Flux Ratios Specified

In some situations it is possible to specify the ratio of the component molar flux to the total flux 

Some situations where the flux ratios may be known are identified below. 

For example, in the synthesis of ammonia (3) from nitrogen (1) and hydrogen (2) following the reaction 

Note that the z sum to unity however, individual z may be positive, zero, or negative. In cases like this one the composition at the surface must be determined in order to satisfy the stoichiometric relations and reaction rate equations (see Examples 8.4.1 and 10.4.1). 

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Inlet reactant fluxes are specified as stoichiometric ratios and Sc of the minimum molar flux to produce this current ... 

Situation 5. Flux ratios are specified. If (fr3CA)Ntot then for a binary system, Eq. (15-56a) becomes... 

Reflectance. The optical property of reflectance is the ratio of reflected flux of light to the incident flux. Unless otherwise specified, the total reflectance is meant, which includes specular and diffuse reflectance. 

The numerator of the right side of this equation is equal to the chemical reaction rate that would prevail if there were no diffusional limitations on the reaction rate. In this situation, the reactant concentration is uniform throughout the pore and equal to its value at the pore mouth. The denominator may be regarded as the product of a hypothetical diffusive flux and a cross-sectional area for flow. The hypothetical flux corresponds to the case where there is a linear concentration gradient over the pore length equal to C0/L. The Thiele modulus is thus characteristic of the ratio of an intrinsic reaction rate in the absence of mass transfer limitations to the rate of diffusion into the pore under specified conditions. 

Model the growth of Si02 in this reactor for the baseline conditions, testing the following two alternate methods for specifying inlet gas composition, (a) Specify that the gas composition (mole fractions) at the inlet manifold are those given above (i.e., a composition boundary condition) (b) Specify that the ratio of the molar fluxes at the manifold are equal to the ratio above (i.e., a flux boundary condition). 

In the correlation method the neutron flux density of the specified region is determined from the ratio of pulse measmement channel count rate to detector sensitivity s(E). If we assume that the neutron spectrum in the area of neutron detector location does not depend on the type of SRP being stored in the pit, then for all the measurements s(E) is a constant value. In the next calculations it can be assumed as 1 and thus, the coimt rate being measured can be assumed equal to the value of proportional neutron flux density. 

The importance (or not) of the distinction between N and P as a model currency is closely related to the concept of the Redfield ratio (Redfield et al. 1963). Because many models impHcidy or expHcitly enforce fixed elemental ratios, the distinction between N and P hmitation is often of fittle importance in models. In most cases a fixed ratio (e.g., Redfield ) model will behave almost identically in terms of primary production, plankton abundance, and carbon fluxes, whether N or P is specified to be the primary fimiting nutrient (the exception is when initial or boundary conditions are drawn from observations in which deviations from the Redfield N P ratio are present). 

Gamma-ray sources for efficiency measurements as standard sources are characterised in terms of photon emission flux in 4tc sr, expressed in s, for each specified gamma-ray. The activity of the source is indicated. When an activity standard is used to determine the efficiency of a y-ray spectrometer as a function of photon energy, certain decay scheme parameters are required (gamma branching ratio, internal conversion coefficient, etc.). In this case, the calibration uncertainty is the combination of the uncertainty on the activity of the standard and of the uncertainties on the parameters of the decay scheme. 

From these equations and data in Table III the value of the molar ratio COHa/CAia for any specified pH can be computed. Because all the added A1 must pass through the monomeric hydrolysis stage, it follows that the flux, ( )A1t, being added to the reactor by the autoburette, can be used in place of CAia to calculate an equivalent OH requirement analogous to COHa. 

The residual depleted mantle (RDM) has a constant volume, which is a free parameter. Mass outflow is specified from plume buoyancy fluxes. The mass inflow contains He and U, with concentrations related to those of the bulk mantle by specified small enrichment factors operating during formation of oceanic lithosphere. The present He/ He ratio is the highest seen at Loihi, while the starting value is solar. 

The location of the capsule is important because the flux profile varies both axially and vertically in the vessel. Rgure 4.4 shows the typical placement of surveillance capsules in the reactor vessel. The capsule will experience a higher neutron flux than the reactor vessel wall, depending on how close to the core the capsule is positioned.The term used to characterize the difference in flux is lead factor, usually defined as the ratio of the neutron flux E> MeV) at the location of the capsule specimens to the peak neutron flux E> MeV) at the RPV inside surface. Sometimes, lead factor is expressed as the ratio of the capsule flux to the flux in the vessel wall at the 1/4-thickness (1/4-T) position (not at the inside wall), so it is important to specify which definition is used in order to avoid confusion. 

Case studies in molecular level resource-ratio analysis decomposed in silico stoichiometric models of E. coli into EFMs (Carlson and Srienc 2004b Carlson 2007, 2009). As mentioned previously, EFMs are minimal biochemical pathways comprised of metabolite transport and chemical reactions the enzyme-based steps require an investment of anabolic resources like nitrogen or iron. EFMs, in this context, represent theoretical proteomes for which investment requirements can be tabulated. Calculation of investment requirements necessitates an assumed relationship between fluxes and enzyme concentrations. This relationship varies depending on specific enzyme properties, as well as the chemical environment. Two scenarios are proposed as bounds on the pathway-level flux-to-enzyme concentration relationships. The first approach is a minimalist relationship between pathway enzymes the concentration ratio of every enzyme pair is set to one. This scenario would utilize varying metabolite pool size and activity modulation including allosteric regulation to achieve a specified flux distribution (this flux-to-enzyme model... 

In deriving an expression for the conversion ratio, account has to be taken of both thermal and epithermal capture of neutrons by the fertile material. Considering a reactor where the fissile material is and the fertile the rate of thermal neutron capture per unit volume in is simply S28< 5 where S28 is the thermal macroscopic absorption cross section of and (j> the thermal neutron flux. (In the present chapter, we use the standard convention of specifying isotope cross sections by where m is... 

A specified volume of II2O added to the blanket has much less effect on breeding ratio than the same amount added to the core. This is a result of both the lower flux in the blanket region and the larger l olume of the system. 

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