Advanced system‐level simulation paradigm for ultra‐wideband systems using SCERNE platform

In this article, a progressive system‐level simulation framework is developed based on Simulation de Chaînes d'Emission/Réception Nouvelle gEnération (SCERNE) platform to simulate an ultra‐wideband (UWB) impulse radar transmitter and accurately predict its performance. With the purpose of demonstrating the usefulness of the SCERNE ability in system‐level modeling, we present and simulate a simplified structure of UWB impulse radar transmitter. First, after simulation each component in different circuit‐level tools such as ADS, CST, and HFSS, each part has been modeled by using different modeling methods to transfer their data into MATLAB environment. Then, we duplicate the transmitter structure in SCERNE toolbox to validate the results. The advantage conferred by the proposed SCERNE toolbox is that fast and accurate bilateral modeling method is available at multi‐medium structures in contrast with conventional unilateral modeling, and so a lower memory and higher accuracy of the behavioral model is achieved. It can also be beneficial when the user is looking for system‐level, as the increased components amounts can help as a surrogate model. The system model can be easily extended to other UWB radar systems by simply changing the input pulse shape, UWB channel environment, transceiver topology, etc. Various effects such as signal quality, and pulse shape that can easily investigate and re‐optimize for high performance are using the developed model. To validate the practicality of the proposed paradigm, the simulations and predictions through model results are being outlined.     

cis-9,trans-11 and trans-10,cis-12 CLA affect lipid metabolism differently in primary white and brown adipocytes of Djungarian hamsters

We explored whether CLA isomers and other C₁₈ FA affect (i) lipid content and FA concentrations in total adipocyte lipids, (ii) FA synthesis from glucose in TAG and phospholipids of primary brown (BAT) and white adipocytes (WAT), and (iii) mRNA expression of uncoupling protein 1 (UCP1) in primary brown adipocytes of Djungarian hamsters (Phodopus sungorus). c9,t11-CLA, oleic, linoleic, and α-linolenic acid increased whereas t10,c12-CLA decreased lipid accumulation in both adipocyte types. t10,c12-CLA treatment affected FA composition mainly in BAT cells. CLA incorporation into lipids, in particular c9,t11-CLA, was higher in BAT. In both cell types, t10,c12-CLA treatment reduced the incorporation of glucose ¹³C carbon into FA of TAG and phospholipids, whereas c9,t11-CLA, linoleic, and α-linolenic acid either did not influence or dose-dependently increased glucose carbon incorporation into FA. UCP1 mRNA expression was inhibited by t10,c12-CLA but increased by c9,t11-CLA, linoleic, and α-linolenic acid. It is concluded that c9,t11-CLA and t10,c12-CLA have distinctly different effects on lipid metabolism in primary adipocytes. The effects of c9,t11-CLA are similar to those of other unsaturated C₁₈ FA. The opposite effects of c9,t11-CLA and t10,c12-CLA are evident in both WAT and BAT cultures; however, brown adipocytes seem to be more susceptible to CLA treatment.     

The interaction of human plasma low density lipoproteins with glycosamino-glycans: Influence of the chemical composition

Human plasma of 5 normolipemic individuals was incubated for 24 hr at 37 C in the presence or in the absence of lecithin: cholesterol acyltransferase (LCAT)-inhibitors. Plasma steored at 4 C served as a control. The low density lipoprotein (LDL) fractions of the samples were isolated and investigated with respected to changes in chemical composition and complexing activity with glycosamino glycans (GAG). Incubation of plasma in the presence of LCAT inhibitors caused a significant increase of LDL triglycerides at the expense of cholesteryl esters. Incubation with active LCAT not only changed the core but also the surface constituents (decrease in phospholipids and in free cholesterol). The amount of GAG bound per mg of LDL was not uniformly changed in samples incubated after LCAT inhibition. LDL isolated from plasma incubated in the presence of LCAT, on the other hand, showed a significant reduction in GAG binding. The ratio of free cholesterol: GAG in the complex was most significantly reduced in LCAT-modified LDL. There was in addition a highly significant correlation between the LDL:GAG ratio in the complex and the free cholesterol and phospholipid content of the LDL samples. It is concluded that alterations in surface lipid constitutents of LDL strongly after their interaction with sulfated polysaccharides, an effect which may be relevant also in vivo for the interaction of LDL with cell surfaces and intercellular matrices.     

Performance of lipid‐based moisture barriers in food products with intermediate water activity

Nine lipid‐based barrier films (three chocolates, acetomonopalmitine, white beeswax, and four commercial blends: two acetoglycerides/beeswax blends, two hydrogenated and fractionated vegetable oils) were characterised using classical water‐related and physical properties of edible barriers, such as water vapour permeability, moisture adsorption isotherm, moisture effective diffusivity, surface hydrophobicity, firmness and solid fat content (20 °C). Classifications based on these properties were established and compared to the barrier efficiency under real conditions of use, i.e. in a model food product (cereal‐based component – intermediary a_w gel). Moisture migrations were performed using self‐supported barriers (300 µm) and fitted with a predictive model based on Fick's Second Law. White beeswax and acetoglycerides enabled the best extensions of the dry‐component shelf life from 2 h to between 100 and 330 h. Moisture effective diffusivity and calculated water vapour permeability combined to a mechanical property evaluation of the barrier were more discriminating to assess the barrier efficiency in the model food than the moisture sorption and experimental water vapour permeability. The importance of combining both water‐related and physical characteristics of the barrier and the advantages of an integrated approach through the simulation of the material behaviour under its real conditions of use with the model are highlighted.     

Hardness results for approximate pure Horn CNF formulae minimization

We study the hardness of approximation of clause minimum and literal minimum representations of pure Horn functions in n Boolean variables. We show that unless P=NP, it is not possible to approximate in polynomial time the minimum number of clauses and the minimum number of literals of pure Horn CNF representations to within a factor of \(2^{\log^{1-o(1)} n}\) . This is the case even when the inputs are restricted to pure Horn 3-CNFs with O(n ^1+ε ) clauses, for some small positive constant ε. Furthermore, we show that even allowing sub-exponential time computation, it is still not possible to obtain constant factor approximations for such problems unless the Exponential Time Hypothesis turns out to be false.     

A?novel method for the quantitative analysis of the water content in lignocellulosic material

A novel method for the determination of the water content in wood has been developed and experimentally tested. Based on the reaction of trimethylchlorosilane with various wood constituents and water, the generation of a by-product (hexamethyldisiloxane) was pursued and quantified via gas-chromatography and the water content was subsequently calculated back. The experiments were carried out with preconditioned spruce wood meal (particle sizes ranging between 60 and 140 microns) using water free solvents and reagents in a water free reaction atmosphere. The results showed that the investigated samples incorporated around 10 wt. % of water after preconditioning for 48 h.     

Extended conjugation in di- and tri- arylmethane dyes. Part 3. The effects of increased planarity in Victoria Blue dyes

The synthesis of novel derivatives of the Victoria Blue series of dyes containing the 3,6-bis(dimethylamino)fluoren-9-yl moiety is reported. The consequent increased planarity of the system results in a large bathochromic shift of the x-band compared to the parent compound.     

Le guide juridique du portail Internet/Intranet

Ohne Zusammenfassung     

Misorientation texture development during grain growth. Part I: Simulation and experiment

Grain growth in two and three dimensions with anisotropic interfacial properties was simulated using the Monte Carlo method. The relative effects of grain boundary energy and mobility anisotropy on number- and area-weighted misorientation distribution functions (MDFs) were compared. Results indicate that energy anisotropy has a measurable effect on misorientation texture development, while mobility anisotropy does not. Qualitatively similar results are obtained in all simulations regardless of dimensionality or crystal symmetry. Microstructures with random orientation texture appear to evolve steady-state MDFs, while those with a preferred orientation do not. Experimentally measured number- and area-weighted MDFs in polycrystalline magnesia are shown to be comparable to those measured in our simulations.     

Method Validation and Quality Management in the Flexible Scope of Accreditation: An Example of Laboratories Testing for Genetically Modified Organisms

Quality assurance is a prerequisite for accurate and reliable results in food and feed testing, ISO/IEC 17025 being recognized worldwide as the base standard. A flexible scope of accreditation enables testing laboratories to react quickly to customer demand and to cope with the large number of new methods, which have to be introduced in the laboratory. Precisely defined procedures for the validation of methods, together with performance and acceptance criteria, are the key points for flexible scope of accreditation. Testing for genetically modified organisms (GMO) is a challenging exercise, especially with more GMOs entering the world market. We describe here the organization and performance of validating quantitative detection methods for GMO testing in the context of the European Union legislation. Operational procedures for method validation organized by the Community Reference Laboratory for Genetically Modified Food and Feed, assisted by the European Network of GMO Laboratories, are described. A protocol for validating methods within an individual laboratory is proposed and discussed in terms of the requirements of flexible scope of accreditation. The system setup can be an example for other similar fields of analytical work.