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Purpose To compare Bruch's membrane opening (BMO)-based spectral domain optical coherence tomography (SD-OCT) and margin based confocal scanning laser tomography (CSLT) of the optic nerve head (ONH) to visual field function in large optic discs (macrodiscs) and to assess performance for glaucoma detection. Methods In a case-control, cross-sectional study, 125 eyes of 125 patients with disc size > 2.45 mm(2), thereof 44 glaucoma and 11 ocular hypertension (OHT) patients and 70 healthy controls underwent SD-OCT and CSLT examination, visual field testing and clinical evaluation. Mean outcome measures BMO-based minimum rim width (BMO-MRW), retinal nerve fiber layer thickness (RNFLT) in SD-OCT, and rim area measured in CSLT were compared and correlated to visual field function. Results All participants had a mean disc area of 2.91 +/- 0.38 mm(2) in CSLT and a BMO area of 2.45 +/- 0.39 mm(2) (r = 0.76; < 0.001). In glaucoma patients, visual field mean deviation was -10.0 +/- 6.1 dB. Global BMOMRW correlated better to visual field function (Spearman's Rho (rho) = 0.71;P < 0.001) than RNFLT (rho = 0.52; P < 0.001) and CSLT rim area (rho = 0.63;P < 0.001). BMO-MRW was significantly decreased with higher visual field loss (P < 0.001). In ROC analysis, diagnostic power to differentiate glaucoma patients and healthy controls was highest for BMO-MRW (Area under curve, AUC = 0.96; sensitivity at 95% specificity = 82%). Rim area in CSLT (AUC = 0.91; sensitivity = 61.0%; P = 0.04) and RNFLT (AUC = 0.89; sensitivity = 61%; P = 0.01) were significantly less powerful. Conclusions In macrodiscs, BMO-MRW has the best diagnostic power to discriminate glaucoma patients from normal controls compared to RNFLT and rim area in CSLT. Additionally, BMO-MRW seems to reflect the structure-function relationship better than the other two parameters.

Purpose To compare Bruch's membrane opening (BMO)-based spectral domain optical coherence tomography (SD-OCT) and margin based confocal scanning laser tomography (CSLT) of the optic nerve head (ONH) to visual field function in large optic discs (macrodiscs) and to assess performance for glaucoma detection. Methods In a case-control, cross-sectional study, 125 eyes of 125 patients with disc size > 2.45 mm(2), thereof 44 glaucoma and 11 ocular hypertension (OHT) patients and 70 healthy controls underwent SD-OCT and CSLT examination, visual field testing and clinical evaluation. Mean outcome measures BMO-based minimum rim width (BMO-MRW), retinal nerve fiber layer thickness (RNFLT) in SD-OCT, and rim area measured in CSLT were compared and correlated to visual field function. Results All participants had a mean disc area of 2.91 +/- 0.38 mm(2) in CSLT and a BMO area of 2.45 +/- 0.39 mm(2) (r = 0.76; < 0.001). In glaucoma patients, visual field mean deviation was -10.0 +/- 6.1 dB. Global BMOMRW correlated better to visual field function (Spearman's Rho (rho) = 0.71;P < 0.001) than RNFLT (rho = 0.52; P < 0.001) and CSLT rim area (rho = 0.63;P < 0.001). BMO-MRW was significantly decreased with higher visual field loss (P < 0.001). In ROC analysis, diagnostic power to differentiate glaucoma patients and healthy controls was highest for BMO-MRW (Area under curve, AUC = 0.96; sensitivity at 95% specificity = 82%). Rim area in CSLT (AUC = 0.91; sensitivity = 61.0%; P = 0.04) and RNFLT (AUC = 0.89; sensitivity = 61%; P = 0.01) were significantly less powerful. Conclusions In macrodiscs, BMO-MRW has the best diagnostic power to discriminate glaucoma patients from normal controls compared to RNFLT and rim area in CSLT. Additionally, BMO-MRW seems to reflect the structure-function relationship better than the other two parameters.

Purpose To analyze the macular structure in a large series of consecutive patients with different types of uveitis using spectral-domain optical coherence tomography (SD-OCT). Patients and methods Five hundred eyes of 500 consecutive patients with anterior, intermediate, posterior, and panuveitis underwent standardized macular examination using SD-OCT. Central retinal thickness (CRT), macular volume (MV), and presence of cystoid macular edema (CME), diffuse macular edema (DME), serous retinal detachment (SRD), epiretinal membrane with (ERM+) and without (ERM-) retinal surface wrinkling were determined. Results The anatomic location of inflammation affected significantly CRT and MV (P<0.001, respectively), with the highest values in intermediate and panuveitis. CME was seen in 25% of all uveitic eyes, DME in 11%, SRD in 8%, ERM+ in 18%, and ERM - in 13%. CME was most frequent in intermediate (40%) and panuveitis (36%); DME was most frequent in panuveitis (18%) and posterior uveitis (17%); SRD was most frequent in panuveitis (15%) and posterior uveitis (10%); ERM+ was most frequent in panuveitis (45%) and intermediate uveitis (30%); and ERM - was most frequent in intermediate (14%) and posterior uveitis (15%). Conclusion SD-OCT of the macula is recommended for all uveitis patients. CRT, MV, and the incidence of CME were highest in intermediate and panuveitis.

Purpose To analyze the macular structure in a large series of consecutive patients with different types of uveitis using spectral-domain optical coherence tomography (SD-OCT). Patients and methods Five hundred eyes of 500 consecutive patients with anterior, intermediate, posterior, and panuveitis underwent standardized macular examination using SD-OCT. Central retinal thickness (CRT), macular volume (MV), and presence of cystoid macular edema (CME), diffuse macular edema (DME), serous retinal detachment (SRD), epiretinal membrane with (ERM+) and without (ERM-) retinal surface wrinkling were determined. Results The anatomic location of inflammation affected significantly CRT and MV (P<0.001, respectively), with the highest values in intermediate and panuveitis. CME was seen in 25% of all uveitic eyes, DME in 11%, SRD in 8%, ERM+ in 18%, and ERM - in 13%. CME was most frequent in intermediate (40%) and panuveitis (36%); DME was most frequent in panuveitis (18%) and posterior uveitis (17%); SRD was most frequent in panuveitis (15%) and posterior uveitis (10%); ERM+ was most frequent in panuveitis (45%) and intermediate uveitis (30%); and ERM - was most frequent in intermediate (14%) and posterior uveitis (15%). Conclusion SD-OCT of the macula is recommended for all uveitis patients. CRT, MV, and the incidence of CME were highest in intermediate and panuveitis.

This thesis is focused on gaining a better knowledge of how to design and test Phillips screwdriver bits. Wear is the primary concern in applications where the bit is used in a power driver. Such applications include drywalling, decking and other construction and home projects. To pursue an optimal design, designers must have an understanding how the bit geometry changes with wear. To make use of the geometrical data, the designer must also have an understanding of the fundamentals of the bit/screw surface contact and its effect on force distribution. This thesis focuses on three areas. First, understanding how the tool and bit are used, and what factors contribute to bit wear. With this understanding, a test rig has been designed to emulate typical users and, in doing so, produce the factors that cause wear. Second, there must be a means to analyze geometric changes in the bit as it wears. A method for doing this was developed and demonstrated for a Phillips bit, but the process can be applied to other bits. Finally, the fundamentals of surface contact must be understood in order to apply the geometrical information obtained to improved bit design.

Im Rahmen geowissenschaftlicher Feldkampagnen im zentralen Königin-­Maud-Land wurden von der Schirmacheroase ausgehend Traversen zum Untersee (Gruberberge), zur NW Insel und zum Kap Ostry (Schelfeiskante) angelegt. Die seit 1988 regelmäßig bestimmten Signalkoordinaten und Akkumulations-bzw. Ablationsraten sowie Radareisdickenmessungen erlauben erste Aussagen zum Geschwindigkeitsfeld und zum Oberflächen- und Subglazialrelief, sowohl im Bereich des die Schirmacheroase im Süden und Osten umfließenden, mehr als 1400 m mächtigen Inlandeises, als auch für den östlichen Rand des nördlich der Oase gelegenen Novolazarevskaya Schelfeises. Im Gebiet nördlich der Gruberberge (71 °15'S, 13°30'E) durchgeführte detailliertere Eisradarmessungen zeigen, daß der Untersee, der größte See im Inneren des Königin-Maud-Landes, vom Anuchingletscher angestaut wird. Die glaziologischen Untersuchungen der Eisdecke in der Umgebung der Schirmacheroase sind für die Erklärung der Oasenentstehung und ihrer Entwicklung erforderlich. Darüber hinaus dienen sie der Interpretation von in Seesediment und Eis enthaltenen Informationen zur regionalen Klima-und Vereisungsgeschichte.

Im Rahmen geowissenschaftlicher Feldkampagnen im zentralen Königin-­Maud-Land wurden von der Schirmacheroase ausgehend Traversen zum Untersee (Gruberberge), zur NW Insel und zum Kap Ostry (Schelfeiskante) angelegt. Die seit 1988 regelmäßig bestimmten Signalkoordinaten und Akkumulations-bzw. Ablationsraten sowie Radareisdickenmessungen erlauben erste Aussagen zum Geschwindigkeitsfeld und zum Oberflächen- und Subglazialrelief, sowohl im Bereich des die Schirmacheroase im Süden und Osten umfließenden, mehr als 1400 m mächtigen Inlandeises, als auch für den östlichen Rand des nördlich der Oase gelegenen Novolazarevskaya Schelfeises. Im Gebiet nördlich der Gruberberge (71 °15'S, 13°30'E) durchgeführte detailliertere Eisradarmessungen zeigen, daß der Untersee, der größte See im Inneren des Königin-Maud-Landes, vom Anuchingletscher angestaut wird. Die glaziologischen Untersuchungen der Eisdecke in der Umgebung der Schirmacheroase sind für die Erklärung der Oasenentstehung und ihrer Entwicklung erforderlich. Darüber hinaus dienen sie der Interpretation von in Seesediment und Eis enthaltenen Informationen zur regionalen Klima-und Vereisungsgeschichte.

The damage to carbon-carbon composites created by projectile impacts has been characterized for a range of test conditions and for several weave constructions and processing variables. A number of subsurface damage modes have been identified (on sectioned specimens) in the vicinity of the crater produced by particulate impingement. In addition, studies are underway to determine the modes of failure which occurred in the material ejected from the crater. Preliminary analyses of the primary subsurface damage modes have been undertaken to define the approach that would elucidate the microstructural dependence of the impact damage.

This volume assesses the state of dust erosion data for composite materials. A survey of the solid particle erosion literature revealed that some experimental data is available for polymeric materials and fiber-reinforced, non-metallic composites. Although not directly applicable to the specific compositions currently of interest, the available data is used to provide initial insights into the magnitude of the erosion problems which may exist for advanced composite materials on aircraft flying through nuclear-generated dust. Using published erosion data, the possibility exists for a significant amount of material removal to occur. Additional investigations are suggested to provide a more relevant estimate of the magnitude of the dust erosion problem. The report also discusses available test facilities and their capabilities and presents an extensive bibliography of relevant literature. Keywords: Nuclear explosions; Rain erosion; Erosion modeling; Mass loss., See also volume 1, AD-C041 295.

The penetration damage created in carbon composites with a range of microstructures has been characterized for both quasi-static and dynamic conditions. Several quasi-static properties of the composites have also been measured. Analyses of the quasi-static penetration have been developed, which appear to present a consistent interpretation of the damage and its relation to the quasi-static properties. A preliminary numerical computation of the dynamic damage has been conducted, with encouraging results. Suggestions for microstructural modifications that should enhance the damage resistance have been made, based on the results of both the observations and analyses.

Some observations of kinking in carbon composites, which identify the modes and morphology of kinking in fibrous materials, are presented. The thermodynamics and mechanics of kinking are analyzed. The analyses indicate the important role of matrix deformation (plastic and elastic) in determining the kink morphology, and identify the matrix yield strength and the distribution of fiber fracture strengths as the primary properties governing kink formation. (Author)

The effect of localized impact damage on the general reliability of composite constructions is of concern in a variety of contexts. The advantages of using instrumented impact test procedures and enhanced data acquisition techniques to quantify the level of damage are illustrated for some specific applications. Using this approach the extent of the damage can then be characterized for controlled and reproducible impact conditions. The procedures outlined and the flexibility they offer in imparting damage to materials or components provide the basis for a constructive damage tolerance methodology., This article is from 'JANNAF CMCS/S&MBS Joint Subcommittee Meeting Held at Pasadena, California on 27-30 November 1984. Volume 1,' AD-B090 908L, p375-384.