On codes over quaternion integers

Decoding algorithms for the correction of errors for cyclic codes over quaternion integers of quaternion Mannheim weight one up to two coordinates are discussed by Özen and Güzeltepe (Eur J Pure Appl Math 3(4):670–677, 2010). Though, Neto et al. (IEEE Trans Inf Theory 47(4):1514–1527, 2001) proposed decoding algorithms for the correction of errors of arbitrary Mannheim weight. In this study, we followed the procedures used by Neto et al. and suggest a decoding algorithm for an $n$ length cyclic code over quaternion integers to correct errors of quaternion Mannheim weight two up to two coordinates. Furthermore, we establish that; over quaternion integers, for a given $n$ length cyclic code there exist a cyclic code of length $2n-1$ . The decoding algorithms for the cyclic code of length $2n-1$ are given, which correct errors of quaternion Mannheim weight one and two. In addition, we show that the cyclic code of length $2n-1$ is maximum-distance separable (MDS) with respect to Hamming distance.     

Ceramic/metal nanocomposites by lyophilization: Processing and HRTEM study

This work describes a wet-processing route based on spray-freezing and subsequent lyophilization designed to obtain nanostructured ceramic/metal powders. Starting from the ceramic powder and the corresponding metal salt, a water-based suspension is sprayed on liquid nitrogen. The frozen powders are subsequently freeze-dried, calcined and reduced. The material was analyzed using X-ray diffraction analysis at all stages. High resolution transmission electron microscopy studies showed a uniform distribution of metal nanoparticles on the ceramic grain surfaces, good interfaces and high crystallinity, with an average metal particle size in the nanometric range.     

Gypsum sand resilient modulus during cyclic soaking and drying

A laboratory investigation and analysis on the resilient modulus of gypsum-rich roadbed sand with a gypsum content of 38.8%, subjected to cyclic soaking and drying with a cycle length of 14 days, is presented and discussed. Eleven pairs of California bearing ratio (CBR) soil specimens were prepared for determining the resilient modulus using the wave propagation technique. After the application of this technique, the CBR load–penetration test was performed on each specimen to make use of the corresponding curve for determining the resilient modulus too. The wave propagation resilient modulus results are generally in good agreement with those based on CBR full load–penetration curve. The paper reveals that the cyclic soaking and drying process converges to an equilibrium state after the fifth cycle resulting in a resilient modulus which is much less than that for the common four days of soaking or that obtained from published correlation studies.     

A model for microstructure evolution in adiabatic shear bands

A mechanical subgrain rotation model is proposed to account for the recrystallized grains which have been observed to form in adiabatic shear bands in a number of materials. The model is based on a “bicrystal” approach using crystal plasticity theory to predict the evolution of subgrain misorientations. These mechanically induced rotations are shown to occur at the high strain rate associated with adiabatic shear band formation. Recrystallized grain formation is proposed to occur by the formation and mechanical rotation of subgrains during deformation, coupled with boundary refinement via diffusion during shear band cooling. This model is referred to as progressive subgrain misorientation recrystallization and appears to account for shear band microstructures in a variety of metals.     

Modeling the mechanical behavior of tantalum

A crystal plasticity model is proposed to simulate the large plastic deformation and texture evolution in tantalum over a wide range of strain rates. In the model, a modification of the viscoplastic power law for slip and a Taylor interaction law for polycrystals are employed, which account for the effects of strain hardening, strain-rate hardening, and thermal softening. A series of uniaxial compression tests in tantalum at strain rates ranging from 10⁻³ to 10⁴ s⁻¹ were conducted and used to verify the model’s simulated stress-strain response. Initial and evolved deformation textures were also measured for comparison with predicted textures from the model. Applications of this crystal plasticity model are made to examine the effect of different initial crystallographic textures in tantalum subjected to uniaxial compression deformation or biaxial tensile deformation.     

Human lymphocyte heme oxygenase 1 as a response biomarker to inorganic arsenic

We propose the use of human lymphocyte heme oxygenase 1 (HO1) as a biomarker of response to environmental arsenic exposure. We report the induction of HO1 in human lymphoblastoid cells (LBs) by arsenite in a dose-related manner. HO1 was identified by SDS-PAGE from its molecular weight and from its detection by Western blotting with anti-HO1. HO1 levels in LBs treated with arsenite increased by de novo synthesis as demonstrated by incorporation of 35S-methionine and by inhibition of HO1 synthesis by actinomycin D. The amount of HO1 in LBs was estimated by quantifying Western blots. HO1 was also induced by 10 microM cadmium or mercuric chloride. We suggest that circulating lymphocyte HO1 levels may be useful in assessing the biological activity of arsenic exposure in vivo under properly controlled conditions of simultaneous urinalysis for arsenic, cadmium, and mercury.     

Calculation of minimum pressure for liquid metal infiltration of a fiber array

The effect of capillary forces on the pressure differential required for infiltration of square and hexagonal arrays of parallel fibers has been evaluated by deriving equations which include the contact angle, fiber diameter, and volume fraction. Three models have been considered as fol-lows: (a) unidirectional liquid flow normal to the fibers, (b) bidirectional flow normal to the fibers, and (c) three-dimensional flow. The three-dimensional model predicts the lowest pressure for infiltration. A comparison is made between the required pressure differential for infiltration based on the work of immersion^[1] and capillary forces. The required pressure differentials based on capillary forces for contact angles greater than 90 deg are always greater than pressure dif-ferentials calculated from the work of immersion.     

Visual node module: An open‐source extension to the ns‐3 network simulator

A wireless visual sensor network is a collective network of directional and battery‐operated sensor nodes equipped with cameras. The field of view of these nodes depends on the camera opening angle, its direction, and its depth of view. Therefore, coverage and object detection in this type of networks are more challenging compared with the traditional wireless sensor networks. Thus, many researchers propose algorithms and solutions in this field that need tests and simulations. In this paper, we focus on network simulator 3 (ns‐3), which is an open‐source and discrete‐event tool suitable for wireless network simulation targeted primarily for research and educational use. The lack of models that can simulate visual sensor nodes in this simulator motivated us to design and develop a new visual node module as an extension of the ns‐3 core libraries and also to adapt the NetAnim tool to present these nodes graphically. This module will help researchers to simulate, test, and visualize their solutions in wireless visual sensor networks field. In this paper, we present the design and implementation of the proposed module. Furthermore, we show how it can be used in ns‐3 to simulate different scenarios of object detection and visualize the results in NetAnim tool.