Disorder, Path Integrals and Localization

Anderson localization is derived directly from the path integral representation of quantum mechanics in the presence of a random potential energy function. The probability distribution of the potential energy is taken to be a Gaussian in function space with a given autocorrelation function. Averaging the path integral itself we find that the localization length, in one-dimension, is given by (E_{{\xi}}/{\sigma})(KE_{cl}/{\sigma}){\xi} where E_{{\xi}} is the "correlation energy", KE_{cl} the average classical kinetic energy, {\sigma} the root-mean-square variation of the potential energy and {\xi} the autocorrelation length. Averaging the square of the path integral shows explicitly that closed loops in the path when traversed forward and backward in time lead to exponential decay, and hence localization. We also show how, using Schwinger proper time, the path integral result can be directly related to the Greens function commonly used to study localization.Comment: 6 pages, no figure

Twill: A Hybrid Microcontroller-FPGA Framework for Parallelizing Single- Threaded C Programs

Increasingly System-On-A-Chip platforms which incorporate both micropro- cessors and re-programmable logic are being utilized across several fields ranging from the automotive industry to network infrastructure. Unfortunately, the de- velopment tools accompanying these products leave much to be desired, requiring knowledge of both traditional embedded systems languages like C and hardware description languages like Verilog. We propose to bridge this gap with Twill, a truly automatic hybrid compiler that can take advantage of the parallelism inherent in these platforms. Twill can extract long-running threads from single threaded C code and distribute these threads across the hardware and software domains to more fully utilize the asymmetric characteristics between processors and the embedded reconfigurable logic fabric. We show that Twill provides a sig- nificant performance increase on the CHStone benchmarks with an average 1.63 times increase over the pure hardware approach and an increase of 22.2 times on average over the pure software approach while reducing the area required by the reconfigurable logic by on average 1.73 times compared to the pure hardware approach

Letter, A. G. Paxton to Mr. and Mrs. Boswell Stevens, February 15, 1960

Letter from A. G. Paxton to Mr. and Mrs. Boswell Stevens, regarding his opinions on farm production, including the need to increase domestic consumption.https://scholarsjunction.msstate.edu/mss-stevens-papers/1014/thumbnail.jp

A Synopsis of the Indian Tribes Within the United States East of the Rocky Mountains, and in the British and Russian Possessions in North America

Published in the American Antiquarian Society\u27s Archaeologia Americana, vol. 2, (1836), pp. 1-422. A 208-page geographical, historical, and cultural introduction is followed by 214 pages of appendices of linguistic materials. Sect. I. Indian Tribes north of the United States Eskimaux. Kinai, Koluschen, &c., on the Pacific Ocean Athapascas, (Northern, Cheppeyans, Copper Mine, &c., Sussees, Tacullies) Sect. II. Algonkin-Lenape and Iroquois, Algonkin-Lenape Northern (Knistinaux, Algonkins, Chippeways, Ottowas, Potowotamies, Mississagues) Northeastern (Labrador, Micmacs, Etchemins, Abenakis) Eastern (New England, Mohicans, Manhattans, Long Island, Delawares and Minsi, Nanticokes, Susquehannocks, Conoys, Powhatans, Mannahoks, Pamlicoes) Western, (Menomonies, Sauks, Foxes, Kickapoos and Mascoutins, Miamis and Piankishaws, Illinois, Shawnoes) Iroquois Northern (Wyandots or Hurons, Extinct Tribes, Five Nations) Southern (Tuteloes, Nottoways, Tuscaroras) Sect. III. Southern Indians, (east of the Mississippi and in Louisiana) Extinct Tribes of Carolina Catawbas; Cherokees (Guess\u27s alphabet) Muskhogees (proper, Seminoles, Hitchittees,) Uchees; Natchez Alibamons and Coosadas Choctaws and Chicasas Southern Indians at the time of De Soto\u27s expedition, Their social state (division into clans, worship of the sun, monarchical government; Natchez) Tribes of Lower Louisiana, east and west of the Mississippi (great diversity of languages) Sect. IV. Indians west of the Mississippi, East of the Rocky Mountains Sioux (Winebagoes, Dahcotas and Assiniboins, Shyennes, Minetares, Mandares, Crows, Quappas, Osages, Kansaws, Ioways, Missouris, Ottoes, Omahaws, Puncas,) Pawnees and Ricaras; habits of western Indians Black Feet, Rapid Indians, other erratic tribes West of the Rocky Mountains: Want of vocabularies; Salish, Atnahs, Shoshonees, Chinooks Sect. V. General Observations. Climate; forests and prairies; geographical notices Conjectures (Asiatic origin; semi-civilization of Mexico; ancient works in United States,) Means of subsistence (hunter state; agricultural labor confined to women,) Labor the only means of preserving and civilizing the Indians, (Cherokee civilization,) Sect. VI. Indian Languages. Diversity of vocabularies and similarity of grammatical forms; gender and number Substantive verb; conversion of nouns, &c. into verbs, reciprocal; pronouns Transitions Tenses and moods, compound words, multiplied forms, defective information Suggestions respecting highly inflected languages Grammatical forms in the earliest stages of society, APPENDIX. No. 1. Grammatical Notices. Eskimaux; Athapascas Algonkin-Lenape, (Massachusetts, Delaware, Chippeway, Micmac,) Iroquois (Onondago, Huron or Wyandot,) Cherokee Sioux; Choctaw Muskhogee; Araucanian No.2. Specimens of Conjugations and Transitions Notes to the Tables of Transitions, &c. Cherokee Alphabet No. 3. Note by the Publishing Committee, respecting Tribes on Northwest Coast of America VOCABULARIES General Table No.1. Comparative Vocabulary for Fifty-three Tribes No. 2. Do. Sixteen Tribes No. 3. Umfreville\u27s Vocabulary No.4. Miscellaneous Vocabularies No. 5. Supplementary Vocabulary, (Muskhogee, Choctaw, Caddo, Mohawk, Seneca, Cherokee,) Short Comparative Vocabulary of the Choctaw and Muskhogee SELECT SENTENCES. Muskhogee, Choctaw, Caddo Ojibway, Cherokee, Seneca, Supplementary Cherokee Transitions The Lord\u27s Prayer in Cherokee, Muskhogee, Choctaw, and Dahcota Albert Gallatin (1761–1849) immigrated to the United States from Switzerland in the 1780s. He was U.S. Senator 1793, U.S. Representative 1795-1801, Secretary of the Treasury 1802-1814, Ambassador to France 1816-1823, Ambassador to Great Britain 1826-1827, co-founder New York University 1831, President of the Bank of the United States 1831-1839, co-founder American Ethnological Society 1842.https://digitalcommons.unl.edu/zeaamericanstudies/1015/thumbnail.jp

Project Tech Top study of lunar, planetary and solar topography Final report

Data acquisition techniques for information on lunar, planetary, and solar topograph

Influence of base and photoacid generator on deprotection blur in extreme ultraviolet photoresists and some thoughts on shot noise

A contact-hole deprotection blur metric has been used to monitor the deprotection blur of an experimental open platform resist (EH27) as the wt % of base and photoacid generator (PAG) were varied. A six times increase in base wt % is shown to reduce the size of successfully patterned 1:1 line-space features from 52 to 39 nm without changing deprotection blur. Corresponding isolated line edge roughness is reduced from 6.9 to 4.1 nm. A two times increase in PAG wt % is shown to improve 1:1 line-space patterning from 47 to 40 nm without changing deprotection blur or isolated line edge roughness. A discussion of improved patterning performance as related to shot noise and deprotection blur concludes with a speculation that the spatial distribution of PAG molecules has been playing some role, perhaps a dominant one, in determining the uniformity of photogenerated acids in the resists that have been studied. © 2008 American Vacuum Society

Knowledge and Perceptions of Electronic Cigarette Use among Pregnant Women

poster abstractThe association between maternal tobacco smoke exposure and restricted fetal growth has been well studied. However, the safety of electronic cigarettes (e-cigarettes) is quite controversial among pregnant women and the public. Research on the health effects of e-cigarette use during pregnancy is limited, particularly because of the health risks and ethical considerations. However, there is concern about the effects of the nicotine on fetal health from e-cigarettes. Some women’s beliefs about e-cigarettes are influenced by information that e-cigarettes may be beneficial as a way to decrease the number of tobacco cigarettes smoked. We conducted a systematic review of the literature to explore the knowledge and perceptions of e-cigarette use among pregnant women. Using pre-designated inclusion and exclusion criteria, relevant articles were located and reviewed searching PubMed, EMBASE, EBSCOhost, CINAHL Complete, and the reference lists of related articles. Full text, English language, peer-reviewed articles relevant to pregnant women’s knowledge and perceptions of e-cigarettes were reviewed. Of the thirty studies, six met the inclusion criteria. The following findings were common among the studies reviewed: 1) study participants had inaccurate information regarding the amount of nicotine in ecigarettes and the effects on the fetus; 2) e-cigarettes were perceived as safe alternatives and could be used for smoking cessation; 3) using e-cigarettes caused less negative side effects than traditional cigarettes; and 4) information obtained from the media about e-cigarettes was confusing for pregnant women. The findings support the need for healthcare providers to assess e-cigarette use among pregnant women and provide accurate information regarding e-cigarettes and the potential impact of use during pregnancy

Propagation of Vortex Electron Wave Functions in a Magnetic Field

The physics of coherent beams of photons carrying axial orbital angular momentum (OAM) is well understood and such beams, sometimes known as vortex beams, have found applications in optics and microscopy. Recently electron beams carrying very large values of axial OAM have been generated. In the absence of coupling to an external electromagnetic field the propagation of such vortex electron beams is virtually identical mathematically to that of vortex photon beams propagating in a medium with a homogeneous index of refraction. But when coupled to an external electromagnetic field the propagation of vortex electron beams is distinctly different from photons. Here we use the exact path integral solution to Schrodingers equation to examine the time evolution of an electron wave function carrying axial OAM. Interestingly we find that the nonzero OAM wave function can be obtained from the zero OAM wave function, in the case considered here, simply by multipling it by an appropriate time and position dependent prefactor. Hence adding OAM and propagating can in this case be replaced by first propagating then adding OAM. Also, the results shown provide an explicit illustration of the fact that the gyromagnetic ratio for OAM is unity. We also propose a novel version of the Bohm-Aharonov effect using vortex electron beams.Comment: 14 pages, 2 figures, submitted to Phys Rev