Bend,Twist, and Turn: First Bendable and Malleable Toughened PLA Green Composites

The future of green electronics possessing great strength and toughness proves to be a promising area of research in this technologically advanced society. This work develops the first fully bendable and malleable toughened polylactic acid (PLA) green composite by incorporating a multifunctional polyhydroxybutyrate rubber copolymer filler that acts as an effective nucleating agent to accelerate PLA crystallization and performs as a dynamic plasticizer to generate massive polymer chain movement. The resultant biocomposite exhibits a 24‐fold and 15‐fold increment in both elongation and toughness, respectively, while retaining its elastic modulus at >3 GPa. Mechanism studies show the toughening effect is due to an amalgamation of massive shear yielding, crazing, and nanocavitation in the highly dense PLA matrix. Uniquely distinguished from the typical flexible polymer that stretches and recovers, this biocomposite is the first report of PLA that can be “bend, twist, turn, and fold” at room temperature and exhibit excellent mechanical robustness even after a 180° bend, attributes to the highly interconnected polymer network of innumerable nanocavitation complemented with an extensively unified fibrillar bridge. This unique trait certainly opens up a new horizon to future sustainable green electronics development.     

A genetic algorithm for dynamic inbound ordering and outbound dispatching problem with delivery time windows

This article considers an inbound ordering and outbound dispatching problem for a single product in a third-party warehouse, where the demands are dynamic over a discrete and finite time horizon, and moreover, each demand has a time window in which it must be satisfied. Replenishing orders are shipped in containers and the freight cost is proportional to the number of containers used. The problem is classified into two cases, i.e. non-split demand case and split demand case, and a mathematical model for each case is presented. An in-depth analysis of the models shows that they are very complicated and difficult to find optimal solutions as the problem size becomes large. Therefore, genetic algorithm (GA) based heuristic approaches are designed to solve the problems in a reasonable time. To validate and evaluate the algorithms, finally, some computational experiments are conducted.     

Ozonated Mineral Oil: Preparation,Characterization and Evaluation of the Microbicidal Activity

The ozonation of vegetable oils has been studied, since the produced ointments have antibacterial and fungicidal activities. However, the ozonation of mineral oils has not been reported in the literature yet, opening an interesting field for examination. In this work, we have shown the ozonation of a commercial mineral oil (Nujol). The main goal was to produce oils containing free ozone, so that this gas could act as antimicrobial agent. It was found that in Nujol, ozone remains for at least 40 days and in the sample ozonized for 15 h its concentration was 7.5 mg mL^?1. Neat Nujol showed no antimicrobial activity against the tested microorganisms, however, when ozonated it showed antimicrobial activity against Enterococcus faecalis, Staphylococcus aureus and Escherichia coli.     

10 kV手车柜接地开关电气闭锁故障处理与改造

针对10 kV手车柜接地开关电气闭锁电磁铁线圈烧毁问题,结合KYN28A-12(Z)型高压金属封闭式真空开关柜结构特点对故障现象进行了分析,确定故障原因有线圈长时间带电运行造成绝缘老化;运行环境潮湿导致线圈内部短路;带电显示器输出继电器接点断开时产生的感应电动势烧坏线圈.从提高闭锁电磁铁线圈运行稳定性方面考虑,采取了在接地开关电气闭锁启动电路中串联阻容电路以及加装除潮装置的改造方案.改造方案实施后,闭锁电磁铁线圈发热量减少,线圈绝缘受潮情况减轻,而串联的阻容电路吸收了线圈断电时产生的感应电动势,闭锁电磁铁线圈再未发生烧毁故障,确保了设备安全可靠运行.     

Mild functionalization of carbon nanotubes filled epoxy composites: Effect on electromagnetic interferences shielding effectiveness

The effect of nitric acid mild functionalized multiwalled carbon nanotubes (MWCNTs) on electromagnetic interference (EMI) shielding effectiveness (SE) of epoxy composites was examined. MWCNTs were oxidized by concentrated nitric acid under reflux conditions, with different reaction times. The dispersion of MWCNTs after functionalization was improved due to the presence of oxygen functional groups on the nanotubes surface. Functionalization at 2 h exhibits the highest EMI SE and electrical conductivity of MWCNTs filled epoxy composites. However, EMI shielding performance of MWCNTs filled epoxy composite declined when the functionalization reaction time was prolonged. This was due to extensive damage on the MWCNT structure, as verified by a Raman spectroscope. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42557.     

A particle method for two‐phase flows with large density difference

A new numerical approach for solving incompressible two‐phase flows is presented in the framework of the recently developed Consistent Particle Method (CPM). In the context of the Lagrangian particle formulation, the CPM computes spatial derivatives based on the generalized finite difference scheme and produces good results for single‐phase flow problems. Nevertheless, for two‐phase flows, the method cannot be directly applied near the fluid interface because of the abrupt discontinuity of fluid density resulting in large change in pressure gradient. This problem is resolved by dealing with the pressure gradient normalized by density, leading to a two‐phase CPM of which the original singlephase CPM is a special case. In addition, a new adaptive particle selection scheme is proposed to overcome the problem of ill‐conditioned coefficient matrix of pressure Poisson equation when particles are sparse and non‐uniformly spaced. Numerical examples of Rayleigh–Taylor instability, gravity current flow, water‐air sloshing and dam break are presented to demonstrate the accuracy of the proposed method in wave profile and pressure solution. Copyright © 2015 John Wiley & Sons, Ltd.     

Arm length dependency of Pt-decorated CdSe tetrapods on the performance of photocatalytic hydrogen generation

Pt-decorated CdSe tetrapods with different arm lengths were tested for the photocatalytic hydrogen generation reaction. Well-defined CdSe tetrapods with controlled wurtzite arm lengths were synthesized by the continuous precursor injection (CPI) approach. Pt nanocrystals with an extremely small size of ～1 nm were directly decorated on the overall surfaces of CdSe tetrapods. Ligand-exchanged Pt-decorated CdSe tetrapods with different arm lengths were employed as photocatalysts for photocatalytic hydrogen generation reaction in the presence of hole scavengers. Pt-decorated CdSe tetrapods with shorter arm length showed the highest photocatalytic efficiency, which is due to higher probability of charge separation.     

A qualitative exploration of arts-based neighbourhood revitalization: The case of ‘The Space at 2106 Main’ in West Tampa,Florida

As cities are compelled to compete for new sources of investment and revenue, arts-based economic development strategies have become the norm. The purpose of this paper is to revisit and reevaluate some of the conventional claims about the arts as an important economic development strategy by exploring a case study called “The Space at 2106 Main” in a rapidly gentrifying neighbourhood called West Tampa. The results of this study suggest that the arts are indeed assuming a greater role in economic policy under the auspices of West Tampa community redevelopment areas (CRA) and the direct actions of various arts related entrepreneurs. The results however, point to a mixed picture that raises difficult questions about the medium to long-term effects of this urban redevelopment strategy, especially on the poor and mostly minority residents of West Tampa.