Modified inverse square sensitometry for the determination of the characteristic curve of radiographic screen/film systems.

To determine the characteristic curve of the radiographic screen/film systems in a short focal spot-film distance, the inverse square sensitometric method was modified by changing the radiation intensity with two kinds of filters. The characteristic curves obtained in the two exposure series with these two kinds of filters were overlapped to obtain a complete one. The characteristic curve thus obtained was almost the same as the one obtained by the original inverse square sensitometric method. The accuracy of the characteristic curves obtained by the modified method was well-reflected in the clinical radiographs.</p

Control of the glass-liquid transition temperature in YBa2Cu3O7-x films

Magnetic field dependences of the glass-liquid transition temperature (Tg) were studied in YBa2Cu3O7−x films containing various types of nanoinclusions. The vortex configuration entangled or straight and pinning strength for each vortex are crucial to the behaviors of Tg. c-axis correlated pinning centers optimize these factors and achieve the upper limit of Tg, which is determined by loss of line tension of vortices, if they are elongated through a thickness of a sample. By optimizing pinning centers, critical temperature, and a matching field, a Tg value of 77 K can be obtained in YBa2Cu3O7−x in a magnetic field as high as 27 T

A Novel High-Speed Electromagnetic Oscillatory Actuator With a Dual Mover for Optical Scanner Applications

In this paper, we propose a high-speed moving magnet-type oscillatory actuator in which a dual-mover structure is designed to reduce magnetic damping force. Both movers have independent resonant frequency, and the actuator is driven at the larger resonant frequency. The smaller mover serves as the optical scanning element and maintains large oscillation amplitude. The larger mover, with moving magnets, serves as the magnetic driving element and maintains relatively smaller amplitude because of the magnetic damping.ArticleIEEE TRANSACTIONS ON MAGNETICS. 50(11):8203504 (2014)journal articl

Nanostructures and flux pinning properties in YBa2Cu3O7−y thin films with double perovskite Ba2LuNbO6 nanorods

Double perovskite Ba2LuNbO6 (BLNO)-doped YBa2Cu3O7−y (YBCO) thin films are fabricated on a SrTiO3 (001) substrate by pulsed laser deposition, and their nanostructures are characterized by transmission electron microscopy and scanning transmission electron microscopy. Cross-sectional observations and elemental mapping reveal that BLNO self-assembles during thin film deposition, and consequently, nanorods extending straight from the substrate to the surface are formed in the YBCO thin films. It is confirmed that stacking faults perpendicular to the growth direction disturb the formation of BLNO nanorods. Strain maps extracted by geometric phase analysis reveal that the tensile strain occurs in the YBCO matrix around the BLNO nanorods. Misfit dislocations are periodically introduced at the interface between the nanorod and the matrix, which results in the inhomogeneous strain of YBCO around the BLNO nanorods. The superconducting properties of the YBCO + BLNO thin films are compared with those of other previously reported YBCO thin films with normal perovskite and double perovskite nanorods

Microscopic characterization of the C–F bonds in fluorine–graphite intercalation compounds

The structures of fluorine–graphite intercalation compounds (F-GICs, C₂.₈F and C₃.₅F) have been analyzed by high-resolution transmission electron microscopy (TEM). Cross-sectional TEM images of the F-GICs indicate that the interlayer distance increases by insertion of fluorine with randomly buckled carbon layers. Such a structure can form by alternation in the bond angle at a carbon atom covalently bonded with fluorine. Electron energy loss spectroscopy combined with TEM indicates that the π-orbital network over the graphitic carbon layer reduces with fluorination. The C–F bond is essentially covalent

シジン ノ ケイザイ シスウ : ディキンスン ト ランプ シュッパン シンタイ

本稿はエミリィ・ディキンスンのオイル・ランプと出版に関する詩・書簡を社会的・経済的・歴史的に考察することを目的とする。最初に考察する"The Lamp burns sure &#8211; within &#8211; "は、詩人が執筆できるよう召使たちがランプに油を充填するのに対し、詩人を指し示すランプは物書きに専心しており、詩人が創作活動に勤しむことができるのは召使たちの下働きのおかげであると解釈できる。次に論じる"Publication &#8211; is the Auction"は、文学市場に作品を産出することが商品として詩人自身の身体を売りに出すという解釈が可能であるため、貧困に陥らない限り、出版を見合わせたいという詩人像が浮かぶ。これらの詩をディキンスンの書簡や社会的・歴史的資料を加えて読むことで、彼女の詩作品が経済的な境遇を背景にもつ産物であると結論付けた。The purpose of this paper is to examine Emily Dickinson\u27s poems and letters concerning the oil lamp and publishing from a social, economic, and historical standpoint. The first poem I explore is "The Lamp burns sure &#8211; within &#8211; ," in which a poet symbolized by a lamp thinks on his/her own writing while domestic servants refill the lamp so the poet can write. This means that the poet can create through the servants\u27 help. The second poem I investigate is "Publication &#8211; is the Auction," one of the interpretations of which is that writing poems for the literary marketplace is selling his/her own physical body as a commodity, so that the poet is unwilling to publish except when in abject poverty. Reading these two poems with Dickinson\u27s letters and social or historical materials leads to the conclusion that her poems are outputs of her literary life and economic surroundings

Delocalization of vortex in SmBa2Cu3O7−δ superconducting films with BaHfO3 nano-rods

Transport measurements revealed flux pinning properties and vortex phases in SmBa2Cu3O7−δ (Sm123) superconducting films with BaHfO3 nano-rods on LaAlO3 substrates. The films have large matching fields BΦ up to 9.9 T, nano-rod diameters of ∼6 nm, and a slight Tc degradation with Tc ∼ 91.8 K by using the low temperature growth technique. According to the transport results, a small critical exponent ∼4 indicates the presence of a Bose-glass phase in the films. Double peaks of the flux pinning force density are unexpectedly observed at high temperatures over 80 K, which is accompanied by steep drops of the crossover magnetic fields between the single vortex pinning and the collective pinning states. The drops are explained by the delocalization of the vortex where the vortex is pinned by many nano-rods in the single vortex pinning state. From the viewpoint of the vortex delocalization, we conclude that BΦ should be less than 11 T for applications at liquid nitrogen temperature

Systematic Variation of Hybrid APCs Into YBCO Thin Films for Improving the Vortex Pinning Properties

The effect of hybrid (columnar and spherical) artificial pinning centers (APCs) on the vortex pinning properties of YBCO thin films is studied in this paper on the basis of variation of critical current density JC with applied magnetic held and also with the orientation of the applied magnetic held. YBCO+BSO3% composite target is used for preparing film with 1-D (columnar) APCs, whereas the same composite target is modified by putting two differently sized (2.2 area% and 3 area%) Y2O3 sectored pieces for preparing films having different concentrations of 3-D (spherical) APCs along with 1-D APCs. Film consisting of only 1-D APCs exhibits enhanced in-held JC values as compared to the one without any APC, and the ones consisting of hybrid APCs exhibit even better JC-B characteristics with increase in the fraction of 3-D APCs. Fp max. values increase systematically with incorporation of 1-D and 1-D + 3-D APCs, and it also shifts toward higher applied magnetic fields. Film with 1-D APCs exhibits strong JC peak at Θ = 0° (H//c-axis), whereas films consisting of hybrid APCs exhibit enhanced JC at all the investigated angular regime. A possible mechanism of vortex pinning in samples with hybrid APCs is also discussed, suggesting the role of 1-D and 3-D APCs

Tuning the microstructure and vortex pinning properties of YBCO-based superconducting nanocomposite films by controlling the target rotation speed

We report the controlled incorporation of perovskite, BaSnO3 (BSO), and double-perovskite, YBa2NbO6 (YBNO), nanocolumnar structures into a YBa2Cu3O7−δ (YBCO) film matrix by controlling the target rotation speed. A surface modified target approach has been employed to deposit YBCO+BSO and YBCO+YBNO nanocomposite films using a laser ablation technique. The effect of target rotation speed on the microstructure and subsequently on the superconducting properties has been studied in detail. The density of BSO and YBNO nanocolumnar structures is found to depend on the target rotation speed, which subsequently affects the vortex pinning properties of the superconducting films in the absence and presence of applied magnetic fields. Three rotation speeds, 3, 2 and 1 s/rot., have been attempted in this study. Compared to pure YBCO, the YBCO+BSO and YBCO+YBNO nanocomposite films exhibit superior in-field critical current density (JC) and also exhibit a strong JC peak for H ∥ c-axis, indicating strong c-axis pinning. The irreversibility line has also been found to improve significantly in the nanocomposite films. For both the target combinations (YBCO+BSO and YBCO+YBNO), the target rotation speed of 2 s/rot. has been found to give the optimum superconducting properties