ドデシルベンゼンスルホン酸ナトリウム(DBS)は,pH1以下の酸性溶液において酢酸エチルに抽出されることを見いだしたので,この性質を利用し,河川水および海水中のDBSの溶媒抽出法を検討した。試料100mlを分液漏斗にとり,硫酸を加えてpHを1以下に調製し,酢酸エチルそれぞれ20mlおよび10mlを用いて2回ふりまぜて抽出し,有機層を合わせて水浴上で蒸発させ,緩衝液20mlを加えてpHを4～5にたもち,クロロホルム1Omlを加えてふりまぜて洗浄したのち,クロロホルム層を分離し,これにふたたび緩衝液1Oml加えて10分間ふりまぜてクロロホルム中に一部抽出されたDBSを逆抽出する。水層を合わせてメチレンブルー法で測定した。
クロロホルムによる洗浄効果は大きく,直接メチレンブルー法にくらべ約1/10～8/10の値となり,無機イオンは妨害しない。本法を河川水,海水に適用したところ,平均回収率95～101%となり,2.6ppb程度の薄い溶液でも88%の回収率となった。

抄録全体を表示

道後平野,大洲盆地および海上大気中の有機リン農薬を測定し以下の結論を得た。有機リン系の農薬は,7,8,9月に大気中の濃度が高く,大気中の残留指数はBHC類より小さく,ダイアジノン>IBP>MEPの順であった。平均存在量は使用量にほぼ比例し,IBP>MEP>ダイアジノンである。また変動係数は,IBP>MEP>ダイアジノンであり,三者ともに濃度の地域差は大きい。濃度的には,ダイアジノンとIBPにのみ相関があり,両者は同時に散布される傾向が強い。愛媛大学-松山工業高校,松山工業高校-北条市,北条市-大洲市の間の相関数が大きく,かつ,他の地点より濃度が低いことから他の地域から移動拡散してきたものと思われる。農薬の一斉散布では,IBP37.3μg/m³にも達するが約100時間で61ng/m³に濃度低下が起こった。海上大気濃度は,陸上大気濃度にくらべて低く,外洋ではおおよそ4ng/m³以下,瀬戸内海でもMEPを除いて陸上大気のバックグラウンド程度であった。

抄録全体を表示

その研究が20世紀に劇的に発展した金属錯体は, 新世紀を迎えて, さらに物理的特性を利用した機能性分子としての活躍が期待されている。その1例として, 代表的な遷移金属の有機金属錯体であり, 優れた電子授受機能をもつフェロセンを取り上げ, 他の機能分子・物質と組み合わせたときに, どのような物理機能を発現するかを述べる。具体的には, フェロセン共役分子, アゾフェロセン, ビフェロセン修飾金クラスターにふれる。

抄録全体を表示

The mechanical stability of the seismic mass (movable electrode) in a PWM electrostatic servo accelerometer which was fabricated by using a silicon micro-machining technique was studied theoretically and experimentally.
The movable electrode is controlled so as to be parallel to the fixed electrodes in the usual servo-operation. From an analysis using an energy model considering electrostatic energy of the electric field between the movable and the fixed electrodes and elastic energy of the cantilever beam which sustains the movable electrode, the occurrence of rotation of the movable electrode around a certain axis was expected at pulse voltages higher than a certain threshold voltage. This threshold voltage V_T is proportional to the square root of the rotational spring constant of the cantilever beam when the movable electrode rotates around a certain axis.
This rotation phenomenon of the movable electrode was confirmed by optical observation of the sensor and the measured threshold voltages V_T were in close agreement with those calculated by the above energy model.
The maximum measurable acceleration α_max in a PWM electrostatic servo accelerometer is proportional to the square of the pulse voltage which is restricted by the threshold voltage V_T and is larger in the sensor structure with larger rotational spring constant of the cantilever beam. for example, α_max for a 2-beam sensor is larger than that for a 1-beam sensor.

抄録全体を表示

Superconducting flywheel energy storage systems using superconducting magnetic bearings have been studied regarding the possibility of contributing to daily load leveling. To make the system feasible for practical application, the levitation force of the radial-type superconducting magnetic bearing must be enhanced. Therefore, we have come up with an idea to change the shape of the cross sections of the permanent magnet and yoke from the present rectangular form to a trapezoidal (or triangular) shape. We analyzed the levitation force in the case where such a permanent magnet and yoke are applied, and produced and actually measured the permanent magnet and yoke. Moreover, anticipating that the adopting the conventional Y superconductor assembly and Gd superconductor assembly, which has better characteristics than the former, would have an effect on levitation force enhancement, we produced these two types of superconducting bearing assemblies and actually measured them. We demonstrate that levitation force is enhanced when the permanent magnet assembly has a trapezoidal cross section and the Gd superconducting bearing assembly is used.

抄録全体を表示

In microstructures such as microsensors and microactuators, a small surface force can occur between two contacting surfaces which affects operations. Therefore, it is very important to clarify the generation mechanism of this surface force and to find a way to decrease it in the devices.
In this study, a microstructure used in evaluating surface force was fabricated by a silicon micromachining technique. This device has a movable plate supported by cantilever beams and two opposing electrodes positioned above and below the movable plate. The surface force acting at the contact area of the movable plate and the opposing electrodes was evaluated as follows: The movable plate made contact with one of the electrodes when an electrostatic force was applied. Then another electrostatic force was applied to remove the movable plate by applying a voltage between it and the other electrode. The surface force was calculated from the voltage needed to separate them. This method was applied to measure the surface force under various conditions in which the amount of water adsorbed on the surface was different.
It was confirmed that the surface force could be lowered by such measures as thermal treatment at about 200°C and hydrophobic treatment of the surface, which decreased the amount of water adsorbed on the surface from the atmosphere. This meant that interaction between the water molecules adsorbed on the surface was one of the main causes of the surface force.
Another way to lower surface force was to make the contact area of the movable plate and the electrodes samller. For example, pyramid type stoppers, formed on the movable plate, were very effective to decrease the surface force.

抄録全体を表示

We have developed a signal conditioning LSI which consists of a sigma delta AD converter, sigma delta DA converter, DSP and PROM. The AD converter of the LSI is able to directly digitize input signal from the sensor element with a swing less than 10mV with 1μV resolution. Therefore no preamplifier for adjusting the input signal from the sensor element to the AD conversion range is needed. The DSP is able to start up without a reset signal, though it is a stored program type signal processor. The sensing system using this DSP has no external parts, power on reset circuit, watch dog timer. The LSI have been integrated in a 0.8μm CMOS process and its chip is 4.3mm × 4.7mm.

抄録全体を表示

Radial-type superconducting magnetic bearings (SMB) have been developed for a 10kWh-class flywheel energy storage system. The bearings consist of an inner-cylindrical stator comprised of YBCO bulk superconductors and an outer-rotor of permanent magnets. The rotor is suspended without contact via the pinning forces of the bulk superconductors, which are arranged such that the c-axis of each bulk is aligned parallel to the radial direction of the cylinder. After the whole system was completed, various tests focusing on both its static and dynamic behaviors were carried out to confirm that the SMB has sufficient performance for 10kWh-class flywheel systems. In this paper, we describe the implementation of the stator part and report the SMB test results; namely, that the rotor was successfully suspended up to 7,500 rpm. Thus, we succeeded in an energy storage of 2.24 kWh.

抄録全体を表示

Amorphous alloy exhibits high permeability and extremely low iron loss compared to magnetic steel sheet. Therefore, it is expected to contribute to the efficiency improvement of electromagnetic application products such as motors, generators, and transformers.
In this paper, we examined an axial-type motor that uses the rolled amorphous core as a stator core for the purpose of applying amorphous alloy to a motor for air-conditioning equipments. We propose the motor structure to use amorphous alloy as a rolled core without complicated processing, and the evaluation results of the trial motor clarified that this structure is able to meet the target motor efficiency of 85% under the conditions that the size of the motor is below φ100mm × 60mm and that ferrite magnets are used.

抄録全体を表示

We examined the claw type teeth motor as one application of the soft magnetic composite to a motor core. In order to understand quantitatively the characteristics of the claw type teeth motor, we used the 3-dimensional electromagnetic field analysis to predict its characteristics in advance and manufactured a trial motor to estimate it. And we examined the advantages of the claw type teeth motor comparing with a conventional slot type motor. The results are: 1. By using the 3-dimensional electromagnetic field analysis, it is able to estimate with high accuracy the characteristics of the 3-phase permanent magnet synchronous claw type teeth motor having a core composed of the soft magnetic composite. 2. The claw type teeth motor is able to achieve about 20% higher output than a conventional slot type motor having an electromagnetic steel core, while both volumes are equal. 3. The motor efficiency of the claw type teeth motor is about 3.5% higher than the conventional motor.

抄録全体を表示

The segment stator core, high density winding coil, high-energy-product permanent magnet are indispensable technologies in the development of a compact and also high efficient motors. The conventional design method for the segment stator core mostly depended on experienced knowledge of selecting a suitable electromagnetic material, far from optimized design. Therefore, we have developed a novel design method in the selection of a suitable electromagnetic material based on the correlation evaluation between the material characteristics and motor performance. It enables the selection of suitable electromagnetic material that will meet the motor specification.

抄録全体を表示

In mirostructures such as microsensors and microactuators, a small surface force can occur between two contacting surfaces which affects their operations. Therefore, it is very important to clarify the generation mechanism of this surface force and to find a way to decrease it in order to realize these devices.
In this study, the surface force between two contacting surfaces in a sample microstructure was evaluated theoretically and the force magnitudes obtained were compared with the measured values which we reported previously. Four kinds of basic physical forces, i.e. van der Waals force; liquid bridge force due to capillary condensation of water molecules from the atmosphere, hydrogen bonding force between adsorbed water molecules, and electrostatic force based on a contact electrification were calculated by modeling the contacting parts in the sample. The sample microstructure has a movable plate supported by cantilever beams and two opposing electrodes. The movable plate and one of the opposing electrodes contact each other when the movable plate is displaced significantly.
We found that the van der Waals force, the liquid bridge force and the hydrogen bonding force could generate surface force magnitudes which were almost equal to the measured surface force.
From the theoretical analysis described above and the earlier experimental results, we concluded that the dominant surface force in usual microstructures is the liquid bridge force due to the capillary condensation of the water when the humidity of the atmosphere around the two contacting surfaces is high; it is the hydrogen bonding force between water molecules adsorbed on the two surfaces when the humidity is relatively low; and it is the van der Waals force when physisorbed water molecules on the surfaces are almost moved out.

抄録全体を表示

A soft magnetic composite (SMC) has some advantages, namely, three-dimensional magnetic isotropy and low eddy current loss. Thus, it can be used to build a new type of motor with a three-dimensional structure, improved space factor of winding improved the power density. A claw teeth motor is one of the motors that have three-dimensional structure, and it is made of an SMC. Due to its structure, the claw teeth motor has an unbalanced three-phase magnetic circuit, which leads to low-order harmonic components in the torque waveform. For reducing the torque ripple, it is important to estimate the magnetic torque and the cogging torque because the total torque is the sum of these torques. In this study a method for decomposing the total torque under the load condition into the magnetic torque and cogging torque is presented. The proposed method can quantitatively estimate low-order harmonic components of the magnetic torque and cogging torque caused by an unbalanced three-phase magnetic circuit for each phase.

抄録全体を表示

The three-dimensional magnetic field analysis has clarified the effect of several structural and manufacturing factors on the properties of the outer rotor type stepping motors. (1) The number of rotor teeth, 128, can make a unit step angle under 0.5 degree and a cogging torque under 1mNm for the outer rotor type stepping motor with the outer diameter under 60mm and with the output torque above 0.4Nm. (2) The permanent magnet flux has an optimal value dependent on the thickness of the laminated core to maximize the motor torque. (3) The lamination stacking error of the small teeth of the rotor and stator has a large effect on the cogging torque of the stepping motor.

抄録全体を表示

The segment stator core, high space factor coil, and high efficiency magnet are indispensable technologies in the development of compact and a high efficiency motors. But adoption of the segment stator core and high space factor coil has not progressed in the field of outer rotor type motors, for the reason that the inner components cannot be laser welded together. Therefore, we have examined a segment stator core combination technology for the purposes of getting a large increase in efficiency and realizing miniaturization. We have also developed a characteristic estimation method which provides the most suitable performance for segment stator core motors.

抄録全体を表示

The segment core method is a popular method employed in motor core manufacturing; however, this method does not allow the stator core precision to be enhanced because the stator is assembled from many cores. The axial eccentricity of rotor and stator and the internal roundness of the stator core are regarded as the main factors which affect cogging torque. In the present study, the way in which a motor with a split-type stator generates a cogging torque is investigated to determine whether high- precision assembly of stator cores can reduce cogging torque. Here, DC brushless motors were used to verify the influence of stator-rotor eccentricity and roundness of the stator bore on cogging torque. The evaluation results prove the feasibility of reducing cogging torque by improving the stator core precision. Therefore, improving the eccentricity and roundness will enable stable production of well controlled motors with few torque ripples.

抄録全体を表示