Preparation of mesoporous silica replica using ordered mesoporous carbon by vapor phase transport of silica source

A new vapor phase transport (VPT) technique to prepare an inverse silica replica of an ordered mesoporous carbon was developed. Tetraethyl orthosilicate (TEOS) was infiltrated in mesoporous carbon CMK-3 as the hard template at 180 °C for 48 h under an autogenous pressure in an autoclave in the presence of water. The samples obtained by removal of CMK-3 retained structural regularity of CMK-3 with little shrinkage of framework, which were characterized by SAXRD, N₂ adsorption, TG-DTA, and SEM. Influence of preparation temperature on the loading amount of silica was investigated. The multi-step replication process was monitored by characterizing the replicated materials as well as intermediate composites.     

Re-evaluation of Radiation-Energy Transfer to an Extraction Solvent in a Minor-Actinide-Separation Process Based on Consideration of Radiation Permeability

ABSTRACT

Absorbed-dose estimation is essential for evaluation of the radiation tolerance of minor-actinide-separation processes. We propose a dose-evaluation method based on radiation permeability, with comparisons of heterogeneous structures seen in the solvent-extraction process, such as emulsions forming in the mixture of the organic and aqueous phases. A demonstration of radiation-energy-transfer simulation is performed with a focus on the minor-actinide-recovery process from high-level liquid waste with the aid of the Monte Carlo radiation-transport code PHITS. The simulation results indicate that the dose absorbed by the extraction solvent from alpha radiation depends upon the emulsion structure, and that from beta and gamma radiation depends upon the mixer-settler-apparatus size. Non-negligible contributions of well-permeable gamma rays were indicated in terms of the plant operation of the minor-actinide-separation process.     

A study on the optimal fabrication method for micro-scale gyroscopes using a hybrid process consisting of electric discharge machining,chemical etching or micro-mechanical milling

For productive manufacturing of an accurate small-scale wine-glass gyroscope, a hybrid fabrication process consisting of either electric discharge machining, chemical etching, or micro-mechanical milling have been proposed. A comparison of silicon cavity fabrication processes has been conducted in terms of productivity, quality and geometrical accuracy, aiming at the use of the cavity as a mold for creating a thin wall diamond hemisphere, which is the main component of a wine-glass gyroscope. The results have shown that the EDM process, combined with chemical etching, can yield the highest productivity but with limited shape accuracy. The use of mechanical micro-milling, while less productive than EDM and etching, produces a superior quality and geometric accuracy.     

Ultrasonic irradiation on hydrolysis of magnesium hydride to enhance hydrogen generation

This paper describes the ultrasonic irradiation on the hydrolysis of magnesium hydride to enhance hydrogen generation; the effects of the ultrasonic frequency and the sample size on the hydrogen generation were mainly examined. In the experiments, three MgH₂ particle and nanofiber samples were soaked in distilled water and ultrasonically irradiated at frequencies of 28, 45, and 100 kHz. Then, the amount of hydrogen generated was measured. We found that the low frequency of ultrasonic irradiation and the relatively small sample size accelerated the hydrolysis reaction MgH₂ + 2H₂O = Mg(OH)₂ + 2H₂ + 277 kJ. In particular, the MgH₂ nanofibers exhibited the maximum hydrogen storage capacity of 14.4 mass% at room temperature at a frequency of 28 kHz (ultrasound irradiation). The results also experimentally validated that a combination of ultrasonic irradiation and MgH₂ hydrolysis is considerably effective for efficiently generating hydrogen without heating and adding any agent.     

Deconvolution processing of HAADF STEM images

A deconvolution processing of high-resolution high-angle annular dark field (HAADF) scanning transmission electron microscopy (STEM) images, combined with maximum entropy method, is applied to two experimental [0 11]-Si images; one having unresolved dumbbells and the other having resolved dumbbells and artificial bright spots. The deconvoluted images for these images show bright spots corresponding to the projected atomic columns and no artificial bright spots. Thus, the deconvolution processing provides almost a real projected atomic structure by eliminating effects of the probe function from HAADF STEM images.     

Decision-making in electrical appliance use in the home

This paper presents the results of a survey as well as an argument from the viewpoint of behavioral economics with the aim of clarifying how consumers make decisions about electrical appliance use in the home. A survey of consumers showed that most have little awareness of the energy efficiency of appliances, the price of the services produced by electrical appliances, or electricity rates. These findings indicate that price does not function as a signal in electricity consumption through electrical appliance use. Rather, we found that consumer decision-making in electricity consumption is dependent on the characteristics of the particular electrical appliances they use. Additionally, we argue that the payment system for home electricity consumption plays an important role in decision-making, causing biases due to aspects of human psychology discussed here in terms of satisficing and heuristics, payment decoupling, and budgeting. We conclude that decision-making about electrical appliance use and electricity consumption in the home is not always rational and is affected both by the particular characteristics of appliances and the payment system for electricity consumption along with human psychology.     

Ferroelectric properties of ultrathin films of Nylon 11

Ferroelectric properties of ultrathin films of Nylon 11 were investigated. The thickness was in the range of 25 to 55 nm. Ferroelectric response was largely affected by thermal annealing and following cooling conditions. Thermal annealing at higher temperature followed by quenching in liquid nitrogen gave larger remanent polarization and smoother surface, whereas cooling down in an ambient atmosphere caused smaller remanent polarization and rough surface. Surface roughness strongly affected the polarization reversal and remanent polarization. Hydrogen bonding in crystal was also significantly related to the polarization reversal and thus remanent polarization.