395 research outputs found

    Sequence of phase formation in planar metal-Si reaction couples

    Get PDF
    A correlation is found between the sequence of phase formation in thin-film metal-Si interactions and the bulk equilibrium phase diagram. After formation of the first silicide phase, which generally follows the rule proposed by Walser and Bené, the next phase formed at the interface between the first phase and the remaining element (Si or metal) is the nearest congruently melting compound richer in the unreacted element. If the compounds between the first phase and the remaining element are all noncongruently melting compounds (such as peritectic or peritectoid phases), the next phase formed is that with the smallest temperature difference between the liquidus curve and the peritectic (or peritectoid) point

    Depth dependence of atomic mixing by ion beams

    Get PDF
    Ion backscattering spectrometry has been used to investigate the depth dependence of atomic mixing induced by ion beams. Samples consisting of a thin Pt (or Si) marker a few tens of angstroms thick buried at different depths in a deposited Si (or Pt) layer were bombarded with Xe+ of 300 keV at 2×10^16 cm^–2 dose and Ar+ of 150 keV at 5×10^15cm^–2 dose. Significant spreading of the marker was observed as a result of ion irradiation. The amount of spreading was measured as a function of depth of the marker, which was then compared with the deposited energy distribution. Measurements of this kind promise new insight into the nature of the interaction between ion beams and solids

    Relaxation of classical many-body hamiltonians in one dimension

    Full text link
    The relaxation of Fourier modes of hamiltonian chains close to equilibrium is studied in the framework of a simple mode-coupling theory. Explicit estimates of the dependence of relevant time scales on the energy density (or temperature) and on the wavenumber of the initial excitation are given. They are in agreement with previous numerical findings on the approach to equilibrium and turn out to be also useful in the qualitative interpretation of them. The theory is compared with molecular dynamics results in the case of the quartic Fermi-Pasta-Ulam potential.Comment: 9 pag. 6 figs. To appear in Phys.Rev.

    Methodological aspects of diagnostics and minimal residual disease monitoring in infant acute leukemias

    Get PDF
    Hereby we present methodological aspects and prognostic significance of minimal residual disease (MRD) monitoring in infant acute leukemias. Based on our own experience we made algorithm for detection of MRD in this group of patients. We conclude that general concordance between MRD detection by flow cytometry and real-time polymerase chain reaction (PCR) for fusion gene transcripts achieved 87.0 %. Concordance was significantly lower during induction in comparison to consolidation/intensification and relapse treatment (78.6; 90.4 and 93.4 %, correspondingly; p = 0.002). It was not dependent on presence of normal B-cell precursors. Concordance between MRD results obtained by qualitative real-time PCR in bone marrow and peripheral blood samples was 84.5 %. Interestingly, all discrepant results (22 samples 15.5 %) were MRD-positive in bone marrow, but negative in peripheral blood. Despite high qualitative concordance rate between MRD detection in bone marrow and peripheral blood samples we could not show prognostic value of MRD monitoring in peripheral blood by fusion gene transcripts. Multivariate analysis revealed that MRD-positivity at time-point 4 in bone marrow was the only significant and independent prognostic factor of unfavorable outcome in the observed group of patients (hazard ratio 7.326; 95 % confidence interval 2.378–22.565)

    IKZF1 Deletions with COBL Breakpoints Are Not Driven by RAG-Mediated Recombination Events in Acute Lymphoblastic Leukemia

    Get PDF
    IKZF1 deletion (ΔIKZF1) is an important predictor of relapse in both childhood and adult B-cell precursor acute lymphoblastic leukemia (B-ALL). Previously, we revealed that COBL is a hotspot for breakpoints in leukemia and could promote IKZF1 deletions. Through an international collaboration, we provide a detailed genetic and clinical picture of B-ALL with COBL rearrangements (COBL-r). Patients with B-ALL and IKZF1 deletion (n = 133) were included. IKZF1 ∆1-8 were associated with large alterations within chromosome 7: monosomy 7 (18%), isochromosome 7q (10%), 7p loss (19%), and interstitial deletions (53%). The latter included COBL-r, which were found in 12% of the IKZF1 ∆1-8 cohort. Patients with COBL-r are mostly classified as intermediate cytogenetic risk and frequently harbor ETV6, PAX5, CDKN2A/B deletions. Overall, 56% of breakpoints were located within COBL intron 5. Cryptic recombination signal sequence motifs were broadly distributed within the sequence of COBL, and no enrichment for the breakpoint cluster region was found. In summary, a diverse spectrum of alterations characterizes ΔIKZF1 and they also include deletion breakpoints within COBL. We confirmed that COBL is a hotspot associated with ΔIKZF1, but these rearrangements are not driven by RAG-mediated recombination

    Tourist Intercultural Competence: A Multidimensional Measurement and its Impact on Tourist Active Participation and Memorable Cultural Experiences

    Get PDF
    Cultural tourism has received increasing attention. Tourists’ intercultural competence represents the abilities to appropriately and efficiently interact with people across different cultures, helping tourists attain developing positive cultural exchange experiences. By adopting both qualitative and quantitative approaches, a multi-dimensional measurement of tourists’ intercultural competence was developed and validated in this study. Four factors of tourists’ intercultural competence were identified: intercultural responsibility, understanding, appreciation, and action. Furthermore, this study examined the association between tourists’ intercultural competence and memorable cultural experience and determined the mediating effects of tourists’ active participation. This study contributes to the cultural tourism literature by proposing a measurement of tourists’ intercultural competences and by establishing a framework illustrating how cultural tourists interact with different cultures, thus attaining memorable cultural experiences. Managerial implications for destination marketing and tourist management are discussed herein

    A Multicriteria Analysis on the Strategies to Open Taiwan's Mobile Virtual Network Operators Services

    Get PDF
    [[abstract]]This study investigates the trends followed by MVNOs (Mobile Virtual Network Operators) in the last three years and analyzes the strategies that can contribute to the success of Taiwan's telecommunications industry and marketing. We apply the method and concept of PATTERN (Planning Assistance Through Technical Evaluation of Relevance Number) to establish relevant systems for searching out the key successful factors of strategies to attract MVNOs. We also use the fuzzy Multi-Criteria Decision Making (MCDM) method for analyzing the different preference of a decision group in the criteria weights and for ranking the alternatives in a fuzzy environment in order to provide a strategy scheme. These results provide a reference to assist telecommunications operators, 3G license owners, potential MVNOs, and equipment manufacturers when working out business plans.[[incitationindex]]SCI[[booktype]]箙
    • 

    corecore