Current evaluation of the tripropellant concept

An analytical study was conducted to determine the specific-impulse advantages of adding metals to conventional liquid-bipropellant systems. These tripropellant systems theoretically offer higher specific impulse and increased propellant density compared with bipropellant systems. Metals considered were Be, Li, and Al. Bipropellant systems were H2/O2, N2H4/N2O4, RP-1/O2, and H2/F2. Thermochemical calculations were performed for sea-level expansion from 6.895-MN/sq. m. (1000-psia) chamber pressure over a wide range of mixture ratios and propellant compositions. Three-dimensional plots characterize the specific impulse of each tripropellant system. Technology issues pertinent to metallized propellant systems are discussed

Global Foreign Exchange Turnover

The most recent six-monthly data on global foreign exchange turnover show a rebound in activity between April and October 2009 across all markets and major currency pairs. The broad-based increase in turnover is in line with the improvement in global economic and financial conditions since early 2009. Despite the rebound, turnover remains below the peak in early 2008.foreign exchange; foreign exchange turnover; foreign exchange outstandings; global financial crisis; Australian dollar

Characterization of aluminum/RP-1 gel propellant properties

Research efforts are being conducted by the NASA Lewis Research Center to formulate and characterize the properties of Al/RP-1 and RP-1 gelled propellants for rocket propulsion systems. Twenty four different compositions of gelled fuels were formulated with 5 and 16 micron, atomized aluminum powder in RP-1. The total solids concentration in the propellant varied from 5 to 60 wt percent. Tests were conducted to evaluate the stability and rheological characteristics of the fuels. Physical separation of the solids occurred in fuels with less than 50 wt percent solids concentration. The rheological characteristics of the Al/RP-1 fuels varied with solids concentration. Both thixotropic and rheopectic gel behavior were observed. The unmetallized RP-1 gels, which were formulated by a different technique than the Al/RP-1 gels, were highly viscoelastic. A history of research efforts which were conducted to formulate and characterize the properties of metallized propellants for various applications is also given

Catalytic ignition of hydrogen and oxygen propellants

An experimental program was conducted to evaluate the catalytic ignition of gaseous hydrogen and oxygen propellants. Shell 405 granular catalyst and a monolithic sponge catalyst were tested. Mixture ratio, mass flow rate, propellant temperature, and back pressure were varied parametrically in testing to determine the operational limits of the catalytic igniter. The test results show that the gaseous hydrogen and oxygen propellant combination can be ignited catalytically using Shell 405 catalyst over a wide range of mixture ratios, mass flow rates, and propellant injection temperatures. These operating conditions must be optimized to ensure reliable ignition for an extended period of time. A cyclic life of nearly 2000, 2 sec pulses at nominal operating conditions was demonstrated with the catalytic igniter. The results of the experimental program and the established operational limits for a catalytic igniter using the Shell 405 catalyst are presented

An evaluation of metallized propellants based on vehicle performance

An analytical study was conducted to determine the improvements in vehicle performance possible by burning metals with conventional liquid bipropellants. These metallized propellants theoretically offer higher specific impulse, increased propellant density and improved vehicle performance compared with conventional liquid bipropellants. Metals considered were beryllium, lithium, aluminum and iron. Liquid bipropellants were H2/O2, N2H4/N2O4, RP-1/O2 and H2/F2. A mission with a delta V = 4267.2 m/sec (14,000 ft/sec) and vehicle with propellant volume fixed at 56.63 cu m (2000 cu ft) and dry mass fixed at 2761.6 kg (6000 lb) was used, roughly representing the transfer of a chemically propelled upper-stage vehicle from a low-Earth orbit to a geosynchronous orbit. The results of thermochemical calculations and mission analysis calculations for bipropellants metallized with beryllium, lithium, aluminum and iron are presented. Technology issues pertinent to metallized propellants are discussed

Activity in Global Foreign Exchange Markets

According to a recent BIS survey, turnover in foreign exchange markets continued to increase between April 2007 and April 2010. Growth was slower than in earlier years, consistent with a slowdown in the underlying demand for foreign exchange owing to the impact of the global financial crisis on international trade and investment. In an exception to this trend, spot turnover increased significantly, driven in part by the ongoing expansion of high-frequency trading.Foreign Exchange Market Turnover; High-frequency Trading; BIS Triennial Survey

Catalytic ignition of hydrogen/oxygen

An experimental program was conducted to evaluate the catalytic ignition of gaseous hydrogen and oxygen. Shell 405 granular catalyst and a unique monolithic sponge catalyst were tested. Mixture ratio, mass flow rate, propellant inlet temperature, and back pressure were varied parametrically in testing to determine the operational limits of a catalytic igniter. The test results showed that the gaseous hydrogen/oxygen propellant combination can be ignited catalytically using Shell 405 catalyst over a wide range of mixture ratios, mass flow rates, and propellant injection temperatures. These operating conditions must be optimized to ensure reliable ignition for an extended period of time. The results of the experimental program and the established operational limits for a catalytic igniter using both the granular and monolithic catalysts are presented. The capabilities of a facility constructed to conduct the igniter testing and the advantages of a catalytic igniter over other ignition systems for gaseous hydrogen and oxygen are also discussed

A British departure from the EU will not inevitably lead to Scottish independence. Referenda are always unpredictable

Determining whether or not a Brexit will inevitably lead to the breakup of the United Kingdom is anything short of an educated guess. Jan Zurawski argues that the example of the volatility of Scotland’s public opinion regarding voting on the independence of their country may as well be replicated when it comes to the European question. Undoubtedly, the Scots are the most pro-European Brits, but whether their conviction in European integration will necessarily translate into another independence campaign is a different question altogether

Jewish Paideia in the Hellenistic Diaspora: Discussing Education, Shaping Identity.

While the integral role of paideia in Greek, Roman, and early Christian history has been widely recognized, the place of paideia in Jewish thought and the resultant influence on late antique Christianity, and thus on Western education as a whole, has been largely neglected. This study examines the theories of ideal Jewish education from three contemporaneous, but unique Diaspora Jews—Philo of Alexandria, the pseudonymous author of the Wisdom of Solomon, and Paul of Tarsus—particularly in light of the role of the Greek Septuagint translations. The purpose is not to locate a unified concept of Jewish Hellenistic paideia, but to allow the views of each author to stand on their own. The diverse educational theories all developed out of a complex amalgam of Jewish and Greco-Roman influences, brought together and reimagined thanks to the Septuagint and the consistent use of paideia as a translation for the Hebrew musar. The translators of the ancient Hebrew scriptures handed down to future generations a textbook and a teacher, a lens through which later Jewish thinkers could merge and morph ancestral traditions with contemporary Platonic and Stoic philosophy in the creation of new and innovative paideutic concepts. With their textbook in hand, these authors would deploy their ideal notions of paideia as a means of contemplating on and shaping the self and Jewish identity. Paideia, then, becomes the mechanism by which the most highly valued constituents of Jewish ethics and culture are formed and employed. The diverse developments in Jewish education explored reveal the varied dynamics both within the Jewish community and between the Jews and the wider cultural world. Paideia became the perfect surrogate, a common, universal good which could touch on every facet determinative in the construction of the self.PhDNear Eastern StudiesUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/133300/1/jasonzur_1.pd