Opposite sides

The terms cis and trans signify, respectively, that the two hydrogen atoms are on the same side or on the opposite side with respect to the perpendicular plane of the double bond. 

Shortcomings of Wang s method like limited pitch of the spiral and blurring in the vertical direction can be improved by the CFBP-algorithm [10], where gaps in the spiral sampling pattern are filled using X-rays measured from the opposite side. 

UPV will indicate if the concrete is homogenius or if there could be a defect. The measurements are made between two trtmsducers on opposite sides of the construction. If a problem does occur its depth and form can be estimated by so called tomography (se figure down below). 

If a system is eoupled with its enviromnent tlirough an adiabatie wall free to move without eonstraints (srieh as the stops of the seeond example above), meehanieal equilibrium, as diseussed above, requires equality of the pressure p on opposite sides of the wall. With a diathemiie wall, themial equilibrium requires that the temperature 0 of the system equal that of its surroundings. Moreover, it will be shown later that, if the wall is pemieable and pemiits exehange of matter, material equilibrium (no tendeney for mass flow) requires equality of a ehemieal potential p. 

Zigmond, 1988). The ATP-hydrolysis that accompanies actin polymerization, ATP —> ADP + Pj, and the subsequent release of the cleaved phosphate (Pj) are believed to act as a clock (Pollard et ah, 1992 Allen et ah, 1996), altering in a time-dependent manner the mechanical properties of the filament and its propensity to depolymerize. Molecular dynamics simulations suggested a so-called back door mechanism for the hydrolysis reaction ATP ADP - - Pj in which ATP enters the actin from one side, ADP leaves from the same side, but Pj leaves from the opposite side, the back door (Wriggers and Schulten, 1997b). This hypothesis can explain the effect of the toxin phalloidin which blocks the exit of the putative back door pathway and, thereby, delays Pi release as observed experimentally (Dancker and Hess, 1990). 

Fig. 1. Periodic boundary conditions protect the inner simulation cell from disturbing effects of having all its particles close to the surface. With PBCs in force, as a particle moves out of the box on one side, one of its images will move back into the box on the opposite side.

For some simulations it is inappropriate to use standard periodic boundary conditions in all directions. For example, when studying the adsorption of molecules onto a surface, it is clearly inappropriate to use the usual periodic boundary conditions for motion perpendicular to the surface. Rather, the surface is modelled as a true boundary, for example by e, plicitly including the atoms in the surface. The opposite side of the box must still be treated when a molecule strays out of the top side of the box it is reflected back into the simulation cell, as indicated in Figure 6.6. Usual periodic boundary conditions apply to motion parallel to the surface. 

When a cycloalkane bears two substituents on different carbons—methyl groups for example—these substituents may be on the same or on opposite sides of the ring When substituents are on the same side we say they are cis to each other if they are on oppo site sides they are trans to each other Both terms come from the Latin m which as means on this side and trans means across... 

In the Z stereoisomer the two lower priority substituents—the methyl group and the hydrogen—are on the same side of the double bond In the E stereoisomer these substituents are on opposite sides of the double bond The ring carbons are the higher ranking substituents at each end of the double bond y... 

Isomeric alkenes may be either constitutional isomers or stereoisomers There is a sizable barrier to rotation about a carbon-carbon double bond which corresponds to the energy required to break the rr component of the double bond Stereoisomeric alkenes are configurationally stable under normal conditions The configurations of stereoisomeric alkenes are described according to two notational systems One system adds the prefix CIS to the name of the alkene when similar substituents are on the same side of the double bond and the prefix trans when they are on opposite sides The other ranks substituents according to a system of rules based on atomic number The prefix Z is used for alkenes that have higher ranked substituents on the same side of the double bond the prefix E is used when higher ranked substituents are on opposite sides... 

Organic chemisfs use an informal nomenclafure sysfem based on Eischer projec lions fo dislmguish belween diasfereomers When fhe carbon chain is vertical and like subsliluenls are on fhe same side of fhe Eischer projecfion fhe molecule is described as fhe erythro diaslereomer When like subsliluenls are on opposite sides of fhe Eischer projecfion fhe molecule is described as fhe threo diaslereomer Thus as seen m fhe... 

Stretching then breaking of the bond to the leaving group Formation of a bond to the nucleophile from the opposite side of the bond that is broken... 

Partial but not complete loss of optical activity m S l reactions probably results from the carbocation not being completely free when it is attacked by the nucleophile Ionization of the alkyl halide gives a carbocation-hahde ion pair as depicted m Figure 8 8 The halide ion shields one side of the carbocation and the nucleophile captures the carbocation faster from the opposite side More product of inverted configuration is formed than product of retained configuration In spite of the observation that the products of S l reactions are only partially racemic the fact that these reactions are not stereospecific is more consistent with a carbocation intermediate than a concerted bimolecular mechanism... 

Relative to each other both hydroxyl groups are on the same side m Fischer pro jections of the erythrose enantiomers The remaining two stereoisomers have hydroxyl groups on opposite sides m their Fischer projections They are diastereomers of d and L erythrose and are called d and l threose The d and l prefixes again specify the con figuration of the highest numbered chirality center d Threose and l threose are enan tiomers of each other... 

Thiol (Section 15 13) Compound of the type RSH or ArSH Th reo (Section 7 11) Term applied to the relative configuration of two stereogenic centers within a molecule The threo stereoisomer has like substituents on opposite sides of a Fischer projection... 

Torsional strain (Section 3 1) Decreased stability of a mole cule associated with eclipsed bonds trans (Section 3 11) Stereochemical prefix indicating that two substituents are on opposite sides of a ring or a double bond (Contrast with the prefix cis )... 

When two different substituents are attached to each carbon atom of the double bond, cis-trans isomers can exist. In the case of c T-2-butene (Fig. 1.11a), both methyl groups are on the same side of the double bond. The other isomer has the methyl groups on opposite sides and is designated as rran5--2-butene (Fig. l.llb). Their physical properties are quite different. Geometric isomerism can also exist in ring systems examples were cited in the previous discussion on conformational isomers. 

Parallelogram (opposite sides parallel). A = ah = ab sin 6, where a and b denote the sides, h the altitude, and 6 the angle between the sides. 

As with all thermodynamic relations, the Kelvin equation may be arrived at along several paths. Since the occurrence of capillary condensation is intimately, bound up with the curvature of a liquid meniscus, it is helpful to start out from the Young-Laplace equation, the relationship between the pressures on opposite sides of a liquid-vapour interface. 

It is easy to see that combining uncertainties in this way overestimates the total uncertainty. Adding the uncertainty for the first delivery to that of the second delivery assumes that both volumes are either greater than 9.992 mL or less than 9.992 mL. At the other extreme, we might assume that the two deliveries will always be on opposite sides of the pipet s mean volume. In this case we subtract the uncertainties for the two deliveries,... 

When first developed, potentiometry was restricted to redox equilibria at metallic electrodes, limiting its application to a few ions. In 1906, Cremer discovered that a potential difference exists between the two sides of a thin glass membrane when opposite sides of the membrane are in contact with solutions containing different concentrations of H3O+. This discovery led to the development of the glass pH electrode in 1909. Other types of membranes also yield useful potentials. Kolthoff and Sanders, for example, showed in 1937 that pellets made from AgCl could be used to determine the concentration of Ag+. Electrodes based on membrane potentials are called ion-selective electrodes, and their continued development has extended potentiometry to a diverse array of analytes. 

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