Fat, Protein, and Mineral Components of Added Ingredients Affect Flavor Qualities of Tomato Soups

Ten tomato soups were prepared with deionized, distilled water, skim or whole milk, or deionized, distilled water with added fat (corn oil), protein (calcium caseinate), and/or minerals (NaCl, KCl, CaCl₂) to equal the composition of whole milk. Tomato soups prepared with whole or skim milk were perceived as sweetest by a sensory panel of 12 trained subjects. Salt taste was probably masked by sweetness from lactose in milk. Added minerals may have increased saltiness either by adding to total Na⁺ content or by freeing Na⁺ from other ingredients making it more available for perception. Saltiness was suppressed by added protein, which increased pH, and may have affected Na⁺ binding. Salt taste intensity correlated positively with tomato flavor.     

Thickening Agents Effects on Sodium Binding and Other Taste Qualities of Soup Systems

Low sodium chicken broth with NaCl added to provide Na⁺ concentrations in typical reduced Na⁺ soups (144 and 288 mg Na⁺/240 mL serving) was thickened with commonly used gum, starch, or flour food additives. Xanthan gum suppressed saltiness as the result of ionic binding of Na⁺, as determined by sensory evaluation and ²³Na NMR spectroscopy. Saltiness was affected by added NaCl (p = 0.0001), thickener (p < 0.01), and added NaCl* thickener (p < 0.01), and positively correlated with chicken and overall flavors (p = 0.0001). Cornstarch provided body, no suppression of salt taste, and the greatest salt enhancement of chicken and overall flavors. In complex food systems, temperature and other factors affected Na⁺ binding as measured by NMR pointing to the need for a new model.     

Compositional Analysis of Oil Samples Implicated in the Spanish Toxic Oil Syndrome

A selected group of 195 oils from the Spanish “Toxic Oil” Syndrome (TOS) epidemic including 29 high-probability “case” and 64 “control” oils were examined to investigate the relationship between oil composition and the risk of TOS. As indicated by fatty acid and sterol patterns, the presence of rapeseed oil was significantly more prevalent in the case than in the control oils, but fatty acid anilides were the most useful markers of case-related samples. Anilides were detected in 62% of case oils and at lower concentrations in 23% of the control samples. The ratios of individual anilides were quite constant in these oils and most consistent with their formation in the original (undiluted) rapeseed oil.     

The effect of a residual stress field on fracture initiation in RPV steel

Whether flaws in structures containing residual (secondary) stresses will extend under particular operational (primary) loads depends on the extent to which the residual stress field affects: (a) the nature and distribution of initiators; (b) the combined (primary + secondary) stresses and strains experienced by potential initiators. This paper compares fractographic data from specimens loaded by only a primary stress with data from specimens also containing a tensile residual stress field. Three‐dimensional elastic–plastic finite element calculations are used to characterize the stress–strain conditions at the initiation sites at the onset of brittle fracture. The introduction of a residual stress changes the dominant stage in fracture nucleation from microcrack extension to particle cracking. This offsets some of the decrease in fracture toughness expected when the residual stress field increases specimen constraint.     

Residual stress and constraint effects on cleavage fracture in the transition temperature regime

Defects in structural components are often associated with welds that may contain significant levels of residual stress. Whilst the primary load acting on the component may induce low constraint conditions at the crack tip, the presence of residual stresses, e.g. due to welding, can modify this constraint level and consequently influence the observed fracture toughness behaviour. This paper presents the results of a combined experimental and numerical programme aimed at exploring this issue. Cleavage fracture toughness data for high and low constraint specimens are presented with and without residual stresses. The results indicate that under certain conditions, the constraint-induced increase in cleavage fracture toughness may be eroded by the presence of a residual stress in the vicinity of the crack. The results are quantified with respect to two-parameter fracture mechanics in which the  T  and  Q  parameters are appropriately defined. Preliminary guidance is provided for the assessment of defects when residual stresses may influence crack-tip constraint.     

Measurement and modelling of residual stress effects on cracks

Defects that form by mechanisms such as fatigue and stress corrosion cracking are influenced both by external loads on engineering structures and internal, residual stresses that are generated during the manufacture and operation. This paper describes a programme of experimental and analytical work on a high‐strength, low‐toughness aluminium alloy (AL2024‐T351) to assess the influence of residual stress on crack opening displacement (COD) and crack‐driving force (CDF) for a range of fatigue crack lengths in compact tension (CT) specimens containing a mechanically induced residual stress field. Comparison of experimentally measured and numerically predicted CODs, at the mid‐plane and surface of CT specimens, show generally good agreement for cracks introduced into the finite‐element model in a progressive, element‐by‐element manner. Cracks introduced in a simultaneous manner give larger than observed CODs. The CDFs for the progressively introduced crack are always smaller than for simultaneously introduced. These results have implications for the assessment of initiation for slowly growing cracks.     

Wheat-area estimation using digital LANDSAT MSS data and aerial photographs

Abstract

A procedure to estimate wheat (Triticum aestivum L) area using a sampling technique based on aerial photographs and digital LANDSAT MSS data was developed. Aerial photographs covering 720km2 were visually analysed. Computer classification of LANDSAT MSS data acquired on 4 September 1979 was performed using unsupervised and supervised algorithms and the classification results were spatially filtered using a post-processing technique. To estimate wheal area, a regression approach was applied using different sample sizes and various sampling units. Based on four decision criteria proposed in this study, it was concluded that (i) as the size of the sampling unit decreased, the percentage of the sample area required to obtain a similar estimation performance also decreased, (ii) the lowest percentage of the area sampled for wheat estimation under established precision and accuracy criteria through regression estimation was 13-09 per cent using 10 km2 as the sampling unit and (iii) wheat-area estimation obtained by regression estimation was more precise and accurate than those obtained by a direct expansion method.