"Pored-domes" of the fenestrated endotheliocyte of the glomerular and peritubular capillaries in the rodent kidney.

The fenestrated endotheliocyte of peritubular and glomerular capillaries in rat and mouse kidneys were observed with SEM and TEM. In the glomerular capillary, so-called "pored-domes" were found not only at the fenestrated areolae but also at the nuclear region of the endotheliocyte. At the region between filtration surface and nuclear region, they accumulated to construct a sponge-like structure. The endotheliocyte of peritubular capillary also showed small "pored-domes". The size and morphology of the pores in the "pored-domes" of glomerular and peritubular capillaries were similar to those of areolae fenestratae of the respective capillary. Based on the findings, we assumed that pored-domes and the sponge-like structure are the reservoir for the fenestrated area of the endotheliocyte to accommodate the rapid expansion of capillary lumen.     

Temperature dependence of signal gain in Er3+-dopedoptical fiber amplifiers

Temperature-dependent signal gain characteristics at signal wavelengths of 1.536 and 1.552 μm in Er³⁺-doped optical fibers with a temperature range of -40 to 80°C are reported for 0.98 and 1.48 μm pumping. The temperature dependences of signal gain strongly depend on fiber length, pump wavelength, and signal wavelength. The fiber length at which signal gain temperature insensitivity occurs is found for the amplification of a 0.98-μm-pump-1.536-μm-signal, a 0.98-μm-pump-1.552-μm-signal, and a 1.48-μm-pump-1.536-μm-signal. It is confirmed theoretically that the temperature dependences result from linear changes in the fluorescence, and absorption cross sections at the signal and pump wavelengths, and a shift in the effective pump wavelength     

10 Gbit/s, 1200 km error-free soliton data transmission using erbium-doped fibre amplifiers

Soliton data signals at 10 Gbit/s have been successfully transmitted for the first time through a 1200 km dispersion-shifted fibre by using 24 erbium-doped fibre amplifiers. A bit error rate below 10/sup -13/ was obtained with 2/sup 20/-1 pseudorandom patterns.<>     

A 2 K-word dictionary search processor (DISP) LSI with anapproximate word search capability

A 2 K-word dictionary search processor (DISP) LSI has been developed. The DISP LSI consists mainly of a 160-kb content addressable memory (CAM) to store keywords and a cellular automaton processor (CAP) to perform concurrent and approximate word searches against the stored keywords. This CAP performs distance calculation based on dynamic programming (DP), which is necessary in approximate word searches, through the use of an array of extremely simple processor elements. CAP hardware size is less than 1/10 of that of a conventional systolic array processor. The DISP LSI, which was fabricated using a 0.8-μm, triple-layer-Al, CMOS fabrication technology, has a die size of 13.02×12.51 mm² and contains about 1.2-million transistors. It operates at a clock frequency of 33 MHz with a 5-V power supply, and it typically consumes 800 mW     

Infinite-distance soliton transmission with soliton controls in time and frequency domains

It is shown by computer runs and simple analysis that one hundred million km soliton transmission is possible by means of soliton transmission controls in the time and frequency domains. This means that limitless transmission is possible. The key to success is to reduce noise by the synchronous modulation technique which can also reduce timing jitter and nonlinear interaction forces. The accumulated noise converges to a fixed low level even after limitless transmission.<>     

Direct dispersion measurement of highly-erbium-doped optical amplifiers using a low coherence reflectometer coupled with dispersive fourier spectroscopy

The group delay and dispersion, including the erbium ion contributions, of the highly erbium-doped silica planar waveguide amplifier and multicomponent glass fibre amplifiers are directly measured at different pump powers using a low coherence reflectometer and dispersive Fourier spectroscopy. This method derives the refractive index spectra of these amplifiers directly from the produced reflectograms without any physical or mathematical assumptions. The dispersion of the planar waveguide amplifier at 500 mW pumping changes between +300 and -200 ps/km/nm with a 0.4 wt.% erbium concentration.<>     

Comparison of measured value and calculated value of multiplestability in forced-flow cooled superconductors

The multiple stability observed exclusively in forced-flow cooled superconductors is numerically calculated, and the result is quantitatively compared with the value measured by J.W. Lue et al. (1980). The calculated and measured values agreed well in certain cases, and did not in others. Based on this comparison, the effects of the transient heat transfer coefficient and ohmic heat generation on the quantitative prediction of stability are discussed. From this comparison, it is learned that a precise understanding of the transient heat transfer coefficient is essential for reliable predictions, and also that the ordinary evaluation method of ohmic heat generation, which considers the flux-flow resistance, tends to overevaluate the situation     

A 0.5-V MTCMOS/SIMOX logic gate

This paper proposes a multithreshold CMOS (MTCMOS) circuit that uses SIMOX process technology. This MTCMOS/SIMOX circuit combines fully depleted low-threshold CMOS logic gates and partially depleted high-threshold power-switch transistors. The low-threshold CMOS gates have a large noise margin for fluctuations in operating temperature in addition to high-speed operation at the low supply voltage of 0.5 V. The high-threshold power-switch transistor in which the body is connected to the gate through the reverse-diode makes it possible to obtain large channel conductance in the active mode without any increase of the leakage current in the sleep mode. The effectiveness of the MTCMOS/SIMOX circuit is confirmed by an evaluation of a gate-chain test element group (TEG) and an experimental 0.5-V, 40-MHz, 16-b ALU, which were designed and fabricated with 0.25-μm MTCMOS/SIMOX technology     

Routing design of tree‐shaped local public communication networks with high reliability and low cost

This paper discusses reliability problems for local public communication networks such as cable television networks and the subscriber‐loops of telecommunication networks. They have tree‐shapes and expand continuously as new customers join. By introducing a simple model, it is shown that most principal reliability measures and cost measures for such networks can be described through the networks' graphical characteristic quantities. Extensive simulations show that the prior provision of trunk pipes and a suitable choice of the route selecting rule for new customers are effective in constructing a highly reliable network with low cost. This revised version was published online in June 2006 with corrections to the Cover Date.     

Driving voltage reduction in a two-phase CCD by suppression ofpotential pockets in inter-electrode gaps

This study reports an optimum design for a two-phase charge-coupled device (CCD) and limitations on its driving voltage reduction. The two-phase CCD to be used as a horizontal-CCD (H-CCD) in a CCD image sensor requires low-voltage and high-speed operation. Reducing the driving voltage, however, may induce potential pockets in the channel under the inter-electrode gaps which results in a fatal decrease in charge-transfer efficiency. In this case it is necessary to optimize the CCD design to be free of pocket generation. For this requirement, we conducted two-dimensional (2-D) device simulations for the two-phase CCD, whose potential barriers are formed by boron ion-implantation. Our simulations indicated that the edge position of the potential barrier region and the dose of boron-ion implantation would be important parameters for controlling the size of potential pockets. At an optimum edge position and a boron dose, the minimum driving voltage appears to be reducible to 1.1 V. Characteristics of potential pockets and methods of their suppression are also discussed