Simple purification and selective enrichment of metallic SWCNTs produced using the arc-discharge method

Purified single-walled carbon nanotubes (SWCNTs) were produced using the arc-discharge method with a combination of air oxidation and dispersion–centrifugation processes in a tetrahydrofuran solution containing an amine as a dispersant. Subsequently, SWCNT samples were analyzed using thermo gravimetric analysis, vis-near infrared absorption spectroscopy, scanning electron microscopy, and Raman spectroscopy. Results revealed that metallic SWCNTs were enriched in a supernatant through the dispersion–centrifugation process.     

Determination of the scattering lengths of gallium isotopes by neutron interferometry with PNO-apparatus in JRR-3M

For carrying out experiments in the field of the so-called precise neutron optics (PNO), we have implemented special multi-purpose apparatus called the “PNO-apparatus” at JRR-3M. Making use of an Si triple-Laue (LLL) neutron interferometer with the PNO-apparatus, we successfully determined the coherent neutron scattering lengths of gallium isotopes, ⁶⁹Ga and ⁷¹Ga. The results are 8.053±0.013 fm for ⁶⁹Ga and 6.170±0.011 fm for ⁷¹Ga, respectively.     

Functional equivalency between Otx2 and Otx1 in development of the rostral head

Mice have two Otx genes, Otx1 and Otx2. Prior to gastrulation, Otx2 is expressed in the epiblast and visceral endoderm. As the primitive streak forms, Otx2 expression is restricted to the anterior parts of all three germ layers. Otx1 expression begins at the 1 to 3 somite stage in the anterior neuroectoderm. Otx2 is also expressed in cephalic mesenchyme. Otx2 homozygous mutants fail to develop structures anterior to rhombomere 3 (r3), and Otx2 heterozygotes exhibit craniofacial defects. Otx1 homozygous mutants do not show apparent defects in early brain development. In Otx1 and Otx2 double heterozygotes, rostral neuroectoderm is induced normally, but development of the mes/diencephalic domain is impaired starting at around the 3 to 6 somite stage, suggesting cooperative interactions between the two genes in brain regionalization. To determine whether Otx1 and Otx2 genes are functionally equivalent, we generated knock-in mice in which Otx2 was replaced by Otx1. In homozygous mutants, gastrulation occurred normally, and rostral neuroectoderm was induced at 7.5 days postcoitus (7.5 dpc), but the rostral brain failed to develop. Anterior structures such as eyes and the anterior neural ridge were lost by 8.5 dpc, but the isthmus and r1 and r2 were formed. In regionalization of the rostral neuroectoderm, the cooperative interaction of Otx2 with Otx1 revealed by the phenotype of Otx2 and Otx1 double heterozygotes was substitutable by Otx1. The otocephalic phenotype indicative of Otx2 haploinsufficiency was also largely restored by knocked-in Otx1. Thus most Otx2 functions were replaceable by Otx1, but the requirement for Otx2 in the anterior neuroectoderm prior to onset of Otx1 expression was not. These data indicate that Otx2 may have evolved new functions required for establishment of anterior neuroectoderm that Otx1 cannot perform.     

The perceiver as perceived: Everyday intuitions about the correspondence bias.

This research examined people's intuitions about the correspondence bias, or the tendency to favor dispositional rather than situational explanations of behavior. In 3 studies, constrained actors overestimated the magnitude of observers' correspondent inferences. Additional studies indicated that this overestimation is due to people's oversimplified theories about the attributional processes of others. In one, Japanese participants, whose culture places greater emphasis on situational explanations of behavior, did not overestimate the correspondent inferences of observers. In other studies, participants indicated that they thought others' attributions are more influenced by an actor's behavior than by the factors constraining the behavior. Discussion focuses on whether people believe others are more prone to the correspondence bias than they are themselves and on the consequences of overestimating the correspondence bias in everyday interaction. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Terence Horgan and John Tienson,Connectionism and the Philosophy of Psychology

Minds and Machines -     

Suppression of elastically accommodated grain-boundary sliding in high-purity MgO

The first high-temperature mechanical spectroscopy experiments on high-purity polycrystalline MgO reveal a monotonically frequency- and temperature-dependent dissipation ‘background’—without any evidence of the superimposed dissipation peak observed in a previous study of a specimen of lower-purity [Webb, S. and Jackson, I. Phys. Chem. Min., 2003 30, 157]. The dissipation and associated relaxation of the shear modulus observed in both studies are well described in an internally consistent manner by a novel Burgers-type model based on a creep function incorporating suitable distributions of anelastic relaxation times. The contrasting patterns for the two materials reinforce an emerging generalisation concerning high-temperature viscoelastic behaviour, whereby the presence of a secondary intergranular phase of relatively low viscosity, and the associated rounding of grain edges, is apparently required to allow elastically accommodated grain-boundary sliding. The absence, in sufficiently pure polycrystalline materials, of a dissipation peak attributable to elastically accommodated grain-boundary sliding is in conflict with classical micromechanical models for grain-boundary sliding, which are therefore being revisited.     

An analog front-end chip set employing an electro-optical mixeddesign on SPICE for 5-Gb/s/ch parallel optical interconnection

A chip set composed of a laser-diode driver (LDD) and an optical receiver (RCV), which incorporates a full 2D (reshape, regenerate) function, has been developed by using silicon bipolar technology for a four-channel 5-Gb/s parallel optical transceiver. An electro-optical mixed design on SPICE of the LDD and the LD is accomplished by describing the rate equations of the LD as an electrical circuit. This design accommodates easy connectivity of the LDD chip to the LD in the optical transmitter module without the need for adjustment of the optical waveform. A pseudobalanced transimpedance amplifier (TIA) and feedforward automatic decision threshold control (ATC) in the RCV minimize the number of off-chip bypass capacitors, eliminate the need for any off-chip coupling capacitors, and keep crosstalk less than -50 dB and low cutoff frequency less than 80 kHz. A prototype parallel optical transmitter module and a prototype receiver module, based on the chip set, demonstrated asynchronous four-channel 5-Gb/s operation. The chip set has a throughput of 20 Gb/s with a power dissipation of 1.3 W at a 3.3-V supply     

The effect of laser texturing of SiC surface on the critical load for the transition of water lubrication mode from hydrodynamic to mixed

Experiments were carried out to verify if the low friction range of SiC in water lubrication can be expanded by micro-pores on the contact surface. Pores were formed by laser, with a diameter of 150 μm and a depth of about 8–10 μm and were distributed in a square array on the contact surface. Seven kinds of textured specimens with different intervals between the pores were tested and compared with the untextured specimen. The effect of the pore area ratio on friction coefficient and the critical load for the transition from hydrodynamic lubrication to mixed lubrication was reported and discussed.