Electromechanical rotary actuator operates over wide temperature range

Electromechanical rotary actuator, which operates over wide temperature range, contains a spring stop which has been calculated to limit internal deceleration loads to a magnitude equal to stall torque. Cryogenic capability is obtained by using dry lubricant on the gears and no lubrication on the bearings

Saturation numbers in tripartite graphs

Given graphs $H$ and $F$, a subgraph $G\subseteq H$ is an $F$-saturated subgraph of $H$ if $F\nsubseteq G$, but $F\subseteq G+e$ for all $e\in E(H)\setminus E(G)$. The saturation number of $F$ in $H$, denoted $\text{sat}(H,F)$, is the minimum number of edges in an $F$-saturated subgraph of $H$. In this paper we study saturation numbers of tripartite graphs in tripartite graphs. For $\ell\ge 1$ and $n_1$, $n_2$, and $n_3$ sufficiently large, we determine $\text{sat}(K_{n_1,n_2,n_3},K_{\ell,\ell,\ell})$ and $\text{sat}(K_{n_1,n_2,n_3},K_{\ell,\ell,\ell-1})$ exactly and $\text{sat}(K_{n_1,n_2,n_3},K_{\ell,\ell,\ell-2})$ within an additive constant. We also include general constructions of $K_{\ell,m,p}$-saturated subgraphs of $K_{n_1,n_2,n_3}$ with few edges for $\ell\ge m\ge p>0$.Comment: 18 pages, 6 figure

Single-top-quark production at hadron colliders

Single-top-quark production probes the charged-current weak interaction of the top quark, and provides a direct measurement of the CKM matrix element V_{tb}. We perform two independent analyses to quantify the accuracy with which the W-gluon fusion (gq -> t\bar{b}q) and (q\bar{q} -> t\bar{b}) signals can be extracted from the backgrounds at both the Tevatron and the LHC. Although perturbation theory breaks down at low transverse momentum for the W-gluon fusion \bar{b} differential cross section, we show how to obtain a reliable cross section integrated over low \bar{b} transverse momenta up to a cutoff. We estimate the accuracy with which V_{tb} can be measured in both analyses, including theoretical and statistical uncertainties. We also show that the polarization of the top quark in W-gluon fusion can be detected at the Fermilab Tevatron and the CERN LHC.Comment: Version to appear in PRD, 31 pages, LaTeX, 8 ps figure

Latin America: Terrorism Issues

[Excerpt] For most countries in Latin America and the Caribbean, threats emanating from terrorism are low. Terrorism in the region is largely perpetrated by groups in Colombia and by the remnants of radical leftist Andean groups. According to the Department of State, most governments in the region have good records of cooperation with the United States on anti-terrorism issues, although progress in the region on improving counterterrorism capabilities is limited by several factors, including corruption, weak governmental institutions, weak or non-existent legislation, and reluctance to allocate sufficient resources. Both Cuba and Venezuela are on the State Department’s list of countries determined to be not cooperating fully with U.S. antiterrorism efforts, and Cuba has remained on the State Department’s list of state sponsors of terrorism since 1982. U.S. officials and some Members of Congress have expressed concern over the past several years about Venezuela’s relations with Iran, with concerns centered on efforts by Iran to circumvent U.N. and U.S. sanctions and on Iran’s ties to Hezbollah, alleged to be linked to two bombings in Argentina in the 1990s. There is disagreement, however, over the extent and significance of Iran’s activities in Latin America. The State Department maintains that there are no known operational cells of either Al Qaeda or Hezbollah-related groups in the hemisphere, although it notes that ideological sympathizers continue to provide financial and moral support to these and other terrorist groups in the Middle East and South Asia

Test evaluation of fuel cell catalysts Quarterly report, Aug. 16 - Nov. 15, 1967

Corrosion testing of nickel, cobalt, nickel cobalt alloy, borides, and other fuel cell catalyst samples for activity in oxidation of hydrazin

Cathodoluminescence and electron microscopy of red quantum dots used for display applications

Cathodoluminescent imaging of the visible light emitted from quantum dots is reported. The shape and uniformity of individual particles is observed in the STEM electron image and the image of the particles created from their visible light collected simultaneously is shown. Visible light images of the 13nm sized particles are reported for clusters of particles. Emission spectra collected from a small clusters of QDs are also reported