Chronologie des EHEC O104:H4 Ausbruchsgeschehens bis zur Gr��ndung der l?nder��bergreifenden Task Force EHEC aus Sicht der Lebensmittel��berwachung in Schleswig-Holstein am Beispiel des Kreises Schleswig-Flensburg

The article describes the chronology of events of the recent EHEC O104:H4 outbreak from the perspective of food inspection in Schleswig-Holstein until the National Task Force EHEC was founded. Taking the district of Schleswig-Flensburg as an example, the collaboration and information exchange between health and food control authorities is described. The Ministry of Agriculture, Environment and Rural Areas of Schleswig-Holstein (MLUR) received the first information about clusters of disorders with symptoms of bloody diarrhoea and HUS from the districts around Hamburg and the city of Hamburg on 19 May 2011. On the same day, the veterinary services and the service for consumer protection in the district of Schleswig-Flensburg were informed about a situation comparable to the one in the environment of Hamburg. Due to this situation, official procedures were initiated to discover the origins of this food-associated outbreak - both at the state and county level and in collaboration with the health authorities. On 1 June 2011, an initial telephone conference was held between the responsible ministries and the food inspection and health authorities of the counties and cities in order to coordinate a joint action. On 3 June 2011, the National Task Force EHEC was founded at the Federal Office for Consumer Protection and Food Safety (BVL) in Berlin. By founding the National Task Force EHEC, the coordination of the clearing process was passed over to the BVL two weeks after the public health authorities had knowledge of accumulated and cross-border cases. On 7 June 2011 an employee of the district Schleswig-Flensburg was sent to the Task Force EHEC in Berlin by the MLUR. The lesson to be learned as a result of the EHEC O104:H4 outbreak is that among the ??dangerous foods?? there are more plant-based foods than often assumed. In the future this must be much more taken into account.     

Non-destructive Estimation of Mandarin Maturity Status Through Portable VIS-NIR Spectrophotometer

Sugar content is one of the most important quality attributes of citrus fruit, either for fresh or for processing market. Since sugars in citrus juice are highly correlated with total soluble solids (TSS) content, which can be determined easily even by the means of a hand refractometer, TSS is one of the most frequently used quality index. Since TSS can be measured only destructively, the results are representative only if carried out on large samples and do not allow classifying marketable fruit one by one according to their specific sugar content. Objective of this experiment was to assess possibility and limits of a non-destructive estimation of citrus fruits internal quality parameters (TSS and titratable acidity) presenting thick peel by the use of a spectrophotometric portable VIS-NIR system. Four hundred fruit of “Miho” satsuma and 150 fruit of “Page” tangelo were used. Each fruit was first subjected to spectrophotometric acquisition and soon after was juiced and TSS and titratable acidity (TA) determined. Partial least squares (PLS) regression analysis was applied for constructing a predictive model based on the spectral normalized response, constructing the model on a sub-sample and verifying the model (prediction test) on independent ones. The TA relative to Page mandarin was predicted in the test with an r = 0.88 and a standard error of prevision (SEP) coefficient of variability of 3.8% while the TSS scored an r = 0.85 and a SEP coefficient of variability equal to 4%. The TA of Miho mandarin was predicted in the test with an r = 0.81 and a SEP coefficient of Variability of 8.3% while the TSS scored an r = 0.84 and a SEP coefficient of variability equal to 5.6%.     

Characteristics of Convective Drying of Pepino Fruit (Solanum muricatum Ait.): Application of Weibull Distribution

The aim of this research was to study the behaviour of the drying kinetics of pepino fruit (Solanum muricatum Ait.) at five temperatures (50, 60, 70, 80 and 90 °C). In addition, desorption isotherms were determined at 20, 40 and 60 °C over a water activity range from 0.10 to 0.90. The Guggenheim, Anderson and de Boer model was suitable to depict the desorption data. A monolayer moisture content from 0.10 to 0.14 g water g⁻¹ d.m. was reported. The equations of Newton, Henderson–Pabis, Modified Page, Wang–Singh, Modified Henderson–Pabis, Logarithmic as well as standardised Weibull were tested for modelling drying kinetics. Besides, Fick’s second law model was used to calculate the water diffusion coefficient which increased with temperature from 2.55 to 7.29 × 10⁻¹⁰ m² s⁻¹, with estimated activation energy of 27.11 kJ mol⁻¹. The goodness of fit of the models was evaluated using sum squared error and chi-square statistical tests. The comparison of the experimental moisture values with respect to the calculated values showed that the standardised Weibull model presented the best goodness of fit, showing that this equation is very accurate for simulating drying kinetics for further optimisation of drying times.     

Averaging method and long-wave asymptotics in vibrational convection in layers with an interface

A scheme for applying an averaging method to the problem of convection in a two-layer system with an interface under the influence of high-frequency vibration is proposed. The derivation of the averaging equations is given, and the stability of the equilibrium of the averaged problem is considered. Long-wavelength asymptotics of steady and oscillatory instability are constructed. The results of numerical calculations for acetonitrile?Cn-hexane and silicone oil?Cfluorinert systems are given. The directions in which the investigation of thermovibrational convection in problems with free surfaces and interfaces can be continued, are indicated.     

Stability of some stationary solutions to the forced KdV equation with one or two bumps

Free-surface flows past submerged obstacles in a channel are considered. The fluid is assumed to be inviscid and incompressible and the flow to be irrotational. The first-order approximation of long nonlinear surface waves over one or two bumps results in a forced Korteweg?Cde Vries (fKdV) equation. Solutions of the stationary fKdV equation are constructed and their stability is studied, either analytically or numerically. These various solutions include solitary waves over a single bump, solitary waves with two humps over a double bump, table-top solutions over a double bump and fronts.     

Decoration of single-walled carbon nanotubes with Pt nanoparticles from an organometallic precursor

Carbon nanotubes (CNTs) are nanomaterials of high interest due to their unique structural, electrical, and mechanical properties. Carbon materials have been widely employed to support metallic nanoparticles for catalysis and electrochemical applications. In this work, we investigated the synthesis of platinum nanoparticles generated from the complex Pt₂(dba)₃ (tris(dibenzylideneacetone) diplatinum) and stabilized with a long alkyl chain amine, hexadecylamine (HDA) and supported on functionalized single-walled carbon nanotubes (SWCNTs). High resolution transmission electron microscopy (HRTEM) studies revealed isolated Pt nanoparticles (2?C3 nm) on SWCNTs. Powder X-ray diffraction (XRD) was used to assess the structure of Pt nanoparticles dispersed on SWCNTs assigned to Pt face-centered cubic (fcc). Additionally, infrared Fourier transform spectroscopy confirmed the presence of the stabilizer at the surface of the Pt nanoparticles even after the purification step and functional groups at the surface of pre-treated SWCNTs. This synthetic method may be an alternative route to prepare small size Pt nanoparticles supported on functionalized SWCNTs.     

EuFe2As2: Magnetic Structure and Local Charge Distribution Anisotropies as Seen by Resonant X-ray Scattering

Non-resonant and element specific magnetic X-ray scattering has been used to determine the orientation of Eu and Fe magnetic moments in EuFe₂As₂ iron pnictide. Experiments have been carried out on single crystal samples at the ESRF. Resonant measurements on magnetic reflections at the Eu L₃ absorption edge indicate that the orientation of the Eu moments in the antiferromagnetic phase (T<T _N=19 K) lie parallel to the crystallographic a-axis. In addition, non-resonant magnetic X-ray measurements indicate that the Fe moments are aligned along the same direction in the spin density-wave ordered phase (T<T _S=190 K). The temperature dependence of the integrated intensities suggests that the Fe magnetic sublattice is barely affected by the onset of Eu ordering at T _N. The observation of non-zero resonant intensity on nuclear-forbidden reflections with wavevector corresponding to the Fe magnetic propagation vector at both the Eu L₃ and As K absorption edges may be interpreted as the result of the polarization of the Eu 5d and As 4p electronic bands via hybridization with the Fe 3d states.     

Microstructure Study at Different Thicknesses of Disc-Shaped YBa2Cu3O7?x Prepared by FQMG Method

The flame-quench-melt-growth (FQMG) method was used for the preparation of bulk YBa₂Cu₃O_7?x (Y123). Both the superconducting and nonsuperconducting regions changing with thickness of superconducting sample were determined by X-ray diffraction (XRD) patterns and also observed at micrographs taken by the polarized optical microscope. It was observed that superconducting forming ratio which was examined for different thicknesses of the sample ranging from 6.54 to 1.58 mm strongly enhanced. This means that a region near the top surface of the sample contains more superconducting phase than the other regions. These observations would be helpful in designing and manufacturing the practical applications of YBCO systems.     

Parameter identification and shape optimization

Simulation of metal forming processes using the Finite Element Method (FEM) is a well established procedure, being nowadays possible to develop alternative approaches, such as inverse methodologies, in solving complex problems. In the present paper, two types of inverse approaches will be discussed, namely the parameter identification and the shape optimization problems. The aim of the former is to evaluate the input parameters for material constitutive models that would lead to the most accurate set of results respecting physical experiments. The second category involves determining the initial geometry of a given specimen leading to a desired final geometry after the forming process. The purpose of the present work is then to formulate these inverse problems as optimization problems, introducing a straightforward methodology of process optimization in engineering applications such as metal forming and structural analysis. To reach this goal, an integrated optimization approach, using a finite element code together with a numerical optimization program, was employed. A gradient-based optimization method, as a combination of the steepest-descent method and the Levenberg-Marquardt techniques, was used. Numerical applications in the parameter optimization category include, namely, the characterization of a non-linear elasto-plastic hardening model and the determination of the parameters for a nonlinear hyperelastic model. It is also discussed the simultaneous identification of both constitutive material model parameters and the friction coefficient parameters. From the point of view of shape optimization problems, the determination of the initial geometry of a specimen in a upsetting billing problem as well as a methodology for defining the most suited blank shape to be formed in a square cup, are discussed. The final results for both categories show that this kind of algorithms have great potential for future developments in more demanding and realistic benchmarks. It is also worth noting that the presented integrated methodology can be easily applied to a first introduction of optimization techniques and numerical simulation to undergraduate courses in engineering.