Effect of Bi2O3 on Impurity Ion Distribution and Electrical Resistivity of Li-Zn Ferrites

Preventing the incorporation of impurities in Li-Zn ferrite grains during sintering is essential for production of ceramics with reproducible magnetic and electrical properties. Li-Zn ferrites of composition Li_0.3Zn_0.4Mn_0.05Fe_2.25O₄ were prepared with Bi₂O₃ and borosilicate sintering additives. The distribution of impurity ions in the sintered ferrites was investigated using transmission electron microscopy (TEM) coupled with energy dispersive spectroscopy (EDS). Ceramics prepared with Bi₂O₃ contained Si, Ca, and S impurities, located at grain boundaries and triple point regions. The low viscosity and good wetting properties of the Bi₂O₃ and to a lesser extent the borosilicate liquid phase allowed impurities to be selectively removed from the growing ferrite phase during sintering, thus improving sample resistivities.     

Fresco: Flexible and Reliable Evolution System for Components

Fresco is a methodology that allows for the dynamic adaptation of component-oriented applications. Fresco aims to support the developer in the realization of dynamic adaptation throughout the entire life cycle of a component. At design time, a tool (DeepCompare) assists the programmer in the preparation of a component with live update functionality. At runtime, a middleware environment called Draco guides the replacement process itself and ensures that a component replacement is executed correctly.In this position paper, the focus is on the design time support and the tool DeepCompare. After the functional development of a component, DeepCompare constructs a meta-model from both the old and the new component versions. These models are compared and equivalent data-structures are identified. This information is subsequently used to partially generate state transition functions. Possible benefits include the verification of the correctness of an update using component invariants and the estimation of the complexity of the upgrade in order to flag certain problem scenarios to the developer.     

Modelling the corrosion behaviour of Al2CuMg coarse particles in copper-rich aluminium alloys

The corrosion behaviour of 2024 aluminium alloy in sulphate solutions was studied; attention was focused on the influence of coarse intermetallic Al₂CuMg particles on the corrosion resistance of the alloy. Model alloys representative of the aluminium matrix and of Al₂CuMg coarse intermetallics were synthesized by magnetron sputtering. Open-circuit potential measurements, current-potential curve plotting and galvanic coupling tests were performed in sulphate solutions with or without chlorides. Further explanations were deduced from the study of the passive films grown on model alloys in sulphate solutions. The results showed that model alloys are a powerful tool to study the corrosion behaviour of aluminium alloys.     

Enhanced detection of oligonucleotides in UV MALDI MS using the tetraamine spermine as a matrix additive.

Matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS) has been used to analyze oligonucleotides. However, success has been limited by cation adduction and high detection limits. Both of these problems are due to the high net negative charge that oligonucleotides carry on the phosphodiester backbone. Comatrixes such as ammonium salts with UV absorbers such as 3-hydroxypicolinic acid, 2,4,6-trihydroxyacetophenone, and 6-aza-2-thiothymine have been used to improve the spectral quality for oligonucleotides in MALDI MS. Organic bases have also been used as co-matrixes; however, the most popular matrix, 3-hydroxypicolinic acid, is not compatible with these additives. We have found that the tetraamine spermine as a matrix additive can successfully eliminate cation adduction and lower the detection limits for DNA in the MALDI experiment, without having to resort to desalting steps. The results suggest that multiply protonated spermine molecules function better than ammonium ions in neutralizing oligonucleotides and displacing alkali cations. Protonated spermine is chemically similar to ammonium ions since it binds to the phosphate backbone and releases protons to the phosphate groups. Spermine can be used successfully with the matrixes 6-aza-2-thiothymine and 80% anthranilic acid/20% nicotinic acid but not with 3-hydroxypicolinic acid. The additive also works well for the analysis of metalated DNA.     

The Signaling Role of CD40 Ligand in Platelet Biology and in Platelet Component Transfusion

The CD40 ligand (CD40L) is a transmembrane molecule of crucial interest in cell signaling in innate and adaptive immunity. It is expressed by a variety of cells, but mainly by activated T-lymphocytes and platelets. CD40L may be cleaved into a soluble form (sCD40L) that has a cytokine-like activity. Both forms bind to several receptors, including CD40. This interaction is necessary for the antigen specific immune response. Furthermore, CD40L and sCD40L are involved in inflammation and a panoply of immune related and vascular pathologies. Soluble CD40L is primarily produced by platelets after activation, degranulation and cleavage, which may present a problem for transfusion. Soluble CD40L is involved in adverse transfusion events including transfusion related acute lung injury (TRALI). Although platelet storage designed for transfusion occurs in sterile conditions, platelets are activated and release sCD40L without known agonists. Recently, proteomic studies identified signaling pathways activated in platelet concentrates. Soluble CD40L is a good candidate for platelet activation in an auto-amplification loop. In this review, we describe the immunomodulatory role of CD40L in physiological and pathological conditions. We will focus on the main signaling pathways activated by CD40L after binding to its different receptors.     

Evaluation framework for adaptive context-aware routing in large scale mobile peer-to-peer systems

The proliferation of novel wireless network technologies creates new opportunities for complex peer-to-peer information dissemination systems. A key challenge that remains in this area is how to select the best algorithms and protocols to communicate effectively on a large scale. In this paper, we focus in particular on large scale mobile networks where effectiveness depends on the requirements of the application at hand and on the context of the peers in the network. We propose a framework for context-aware adaptive information sharing that allows the evaluation of and comparison with alternative information routing protocols using network metrics to measure a variety of quality attributes of the information dissemination protocols. These metrics can then be used to verify which protocol is best suited for a particular application. We illustrate our evaluation framework with different information dissemination protocols in an inter-vehicle communication scenario.     

Exploring the role of customer relationship management (CRM) systems in customer knowledge creation

This study explores how customer relationship management (CRM) systems support customer knowledge creation processes [48], including socialization, externalization, combination and internalization. CRM systems are categorized as collaborative, operational and analytical. An analysis of CRM applications in three organizations reveals that analytical systems strongly support the combination process. Collaborative systems provide the greatest support for externalization. Operational systems facilitate socialization with customers, while collaborative systems are used for socialization within an organization. Collaborative and analytical systems both support the internalization process by providing learning opportunities. Three-way interactions among CRM systems, types of customer knowledge, and knowledge creation processes are explored.     

Microstructural and Microchemical Characterization of Roman Period Terra Sigillate Slips from Archeological Sites in Southern France

Terra Sigillata is a fine ware produced during the Roman period. Its great success was because of its remarkable gloss (or slip), which provides a bright deep red color. Transmission electron microscopy and X-ray powder diffraction techniques were used to characterize the microstructure and microcomposition of Roman period Terra Sigillata slip from two sites in southern France. Investigations on eight samples are presented. The slip coatings have similar structures and compositions, consisting of sub-micrometric hematite (≤μm) and nanometric corundum (few tens nm) crystals in a glass matrix with inclusions of spinel and quartz crystals of varying size depending on the extent of preparation by eleutriation. The firing temperature, determined in previous studies, was in the range of 1020°–1080°C. The matrix does not contain iron or other metallic ions. Hematite and corundum crystals are homogeneously dispersed in the matrix and, together, confer the specific red-orange color to the sigillata.