Measurement of groove features and dimensions of the vertical test cathode and the choke joint of the superconducting electron gun cavity of the Energy Recovery LINAC

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Bis[1-(1-adamantyliminomethyl)-2-naphtholato-κ2 N,O]cobalt(II)

The title compound, [Co(C21H22NO)2], crystallizes with two mol­ecules in the asymmetric unit. The coordination environments of the two CoII ions are distorted tetra­hedral. The primary structural difference between the two independent complex mol­ecules lies in the orientations of their adamantyl groups

Weighing matrices and spherical codes

Mutually unbiased weighing matrices (MUWM) are closely related to an antipodal spherical code with 4 angles. In the present paper, we clarify the relationship between MUWM and the spherical sets, and give the complete solution about the maximum size of a set of MUWM of weight 4 for any order. Moreover we describe some natural generalization of a set of MUWM from the viewpoint of spherical codes, and determine several maximum sizes of the generalized sets. They include an affirmative answer of the problem of Best, Kharaghani, and Ramp.Comment: Title is changed from "Association schemes related to weighing matrices

Built‐in biaxial strain dependence of Γ‐X transport in GaAs/InxAl1−xAs/GaAs pseudomorphic heterojunction barriers (x=0, 0.03, and 0.06)

The effects of built‐in biaxial strain on Γ‐X transport in n‐GaAs/i‐InxAl1−xAs/n‐GaAs pseudomorphic single‐barrier structures (x=0, 0.03, and 0.06) are studied by measuring temperature‐dependent I‐V characteristics. For the accurate characterization of electron transport across each barrier, a self‐consistent numerical model is used to analyze the experimental results. For each structure, the four barrier parameters defined from the thermionic‐field‐emission theory, the effective Richardson constant A∗, the conduction‐band offsets ΔEc1,2, and a tunneling mass mn∗ are extracted by calculating the theoretical I‐V characteristics and fitting them to the experimental I‐V‐T data. The experimentally obtained X‐point conduction‐band shifts with the addition of indium are compared with the theoretical results calculated based on the model‐solid theory. The results indicate that the addition of indium not only splits the degenerate X minima of the InxAl1−xAs barrier, but also shifts the relative barrier heights of both longitudinal and transverse X valleys due to the alloy‐dependent band‐structure modification. The comparison between the experimental and theoretical results illustrates that the transverse X valleys are the main conduction channel for the Γ‐X transport across InxAl1−xAs pseudomorphic barriers. © 1994 American Institute of Physics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70663/2/JAPIAU-76-12-7907-1.pd

Origin of the time dependence of wet oxidation of AlGaAs

The time-dependence of the wet oxidation of high-Al-content AlGaAs can be either linear, indicating reaction-rate limitation, or parabolic, indicating diffusion-limited rates. The transition from linear to parabolic time dependence can be explained by the increased rate of the formation of intermediate As{sub 2}O{sub 3} vs. its reduction to elemental As. A steadily increasing thickness of the As{sub 2}O{sub 3}-containing region at the oxidation front will shift the process from the linear to the parabolic regime. This shift from reaction-rate-limited (linear) to diffusion-limited (parabolic) time dependence is favored by increasing temperature or increasing Al mole fraction

Self-pulsing oxide-confined vertical-cavity lasers with ultralow operating current

Includes bibliographical references (page 460).Selectively oxidised vertical-cavity lasers which exhibit self-pulsatin glasing at currents as low as 470nA are reported. Characteristics including linearly polarised emission, narrow linewidths and coherent near- and far-field diffraction indicate that these devices operate as lasers at DC currents 1mA

Absorbent particles, especially catamenials, having improved fluid directionality, comfort and fit

Absorbent articles, especially sanitary napkins, contain fibers with intra-fiber capillary channels. In-use, the capillary channel fibers direct menses to a storage layer, thereby minimizing product failure and staining of undergarments. The capillary channel fibers can protrude into, or through, a topsheet to provide very aggressive transport of vaginal discharges

Ferrite-damped higher-order mode study in the Brookhaven energy-recovery linac cavity

A superconducting energy-recovery linac (ERL) is under construction at Brookhaven National Laboratory (BNL) to serve as a test bed for an application to upgrades of the Relativistic Heavy Ion Collider (RHIC). The damping of higher-order modes in the superconducting five-cell cavity is of paramount importance and represents the topic of this paper. Achieving the damping by the exclusive use of two ferrite absorbers and the adoption of a space-saving step instead of the conventional taper are part of the exploratory study. Absorber properties which are portable to simulation programs for the ERL cavity have been obtained by measuring the absorber as a ferrite-loaded pill-box cavity. Measured and simulated results for the lowest dipole modes in the prototype copper cavity with one absorber are discussed. First room-temperature measurements of the fully assembled niobium cavity string are presented which confirm the effective damping of higher-order modes by the ferrite absorbers, and which give credibility to the simulated R over Q's in the ERL.open1

Uniformity and performance of selectively oxidized VCSEL arrays

The authors report the uniformity characteristics of low threshold 1,060 nm and high power 850 nm 8 x 8 individually addressable oxide-confined VCSEL arrays. Uniformity of lasing thresholds and operating characteristics are described, as well as thermal issues for 2-dimensional laser arrays

A Survey of Finite Algebraic Geometrical Structures Underlying Mutually Unbiased Quantum Measurements

The basic methods of constructing the sets of mutually unbiased bases in the Hilbert space of an arbitrary finite dimension are discussed and an emerging link between them is outlined. It is shown that these methods employ a wide range of important mathematical concepts like, e.g., Fourier transforms, Galois fields and rings, finite and related projective geometries, and entanglement, to mention a few. Some applications of the theory to quantum information tasks are also mentioned.Comment: 20 pages, 1 figure to appear in Foundations of Physics, Nov. 2006 two more references adde