn E. 01 January 2009 (has links)
In order to increase the efficiency and economic viability of solid oxide fuel cells (SOFCs), new materials for the cathode, anode, and electrolyte of the cells must be found. SOFCs have a ceramic electrolyte, which is commonly made of fully stabilized zirconia. Due to increased material degradation rates at elevated temperatures ( ~ 1000°C) of current SOFCs, materials for the manufacture of intermediate temperature SOFCs, which operate in the range of 700-800°C, are currently under study. In this study, the manufacturing process for scandia-ceria stabilized zirconia powder (1 0mol¾ Sc2O3, lmol¾ CeO2, 89mol% ZrO2), from Daiichi Kigenso Kagaku Kogyo (DKKK) is developed, including tape casting and sintering procedures to result in pellets of high enough quality to produce single button cells. It is found that a slip prepared with about 44 wt% zirconia powder and increased proportions of solvents, dispersant, binder and plasticizers produces a favorable viscosity of about 7 40cP after deairing, and will produce tapes that are reasonably smooth and of stable thickness. Since the single cell will be structurally based upon this electrolyte material, the physical properties of the pellets are important, in addition to the electrochemical properties of the constituent materials. Tapes cast at 500µm, at 50% feed rate with a 50°C drying temperature, laminated and sintered at 1500°C on setter plates will produce flat, smooth, stiff pellets for the production of single buttons for use as the electrolyte. Cathode (50-50 mixture of La0.6Sr0_4Fe0_8Co0.2O3 + 20mol% Gd2O3 80mol% CeO2) and Anode (35 wt% DKKK powder, 65 wt% NiO) materials were hand-painted on to either side of the electrolyte and sintered to create a complete SOFC cell consisting of cathode, electrolyte, and anode.
69

Estudos da formação de protoporfirina IX induzida por ácido aminolevulínico: um enfoque para o aprimoramento da Terapia Fotodinâmica / Studies of aminolevulinic acid-induced protoporphyrin IX production: an approach for optimization of Photodynamic Therapy

Rodrigues, Phamilla Gracielli Sousa 13 December 2016 (has links)
A terapia fotodinâmica (TFD) é uma técnica não invasiva usada no tratamento de lesões de pele, como câncer basocelular, queratose actínica, e doença de Bowen, dentre outros. Basicamente, a combinação da administração de um fotossensibilizador (FS), com a irradiação de luz adequada e o oxigênio celular, gera uma série de reações oxidativas que provocam a morte do tecido. Contudo, o principal efeito colateral desta terapia é a fotossensibilidade prolongada ocasionada pela administração de fotossensibilizadores sistêmicos. Por outro lado, a via tópica não apresenta esta limitação, pois o tratamento é realizado no local da lesão através de pró-drogas. O ácido aminolevulínico, ALA, está entre as pró-drogas mais utilizadas para indução do acúmulo do agente fotossensível na pele, a protoporfirina IX, ou PpIX. Contudo, a via tópica não permite penetração suficiente e homogênea do creme para o tratamento de lesões espessas. Visando a melhoria da TFD, foram realizados estudos in vivo e in vitro. Nos estudos in vivo, técnicas mecânicas - rolos de microagulhas, tape stripping e injeção livre de agulhas foram estudadas buscando encontrar a mais eficiente nos quesitos de: promoção da penetração da pró-droga no tecido, distribuição homogênea e de indução do acúmulo de PpIX. Para isto, foi o utilizado o modelo porcino, in vivo, conhecido como o modelo que possui a pele mais similar à pele humana. Os resultados in vivo mostram que as técnicas têm resultados similares na produção de PpIX e na distribuição de porfirina mais homogênea na superfície. Além disso, todas as técnicas estudadas in vivo têm se destacado em promover uma entrega mais homogênea de ALA também na profundidade da pele quando comparadas ao grupo controle. Nos estudos in vitro, foram examinadas possíveis diferenças na capacidade de formação da PpIX e/ou de resistência de células ao tratamento por TFD entre células expressando diferentes características de transição epitélio-mesenquimal. Os resultados in vitro indicam que as células com características epitélio-mesenquimal mais acentuadas produzem mais PpIX e são mais responsivas à TFD. Estes resultados indicam que a TFD tem maior efetividade no tratamento de células mesenquimais, e os estudos in vivo mostram que no tecido normal há maior seletividade de produção na camada da epiderme e apêndices da pele sugerindo que a terapia pode ser utilizada com maior eficiência em lesões superficiais e, até mesmo diminuir as taxas de recorrência devido a heterogeneidade de distribuição do creme na pele quando umas das técnicas mecânicas são utilizadas. / Photodynamic therapy (PDT) is a noninvasive technique used to treat skin lesions, such as basal cell cancer, actinic keratosis and Bowen\'s disease. Basically, the administration of a photosensitizer (PS), combined with the illumination of adequate light and the cellular oxygen, generate a series of oxidative reactions that cause tissue death. However, the major side effect of the treatment is prolonged photosensitivity caused by the systemic administration of photosensitizers. On the other hand, the topical therapy does not show this limitation, and it is performed at the lesion site via prodrugs. The aminolevulinic acid, ALA, is the most popular pro-drug in topical PDT. This prodrug induces PpIX production that is a photosensitive porphyrin. However, when ALA is used topically, the cream does not provide enough or homogeneous penetration for the treatment of deep lesions. Therefore, with the aim of improving PDT therapy, studies in vivo and in vitro were performed. In the in vivo analysis, mechanical techniques - microneedle roller, tape stripping, and needle-free injection- were studied looking for the most effective regarding to improve the following purposes: promoting penetration of the prodrug into the tissue, homogeneous distribution, and at inducing PpIX accumulation. The evaluations were made by fluorescence spectroscopy, biopsy of skin, and fluorescence images, using the porcine model, in vivo, known as the most similar of human skin tissue. The in vivo results showed that all techniques have similar results in the production of PpIX, and perform a more homogeneous porphyrin distribution in the skin surface. Moreover, all the techniques have excelled in promoting a homogeneous distribution of PpIX in the deep of the skin when compared to the control group. In addition to the skin penetration, studies of PpIX production were performed in vitro in cells expressing different levels of epithelial-mesenchymal transition characteristics. The studies were made in regard to a possible difference in PpIX formation capacity and / or a resistance to the PDT treatment. The in vitro results showed that cells with more epithelial-mesenchymal characteristics produce more PpIX and are more responsive to the PDT therapy. These results indicate that PDT therapy may have a better effectiveness in the treatment of mesenchymal cells and also the results in vivo showed that the ALA-induced PpIX in normal tissue seems to be selective to epidermal and skin appendages, indicating that the topical therapy may be used with a higher efficiency in superficial injuries providing lower recurrence rates when they combine with one of the techniques studied.
70

Ácido ferúlico em protetores solares: desenvolvimento e eficácia multifuncional in vitro, ex vivo e in vivo / Ferulic acid in sunscreens: development and multifunctional effectiveness in vitro, ex vivo and in vivo.

Peres, Daniela D\'Almeida 25 August 2015 (has links)
A conscientização da população com relação aos malefícios da radiação ultravioleta (UV) levaram à adoção de hábitos preventivos, com destaque para a utilização diária de formulações fotoprotetoras. Ainda que os filtros solares tradicionais sejam efetivos na absorção ou reflexão da radiação UV, sabe-se que a sua atuação contra os radicais livres é limitada, fator que exige a incorporação de compostos antioxidantes às preparações, visando proteção cutânea de excelência. O presente trabalho objetivou o desenvolvimento e avaliação de formulações multifuncionais contendo os filtros solares bemotrizinol e octil triazona, acrescidos do composto bioativo ácido ferúlico - reconhecido pelas suas propriedades antioxidante e fotoprotetora. As formulações foram desenvolvidas de acordo com um delineamento experimental do tipo fatorial (DoE 23) e avaliadas por meio de metodologias in vitro, in vivo e ex vivo para determinação de sua eficácia fotoprotetora e potencial antioxidante. As emulsões foram consideradas estáveis, seguras, com valor de pH biocompatível com a pele e viscosidade aparente adequada ao uso proposto. O delineamento experimental comprovou o potencial antioxidante e fotoprotetor do ácido ferúlico, visto que a presença deste promoveu aumento de até 90% na atividade antioxidante in vitro das formulações, bem como acréscimo de 32% no Fator de Proteção Solar (FPS) in vivo e 24% no Fator de Proteção UVA (UVA-PF). Por meio do ensaio ex vivo, a formulação contendo o ácido ferúlico apresentou tendência em aumentar a atividade antioxidante natural da pele, comparativamente à formulação contendo apenas os filtros solares e à pele não tratada; ademais, houve queda no potencial antioxidante da pele após a exposição à radiação UV, enfatizando a necessidade de proteção cutânea frente aos danos oxidativos. Os resultados comprovaram os efeitos antioxidante e fotoprotetor combinados do ácido ferúlico, em especial quando em sinergismo com filtros solares, tornando o composto bioativo um candidato promissor no desenvolvimento de formulações multifuncionais inovadoras, seguras e eficazes contra os efeitos nocivos decorrentes da exposição solar. / The public awareness regarding the harmful effects of ultraviolet (UV) radiation led to preventive habits, especially the daily use of sunscreens. Although traditional solar filters are effective in UV radiation absorption or reflection, it is known that their activity against free radicals is restricted, an aspect that requires the incorporation of antioxidants to preparations, aiming superior skin protection. Here, we developed and evaluated multifunctional formulations containing the sunscreens bemotrizinol and ethylhexyl triazone plus the bioactive compound ferulic acid - known for its antioxidant and photoprotective properties. Formulations were developed according to a factorial experimental design (DoE 23) and evaluated using in vitro, in vivo and ex vivo methods to determine its photoprotective effectiveness and antioxidant potential. The emulsions were considered stable, safe, with pH value biocompatible with the skin and apparent viscosity suitable for the proposed use. The experimental design evidenced the photoprotective and antioxidant potential of ferulic acid, once its presence increased to 90% the in vitro antioxidant activity of the formulations, as well as 32% increase in the in vivo Sun Protection Factor (SPF) and 24% increase in the UVA Protection Factor (UVA-PF). Through the ex vivo assay, the formulation containing ferulic acid tended to increase the natural antioxidant activity of the skin, compared to the formulation containing only UV filters or the untreated skin; moreover, there was a decrease in the antioxidant potential of the skin after UV radiation exposure, emphasizing the need for skin protection against oxidative damage. The results confirmed the antioxidant and photoprotective effects of ferulic acid, especially when in synergy with UV filters, making the bioactive compound a promising candidate in the development of innovative, safe and effective multifunctional formulations against the harmful effects of sun exposure.

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