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TOPOLOGICAL LOCALISATION OF DEFECTS AT ATOMIC SCALE
Jean-Paul Jernot,Patricia Jouannot-Chesney,Christian Lantuéjoul,Gérard Nouet
Image Analysis and Stereology , 2002, DOI: 10.5566/ias.v21.p191-198
Abstract: The problem addressed in this paper is the detection of defects on atomic structures. The procedure proposed is in two steps. At first a tessellation is built starting from the atoms. It consists of a partition of the space into cells, and is used to define the neighbourhood relationships between the atoms. Then, the local contribution to a topological parameter, namely the Euler-Poincare characteristic, is defined and measured for each cell. Within a regular tessellation, made of identical cells, this local contribution is equal to zero. Any local deviation from regularity corresponds to a tessellation containing cells with non-zero contributions. This allows us to locate the defects from a topological criterion and opens the way to a fully automatic detection of interfaces at atomic scale. The procedure is applied in 2D space for the detection of edge dislocations, grain boundaries and twins from HREM models and images. A 3D example is also given to illustrate its generality.
Confocal Raman microscope mapping as a tool to describe different mineral and organic phases at high spatial resolution within marine biogenic carbonates: case study on Nerita undata (Gastropoda, Neritopsina)
G. Nehrke,J. Nouet
Biogeosciences (BG) & Discussions (BGD) , 2011,
Abstract: Marine biogenic carbonates formed by invertebrates (e.g. corals and mollusks) represent complex composites of one or more mineral phases and organic molecules. This complexity ranges from the macroscopic structures observed with the naked eye down to sub micrometric structures only revealed by micro analytical techniques. Understanding to what extent and how organisms can control the formation of these structures requires that the mineral and organic phases can be identified and their spatial distribution related. Here we demonstrate the capability of confocal Raman microscopy applied to cross sections of a shell of Nerita undata to describe the distribution of calcite and aragonite including their crystallographic orientation with high lateral resolution (~300 nm). Moreover, spatial distribution of functional groups of organic compounds can be simultaneously acquired, allowing to specifically relate them to the observed microstructures. The data presented in this case study highlights the possible new contributions of this method to the description of modalities of Nerita undata shell formation, and what could be expected of its application to other marine biogenic carbonates. Localization of areas of interest would also allow further investigations using more localized methods, such as TEM that would provide complementary information on the relation between organic molecules and crystal lattice.
Confocal Raman microscope mapping as a tool to describe different mineral and organic phases at high spatial resolution within marine biogenic carbonates: case study on Nerita undata (Gastropoda, Neritopsina)
G. Nehrke,J. Nouet
Biogeosciences (BG) & Discussions (BGD) , 2011, DOI: 10.5194/bg-8-3761-2011
Abstract: Marine biogenic carbonates formed by invertebrates (e.g. corals and mollusks) represent complex composites of one or more mineral phases and organic molecules. This complexity ranges from the macroscopic structures observed with the naked eye down to sub micrometric structures only revealed by micro analytical techniques. Understanding to what extent and how organisms can control the formation of these structures requires that the mineral and organic phases can be identified and their spatial distribution related. Here we demonstrate the capability of confocal Raman microscopy applied to cross sections of a shell of Nerita undata to describe the distribution of calcite and aragonite including their crystallographic orientation with high lateral resolution (~300 nm). Moreover, spatial distribution of functional groups of organic compounds can be simultaneously acquired, allowing to specifically relate them to the observed microstructures. The data presented in this case study highlights the possible new contributions of this method to the description of modalities of Nerita undata shell formation, and what could be expected of its application to other marine biogenic carbonates. Localization of areas of interest would also allow further investigations using more localized methods, such as TEM that would provide complementary information on the relation between organic molecules and crystal lattice.
Confocal Raman microscopy as a tool to describe different mineral and organic phases at high spatial resolution within marine biogenic carbonates: case study on Nerita undata (Gastropoda, Neritopsina)
G. Nehrke,J. Nouet
Biogeosciences Discussions , 2011, DOI: 10.5194/bgd-8-5563-2011
Abstract: Marine biogenic carbonates formed by invertebrates (e.g. corals and mollusk shells) represent complex composites of one or more mineral phases and organic molecules. This complexity ranges from the macroscopic structures observed with the naked eye down to sub micrometric structures only revealed by micro analytical techniques. Understanding to what extent and how organisms can control the formation of these structures requires that the mineral and organic phases can be identified and their spatial distribution related. Here we demonstrate the capability of confocal Raman microscopy applied to cross sections of a shell of Nerita undata to describe the distribution of calcite and aragonite including their crystallographic orientation with high lateral resolution (~300 nm). Moreover, spatial distribution of functional groups of organic compounds can be simultaneously acquired, allowing to specifically relate them to the observed microstructures. The data presented in this case study highlights the possible new contributions of this method to the description of modalities of Nerita undata shell formation, and what could be expected of its application to other marine biogenic carbonates. Localization of areas of interest would also allow further investigations using more localized methods, such as TEM that would provide complementary information on the relation between organic molecules and crystallographic lattice.
Atomistic Simulation of Undissociated 60° ; Basal Dislocation in Wurtzite GaN.  [PDF]
I. Belabbas, J. Chen, Ph. Komninou, G. Nouet
Modeling and Numerical Simulation of Material Science (MNSMS) , 2013, DOI: 10.4236/mnsms.2013.34B003
Abstract:

We have carried out computer atomistic simulations, based on an efficient density functional based tight binding method, to investigate the core configurations of the 60°basal dislocation in GaN wurtzite. Our energetic calculations, on the undissociated dislocation, demonstrate that the glide configuration with N polarity is the most energetically favorable over both the glide and the shuffle sets.

The Major Y-Chromosome Haplogroup R1b-M269 in West-Europe, Subdivided by the Three SNPs S21/U106, S145/L21 and S28/U152, Shows a Clear Pattern of Geographic Differentiation  [PDF]
Gérard Lucotte
Advances in Anthropology (AA) , 2015, DOI: 10.4236/aa.2015.51003
Abstract: More than 2600 unrelated males from West-Europe were analysed by molecular hybridization experiments for the p49a,fTaq I polymorphisms. A total of 895 subjects (34%), belonging to haplogroup M269, were identified and further analysed for the three SNPs, S21/U106, S145/L21 and S28/U152; these three SNPs define the Northwest, West and South European sub-haplogroups, respectively. These haplogroups showed quite different frequency distribution patterns within West-Europe, with frequency peaks in Northern Europe, in Brittany in France and in Northern Italy/Southern France.
Exploration of the Face of the Turin Shroud. Pollens Studied by SEM Analysis  [PDF]
Gérard Lucotte
Archaeological Discovery (AD) , 2015, DOI: 10.4236/ad.2015.34014
Abstract: We studied by SEM-EDX analysis the pollens on the Face of the Turin Shroud. A total of ten pollen grains were found; they were photographed, characterised and analysed. Three of them (pollens p6, p7 and p10) belong to Ceratonia siliqua, the carob tree; one of them (pollen p1) belongs to Balanites aegyptiaca (the palm tree of the desert), and another one (pollen p9) belongs to Cercis siliquastrum (the Judean tree). These three plants have their geographical distributions in the Near-East; that is indicative of a Palestinian origin of the Turin Shroud. Two pollen grains (p3 and p4) belong to Myosotis ramosissima. Probably myositis flowers were deposited later on the Turin Shroud, as reverence for this venerable and symbolic object.
Cancer induction pathways and HF-EMF irradiation  [PDF]
Gérard Ledoigt, Dominique Belpomme
Advances in Biological Chemistry (ABC) , 2013, DOI: 10.4236/abc.2013.32023
Abstract:

The response of cells to different types of electromagnetic fields can be induced by low-level (athermal) high frequency (HF) electromagnetic field (EMF) exposure associated with mobile phone technologies. There are many examples of biological effects involving the epigenome. EMF could trigger protein activation mediated by ligands, such as Ca2+, that alter the conformation of binding proteins, especially the NADPH plasmic membrane oxidase, so inducing increased formation of reactive oxygen species (ROS) that may alter proteomic functions. Classical antiapoptotic and procarcinogenic signaling mechanisms that are commonly found activated in human malignancies and in inflammation mainly involve the transcription factor NF-κB. The microenvironment that exists during chronic inflammation can contribute to cancer progression. The data support the proposition that long term HF-EMF exposure caused by improper use of cell phones may potentially cause cancer.

An Efficient Noisy-ICA Based Approach to Multiuser Detection in IDMA Systems  [PDF]
Abdelkrim Hamza, Salim Chitroub, Gérard Salut
Int'l J. of Communications, Network and System Sciences (IJCNS) , 2010, DOI: 10.4236/ijcns.2010.39102
Abstract: Interleaved Division Multiple Access (IDMA) is a new access scheme that has been proposed in the literature to increase the capacity of wireless channels. The performance of such systems depends on the accuracy of the channel state information at the receiver. In this paper, a Noisy-Independent Component Analysis (N-ICA) based IDMA receiver for multiple access communication channels is proposed. The N-ICA component is applied as a post processor. Unlike other IDMA receivers, the proposed scheme detects and separates the transmitted symbols without channel state information tracking. The performance of the proposed technique is presented in terms of raw bit error rate (BER) without channel coding for different signal to noise ratios (SNR). Simulation results demonstrate that N-ICA post processor provides an improvement in performance in terms of bit error rate (BER) in loaded systems. When the system is not loaded, the proposed post processor presents the same performance as conventional IDMA receiver with less iterations leading to a complexity reduction.
Bleustein-Gulyaev SAWS with Low Losses: Approximate Direct Solution  [PDF]
Martine Rousseau, Gérard A. Maugin
Journal of Electromagnetic Analysis and Applications (JEMAA) , 2011, DOI: 10.4236/jemaa.2011.34020
Abstract: The main properties (attenuation along the surface, attenuation in depth, additional radiation in depth, dispersion in propagation space) of Bleustein-Gulyaev surface acoustic waves (SAWs) in electroelasticity are determined in terms of a perturbation due to viscosity. This paves the way for a study of the perturbed motion of associated quasi-particles in the presence of low losses.
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