Phase composition and transformations in magnetron-sputtered (Al,V)2O3 coatings

Coatings of (Al1-xVx)2O3, with x ranging from 0 to 1, were deposited by pulsed DC reactive sputter deposition on Si(100) at a temperature of 550 {\deg}C. XRD showed three different crystal structures depending on V-metal fraction in the coating: {\alpha}-V2O3 rhombohedral structure for 100 at.% V, a defect spinel structure for the intermediate region, 63 - 42 at.% V. At lower V-content, 18 and 7 at.%, a gamma-alumina-like solid solution was observed, shifted to larger d-spacing compared to pure {\gamma}-Al2O3. The microstructure changes from large columnar faceted grains for {\alpha}-V2O3 to smaller equiaxed grains when lowering the vanadium content toward pure {\gamma}-Al2O3. Annealing in air resulted in formation of V2O5 crystals on the surface of the coating after annealing to 500 {\deg}C for 42 at.% V and 700 {\deg}C for 18 at.% V metal fraction respectively. The highest thermal stability was shown for pure {\gamma}-Al2O3-coating, which transformed to {\alpha}-Al2O3 after annealing to 1100{\deg} C. Highest hardness was observed for the Al-rich oxides, ~24 GPa. The latter decreased with increasing V-content, larger than 7 at.% V metal fraction. The measured hardness after annealing in air decreased in conjunction with the onset of further oxidation of the coatings

The Relationships Among Competitiveness, Age and Ability In Distance Runners

The purpose of this study was to examine relationships suggested by general achievement motivation literature and the popular literature in sport using the Sport Orientation Questionnaire (SOQ). The current study examined if faster runners are more competitive than slower runners, if older athletes were less competitive than younger athletes, and if faster runners were more goal oriented than slower runners. Distance runners (n=80), ranging from 10 to 61 years old completed race packets containing a cover letter, consent forms, the SOQ and a demographic questionnaire. Runners averaged 32.9 years of age and reported levels of competitiveness and goal orientation consistent with previous research. Results indicated that competitiveness and age were negatively related (r = -.44, p \u3c 001) and competitiveness and personal best times for all race distances were positively associated (r = .28, p \u3c .05 to .33, p \u3c .01). Ability and goal orientation were unrelated. In conclusion, both ability and age, in addition to a variety of significant social and cognitive correlates, may contribute to the development and decline of competitiveness. Future research should examine the way that competitiveness and related cognitions develop and wane over the life span

Factor Structure of the Athletic Identity Measurement Scale With Athletes With Disabilities

Individuals who perceive themselves as athletes are thought to have self-schemas composed of, in part, an athletic identity (Brewer, Van Raalte, & Linder, 1993). The recent development of the Athletic Identity Measurement Scale (AIMS) has allowed sport psychology researchers to assess athletic identity. Research with adolescent athletes with disabilities has suggested that the AIMS is composed of 4 factors (Martin, Mushett, & Eklund, 1994). The purpose of the current study was to further examine the psychometric properties of the AIMS. Seventy-eight international swimmers (34 females, 44 males) with disabilities, ranging in age from 12 to 44 (M = 23.4 years), participated in the present study. Using structural equation modeling procedures, a confirmatory factor analysis determined that the data fit the 4-factor model specified in the Martin et al. (1994) study, thus providing support for the multidimensionality of the AIMS

Social physique anxiety and physical activity in early adolescent girls : the influence of maturation and physical activity motives

This study considered the influence of maturation on social physique anxiety (SPA), the relationship between SPA and current and future physical activity (PA) levels and the influence of motives for physical activity on this relationship in early adolescent girls (n=162; mean age=11.80±0.33 years). Participants completed the Pubertal Development Scale, the modified Social Physique Anxiety Scale and the Motives for Physical Activity Scale at baseline and the Physical Activity Questionnaire for Older Children at baseline and 6 months later. The girls became less active across the 6 months and girls in the early stages of maturation had significantly lower SPA than the girls in the middle and late stages of maturation. SPA was not related to current or future physical activity in the sample as a whole. Cluster analysis identified four groups with different motive profiles and the High Appearance and Fitness group demonstrated a moderate negative relationship between SPA and PA at phase 1, whereas the other groups did not. These findings indicate that SPA may increase with maturation and the relationship between SPA and PA is dependent on reasons for being active. For girls who are motivated to be active primarily by body-related reasons SPA is likely to lead to lower levels of PA

Strain-induced ferroelectricity in CaTiO3_3 from first principles

First principles calculations are used to investigate the effects of epitaxial strain on the structure of the perovskite oxide CaTiO$_3$, with particular focus on the stabilization of a ferroelectric phase related to a polar instability hidden in the orthorhombic equilibrium bulk $Pbnm$ structure but found in previous first-principles studies of the ideal cubic perovskite high-symmetry reference structure. At 1.5% strain, we find an epitaxial orientation transition between the $ab$-$ePbnm$ phase, favored for compressive strains, and the $c$-$ePbnm$ phase. For larger tensile strains, a polar instability develops in the $c$-$ePbnm$ phase and an epitaxial-strain-induced ferroelectric phase is obtained with polarization along a $$ direction with respect to the primitive perovskite lattice vectors of the square substrate.Comment: 4 pages, 2 figure

Reversible Fluorination of Graphene: towards a Two-Dimensional Wide Bandgap Semiconductor

We report the synthesis and evidence of graphene fluoride, a two-dimensional wide bandgap semiconductor derived from graphene. Graphene fluoride exhibits hexagonal crystalline order and strongly insulating behavior with resistance exceeding 10 G$\Omega$ at room temperature. Electron transport in graphene fluoride is well described by variable-range hopping in two dimensions due to the presence of localized states in the band gap. Graphene obtained through the reduction of graphene fluoride is highly conductive, exhibiting a resistivity of less than 100 k$\Omega$ at room temperature. Our approach provides a new path to reversibly engineer the band structure and conductivity of graphene for electronic and optical applications.Comment: 7 pages, 5 figures, revtex, to appear in PR

Структура заболеваемости поллинозом в Витебской области

ГИПЕРСЕНСИБИЛИЗАЦИЯ НЕМЕДЛЕННОГО ТИПАПОЛЛИНОЗСЕННАЯ ЛИХОРАДК

Jetset: selecting the optimal microarray probe set to represent a gene

<p>Abstract</p> <p>Background</p> <p>Interpretation of gene expression microarrays requires a mapping from probe set to gene. On many Affymetrix gene expression microarrays, a given gene may be detected by multiple probe sets, which may deliver inconsistent or even contradictory measurements. Therefore, obtaining an unambiguous expression estimate of a pre-specified gene can be a nontrivial but essential task.</p> <p>Results</p> <p>We developed scoring methods to assess each probe set for specificity, splice isoform coverage, and robustness against transcript degradation. We used these scores to select a single representative probe set for each gene, thus creating a simple one-to-one mapping between gene and probe set. To test this method, we evaluated concordance between protein measurements and gene expression values, and between sets of genes whose expression is known to be correlated. For both test cases, we identified genes that were nominally detected by multiple probe sets, and we found that the probe set chosen by our method showed stronger concordance.</p> <p>Conclusions</p> <p>This method provides a simple, unambiguous mapping to allow assessment of the expression levels of specific genes of interest.</p

Imaging, Structural and Chemical Analysis of Silicon Nanowires

Laser ablation has been used to grow silicon nanowires with an average diameter of 6.7 nm ± 2.7 nm surrounded by an amorphous SiOx sheath of 1-2 nm. This paper reports the imaging, chemical and structural analysis of these wires. Due to the growth temperature and the presence of calcium impurities and trace oxygen, two distinct types of wires are found. They appear to grow by two different processes. One requires a metal catalyst, the other is catalyzed by oxygen