Extended range harmonic filter

Two types of filters, leaky-wall and open-guide, are combined into single component. Combination gives 10 db or greater additional attenuation to fourth and higher harmonics, at expense of increasing loss of fundamental frequency by perhaps 0.05 to 0.08 db. Filter is applicable to all high power microwave transmitters, but is especially desirable for satellite transmitters

The relationship between cooling flows and metallicity measurements for X-ray luminous clusters

We explore the relationship between the metallicity of the intracluster gas in clusters of galaxies, determined by X-ray spectroscopy, and the presence of cooling flows. Using ASCA spectra and ROSAT images, we demonstrate a clear segregation between the metallicities of clusters with and without cooling flows. On average, cooling-flow clusters have an emission-weighted metallicity a factor ~ 1.8 times higher than that of non-cooling flow systems. We suggest this to be due to the presence of metallicity gradients in the cooling flow clusters, coupled with the sharply peaked X-ray surface brightness profiles of these systems. Non-cooling flow clusters have much flatter X-ray surface brightness distributions and are thought to have undergone recent merger events which may have mixed the central high-metallicity gas with the surrounding less metal-rich material. We find no evidence for evolution in the emission-weighted metallicities of clusters within z~0.3.Comment: Submitted to MNRAS letters (December 1997). 6 pages, 2 figures in MNRAS LaTex style. Minor revision

Sugar Maple Borer (Coleoptera: Cerambycidae) Activity Associated With Periods of Severe Defoliation

A perusal of previous research on sugar maple borer, Glycobius speciosus, in northern New York State strongly associates severe early and late season defoliation with increased borer damage. This re-examination of earlier work suggests foliage protection may be necessary when forest management objectives are concerned with wood volume and quality

Colonel Utley\u27s Emancipation - Or, How Lincoln Offered to Buy a Slave

The reputation of Abraham Lincoln has see-sawed over the last half-century on the fulcrum of race, and the results have not been happy for that reputation. As Gerald Prokopowicz has written, the big question about Lincoln and slavery runs today like this: Was Lincoln really the Great Emancipator that we have traditionally been brought up to admire, or was he just a clever, lying, racist, white male politician who had no interest in the well-being of black America other than when it served his political interests? No longer is it necessary, as one historian has wryly remarked, for politicians to get right with Lincoln. Historians now yearn to get right with Frederick Douglass, and to judge by the recent freshet of literature on Lincoln and Douglass, it is now incumbent on Lincoln to be gotten right with Frederick Douglass, too. One of the most damaging accusations leveled against the possibility of justifying Lincoln on race appears in Lerone Bennett\u27s infamous screen, Forced into Glory: Abraham Lincoln\u27s White Dream, where, as the finale to a battery of accusations of racism, Bennett\u27s Lincoln personally ordered Union officers to return runaway slaves to slavemasters and turned a blind eye to Kentuckians, for example, who were selling and reenslaving African-Americans freed by the war and congressional acts. [excerpt

Apparatus for igniting solid propellants Patent

Solid propellant ignition with hypergolic fluid injected to predetermined portions of propellan

Method of igniting solid propellants Patent

Method for igniting solid propellant rocket motors by injecting hypergolic fluid

Spin swap vs. double occupancy in quantum gates

We propose an approach to realize quantum gates with electron spins localized in a semiconductor that uses double occupancy to advantage. With a fast (non-adiabatic) time control of the tunnelling, the probability of double occupancy is first increased and then brought back exactly to zero. The quantum phase built in this process can be exploited to realize fast quantum operations. We illustrate the idea focusing on the half-swap operation, which is the key two-qubit operation needed to build a CNOT gate.Comment: 5 pages, 2 figure