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31.
The possibility of using the oil-point and compression tests for evaluation of dried rapeseeds processability was examined. Seeds of initial moisture 10, 14, 18 and 22% (w/w) were dried at 60, 80, 100 and 120°C to a final moisture of 6·5% (w/w). The values of pressure ( P 0 ), work ( L 0 ) and strain (ε0) determined by the oil-point test, and pressure at strain ε=0·45 mm mm−1 ( Pε ) and degree of elasticity ( D ) determined by the compression test for bulk dried seeds differed markedly from those found for non-dried seeds. The P 0 , L 0 and Pε values were strongly correlated with the initial moisture of rapeseeds and drying temperature. All the strain values (ε0) were lower than those for non-dried seeds, and their changes depended solely on the initial moisture of seeds. Changes in the degree of elasticity were irregular and did not reach the value characteristic for overdried seeds, ie 100%. High correlation of the agglomeration test data (Δ1–3 values) with those of the P 0 , L 0 and Pε made it possible to develop appropriate equations that proved the usefulness of the variables for determining the dried rapeseed processability.  相似文献   
32.
Jadwiga Wie&#x;ckowska 《Fuel》1978,57(12):781-784
These studies concern residues of the vacuum petroleum distillation of crude oil, used as binders for briquetting comminuted materials. The residues have been separated into the group components asphaltenes, resins, and oils. Chemical analyses of these components and calculations of some structural parameters by means of the Hazelwood and van Krevelen methods have been carried out on all these materials in order to indicate differences between the residues. The chemical constitutions of the binders examined do not differ basically but there are differences between some physical and rheological properties (viscosity, ductility), electrical properties (specific resistance, dielectric loss factor) and in molar refraction and in the carbon aromaticity (from volatile matter).  相似文献   
33.
Thirteen edible oils: sunflower, avocado, hemp, high-linolenic flax, low-linolenic flax, safflower, walnut, roasted sesame, rice, corn, rapeseed, pumpkin seed, and hazel were studied in this work. Their fatty acid composition, iodine, acidic, peroxide, and saponification values were determined. Infrared and Raman spectra of the oils were recorded in the range 400–3200 cm?1. The integral intensities of the bands at about 1655 and 2852 cm?1 corresponding to ν(C=C) and ν(CH2) vibrations were evaluated and used to construct a relationship between the spectroscopic data and the iodine value. The following linear dependencies were obtained: Iν(C=C)/Iν(CH2) = 7.449 × 10?4 × iodine value – 0.0339 and Iν(C=C)/Iν(CH2) = 9.299 × 10?4 × iodine value – 0.023 for the infrared and Raman spectra with a correlation coefficient 0.988 and 0.976, respectively. These calibration lines can be used to determine the iodine value for oils with unknown unsaturation level, and may be applied for margarines and other fatty materials.  相似文献   
34.
Articular cartilage dysfunctions are major cause of pain and disability and lead to serious health complications. Cell-based therapies are proposed as treatment methods for cartilage regeneration. In this study, we proposed polyurethane/poly(L-lactide-co-D, L-lactide)-based electrospun nonwovens as carriers for the delivery of human adipose-derived stromal stem cells. We found that 6:4 and 8:2 polyurethane/poly(L-lactide-co-D, L-lactide) initially enhance proliferative rate of human adipose-derived stromal stem cells, shorten their population doubling time, promote creation of functional chondrogenic nodules during chondrogenic differentiation, improve the collagen-2-to-collagen-1 protein ratio, and upregulate the expression of collagen-2 and aggrecan genes.  相似文献   
35.
36.
The results of an investigation of the composition of the residual atmosphere in an open vacuum and inside a quasiclosed volume during electron-beam vaporization of molybdenum and niobium are presented.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 46, No. 6, pp. 949–952, June 1984.  相似文献   
37.
The taste responsiveness of six squirrel monkeys, five pigtail macaques, four olive baboons, and four spider monkeys to polycose, a starch-derived polysaccharide, was assessed in two-bottle preference tests of brief duration (2 min). In experiment 1, the monkeys were given the choice between tap water and defined concentrations of polycose dissolved in tap water. In experiment 2, the animals were given the choice between polycose and sucrose, fructose, glucose, lactose, and maltose presented in equimolar concentrations of 100 and 200 mM, respectively. The animals were found to prefer concentrations of polycose as low as 10 mM (pigtail macaques), 30 mM (olive baboons and spider monkeys), and 60 mM (squirrel monkeys) over tap water. Relative taste preferences were stable across the concentrations tested and indicate an order of relative effectiveness (sucrose > polycose maltose) in squirrel monkeys, spider monkeys, and olive baboons that is similar to the order of relative sweetness in humans. Pigtail macaques, however, displayed an order of relative effectiveness (maltose > polycose sucrose) that differs markedly from that found in the other primate species tested and is similar to relative taste preferences found in rodents such as rats. Both the high sensitivity of the pigtail macaques to polycose and their vivid predilection for this polysaccharide and its disaccharide constituent maltose suggest that Macaca nemestrina, unlike other primates, but like rodents, may have specialized taste receptors for starch.  相似文献   
38.
Jadwiga Wieckowska 《Fuel》1980,59(3):190-196
Changes of composition, structure, and contents of some functional groups, of oils from petroleum binders, in relation to temperature of carbonization from about 710 K to 1200 K have been investigated. Oils from carbonization of petroleum binders are of hydrocarbon type, and their elemental compositions are almost independent of carbonization temperature. During the thermal decomposition of these binders, about 75–80 wt % of gaseous and vapour products are emitted. As carbonization temperature increases, molecular weights of the oils increase from about 250 to about 290; their density, index of refraction, and molar refraction increase. Structural analysis of the oils showed that they contained about 30% of cyclic hydrocarbons (aromatic and cycloalkane) as well as alkanes. The number of rings in the average structural unit of oil increases with increase of carbonization temperature, especially the number of aromatic rings. About 60–70 vol % distills before 633 K under atmospheric pressure; the distillate is paraffinic, while the residue after distillation is aromatic-alicyclic. Oils from carbonization of P-70 asphalt have similar compositions and chemical natures, but lower molecular weights, than oils from carbonization of residues after vacuum distillation of crude oil. Oils from carbonization of pitch are decidedly aromatic.  相似文献   
39.
Feed control is essential for the safety of animal-origin food. It is estimated that more than 80% of human exposure to dioxins and related compounds comes from the consumption of animal-origin food, and farm animals are exposed to dioxins mainly through the feed. A monitoring programme for dioxins (polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs)) and dioxin-like polychlorinated biphenyls (DL-PCBs) was conducted in the Polish feed market between 2004 and 2017. Using two complementary ISO 17025-accredited analytical methods (bioassay and high-resolution gas chromatography/high-resolution mass spectrometry (HRGC/HRMS)), 2919 samples of plant, animal and minerals origin were analysed. The total number of samples exceeding the maximum limit (ML) was 52, which is 1.8% of all tested samples. They all contained PCDD/Fs in concentrations over the ML, and in 16 samples the limit for the sum of PCDD/F/DL-PCBs was also exceeded. The highest dioxins level was found in feedstuffs derived from Baltic fish; the fish oil was followed by fish meal. Low-chlorinated furans (2.3,7,8 TCDF, 2,3,4,7,8-PCDF and 1,2,3,7,8-PeCDF) were dominant and these congeners accounted for the toxicity expressed in WHO toxic equivalents (WHO-TEQ). In this category, 155 out of the 498 samples (32%) exceeded the action threshold (AT) for PCDD/Fs and in 10 samples (2.0%) for DL-PCBs. Non-compliant fish meals were found in 34 (5.6%) of the tested samples, in 0.7% of compound feeds, and in 1.5% of plant-origin materials. Seven dried plant-derived materials contained PCDD/F level above ML, including alfalfa, maize, apple, basil and beet pulp pellets containing molasses. The dry vegetable materials were mostly contaminated by the 2,3,7,8-furans, the congeners arising from a faulty drying process. No significant time trend can be seen. From the obtained results, it can be concluded that concentrations of PCDD/Fs and DL-PCBs in Polish feed materials were sufficiently low to ensure low concentrations in animal-derived products.  相似文献   
40.
The aim of this investigation was to analyse the composition of dietary fibre from aronia pomace preparations and to evaluate its influence on cadmium and magnesium binding. The authors wanted also to estimate to what extent additional enzymatic processing could affect the sorption capacity of the aronia fibre.  相似文献   
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