Exposure assessment of engineered nanomaterials in the workplace

Nanotechnology is a rapidly growing field and numerous products containing engineered nanomaterials are already in the market. With the increasing use of engineered nanomaterials, it is expected to increase the exposures to nanomaterials in the workplace. However, the researches on the exposure assessment of nanomaterials to humans and the environment are just a beginning step, as the nanotechnology industries are expanding. Questionnaire surveys conducted by various organizations reveal that many nanotechnology companies are searching for information on exposure measurement for the protection of workers who handle nanomaterials. We analyze the trends of researches on the occupational exposure measurement of engineered nanomaterials and investigate the methodologies of exposure assessment recommended by the related working groups. This work is expected to fill the gaps in knowledge on the exposure assessment of nanomaterials.     

Polynorbornene/fluorosilica hybrids for hydrophobic and oleophobic coatings

Polynorbornene dicarboxylic anhydride (PNA)/fluorosilica hybrid coating materials with good hydrophobicity, oleophobicity, transparency, thermal stability, and hardness were synthesised using a sol–gel method. The surface structure, transparency, hydrophobicity, oleophobicity, and surface free energy of the coating could be controlled by adjusting the fluorosilane ratio. The maximum static water and oil contact angles of films were 112° and 87°, respectively. The PNA/fluorosilica hybrid films exhibited good transparency and colourlessness. The marks written using water and oil-based pens on the films could be erased with a tissue even after eight times. In addition, the hardness of the hybrid films was enhanced to 4H with increasing fluorosilane content.     

Development of a scale for fantasy state in digital games

Digital games appear to motivate players intrinsically. Of various game features, fantasy in particularly plays a crucial role in enhancing motivation and is a key factor in immersion in gameplay. As with its inherent value, fantasy also plays a vital role in distinguishing digital games itself from other media. Despite its significance, fantasy has received little attention, and this concept is still ambiguous to define with any certainty. This study thus aims to create a framework to explore a dimension of fantasy and to develop a scale to measure a state of fantasy in digital games. As a result, four factors were extracted, which were ‘identification’, ‘imagination’, ‘analogy’, and ‘satisfaction’, to account for fantasy state in digital gameplay. Based on these factors, a fantasy scale in digital games (FSDGs) included 16 items was developed.     

Enhanced adhesion of osteoblastic cells on polystyrene films by independent control of surface topography and wettability

We independently controlled surface topography and wettability of polystyrene (PS) films by CF₄ and oxygen plasma treatments, respectively, to evaluate the adhesion and proliferation of human fetal osteoblastic (hFOB) cells on the films. Among the CF₄ plasma-treated PS films with the average surface roughness ranging from 0.9 to 70 nm, the highest adhesion of hFOB cells was observed on a PS film with roughness of ~ 11 nm. When this film was additionally treated by oxygen plasma to provide a hydrophilic surface with a contact angle less than 10°, the proliferation of bone-forming cell was further enhanced. Thus, the plasma-based independent modification of PS film into an optimum nanotexture for human osteoblast cells could be appplied to materials used in bone tissue engineering.     

Synthesis and nonlinear optical properties of a novel polyurethane containing cyanovinylthiophene with enhanced thermal stability of dipole alignment for electro‐optic applications

Stabilization of electrically induced dipole alignment is one of the important criteria in the development of nonlinear optical (NLO) polymers for electro‐optic device applications. Polyurethanes for NLO applications have attracted attention because of their high thermal stability due to hydrogen bonding. In the work reported here, we designed and synthesized a new type of NLO polyurethane, in which the pendant NLO chromophores are part of the polymer backbone. This mid‐type NLO polymer is expected to have the merits of both main‐chain and side‐chain NLO polymers, namely stable dipole alignment and good solubility. 1‐[3,4‐Di‐(2‐hydroxyethoxy)phenyl]‐2‐(2‐thienyl)ethene was prepared and condensed with 3,3′‐dimethoxy‐4,4′‐biphenylenediisocyanate to yield a polyurethane. This polyurethane was reacted with tetracyanoethylene to give a novel Y‐type polyurethane (7) containing 1‐(3,4‐dioxyphenyl)‐2‐[5‐(1,2,2‐tricyanovinyl)‐2‐thienyl]ethenes as NLO chromophores, which constitute part of the polymer backbone. Polyurethane 7 is soluble in common organic solvents such as N,N‐dimethylformamide and dimethylsulfoxide. It shows a thermal stability up to 280 °C from thermogravimetric analysis with a glass transition temperature obtained from differential scanning calorimetry of ca 162 °C. The second harmonic generation (SHG) coefficient (d₃₃) of a poled polymer film of he polyurethane at 1560 nm fundamental wavelength is ca 1.11 × 10^?18 C. Polymer 7 exhibits an enhanced thermal stability and no significant SHG decay is observed below 150 °C, which is acceptable for NLO device applications. Copyright © 2009 Society of Chemical Industry     

Measurement development for cultural characteristics of mobile Internet users at the individual level

Culture plays an important role in how an information technology is developed and used. However, few studies attempt to identify the cultural traits most relevant to the specific technology being examined. The main purpose of this study is to develop measures for cultural characteristics of individual users with a specific information technology, the mobile Internet. We propose measures for four cultural characteristics important in the context of the mobile Internet, which are expected to be widely used in the future. The proposed measures were verified empirically through online surveys conducted in seven countries. The results indicate that the measures have high validity and reliability, as well as comparability among the seven countries. The paper ends with a discussion of the study’s limitations and implications.     

Sensing and gait planning of quadruped walking and climbing robot for traversing in complex environment

In this paper, a general study on improving adaptability of quadruped walking and climbing robot in complex environment is presented. First, a sensing system composed of range and gyroscope sensors in a novel arrangement is developed. By combining the sensing signals and the internal state of the robot, the surface geometry of the environment is sufficiently reconstructed in real-time. Secondly, a planning algorithm for the robot to overcome the reconstructed environment is conducted. Based on the reshaped surface, the planning algorithm not only provides the exact body trajectory and foot positions but also the adaptability of the robot in a specific environment. A method to improve the adaptability of the walking and climbing robot is also introduced. Thanks to the adherent ability of the robot, the center of gravity of the robot is allowed to move outside the support polygon to increase the reach-ability of the next swing leg. Finally, the effectiveness of the proposed approach is verified by the performances of the experiments in complex environments using a quadruped walking and climbing robot named MRWALLSPECT IV.