The depletion of traditional energy resourcesas well as the desire to reduce high CO 2 emissions associated with their use has led to significant interest in developing sustainable and clean energy products, [1][2][3][4] such as electricity produced from wind-or solar-based technologies. Because of the intermittent availabilityof these resources the realization of their full potential will also require the development of new and advanced energy-storage and delivery systems. Supercapacitors, as a new class of energy storage devices, are now attracting intensive attention [2] because of their ability to store energy comparable to certain types of batteries, but with the advantage of delivering the stored energy much more rapidly than batteries.[3] This property makes supercapacitor ideal to augment traditional batteries in many different applications. However, to become primary devices for power supply, supercapacitors must be developed further to improve their abilities to deliver, simultaneously, high energy and power. [5] To realize this objective, nanostructured electrodes have been developed from a variety of different functional materials.[6-10] Despite significant progress, however, most of the processes for the fabrication of electrodes are either too delicate, [11][12][13][14] which makes them less viable for large-scale industrial applications, or require additives, [15,16] which deteriorates the performance of the electrodes. In addition, previously reported electrode materials with the desirable specific capacitance typically show high resistances, [9,13,17] which not only restrict the power performance but also prevent the utilization of thick electrodes. Based on these considerations, the goal of the present work was to build an advanced supercapacitor electrode using a simple and scalable fabrication technique and to optimize the electrode performance using a controlled functional material and a well-defined electrode network with minimum resistivity. First, Ni nanoparticles were synthesized using a modified polyol process.[18] After a simple mechanical compaction of the as-prepared (AP) nanoparticles and a subsequent lowtemperature annealing process, monolithic and mechanically robust, stable, and low-resistivity NiO/Ni nanoporous composite electrodes were obtained with both maximized energy and power densities.The structure of the AP Ni particles was characterized by X-ray diffraction (XRD; Figure 1 a) and electron diffraction (ED; Figure 1 b). The particle size estimated from the Scherrer method was 4.4 nm, and several particles formed larger aggregates with a diameter smaller than 20 nm (Figure 1 b); these findings are in agreement with the measured Brunauer-Emmett-Teller (BET) surface area of 40 m 2 g À1 . The AP particles were then mechanically compacted into monolithic pellets and used as prototype electrodes. These pellets are stable, easy to handle, and did neither require additives nor a supporting substrate. Scanning electron microscopic images obtained at both the surface and crosssection...

To date, knowledge gaps and associated uncertainties remain unaddressed on the effects of nanoparticles (NPs) on plants. This study was focused on revealing some of the physiological effects of magnetite (Fe(3)O(4)) NPs on perennial ryegrass (Lolium perenne L.) and pumpkin (Cucurbita mixta cv. white cushaw) plants under hydroponic conditions. This study for the first time reports that Fe(3)O(4) NPs often induced more oxidative stress than Fe(3)O(4) bulk particles in the ryegrass and pumpkin roots and shoots as indicated by significantly increased: (i) superoxide dismutase and catalase enzyme activities, and (ii) lipid peroxidation. However, tested Fe(3)O(4) NPs appear unable to be translocated in the ryegrass and pumpkin plants. This was supported by the following data: (i) No magnetization was detected in the shoots of either plant treated with 30, 100 and 500 mg l(-1) Fe(3)O(4) NPs; (ii) Fe K-edge X-ray absorption spectroscopic study confirmed that the coordination environment of Fe in these plant shoots was similar to that of Fe-citrate complexes, but not to that of Fe(3)O(4) NPs; and (iii) total Fe content in the ryegrass and pumpkin shoots treated with Fe(3)O(4) NPs was not significantly increased compared to that in the control shoots.

A memory effect has been demonstrated in magnetic nanowire arrays. The magnetic nanowire array has the ability to record the maximum magnetic field that the array has been exposed to after the field has been turned off. The origin of the memory effect is the strong magnetic dipole interaction among the nanowires. Switching field distributions among nanowires has been studied with a first‐order reversal curve technique to elucidate the discrepancy between the experimental result and the theoretical explanation. Based on the memory effect, a novel and extremely low cost EMP detection scheme is proposed.

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