Noncontact energy transfer system using immittance converter

Noncontact energy transfer systems are widely used in industrial material handling systems. This paper proposes a new noncontact energy transfer system using a tuned pickup coil and an immitance converter inductively coupled to a parallel transmission line excited by a high‐frequency constant‐current source. In a noncontact energy transfer system which supplies continuous energy to movers by electromagnetic induction, the efficiency is low owing to low excitation impedance because of the wide air gap of the magnetic core in the pickup coil. The excitation impedance can be increased by the resonance with a capacitor connected parallel to the pickup coil. The resonant pickup coil works as a high‐frequency constant‐current source for the load. We propose using an immittance converter to transform the high‐frequency constant‐current source into a high‐frequency constant‐voltage source. Then, the high‐frequency constant‐voltage source is rectified into a constant‐voltage dc source, and supplies power to an inverter for motor driving. In this paper, the configuration of this new noncontact energy transfer system and its characteristics are described. The experimental results and simulation waveforms are also described. © 2001 Scripta Technica, Electr Eng Jpn, 136(4): 58–64, 2001     

Artificial neural network predictive model for allergic disease using single nucleotide polymorphisms data

The purpose of this study was to develop a novel diagnostic prediction method for allergic diseases from the data of single nucleotide polymorphisms (SNPs) using an artificial neural network (ANN). We applied the prediction method to four allergic diseases, such as atopic dermatitis (AD), allergic conjunctivitis (AC), allergic rhinitis (AR) and bronchial asthma (BA), and verified its predictive ability. Almost all the learning data were precisely predicted. Regarding the evaluation data, the learned ANN model could correctly predict a diagnosis with more than 78% accuracy. We also analyzed the SNP data using multiple regression analysis (MRA). Using the MRA model, less than 10% of patients with the above allergic diseases were correctly diagnosed, while this figure was more than 75% for persons without allergic diseases. From these results, it was shown that the ANN model was superior to the MRA model with respect to predictive ability of allergic diseases. Moreover, we used two different methods to convert the genetic polymorphism data into numerical data. Using both methods, diagnostic predictions were quite precise and almost the same predictive abilities were observed. This is the first study showing the application and usefulness of an ANN for the prediction of allergic diseases based on SNP data.     

Hidden Markov model-based prediction of antigenic peptides that interact with MHC class II molecules

Elucidating the interaction between major histocompatibility complex (MHC) molecules and antigenic peptides is fundamental to better understanding of the processes involved in immune responses and for the development of innovative immunotherapies. In the present study, hidden Markov models (HMM) were combined with the successive state splitting (SSS) algorithm for optimization of the HMM structure, to predict peptide binders to the human MHC class II molecule HLA-DRB1*0101. The predictive performance of our model (S-HMM) was compared with fully connected HMM and artificial neural network (ANN) methods using the relative operating characteristic (ROC) analysis. The S-HMM predictions had values of ROC > or = 0.85 which was at least as good, or better than the comparison methods. In addition, S-HMM is trained on positive data only and does not require exhaustive data preprocessing, such as peptide alignment. Our results demonstrated that S-HMM combines the high accuracy of predictions with the simplicity of implementation and is therefore useful for analyzing MHC class II binding peptides. In particular the S-HMM may be trained using only positive data and, the preprocessing of training data, such as peptide alignment and the selection of binding cores, is not required in this method.     

Development of HTS (high-temperature-superconductor) current leads for 1-MW/1-kWh modular SMES system

We are developing high-temperature-superconductor (HTS) current loads for a 1-MW/1-kWh modular SMES system. In the modular SMES system, a pair of current leads would be installed in each module so that the heat load to the low-temperature end through the leads is minimized. Design study of the lead configuration including the safety lead and its thermal characteristics is presented herein. The safety lead composed of stainless steel is placed in parallel to the bulk HTS. A test unit for verification of safe operation has been developed and the simulated bulk HTS quench test has been demonstrated. The maximum temperature of the safety lead reached 200 K and the terminal voltage of the safety lead was only 1.2 V in the case of a 1000-A quench test. This temperature rise was well below the designed value. © 1997 Scripta Technica, Inc. Electr Eng Jpn, 120(1): 23–32, 1997     

Immittance converters suitable for power electronics

An immittance converter has fine performance in many power electronics applications. Its function is to convert voltage sources into current sources and current sources into voltage sources. The immittance converter has an input impedance that is proportional to the admittance of loads connected across output terminals. Therefore, in this converter, the output current is proportional to the input voltage and the input current is proportional to the output voltage. Consequently, it converts a constant voltage source into a constant current source and a constant current source into a constant voltage source. When an immittance converter operates at a resonant frequency and is inserted to high-frequency link systems, voltage source outputs turn into current source outputs and current source outputs turn into voltage source outputs. Some power electronics applications of this converter are photovoltaic inverters and dc-dc converters with constant current outputs. It is well known that a quarter-wavelength transmission line shows immittance conversion characteristics. However, it has a very long line length for its switching frequency (e.g., 20 kHz), and is not suitable for power electronics applications. Therefore we propose five immittance converters that consist of lumped L and C elements and show the immittance conversion characteristics at a resonant frequency. These immittance converters are much smaller and lighter than the transmission line. Their principles, basic circuits, and basic characteristics are described in this paper. We also evaluate their application to high-frequency link systems of power electronics. © 1998 Scripta Technica, Electr Eng Jpn, 124(2): 53–62, 1998     

Observation of the Structure, Moisture Distribution, and Oil Distribution in the Coating of Tempura by NMR Micro Imaging

ABSTRACT: The 3-layered fine structure of the coating of the Japanese oil-fried battered food, tempura, was observed by nuclear magnetic resonance micro imaging. The porosity of the intermediate layer was correlated to the moisture content of the batter. Chemical shift imaging, which gave moisture distribution and oil distribution images, revealed the changes in the coating after cooking. The oil was detected to a depth of only 1 mm in the outer layer immediately after frying, and its distribution slightly expanded in the surface layer with time after frying. Water quickly transferred from bean curd (tofu) as 1 ingredient, to the coating along the porous network wall within 25 min after frying.     

New antibacterial diterpenoids from the Sarcodon scabrosus fungus

The structures of new antibacterial diterpenoids that had been isolated from Sarcodon scabrosus were established by chemical and spectral means to be sarcodonin L (2) and M (3), both having the cyathane skeleton. Other antibacterial compounds were identified to be allocyathin B2 (1), sarcodonin G (4) and sarcodonin A (5) by comparing their spectral data with those of authentic samples.     

A protease sensitive region of plant and animal ribonucleases belonging to the RNase T2 family

Recombinant RNase LE from tomato and squid liver RNase Tp, typical plant/animal type RNases belonging to the RNase T2 family, were subjected to limited digestion with several proteases, and the cleavage sites were analyzed by Edman degradation. Recombinant RNase LE was cleaved specifically at the 24th Lys by lysylendopeptidase and trypsin, and RNase Tp was cleaved at the 21st Glu by V8 protease. These cleavage sites are located very close to those where the cleavage during preparation of several animal RNase T2 family enzymes was observed. From this finding, it was concluded that the short segment around the 20th amino acid residue in plant/animal RNases is located on the surface of the molecules and forms loops, and is thus very sensitive to proteases.     

Crystallization and preliminary crystallographic analysis of a 2,3-dihydroxybiphenyl dioxygenase from Pseudomonas sp. strain KKS102 having polychlorinated biphenyl (PCB)-degrading activity

A study of the clinical, radiological, and pathological correlations in 43 patients with solitary cysticercus granuloma and epilepsy focused on factors that might help in predicting the presence of the parasite in the granuloma and those that might influence the formation of oedema around the granuloma. The duration of symptoms (< six months and > or = six months) and CT morphology of the granuloma (ring and disc, type A; nodular lesion, type B) were studied as factors that could possibly predict the presence of the parasite in the granuloma. The influence of sex of the patient and the presence of a neutrophilic response in the granuloma on the intensity of oedema around the lesion as seen on CT was also studied. The pathological features were studied in the excised granulomas. The intact or degenerated form of the cysticercus was evident in 22 of 43 specimens. Neither the duration of seizures (P = 0.17) nor the type of lesion on CT (P = 0.16) was predictive of the presence of the parasite in the granuloma. The sex of the patient (P = 0.51) and the neutrophilic response in the specimen (P = 0.73) did not correlate with the degree of oedema on CT indicating that neither of these host factors was a major determinant of oedema production. The findings point to the varied and unpredictable natural history of solitary cysticercus granulomas and the complex nature of host-parasite interactions in individual patients. The inability to predict the presence of the parasite in the granuloma on the basis of the clinical or radiological features precludes a selection of patients with such lesions for cysticidal drug treatment.