Electronic Dynamics Due to Exchange Interaction with Holes in Bulk GaAs

We present an investigation of electron-spin dynamics in p-doped bulk GaAs due to the electron-hole exchange interaction, aka the Bir-Aronov-Pikus mechanism. We discuss under which conditions a spin relaxation times for this mechanism is, in principle, accessible to experimental techniques, in particular to 2-photon photoemission, but also Faraday/Kerr effect measurements. We give numerical results for the spin relaxation time for a range of p-doping densities and temperatures. We then go beyond the relaxation time approximation and calculate numerically the spin-dependent electron dynamics by including the spin-flip electron-hole exchange scattering and spin-conserving carrier Coulomb scattering at the level of Boltzmann scattering integrals. We show that the electronic dynamics deviates from the simple spin-relaxation dynamics for electrons excited at high energies where the thermalization does not take place faster than the spin relaxation time. We also present a derivation of the influence of screening on the electron-hole exchange scattering and conclude that it can be neglected for the case of GaAs, but may become important for narrow-gap semiconductors.Comment: 14 pages, 5 figures, formatted using SPIE templat

Eskimo languages in Asia, 1791 on, and the Wrangel Island-Point Hope connection

Merck’s statement about four “Sedentary Chukchi” (Eskimo) languages or language varieties along the coast of Chukotka in 1791 is thoroughly remarkable and worthy of careful interpretation. By his statement of their geographical distribution, the first three languages are very easy to identify, as 1) Sirenikski, 2) Central Siberian Yupik, explicitly including St. Lawrence Island, and 3) Naukanski. Merck’s language number four, “Uwelenski” he claims, startlingly, to be spoken along the Arctic Coast of Chukotka from Uelen as far as Shelagski Cape, 600 miles to the northwest. Serendipitously enough, Merck has 70 or so ”Uwelenski” words of cultural interest transcribed throughout his text. Careful studies of these words by this writer and also by Mikhail Chlenov show that “Uwelenski” is in fact a dialect of Central Siberian Yupik, thus part of a language continuum spoken from St. Lawrence Island to the Chaplino corner and the East coast of Chukotka, thence to the North coast of that mainland, treating Naukan as a “third Diomede” rather than as a mainland interruption. However there is no evidence that language number four, “Uwelenski,” actually a dialect of Merck’s language number two, was spoken beyond Kolyuchin Bay. Beyond that point, however, there was indeed a fourth Eskimo language. The second half of the paper concludes, from at least seven independent sources, that that fourth language was in fact none other than North Alaskan Inupiaq, spoken intermittently in pockets between Kolyuchin and Shelagski Cape, at least since the opening of Russian posts at Kolyma and into the nineteenth century, by north Alaskans from the Point Hope area, who also used Wrangel Island as a stopping place.Ce que constate Merck à propos des quatre langues «tchouktches sédentaires» (Eskimo), ou quatre variétés de langue le long de la côte Tchouktche en 1791, est absolument remarquable et mérite d’être interprété avec soin. Par sa description de leur répartition géographique, il est très facile d’identifier les trois premières langues comme étant 1) le sirenikski, 2) le yupik sibérien central, y compris expressément l’île St Laurent et 3) le naukanski. Étonnament, Merck prétend que sa langue numéro 4, le «Uwelenski», était parlée le long de la côte arctique de la Tchoukotka, depuis Ouelen aussi loin que le cap Tchelagsky, à environ 1000 km (600 milles) au nord-ouest. Assez heureusement, Merck, tout au long de son texte, transcrit quelque 70 mots «Uwelenski» d’intérêt culturel. L’étude méticuleuse de ces mots par l’auteur et par Mikhail Chlenov montre que le «Uwelenski » est en fait un dialecte du Yupik sibérien central, par conséquent une langue parlée en continu depuis l’île St Laurent jusqu’à l'avancée de Chaplino et de la côte est de la Tchoukotka, et de là, jusqu’à la côte nord du continent. Ceci amène à considérer Naukan comme une «troisième Diomède» plutôt que comme une interruption du continent. Cependant, il n’y a pas d’indication que la langue numéro quatre «Uwelenski », en fait un dialecte de la langue numéro deux de Merck, n’ait jamais été parlée au-delà de la baie de Kolioutchine. Au-delà de ce point, pourtant, il y avait bien une quatrième langue eskimo. La deuxième moitié de cet article conclut, à partir d’au moins sept sources indépendantes, que cette quatrième langue était en fait nulle autre que l’inupiaq du nord de l’Alaska, parlé de façon intermittente, par poches, entre Kolioutchine et le cap Tchelagsky, au moins depuis l’établissement des postes russes de la Kolyma jusque dans le 19e siècle par des Nord-Alaskiens (ceux de la région de Point Hope), qui utilisaient aussi l’île Wrangel comme point d’étape

Adjusting to Life in Mexico – One Couple’s Adaptation Process and Suggestions for Coping

In this paper I present challenges which confronted Sharon Beckett, my partner, and me as we underwent the process of adapting to life in Mexico during a three month stay. Some of the issues are unique to a couple with our respective back­ grounds, but, many are applicable to any couple or individual traveling to Mexico or other foreign countries. I discuss some guidelines and principles of interacting which proved helpful to us in Mexico and also offer some suggestions for coping to couples or individuals going abroad. The primary source of data for the paper is a daily journal which I kept in Mexico throughout our stay

Rape on the Washington Southern: The Tragic Case of \u3ci\u3eHines v. Garrett\u3c/i\u3e

In 1919, Ms. Julia May Garret, a young Virginian woman, was brutally raped by two different men as she was walking home after the Washington Southern Railway failed to stop at her designated station. What followed was a legal battle that created precedent still discussed in American casebooks today. Although most case law recognizes that the criminal acts of third parties severs liability because such conduct is considered unforeseeable, Hines v. Garrett held that the harm Ms. Garrett suffered was within the risk created by the railroad’s negligence, and as a common carrier, the railroad owed her a duty to protect against that risk if she did not voluntarily disembark. This article dives into the historical backdrop of this pivotal Virginian case by providing details on Ms. Garrett’s daily commute, the assaults, the police investigation, the lawsuit, both the trial and appeal, and the Virginia Supreme Court’s ultimate decision. Further, this article provides insight into the aftermath of this case and how the parties’ lives proceeded at its conclusion. Julia May Garrett\u27s story, it turns out, is more than a story of proximate cause. It is in many ways a story about Virginia

Geometry and Destiny

The recognition that the cosmological constant may be non-zero forces us to re-evaluate standard notions about the connection between geometry and the fate of our Universe. An open Universe can recollapse, and a closed Universe can expand forever. As a corollary, we point out that there is no set of cosmological observations we can perform that will unambiguously allow us to determine what the ultimate destiny of the Universe will be.Comment: 7 pages, Gravity Research Foundation Essa

Public Services Meet Private Law

Some plaintiffs\u27 lawyers believe that expenses incurred by governments after the criminal use of their products take issue with the claim that the government services for which compensation is claimed are free for all, and therefore ineligible for tort recovery. They argue that government services should not subsidize tortfeasors, and that proper accounting requires tortfeasors to internalize the social costs of their alleged misbehavior. They would do away with what they call the free public services doctrine (FPSD), which one author described as holding that a governmental entity may not recover from a tortfeasor the costs of public services occasioned by the tortfeasor\u27s wrong. On the other side of the political spectrum, proponents of federal tort reform have sought to specifically immunize certain defendants from cost recoupment suits. Of course such legislation, if enacted, would imply that the recoupment suits could have been allowed as a general common law matter in its absence. This Article contends that both camps would benefit from a more thorough understanding of the Free Public Services Doctrine\u27s place within the common law of tort. FPSD is in reality, contra its critics\u27 claims, a universally applied illustration of fundamental common law tort concepts: duty, proximate cause and damages. Wherever these elements remain requirements for common law liability, public service cost recoupment should be denied