Relation between scuffing resistance and the increase in surface hardness during tests under conditions of rolling/sliding

The effect on scuffing resistance of a change in the condition of the rubbing surfaces, especially surface hardness, was investigated using a two-disc machine. Scuffing resistance increased with increasing surface hardness during testing. The increase of surface hardness by work hardening is more beneficial in preventing scuffing than is a change in carbon content or heat treatment. Work-hardened disc surfaces allow surface film formation as a result of plastic deformation. Materials with large Meyer indices and high surface hardness are less prone to scuffing.     

Proportion of aflatoxin B1 contaminated kernels and its concentration in imported peanut samples

Moldy and split peanut kernels were separated from peanuts exported from Brazil, Sudan, India and Taiwan by visual inspection. The remaining peanuts from Brazil, Sudan and India were roasted lightly and the skins were removed. Stained peanuts were separated from the others. Aflatoxin was detected in moldy and stained peanuts. There was a positive correlation between % of aflatoxin-contaminated peanut kernels and aflatoxin B1 concentration in whole samples. Aflatoxin concentration of moldy peanuts was higher than that of stained peanut kernels.     

Fast template matching algorithm for contour images based on its chain coded description applied for human face identification

A new matching algorithm for contour images described by chain coded expression is presented. In our face authentication system, the isodensity contours has been introduced to differentiate between the facial features. These isodensity contours can be transformed into chain codes. By using these coded isodensity contours, remarkable improvement in the processing performance can be expected in terms of the processing time and memory requirements.From the computer simulation performed using images of 50 people, it turned out clear that the processing time was decreased to approximately one-seventh compared to the conventional method. With respect to memory requirement, it was reduced to a quarter.     

Active anion manipulation for emergence of active functions in the nanoporous crystal 12CaO·7Al<Subscript>2</Subscript>O<Subscript>3</Subscript>: a case study of abundant element strategy

This article reviews our approach to render 12CaO · 7Al₂O₃ (C12A7) electronically active using a new concept of ‘active anion manipulation’, where nanostructures embedded within the C12A7 crystal lattice are intentionally utilized to generate chemically unstable (‘water-free active’) anions. Anionic active oxygen radicals, O⁻ and O₂⁻, are formed efficiently in C12A7 cages under high oxygen activity conditions. The configuration and dynamics of O₂⁻ in cages are revealed by a combination of continuous-wave and pulsed electron paramagnetic resonance (EPR). It is demonstrated that metal-loaded C12A7 is a promising oxidation catalyst for syngas (CO + H₂) formation from methane. Furthermore, the O⁻ ion, the strongest oxidant among active oxygen species, can be extracted from the cage into an external vacuum by applying an electric field with thermal assistance, generating a high-density O⁻ beam in the order of μA cm⁻². In contrast, heat treatment of C12A7 in a hydrogen atmosphere forms H⁻ ions in the cages. The resultant C12A7:H⁻ exhibits a persistent insulator-conductor conversion upon ultraviolet-light or electron-beam irradiation. The irradiation-induced conversion mechanism is examined by first-principle theoretical calculations. Furthermore, the presence of a severely reducing environment causes the complete substitution of electrons for anions in the cages. The resulting C12A7:e⁻, which exhibits excellent stability and an electrical conductivity greater than 100 S cm⁻¹, is regarded as an ‘electride’, an ionic compound in which electrons serve as anions. The C12A7 electride exhibits a high potential for applications involving cold cathode and thermal field electron emissions due to its small work function. Electride fabrication methods suitable for large-scale production via melt processing are described. It is also demonstrated that proton or inert gas ion implantations into C12A7 thin films at elevated temperatures are effective for both H⁻ and electron doping.     

Gold nanoparticle distribution monitor for drug delivery system based on optically assisted ultrasonic velocity-change imaging

Optical absorption images of the tissue mimic phantom including gold nanoparticles were obtained by detecting the ultrasonic velocity-change caused by light irradiation. A series of experimental results showed the possibility as a nanoparticle distribution monitor for the drug delivery system.     

Countering the Segregation of Transition‐Metal Ions in LiMn1/3Co1/3Ni1/3O2 Cathode for Ultralong Life and High‐Energy Li‐Ion Batteries

High‐voltage layered lithium transition‐metal oxides are very promising cathodes for high‐energy Li‐ion batteries. However, these materials often suffer from a fast degradation of cycling stability due to structural evolutions. It seriously impedes the large‐scale application of layered lithium transition‐metal oxides. In this work, an ultralong life LiMn_1/3Co_1/3Ni_1/3O₂ microspherical cathode is prepared by constructing an Mn‐rich surface. Its capacity retention ratio at 700 mA g^?1 is as large as 92.9% after 600 cycles. The energy dispersive X‐ray maps of electrodes after numerous cycles demonstrate that the ultralong life of the as‐prepared cathode is attributed to the mitigation of TM‐ions segregation. Additionally, it is discovered that layered lithium transition‐metal oxide cathodes with an Mn‐rich surface can mitigate the segregation of TM ions and the corrosion of active materials. This study provides a new strategy to counter the segregation of TM ions in layered lithium transition‐metal oxides and will help to the design and development of high‐energy cathodes with ultralong life.     

Vapor generation model for flashing in the initial blowdown phase

A vapor generation model for flashing in the initial blowdown phase is proposed based on a wall nucleation theory and a bubble transport model. Comparisons are made between the proposed model and the TRAC-PF1 model by using the MINCS code through analyses of three blowdown experiments with different scales. The present model well predicts the pressure undershoot in the vessel, while the TRAC model can not predict this typical thermodynamic nonequilibrium phenomenon.     

Synthesis and properties of carbons dispersed with α-iron particles from divinylbenzene-vinylferrocene

α-Iron-dispersed carbon was synthesized, through pressure pyrolysis of divinylbenzene-vinylferrocene above 750°C, and by reduction of magnetite-dispersed carbon. Divinylbenzenevinylferrocene copolymer was pyrolysed at 125 MPa above 750°C to yield carbons dispersed with α-iron accompanied by cementite. Magnetite in the carbon matrix was reduced to α-iron after heat treatments at 500°C in a flow of hydrogen. Carbons synthesized by the pressure pyrolysis of divinylbenzene-vinylferrocene at 800°C and 125 MPa contained iron-compound particles up to 200 nm, whereas the median diameter of α-iron particles in the carbon matrix after reduction treatments was 20 nm. α-Iron-dispersed carbon had a Curie temperature of 770°C. The saturation magnetization of iron-dispersed carbon increased with increasing the pyrolysis temperature of divinylbenzene-vinylferrocene copolymer, and reached a constant value of 183 e.m.u.g⁻¹ at 800°C. The saturation magnetization of α-iron-dispersed carbon after the reduction treatment revealed practically the theoretical value of α-iron. Carbons finely dispersed with only α-iron particles were synthesized successfully by reduction of magnetitedispersed carbons.