Tunable Magnetism in Nanoporous CuNi Alloys by Reversible Voltage‐Driven Element‐Selective Redox Processes

Voltage‐driven manipulation of magnetism in electrodeposited 200 nm thick nanoporous single‐phase solid solution Cu₂₀Ni₈₀ (at%) alloy films (with sub 10 nm pore size) is accomplished by controlled reduction‐oxidation (i.e., redox) processes in a protic solvent, namely 1 m NaOH aqueous solution. Owing to the selectivity of the electrochemical processes, the oxidation of the CuNi film mainly occurs on the Cu counterpart of the solid solution, resulting in a Ni‐enriched alloy. As a consequence, the magnetic moment at saturation significantly increases (up to 33% enhancement with respect to the as‐prepared sample), while only slight changes in coercivity are observed. Conversely, the reduction process brings Cu back to its metallic state and, remarkably, it becomes alloyed to Ni again. The reported phenomenon is fully reversible, thus allowing for the precise adjustment of the magnetic properties of this system through the sign and amplitude of the applied voltage.     

Leistungsfähige Spiegel für solarthermische Kraftwerke

High efficient mirrors for Concentrating Solar Power plants Mirrors are an essential component of CSP plants. Wet chemically coated silver mirrors supplied by Flabeg GmbH achieve an average specular and solar weighted reflectivity of 94.4%. Almost 30 years of field experience prove the durability of the coating. First surface mirrors could provide higher reflectivity, but so far either the necessary durability is not met or the costs are not competitive. Another approach to increase reflectivity is to equip the mirror with an antisoiling coating. This type of mirror is currently under field testing, showing already promising results. New paint systems for silvered mirrors will expand the locations for power plants to the shore or into tropical regions.     

Non-hydrolytic sol–gel route to a family of hybrid mesoporous aluminosilicate ethanol dehydration catalysts

Journal of Materials Science - Hybrid materials are intensely studied for potential applications in heterogeneous catalysis. Organic groups at the catalyst surface can modify not only its...     

Design space exploration of gyrocopter‐type airborne wind turbines

This paper presents a multidisciplinary framework for the design and analysis of gyrocopter‐type airborne wind turbines. In this concept, four rotary wings provide lift to a flying vehicle, and excess power is extracted using gearboxes and generators before being transferred to the ground through electrical conductors embedded in a structural tether. A physical breakdown of the system was performed, and five models were constructed: wind model, rotor aerodynamics, structural mass, electrical system, and tether (structures and aerodynamics). A stochastic optimizer in the framework enforces interdisciplinary compatibility and maximizes electrical power transmitted to the ground under various operating conditions. The framework is then used to explore the design space of this advanced concept in numerous flight conditions. The effect of implementing new technologies was also studied in order to evaluate their effect on the overall performance of the system. It is shown through a 1.3MW design that a gyrocopter‐type airborne generator could provide more power than a ground‐based wind turbine for a given blade radius, although only a fraction of the available wind power can be harvested using off‐the‐shelf technologies and components. The work presented in this study demonstrates the challenges of designing a high altitude wind generator and shows that performance is affected by complex interactions between each subsystem. Copyright © 2015 John Wiley & Sons, Ltd.     

Low thermal inactivation of Escherichia coli ATCC 25922 in pineapple,orange and watermelon juices: Effect of a prior acid‐adaptation and of carvacrol supplementation

Past research on the association of natural antimicrobials and low temperatures for fruit juices pasteurization has not targeted acid‐adapted strains which are yet the most relevant strains in these products. We found that previously acid‐adapted Escherichia coli ATCC 25922 cells exhibited an increase of their resistance to thermal inactivation at 55 °C for 5 min both in the presence and absence of carvacrol (30 µL/L). The inactivation of E. coli was more intense in pineapple (pH 3.25) and orange (pH 3.61) juice, than in watermelon juice (pH 5.4). Supplementation of juices with carvacrol decreased the survival of both acid‐adapted and non‐adapted bacterial cells. Our results suggest that the supplementation of fruit juices with natural antimicrobials, such as carvacrol, may contribute to counteract the mild thermal tolerance developed by acid‐adapted bacteria. Given the different properties of fruit juices, such combined treatments need to be developed specifically for each fruit product.

Practical applications

Supplementation of fruit juices with natural antimicrobials has been described to increase the efficiency of microbial mild thermal inactivation treatments. However, its effect on the thermal resistance of acid‐adapted cells has not previously been addressed. We observed that acid adaptation enhances mild thermal tolerance. Our results suggest that natural antimicrobials can effectively counteract the mild thermal tolerance of acid‐adapted cells. The combination of mild temperature treatments and natural antimicrobials is a firm alternative to conventional pasteurization to ensure the safety of fruit juices without affecting their nutritional properties. Moreover, this combined strategy does not require expensive novel technologies or high energy consumption.     

基于贝叶斯信息准则的非侵入式负荷事件检测算法

用户负荷数据监测是实现需求侧管理的基础,非侵入式负荷监测技术是负荷监测的重要发展方向,而事件检测是非侵入式负荷监测中的一个关键环节。对适用于模型选取问题的贝叶斯信息准则进行建模,将贝叶斯信息准则首次运用到事件检测当中,利用快速事件检测算法降低贝叶斯信息准则检测算法的误检率,并能解决CUSUM算法中产生的漏检问题。最后采用真实数据集进行测试。实验结果表明,相比于CUSUM算法,基于贝叶斯信息准则的事件检测算法能达到更好的检测准确性,并且能明显提高计算运行的速度。     

Simulation of a helicopter’s main gearbox semiactive suspension with bond graphs

This paper presents a bond graph model of a helicopter’s semiactive suspension and the associated simulations. The structural and modular approach proposed with bond graph permits a systematic modeling of mechatronic multibody systems. This approach was carried out thanks to the use of the singular perturbation method, which is a variant of penalty formulation. The model is then built as an assembly of components or modules (rigid bodies and compliant kinematic joints) by following the structure of the actual system.The bond graph model of the passive suspension with fixed flapping masses has been verified with another multibody tool for three different excitations (pumping, roll, and yaw). Next, the passive model, augmented with electrical actuators and controllers, is called the semiactive suspension model. Simulations on the semiactive suspension model have been conducted.     

Extraction Properties of 6,6′‐Bis‐(5,6‐dipentyl‐[1,2,4]triazin‐3‐yl)‐[2,2′]bipyridinyl (C5‐BTBP)

Abstract

The extraction of americium(III) and europium(III) into a variety of organic diluents by 6,6′‐bis‐(5,6,‐dipentyl‐[1,2,4]triazin‐3‐yl)‐[2,2′]bipyridinyl (C5‐BTBP) has been investigated. In addition to determining the stoichiometry for the extraction, the dependence of extraction on contact time and temperature was also studied. The resistance of the ligand to gamma irradiation and the possibility to recycle the organic phase after stripping were tested to determine how the molecule would perform in a radiochemical process. Different organic diluents gave different extraction results, ranging from no extraction to distribution ratios of over 1000 for americium(III). In 1,1,2,2‐tetrachloroethane, the extraction and separation of americium from europium and the extraction kinetics were good; a separation factor above 60 was obtained at equilibrium, ～5 min contact time. The extraction capabilities are adequate for C5‐BTBP to be used in a process for separating trivalent actinides from lanthanides. However, C5‐BTBP is susceptible to radiolysis (americium extraction decreases ～80% after a dose of 17 kGy) and may not be the best choice in the processing of spent nuclear fuel. Nonetheless it is a useful starting point for further development of this type of molecule. It could also prove useful for analytical scale separations for which radiolytic instability is less important.