Power swing analysis in a future metropolitan electric power system on a contingent trip of cryogenic high-power cables

A cryogenic power cable is expected to be capable of carrying bulk power as a main transmission line in a future metropolitan electric power system. It is important to establish a strategy of how to sustain power supply when such a highly densified power supply route trips from the network due to contingency. It is proposed here that the bulk power transmitted by the cryogenic cable could be distributed into the parallel conventional transmission lines by suitable circuit breaker operations in the system. In this process, power-flow routes are forced to be changed with a remarkable modification in the system configuration. In this paper, the power swings associated with the large power-flow change following contingent faults are analyzed by means of a transient network analyzer. It is found that the proposed system modification could be realized without any harmful power swing if the parameters in generators as well as in control devices have conventional magnitudes. It is shown also by simulations that the margin to occurrence in an unstable power swing is left sufficient even if the parameters deviate somewhat from the present magnitudes.     

Development of cable fault location method using fiber optic distributed temperature sensor

When ground-fault problems occur on a cable line, immediate fault location and restoration are required. Therefore, various new methods to locate the fault point instantaneously have been investigated to replace such conventional methods as the Murray loop method and the pulse radar method [1]. These methods require a long time to locate the fault point. One possible fault location method is to sense the temperature rise following a ground fault using a fiber optic distributed temperature sensor. Application of this method was found feasible through sensing the temperature rise at a ground-fault test using a thermocouple as a temperature sensor with test cables [4]. A power/optical composite cable was prepared experimentally and after verifying its thermal mechanical performance, the temperature rise at an incidence of a fault was determined and the anticipated performance was demonstrated in a ground-fault test. This article describes the outline of the test.     

Effects of Digital Doping of Mn on Giant Magneto-Optical Properties of Zn1−x Mn x Se Quantum Wells

We have studied effects of the digital-doping profile of MnSe layers on the giant magneto-optical properties in Zn_1?x Mn _x Se-based quantum wells. The giant Zeeman shift energy increases monotonically with increasing spatial overlap of the exciton wavefunction with the 0.5 monatomic-thick effective Mn layers at the interfaces between the digitally doped MnSe layers and nonmagnetic ZnSe layers. Also, a field-induced enhancement factor of the excitonic photoluminescence intensity, because of the suppression of the exciton energy transfer into the d-d transition of Mn-ions, increases linearly with increasing such overlap of the exciton wavefunction with the effective Mn layer. In addition, the formation energy as large as 18.6 meV and the formation time of the magnetic polaron are determined, which are also affected by the digital-doping profile.     

Breast carcinoma with myeloid metaplasia--a case report

A 49 year-old female had been suffering from primary myelofibrosis since February 1987 without receiving any treatment. In 1994, a breast mass was detected. Breast tumor biopsy revealed tubular carcinoma with intraductal components and multinucleated giant cells in the loose and myxoid stroma. The giant cells were thought to be megakaryocytes because both Factor VIII and platelet glycoprotein GP IIIa were detected in their cytoplasm. While additional mastectomy specimens and the axillary lymph nodes also revealed prominent myeloid metaplasia, there was no proliferation of the cancer cells. Granulocytic series stained for chloroacetate esterase and very few erythrocytic series were observed. This is the first case in which breast carcinoma and myeloid metaplasia coexisted in the same breast tumor.     

A novel technique for a DC brushless motor without position sensors

A dc brushless motor is a kind of synchronous motor driven by an inverter and requires sensors to detect the rotor position. As one of the methods, the induced voltages of a brushless motor have been utilized in practice. However, there are some problems in this method, e.g., the motor can obtain insufficient torque due to the low induced voltages in a low-speed range. This paper proposes a new method which controls the inverter angular frequency ω₁ by using inherent characteristics wherein the torque current i_r is almost proportional to the internal phase angle φ where the primary flux of a synchronous motor is controlled to be constant. If the parameters of a motor are given exactly, the speed regulation is quite small and the transient characteristics with high response and high starting torque are obtained. Furthermore, it is possible to operate a synchronous motor in the field-weakening range. Here, the principle of the control method and the performance characteristics of a dc brushless motor having no position sensors are discussed. The simulation and the experimental results of the tested machine show that the proposed method is very useful for practical applications.     

The dual coated pit pathway hypothesis: vertebrate cells have both ancient and modern coated pit pathways for receptor mediated endocytosis

The SimPlate Total Plate Count (TPC) test, developed by IDEXX Laboratories, Inc., detects and quantitates total bacterial concentration in food after 24 h of incubation. The performance of SimPlate TPC was compared with that of the plate count agar (PCA) method for enumerating total bacterial concentration of 255 food samples representing 15 different food matrixes. Total bacterial counts on SimPlate TPC were measured after 24 h of incubation and plotted against values obtained from PCA after 48 h. Simple regression analysis of the data showed strong correlation between the methods (r = 0.95); the sensitivity of SimPlate TPC for foodborne bacteria was 96% relative to PCA (slope = 0.96). It was concluded that SimPlate TPC is a suitable alternative for the detection and quantitation of foodborne bacteria. The method has been granted Performance Tested Certification by the AOAC Research Institute.     

Molecular biological approach to functions of telencephalin, a cell adhesion molecule and HNK-1 carbohydrate epitope, which is commonly expressed on cell adhesion molecules in the nervous system

Cell surface carbohydrates modulate a variety of cellular functions, including recognition and adhesion. The HNK-1 carbohydrate epitope, which is recognized by the monoclonal antibody HNK-1, is specifically expressed on a series of cell adhesion molecules and also on some glycolipids in the nervous system over a wide range of species from insect to mammal. The HNK-1 epitope is spatially and temporally regulated during the development of the nervous system and associated with neural crest cell migration, neuron to glial cell adhesion, outgrowth of astrocytic processes and migration of cell body, as well as the preferential outgrowth of neurites from motor neurons. These observations together with the unusual chemical nature of the HNK-1 epitope, namely a non-reducing terminal 3-sulfoglucuronic acid residue, prompted us to study the biosynthesis of the NHK-1 epitope, in which a unique glucuronyltransferase(s) plays a key role. We found that the respective glucuronyltransferases are involved in the biosynthesis of the HNK-1 epitope on glycoproteins (GlcAT-P) and on glycolipids (GlcAT-L). Then, we isolated a novel glucuronyltransferase (GlcAT-P) specific for glycoprotein substrates and its cDNA from the rat brain. The primary structure deduced from the cDNA sequence predicted a type II transmembrane protein with 347 amino acids. Transfection of the GlcAT-P cDNA into COS-1 cells induced not only expression of the HNK-1 epitope on the cell surface but also marked morphological changes of the cells, suggesting that the HNK-1 epitope was associated with the cell-substratum interaction. The GlcAT-P cDNA obtained in this study will be a useful molecular tool to open the way for further steps in the elucidation of the biological function of the HNK-1 carbohydrate epitope in the development of the nervous system.     

Fast computation of computer-generated hologram using Xeon Phi coprocessor

We report fast computation of computer-generated holograms (CGHs) using Xeon Phi coprocessors, which have massively x86-based processors on one chip, recently released by Intel. CGHs can generate arbitrary light wavefronts, and therefore, are promising technology for many applications: for example, three-dimensional displays, diffractive optical elements, and the generation of arbitrary beams. CGHs incur enormous computational cost. In this paper, we describe the implementations of several CGH generating algorithms on the Xeon Phi, and the comparisons in terms of the performance and the ease of programming between the Xeon Phi, a CPU and graphics processing unit (GPU).