Wyoming samples

A complication now arises. The surface tensions of A and B in Eq. IV-2 are those for the pure liquids. However, when two substances are in contact, they will become mutually saturated, so that 7a will change to 7a(B) and 7b to 7B(A). That is, the convention will be used that a given phase is saturated with respect to that substance or phase whose symbol follows in parentheses. The corresponding spreading coefficient is then written 5b(A)/a(B)-  [c.105]

Values of are small for weak acids and they range very widely (Table 4.1). It is common practice to quote values as the negative logarithm to the base ten, i.e. — logjo K.. since such numbers are less cumbersome and positive when Aj < 1. The symbol for -logio is by convention "p/ fhus -logjo becomes pK,. Table 4.1 shows some typical pAg values.  [c.86]

The terms as and trans are ambiguous however when it is not obvious which substituent on one carbon is similar or analogous to a reference substituent on the other Fortunately a completely unambiguous system for specifying double bond stereo chemistry has been developed based on an atomic number criterion for ranking sub stituents on the doubly bonded carbons When atoms of higher atomic number are on the same side of the double bond we say that the double bond has the Z configuration where Z stands for the German word zusammen, meaning together When atoms of higher atomic number are on opposite sides of the double bond we say that the config uration is E The symbol E stands for the German word entgegen, meaning opposite  [c.194]

Variations in isotope ratios are not large so the fractionation factor a does not differ much from 1. However, it is the variation itself that is important, and to accentuate this effect clearly it is usual to subtract 1 from a. Then, for convenience, it is usual to multiply the variation by 1000, and, finally, the resulting number is given the symbol 5 (delta Figure 48.3). For a sample isotope ratio Rj measured against a standard reference ratio R, delta is regarded as referring to the sample. For a sample (A) and a reference substance (R), a series of equations (Figure 48.3) can be applied. Similar quantitative comparisons are made in everyday life when ratios are discussed. Ratios are often written as fractions (e.g., 3/5) or decimals (0.6), and it becomes convenient to multiply them by 100, when they become percentages (60%). However, when differences in ratios need to be emphasized, a slightly different formula is used the percentage change is used. The same type of formulation is used for isotope measurements, the 5 value being a difference in ratios relative to  [c.358]

Note that subtracting an amount log a from the coordinate values along the abscissa is equivalent to dividing each of the t s by the appropriate a-p value. This means that times are represented by the reduced variable t/a in which t is expressed as a multiple or fraction of a-p which is called the shift factor. The temperature at which the master curve is constructed is an arbitrary choice, although the glass transition temperature is widely used. When some value other than Tg is used as a reference temperature, we shall designate it by the symbol To.  [c.258]

Chain transfer arises when a hydrogen or some other atom, say, X in general, is transferred from some molecule in the system to the polymer radical. Tliis terminates the growth of the original radical but replaces it with a new one the fragment of the species from which X was extracted. These latter molecules will be designated by attaching the letter X to their symbol in this discussion. Thus if chain transfer involves an initiator molecule, we represent the latter IX in this section. Chain transfer can occur with any molecule in the system. The following reactions specifically describe transfer to initiator, monomer, solvent, and polymer molecules  [c.388]

When we discussed random walk statistics in Chap. 1, we used n to represent the number of steps in the process and then identified this quantity as the number of repeat units in the polymer chain. We continue to reserve n as the symbol for the degree of polymerization, so the number of diffusion steps is represented by V in this section.  [c.628]

The phrase total angular momentum is commonly used to refer to a number of different quantities. Here it implies orbital plus electron spin but it is also used to imply orbital plus electron spin plus nuclear spin when the symbol F is used.  [c.208]

When m = n the Coulomb integral is assumed to be the same for each atom and is given the symbol a  [c.267]

When m 7 n the resonance integral is assumed to be the same for any pair of directly bonded atoms and is given the symbol /i  [c.268]

Because of the ovedapping roles of coal in industry, many of the technologies covered here have been developed for synthetic fuel appHcations, but they also have been used or have demonstrated potential for production of significant quantities of chemicals. The scope of an article on coal as a chemical source would not be complete without coverage of synfuel processes, but the focus will be on the chemical production potential of the processes, looking toward a future when coal again may become the principal feedstock for chemical production.  [c.161]

The remainder of the nmr description adopts a macroscopic perspective of the spin system in which the Bq field is appHed along the -axis. Groups of nuclei experiencing the same Bq are called spin packets. When placed in a 5q field, spin packets precess about the direction of Bq just as a spinning top on earth precesses about the direction of the gravitational field. The precessional frequency, also called the T,arm or frequency, CO, is equal to 2 7TV. The direction of the precession is clockwise about Bq, and the symbol COq is reserved for spin packets experiencing exacdy Bq. It is often helphil in nmr and MRI to adopt a rotating frame of reference to describe the motion of magnetization vectors. This frame of reference rotates about the -axis at COq. The axes in the rotating frame of reference are referred to as V, andj/.  [c.54]

Equations 116, 117, 121, 122, and 124 are the general property relations between partial molar properties and solution properties. The symbol M may represent the molar value of any extensive thermodynamic property, for example, U, H, S, Pi, or G. When M = if, the derivatives (dH/ T)p and (dH/dP)j- are given by equations 75 and 79. Equations 121, 122, and 124 then become the following  [c.491]

Mustard and Related Vesicants. Mustard, bis(2-chloroethyl) sulfide [505-60-2] (Chemical Agent Symbol HD), C1(CH2)2S(CH2)2C1, is a colodess, oily hquid when pure. Most samples have a characteristic garliclike odor. It is primarily a vesicant bUsters are formed by either Hquid or vapor contact. Mustard also attacks the eyes and lungs and is a systemic poison, so that protection of the entire body must be provided. It is insidious in its action there is no pain at the time of exposure, and symptoms usually do not appear until several hours after exposure.  [c.397]

An amendment to the law aboHshed the notice requirement for all works pubHshed on or after March 1, 1989. For such works, no copyright notice is required. Notice, however, is stiH required on all copies of works first pubHshed before that date. In addition, notice is stiU widely used even when it is not required so as to inform the world of the copyright status of the work. Notice consists of the symbol (the letter i in a circle), the word Copyright, or the abbreviation Copr the name of the copyright owner and the year of first pubHcation.  [c.265]

Symbol M may represent the molar value of any extensive thermodynamic property for example, V, U, H, S, or G. When M H, the  [c.517]

In the A convention a locant is used to indicate the atom, and the symbol A (suggesting ligand ) is added as the bearer of the valence superscript, which is written in arabic numerals as shown in examples (110)-(112). In order to determine the bonding number which appears in the superscript, one counts the total number of classical bonds to adjacent skeletal atoms and adds this number to that of the hydrogen atoms (or equivalent substituents) borne by the atom. When applying the A convention to fusion names the locant is derived from the numbering of the overall ring system, and not of a component ring. It may be necessary to include indicated hydrogen to specify isomers, e.g. (113) and (114). Prefix forms are derived in the usual manner when it is necessary to name a heterocyclic radical as a substituent, e.g. (115).  [c.32]

To permit a more general discussion, we can replace the snowplow with a piston, and replace the snow with any fluid (Fig. 2,3), We consider the example shown in a reference frame in which the undisturbed fluid has zero velocity. When the piston moves, it applies a planar stress, a, to the fluid. For a non-viscous, hydrodynamic fluid, the stress is numerically equal to the pressure, P, The pressure induces a shock discontinuity, denoted by which propagates through the fluid with velocity U. The velocity u of the piston, and the shocked material carried with it (with respect to the stationary frame of reference), is called the particle velocity, since that would be the velocity of a particle caught up in the flow, or of a particle of the fluid.  [c.9]

Dislocation motion produces plastic strain. Figure 9.4 shows how the atoms rearrange as the dislocation moves through the crystal, and that, when one dislocation moves entirely through a crystal, the lower part is displaced under the upper by the distance b (called the Burgers vector). The same process is drawn, without the atoms, and using the symbol 1 for the position of the dislocation line, in Fig. 9.5. The way in  [c.96]

The term a Tra crops up so frequently in discussing fast fracture that it is usually abbreviated to a single symbol, K, having units MN m " it is called, somewhat unclearly, the stress intensity factor. Fast fracture therefore occurs when  [c.135]

A phase is a region of material that has uniform physical and chemical properties. Phases are often given Greek symbols, like a or fi. But when a phase consists of a solid solution of an alloying element in a host metal, a clearer symbol can be used. As an example, the phases in the lead-tin system may be symbolised as (Pb) - for the solution of tin in lead, and (Sn) - for the solution of lead in tin.  [c.25]

This expression states that there will be energy free to do work when Q exceeds AE. Expressed in another way work ean be done, that is an action can proceed, if AE - 0 is negative. If the difference between AE and Q is given the symbol AA, then it can be said that a reaction will proceed if the value of AA is negative. Since the heat term is the product of temperature T and change of entropy AS, for reactions at constant temperature then  [c.93]

Instrumentation normally is denoted by a circle in which the variable being measured or controlled is denoted by an appropriate letter symbol inside the circle. When the control device is to be located remotely, the circle is divided in half with a horizontal line. Table 1.3 gives various instrumentation symbols and corresponding letter codes. The specific operating details and selection criteria for various process instrumentation are not discussed in this book. The reader is referred to earlier works by Cheremisinoff [1,2] for discussions on essential control and measurement instrumentation.  [c.8]

As with the crowns, the situation becomes more complicated when there are other heteroatoms or substituents in one of the cryptand bridges. The symbol B is used to designate a benzo- or catechol unit in the bridge and subscripts are used to designate heteroatoms when non-oxygen heteroatoms are present. Examples of this are shown in structures 12 and 13 above.  [c.5]

Tn normal work, "C is used in preference to the absolute temperature K. However, it is essential that K be used when working with the gas laws, radiation, and the coefficient of cubical expansion. The symbol for normal temperature is 0 followed by a suffix, while T always denotes absolute temperature.  [c.1398]

The idea that a shared electron pair constitutes a covalent bond ignores any difficulty about the actual position and nature of the electrons in the combining atoms or in the resulting molecule. The idea that electrons are particles revolving in orbits or situated in shells is inadequate when we desire to picture electrons in covalent bonds. It is, however, known that a beam of electrons can undergo diffraction, and that they therefore possess a wave-like nature like light waves. It has also been found that there is a simple relationship between the momentum of an electron (characteristic of its particle-nature) and the wavelength (characteristic of its wave-nature). But if we give a definite wavelength or amplitude to an electron, then its position in space becomes uncertain, i.e. it cannot be pin-pointed. Instead, the wave amplitude (strictly, the square of the amplitude) can be used to represent the probability of finding the electron at a given point in an atom or molecule. This amplitude is usually given the symbol ij/ (psi) and is called a ware function. For hydrogen (or helium), with one (or two) electron in the K shell , ij/ is found to depend only on the distance from the nucleus, diminishing as this distance increases hence our picture of the hydrogen atom is that shown in Figure 2.7.  [c.54]

The symbol when interposed between two vectors means that a matrix is to be formed. Tlie ijth element of the matrix u v is obtained by multiplying u, by Vy.  [c.287]

When this overall sign is positive, the funetion P is termed "even" and its term symbol is appended with an "e" superseript (e.g., the 2p level of the O atom, whieh has Is22s22p4 oeeupaney is labeled 2pe) if the sign is negative P is ealled "odd" and the term symbol is so amended (e.g., the 2p level of Is22si2pi B+ ion is labeled 2po).  [c.257]

When this overall sign is positive, the function F is gerade and its term symbol is appended with a "g" subscript (e.g., the level of the O2 molecule, which has 7iu" 7ig 2 occupancy is labeled 2ig) if the sign is negative, F is ungerade and the term symbol is so amended (e.g., the If level of the ItIu configuration of the  [c.262]

There is one further addition to fhe sfafe symbolism fhaf we have nof mentioned so far. This is fhe superscripf o as in fhe ground sfafe of boron, 7 1/2 The symbol implies fhaf fhe arifhmefic sum for all fhe elecfrons in fhe atoms is an odd number, f in fhis case. When fhere is no such superscripf fhis implies fhaf fhe sum is an even number for example if is 4 in fhe case of oxygen.  [c.212]

The first recorded mention of mercury metal was by Aristotle in the fourth century BC, at a time when it was used in religious ceremonies. By the time of Pliny, mercury was a familiar substance, and its preparation by roasting cinnabar was well known. The ancient Egyptians, Greeks, and Romans used mercury for cosmetic and medical preparations, and for amalgamation. Although it resembles a metal, mercury s Hquid nature usually caused it to be classified among the "waters." It was not until sometime in the period 500—700 AD that mercury was accepted as a metal, and the astrological symbol that had been assigned to tin was given to mercury. The abiHty of mercury to impart a silvery color to other metals also gave it a special position among the alchemists (1).  [c.104]

Before the 13th CGPM in 1967, when this definition was adopted, the unit was called the degree Kelvin (symbol °K, now K).  [c.308]

Population density (n) has dimensions number/(volume)(length) it is a key quantity in the discussion of CSD, a function of the characteristic crystal dimension E, and it is defined so that it is independent of the magnitude of the system. When a total population density is used, the symbol is n and the units are number/length. Population density is defined by letting AiVbe the number of crystals per unit system volume in a size range from E to L + AL, so that  [c.347]

One type of selector device chooses as its output signal the highest (or lowest) of two or more input signals. This approach is often referred to as auctioneering. On instrumentation diagrams, the symbol HS denotes high selector and LS a low selector. For exampfe, a high selector can be used to determine the hot-spot temperature in a fixed-bed chemical reac tor. In this case, the output from the high selector is the input to the temperature controller. In an exothermic-catalytic reaction, the process may run away due to disturbances or changes in the reactor. Immediate action should be taken to prevent a dangerous rise in temperature. Because a hot spot may potentially develop at one of several possible locations in the reactor, multiple (redundant) measurement points should be employed. This approach minimizes the time required to identify when a temperature has risen too high at some point in the bed.  [c.733]

An attempt has been made to bring together most of the methods currently available for project evaluation and to present them in such a way as to make the methods amenable to modern computational techniques. To this end the practices of accountants and others have been reduced, where possible, to mathematical equations which are usually solvable with an electronic hand calculator equipped with scientific function keys. To make the equations smtable for use on high-speed computers an attempt has been made to devise a nomenclature vmich is suitable for machines using ALGOL, COBOL, or FORTRAN compilers. The number of letters and numbers used to define a variable has usually been limited to five. The letters are mnemonic in Enghsh wherever possible and are derived in two ways. First, when a standard accountancy phrase exists for a term, this has been abbreviated in capital letters and enclosed in parentheses, e.g., (ATR), for assets-to-turnover ratio (DCFRR), for discounted-cash-flow rate of return. Clearly, the parentheses are omitted when the letter group is used to define the variable name for the computer. Second, a general symbol is defined for a type of variable and is modified by a mnemonic subscript, e.g., an annual cash quantity Afc, annual total capital outlay, /year. Clearly, the symbols are written on one line when the letter group is used to define a variable name for the computer. In other cases, when well-known standard symbols exist, they have been  [c.803]

Semiflow or batch flow operations may employ a single stirred tank or a series of them. Some of the reactants are loaded into the reac tors as a single charge and the remaining ones are then fed gradually. This mode of operation is especially favored when large heat effects occur and heat-transfer capability is limited, since exothermic reactions can be slowed down and endothermic rates maintained by limiting the concentrations of some of the reactants. Other situations maldng this sort of operation desirable occur when high concentrations may result in the formation of undesirable side products, or when one of the reactants is a gas of limited solubility so that it can be fed only at the dissolution rate.  [c.2070]

Shock waves are the ubiquitous result of matter moving at velocities faster than the speed at which adjacent material can move out of the way. Examples range in scale from the shock waves generated by the collapse of microscopic cavitation bubbles to light-year scale collisionless shocks in the interstellar medium. The concept of a shock wave is well illustrated by the flow of snow in front of a moving snowplow (Fig. 2.1). When a plow begins moving into fresh, loose snow, a layer of packed snow builds up on the blade. The interface between the fresh snow and packed snow moves out ahead of the blade at a speed greater than that of the plow.  [c.7]

Fig. 2.7. Many metals are made up of /wo phases. This figure shows some of the shapes that they con hove when boundary energies dominate. To keep things simple we hove sectioned the tetrokoidecohedral grains in the way that we did in Fig. 2.6(b). Note that Greek letters ore often used to indicate phases. We hove called the major phase a and the second phase (. But y is the symbol for the energy (or tension) of groin boundaries (y J and interphose interfaces (y ). Fig. 2.7. Many metals are made up of /wo phases. This figure shows some of the shapes that they con hove when boundary energies dominate. To keep things simple we hove sectioned the tetrokoidecohedral grains in the way that we did in Fig. 2.6(b). Note that Greek letters ore often used to indicate phases. We hove called the major phase a and the second phase (. But y is the symbol for the energy (or tension) of groin boundaries (y J and interphose interfaces (y ).
In addition to an enhanced dielectric constant dependent on temperature and frequency, polar molecules exhibit quite high dielectric power losses at certain frequencies, the maximum power loss corresponding to the point of inflection in the dielectric constant-frequency curve Figure 6.3). At very low frequencies, as already mentioned, the dipole movements are able to keep in phase with changes in the electric field and power losses are low. As the frequency is increased the point is reached when the dipole orientation cannot be completed in the time available and the dipole becomes out of phase. It is possible to have a mental picture of internal friction due to out-of-step motions of the dipoles leading to the generation of heat. Measures of the fraction of energy absorbed per cycle by the dielectric from the field are the power factor and dissipation factor. These terms arise by considering the delay between the changes in the field and the change in polarisation which in turn leads to a current in a condenser leading the voltage across it when a dielectric is present. The angle of lead is known as the phase angle and given the symbol 0. The value 90-9 is known as the loss angle and is given the symbol S. The power factor is defined as cos 6 (or sin 8) and the dissipation factor as tan 8 (or cot 0). When 8 is small the two are equivalent. Also quoted in the literature is the loss factor which is numerically the product of the dissipation factor and the dielectric constant.  [c.114]

See pages that mention the term Wyoming samples : [c.210]    [c.526]    [c.1144]    [c.661]    [c.683]    [c.28]    [c.118]    [c.398]    [c.239]    [c.541]    [c.229]    [c.101]   
Sourse beds of petroleum (1942) -- [ c.200 , c.201 , c.202 , c.203 , c.204 , c.205 , c.206 , c.207 , c.208 , c.209 , c.210 , c.211 , c.212 , c.213 , c.214 , c.215 , c.216 , c.217 , c.218 , c.219 , c.220 , c.221 , c.222 , c.223 , c.224 , c.225 , c.226 , c.227 , c.228 , c.229 , c.230 , c.243 , c.406 ]