Determining Effective Interface Fracture Properties of 3D Fiber Reinforced Foam Core Sandwich Structures

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/106494/1/AIAA2013-1547.pd

K−K^- - nucleus relativistic mean field potentials consistent with kaonic atoms

$K^-$ atomic data are used to test several models of the $K^-$ nucleus interaction. The t($\rho$)$\rho$ optical potential, due to coupled channel models incorporating the $\Lambda$(1405) dynamics, fails to reproduce these data. A standard relativistic mean field (RMF) potential, disregarding the $\Lambda$(1405) dynamics at low densities, also fails. The only successful model is a hybrid of a theoretically motivated RMF approach in the nuclear interior and a completely phenomenological density dependent potential, which respects the low density theorem in the nuclear surface region. This best-fit $K^-$ optical potential is found to be strongly attractive, with a depth of 180 \pm 20 MeV at the nuclear interior, in agreement with previous phenomenological analyses.Comment: revised, Phys. Rev. C in pres

Effects of Ply Stacking Sequence in 3D Fiber Reinforced Foam Core Sandwich Structures with Defects

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140407/1/6.2014-0504.pd

The Amplitude of Non-Equilibrium Quantum Interference in Metallic Mesoscopic Systems

We study the influence of a DC bias voltage V on quantum interference corrections to the measured differential conductance in metallic mesoscopic wires and rings. The amplitude of both universal conductance fluctuations (UCF) and Aharonov-Bohm effect (ABE) is enhanced several times for voltages larger than the Thouless energy. The enhancement persists even in the presence of inelastic electron-electron scattering up to V ~ 1 mV. For larger voltages electron-phonon collisions lead to the amplitude decaying as a power law for the UCF and exponentially for the ABE. We obtain good agreement of the experimental data with a model which takes into account the decrease of the electron phase-coherence length due to electron-electron and electron-phonon scattering.Comment: New title, refined analysis. 7 pages, 3 figures, to be published in Europhysics Letter

Accurate Crop Spraying with RTK and Machine Learning on an Autonomous Field Robot

The agriculture sector requires a lot of labor and resources. Hence, farmers are constantly being pressed for technology and automation to be cost-effective. In this context, autonomous robots can play a very important role in carrying out agricultural tasks such as spraying, sowing, inspection, and even harvesting. This paper presents one such autonomous robot that is able to identify plants and spray agro-chemicals precisely. The robot uses machine vision technologies to find plants and RTK-GPS technology to navigate the robot along a predetermined path. The experiments were conducted in a field of potted plants in which successful results have been obtained.Comment: 7 pages, 12 figures, Journa

Solitonic approach to the dimerization problem in correlated one-dimensional systems

Using exact diagonalizations we consider self-consistently the lattice distortions in odd Peierls-Hubbard and spin-Peierls periodic rings in the adiabatic harmonic approximation. From the tails of the inherent spin soliton the dimerization d_\infty of regular even rings is found by extrapolations to infinite ring lengths. Considering a wide region of electron-electron onsite interaction values U>0 compared with the band width 4t_0 at intermediately strong electron-phonon interaction g, known relationships obtained by other methods are reproduced and/or refined within one unified approach: such as the maximum of d_\infty at U \simeq 3 t_0 for g \simeq 0.5 and its shift to zero for g \to g_c \approx 0.7. The hyperbolic tangent shape of the spin soliton is retained for any U and g <~ 0.6. In the spin-Peierls limit the d_\infty are found to be in agreement with results of DMRG computations.Comment: 4 pages, 4 figures, Physical Review B, Rapid Communications, v. 56 (1997) accepte

Lambda(1405) N to Y N transition in nuclear medium for non-mesonic absorption of Kbar in nucleus

Non-mesonic transition of Lambda(1405) N to YN is investigated as one of the essential processes for the non-mesonic absorption of Kbar in nuclei. Using one-meson exchange model in the calculation of the transition, we find that the non-mesonic transition ratio Gamma_{Lambda N} / Gamma_{Sigma N} depends strongly on the ratio of the Lambda(1405) (Lambda^*) couplings to Kbar N and pi Sigma. Especially a larger Lambda^*-Kbar N coupling leads to enhancement of the transition to Lambda N. Using the chiral unitary model for the description of the Lambda^*, we obtain Gamma_{Lambda N} / Gamma_{Sigma^{0} N} is approximately 1.2 which is almost independent of the nucleon density, and find the total non-mesonic decay width of the Lambda^* in uniform nuclear matter to be 22 MeV at the normal density.Comment: Talk given at 10th International Conference on Hypernuclear and Strange Particle Physics: Hyp-X, Tokai, Japan, 14-18 Sep 200

Sustainable Urban Transformation and the Green Urban Economy

This chapter explores the connections between the concepts of sustainable urban transformation and the green urban economy, proposes a framework for understanding how these concepts “fit” together, and makes some practical suggestions for local governments (and national and international policy)