How does response bias emerge in lengthy sequential preference judgments?

Behaviormetrika - Internet surveys are currently used in many academic and marketing research fields. However, the results for these surveys occasionally show traces of response bias. In our study,...     

Estimation of endotoxin-like substances in deep seawater by using bioassay.

Deep seawater has recently been under trial as a fundamental material for mineral water, food, face lotion and an efficacious reagent for the cure of atopic dermatitis in Japan. However, little is known about the biologically effective substances, including toxic compounds in deep seawater. In this study, we investigated the effects of deep seawater on the function of murine macrophages in vitro, and examined the endotoxin-like substances in seawater. Mitochondrial activity and NO production in macrophage cells cultured with stimulants were enhanced in a depth dependent manner by pretreatment with deep seawater. In addition, fractions from deep seawater, enriched by hydrophobic column chromatography, activated the macrophage cells much more than the corresponding fractions from surface seawater. Furthermore, the effects of the fractions on macrophage cells remained significant, even with the addition of polymyxin B. which is a specific inhibitor of endotoxins. These results indicate that endotoxins and unknown substances, which affect macrophage functions, exist in a depth dependent manner in seawater.     

Stability analysis of rock blocks around a tunnel using a statistical joint modeling technique

A three-dimensional statistical joint modeling technique was used to analyze the stability of rock blocks around a tunnel. The rock blocks generated from the joints and the tunnel were analyzed for their volume, height, perimeter, safety factor, and probability of occurrence. All these procedures were programmed into the computer program blocstab. The characteristics of rock block occurrence due to the variation of joint persistence (diameter), orientation and volumetric frequency were investigated. The rock block stability around a storage cavern of liquefied petroleum gas in Korea was analyzed as a case study. Here, the joints were assumed to follow the Baecher disk model for their shape and location, and their orientations were modeled by the Fisher distribution. The joint diameter distribution was estimated by using the window sampling method recently developed by Song and Lee.     

Mine Ventilation Network Optimization Based on Airflow Asymptotic Calculation Method

The main objective of mine ventilation network optimization studies is to develop a reasonable method for ventilation system control that minimizes the total cost of mine ventilation. The fundamental principles for ventilation network optimization are discussed, and a multi-objective optimization model is established from the viewpoint of total cost. Furthermore, an optimization algorithm based on the airflow asymptotic calculation is presented by the hierarchical analysis of objective functions and analysis of the structure characteristics of a ventilation network. In the proposed approach, the regulated branches are determined by the directed path matrix; the optimal solution is obtained by airflow asymptotic calculation using the existing software for ventilation network analysis, and it does not need to solve the large-scale nonlinear programming problem. The results of example analysis validated the reliability of this approach.     

大气等离子喷涂不同粉末在不锈钢基体上沉积行为的研究

采用大气等离子喷涂,将直径为数十微米的 Cu ,Ti ,Al和 Fe粉末沉积在经镜面抛光后的SUS304不锈钢基体上。通过对粉末颗粒沉积物的正面和截面形貌的观察,探讨了不同粉末材料颗粒的热喷涂沉积行为。结果表明,Cu和Fe熔滴在不锈钢基体上均有明显的溅射沉积,这两种颗粒沉积物的形貌各异;Al熔滴在基体表面有轻微溅射,而Ti熔滴为规则的盘状沉积,沉积物上可见明显的裂纹。     

化学环境侵蚀下的岩石破裂特性——第一部分:试验研究

 通过不同应力状态下的试验 ,对岩石破裂特性的化学环境的侵蚀进行了考查 :与空气侵蚀条件相比 ,裂纹尖端的水或化学溶液使岩石的破裂韧度明显地降低 ;应力腐蚀破裂也明显地受到化学环境的影响 ,并依赖于ζ电位 ;抗拉强度明显地受到化学集结物的影响 ,并依赖于ζ电位 ,而三轴强度不会因化学集结物的变化而明显地变化。     

Determination of refractive index and absorption coefficient of iron- oxide-bearing slags

The refractive index and absorption coefficient of amorphous Fe₂O₃-SiO₂-CaO-Al₂O₃ slags have been determined at room temperature as functions of the basicity of [mass pct CaO]/[mass pct SiO₂] and the Fe₂O₃ concentration. The refractive index has been measured by an ellipsometer at 546 nm, and the absorption coefficient has been determined from transmittance measured by a spectrophotometer in the wavelength range of 350 to 1000 nm. The refractive index increases with increasing basicity of [CaO]/[SiO₂] and the Fe₂O₃ concentration. On the other hand, with decreasing basicity of [CaO]/[SiO₂], the absorption coefficient is increased in the near-infrared region, and the absorption edge by the charge transfer band is shifted to a shorter wavelength. With increasing Fe₂O₃ concentration, the absorption coefficient is increased in the measured wavelength range, and the absorption edge by the charge transfer band is shifted to a longer wavelength. These dependences of refractive index and absorption coefficient on the basicity and the Fe₂O₃ concentration are discussed.     

Reinvestigation of the Solidification Point of CaO by Digital Pyrometry

The solidification point of calcia which has been distributed by the Commission on High-Temperature and Solid-State Chemistry of the International Union of Pure and Applied Chemistry was measured by digital pyrometry using an arc imaging furnace. The solidification point was determined to be 2899°C with ±3°C as the standard deviation for this sample. The reliability of this solidification point was determined to be within ±17°C based upon discussions of the measuring system and the material.