Fabrication of conducting poly(3-thiophene boronic acid)-grafted multi-walled carbon nanotubes by oxidative polymerization

Composite materials of multi-walled carbon nanotubes (MWNTs) and a conducting polymer, poly(3-thiophene boronic acid) (PTBA) were prepared by in-situ oxidative polymerization of TBA in the presence of MWNTs and potassium dichromate. The MWNTs which were previously surface functionalized with acid chloride groups were reacted with TBA using a simple "chemical grafting" technique. It was observed that the nanotubes were dispersed uniformly in the pi-conjugated polymer matrix and entrapped by the polymer. The conductivity of the composites was higher than that of the pure polymer from a conventional four-probe technique, which indicates that the fabrication of MWNTs into the polymer matrix significantly improves the conductivity of the polymer due to the intrinsic properties of MWNTs.     

Fluorescent Diagnostic Probes in Neurodegenerative Diseases

Neurodegenerative diseases are debilitating disorders that feature progressive and selective loss of function or structure of anatomically or physiologically associated neuronal systems. Both chronic and acute neurodegenerative diseases are associated with high morbidity and mortality along with the death of neurons in different areas of the brain; moreover, there are few or no effective curative therapy options for treating these disorders. There is an urgent need to diagnose neurodegenerative disease as early as possible, and to distinguish between different disorders with overlapping symptoms that will help to decide the best clinical treatment. Recently, in neurodegenerative disease research, fluorescent-probe-mediated biomarker visualization techniques have been gaining increasing attention for the early diagnosis of neurodegenerative diseases. A survey of fluorescent probes for sensing and imaging biomarkers of neurodegenerative diseases is provided. These imaging probes are categorized based on the different potential biomarkers of various neurodegenerative diseases, and their advantages and disadvantages are discussed. Guides to develop new sensing strategies, recognition mechanisms, as well as the ideal features to further improve neurodegenerative disease fluorescence imaging are also explored.     

Research Issues in Smart Vehicles and Elderly Drivers: A Literature Review

This article reviewed both studies on general smart car technologies and human–computer interaction (HCI)/human–vehicle interaction studies that were published in journals and conferences so that the current status of research can be identified and future research directions can be suggested. Furthermore, previous studies on elderly drivers were reviewed, as these drivers could be the most vulnerable social group in terms of new technology acceptance. A total of 257 articles for HCI research and 45 articles for elderly drivers were selected and reviewed from 11,267 collected articles (2010–2014). According to the results, most articles were mainly related to safety and adaptive features (e.g., driver’s state recognition, vehicle surrounding monitoring, driver action-suggestion), and infotainment research in terms of HCI (e.g., information technology devices–vehicle interaction, vehicle–vehicle interaction) was relatively insufficient despite its high research demand. According to the results of the literature review and technological trends analysis based on previous technical road maps, from HCI/human factors engineering (HFE) perspectives, research related to “Assistance systems,” “Physiological & mental state recognition,” “Position sensor technology,” “Behavior recognition,” and “Infotainment” was suggested to HCI/HFE researchers for further research. In particular, HCI/HFE researchers need to focus on research on acceptable levels of automation, observing new driving behaviors, investigation of driver characteristics to develop personalized services, and new technology acceptance to develop and improve smart cars in the future.     

A new method for investigating prototype learning.

Past researchers studied prototype learning by asking subjects to categorize exemplars constructed from different prototypes. This procedure is less than ideal because learning must be inferred from the percentage of correct categorizations pooled across many trials or subjects or both. An alternative procedure is proposed in which subjects are asked to reproduce their estimate of the prototype on each trial, thereby providing trial-by-trial information about changes in the estimated prototype. This procedure provides straightforward tests of three basic properties implied by several prototype learning models: additivity across exemplars, noninterference among features, and time invariance of serial position effects. An experiment is reported and the results provide reasonably good support for the properties of additivity and noninterference, but clear violations of time invariance were observed. The implications of the results for distributed-memory models and multiple-trace models of prototype learning are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Crisis and Organisational Paralysis: The Lingering Problem of Korean Public Administration

This essay argues that the Korean crisis is caused by the enduring problems of administrative culture, such as central control of decision‐making, corruption, passive learning, moral decay, and a lack of self‐governance and autonomy of administrators. The crisis has brought organisational paralysis because public administrators are not capable of responding to and coping with the crisis situation. The authors state that solutions to these problems are difficult and require strategies beyond short‐term, instrumental solutions because change involves education and raising consciousness of public servants at all levels.     

Copper dissolution and electrochemical behavior in EDTA- and EDA-based solutions for steam generator chemical cleaning

Copper dissolution and electrochemical behavior have been investigated in order to find out which parameters are critical and important during the two major copper removal processes for chemical cleaning of nuclear steam generator and to evaluate safety aspects and effectiveness of these processes. Hydrogen peroxide was very effective for the process using EDTA-based solution at 38 °C to control the corrosion potential of copper into an optimum potential range from −0.3 to +0.2 V for copper sludge dissolution. Corrosion rates of carbon steel SA 285 Gr.C and Alloy 600 were very small in this potential range. The process using EDA-based solution at 60 °C was effective to dissolve copper sludge if the corrosion potential of copper could be controlled above −0.3 V. However, it was very difficult under the laboratory conditions to raise its corrosion potential to this range by air blowing and stirring.     

Viscoelastic characterization of semiconducting dodecylbenzenesulfonic acid doped polyaniline electrorheological suspensions

Dodecylbenzenesulfonic acid (DBSA)‐doped polyaniline particles were synthesized via emulsion polymerization, and electrorheological (ER) fluids were prepared by dispersing the synthesized polyaniline particles in silicone oil. The viscoelastic properties of DBSA‐doped polyaniline/silicone oil ER systems were examined using a vertical oscillation rheometer (VOR), which is designed for the rheological measurement of ER fluids, with a high voltage generator. Viscoelastic data obtained from the VOR were compared with those obtained from a commercial Physica rotational rheometer. The data from VOR were quite reliable in a broad range of both strain and frequency. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 79: 108–114, 2001     

The circumferential tensile properties of zirconium alloy fuel claddings under a simulated high burn-up environment

To study the circumferential tensile properties of fuel claddings under a simulated high burn-up environment, ring tensile tests were carried out at both room temperature and 350 °C for Zr-Nb based fuel claddings such as Zr-Nb based HANA-6 (Zr-1.10Nb-0.05Cu), HANA-4 (Zr-1.50Nb-0.40Sn-0.20Fe-0.10Cr) and Zircaloy-4 (Zr-1.26Sn-0.23Fe-0.12Cr) cladding after they had been differently charged with hydrogen up to 2,850 ppm. The results showed that the HANA-6 cladding maintained more than a 20% circumferential elongation at room temperature without a decrease in its maximum strength when it was charged with hydrogen up to about 1,500 ppm, although the maximum circumferential strength and elongation of the Zircaloy-4 cladding decreased with increasing hydrogen content above 500 ppm. The circumferential elongation of the above claddings decreased as the hydrogen content increased at both room temperature and 350 °C but the strength increased a little with the hydrogen content at 350 °C. The maximum circumferential strength of the HANA-4 cladding also increased with the hydrogen content up to a level of 1,109 ppm, even at room temperature. It seemed that the Nb in the matrix contributed to better circumferential elongation and resistance to hydrogen embrittlement in the Zr-Nb based HANA-4 and HANA-6 claddings than was present in the Zircaloy-4 cladding.     

Microstructure and XRD analysis of brazing joint for duplex stainless steel using a Ni–Si–B filler metal

Brazing of a nitrogen-containing duplex stainless steel was preformed using a nickel-based filler metal (Ni-4.5wt.%, Si-3.2wt.%, B). The microstructure of the brazed joint was investigated using scanning electron microscopy, energy dispersive spectrometry, electron probe microanalyzer, and layer-by-layer X-ray diffraction analysis. The results indicated that before completion of isothermal solidification, BN, Ni₃B and Ni₃Si precipitates formed at the interface, in the athermally solidified zone and isothermally solidified zone, respectively. After isothermal solidification, only γ-Ni phase appeared in the brazed interlayer. The appearance of hardness peak values in the athermally solidified zone and the interface most probably corresponded to the formation of Ni₃B and BN, respectively.