Improved Current Densities in MgB2 By Liquid-Assisted Sintering

Polycrystalline MgB2 samples with GaN additions were prepared by reaction of Mg, B, and GaN powders. The presence of Ga leads to a low melting eutectic phase which allowed liquid phase sintering and produces plate-like grains. For low-level GaN additions (5% at. % or less), the critical transition temperature, Tc, remained unchanged and in 1T magnetic field, the critical current density, Jc was enhanced by a factor of 2 and 10, for temperatures of \~5K and 20K, respectively. The values obtained are approaching those of hot isostatically pressed samples.Comment: 12 pages, 1 table, 4 figures, accepted in Applied Physics Letter

Structural Aspects of Traditional Cretan Masonry

Glowacki, K.T., J. M. Nichols, and N. L. Holland. “Structural Aspects of Traditional Cretan Masonry.” In Proceedings of the 15th International Brick and Block Masonry Conference, Florianópolis, Brazil, June 3–6, 2012, edited by Humberto Ramos Roman and Guilherme Aris Parsekian, CD-ROM, Paper No. 1C4. Florianopolis, Brazil: 15 IBMAC. ISBN: 9788563273109. (DOI: 10.13140/RG.2.1.1304.2728).The island of Crete has a long tradition of stone masonry construction, beginning over 8000 years before present. As noted by architectural historians, the vernacular architecture of modern (pre-World War II) villages on Crete has many close parallels with house remains uncovered in the archaeological record of the Minoan Bronze Age (ca. 3000-1050 BCE). Archaeologists have used modern ethnographic comparisons effectively to shed light upon issues ranging from the interpretation of ancient house plans to a better understanding of construction techniques, the use of local resources, and the effects of abandonment processes on the built environment. A full-scale replica of a typical Cretan house from the 12th-11th century BCE (Late Minoan IIIC period) is planned for construction in College Station. The first stage of the building will comprise a single room, ca. 6.20 m by 5.20 m, constructed of stacked limestone with minimal earth mortar, timber ceiling beams and laths, a layer of brush, and topped with a flat clay overlay. The purpose of this paper is to outline the design and structural analysis of the building, and to discuss issues related to construction processes, climate, and ventilation that may apply to both archaeological/historical and modern contexts. Modern interest in this traditional type of building technique stems from the use of limestone blocks in construction, and the potential it has to be a key element of the greening of building construction practices. This study forms one element of a major study of limestone and its uses

Octupole strength in the neutron-rich calcium isotopes

Low-lying excited states of the neutron-rich calcium isotopes $^{48-52}$Ca have been studied via $\gamma$-ray spectroscopy following inverse-kinematics proton scattering on a liquid hydrogen target using the GRETINA $\gamma$-ray tracking array. The energies and strengths of the octupole states in these isotopes are remarkably constant, indicating that these states are dominated by proton excitations.Comment: 15 pages, 3 figure

Spectroscopy of 54^{54}Ti and the systematic behavior of low energy octupole states in Ca and Ti isotopes

Excited states of the $N=32$ nucleus $^{54}$Ti have been studied, via both inverse-kinematics proton scattering and one-neutron knockout from $^{55}$Ti by a liquid hydrogen target, using the GRETINA $\gamma$-ray tracking array. Inelastic proton-scattering cross sections and deformation lengths have been determined. A low-lying octupole state has been tentatively identified in $^{54}$Ti for the first time. A comparison of $(p,p')$ results on low-energy octupole states in the neutron-rich Ca and Ti isotopes with the results of Random Phase Approximation calculations demonstrates that the observed systematic behavior of these states is unexpected.Comment: 7 pages, 8 figure

Spectroscopy of 54^{54}Ti and the systematic behavior of low energy octupole states in Ca and Ti isotopes

Excited states of the $N=32$ nucleus $^{54}$Ti have been studied, via both inverse-kinematics proton scattering and one-neutron knockout from $^{55}$Ti by a liquid hydrogen target, using the GRETINA $\gamma$-ray tracking array. Inelastic proton-scattering cross sections and deformation lengths have been determined. A low-lying octupole state has been tentatively identified in $^{54}$Ti for the first time. A comparison of $(p,p')$ results on low-energy octupole states in the neutron-rich Ca and Ti isotopes with the results of Random Phase Approximation calculations demonstrates that the observed systematic behavior of these states is unexpected.Comment: 7 pages, 8 figure

Universal interpretations of vocal music

Despite the variability of music across cultures, some types of human songs share acoustic characteristics. For example, dance songs tend to be loud and rhythmic, and lullabies tend to be quiet and melodious. Human perceptual sensitivity to the behavioral contexts of songs, based on these musical features, suggests that basic properties of music are mutually intelligible, independent of linguistic or cultural content. Whether these effects reflect universal interpretations of vocal music, however, is unclear because prior studies focus almost exclusively on English-speaking participants, a group that is not representative of humans. Here, we report shared intuitions concerning the behavioral contexts of unfamiliar songs produced in unfamiliar languages, in participants living in Internet-connected industrialized societies (n = 5,516 native speakers of 28 languages) or smaller-scale societies with limited access to global media (n = 116 native speakers of three non-English languages). Participants listened to songs randomly selected from a representative sample of human vocal music, originally used in four behavioral contexts, and rated the degree to which they believed the song was used for each context. Listeners in both industrialized and smaller-scale societies inferred the contexts of dance songs, lullabies, and healing songs, but not love songs. Within and across cohorts, inferences were mutually consistent. Further, increased linguistic or geographical proximity between listeners and singers only minimally increased the accuracy of the inferences. These results demonstrate that the behavioral contexts of three common forms of music are mutually intelligible cross-culturally and imply that musical diversity, shaped by cultural evolution, is nonetheless grounded in some universal perceptual phenomena