Quantitative determination of traces of free gossypol in fats,oils, and fatty acids by paper chromatography

Summary A quantitative method for the determination of traces of free gossypol in oils and fatty acids was developed. The method is based on the concentration of gossypol by extraction and quantitative paper chromatography of the extract. The method is specific for free gossypol and is not subject to interferences. The new method is both accurate and reproducible. The lower limit of detection is 10 p.p.m. The method is intended primarily for p.p.m. levels but is suitable for all concentrations. With slight modifications the method is applicable to meals. Presented at the fall meeting of the American Oil Chemists’ Society, Cincinnati, O., September 30 to October 2, 1957.     

On the use of a synthetic online/batch workload for computer selection

The overall evaluation and decision process for the selection of a new computer system for the universities at Graz using a mixed synthetic online/batch workload is described. In particular the method for defining this workload for the evaluation process is explained. Furthermore the possibility of constructing assessment functions, that can be used for the comparison of different systems, is discussed.     

Effect of the addition of hardfats on the physical properties of cocoa butter

Fully hydrogenated oils, also known as hardfats, are currently employed in a limited number of applications in the food and chemical industries. The use of these compounds has been proposed for the improvement or standardization of the physical properties of lipid systems, showing great potential for use in the production of chocolate, confectionery, and similar products. This work evaluated the addition of different hardfats on the physicochemical properties of cocoa butter (CB). Fully hydrogenated oils with significantly different chemical composition, obtained from palm kernel oil (FHPKO), palm oil (FHPO), cottonseed oil (FHCO), soybean oil (FHSO), and crambe oil (FHCrO), were evaluated for their fatty acid and triacylglycerol compositions. Blends of CB/hardfats, at concentrations of 1, 3, and 5% w/w were studied by determining the melting point, solid fat profiles, microstructure, and consistency. Hardfats FHPO, FHCO, FHSO e FHCrO proved to be effective additives to modulate the physical properties of CB. Major changes on the physical properties of CB were performed by the FHSO. FHPKO was found unsatisfactory as a modifier of the CB. Practical applications : The use of hardfats as crystallization additives in products containing CB is here recommended for technological adjustments of CB formulations in relation to attributes like heat resistance and hardness, often necessary when commercialized in regions of warm climates or with large variation in temperature. The hardfats may act as potential modulators of CB crystallization, aiming to obtain higher quality products and significant cost reduction of industrial processing.     

Hypothesis generation guided by co-word clustering

Co-word analysis was applied to keywords assigned to MEDLINE documents contained in sets of complementary but disjoint literatures. In strategical diagrams of disjoint literatures, based on internal density and external centrality of keyword-containing clusters, intermediate terms (linking the disjoint partners) were found in regions of below-median centrality and density. Terms representing the disjoint literature themes were found in close vicinity in strategical diagrams of intermediate literatures. Based on centrality-density ratios, characteristic values were found which allow a rapid identification of clusters containing possible intermediate and disjoint partner terms. Applied to the already investigated disjoint pairs Raynaud"s Disease - Fish Oil, Migraine - Magnesium, the method readily detected known and unknown (but relevant) intermediate and disjoint partner terms. Application of the method to the literature on Prions led to Manganese as possible disjoint partner term. It is concluded that co-word clustering is a powerful method for literature-based hypothesis generation and knowledge discovery.     

Temperature derivative of the pressure of4He at the superfluid transition

We present new measurements of the temperature derivative of the pressure along the superfluid transition line in ⁴ He near saturated vapor pressure. These results indicate that the second derivative (₂P/PT) is finite at saturated vapor pressure. The data agree with earlier measurements by Kierstead.     

A High-Resolution Thermometer for the Range 1.6 to 5 K

This paper presents a detailed design, a theoretical analysis, and experimental tests of a high-resolution thermometer for use in the temperature range from 1.6 to 5 K. The device uses a dc-SQUID magnetometer to determine the change in magnetization with temperature of a paramagnetic salt in a magnetic field. The field is provided by a small permanent magnet attached to the thermometer. Measurements of the sensitivity of the device agree well with the theoretical analysis. Near 2.17 K (the superfluid transition of ⁴ He at saturated vapor pressure) the thermometer has a specific sensitivity of 4000 ₀ /K Gauss. There it achieves a temperature resolution better than 10 ^–9 K when it is charged with a field of about 300 Gauss. At 4.2 K, the specific sensitivity is smaller by a factor of 50, but should still allow temperature measurements with a resolution better than 10 ^–7 K. Near 2.17 K, drifts of the device are below the level of 10 ^–13 K/s. The thermometer has a small mass of about 7 g (excluding the magnet), and thus the advantage of relatively small cosmic radiation heating during microgravity experiments in Earth orbit.     

Second sound very near Tλ

The results of an experimental investigation of the evolution of planar, non-linear, second-sound pulses in superfluid⁴He, to within 650 nK of the -transition, are presented. A new method for extracting the second-sound velocity and damping is demonstrated. As predicted from two-fluid hydrodynamics, the pulses are well modeled by the solutions of Burgers' equation. The second-sound velocity (u ₂₀) and damping (D ₂) are extracted from fits of the model to the data. Damping data are obtained in this fashion to 3×10^–7 in reduced temperature at saturated vapor pressure; nearly two decades closer to T then any previous measurements. The superfluid density is extracted from theu ₂₀ measurements and the critical exponent, , is determined. A study of very large amplitude pulses near T is also presented. These pulses extend well beyond the range of validity of Burgers' equation. The amplitude of the shock that forms at the trailing edge of the pulse is observed to saturate as a function of heater power and then decrease suddenly, as has been previously observed away from T. However, the pulse shapes are quite different from any previously observed.     

Multistage and tandem mass spectrometry of glycosylated triterpenoid saponins isolated from Bacopa monnieri: comparison of the information content provided by different techniques

Whereas all state-of-the-art techniques in mass spectrometry (MS) have been extensively applied to oligosaccharides derived from glycoproteins, less effort has been devoted to the analysis of smaller glycoconjugates. In the present study, the application of a variety of MS techniques for the analysis of two dammarane-type triterpenoid saponins isolated from B. monnieri is reported. The structural information provided by ESI-ion trap (IT)-, AP-MALDI-IT-, and MALDI-IT/reflectron time-of-flight (RTOF)-MS, all utilizing low-energy collision-induced dissociation (CID), and MALDI-TOF/RTOF-MS, facilitating postsource decay and high-energy CID analysis, was compared. The applied desorption/ionization technique does not influence the fragmentation of identical precursor ions in low-energy CID. All three fragmentation techniques clearly yield the sequence and branching of the glycan moiety as well as the molecular mass of the intact aglycon. Cross-ring cleavage of the branching sugar, which gives some information about the sugar linkages, was mainly observed in low-energy CID. High-energy CID, on the other hand, yielded some additional diagnostic fragment ions from the aglycon moiety. Internal cleavage ions are formed by alternative mechanisms in high-energy CID and are assumed to be diagnostic for some linkages. However, none of the applied MS techniques facilitates the identification of those saponins that differ only by their aglycon moiety (i.e., jujubogenin or pseudojujubogenin).