Development of spherical ultrasonic motor for pipe inspection robot

We present a pipe inspection robot using a newly developed spherical ultrasonic motor (SUSM) as a camera actuator. The novel SUSM has improved the range of movement compared to previous SUSMs, and the robot can point a camera in any direction. In this study, we determined a method for controlling the rotational direction and strategic control from the kinematics and characteristics of ultrasonic motors. The rotational directions were defined by the phase differences of the applied voltages, and the rotational speeds were changed with the frequencies. Additionally, we developed a very small position sensing system using rotary potentiometers. In the control experiment performed using the sensing system, the SUSM showed the returnability to the default position from several specified points, within an accuracy of 1°

Produção de serapilheira em reflorestamento com paricá (Schyzolobium parahyba var. amazonicum) em áreas degradadas em Aurora do Pará, Pará.

Resumo: 509

In situ observation of atmospheric oxygen and carbon dioxide in the North Pacific using a cargo ship

Atmospheric oxygen (O2) and carbon dioxide (CO2) variations in the North Pacific were measured aboard a cargo ship, the New Century 2 (NC2), while it cruised between Japan and the United States between December 2015 and November 2016. A fuel cell analyzer and a nondispersive infrared analyzer were used for the measurement of O2 and CO2, respectively. To achieve parts-per-million precision for the O2 measurements, we precisely controlled the flow rates of the sample and reference air introduced into the analyzers and the outlet pressure. A relatively low airflow rate (10 cm3 min−1) was adopted to reduce the consumption rate of the reference gases. In the laboratory, the system achieved measurement precisions of 3.8 per meg for δ(O2 ∕ N2), which is commonly used to express atmospheric O2 variation, and 0.1 ppm for the CO2 mole fraction. After the in situ observation started aboard NC2, we found that the ship's motion caused false wavy variations in the O2 signal with an amplitude of more than several tens of ppm and a period of about 20 s. Although we have not resolved the problem at this stage, hourly averaging considerably suppressed the variation associated with ship motion. Comparison between the in situ observation and flask sampling of air samples aboard NC2 showed that the averaged differences (in situ–flask) and the standard deviations (±1σ) are −2.8 ± 9.4 per meg for δ(O2 ∕ N2) and −0.02 ± 0.33 ppm for the CO2 mole fraction. We compared 1 year of in situ data for atmospheric potential oxygen (APO; O2 +1.1 × CO2) obtained from the broad middle-latitude region (140° E–130° W, 29° N–45° N) with previous flask sampling data from the North Pacific. This comparison showed that longitudinal differences in the seasonal amplitude of APO, ranging from 51 to 73 per meg, were smaller than the latitudinal differences.</p

Observation of B0bar --> D(*)0 p pbar

The B meson decay modes B --> D p pbar and B --> D* p pbar have been studied using 29.4 fb^{-1} of data collected with the Belle detector at KEKB. The B0bar --> D0 p pbar and B0bar --> D*0 p pbar decays have been observed for the first time with branching fractions Br(B0bar --> D0 p pbar) =(1.18\pm 0.15\pm 0.16) 10^{-4} and Br(B0bar --> D*0 p pbar) =(1.20^{+0.33}_{-0.29}\pm 0.21) 10^{-4}. No signal has been found for the B+ --> D+ p pbar and B+ --> D*+ p pbar decay modes, and the corresponding upper limits at 90% C.L. are presented.Comment: 6 pages, 3 figures, submited to Phys. Rev. Let

Observation of Double cc bar Production in e+ e- Annihilation at sqrt{s} ~ 10.6 GeV

We report the observation of prompt J/psi via double ccbar production from the e+e- continuum. In this process one ccbar pair fragments into a J/psi meson while the remaining pair either produces a bound charmonium state or fragments into open charm. Both cases have been observed: the first by studying the mass spectrum of the system recoiling against the J/psi, and the second by reconstructing the J/psi together with a charmed meson. We find cross-sections of \sigma(e+ e- -> J/psi eta_c (gamma)) * BR (eta_c -> >=4 charged) = 0.033 (+0.007 -0.006)(stat) \pm 0.009(syst)pb and \sigma(e+ e- -> J/psi D*+ X) = 0.53 (+0.19 -0.15)(stat) \pm 0.14(syst) pb, and infer \sigma(e+ e- -> J/psi c cbar) / \sigma(e+ e- -> J/psi X) = 0.59 (+0.15 -0.13)(stat) \pm 0.12(syst). These results are obtained from a 46.2/fb data sample collected near the Upsilon(4S) resonance, with the Belle detector at the KEKB asymmetric energy e+ e- collider.Comment: 7 pages, 2 figures, to be submitted to Physical Review Letter

Observation of chi_c2 Production in B-meson Decay

We report the first observation of chi_c2 production in B-meson decays. We find an inclusive B -> chi_c2 X branching fraction of (1.80^{+0.23}_{-0.28}+/- 0.26) 10^-3. The data set, collected with the Belle detector at the KEKB e^+e^- collider, consists of 31.9 million B\bar B events. We also present branching fractions and momentum spectra for both chi_c1 and chi_c2 production.Comment: 5 pages with 2 figure

A Measurement of Lifetime Difference in D0D^0 Meson Decays

We report a measurement of the $D^0$-$\bar{D}{}^0$ mixing parameter $y_{CP}$ using 23.4 fb$^{-1}$ of data collected near the $\Upsilon$(4S) resonance with the Belle detector at KEKB. $y_{CP}$ is measured from the lifetime difference of $D^0$ mesons decaying into the $K^-\pi^+$ state and the CP even eigenstate $K^-K^+$. We find $y_{CP}=(-0.5\pm 1.0{}^{+0.7}_{-0.8})\times10^{-2}$, where the first error is statistical and the second systematic, corresponding to a 95% confidence interval $-0.030 < y_{CP} < 0.020$.Comment: 10 pages, 3 figure

Observation of Large CP Violation in the Neutral B Meson System

We present a measurement of the Standard Model CP violation parameter sin 2phi_1 based on a 29.1 fb^{-1} data sample collected at the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+e- collider. One neutral B meson is fully reconstructed as a J/psi Ks, psi(2S) Ks, chi_c1 Ks, eta_c Ks, J/psi K_L or J/psi K^{*0} decay and the flavor of the accompanying B meson is identified from its decay products. From the asymmetry in the distribution of the time intervals between the two B meson decay points, we determine sin 2phi_1 = 0.99 +- 0.14(stat) +- 0.06(syst). We conclude that we have observed CP violation in the neutral B meson system.Comment: 4 figures, to appear in Phys. Rev. Letter