840 research outputs found
The smallest strictly Neumaier graph and its generalisations
No full textA regular clique in a regular graph is a clique such that every vertex outside of the clique is adjacent to the same positive number of vertices inside the clique. We continue the study of regular cliques in edge-regular graphs initiated by A. Neumaier in the 1980s and attracting current interest. We thus define a Neumaier graph to be an non-complete edge-regular graph containing a regular clique, and a strictly Neumaier graph to be a non-strongly regular Neumaier graph. We first prove some general results on Neumaier graphs and their feasible parameter tuples. We then apply these results to determine the smallest strictly Neumaier graph, which has 16 vertices. Next we find the parameter tuples for all strictly Neumaier graphs having at most 24 vertices. Finally, we give two sequences of graphs, each with ith element a strictly Neumaier graph containing a 2i-regular clique (where i is a positive integer) and having parameters of an affine polar graph as an edge-regular graph. This answers questions recently posed by G. Greaves and J. Koolen
A general construction of strictly Neumaier graphs and a related switching
No full textWe present a construction of Neumaier graphs with nexus 1, which generalises
two known constructions of Neumaier graphs. We also use W. Wang, L. Qiu, and Y.
Hu switching to show that we construct cospectral Neumaier graphs. Finally, we
show that several small strictly Neumaier graphs can be obtained from our
construction, and give a geometric or algebraic description for each of these
graphs
Bilayer Graphene Transistors for Analog Electronics
No full texthttp://www.gianlucafiori.org/articles/bilayer_electronics.pd
Velocity saturation in few-layer MoS2 transistor
No full texthttp://www.gianlucafiori.org/articles/fiori_MoS2.pd
Current Saturation and Voltage Gain in Bilayer Graphene Field Effect Transistors
No full texthttp://www.gianlucafiori.org/articles/nl2012.pd
An Optimal Subgradient Algorithm with Subspace Search for Costly Convex Optimization Problems
No full textThis paper presents an acceleration of the optimal subgradient algorithm OSGA (Neumaier in Math Program 158(1–2):1–21, 2016) for solving structured convex optimization problems, where the objective function involves costly affine and cheap nonlinear terms. We combine OSGA with a multidimensional subspace search technique, which leads to a low-dimensional auxiliary problem that can be solved efficiently. Numerical results concerning some applications are reported. A software package implementing the new method is available.© The Author(s) 201
Interpretation of graphene mobility data by means of a semiclassical Monte Carlo transport model
No full textIn this paper we compare experimental data and simulations based on a semiclassical model in order to investigate the relative importance of a several scattering mechanisms on the mobility of graphene nano-ribbons. Furthermore, some new experimental results complementing the range of ribbon widths available in the literature are also reported.
We show that scattering with remote phonons originating in the substrate insulator can appreciably reduce the mobility of graphene and it should not be neglected in the interpretation of graphene mobility data. In fact by accounting for remote phonon scattering we could reproduce fairly well the experimentally observed dependence of the mobility on the ribbon width, the temperature and the inversion density, whereas the agreement with experiments is much worse when remote phonons are not included in the calculations
Flicker noise in graphene-based Hall sensors
No full textWe present an investigation of shot noise in graphene-based Hall sensors, with the purpose of evaluating their detection limit and of developing strategies to improve their characteristics. We perform measurements on two devices, one with a defective contact that could however be used as a gate to control the carrier density in the device and the other with all contacts working. We discuss the results in terms of the dependence of the noise power spectral density on the carrier density and on the DC bias current. Finally, we provide an estimate of the detection limit, pointing out that the approach commonly used in the literature for its evaluation is flawed
Magnetic resonance imaging at 1.5 T with immunospecific contrast agent in vitro and in vivo in a xenotransplant model.
No full textOBJECT:
Demonstrating the feasibility of magnetic resonance imaging (MRI) at 1.5 T of ultrasmall particle iron oxide (USPIO)-antibody bound to tumor cells in vitro and in a murine xenotransplant model.
METHODS:
Human D430B cells or Raji Burkitt lymphoma cells were incubated in vitro with different amounts of commercially available USPIO-anti-CD20 antibodies and cell pellets were stratified in a test tube. For in vivo studies, D430B cells and Raji lymphoma cells were inoculated subcutaneously in immunodeficient mice. MRI at 1.5 T was performed with T1-weighted three-dimensional fast field echo sequences (17/4.6/13 degrees ) and T2-weighted three-dimensional fast-field echo sequences (50/12/7 degrees ). For in vivo studies MRI was performed before and 24 h after USPIO-anti-CD20 administration.
RESULTS:
USPIO-anti-CD20-treated D430B cells, showed a dose-dependent decrease in signal intensity (SI) on T2*-weighted images and SI enhancement on T1-weighted images in vitro. Raji cells showed lower SI changes, in accordance to the fivefold lower expression of CD20 on Raji with respect to D430B cells. In vivo 24 h after USPIO-anti-CD20 administration, both tumors showed an inhomogeneous decrease of SI on T2*-weighted images and SI enhancement on T1-weighted images.
CONCLUSIONS:
MRI at 1.5 T is able to detect USPIO-antibody conjugates targeting a tumor-associated antigen in vitro and in vivo
Left off the map again: [Book Review] Cultures in contention
No full textBook reviewReview of the book "Cultures in contention" edited by Douglas Kahn and Diane Neumaier (Seattle: The Real Comet Press, 1985).https://viuspace.viu.ca/bitstream/handle/10613/5047/Alexander.Cultures.pdf?sequence=5The following book review originally appeared as: Alexander, D. (1986). Left off the map again
[Review of the book "Cultures in contention", edited by D. Kahn and D. Neumaier]. Fuse, IX(6), 42-
44.
Fuse was a Canadian arts and culture magazine published by Artons Cultural Affairs Society and
Publishing Inc. from 1979-2013
- …
