Projection and prospects for rapeseed and mustard seed

Rapeseed is number five among the oilseeds of the world. During the last 10 years the crop has increased more in per cent than any other oilseed crop. In the FAO prospects an annual rate of increase of 4.7% is foreseen. The fatty acid composition will change during the next years so that erucic acid will be practically removed. The content of glucosinolates will also be reduced dramatically, and consequently the meal will be accepted much more readily.     

Inverse dynamics of spatial open-chain flexible manipulators with lumped and distributed actuators

This article addresses the problem of inverse dynamics for three-dimensional flexible manipulators with both lumped and distributed actuators. A recursive procedure is presented for computing the lumped inverse dynamic torques and the distributed piezoelectric actuator inputs for simultaneously tracking a prescribed end-point trajectory and reducing induced vibrations in the manipulator. The procedure sequentially solves for the non-causal inverse dynamic torques and piezoelectric voltages applied to each link in the manipulator, starting from the last element in the chain and proceeding to the base element. The method allows trajectory tracking wherein controllability of the structural vibrations is assured in all possible configurations through the use of only one motor at each intermediate joint and three motors at the ground. Numerical simulation shows that the elastic vibrations can be reduced significantly through the use of distributed actuators while at the same time satisfying the trajectory tracking requirement through the use of inverse dynamics. © 1994 John Wiley & Sons, Inc.     

Nutritional composition of blubber and meat of hooded seal (Cystophora cristata) and harp seal (Phagophilus groenlandicus) from Greenland

Seal blubber and skin are widely used, but the utilisation of blubber and meat for human consumption is limited. The aim of this study was to evaluate the nutritional composition of seal blubber and meat. The fatty acid composition, selected minerals and trace-elements, vitamins, amino acids and proximal composition of blubber and meat from hooded seal (Cystophora cristata) and harp seal (Phagophilus groenlandicus) from the “West Ice” near Greenland were analysed. The results showed that seal blubber is an excellent source of long- and very long-chain (VLC) n − 3 polyunsaturated fatty acids (PUFAs), in addition to long- and VLC monounsaturated fatty acids (MUFAs). Eicosapentaenoic acid (EPA) content contributed to a clear separation between blubber and meat from the two species. The blubber of harp seal showed the highest EPA (9.2%), whereas the muscle of harp seal showed the lowest EPA (3%) content. Seal meat is lean with less than 2% total fat, mainly composed of MUFAs, long- and VLC n − 3 PUFAs. In addition, the meat contains a high amount of proteins with a well-balanced amino acid composition. The trace-element content of seal meat is very high, particularly iron (379 μg/g muscle in hooded seal) and zinc (30 μg/g muscle in harp seal), as also is the vitamin content, especially vitamins A, D₃ and B₁₂. The seals included in this study varied greatly in age and size, which in turn may be the principal reason for the great individual variation observed in nutritional composition. On average, however, consumption of only 40 g seal meat covers the recommended daily intakes of iron and vitamin B₁₂ for young women. In conclusion, as long as the products fulfil the amending legislations regarding contaminants, both seal blubber and meat, from the present species, represent high quality food regarding nutrients and bioactive components beneficial for human health.     

Isokinetic effects in ethane hydrogenolysis and their relation to the mechanism of the reaction

Literature data on the kinetics of ethane hydrogenolysis over metal catalysts are used to indicate the existence of isokinetic temperatures, . For platinum = 725 K, for Ni is probably in the same temperature range. For Fe and Co on the other hand is found at much lower values, about 330 K for Fe and 320 K for Co. From an analysis of the model of selective energy transfer, these values support the proposition of Sinfelt that the elements of high atomic number in one and the same transition metal series favour the splitting of the carbon-carbon bond as rate determining step, whereas those elements that have lower atomic numbers cause the splitting of the metal-carbon bond to be the rate determining step.     

Post-mortem degradation of myosin heavy chain in intact fish muscle: Effects of pH and enzyme inhibitors

Fish muscle is rapidly degraded during post-mortem storage, due to proteolytic enzymes acting probably both on muscle cells and connective tissue. In this work we have developed a model system which may be used to study the enzymatic degradation occurring in intact post-mortem fish muscle. Degradation of myosin heavy chain (MHC) was monitored in muscle with pH adjusted to 6.05, 6.3 and 6.9 and in the presence of the enzyme inhibitors PMSF, EDTA, phenanthroline, pepstatin A, antipain, E-64 and the cysteine proteinase activator dithiothreithol (DTT). After storage, myofibrillar proteins were isolated and MHC-specific antibodies used to study the degradation in the different samples. MHC from muscle with pH 6.05 and 6.3 was degraded, while no severe degradation was observed at pH 6.9. Introduction of enzyme inhibitors into the muscle tissue clearly showed that mainly cysteine and aspartic proteinases are responsible for the in situ MHC degradation. This is supported by the severe breakdown of MHC in the muscle samples containing DTT.