Successive phase transitions in KMgCl3

Crystalline KMgCl₃ undergoes phase transitions at 296, 224, 212 and 142°C. Observations under a polarizing microscope showed that the transition sequence is the same as that known in CsPbCl₃. The room temperature phase of KMgCl₃ is found to be monoclinic from the fact that the extinction position varies as temperature changes, though it has been reported to be orthorhombic.     

Cooling airflow in unidirectional ventilated open-type motor for electric vehicles

In this paper, the cooling airflow in a unidirectional ventilated open-type motor for electric vehicles (EV) was studied. Numerical fluid analysis was performed on the airflow in the motor through a ventilation path outside the stator iron core inside the frame. It is confirmed that there was a flow separation where air did not flow along the path surfaces. This was observed in a flow visualization experiment using water instead of air. We propose a new structure to prevent air separation and confirm its effectiveness by a visualization experiment. It is also shown that another structure with paths both inside and outside the stator iron core in the frame improves the motor's cooling performance. These structures are effective for EV motor downsizing.     

Direct observation of the deformation and the band gap change from an individual single-walled carbon nanotube under uniaxial strain

We have fabricated a new device for applying uniaxial strain to an individual suspended SWNT, and the form and the photoluminescence (PL) of an individual suspended SWNT under stretching are investigated. The processes of deformation and break of a SWNT under stretching are directly observed by scanning electron microscopy (SEM). From the PL measurements, the emission energy shifts due to the band gap change are measured under the elastic strain. The behaviors of the emission shifts can be related to the deformation processes observed by SEM. Moreover, the emission intensity reduction due to the elastic strain of a SWNT is also observed just before breaking.     

Calculations of positron states in BEDT-TTF based organic superconductors

We have calculated positron distributions on a series of BEDT-TTF based organic conductors, whose anion species are I₃, Cu(NCS)₂, Cu(CN)[N(CN)₂], Cu[N(CN)₂]Br and KHg(SCN)₄. The results are discussed in connection with Fermiological studies by the positron annihilation method. Lifetimes and band masses of positrons have been calculated also.     

New process for producing an extrusion laminated film without any chemical primer—non anchor coating extrusion laminating process

A new process, the Non Anchor Coating Extrusion Laminating Process for producing an extrusion laminated film without any chemical primer, was investigated. Good adhesive properties were obtained by combining an ozone treatment of a molten polyethylene (LDPE) web and an activation treatment of the polyamide (ONy) substrate film. The adhesion mechanism induced by the new process was studied by FT-IR, ESCA and extraction of unreacted polyamide from the laminated samples. The peel strength between the ONy and LDPE laminated films produced with this process was greater than that for laminated film made with a conventional lamination process using anchor coating agents. A model of the adhesive mechanism is proposed. Hydrogen and covalent bonds through oxygenated functional groups are responsible for the enhanced adhesion.     

Minimization of effect of CBN wheel wear on ground gear errors

Resistance to wear of CBN grinding wheels is much higher than that of conventional (Al₂O₃) wheels. However, CBN grinding wheels are seldom used in gear grinding, when production scale is small, due to the difficulty in truing. Moreover, wear of the grinding wheel greatly affects the accuracy of tooth trace, in most cases. Considering this problem, the authors proposed new processes in which the accuracy of the tooth trace and tooth profile was hardly affected by wear of the wheel. While grinding was performed using a conventional method, a concave tooth-trace error of about 2 μm occurred after grinding only 30 teeth. In one of the proposed methods, the concave tooth trace error never occurred even when 2000 teeth were ground by the same wheel. In the third method, the CBN layer is effectively used for gear grinding by giving an additional motion which is independent of the tooth profile generating motion.     

Environmentally benign tribo-systems for metal forming

The growing awareness of environmental issues and the requirements to establish solutions diminishing the impact on working environment as well as external environment has initiated ever increasing efforts to develop new, environmentally benign tribological systems for metal forming. The present paper gives an overview of these efforts substituting environmentally hazardous lubricants in cold, warm and hot forging as well as sheet forming and punching/blanking by new, less harmful lubricants and furthermore describes other measures directed towards the same goal such as development of anti-seizure tool materials and coatings and application of structured workpiece and tool surfaces.     

In vitro transactivation potencies of black-footed albatross (Phoebastria nigripes) AHR1 and AHR2 by dioxins to predict CYP1A expression in the wild population

Our previous studies have detected high levels of dioxins and related compounds (DRCs) including polychlorinated dibenzo-p-dioxins (PCDDs), furans (PCDFs), and coplanar PCBs (Co-PCBs) in the black-footed albatross (BFA), Phoebastria nigripes, from the North Pacific region. We have also cloned two aryl hydrocarbon receptors, AHR1 and AHR2, of the BFA. To evaluate the sensitivity to DRCs in the BFA and to assess the status of cytochrome P450 1A (CYP1A) induction in the wild population, this study investigated the mRNA expression levels of BFA AHR1 and AHR2 and also the transactivation potencies of each AHR by 15 selected DRC congeners. Quantitative real-time PCR of BFA AHR mRNAs showed that hepatic AHR1 is more highly expressed than AHR2. Transactivation by graded concentrations of individual DRCs was measured in COS-7 cells, where BFA AHR1 or AHR2 was transiently transfected. For congeners that exhibited AHR-mediated dose-dependent activities, 50% effective concentration (EC(50)) and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) relative potencies (REPs) were estimated. Based on the estimates of the REPs, TCDD induction equivalency factors (IEFs) were determined. For BFA AHR1, PeCDF was equipotent to TCDD, but other congeners exhibited lower IEFs. For BFA AHR2, PCDD/F congeners except OCDD/F showed IEFs ≥ 1.0. Using BFA AHR1- or AHR2-IEFs and hepatic concentrations of DRCs in North Pacific BFAs, TCDD induction equivalents (IEQs) were calculated. We further constructed nonlinear regression models on the relationships between BFA AHR1- or AHR2-IEF derived total IEQ or WHO-TEF derived total TEQ and ethoxyresorufin-O-deethylase activity (EROD) in the liver of wild BFAs. The results indicated that the relationships of BFA AHR1- and AHR2-based IEQs and EROD were predictable from BFA AHR1- and AHR2-mediated transactivation by TCDD, respectively. Collectively, these results suggest that the in vitro assay incorporating the AHR of species of concern would be a useful tool to predict the sensitivity to DRCs in the species and CYP1A induction in the wild population.