Hazard analysis and assessment – key process in food safety management. Case study: meat industry

Food safety is related to the presence of hazards of food origin in food products in the moment of consumption. As these hazards may occur in any stage of food chain, adequate control throughout this one is essential. Due to the fact that most laboratory analyses made on food require some time to be interpreted (it is usually equal or longer than foods’ shelf–life) is practically impossible to make these analyses and afterwards to deliver them to consumers. Three types of dangers and hazards respectively are associated with food products: biological, chemical and physical ones. Hazard assessment is made depending on their seriousness and probability of manifestation. To get very good results it is recommended to consider HACCP implementation as a working instrument and not as an objective, especially not as an objective imposed by the control authorities of the state

Non-neoclassical up/down asymmetry of impurity emission on Alcator C-Mod

We demonstrate that existing theories are insufficient to explain up/down asymmetries of argon x-ray emission in Alcator C-Mod ohmic plasmas. Instead of the poloidal variation, ñ[subscript z]/〈n[subscript z]〉, being of order the inverse aspect ratio, ϵ, and scaling linearly with B[subscript t][superscript _ over n][subscript e]/I[2 over p], it is observed over 0.8 < r/a < 1.0 to be of order unity and exhibits a threshold behaviour between 3.5 <B[subscript t][superscript _ over n][subscript e]/I[subscript p] < 4.0 (T10[superscript 20] m[superscript −3] MA[superscript −1]). The transition from a poloidally symmetric to asymmetric impurity distribution is shown to occur at densities just below those that trigger a reversal of the core toroidal rotation direction, thought to be linked to the transition between the linear and saturated ohmic confinement regimes. A possible drive is discussed by which anomalous radial transport might sustain the impurity density asymmetry as the ratio of the perpendicular to parallel equilibration times, τ[subscript ⊥,z]/τ[subscript ∥,z], approaches unity. This explanation requires a strong up/down asymmetry in radial flux which, while not observable on C-Mod, has been measured in TEXT and Tore Supra ohmic plasmas.United States. Dept. of Energy (Contract DE-FC02-99ER54512)United States. Dept. of Energy (Fusion Research Postdoctoral Research Program

Possible mechanism responsible for observed impurity outward flow under radio frequency heating

The effect of poloidal asymmetry of impurities on impurity transport driven by electrostatic turbulence in tokamak plasmas is analyzed. It is found that in the presence of in-out asymmetric impurity populations the zero-flux impurity density gradient (the so-called peaking factor) is significantly reduced. A sign change in the impurity flux may occur if the asymmetry is sufficiently large. This may be a contributing reason for the observed outward convection of impurities in the presence of radio frequency heating. The effect of in-out asymmetry is most significant in regions with low temperature gradients. In the trapped electron mode dominated case also an up-down asymmetry can lead to a sign change in the peaking factor from positive to negative. The effect of ion parallel compressibility on the peaking factor is significant, and leads to positive peaking factors in regions with high temperature gradients, even in the presence of in-out asymmetry.Comment: 19 pages, 14 figure

Influence of strong disorder on superconductivity of MgB2 thin films

We investigated the influence of disorder on superconductivity of MgB2 films, prepared in a single deposition run onto two different substrates: (100)-MgO and on (128° rot)-LiNbO3 with trigonal crystal structure which does not match to the MgB2 structure. As expected, the microstructure of both films crucially differs. The REM study shows a very homogeneous, smooth morphology of the MgB2 film on MgO, but a very rough inhomogeneous film structure on LiNbO3. Although the MgB2 film on LiNbO3 is strongly disordered, its critical temperature Tc=33.5 K is practically the same as for the film deposited on MgO. Possible reasons of such unusual Tc behavior are discussed

Recent results from the electron cyclotron heated plasmas in Tokamak à Configuration Variable (TCV)

In noninductively driven discharges, 0.9 MW second harmonic (X2) off-axis co-electron cyclotron current drive deposition is combined with 0.45 MW X2 central heating to create an electron internal transport barrier (eITB) in steady plasma conditions resulting in a 1.6-fold increase of the confinement time (tau(Ee)) over ITER-98L-mode scaling. The eITB is associated with a reversed shear current profile enhanced by a large bootstrap current fraction (up to 80%) and is sustained for up to 10 current redistribution times. A linear dependence of the confinement improvement on the product of the global shear reversal factor (q(0)/q(min)) and the reversed shear volume (rho(q-min)(2)) is shown. In other discharges heated with X2 the sawteeth are destabilized (respectively stabilized) when heating just inside (respectively outside) the q=1 surface. Control of the sawteeth may allow the avoidance of neoclassical tearing modes that can be seeded by the sawtooth instability. Results on H-mode and highly elongated plasmas using the newly completed third harmonic (X3) system and achieving up to 100% absorption are also discussed, along with comparison of experimental results with the TORAY-GA ray tracing code [K. Matsuda, IEEE Trans. Plasma Sci. PS-17, 6 (1989); R. H. Cohen, Phys. Fluids 30, 2442 (1987)]. (C) 2003 American Institute of Physics

Influences of the circular economy in industrial engineering

Abstract Epoxy resins are some of the best-performing resins currently available on the industrial market. By adding additional filler materials (glass, porcelain), the epoxy resin acquires superior mechanic and thermal properties. The areas in which epoxy resins are used are multiple: metal coating, electronics and electrotechnics, manufacture of paints and adhesives, obtaining plastics with special properties or in construction. Epoxy paints are used indoors because they are UV-sensitive (they get the appearance of chalk) on the outside. However, they are very good as corrosion-resistant primer and very good protection against water and humidity. That is why they are used as a first layer in the automotive or shipbuilding industry. Epoxy adhesives are very resistant and are used in many areas: airplane, car, bicycle construction. Therefore, when making the frame to pour a resin, it should be taken into account that there are few materials that do not stick very well.</jats:p