An implementation of a TMN-based SDH management system in Japan

Synchronous digital hierarchy (SDH) equipment based on fiber optics, SDH interfaces, and supporting operation systems (OSs) was introduced into Nippon Telegraph and Telephone (NTT)'s transmission-line networks beginning in 1989. One of the major problems in the first phase was less intelligent proprietary interfaces between network elements (NEs) and OSs, which caused limited connectivity among different types of NEs and OSs. A second problem was the lack of reusability of software modules for a specific type of equipment for other types of equipment. At the beginning of the second phase, the principles of the telecommunications management network (TMN) were adopted to provide good tools for defining standard interfaces and object oriented modeling. The article describes problems encountered in the first phase SDH network management system and summarizes advantages expected from making use of TMN-related standards available at the design stage of the second phase SDH network management system. It outlines the new SDH network management system, followed by results from the application of the TMN-related standards to real networks     

Transanal endoscopic microsurgery in Italy

The Italian experience with Transanal Endoscopic Microsurgery (TEM) started in 1991. Until April, 1994, 122 patients were operated on by such a technique in six centres. The surgical protocol in the 66 patients with benign lesions was similar to that described by Buess. In contrast to the German experience, the indications of TEM for cancer have been extended to more advanced tumours and in 22 out of 56 patients with rectal carcinoma adjuvant radiation- or radiation-chemotherapy have been applied according to various protocols. In 88% of TEM for rectal tumours the operation has been carried out according to a full-thickness technique, with or without perirectal fat excision. Postoperative morbidity of TEM for adenoma was 15.8% and that of TEM for carcinoma 29.6%. There was no postoperative mortality. Local recurrence rate after TEM for adenoma was 10.5%, while that after TEM for cancer was 9.25%. No local recurrence has been reported among patients treated with a combination of TEM and adjuvant radiation treatments. The median follow-up in the 6 centres ranged between 7 and 16 months. A randomised prospective clinical trial has been planned in order to evaluate the role of transanal endoscopic microsurgery in the treatment of locally advanced rectal cancer.     

铝酸钙水泥对焦宝石基喷涂料性能的影响

以焦宝石颗粒及细粉为主要原料，铝酸钙水泥为结合系统。分别研究了不同铝酸钙水泥含量对焦宝石基喷涂料性能的影响。结果表明．焦宝石基喷涂料的抗折强度随着铝酸钙水泥含量的增加呈上升趋势。但经过600℃、1000℃和1300℃烧结后的焦宝石基喷涂料的耐压强度随着铝酸钙水泥含量的增加呈先增加后减小的趋势。     

Carrier transport and structural properties of polysilicon films prepared by layer-by-layer technique

Polycrystalline silicon (poly-Si) films have been deposited on glass substrates by a layer-by-layer technique at very low temperature, 300°C, using fluorinated precursors. The electronic transport was characterized by Hall effect and conductivity measurements over a wide temperature range, 100 K to 400 K. The structure of the materials is a function of the film thickness. The measured Hall mobility increases as the thickness increases. The Hall mobility Arrhenius plot shows linear dependence with a negative slope over the temperature range examined, suggesting that carrier conduction is limited by grain boundary barriers.     

A 29-ns 64-Mb DRAM with hierarchical array architecture

A 29-ns (RAS access time), 64-Mb DRAM with hierarchical array architecture has been developed. For consistent high yields and high speed, a CMOS segment driver circuit is used as a hierarchical word line scheme. To achieve high speed, precharge signal (PC) drivers for equalizing the bit lines pairs, and shared sense amplifier signal (SHR) drivers are distributed in the array. To enhance sense amplifiers speed in low array voltage, an over driven sense amplifier is adopted. A hierarchical I/O scheme with semidirect sensing switch is introduced for high speed data transfer in the I/O paths. By combining these proposed circuit techniques and 0.25-μm CMOS process technologies with phase-shift optical lithography, an experimental 64-Mb DRAM has been designed and fabricated. The memory cell size is 0.71×1.20 μm ², and the chip size is 15.91×9.06 mm². A typical access time under 3.3 V power supply voltage is 29 ns     

Numerical diffusion in single-phase multi-dimensional thermal-hydraulic analysis

Higher-order difference schemes, including QUICK and its related schemes, are discussed through several numerical experiments with the focus on their performance to reduce numerical diffusion and to suppress local unphysical oscillations. Finally, these schemes are applied to in-vessel thermal-hydraulic analysis and their effectiveness on the analysis is demonstrated.     

Early neurologic complications following allogeneic bone marrow transplant for leukemia: a prospective study

BACKGROUND: Bone marrow transplant (BMT) is used for both neoplastic and nonneoplastic diseases. Following BMT, particularly during the first 3 months, patients have a number of neurologic complications. We evaluated the early neurologic complications following BMT and their influence on survival. METHODS: We prospectively followed 115 consecutive patients having BMT for leukemia, for a median period of 90 days after transplantation. RESULTS: Sixty-four patients (56%) had neurologic complications. Sixteen developed more than one complication. Twenty-seven patients (25%) had major neurologic complications: metabolic encephalopathy (8), seizures (8), psychiatric symptoms (3), cerebral hemorrhage (1), cerebral abscess (1), leukemic meningitis (1), peripheral neuropathies (5), and myopathies (2). Forty patients (35%) had minor complications, including headache (16) and tremor (31). Major neurologic complications occurred after engraftment in most patients. Metabolic encephalopathy correlated with graft-versus-host disease (GVHD) (p < 0.03). Seven percent of patients had generalized seizures that occurred without signs of structural cerebral lesions. Probability of survival at day 90 was lower in patients with than in those without major central nervous system complications (63% versus 87.5%, p < 0.01). CONCLUSIONS: Neurologic complications are frequent during the first 3 months following BMT and affect patient survival. Drug neurotoxicity and acute GVHD are the main factors influencing their occurrence.     

Estimation of creep crack growth rate in IN-100 based on the Q* parameter concept

Since the high-strength Ni-based superalloy, cast IN-100, is considered to be brittle at high temperatures, the stable creep crack growth region is limited. Therefore, technically, it is very difficult to perform creep tests and there are few experimental results on the creep crack growth behaviour of this material. We performed creep crack growth tests using Ni-based superalloy, cast IN-100, and derived the Q* parameter for this material, which characterizes the creep crack growth rate. Using this Q* parameter, we derived a law for the creep rupture life of this material.     

Effect of an additive on the radiation resistance of polyethylene and ethylene–propylene copolymer

In low-density polyethylene containing the additive propylfluorancene, radiation energy received by polyethylene is transferred to propylfluorancence, and the production of radicals at 77 K in polyethylene is suppressed. Propylfluoranncene also increases the rate of the decay of radicals of polyethylene at room temperature. The depression of radical production and accelaration of radical decay at room temperature results in the depression of gas production and crosslinks at room temperature in low-density polyethylene containing propylfluorancene. Similar results were obtained in ethylen–propylene copolymer containing the same additive.     

Thermodynamics of alcohol-unassociated active component liquid mixtures

An associated solution theory based on the UNIQUAC equation is developed to describe the excess properties of the alcohols in unassociated active components. The theory includes two association constants: the one for the alcohols, the other for alcohol-unassociated active component complexes. The theory reproduces well the activity coefficients of the ethanol—trichloromethane system having a maximum and a minimum and it also fits very skewed excess enthalpy curves for alcohol—benzene, alcohol—tetrachloromethane, etc. Prediction of ternary vapor—liquid and liquid—liquid equilibrium and excess enthalpy data has been carried out with good accuracy from binary parameters without adding any ternary constant.