Experimental and Analytical Study of Rolling-Velocity Amplification during the Thrusting Process for Two 10-Inch-Diameter Spherical Rocket Motors in Free Flight

Two 10-inch-diameter spherical rocket motors have been flight tested at the NASA Wallops Station. These tests were conducted to measure "spin-up" or amplification of the spinning velocity of the motor during the thrusting process due to internal swirling of the exhaust gases. Model 1, a heavy-wall motor, experienced an increase in spin rate during thrusting of about 10 percent, whereas model 2, a flight-type motor with a lightweight motor case, experienced an increase of about 19 percent. The propellant weight and geometry were the same for both motors. A simple relationship for "spin-up" which satisfies these measured results is reported herein. Both models were spin stabilized throughout their flights. A theoretical method of predicting spin-up was derived and used to extend the measured 10-inch-motor results to spherical rocket motors of other sizes having a similar propellant geometry. This method is presented and its predictions are shown to compare favorably with the measured flight results

Political thought of Friedrich von Gentz, 1800-1812

This thesis focuses on the political writings of Friedrich von Gentz, a German writer and political advisor, between the years 1800 and 1812. Scholarship has tended to focus on the years 1791­1801 and Gentz’s political conversion from support of to opposition to the French Revolution, his translation of Edmund Burke’s work, and his contribution to debates over international relations in the years 1800 and 1801. This thesis both reassesses his stance on international relations, presenting him as a complex thinker rather than a crude realist, and unpacks three relatively unexplored areas of his thought, those of international law, civil society and censorship. The first chapter explores Gentz’s defence of the balance of power against the theoretical objections of philosophers like Immanuel Kant and the practical threats of diplomats like Alexandre D’Hauterive. It shows that Gentz was not purely concerned with power but included a subtle and high regard for the role of domestic constitutions, culture, commerce and moral formation. The second chapter considers Gentz’s understanding of international law and, as an illustration of this, his views on the issue of neutral rights at sea. Gentz held to a dualist conception of international law that blended both natural and positive law, and he defended it against attacks from both sides. The third chapter unpacks Gentz’s changing thought on commerce and civil society amidst the instability of Napoleonic expansion. He believed that there was a causal chain that led from the rise of commerce, to the decline of civil society and on to a universal monarchy of a Montesquieuian mould. The fourth chapter considers Gentz’s writings on the press at the time of Napoleon in order to assess the claim he betrayed his 1797 defence of a free press when he supported the 1819 Karlsbad Decrees. It is shown that Gentz developed his views in light of the Napoleonic experience and did not simply sell out to the powers that be. Overall, this thesis argues for the greater richness and complexity of Gentz’s thought than hitherto realised and for the many­sided character to his conservatism, which in turns points to the many­sided nature of conservatism in general

Towards Integrative Systematics of Anthozoa (Cnidaria): Evolution of Form in the Order Zoanthidea

A decade of research inferring evolutionary relationships from nucleotide sequences has demonstrated a fundamental misconception of the evolution of form in Zoanthidea. Morphological features that define current taxa are plesiomorphic or homoplastic and do not circumscribe clades of species delineated by ecological and molecular characters. Although molecular data have been critical in exposing this deficiency, their parataxonomic application to Zoanthidea has created a barrier to comprehensive revision within the order. Species descriptions and higher taxon definitions based on nucleotide sequences isolate new taxa from the existing taxonomic system and restrict the application of novel systematics hypotheses to a fraction of the known diversity of taxa. This creates competing taxonomic systems that do not benefit from the knowledge contained in the opposing system. To enable the integration of modern molecular data with more than a century of morphological research, characters that can simultaneously span the parataxonomy barrier, existing taxonomic system and historical record must be identified. Here, we test the utility of morphological characters for integrative systematics by reviewing commonly described and novel morphological characters, assessing independence of character components and analysing character homoplasy and ancestral states on the most comprehensive molecular phylogeny available. The results indicate a rich diversity of form that span the full range of homoplasy values, including more than a dozen independent characters useful to systematics or differentiating closely related species. The least homoplasious characters include traditionally targeted (fifth mesenteries, marginal muscle arrangement, encircling sinus) and novel (fissure morphology, basal canals of the mesenteries) features. These analyses represent a first step in identifying characters necessary for reunification and revision of Zoanthidea systematics

Flight Performance of a Spin-Stabilized 20-Inch-Diameter Solid-Propellant Spherical Rocket Motor

A successful flight test of a spin-stabilized 20-inch-diameter solid-propellant rocket motor having a propellant mass fraction of 0.92 has been made. The motor was fired at altitude after being boosted by a three-stage test vehicle. Analysis of the data indicates that a total impulse of 44,243 pound-second with a propellant specific impulse of approximately 185 was achieved over a total action time of about 12 seconds. These results are shown to be in excellent agreement with data from ground static firing tests of these motors. The spherical rocket motor with an 11-pound payload attained a velocity of 15,620 feet per second (m = 16.7) with an incremental velocity increase for the spherical motor stage of 12,120 feet per second

A Survey of Alkali Line Absorption in Exoplanetary Atmospheres

We obtained over 90 hours of spectroscopic observations of four exoplanetary systems with the Hobby-Eberly Telescope (HET). Observations were taken in transit and out of transit, and we analyzed the differenced spectra---i.e., the transmission spectra---to inspect it for absorption at the wavelengths of the neutral sodium (\ion{Na}{1}) doublet at $\lambda\lambda5889, 5895$ and neutral potassium (\ion{K}{1}) at $\lambda7698$. We used the transmission spectrum at \ion{Ca}{1} $\lambda6122$---which shows strong stellar absorption but is not an alkali metal resonance line that we expect to show significant absorption in these atmospheres---as a control line to examine our measurements for systematic errors. We use an empirical Monte Carlo method to quantity these systematic errors. In a reanalysis of the same dataset using a reduction and analysis pipeline that was derived independently, we confirm the previously seen \ion{Na}{1} absorption in HD 189733b at a level of $(-5.26\pm1.69)\times10^{-4}$ (the average value over a 12 \AA{} integration band to be consistent with previous authors). Additionally, we tentatively confirm the \ion{Na}{1} absorption seen in HD 209458b (independently by multiple authors) at a level of $(-2.63\pm0.81)\times10^{-4}$, though the interpretation is less clear. Furthermore, we find \ion{Na}{1} absorption of $(-3.16\pm2.06)\times10^{-4}$ at $<3\sigma$ in HD 149026b; features apparent in the transmission spectrum are consistent with real absorption and indicate this may be a good target for future observations to confirm. No other results (\ion{Na}{1} in HD 147506b and \ion{Ca}{1} and \ion{K}{1} in all four targets) are significant to $\geq 3\sigma$, although we observe some features that we argue are primarily artifacts.Comment: 38 total pages (preprint format), 9 color figures, 4 tables, accepted for publication in Ap

Possible thermochemical disequilibrium in the atmosphere of the exoplanet GJ 436b

The nearby extrasolar planet GJ 436b--which has been labelled as a 'hot Neptune'--reveals itself by the dimming of light as it crosses in front of and behind its parent star as seen from Earth. Respectively known as the primary transit and secondary eclipse, the former constrains the planet's radius and mass, and the latter constrains the planet's temperature and, with measurements at multiple wavelengths, its atmospheric composition. Previous work using transmission spectroscopy failed to detect the 1.4-\mu m water vapour band, leaving the planet's atmospheric composition poorly constrained. Here we report the detection of planetary thermal emission from the dayside of GJ 436b at multiple infrared wavelengths during the secondary eclipse. The best-fit compositional models contain a high CO abundance and a substantial methane (CH4) deficiency relative to thermochemical equilibrium models for the predicted hydrogen-dominated atmosphere. Moreover, we report the presence of some H2O and traces of CO2. Because CH4 is expected to be the dominant carbon-bearing species, disequilibrium processes such as vertical mixing and polymerization of methane into substances such as ethylene may be required to explain the hot Neptune's small CH4-to-CO ratio, which is at least 10^5 times smaller than predicted