Azimuth laying system Patent

Inertial gimbal alignment system for spacecraft guidanc

The effects of clouds on the light produced by lightning

A Monte Carlo simulation of the effects of finite clouds on the light impulses was produced by point and finite lightning sources within cubical, cylindrical, and spherical clouds. It is shown that absorption is essentially negligible in the visible and near infrared. The fractions of photons which escape various cloud surfaces are a function of position and geometry of the source. The light emission is high for intracloud discharges and the incloud portion of cloud to ground discharges. It is concluded that the characteristic dimensions of the light escaping from a cloud surface are typically 60 to 70% of the cloud dimensions while the time broadening of an impulse by multiple scattering can be tens of microseconds or more

Considering Instructional Time and Comprehension Rate when Evaluating the Effectiveness of Reading Interventions in Classrooms

The purpose of this investigation was to replicate and extend research done by Daly et al. (1998), which focused on the functional analysis of academic problems. This research examined comprehension and amount of instructional time as dependent variables to determine the effectiveness and efficiency of reading interventions (repeated reading, contingent reinforcement for rapid reading, and listening passage preview). Results suggest that when evaluating increases in oral reading fluency (words read correct per minute), each participant obtained greatest gains using different combinations of interventions. However, when examining instructional time specifically, it becomes clear that the contingent reinforcement and listening passage preview interventions showed greatest gains when evaluating the amount of time that educators spend with students. This indicates that methods may be available that show substantial improvements in reading fluency and require less teacher time. When examining comprehension, contingent reinforcement showed improvements when evaluating factual, inferential, and total comprehension

Development of a digital electronic rebalance loop for a dry tuned-rotor two degree-of-freedom gyroscope

Digital electronic rebalance loops were designed and implemented in brassboard form to capture both X and Y axes of the Kearfott Gyroflex. The loops were width-modulated binary types using a 614.4 kHz keying signal and a 2.4 kHz sample frequency. The loops were designed for a torquing rate of 2 deg/sec (70.6 mA torquing current) and a data resolution of 23.4 milli-arc-sec per data pulse. Design considerations, implementation details, and preliminary experimental results are presented

Space shuttle with external hydrogen drop tanks

Guidelines for using space shuttle configuration to determine effects of carrying ascent LH2 propellant in external drop tank

On the Concept of a Notational Variant

In the study of modal and nonclassical logics, translations have frequently been employed as a way of measuring the inferential capabilities of a logic. It is sometimes claimed that two logics are “notational variants” if they are translationally equivalent. However, we will show that this cannot be quite right, since first-order logic and propositional logic are translationally equivalent. Others have claimed that for two logics to be notational variants, they must at least be compositionally intertranslatable. The definition of compositionality these accounts use, however, is too strong, as the standard translation from modal logic to first-order logic is not compositional in this sense. In light of this, we will explore a weaker version of this notion that we will call schematicity and show that there is no schematic translation either from first-order logic to propositional logic or from intuitionistic logic to classical logic

XPS and AFM study of interaction of organosilane and sizing with e-glass fibre surface

Organosilanes are often used in commercial sizings for glass fibres to provide wettability with the resin and promote strong interfacial adhesion to the matrix in a fibre reinforced polymer composite. The silane treatment is introduced as part of a complex deposition from an aqueous emulsion immediately at the spinaret and determines the optimum properties of the cured composite. To understand the interaction of organosilanes contained in sizings for glass surfaces, XPS was used to investigate the adsorption of γ-aminopropyltriethoxysilane (APS) from a simple sizing system containing a polyurethane (PU) film former. It has been found that both APS and the sizing (containing APS and PU) deposits on E-glass fibre surfaces contained components of differing hydrolytic stability. The differences observed in the AFM images of APS coated E-glass fibres before and after water extraction also confirmed that the APS deposit contained components with different water solubility

Regeneration of thermally recycled glass fibre for cost-effective composite recycling : increasing the strength of thermally conditioned glass fibres using cost effective recover treatments

The paper reports an extensive study on the regenerating performance of thermally treated glass fibres using two different chemically based treatments routes. The effectiveness of these two different treatments was investigated on strength recovery of glass fibres thermally treated with the conditions imitating composite recycling technology. The regenerated strength levels of these ReCoVeRed fibres must also be further protected and maintained by the use of standard fibre sizing technology similar to standard glass fibre products. Consequently, the effect on fibre strength of the combination of our ReCoVeR treatments with the standard silane coatings was also studied. Significant increase of fibre strength was obtained through the ReCoVeR and coatings treatments, achieving up to 200% increase in fibre strength in comparison with the glass fibre thermally treated

Trigonometric vehicle guidance assembly which aligns the three perpendicular axes of two three-axes systems Patent

Electrical and electromechanical trigonometric computation assembly and space vehicle guidance system for aligning perpendicular axes of two sets of three-axes coordinate reference