Prevalency

While tax and royalty fiscal systems are common, another prevalent form of fiscal system is the Production Sharing Contract, in which the investor (e.g. oil company) enters into an agreement with the host government to explore and potentially appraise and develop an area. The investor is a contractor to the host government, who retains the title of any produced hydrocarbons. 

In general, radioscopic X-ray inspection systems are used in the serial examination of industrial workpieces since they enable a flexible adjustment of the beam direction and of the inspection perspective as well as on-line viewing of the radioscopic image. In the past few years this economic and reliable method has become prevalent in weld inspection during the manufacturing process of pipes. The configuration of such radioscopic systems is schematically represented in fig. 1. 

Near drum wastage is the most prevalent type of wastage documented. It cart be found anywhere in the generating bank but is most common on the wall tubes, in tlic row immediately next to soot blower lanes and in the hot and cold row s. Three types of near drum w astagc have been documented. 

Because of their prevalence in physical adsorption studies on high-energy, powdered solids, type II isotherms are of considerable practical importance. Bmnauer, Emmett, and Teller (BET) [39] showed how to extent Langmuir s approach to multilayer adsorption, and their equation has come to be known as the BET equation. The derivation that follows is the traditional one, based on a detailed balancing of forward and reverse rates. 

At the limit of extremely low particle densities, for example under the conditions prevalent in interstellar space, ion-molecule reactions become important (see chapter A3.51. At very high pressures gas-phase kinetics approach the limit of condensed phase kinetics where elementary reactions are less clearly defined due to the large number of particles involved (see chapter A3.6). 

The nomesonant background prevalent in CARS experiments (discussed above), although much weaker than the signals due to strong Raman modes, can often obscure weaker modes. Another teclmique which can suppress the nonresonant background signal is Raman induced Kerr-efifect spectroscopy or RIKES [96, 97]. 

Elemental and chemical-state resolution affords the possibility of detecting only a monolayer or even a fraction of a monolayer. This approach is prevalent in PD and in metiiods based on x-ray fluorescence. 

The scan rate, u = EIAt, plays a very important role in sweep voltannnetry as it defines the time scale of the experiment and is typically in the range 5 mV s to 100 V s for nonnal macroelectrodes, although sweep rates of 10 V s are possible with microelectrodes (see later). The short time scales in which the experiments are carried out are the cause for the prevalence of non-steady-state diflfiision and the peak-shaped response. Wlien the scan rate is slow enough to maintain steady-state diflfiision, the concentration profiles with time are linear within the Nemst diflfiision layer which is fixed by natural convection, and the current-potential response reaches a plateau steady-state current. On reducing the time scale, the diflfiision layer caimot relax to its equilibrium state, the diffusion layer is thiimer and hence the currents in the non-steady-state will be higher. 

Schemes for classifying surfactants are based upon physical properties or upon functionality. Charge is tire most prevalent physical property used in classifying surfactants. Surfactants are charged or uncharged, ionic or nonionic. Charged surfactants are furtlier classified as to whetlier tire amphipatliic portion is anionic, cationic or zwitterionic. Anotlier physical classification scheme is based upon overall size and molecular weight. Copolymeric nonionic surfactants may reach sizes corresponding to 10 000-20 000 Daltons. Physical state is anotlier important physical property, as surfactants may be obtained as crystalline solids, amoriDhous pastes or liquids under standard conditions. The number of tailgroups in a surfactant has recently become an important parameter. Many surfactants have eitlier one or two hydrocarbon tailgroups, and recent advances in surfactant science include even more complex assemblies [7, 8 and 9].

One prevalent strategy for this involves tire use of a phase transfer agent, such as tetraoctyl ammonium bromide, to bring gold and silver salts into an organic phase [12, and. Reduction of tire metal salts... 

Among many approaches to manipulating a relational database, the most prevalent one is a language called SQL (Structured Query Language) [2]. 

The comparatively wide prevalence of micro-methods of quantitative organic analysis, applied more particularly to the estimation of the constituent elements in an organic compound, may cause the advisability of including the macro-methods in Part IV to be questioned. Quite apart, however, from the fact that the micro-methods still find no place in many laboratories, we consider that thorough practice in the macro-methods of quantitative analysis to be not only an excellent introduction to the micro-methods themselves, but also a valuable training in exact manipulation generally. 

There is no one best way to specify geometry. Usually, a Z-matrix is best for specifying symmetry constraints if properly constructed. Cartesian coordinate input is becoming more prevalent due to its ease of generation by graphical user interface programs. 

This chapter provides only a brief discussion of relativistic calculations. Currently, there is a small body of references on these calculations in the computational chemistry literature, with relativistic core potentials comprising the largest percentage of that work. However, the topic is important both because it is essential for very heavy elements and such calculations can be expected to become more prevalent if the trend of increasing accuracy continues. 

Rearrangement is especially prevalent with primary alkyl halides of the type RCH2CH2X and R2CHCH2X Aluminum chloride induces ionization with rearrangement to give a more stable carbocation Benzylic halides and acyl halides do not rearrange... 

The slit-shaped model has come into prominence in recent years, as electron microscopy has revealed the prevalence of solids composed of platelike particles the technique, indeed, has now developed to the point where it is possible to identify the presence of slit-shaped pores, and even to measure their width. In the ideal case where the sides of the slit are truly planar and parallel, the hysteresis takes an extreme form since the mean radius of curva-... 

Manufacturing approaches for selected bioproducts of the new biotechnology impact product recovery and purification. The most prevalent bioseparations method is chromatography (qv). Thus the practical tools used to initiate scaleup of process Hquid chromatographic separations starting from a minimum amount of laboratory data are given. 

A.- ng deduction. This is an irreversible reaction which is a foremost determinant of the secretion rate of cortisol (double bonds and C-3 carbonyl). Catalyzed predominantiy by cortisone P-reductase and 3a-hydroxysteroid dehydrogenases, SP sterols result, although 5a sterols are more prevalent in the case of other glucocorticoids. Urocortisol and urocortisone result from the metabohsm of cortisol and cortisone, respectively. Compounds can be complexed to glucuronic acid at this point. 

Another variant of the friction welding process, linear friction welding, uses servo-hydrauHcs pumps to vibrate parts back and forth against each other. Bond areas of approximately 1000 mm can be joined the attachment of turbine blades to rotors is a prevalent apphcation of this technology. 

Shipment, Stora.ge, ndPrice. Tank cars and tank trailers, selected to prevent color formation, are of aluminum or stainless steel, or lined with epoxy or phenoHc resins dmms are lined with phenoHc resins. Flexible stainless steel hose is used for transfer. Because of butanediol s high freezing point (about 20°C) tank car coil heaters are provided. The U.S. Hst price for bulk quantities in 1991 was about 2.18/kg, but heavy discounting was prevalent for large contracts. 

Polyimide. Polyimide is a biaxiaHy oriented high performance film that is tough, flexible, and temperature- and combustion-resistant. Its room temperature properties compare to poly(ethylene terephthalate), but it retains these good characteristics at temperatures above 400°C. Its electrical resistance is good and it is dimensionally stable. The principal detriment is fairly high moisture absorbance. The main uses are for electrical insulation, particularly where high temperatures are prevalent or ionizing radiation is a problem. The films may be coated to reduce water absorption and enhance... 

Technological History (26,54—61). As a first approach, there are three groups of components supports, paint media, and pigments. The support is the substrate upon which the paint layers are laid down. This can be a specially prepared area on a wall for a wall painting, a wooden panel as in a panel painting, or a fabric in canvas paintings. Paper is a prevalent support in Oriental painting. Other supports are encountered less frequently, eg, metal panels such as copper sheet. 

The proteinaceous gelatins in the various animal glues were also widely used as paint media, as well as in illuminations. Glues, the traditional media in Oriental painting, remained the prevalent binders for ground layers in European painting long after oils had become virtually the only medium for the color layers. 

The earhest written references to the use of oils as paint media date from the twelfth century. The van Eycks, who traditionally have been credited as the inventors of oil painting, improved the technique to such a degree that oil quickly replaced egg tempera as the prevalent medium. 

Vanilla. Vanilla is the dried, cured, fuU-sized, but not fully ripe fmit pods (beans) of Vanillaplanifolia And. and V. tahitensis J. W. Moore (Orchidaceae). The vine is native to the tropical rain forests of southern Mexico, Central America, the West Indies, and northern South America. Plantings were started in Madagascar, Reunion, Java, Mauritius, and Zanzibar in 1840. The Madagascar-type bean is stUl the most important, but Indonesia produces more than Malagasy. The stmcture of the flower prevents self-pollination and therefore, where insects are not prevalent, hand pollination is necessary. 

Liquid Displacement Gas Meter Provers. The Hquid displacement prover is the most prevalent standard for the caHbration of flow meters at low to moderate gas flow rates. The method consists of displacing a known volume of Hquid with gas (Fig. 2). Gas entering the inverted beU causes it to rise and a volume increment can be timed. Typical prover capacities are 1 m or less although capacities as large as 20 m are available. Accuracies can be on the order of 0.5% of actual flow rate. 

Prevalence of treatment occurring in product R = rare to occasional F = frequent W = widespread or near-total. 

---