Redundant actuator development program

Two concepts of redundant secondary actuator mechanization, applicable to future advanced flight control systems, were studied to quantitatively assess their design applicability to an AST. The two actuator concepts, a four-channel, force summed system and a three-channel, active/standby system have been developed and evaluated through analysis, analog computer simulation, and piloted motion simulation. The quantitative comparison of the two concepts indicates that the force summed concept better meet performance requirements, although the active/standby is superior in other respects. Both concepts are viable candidates for advanced control application dependent on the specific performance requirements

Production of superconductor/carbon bicomponent fibers

Certain materials are unable to be drawn or spun into fiber form due to their improper melting characteristics or brittleness. However, fibrous samples of such materials are often necessary for the fabrication of intricate shapes and composites. In response to this problem, a unique process, referred to as the piggyback process, was developed to prepare fibrous samples of a variety of nonspinnable ceramics. In this technique, specially produced C shaped carbon fibers serve as micromolds to hold the desired materials prior to sintering. Depending on the sintering atmosphere used, bicomponent or single component fibers result. While much has been shown worldwide concerning the YBa2Cu3O(7-x) superconductor, fabrication into unique forms has proven quite difficult. However, a variety of intricate shapes are necessary for rapid commercialization of the superconducting materials. The potential for producing fibrous samples of the YBa2Cu3O(7-x) compound by the piggyback process is being studied. Various organic and acrylic materials were studied to determine suspending ability, reactivity with the YBa2Cu3O(7-x) compound during long term storage, and burn out characteristics. While many questions were answered with respect to the interfacial reactions between YBa2Cu3O(7-x) and carbon, much work is still necessary to improve the quality of the sintered material if the fibers produced are to be incorporated into useful composite or cables

The Effects of Using Direct Instruction and the Equal Additions Algorithm to Promote Subtraction with Regrouping skills of Students with Emotional and Behavioral Disorders with Mathematics Difficulties

Students with emotional and behavioral disorders (E/BD) display severe social and academic deficits that can adversely affect their academic performance in mathematics and result in higher rates of failure throughout their schooling compared to other students with disabilities (U.S. Department of Education, 2005; Webber & Plotts, 2008). Furthermore, students with E/BD are at a greater risk of being served in more exclusionary and restrictive settings compared to their peers as a result of their poor social skills and chronic disruptive behaviors (Gagnon & Leone, 2005; Furney, Hasazi, Clark-Keefe, & Hartnett, 2003; U.S. Department of Education, 2005; Whorton, Siders, Fowler, & Naylor, 2000). This is of great concern as students with E/BD often receive lower grades, fail more classes, have higher drop-out rates, have fewer employment opportunities, and have increased involvement in the legal system (Bullock & Gable, 2006; Cullinan & Sabornie, 2004; Jolivette, Stichter, Nelson, Scott, & Liaupsin, 2000; Kauffman, 2001). The purpose of this study was to analyze the effect of the equal additions algorithm on subtraction with regrouping on the subtraction performance of fourth-grade students with E/BD and mathematics difficulties. The equal additions algorithm was taught using a direct instruction technique. This study investigated 3 participants at the fourth grade level in a residential treatment facility which serves students with E/BD. A multiprobe multiple baseline across participants design was used for this study. Assessments used for this study included (a) Woodcock Johnson III (WJIII), (b) the ENRIGHT, (c) a student questionnaire, (d) baseline probes, and (e) an error analysis student profile. Data was analyzed by visual analysis. The results suggest that when the equal additions algorithm was systematically implemented students were able to successfully complete subtraction with regrouping problems and errors dramatically decreased. Limitations and future for research directions are discussed

Nested ceramic fibers and piggyback micro-mold method for producing same

Special C-shaped carbon fibers, melt spun from mesophase pitch, were used as micro-molds to form nested dual fibers and ceramic fibers. By wetting these carbon fibers in a wet chemical precursor, and subsequently heat treating, ceramic fibers of various compositions were formed. Also, through proper control, carbon-ceramic nested fibers were produced. The ceramic materials were silica, alumina, silicon carbide, hydroxyapatite, and zirconia. The ceramic fibers could be formed with non-circular transverse cross-sectional perimeters

Production of superconductor/carbon bicomponent fibers

Certain materials are unable to be drawn or spun into fiber form due to their improper melting characteristics or brittleness. However, fibrous samples of such materials are often necessary for the fabrication of intricate shapes and composites. In response to this problem, a unique process, referred to as the piggyback process, was developed to prepare fibrous samples of a variety of nonspinnable ceramics. In this technique, specially produced C-shaped carbon fibers serve as micromolds to hold the desired materials prior to sintering. Depending on the sintering atmosphere used, bicomponent or single component fibers result. While much has been demonstrated worldwide concerning the YBa2Cu3O(7-x) superconductor, fabrication into unique forms has proven quite difficult. However, a variety of intricate shapes are necessary for rapid commercialization of the superconducting materials. The potential for producing fibrous samples of the YBa2Cu3O(7-x) compound by the piggyback process is being investigated. Various organic and acrylic materials were investigated to determine suspending ability, reactivity with the YBa2Cu3O(7-x) compound during long term storage, and burn out characteristics. While many questions were answered with respect to the interfacial reactions between YBa2Cu3O(7-x) and carbon, much work is still necessary to improve the quality of the sintered material if the fibers produced are to be incorporated into useful composites or cables. Additional research is necessary to evaluate quality of the barrier layer during long soakings at the peak temperature; adjust the firing schedule to avoid microcracking and improve densification; and increase the solids loading in the superconductive suspension to decrease porosity

Oxygenated pitch and processing same

A method is provided which includes infusing oxygen into pitch material without stabilizing the oxygen-infused pitch material. In addition, the invention includes further processing steps (including heat stabilization in either an inert atmosphere or an oxygen-containing atmosphere, deformation, pyrolysis, and/or composite formation) performed after or in conjunction with the oxygenation process. Moreover, the invention includes the composition of matter (in any of a number of different physical forms such as powder, fiber, shaped article, composites) resulting from the practice of this oxygenation process, either alone or in conjunction with the further processing steps. The composition has a homogeneous distribution of oxygen and can be heat stabilized in an inert atmosphere

High strength, melt spun carbon fibers and method for producing same

Hollow carbon fibers and carbon fibers having a generally C-shaped transverse cross-sectional area are produced by extruding a carbonaceous anisotropic liquid precursor through a spinneret having a capillary with a generally C-shaped cross-sectional area, into a fiber filament, controlling the viscosity of the molten precursor, the pressure of the molten precursor and the linear take-up speed of the filament to yield a fiber filament having a cross-sectional area shaped substantially like the shape of the cross-sectional area of the capillary and further having a line-origin microstructure, rendering the filament infusible, heating the filament in an inert pre-carbonizing environment at a temperature in the range of 600.degree. C. to 1000.degree. C. for 1 to 5 minutes, and heating the filament in an inert carbonizing environment at a temperature in the range of 1550.degree. C. to 1600.degree. C. for 5 to 10 minutes, to substantially increase the tensile strength of the filament. The carbon fiber filament so produced has a line-origin microstructure in which the origin line is located and shaped substantially as a line which constitutes the line formed by uniformly collapsing the perimeter of the transverse cross-sectional area of the fiber filament upon itself. The carbon fiber filament has a tensile strength greater than 200 ksi and as high as the 700 to 800 ksi range, yet a modulus of elasticity on the order of 25-35 msi. The top to bottom outside diameter of the fiber\u27s transverse cross-sectional area is on the order of 30 to 50 microns, and the wall thicknesses are on the order of 8 to 15 microns

Method for producing high strength, melt spun carbon fibers

Hollow carbon fibers and carbon fibers having a generally C-shaped transverse cross-sectional area are produced by extruding a carbonaceous anisotropic liquid precursor through a spinneret having a capillary with a generally C-shaped cross-sectional area, into a fiber filament, controlling the viscosity of the molten precursor, the pressure of the molten precursor and the linear take-up speed of the filament to yield a fiber filament having a cross-sectional area shaped substantially like the shape of the cross-sectional area of the capillary and further having a line-origin microstructure, rendering the filament infusible, heating the filament in an inert pre-carbonizing environment at a temperature in the range of 600.degree. C. to 1000.degree. C. for 1 to 5 minutes, and heating the filament in an inert carbonizing environment at a temperature in the range of 1550.degree. C. to 1600.degree. C. for 5 to 10 minutes, to substantially increase the tensile strength of the filament. The carbon fiber filament so produced has a line-origin microstructure in which the origin line is located and shaped substantially as a line which constitutes the line formed by uniformly collapsing the perimeter of the transverse cross-sectional area of the fiber filament upon itself. The carbon fiber filament has a tensile strength greater than 200 ksi and as high as the 700 to 800 ksi range, yet a modulus of elasticity on the order of 25-35 msi. The top to bottom outside diameter of the fiber\u27s transverse cross-sectional area is on the order of 30 to 50 microns, and the wall thicknesses are on the order of 8 to 15 microns

Oxygenated pitch and processing same

A method is provided which includes infusing oxygen into pitch material without stabilizing the oxygen-infused pitch material. In addition, the invention includes further processing steps (including heat stabilization in either an inert atmosphere or an oxygen-containing atmosphere, deformation, pyrolysis, and/or composite formation) performed after or in conjunction with the oxygenation process. Moreover, the invention includes the composition of matter (in any of a number of different physical forms such as powder, fiber, shaped article, composites) resulting from the practice of this oxygenation process, either alone or in conjunction with the further processing steps. The composition has a homogeneous distribution of oxygen and can be heat stabilized in an inert atmosphere

Lecteur de thermoluminescence permettant l'analyse des spectres d'émission

Nous présentons un appareil conçu dans un but de recherche fondamentale pour obtenir des données quantitatives sur la thermoluminescence. Il peut être utilisé pour la mesure intégrale des émissions lumineuses et pour leur analyse en longueur d'onde. Nous indiquons les performances et le domaine d'emploi de l'appareil. Un exemple d'étude de spectre est donné