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,...     

Concentrated emulsion polymerization for preparation of β‐cyclodextrin‐supported chromatography columns

Concentrated inverse emulsion polymerization was used for making chromatography columns (based on crosslinked polystyrene divinylbenzene (PS‐DVB)) with pore sizes less than 10 μm. According to DSC‐thermal gravimetry thermograms, it was confirmed that the residual monomer concentration after polymerization process is negligible. For application of these columns in chiral chromatography, the β‐cyclodextrin is chemically fixed on the PS‐DVB resin pore surface. The presence of hydroxyl groups in the PS‐DVB resin after chemical modification was confirmed by FTIR spectroscopy. By chemical modification of the PS‐DVB resin, thermal stability increased up to 446°C. The structure of columns was analyzed by scanning electron microscopy (SEM). SEM evaluations showed that the porous structure of PS‐DVB resin was maintained intact after the chemical modification with β‐cyclodextrin. According to X‐ray data, presence of the crystalline domain that is related to β‐cyclodextrin is confirmed.© 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 857–863, 2006     

Preparation and characterization of fluorescent polymer magnetic particles

Magnetic iron oxide (maghemite, Fe₃O₄) particles were encapsulated with fluorescent polymer phase. The resulting fluorescent magnetic polymer particles were characterized by Fourier transform infrared spectroscopy (FTIR), thermal gravimeter analysis (TGA), reflection optical microscopy, differential scanning calorimeter (DSC), Fritsch particle sizer, scanning electron microscopy (SEM), powder X‐ray diffractometer (XRD), and vibrating sample magnetometer (VSM) measurements. FTIR and XRD confirmed the presence of iron oxide in polymer phase. The TGA and DSC measurements indicated that the magnetic polymer particles have more than 50% iron oxide content and high thermal stability. SEM and reflection optical microscopy under UV light revealed that all maghemite particles were embedded in the polymer spheres and have fluorescent characteristics. The size‐distribution analysis of prepared magnetic particles was shown that the means diameter of the particles slightly increased. According to our magnetometry data, shape of the loops evidences the ferromagnetic character of the material and no evidence of superparamagnetism was seen. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Influence of decellularized pericardium matrix on the behavior of cardiac progenitors

Following myocardial infarction, heart muscle has a limited capacity of self‐healing. Biological platforms providing the natural biochemical and biophysical cues of the native myocardium might be crucial to address current therapeutic shortcomings. The aim of this study was to assess the effect of decellularized human pericardium (DPc), as a bioactive platform, on viability, attachment, proliferation and differentiation of human cardiac progenitors (CPs), and evaluate the possibility of using DPc as a substitute of tissue culture polystyrene (TCPS) substrate for culturing CPs in vitro. The decellularization process removed more than 99% of the cellular components from Pc, yet well preserved its macro‐/micro‐structure and extracellular collagen and glycosaminoglycan content. DPc supported the viability, attachment, metabolism and proliferation of CPs, and enhanced their differentiation into mature cardiomyocytes compared to TCPS. Decellularized pericardium appeared thus to have a high potential for cardiac cell culture and could be applied as a superior alternative to common TCPS. DPc could be then utilized for further tissue engineering applications. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43255.     

SBR COMPOSITES REINFORCED WITH N-ISOPROPYL-N'PHENYL-P-PHENYLENEDIAMINE-MODIFIED CLAY

SBR compounds including the N-isopropyl-N'-phenyl-p-phenylenedianfine-modified clay (organoclay) were prepared. Effects of modified clay and antioxidant (IPPD) contents on mechanical and rheological properties of SBR composites were studied. FTIR results confirmed that the clay was chemically modified by IPPD and changed into an organoclay. X-ray diffraction (XRD) results confirmed the increase in interlayer distance of the clay due to the insertion of IPPD. Rheological and cure characteristics of SBR compounds were determined using RPA (Rubber Process Analyzer) and rheometer. Scorch time and cure time of SBR compounds decreased with introduction of the organoclay. Mechanical properties and heat aging resistance of the SBR composites were improved significantly by incorporation of the organoclay.     

A novel design of ultra-broadband,high-gain and high-linearity variable gain distributed amplifier in 0.13 μm CMOS technology

A high-gain, high-linearity and ultra-broadband variable gain distributed amplifier (VGDA) based on employing multiple techniques is presented to substantially increase the gain. The complete design is composed of two major parts including a VGDA part followed by a single stage distributed amplifier (SSDA) part. The VGDA part makes it possible to achieve different gain settings. For high gain considerations, the SSDA part cascades with the VGDA part that takes the benefits of the multiplicative gain mechanism. A theory is presented to enhance the linearity without imposing further DC power consumption. This idea has been validated by simulation results as expected. The design is analysed and simulated in the standard 0.13 μm CMOS technology. It presents the large gain tuning range of 35 dB, from –5 dB attenuation gain up to +30 dB maximum amplification gain, in relation to the control voltage (V_ctr) that varies between 0.42 and 1.1 V. At the maximum amplification gain setting, it presents a DC up to 16 GHz 3 dB bandwidth, an average noise figure of 3.2 dB and an IIP3 of –2 dB m. Furthermore, it dissipates 46.42 mW from 0.7 and 0.9 V power supplies of the drain lines of VGDA and SSDA parts, respectively. Additionally, the Monte Carlo (MC) simulation has been performed to predict an estimate of the accuracy of performance of the proposed design under various conditions.     

Application of concentrated emulsion polymerization for preparation of ion‐exchange chromatography columns

Concentrated inverse emulsion polymerization was used for making chromatography columns [based on crosslinked polystyrene divinylbenzene (PS–DVB)] with pore sizes less than 10 μm. For application of these columns in ion‐exchange chromatography, the sulfonation process was performed by concentrated sulfuric acid. According to X‐ray fluorescence analysis and ASTM D2187‐94 standard test method, the total capacity of resins (sulfonated PS–DVB) increased with increasing time. To obtain high‐capacity resins, the sulfonation process was carried out over two steps. The optimum sulfonation time for the first and second sulfonation steps was 24 and 48 h, respectively. By increasing the DVB content, the capacity of resins passed through a maximum; thus the optimum amount of DVB, as crosslinking agent in the sulfonation process, was 22.5%. The structure of columns was analyzed by scanning electron microscopy (SEM). SEM evaluations showed that the porous structure of PS–DVB resin was maintained intact after the sulfonation steps. According to DSC–thermal gravimetry thermograms, it was confirmed that the residual monomer concentration after polymerization process was negligible. Also, the PS–DVB resins exhibit thermal stability up to 300°C and this quantity would increase with increasing amount of DVB weight percentage. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 2973–2979, 2004     

Effects of hot rolling and homogenisation treatment on low alloy steel ingot

ABSTRACT

The effects of hot rolling and homogenisation treatment on the microstructure and mechanical properties of low-alloy transformation-induced plasticity (TRIP) steel were studied. With increasing the reduction in thickness during rolling, the band spacing and the average ferrite grain size decreased with the consequent enhancement of mechanical properties. Homogenisation treatment resulted in the gradual fading of the banded morphology, more homogeneous microhardness profile, and twice total elongation compared to the as-cast counterpart. The experimentally observed homogenisation time judged by the disappearance of the banded structure was in agreement with the obtained values based on the band spacing and elemental analysis. This work provided scientific evidence for the assumptions used to derive the homogenisation formulae.     

A New Method for Developing Seismic Collapse Fragility Curves Grounded on State-Based Philosophy

International Journal of Steel Structures - Since the current process to achieve the collapse fragility curve in practical applications seems too complicated, also time-consuming to dominant by...