Enabling autonomicity in wireless mesh networks with the ETSI AFI GANA reference model

The distributed nature of wireless mesh networks (WMNs) allows them to benefit from multiple autonomic functionalities. However, the existing landscape of self‐x solutions (eg, self‐configuration) is fragmented and the lack of a standardized framework through which interoperable autonomics can be developed has been hampering adoption and deployment of autonomics in real‐world service networks. There is a need for a standardized architectural framework that enables to comprehensively support and integrate interoperable components for autonomicity in WMNs. Such an architecture (autonomicity‐enabled wireless mesh architecture) is currently being standardized by the working group called Evolution of Management towards Autonomic Future Internet (AFI) in the European Telecommunications Standards Institute within the Network Technologies Technical Committee. The proposed autonomic wireless mesh architecture is an instantiation of the AFI GANA (Generic Autonomic Network Architecture) reference model, a standards‐based approach to autonomics. This paper complements and extends the early version of the architecture by further detailing the architectural principles and providing experimental and validation results. First, we provide a brief overview of the AFI GANA reference model and then show how each of its building blocks can be instantiated for WMNs. We evaluate the proposed architecture by implementing and testing the 4 basic self‐x functionalities defined by the GANA model. The provided guidelines can now help researchers and engineers build autonomicity‐enabled WMNs using a standardized framework that enables adoption and deployment of autonomics by industry, thereby enabling researchers and engineers to contribute to the further evolution of the standard in the European Telecommunications Standards Institute.     

Electrical conductivity and defect disorder of tantalum‐doped TiO2

The present work reports the electrical properties of polycrystalline Ta‐doped TiO₂ (0.39 at.% Ta) determined in situ at elevated temperatures (1173‐1323 K) in the gas phase of controlled oxygen activity (10^?12 Pa to 10⁵ Pa). The effect of oxygen activity on the electrical conductivity and thermoelectric power of TiO₂ is discussed in terms of defect disorder, including (1) the intrinsic electronic disorder that is governed by electronic compensation in the strongly reducing regime, (2) the extrinsic electronic disorder that is governed by electronic charge compensation in the reducing regime, and (3) the extrinsic ionic disorder that is governed by ionic compensation in the oxidizing regime. It is shown that tantalum ions are incorporated into the titanium sublattice of TiO₂ leading to the formation of donor‐type energy levels. The Arrhenius‐type plot of the electrical conductivity data leads to the determination of the formation enthalpy terms. The obtained results are considered in terms of the effect of tantalum and oxygen activity on the defect disorder and the associated key performance‐related properties in the light‐induced partial water oxidation.     

Electrical model of the alkaline electrolyser dedicated for SPICE

In this paper, properties of the alkaline electrolyser fed from the voltage source, producing the rectangular pulse train, were investigated. A model of this electrolyser for SPICE in the form of an electrical network was proposed. The structure of this electrical model was described, and the values of parameters of the model were presented. The correctness of this model was verified experimentally in a wide range of frequency. Using the worked out model, several characteristics of the electrolyser were calculated, and the influence of amplitude, frequency, and the duty factor of the supplying voltage on productivity and watt‐hour efficiency of the electrolysis process was discussed. The investigations were performed for 2 different concentration values of the KOH solution.     

Heat stability of betacyanins in red beet juice and in betanin solutions

Summary The losses of red pigments during heating and their regeneration after heating were investigated in red beet juice and pure betanin solutions. The experiments were carried out with equal access of oxygen and a similar level of the initial content of the pigment. The presence of heavy metal ions in trace amounts had a great destructive influence on the pigment in solutions of pure betanin. In red beet juice compounds which decrease and compounds which increase the retention of betanin both occured during heating and regeneration. The group of compounds that decrease betanin stability included some metal ions, e.g. Cu(II) and Fe(III), along with certain amino acids. The negative influence of the metal ions in beet juice decreased probably due to the presence of metal-complexing agents.

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Stabilität der Betacyane während der Erhitzung des Rote-Beete-Saftes und der Betanin-Lösungen

Zusammenfassung Es wurden die Verluste an rotem Farbstoff im Rote-Beete-Saft und in Betanin-Lösungen während der Erhitzung mit der Regeneration des Farbstoffes in den erhitzten Proben verglichen. Die Versuche wurden bei gleichem Sauerstoffdruck und bei vergleichbarer Menge des Farbstoffes zu Beginn durchgeführt. Die Anwesenheit von Spuren an Schwermetallen in den Lösungen von reinem Betanin wirkt zerstörend auf den Farbstoff. Im Rote-Beete-Saft treten sowohl Verbindungen auf, die die Betanin-Retention während der Erhitzung und die Regeneration vermehren, wie auch solche, die sie vermindern. Zur Gruppe der Verbindungen, die die Stabilität von Betanin verringern, gehören die Ionen einiger Schwermetalle wie Cu(II) und Fe(III) und einige Aminosäuren. Die negative Wirkung der Metallionen im Saft wird wahrscheinlich durch Anwesenheit metallkomplexierender Verbindungen vermindert.

     

Effect of Co content on the catalytic activity of CoSiBEA zeolite in the selective catalytic reduction of NO with ethanol: Nature of the cobalt species

The effect of Co content on the catalytic activity of CoSiBEA zeolites in the selective catalytic reduction (SCR) of NO with ethanol is investigated. The Co_xSiBEA zeolites (x = 0.3, 0.7, 3.6 and 6.75 Co wt.%) are prepared by a two-step postsynthesis method which allows to control the introduction of cobalt into zeolite and thus to obtain catalysts with specific Co sites. The nature of the active sites is characterized by XRD, diffuse reflectance UV–vis, H₂-TPR and XPS.

The catalytic activity of Co_xSiBEA strongly depends on the nature and environment of Co species. Zeolites with isolated lattice tetrahedral Co(II) (Co_0.3SiBEA and Co_0.7SiBEA samples) are active in SCR of NO with ethanol with selectivity toward N₂ exceeding 85% for NO conversion from 20 to 70%. When additional isolated extra-lattice octahedral Co(II) species appear (Co_3.6SiBEA sample), the full oxidation of ethanol by dioxygen becomes a very important reaction pathway. In presence of additional cobalt oxides (Co_6.75SiBEA sample), the activity and selectivity toward N₂ substantially change and full oxidation of ethanol to CO₂ is the main reaction pathway and full NO oxidation also takes place in the temperature range 550–775 K. The lack of correlation between the activity in SCR of NO with ethanol and NO oxidation to NO₂ suggests that the two reactions are more competitive than sequential.     

Quotient Complexity of Closed Languages

A language L is prefix-closed if, whenever a word w is in L, then every prefix of w is also in L. We define suffix-, factor-, and subword-closed languages in an analogous way, where by factor we mean contiguous subsequence, and by subword we mean scattered subsequence. We study the state complexity (which we prefer to call quotient complexity) of operations on prefix-, suffix-, factor-, and subword-closed languages. We find tight upper bounds on the complexity of the subword-closure of arbitrary languages, and on the complexity of boolean operations, concatenation, star, and reversal in each of the four classes of closed languages. We show that repeated applications of positive closure and complement to a closed language result in at most four distinct languages, while Kleene closure and complement give at most eight.     

Solvability of reactions in rigid multibody systems with redundant nonholonomic constraints

The problem of calculating joint reaction forces in rigid body mechanisms with redundant constraints, both geometric and nonholonomic, is discussed. When constraint equations are dependent, some of the constraint reactions are unsolvable, i.e., cannot be uniquely determined using a rigid body model, whereas some others may be solvable. In this paper, analytic conditions, which must be fulfilled to obtain unique values of selected reaction forces in the presence of dependent nonholonomic constraints, are presented and proven. The concept of direct sum, known from linear algebra, is exploited. These purely mathematical conditions are followed by numerical methods that enable detection of constraints with uniquely solvable reactions. Similar conditions and methods were proposed earlier for holonomic systems. In this contribution, they are generalized to the case of linear nonholonomic constraints. An example of constraint reactions solvability analysis, for a mechanism subjected to redundant nonholonomic constraints, is presented.     

On the unique solvability of a direct dynamics problem for mechanisms with redundant constraints and Coulomb friction in joints

The uniqueness of simulated motion of an overconstrained rigid body mechanism with joint friction is studied. The investigated issue originates in the problem of joint reactions solvability. It is known that in case of redundant constraints existence the constraint reaction forces cannot be — in general — uniquely determined. It can be proved, however, that — under certain conditions — selected reactions can be specified uniquely. Analytical and numerical methods for reactions solvability analysis are available. It is shown in this paper that indeterminacy of normal reactions results in indeterminacy of friction forces, and moreover, non-uniqueness of friction forces results in non-uniqueness of simulated motion. A method of finding these joints, for which friction forces are unique, is presented. It is also proved that if only uniquely solvable friction effects are introduced, then simulated motion of the mechanism is unique, otherwise it is not. Finally, examples of dynamic analysis of overconstrained mechanisms with joint friction are presented; unique and non-unique results are obtained.     

rs7041 and rs4588 Polymorphisms in Vitamin D Binding Protein Gene (VDBP) and the Risk of Diseases

The purpose of the study was to investigate the role of vitamin D binding protein (VDBP, DBP) and its polymorphism in the vitamin D pathway and human health. This narrative review shows the latest literature on the most popular diseases that have previously been linked to VDBP. Vitamin D plays a crucial role in human metabolism, controlling phosphorus and calcium homeostasis. Vitamin D binding protein bonds vitamin D and its metabolites and transports them to target tissues. The most common polymorphisms in the VDBP gene are rs4588 and rs7041, which are located in exon 11 in domain III of the VDBP gene. rs4588 and rs7041 may be correlated with differences not only in vitamin D status in serum but also with vitamin D metabolites. This review supports the role of single nucleotide polymorphisms (SNPs) in the VDBP gene and presents the latest data showing correlations between VDBP variants with important human diseases such as obesity, diabetes mellitus, tuberculosis, chronic obstructive pulmonary disease, and others. In this review, we aim to systematize the knowledge regarding the occurrence of diseases and their relationship with vitamin D deficiencies, which may be caused by polymorphisms in the VDBP gene. Further research is required on the possible influence of SNPs, modifications in the structure of the binding protein, and their influence on the organism. It is also important to mention that most studies do not have a specific time of year to measure accurate vitamin D metabolite levels, which can be misleading in conclusions due to the seasonal nature of vitamin D.     

NMR and MD Analysis of the Bonding Interaction of Vancomycin with Muramyl Pentapeptide

The article describes an NMR spectroscopy study of interactions between vancomycin and a muramyl pentapeptide in two complexes: vancomycin and a native muramyl pentapeptide ended with D-alanine (MPP-D-Ala), and vancomycin and a modified muramyl pentapeptide ended with D-serine (MPP-D-Ser). The measurements were made in a 9:1 mixture of H₂O and D₂O. The obtained results confirmed the presence of hydrogen bonds previously described in the literature. At the same time, thanks to the pentapeptide model used, we were able to prove the presence of two more hydrogen bonds formed by the side chain amino group of L-lysine and oxygen atoms from the vancomycin carboxyl and amide groups. This type of interaction has not been described before. The existence of these hydrogen bonds was confirmed by the ¹H NMR and molecular modeling. The formation of these bonds incurs additional through-space interactions, visible in the NOESY spectrum, between the protons of the L-lysine amino group and a vancomycin-facing hydrogen atom in the benzylic position. The presence of such interactions was also confirmed by molecular dynamics trajectory analysis.