Thermal properties of fats and oils. VIII. Specific heats,heats of fusion,and entropy of alpha and beta tung oils

Summary Beta tung oil belongs to that group of substances which are capable of existing in more than one crystalline form, each of which has a distinet melting point. Three different melting points of the beta tung oil were observed, each dependent upon the rate of cooling. Forms I, II, and III have been used to distinguish beta tung oil melting at 52.8°, 44°, and 28° C., respectively. Equations were developed to express in cals./g./°C. the specific heats of the stable forms of tung oil. Alpha tung oil Solid state (−184° to −43°C.)C _p =0.404+0.001t Liquid state (9° to 80°C.)C _p =0.463+0.0011t Beta tung oil Solid state (−178° to 27°C.)C _p =0.390+0.0013t Liquid state (67° to 87° C.)C _p =0.489+0.00016t The specific heat of beta tung oil was found to be higher when the sample was rapidly cooled than when it was slowly cooled or tempered. The heat of fusion of the beta form of tung oil was caleulated to be 16.12 cals./g., and for the alpha form to be 21.02 cals./g. Entropies at 298.16°K. were 231.04 and 252.15 entropy units for the two forms of these oils, respectively. The liquid glycerides present at any temperature in the melting range were estimated from the data for the heat contents of the oils. The rate of liquidphase formation at constant heat input of both alpha and beta tung oils, unlike that of cottonseed and peanut oils, increased sharply during the final 10° of the interval owing to the greater homogeneity of the glycerides of the former. A report of a study made under the Research and Marketing Act of 1946. One of the laboratories of the Bureau of Agricultural and Industrial Chemistry, Agricultural Research Administration. U. S. Department of Agriculture.     

纱线扭结行为的新测试方法

新研发的ITV纱线扭结测试仪的问世,第一次使批量测试成为可能,还使对纱线扭结行为的测试结果具有了统计学上的重要意义。该仪器除能对纱线扭结行为进行测试外,还能分析不同纱线参数对纱线扭结的影响。此外,判断蒸汽定型对纱线扭结行为的影响是一项重要的研究内容,因为其直接与节能降耗有关。     

长丝纱上浆的新工艺

介绍了德国邓肯道夫纺织工艺研究所完成的研究工作。该课题包括长丝纱上浆前的预洗除杂、高速上浆、烘干,以及新型浆料的开发。     

Abstracts

Journal of the American Oil Chemists' Society -     

室内装饰织物用新型"atmofil"DSE纱线

介绍了用涡流包覆变形工艺和喷气变形工艺生产差异收缩自伸长纱线(DSE).分析了DSE纱线的结构和加工性能.     

Survey of Fusarium toxins in foodstuffs of plant origin marketed in Germany

A total of 219 samples of foodstuffs of plant origin, consisting of grain-based food, pseudocereals and gluten-free food as well as vegetables, fruits, oilseeds and nuts, were randomly collected during 2000 and 2001 in food and health food stores. A spectra of 13 trichothecene toxins including diacetoxyscirpenol (DAS), 15-monoacetoxyscirpenol (MAS), scirpentriol (SCIRP), T-2 and HT-2 toxins (T-2, HT-2), T-2 triol, T-2 tetraol, neosolaniol (NEO) of the A-type as well as deoxynivalenol (DON), 3- and 15-acetyl-DON (3-, 15-ADON), nivalenol (NIV), and fusarenon-X (FUS-X) of the B-type were determined by gas chromatography/mass spectrometry. Analysis of zearalenone (ZEA), alpha- and beta-zearalenol (alpha- and beta-ZOL) was made by high-performance liquid chromatography with fluorescence and UV-detection. Detection limits ranged between 1 and 19 microg/kg. Out of 84 samples of cereal-based including gluten-free foods, 60 samples were positive for at least one of the toxins DON, 15-ADON, 3-ADON, NIV, T-2, HT-2, T-2 tetraol and ZEA, with incidences at 57%, 13%, 1%, 10%, 12%, 37%, 4% and 38%, respectively, whereas SCIRP and its derivatives MAS and DAS, T-2 triol, Fus-X as well as alpha- and beta-ZOL were not detected in any sample of this subgroup. Contents of DON ranged between 8 and 389 microg/kg, for all other toxins determined concentrations were below 100 microg/kg. The pseudocereals amaranth, quinoa and buckwheat were free of the toxins investigated. Ten of 85 samples of vegetables and fruits were toxin positive. ZEA and the type A trichothecenes MAS, SCIRP, DAS, HT-2 were detected in 7, 3, 2, 1 and 1 samples, respectively. Out of 35 samples of oilseeds and nuts, 7 samples were toxin positive. HT-2, T-2 and ZEA were detected in 4, 3 and 4 samples, respectively. In vegetables and fruits as well as in oilseeds and nuts, toxin levels were below 50 microg/kg. None of the B-type trichothecenes analysed was found for both subgroups.