Hybrid Research Articles

518 永久磁石内蔵型ハイブリッド磁気軸受の開発(新しい磁気浮上方式,OS-3:磁気浮上・磁気軸受の制御)

This paper proposes a new type of Hybrid (HB) magnetic bearings which has permanent magnet (PM) within the stator. It is intended for a magnetic bearing to have high efficiency, good dynamic response and low cost. HB magnetic bearing is recognized as an efficient one. But the bias PMs should be installed between the radial magnetic bearings. It requires thick magnetic circuit and produces flux leakage. Hence a new magnetic bearing is proposed based on the HB type. The bias PMs are installed inside the radial magnetic bearing. Hence all the magnetic circuit is closed inside the radial magnetic bearing and it is relatively free from the flux leakage. This magnetic bearing system is controlled using the hall diode as a position sensor which locates on the top of PMs.

New design of hybrid-type self-bearing motor for small, high-speed spindle

A new structure of hybrid (HB)-type self-bearing motor is proposed for miniature spindle motors. The proposed design combines the HB-type self-bearing motor and HB active magnetic bearing in the common stator and rotor pair to generate large radial forces. First, the principle and theoretical background are introduced. Then, the air gap flux is analyzed by the finite element method, and radial forces for the proposed and standard-type HB self-bearing motors are compared. Finally, experiments are conducted to confirm the performance of the proposed motor. The motor can run at relatively high rotating speed with relatively high torque compared with its small size. The levitation is very stable and the motor indicates good performance for practical application.

Effects of heterosis on growth in height and its segments: a cross-sectional study of the Khasi girls in Northeast India

Background: It is generally believed that improvement in environmental quality is the main factor responsible for the better growth and nutritional status of children in developing countries. However, it is still not clear whether this better growth performance is also associated with heterosis and/or gene flow that may take place as a result of the geographical movement of individuals, or migration. Aim: The present paper attempts to examine the effects of heterosis on physical growth of girls in height and its segments. Subjects and methods: A cross-sectional sample of the Khasi girls of Shillong in Northeast India was considered in the present analysis. The height and sitting height of 1368 girls aged 3-18 years were measured with a Harpenden anthropometer, following standard techniques. The sample was divided into two groups, namely hybrid (HB) and non-hybrid (NHB) girls, in order to test the effects of heterosis using analysis of covariance with the household income as a covariate. The Preece-Baines model 1 (M. A. Preece and M. F. Baines, Annals of Human Biology, 5, 1-24, <citeref rid="bib43">1978</citeref>) was used to fit the adjusted means of height and its segments with a view to assess the variation in adult height, age at peak velocity and size at peak velocity. Results: Both HB and NHB girls were similar in age at maximum increment for height (12 years) and sitting height (13 years), although it was much earlier in the former (10.5 years) than in the latter (11.9 years) with respect to subischial length. The results indicated that HB girls were larger than NHB girls across ages. Such a higher anthropometric status in HB girls was mainly due to their higher growth velocities before the adolescent period. The effect of heterosis after household income was highly significant at many ages from 6 to 18 years, although it was not clearly perceptible in the case of subischial length. Conclusion: Subject to further studies, the role of heterosis and/or gene flow in influencing growth and development of children cannot be completely ruled out, especially after 5 years of age when the variation in growth patterns is likely to be associated not only with environmental quality but also with genetic mechanisms.

208 永久磁石内蔵ハイブリッド磁気軸受の開発

Recently small magnetic bearing is widely requested for small rotary machines. Standard active magnetic bearing (AMB) has problems of low efficiency and temperature rise. Hybrid (HB) type AMB can improve these problems. However, the traditional HB type AMB has bias permanent magnet between the two radial magnetic bearings. This structure requires long magnetic circuit causing heavy casing and flux leakage. This paper proposes smart HB type AMB which has internal permanent magnet inside the radial magnetic bearings. The fundamental principle is introduced, followed by the design of the experimental setup.

Characteristics of 3-Phase Synchronous Inductor Motor

This paper treats the 3-phase synchronous inductor motor which is the same structure as the PM type or HB (hybrid) type 3-phase stepping motor. The characteristics of the synchronous inductor motor when it is driven by a single-phase power supply using a phase shifting capacitor are analyzed. Motor performance is examined in the connection with the capacitance of capacitor, and the selecting method of capacitance for obtaining good performance is proposed. Effects of motor constants on the characteristics of the motor are discussed. Moreover, starting characteristics of the motor driven by a single-phase power supply are also examined.

Enhanced photocurrent generation and photooxidation of benzene sulfonate in a continuous flow reactor using hybrid TiO2 thin films immobilized on OTE electrodes

Abstract The enhancement of photocurrent and photodegradation of organic pollutants was investigated using hybrid TiO 2 thin films prepared by a combined paste/sol–gel technique to immobilize the TiO 2 particles onto optically transparent electrodes (OTEs); they were connected in series in a continuous flow, bench-top, two-compartment photoreactor. The benzene sulfonate (BS) of the model substrate surfactant used was photodegraded in aqueous media to test the efficacy of the TiO 2 /OTE electrode preparation and the construction of the photoreactor. Results indicate that the hybrid TiO 2 film/OTE electrodes were more efficient than either the pasted TiO 2 /OTE electrode or the sol–gel TiO 2 /OTE electrode for the photodegradation of BS, as evidenced by the evolution of carbon dioxide and the photocurrent generated. The extent of ring opening and generated photocurrent during the photodegradation of BS with the hybrid (HY) electrode was correlated to the pasted TiO 2 electrode and to the number of dip-coatings in the sol–gel. High photocurrents were generated in the cylindrical large photoreactor under continuous flow of the aqueous BS solution. Optimization of experimental factors for optimal efficiency of the setup was addressed with regard to the preparation of the HY electrodes, and to their size and location in the photoreactor.

Control of Hybrid (HB) Type Magnetic Bearings with Axial GAP Combined Motor-Bearing

HB type inclination control magnetic bearing had been developed to stabilize a flexible rotor which run over the bending critical speed. However one end of the rotor was supported by a ball bearing and the rotor was driven by a DC motor via rubber coupling. In this paper, a combination of HB radial magnetic bearings and axial gap combined motor-bearing is developed to remove the ball bearing and the DC motor. This driving unit is controlled by a PD controller. The rotor has the first bending mode at about 300 [Hz]. To overcome spillover instability, H∞ controller is designed and applied to HB type magnetic bearings. Finally, the developed driving unit is applied to a flexible rotor which can run over fifth bending critical speed.

Suppression of fatigue cracking with nanometer-scale multilayered coatings

The current study investigates the development of a novel hybrid surface modification (HSM) technique to improve the surface integrity of Ti–6Al–4V alloy. The approach combines the mechanical shot peening (SP) and the deposition by Physical Vapour Deposition (PVD) of a tungsten-doped diamond-like carbon coating (WC/C) on Ti–6Al–4V surfaces. The mechanical shot peening induced high surface roughness increasing the metallurgical bonding sites for the PVD deposition, whereas mainly the grain growth during the deposition, was successfully eliminated. The mechanical SP process induced the high strain lattice misorientations evident for increasing the dislocation density in the crystalline structure. The Electron Backscatter Diffraction (EBSD) results suggest that subjecting the SP specimens to a temperature of 240 °C for more than 3 h during coating deposition, results in a reduction of dislocation densities, presumably as a result of dislocation annihilation by heat-activated dislocation mobilisation. Hence, the presented Grain Orientation Spread maps suggest that some degree of macro and micro stress relaxation may have occurred during the coating deposition treatment. Further, the Raman spectroscopy confirms the existence of beneficial compressive residual stresses on both PVD and hybrid (HY) coated surfaces. Comparatively, the HY surfaces show a high hardness of 12.08 GPa and high elasticity indices (H/E ratios) of 0.1.

VNTR-based diversity analysis of 2x and 4x full-sib Musa hybrids

Summary of inheritance of maternal (AAB genome) and paternal (AA genome) VNTR amplification fragments in the full -sib 2x and 4x progeny populations. ____________________________________________________________________________ Maternal fragments Paternal fragments (Obino l’Ewai) (Calcutta 4) # % # % ____________________________________________________________________________ Diploid progeny Segregation 10 46 15 65 No segregation 8 36 3 13 Absent 4 18 5 22 Tetraploid progeny Segregation a 18 82 20 87 b No segregation 4 18 1 4 Absent 0 0 2 9 _________________________________________________________________________ ___ a segregation of 7 fragments solely due to absence of that fragment in TMPx 548 -9 b segregation of 1 fragment solely due to absence of that fragment in TMPx 548 -9 TMPx 7002-1 are most closely related to the maternal genotype (Obino l’Ewai). In cont rast, all the diploid hybrids form two groups associated at the 60% level of similarity, which are distinct from both parental genotypes (Figure 1). The major exceptions are TMPx 548 -9, which is separated at the 20% level of similarity from all other genotypes, tested and hybrid 5860-1 (4x) that is grouped with the diploid progeny. Hybrid 5860-1 (4x) was found to haveCalcutta 4 were very similar; 0.42 (±0.046) and 0.39775% similarity to TMP2x 1549 -5, both of which have 65% similarity to hybrid 1549-7 (2x) (Figure 1). This anomaly may be a consequence of hybr id 5860-1 (4x) possessing a high proportion of bi-allelic loci in common with these particular diploid full -sibs, as compared to multi -allelic loci of the other tetraploid hybrids. Clearly, this type of molecular marker analysis can not be used for inferring hybrid ploidy. Finally, TMP2x 1448 -1 and hybrid 1586 -2 (2x) appear particularly distinct from the majority of their 2x and 4x full -sib hybrids (Table 2). Both diploid and tetraploid hybrids had comparable mean levels of similarity to Calcutta 4 (32.2% and 34.3 %, respectively). However, tetraploid hybrids had more fragments in common with Obino l’Ewai than their diploid full-sibs (56.1% and 44.6%, respectively). This relationship was expected because the tetraploid hybrids have 75% of their genes donated by the maternal plantain 2n gametes (and the remaining 25% from the diploid banana), while their diploid full-sibs inherit 50% of their genes from each parent. The average phenotype of the tetraploid hybrids was also more closely related to Obino l’Ewai than Calcutta 4 (Table 3). The phenotypic distance between the tetraploid hybrids and Obino l’Ewai was 0.322 (±0.027), while the phenotypic distance between the tetraploid hybrids and Calcutta 4 was 0.470 (±0.021). Conversely, the phenotypic distance indic es for comparisons of diploid hybrids with Obino l’Ewai and (±0.043), respectively. This was expected based on the gametic contributions to diploid and tetraploid hybrids described above. For the relationship between hybrids and Obino l’Ewai, there was a significant association between the genetic similarity (based on VNTR) and the phenotypic resemblance (r = -0.546, P = 0.042). The linear relationship (R

Jumping performance and short-term repeatability of newly metamorphosed hybrid and parental leopard frogs ( Rana sphenocephala and Rana blairi )

Differential fitness between hybrid and parental genotypes plays a critical role in explaining the maintenance of natural hybrid zones as well as the production of novel genetic variation that may lead to diversification. Because locomotor performance is a reliable and practical measure of potential fitness related to morphological variation, we tested for differences in jumping performance among parental and hybrid genotypes of newly metamorphosed leopard frogs (Rana sphenocephala and Rana blairi). Tadpoles of the parental species and primary and backcross hybrid tadpoles, generated from artificial crosses (a total of five genotypes), were reared at two initial larval densities. Locomotor performance of newly metamorphosed frogs, as measured by jumping ability, was tested three times over 6 days in the laboratory at 24-25°C. Maximum and average jump lengths were greater for metamorphs reared at low larval density than for those reared at high density. Regression analyses indicated that 70-79% of the variation in jump length was due to body mass. When reared at low density, metamorphs of two F1 backcross genotypes (HB and HS) and one primary hybrid genotype (SB) jumped shorter distances than either parental species. When reared at high density, hybrid performance was indistinguishable from that of the parentals, except for one backcross hybrid (HB). Moderately high short-term repeatabilities (0.47-0.66) of metamorphs reared at the high density indicate that measures of performance in newly metamorphosed frogs can be predictive. We suggest that, owing to poor jumping performance, some hybrid frogs would be at a selective disadvantage relative to their parental species in the terrestrial environment and thus would partially reinforce mechanisms of reproductive isolation in this leopard frog system. Yet equivalent performance of some hybrids relative to the parentals, at least when reared at low density, suggests that hybrid lineages also have the potential to evolve independently in some environments.

Simulation Modeling and Performance Evaluation of Multiple Access Protocols

This paper presents an object-oriented simulation model that can be used to evaluate the perfor mance of MAC (Multiple ACcess) protocols. It is intended for satellite communication networks in which the propagation delay plays a major role on the performance of the communication channel. The model has been used to evaluate the perfor mance of multiple access protocols for NASA's Mars Regional Network in the Martian environ ment with some specific requirements. These re quirements include protocol robustness, stringent use of power and buffer memory, channel stabil ity, and low complexity of the control algorithm. The simulation model can accommodate different classes of MAC protocols including fixed assign ments, demand assignments, random access, hy brid of random access, and adaptive protocols. While the simulation model has been developed to evaluate the MAC protocols for the Martian envi ronment, it is intended to accommodate other multiple access protocols with different require ments.

A Three-Phase Hybrid Stepping Motor Drive System Combined with Position-Sensorless Closed-Loop Control

This paper proposes a drive system for a three-phase hybrid (HB) stepping motor, combining sensorless closed-loop control with conventional open-loop control. It is characterized by the sophisticated control providing both prevention of pulling out from synchronism and suppression of rotor natural oscillation, without any position sensor attached to the motor shaft. Switching technique in chopper control is described, which can enlarge a speed range controllable in the sensorless closedloop control. Moreover, starting and stopping sequences are developed to reduce mechanical natural oscillation caused in transient state. Finally, the proposed drive system is compared with a conventional constant-current open-loop drive system experimentally. It is shown that the proposed drive system can perform a switchover from the starting to the sensorless closed-loop operation within 20ms, and can reduce the natural oscillation caused just after positioning.

Model-Based Motion and Force Control for Flexible-Joint Robot Manipulators

Two model-based control algorithms to control the motion and force of flexible-joint robot manipulators are presented. Both algorithms are based on the feedback-linearization concept, and utilize a fourth-order feedback-linearizable model of the flexible-joint manipulators. The first algorithm, dynamic hy brid controller, deals with the problem where the flexible-joint robot is constrained by a rigid environment, and aims at di rect control of the contact forces. A constraint frame is derived that enables decoupling of the system into a position subsystem and a force subsystem. A nonlinear feedback-control law is designed to first decouple and linearize the constrained flexible- joint manipulator system, then impose desired closed-loop characteristics in each subsystem independently. The second algorithm, impedance controller, aims at regulating the rela tionship between the contact force and the difference between the commanded and true positions of the end point. A desired target impedance is designed for the end point of the flexible- joint robot manipulator in the reference frame. A nonlinear feedback controller is designed to linearize the system and to impose the target impedance. The same controller is used when the robot is performing compliant and free motions. An experimental two-link, flexible-joint robot manipulator in con tact with a straight wall is used to evaluate and compare the performance of the two controllers.

Arylsulfatase A lysosomal enzyme Map position 22q13.3

Metachromat ic l eukodys t rophy is an au tosomal recessive d i sorder of myel in metabol i sm caused by a deficiency of the lysosomal enzyme arylsul fa tase A (ARSA) [1]. The ARSA gene has p rev ious ly been local ized to chromosome 22 between 22q13 and qter us ing h u m a n rodent hybr id clones [2]. The human ARSA cDNA probe conta ined the whole coding region and consis ted of a 2.0-kb insert in pBluescript [3]. Fluorescence in situ hybr id iza t ion was as descr ibed in [4], except that no prereassocia t ion was necessary and chromosomes were s ta ined before analysis with both p r o p i d i u m iod ide (as counters ta in) and DAPI (for chromosome identification). Twenty metaphases from a normal male all showed specific label l ing of one or both chromat ids of chromosome 22 in the region ex tending from dis ta l 22q13.31 to 22q13.33. Two non-specific backg round dots were observed. A similar result was shown in a second normal male (15 h igh-resolu t ion metaphases) , conf irming the distal 22q13.3 posi t ion. 1. Gieselmann Vet al. (1995) Hum Mutat 4: 233-242. 2. Geurts van Kissel AHM et al. (1980) Cytogenet Cell Ganet 28: 169-!72. 3. Stein C et al. (1989) J Biol Chem 264: 1252-1259. 4. Callen DF et al. (1990) Ann Gfnft 33: 219-221.

Comparative Growth and Development of Nicholas and Hybrid Toms from 16 to 82 Days and Effects of Protein Restriction from 0 to 59 Days on Growth of Hybrid Toms Through 125 Days of Age

The objective of this experiment was to study age and diet effects on serial growth of economically important carcass parts of Nicholas (NIC) and Hybrid (HYB) toms. At approximately 14-d intervals from 16 to 82 d, BW and the weight of selected carcass parts were compared in toms from both commercial strains. There were no overall strain differences in BW, although NIC toms were heavier from 31 to 72 d, which resulted in a significant strain by age interaction (P ≤ 0.021). The absolute weight of the Pectoralis major (PMAJ; P ≤ 0.022) and tibia plus associated muscles (Drum; P ≤ 0.051) were increased in NIC toms. The relative weight of the PMAJ (P ≤ 0.004) and abdominal fat (72 and 82 d; P ≤ 0.023) also were heavier in NIC toms. The relative weight of the drum and Gastrocnemius muscle (GASTROC) was heavier in HYB toms, however (P ≤ 0.001).A separate set of HYB poults was fed a diet deficient in protein or lysine (PD) from 0 to 8 wk and their growth and carcass development were compared with those fed a Control diet (NRC, 1984). Comparisons also were made at approximately 14-d intervals from 16 to 125 d. The PD diet from 0 to 8 wk significantly reduced BW and absolute breast muscle and leg portion weights. The relative weight of the PMAJ and Pectoralis minor (PMIN) were also reduced in toms fed the PD diets but the thigh and drum (125 d) were increased.

Development of Three-Phase HB-type Stepping Motors.

In hybrid (HB) type stepping motors, two and five-phases are used respectively for medium and high resolution purposes, but three-phase motors have been disregarded. Then we started in the development of three-phase HB-type motors, believing in their possibilities. In this paper, design consideration and measured performance of three-phase HB-type motors are described. The developed motor (B) with 3.7° step angle has comparable torque characteristics and reduced vibration as compared with the usual two-phase motor, and the motor (A) with 0.6° step angle is able to rotate at a speed of over 2, 000 rpm by attaching an elastic inertia damper. In conclusion, three-phase HB-type stepping motors are expected to have a bright future.

Characterization of Carcass Development from 14 to 145 Days of Age in Turkey Hens from Two Strains

Body weight and carcass components were measured from 14 to 145 d in Nicholas (NIC) and Hybrid (HYB) strain turkey hens. At most ages, BW of HYB hens was greater than that of NIC and there were small but significant differences in the weight of the Pectoralis minor (PMIN). The relative weight of the PMIN increased in HYB hens from 98 to 145 d. No strain differences in either the absolute or relative weights of the Pectoralis major (PMAJ) were observed. The absolute and relative weights of the tibia plus associated muscles (DRUM) and femur plus associated muscles (THIGH) were significantly heavier in HYB hens. The same was true for the Gastrocnemius muscle (GASTROC). The relative weight of the abdominal fat pad (ABFAT) was significantly increased in NIC hens compared with HYB hens from 70 to 145 d.There was a linear relationship between the relative weight of the PMAJ and BW in hens from both strains (NIC, r2 = .69; HYB, r2 = .51). The relationship between the relative weight of the PMIN and BW was best described with a quadratic model but the r2 in both strains was considerably lower than that for the PMAJ (NIC, r2 = .26; HYB, r2 = .36). The linear relationship between BW and the relative weights of the THIGH and DRUM was negative and positive for ABFAT.

A survey of asynchronous finite-difference methods for parabolic PDEs on multiprocessors

A major obstacle to achieving significant speed-up on parallel machines is the overhead associated with synchronizing the concurrent processes. Removing the synchronization constraint has the potential of speeding up the computation. Recently developed asynchronous finite-difference schemes for parabolic PDEs designed for parallel computation are surveyed. Specifically, we consider the asynchronous (AS), corrected asynchronous (CA), time stabilizing (TS), parametric (PAR), and hybrid (HYB) schemes. The AS scheme is applicable only to steady-state problems. AS, CA, and TS provide first-order spatial approximations. TS, however, minimizes the first-order errors by maintaining the time stabilizing property which also enables it to be implemented on parallel machines in which some processors have persistent speed differences. The PAR algorithm gives a second-order approximation that is inefficient. The HYB algorithms are high-order schemes which have the potential to be applicable also to nonlinear problems.

Bistable optical device realization with thin Cds films

A thin (6 μm) CdS film thermally laser induced optical device (LIOD) was realized at 210 K using the 514.5 nm argon laser line. It is demonstrated for the first time that the observation of equally contrasted all optical (all-OB) and hybrid (HB) bistable loops is possible in thin CdS films. Furthermore, it is pointed out that the photocurrent dependence on temperature is different in sprayed and evaporated CdS films resulting in opposite HB loop fashions: clockwise for the sprayed and anti-clockwise for the evaporated thin films.

The Fueling of Active Galaxies

Collisions of galaxies are often invoked to explain vio lent phenomena in the universe. The dynamics of in teracting galaxies is intrinsically three-dimensional and involves both gas and stellar dynamics. In general, a computational approach is needed to model galactic collisions. Galaxy encounters are studied using a hy brid N-body/hydrodynamics code, capable of integrat ing systems of stars, gas, and dark matter in a fully self-consistent manner. These experiments demon strate that gravitational coupling between gas and stars in galactic interactions can drive most of the gas throughout a galaxy into the nucleus of a merger rem nant. The high densities in these gas concentrations are likely to result in strong bursts of star formation. Hence, this process may explain the nuclear starbursts in some systems of interacting galaxies. Further col lapse of these gas concentrations can trigger even more intense activity if some gas is eventually ac creted by a supermassive black hole. Such an evolu tionary sequence may account for some quasars and active galactic nuclei.