In order to understand how the doping with self-assembled nanorods of different sizes and concentrations as well as applied magnetic fields affect the critical current anisotropy in YBa 2 cu 3 o 7−x (YBCO) thin films close to YBCO c-axis, we present an extensive and systematic computational study done by molecular dynamics simulation. the simulations are also used to understand experimentally measured J c (θ) curves for BaHfO 3 , BaZrO 3 and BaSno 3 doped YBCO thin films with the help of nanorod parameters obtained from transmission electron microscopy measurements. our simulations reveal that the relation between applied and matching field plays a crucial role in the formation of J c (θ)-peak around YBCO c-axis (c-peak) due to vortex-vortex interactions. We also find how different concentrations of different size nanorods effect the shape of the c-peak and explain how different features, such as double c-peak structures, arise. In addition to this, we have quantitatively explained that, even in an ideal superconductor, the overdoping of nanorods results in decrease of the critical current. our results can be widely used to understand and predict the critical current anisotropy of YBco thin films to improve and develop new pinscapes for various transport applications.High temperature superconductors (HTS) are expected to have large number of applications in different fields of technology and power industry in the future 1-3 . Since all known HTS are of type II, the critical current passed through them is highly dependent on the surrounding magnetic field due to the movement of vortices. Thus, to enhance and widen the usability of HTS, the dynamics of vortices need to be well understood.Among the high temperature superconductors, YBa 2 Cu 3 O 7−x (YBCO) seems the most practical choice when thinking for the applications 1 . The intrinsic anisotropy of the critical current, in thin films and coated conductors, can be modified by adding impurities within the lattice of YBCO which pin the vortices restricting their movement. Based on growth conditions and lattice mismatch between the YBCO and the dopant as well as their elastic properties 4,5 , impurities such as Y 2 O 3 6 , BaCeO 3 7-9 and BaZrO 3 (BZO) 10,11 can form uncorrelated randomly distributed nanoparticles within the YBCO lattice. Under optimized deposition conditions, via a spontaneous phase-separation and strain-driven self-assembly process during film deposition 12 , self-assembly of nanorods of BaHfO 3 (BHO) 1 , BaZrO 3 (BZO) 4,13,14 , BaSnO 3 (BSO) 15,16 , Ba 2 YTaO 3 (BYTO) 17 or Ba 2 YNbO 6 (BYNO) 18 within the YBCO lattice can be realized.Recently, a topic of interest has been to add both point-like nanodots and nanorods within the YBCO lattice simultaneously. This has been achieved by doping YBCO simultaneously with both BYTO and BYNO (referred as BYNTO) with an additional rare earth oxide, leading to continuous niobiate/tantalate nanorods and rare-earth oxide nanoparticles 19 . A lot of experimental research has been done in order to understand the...

No abstract

To maximize the flux pinning in high-temperature superconductor (HTS) thin film applications, we have experimentally studied the effect of BaZrO 3 (BZO) nanorod den- sity within the YBa 2 Cu 3 O 6+x (YBCO) lattice. Even though the BZO decreases the self-field critical current density J c (0) and the absolute J c (B) at high fields is observed being the highest for 4 % BZO doped YBCO, the maximized pinning property is ob- served at the level of 10 % of BZO, when the distance between the outer edge of the nanorods is in the order of the diameter of the nanorod. In general, as also theoretically calculated, the flux pinning is increased even above 10 % of BZO, but the improvement is limited by disturbance of the nanorod growth, weakening the flux pinning and de- creasing the absolute J c drastically. The results evidently show that by maximizing the flux pinning using higher BZO doping concentration than earlier expected and tak- ing care of the maximum self-field J c (0) , which is strongly dependent on the electron mean free path, would offer the keys to resolve the challenges in the future HTS power applications.

A nanograined YBCO target, where a great number of grain boundaries, pores etc. exist, is shown to hold an alternative approach to future pulsed laser deposition based high-temperature superconductor thin film and coated conductor technologies. Although the nanograined material is introduced earlier, in this work, we comprehensively demonstrate the modified ablation process, together with unconventional nucleation and growth mechanisms that produces dramatically enhanced flux pinning properties. The results can be generalized to other complex magnetic oxides, where an increased number of defects are needed for modifying their magnetic and electrical properties, thus improving their usability in the future technological challenges.

Background Achieving the elimination of soil-transmitted helminth (STH) infections requires a sufficient understanding of the current epidemiological status of STH endemicity. We aimed to examine the status of STH in Myanmar – a country with the eighth highest STH prevalence in the world, 10 years after instigation of the national deworming programme. Methods In August 2016 we screened for STH infections using Kato Katz (KK) microscopy and real-time PCR (qPCR) in schoolchildren from the Bago Region township of Phyu, a STH sentinel site in Myanmar. Ten schools were randomly selected, and one stool sample each from a total of 264 students was examined. Prevalence and intensity of infection were calculated for each STH. Results High prevalence of STH was identified in the study area with 78.8% of the schoolchildren infected with at least one STH by qPCR, and 33.3% by KK. The most prevalent STH was Trichuris trichiura, diagnosed by both KK (26.1%) and qPCR (67.1%), followed by Ascaris lumbricoides (15.5% KK; 54.9% qPCR). No hookworm infections were identified by KK; however, the qPCR analysis showed a high prevalence of Ancylostoma sp. infection (29.6%) with few Necator americanus (1.1%) infections. Conclusions Despite bi-annual deworming of schoolchildren in the fourth-grade and below, STH prevalence remains stubbornly high. These results informed the expansion of the Myanmar National STH control programme to include all school-aged children by the Ministry of Health and Sports in 2017, however further expansion to the whole community should be considered along with improving sanitation and hygiene measures. This would be augmented by rigorous monitoring and evaluation, including national prevalence surveys.