7,252 research outputs found

    [Review of] Nasario Garcia. Recuerdos de los Viejitos, Tales of the Rio Puerco

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    The editor indicated in his foreword that he had several purposes for collecting and assembling the sixty-four stories that comprise this book. First, he had noted that little had been written concerning the history of the Rio Puerco region of New Mexico, and the little that had been written had not included the actual first person narratives of the people who had lived there. These, the collector believed, the ... vibrant oral history and literature from a previously unrecorded area can now further enrich the age old cultural heritage of Hispanic New Mexico

    [Review of] Rudolfo A. Anaya. Heart of Aztlan

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    Heart of Aztlan is a novel which portrays life in Barelas, a barrio of Albuquerque, during the post-Korean War period. While the characters within the novel are fictitious, the situations in which they found themselves were only too real. The mood of the novel was one of hope while the characters continually found themselves in a situation of apparent hopelessness. The author\u27s dedication, perhaps better than any other words, summed up this seeming paradox. This book is dedicated to the good people of Barelas ... and to people everywhere who have struggled for freedom, dignity, and the right to self determination

    Entanglement renormalization for disordered systems

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    We propose a tensor network method for investigating strongly disordered systems that is based on an adaptation of entanglement renormalization [G. Vidal, Phys. Rev. Lett. 99, 220405 (2007)]. This method makes use of the strong disorder renormalization group to determine the order in which lattice sites are coarse-grained, which sets the overall structure of the corresponding tensor network ansatz, before optimization using variational energy minimization. Benchmark results from the disordered XXZ model demonstrates that this approach accurately captures ground state entanglement in disordered systems, even at long distances. This approach leads to a new class of efficiently contractible tensor network ansatz for 1D systems, which may be understood as a generalization of the multi-scale entanglement renormalization ansatz for disordered systems.Comment: 14 pages, 21 figure

    Construction Of A Rich Word Containing Given Two Factors

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    A finite word ww with w=n\vert w\vert=n contains at most n+1n+1 distinct palindromic factors. If the bound n+1n+1 is attained, the word ww is called \emph{rich}. Let \Factor(w) be the set of factors of the word ww. It is known that there are pairs of rich words that cannot be factors of a common rich word. However it is an open question how to decide for a given pair of rich words u,vu,v if there is a rich word ww such that \{u,v\}\subseteq \Factor(w). We present a response to this open question:\\ If w1,w2,ww_1, w_2,w are rich words, m=max{w1,w2}m=\max{\{\vert w_1\vert,\vert w_2\vert\}}, and \{w_1,w_2\}\subseteq \Factor(w) then there exists also a rich word wˉ\bar w such that \{w_1,w_2\}\subseteq \Factor(\bar w) and wˉm2k(m)+2\vert \bar w\vert\leq m2^{k(m)+2}, where k(m)=(q+1)m2(4q10m)log2mk(m)=(q+1)m^2(4q^{10}m)^{\log_2{m}} and qq is the size of the alphabet. Hence it is enough to check all rich words of length equal or lower to m2k(m)+2m2^{k(m)+2} in order to decide if there is a rich word containing factors w1,w2w_1,w_2

    Equilibrium ultrastable glasses produced by random pinning

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    Ultrastable glasses have risen to prominence due to their potentially useful material properties and the tantalizing possibility of a general method of preparation via vapor deposition. Despite the importance of this novel class of amorphous materials, numerical studies have been scarce because achieving ultrastability in atomistic simulations is an enormous challenge. Here we bypass this difficulty and establish that randomly pinning the position of a small fraction of particles inside an equilibrated supercooled liquid generates ultrastable configurations at essentially no numerical cost, while avoiding undesired structural changes due to the preparation protocol. Building on the analogy with vapor-deposited ultrastable glasses, we study the melting kinetics of these configurations following a sudden temperature jump into the liquid phase. In homogeneous geometries, we find that enhanced kinetic stability is accompanied by large scale dynamic heterogeneity, while a competition between homogeneous and heterogeneous melting is observed when a liquid boundary invades the glass at constant velocity. Our work demonstrates the feasibility of large-scale, atomistically resolved, and experimentally relevant simulations of the kinetics of ultrastable glasses.Comment: 9 pages, 5 figure

    Estimating the Benefits of Water Quality Improvements in the Upper Narragansett Bay

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    An EPA-sponsored study of the benefits to Rhode Island residents of the water quality improvement in the Upper Narragansett Bay showed that the estimated annual costs (2.9million)exceededtheexpectedannualbenefits(2.9 million) exceeded the expected annual benefits (2.0 million). That analysis evaluated only user benefits which were measured via expenditures; nonuser (intrinsic) benefits were not included. This study estimated the benefits to Rhode Island residents using the "Contingent Valuation" approach and responses from 435 residents to a 1985 survey about swimming and shellfishing. Aggregate annual benefits were estimated to be in the range of 3060millionfor"swimmable"and30-60 million for "swimmable" and 30-70 million for "shellfishable" water quality, depending on the type of measure (mean or median) and survey format. Secondary objectives of the study were to test different versions of "willingness to pay" questions and compare mean and median values for measurement. Aside from payment vehicle bias, we found no evidence of serious bias.contingent valuation, pollution, water quality benefits, Environmental Economics and Policy, Resource /Energy Economics and Policy,
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