Clockwise direction

We assume an elemental node mmibering order in the clockwise direction, as shown in Figure 6.5. 

A carbon atom in a ring can be a chirality center if it bears two different sub stituents and the path traced around the ring from that carbon m one direction is differ ent from that traced m the other The carbon atom that bears the methyl group m 1 2 epoxypropane for example is a chirality center The sequence of groups is O—CH2 as one proceeds clockwise around the ring from that atom but is CH2—O m the counter clockwise direction Similarly C 4 is a chirality center m limonene... 

If the observed order of priority of the remaining three functions (a > 6 > c) is in a clockwise direction, the absolute configuration is designated R (rectus or right) if counterclockwise, the configuration is S (sinister or left). The concepts of stereochemistry and chiraUty have been extensively discussed and reviewed (27—29). 

Figure 1.3 The "handedness" of amino acids Looking down the H-Ca bond from the hydrogen atom, the L-form has CO, R, and N substituents from Cq going In a clockwise direction. There is a mnemonic to remember this for the L-form fhe groups read CORN in clockwise direcfion.

FIGURE 6.2 The amide or peptide bond planes are joined by the tetrahedral bonds of the ff-carbon. The rotation parameters are p and Ip. The conformation shown corresponds to clockwise rotation as viewed from Starting from 0°, a rotation of 180° in the clockwise direction ( + 180°) is equivalent to a rotation of 180° in the counterclockwise direction (—180°). (truing G s)... 

Nomenclature follows the well-established oxa-aza convention of organic chemistry. Numbering begins with the apex atom of lowest coordination and successive rings or belts of polyhedral vertex atoms are numbered in a clockwise direction with C atoms being given the lowest possible numbers within these rules. ... 

Azimuth Direction of a course measured in a clockwise direction from 0° to 360° as North also bearing. 

Using the example of a transportation maintenance facility, Figure 7.7 shows that a counter-clockwise rotation of the traffic flow could achieve minimum crossing and give a graduation of decreasing traffic density in the counter-clockwise direction as vehicles are diverted off the main stream (Figure 7.8). 

The shafts are slowly rotated in a clockwise direction in 90° increments. Measurements, including positive and negative signs, should be recorded at the 12, 3, 6 and 9 o clock positions. 

Turn the shafts in a clockwise direction and record the data at each hold-down bolt centerline until readings have been taken at all positions. 

Dextrorotatory (Section 9.3) A word used to describe an optically active substance that rotates the plane of polarization of plane-polarized light in a right-handed (clockwise) direction. 

In the interaction of the local 2pv orbitals, two more bonding molecular orbitals are formed against one less bonding. In all previous cases the opposite occurred. This is due to the negative overlap between adjacent 2py orbitals—whether, by convention, all positive lobes point in the clockwise direction, or whether all positive lobes point in the anticlockwise direction. The two bonding 2pv combinations in fact fall below the two antibonding (hybrid 2s, 2px) combinations. The former each have two electrons while the latter are empty. The six electrons of the three C—C bonds are nicely accounted for. The method creates simultaneously the acc and or c molecular orbitals of cyclopropane (note that the latter three lie relatively close in energy). 

The conveyor belt is shown schematically in Fig. 10-11. Warm and salty surface currents in the western North Atlantic (e.g., the Gulf Stream) transport heat to the Norwegian-Greenland Seas where it is transferred to the atmosphere. This heat helps moderate the climate of northern Europe. The cooling increases the density resulting in formation of the now cold and salty North Atlantic Deep Water (NADW) (Worthington, 1970). The NADW travels south through the North and South Atlantic and then joins the Circumpolar Current that travels virtually unimpeded in a clockwise direction around the Antarctic Continent. 

The radial frequency co of a periodic function is positive or negative, depending on the direction of the rotation of the unit vector (see Fig. 40.5). co is positive in the counter-clockwise direction and negative in the clockwise direction. From Fig. 40.5a one can see that the amplitudes (A jp) of a sine at a negative frequency, -co, with an amplitude. A, are opposite to the values of a sine function at a positive frequency, co, i.e. = Asin(-cor) = -Asin(co/) = This is a property of an antisymmetric function. A cosine function is a symmetric function because A -Acos(-co/) = Acos(cor) = A. (Fig. 40.5b). Thus, positive as well as negative... 

Tbe linear transformation expressed by Eq. (104) has the same form if the vector is rotated in the clockwise direction by the angle

coordinate axes remain fixed. 

If the analyzer is rotated in a clockwise direction, the rotation, a (measured in... 

A substance that rotates plane-polarized light in the clockwise direction is said to be dextrorotatory, and one that rotates plane-polarized light in a counterclockwise direction is said to be levorotatory (Latin dexter, right and laevus, left). 

Fig. 8. This is a snapshot of a spatial particle distribution. The plane shown is the horizontal cross-section just below the disc of a Rushton turbine in a flat-bottomed stirred tank. The impeller revolves in the counter clockwise direction. Particle size is some 0.468mm Re = 1.5- - x 105 volume fraction amounts to 3.6% number of particles tracked in the simulation just over 6.7 million. Reproduced with permission from Derksen (2003).

The Burgers vector of a screw dislocation can be determined in exactly the same way as an edge dislocation, following the FS/RH (perfect crystal) convention. A closed Burgers circuit is completed in a clockwise direction around the dislocation (Fig. 3.7a). An identical circuit in both direction and number of steps is completed in a perfect crystal (Fig. 3.7b). This will not close. The vector needed to close the circuit in the perfect crystal, running from the finish atom to the start atom, is the... 

Enantiomers have identical chemical and physical properties in the absence of an external chiral influence. This means that 2 and 3 have the same melting point, solubility, chromatographic retention time, infrared spectroscopy (IR), and nuclear magnetic resonance (NMR) spectra. However, there is one property in which chiral compounds differ from achiral compounds and in which enantiomers differ from each other. This property is the direction in which they rotate plane-polarized light, and this is called optical activity or optical rotation. Optical rotation can be interpreted as the outcome of interaction between an enantiomeric compound and polarized light. Thus, enantiomer 3, which rotates plane-polarized light in a clockwise direction, is described as (+)-lactic acid, while enantiomer 2, which has an equal and opposite rotation under the same conditions, is described as (—)-lactic acid. 

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