Underlying Mechanism of Inkjet Printing of Uniform Organic Semiconductor Films Through Antisolvent Crystallization

An underlying mechanism is reported for the formation of highly uniform crystalline organic semiconductor films by the double‐shot inkjet printing (IJP) technique utilizing antisolvent crystallization. It is demonstrated that the ability to form uniform films with this technique can be attributed to the unique nature of the initial contact dynamics between the chemically different microdroplets before occurrence of solute crystallization. Experiments are conducted systematically where a single microdroplet is over‐deposited by the IJP technique on a chemically different sessile droplet, for ten kinds of pure and miscible solvent combinations. The subsequent behavior is observed by high speed camera. The initial contact dynamics can be classified into three dramatically different cases that are respectively referred to as wetting, dewetting, and sinking. These phenomena are unique to microdroplets and the conditions for the occurrence of each type of phenomenon can be consistently explained by the fact that the initial contact dynamics are driven by the difference of surface tension of the liquids. Among the three kinds of dynamics, the wetting phenomenon creates a thin solution layer on the antisolvent droplet surface and can be used thus to manufacture uniform semiconductor films, where the coffee ring effect can be eliminated.     

Immune algorithm combined with estimation of distribution for traveling salesman problem

This paper describes an artificial immune algorithm (IA) combined with estimation of distribution algorithm (EDA), named IA‐EDA, for the traveling salesman problem (TSP). Two components are incorporated in IA‐EDA to further improve the performance of the conventional IA. First, aiming to strengthen the information exchange during different solutions, two kinds of EDAs involving univariate marginal distribution algorithm and population‐based incremental learning are altered based on the permutation representation of TSP. It is expected that new promising candidate solutions can be sampled from the constructed probabilistic model of EDA. Second, a heuristic refinement local search operator is proposed to repair the infeasible solutions sampled by EDA. Therefore, IA‐EDA can alleviate the deficiencies of the conventional IA and can find better solutions for TSP by well balancing the exploitation and exploration of the search. Experiments are conducted based on a number of benchmark instances with size up to 100 000 cities. Simulation results show that IA‐EDA is effective for improving the performance of the conventional IA and can produce better or competitive solutions than other hybrid algorithms. © 2016 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

Performance of a laser disdrometer with hydrometeor imaging capabilities and fall velocity estimates for snowfall

A low‐cost laser disdrometer (LLD), which is a type of high‐speed line‐image scanner, has been developed and calibrated for raindrops. The disdrometer measures hydrometeor's particle‐size distribution (PSD) and fall velocities, as well as record hydrometeor images. Hydrometeor imaging is advantageous for hydrometeor classification. All hydrometeor types, raindrops, graupels, snowflakes, and ice crystals, can mix with snowfall. Snowfall sensing requires a wide sensing light sheet to capture large‐sized snowflakes. Accordingly, a new LLD equipped with a 35‐mm sensing light sheet has been developed. This paper demonstrates and evaluates the new drisdrometer's snowfall‐evaluation performance. The wide sensing light sheet captures images of large‐sized (14 mm) snowflakes reasonably well, and the PSD and the fall velocities correlate with those measured with the commercially available Parsivel laser disdrometer. © 2016 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

Design of Phosphonium-Type Zwitterion as an Additive to Improve Saturated Water Content of Phase-Separated Ionic Liquid from Aqueous Phase toward Reversible Extraction of Proteins

We designed phosphonium-type zwitterion (ZI) to control the saturated water content of separated ionic liquid (IL) phase in the hydrophobic IL/water biphasic systems. The saturated water content of separated IL phase, 1-butyl-3-methyimidazolium bis(trifluoromethanesulfonyl)imide, was considerably improved from 0.4 wt% to 62.8 wt% by adding N,N,N-tripentyl-4-sulfonyl-1-butanephosphonium-type ZI (P₅₅₅C4S). In addition, the maximum water content decreased from 62.8 wt% to 34.1 wt% by increasing KH₂PO₄/K₂HPO₄ salt content in upper aqueous phosphate buffer phase. Horse heart cytochrome c (cyt.c) was dissolved selectively in IL phase by improving the water content of IL phase, and spectroscopic analysis revealed that the dissolved cyt.c retained its higher ordered structure. Furthermore, cyt. c dissolved in IL phase was re-extracted again from IL phase to aqueous phase by increasing the concentration of inorganic salts of the buffer solution.     

Diosgenin attenuates inflammatory changes in the interaction between adipocytes and macrophages

Obese adipose tissues are characterized by the enhanced infiltration of macrophages. It is considered that the paracrine loop involving monocyte chemoattractant protein‐1, tumor necrosis factor‐α, and the free fatty acid between adipocytes and macrophages establishes a vicious cycle that aggravates inflammatory changes and insulin resistance in obese adipose tissues. Diosgenin, a saponin aglycon found in a variety of plants, has anti‐inflammatory properties. In the present study, we examined the effect of diosgenin on the inflammatory changes in the interaction between adipocytes and macrophages. A coculture of 3T3‐L1 adipocytes and RAW 264 macrophages markedly enhanced the production of tumor necrosis factor‐α, monocyte chemoattractant protein‐1, and nitric oxide compared with the sum of their single cultures; however, treatment with diosgenin inhibited the production of these proinflammatory mediators. Diosgenin also suppressed the inflammation in RAW 264 macrophages that was induced by the conditioned medium derived from 3T3‐L1 adipocytes. Furthermore, diosgenin inhibited the conditioned medium‐induced degradation of inhibitor κB and the phosphorylation of c‐jun N‐terminal kinase in macrophages. These results indicate that diosgenin exhibits anti‐inflammatory properties in the interaction of adipocytes and macrophages by inhibiting the inflammatory signals in macrophages. Diosgenin may be useful for ameliorating the inflammatory changes in obese adipose tissues.     

Simulations of Phase Slippage in an Aperture Array

To understand the origins of synchronous and asynchronous phase slippages observed in an array of apertures connecting two reservoirs of superfluid ⁴He, we have investigated the role of thermal fluctuations in the critical velocity and the possible effects of having an array rather than a single aperture through several model simulations. The results are compared with recent experiments carried out near the superfluid transition temperature with an array of apertures as well as those carried out at low temperatures with a single aperture.     

Insulation failure in telecommunication cables resulting from water condensation in aerial terminal closures and its prevention using a humidity-controlling polymer

Insulation failure in telecommunications cables after extended use in aerial terminal closures has been examined. Extensive cracking and sea salt deposition were observed on the polyethylene (PE) insulation of wires in a terminal closure recovered from the field after 27 years of service. The insulation failure mechanism appears to be the formation, by bulk water condensation with deposited sea salt dissolution on degraded PE insulation, of ionically conductive pathways among the PE insulation cracks. An experiment using wires with PE insulation that was deliberately cut to simulate cracking showed that controlling the humidity within the terminal closure is an efficient way to prevent insulation failure. A field experiment showed that placing a polymer that absorbs moisture when the humidity is high and releases it when the humidity is low in the closure effectively buffered changes in humidity, thus preventing water condensation. Another experiment using wires with deliberately cut insulation in a terminal closure with 100% RH and with the water-absorbent polymer placed inside showed that the resistance of the wires stayed at around 10⁸ Omega without fluctuation. Since the absorbent polymer continues to function for many years, this proposed prevention method is well suited for practical application     

Trajectory tracking control of mobile robot by time‐based spline approach

A mobile robot must move without unacceptable rapid motion. To address this issue, we propose a preview controller using the time‐based spline approach. With this approach, it is also important to plan an adequate trajectory. Here an approach to trajectory planning which has the trajectory determination strategy via a virtual manipulator is proposed. Numerical and experimental results are shown to confirm the proposed algorithm. © 2005 Wiley Periodicals, Inc. Electr Eng Jpn, 151(4): 65–71, 2005; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.10349     

Preliminary Report: Heat Pulse Propagation in Solid 4He up to 56 bar Between 40 and 500 mK

Heat pulse propagation in the solid ⁴He has been studied between 40 and 500 mK. Response to heat pulses are detected by a titanium film superconducting transition edge bolometer. Crossover behavior from second sound in normal solid above 500 mK to ballistic propagation below 200 mK is observed. Detailed study is made to search for possible modification of this propagation behavior by the appearance of supersolidity. It is found, that the ballistic phonon propagation velocity remains constant, within 0.3% scatter of data, below 100 mK at all pressures measured between 25 and 56 bar. The temporal evolution of the detected pulse shape has not revealed any anomaly below 200 mK.