Anti-Miscegenation Laws in the United States

Still another thesis on Rubik’s cube? Is there still something new to write on that puzzle? In this document, we approach the cube with a rather unusual question: “how would you solve the cube if, instead of using the 6 classical rotations, you were restricted to a set of arbitrary moves?” To answer that question, we will dive into group theory. Inspired by some previous work on the factorization of the symmetric group, we have developed an algorithm that answers our initial question. However, being able to solve the cube with any set of moves has a trade-off: while some algorithms solve the cube in 20 moves, ours requires several thousands. One could go further than this thesis by: improving our algorithm, providing rigourous bounds on its complexity, or generalizing the algorithm to the n × n × n cube.

High-resolution Surface Analysis by Microarea Auger Spectroscopy: Computerization and Characterization

A custom scanning Auger electron microscope (SAM) capable of introducing a 3-5 keV electron beam of several nA into a 30 nm diameter sample area was fitted with a sample introduction system and was fully computerized to be used for materials science research. The method of multispectral Auger imaging was devised and implemented. The instrument was applied to various problems in materials science, including the study of the fiber/matrix interface in a SiC reinforced titanium alloy, the study of SiC whiskers in Al alloy 2124 (in cooperation with NASA-Langley), the study of NiCrAl superalloys (in collaboration with NASA-Lewis), the study of zircalloy specimens (in collaboration with Stanford University), and the microstructure of sintered SiC specimens (in collaboration with NASA-Lewis). The report contains a number of manuscripts submitted for publication on these subjects

Flexible seal for valves Patent

Flexible inflatable seal for butterfly valve

On the representation of integers by quadratic forms

Let Q be a non-singular quadratic form with integer coefficients. When Q is indefinite we provide new upper bounds for the least non-trivial integral solution to the equation Q=0. When Q is positive definite we provide improved upper bounds for the least positive integer k such that the equation Q=k is insoluble in integers, despite being soluble modulo every prime power.Comment: 33 page

\u3cem\u3eThe Gran Para\u3c/em\u3e: The Delicate Dance of South American Privateering from Baltimore

The Consul General of Portugal filed a libel in the District Court of Maryland, alleging silver and gold coin had been taken out of the Portuguese ship, Gran Para, and the specie subsequently deposited in the Marine Bank of Baltimore. In 1818, The Gran Para was sailing to Lisbon from Rio de Janeiro when the privateer, La Irresistible, captained by John Daniel Danels, took her cargo as prize. The lower courts entered decrees in favor of the Consul of Portugal, restoring property to the original owners. The Supreme Court affirmed the lower court decrees, finding it very clear that La Irresistible was armed and manned in Baltimore, in violation of the laws and of the neutral obligations of the United States. Chief Justice Marshall delivered the opinion of the court. The Court found La Irresistible was not commissioned as a privateer, nor did she attempt to act as one; the size of the crew and the lack of a cargo evidenced the ship’s intent to sail against a nation with whom the United States was at peace

Integral points on cubic hypersurfaces

Let g be a cubic polynomial with integer coefficients and n>9 variables, and assume that the congruence g=0 modulo p^k is soluble for all prime powers p^k. We show that the equation g=0 has infinitely many integer solutions when the cubic part of g defines a projective hypersurface with singular locus of dimension <n-10. The proof is based on the Hardy-Littlewood circle method.Comment: 18 page

Current viewpoints on oxide adherence mechanisms

Additional hot stage Auger experiments have provided surface segregation data for NiCrAl + or - Y or Zr alloys in agreement with other investigations. This data, combined with experimental and theoretical evidence of the Al2O3-metal bond strength, is presented in support of a chemical mechanism of Al2O3 scale adhesion. Both the detrimental effects of sulfur segregation and the beneficial effects of dopant segregation may be important. Chemical features of the dopants are compared in light of these proposed mechanisms, namely delta H sub f (sulfide), delta H sub f (oxide), electron orbital configuration, and insolubility in Ni

Sums of arithmetic functions over values of binary forms

Given a suitable arithmetic function h, we investigate the average order of h as it ranges over the values taken by an integral binary form F. A general upper bound is obtained for this quantity, in which the dependence upon the coefficients of F is made completely explicit.Comment: 12 page

Binary forms as sums of two squares and Ch\^atelet surfaces

The representation of integral binary forms as sums of two squares is discussed and applied to establish the Manin conjecture for certain Ch\^atelet surfaces defined over the rationals.Comment: 33 page