Introduction: Neutron contamination is very harmful for the patients receiving radiation therapy due to the high relative biological effect of neutrons. Medical linear accelerators head are made up of materials with high atomic numbers, and High-energy photons interaction with heavy materials can produce neutron contamination. In this study, neutron equivalent dose, neutron spe...

Background: Attenuation coefficient (μ) plays an important role in calculations of treatment planning systems, as well as determination of dose distributions in external beam therapy, dosimetry, protection, phantom materials and industry. So, its exact measurement or calculation is very important. The aim of this study was to evaluate the μ in different points in the water phantom anal...

in vitro propagated and conventional runner propagated plantlets of strawberry (fragaria×ananassa duch) cv. ‘festival’ were transferred to the field and the size of crown for plants derived from both sources of planting material were compared. four sizes of the crown, i.e., < 0.5, 0.5-0.8, 0.8-1, and > 1 cm were taken from both sources of planting material. the results obtained flashed that veg...

Neural network dynamics are governed by the interaction of spiking neurons. Stochastic aspects of single-neuron dynamics propagate up to the network level and shape the dynamical and informational properties of the population. Mean-field models of population activity disregard the finite-size stochastic fluctuations of network dynamics and thus offer a deterministic description of the system. H...

We analyze a master equation formulation of stochastic neurodynamics for a network of synaptically coupled homogeneous neuronal populations each consisting of N identical neurons. The state of the network is specified by the fraction of active or spiking neurons in each population, and transition rates are chosen so that in the thermodynamic or deterministic limit (N → ∞) we recover standard ac...

Microelectromechanical systems MEMS have led to the development of a host of tiny machines and sensors over the past decade. Plasma physics is in great need of small detectors for several reasons. First of all, very small detectors do not disturb a plasma, and secondly some detectors can only work because they are very small. We report on the first of a series of small sub-Debye length probes f...

Vladimiro Mujica‡ Computational Chemistry Group, NIST Center for Theoretical and Computational Nanosciences, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA; Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113, USA; Argonne National Laboratory, Center for Nanoscale Materials, Argonne, Illinois 60439-4831, USA; and...

Defection by an electricfield has been tested asameans to deposit size selected clusters. A hollow-cathode, glow-discharge, source has been used for the production of Cu clusters in the size range between 4 and 38 nm, while afield emission scanning microscope has been usedfor HREM investigation of the size and morphology of clusters supported on Alfoil. The deflected negative clusters demonstra...

We study the short-time dynamics of a mean-field model with nonconserved order parameter (Curie–Weiss with Glauber dynamics) by solving the associated Fokker–Planck equation. We obtain closed-form expressions for the first moments of the order parameter, near to both the critical and spinodal points, starting from different initial conditions. This allows us to confirm the validity of the short...

Pulsed field gel electrophoresis (PFGE) is a quick and reliable procedure to resolve DNA molecules larger than 30 kb by applying an electric field that periodically changes direction. This technique can be used to estimate genome size of a microorganism, to reveal if a genome is circular or linear, to indicate the presence of megaplasmids, and to show if a strain contains only one or more chrom...