Gas pressure sintering of Beta-Sialon with Z=3

An experiment conducted on beta-sialon in atmospheric pressure, using a temperature of 2000 C and 4 MPa nitrogen atmosphere, is described. Thermal decomposition was inhibited by the increase of the nitrogen gas pressure

Important Factors on Sidewalks with Vendor Activities Based on Pedestrian Perception by Gender and Age

This paper presents an investigation of important factors relating sidewalk performance based on pedestrian perceptions by gender and age. Exploratory factor analysis technique and reliability test of the variables are performed on 45 items of sidewalk current condition in order to extract dimensions of pedestrian perceptions in Jakarta and Bangkok. Based on age, male respondents reveals that eight factors are identified as important on sidewalk performance, and labeled on the basis of the attributed covered as sidewalk interaction, comfort, space availability, safety, vendor problems, walking path, vendor regulation, and vendor's attraction. On the other hand, the first seven factors are similarly stated by female respondents. Grouped by age, young respondents reveal nine factors are considered important and arbitrarily named as comfort, sidewalk interaction, safety, vendor's attraction, vendor problems, vendor regulation, walking path, space availability, and sidewalk condition. The presence of vendors are often deemed as obstruction for walking flow, but their activities should be accommodated by establishing policies and management to accept high performance of the sidewalks and to support the city's economy

Epitaxial ferromagnetic Fe3_{3}Si/Si(111) structures with high-quality hetero-interfaces

To develop silicon-based spintronic devices, we have explored high-quality ferromagnetic Fe$_{3}$Si/silicon (Si) structures. Using low-temperature molecular beam epitaxy at 130 $^circ$C, we realize epitaxial growth of ferromagnetic Fe$_{3}$Si layers on Si (111) with keeping an abrupt interface, and the grown Fe$_{3}$Si layer has the ordered $DO_{3}$ phase. Measurements of magnetic and electrical properties for the Fe$_{3}$Si/Si(111) yield a magnetic moment of ~ 3.16 $mu_{B}$/f.u. at room temperature and a rectifying Schottky-diode behavior with the ideality factor of ~ 1.08, respectively.Comment: 3 pages, 3 figure

Isoscalar Giant Resonance Strengths in 32^{32}S and possible excitations of superdeformed and 28^{28}Si + α\alpha cluster bandheads

Isoscalar giant resonances and low spin states in $^{32}$S have been measured with inelastic $\alpha$ scattering at extremely forward angles including zero degrees at E$_{\alpha}$ = 386 MeV. By applying the multipole decomposition analysis, various excited states are classified according to their spin and parities (J$^{\pi}$), and are discussed in relation to the super deformed and $^{28}$Si + $\alpha$ cluster bands

MgO barrier-perpendicular magnetic tunnel junctions with CoFe/Pd multilayers and ferromagnetic insertion layers

The authors studied an effect of ferromagnetic (Co20Fe60B20 or Fe) layer insertion on tunnel magnetoresistance (TMR) properties of MgO-barrier magnetic tunnel junctions (MTJs) with CoFe/Pd multilayer electrodes. TMR ratio in MTJs with CoFeB/MgO/Fe stack reached 67% at an-nealing temperature (Ta) of 200 degree C and then decreased rapidly at Ta over 250 degree C. The degradation of the TMR ratio may be related to crystallization of CoFe(B) into fcc(111) or bcc(011) texture result-ing from diffusion of B into Pd layers. MTJs which were in-situ annealed at 350oC just after depo-siting bottom CoFe/Pd multilayer showed TMR ratio of 78% by post annealing at Ta =200 degree C.Comment: 12 pages, 4 figure

Modified Spin Wave Thoery of the Bilayer Square Lattice Frustrated Quantum Heisenberg Antiferromagnet

The ground state of the square lattice bilayer quantum antiferromagnet with nearest and next-nearest neighbour intralayer interaction is studied by means of the modified spin wave method. For weak interlayer coupling, the ground state is found to be always magnetically ordered while the quantum disordered phase appear for large enough interlayer coupling. The properties of the disordered phase vary according to the strength of the frustration. In the regime of weak frustration, the disordered ground state is an almost uncorrelated assembly of interlayer dimers, while in the strongly frustrated regime the quantum spin liquid phase which has considerable N\'eel type short range order appears. The behavior of the sublattice magnetization and spin-spin correlation length in each phase is discussed.Comment: 15 pages, revtex, figures upon reques

2α+t2\alpha+t cluster structure in 11^{11}B

The cluster structures of the excited states in $^{11}$B are studied by analyzing the isoscalar monopole and quadrupole strengths in the $^{11}$B($d$,$d'$) reaction at $E_d=200$ MeV. The excitation strengths are compared with the predictions by the shell-model and antisymmetrized molecular-dynamics (AMD) calculations. It is found that the large monopole strength for the $3/2^-_3$ state at $E_x=8.56$ MeV is well described by the AMD calculation and is an evidence for a developed $2\alpha+t$ cluster structure.Comment: Revised according to the referees' comment

Quantum Phase Transition in the Frustrated Heisenberg Antiferromagnet

Using the J_1-J_2 model, we present a description of quantum phase transition from Neel ordered to the spin-liquid state based on the modified spin wave theory. The general expression for the gap in the spectrum in the spin-liquid phase is presented.Comment: 8 pages of REVTeX 3.0, one PostScript file appended (Eq. 15 corrected, two recent references added, + some minor changes

Classical and quantum chaos in a circular billiard with a straight cut

We study classical and quantum dynamics of a particle in a circular billiard with a straight cut. This system can be integrable, nonintegrable with soft chaos, or nonintegrable with hard chaos, as we vary the size of the cut. We use a quantum web to show differences in the quantum manifestations of classical chaos for these three different regimes.Comment: LaTeX2e, 8 pages including 3 Postscript figures and 4 GIF figures, submitted to Phys. Rev.