Composition and quality attributes of conventionally and organically farmed Pangasius fillets (Pangasius hypophthalmus) on the German market

A range of conventionally and organically farmed Pangasius or sutchi catfish fillets available on the German market were analysed to compare both composition and quality. Differentiation of Pangasius hypophthalmus from Pangasius bocourti was achieved by RFLP-SSCP analysis. The protein content of conventionally farmed fillets ranged between 13.3 and 15.7%, whereas organically produced fillets had significantly higher protein contents of between 17.0 and 17.4%. No difference in the fat content between farming methods was observed, which varied between 1.4 and 3.2%. Polyunsaturated fatty acids represented about 24% of the total fatty acids with a high level of linoleic acid. The comparison of the proximate composition indicated that water was added to most of the conventionally farmed products, in different amounts, as well as water-binding capacity enhancing additives. Differential scanning calorimetry was used to demonstrate the presence of polyphosphate on muscle proteins. Differences in texture, water-binding capacity and colour are discussed.     

Computation of plate columns for NOx absorption by a new stage-to-stage method

A new stage-to-stage method has been developed for the calculation of NX_x absorption columns. Each stage of the absorption column is simulated as a combination of a bubble column reactor (absorption) and an adiabatic plug for reactor (oxidation). The bubble column reactor is modelled as two single stirred tank reactors, one as a gas-phase and one as a liquid-phase reactor, both coupled by mass and heat transfer. In this hydrodynamic model, a dynamic approach is adopted, in which the gas-phase transport of N₂O₄ is the limiting step for the absorption. A gas-phasepseudo-enhancement for factor for N₂O₄ is therefore introduced. The balance equations for a single phase of the bubble column are solved with a Newton-Raphson algorithm. The entire column calculation is divided into a gas and a liquid side. On both sides, the stage-to-stage method is applied in such way that the overall calculation is performed as a loop process. The direction of the loop calculation follows that of the flow: gas-side upwards and liquid-side downwards.     

Hydrolyse des Fleischextraktes

Ohne ZusammenfassungMitteilung aus der staatlichen Untersuchungsanstalt für Lebensmittel in Graz.     

Experimental Evidence for the Existence of the Ti3B4 Phase

Experimental evidence for the formation of Ti₃B₄ with an orthorhombic Ta₃B₄-type structure is presented. This phase forms by a peritectic reaction between TiB₂ and liquid at ∼2200°C and is stable to temperatures at least as low as 1690°C, the lowest temperature at which samples were annealed. No evidence was found to indicate the presence of a second high-temperature form of this phase, as has been reported in the literature.     

Organizing Technology Transfer from Research to Production

An overview of issues to be considered when organizing the transfer of technology from the research arena to the production environment will be presented. The discussion will focus on the coordination and implementation of a transfer program for a product with emphasis being given to those factors peculiar to the pharmaceutical industry. The success of any program is highly dependent on the effectiveness of the communication preceding its implementation. Therefore, the preparation and distribution of a complete document summarizing raw material and equipment requirements, manufacturing and packaging processses, process validation parameters, quality control procedures, as well as a detailed plan of action outlining expected results and time frames, must be disseminated prior to the scale-up experience. Input from the marketing and manufacturing centers must also be integrated into the plan to ensure that the right product is developed at the right price within the desired time frame. An outline encompassing these critical aspects of a transfer program will be presented.     

Load and health monitoring in glass fibre reinforced composites with an electrically conductive nanocomposite epoxy matrix

Fibre reinforced polymers (FRPs) are an important group of materials in lightweight constructions. Most of the parts produced from FRPs, like aircraft wings or wind turbine rotor blades are designed for high load levels and a lifetime of 30 years or more, leading to an extremely high number of load cycles to sustain. Consequently, the fatigue life and the degradation of the mechanical properties are aspects to be considered. Therefore, in the last years condition monitoring of FRP-structures has gained importance and different types of sensors for load and damage sensing have been developed.

In this work a new approach for condition monitoring was investigated, which, unlike other attempts, does not require additional sensors, but instead is performed directly by the measurement of a material property of the FRP. An epoxy resin was modified with two different types of carbon nanotubes and with carbon black, in order to achieve an electrical conductivity. Glass fibre reinforced composites (GFRP) were produced with these modified epoxies by resin transfer moulding (RTM). Specimens were cut from the produced materials and tested by incremental tensile tests and fatigue tests and the interlaminar shear strength (ILSS) was measured. During the mechanical tests the electrical conductivity of all specimens was monitored simultaneously, to assess the potential for stress/strain and damage monitoring.

The results presented in this work, show a high potential for both, damage and load detection of FRP structures via electrical conductivity methods, involving a nanocomposite matrix.     

Removal of acetic acid from water by catalytic distillation. Part 2: Modeling and simulation studies

A simulation program has been established by incorporating basic models for reaction kinetics, vapor–liquid equilibrium and mass transfer into Aspen Plus (Aspen Technology Inc., 1996) to simulate the catalytic distillation process for the removal of dilute acetic acid from water. The simulated concentration profiles agree well with those measured under various operating conditions.