Fault-tolerant sub-lithographic design with rollback recovery

Shrinking feature sizes and energy levels coupled with high clock rates and decreasing node capacitance lead us into a regime where transient errors in logic cannot be ignored. Consequently, several recent studies have focused on feed-forward spatial redundancy techniques to combat these high transient fault rates. To complement these studies, we analyze fine-grained rollback techniques and show that they can offer lower spatial redundancy factors with no significant impact on system performance for fault rates up to one fault per device per ten million cycles of operation (P(f) = 10(-7)) in systems with 10(12) susceptible devices. Further, we concretely demonstrate these claims on nanowire-based programmable logic arrays. Despite expensive rollback buffers and general-purpose, conservative analysis, we show the area overhead factor of our technique is roughly an order of magnitude lower than a gate level feed-forward redundancy scheme.     

Simultaneous determination of phenylhydrazine and hydrazine by a nanostructured electrochemical sensor

In the present paper, the use of a nanostructured electrochemical sensor was described for simultaneous determination of phenylhydrazine (PhH) and hydrazine (HZ). This electrochemical sensor was prepared by a simple and rapid method by modification of carbon paste electrode with a derivative of hydroquinone and TiO₂ nanoparticles. The modified electrode showed an excellent character for electrocatalytic oxidation of PhH. Using differential pulse voltammetry, a highly selective and simultaneous determination of PhH and HZ has been explored at the modified electrode. Differential pulse voltammetry peak currents of PhH and HZ increased linearly with their concentration at the ranges of 2.0 × 10^? 6 to 1.0 × 10^? 3 M and 7.5 × 10^? 5–1.0 × 10^? 3 M, respectively and the detection limits for PhH and HZ were 7.5 × 10^? 7 M and 9.0 × 10^? 6 M, respectively.     

Single section,octave bandwidth,high‐power combiner in the UHF band

In this work, a planar broadband high‐power combiner in the ultra‐high‐frequency band (UHF) is presented. The proposed broadband combiner is a modified version of the conventional Wilkinson power combiner. The isolation resistor of 100 Ω in the conventional Wilkinson combiner is replaced by two 50 Ω terminating resistors. Two overlay couplers transform the terminating resistors to a floating resistor between the input branches. Terminating resistors are preferred to a floating resistor because of higher power handling and lower parasitics. Even‐ and odd‐mode method is employed for the analysis. The design goal is 20 dB isolation and ports return loss in an octave bandwidth. To verify the design concept, a high‐power combiner in the frequency range of 470 to 860 MHz used for digital video broadcasting‐terrestrial (DVB‐T) applications is designed and constructed. Full‐wave simulations are compared with measurements. The fabricated power combiner handles 400 W output power. Analytical formulations presented in this work are not restricted to UHF band and can be used to design an octave bandwidth combiner in other frequency bands.     

Biosynthesis of tin oxide (SnO2) nanoparticles using jujube fruit for photocatalytic degradation of organic dyes

In this study, tin oxide (SnO₂) nanoparticles were synthesized via a green route using jujube fruit as a non-toxic, renewable reducing agent, and excellent stabilizer. The biosynthesized SnO₂ nanoparticles were characterized by X-ray diffraction analysis (XRD), Fourier-Transform infrared (FT-IR), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX). Moreover, the photocatalytic activity of the novel SnO₂ nanoparticles was investigated for degradation of two organic dyes which were named methylene blue (MB) and eriochrome black-T (EBT) under direct sunlight. An excellent performance was observed and about 90% and 83% of degradation efficiencies were achieved for MB and EBT, respectively. The high stability of the photocatalyst also makes SnO₂ nanoparticles easily to reuse at least four times without any remarkable loss in activity.     

Activating solution gas drive as an extra oil production mechanism after carbonated water injection

Enhanced oil recovery (EOR) methods are mostly based on different phenomena taking place at the interfaces between fluid-fluid and rock-fluid phases. Over the last decade, carbonated water injection (CWI) has been considered as one of the multi-objective EOR techniques to store CO₂ in the hydrocarbon bearing formations as well as improving oil recovery efficiency. During CWI process, as the reservoir pressure declines, the dissolved CO₂ in the oil phase evolves and gas nucleation phenomenon would occur. As a result, it can lead to oil saturation restoration and subsequently, oil displacement due to the hysteresis effect. At this condition, CO₂ would act as insitu dissolved gas into the oil phase, and play the role of an artificial solution gas drive (SGD).In this study, the effect of SGD as an extra oil recovery mechanism after secondary and tertiary CWI (SCWI-TCWI) modes has been experimentally investigated in carbonate rocks using coreflood tests. The depressurization tests resulted in more than 25% and 18% of original oil in place (OOIP) because of the SGD after SCWI and TCWI tests, respectively. From the ultimate enhanced oil recovery point of view, the efficiency of SGD was observed to be more than one-third of that of CWI itself. Furthermore, the pressure drop data revealed that the system pressure depends more on the oil production pattern than water production.     

Incorporation of chitosan nanoparticles into silk fibroin-based porous scaffolds: Chondrogenic differentiation of stem cells

A silk fibroin-chondroitin sulfate-sodium alginate (SF-CHS-SA) porous scaffold containing chitosan nanoparticles (NPs) was investigated. The proliferation of adipose-derived stem cells (ASCs) was studied by SEM, fluorescent microscopy, alcian blue staining, dimethylmethylene blue assay, and real-time polymerization chain reaction. The results showed that incorporation of NPs into the scaffold improved compressive modulus (5.6 ± 0.15 MPa). The amount of glycosaminoglycan expression of the ASCs was reached to 8.9 ± 0.3 µg/mL. The gene expressions of aggrecan, collagen II, and SOX9 of the ASCs were significantly improved. This study revealed that the prepared scaffold can be used as a substrate for cartilage tissue engineering.