Regular network polyesters from benzenepolycarboxylic acids and glycol

Regular network polyesters were prepared from trimesic (Y), pyromellitic (X) or mellitic (Y_H) acids and 1,6-hexanediol (6G). Prepolymers prepared by melt-polycondensation were cast from dimethylformamide solution and post-polymerized at 260°C for various times to form a network. The resultant films were transparent, flexible and insoluble in organic solvents. Degrees of reaction estimated from the infra-red absorbance of ester and methylene groups were 95, 95 and 96% for 6GY, 6GX and 6GY_H post-polymerized for 12 h, respectively. X-ray diffraction intensity curves showed the formation of some ordered structure owing to the regular networks, and the degrees of ordering were 6GY> 6GX> 6GY_H. Densities were 1.227, 1.290 and 1.289 g cm⁻³ and heat distortion temperatures measured by thermomechanical analysis were 75, 72 and 75°C for 6GY, 6GX and 6GY_H post-polymerized for 12 h, respectively. Tensile strengths were in the order 6GY> 6GX> 6GY_H and Young's moduli were 6GY_H = 6GX> 6GY. Dye absorptions were 6GX> 6GY> 6GY_H, and water absorptions and weight losses in alkali solution were 6GY_H > 6GX> 6GY. These effects of the number of functional groups on the benzene ring on the structure and properties were discussed, and compared with those of previously reported network polymers.     

Effects of oral administration of soybean lecithin transphosphatidylated phosphatidylserine on impaired learning of passive avoidance in mice

Soybean lecithin transphosphatidylated phosphatidylserine (SB-tPS) was investigated for its effect on the impaired learning of a passive avoidance task by mice induced by scopolamine or cycloheximide. SB-tPS (240, 360, 480 mg/kg) administered orally significantly prolonged the step-through latency shortened by scopolamine. SB-tPS (240 mg/kg) administered orally also prolonged the step-through latency shortened by cycloheximide. These results suggest that the effect of SB-tPS on the impaired learning behavior may be related not only to the cholinergic system but also the serotonergic system.     

A study on the role of ultrasonography in antenatal care in Thailand with focus on the appropriate technology

The authors investigated the state of antenatal care, outcome of deliveries and use of ultrasonography at the Maternal and Childhood Health Hospital in Khonkane province, Thailand. The study was conducted before (stage I) and after (stage II) the introduction of the second ultrasonographic equipment in an attempt to set up a proper standard of technological level of clinical laboratory services and to investigate the usefulness of introducing ultrasonography into the prenatal care in developing countries. As a result, about 60% of first antenatal visits were in their second or third trimester, about 80% of pregnancies terminated by normal vaginal deliveries, parity, rate of cesareans sections and pre-term labors were not significantly different in both stages. Ultrasonography was performed on 16% of the first antenatal visits in stage I, while, in stage II, it was performed on 31.3% of them. Ultrasonography was used most frequently to determine the gestational age and presentation of the fetus in both years (70.3% and 79.1% respectively in stage I and stage II). In most of the cases, ultrasonography was performed only once during the gestation. Thus, it was proved that technical training must be provided with introduction of new equipment to medical facilities and utilization of medical technologists for ultrasonography was another concern in developing countries. Beside, it was important to determine the proper period during the gestation when ultrasonography should be applied and to adopt an effective public health service including health education and health insurance to promote antenatal visits in time during the proper periods.     

High-efficiency drive due to power factor control of a permanentmagnet synchronous motor

A drive system of a permanent magnet motor without a magnetic position detector is described. Generally, the position data of a magnet is obtained from the terminal voltage of the motor. In the newly developed method, the inverter DC-link current waveform provides the control signal for driving a permanent magnet motor without a detector. Since the power factor of the motor is controlled around 1.0, the motor runs at a higher efficiency than one controlled by the conventional method. Therefore, this control method saves energy. Current pulsation induced by sudden load fluctuations has been studied and its stabilization has been achieved. This paper provides the principle and operation of the new control method, simulated characteristics, and experimental results     

Variations in anatomy and ultraviolet microspectrometry between normal and brown midrib mutant maizes possessing different rumen degradabilities

Normal and brown midrib mutant (bmr) maize (Zea mays L) were examined for variations in their morphological composition. The degradability of the leaf blade, leaf sheath and stem, proportional area of specific tissues in leaf blade, and the ultraviolet (UV) absorption spectra of cell walls were measured and related to variations in cell wall degradability by rumen microorganisms. The UV and infrared (IR) absorption spectra of the lignins isolated from leaf blades of both types, before and after reduction with sodium borohydride, were recorded. The bmr3 maize had higher dry matter (DM) and neutral detergent fibre (NDF) degradabilities for leaf blade, leaf sheath, and stem than the normal counterpart. Approximately 35% and 26% of the observed difference in DM degradability was attributed to the difference in DM degradability of stem and leaf blade, respectively, and 39% to the difference in DM composition of stem. Distinct differences in tissue degradation of the leaf blades were observed for mesophyll cell walls in the midrib portion, which were thinner and of greater number in the bmr3 maize. Sclerenchyma cells were present only in the vascular bundles in the bmr3 leaf blade, while in the normal type those cells were underneath the epidermis tissue. The bmr3 plant also had large epidermal cells. UV microspectrometry of mesophyll cell walls of the bmr3 maize showed their lower UV absorbance around 320 nm compared to that of the normal, but not at 280 nm. Considerable increase in the UV absorbance at 280 nm was observed for the isolated lignins after reduction, suggesting a lesser degree of lignification in the bmr3 maize tissues. Lowered UV absorbance of the isolated lignin around 320 nm after reduction was associated with the removal of the IR bands at 1730, 1660, 1600, and 1250 cm^?1.     

Flow dynamics in Taylor–Couette flow reactor with axial distribution of temperature

In this study, the flow dynamics of a Taylor–Couette flow with an axial distribution of temperature was experimentally investigated. The flow can be classified into three patterns based on the balance between the centrifugal force and the buoyancy. If the buoyancy is dominant, global heat convection is observed instead of Taylor vortices (Case I). When the buoyancy is comparable to the centrifugal force, the Taylor vortices and global heat convection appear alternately (Case II). If the centrifugal force is sufficiently high to suppress the buoyancy, stable Taylor vortices are observed (Case III). The characteristics of the mixing/diffusion are investigated by conducting a decolorization experiment on a passive tracer. In Case II, the tracer is rapidly decolorized in the presence of the global heat convection instead of the Taylor vortices. This result implies that the interaction between the centrifugal force and the buoyancy would induce an anomalous transport. © 2017 American Institute of Chemical Engineers AIChE J, 64: 1075–1082, 2018     

Pressure effect on anomalous suppression ofT c around x=1/8 in La2−xBaxCuO4 and La1.8−xx Nd0.2BaxCuO4

In La_2–xBa_xCuO₄ (LBCO) and La_1.8–xNd_0.2Ba_xCuO₄ (LNBCO), the low-temperature structural change at T₁ (=60–110K), resulting from tilt of the CuO₆ octahedra, is easily suppressed at high pressures. However, the structural change of LNBCO (x=0.125) remains up to 2GPa though it jumps from T₁(110K) to T* (60K), where the electric resistivity begins to upturn, at 0-1.5GPa. The upturn of is also suppressed at high pressures, and the superconducting critical temperature T_c is fully restored except in a very narrow x-range around x=0.125. The T_c for x 0.125 is appreciably lower at 2GPa than those for other Ba-contents.     

Correction to: Semi-automation of gesture annotation by machine learning and human collaboration

Language Resources and Evaluation -     

Performance Maintenance of Dye-Sensitized Solar Cells Using a Latent Heat Storage Material

Recently, there has been considerable interest in various renewable energies. Among them, solar cell production has increased markedly because the photovoltaic is a clean and safe power generation method. The dye-sensitized solar cell (DSSC) has attracted much attention as an alternative to silicon solar cells due to lower manufacturing costs and plentiful resources for DSSC production. However, the performance of DSSCs has been limited by their durability and low photoelectric conversion efficiency. Temperature control of DSSCs via phase-change materials (PCMs) is expected to improve performance. In this study, DSSCs were heated or cooled with a heat exchanger copper block that was in contact with a PCM (heptadecane), while being irradiated by a solar simulator light source. The durability and photoelectric conversion efficiency of the DSSC improved under PCM temperature control.     

Symbol emergence in robotics: a survey

Humans can learn a language through physical interaction with their environment and semiotic communication with other people. It is very important to obtain a computational understanding of how humans can form symbol systems and obtain semiotic skills through their autonomous mental development. Recently, many studies have been conducted regarding the construction of robotic systems and machine learning methods that can learn a language through embodied multimodal interaction with their environment and other systems. Understanding human?-social interactions and developing a robot that can smoothly communicate with human users in the long term require an understanding of the dynamics of symbol systems. The embodied cognition and social interaction of participants gradually alter a symbol system in a constructive manner. In this paper, we introduce a field of research called symbol emergence in robotics (SER). SER represents a constructive approach towards a symbol emergence system. The symbol emergence system is socially self-organized through both semiotic communications and physical interactions with autonomous cognitive developmental agents, i.e. humans and developmental robots. In this paper, specifically, we describe some state-of-art research topics concerning SER, such as multimodal categorization, word discovery, and double articulation analysis. They enable robots to discover words and their embodied meanings from raw sensory-motor information, including visual information, haptic information, auditory information, and acoustic speech signals, in a totally unsupervised manner. Finally, we suggest future directions for research in SER.