1,687 research outputs found
Molecular dynamics simulation of the nanoindentation process in Cr/CrN and (Cr/CrN)2 thin films
Molecular dynamics (MD) simulations were carries out for studying the influenceof nanoindentation in the atomistic deformation mechanisms of Cr/CrN and(Cr/CrN)2 coatings with BCC and FCC crystalline structures for Cr and CrN,respectively. The Morse potential was employed in order to determine the atomicinteraction forces of the Cr-Cr and Cr-N atoms. A non-deformable potential solidsphere was implemented for determining the role of the nanoindenter. The OliverParr method (OP) was used to obtain the hardness and elastic modulus of the Cr/CrN and (Cr/CrN)2 layers, resulting in values of 18 and 20 GPa for Cr/CrN and (Cr/CrN)2, respectively. The Cheng method was used for correcting the hardness values obtained by the OP method. The Cheng correction showed higher hardness values since it avoids the influence of the scale effect. Regarding the elasticity modulus, Cr/CrN and (Cr/CrN)2 exhibited values of 217.86 GPa and 258.9 GPa, respectively. Simulations of the temperature influence on the hardness were carried out over a range of 300-1000 K. Results indicate that the hardness decreased as a function of the temperature.Fil: Amaya Roncancio, Sebastian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich". Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich"; ArgentinaFil: Arias Mateus, D. F.. Universidad Católica de Pereira; ColombiaFil: Segura Giraldo, B.. Universidad Nacional de Colombia; ColombiaFil: de la Roche, J.. Universidad Nacional de Colombia; ColombiaFil: Restrepo Parra, E.. Universidad Nacional de Colombia; Colombi
Effect of soybean and tuna gonad in the diet of juvenile bullseye puffer fish Sphoeroides annulatus.
Response to comment on 'Amphibian fungal panzootic causes catastrophic and ongoing loss of biodiversity'
Lambert et al. question our retrospective and holistic epidemiological assessment of the role of chytridiomycosis in amphibian declines. Their alternative assessment is narrow and provides an incomplete evaluation of evidence. Adopting this approach limits understanding of infectious disease impacts and hampers conservation efforts. We reaffirm that our study provides unambiguous evidence that chytridiomycosis has affected at least 501 amphibian species
Finite size effects near the onset of the oscillatory instability
A system of two complex Ginzburg - Landau equations is considered that applies at the onset of the oscillatory instability in spatial domains whose size is large (but finite) in one direction; the dependent variables are the slowly modulated complex amplitudes of two counterpropagating wavetrains. In order to obtain a well posed problem, four boundary conditions must be imposed at the boundaries. Two of them were already known, and the other two are first derived in this paper. In the generic case when the group velocity is of order unity, the resulting problem has terms that are not of the same order of magnitude. This fact allows us to consider two distinguished limits and to derive two associated (simpler) sub-models, that are briefly discussed. Our results predict quite a rich variety of complex dynamics that is due to both the modulational instability and finite size effects
Prognostic impact of macrometastasis linear size in sentinel node biopsy for breast carcinoma
AIM: The aim of the present study was to evaluate the risk of axillary non-sentinel lymph-node metastases (ALN) in breast cancer patients presenting macrometastasis (Mac-m) in the sentinel lymph node (SN). MATERIALS AND METHODS: A retrospective series of 1464 breast cancers from patients who underwent ALN dissection following the diagnosis of Mac-m in the sentinel node (SN) was studied. In all the cases the MAC-m linear size was evaluated and correlated with presence or absence of non-SN ALN metastases. RESULTS: Non-SN metastases were detected in 644\1464 cases (43.98%). The risk of further axillary metastases ranged from 20.2% (37/183) in cases with Mac-m between 2 and 2.9 mm, to 65.3% (262/401) in cases with Mac-m measuring > 10 mm. The risk of non-SN ALN metastases showed a 3% increase, parallel to each mm increment in SN metastasis size. The data evaluated with the receiver operating characteristic (ROC) curve showed that the Mac-m could be subdivided according to a new cut-off of 7 mm. pT1 tumours, with Mac-m < 7 mm had a risk of non-SN ALN metastases of <30%. Furthermore 109/127 of these (85.8%) had 3 or less non-SN ALN -metastases. CONCLUSIONS: The present data give a detailed description on the risk of non-SN ALN involvement, that may be useful in the evaluation of breast cancer patients. It is suggested that a Mac-m size of <7 mm is related to a low residual axillary disease burden in breast cancer patients with small (pT1) tumours
Highlights from the Pierre Auger Observatory
The Pierre Auger Observatory is the world's largest cosmic ray observatory.
Our current exposure reaches nearly 40,000 km str and provides us with an
unprecedented quality data set. The performance and stability of the detectors
and their enhancements are described. Data analyses have led to a number of
major breakthroughs. Among these we discuss the energy spectrum and the
searches for large-scale anisotropies. We present analyses of our X
data and show how it can be interpreted in terms of mass composition. We also
describe some new analyses that extract mass sensitive parameters from the 100%
duty cycle SD data. A coherent interpretation of all these recent results opens
new directions. The consequences regarding the cosmic ray composition and the
properties of UHECR sources are briefly discussed.Comment: 9 pages, 12 figures, talk given at the 33rd International Cosmic Ray
Conference, Rio de Janeiro 201
The Pierre Auger Observatory III: Other Astrophysical Observations
Astrophysical observations of ultra-high-energy cosmic rays with the Pierre
Auger ObservatoryComment: Contributions to the 32nd International Cosmic Ray Conference,
Beijing, China, August 201
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