Theoretical Rocket Performance of Liquid Methane with Several Fluorine-Oxygen Mixtures Assuming Frozen Composition

Theoretical rocket performance for frozen composition during expansion was calculated for liquid methane with several fluorine-oxygen mixtures for a range of pressure ratios and oxidant-fuel ratios. The parameters included are specific impulse, combustion-chamber temperature, nozzle-exit temperature molecular weight, characteristic velocity, coefficient of thrust, ratio of nozzle-exit area to throat area, specific heat at constant pressure, isentropic exponent, viscosity, and thermal conductivity. The maximum calculated value of specific impulse for a chamber pressure of 600 pounds per square inch absolute (40.827atm) and an exit pressure of 1 atmosphere is 315.3 for 79.67 percent fluorine in the oxidant

Simulations of the angular dependence of the dipole-dipole interaction among Rydberg atoms

The dipole-dipole interaction between two Rydberg atoms depends on the relative orientation of the atoms and on the change in the magnetic quantum number. We simulate the effect of this anisotropy on the energy transport in an amorphous many atom system subject to a homogeneous applied electric field. We consider two experimentally feasible geometries and find that the effects should be measurable in current generation imaging experiments. In both geometries atoms of $p$ character are localized to a small region of space which is immersed in a larger region that is filled with atoms of $s$ character. Energy transfer due to the dipole-dipole interaction can lead to a spread of $p$ character into the region initially occupied by $s$ atoms. Over long timescales the energy transport is confined to the volume near the border of the $p$ region which is suggestive of Anderson localization. We calculate a correlation length of 6.3~$\mu$m for one particular geometry.Comment: 6 pages, 5 figures, revised draf

New Insights into the Mechanism of Ruthenium-Catalyzed Olefin Metathesis Reactions

Over the past two decades, olefin metathesis has emerged as a mild and efficient method for the formation of carbon−carbon double bonds. In particular, (PCy_3)_2(Cl)_2RuCHPh (1)^2 has found extensive use in organic and polymer chemistry due to its high reactivity with olefins in the presence of a diverse array of functional groups. Recently, a new family of ruthenium-based olefin metathesis catalysts have been prepared by the substitution of a single PCy_3 ligand of 1 with an N-heterocyclic carbene. These new alkylidenes, particularly [Figure 1], exhibit dramatically increased activity over the parent system in ring-opening metathesis polymerization, ring-closing metathesis,4a and cross metathesis reactions. The mechanism of olefin metathesis reactions catalyzed by 1 has received intense investigation in our group and others and early studies established that phosphine dissociation is a crucial step along the reaction coordinate. As such, it has been suggested that the high activity of 2 and its analogues is due to their increased ability to promote this critical phosphine dissociation step. We report herein a detailed mechanistic study of phosphine exchange and initiation kinetics in alkylidenes 1 and 2. This study provides new and surprising evidence concerning the origin of the large activity differences between these two catalysts

Religion, Morality, and the Law

Some Reflections on Multiculturalism, \u27Equal Concern and Respect,\u27 and the Establishment Clause of the First Amendment lecture given by Sanford Levinson, who occupies the W. St. John Garwood and W. St. John Garwood Jr., Regents Chair in the Law at the University of Texas Law School. Abraham, Isaac, and the State: Faith-healing and Legal Intervention lecture given by Henry J. Abraham, who is the James Hart Professor of Government and Foreign Affairs at the University of Virginia. Is the Idea of Human Rights Ineliminably Religious? lecture given by Michael Perry who occupies the Howard J. Trienens Chair in Law at Northwestern University

Flip the Prison: Using a Holistic, Interdisciplinary Approach to Transform Closed Prisons and Adjudicated Youth

Flip the Prison: Is a collective Impact Model for transforming closed prisons into farms and educational centers utilizing mental health therapy, youth focused, sustainable agricultural entrepreneurship and service learning to stabilize adjudicated youth in the community. Of interest to educators, mental health clinicians, veterans, community leaders, clergy and entrepreneurs

Pilot Test of a Novel Method for Assessing Community Response to Low-Amplitude Sonic Booms

A pilot test of a novel method for assessing residents annoyance to sonic booms was performed. During a two-week period, residents of the base housing area at Edwards Air Force Base provided data on their reactions to sonic booms using Smartphone-based interviews. Noise measurements were conducted at the same time. The report presents information about data collection methods and about test participants reactions to low-amplitude sonic booms. The latter information should not be viewed as definitive for several reasons. It may not be reliably generalized to the wider U.S. residential population (because it was not derived from a representative random sample) and the sample itself was not large

Two Types of Resistance to the Diamondback Moth (Lepidoptera: Plutellidae) in Cabbage

Survival of larvae of the diamondback moth, Plutella xylostella (L.) was reduced on several genotypes of cabbage from the breeding program at Geneva, N.Y. Polar fractions of ethanol extracts of partially resistant lines 2535 and 2503, when incorporated into diet, reduced survival of P. xylostella larvae by 14.9 and 19.0%, respectively. Whether this effect was due to reduced feeding or postingestive toxicity was not determined. Although survival on glossy-leafed line 2518 was very low in the field and larvae on this line failed to form visible feeding mines during the first 72 h after egg hatch, extracts from 2518 had no activity. Survival of larvae confined on leaf disks of 2518 in the laboratory was much greater (80% of controls) than it was on whole plants in the field (0.36% of controls). In the field, neonate P. xylostella dispersed two to three times more rapidly on the leaves of 2518 than on other lines. Resistance to P. xylostella in the lines investigated was therefore due to at least two mechanisms, (1) antibiosis or nonpreference due to extractable compounds present in normal bloom resistant cabbage genotypes, 2503 and 2535, and (2) possible nonpreference for glossy-leafed 2518 by neonate larvae, as suggested by the greater dispersal rates of neonates on these plants. Survival is relatively high on 2518 in leaf disk bioassays in the laboratory, suggesting that nonpreference in combination with environmental stresses to larvae in the field may produce P. xylostella resistance in the glossy 251

Forum: What’s the Matter With the Supreme Court?

1 Mapa, col. Dins: Roux, Joseph, Recueil de plns et rades de la Mediterranée. Marsella, 1764. Pl. 129A. Datació aproximada.19 x 24 c