Effect of spatial structure on colorfulness adaptation for natural images

We examined whether the perception of the colorfulness of an image is influenced by the adaptation of the visual system to natural and shuffled images with different degrees of saturation. In the experiment, observers first became adapted to several images with different levels of saturation and then their colorfulness perception of a test image was measured. The results show that their perception of colorfulness was influenced by their adaptation to the saturation of images. The effect was stronger following adaptation to natural images than to images consisting of a shuffled collage of randomized color blocks, which suggests that the naturalness of the spatial structure of an image affects the strength of the effect.     

Kinetic parameters for anodic oxidation of hypochlorite ion on Pt and Pt oxide electrodes in alkaline solution

Kinetic parameters for the anodic oxidation of hypochlorite ion have been determined by means of normal pulse voltammetry by using a platinum disk as the working electrode. By using the working electrode that formed an oxide film by electrochemical pretreatment, the effect of the lattice oxygen of the surface oxide on the reaction was also examined. The measurement results were analyzed by the classical method, and then the analytical results were evaluated by digital simulation. The normal pulse voltammogram of the hypochlorite ion showed quasi-reversible oxidation waves. The apparent rate constant was calculated to be 5.0-8.1 × 10⁻⁴ cm s⁻¹, depending on the electrode surface state. At the low-concentration range of <4.0 mg Cl dm⁻³, the oxidation current was concentration dependent at the cathodically polarized electrode, while it became independent after the anodic polarization.     

Electrooxidation of C1 to C3 alcohols with Pt and Pt–Ru sputter deposited interdigitated array electrodes

The electrooxidation of methanol, ethanol, and 2-propanol was investigated with interdigitated array electrodes (IDAEs). The IDAE oxidizes alcohol at the generator and reduces the reaction intermediates produced by the oxidation process at the collector. Thus, the reaction intermediates can be estimated with the IDAE. The IDAE in the present work was made of sputter deposited Pt and Pt–Ru. The use of Ru free and added electrodes provides information on the effect of Ru addition on the alcohol oxidation. Cyclic voltammetric analyses revealed that Ru addition enhances the oxidation currents and reduces the E_onset of the alcohols. The detectable reaction intermediate at the methanol and ethanol oxidation was proton, while the intermediate species was acetone in 2-propnaol oxidation.     

Serial Changes of Serum Growth Factor Levels and Liver Regeneration after Partial Hepatectomy in Healthy Humans

This study aimed to investigate the associations of the serial changes of serum levels of various growth factors with liver regeneration after hepatectomy in healthy liver donors. Sixteen healthy liver donors who underwent conventional liver resection were included. Serum levels of various growth factors before hepatectomy and on postoperative day (POD) 1, 3, 5 and 7 were measured. Liver volume data calculated by multi-detector computed tomography using workstation. The ratio of remnant liver volume on POD 0 to liver volume before the operation was 51% ± 20%. The ratio of liver volume on POD 14 to liver volume on POD 0 were inversely correlated with remnant liver volume on POD 0 (r = −0.91). The ratio of liver volume on POD 14 to liver volume on POD 0 were significantly correlated with serum hepatocyte growth factor (HGF) levels on POD 1 (r = 0.54), serum leptin levels on POD 1 (r = 0.54), and serum macrophage colony-stimulating factor (M-CSF) levels on POD 5 (r = 0.76) and POD 7 (r = 0.80). These results suggest that early-phase elevation of serum levels of HGF, leptin and M-CSF may be associated with the acceleration of liver regeneration after hepatectomy in humans.     

Uniformity of gallium doped zinc oxide thin film prepared by pulsed laser deposition

Recently, transparent conducting oxide thin films have attracted attention for the application to transparent conducting electrodes. In this work, we evaluated the uniformity of electrical, optical and structural properties for gallium doped zinc oxide thin films prepared on the 10 × 10 cm² silica glass substrate by pulsed laser deposition. The resistivity, carrier concentration, mobility, bonding state and atomic composition of the film were uniform along in-plane and depth direction over the 10 × 10 cm² area of the substrate. The film showed the average transmittance of 81-87%, resistivity of 1.4 × 10^− 3 Ω cm, carrier concentration of 9.7 × 10²⁰/cm³ and mobility of 5 cm²/Vs in spite of the amorphous X-ray diffraction pattern. The gradual thickness distribution was found, however, the potential for large-area and low temperature deposition of transparent conducting oxide thin film using pulsed laser deposition method was confirmed.     

Microstructures and mechanical responses of powder metallurgy non-combustive magnesium extruded alloy by rapid solidification process in mass production

Spinning Water Atomization Process (SWAP), which was one of the rapid solidification processes, promised to produce coarse non-combustible magnesium alloy powder with 1–4 mm length, having fine α-Mg grains and Al₂Ca intermetallic compounds. It had economical and safe benefits in producing coarse Mg alloy powders with very fine microstructures in the mass production process due to its extreme high solidification rate compared to the conventional atomization process. AMX602 (Mg–6%Al–0.5%Mn–2%Ca) powders were compacted at room temperature. Their green compacts with a relative density of about 85% were heated at 573–673 K for 300 s in Ar gas atmosphere, and immediately consolidated by hot extrusion. Microstructure observation and evaluation of mechanical properties of the extruded AMX602 alloys were carried out. The uniform and fine microstructures with grains less than 0.45–0.8 μm via dynamic recrystallization during hot extrusion were observed, and were much small compared to the extruded AMX602 alloy fabricated by using cast ingot. The extremely fine intermetallic compounds 200–500 nm diameter were uniformly distributed in the matrix of powder metallurgy (P/M) extruded alloys. These microstructures caused excellent mechanical properties of the wrought alloys. For example, in the case of AMX602 alloys extruded at 573 K, the tensile strength (TS) of 447 MPa, yield stress (YS) of 425 MPa and 9.6% elongation were obtained.     

Microstructure and mechanical properties of hot extruded Mg–Al–Mn–Ca alloy produced by rapid solidification powder metallurgy

The microstructure and mechanical properties of hot extruded Mg–Al–Mn–Ca alloy was investigated. Both rapid solidified powders and cast billets were extruded at 573, 623 and 673 K to optimize the processing conditions for obtaining better mechanical response. Powder was consolidated to prepare the extrusion billets using both cold compaction and Spark Plasma Sintering at 473 K. The tensile properties of the extruded alloy were then evaluated and correlated to the observed microstructure. The results show that the use of rapid solidified powder could lead to effective grain refinement, which in turn resulted in the improved mechanical response, especially compared to the extruded conventional cast material.     

Product modularity for life cycle design

Modular design is an important elemental technique in life cycle design for improving, e.g., maintainability, upgradability, reusability, and recyclability. Appropriate modular structure differs according to applied life cycle options; e.g., while the modular structure for recycling should be based on material kinds, the structure for upgrading should be based on functions to be obsolete. This paper proposes a method for determining modular structure by aggregating various attributes related to a product life cycle and evaluating geometric feasibility of modules. This paper also illustrates the prototype system that implements the proposed method and a case study of a printer.     

Cavitation resistance of powder metallurgy aluminum matrix composite with AlN dispersoids

The cavitation erosion resistance of P/M aluminum alloy sintered composite with AlN dispersoids, prepared via the in situ synthesis and the conventional premixing process, was evaluated by using a magnetostrictive-vibration type equipment. In situ synthesized AlN particles were effective for the improvement of the erosion resistance of the composite because of their good bonding with the aluminum matrix. The additive AlN by the premixing process were easily detached from the specimen surface due to the insufficient coherence with the matrix, and caused the poor resistance. The cavitation resistance also depended on the porosity of the sintered composite. The continuously opened pores accelerated the wear phenomena by the cavitation due to the high pressure attack on the primary particle boundaries of sintered materials in the collapse of the bubbles.