Lateral Displacement of an AFM Tip Observed by In-Situ TEM/AFM Combined Microscopy: The Effect of the Friction in AFM

When the lateral displacement of an AFM tip due to friction is comparable to or larger than the scan size, for example during atomic-scale friction measurement, the interpretation of the friction image is different from the situation where the scan size is much larger than the lateral displacement of the tip and the image is a simple direct mapping of the friction value. This is because, due to the lateral displacement of the tip, the tip is not at the position where the scan indicates, as can be clearly observed by an in-situ TEM/AFM combined microscopy and atomic-scale friction analysis. This lateral displacement of the tip at the nanometer scale affects the shape of the force-distance curve. We discuss the effect of the tip lateral displacement in AFM data and its normal load dependence.     

Reconstruction method of local density fluctuation for heavy ion beam probe measurements

Heavy ion beam probe (HIBP) is an excellent diagnostic to measure the density and potential fluctuations simultaneously in magnetically confined plasmas. However, it has been well known that the density fluctuation measured with the HIBP is not local but contains the fluctuations along the beam orbits. In this article, a method is proposed to evaluate local density fluctuation in the HIBP measurements by removing the well-known path integral effects. The reconstructed density fluctuation amplitude and power spectrum are shown, for example, by applying the proposed method on the density fluctuation measurement data obtained in a toroidal helical plasma, Compact Helical System.     

Effect of rotational oscillation upon fluid forces about a circular cylinder

The present work aims at a computational study of the effect of various parameters that influence fluid-force behavior when a circular cylinder is subjected to rotational oscillations. A numerical simulation is conducted using the unsteady form of Reynolds-averaged Navier-Stokes equations combined with the k-ε model of turbulence. The study is carried out to examine the influence of various flow parameters, such as oscillation non-dimensional frequencies (0.1-2), rotational non-dimensional amplitudes (0.25-3) and Reynolds numbers (2000-30,000). Special attention is focused on the resonance condition at lower frequency and the subsequent drag reduction at higher frequency. It is found that the peak value of fluid forces on the circular cylinder increases abruptly when the forcing frequency is closer to the vortex shedding frequency. This is followed by a drag reduction at higher forcing frequencies, which becomes very strong at a non-dimensional oscillation frequency around 1 and at rotational amplitudes larger than 1. The former phenomenon is found to intensify with an increase in Reynolds numbers, but the latter almost preserves its strength in the range of Reynolds numbers considered here.     

Evaluation of the Effects of Microgravity on Activated Primary Human Hepatic Stellate Cells

In recent years, research has been conducted to develop new medical treatments by simulating environments existing in space, such as zero-gravity. In this study, we evaluated the cell proliferation and gene expression of activated primary human hepatic stellate cells (HHSteCs) under simulated microgravity (SMG). Under SMG, cell proliferation was slower than in 1 G, and the evaluation of gene expression changes on day 1 of SMG by serial analysis of gene expression revealed the presence of Sirtuin, EIF2 signaling, hippo signaling, and epithelial adherence junction signaling. Moreover, reactive oxygen species were upregulated under SMG, and when N-acetyl-cystein was added, no difference in proliferation between SMG and 1 G was observed, suggesting that the oxidative stress generated by mitochondrial dysfunction caused a decrease in proliferation. Upstream regulators such as smad3, NFkB, and FN were activated, and cell-permeable inhibitors such as Ly294002 and U0126 were inhibited. Immunohistochemistry performed to evaluate cytoskeletal changes showed that more β-actin was localized in the cortical layer under SMG.     

Package images modulate flavor perception for orange juice

Most food packages contain images as well as textual information. While the influence of textual information on flavor evaluation has been well studied, the influence of images remains unexplored. Thus, this study investigated how the valence and congruency of images on juice packages influence flavor evaluations. There were 85 participants divided between four experimental conditions: (1) pleasant/congruent, with pleasant orange pictures; (2) unpleasant/congruent, with unpleasant orange pictures; (3) pleasant/incongruent, with pictures of pleasant non-food objects; and (4) unpleasant/incongruent, with pictures of unpleasant non-food objects. In each condition, pictures were attached to cups filled with juice. The participants rated the palatability, goodness of aroma, sweetness, bitterness, sourness, richness, freshness, and artificiality of 6 samples of the same juice. Juices presented with pleasant images were rated as more palatable and fresh. Juices presented with congruent images were rated with better aromas. This data shows that images on juice packages influence flavor evaluation.     

Package images modulate flavors in memory: Incidental learning of fruit juice flavors

The effect of package images on incidental flavor memory for fruit juice was investigated. Ninety-two participants were allocated to three experimental conditions: (1) apple-label, (2) peach-label, and (3) control-label. In each condition, participants tasted a target flavor stimulus, a 1:1 mixture of 100% pure apple juice and 100% pure peach juice with pictures attached to the cups. Ten minutes later, participants were confronted with samples consisting of varying ratios of 100% peach to 100% apple juice, and were asked to rate their similarity to the target stimuli. Participants were also asked to rate how congruent the juice flavor and the image were at the initial tasting. Apple images modulated memories of the flavors of target stimuli: they shifted toward that of apples. This modulation occurred in participants who perceived the label and flavor as congruent. Peach images did not modulate memories, possibly because the subjects had significantly less experience of drinking peach juice than apple juice. These results reveal that flavor memory can be biased toward that of the image labels during initial tasting. However, memory bias depends on the perceived congruency between labels and flavors, and tasters’ prior experiences.     

A dual-phase-controlled dynamic latched amplifier for high-speedand low-power DRAMs

A dual-phase-controlled dynamic latched (DDL) amplifier for a differential data transfer scheme designed to achieve both high speed and low power in DRAMs is described. This circuit reduces the excessive operating margin caused by device fluctuations by using a pair of dynamic latched amplifiers, controlled by a dual-phase clock, to automatically correct the output data. Two circuit technologies are used in the DDL amplifier to achieve 200-MHz operation in a 1-Gb SDRAM using 0.13-μm technology: a cycle-time-progressive control circuit that increases the operating frequency and a shared DDL amplifier technique that reduces the area penalty of the DDL amplifier. These techniques and circuits reduce the access time to 10 ns, which is 1.2 ns less than that of the conventional dynamic amplifier, while also reducing the operating current to less than 10% that of the static amplifier     

Synthesis of 1- and 2-Chloro-7 H -benz[ de ]anthr-7-one

Chloro-7 H -benz[ de ]anthr-7-ones (chlorobenzanthrones) are useful as starting materials for synthesis of larger polycyclic aromatic compounds by means of condensation. In the synthesis, the position of the chlorine atom is very important because the structure of condensation products strongly depends on it. For this reason, we have synthesized several chlorobenzanthrones. Although 3- and 4-chlorobenzanthrone were prepared by direct chlorination of benzanthrone and by glycerol condensation of 2-chloroanthraquinone, respectively, the synthesis of 1- and 2-chlorobenzanthrone has not yet been successful. In the present study, we attempted to synthesize them by use of the Sandmeyer reaction. First, we nitrated benzanthrone with nitric acid; 1- and 2-nitrobenzanthrone were obtained by nitration in nitrobenzene at 50-60° and in glacial acetic acid at 105-110°, respectively. Then the nitroderivatives were reduced to corresponding aminoderivatives; the reduction was performed with sodium sulfide for 1-nitrobenzanthrone and with hydrogen chloride and tin for 2-nitrobenzanthrone. Finally, chlorination was carried out by use of the Sandmeyer reaction. The products were separated and purified by column-chromatography. The position of chlorination was confirmed by NMR spectroscopy.     

Analysis of photonic crystal waveguide gratings with coupled-mode theory and a finite-element method

Both rod and air-hole types of photonic crystal waveguide gratings are proposed and their coupling coefficients and transmission characteristics are effectively investigated by using a simple coupled-mode theory combined with a finite-element method. The results obtained are compared with the results obtained by using a full numerical simulation method. A new definition for unperturbed waveguides is introduced to obtain accurate coupling coefficients. It is shown that, by using a pi-phase-shifted waveguide structure in the case of an air-hole type of photonic crystal waveguide grating, the coupling coefficient is strongly enhanced. The accuracy of the method is discussed through numerical examples of high-index-contrast waveguide gratings.