11–23% Cr steels for solid oxide fuel cell interconnect applications at 800 \ub0C – How the coating determines oxidation kinetics

The present work investigates the low-cost steels AISI 441, AISI 430, and AISI 444 against the tailor-made high Cr steel Crofer 22 APU (22.9 wt% Cr) at 800 \ub0C in simulated solid oxide fuel cell (SOFC) cathode conditions. Furthermore, a low Cr steel, AISI 409 (11.4 wt% Cr) is included in the study. The oxidation, chromium evaporation, and area-specific resistance (ASR) of the uncoated and Ce/Co-coated steels are studied for up to 3000 h. Ce/Co-coated steels showed significant improvement in behaviour compared to their uncoated counterparts. The oxidation and chromium evaporation behaviour between the uncoated steels varied substantially while the Ce/Co coated steels exhibited highly similar behaviour. The area-specific resistance of the coated low-cost steels was on par with Crofer 22 APU. However, 430 formed a continuous silica layer, resulting in a higher ASR after 3000 h. Cross-sections of the uncoated and Ce/Co-coated steels were analysed using a scanning electron microscope and energy dispersive X-ray spectroscopy

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The aluminum–zinc-vacancy (Al Zn −V Zn ) complex is identified as one of the dominant defects in Al-containing n -type ZnO after electron irradiation at room temperature with energies above 0.8 MeV. The complex is energetically favorable over the isolated V Zn , binding more than 90% of the stable V Zn ’s generated by the irradiation. It acts as a deep acceptor with the (0/− ) energy level located at approximately 1 eV above the valence band. Such a complex is concluded to be a defect of crucial and general importance that limits the n -type doping efficiency by complex formation with donors, thereby literally removing the donors, as well as by charge compensation

A Comparison of the Oxidation and Nitridation Properties of Selected Chromia- and Alumina-Forming Alloys at 800 degrees C

Three FeCrAl alloys and two chromia-formers (a stainless steel, and a Ni-base alloy) have been exposed in four environments (dry air, air + 20% H2O, 20% H-2 + 20% H2O + Ar and 95% N-2 + 5% H-2) for 168 h at 800 degrees C. The corroded samples were investigated by SEM/EDS, XRD and gravimetry, and the formation of CrO2(OH)(2)(g) was measured as a function of time using a denuder technique. The Fe-base alloy formed a Cr-rich protective oxide scale in dry air and wet air but suffered break-away oxidation in 20% H-2 + 20% H2O + Ar. In contrast, the Ni-base alloy suffered extensive NiO formation and internal oxidation in dry air and wet air but formed a protective chromia scale in 20% H-2 + 20% H2O. All three FeCrAl alloys formed protective alumina scales in dry air, wet air and 20% H-2 + 20% H2O + Ar. The FeCrAl alloy Kanthal APMT was severely nitrided in the 95% N-2 + 5% H-2 environment due to defects in the oxide scale associated with RE-rich inclusions which allowed nitrogen to enter the alloy. In contrast, the two Cr-lean FeCrAl alloys Kanthal EF101 and Kanthal EF100 did not suffer nitridation at all

OligoSpawn: a software tool for the design of overgo probes from large unigene datasets

BACKGROUND: Expressed sequence tag (EST) datasets represent perhaps the largest collection of genetic information. ESTs can be exploited in a variety of biological experiments and analysis. Here we are interested in the design of overlapping oligonucleotide (overgo) probes from large unigene (EST-contigs) datasets. RESULTS: OLIGOSPAWN is a suite of software tools that offers two complementary services, namely (1) the selection of "unique" oligos each of which appears in one unigene but does not occur (exactly or approximately) in any other and (2) the selection of "popular" oligos each of which occurs (exactly or approximately) in as many unigenes as possible. In this paper, we describe the functionalities of OLIGOSPAWN and the computational methods it employs, and we report on experimental results for the overgo probes designed with it. CONCLUSION: The algorithms we designed are highly efficient and capable of processing unigene datasets of sizes on the order of several tens of Mb in a few hours on a regular PC. The software has been used to design overgo probes employed to screen a barley BAC library (Hordeum vulgare). OLIGOSPAWN is freely available at

GeneHopper: a web-based search engine to link gene-expression platforms through GenBank accession numbers

Global gene-expression analysis is carried out using different technologies that are either array- or sequence-tag-based. To compare experiments that are performed on these different platforms, array probes and sequence tags need to be linked. An additional challenge is cross-referencing between species, to compare human profiles with those obtained in a mouse model, for example. We have developed the web-based search engine GeneHopper to link different expression resources based on UniGene clusters and HomoloGene orthologs databases of the National Center for Biotechnology Information (NCBI)

Exploring the Effect of Silicon on the High Temperature Corrosion of Lean FeCrAl Alloys in Humid Air

A new approach to reduce the chromium and aluminium concentrations in FeCrAl alloys without significantly impairing corrosion resistance is to alloy with 1-2 wt.% silicon. This paper investigates the "silicon effect" on oxidation by comparing the oxidation behavior and scale microstructure of two FeCrAl alloys, one alloyed with silicon and the other not, in dry and wet air at 600 degrees C and 800 degrees C. Both alloys formed thin protective oxide scales and the Cr-evaporation rates were small. In wet air at 800 degrees C the Si-alloyed FeCrAl formed an oxide scale containing mullite and tridymite together with alpha- and gamma-alumina. It is suggested that the reported improvement of the corrosion resistance of Al- and Cr-lean FeCrAl\u27s by silicon alloying is caused by the appearance of Si-rich phases in the scale

Affordable phenotyping of winter wheat under field and controlled conditions for drought tolerance

Drought stress is one of the key plant stresses reducing grain yield in cereal crops worldwide. Although it is not a breeding target in Northern Europe, the changing climate and the drought of 2018 have increased its significance in the region. A key challenge, therefore, is to identify novel germplasm with higher drought tolerance, a task that will require continuous characterization of a large number of genotypes. The aim of this work was to assess if phenotyping systems with low-cost consumer-grade digital cameras can be used to characterize germplasm for drought tolerance. To achieve this goal, we built a proximal phenotyping cart mounted with digital cameras and evaluated it by characterizing 142 winter wheat genotypes for drought tolerance under field conditions. The same genotypes were additionally characterized for seedling stage traits by imaging under controlled growth conditions. The analysis revealed that under field conditions, plant biomass, relative growth rates, and Normalized Difference Vegetation Index (NDVI) from different growth stages estimated by imaging were significantly correlated to drought tolerance. Under controlled growth conditions, root count at the seedling stage evaluated by imaging was significantly correlated to adult plant drought tolerance observed in the field. Random forest models were trained by integrating measurements from field and controlled conditions and revealed that plant biomass and relative growth rates at key plant growth stages are important predictors of drought tolerance. Thus, based on the results, it can be concluded that the consumer-grade cameras can be key components of affordable automated phenotyping systems to accelerate pre-breeding for drought tolerance

Efficacy of an external chromia layer in reducing nitridation of high temperature alloys

Six high temperature alloys have been exposed in N2/H2 environments at 900 \ub0C. In order to study the efficacy of a chromia barrier layer against nitrogen ingress, experiments were performed in two environments having the same N2/H2 ratio but slightly different water content, chromia formation being spontaneous in one case only. The samples were evaluated by SEM/STEM/EDX, XRD, gravimetry and GD-OES. The presence of an external chromia scale reduced nitridation of the alloy by 50–95%. Furthermore, in the presence of a continuous alumina layer no nitridation of the alloy was detected

Genome-Wide Association Analysis and Genomic Prediction for Adult-Plant Resistance to Septoria Tritici Blotch and Powdery Mildew in Winter Wheat

Septoria tritici blotch (STB) caused by the fungal pathogen Zymoseptoria tritici and powdery mildew (PM) caused by Blumeria graminis f.sp tritici (Bgt) are among the forefront foliar diseases of wheat that lead to a significant loss of grain yield and quality. Resistance breeding aimed at developing varieties with inherent resistance to STB and PM diseases has been the most sustainable and environment-friendly approach. In this study, 175 winter wheat landraces and historical cultivars originated from the Nordic region were evaluated for adult-plant resistance (APR) to STB and PM in Denmark, Estonia, Lithuania, and Sweden. Genome-wide association study (GWAS) and genomic prediction (GP) were performed based on the adult-plant response to STB and PM in field conditions using 7,401 single-nucleotide polymorphism (SNP) markers generated by 20K SNP chip. Genotype-by-environment interaction was significant for both disease scores. GWAS detected stable and environment-specific quantitative trait locis (QTLs) on chromosomes 1A, 1B, 1D, 2B, 3B, 4A, 5A, 6A, and 6B for STB and 2A, 2D, 3A, 4B, 5A, 6B, 7A, and 7B for PM adult-plant disease resistance. GP accuracy was improved when assisted with QTL from GWAS as a fixed effect. The GWAS-assisted GP accuracy ranged within 0.53-0.75 and 0.36-0.83 for STB and PM, respectively, across the tested environments. This study highlights that landraces and historical cultivars are a valuable source of APR to STB and PM. Such germplasm could be used to identify and introgress novel resistance genes to modern breeding lines

Endless forms of sexual selection

In recent years, the field of sexual selection has exploded, with advances in theoretical and empirical research complementing each other in exciting ways. This perspective piece is the product of a "stock-taking\u27\u27 workshop on sexual selection and sexual conflict. Our aim is to identify and deliberate on outstanding questions and to stimulate discussion rather than provide a comprehensive overview of the entire field. These questions are organized into four thematic sections we deem essential to the field. First we focus on the evolution of mate choice and mating systems. Variation in mate quality can generate both competition and choice in the opposite sex, with implications for the evolution of mating systems. Limitations on mate choice may dictate the importance of direct vs. indirect benefits in mating decisions and consequently, mating systems, especially with regard to polyandry. Second, we focus on how sender and receiver mechanisms shape signal design. Mediation of honest signal content likely depends on integration of temporally variable social and physiological costs that are challenging to measure. We view the neuroethology of sensory and cognitive receiver biases as the main key to signal form and the \u27aesthetic sense\u27 proposed by Darwin. Since a receiver bias is sufficient to both initiate and drive ornament or armament exaggeration, without a genetically correlated or even coevolving receiver, this may be the appropriate \u27null model\u27 of sexual selection. Thirdly, we focus on the genetic architecture of sexually selected traits. Despite advances in modern molecular techniques, the number and identity of genes underlying performance, display and secondary sexual traits remains largely unknown. In-depth investigations into the genetic basis of sexual dimorphism in the context of long-term field studies will reveal constraints and trajectories of sexually selected trait evolution. Finally, we focus on sexual selection and conflict as drivers of speciation. Population divergence and speciation are often influenced by an interplay between sexual and natural selection. The extent to which sexual selection promotes or counteracts population divergence may vary depending on the genetic architecture of traits as well as the covariance between mating competition and local adaptation. Additionally, post-copulatory processes, such as selection against heterospecific sperm, may influence the importance of sexual selection in speciation. We propose that efforts to resolve these four themes can catalyze conceptual progress in the field of sexual selection, and we offer potential avenues of research to advance this progress