Energy Efficiency Trade-Off Between Duty-Cycling and Wake-Up Radio Techniques in IoT Networks

Wireless Personal Communications - For robust monitoring, control and proper energy management of renewable energy sources (RES), wireless sensing networks (WSNs) are proved to be a vital solution....     

Isolation of Failing Scan Cells through Convolutional Test Response Compaction

This paper describes a non-recursive fault diagnosis technique for scan-based designs with convolutional test response compaction. The proposed approach allows a time-efficient and accurate identification of failing scan cells using Gauss–Jordan elimination method.

Synthesis and Surface Active Properties of Novel Carbohydrate-based Cationic Surfactants

The synthesis of new cationic carbohydrate surfactants is presented in this paper. The obtained surfactants have structures that are typical for saponins, which contain fatty amide hydrophobic chains and hydrophilic heads with cationic carbohydrate units. Their surface active properties and biodegradability have been studied. For two types, the biodegradability was above 85% and comparable to standard carbohydrate surfactants.     

Experimental investigation of the effect of fuel nozzle geometry on the stability of a swirling non-premixed methane flame

An experimental investigation on the stability of a swirling non-premixed methane flame is reported in this paper. Methane gas is supplied through a central nozzle, and combustion (co-flow) air is supplied through an annulus surrounding the nozzle. Two main parameters were varied independently, which are the nozzle geometry and swirl strength; however the exit velocity of the central (fuel nozzle) jet and co-airflow were also varied to provide a wide range of test conditions. Two nozzles were tested: a contracted circular (referred to hereafter as CCN) and a rectangular (referred to hereafter as RN), which have similar equivalent diameter, D_e (defined as the diameter of a round slot having the same exit area as the nozzle geometry). The contracted circular nozzle has a diameter of 4.82 mm, and the rectangular nozzle has a diameter of 4.71 with an aspect ratio of 2:1. The swirl strength of the co-flow was varied by changing the vanes’ angle. The main results obtained from this study show that the rectangular nozzle exhibits higher entrainment and jet spreading rates compared with its CCN counterpart. In addition, the results revealed that increasing the swirl strength creates a flow recirculation zone which is larger with the RN compared with that of the corresponding CCN. These flow features associated with the RN lead to an enhanced mixing which consequently promotes better flame stability compared with its CCN counterpart.     

Application of the SIMS Method in Studies of Cr Segregation in Cr-Doped CoO: I, Aspects of Quantitative Analysis

Aspects of calibration of intensities of SIMS secondary ions vs concentration as well as sputtering time vs depth are considered for Cr-doped CoO. Advantages and limitations of the SIMS method in quantitative analysis of segregation-induced concentration profiles in oxide crystals are discussed. The studies indicate a substantial effect due to charging the surface during sputtering. The depth calibration was performed by using the Ta₂O₅/Ta system as a standard. Good depth resolution was revealed. The calibration dependence of Cr intensities on concentration is characterized by a wide scatter of data caused by charging the surface. Very good shape reproducibility of the intensity ratio vs depth profiles was revealed. Therefore, normalized intensity ratios can be used for calibration.     

Genetic Variability in DNA Repair Proteins in Age-Related Macular Degeneration

The pathogenesis of age-related macular degeneration (AMD) is complex and involves interactions between environmental and genetic factors, with oxidative stress playing an important role inducing damage in biomolecules, including DNA. Therefore, genetic variability in the components of DNA repair systems may influence the ability of the cell to cope with oxidative stress and in this way contribute to the pathogenesis of AMD. However, few reports have been published on this subject so far. We demonstrated that the c.977C>G polymorphism (rs1052133) in the hOGG1 gene and the c.972G>C polymorphism (rs3219489) in the MUTYH gene, the products of which play important roles in the repair of oxidatively damaged DNA, might be associated with the risk of AMD. Oxidative stress may promote misincorporation of uracil into DNA, where it is targeted by several DNA glycosylases. We observed that the g.4235T>C (rs2337395) and c.–32A>G (rs3087404) polymorphisms in two genes encoding such glycosylases, UNG and SMUG1, respectively, could be associated with the occurrence of AMD. Polymorphisms in some other DNA repair genes, including XPD (ERCC2), XRCC1 and ERCC6 (CSB) have also been reported to be associated with AMD. These data confirm the importance of the cellular reaction to DNA damage, and this may be influenced by variability in DNA repair genes, in AMD pathogenesis.     

Relaxation processes and intermolecular interactions in PVME hydrogels in sub-zero temperatures: Glass transition and pre-melting of ice

The phase transition observed by various methods in poly(vinyl methyl ether)/water systems at around 18 °C has been assigned by some investigators to the pre-melting of water and by others to a glass transition of the polymer. In this study, broadband dielectric spectroscopy and temperature modulated differential scanning calorimetry were used to identify this transition in radiationally crosslinked poly(vinyl methyl ether) hydrogels, as well as to analyse sub-zero relaxation processes in such a three-phase (polymer/ice/liquid water) system. The process at 18 °C was related to the pre-melting of water induced by the segmental motions of the polymer; however, it was seen to be one transition due to the cooperative motions of both compounds. The atypical (two regimes) temperature dependence of the segmental motion process was observed and was related to confinement of the polymer chains between ice clusters below approximately ?24 °C; furthermore, the main dielectric process of hexagonal ice was identified and a Maxwell-Wagner effect was observed.     

Studies on curing urethane prepolymers with aniline–formaldehyde resins

Commercial aniline–cresol–formaldehyde resin, two model aniline–formaldehyde and aniline–cresol–formaldehyde resins, and methylenedianiline have been used as curatives for NCO-terminated urethane prepolymer prepared from polyoxypropylenediol and toluene-diisocyanate. Based on viscoelastic behavior of the investigated systems and changes in their IR spectra, it has been concluded that phenolic OH groups present in aniline–cresol–formaldehyde resin do not play an important role in the curing process carried out at RT despite earlier suggestions to the contrary. The explanation for specific behavior of systems where urethane prepolymers have been cured with commercial aniline–cresol–formaldehyde resin is presumably the presence of small amount of solvent (benzyl alcohol) in that resin, which may influence the reaction kinetics.