Growth of dense CNT on the multilayer graphene film by the microwave plasma enhanced chemical vapor deposition technique and their field emission properties

Catalyst assisted carbon nanotubes (CNTs) were grown on multilayer graphene (MLG) on copper and silicon substrates by the microwave plasma enhanced chemical vapor deposition technique. The transmission of the MLG was found to vary between 82 to 91.8% with the increase of deposition time. Scanning electron microscopy depicted that the MLG film survived at the deposition condition of CNTs with the appearance of the damaged structure due to the plasma. Growth of CNTs was controlled by adjusting the flow rates of methane gas. The density of carbon nanotubes was observed to increase with a higher supply of methane gas. It was observed that the field emission properties were improved with the increased density of CNTs on MLG. The lowest turn-on field was found to be 1.6 V mu m(-1) 1 accompanied with the highest current density of 2.8 mA cm(-2) for the CNTs with the highest density. The findings suggested that the field emission properties can be tuned by changing the density of CNTs

Improvement of structure and quality of nanoscale multilayered composite coatings, deposited by filtered cathodic vacuum arc deposition method

This article studies the specific features of cathode vacuum arc deposition of coatings used in the production of cutting tools. The detailed analysis of the major drawbacks of arc-Physical Vapour Deposition (PVD) methods has contributed to the development of the processes of filtered cathodic vacuum arc deposition to form nanoscale multilayered composite coatings of increased efficiency. This is achieved through the formation of nanostructure, increase in strength of adhesion of coating to substrate up to 20%, and reduction of such dangerous coating surface defects as macro- and microdroplets up to 80%. This article presents the results of the studies of various properties of developed nanoscale multilayered composite coating. The certification tests of carbide tool equipped with cutting inserts with developed nanoscale multilayered composite coating compositions in longitudinal turning (continuous cutting) and end symmetric milling, and intermittent cutting of steel C45 and hard-to-cut nickel alloy of NiCr20TiAl showed advantages of tool with nanoscale multilayered composite coating as compared to the tool without coating. The lifetime of the carbide inserts with developed NMCC based on the system of Ti-TiN-(NbZrTiCr)N (filtered cathodic vacuum arc deposition) was increased up to 5-6 times in comparison with the control tools without coatings and up to 1.5-2.0 times in comparison with nanoscale multilayered composite coating based on the system of Ti-TiN-(NbZrTiCr)N (standard arc-PVD technology). © The Author(s) 2017

Large Direct Repeats Flank Genomic Rearrangements between a New Clinical Isolate of Francisella tularensis subsp. tularensis A1 and Schu S4

Francisella tularensis subspecies tularensis consists of two separate populations A1 and A2. This report describes the complete genome sequence of NE061598, an F. tularensis subspecies tularensis A1 isolated in 1998 from a human with clinical disease in Nebraska, United States of America. The genome sequence was compared to Schu S4, an F. tularensis subspecies tularensis A1a strain originally isolated in Ohio in 1941. It was determined that there were 25 nucleotide polymorphisms (22 SNPs and 3 indels) between Schu S4 and NE061598; two of these polymorphisms were in potential virulence loci. Pulsed-field gel electrophoresis analysis demonstrated that NE061598 was an A1a genotype. Other differences included repeat sequences (n = 11 separate loci), four of which were contained in coding sequences, and an inversion and rearrangement probably mediated by insertion sequences and the previously identified direct repeats I, II, and III. Five new variable-number tandem repeats were identified; three of these five were unique in NE061598 compared to Schu S4. Importantly, there was no gene loss or gain identified between NE061598 and Schu S4. Interpretation of these data suggests there is significant sequence conservation and chromosomal synteny within the A1 population. Further studies are needed to determine the biological properties driving the selective pressure that maintains the chromosomal structure of this monomorphic pathogen

Spectrum, Volume 48, Issue 7

Highlights include: La Hispanidad Celebrates Social Justice Week -- Marching into Women\u27s History Month -- One Year After... -- Native Ukrainian Speaks at SHU -- Is SHU\u27s Campus Accessible to Everyone? -- SHU is Stronger Together -- Sacred Heart Professor Finalist for PR and Social Impact Award -- SHU Names New Interim Chief Diversity & Inclusion Officer -- Audrey\u27s Corner: Poems for Social Justice -- TAP Presents Sweat -- Upcoming Multicultural Council Showcase -- The Every Heart is Sacred Initiative -- Ukraine Paralympic Team -- Jasmine Rogers: More than an Athlet

Complete Genomic Characterization of a Pathogenic A.II Strain of Francisella tularensis Subspecies tularensis

Francisella tularensis is the causative agent of tularemia, which is a highly lethal disease from nature and potentially from a biological weapon. This species contains four recognized subspecies including the North American endemic F. tularensis subsp. tularensis (type A), whose genetic diversity is correlated with its geographic distribution including a major population subdivision referred to as A.I and A.II. The biological significance of the A.I – A.II genetic differentiation is unknown, though there are suggestive ecological and epidemiological correlations. In order to understand the differentiation at the genomic level, we have determined the complete sequence of an A.II strain (WY96-3418) and compared it to the genome of Schu S4 from the A.I population. We find that this A.II genome is 1,898,476 bp in size with 1,820 genes, 1,303 of which code for proteins. While extensive genomic variation exists between “WY96” and Schu S4, there is only one whole gene difference. This one gene difference is a hypothetical protein of unknown function. In contrast, there are numerous SNPs (3,367), small indels (1,015), IS element differences (7) and large chromosomal rearrangements (31), including both inversions and translocations. The rearrangement borders are frequently associated with IS elements, which would facilitate intragenomic recombination events. The pathogenicity island duplicated regions (DR1 and DR2) are essentially identical in WY96 but vary relative to Schu S4 at 60 nucleotide positions. Other potential virulence-associated genes (231) varied at 559 nucleotide positions, including 357 non-synonymous changes. Molecular clock estimates for the divergence time between A.I and A.II genomes for different chromosomal regions ranged from 866 to 2131 years before present. This paper is the first complete genomic characterization of a member of the A.II clade of Francisella tularensis subsp. tularensis