Showing papers by "Chiba Institute of Technology published in 2016"

A New Automotive VLC System Using Optical Communication Image Sensor

Abstract: As a new technology for next-generation vehicle-to-everything (V2X) communication, visible-light communication (VLC) using light-emitting diode (LED) transmitters and camera receivers has been energetically studied. Toward the future in which vehicles are connected anytime and anywhere by optical signals, the cutting-edge camera receiver employing a special CMOS image sensor, i.e., the optical communication image sensor (OCI), has been prototyped, and an optical V2V communication system applying this OCI-based camera receiver has already demonstrated 10-Mb/s optical signal transmission between real vehicles during outside driving. In this paper, to reach a transmission performance of 54 Mb/s, which is standardized as the maximum data rate in IEEE 802.11p for V2X communication, a more advanced OCI-based automotive VLC system is described. By introducing optical orthogonal frequency-division multiplexing (optical-OFDM), the new system achieves a more than fivefold higher data rate. Additionally, the frequency response characteristics and circuit noise of the OCI are closely analyzed and taken into account in the signal design. Furthermore, the forward-current limitation of an actual LED is also considered for long operational reliability, i.e., the LED is not operated in overdrive. Bit-error-rate experiments verify a system performance of 45 Mb/s without bit errors and 55 Mb/s with $\text{BER}\ .

AKATSUKI returns to Venus

Abstract: AKATSUKI is the Japanese Venus Climate Orbiter that was designed to investigate the climate system of Venus. The orbiter was launched on May 21, 2010, and it reached Venus on December 7, 2010. Thrust was applied by the orbital maneuver engine in an attempt to put AKATSUKI into a westward equatorial orbit around Venus with a 30-h orbital period. However, this operation failed because of a malfunction in the propulsion system. After this failure, the spacecraft orbited the Sun for 5 years. On December 7, 2015, AKATSUKI once again approached Venus and the Venus orbit insertion was successful, whereby a westward equatorial orbit with apoapsis of ~440,000 km and orbital period of 14 days was initiated. Now that AKATSUKI’s long journey to Venus has ended, it will provide scientific data on the Venusian climate system for two or more years. For the purpose of both decreasing the apoapsis altitude and avoiding a long eclipse during the orbit, a trim maneuver was performed at the first periapsis. The apoapsis altitude is now ~360,000 km with a periapsis altitude of 1000–8000 km, and the period is 10 days and 12 h. In this paper, we describe the details of the Venus orbit insertion-revenge 1 (VOI-R1) and the new orbit, the expected scientific information to be obtained at this orbit, and the Venus images captured by the onboard 1-µm infrared camera, ultraviolet imager, and long-wave infrared camera 2 h after the successful initiation of the VOI-R1.

Au Nanoparticle-Embedded Carbon Films for Electrochemical As3+ Detection with High Sensitivity and Stability

Abstract: Au nanoparticle (AuNP)-embedded carbon films were formed with a one-step reproducible process by using unbalanced magnetron (UBM) cosputtering to make it possible to detect As3+ in water. The sputtered Au components formed NPs (typically 5 nm in diameter) spontaneously in the carbon films, owing to the poor intermiscibility of Au with carbon. The surface contents of embedded AuNPs in the carbon film were widely controllable (Au = 13–21 at %) by regulating the target powers of Au and carbon individually. The obtained film had a flat surface (Ra = 0.1 nm) despite the fact the AuNPs were partially exposed at the surface. By anodic stripping voltammetry (ASV) As3+ detection, a limit of detection of 0.55 ppb and linear dynamic range of 1–100 ppb were obtained with our electrode. These values meet the requirements imposed by international regulation. Moreover, our electrode structure realized good electrode stability for repetitive ASV measurements (relative standard deviation (RSD) = 11.7%, n = 15) because the...

Cohesion of Amorphous Silica Spheres: Toward a Better Understanding of the Coagulation Growth of Silicate Dust Aggregates

Abstract: Adhesion forces between submicrometer-sized silicate grains play a crucial role in the formation of silicate dust agglomerates, rocky planetesimals, and terrestrial planets. The surface energy of silicate dust particles is the key to their adhesion and rolling forces in a theoretical model based on the contact mechanics. Here we revisit the cohesion of amorphous silica spheres by compiling available data on the surface energy for hydrophilic amorphous silica in various circumstances. It turned out that the surface energy for hydrophilic amorphous silica in a vacuum is a factor of 10 higher than previously assumed. Therefore, the previous theoretical models underestimated the critical velocity for the sticking of amorphous silica spheres, as well as the rolling friction forces between them. With the most plausible value of the surface energy for amorphous silica spheres, theoretical models based on the contact mechanics are in harmony with laboratory experiments. Consequently, we conclude that silicate grains with a radius of $0.1~\mu$m could grow to planetesimals via coagulation in a protoplanetary disk. We argue that the coagulation growth of silicate grains in a molecular cloud is advanced either by organic mantles rather than icy mantles or, if there are no mantles, by nanometer-sized grain radius.

Tracking the spatiotemporal variations of statistically independent components involving enrichment of rare-earth elements in deep-sea sediments.

Abstract: Deep-sea sediments have attracted much attention as a promising resource for rare-earth elements and yttrium (REY). In this study, we show statistically independent components characterising REY-enrichment in the abyssal ocean that are decoded by Independent Component Analysis of a multi-elemental dataset of 3,968 bulk sediment samples from 101 sites in the Pacific and Indian oceans. This study for the first time reconstructs the spatiotemporal variations of the geochemical signatures, including hydrothermal, hydrogenous, and biogenic calcium phosphate components that were closely involved in the formation of REY-rich mud over the past 65 million years. An underlying key factor of significant REY-enrichment is a sufficiently low sedimentation rate that enables the mud to accumulate REY from seawater. In the early Cenozoic, a remarkably small supply of aeolian dust, compared with any other time and region, facilitated the deposition of very high-grade REY-rich mud in the South Pacific. This indicates an important link between the genesis of the seafloor mineral resources and Earth's dynamic phenomena such as climate change and plate tectonics.

Discovery of extremely REY-rich mud in the western North Pacific Ocean

Abstract: Copyright © 2016 by The Geochemical Society of Japan. ment of green technologies, including electric and hybrid vehicles, compact and long-life LED lights, and wind power generation, is required to shift human society toward sustainable growth. Rare-earth elements and yttrium, hereinafter together called REY, are essential elements for products with these advanced and green technologies, because of the magnetic and optical properties of REY that result from the characteristic configurations of electrons in these elements. With rising economic growth in Discovery of extremely REY-rich mud in the western North Pacific Ocean

Phase diagram and collective excitations in an excitonic insulator from an orbital physics viewpoint

Abstract: An excitonic-insulating system is studied from a viewpoint of the orbital physics in strongly correlated electron systems. An effective model Hamiltonian for low-energy electronic states is derived from the two-orbital Hubbard model with a finite-energy difference corresponding to the crystalline-field splitting. The effective model is represented by the spin operators and the pseudospin operators for the spin-state degrees of freedom. The ground-state phase diagram is analyzed by the mean-field approximation. In addition to the low-spin state and high-spin state phases, two kinds of the excitonic-insulating phases emerge as a consequence of the competition between the crystalline-field effect and the Hund coupling. Transitions to the excitonic phases are classified to an Ising-type transition resulted from a spontaneous breaking of the ${Z}_{2}$ symmetry. Magnetic structures in the two excitonic-insulating phases are different from each other: an antiferromagnetic order and a spin nematic order. Collective excitations in each phase are examined using the generalized spin-wave approximation. Characteristics in the Goldstone modes in the excitonic-insulating phases are studied through the calculations of the dynamical correlation functions for the spins and pseudospin operators. Both the transverse and longitudinal spin excitation modes are active in the two excitonic-insulating phases in contrast to the low-spin state and high-spin state phases. Relationships of the present results to the perovskite cobalt oxides are discussed.

Hyperon-mixed neutron star with universal many-body repulsion

Abstract: Neutron stars with large masses \( \sim 2M_{\odot}\) require the hard stiffness of equation of state (EoS) of neutron-star matter. On the other hand, hyperon mixing brings about remarkable softening of EoS. In order to solve this problem, a multi-pomeron exchange potential (MPP) is introduced as a model for the universal many-body repulsion in baryonic systems on the basis of the Extended Soft Core (ESC) baryon-baryon interaction. The strength of MPP is determined by analyzing the nucleus-nucleus scattering with the G -matrix folding model. The interactions in \( \Lambda N\) , \( \Sigma N\) and \( \Xi N\) channels are shown to be consistent with experimental indications. The EoS in neutron-star matter with hyperon mixing is obtained from ESC in addition of MPP, and mass-radius relations of neutron stars are derived. The maximum mass is shown to reach \( 2M_{\odot}\) even in the case of including hyperon mixing on the basis of model-parameters determined by terrestrial experiments.

Geology and geochemistry of ferromanganese nodules in the Japanese Exclusive Economic Zone around Minamitorishima Island

Abstract: Copyright © 2016 by The Geochemical Society of Japan. moteness is an obstacle to mining operations. However, large Fe-Mn nodules have also been found to be densely distributed on a seamount in the eastern part of the Japanese Exclusive Economic Zone (EEZ) around Minamitorishima (Marcus) Island, Japan, where their resource potential is more promising because they are located closer to the main islands of Japan than the CCZ. Thus, further exploration in the EEZ can be expected, along with future development followed by the self-sufficiency and the stabilization of the market for critical metals. In this report, we describe results of a geological survey using the submersible SHINKAI 6500 and a multiple narrow-beam echo sounder system during cruise YK10-05 of R/V Yokosuka. We also present the results of chemical analyses to define geochemical features for representative Fe-Mn nodules and adjacent Fe-Mn crusts. Geology and geochemistry of ferromanganese nodules in the Japanese Exclusive Economic Zone around Minamitorishima Island

Hepatitis C virus utilizes VLDLR as a novel entry pathway

Abstract: Various host factors are involved in the cellular entry of hepatitis C virus (HCV). In addition to the factors previously reported, we discovered that the very-low-density lipoprotein receptor (VLDLR) mediates HCV entry independent of CD81. Culturing Huh7.5 cells under hypoxic conditions significantly increased HCV entry as a result of the expression of VLDLR, which was not expressed under normoxic conditions in this cell line. Ectopic VLDLR expression conferred susceptibility to HCV entry of CD81-deficient Huh7.5 cells. Additionally, VLDLR-mediated HCV entry was not affected by the knockdown of cellular factors known to act as HCV receptors or HCV entry factors. Because VLDLR is expressed in primary human hepatocytes, our results suggest that VLDLR functions in vivo as an HCV receptor independent of canonical CD81-mediated HCV entry.

Kinetic and Thermodynamic Analyses of Interaction between a High-Affinity RNA Aptamer and Its Target Protein

Abstract: AML1 (RUNX1) protein is an essential transcription factor involved in the development of hematopoietic cells. Several genetic aberrations that disrupt the function of AML1 have been frequently observed in human leukemia. AML1 contains a DNA-binding domain known as the Runt domain (RD), which recognizes the RD-binding double-stranded DNA element of target genes. In this study, we identified high-affinity RNA aptamers that bind to RD by systematic evolution of ligands by exponential enrichment. The binding assay using surface plasmon resonance indicated that a shortened aptamer retained the ability to bind to RD when 1 M potassium acetate was used. A thermodynamic study using isothermal titration calorimetry (ITC) showed that the aptamer–RD interaction is driven by a large enthalpy change, and its unfavorable entropy change is compensated by a favorable enthalpy change. Furthermore, the binding heat capacity change was identified from the ITC data at various temperatures. The aptamer binding showed a large ...

Thermal and mechanical properties of bio-based polymer networks by thiol-ene photopolymerizations of gallic acid and pyrogallol derivatives

Abstract: Allylated pyrogallol (A3PG) and acrylated pyrogallol (Ac3PG) as bio-based trienes, and allylated gallic acid (A4GA) and acrylated allyl gallate (Ac3A1GA) as bio-based tetraenes were synthesized from pyrogallol and gallic acid, respectively. Thiol-ene photopolymerizations of the bio-based polyenes and a pentaerythritol-based primary tetrathiol (pS4P) at the allyl/SH ratio of 1/1 produced photo-cured resins (A3PG-pS4P, Ac3PG-pS4P, A4GA-pS4P and Ac3A1GA-pS4P). The FT-IR spectral analysis revealed that thiol-ene reactions of thiol/allyl and thiol/acryloyl groups smoothly proceeded. Gel fractions of acryl-based cured resins were a little higher than those of allyl-based cured resins. The swelling test and dynamic mechanical analysis revealed that GA- and acryl-based cured resins exhibited higher crosslinking densities than PG- and allyl-based cured resins, respectively. A higher order of tan δ peak temperature was Ac3PG-pS4P (48.3 ° C) > Ac3A1GA-pS4P (24.1 ° C) > A4GA-pS4P (22.1 ° C) > A3PG-pS4P (−7.8 ° C). Ac3PG-pS4P displayed the highest 5 % weight loss temperature, tensile strength and tensile modulus among all of the cured resins.

Fate of HIV-1 cDNA intermediates during reverse transcription is dictated by transcription initiation site of virus genomic RNA.

Abstract: Retroviral reverse transcription is accomplished by sequential strand-transfers of partial cDNA intermediates copied from viral genomic RNA. Here, we revealed an unprecedented role of 5′-end guanosine (G) of HIV-1 genomic RNA for reverse transcription. Based on current consensus for HIV-1 transcription initiation site, HIV-1 transcripts possess a single G at 5′-ends (G1-form). However, we found that HIV-1 transcripts with additional Gs at 5′-ends (G2- and G3-forms) were abundantly expressed in infected cells by using alternative transcription initiation sites. The G2- and G3-forms were also detected in the virus particle, although the G1-form predominated. To address biological impact of the 5′-G number, we generated HIV clone DNA to express the G1-form exclusively by deleting the alternative initiation sites. Virus produced from the clone showed significantly higher strand-transfer of minus strong-stop cDNA (-sscDNA). The in vitro assay using synthetic HIV-1 RNAs revealed that the abortive forms of -sscDNA were abundantly generated from the G3-form RNA, but dramatically reduced from the G1-form. Moreover, the strand-transfer of -sscDNA from the G1-form was prominently stimulated by HIV-1 nucleocapsid. Taken together, our results demonstrated that the 5′-G number that corresponds to HIV-1 transcription initiation site was critical for successful strand-transfer of -sscDNA during reverse transcription.

Geological factors responsible for REY-rich mud in the western North Pacific Ocean: Implications from mineralogy and grain size distributions

Abstract: Copyright © 2016 by The Geochemical Society of Japan. increased access to REY resources are critically needed. Recently, Kato et al. (2011) reported the existence of extensive new REY resources on the abyssal seafloor of many areas of the Pacific Ocean. They referred to pelagic sediment with total REY contents (ÂREY) greater than 400 ppm as “REY-rich mud”. By chemical analyses of sediment samples from two Deep Sea Drilling Project/ Ocean Drilling Program (DSDP/ODP) cores (DSDP Hole 198A and ODP Hole 800A), Kato et al. (2012) identified REY-rich mud within the Japanese Exclusive Economic Zone around Minamitorishima Island (Minamitorishima Geological factors responsible for REY-rich mud in the western North Pacific Ocean: Implications from mineralogy and grain size distributions

Geochemistry of REY-rich mud in the Japanese Exclusive Economic Zone around Minamitorishima Island

Abstract: KOICHIRO FUJINAGA,1,2 KAZUTAKA YASUKAWA,3,1 KENTARO NAKAMURA,3 SHIKI MACHIDA,4 YUTARO TAKAYA,5,2,4 JUNICHIRO OHTA,6 SHUHEI ARAKI,3 HANJIE LIU,3 RYO USAMI,3 RYOTA MAKI,3 SATORU HARAGUCHI,6 YOSHIRO NISHIO,7 YOICHI USUI,4 TATSUO NOZAKI,4,8,2 TOSHITSUGU YAMAZAKI,9,10 YUJI ICHIYAMA,11 AKIRA IJIRI,12,4 FUMIO INAGAKI,12,4 HIDEAKI MACHIYAMA,4 KOICHI IIJIMA,4 KATSUHIKO SUZUKI,4 YASUHIRO KATO2,3,1,4* and KR13-02, MR13-E02 LEG 2 AND KR14-02 CRUISE MEMBERS

Establishing Trust in the Emerging Era of IoT

Abstract: IoT (Internet of Things) is changing the world. Today, we see that the Internet is reaching every bit in the world. IoT environment contains mobile devices, automotive equipments, and home appliances. Everything is sensed, actuated, and integrated into the Internet. Accordingly, the related problems are fast emerging. Considering the fact that the IoT is closely connected to human activities, and that the problems essential to them are tangled with traditional technical problems, it is quite natural that new challenges emerge there. Device control and privacy related security problems are their typical concerns. On the other hand, continuous efforts have been made for establishing trust in the untrusted Internet. Particularly, since it became clear that mutual trust was essential to securely and trustfully expand the market of e-commerce in the Internet, a number of technical solutions have been proposed and deployed. Furthermore, a kind of social infrastructure -- trust frameworks have been deployed and are operated as the trust anchors in the Internet. In our work, trust establishment in IoT environments is investigated along the line of the trust framework in identities. First, our IoT architecture is proposed. Control and data service layer is placed on top of the device layer and the wireless communications. Trust establishment on the service layer includes that of device control and wireless security. Here, we consider "area"-wise trust, where its level is assessed in terms of device identification, monitoring of device behaviors, connection process to devices and connection protocols that are parallel to the assessment criteria in the conventional trust framework. Secure mobile network as the anchor of IoT trust is also discussed.

Highly intense monocycle terahertz vortex generation by utilizing a Tsurupica spiral phase plate.

Abstract: Optical vortex, possessing an annular intensity profile and an orbital angular momentum (characterized by an integer termed a topological charge) associated with a helical wavefront, has attracted great attention for diverse applications due to its unique properties. In particular for terahertz (THz) frequency range, several approaches for THz vortex generation, including molded phase plates consisting of metal slit antennas, achromatic polarization elements and binary-diffractive optical elements, have been recently proposed, however, they are typically designed for a specific frequency. Here, we demonstrate highly intense broadband monocycle vortex generation near 0.6 THz by utilizing a polymeric Tsurupica spiral phase plate in combination with tilted-pulse-front optical rectification in a prism-cut LiNbO3 crystal. A maximum peak power of 2.3 MW was obtained for THz vortex output with an expected topological charge of 1.15. Furthermore, we applied the highly intense THz vortex beam for studying unique nonlinear behaviors in bilayer graphene towards the development of nonlinear super-resolution THz microscopy and imaging system.

Ligand-Induced Formation of Copper(I) Iodide Clusters: Exocyclic Coordination Polymers with Bis-dithiamacrocycle Isomers

Abstract: A comparative study on the formation of guest clusters induced by different shapes (or sizes) of exocyclic binding sites embedded in the bis-macrocyclic host isomers is reported. CuI reacts with two regioisomers of a bis-dithiamacrocycle, o-bis-L (W-shaped binding site) and m-bis-L (U-shaped binding site), to yield one-dimensional coordination polymers {[(μ4-Cu4I4)(o-bis-L)]·2CH3CN}n (1a) and [(μ4-Cu2I2)(m-bis-L)]n (2). In 1a, the o-bis-L ligand isomer is linked by a spacious cubane [Cu4I4] cluster, while the m-bis-L ligand in 2 is linked by a smaller rhomboid [Cu2I2] cluster because of the different exocyclic binding sites. The results observed illustrate the possibility for the metal clusters including [CunIn] (n = 2 or 4) to adopt a controlled formation through the binding site alternation or design. Because of the adaptive cluster formations, the products show different photophysical properties. Additionally, sliding of the one-dimensional chains in 1a was observed upon loss of the lattice solvent mol...

First-principles lattice dynamics and Raman scattering in ionic conductor β-Ag2S

Abstract: The phonon structure of the silver sulfide Ag2S was investigated, experimentally using Raman spectroscopy, and theoretically using the density-functional perturbation theory for the first time. Seven Raman-active modes were observed and identified at 23, 39, 42, 44, 62, 65, and 243 cm−1. Symmetry assignments of all the vibrational modes were derived from considerations of point group symmetry. The phonon band structure and the relative Raman intensities were also investigated by ab initio calculations and compared with the experimental data. The temperature, laser power, and illumination time dependencies of frequency, linewidth, and intensity of the Raman-active modes are discussed. In the Raman spectra at higher frequencies 1300–1700 cm−1, additional broad Raman modes observed in all samples at higher laser powers 8–10 mW were ascribed to luminescence from β-Ag2S. The phonon and Raman spectra of the β-Ag2S provide a useful insight into the β-Ag2S → α-Ag2S phase transition. Finally, calculated infrared vibrational mode frequencies were compared with measured infrared mode frequencies.

Development of a prototype of the Tomo-e Gozen wide-field CMOS camera

Abstract: The Tomo-e Gozen is an extremely wide-field optical camera for the Kiso 1.0-m Schmidt telescope. It is capable of taking consecutive frames with a field-of-view of 20 deg2 and a sub-second time-resolution, which are achieved by 84 chips of 2k×1k CMOS sensor. This camera adopts unconventional designs including a lightweight structure, a nonvacuumed and naturally-air cooled system, front-side-illuminated CMOS sensors with microlens arrays, a sensor alignment along a spherical focal plane of the telescope, and massive readout electronics. To develop technical components necessary for the Tomo-e Gozen and confirm a feasibility of its basic design, we have developed a prototype-model (PM) of the Tomo-e Gozen prior to the final-model (FM). The Tomo-e PM is equipped with eight chips of the CMOS sensor arranged in a line along the RA direction, covering a sky area of 2.0 deg2. The maximum frame rate is 2 fps. The total data production rate is 80 MByte sec-1 at 2 fps, corresponding to approximately 3 TByte night-1. After laboratory testing, we have successfully obtained consecutive movie data at 2 fps with the Tomo-e PM in the first commissioning run conducted in the end of 2015.

Weighted tensor nuclear norm minimization for color image denoising

Abstract: Although non-local image denoising has attracted much research effort due to its superior performance, little attention has focused on its color extension. Most existing non-local color image denoising methods process the color channels of an input image separately. However, in order to improve the performance of color image denoising, all color channels should be processed jointly for fully utilizing the interchannel dependency. This paper proposes a new non-local and inter-channel dependency aware prior, named weighted tensor nuclear norm (WTNN), and it is defined on a 3rd-order tensor from a patch cluster of an input image. We also present an effective algorithm for color image denoising using the WTNN. Experimental results clearly show that the proposed algorithm outperforms a state-of-the-art color image denoising method, known as CBM3D.

Shock compression response of forsterite above 250 GPa

Abstract: Forsterite (Mg2SiO4) is one of the major planetary materials, and its behavior under extreme conditions is important to understand the interior structure of large planets, such as super-Earths, and large-scale planetary impact events. Previous shock compression measurements of forsterite indicate that it may melt below 200 GPa, but these measurements did not go beyond 200 GPa. We report the shock response of forsterite above ~250 GPa, obtained using the laser shock wave technique. We simultaneously measured the Hugoniot and temperature of shocked forsterite and interpreted the results to suggest the following: (i) incongruent crystallization of MgO at 271 to 285 GPa, (ii) phase transition of MgO at 285 to 344 GPa, and (iii) remelting above ~470 to 500 GPa. These exothermic and endothermic reactions are seen to occur under extreme conditions of pressure and temperature. They indicate complex structural and chemical changes in the system MgO-SiO2 at extreme pressures and temperatures and will affect the way we understand the interior processes of large rocky planets as well as material transformation by impacts in the formation of planetary systems.

Target-less camera-LiDAR extrinsic calibration using a bagged dependence estimator

Abstract: The goal of this study is to achieve automatic extrinsic calibration of a camera-LiDAR system that does not require calibration targets. Calibration through maximization of statistical dependence using mutual information (MI) is a promising approach. However, we observed that existing methods perform poorly on outdoor data sets. Because of their susceptibility to noise, objective functions of previous methods tend to be non-smooth, and gradient-based searches fail in local optima. To overcome these issues, we introduce a novel dependence estimator called bagged least-squares mutual information (BLSMI). BLSMI is a combination of methods composed of a kernel-based dependence estimator and noise reduction by bootstrap aggregating (bagging), which can handle richer features and robustly estimate dependence. We compared ours with previous methods using indoor and outdoor data sets, and observed that our method performed best in terms of calibration accuracy. While previous methods showed degraded performance on outdoor data sets because of the local optima problem, our method exhibited high calibration accuracy both on indoor and outdoor data sets.

Cation-Selective and Anion-Controlled Fluorogenic Behaviors of a Benzothiazole-Attached Macrocycle That Correlate with Structural Coordination Modes.

Abstract: We report how the metal cation and its counteranions cooperate in the complexation-based macrocyclic chemosensor to monitor the target metal ion via the specific coordination modes. The benzothiazolyl group bearing NO2S2-macrocycle L was synthesized, and its mercury(II) selectivity (for perchlorate salt) as a dual-probe channel (UV–vis and fluorescence) chemosensor exhibiting the largest blue shift and the fluorescence turn-off was observed. In the mercury(II) sensing with different anions, except ClO4– and NO3–, no responses for mercury(II) were observed with other anions such as Cl–, Br–, I–, SCN–, OAc–, and SO42–. A crystallographic approach for the mononuclear mercury(II) perchlorate complex [Hg(L)(ClO4)2]·0.67CH2Cl2 (1) and polymeric mercury(II) iodide complex [Hg(L)I2]n (2) revealed that the observed anion-controlled mercury(II) sensing in the fluorescence mainly stems from the endo- and exocoordination modes, depending on the anion coordinating ability, which induces either the Hg–Ntert bond format...

Emerging Technology for Head-Positioning System in HDDs

Abstract: The recent rapid growth of the information industry has strongly increased the demand for large-capacity hard disk drives (HDDs). This means that increasing the areal recording density has become an important technical challenge in HDD development. To increase the HDD areal recording density, we have developed emerging technologies for highaccuracy positioning control of magnetic heads in the head-positioning system of HDDs. This paper introduces two examples of emerging technologies for future HDDs: “Vibration Control with Thin-Film-Coil Actuator” and “HighBandwidth Control with Thermal Actuator”. The former utilizes a film-coil actuator attached to a coil of a voice-coil motor. The latter utilizes a thermal actuator in the magnetic head. These control systems employ triple-stage-actuator systems to improve the control performance of the head-positioning system. The validation results showed that these control systems enable us to achieve high-accuracy positioning control of magnetic heads for future HDDs.

Pedometer-determined physical activity among youth in the Tokyo Metropolitan area: a cross-sectional study

Abstract: Providing large-scale descriptive data of objectively measured physical activity in youth is informative for practitioners, epidemiologists, and researchers. The purpose of this study was to present the pedometer-determined physical activity among Japanese youth using the Tokyo Metropolitan Survey of Physical Fitness, Physical Activity and Lifestyle 2011. This study used a school-based survey. The Tokyo Metropolitan Board of Education originally collected pedometer-determined steps per day in the fall of 2011. Data were collected from 15,471 youth aged 6 to 18 years living in Tokyo. Participants were asked to wear pedometers for 14 consecutive days, and daily steps logged in the final 7 days were selected for this analysis. At the primary and junior high school levels, boys (12,483 and 9476, respectively) had a significantly higher mean number of steps per day than did girls (10,053 and 8408, respectively). There was no significant difference in the mean number of steps per day between the sexes at the high school level. Mean steps per day decreased consistently with age and grade level; the lowest overall steps per day was observed in the last year of junior high school, although there was a slight increase in the subsequent year, the first year of high school. This study demonstrates a trend toward reduced physical activity with age in Japanese youth and a substantial difference in the number of steps per day between boys and girls in Tokyo. The age-related reduction in steps per day was greater in boys because they attained a higher peak value prior to this reduction, and sex-related differences in the step count disappeared in high school students.

Asymmetric Synthesis of an Amino Acid Derivative from Achiral Aroyl Acrylamide by Reversible Michael Addition and Preferential Crystallization.

Abstract: Single-handed alpha-amino acid derivatives were generated from achiral precursors without an external chiral source. Conjugate addition of phenethylamine to an achiral aroylacrylamide under homogeneous conditions gave the alpha-amino amides in quantitative yields, which crystallized as a conglomerate of a P21 crystal system. Dynamic preferential crystallization or attrition-enhanced deracemization resulted in the formation of enantiomorphic crystals of 99% ee.

Guest-triggered assembly of zinc(II) supramolecular isomers with accompanying dimensional change and reversible single-crystal-to-single-crystal transformation

Abstract: Solvent-directed assembly of two-dimensional (2D) and 3D supramolecular isomers as well as guest-exchange induced transformation of the 2D isomer accompanied by photoluminescence switching are reported. Solvothermal reaction of Zn(NO3)2·4H2O, 1,4-bis(4-pyridyl)piperazine (bpp), and benzene-1,3-dicarboxylic acid (H2bdc) in dimethylformamide (DMF) afforded a self-penetrated 3D coordination polymer, {[Zn2(bpp)2(bdc)2]·4DMF·4H2O}n (1), adopting a firewood-like stacking structure. When the above synthetic procedure was repeated employing dimethylacetamide (DMA) as a solvent, a 2D coordination polymer, {[Zn2(bpp)2(bdc)2]·4DMA·6H2O}n (2), was obtained, whose structure shows a crinkled square (4,4) grid type, as a supramolecular isomer of 1. The dimensional difference between isomers 1 and 2 stems mainly from the directional arrangement and the conformation of the bpp ligand. In the guest-exchange experiment, isomer 2 with the crinkled square grid structure not only represents a reversible spreading–folding conversion due to the conformational change of the bpp ligand but also displays a photoluminescence switching behaviour.