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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.
321

A study of the role of acrylic paints in the secondary and junior high school art curriculum

Benski, Alice Atkinson 01 May 1970 (has links)
It was my purpose to study the role of acrylic paints and other products in the secondary high school and junior high school art curriculum in the area of painting, and related activities and to make a realistic evaluation of this medium. Because of its comparative newness and because of a general lack of knowledge of and experience with it, I felt such a study would fill a need relative to the utilization of acrylic products in the classroom. In preparation I read the material which was available on painting with acrylics'. The number of books published on the subject is limited. I talked with art teachers and found that many had only a cursory acquaintance with acrylics or had not used them at all. With this background I became involved in as many aspects of the use of acrylics in. the classroom as I could. A skeptic at first, I became increasingly enthusiastic as my work progressed. From my own experiences with acrylics, I devised some experiments which, for the most part, I took into the classroom and with which I involved students ranging from third grade to high school level. After my own experiences with acrylics as both artist and teacher, it is my conviction that acrylics can be invaluable in the art curriculum, and that they can be most helpful in providing a significant contemporary approach to the fundamentals of painting and other techniques. There are five chapters and an appendix in this thesis report. The first chapter provides an introduction to the acrylic products, with a brief summary of their-development as a fine arts medium, their cost, handling characteristics and their advantages and disadvantages. The second chapter is concerned with the individual acrylic products and with equipment and supplies. Painting techniques and suggestions for the use of acrylics are discussed in the third chapter. Suggestions for additional uses in the related activities of collage, mosaic, printing, drawing, transparent design and other techniques are contained in the fourth chapter. In the fifth chapter I state my conclusions concerning the medium. Photographs of student work and my work are included as a supplement to the text. A list of local suppliers and a list of manufacturers are included in the appendix, as well as photographs of my thesis paintings.
322

A laboratory study of the adhesion of a restorative acrylic resin and a polycarboxylate cement on bovine enamel etched with fifty per cent phosphoric acid

Lee, Brian Dalvin, 1942- January 1970 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / The purpose of this laboratory study was to determine whether etching of flat bovine enamel surfaces with a 50 per cent aqueous solution of phosphoric acid for 60 seconds increases the bonding of a conventional restorative acrylic resin and a new polycarboxylate cement. The test specimens were subjected to 24 hours, 30 days and six months storage in water and then subjected• to temperature stress cycling and intermittent tensile stress cycling. A tensile test was used to measure the bond strength of both materials. The results of the Newman-Keul's test showed that pretreating the enamel surface with 50 per cent phosphoric acid significantly increased the bonding of the restorative resin, and that the cavity sealer supplied by the manufacturer further improved the resin attachment to enamel surfaces previously etched with phosphoric acid. The bonding of the resin to acid-etched enamel surfaces pretreated with or without the cavity sealer was unaffected by prolonged storage in water, temperature stress cycling, and intermittent tensile stress cycling. However, a significant reduction in the adhesion of the acrylic resin to polished-enamel surfaces pretreated with or without the cavity sealer was observed when the test specimens were subjected to the same testing conditions. The data obtained for the polycarboxylate cement test specimens showed that etching of the enamel surface with phosphoric acid also provided slightly higher adhesive values than the control specimens. Results obtained revealed that prolonged storage in water, and temperature and mechanical stress cycling did not affect the adhesion of the polycarboxylate cement to acid-etched enamel surfaces. However, thermal and mechanical stress cycling after prolonged storage in water appeared to decrease the adhesion of the cement to polished enamel surfaces. When Ca45 was used to assess the marginal seal of resin restorations placed into acid-etched Class V cavity preparations in extracted human teeth, the autoradiographs showed that etching of the cavity preparations with 50 per cent phosphoric acid improved the marginal seal of the restorative resin after one-week storage in water. When both the acid-etched and control restorations were thermal stress cycled 2500 times at a 40°C temperature differential, a slight improvement in the marginal seal of the acid-etched restorations was observed.
323

Composite versus amalgam: A three-year clinical study in posterior primary teeth

Nelson, Gayle V. January 1984 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / Clinical studies on composite resins in Class II Resotrations place in adults indicate that wear is the predominant problem. However, little has been published on the use of composites for such restorations in primary teeth. The purpose of this study was to compare amalgam to composite resins in such restorations. Two composite resins (Adaptic and Radio-opaque Adaptic) served as the Experiemental material and amalgam, (Dispersalloy) was the control . One operator placed 57 sets, one restoration of each of the three materials per set, in 50 patients at the Riley Children's Hospital in Indianapolis. Evaluations were made at baseline, six months, one year, two years, and three years using the Ryge-USPHS criteria and by means of casts poured from elastomeric impressions. Results of the Ryge-USPHS criteria indicated no wear or color change of the composites after two years (p=N.S.). However, of the 49 sets that returned at one year, two composites had caries around the restoration. This particular observation was monitored at the three-year time interval and found not to increase around any other composite restorations. Composite restorations in posterior primary teeth compared equally to amalgam (Dispersalloy) for the first two years of the project. The loss of anatomic form was significant after three years (p=.05).
324

Effect of interim fixed prosthodontics materials and flowable composite resins on polymerization of polyvinyl siloxane impressions

Alsayed, Hussain D. January 2017 (has links)
Indiana University-Purdue University Indianapolis (IUPUI)
325

Preconcentration of Trace Metal Ions from Natural Waters: Complexation with Meso-Tetra (p-sulfonatophenyl) porphine and Adsorption onto XAD Resins

Zweep, Carol 01 1900 (has links)
<P> A new preconcentration method had been developed for the determination of some trace-metal ions in lakewater. This method is based on the formation of their TPPS4 complexes at elevated temperatures in solution and adsorption of the complexes onto a column of the macroporous acrylic ester resin, XAD-7. The complexes are eluted with a methanolic solution and the metal concentration determined by graphitefurnace atomic absorption spectroscopy. Optimal conditions were established for the group preconcentration of Cd, Cu, Ni and Pb. The concentration of these trace metals in several lakewater samples were determined successfully, with a precision comparable to that of the accepted Chelex-100 method. Application of the method to natural seawater samples failed, largely because of aggregation in the highly saline medium. </p> <P> Adsorption isotherms of TPPS4 and its complexes on XAD resins were obtained. Adsorption onto XAD-2 and XAD-4 resins likely involves n-n interactions while adsorption onto XAD-7 is probably due to weak Van der Waals forces. The adsorption at high TPPS4 concentrations is complicated by aggregation. </p> <P> An attempt to create a simple chelating ion-exchange resin by adsorption of TPPS4 onto XAD resin failed. Similarly, the development of a rapid room-temperature preconcentration method specifically for Pb and Cd in natural waters was not successful. </p> / Thesis / Master of Science (MSc)
326

An Evaluation of the Bond Strength and Failure Site of Composite Resin and Glass Ionomer in Identical Orthodontic Direct Bonding Systems

Fryar, Brian C. January 1989 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / Glass ionomers offer several advantages for orthodontic cementation of brackets including no etching of enamel, fluoride release, and ease of debonding. This study compared in vitro bond strengths of glass ionomers with a composite resin. Two luting glass ionomers, (Ketaccem and Fuji I), two restorative ionomers, (Ketac-fil and Fuji II), and an orthobonding resin, (System 1 +), were used. Extracted human maxillary premolars were selected for a sample of 22 per cement. The teeth were pumiced prior to bonding. Ormco minimesh bicuspid brackets were bonded following manufacturer's directions. Only the teeth bonded with resin cement were etched. After bonding the teeth were stored in water at 37 C for 7 days and thermocycled 2500 times through a 40° c differential. Tensile bond strengths were measured at a crosshead speed of 0.5mm/min. Debonded specimens were examined to record failure modes. System 1+ had a bond strength of 103 +/- 21 kg/cm2 with 80% cohesive failure in the cement. Ketac-fil, Ketaccem and Fuji II were not significantly different and had strengths of 32.6 +/- 6.4, 31.9 +/- 7.1 and 33.7 +/- 8.5 respectively. Failure was 93% cohesive in the cements. Fuji I had a strength of 26. 6 +/- 4. 7 with 89% cohesive failure and was significantly weaker than the others. Although the strengths of the glass ionomers studied were substantially lower than the resin, they failed consistently in cohesive fracture through the cement with relatively small deviations. Since the minimum bond strength required for clinical success is not known, only a controlled clinical study can determine the ultimate effectiveness of glass ionomers as orthodontic bonding adhesives.
327

Evaluation of Tensile Bond Strength, Fluoride Release, Hardness, and Solubility of a Fluoride Containing Adhesive Resin

Brandt, Marybeth January 1994 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / Direct bonding of orthodontic brackets often results in decalcification of tooth structure surrounding bracket sites. Glass ionomer cements, while typically leaching fluoride over time, often exhibit a significantly lower bond strength. Fluoride-containing resins generally release high concentrations of fluoride for a short time, then cease to release any significant amount. The purpose of this study was to evaluate the tensile bond strength, fluoride release, hardness, solubility, and sorption of a newly formulated fluoride containing resin. The experimental resins were prepared with 5% and 7.5% fluoride (F-) monomer, and were compared to a fluoride-free control adhesive (Rely-a-Bond Phase II™, Reliance Orthodontics Inc ., Itasca, Ill .). To evaluate tensile bond strength, orthodontic brackets were bonded to bovine teeth and debonded using an lnstron machine. Fluoride release was tested using resin disks stored in deionized water. The fluoride content of the water was determined with an ion-specific electrode. Hardness, solubility, and sorption were tested using disks made of each material. Comparison of experimental and control resins by ANOVA followed by General Linear Models multiple comparisons revealed the control to show a statistically significant difference (p<.0001) for tensile bond strength. Experimental Control 5%F- 7.5%F- Peak Stress (MPa) 4.48±0.65 3.83±0.76 5.31±0.97. Fluoride continued to be released from the experimental resins (5% and 7.5% F-) at 18 days. The control was significantly harder than either of the experimental resins at 1 hour, 24 hours, 1 week, and 1 month (p<.0001). The 5% F- resin exhibited slight solubility (0.10 percent), while the 7.5%F- resin and the control exhibited very little solubility (0.01 percent). Phase II™ exhibited significantly lower sorption at 21 days (0.60 percent, p<.001) than either the 5%F- resin (1.69 percent) or the 7.5%F- resin (1.63 percent). These results indicate that while the experimental resin had lower bond strength, lower hardness, and higher sorption than the control, measurable fluoride was released from the experimental resins for up to 18 days. Further testing is indicated to determine the clinical acceptability of this adhesive.
328

The rheological properties of aluminum borate whisker filled resins

Kambara, Hajime January 1994 (has links)
No description available.
329

Magnetic resonance imaging of elastomers and ion exchange resins

Kogovsek, Laurie Maylish January 1994 (has links)
No description available.
330

Vibrational, crystallographic, and mechanistic studies of benzoxazine monomers and their resulting polybenzoxazines as novel phenolic resins

Dunkers, Joy Patricia January 1994 (has links)
No description available.

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