Convenient Preparation of 2,7,8‐Trimethyl‐6‐hydroxychroman‐2‐carboxylic Acid (γ‐Trolox)

The title chroman is useful in synthesis and as a water‐soluble analog of γ‐tocopherol, a member of the vitamin E family. This new synthesis of γ‐trolox proceeds via selective aromatic demethylation of Trolox, the more easily available 2,5,7,8‐tetramethyl homolog compound. This route is shorter than the previous synthesis, avoids the use of cyanide and methoxybutadiene, and requires no chromatography.     

Reaction probabilities and high energy trajectories for collinear H−H2 collisions

Classical trajectory studies of the collinear H + H₂ system, under the influence of a Sato potential, have been used to obtain reaction probabilities over a wide range of collision energies. Although the low energy trajectories are simple, some high energy trajectories are complicated and lead to the reactants being in close proximity for long enough to be considered a complex. The excess energy may be liberated in vibrational or translational form.     

High-pressure and -temperature ion exchange of aluminosilicate and gallosilicate natrolite

The simultaneous application of high pressure and high temperature has been used to achieve direct ion exchange of large cesium cations for the small sodium cations found in the zeolite natrolite by putting it into a superhydrated state with increased pore size. The larger cations remain trapped upon pressure release, and thus, this method is a means of producing new cationic forms of zeolites.     

Using fuzzy cognitive mapping techniques to model situation awareness for army infantry platoon leaders

This paper describes work on the development of an actionable model of situation awareness for Army infantry platoon leaders using fuzzy cognitive mapping techniques. Developing this model based on the formal representation of the platoon leader provided by the Goal-Directed Task Analysis (GDTA) methodology advances current cognitive models because it provides valuable insight on how to effectively support human cognition within the decision-making process. We describe the modeling design approach and discuss validating the model using the VBS2 simulation environment.