Search Results
The objective of the research was to obtain aerated gels by magnesium and iron(II) ion induced gelation of preheated whey protein isolate dispersions. Preliminary research allowed finding conditions of the pH, protein, and ion concentrations to produce aerated gels capable of holding air bubbles. A novel method applying gelation and aeration process simultaneously was used. Aeration using a laboratory mixer at 2000 r.p.m. produced stronger aerated gels than using a homogenizer at 8000 r.p.m. The gelation process was monitored using an ultrasound viscometer and a constant increase of dynamic viscosity was noted. A different aerated gel microstructure was observed for magnesium and iron(II) induced gels, which probably resulted in differences in the texture and viscosity, as well. The aeration process decreased hardness. In some cases texture parameters correlated with the viscosity measured using an ultrasound viscometer. Aerated whey protein gels could be applied as matrices for food applications or to controlled release of active ingredients.
According to international studies the consumer preference of apple varieties is defined by the flavour and texture and the consumers’ opinion about the heavily sour character, the mushy texture and the barely chewable peel is negative. However, the preference level and nutritional values of the apple juices are determined by the variety used, the maturity level and the processing of the fruits. In our study we conducted the external and internal preference mapping of two apple juices with 100% fruit content according to the industrial practice. It propounded several questions about the method of the preference mapping which were the following: product specific training of the assessors, panel performance monitoring, number of samples, representativity, scale use and marking, reasons of the singular matrix, segmentation method, segmentation criterion, power of the paired post-hoc analysis, number of the principal components (PC’s), etc. Finding the answers of the questions above it is possible to establish a good preference mapping practice.
The climatology of soil respiration in Hungary is presented. Soil respiration is estimated by a Thornthwaite-based biogeochemical model using soil hydrophysical data and climatological fields of precipitation and air temperature. Soil respiration fields are analyzed for different soil textures (sand, sandy loam, loam, clay loam and clay) and time periods (year, growing season and months). Strong linear relationships were found between soil respiration and the actual evapotranspiration for annual and growing season time periods. In winter months soil respiration is well correlated with air temperature, while in summer months there is a quite variable relationship with water balance components. The strength of linear relationship between soil respiration and climatic variables is much better for coarser than for finer soil texture.
Abstract
Energy dispersive X-ray fluorescence spectroscopy is employed to determine the concentration of nineteen elements in seven profiles representing the aridisols and vertisols groups from agricultural plains of Sudan. A significant variation in the concentration of alkaline and alkaline earth elements in the different regions is observed, which is discussed in relation to the texture of the soil and climatic factors. Uranium, determined by the delayed neutron technique, is observed to increase with depth in one area.
Abstract
Light transmittance was measured during heating of thin NaPO3 glass plates at different heating rates. According to the results, the crystallization of orthorhombic textured NaPO3 glass proceeds from sample surfaces into their interior due to the foregoing surface nucleation. The glass surface crystallization process resulted in the sigmoidal decrease of the optical transmittance. Elaborated data lead to the activation energy of glass surface crystallization of the value of 182.8 kJ mol -1.
Summary
The amount and dislocation of the gamma-radionuclides (artificial cesium and natural potassium) in the Haplic podsol profiles of the Tatra Mountains have been described. These soils belong to the group of penetrable formations what is a result of their texture. They provide a good example of percolation and sorption possibilities of the radionuclides within the soil profile. The highest concentration of radionuclides has been detected in raw humus and spodic (illuvial humus-iron) layers, at the surface.
Abstract
The sintering and the structure of clinkers, modified by the introduction of different ionic forms of sulfur and phosphorus into the raw mix, were examined. One reference synthetic mixture and 25 modified mixtures were prepared by mixing the reference sample with 0.5, 1.0, 1.5, 2.0 and 2.5%w/w of chemical grade CaSO4, CaS, Ca3(PO4)2, CaHPO4 and Ca(H2PO4)2. Free lime content in all samples was measured. The sintering reactions in samples were recorded by means of differential thermal analysis. The texture of the clinkers was examined using a scanning electron microscope and EDX. It is concluded that, despite of their relatively low doping concentration in the raw mix, P and S affect considerably its reactivity and the texture of the clinker. The various ionic forms of the same element (SO4 2-, S2- for S, PO4 3-, HPO4 2- and H2PO4 - for P) exhibit a different and unequivocal effect on the reactivity of the synthetic raw mix and on the texture of the corresponding clinkers. S (in both forms) and P (added as HPO4 2-) are mainly dissolved in the melt and they have a positive effect on the burnability of the raw mix. P (added as PO4 3- or H2PO4-) is preferentially accumulated in belite. In this case further stabilization of β-C2S occurs and the binding of the free lime is hindered.
Abstract
We studied the chemical compatibility of Ag, Ag(In)alloy, Y2BaCuO5 (the so-called Y-211 green phase) and YBa2Cu3O7–δ (Y-123) phase in order to check if better grain growth and alignment with minimum contamination were possible during the Y-123melt texturing. We demonstrate that the addition of silver to Y-123 always led to an enhanced texture. The typical microstructure of the composite Y-123 plus Y-211 (that is believed essential for high critical currents in these High Tc superconductors) was not disturbed by addition of silver up to 7.5 wt%, while higher concentrations of metal led to a degradation of the texture. DTA–TG analysis was used to investigate the influence of Ag and Ag(In) alloy on the Y–Ba–Cu–O equilibria around the Y-123 phase. We found a very unexpected thermal behaviour, similar to an eutectic equilibrium, when the silver concentration was increased to35 wt%. We believe that this effect was essentially due to the increasingly higher concentration of silver that could react with the secondary phases present in the melt.
Abstract
The size distribution, elemental composition, shape and surface texture of harmattan particulates of distinctly located points have been examined. The characterized particle size ranges are 0.7–16.4 
m and 0.6–19.7 m for Kano and Ife, respectively. A total of 12 elements (Al, Si, P, S, Cl, K, Ca, Mn, Ti, Fe, Cu, and Zn) were detected with varying degrees of concentration. The plotted element concentration curves favored micron and submicron particle diameters. The particle shapes exhibit high/low sphericity. The plotted size distribution curves exhibited a marked downward shift in particle diameter from Kano to Ife.
Twenty Roman Age home-made sherds from Central Italian San Potito locality were studied by petrographic microscopic method. The ceramics were divided into five petrographic groups on the basis of their composition and structural-textural features. Two groups of the ceramics were tempered with clasts of alkaline volcanic origin, which seem to originate from Central-Italian volcanic territory components. The ceramics belonging to the other three groups contained large amounts of limestone and carbonatic fossils, the origin of the raw material was a marine clayish sediment, perhaps flysch.
