Mechanical behaviour and durability of high volume fly ash cementitious composites

The purpose of this research is to separate different morphological particles of ASTM class F fly ash, and study their effect on mechanical behaviour and durability of high volume cementitious mixtures. In this research wet separation of raw fly ash is carried out, which resulted in three layers of different morphological particles. The first layer of particles float, comprise of about 1-5% of fly ash, is identified as cenospheres or hollow spheres. The second layer of particles is measured to be 55-60% of raw fly ash and consisting of porous spherical and rounded particles rich in Si and Al. The third layer particles is measured to be about 35-40% of raw fly ash. High volume fly ash cementitious composites containing second or third layer particles are tested under compression and bending, highlighting a higher strength and ductility in comparison to cementitious ones containing raw fly ash particles.&nbsp

Rheological and Technological Quality of Minor Wheat Species and Common Wheat

Wheat is an important food grain source that nurtures millions of people around the world. Not only does wheat contain a large number of nutrients such as protein, wet gluten, etc., but also it has a lot of antioxidants such as dietary fibre, tocopherols, tocotrienols, etc. In a majority of cases, attention has been drawn to evaluate the grain yield and its components rather than its quality. The present investigation was carried out to evaluate the differences between minority wheat species and common wheat to determine the best rheological characteristics, technological quality as well as correlations between rheological and technological traits. The results revealed that hulled wheat species had a high protein content and wet gluten content. Einkorn and emmer were not suitable for ‘classical’ baking processing. But there is potential for other products, e.g. wheat rice (einkorn) or pasta (emmer). Spelt should be possible to be used in ‘classical’ baking industry, but the best solution is to use grain as a mixture with bread wheat. Also, this study showed a genotype variation in the antioxidant activity of einkorn, emmer, spelta and Triticum aestivum

Decomposition of cutting forces in quasi-orthogonal CNC milling

Decomposition of cutting forces in quasi-orthogonal CNC milling. The paper is focused on the analysis of cutting forces in milling of MDF boards on the CNC machine called SCM Tech 99 L. The Kistler 9257 B is top-of-the-line dynamometer with DynoWare software used to measure power and analyse data. The forces were examined and analysed using quasi-orthogonal milling with a single-edged blade. The resulting force values were compared with each other depending on the conventional and climb milling of the edge of the MDF board at various feed speeds.Rozkład sił skrawających w quasi-prostopadłym frezowaniu CNC. W pracy przeanalizowano siły skrawania podczas frezowania płyt MDF na obrabiarce CNC SCM Tech 99 L. Do pomiaru mocy i analizy danych wykorzystano dynamometr Kistler 9257 B z oprogramowaniem DynoWare. Pomiaru sił dokonano w trakcie quasi-prostopadłego frezowania przy wykorzystaniu pojedynczego ostrza. Uzyskane wartości sił porównano ze sobą w zależności sposobu skarawania płyty MDF (przeciwbieżne i współbieżne) przy różnych prędkościach posuwu

Digital two-parametric processing of the output data from radiation detectors

In this paper, we present the results of digital processing of pulses produced by several types of detectors. We introduce a new high quality discrimination method, and the output from this new method is compared with those from classic methods. Also, a new function to determine separation quality of various discrimination methods is defined in this paper. Our results show how the quality of the particle type identification depends on the sampling rate as well as the method of sampled data processing

DETERMINING THE ROLE OF INDIVIDUAL FLY ASH PARTICLES IN INFLUENCING THE VARIATION IN THE OVERALL PHYSICAL, MORPHOLOGICAL, AND CHEMICAL PROPERTIES OF FLY ASH

The properties of fly ashes vary because of the differences in the properties of their individual particles, and the determination of variation in these properties is of interest to the industries which use pulverized raw fly ash in applications, such as in cementitious materials and in the recovery of certain rare elements from raw fly ash. To investigate the differences in individual particles, four pulverized raw fly ashes from thermal power plants of the Czech Republic were used in this research. It was observed from FE-SEM that all four fly ashes consist of glassy hollow spherical, solid spherical, porous spherical, bright spherical, porous slaggy and compact slaggy particles. Box and whisker diagrams were plotted from the data of EDX individual particle analyses, which showed that the data of percentages for the Si, Al, and Fe elements is more scattered as compared to other elements. It was further observed from ternary phase diagrams and pseudo coloured images, that nature of fly ash particles changes from alumino silicate glassy to alumino silicate calcite metallic to pure ferro-metallic,where glassy particles showed high percentages and pure calcite particles were absent in fly ashes. Furthermore, a comparison between the XRF, the EDX total area analyses, showed that the EDX individual particle analysis gives more realistic and reliable data with median, mean, and the standard deviation for percentages of each element present in the fly ashes

Data from: Phylogenetic relatedness determined between antibiotic resistance and 16S rRNA genes in actinobacteria

Background: Distribution and evolutionary history of resistance genes in environmental actinobacteria provide information on intensity of antibiosis and evolution of specific secondary metabolic pathways at a given site. To this day, actinobacteria producing biologically active compounds were isolated mostly from soil but only a limited range of soil environments were commonly sampled. Consequently, soil remains an unexplored environment in search for novel producers and related evolutionary questions. Results: Ninety actinobacteria strains isolated at contrasting soil sites were characterized phylogenetically by 16S rRNA gene, for presence of erm and ABC transporter resistance genes and antibiotic production. An analogous analysis was performed in silico with 246 and 31 strains from Integrated Microbial Genomes (JGI_IMG) database selected by the presence of ABC transporter genes and erm genes, respectively. In the isolates, distances of erm gene sequences were significantly correlated to phylogenetic distances based on 16S rRNA genes, while ABC transporter gene distances were not. The phylogenetic distance of isolates was significantly correlated to soil pH and organic matter content of isolation sites. In the analysis of JGI_IMG datasets the correlation between phylogeny of resistance genes and the strain phylogeny based on 16S rRNA genes or five housekeeping genes was observed for both the erm genes and ABC transporter genes in both actinobacteria and streptomycetes. However, in the analysis of sequences from genomes where both resistance genes occurred together the correlation was observed for both ABC transporter and erm genes in actinobacteria but in streptomycetes only in the erm gene. Conclusions: The type of erm resistance gene sequences was influenced by linkage to 16S rRNA gene sequences and site characteristics. The phylogeny of ABC transporter gene was correlated to 16S rRNA genes mainly above the genus level. The results support the concept of new specific secondary metabolite scaffolds occurring more likely in taxonomically distant producers but suggest that the antibiotic selection of gene pools is also influenced by site conditions

Supporting information to the Figure 4

Phylogenetic relationships of 47 collection strains harboring erm resistance genes. An alignment of 16S rRNA gene sequences. A phylogram constructed by neighbor-joining method based on Jukes-Cantor distance matrices calculated from 1000 bootstrap replicates of the alignment