Blockchain for Collaborative Businesses

Mobile Networks and Applications - Blockchain applications have continuously improved ever since its first debut on cryptocurrency. From then on, its uses have branched out from the financial...     

Polyetherimide-LaNi5 composite films for hydrogen storage applications

This study investigates the preparation of polyetherimide (PEI) – LaNi₅ composites films for hydrogen storage. Prior to the polymer addition, LaNi₅ was ball-milled at different conditions (250, 350, and 450 RPM) and annealed at 500 °C for 1 h under vacuum. The composites were produced with BM-LaNi₅-350 (PEI/LaNi₅-350) and annealed BM-LaNi₅-350 (PEI/LaNi₅-350-TT). Membranes were successfully produced through solvent casting assisted by an ultrasonic bath. The particles dispersion and the film morphology did not change after hydrogenation cycles. In the H₂ sorption experiments at 43 °C and 20 bar, the films stored H₂ without incubation time; both samples reached a capacity of ~0.6 wt%. The H₂ sorption kinetics of PEI/LaNi₅-350 was comparable to that of BM-LaNi₅-350, whereas PEI/LaNi₅-350-TT presented significantly slower kinetics. LaNi₅ oxidation was hindered by PEI, showing that it can be explored to improve metal hydrides air resistance. The results demonstrated that PEI films filled with LaNi₅ are promising materials for hydrogen storage.     

Influence of age and health on immune functions and trace elements

Apparently healthy elderly donors were screened according to a simple protocol that included clinical examination and the determination of hematological and biochemical values. This screening was performed to detect subclinical alterations which might interfere with immune responses and trace element status. The elderly were divided into two groups. The first group consisted of 22 (age 76 +/- 1 years) positively selected elderly (PSE), i.e. healthy subjects with no hematological and laboratory alterations, the second one comprised 13 (age 75 +/- 1 years) negatively selected elderly (NSE). Data were then compared with those obtained from 40 (age 35 +/- 2 years) healthy young controls. In both groups of elderly donors, plasma zinc levels were normal, while plasma copper concentrations were increased. Intracellular values of zinc and copper in mono- and polymorphonuclear cells from both groups of elderly were within reference limits. After in vitro activation, granulocyte chemiluminescence activity was impaired only in NSE. A decrement in the number of circulating CD3 lymphocytes and an increase in CD8d, CD57 cells were found in PSE, while NSE showed an increased number of CD3,DR cells and CD8d, CD57, CD8b,CD57 and CD16,CD56 positive cells. Our results indicate that only plasma copper levels were affected by age, whereas subclinical alterations in hematological or biochemical values appear to impair immune responses in the elderly.     

Phospholipase A2 activity and calpactin I levels in rat lymphokine-activated killer cells: correlation with the cytotoxic activity

The interaction of carnitine with human placental brush-border membrane vesicles was investigated. Carnitine was found to associate with the membrane vesicles in a Na(+)-dependent manner. The time course of this association did not exhibit an overshoot, which is typical of a Na+ gradient-driven transport process. The absolute requirement for Na+ was noticeable whether the association of carnitine with the vesicles was measured with a short time incubation or under equilibrium conditions, indicating Na(+)-dependent binding of carnitine to the human placental brush-border membranes. The binding was saturable and was of a high-affinity type with a dissociation constant of 1.37 +/- 0.03 microM. Anions had little or no influence on the binding process. The binding process was specific for carnitine and its acyl derivatives. Betaine also competed for the binding process, but other structurally related compounds did not. Kinetic analyses revealed that Na+ increased the affinity of the binding process for carnitine and the Na+/carnitine coupling ratio for the binding process was 1. The dissociation constant for the interaction of Na+ with the binding of carnitine was 24 +/- 4 mM. This constitutes the first report on the identification of Na(+)-dependent high-affinity carnitine binding in the plasma membrane of a mammalian cell. Studies with purified rat renal brush-border membrane vesicles demonstrated the presence of Na+ gradient-driven carnitine transport but no Na(+)-dependent carnitine binding in these membrane vesicles. In contrast, purified intestinal brush-border membrane vesicles posses neither Na+ gradient-driven carnitine transport nor Na(+)-dependent carnitine binding.     

On the solvability of the positive real lemma equations

In this paper, we consider the classical equations of the positive real lemma under the sole assumption that the state matrix A has unmixed spectrum: σ(A)∩σ(−A)=. Without any other system-theoretic assumption (observability, reachability, stability, etc.), we derive a necessary and sufficient condition for the solvability of the positive real lemma equations.     

From real to metaphoric maps: Cartography as a visual language for organizing and sharing knowledge

In this paper we discuss about geographic representations as a basis for describing, organizing, accessing and understanding heterogeneous shared information on the web. Maps are popular on the web, because of the reference to space, the most important domain of human experience, the proliferation of location aware devices and services and the availability of a set of tools that enable an heterogeneous population of users to explore and even modify these representations.Metaphorical maps, representing concepts and relations of a specific knowledge domain with symbols taken from another well known and widely used domain, couple the benefits of cartographic representation with the power and intuitiveness of the metaphor, permitting the communication and sharing of such knowledge.We introduce a classification of maps based on antinomies between real and imaginary worlds, and between direct and metaphoric knowledge; we argue that cartography can be used as a visual language for organizing and sharing knowledge related to different semantic domains, supporting our arguments with examples. Finally, we define a set of functions and related data structures able to support a user in browsing cartographic representations using state-of-art tools and systems available on the web.     

Constructive model-based analysis for safety assessment

The aerospace industry still uses fault trees to perform reliability analysis. This is because fault-tree modeling and analysis (FTA) seems easier to practical engineers when compared with Markov models, even though FTA provides a weaker form of analysis. In this paper, we propose an automatic strategy for generating Markov-based models and corresponding analysis formulations, according to ARP 4761, directly from Simulink diagrams annotated with failure information. The generated Markov-based models are expressed in the formal language PRISM, and the analysis is carried out by the PRISM model checker. The strategy is compositional and based on a comprehensive set of translation rules from Simulink to PRISM. We briefly address soundness and completeness of the rules and, to illustrate the application of the strategy, we apply it to a classical avionics case study: an actuator control system.