Microstructure and Mechanical Properties of Warm-Sprayed Titanium Coating on Carbon Fiber-Reinforced Plastic

Polymer materials are increasingly dominating various engineering fields. Recently, polymer-based composite materials’ surface performances—in particular, surface in relative motion—have been improved markedly by thermal spray coating. Despite this recent progress, the deposition of high-strength materials—producing a coating thickness of the order of more than 500 μm—remains highly challenging. In the present work, a highly dense and thick titanium coating was successfully deposited onto the carbon fiber-reinforced plastic (CFRP) substrate using a newly developed high-pressure warm spray (WS) system. The coating properties, such as hardness (300 ± 20 HV) and adhesion strength (8.1 ± 0.5 MPa), were evaluated and correlated with the microstructures of the coating. In addition, a wipe-test and in situ particle velocity and temperature measurement were performed to validate the particle deposition behavior as a function of the nitrogen flow rate in the WS system. It was found that the microstructures, deposition efficiency, and mechanical properties of the coatings were highly sensitive to nitrogen flow rates. The coating porosity increased with increasing nitrogen flow rates; however, the highest density was observed for nitrogen flow rate of 1000 standard liters per minute (SLM) samples due to the high fraction of semi-molten particles in the spray stream.     

Catalyst-free growth of ZnO nanowires on various-oriented sapphire substrates by pulsed-laser deposition

Catalyst-free growth of one-dimensional zinc oxide (ZnO) nanowires is reported. ZnO nanowires were synthesized on ZnO buffer layers deposited on various-oriented sapphire substrates. Syntheses of ZnO buffer layers and nanowires were performed by ultraviolet pulsed-laser deposition. ZnO nanowire's number density was the lowest in the case of using m-cut sapphire substrates. ZnO nanowires grown on a-cut sapphire substrates had vertical alignment with distances of tens to hundreds of nanometers. On the other hand, ZnO nanowires grown on c-cut sapphire substrates had the biggest nucleation rate. The dependence of crystalline orientation of ZnO buffer layers on the orientation of sapphire substrates were investigated by electron back scatter diffraction measurement. From their results, the growth models of ZnO buffer layers were suggested and the variations in morphological properties of ZnO nanowires were discussed.     

A Multiagent‐Based Microgrid Operation Method

In this paper, we propose an autonomous microgrid operation using a multiagent approach. The proposed multiagent system consists of seven types of agent: a single microgrid controller agent (MGC), several load agents (LAGs), several gas‐turbine (gas‐engine) agents (GAGs), several photovoltaic generation agents (PVAGs), several wind‐turbine generation agents (WTAGs), several battery agents (BAGs), and a single grid agent (GridAG). In a microgrid, LAGs act as consumers or buyers, GAGs, PVAGs, and WTAGs act as producers or sellers, and BAGs act as prosumers or sellers/buyers. In order to verify the performance of the proposed system, it is applied to a simple model system with different electrical power prices. From the simulation results, it can be seen that the proposed multiagent system can perform microgrid operations efficiently.     

Decentralized navigation method for a robotic swarm with nonhomogeneous abilities

This paper addresses the navigation of a robotic swarm with nonhomogeneous abilities, including sensing range, maximum velocity, and acceleration. With this method, the robotic swarm moves in a two-dimensional plane, and each follower distributedly constructs and maintains local directed connection using only local information to achieve maintenance of global connectivity. We also ensure the swarm is stable when the leader moves at a constant velocity. Validity and effectiveness of the proposed control strategy are shown by theoretical analysis, experiments with real robots, and numerical simulations.     

Estimation of the biobased carbon content of polypropylene resin in composites on the basis of the carbon 14 concentration

The aim of this study was to estimate a procedure for the biobased carbon content of polypropylene (PP) resin isolated from composites containing additives or fillers on the basis of the carbon 14 concentration ratio, as measured by accelerated mass spectrometry (AMS). To reliably estimate the biobased carbon content of plastics, additives and fillers in the composites had to be removed because they often contain significant amounts of biobased carbon. To obtain specimens with purity suitable for estimation, an isolation procedure for PP from the composites was devised. The dissolution of the composites in 1,2,3,4‐tetrahydronaphthalene at 150°C, followed by immediate centrifugation of the hot solution, yielded PP as semicrystalline precipitates by allowing the hot solution to cool during centrifugation. The recovery of the resin through the scooping off of the precipitates was typically 90%. This simple procedure provided a suitable specimen for the estimation of biobased carbon content by AMS on the basis of ASTM D 6866. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2014 , 131, 39978.     

Civic Technology and Community Building: Interaction Effects Between Integrated Connectedness to a Storytelling Network (ICSN) and Internet and Mobile Uses on Civic Participation

This study draws on communication infrastructure theory (CIT) to examine the extent to which expressive uses of Internet and mobile devices moderate the relationship between integrated connectedness to a storytelling network (ICSN) and offline and online civic participation. Data collected through a Web survey of a U.S. national online panel (N = 1201) reveal that the relationships of ICSN with offline and online civic participation are conditioned by locality‐oriented expressive uses of Internet and mobile media. With these findings, this study discusses theoretical insights, policy implications, and practical applications.     

Identification of Chimeric αβγ Diterpene Synthases Possessing both Type II Terpene Cyclase and Prenyltransferase Activities

Two unusual diterpene synthases composed of three domains (α, β, and γ) were identified from fungal Penicillium species. They are the first enzymes found to possess both type II terpene cyclase (TC) and prenyltransferase (PT) activities. These enzymes were characterized by heterologous expression in Aspergillus oryzae and in vitro experiments with wild-type, mutated, and truncated enzymes. The results revealed that the α domain in the C-terminal region of these enzymes was responsible for the PT activity, whereas the βγ domains in the N-terminal region composed the type II TC, and formed copalyl diphosphate ( 2 ). Additionally, between the α and βγ domains, there is a characteristic linker region, in which minimal secondary structure is predicted. This linker does not exist in the characterized three-domain (αβγ) terpene synthases known as monofunctional type I or type II TCs, or bifunctional type I and type II TC enzymes. Therefore, both the catalytic activities and protein architecture substantially differentiate these new enzymes from the previously characterized terpene synthases.