An Adaptive Multiple Beam System Concept

An adaptive multiple beam system, which has flexibility to adapt beam power to varying beam traffic, is proposed. The multiple beam transmitter, which is called "hybrid transponder" in this paper, consists of a pair of multiport hybrids and a set of amplifying elements. Power combining, isolation, and intermodulation characteristics of this multiport network are analyzed. Also, a new interbeam exchange and feeder link connection concept, which serves as the basis for an adaptive multiple beam system, is proposed. Finally, characteristics of an experimental 8-amplifier 8-port hybrid transponder are described.     

Development of advanced power system analog simulator

The digital simulation method has been utilized to analyze phenomena in power systems. Since different algorithms can be applied, depending on the phenomena to be analyzed, digital simulation allows for high-precision analysis. However, it also has a disadvantage: it produces continuous phenomena which occur in actual systems only fragmentarily. Thus, when discussing important projects at research centers such as IREQ in Canada, an analog simulator issued to continuously analyze the phenomena from the moment the fault occurs until steady state. These analog simulators, however, consist of only a few generator models. They are only effective for analyzing phenomena in small-scale systems and do not allow for analysis of phenomena in large-scale systems over a long period of time. For this reason, the Kansai Electric Power Company (KEPCO) in cooperation with Hitachi, Ltd., and Fuji Electric Co., Ltd., has developed the world's largest power system simulator (APSA: Advanced Power System Analyzer). The simulator will be used to analyze the evolution of accidents in actual systems and to analyze continuous system phenomena over a long period. This paper describes an outline of the simulator.     

Detection of cortical activities on eye movement using functional magnetic resonance imaging

Cortical activity during eye movement was examined with functional magnetic resonance imaging. Horizontal saccadic eye movements and smooth pursuit eye movements were elicited in normal subjects. Activity in the frontal eye field was found during both saccadic and smooth pursuit eye movements at the posterior margin of the middle frontal gyrus and in parts of the precentral sulcus and precentral gyrus bordering the middle frontal gyrus (Brodmann's areas 8, 6, and 9). In addition, activity in the parietal eye field was found in the deep, upper margin of the angular gyrus and of the supramarginal gyrus (Brodmann's areas 39 and 40) during saccadic eye movement. Activity of V5 was found at the intersection of the ascending limb of the inferior temporal sulcus and the lateral occipital sulcus during smooth pursuit eye movement. Our results suggest that functional magnetic resonance imaging is useful for detecting cortical activity during eye movement.     

Sintering of diamond with cobalt

Diamond powder was sintered by aid of a cobalt at 1600–1800°C and 80–100 kbar. The microstructural observation of the resultant compacts showed that the masses were held together by diamond-to-diamond bonding. The compacts had Knoop microhardness of 5000–8000 kg/mm². The sintering process of the specimen is described.     

Timing jitter due to carrier linewidth of laser-diode pulse sourcesin ultra-high speed soliton transmission

We theoretically analyze the timing jitter due to both the carrier phase noise of laser-diode (LD) pulse sources and the Gordon-Haus effect in soliton transmission. A formula is derived for the timing jitter in terms of the carrier linewidth, one of the measurable parameters common to all types of LD pulse sources. The transmission distance restricted by the timing jitter is analyzed, and the carrier linewidths required for ultra-long distance and ultra-high speed soliton transmission are estimated as well. Recirculating loop experiments at 10 Gb/s are demonstrated using two pulse sources; a gain-switched DFB-LD and a sinusoidally driven monolithically integrated MQW-DFB-LD/MQW-EA modulator, which have different carrier linewidths due to their different pulse formation processes. The difference in the carrier linewidths of the two pulse sources is measured by the proposed technique which is based on the optical heterodyne method. The observed difference between the two pulse sources in terms of timing jitter accumulation and timing jitter reduction with optical bandpass filters for the two pulse sources well support the theoretical predictions     

Surface modification of aromatic polyamide film by aminoethanethiol solution for silicon rubber composites

The surface modification of poly(p-phenylene terephthalamide) (PPTA) film with 2-aminoethanethiol (AET) to adhere to silicon rubber was investigated. The combination of the AET treatment and the silane coupling treatment is an effective surface modification of the PPTA film for this adhesion. The x-ray photoelectron spectroscopy (XPS) analyses show that the AET treatment does not generate sulfur functionalities at the surface of the PPTA film but does generate oxygen functionalities. In the AET treatment process, a part of the amide groups near the surface of the PPTA film is hydrolyzed to form carboxylic acid groups and amino groups. The oxygen functionalities are condensed at the film surface, and nitrogen functionality is diluted at the film surface. The C(O)O moiety at the PPTA film surface may be a key factor for the adhesion with silicon rubber. The C(O)O moiety is mobile from the bulk of the PPTA film to the film surface. Hot water treatment of the original PPTA film makes the impossible adhesion with the silicon rubber possible. The hot water treatment, however, is not as powerful a surface modification as the AET treatment. © 1995 John Wiley & Sons, Inc.     

A 14-ns 1-Mbit CMOS SRAM with variable bit organization

The authors describe a 14-ns 1-Mb CMOS SRAM (static random-access memory) with both 1M word×1-b and 256 K word×4-b organizations. The desired organization is selected by forcing the state of an external pin. The fast access time is achieved by the use of a shorter divided-word-line (DWL) structure, a highly sensitive sense amplifier, a gate-controlled data-bus driver, and a dual-level precharging technique. The 0.7-μm double-aluminum and triple-polysilicon process technology with trench isolation offers a memory cell size of 41.6 μm² and a chip size of 86.6 mm ². The variable bit-organization function reduces the testing time while keeping the measurement accuracy of the access times     

Serratia liquefaciens as a new host superior for overproduction and purification using the N-acetylneuraminate lyase gene of Escherichia coli

A new way of inferring and presenting psychiatric signs and symptoms as a correlate of cerebral bioimpedance pattern is proposed. The basal principles of bioimpedance have been applied through promising techniques already developed and used. The biophysical electrical shunt model meets the fundamental criteria for static and dynamic regional extracellular fluid volume alterations and ionic density, velocity and compositional changes in the same spatial and temporal units. Bioimpedance technology applied by a suitable method can potentially utilize bioimpedance essentials to display high sensitivity and specificity resolution revealing regional extracellular iono-liquid disturbances in the brain. We suggest that the theoretical model for utilizing bioimpedance as a function for estimating psychiatric signs and symptoms may open new horizons in the neuroscience of biotyping mental disorders.