A bonding evaluation that investigated the cryogenic tensile strength of several different adhesives / resins was performed. The test materials consisted of 6061 aluminum test pieces adhered to a wet-wound graphite laminate in order to simulate the bond created at the liner-composite interface of an aluminum lined composite overwrapped pressure vessel. It was found that for cryogenic applications, a flexible, low modulus resin system must be used. Additionally, the samples prepared with a thin layer of cured resin - or prebond - performed significantly better than those without. It was found that it is critical that the prebond surface must have sufficient surface roughness prior to the bonding application. Also, the aluminum test pieces that were prepared using a surface etchant slightly outperformed those that were prepared with a grit blast surface finish and performed significantly better than those which had been scored using sand paper to achieve the desired surface finish. An additional impact investigation studied the post impact tensile strength of composite rings in a cryogenic environment. The composite rings were filament wound with several combinations of graphite and aramid fibers and were prepared with different resin systems. The rings were subjected to varying levels of Charpy impact damage then pulled to failure in tension. It was found that the addition of elastic aramid fibers with the carbon fiber mitigate the overall impact damage and drastically improve the post impact strength of the structure in a cryogenic environment.

This thesis will be concerned entirely with general obligation bonding in the city of Logan, Utah. Many worth-while improvements have been acquired by Logan City through the general obligation bonding method. The question of whether or not to go into debt for a certain project has caused many interesting arguments to be put forth by the Logan populace. A study of these arguments and their results is the object of this thesis. Logan City has never had to default on any debt incurred. Its credit rating is very good. Other cities of comparable size that have had trouble meeting their obligations could profit by considering how Logan has been able to pay its debts and improve the city at the same time. General obligation bonding is a part of the method employed for city improvement. But as before stated, these bonds cannot be issued unless an affirmative vote of those voting is obtained from the property holders. This thesis proposes to study the issues and purposes for which general obligation bonds were needed, to find out whether or not those in favor of the bonds had good foresight. Whether those against the bonds were looking out for the best interest of Logan and the interest shown by the public, as indicated in the number which turned out to vote, will also be studied.

Ultrasonic welding (UW), as a solid-state joining process, uses an ultrasonic energy source (usually with a frequency of 20 kHz or above) to induce oscillating shears between the faying surfaces to produce metallurgical bonds between a wide range of metal sheets [1, 2], thin foils [3], semiconductors [4], plastics [5], glass [6], and ceramics [7]. In contrast to traditional fusion welding processes, ultrasonic welding has several inherent advantages [3,8] derived from its solid-state process characteristics, and has been in use as a versatile joining method in the electronics, automotive, and aerospace industries since the 1950s

Over 200 million dental restorations are performed each year in America. A dental restoration require a strong bonding of restoration to tooth structure and relies on the dental adhesive to create this mechanical and chemical bonding. Dental adhesion or bonding is the process of forming an adhesive joint between the composite and tooth substrate: dentin or enamel. Clinical problems such as microleakage at the restoration tooth interface, influx of fluids, or bacteria growth at the cavity wall can be prevented with adhesives that obtain a more intimate bonding. Longevity of the restoration can be enhanced by the adhesive that creates the tight bonding to reduce problems such as postoperative sensitivity, marginal staining, and recurrent caries. The goal of this research project is to investigate the influence of active scrubbing application as compared to passive non-scrubbing application of the etchant component in 4th generation etch-and-rinse adhesive systems. Shear bond stresses have been measured and compared between application techniques. Verification of resin infiltration depth with each etchant application has been examined with scanning electron microscopy by mounting the etched and bonded enamel surface of the tooth in epoxy and slicing the tooth longitudinally producing a transverse, depth-wise view. Results from this study have clarified the role of resin tag formation as well as tooth morphology during an active acid etchant application for dental restoration.

Indiana University-Purdue University Indianapolis (IUPUI) / BACKGROUND: Phosphoric acid treatment has been reported to be relevant for zirconia cleaning after contamination. However, its interaction with different primers is not well known and needs to be investigated. OBJECTIVES: To compare the shear bond strengths (SBS) of resin cement to Y-TZP after phosphoric acid pretreatment and different chemical conditioning protocols, and to test the durability of SBSs after long term storage and thermal cycling conditions. To investigate the effect of phosphoric acid 75 on the surface roughness of a yttrium-stabilized tetragonal zirconia polycrystal ceramic (Y-TZP). METHODS: Sixty bars of zirconia (30 X 5 X 2 mm) were polished and glued to acrylic tubes. Each bar received 3 different surface treatments (control, phosphoric acid and air-abrasion). The bars were randomly assigned into five groups according to different primers applied (No primer, Clearfil ceramic primer, Monobond Plus, Z-prime plus and AZ primer). After that, resin cement was mixed, injected into a mold, and light cured. The specimens were tested in shear on a universal testing machine. Half of the specimens were tested after 24 h water storage and the other half were tested after 90 days of water storage and thermocycling. Non-contact profilometer was used to assess the effect of the three surface pretreatments on surface roughness of zirconia. Mode of failure and surface roughness were evaluated with SEM. Statistical analyses were conducted with mixed-model ANOVA and chi-square tests. RESULTS: The results indicated that Monobond Plus primer showed higher SBS after phosphoric acid treatment compared to other primers used. SBS of all air abrasion groups were higher than phosphoric acid groups. Long term water storage and thermocycling led to a statistically significant decrease in SBS for all groups except Monobond Plus, Z-prime plus and AZ primer after air abrasion treatment. Surface roughness measurements showed no significant differences among the surface treatments. CONCLUSION: Monobond Plus provided the highest SBS to zirconia after phosphoric acid treatment. The findings suggest that the air abrasion is the best surface treatment after contamination of zirconia surface. Monobond Plus, Z-prime plus and AZ primer showed durable SBS after air abrasion treatment and aging process.

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Indiana University-Purdue University Indianapolis (IUPUI) / Ideal orthodontic springs are able to provide a controlled moment-to-force (M/F) ratio and a low load deflection rate. A great deal of research has gone into describing force systems generated by orthodontic springs. Most studies investigating the force system generated by T-loops have used rigid fixation for the spring ends. This is practical for laboratory studies, but it does not truly represent clinical situations in which orthodontic brackets are used to anchor spring ends. Results from laboratory studies have been applied to clinical situations without regard to what effect, if any, the method of end fixation may have. It is the goal of this study to determine the effects of spring fixation on generated force systems. The springs were held by rigid fixation and bracket ligation with either elastomeric or steel ligature ties. Comparison of these fixation methods was made by testing T-loops of different dimensions, with and without heat treatment at various activation distances. In theory, the wire is ligated rigidly against the bracket, so that the combination acts as a single unit by rigid fixation. Thus, there should be no difference between the generated force systems when spring ends are held by rigid fixation, or when they are held in place with orthodontic brackets and ligated by either elastomeric or steel ligature ties. However, the results indicate that are significant differences among the methods of fixation for each spring variation and heat treatment. The rigid fixation method consistently produced smaller moments and M/F ratios for all springs with every activation and heat treatment combination.

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.

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.

AN ABSTRACT OF THE THESIS OFRosemary Pearl Moore, for the Master of Fine Arts in Playwriting, presented on April 3, 2023, at Southern Illinois University Carbondale. TITLE: A LOVE LETTER TO PAST, PRESENT, & FUTURE FRIENDS: THE DEVELOPMENT PROCESS OF MURPHY’S LAW OF PRETENDERS MAJOR PROFESSOR: Dr. Jacob JuntunenThis thesis examines the process of taking Murphy’s Law of Pretenders from pre-writing to a full production at Southern Illinois University in March 2023 and my own growth during this time. My inspiration ranges from different aspects of pop culture to looking a staged versions of Little Women by Louise May-Alcott to The Lion, the Witch, and the Wardrobe by C.S. Lewis. Murphy’s Law of Pretenders continues to explore my style of taking realism and fantasy while exploring deeper issues like mental health, and the idea of what forms does friendship take and what does it do to us.Chapter One examines the process before I started writing the play. Chapter Two explores the development process from the feedback and advice that was provide for me while I was here at Southern Illinois University. Chapter Three dives into the production process here with the director, actors, and designers in The School of Theater and Dance here at Southern Illinois University. Chapter Four details what I’ve learned from my experiences here at Southern Illinois University, and what I hope for the future of my writing. Chapter Five is the play itself, Murphy’s Law of Pretenders, where you will find what I am most proud of from this process.