Wrinkle/slack model and finite element dynamics of membrane

This paper reviews conventional wrinkle models for anisotropic membrane and shows the relation between the models. A new wrinkle model is proposed which assumes virtual shear as well as virtual elongation of the membrane to estimate the real strain in the wrinkled region. This model coincides with the other models if the virtual shear and elongation is determined so that the strain energy is minimized. Another wrinkle/slack model is proposed for the dynamic analysis of thin isotropic membrane undergoing large overall motion with wrinkle and slack. It can take into account the residual compressive stress in the wrinkled and slack regions, i.e. the stiffness in the post‐buckling state. It is shown that the proposed model is a generalization of the conventional ones. Finite element formulation of the proposed model is described. Furthermore, the energy momentum conservation framework is constructed for the proposed membrane element, which achieves the unconditionally stable time integration. The total of the proposed method enables us to compute the overall motion of thin isotropic membrane such as the deployment of folded membrane, which has been one of the most difficult problems in aerospace engineering. Copyright © 2005 John Wiley & Sons, Ltd.     

Further analysis of perception of the standard Müller-Lyer figures in pigeons (Columba livia) and humans (Homo sapiens): Effects of length of brackets.

Nakamura, Fujita, Ushitani, & Miyata (2006) have shown that pigeons perceive the standard Müller-Lyer illusion. In this report, the authors examined effects of bracket sizes on perception of this illusion in pigeons (Columba livia) and humans (Homo sapiens). In Experiment 1, three pigeons were retrained to classify six lengths of target lines into “long” and “short” by pecking two keys on the monitor, ignoring the two brackets oriented toward the same direction. In the tests that followed, the standard Müller-Lyer figures of different bracket sizes were presented. All birds chose “long” more frequently for the figures having inward-pointing brackets (>), regardless of bracket sizes. The overestimation of the target lines of inward-pointing figures continued to increase in pigeons, whereas it decreased as the bracket size became longer in humans (Experiment 2). The results suggest that these two species perceive the standard Müller-Lyer illusion with long brackets in different ways. Perhaps pigeons might not perceive illusions induced by contrast with the surrounding stimuli. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Ductile fracture strength of nickel-based alloy plates with a surface flaw

Limit-load analysis is applied to fracture analyses of flawed components made of materials with high ductility in the JSME code for inservice inspection for nuclear power plant. However, the applicability of limit-load analysis to Ni-based alloys has not yet been clarified. Furthermore, flow-stress level for Ni-based alloy has not been verified by experiments. To clarify applicability of limit-load analysis and actual flow-stress level for Ni-based alloys, the ductile fracture tests were conducted.     

Direct synthesis of well dispersed ZnO nanorods without using additional surfactant

Without using additional surfactant as structure-directing agent, well dispersed ZnO nanorods were directly synthesized in the dimethyl sulfoxide (DMSO) and alcohol mixture solution by a one-step wet chemical method. The experiment results demonstrated that alcohol molecular with longer chain is helpful for the growth of ZnO nanorods. The absorption and emission spectra of as-synthesized ZnO nanorods were also presented in this paper.     

Synthesis and characterization of BN thin films prepared by plasma MOCVD with organoboron precursors

Boron nitride (BN) films have contributed to improvement of tribological parts. For this study, we prepared films using plasma MOCVD with an organoborate precursor and investigated the mechanical properties and structure of BN films. The BN films were formed on specimens of silicon wafers and tungsten carbide (WC) substrates at low temperatures of less than 500 °C. Hardness tests were carried out to evaluate mechanical properties of BN films. The structure of BN films was investigated using XRD, Raman, and FT-IR spectra.     

Actual flow calibration of a feedwater flowmeter using a high Reynolds number facility at NMIJ

The results of calibration tests of the feedwater flowrate of ultrasonic flowmeters used in a nuclear power plant for variety of upstream conditions obtained using the new high Reynolds number calibration facility at NMIJ are described. In this examination, the measurements are performed for five pattern pipe layouts with one or two elbows. The flow conditioners installed upstream of the flowmeter are the tube bundle type and the Mitsubishi, which are normally used in nuclear power plants. The calibration result for each flowmeter are largely different for each flow conditioner and each upstream pipe layout, except in some special cases. Moreover, the trend of the correction factor with Reynolds number is not uniform for each case. Furthermore, some differences were observed for individual flowmeters. It is recommended that the feedwater flowmeter, especially when used to perform measurement uncertainty recapture, is calibrated based on the actual pipe layout and the Reynolds number corresponding to the actual nuclear power plant conditions.     

Intermittent Operation Control Scheme for Reducing Power Consumption of UWB-IR Receiver

A low power ultra-wideband impulse radio (UWB-IR) receiver was developed in 0.18-mum CMOS. All circuits of the receiver AFE operate intermittently with a sampling clock of an analog-digital converter (ADC). The sampling rate of the ADC is equal to the pulse repetition frequency of the received signals. Power consumption of the receiver AFE is reduced by 60% using a developed intermittent operation scheme without degrading of receiver sensitivity. As a result, the power consumption of the receiver AFE is 38 mW. The receiver has a data rate of 258 kb/s over a distance of 52 m and of 10.7 Mb/s over a distance of 14 m.     

Analysis of magnetically induced ELF current in biological spherical model with biomembrane

In this paper a biological three‐medium spherical model which consists of tissue, its membrane, and the extratissue medium is employed, and detailed distributions and characteristics of the induced current in the modeled structure are calculated by using a semianalytical solution developed for this model. It is demonstrated that both the change in the thickness and electrical properties of the biomembrane and the difference in conductivity between the inner and outer substances significantly affect the current passing through the membrane and the resultant profiles of the induced current. These analytical results are consistent with the experimental results, suggesting the influence of real membranes, and they indicate an important influence of the biomembrane on the induced current characteristics under specific membrane conditions. © 2001 Scripta Technica, Electr Eng Jpn, 135(2): 17–25, 2001     

High-power ultralow-chirp 10-Gb/s electroabsorption modulator integrated laser with ultrashort photocarrier lifetime

A high-power, ultralow-chirp electroabsorption modulator (EAM) integrated with a distributed-feedback laser diode (EML) having ultrashort lifetime of photogenerated holes in the EAM quantum-well (QW) structure is reported for the first time. A shallow QW structure having a small valence band offset to enhance the sweepout of photogenerated holes was employed as EAM absorption layer. The measured hole lifetimes were 7-11 ps, and the measured frequency chirp (/spl alpha/-parameter) was low or negative at low EAM reverse bias voltages even under high optical output power conditions. Successful 10-Gb/s 80-km normal-dispersion single-mode fiber transmission (chromatic dispersion D=1600 ps/nm) and the record average fiber optical output power (P/sub f/) of +5.3 dBm were achieved at 25/spl deg/C. In addition, semicooled operation of EML at enhanced bit rates has been demonstrated for application in small-form-factor protocol-agnostic optical transceivers. A 10.7-Gb/s 1600-ps/nm transmission was achieved at 45/spl deg/C and P/sub f/=+3.0 dBm.