SDH network evolution in Japan

NTT has entered the second phase of its deployment of synchronous digital hierarchy (SDH)-based transmission systems, with a primary focus on creating a more reliable network with lower costs and improving network operation systems for these SDH-based network elements. This article describes the evolution of NTT's network from a plesiochronous digital hierarchy (PDH)-based network to an SDH-based network. First, we see the evolution from a network element point-of-view. Then, we focus on the network operation system, which has been unified to achieve flow-through operation     

The impact of detergent phosphorus bans on receiving water quality

One of the chemicals most clearly exemplifying scientific and political controversy concerning efforts to control its discharge to surface waters is phosphorus and its complexes. These materials are discharged as natural components of domestic wastewaters and include phosphorus from human waste and food waste as well as residual detergent phosphorus. Significant amounts of phosphorus also reach surface waters from non-point sources such as agricultural and urban runoff. This paper presents results of several field and laboratory investigations designed to position the impact of detergent phosphorus contributions to surface water quality. In a number of areas where legislation banned the sale of phosphorus detergents, limnological investigations were carried out to assess the impact of the ban upon receiving water quality. Field studies in natural lakes demonstrate that reductions of phosphorus in wastewaters, even up to 50%, may not substantially improve the trophic status of lakes. The consistent conclusion emerging from these studies is that the elimination of detergent phosphorus has not measurably improved lake water quality.     

Magnetic resonances of helical textures in 3He-A

The NMR frequencies of the helical texture in ³He-A in the presence of a magnetic field parallel to the superflow are reexamined in the entire stability region. The effects of the anisotropic contribution to the spin susceptibility are explicitly included and are shown to leave previous results qualitatively unchanged. On the other hand, we find that the anisotropic contribution gives rise to quantitative corrections of maximally 20% at T/T _c = 0.95, while its contribution in the immediate vicinity of T _c is negligibly small.Work supported in part by the National Science Foundation under grant number DMR 76-21032.Guggenheim Fellow 1979–1980.     

Novel resonant tunneling transistor with high transconductance atroom temperature

A resonant tunneling transistor (RTT) utilizing a novel heterodimensional Schottky gate technology is described. The gate is formed by electroplating Pt/Au onto the side of an AlGaAs/GaAs double barrier structure. The gate voltage modulates the drain current by modulating the area of the quasi-two dimensional electron accumulation layer which forms above the source barrier under drain-source bias. Room temperature transistor characteristics included a peak current of 225 mA/mm and peak transconductance of 218 mS/mm. The ultrafine fabrication process is also discussed     

Function symmetries and decoded-PLA realization

Decoded PLA (programmable logic array) has a distinct advantage over ordinary PLA, in that it can realize complex functions with smaller chip area. This paper shows that decoded PLA is particularly suitable if the function to be realized has some form of symmetry. The paper describes a new approach for d-PLA realizations using symmetries. It also describes the computer simulation which helps in the detection and use of such symmetries. Two such realizations are also described.     

Basic design of 70-MW-class superconducting generators

The application of superconductivity technology to electric power apparatus is very important from the viewpoint of energy saving. Especially, the superconducting generators using superconductors as the field windings have many merits compared with conventional generators. Super-GM has been researching and developing 70-MW-class model machines since FY 1988 for a scheduled period of eight years, aiming at a 200-MW-class superconducting generator. This paper describes the basic specifications and designs of 70-MW-class superconducting generators by Super-GM and also describes the propriety of these basic specifications and designs.     

Evaluation of myocardial uptake of beta-methyl-(123I)-iodophenylpentadecanoic acid (123I-BMIPP)

To evaluate the myocardial uptake of beta-methyl-(123I)-iodophenylpentadecanoic acid (123I-BMIPP), nineteen patients with ischemic heart disease including left ventricular hypertrophy (mean age 63 +/- 7.8, 14 males and 5 females) underwent BMIPP myocardial scintigraphy. Myocardial uptake (MU) of BMIPP to the total injected dose was calculated from anterior view of the planar image in all subjects, and was compared with plasma glucose (BS), triglyceride (TG), and free fatty acid (FFA). It was also compared with left ventricular mass (LVM) calculated with echocardiography. MU was not related to BS, TG, and FFA, however had the positive correlation with LVM (r = 0.676, p < 0.01). Myocardial uptake per left ventricular mass (MU/LVM) had the negative correlation with LVM (r = -0.671, p < 0.01). Further studies for the significance of MU/LVM will be required.