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981.
The amounts of substances migrating from plastics into foodstuffs with high fat contents are in most cases higher than in foodstuffs with water contents. This increase in migration commonly is due to the higher solubility of the migrating organic compounds in fat compared to water. The increase in migration is not necessarily due to an increase in the substance's diffusion coefficient due to interactions between the fat and the plastic as is often assumed. Ethanol is a good simulant for fatty foods because it has little interaction with many plastics, e.g. polyolefins, migrants are readily soluble in it, and because it is easy to work with analytically. The utilizable limits of ethanol and ethanol/water mixtures as food simulants are developed from the physical background of diffusion. The use of ethanol and ethanol/water mixtures is supported by published experimental migration results.  相似文献   
982.
Investigation of the effects of varying air velocity, slice thickness, and pre-treatment with sodium chloride solutions and surface active agents on drying potato slices indicated that the drying occurred entirely in the falling rate period and was controlled by the mechanism of liquid diffusion. The rate of drying, and therefore the diffusion coefficients, increased with the addition of sodium chloride and surface active agents. Diffusion coefficients were also influenced by air velocity and slice thickness, suggesting that the rate of drying of potato slices is controlled by a combination of internal and external resistances.  相似文献   
983.
Flour blends of quinoa-wheat containing 0, 5, 10, 15, and 20% of manually dehulled quinoa meal or flour were evaluated for dough mixing and breadmaking properties and liking of the bread by a small panel. Increasing amounts of quinoa meal or flour increased farinograph absorption and dislike of bread for most of the panel. Dough development time increased with increase in meal but decreased with increase in quinoa flour. At 10% inclusion levels differences in liking from control 100% wheat flour bread were smaller for flour or water extracted meal to most of the panel, than with 10% non-extracted meal. This suggests that 10% inclusion of flour or water extracted meal may have potential for further investigation.  相似文献   
984.
Contents Surface charge accumulation and its decay at a GIS spacer are studied at atmospheric conditions employing a two step-calibration method. The results show that the accumulation saturates within 30 minutes; the dominant mechanism of surface charge accumulation is the drift of charged particles via air, while that of the decay is surface conduction. The characteristics are similar at both polarities.
Sättigungskonzentration und Abklingverhalten der Oberflächenladung an einem mit Gleichspannung beanspruchten Abstandshalter unter atmosphärischen Bedingungen
Übersicht Die Konzentration und das Abklingen von Oberflächenladungen an einem GIS Abstandshalter wurden unter atmosphärischen Bedingungen mit Hilfe eines zweistufigen Kalibrierungsverfahrens untersucht. Die Ergebnisse zeigen eine Sättigung der Ladungskonzentration innerhalb von 30 Minuten. Als Hauptursache der Ladungskonzentration ist die Drift geladener Teilchen in Luft anzusehen, während das Abklingen auf die Oberflächenleitung zurückzuführen ist. Ähnliche Charakteristiken ergeben sich mit beiden Polaritäten.
  相似文献   
985.
A cable fault location instrument based on the detection of traveling wave currents was developed. It is different from the conventional pulse radar method based on voltage detection. Measurement is automated, and the distance to the fault point is displayed by merely pushing a switch. In a branched or crossbonded line, the fault point can be located without interference from the branched or the crossbonded point. Tests performed in both real and simulated lines confirmed the practical utility of this instrument  相似文献   
986.
987.
It is shown that the degree of the stress-strain state created by temperature field can be estimated by using the electromechanical conversion phenomenon. It is established that the electromagnetic response to impact excitation of composite materials is a structure-sensitive characteristic.  相似文献   
988.
The authors describe a case of one patient who underwent duodenocephalopancreasectomy for CBD cancer 6 years ago and developed gastrointestinal bleeding caused by a fistula between the hepatic artery and the jejunal stump. They discuss the differential diagnosis problem in the gastrointestinal bleeding syndrome caused by this rare pathology.  相似文献   
989.
The regular associated solution model for binary systems has been modified by incorporating the size of the complex as an explicit variable. The thermodynamic properties of the liquid alloy and the interactions between theA μB type of complex and the unassociated atoms in anA-B binary have been evaluated as a function of relative size of the complex using the activity coefficients at infinite dilution and activity data at one other composition in the binary. The computational procedure adopted for determining the concentration of clusters and interaction energies in the associated liquid is similar to that proposed by Lele and Rao. The analysis has been applied to the thermodynamic mixing functions of liquid Al-Ca alloys believed to contain Al2Ca associates. It is found that the size of the cluster significantly affects the interaction energies between the complex and the unassociated atoms, while the equilibrium constant and enthalpy change for the association reaction exhibit only minor variation, when the equations are fitted to experimental data. The interaction energy between unassociated free atoms remains virtually unaltered as the size of the complex is varied between extreme values. Accurate data on free energy, enthalpy, and volume of mixing at the same temperature on alloy systems with compound forming tendency would permit a rigorous test of the proposed model.  相似文献   
990.
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