Barns and Farms

The art of Ed Ruscha has been a consistent and important presence on the art scene since 1960. Yet his works have not received the high visibility media coverage that the work of many of his peers, such as Jasper Johns and Andy Warhol, have garnered. This situation can, in part, be attributed to the fact that contemporary art criticism has tended to center around clearly defined movements, and Ruscha\u27s work has resisted easy categorization. In addition, interpretations of his work have shifted over the past few decades--his work has been cited in discussions of Pop art, Conceptual art and, most recently, strategies of postmodernist appropriation. As a result of this elusive quality, his work has tended to receive only cursory mention in general overviews of the art historical chronology. Since his emergence on the art scene in the early 1960s, Ruscha\u27s work has evolved and matured. However, the one consistent and most significant aspect throughout his work is the emphasis on the work as the central focus of his art. An understanding of Ruscha\u27s use of the word is critical to a comprehension of his oeuvre. Moreover, his emphasis on the verbal is crucial because it illustrates important issues in the art world during the past three decades. Ed Ruscha\u27s works are thus incisive in their ability to lay bare critical aspects of art production and, reception, and it is this added dimension that lends greater import to his art. In the early years of his career, Ruscha\u27s paintings were closely associated with the Pop art movement of the1960s because of their focus on images from the contemporary urban, consumer-oriented environment. Pop was a pivotal movement in the historical continuum of art in part because of its insistence on figuration, in contrast to the overwhelming predominance of abstraction in preceding and concurrent movements such as Abstract Expressionism, Post-Painterly Abstraction, and Minimal art. Through its content, style, and presentation, Pop art blatantly exposed the commodification of art and of our society in general, and Ruscha\u27s paintings reinforced this

Non-equilibrium dynamics in an interacting nanoparticle system

Non-equilibrium dynamics in an interacting Fe-C nanoparticle sample, exhibiting a low temperature spin glass like phase, has been studied by low frequency ac-susceptibility and magnetic relaxation experiments. The non-equilibrium behavior shows characteristic spin glass features, but some qualitative differences exist. The nature of these differences is discussed.Comment: 7 pages, 11 figure

River Dike Failure in Japan by Earthquakes in 1993

Hokkaido, Japan was attacked by earthquakes of magnitude 7.8 twice in January and July, 1993. One is the Kushiro-Oki Earthquake and the other the Hokkaido Nansei-Oki Earthquake. River dikes were severely damaged by liquefaction of sand. The former caused liquefaction of subsided dike materials and the latter caused liquefaction of sand of the foundation bed. Relations between dimensional elements of dike and peat bed and stress relaxation within dike were analyzed. Old channels recently filled with sandy materials were distinguished from pointbar zones in ancient river bed covered with silty sediment, based on degree of damage due to liquefaction. Repairing works were completed by the end of the year precedent the snow season

Spin Driven Jahn-Teller Distortion in a Pyrochlore system

The ground-state properties of the spin-1 antiferromagnetic Heisenberg model on the corner-sharing tetrahedra, pyrochlore lattice, is investigated. By breaking up each spin into a pair of 1/2-spins, the problem is reduced to the equivalent one of the spin-1/2 tetrahedral network in analogy with the valence bond solid state in one dimension. The twofold degeneracy of the spin-singlets of a tetrahedron is lifted by a Jahn-Teller mechanism, leading to a cubic to tetragonal structural transition. It is proposed that the present mechanism is responsible for the phase transition observed in the spin-1 spinel compounds ZnV$_2$O$_4$ and MgV$_2$O$_4$.Comment: 4 pages, 3 eps figures, REVTeX, to appear in Phys. Rev. Let

Species of Bursaphelenchus Fuchs, 1937 (Nematoda: Parasitaphelenchidae) and other nematode genera associated with insects from Pinus pinaster in Portugal

Insects associated with maritime pine, Pinus pinaster, in Portugal were collected and screened for the presence of Bursaphelenchus species. Nematodes were identified using Internal Transcribed Spacers-Restriction Fragment Length Polymorphism (ITS-RFLP) analysis of dauer juveniles and morphological identification of adults that developed from dauer juveniles on fungal cultures or on cultures in pine wood segments at 26 C. Several associations are described: Bursaphelenchus teratospicularis and Bursaphelenchus sexdentati are associated with Orthotomicus erosus; Bursaphelenchus tusciae, B. sexdentati and/or Bursaphelenchus pinophilus with Hylurgus ligniperda and Bursaphelenchus hellenicus with Tomicus piniperda, Ips sexdentatus and H. ligniperda. An unidentified Bursaphelenchus species is vectored by Hylobius sp. The previously reported association of Bursaphelenchus xylophilus with Monochamus galloprovincialis was confirmed. The association of Bursaphelenchus leoni with Pityogenes sp. is not definitively established and needs further studies for clarification. Other nematode genera besides Bursaphelenchus were found to be associated with the insects sampled, including two different species of Ektaphelenchus, Parasitorhabditis sp., Parasitaphelenchus sp., Contortylenchus sp. and other unidentified nematodes. The Ektaphelenchus species found in O. erosus is morphologically similar to B. teratospicularis found in the same insect; adults of both the species are found in cocoon-like structures under the elytra of the insects. Introduction Approximately one third of the nematodes belonging to the order Aphelenchida Siddiqi, 1980 are associated with insects (Poinar, 1983). These nematodes establish a variety of associations with the insects, which may be described as commensalism, e.g. phoresy (to the benefit of the nematode but not affecting the insect), mutualism (both the organisms benefit) or parasitism (nematodes benefit at the expense of the insect) (Giblin-Davis, 2004). Most Bursaphelenchus Fuchs, 1937 species are mycetophagous, feeding on fungi in the galleries of bark beetles and thu

Soft x-ray magnetic circular dichroism study of weakly ferromagnetic Zn1−x_{1-x}Vx_xO thin film

We performed a soft x-ray magnetic circular dichroism (XMCD) study of a Zn$_{1-x}$V$_x$O thin film which showed small ferromagnetic moment. Field and temperature dependences of V 2$p$ XMCD signals indicated the coexistence of Curie-Weiss paramagnetic, antiferromagnetic, and possibly ferromagnetic V ions, quantitatively consistent with the magnetization measurements. We attribute the paramagnetic signal to V ions substituting Zn sites which are somewhat elongated along the c-axis

Metal-insulator Crossover Behavior at the Surface of NiS_2

We have performed a detailed high-resolution electron spectroscopic investigation of NiS$_2$ and related Se-substituted compounds NiS$_{2-x}$Se$_x$, which are known to be gapped insulators in the bulk at all temperatures. A large spectral weight at the Fermi energy of the room temperature spectrum, in conjunction with the extreme surface sensitivity of the experimental probe, however, suggests that the surface layer is metallic at 300 K. Interestingly, the evolution of the spectral function with decreasing temperature is characterized by a continuous depletion of the single-particle spectral weight at the Fermi energy and the development of a gap-like structure below a characteristic temperature, providing evidence for a metal-insulator crossover behavior at the surfaces of NiS$_2$ and of related compounds. These results provide a consistent description of the unusual transport properties observed in these systems.Comment: 12 pages, 3 figure

High-energy spectroscopic study of the III-V nitride-based diluted magnetic semiconductor Ga1−x_{1-x}Mnx_{x}N

We have studied the electronic structure of the diluted magnetic semiconductor Ga$_{1-x}$Mn$_{x}$N ($x$ = 0.0, 0.02 and 0.042) grown on Sn-doped $n$-type GaN using photoemission and soft x-ray absorption spectroscopy. Mn $L$-edge x-ray absorption have indicated that the Mn ions are in the tetrahedral crystal field and that their valence is divalent. Upon Mn doping into GaN, new state were found to form within the band gap of GaN, and the Fermi level was shifted downward. Satellite structures in the Mn 2$p$ core level and the Mn 3$d$ partial density of states were analyzed using configuration-interaction calculation on a MnN$_{4}$ cluster model. The deduced electronic structure parameters reveal that the $p$-$d$ exchange coupling in Ga$_{1-x}$Mn$_{x}$N is stronger than that in Ga$_{1-x}$Mn$_{x}$As.Comment: 6pages, 10figures. To be published to Phys. Rev.