A study on the nickel-rich ternary Ti–Ni–Al shape memory alloys

The transformation sequence and hardening effects of 400 °C aged Ti47.5Ni50.65Al1.85 and Ti49.5Ni50.13Al0.37 shape memory alloys have been investigated by electrical resistivity tests, internal friction measurements, hardness tests and TEM observations. Both solution hardening and precipitation hardening are found to occur in these alloys. The hardening effects of Ti47.5Ni50.65Al1.85 alloy are obvious and much higher than those of Ti49.5Ni50.13Al0.37 alloy due to the former having the larger Ni/Ti ratio and a higher Al solute content in its matrix. The transformation sequence of 400 °C aged Ti47.5Ni50.65Al1.85 alloy shows B2↔R-phase only for an ageing time of more than 10 h and that of 400°C aged Ti49.5Ni50.13Al0.37 alloy shows the sequence B2↔R-phase↔B19′ or B2↔R-phase with different ageing times. All of these characteristics are associated with Ti11Ni14 precipitates during the ageing process. These aged Ti–Ni–Al alloys exhibit very good shape memory effects, in which the maximal shape recovery occurs at the peak of hardness. This revised version was published online in November 2006 with corrections to the Cover Date.     

Multipurpose controller design using parametric optimization with dynamic constraints

A systematic and effective design procedure for a class of linear multivariable feedback control systems is proposed For simultaneously achieving robust tracking of the prescribed input signal via the Q-parametrization approach and internal model principle, the prescribed transient specifications by choosing an appropriate performance criterion, robust stabilization, and sensitivity minimization. The problem can best be cast in the form of an optimization problem with dynamic constraints. A numerical method is formulated to solve the optimization problem with dynamic constraints using a non-linear programming method. A numerical example is provided to illustrate the main results of the paper.     

Application of the Persidskii theorem to non-linear system stabilization via dynamic output feedback

We consider the stabilization problem in the sense of Lyapunov of a class of ‘k-bounded’ non-linear systems via dynamic output feedback, where the non-linearities of the systems are not necessarily continuously differentiable but satisfy ‘k-bounded’ conditions. The factorization theory of linear systems and the quasi-stability result of Persidskii are combined to provide such a dynamic output feedback scheme.     

Analysis of Volatile Flavor Components in Steamed Rangia Clam by Dynamic Headspace Sampling and Simultaneous Distillation and Extraction

The volatile flavor components of steamed rangia clam (Rangia cuneata) were extracted by dynamic headspace sampling (DHS) and simultaneous distillation/extraction (SDE) techniques, and analyzed by gas chromatography/mass spectrometry (GC/MS) and GC-coupled aroma perception. Twenty-two heterocyclic aroma compounds were identified. Volatile flavor compounds in other chemical classes, such as aldehydes, alcohols, ketones, and terpenes, also were identified. The unique clam aromas were contributed by a combination of S-, and N- containing compounds and ketones. In general, sampling methods (DHS and SDE) complemented each other in compounds detected in the sample. However, SDE gave more information on characteristic steamed clam flavors.     

Factors Affecting Quality of Fish Oil Mayonnaise

Packaging conditions, antioxidants, metals, and storage temperature affected the quality of fish oil mayonnaise (FOM). TBHQ was a successful antioxidant but ascorbate was not. Nitrogen retarded oxidation more than TBHQ. The metal content of FO was as low as soy oil (SO), suggesting that differences in quality deterioration were not due to metal content. FOM was more stable at refrigerator temperatures (2°C) than at higher temperatures (30°C). The sensory quality of deodorized FOM was equal to SO mayonnaise using TBHQ (0.02%), nitrogen, and storing at 2°C for 14 wk.     

Identification and Quantification of the "Popcorn"-like Aroma in Louisiana Aromatic Delia Rice (Oryza sativa, L.)

The “popcorn” like aroma was identified as 2-acetyl-l-pyrroline. Cooked Delia white rice contained almost 300 ng 2-acetyl-1-pyrroline per g (dry weight) rice, while cooked Lemont white rice (nonaromatic cultivar) contained 4 ng per g (dry weight). Delia white rice contained almost four times more 2-acetyl-l-pyrroline as the average (73 ppb) in two batches of Jasmine white rice imported from Thailand and comparably analyzed.     

Destructive Effect of Aspartame on Ascorbic Acid in Cu-catalyzed Solutions

The effect of aspartame on the early stage of ascorbic acid oxidation in solutions was studied by measuring ascorbic acid retention in an open system at 30°C and the oxygen uptake in a closed system at 33°C. Comparisons were also made between aspartame (0.06% and 0.12%) and sucrose (10% and 20%) in Cu-catalyzed and noncatalyzed solutions at 30°C. Copper activity in aspartame solution was measured by using a cupric ion selective electrode. Aspartame increased the rate of ascorbic acid oxidation in all tested solutions. In the presence of copper the oxidation rate of ascorbic acid was significantly higher in aspartame solutions than in sucrose solutions despite the fact that aspartame showed Cu-complex capacity in solution.