Hygroscopic Properties and Shrinkage of Southern Yellow Pine Plywood

Five constructions of southern yellow pine plywood, unidirectionally laminated veneer, and loblolly pine solid wood were used for investigation of hygroscopic properties at several RH conditions. EMC values of the southern yellow pine plywood between 20% RH and 90% RH were approximately 1% lower than corresponding values of loblolly pine solid wood. Most plywood panels shrank less along the face grain than across. From water-soaked condition to about 4.5% MC, thickness shrinkages of plywood varied from 7% to 9% while length shrinkages were always less than 1% except for 1/2-inch, 4-ply plywood. The ratio of number of glue lines to plywood thickness influenced thickness and volume shrinkage. Plywood with a higher ratio had a tendency to shrink less. FSP values were determined by two intersection point methods-one with volumetric shrinkage, the other with MOE. The respective approximate FSP values were 28.7% and 27.3% MC for plywood, and 31.0% and 27.5% for solid wood

Enhancing complex-network synchronization

Heterogeneity in the degree (connectivity) distribution has been shown to suppress synchronization in networks of symmetrically coupled oscillators with uniform coupling strength (unweighted coupling). Here we uncover a condition for enhanced synchronization in directed networks with weighted coupling. We show that, in the optimum regime, synchronizability is solely determined by the average degree and does not depend on the system size and the details of the degree distribution. In scale-free networks, where the average degree may increase with heterogeneity, synchronizability is drastically enhanced and may become positively correlated with heterogeneity, while the overall cost involved in the network coupling is significantly reduced as compared to the case of unweighted coupling.Comment: 4 pages, 3 figure

Monolithic millimeter-wave diode grid frequency multiplier arrays

Monolithic diode frequency multiplier arrays, including barrier-N-N(+) (BNN) doubler, multi-quantum-barrier-varactor (MQBV) tripler, Schottky-quantum-barrier-varactor (SQBV) tripler, and resonant-tunneling-diode (RTD) tripler arrays, have been successfully fabricated with yields between 85 and 99 percent. Frequency doubling and/or tripling have been observed for all the arrays. Output powers of 2.4-2.6 W (eta = 10-18 percent) at 66 GHz with the BNN doubler and 3.8-10 W (eta = 1.7-4 percent) at 99 GHz with the SQBV tripler have been achieved

Monolithic millimeter-wave diode array beam controllers: Theory and experiment

In the current work, multi-function beam control arrays have been fabricated and have successfully demonstrated amplitude control of transmitted beams in the W and D bands (75-170 GHz). While these arrays are designed to provide beam control under DC bias operation, new designs for high-speed electronic and optical control are under development. These arrays will fill a need for high-speed watt-level beam switches in pulsed reflectometer systems under development for magnetic fusion plasma diagnostics. A second experimental accomplishment of the current work is the demonstration in the 100-170 GHz (D band) frequency range of a new technique for the measurement of the transmission phase as well as amplitude. Transmission data can serve as a means to extract ('de-embed') the grid parameters; phase information provides more complete data to assist in this process. Additional functions of the array beam controller yet to be tested include electronically controlled steering and focusing of a reflected beam. These have application in the areas of millimeter-wave electronic scanning radar and reflectometry, respectively

Performance Comparison between Consequent-Pole and Inset Modular Permanent Magnet Machines

This paper proposes some consequent-pole modular permanent magnet machines with different flux gap widths and slot/pole number combinations. The corresponding inset modular permanent magnet machines having the same magnet volume are also presented for comparison. It has been demonstrated that the output torques of the consequent pole modular machines are always higher than those of the inset modular machines regardless of flux gap widths and slot/pole number combinations. Other electromagnetic performances such as back-EMF, cogging torque, and iron losses, etc. are calculated by 2D FEA software and compared as well. The advantages and disadvantages of consequent and inset modular permanent magnet machines are summarized in this paper

Deuteron Electromagnetic Form Factors in the Intermediate Energy Region

Based on a Perturbative QCD analysis of the deuteron form factor, a model for the reduced form factor is suggested. The numerical result is consistent with the data in the intermediate energy region.Comment: 9 pages, to appear in Phys.Rev.

Phenotypic and functional characterization of corneal endothelial cells during in vitro expansion.

The advent of cell culture-based methods for the establishment and expansion of human corneal endothelial cells (CEnC) has provided a source of transplantable corneal endothelium, with a significant potential to challenge the one donor-one recipient paradigm. However, concerns over cell identity remain, and a comprehensive characterization of the cultured CEnC across serial passages has not been performed. To this end, we compared two established CEnC culture methods by assessing the transcriptomic changes that occur during in vitro expansion. In confluent monolayers, low mitogenic culture conditions preserved corneal endothelial cell state identity better than culture in high mitogenic conditions. Expansion by continuous passaging induced replicative cell senescence. Transcriptomic analysis of the senescent phenotype identified a cell senescence signature distinct for CEnC. We identified activation of both classic and new cell signaling pathways that may be targeted to prevent senescence, a significant barrier to realizing the potential clinical utility of in vitro expansion