Isolation and characterization of a novel 5-oxoprolinase (without ATP-hydrolyzing) from Alcaligenes faecalis N-38A

A screening test was undertaken to isolate a microorganism that produced 5-oxoprolinase (without ATP-hydrolyzing). The 5-oxoprolinase (without ATP-hydrolyzing) activity (decyclization activity toward L-pyroglutamate) was found in a cell-free extract of Alcaligenes faecalis N-38A, newly isolated from a soil sample. The enzyme was purified as a homogeneous preparation. The molecular weight of the enzyme was estimated to be 47,000. The decyclization activity was specific for L-pyroglutamate, and independent of ATP and metal ions. The reaction was a reversible one, i.e., cyclization reaction of L-glutamate to yield pyroglutamate was identified.     

Repeatedly foldable AMOLED display

In this study, a 5.9‐inch foldable active‐matrix organic light emitting diode (AMOLED) display was developed. A folding test was performed repeatedly. The display survived the folding test (100,000 folds) with a curvature radius of 2 mm. To protect an organic light emitting diode (OLED) against moisture, inorganic passivation layers are provided on the upper and lower sides of the flexible display. Using our transfer technology, high density passivation layers can be obtained. The measured water vapor transmission rate of the layer is 7 × 10^?6 g/m²?day or less, which improves OLED reliability. With these techniques, we have developed a book‐type display, which is repeatedly foldable like a book, and a tri‐fold display including a display area, which is foldable in three.     

Performance Comparison of Circuits for Pole‐Mounted STATCOM Using SiC Devices

The recent years have seen an increasing trend in the cumulative installed capacity of distributed generators. As a result, voltage management may become difficult in existing power distribution systems in the future. A STATCOM (STAtic synchronous COMpensator) is a promising option for solving this problem because it can control reactive power rapidly and continuously. For a distribution system, STATCOM needs to be pole‐mounted to realize its low cost. However, a transformer for a STATCOM is large and heavy, and hence it is difficult to install a STATCOM on a distribution pole. We adopt a transformerless STATCOM to reduce STATCOM size and use SiC devices with low‐loss performance to obtain a more compact and efficient STATCOM. There are a large number of circuits available for a STATCOM, and there has been considerable research on performance comparisons among these circuits. However, these comparisons were drawn under different conditions, including switching frequency and level number for the circuits. In addition, these comparisons do not include the use of SiC devices. We made an equitable comparison for a 100 kVa pole‐mounted STATCOM using SiC devices. We discuss the performance and characteristics of each circuit in terms of efficiency and volume.     

Switched capacitor circuit for 1/f noise generation using a power-law circuit

A simple switched capacitor (SC) circuit is given which realizes a one-dimensional discrete dynamical system X_n+1 = X_n + ux^z generating intermittent chaos with a 1/f-shaped power spectrum. an integrated circuit with a pair of logarithmic and antilogarithmic amplifiters can easily realize the power-law term x^z which plays a key role in generating l/fnoise. an inevitable small offset voltage ? in the SC circuit governs the cut-off frequency of 1/f noise, and when the dynamical system is modified by introducing an effective ?, the ‘indirect method’ enables us to get the precise power spectrum in the modified system.     

Observation of iron silicide formation by plan-view transmission electron microscopy

The formation and the phase transitions of iron silicide by solid-phase epitaxy have been investigated by means of plan-view transmission electron microscopy, which enables us to observe a clean interface between Fe and Si. Layers of Fe were deposited on Si (100) at room temperature in an ultrahigh vacuum chamber. The sample was annealed in the electron microscope at a temperature between 673 and 1073 K. After annealing at 673 K, FeSi crystallites were formed with various orientations. When the annealing temperature was increased to 973 K, we found that the crystallites suddenly started to coalesce into grains of several hundreds of nanometers in size and polycrystalline beta-FeSi2 was formed. These phase transitions were also confirmed with electron energy-loss spectroscopy.     

Prolongation of ventricular action potential due to sympathetic stimulation

The changes of monophasic action potential durations due to stellate stimulation for the period of 3 sec were studied in dogs with suction electrodes from the anterior surface of the right ventricle and the posterior surface of the left ventricle. Prolongation of monophasic action potential duration was observed from the period of 2 to 3 sec during stimulation to that of 10 to 20 sec after the termination of stimulation. Prolongation of monophasic action potential duration due to right stellate stimulation was predominant in the right ventricle and that due to left stellate stimulation was predominant in the left ventricle. The transient T wave change in the surface electrocardiogram occurring immediately after the beginning of stellate stimulation could be explained by this local difference in prolongation of ventricle repolarization. Since the onset of prolongation of monophasic action potential duration preceded increase in blood pressure following stellate stimulation, this prolongation of monophasic action potential duration did not result from the hemodynamic changes and could be a primary effect of the sympathetic nerve stimulation.     

Investigation of gas-liquid interface in atmospheric-pressure micro plasma with solution

An atmospheric-pressure glow-discharge micro plasma in contact with liquid paraffin is stably generated by using a capacitively coupled plasma method with a mesh electrode. When characteristics of the plasma are measured in the boundary between the micro plasma (gas-phase) and liquid paraffin (liquid-phase) using optical emission spectroscopy, spectrum peaks of the emission of CH and C₂ which dissociate from paraffin are observed. The result indicates that solution can feed particles to the plasma at gas-liquid interface and this plasma is accordingly expected to promote an attractive plasma process for creating materials consisting of elements in various solutions.     

A reinforcement learning with switching controllers for a continuous action space

Reinforcement learning (RL) attracts much attention as a technique for realizing computational intelligence such as adaptive and autonomous decentralized systems. In general, however, it is not easy to put RL to practical use. This difficulty includes the problem of designing a suitable action space for an agent, i.e., satisfying two requirements in trade-off: (i) to keep the characteristics (or structure) of an original search space as much as possible in order to seek strategies that lie close to the optimal, and (ii) to reduce the search space as much as possible in order to expedite the learning process. In order to design a suitable action space adaptively, in this article, we propose a RL model with switching controllers based on Q-learning and an actor-critic to mimic the process of an infant’s motor development in which gross motor skills develop before fine motor skills. Then a method for switching controllers is constructed by introducing and referring to the “entropy.” Further, through computational experiments by using a path-planning problem with continuous action space, the validity and potential of the proposed method have been confirmed.