Rast’s method

III. Depression of the Freezing-point of Camphor (Rast s Method). 

A new treatment for S = 7/2 systems has been undertaken by Rast and coworkers [78, 79]. They assume that in complexes with ligands like DTPA, the crystal field symmetry for Gd3+ produces a static ZFS, and construct a spin Hamiltonian that explicitly considers the random rotational motion of the molecular complex. They identify a magnitude for this static ZFS, called a2, and a correlation time for the rotational motion, called rr. They also construct a dynamic or transient ZFS with a simple correlation function of the form (BT)2 e t/TV. Analyzing the two Hamiltonians (Rast s and HL), it can be shown that at the level of second order, Rast s parameter a2 is exactly equivalent to the parameter A. The method has been applied to the analysis of the frequency dependence of the line width (ABpp) of GdDTPA. These results are compared to a HL treatment by Clarkson et al. in Table 2. 

In clinical diagnosis of sensitivity to allergens in food, the two methods used most frequently are the skin prick test (SPT) and the radioallergosorbent test (RAST). These tests have been used reliably for the diagnosis of allergy to peas, codfish, peanuts, egg white, wheat and wheat flour but were only partly reliable in detecting allergy to cow s milk, sardines, and white bea ns ( ). 

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