TAMER: an adaptive task allocation method for aging reduction in multi-core embedded real-time systems

The Journal of Supercomputing - Technology scaling has exacerbated the aging impact on the performance and reliability of integrated circuits. By entering into nanotechnology era in recent years,...     

Prehydrolysis in softwood pulping produces a valuable biorefinery fraction for material utilization

A scaled-up prehydrolysis process was elaborated to demonstrate an industrially feasible operation step in a pulping process that generates a valuable side product in addition to the cellulose pulp. The valuable side product is aqueous process liquor, a softwood hydrolysate (SWH) herein produced in 60 L batches, and its components were recovered and utilized as materials. The process parameters were shown to influence the yield, composition, and quality of the obtained hydrolysates. Furthermore, the process conditions were shown to influence the ability of SWHs to form free-standing, foldable films in blends with either microfibrillated cellulose (MFC) or carboxymethyl cellulose (CMC). Films with oxygen permeabilities (OP) as low as 0.35 cm(3) μm day(-1) m(-2) kPa(-1) at 50% relative humidity, were produced from aqueous solutions providing a viable and green alternative to petroleum-based packaging barriers. The OPs were very low regardless of SWH film composition and upgrading conditions, whereas the films' tensile performance was directly controlled by the ratio of SWH to cocomponent.     

Wavelet correlogram: A new approach for image indexing and retrieval

In this paper, a new algorithm for content-based image indexing and retrieval is presented. The proposed method is based on a combination of multiresolution image decomposition and color correlation histogram. According to the new algorithm, wavelet coefficients of the image are computed first using a directional wavelet transform such as Gabor wavelets. A quantization step is then applied before computing one-directional autocorrelograms of the wavelet coefficients. Finally, index vectors are constructed using these one-directional wavelet correlograms. The retrieval results obtained by application of our new method on a 1000 image database demonstrated a significant improvement in effectiveness and efficiency compared to the indexing and retrieval methods based on image color correlogram or wavelet transform.     

Vibration-Induced Attraction of a Particle Towards a Wall in Microgravity—The Mechanism of Attraction Force

The effects of small vibrations on a particle oscillating near a solid wall in a fluid cell, relevant to material processing such as crystal growth in space, have been investigated by three dimensional direct numerical simulations. Simulations have been conducted for a solid spherical particle suspended in a fluid cell filled with a fluid of 1 cSt viscosity, vibrating sinusoidally in a horizontal direction. The simulations revealed the existence of a vibration-induced force attracting the particle towards the nearest cell wall which varied with the cell vibration frequency. The mechanism for this attraction force as well as an example showing the effects of this force on the particle are presented in this paper. The predicted flow patterns around the particle unveiled an accelerated flow in the gap between the particle and the nearest wall as well as a pressure decrease in accordance with Bernoulli’s principle, which would result in the attraction force.     

Comparison Between Wear Resistance of Functionally Graded And Homogenous Al-SiC Nanocomposite Produced by Friction Stir Processing (FSP)

In the present work, wear resistance of a homogeneous and functionally graded Al/SiC nanocomposite produced by friction stir processing was studied. According to the wear test results, the friction coefficient of the functionally graded nanocomposite was slightly less than that of the homogeneous nanocomposite (i.e., 0.7 compared to 0.8); this may be due to higher surface hardness of the functionally graded composite. In both cases, the weight loss increased with increasing applied loads; however, weight loss for the functionally graded nanocomposite was lesser under each applied load. Regarding surface studies by Scanning Electron Microscope (SEM) and Optical Microscope (OM), the functionally graded nanocomposite showed less micro-galling and other surface damages; this can be attributed to its surface hardness and high work of fracture.     

Effect of Viscosity on Vibration-Induced Motion of a Spherical Particle Suspended in a Fluid Cell

Production of protein and semi-conductor crystals with advanced quality and properties is possible under microgravity conditions due to the suppression of convection effects. However, aboard space platforms, g-jitter induced motions of solid particles can cause unsteady convection that may result in degradation of the properties of crystals produced. There are different effects of g-jitter on small particles suspended in a fluid cell which are not fully understood. To investigate these small vibration effects, ground experiments were conducted by suspending a spherical particle with a thin wire in a rectangular fluid cell and subjecting the cell and particle to horizontal vibrations with different frequencies and amplitudes. The fluid viscosity was varied to investigate the attraction or repulsion force induced in the direction normal to the direction of the vibration. The force was found to change from attraction to repulsion with an increase in the fluid viscosity and increase with the increasing vibration frequency and amplitude.     

Correction to: On the relationship between similar requirements and similar software

Requirements Engineering -     

Effects of substrate and environmental adsorbates on the electronic properties and structural stability of antimonene

The structural stability of some two-dimensional materials at ambient conditions is obviously attributed to their low sensitivity to exposure of humidity and air. Recently exfoliated antimonene, differently from another group-VA material, phosphorene, possesses a high structural integrity at ambient conditions. Considering the kinship of phosphorene and antimonene, there is a need to comprehensively examine the interaction of the H₂O and O₂ molecules with the antimonene surface to understand the difference in the structural stability of these materials. The calculations predict that antimonene, similarly to phosphorene, shows higher affinity to oxygen rather than water. Surprisingly, for antimonene, the barrier for the O–O bond splitting to form O–Sb bonds is found to be much lower than that of for phosphorene. However, antimonene, in contrast to phosphorene, preserves structural integrity upon oxidation which may be attributed to a stronger interaction and hybridization of atoms in antimonene compared to the atoms in phosphorene. In addition, the oxidation ability of antimonene can be significantly controlled by the graphene and BN substrates.     

Optimization of Mechanical and Wear Properties of Functionally Graded Al6061/SiC Nanocomposites Produced by Friction Stir Processing(FSP)

The objective of present work is to apply the friction stir processing(FSP) to fabricate functionally graded Si C particulate reinforced Al6061 composite and investigate the effect of Si C particle mass fraction distribution on the mechanical properties and wear behavior of Al6061/Si C composite. Regarding the obtained results in this work, with increasing Si C mass fraction, elongation decreased, but hardness enhanced. However, the optimized functionally graded composite with the highest tensile strength and wear resistance was achieved for composite with 10 wt% surface Si C. Also,the results showed that wear resistance and tensile strength decreased for composite with 13 wt% surface Si C, due to reinforcement particle clustering depending on high Si C mass fraction.     

Multi-objective optimization of a circular dual back-plate MEMS microphone: tradeoff between pull-in voltage,sensitivity and resonance frequency

Microsystem Technologies - In this study, the optimization of a circular dual back-plate condenser microphone has been done in order to increase the pull-in voltage, sensitivity and resonance...