A NOVEL METHOD FOR MEASURING TEXTURE USING A FOOD PROCESSOR

ABSTRACTMeasurement of food texture is becoming increasingly important to help prevent mis-swallowing in elderly individuals. However, it is difficult to estimate food texture for mastication and swallowing. In this study, a mixing-recording method was applied to measure food texture. A commercial food processor was used to homogenize food gels, and the torque was monitored as an electric current value, which was correlated with the viscosity of Newtonian fluid. Agar and gelatin gels at several concentrations were applied to the mixing-recording system, and individual mixing curves were obtained. The current values had a different tendency at each mixing stage. At the beginning of the mixing, when lumps of the original gel were present, current values of gelatin were higher than those of agar. From the middle of mixing, the fractured pastes of high-concentration agar gels had little mobility, and current values decreased, indicating that gelatin was more cohesive than agar. The current values of low-concentration agar and gelatin were correlated with the hardness of the gels and were aligned on the same correlation curve, indicating that the viscosity of the fractured paste was correlated with the original gel hardness under certain conditions. Moreover, measurements of agar gels of different sizes revealed that the texture was size dependent. Thus, the mixing-recording method had several advantages over conventional methods, including time- and size-dependent fracturing and bolus properties, and could be useful for the measurement of food texture in terms of mastication and swallowing.

Influence of Hydrodynamic Structure on Mixing Time of Alloy Additions with Liquid Steel in One Strand Tundish

The knowledge of the hydrodynamic pattern aids in designing new and modernizing existing tundishes. The device under examination is an one-strand tundish of a capacity of 30 Mg. Computer simulation of the liquid steel flow, tracer and alloy addition behaviour in turbulent motion conditions was done using the Ansys-Fluent®computer program. The hydrodynamic conditions of steel flow were determined based on the distribution of the characteristics of tundish liquid steel residence time distribution (RTD). The alloy addition was introduced to the liquid steel by the pulse-step method. Based on computer simulations carried out, steel flow fields and RTD and mixing curves were obtained, and the shares of stagnant volume flow and active flow and the mixing time were computed. Dispersion of the alloy addition in liquid steel during its flow through the tundish is a dynamic process which is determined by the hydrodynamic conditions occurring in the tundish working space.

Chemical Homogenization Of Liquid Steel Flowed Through Continuous Casting Slab Tundish During Alloying Process

This paper presents the results of research on the behaviour of an alloy addition in steel flowing through the tundish used for casting slabs. The device under examination is a wedge-shaped single-nozzle tundish of a capacity of 30 Mg. Due to the complexity of alloy addition dissolution and dispersion in metallurgical processes, a decision was made to use the Species Model available within the Ansys-Fluent®program. For describing the turbulence, the Realizable k-ɛmodel was chosen. By defining the heat losses on respective planes making up the virtual model, the non-isothermal conditions existing during the flow of liquid steel through the tundish were considered. From the performed numerical simulations, the fields of steel flow and steel temperature and alloy addition concentration in the tundish working space were obtained. In order to accurately illustrate the process of chemical homogenization in the tundish working space, mixing curves were recorded. Based on the obtained results (mixing curves), the mixing time needed for achieving the 95% level of chemical homogenization was calculated.

Temporal Variability in the Quality of Produced Water from Wells Tapping the Ozark Aquifer of Southeast Kansas

State and local agencies have become concerned that the available water supply from the Ozark aquifer in the Tri-state region of southeast Kansas, southwest Missouri, and northeastern Oklahoma may become unusable or require additional water treatment because of deteriorating quality resulting from overdevelopment. Many southwest Missouri and southeast Kansas water supplies withdraw water from a 30-60-mi (48-96-km)-wide transition zone in the Ozark aquifer that separates calcium, magnesium-bicarbonate ground water with low dissolved solids to the east from sodium-chloride brines to the west. Water-quality deterioration within the transition zone could potentially come about as a result of eastward migration or upward movement from deeper horizons of saline water. This study assessed variability in the quality of water produced from wells within the transition zone in southeast Kansas across a variety of time scales. Water samples were collected monthly from nine wells located in the transition zone over a two-year period and frequently during two 50+ hr chemical-quality pumping tests of Pittsburg well 8. The samples were analyzed for conductance and pH, and all major and selected minor dissolved inorganic constituents. Mixing curves of chloride versus bicarbonate/chloride ratio and chloride versus sodium/chloride ratio demonstrate that the produced water from Ozark aquifer wells is a mixture of low dissolved solids, calcium, magnesium-bicarbonate ground waters and sodium-chloride brines. Produced water from wells tapping sources in the Ozark and the overlying Springfield Plateau aquifers is a blend of waters from these sources, although the data suggest that the contribution from the Springfield is small relative to the Ozark aquifer. Fluctuations in the quality of the produced water during pumping most likely result from complex mixing of waters of differing quality from different parts of the Ozark aquifer within the well bore. This is borne out by bicarbonate/chloride ratio versus chloride concentration mixing curves and the dissolved constituent ratios indicative of bicarbonate and sodium in excess of that required to balance calcium + magnesium and chloride, respectively. Comparison of the 1979-1980 data with the 2006-08 data from this project indicates that the chloride concentration in some of the sampled supplies has increased. Based on extrapolation of the maximum estimated rate of chloride concentration increase, the earliest that water from Pittsburg wells 8 and 10 would exceed the recommended drinking water limit for chloride is estimated to be by the years 2045 and 2060, respectively, assuming continuation of the present rates of pumping.

Excess properties (VE, εE, and HE) of the binary system pyridine (1) + sulfolane (2)

Volumes of mixing and dielectric constants of the binary system pyridine (1) + sulfolane (2) were measured over the entire composition range, 0 ≤ x ≤ 1, at selected temperatures ranging between 293.16 and 323.16 K. Mixing enthalpies were also measured at 303.16 K. Deviations from ideality of the measured properties are consistent with the regular behaviour of sulfolane systems, as evidenced by previous works. Nevertheless the occurrence, in the pyridine-rich region, of a sharp maximum in excess dielectric constants versus composition curves, and of a deep minimum in enthalpies of mixing curves, substantiates the supposition that small dipolar interactions occur between molecules of the components. These steadily decrease in magnitude with increasing temperature and sulfolane content in solution.

Enzymatic and Physical Studies on the Triplex dTn∙dAn∙rUn

The triplex dTn∙dAn∙rUn was studied as a model system both enzymatically and physically with a view that a rational approach for attempting to isolate triplexes from in vivo situations might emerge. The triplex was characterized by mixing curves and by its equilibrium buoyant density. In 5 mM Na phosphate, pH 7.3, for KCl concentrations below 0.4 M the triplex dissociated into dTn∙dAn + rUn, dissociation being complete at about 0.3 M KCl. If MgCl2 replaced KCl a strongly cooperative dissociation occurred at 1 mM MgCl2. Whereas with alkaline titration of dTn∙dAn∙rUn, rUn was dissociated first followed by dTn∙dAn, acidic titration resulted in the whole triplex dissociating together. Both transcription and replication of dTn∙dAn were strongly inhibited by formation of a triplex. The DNA and RNA moieties in the triplex are somewhat protected against DNase I and pancreatic RNase degradation, when compared with duplex dTn∙dAn or rUn. Spermine binds equally well to dTn∙dAn and dTn∙dAn∙rUn which is consistent with spermine binding in the minor groove and RNA in the major groove of DNA.