Units common

We have paid particular attention to industrial processes and have tried to give some indication of the use of particular chemicals. In order to give some idea of the relative magnitudes of production we have included data on annual production. In this, because of availability of data, we have not been entirely consistent in including common data or common units. (World, U.S. or European production figures are used as seem most appropriate or up-to-date - and it must be remembered that for most speciality chemicals U.S. production is dominant.)... [Pg.5]

Although the terms solute and solution are often associated with liquid samples, they can be extended to gas-phase and solid-phase samples as well. The actual units for reporting concentration depend on how the amounts of solute and solution are measured. Table 2.4 lists the most common units of concentration. [Pg.15]

Absorbance is the more common unit for expressing the attenuation of radiation because, as shown in the next section, it is a linear function of the analyte s concentration. [Pg.384]

In Equation 7.1, n+/n is the ratio of the number of positive ions to the number of neutrals evaporated at the same time from a hot surface at temperature T (K), where k is the Boltzmann constant and A is another constant (often taken to be 0.5 see below). By inserting a value for k and adjusting Equation 7.1 to common units (electronvolts) and putting A = 0.5, the simpler Equation 7.2 is obtained. [Pg.46]

Viscosity is equal to the slope of the flow curve, Tf = dr/dj. The quantity r/y is the viscosity Tj for a Newtonian Hquid and the apparent viscosity Tj for a non-Newtonian Hquid. The kinematic viscosity is the viscosity coefficient divided by the density, ly = tj/p. The fluidity is the reciprocal of the viscosity, (j) = 1/rj. The common units for viscosity, dyne seconds per square centimeter ((dyn-s)/cm ) or grams per centimeter second ((g/(cm-s)), called poise, which is usually expressed as centipoise (cP), have been replaced by the SI units of pascal seconds, ie, Pa-s and mPa-s, where 1 mPa-s = 1 cP. In the same manner the shear stress units of dynes per square centimeter, dyn/cmhave been replaced by Pascals, where 10 dyn/cm = 1 Pa, and newtons per square meter, where 1 N/m = 1 Pa. Shear rate is AH/AX, or length /time/length, so that values are given as per second (s ) in both systems. The SI units for kinematic viscosity are square centimeters per second, cm /s, ie, Stokes (St), and square millimeters per second, mm /s, ie, centistokes (cSt). Information is available for the official Society of Rheology nomenclature and units for a wide range of rheological parameters (11). [Pg.167]

For the 1994 crops, 33 beet sugar factories in the United States processed 28.8 X 10 t of beets from 586,000 ha into 4.23 x 10 t (93 x 10 Cwt) of sugar 56% of the domestic production and 47% of the U.S. market. Cwt or hundred-weight of sugar is 100 lbs and is the common unit of commerce in the United States. This is a record level of production, an increase of 12% from the 1990 and 1991 crops. The average factory has a daily processing capacity of 4885 t compared to <3700 t in 1982. Since 1994, three factories in California have been closed and the constmction of one new factory has been announced for central Washington State. European factories process 10,000—15,000 t/d. [Pg.23]

The dimensions of permeabiUty become clear after rearranging equation 1 to solve for P. The permeabiUty must have dimensions of quantity of permeant (either mass or molar) times thickness ia the numerator with area times a time iaterval times pressure ia the denomiaator. Table 1 contains conversion factors for several common unit sets with the permeant quantity ia molar units. The unit nmol/(m-s-GPa) is used hereia for the permeabiUty of small molecules because this unit is SI, which is preferred ia current technical encyclopedias, and it is only a factor of 2, different from the commercial permeabihty unit, (cc(STP)-mil)/(100 in. datm). The molar character is useful for oxygen permeation, which could ultimately involve a chemical reaction, or carbon dioxide permeation, which is often related to the pressure in a beverage botde. [Pg.487]

The water-vapor transmission rate (WVTR) is another descriptor of barrier polymers. Strictly, it is not a permeabihty coefficient. The dimensions are quantity times thickness in the numerator and area times a time interval in the denominator. These dimensions do not have a pressure dimension in the denominator as does the permeabihty. Common commercial units for WVTR are (gmil)/(100 in. d). Table 2 contains conversion factors for several common units for WVTR. This text uses the preferred nmol/(m-s). The WVTR describes the rate that water molecules move through a film when one side has a humid environment and the other side is dry. The WVTR is a strong function of temperature because both the water content of the air and the permeabihty are direcdy related to temperature. Eor the WVTR to be useful, the water-vapor pressure difference for the value must be reported. Both these facts are recognized by specifying the relative humidity and temperature for the WVTR value. This enables the user to calculate the water-vapor pressure difference. Eor example, the common conditions are 90% relative humidity (rh) at 37.8°C, which means the pressure difference is 5.89 kPa (44 mm Hg). [Pg.487]

The second term in brackets in equation 36 is the separative work produced per unit time, called the separative capacity of the cascade. It is a function only of the rates and concentrations of the separation task being performed, and its value can be calculated quite easily from a value balance about the cascade. The separative capacity, sometimes called the separative power, is a defined mathematical quantity. Its usefulness arises from the fact that it is directly proportional to the total flow in the cascade and, therefore, directly proportional to the amount of equipment required for the cascade, the power requirement of the cascade, and the cost of the cascade. The separative capacity can be calculated using either molar flows and mol fractions or mass flows and weight fractions. The common unit for measuring separative work is the separative work unit (SWU) which is obtained when the flows are measured in kilograms of uranium and the concentrations in weight fractions. [Pg.81]

The Iduematic viscosity (v) is defined as the ratio of the absolute viscosity to density at the same temperature and pressure. The most common unit corresponding to the poise is the stoke (1 cmVsec). The SI unit would be mVsec. [Pg.406]

The quantity of a solute adsorbed can be given conveniently in terms of moles or volume (for adsorption) or ion-equivalents (for ion exchange) per unit mass or volume (dry or wet) of sorbent. Common units for adsorption are moV(m of fluid) for the fluid-phase concentration Cj and moV(kg of clean adsorbent) for adsorbed-phase concentration /ij. For gases, partial pressure may replace concentration. [Pg.1503]

Because of the diversity of the sources for this book the Izod data frequently referred to are expressed in a variety of units according to the test method used and no attempt has been made to convert the data to the use of a common unit. [Pg.193]

Current Density—the average current flowing in an electrolyte (common units are amperes per square foot (A/ft ), amperes per square decimeter (A/dm ), amperes per square centimeter (A/cm ), or milliamperes per square centimeter (mA/cm ) of either cathode or anode surface. [Pg.47]

Common unit for Relationship between rate constant rate constants... [Pg.131]

Some examples and considerations for specific common unit operations follow. [Pg.68]

This step takes the information from Steps 6 and 8. The frequency of an accident multiplied by the consequences is the risk. The consequences need to be in common units to get a measure of the risk. Of course, multiple consequence measures may be used and give multiple risk measures frequency of fatalities, frequency of injuries, frequency of fishkill, frequency of monetary loss. Judgment must be used to rank there relative significance. [Pg.303]

Another viscosity unit is the kinematic viscosity u. This is the ratio of viscosity to density. Common units used for this are the stoke (1 cm- s" ) and the centistoke (1 mm s ). [Pg.47]

Liquid injection incinerators are currently the most commonly used type of incinerator for hazardous waste disposal. A wide variety of units are marketed today, mainly horizontally and vertically fired types a less common unit is the tangentially fired vortex combustor. [Pg.154]

The term g in Equation 2-56 is the dynamic viscosity of the fluid. The dynamic viscosity is the ratio of the shear stress to the shear rate. It has units of (force x time)/(area). The most common unit of viscosity is the centipoise (1 centipoise = 0.01 g/cm - s). Dynamic viscosity may be a function of temperature, pressure, and shear rate. [Pg.172]

A permeability of 1 darcy is much higher than that commonly found in sedimentary rock, particularly reservoir rocks. Consequently, a more common unit is the milli-darcy, where... [Pg.260]

Relatjon.s between common units of power are as follow.s. [Pg.280]

The logarithm base in Eq. (4-5) determines the units of self information. The two most common units are bits (base 2) and nats (base e) the conversion between them is given by... [Pg.195]

The vast majority of the kinetic detail is presented in tabular form. Amassing of data in this way has revealed a number of errors, to which attention is drawn, and also demonstrated the need for the expression of the rate data in common units. Accordingly, all units of rate coefficients in this section have been converted to mole.l-1.sec-1 for zeroth-order coefficients (k0), sec-1 for first-order coefficients (kt), l.mole-1.sec-1 for second-order coefficients (k2), l2.mole-2.sec-1 for third-order coefficients (fc3), etc., and consequently no further reference to units is made. Likewise, energies and enthalpies of activation are all in kcal. mole-1, and entropies of activation are in cal.deg-1mole-1. Where these latter parameters have been obtained over a temperature range which precludes the accuracy favoured by the authors, attention has been drawn to this and also to a few papers, mainly early ones, in which the units of the rate coefficients (and even the reaction orders) cannot be ascertained. In cases where a number of measurements have been made under the same conditions by the same workers, the average values of the observed rate coefficients are quoted. In many reactions much of the kinetic data has been obtained under competitive conditions such that rate coefficients are not available in these cases the relative reactivities (usually relative to benzene) are quoted. [Pg.1]

Relations between common units can be found in Table 5 of Appendix IB. We use these relations to construct a conversion factor of the form... [Pg.31]

Physical quantity Common unit Abbreviation SI equivalent... [Pg.909]

It should therefore not be surprising that for relatively small-scale operations involving solids handling within the fine and intermediate chemicals industry, batch operation is preferred. Similarly, continuous processes that involve precipitation or crystallization, a common unit operation in fine chemicals, are rare. Small-scale examples are known, for instance, a continuous crystallization process was used by Bristol-Myres Squibb in order to improve dissolution rates and bioavailability of the product [12]. The above does indicate that not all process or parts thereof are suited for conversion from B2C, given the current technology. [Pg.311]

A unit equality may link SI units and non-SI units (1 quart = 0.946353 L), decimally related units (10 c = 1 m ), or base units and derived units (1 L = 10 m ). Some of the more common unit equalities are given on the inside back cover of this text. Examples and treat unit conversions. [Pg.33]

Different units are used to count objects in daily life. What is a common unit you use to measure the number of eggs The number of shoes Why aren t moles used to measure these amounts ... [Pg.83]

Suggested techniques for use in estimating the split-fraction coefficients for some of the more common unit operations are given below. [Pg.185]

Viruses are smaller than cells, ranging in size from 0.02 pin to 0.3 pm. A common unit of measure for viruses is the nanometer (abbreviated nm), which is 1000 times smaller than a pm and one million times smaller than a millimeter. [Pg.106]

Thus, after canceling common units, the conversion factor relating slugs to lbm is 32.174 lbm/slug. [Pg.19]

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