A generic accounting scheme for next generation networks

Accounting is generally considered as one of the most challenging issues in modern and future mobile networks. As multi-domain complex heterogeneous environments are becoming a common terrain, accounting procedures performed by network and service providers have turned into a key aspect. However, in order for these networks to reliably deliver modern real-time services, they should, among other things, provide accurate accounting services, particularly billing. This work elaborates on the accounting process, proposing a novel and robust accounting system. The requirements of the proposed mechanism are defined and all the accounting scenarios that the system should cope with are examined. All the proposed accounting extensions are implemented by means of Diameter AVPs and commands. Our mechanism is generic and capitalizes on the existing AAA infrastructure, thus providing secure means to transfer and store sensitive billing data. More importantly, it can be easily incorporated into the providers’ existing mechanisms regardless of the underlying network technology. At the same time, its generic nature allows for interoperability between different network operators and service providers. Through extensive experimentation, we can also infer that our scheme is lightweight, scalable, and easy to implement requiring only minor modifications to the core Diameter protocol.     

Manipulating Organic Semiconductor Morphology with Visible Light

A method is presented to manipulate the final morphology of roll-to-roll slot-die coated poly(3-hexylthiophene) (P3HT) by optically exciting the p-type polymer in solution while coating. These results provide a comprehensive picture of the entire knowledge chain, from demonstrating how to apply the authors’ method to a fundamental understanding of the changes in morphology and physical properties induced by exciting P3HT while coating. By combining results from density functional theory and molecular dynamics simulations with a variety of X-ray experiments, absorption spectroscopy, and THz spectroscopy, the relationship between morphology and physical properties of the thin film is demonstrated. Specifically, in P3HT films excited with light during deposition, changes in crystallinity and texture with more face-on orientation and increased out-of-plane charge mobility are observed.     

Inhibition by cardiolipins of platelet-activating factor-induced rabbit platelet activation

Evidence is presented that cardiolipin, a naturally occurring phospholipid, inhibits the aggregatory effect of platelet-activating factor (paf) on rabbit plateletsin vitro. Bovine heart cardiolipin was shown to inhibit the aggregation of washed rabbit platelets induced by 1×10⁻¹⁰ M and 2×10⁻¹⁰ M paf with IC₅₀ values (doses for half-maximal inhibition) of 8.4±0.8×10⁻⁷ M and 2.6±0.6×10⁻⁶ M, respectively. Phosphonocardiolipin was also able to inhibit platelet aggregation induced by 1× 10⁻¹⁰ M paf with an IC₅₀ value of 3±1×10⁻⁷M. Both compounds, in concentrations up to 1×10⁻⁵ M, were unable to aggregate washed rabbit platelets and failed to inhibit the aggregation induced by 0.9 and 1.8 μM adenosine diphosphate or 0.2–1.0 μM arrchidonic acid. By contrast, the acetylated derivative of cardiolipin exerted an aggregatory effect on aspirin-treated rabbit platelets in the presence of creatine phosphate/creatine phosphokinase. This aggregation was inhibited by the specific paf antagonists BN 52021 and WEB 2086. Also, platelets treated with acetyl-cardiolipin were insensitive to the aggregatory effect of paf. Phosphatidic acid, phosphatidylglycerol,bis(dipalmitoylglycero)phosphate and their phosphono analogues were totally inactive. Similar data were obtained when platelet-rich plasma was used instead of washed rabbit platelets. Our results support the hypothesis that the effect of cardiolipin is mediated through specific paf receptors that act on the rabbit platelet membrane.     

Mechanical properties of short fiber reinforced thermoplastic blends

An immiscible thermoplastic component was added to a conventional short fiber reinforced polymer to study its effect on the mechanical properties of the composite. Because of the preferential wetting of the fiber reinforcement a continuous network was formed of fibers ‘welded’ together by the minor component within the matrix polymer.Polyethylene (PE) was used as the matrix, polyamide-6 (PA6) as dispersed polymer phase and glass fibers (GF) as reinforcement. The obtained composite retained unusually high values of the elasticity modulus at temperatures above the melting point of the matrix. The upper limit of the ‘applicability’ of the material is determined by the melting point of the minor component. A simple model was derived to describe the mechanical properties of the composite. The model shows a good agreement with the experimental data. The influence of the model parameters on the predictions of the model was examined.     

Plasma Lipoproteins and Triacylglycerol are Predictors of Small,Dense LDL Particles

Recently published data suggest that the assessment of LDL subfraction profiles may contribute to the determination of the cardiovascular risk. In this study, we tested the ability of various metabolic parameters to estimate the presence or the preponderance of small, dense LDL particles (sdLDL). One hundred and fifty individuals attending the Outpatient Clinics of the University Hospital of Ioannina for suspected metabolic abnormalities were included in the study. Individuals were excluded if they were found to be diabetic or if they had a history of cardiovascular disease. Patients with thyroid dysfunction, liver or kidney diseases as well as those receiving drugs that may interfere with lipids or glucose metabolism were also excluded from the study. The ability of the various parameters to identify individuals with pattern B LDL phenotype or, alternatively, with measurable quantities of sdLDL particles was tested with the calculation of the areas under the ROC curves. The ratio of triglycerides to HDL-C was the best predictor of the presence of the pattern B LDL phenotype. Nevertheless, when the variable of interest was the presence of measurable quantities of sdLDL subfractions, the ratio of apoB to apoAI had the best predictive ability. In conclusion the ratios of apoB to apoAI and of triglycerides to HDL-C can reliably predict the presence of measurable quantities of sdLDL particles and of the pattern B LDL phenotype, respectively. However, since the quantitative determination of sdLDL concentrations may contribute to the determination of the cardiovascular risk, whereas the role of the LDL particle size remains controversial, apoB to apoAI ratio could provide more valuable information compared to markers that simply predict the presence of the pattern B LDL phenotype.     

Optical memristive switches

Optical memristive switches are particularly interesting for the use as latching optical switches, as a novel optical memory or as a digital optical switch. The optical memristive effect has recently enabled a miniaturization of optical devices far beyond of what seemed feasible. The smallest optical – or plasmonic – switch has now atomic scale and in fact is switched by moving single atoms. In this review, we summarize the development of optical memristive switches on their path from the micro- to the atomic scale. Three memristive effects that are important to the optical field are discussed in more detail. Among them are the phase transition effect, the valency change effect and the electrochemical metallization.     

Subcellular trace element distribution in Geosiphon pyriforme

Geosiphon pyriforme is a unique endosymbiotic consortium consisting of a soil dwelling fungus and the cyanobacterium Nostoc punctiforme. At present this symbiosis becomes very interesting because of its phylogenetic relationship to the arbuscular mycorrhizal (AM) fungi. Geosiphon pyriforme could be an important model system for these obligate symbiotic fungi, which supply 80–90% of all land plant species with nutrients, in particular phosphorous and trace elements. Combined PIXE and STIM analyses of the various compartments of Geosiphon give hints for the matter exchange between the symbiotic partners and their environment and the kind of nutrient storage and acquisition, in particular related to nitrogen fixation and metabolism. To determine the quality of our PIXE results we analysed several geological and biological standards over a time period of three years. This led to an overall precision of about 6% and an accuracy of 5–10% for nearly all detectable elements. In combination with the correction model for the occurring mass loss during the analyses this holds true even for biological targets.     

Thermoeconomic modeling and parametric study of hybrid SOFC–gas turbine–steam turbine power plants ranging from 1.5 to 10 MWe

Detailed thermodynamic, kinetic, geometric, and cost models are developed, implemented, and validated for the synthesis/design and operational analysis of hybrid SOFC–gas turbine–steam turbine systems ranging in size from 1.5 to 10 MWe. The fuel cell model used in this research work is based on a tubular Siemens-Westinghouse-type SOFC, which is integrated with a gas turbine and a heat recovery steam generator (HRSG) integrated in turn with a steam turbine cycle. The current work considers the possible benefits of using the exhaust gases in a HRSG in order to produce steam which drives a steam turbine for additional power output. Four different steam turbine cycles are considered in this research work: a single-pressure, a dual-pressure, a triple pressure, and a triple pressure with reheat. The models have been developed to function both at design (full load) and off-design (partial load) conditions. In addition, different solid oxide fuel cell sizes are examined to assure a proper selection of SOFC size based on efficiency or cost. The thermoeconomic analysis includes cost functions developed specifically for the different system and component sizes (capacities) analyzed. A parametric study is used to determine the most viable system/component syntheses/designs based on maximizing total system efficiency or minimizing total system life cycle cost.     

Ultrahigh-density spin-polarized hydrogen isotopes from the photodissociation of hydrogen halides:new applications for laser-ion acceleration,magnetometry,and polarized nuclear fusion

Recently,our group produced spin-polarized hydrogen(SPH)atoms at densities of at least 10¹⁹cm^-3from the photodissociation of hydrogen halide molecules with circularly polarized UV light and measured them via magnetization-quantum beats with a pickup coil.These densities are approximately 7 orders of magnitude higher than those produced using conventional methods,opening up new fields of application,such as ultrafast magnetometry,the production of polarized MeV and GeV particle beams,such as electron beams with intensities approximately 10⁴higher than current sources,and the study of polarized nuclear fusion,for which the reaction cross sections of D-T and D-(3)^He reactions are expected to increase by 50%for fully polarized nuclear spins.We review the production,detection,depolarization mechanisms,and potential applications of high-density SPH.     

The ADREA-HF CFD code for consequence assessment of hydrogen applications

Application of the CFD methodology for risk assessment of hydrogen applications and associated support of regulation, codes and standards has been growing its momentum during the last years. The CFD tools applied should prove to be “adequately” validated for hydrogen applications. This contribution focuses on the hydrogen related validation work performed with the CFD code ADREA-HF. The code is a three dimensional transient fully compressible flow and dispersion CFD solver, able to treat highly complex geometries using the porosity formulation on Cartesian grids. The ADREA-HF validation effort was performed within various EC co-funded projects (EIHP, EIHP-2, HyApproval, HyPer, HySafe). Various types of hydrogen release scenarios were considered, including gaseous and liquefied releases, open, semi-confined and confined environments, sonic (under-expanded) and low momentum releases. In parallel to its validation the ADREA-HF code has been extensively used for regulations, codes and standards support.