Relative quantity

Weighing is the operation of determining the mass of any material as represented by one or more objects or by a quantity of bulk material. Proportioning is the control, by weighing, of relative quantities of two or more ingredients according to a specific recipe in order to make a mixed product, or to prepare the ingredients for use in a chemical process. 

Economic Aspects. The market prices for cinnamyl alcohol quoted in Table 5 have been adjusted to reflect an average price for the relative quantities of the different grades sold. As of this writing, DSM is the only significant suppHer for this material. 

In Secondary Ion Mass Spectrometry (SIMS), a solid specimen, placed in a vacuum, is bombarded with a narrow beam of ions, called primary ions, that are suffi-ciendy energedc to cause ejection (sputtering) of atoms and small clusters of atoms from the bombarded region. Some of the atoms and atomic clusters are ejected as ions, called secondary ions. The secondary ions are subsequently accelerated into a mass spectrometer, where they are separated according to their mass-to-charge ratio and counted. The relative quantities of the measured secondary ions are converted to concentrations, by comparison with standards, to reveal the composition and trace impurity content of the specimen as a function of sputtering dme (depth). 

Quantum well interface roughness Carrier or doping density Electron temperature Rotational relaxation times Viscosity Relative quantity Molecular weight Polymer conformation Radiative efficiency Surface damage Excited state lifetime Impurity or defect concentration... 

There is an interesting consequence to the above discussion on composite peak envelopes. If the actual retention times of a pair of solutes are accurately known, then the measured retention time of the composite peak will be related to the relative quantities of each solute present. Consequently, an assay of the two components could be obtained from accurate retention measurements only. This method of analysis was shown to be feasible and practical by Scott and Reese [1]. Consider two solutes that are eluted so close together that a single composite peak is produced. From the Plate Theory, using the Gaussian form of the elution curve, the concentration profile of such a peak can be described by the following equation ... 

Because some hydrocracking occurs, Powerforming also produces saturated C to Q light hydrocarbons. The methane and ethane formed normally are consumed as refinery fuel. Propane and butane products are frequently marketed as LPG. The relative quantities of each of these products vary considerably with feed quality, operating conditions and octane severity. 

Steam condensate systems often are used to generate lower pressure steam by flashing to a lower pressure. Tien this occurs, some steam is formed and some condensate remains, Tvith the relative quantities depending upon the pressure conditions. Figure 2-53 is a typical situation. 

Theoretical mathematical expression of energy measurement related to the second law of thermodynamics. Essentially a measurement of relative quantities of energy distribution, and reported in units of Btu/lb. or J/kg. 

In principle, a measurement of upon water adsorption gives the value of the electrode potential in the UHV scale. In practice, the interfacial structure in the UHV configuration may differ from that at an electrode interface. Thus, instead of deriving the components of the electrode potential from UHV experiments to discuss the electrochemical situation, it is possible to proceed the other way round, i.e., to examine the actual UHV situation starting from electrochemical data. The problem is that only relative quantities are measured in electrochemistry, so that a comparison with UHV data requires that independent data for at least one metal be available. Hg is usually chosen as the reference (model) metal for the reasons described earlier. 

Praseodymium di-iodide, Prl2, can essentially be made in the same way. If sufficient care is taken to exclude air and moisture, oxidic impurities can be avoided. To avoid the formation of Pr2ls, praseodymium metal is used in excess as chunks to easily remove the unreacted metal after the reaction is completed. The pure compound Prl2 is thus obtained, with a reaction temperature well above the peritectic temperature, around 800 °C. Reaction times seem not to matter much, a few days are usually sufficient, perhaps even less. The cooling procedure, however, is crucial as it determines the phases (I through V) that are formed and their relative quantities. Section 4.3 will deal with this issue. 

Very often, we will not include the reference pressure, p° but implicitly assume that p represents a relative quantity. A reaction is elementary if it occurs in a single step that cannot be divided into further substeps, and proceeds exactly as expressed by the reaction equation (Eq. 1). For an elementary step, the rate equals... 

A cosolvent used as a miscible additive to CO2 changed the properties of the supercritical gas phase. The addition of a cosolvent resulted in increased viscosity and density of the gas mixture and enhanced extraction of the oil compounds into the C02-rich phase. Gas phase properties were measured in an equilibrium cell with a capillary viscometer and a high-pressure densitometer. Cosolvent miscibility with CO2, brine solubility, cosolvent volatility, and relative quantity of the cosolvent partitioning into the oil phase are factors that must be considered for the successful application of cosolvents. The results indicate that lower-molecular-weight additives, such as propane, are the most effective cosolvents to increase oil recovery [1472]. 

In 1895, the worldwide production of raw cocoa or unroasted cocoa beans was about 75,000 metric tons. One hundred years later, raw cocoa production has increased almost 40-fold to the forecasted 1995-1996 production of 2,760,000 metric tons (Table 2).15 The majority of today s world cocoa supply comes from Ghana, Nigeria, Ivory Coast, and the Republic of Cameroon even though cacao is not indigenous to east Africa. Although Africa historically has been and still is the largest producer of the world s cocoa supply, the relative quantities produced within African countries... 

To illustrate the relative quantities vs time curve, see Figures 3 and 4. Here we assume that the product is distilled from a high boiling solvent or high boiling by-products. With 5% P remaining as bottoms, the plant case took four times as long and had three times as much tar when compared with the lab case. 

The solution of HC2H302 and C2H302 in H20 results in the relative quantities of each of the species in the equation as shown under the equation. If H30+ is added to the equilibrium system, the equilibrium shifts to use up some of the added H30+. If the acetate ion were not present to take up the added H30+, the pH would drop. Since the acetate ion reacts with much of the added H, 0+, there is little increase in H30+ and little drop in pH. If OH- is added to the solution, it reacts with the H,0+ present. But the removal of that H30+ is a stress, which causes this equilibrium to shift to the right, replacing much of the H30+ removed by the OH-. The pH does not rise nearly as much in the buffered solution as it would have in an unbuffered solution. 

A most striking result from the work described above is that the composition of the bottoms product and residues from the dissolution reaction did not depend on the chemical structure of the original coal material only their relative quantities differed. This supports the view of a mechanism involving the stabilisation of reactive fragments rather than an asphaltene-intermediate mechanism. The formation of a carbon-rich condensed material as a residue of the reaction and the fact that hydrogen transfer occurred largely to specific parts of the coal further supports this view. 

Reaction takes place only within the plug flow element of the recycle reactor, and the gross product stream from this element is divided into two portions one becomes the net product and the second is mixed with fresh feed. The mixture of the fresh feed and recycle stream is then fed to the plug flow element. By varying the relative quantities of the net product and recycle streams, one is able to obtain widely varying performance characteristics. At... 

Note that for reactions which do not practically proceed in the dark (fifo = 0) the photocatalytic effect can be characterized not by the relative quantity (52) ... 

The proteins uniquely identified in the whole section corresponded to proteins typically found in blood or associated with the extracellular matrix. LCM effectively minimized the presence of these proteins in the microdissected sample. The enrichment effect is better illustrated by comparing the relative quantities of proteins identified in each sample (Fig. 20.2). 

It must be also considered that the reaction rates of different thermal processes which can occur simultaneously are influenced by the treatment conditions (temperature, heating rate, pressure, static or dynamic atmosphere). This will affect the relative quantities of the products formed and in some cases also their nature, when recombination reactions give rise to secondary degradation products. On account of its sensitivity and resolution power Py-GC/MS will also provide useful information on minor components present in a material, including low molecular weight additives and pigments. 

The presence of sulfur compounds, especially thiophene, in the reagents leads to low yields and a dark-colored product. A good grade of thiophene-free benzene should be used. The benzene may be dried by distillation or by allowing it to stand over calcium chloride. The benzene which is recovered in this preparation may be used in future runs after it has been extracted with alkali, washed, and dried. Small amounts of carbon tetrachloride in the benzene do not interfere, since the quantities of benzene and carbon tetrachloride used are in excess of the relative quantity of the aluminum chloride. 

All steady state fluorescence experiments were conducted with the sample placed in a thermostated cell with temperature maintained at 30°C. The concentrations of anthracene and initiator used were 0.000505 and 0.00608 moles per liter, respectively. The relative quantities of solvents (n-propanol and glycerol) were adjusted from 0 to 100% to achieve solutions of different viscosities, while maintaining the same molar concentration of the reactive solutes. 

The variability of a measurement. As in the case of error, above, it may be expressed as an absolute or relative quantity. Standard deviations are the most valuable precision indicators (vide infra). 

Isotope Ratio Mass Spectrometry (IRMS) The measurement of the relative quantity of the different isotopes of an element in a material using a mass spectrometer. 

Beyond the qualitative molecular information afforded by NMR, one can also obtain quantitative information. Depending on the sample, NMR can measure relative quantities of components in a mixture as low as 0.1-1% in the solid state. NMR limits of detection are much lower in the liquid state, often as low as 1000 1 down to 10,000 1. Internal standards can be used to translate these values into absolute quantities. Of course, the limit of quantitation is not only dependent on... 

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