Practical implementation and packaging technologies for alarge-scale ATM switching system

The practical implementation of a trial large-scale asynchronous transfer mode (ATM) switching system and its packaging technologies are described. The architecture of the ATM switching system is discussed with an emphasis on system scalability. A building block architecture in which switching capacity can be expanded in a modular fashion is introduced. The design of the ATM switching system, including the ATM switch element, is described. The implementation of the VLSIs for the ATM switch which realize a highly modular system is explained. Bit-slice techniques are effectively used to realize a high-speed switch element as a CMOS VLSI chipset. An edge-to-edge orthogonal packaging technique is also presented     

Acoustic emission and fracture behavior of GFRP woven laminates at cryogenic temperatures

This paper describes an experimental and analytical study on fracture and damage behavior of GFRP woven laminates at cryogenic temperatures. CT (compact tension) tests were carried out at room temperature, liquid nitrogen temperature (77 K) and liquid helium temperature (4 K) to evaluate the critical values of the fracture mechanics parameters. During the CT tests, AE (acoustic emission) method was implemented. AE signals can identify the critical load at which gross failure occurs. A FEA (finite element analysis) was also applied to calculate the fracture mechanics parameters. The failure criteria (Hoffman criterion and maximum strain criterion) or the damage variable based on the continuum damage mechanics was incorporated into the model to interpret the experimental measurements and to study the damage distributions within the specimen. Several methods of calculating J-integral are discussed.     

A 1920(H)×1035(V) pixel high-definition CCD image sensor

A 1920(H)×1035(V)-pixel high-definition CCD (charge-coupled-device) image sensor compatible with an 1125-scanning-lines and 16:9 aspect-ratio television system is described. The device basically uses an interline scheme with a vertical overflow drain. To maintain 74.25-MHz ultrahigh-data-rate operation, the device adopts a dual-channel configuration for the horizontal CCD (H-CCD) register. To accomplish both vertical signal charge transfer in the vertical CCD (V-CCD) register and signal charge distribution from the V-CCD registers into the dual-channel horizontal CCD registers simultaneously within a 3.77-μs short horizontal blanking period, a one-horizontal-period signal storage memory electrode and optical black memory are introduced. Bipolar buffer transistor chips are hybridized in the same package as the device, so as to reduce parasitic capacitance at CCD output terminals and maintain a wide-bandwidth operation. The device operates successfully and 1000-TV-line limiting resolution was obtained for both vertical and horizontal directions. Total random noise was evaluated to be 41 electrons. Dynamic range reached 66 dB. Signal-to-noise ratio for a black/white (B/W) camera was 51.5 dB under F4.0 and 2000-lux illumination conditions     

Degradation mechanism of an H2-permselective amorphous silica membrane

Degradation mechanism of H₂ permselectivity under atmosphere of steam/N₂ = 3 at 773 K was investigated among amorphous silica membranes on γ-Al₂O₃-coated α-Al₂O₃ or Ni-doped γ-Al₂O₃-coated α-Al₂O₃ synthesized by counter diffusion chemical vapor deposition. Helium and H₂ permeance drastically decreased during the first few hours of hydrothermal exposure. On the other hand, N₂ permeance fluctuated during hydrothermal treatment in silica membrane on γ-Al₂O₃-coated α-Al₂O₃. The degree of N₂ permeance change depended on the hydrothermal stability of the intermediate layer. Hydrogen permselectivity was affected by both the densification of amorphous silica and the sintering of the intermediate layer during hydrothermal exposure.     

Relation of crack-induced current shunting to transport current and n-value in DyBCO-coated superconductor

Transport current and n-value of DyBCO-coated conductor pulled in tension were measured experimentally and their relation to crack-induced current shunting was analyzed with the partial crack-current shunting model. The following features were revealed. The shunting current increases with increasing transport current and with increasing crack size. At low voltage where shunting current is low, the transport current of cracked sample normalized with respect to the transport current in non-cracked state is described with the modified ratio of non-cracked area to overall cross-sectional area of superconducting layer. At high voltage where the shunting current is high, the normalized transport current becomes higher than the modified ratio of non-cracked area. The increase in shunting current with transport current (and voltage) leads to a decrease in n-value at high current (voltage). This phenomenon is enhanced by crack extension.     

Inflammation Causes Exacerbation of COVID-19: How about Skin Inflammation?

COVID-19 is a recently emerged viral infection worldwide. SARS-CoV-2, the causative virus, is believed to have emerged from bat coronaviruses, probably through host conversion. The bat coronavirus which has the highest gene homology to SARS-CoV-2 specifically infects deep forest bats in China whose habitat extends through the Middle East to Southern Europe. Host conversion might have occurred due to the deforestation by humans exposing wild bats to the environment they had never encountered before. SARS-CoV-2 infects cells through two mechanisms: through its receptor ACE2 with the help of enzyme TMPRSS and through membrane fusion with the help of elastases in the inflammatory condition. Obesity, hypertension, diabetes mellitus, and pulmonary diseases cause poor prognosis of COVID-19. Aging is another factor promoting poor prognosis. These diseases and aging cause low-level and persistent inflammation in humans, which can promote poor prognosis of COVID-19. Psoriasis and atopic dermatitis are the major inflammatory skin diseases. These inflammatory skin conditions, however, do not seem to cause poor prognosis for COVID-19 based on the epidemiological data accumulated so far. These mechanisms need to be elucidated.     

Effect of intensified discharge in the vicinity of ribs on PDP performance

It was determined that the discharge in the vicinity of ribs should be intensified to obtain low‐voltage, high‐luminous efficacy, and high module efficiency. One possible way is to increase the space between ribs and the discharge surface. Even if the amount of space increases by only 2 or 3 µm, it still results in low discharge voltage, large discharge current, and high luminous efficacy. For that reason it might be important to control the micron‐sized particles included in the MgO crystal dispersed layers. Another preferable way is to use ribs with a low electric permittivity (ε) that are represented by porous ribs. Moreover, low‐ε ribs diffuses the high‐energy spots in plasma, resulting in a high luminous efficacy. They feature a significantly lower sustain voltage and a smaller parasitic capacitance as well to facilitate a help high module efficiency. Also, highly porous ribs are expected to increase their practical use in aspects of mechanical strength and impurity gas exhaustion.     

Structure-conductivity relationsihp in polymer electrolytes formed by network polymers from poly[dimethylsiloxane-g- poly(ethylene oxide)] and litegum perchlorate

The combination of LiClO₄ and network polymers from poly[dimethyl-siloxane-g-poly(ethylene oxide)] has been applied to polymer electrolytes as an Li⁺ ion conductor, and the structure/conductivity relationship has been investigated. The ionic conductivity is about 10⁻⁶ S cm⁻¹ at room temperature. The polymer electrolytes form a micro-heterogeneous structure from the constituent segments, and the incorporated LiClO₄ preferentially interacts with the poly(ethylene oxide) segments. The segmental motion of poly(ethylene oxide) appears to contribute to the ionic migration, while that of poly(dimethylsiloxane) does not. Not all of the incorporated LiClO₄ functions as carrier ions.     

Tumor necrosis factor alpha-mediated tumor regression by the in vivo transfer of genes into the artery that leads to tumors

We report that tumor necrosis factor (TNF) alpha induced a strong antitumor immune reaction when it was produced in arteries leading to tumors by gene transfer in vivo. We used a mouse model carrying a sarcoma-180 tumor in the right footpad and injected the fusogenic liposomes encapsulating the human TNF-alpha gene into the right femoral artery. Under this condition, human TNF-alpha was detected only in the artery leading to the tumor and in the tumor. There was a significant regression in tumor growth when the TNF-alpha gene was delivered into the right femoral artery, with 4 of 11 mice completely cured. No regression was observed when the TNF-alpha gene was delivered into the left femoral artery or into the tumor or when the luciferase gene was administered. Tumor regression was inhibited by the injection of anti-TNF-alpha, anti-CD4, or anti-CD8 monoclonal antibody, and CD8+ T cells accumulated in the tumors of TNF-alpha-treated mice. These results suggest that TNF-alpha expressed locally in the arteries leading to tumors efficiently suppresses tumor growth through reinforcement of an antitumor immune reaction. The significance of this phenomenon for cancer gene therapy was discussed.