Improvement of bitumen-waste product in leachability—Leachability of bitumen product containing BWR's evaporator concentrate

The method has been developed to improve the bitumen product which incorporates an evaporator concentrate from a BWR, with respect to the swelling and leaching. The leachability of the product has been measured by the method recommended by the IAEA. The swelling of the product is successfully prevented by the addition of calcium chloride. The specimen containing the waste up to Wa/B (Weight ratio of Na₂SO₄ + CaCl₂ and bitumen) = 60:40 shows no pronounced swelling, when it is immersed in water. The cumulative fractions of ¹³⁷Cs and ⁶⁰Co leached from a specimen which does not contain CaCl₂ are 0.65 and 0.2 at the leaching time of 30 days. On the hand, the corresponding value at 100 days for the specimen with calcium chloride addition is 5 × 10^?4 for ¹³⁷Cs and 1 × 10^?4 for ⁶⁰Co. The coating of the specimen surface with a fresh bitumen (5 mm thickness) reduces the leachability further. These results indicate that this method is effective to improve the bitumen product incorporating BWR's evaporator concentrate.     

Microstructure of External Stress Whiskers and Mechanical Indentation Test Method

Lead-free commercial products have been dramatically increasing in the world markets as the restriction of certain hazardous substances (RoHS) directive in the European Union has been enacted. At the same time, the problem of “tin whiskers” has become one of the most serious problems in the industry. Growth of tin whiskers is believed to be related to residual stress inside the tin plating film and external compressive stress. Whiskers in fine-pitch connectors have affected the practical production of advanced digital equipment. The Japan Electronics and Information Technology Industries Association (JEITA) has proposed a new testing method to evaluate tin whiskers, especially for the fine-pitch connectors. This paper describes the microstructures of external stress whiskers and the mechanical indentation test method.     

Informative patches sampling for image classification by utilizing bottom-up and top-down information

In image classification based on bag of visual words framework, image patches used for creating image representations affect the classification performance significantly. However, currently, patches are sampled mainly based on processing low-level image information or just extracted regularly or randomly. These methods are not effective, because patches extracted through these approaches are not necessarily discriminative for image categorization. In this paper, we propose to utilize both bottom-up information through processing low-level image information and top-down information through exploring statistical properties of training image grids to extract image patches. In the proposed work, an input image is divided into regular grids, each of which is evaluated based on its bottom-up information and/or top-down information. Subsequently, every grid is assigned a saliency value based on its evaluation result, so that a saliency map can be created for the image. Finally, patch sampling from the input image is performed on the basis of the obtained saliency map. Furthermore, we propose a method to fuse these two kinds of information. The proposed methods are evaluated on both object categories and scene categories. Experiment results demonstrate their effectiveness.     

Synthesis of ZnOAl2O3 core-shell nanocomposite materials by fast and facile microwave irradiation method and investigation of their optical properties

Alumina (Al₂O₃) coated ZnO core-shell structures were synthesized by a novel, fast, and facile route utilizing microwave (MW) irradiation to control photocatalytic property of ZnO. The phase analysis and the core–shell structure development were corroborated by X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), X-ray fluorescence (XRF), transmission electron microscopy (TEM), field emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray (EDX) analysis and Fourier transform infrared spectroscopy (FT-IR). The XPS results affirmed that elements on the coated surface were Al and O. Zeta potential analysis predicted the presence of Al₂O₃ layer on ZnO due to almost similar zeta potential curve for pure Al₂O₃ and Al₂O₃ coated ZnO nanoparticles. There was no significant change in band gap energy of ZnO after amorphous Al₂O₃ coating as obtained from derived data of the reflectance spectra but gradual decreasing of reflectance in the visible range, measured by UV–vis spectroscopy, of the prepared core-shell nanoparticle may be due to the coating of amorphous Al₂O₃ on ZnO. The photocatalytic efficiency of ZnO was reduced after amorphous Al₂O₃ layer as confirmed by the photodegradation of methylene blue under UV irradiation.     

Rotary scanning wireless temperature measurement method for hyperthermia using ferromagnetic implants

Recently, the use of a ferromagnetic material in a soft‐heating method has garnered much attention as a novel method for cancer treatment. By concurrently using this material as a thermal probe, we are currently developing a minimally invasive heating and wireless temperature measurement system. To make the approach feasible in a clinical setting, it is vital to overcome the key challenge of heating the local tumor at a constant temperature. In previous conventional approaches, it was necessary to switch the induction‐heating power supply on/off after the target tumor temperature was reached. However, it cannot determine the temperature of the material during the power‐off period. Therefore, we changed this approach and found that by adjusting the distance between the heating coil and the material while maintaining a constant current flow in heating coil, the drift problem, which happened just after power is supplied during the on/off operation, did not occur any longer. Accordingly, it was not required to use multiple sensors to reduce the drift, thereby minimizing the cost. This study verifies the validity of our wireless thermometry approach while performing rotary scanning and proposes a technique for determining achievement of the target temperature. This knowledge complements other approaches for cancer treatment utilizing hyperthermia. © 2015 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

Development of a chirped pulse amplification laser with zigzag slab Nd:glass amplifiers dedicated to x-ray laser research

A chirped pulse amplification laser with zigzag slab Nd:glass amplifiers dedicated to x-ray laser research is described. The laser provides a 1.6 ps duration pulse with approximately 7 J energy at a repetition rate of 0.1 Hz. In the power amplifier system, laser light is amplified in a two-step manner: The first step is image-relayed multipass amplification up to approximately 1 J with a 10 mm x 10 mm beam. The second step is double-pass amplification up to >10 J with a 10 mm x 90 mm beam. By using this laser system, the saturated amplification of the Ni-like Ag laser at a wavelength of 13.9 nm has been successfully demonstrated.     

X-ray absorption fine structure study on residue bromine in carbons with different degrees of graphitization

The structure of bromine residue compounds was investigated by X-ray absorption fine structure (XAFS) in order to interpret where and how bromine is present in carbons with different degrees of graphitization. The residue compounds can be classified into three groups, as obtained from X-ray absorption near edge structure (XANES) spectra and the values of the intramolecular distance r_Br–Br determined by extended X-ray absorption fine structure (EXAFS). In Group I, prepared from the host carbons heat treated at temperatures higher than 1900 °C, bromine exists in the interlayer space of graphite in the form of Br₂ molecules with interaction of the π electrons of graphite. In Group III, from carbon heat treated at 1000 °C, most of the bromine probably reacts with carbon atoms having a dangling bond or functional groups. For Group II, where the host carbons are heat treated at intermediate temperatures, it is likely that bromine exists in undeveloped defects with a unique electronic state.     

Mutants of the nematode Caenorhabditis elegans that are defective specifically in their attraction to cycloheximide

The nematode Caenorhabditis elegans exhibits chemotaxis toward a wide variety of chemicals including water-soluble molecules and volatile organic compounds. We have previously discovered that C. elegans wild-type strain N2 is strongly attracted by cycloheximide which has long been known as a bitter tastant for humans and other mammals. We describe here the isolation and initial characterization of the first mutants which were defective specifically in their attraction to cycloheximide. In our screenings, we selected two mutants that were defective in chemotaxis to cycloheximide but normal in their attraction to NH4Cl and histidine. These mutants also avoided quinine hydrochloride, CuSO4 and high concentrations of NaCl similar to the wild-type strain N2. Furthermore, no observable defect was detected in their attraction to volatile odorants such as isoamyl alcohol and diacetyl. Dye-filling experiments suggested that they have no morphological defect in the sensory endings of the amphid neurons.