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Flexible transparent electrodes on flexible plastic sheets are in significant demand for use in flexible perovskite solar cells (f-PSCs). However, the combination of the broadband high optical transparency and low electrical resistivity required for the tandemization of f-PSCs sets a stringent requirement on flexible transparent electrodes that are based on traditional Sn-doped In2O3 (ITO) films, owing to the high free-carrier concentration needed to reduce the electrical resistivity. Herein, we used excimer laser irradiation to achieve a Ce and H codoped In2O3 (ICO:H) film on flexible polyethylene terephthalate (PET) that had ultrahigh electron mobility of 133 cm2/Vs, which is the highest among those reported for flexible transparent electrodes, and low sheet resistance of 14.2 Ω/□, which is approximately three times lower than the 40 Ω/□ sheet resistance of commercially available ITO/PET. Furthermore, compared to ITO, this ICO:H film had higher infrared transparency. These nontrivial performances were achieved by an optimized excimer-laser solid-phase crystallization process guided by the correlation between laser pulse counts and the volume fractions of the amorphous and crystalline phases in the films. These high performances resolved the problems faced by ITO films, thus facilitating the performance of flexible solar cells and optoelectronic devices.

The fabrication of crystalline oxide films using excimer laser-assisted metal organic decomposition (ELAMOD) involves deploying pulsed UV laser irradiation to achieve photochemical and photothermal reactions of metal–organic materials or amorphous oxide materials. In this study, ELAMOD was used to fabricate SrFeO3−δ thin films under various atmospheric conditions in order to clarify the effect of such conditions on ELAMOD-produced films. Analysis of lattice constants and work functions of the films revealed that performing ELAMOD in air and vacuum induced reduction while performing it in O2 induced oxidation. The extents of reduction and oxidation were enhanced by increasing the laser fluence. Such an ability to control reduction and oxidation when performing ELAMOD should be helpful for the fabrication of functional oxide films.

Switching ability for infrared-light (IR) of commercial glass is of great interest for realizing practical smart windows which enable energy savings. In this article, we report on highly oriented growth of vanadium dioxide (VO2) films on ZnO-buffered glass substrates by means of biased reactive sputtering technique and their high switching ability for IR against temperature based on the insulator-metal transition (IMT). In addition, lower shift of transition temperature down to 55 °C was realized without deterioration of IMT properties in which resistance change nearly three orders of magnitude was kept. Shortening of in-plane V-V atoms distance through the effect of in-plane compressive stress responsible for energetic ion irradiation to biased substrate was supposed to contribute the achievement of controlled IMT temperatures. Large switching of around 50% for transmittance of IR with wavelength of 2.5 µm was realized under controlled phase transition temperatures. We emphasized that high biasing power enabled the shift of transition temperature for IR to nearly room temperature (～38 °C) by combination of the shortening of V-V distance and the oxygen defect formation, while the IMT reveals gradual change at biasing power higher than certain threshold value.

An up to 63% enhancement in critical current density (J c) was achieved for 1 μm thick YBa2Cu3O7 (YBCO) films at self-field at 77 K by irradiation with 24–84 MeV Au ions. This enhancement is highly unusual, since in YBCO films, J c at self-field (J c sf) is generally insensitive to ion irradiation, unlike J c in magnetic fields. Our observed film-thickness dependence of the irradiation effect and our microstructure imaging indicate that this rare observation is attributed to an extremely “clean” (i.e. less-disordered) microstructure in the top 700 nm of the layer of our 1 μm thick films prepared via fluorine-free metal-organic deposition. Our results directly indicate that discontinuous 1D vortex-pinning centers (pins) that have the following features effectively enhance MA cm−2-order J c sf at 77 K of YBCO films; namely, 5–10 nm in diameter, ∼20 nm in size along a pin track, have a ∼20 nm gap between the pins in a pin track, and are directed in the c-axis.

Vanadium oxide thin films (VO2 Monoclinic (M) or V2O5) on silica glass substrates were prepared by Metal-Organic Deposition (MOD) using Infra-Red furnace (Thermal-MOD) and Excimer Laser Assisted Metal-Organic Deposition (ELAMOD). On one hand, using thermal process (i.e. Infra-Red furnace sintering) for 90 min at 300 °C in air and O2 atmosphere, V2O5 was formed and in N2 atmosphere at 500 °C for 90 min, VO2 (M) was formed. On the other hand, VO2 (M) was obtained with laser (ELAMOD) sintering at 300 °C, with no specific atmosphere control (ambient air), for only 1 min and without any resort to a buffer layer to achieve homogeneous coverage. Formation mechanism of the VO2 (M) with thermal MOD process and UV laser process is discussed.

Excimer laser irradiation (ELI) has recently been revealed to simultaneously increase the work function (ϕ) and carrier concentration (N) in doped In2O3 films, suggesting a potential benefit in fabricating transparent conducting oxides (TCOs) for organic light emitting diodes (OLEDs). However, the phenomenon apparently contradicts with a basic physical argument: the Fermi (EF)-to-vacuum-level separation ϕ should decrease as EF is shifted upward by increasing electronic N. To resolve this puzzle, we performed Hall effect measurements, hard/soft-x-ray, and ultraviolet photoelectron spectroscopy on polycrystalline Sn-doped In2O3 films treated with KrF-ELI (λ = 248 nm). Our data reveal that the contradiction resides in astonishingly distinct ELI effects between bulk and the surface. Namely, ELI generates electronic carriers in the bulk via extrinsic (Sn)-dopant activation, while it depopulates the carriers on the surface that causes a huge (1.1 eV) surface-band-bending reversal from downward (electron-accumulation) to upward (-depletion). The spectroscopic evidence reveals that higher ϕ and N were obtained by ELI in vacuum than in the air atmosphere. Our results suggest that ELI is a promising technique for fabricating high-performance TCO for OLED applications.

We developed a technique to produce stoichiometric VO2 films with a well-defined (010) orientation, using an Al-doped ZnO (AZO) thin film and topotactic oxidation. The AZO seed layer was prepared on a glass substrate by radio frequency magnetron sputtering (RF-MS), and then the V2O3 film was deposited on the AZO film by RF-MS. Finally, the V2O3 film was post-annealed, and underwent topotactic oxidation in air to convert the V2O3 phase to the VO2 phase. The AZO seed layer converted V2O3 to VO2 while maintaining the crystallographic orientation. Consequently, well-defined (010) orientated 200-nm-thick VO2 films with large change in electrical resistivity of 1.55 × 103 times together with large change in optical transmittance of 64.3% at wavelength of 2000 nm, before and after the transition, were successfully obtained by combination with AZO seed layer and topotactic oxidation.

The authors investigated the relationship between the content of incorporated Ar atoms and the crystalline polarity of polycrystalline Al-doped ZnO (AZO) films and examined the influence of this relationship on the resulting growth rate, crystallographic texture, and electrical properties. They deposited AZO films on glass and c-plane sapphire substrates via radio-frequency magnetron sputtering at substrate temperatures (Ts) of 100 or 200 °C using sintered AZO targets with an Al2O3 content of 2.0 wt. %. The incorporation of a large amount of Ar atoms induced a change in the crystalline polarity from Zn-polar to O-polar, the latter of which is associated with numerous obstacles, such as a lower deposition rate, large residual compressive stress, and increased electrical resistivity. The authors demonstrated that increasing the Ts led to a reduction in the amount of unintentionally retained Ar atoms, thereby affording Zn-polar AZO films with their associated advantages.The authors investigated the relationship between the content of incorporated Ar atoms and the crystalline polarity of polycrystalline Al-doped ZnO (AZO) films and examined the influence of this relationship on the resulting growth rate, crystallographic texture, and electrical properties. They deposited AZO films on glass and c-plane sapphire substrates via radio-frequency magnetron sputtering at substrate temperatures (Ts) of 100 or 200 °C using sintered AZO targets with an Al2O3 content of 2.0 wt. %. The incorporation of a large amount of Ar atoms induced a change in the crystalline polarity from Zn-polar to O-polar, the latter of which is associated with numerous obstacles, such as a lower deposition rate, large residual compressive stress, and increased electrical resistivity. The authors demonstrated that increasing the Ts led to a reduction in the amount of unintentionally retained Ar atoms, thereby affording Zn-polar AZO films with their associated advantages.

The perovskite oxide BaSnO3 has received much attention because of its excellent electronic properties for use in electronic devices such as solar cells. In this study, BaSnO3 thin films were successfully deposited onto SiO2 glass substrates using excimer laser-assisted metal organic decomposition (ELAMOD). The films could not be obtained using the thermal decomposition process because Ba reacts readily with a SiO2 substrate. Results of a transmission electron microscopy and numerical simulation of heat generation and transfer under laser irradiation revealed local and rapid generation of heat in the ELAMOD process resulting in a suppression of the reaction between Ba and SiO2 and hence enabling BaSnO3 thin film formation on SiO2 substrates.

We have developed an excimer laser annealing method to achieve low electrical resistivity (ρ) and a high work function in amorphous In2O3:Zn (IZO) films on polyethylene terephthalate (PET) substrates. The effect of excimer laser irradiation of the films on crack formation, electrical properties (ρ, carrier concentration, and Hall mobility), and work function were investigated. KrF excimer laser irradiation produced cracks in the surface of the IZO films on PET as a result of thermal expansion of the PET substrate. By inserting an amorphous SiO2 layer as a heat barrier between the IZO layer and PET substrate, crack formation was prevented. Moreover, it was found that the work function of IZO film could be controlled by the laser fluence and repetition rate. Irradiation of a 150-nm-thick amorphous IZO film on a SiO2-coated PET substrate achieved a low ρ of 3.55 × 10−4 Ω cm and a high work function of 5.4 eV due to the reduction of oxygen and carbon while maintaining a flat surface.

Background: Lead V1 on electrocardiography (ECG) can detect the dominant frequency (DF) of atrial fibrillation (AF) in the right atrium (RA). Paroxysmal AF is characterized by a frequency gradient from the left atrium (LA) to the right atrium (RA). We examined the ability of magnetocardiography (MCG) to detect regional DFs in both the atria. Methods: Study subjects comprised 18 consecutive patients referred for catheter ablation of persistent AF. An MCG system with 64 magnetic sensors was used to perform MCG in the frontal, lateral, and back planes prior to the ablation procedure in each patient. DFMCG and organization index (OIMCG) were calculated using fast Fourier transformation. Intracardiac electrograms (ICEs) in both the atria and the coronary sinus (CS) were mapped at 17 sites. Regional DFsICE were also determined. Results: Mean LA DFICE was higher than mean RA DFICE (6.4070.66 versus 6.1670.80 Hz, P¼0.03). DFMCG in the channel having the highest OIMCG was 6.6170.88 Hz in the frontal plane, 6.5270.64 Hz in the lateral plane, and 6.4270.62 Hz in the back plane (P¼0.3). In each plane, DFMCG correlated with DFICE at the RA appendage (R¼0.95, Po0.0001), the LA appendage (R¼0.91, Po0.0001), and the CS (R¼0.93, Po0.0001). DFECG in V5 modestly correlated with DFICE at the LA appendage (R¼0.82, Po0.0001). Conclusions: MCG could more precisely detect the DFs in the LA and the CS than ECG. However, the usefulness of pre-procedural detection of the AF frequency gradient for ablation therapy needs to be evaluated in future prospective studies.

BackgroundRivaroxaban is an oral anticoagulant that effectively prevents thromboembolic complications using fixed doses without requiring laboratory monitoring. In this study, we aimed to examine the coagulation status in patients with non-valvular atrial fibrillation (NVAF) treated with rivaroxaban compared with warfarin.Methods and resultsThe study group consisted of 85 consecutive Japanese patients with NVAF who received rivaroxaban (n=33) or warfarin (n=52) from June 2013 to February 2014. We compared the coagulation status between the rivaroxaban and warfarin treatments. The prothrombin time (PT) values did not significantly differ between the two groups. However, the prothrombin fragment 1+2 (F1+2) level, a marker of thrombin generation, was significantly higher in the rivaroxaban group than the warfarin group (202±88pmol/l vs. 114±79pmol/l, p

Printed electronics is creating many new products given the benefits of the technology compared to conventional electronics, such as thinness, flexibility, cost, ease of manufacture, fast production turn around, “green” technology, power efficiency and more. For this purpose, we have developed the photo reaction of nano-particle method (PRNP) for the preparation of the patterned metal oxide thin film on organic and glass substrates. In this paper, we demonstrate the preparation of transparent conducting thin film or resister film by the PRNP process, and their properties of the obtained films. By using the combination of the two procedures, the resistivity of the film was 5.94×10−4 Ωcm. The resulting ITO film showed mobility as high as 9.99 cm2 V−1 s−1at the carrier density of 1.05 ×1021 cm−3.Also, flexible resistor thin film(RuO2) on PI substrate was prepared by ELAMOD.

Aims The long-term prognosis of subjects with supraventricular premature complexes (SVPCs) remains unclear in the general population. The aim of this study was to examine the prognostic significance of SVPCs in community-based health checkups. Methods and results We assessed 63 197 individuals (mean age, 58.8 ± 9.9 years; 67.6% women) who participated in annual community-based health checkups in 1993 and were followed until 2008. The primary endpoint was stroke death, cardiovascular death (CVD), or all-cause death during a 14-year mean follow-up, and the secondary endpoint was first atrial fibrillation (AF) event in subjects without self-reported heart diseases or AF at baseline. Compared with subjects without SVPCs, the multivariate-adjusted hazard ratios (HRs) [95% confidence interval (CI)] of stroke death, CVD, and all-cause death in subjects with SVPCs were 1.24 (0.98–1.56) for men and 1.63 (1.30–2.05) for women, 1.22 (1.04–1.44) for men and 1.48 (1.25–1.74) for women, and 1.08 (0.99–1.18) for men and 1.21 (1.09–1.34) for women, respectively. Atrial fibrillation occurred in 386 subjects during the follow-up (1.05/1000 person-years). The presence of SVPCs at baseline was the significant predictor of AF onset [HRs (95% CI): 4.87 (3.61–6.57) for men and 3.87 (2.69–5.57) for women]. Propensity score matched analyses also revealed the presence of SVPCs was significantly associated with increased risks of AF incidence and CVD even after adjusting the potential confounders. Conclusion The presence of SVPCs in 12-lead electrocardiograms was a strong predictor of AF development, and associated with increased risk of CVD in general population.

Causative arrhythmias of sudden cardiac arrest (SCA) are changing in this age of improved coronary care.The purpose of this study was to examine the frequency of terminal arrhythmias and the electrical events prior to SCA.We analyzed 24-hour Holter recordings of 132 patients enrolled from 41 institutions who either died (n = 88) or had an aborted death (n = 44). The Holter recordings were obtained for diagnosing and evaluating diseases and arrhythmias in those without any episodes suggestive of SCA.In 97 patients (73%), SCA was associated with ventricular tachyarrhythmias and in 35 (27%) with bradyarrhythmias. The bradyarrhythmia-related SCA patients were older than those with a tachyarrhythmia-related SCA (70 ± 13 years vs. 58 ± 19 years, P.001). The most common arrhythmia for a tachyarrhythmia-related SCA was ventricular tachycardia degenerating to ventricular fibrillation (45%). The bradyarrhythmia-related SCA was caused by asystole (74%) or AV block (26%). Spontaneous conversion was observed in 37 patients (38%) with ventricular tachyarrhythmias. Of those, 62% of the patients experienced symptoms including syncope, chest pain, or convulsion. Multivariate logistic analysis revealed that independent predictors of mortality for tachyarrhythmia-related SCAs were advanced age (odds ratio 1.04, 95% confidence interval 1.02-1.08) and ST elevation within the hour before SCA (odds ratio 3.54, 95% confidence interval 1.07-13.5). In contrast, the presence of preceding torsades de pointes was associated with spontaneous conversion (odds ratio 0.20, 95% confidence interval 0.05-0.66).The most frequent cause of SCA remains ventricular tachyarrhythmias. Advanced age and ST elevation before SCA are risk factors for mortality in tachyarrhythmia-related SCAs.

Article history:Received 21 November 2011Accepted 13 April 2012Keywords:FCP1CTD phosphataseCardiac hypertrophyEndothelin-1RNA polymerase II Aims: Cardiac hypertrophy is associated with the increase of total amount of RNA, which is in accordance withRNA polymerase II (RNAPII) activation via C-terminal domain (CTD) phosphorylation of the largest subunit ofRNAPII. It has been demonstrated that endothelin-1 (ET-1) phosphorylates CTD at the hypertrophic responseincardiomyocytes.However,itisunclearwhetherET-1-inducedhypertrophyisaffectedbytheCTDphosphatase,transcription factor IIF-interacting CTD phosphatase1 (FCP1).Mainmethods: We analyzed whether ET-1-induced cardiomyocyte hypertrophy was affected by overexpressionof FCP1 or dominant-negative form of FCP1 (dnFCP1) in neonatal rat cardiomyocytes.Key findings: The level of ET-1-induced RNAPII CTD phosphorylation was decreased by FCP1 overexpression,whereas it was sustained by dnFCP1. Global RNA synthesis evaluated by [ 3 H]-uridine incorporation showedthat the ET-1-induced increase in RNA synthesis was suppressed by FCP1 and was augmented by dnFCP1. ET-1-induced increase in cell surface area was suppressed by FCP1 and was preserved by dnFCP1. Furthermore, theET-1-induced increase in molecular markers of cardiac hypertrophy, expression of ANP and β-MHC gene, wassuppressed by FCP1 and was not inhibited by dnFCP1.Significance: ET-1-inducedcardiachypertrophyandCTDphosphorylationlevelarefunctionallyregulatedbyFCP1.These findings suggest that FCP1 plays an important role in ET-1-induced cardiac hypertrophy via controllingphosphorylation level of the RNAPII CTD.© 2012 Elsevier Inc. All rights reserved.

The magnetic-field angle dependence of the critical current density J c ( H , θ ) was measured over a wide temperature range (20–85 K) in high- J c YBa 2 Cu 3 O 7 (YBCO) and DyBa 2 Cu 3 O 7 (DyBCO) epitaxial films belonging to two categories. The films in the first category were prepared by thermal co-evaporation and were characterized by a high density of nanometer-sized precipitates (mostly ab -plane. Relatively broad J c ( θ ) peaks around H // ab in the shape of a stratovolcano were observed at 77–80 K in the co-evaporated YBCO and DyBCO films in the first category, and the J c ( H , θ ) data were scaled to be a single curve when plotted against scaled fields using an effective anisotropy parameter. However, the J c ( θ ) curves became more gradual at 60–70 K and the scaling behavior was broken because the radius of nano-precipitates was not sufficiently smaller than the temperature dependent Ginzburg–Landau coherence length ξ ( T ) at these temperatures. In contrast, sharp J c ( θ ) peaks around H // ab were observed in the FF-MOD YBCO films in the second category at all temperatures in the range 20–85 K. Anisotropic scaling analysis showed that the pinning was apparently due to small random pins and pins correlated with the ab -plane, and the linear pins whose radius is sufficiently smaller than ξ ( T ) can cause the observed J c ( H , θ ). The temperature dependence of J c due mainly to the random pinning was approximately ∼(1 − T / T c ) 2 (1 + T / T c ) 2 for the FF-MOD thin films (dislocation pins), which is consistent with a simple theoretical model based on core pinning interactions. The T dependence of J c for the co-evaporated films (nano-precipitate pins) was ∼(1 − T / T c ) m (1 + T / T c ) 2 ( m = 2.1–2.6), which deviates from m = 2.5 expected from the simple theoretical model because nano-precipitates are not sufficiently smaller than ξ ( T ) at T ⩽ 70 K.

It is currently estimated that with the increasing numbers of IT equipment, the amount of information data used by society will reach 200 times the present volume by 2025. Under such circumstances,...

We have prepared metal organic deposition (MOD)-YBCO thick films by repeating the coating-pyrolysis-crystallization procedure onto ∼100-nm-thick evaporated and MOD templates. Surface morphology of the template was found to strongly affect the homoepitaxial growth of MOD-YBCO layers on the template; namely, the epitaxial growth of MOD-YBCO on the evaporated template was much easier than that on the MOD template. A 220-nm-thick epitaxial MOD-YBCO film was successfully prepared on the 100-nm-thick evaporated-YBCO template to obtain a 320-nm-thick YBCO film, which exhibited Jc = 2.44 MA/cm2 and Ic = 78 A/cm. The Ic value has significantly increased from 37 A/cm for the evaporated-template.

We have studied the thickness (t) dependence of the critical-current density (Jc) of epitaxial YBCO films grown by fluorine-free MOD to understand the origin of strong depletion of Jc by film thickening. We have grown more than thirty samples with t varied from 0.2 to 1.4 μm, and obtained a detailed Jc-vs-t relation with good statistics. It was found that Jc is strongly suppressed by increasing t, and the rate of suppression is changed at around t=0.4 μm. Numerical fitting of the data revealed that the Jc-t curve above 0.4 μm is well reproduced by a t-inverse-type function. We discuss implications of these observations comparing with cross-sectional TEM results, which show a characteristic vertical distribution of microstructural disorder. This study is based on a half-photolytic F-free MOD process using a uv-excimer lamp which we have recently developed for fabrication of micron-order-thick epitaxial YBCO films.

It has been difficult to prepare Y123 films with a thick ness greater than 400 nm by using a single coating-preflring procedure in metal organic deposition (MOD), since shrinkage of the film causes cracks in the pyrolysis process. In the present study, we developed a novel coating solution for crack-free films with thicknesses greater than 500 nm. We used a Y-, Ba-, and Cu-acetylacetonate-based solution (metal content: ~2mol metal/L) with various additives for the coating solution. We prepared prefired films on CeO2-buffered YSZ (CbYSZ) or CeO2-buffered SrTiO3 (CbSTO) substrates using the single coating-preflring process and this solution. When using some additives, we could obtain crack-free preflred films with thicknesses corresponding to 350-800 nm after crystallization to Y123. These prefired films were heat-treated at high-temperatures, resulted in epitaxial Y123 films. The Jc and Ic of the film on CbSTO was ~2.3 MA/cm2 and 143 A/cm, respectively.

Using a high-temperature superconductor, we constructed and tested a model superconducting fault current limiter (SFCL). The superconductor and a vacuum interrupter serving as the commutation switch were connected in parallel using a bypass coil. When the fault current flows in this equipment, the superconductor is quenched and the current is then transferred to the parallel coil due to the voltage drop in the superconductor. This large current in the parallel coil actuates the magnetic repulsion mechanism of the vacuum interrupter and the current in the superconductor is interrupted. Using this equipment, the current flow time in the superconductor can easily be minimized. On the other hand, the fault current is also easily limited by the large reactance of the parallel coil. This system has many advantages. Thus, we introduced an electromagnetic repulsion switch. High-speed reclosing after interrupting the fault current in the electrical power system is essential. Thus, the SFCL should recover to the superconducting state before high-speed reclosing. But the superconductor generates heat at the time of quenching, and it takes time to recover to the superconducting state. Therefore, the recovery time is an issue. In this paper, we study the superconductor recovery time. We also propose an electromagnetic repulsion switch with a reclosing system. © 2011 Wiley Periodicals, Inc. Electr Eng Jpn, 175(3): 12–19, 2011; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/eej.21072

We have studied environment-resistive coatings (ERC) for the thin-film-based superconducting fault-current limiter (SFCL) Ag/Au–Ag/YBa2Cu3O7/CeO2/Al2O3. We evaluated nine candidate ERC materials by two accelerating-environment tests, and revealed that the shellac- and the fluorine-resin have a high environmental resistance. Especially, the shellac resin almost completely protected Jc of an element exposed to 60 °C saturated water vapor for 2 h (3.4–>3.2 MA/cm2). We also performed a practical operation test of SFCL using an element half covered by shellac, and found that the ERC does not diminish the current limiting properties similarly to the previous results of the Teflon-coated SFCL [1] .

Many alternative energy power generation systems create dc electricity. Also, many devices consume dc converted from ac. Therefore, it may be possible to reduce conversion losses and CO2 emissions by adopting dc distribution. We assume that superconducting cables will be used for dc distribution because their electrical resistance is almost zero. However, if a superconducting cable is adopted, it is of great concern that if an excessive current flows because of, for instance, a short circuit, there is a possibility that this current cannot be interrupted by a circuit breaker alone. We propose that the fault current is limited by a Superconducting Fault Current Limiter (SFCL), and that this limited current is then interrupted by a dc circuit breaker. In this paper, we have separately investigated the SFCL and dc breaker, and their use in combination.

Preparation of epitaxial YBa 2 Cu 3 O 7 (YBCO) films on cerium oxide-buffered sapphire (r-cut α-Al 2 O 3 ) substrates by an excimer-laser-assisted metalorganic deposition (ELAMOD) is reported. The ELAMOD process has been developed to bring about the advantage of shorter heating time than that in the conventional metalorganic deposition; the coated films are irradiated by an excimer laser beam before firing. We initiated the ELAMOD-YBCO process using a homogenized 8-mm-square laser beam which irradiates the coated surface in a fixed substrate mode. In order to extend the process applicable to large-area films, a scan irradiation mode was employed and a high critical-current density over 6 MA/cm 2 has been observed. In the process, an appropriate choice of laser energy is difficult but crucial to obtain YBCO films with high superconducting properties. Then, laser irradiation from backside of the substrate was examined and proved to be beneficial to extend the experimental window of the laser energy. Moreover, a newly developed ELAMOD process using a 90-mm-wide line-beam is also reported which has a potential ability for large-area applications.

c-axis-oriented epitaxial YBa2Cu3O7-delta (YBCO) superconducting films were prepared on perovskite-type single crystal substrates, i.e., SrTiO3, LaAlO3, NdGaO3 and YAlO3 with cerium oxide (CeO2) buffer layers by fluorine-free metalorganic deposition (MOD) at relatively low heating rates. The YBCO films on these CeO2-buffered substrates exhibited high critical current densities with an average of 3-5 MA/cm2 at 77.3 K. Using CeO2 buffer layers we could avoid the occurrence of undesired a-axis-oriented grains of YBCO on these substrates despite employing lower heating rates. The lattice constants of YBCO films, CeO2 buffer and substrates were compared. It was found that both the YBCO films and CeO2 buffer were elastically deformed.

We have proposed a superconducting thin-film fault current limiter (FCL) that uses high-resistivity Au-Ag alloy shunt layers for the protection against ldquohot spotsrdquo. Its design enables reduction of the total length of FCL elements that can withstand high electric fields E > 40 Vpeak/cm, thus greatly reducing the cost of FCLs. In this paper, two methods to increase current capacity of the FCLs were demonstrated. The first method protects the films from hot spots by using capacitors in addition to external resistors. The capacitors decrease rapid voltage rise in the films at the moment of quenching. The second method maximizes the rated current of two parallel-connected thin films by using parallel connections via superconducting tapes, even if the critical currents of these films are largely different. We then successfully tested two parallel-connected YBCO films prepared by a low-cost, metal organic deposition (MOD) method. Over-current tests showed that (a) superconducting transport currents up to 380 Apeak flowed 5 cycles without quenching, which is more than 1.3 times larger than the peak value of the 200 Arms rated current and (b) after switching, E = 45.7 Vpeak/cm was achieved without film degradation.

Background: Magnetocardiography (MCG) is a new technique for visualizing a current distribution in the myocardium. In recent years, current distribution parameters (CDPs) have been developed based on the distribution. The CDPs reflect spatial-time current abnormalities in patients with coronary heart disease (CHD). However, the criteria and scoring method of the abnormalities using CDPs are still controversial. Method: We measured MCG signals for 101 normal controls and 56 CHD patients (single-, double-, and triple-vessel diseases) using a MCG system. The CDPs (maximum current vector [MCV], total current vector [TCV], current integral map, and current rotation) during ventricular repolarization were analyzed. To evaluate the CDPs that are effective in distinguishing between normal controls and CHD patients, the areas under the receiver operating characteristic curve (Az) are calculated. Furthermore, the total scores (“0” to “4”) of four CDPs with high Az values are also calculated. Results: MCV and TCV angles at the T-wave peak had the highest Az value. Furthermore, TCV angular differences between the ST-T segment also had high Az values. Using the four CDPs, the averaged total score for patients with triple-vessel disease was the highest (“2.67”) compared to the other groups (normal controls: 0.53). Furthermore, based on the assumption that subjects with a total score over “1” were suspected of having CHD, sensitivity and specificity were 85.7% and 74.3%, respectively. Conclusion: We concluded that the score and criteria using MCV and TCV during repolarization in CHD patients can reflect lesion areas and time changes of electrical activation dispersion due to ischemia.

We performed fault current limiting tests using YBCO thin films and investigated the reasons for their breakdown during current limiting. There were two patterns of film breakdown. One occurred immediately after current limiting and the other occurred during current limiting. In film breakdown, the quench propagation speed showed almost no change with increasing energy consumption per unit time, but the energy consumption per unit area increased with increasing energy consumption per unit time. Therefore, local areas of the film reached the melting point and arcing occurred. It is therefore concluded that the performance of the films can be improved by decreasing the energy consumption per unit time. Connecting a parallel capacitor to the film in order to limit the energy consumption per unit time is proposed and tested as a measure to improve the current limiting performance of thin films. © 2008 Wiley Periodicals, Inc. Electr Eng Jpn, 166(1): 20–27, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20709

Background: We need to know the magnetocardiogram (MCG) features regarding waveform and two-dimensional current distribution in normal subjects in order to classify the abnormal waveform in patients with heart disease. However, a standard MCG waveform has not been produced yet, therefore, we have first made the standard template MCG waveform. Methods and Results: We used data from 464 normal control subjects' 64-channel MCGs (268 males, 196 females) to produce a template MCG waveform. The measured data were averaged after shortening or lengthening and normalization. The time interval and amplitude of the averaged data were adjusted to mean values obtained from a database. Furthermore, the current distributions (current arrow maps [CAMs]) were calculated from the produced templates to determine the current distribution pattern. The produced template of the QRS complex had a typical shape in six regions that we defined (M1, M2, M3, M4, M5, and M6). In the P wave, the main current arrow in CAMs pointing in a lower-left direction appeared in M1. In the QRS complex, the typical wave appeared in each region, and there were two main current arrows in M2 and M5. There were negative T waves in M1, M4, and M5, and positive T waves in M3 and M6, and the main current arrow pointing in a lower-left direction appeared in M2. Conclusion: Template MCG waveforms were produced. These morphologic features were classified into six regions, and the current distribution was characterized in each region. Consequently, the templates and classifications enable understanding MCG features and writing clinical reports.

Epitaxial YBa2Cu3O7−y (Y123) films of 200- and 850-nm thicknesses were prepared on CeO2-buffered YSZ substrates by metal–organic deposition (MOD) using a fluorine-free metal acetylacetonate-based solution. After the heat treatment at 765 °C in an atmosphere with pO2 = 10 Pa followed by cooling in O2 atmosphere, the 200-nm thick film demonstrated a high critical current density (Jc) of >4 MA/cm2, whereas the 850-nm thick one showed a low-Jc of ∼0.3 MA/cm2. X-ray diffraction (XRD) analyses exhibited that c-axis oriented Y123 had grown in both films. In order to investigate the crystallization behavior of Y123 films, some specimens were quenched from various intermediate stages during the annealing schedule. The XRD results showed that the c-axis oriented Y123 started to grow at a temperature as low as 730 °C. The growth of Y123 in the 200-nm thick film seems to be saturated after the temperature dwell at 765 °C for 30 min. Scanning electron microscopy exhibited that the 200-nm thick films had very smooth matrices with a number of small precipitates on the surfaces, whereas the 850-nm thick films quenched after the dwell at 765 °C had rougher surfaces and no continuous matrices. The degradation of Jc in the 850-nm thick films was probably caused by occurrence of randomly oriented Y123 grains from the inside of the film to the surface.

The prevalence and characteristics of sleep-disordered breathing (SDB) in patients with ventricular arrhythmias, such as premature ventricular complexes and ventricular tachycardia, are unknown. Therefore, this study was conducted to evaluate the prevalence of SDB in patients with severe ventricular arrhythmias and normal left ventricular (LV) function. Thirty-five patients (63% men, mean age 57.4 +/- 13.8 years) underwent a sleep study. All patients had ventricular tachycardia or frequent premature ventricular complexes (or=300/hour) and had been referred to the cardiology department for medication, catheter ablation therapy, or the implantation of a cardioverter-defibrillator. Patients with heart failure with LV ejection fractions50% were excluded; in the remaining patients, the mean LV ejection fraction was 63.9 +/- 8.0%. Twenty-one patients (60%) had SDB with apnea-hypopnea indexesor=5/hour, and the average apnea-hypopnea index was 22.7 +/- 17.9/hour. Twelve patients (34%) had moderate to severe SDB, with an average apnea-hypopnea index of 33.6 +/- 16.6/hour. Central dominant sleep apnea was evident in 3 patients with SDB. The average age and body mass index were significantly higher in patients with SDB than in those without SDB (age 62.0 +/- 12.8 vs 50.6 +/- 12.7 years, body mass index 26.3 +/- 4.0 vs 21.2 +/- 2.0 kg/m2). In conclusion, this study found a high prevalence of SDB in patients with ventricular arrhythmias and normal LV function.

Epitaxial VO2 films were prepared on the C-planes of α-Al2O3 substrates by a metal organic deposition (MOD) process. It was difficult to obtain the single phase of (010)M-oriented VO2 films, in which the subscript M refers to the monoclinic indices, by the heat treatment of amorphous precursor films in the VO2-stable region after the pyrolysis of the coating solution. The product films consisted of discontinuous circular grains of 1–2 µm size on the substrate surface. Therefore, we prepared the (010)M-oriented epitaxial VO2 films using postepitaxial topotaxy (PET), that is, topotactic oxidation of (0001)-oriented epitaxial V2O3 films. First, epitaxial V2O3(0001) films were obtained by MOD starting with a vanadium naphthenate solution. Second, the epitaxial V2O3(0001) films were topotactically oxidized at 500 °C in an Ar–O2 gas mixture with pO2 = 10-4 atm to obtain (010)M-oriented epitaxial VO2 films. The epitaxial relationships were VO2(010)M ∥ α-Al2O3(0001) and VO2[100]M ∥ α-Al2O3[0110], [1010], [1100]. The VO2(010)M films exhibited metal–semiconductor transitions with hysteresis loops at 60–80 °C. The resistivity change before and after the transition of the VO2(010)M film oxidized for 6 h was three orders of magnitude.

In routine substrate mapping of the left ventricle, an abnormal area is defined as having an amplitude1.5 mV. However, that is usually too large for catheter ablation in post-infarction ventricular tachycardia (VT) and the use of strict voltage criteria may produce better outcomes.Twenty patients with post-infarction VT underwent substrate mapping using an electroanatomic mapping system. Strict voltage criteria were defined as: non-arrhythmogenic area,0.6 mV; low-voltage area (LVA),0.1 toor=0.6 mV; scar,or=0.1 mV. Radiofrequency applications targeted the LVA only, which was 48+/-26 cm(2), 55% smaller than that of the generally targeted area with an amplitudeor=1.5 mV. The prevalence of delayed electrograms (durationor=150 ms) was significantly higher in the LVAs than in the border areas with an amplitude of0.6 toor=1.5 mV (33.2% vs 3.7%, p0.001). With the exception of 2 instances of peri-mitral VT, all VT isthmuses resided within the LVA. During follow-up of 24+/-13 months, 16 patients (80%) have been free of any VT episodes.Catheter ablation targeting LVAs with an amplitudeor=0.6 mV appears to be useful for efficient and effective treatment of post-infarction VT.

Epitaxial YBa 2 Cu 3 O 7 (YBCO) films were prepared on cerium oxide-buffered sapphire ( r -cut α-Al 2 O 3 ) substrates by an excimer-laser-assisted metalorganic deposition (ELAMOD) using a scanning substrate mode. The substrate surface was scanned under homogenized KrF excimer laser beam irradiation after application of a fluorine-free ingredient solution. The ELAMOD process has brought about the advantages of shorter heating time as well as higher critical current density ( J c ) of the YBCO films. The J c values over 6 MA/cm 2 were measured by an inductive method at 77.3 K for the laser-irradiated areas. The scanning laser irradiation is considered to produce a desirable precursor for crack free films with high- J c and to shorten the total time of heat treatment, in which three metal components are well-dispersed in short time. Such a precursor has contributed to prevent the occurrence of impurity phases, resulting in the high- J c YBCO films. The X-ray diffraction measurement of the irradiated area clearly showed a complete c -axis-oriented YBCO and no impurity phases, whereas a -axis-oriented YBCO was dominant in the area without irradiation. The ELAMOD process using the scanning substrate mode has a potential ability to apply to continuous production of the large-area films or long tapes of YBCO.

Epitaxial YBa 2 Cu 3 O 7− y (YBCO) films of 120–550 nm thickness have been prepared by fluorine-free metalorganic deposition using a metal acetylacetonate-based coating solution on yttria-stabilized zirconia (YSZ) substrates with an evaporated CeO 2 buffer layer. The YBCO films were highly (0 0 1)-oriented by X-ray diffraction θ –2 θ scanning and ϕ scanning. The YBCO films 120–400 nm in thickness demonstrated high critical current densities ( J c ) with an average in excess of 3 MA/cm 2 at 77 K using an inductive method. In particular, a 210-nm-thick film showed a J c of 4.5 MA/cm 2 . These excellent properties are attributed to the high crystallinity, small in-plane fluctuation due to high epitaxy and to the microstructure free from grain boundaries in the YBCO films. Further increase of film thickness increased the fraction of irregularities, i.e., precipitates and micropores, in the film surfaces, resulting in lower J c values.

Epitaxial (YBCO) films were prepared on cerium oxide-buffered (40 nm)-cut single-crystal sapphire substrates by a novel excimer-laser-assisted metalorganic deposition (ELAMOD). Laser irradiation after application of a fluorine-free ingredient solution onto the substrates revealed to have the advantages of shorter heating (prefiring and heat-treatment) time and higher superconducting current density . The in excess of 5 was measured by an inductive method at 77.3 K. The laser irradiation is considered to produce a desirable precursor, in which three metal components are well-mixed in short time. The X-ray diffraction measurement of the irradiated area clearly showed a complete -axis oriented YBCO and no impurity phase, whereas -axis oriented YBCO was also observed in the area without irradiation. The ratio of the -axis component decreased with an increase of the laser irradiation.

12 cm-long rectangular MOD-YBa2Cu3O7 (YBCO) films were prepared by MOD on R-plane sapphire substrates with an evaporated-CeO2 buffer layer. The substrates were coated with a fluorine-free solution by two methods; spin coating and wire-bar coating. Distribution of inductive Jc of the spin-coated and wire-bar-coated Alms was investigated. In the inductive measurement of superconducting YBCO films, the data are presumed to be affected by film edges if the width is comparable to the diameter of the probe coil. However, the present results showed that the edge effect is less significant if the coil does not cross the film edges and that the inductive Jc agrees well with the transport Jc . YBCO films with high Jc were obtained by both the coating methods. At present, the Jc values and uniformity of Jc in YBCO films prepared by spin coating were higher than those by wire-bar coating.

Switching power densities of current limiting elements consisting of metal organic deposition YBa2Cu3O7 (MOD-YBCO) thin films with high-resistivity Au-Ag alloy shunt layers and non-inductive Manganin resistors are evaluated. Despite the non-uniform critical current density distribution in MOD-YBCO films, the use of a high-resistivity Au-Ag shunt layer allows MOD-YBCO-based elements to achieve switching power densities comparable to those obtained for elements based on co-evaporated YBCO thin films. The present MOD-YBCO-based elements are capable of withstanding electric fields of 46 V/cm with a switching power density of 2.0 kVA/cm2. These results indicate that low cost MOD-YBCO thin films are promising for practical fault current limiters. In addition, relationships between the uniformity of Jc distribution and current limiting properties are also discussed.

Using a high temperature superconductor, we proposed a model superconducting fault current limiter (SCFCL) with the high-speed commutation switch. The high-speed commutation switch consists of the parallel coil, the electromagnetic repulsion plate and the vacuum interrupter. In this SCFCL, the current in the superconductor is interrupted within 0.5 cycles. By using this equipment, the current flow time in the superconductor can be easily minimized. We studied resistive type SCFCL with the high-speed commutation switch and use YBCO thin film. For applying to high voltage, it is a problem that the superconductors in series connection don't quench immediately for the Ic variations of the various superconductors. In this paper, we conducted the series connection test using YBCO thin films without a metal layer. The research is aimed at the scalability of small models towards commercial size fault current limiter (FCL).

Epitaxial YBa2Cu3O7 (Y123) films have been prepared by fluorine-free metalorganic deposition (MOD) using a metal acetylacetonate-based coating solution on cerium oxide (CeO2: 40 nm)-buffered yttria-stabilized zirconia (CbYSZ) substrates. The 210-nm-thick Y123 film demonstrated a high critical current density (Jc), the average Jc being 4.5 MA/cm2 at 77.3 K using an inductive method. However, with increasing thickness the Jc values decreased; the average Jc was 3.4 and 2.2 MA/cm2 for 400-nm- and 550-nm-thick films, respectively. In low-magnification cross sectional transmission electron microscopy (XTEM) images for the films, the stripe-like contrast due to the c-axis orientation of Y123 was clearly seen from the interface with CeO2 to the surface. The whole c-axis-oriented Y123 layers were very dense even in the 550-nm-thick film. Full width at half maximum (FWHM) of Deltaomega for the 308/038 reflections in XRD omega - 2thetas scanning decreased with increasing film thickness. High resolution XTEM images of the 550-nm-thick film showed wavy c-planes of Y123 due to the short stacking faults near the interface with CeO2 buffer and near the surface whereas the c-planes were very flat but contained long stacking faults in the middle part of the film. It is suggested that the absence of wavy stacking faults, which probably work as pinning centers, decreased Jc in the thicker films. Further decrease in Jc in the 550-nm-thick film is presumably caused by the roughness in the outer layer near the surface.

La 0.8 Sr 0.2 MnO 3 films were prepared on SrTiO 3 (STO) and LaAlO 3 (LAO) substrates using excimer laser-assisted metal organic deposition (ELAMOD). For the LAO substrate, no epitaxial L a0.8 Sr 0.02 MnO 3 film was obtained by laser irradiation in the fluence range from 60 to 110 mJ/cm 2 with heating at 500 °C. On the other hand, an epitaxial La 0.8 Sr 0.2 MnO 3 film on the STO substrate was formed by laser irradiation in the fluence range from 60 to 100 mJ/cm 2 with heating at 500 °C. To optimize the electrical properties for an IR sensor, the effects of the laser fluence, the irradiation time and the film thickness on the temperature dependence of the resistance and temperature coefficient of resistance (TCR: defined as 1/R-(dR/dT)) of the LSMO films were investigated. An LSMO film on the STO substrate that showed the maximum TCR of 3.9% at 265 K was obtained by the ELAMOD process using the KrF laser.