Right-thumb rule

Based on the right-hand thumb rule described in the text, and assuming that only an equilibrium magnetization directed along the z-axis exists, draw the positions of the magnetization vectors after the application of ... 

Fig. 4.17. The Right Hand Rule (I thumb, B index finger, Fl middle finger) to determine the direction of the Lorentz Force (a) the current corresponds to the direction where positive charges move, i.e., the figure directly applies for positive ions, (b) A real magnet yoke without coils and flight tube. With kind permission of Thermo Electron (Bremen) GmbH, (left) and Waters Corporation, MS Technologies, Manchester, UK (right).

Let us go back to radical brominations (cf. Section. 1.7.3). The bromination of alkyl aromatics takes place completely regioselectively only the benzylic position is bromi-nated. The intermediates are the most stable radicals that are available from alkyl aromatics, namely, benzylic radicals. Refluxing orf/zo-xylene reacts with 2 equiv. of bromine to give one monosubstitution per benzylic position. The same transformation occurs when the reactants are irradiated at room temperature in a 1 2 ratio (Figure 1.22, right). The rule of thumb SSS applies to the reaction conditions that afford these benzylic substitutions chemoselectively. SSS stands for searing heat + sunlight —> side chain substitution. ... 

Figure 1.39. Vector (cross) product of two vectors. The orientation of V3 is determined using the right-hand rule thumb of the right hand is aligned with Vj, index finger with V2, then V3 is aligned with the middle finger. Tails of all vectors face the middle of the palm.

In this way so-called 90° and 180° pulses as well as pulses with arbitrary flip angles can be applied. The nomenclature used is that for mathematically positive rotations [Eml]. Here the right hand rule applies, where the thumb of the right hand points into the direction of the rotation axis and the fingers point into the direction of the rotation. 

If pressure is increased, the reaction is shifted to the right since fewer moles (2) are formed than are reacting (4). This is summarized in the useful thumb-rule called le Chatelier s principle, which can be stated as follows ... 

The cumulative variance, vCumul of the PCA scores shows how much of the total variance is preserved by a set of PCA components (Figure 3.5, right). As a rule of thumb, the number of considered PCA components should explain at least 80%, eventually 90% of the total variance. 

The pressures and temperatures of the Lw-H-V and the I-H-V lines mark the limits to hydrate formation. At higher temperatures or lower pressures of both lines, hydrate cannot form and the system will contain only aqueous and hydrocarbon fluid phases, while hydrate formation can occur to the left of Lw-H-V and I-H-V. Since ice and hydrates both cause flow problems, a gas pipeline rule of thumb is to keep the system temperature above the ice point and to the right of the Lw-H-V and the I-H-V lines, or to displace the Lw-H-V line below the pipeline operating conditions by injection of a thermodynamic inhibitor such as methanol. 

---