Local spin and charge properties of beta-Ag0.33V2O5 studied by 51V NMR

Local spin and charge properties were studied on beta-Ag0.33V2O5, a pressure-induced superconductor, at ambient pressure using 51V-NMR and zero-field-resonance (ZFR) techniques. Three inequivalent Vi sites (i=1, 2, and 3) were identified from 51V-NMR spectra and the principal axes of the electric-field-gradient (EFG) tensor were determined in a metallic phase and the following charge-ordering phase. We found from the EFG analysis that the V1 sites are in a similar local environment to the V3 sites. This was also observed in ZFR spectra as pairs of signals closely located with each other. These results are well explained by a charge-sharing model where a 3d1 electron is shared within a rung in both V1-V3 and V2-V2 two-leg ladders.Comment: 12pages, 16figure

Exploration of Finite 2D Square Grid by a Metamorphic Robotic System

We consider exploration of finite 2D square grid by a metamorphic robotic system consisting of anonymous oblivious modules. The number of possible shapes of a metamorphic robotic system grows as the number of modules increases. The shape of the system serves as its memory and shows its functionality. We consider the effect of global compass on the minimum number of modules necessary to explore a finite 2D square grid. We show that if the modules agree on the directions (north, south, east, and west), three modules are necessary and sufficient for exploration from an arbitrary initial configuration, otherwise five modules are necessary and sufficient for restricted initial configurations

Dual nature of improper ferroelectricity in a magnetoelectric multiferroic

Using first principles calculations, we study the microscopic origin of ferroelectricity (FE) induced by magnetic order in the orthorhombic HoMnO3. We obtain the largest ferroelectric polarization observed in the whole class of improper magnetic ferroelectrics to date. We find that the two proposed mechanisms for FE in multiferroics, lattice- and electronic-based, are simultaneously active in this compound: a large portion of the ferroelectric polarization arises due to quantum-mechanical effects of electron orbital polarization, in addition to the conventional polar atomic displacements. An interesting mechanism for switching the magnetoelectric domains by an electric field via a 180-degree coherent rotation of Mn spins is also proposed.Comment: 6 pages, 4 figures. Submitted for publicatio

Preparation in Assessment for Early Childhood Educators in Hawai‘i

Report to the Hawai‘i State Executive Office on Early LearningThe purpose of this study was to investigate the extent to which programs that prepared early childhood educators in Hawai‘i included various aspects of early childhood assessment. It was an attempt to establish a baseline of what existed with regard to instruction in early childhood assessment among preparation programs. Participants included 9 program coordinators and 43 faculty members from 12 of the 14 preparation programs in the State. The programs included four associate, three bachelor, and five post-baccalaureate degree programs. Participants completed online surveys. Program coordinators responded to questions about whether candidates in their programs were required to learn about and how to conduct assessment in various areas, and how assessment content was delivered. They also reported on more general information about their programs, such as enrollment, target student populations, and numbers of faculty. Faculty members responded to questions about whether they taught candidates about and how to conduct assessment in various areas and whether they would find it helpful to have professional development opportunities in these areas. Results indicated that all faculty members reported teaching candidates about and how to conduct assessments in the areas of different developmental domains and using authentic assessment tools. There were a number of discrepancies regarding what coordinators reported was required and what faculty members suggested that they taught. The greatest discrepancies were in the areas of formal assessment, particularly regarding readiness and achievement tests and using assessment data to inform local programming and policy. Compared to the other types of programs, there appeared to be the most alignment across coordinators and faculty members in the associate degree programs.The Hawai‘i State Executie Office on Early Learning and the University of Hawai‘i System Office of the Vice President for Academic Affair

Bridging the Divide Between Preschool and Elementary School: How Preschool-Elementary Collaborations Can Promote Young Children’s Transition to Kindergarten

Previous research indicates that many children have difficulty transitioning from preschool to kindergarten, which may be attributed to differences between the two settings. The purpose of this study was to investigate preschool and elementary school educators’ perceptions of the similarities of and differences between the two types of settings and their perceptions of how preschool-elementary collaborations could facilitate young children’s transition to kindergarten. Twelve early childhood educators from elementary and preschool settings were interviewed. All educators saw more differences compared to similarities between the two settings. For example, they viewed elementary school as more focused on academic domains. Educators noted that the elementary school curriculum and flow of day was generally more structured, and that preschools tended to promote greater family engagement. Participants suggested that by engaging in joint activity together, these two groups of educators could learn about each others' institutions and find ways to facilitate kindergarten transition.U.S. Department of Education (USDOE), PR/Award No. S362A11001

Theoretical investigation of magnetoelectric effects in Ba2CoGe2O7

A joint theoretical approach, combining macroscopic symmetry analysis with microscopic methods (density functional theory and model cluster Hamiltonian), is employed to shed light on magnetoelectricity in Ba2CoGe2O7. We show that the recently reported experimental trend of polarization guided by magnetic field can be predicted on the basis of phenomenological Landau theory. From the microscopic side, Ba2CoGe2O7 emerges as a prototype of a class of magnetoelectrics, where the cross coupling between magnetic and dipolar degrees of freedom needs, as main ingredients, the on-site spin-orbit coupling and the spin-dependent O p - Co d hybridization, along with structural constraints related to the noncentrosymmetric structural symmetry and the peculiar configuration of CoO4 tetrahedrons.Comment: 5 pages, 4 figures, submitted for publicatio

Chandra deep X-ray observation on the Galactic plane

Using the Chandra ACIS-I instruments, we have carried out the deepest X-ray observation on a typical Galactic plane region at l 28.5 deg, where no discrete X-ray sources have been known previously. We have detected, as well as strong diffuse emission, 275 new point X-ray sources (4 sigma confidence) within two partially overlapping fields (~250 arcmin^2 in total) down to ~3 x 10^{-15} erg s^{-1} cm^{-2} (2 -- 10 keV) or ~ 7 x 10^{-16} erg s^{-1} cm^{-2} (0.5 -- 2 keV). We have studied spectral distribution of these point sources, and found that very soft sources detected only below ~ 3 keV are more numerous than hard sources detected only above ~ 3 keV. Only small number of sources are detected both in the soft and hard bands. Surface density of the hard sources is almost consistent with that at high Galactic regions, thus most of the hard sources are considered to be Active Galactic Nuclei seen through the milky way. On the other hand, some of the bright hard X-ray sources which show extremely flat spectra and iron line or edge features are considered to be Galactic, presumably quiescent dwarf novae. The soft sources show thermal spectra and small interstellar hydrogen column densities, and some of them exhibit X-ray flares. Therefore, most of the soft sources are probably X-ray active nearby late type stars.Comment: Contribution to the proceedings of the "New Visions of the X-Ray Universe in the XMM-Newton and Chandra Era" symposium at ESTEC, The Netherlands. 26-30 Nov. 200

Positions of Point-Nodes in Borocarbide Superconductor YNi2B2C

To determine the superconducting gap function of YNi2B2C, we calculate the local density of states (LDOS) around a single vortex core with the use of Eilenberger theory and the band structure calculated by local density approximation assuming various gap structures with point-nodes at different positions. We also calculate the angular-dependent heat capacity in the vortex state on the basis of the Doppler-Shift method. Comparing our results with the STM/STS experiment, the angular-dependent heat capacity and thermal conductivity, we propose the gap-structure of YNi2B2C, which has the point-nodes and gap minima along . Our gap-structure is consistent with all results of angular-resolved experiments.Comment: 7 pages, 5 figure