MOD derived pyrochlore films as buffer layer for all-chemical YBCO coated conductors

We report a detailed study performed on La2Zr2O7 (LZO) pyrochlore material grown by Metal-Organic Decomposition (MOD) method as buffer layers for YBa2Cu3O7-x (YBCO) coated conductors. High quality epitaxial LZO thin films have been obtained on single crystal (SC) and Ni-5%at.W substrates. In order to evaluate structural and morphological properties, films have been characterized by means of X-ray diffraction analyses (XRD), atomic force microscope (AFM) and scanning electron microscope (SEM). Precursors solutions and heat treatments have been studied by thermogravimetric analyses (TG-DTA-DTG) and infrared spectra (FT-IR) with the aim of optimizing the annealing process. Thin films of YBCO have been deposited by pulsed laser ablation (PLD) on this buffer layers. The best results obtained on SC showed YBCO films with critical temperature values above 90 K, high self field critical current density values (Jc > 1 MA/cm2) and high irreversibility field values (8.3 T) at 77 K together with a rather high depinning frequency vp (0.5 T, 77 K)>44 GHz as determined at microwaves. The best results on Ni-5%at.W has been obtained introducing in the heat treatment a pyrolysis process at low temperature in air in order to remove the residual organic part of the precursor solution

Current insights and advances into plant male sterility: new precision breeding technology based on genome editing applications

Plant male sterility (MS) represents the inability of the plant to generate functional anthers, pollen, or male gametes. Developing MS lines represents one of the most important challenges in plant breeding programs, since the establishment of MS lines is a major goal in F1 hybrid production. For these reasons, MS lines have been developed in several species of economic interest, particularly in horticultural crops and ornamental plants. Over the years, MS has been accomplished through many different techniques ranging from approaches based on cross-mediated conventional breeding methods, to advanced devices based on knowledge of genetics and genomics to the most advanced molecular technologies based on genome editing (GE). GE methods, in particular gene knockout mediated by CRISPR/Cas-related tools, have resulted in flexible and successful strategic ideas used to alter the function of key genes, regulating numerous biological processes including MS. These precision breeding technologies are less time-consuming and can accelerate the creation of new genetic variability with the accumulation of favorable alleles, able to dramatically change the biological process and resulting in a potential efficiency of cultivar development bypassing sexual crosses. The main goal of this manuscript is to provide a general overview of insights and advances into plant male sterility, focusing the attention on the recent new breeding GE-based applications capable of inducing MS by targeting specific nuclear genic loci. A summary of the mechanisms underlying the recent CRISPR technology and relative success applications are described for the main crop and ornamental species. The future challenges and new potential applications of CRISPR/Cas systems in MS mutant production and other potential opportunities will be discussed, as generating CRISPR-edited DNA-free by transient transformation system and transgenerational gene editing for introducing desirable alleles and for precision breeding strategies

Effect of annealing on structure and superconducting properties in Fe(Se,Te)

Abstract In this paper, the effect of post synthesis annealing treatments on a Fe(Se,Te) polycrystalline material is evaluated and discussed. The samples have been obtained via melting route. The material has been subjected to a high-temperature annealing treatment, carried out for 45 h at 680 °C. The role of the cooling step was investigated comparing samples obtained after a controlled cooling or after quenching in liquid nitrogen. From a morpho-structural point of view, the annealing treatment improves homogeneity, with respect to pristine samples, and influences secondary phase precipitate morphology. Regarding superconducting properties, a key role of the cooling procedure is assessed: controlled cooling leads in fact to a significant improvement of high field behaviour with respect to the melted material, while quenched samples are characterized by a worsening of the superconducting properties. Despite the overall worsening, however, the quenched samples show evidence of the presence of superconducting phases characterized by a remarkably high critical temperature (Tc > 18 K), observed for these materials only in films or under pressure

Comprehensive transcript profiling of two grapevine rootstock genotypes contrasting in drought susceptibility links the phenylpropanoid pathway to enhanced tolerance

In light of ongoing climate changes in wine-growing regions, the selection of drought-tolerant rootstocks is becoming a crucial factor for developing a sustainable viticulture. In this study, M4, a new rootstock genotype that shows tolerance to drought, was compared from a genomic and transcriptomic point of view with the less drought-tolerant genotype 101.14. The root and leaf transcriptome of both 101.14 and the M4 rootstock genotype was analysed, following exposure to progressive drought conditions. Multifactorial analyses indicated that stress treatment represents the main factor driving differential gene expression in roots, whereas in leaves the genotype is the prominent factor. Upon stress, M4 roots and leaves showed a higher induction of resveratrol and flavonoid biosynthetic genes, respectively. The higher expression of VvSTS genes in M4, confirmed by the accumulation of higher levels of resveratrol in M4 roots compared with 101.14, was coupled to an up-regulation of several VvWRKY transcription factors. Interestingly, VvSTS promoter analyses performed on both the resequenced genomes highlighted a significantly higher number of W-BOX elements in the tolerant genotype. It is proposed that the elevated synthesis of resveratrol in M4 roots upon water stress could enhance the plant’s ability to cope with the oxidative stress usually associated with water deficit

The family Caecidae in the South-West Pacific (Gastropoda: Rissooidea)

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Evaluating the Conservation State of Naturally Aged Paper with Raman and Luminescence Spectral Mapping: Toward a Non-Destructive Diagnostic Protocol

Micro-Raman and luminescence spectroscopy were combined with morphological analysis to study the conservation state of differently degraded paper samples, dated from 1873 to 2021. The aim of the work reported in this paper was to obtain ageing markers based on variations of Raman and fluorescence spectral features. Raman and luminescence spectra were acquired by scanning non-printed areas of books, and Raman and fluorescence maps were built by contrasting spectral parameters point by point, obtaining a micron-scale space resolved imaging of the degradation pattern. Complementary information on paper morphology and surface compactness were obtained by high-resolution scanning electron and atomic force microscopy. The proposed non-destructive procedure is particularly interesting for precious and ancient samples to analyze their degradation processes and to evaluate the performance and effectiveness of restoration treatments

2D Numerical Simulations of HTS Cable-in-Conduit Conductor Cables

International audienceAmong the designs of high-temperature superconducting (HTS) cables considered for fusion magnet applications, the Twisted Stacked Tape Cable-in-Conduit-Conductor (TSTC-CICC) has gained considerable interest due to its easy manufacturing process, very high tape length usage, and flexibility capabilities. Over the past decade, ENEA has launched several experimental campaigns aimed primarily at studying the electromechanical capabilities of these TSTC-CICCs. In order to clarify different aspects of the experimental results, we have developed a 2D finite element (FE) model based on the recently proposed T-A formulation. The simulations have been implemented using a commercial FE analysis, solver and multiphysics simulation software. Such FE model includes the contact resistance of the electrical terminations used to inject the current and takes into account the angular dependence of the critical current on the local magnetic field. This 2D model allows to reproduce the experimental V-I results obtained in TSTC-CICCs with excellent agreement. Furthermore, the numerical simulations have allowed to deepen the understanding of those mechanisms that govern the current distribution inside the cable. The numerical model will be used to analyze the ac losses of a fully energized cable, to improve the capabilities of existing designs and to find an optimal configuration

Nanodiamond influence on the nucleation and growth of YBCO superconducting film deposited by metal-organic decomposition

It was recently shownthat the introduction of nanodiamond(ND)into a superconducting metal-organic deposited YBa2Cu3O7-& delta; (YBCO) film produces anincrease in critical current density in self-field conditions (B = 0 T). Such improvement appears to be due to the formationof denser and smoother films than the samples deposited without ND.This paper presents the work done to understand the role of ND duringYBCO nucleation and growth. A detailed study on YBCO+ND films quenchedat different temperatures of the crystallization process was carriedout. Results showed that the reaction responsible for YBCO productionappeared effectively affected by ND. In particular, ND stabilizesone of the YBCO precursors, BaF2(1-x)O x , whose conversion into YBCO requiresa prolonged time. Therefore, the YBCO nucleation is slowed down byND and begins when the experimental conditions favor both thermodynamicallyand kinetically the formation of YBCO along the c-axis. This effect has important implications because the growthof a highly epitaxial c-axis YBCO film enables excellentsuperconducting performance.Thenucleation and growth of a YBCO epitaxial film can bedelayed by the presence of nanodiamond (ND). Since YBCO nucleationoccurs at a higher temperature, the c-axis grainformation is favored from both a thermodynamic and kinetic point ofview. This effect can explain the improvement of superconducting propertiesobserved in a YBCO+ND film