Volumetric measurements

It is likely that volumetric measures were used for quantity deterrnination when commodities were first bartered however, it has been established with certainty that weighing scales or balances have been in use for at least 7,000 years (1). Measuring by weight instead of by volume eliminates some very considerable inaccuracies from, for example, changes in specific gravity of liquids with temperature, or changes in density of solids owing to voids. 

Density is lower Verify proper temperatures before drumming. and drum may be, volumetric measurement overfilled due to high material temperatures. CCPS G-15 CCPS G-22 CCPS G-29... 

To estimate the current yield of magnesium alloys, the weight loss is determined indirectly over the volumetric measurement of the evolved hydrogen in the apparatus in Fig. 6-9 in Section 6.2.4. The mass balance for oxygen-free media follows from Eqs. (6-1) and (6-5a,b) or (6-14) ... 

Iron was present as Fe " in the calcined precursors. For all the catalysts the reduction procedure described in Sec. 2.1 resulted in incomplete reduction of the Fe to metallic iron. This is in agreement with the findings of previous authors [6,11]. The individual percentage reductions of Fe to Fe°, as determined by the separate gravimetric and volumetric measurements (Sec. 2.2), are shown in Table 1. The values are calculated on the assumption that all the Fe is reduced to Fe prior to the onset of reduction to Fe°. There is good agreement between the two methods. Table 1 also records the actual Fe/(Fe + Mg) ratio in the catalysts as determined by atomic absorption spectroscopy (AAS) on the calcined precursors. 

J. Gotz, D. Grog, P. Kohler 2003, (Online observation of dough fermentation by magnetic resonance imaging and volumetric measurements), Zeitschrift Lebensm.-Unters. F A (Eur. Food Res. Technol.) 217, 504-511. 

The determination of these curves requires not only the measurement of small amounts of heat in a microcalorimeter, but also the simultaneous determination of the corresponding quantity of adsorbed gas. Volumetric measurements are to be preferred to gravimetric measurements for these determinations because it would be very difficult indeed to ensure a good, and reproducible, thermal contact between a sample of adsorbent, hanging from a balance beam, and the inner cell of a heat-flow calorimeter. 

All items of equipment must be considered, including balances and volumetric measuring devices, not just the expensive equipment. In terms of instrumentation, while a method using a mass spectrometer may be ideal for the study, if no such equipment is available the job will have to be contracted out to another laboratory, or another approach agreed with the customer. Neutron activation or radiochemical measurements require special equipment and dedicated laboratory facilities and safety procedures. Such techniques are often not generally available and are better left to specialist laboratories. 

The present paper focuses on the interactions between iron and titania for samples prepared via the thermal decomposition of iron pentacarbonyl. (The results of ammonia synthesis studies over these samples have been reported elsewhere (4).) Since it has been reported that standard impregnation techniques cannot be used to prepare highly dispersed iron on titania (4), the use of iron carbonyl decomposition provides a potentially important catalyst preparation route. Studies of the decomposition process as a function of temperature are pertinent to the genesis of such Fe/Ti02 catalysts. For example, these studies are necessary to determine the state and dispersion of iron after the various activation or pretreatment steps. Moreover, such studies are required to understand the catalytic and adsorptive properties of these materials after partial decomposition, complete decarbonylation or hydrogen reduction. In short, Mossbauer spectroscopy was used in this study to monitor the state of iron in catalysts prepared by the decomposition of iron carbonyl. Complementary information about the amount of carbon monoxide associated with iron was provided by volumetric measurements. 

A concentrated essential oil. Folding is a gravimctric/volumetric measure of the strength of a concentrated essential oil expressed as a multiple of a standard. A folded Citrus oil would be compared to the expressed oil (steam distilled oil in the case of distilled Lime oil), e.g. 5 x Orange oil. 

Litre—is defined as the volume occupied hy one kilogram of water at its temperature of maximum density (4°C) and subjected to normal atmospheric pressure . The litre is considered as the standard unit of volume for all volumetric measurements. 

Compared to other biomolecular systems, lipid bilayer membranes and lyotropic lipid mesophases in general have been shown to respond most sensitively to hydrostatic pressure. The methods used in the high pressure studies have mainly included X-ray and neutron diffraction, fluorescence, IR and Raman spectroscopy, light transmission and volumetric measurements. Only a small amount of work has been performed using NMR techniques combined with high-pressure, a field which was pioneered by Jonas and co-workers " although the method is very powerful, non-invasive and allows the study of a series of structural and dynamic properties of the systems in detail and with atomic resolution. 

Reyes, A., Haro, M., Gascon, T, Artigas, H., and Lafuente, C. Vapor-liquid equilibrium and volumetric measurements for binary mixtures of 1,4-dioxane with isomeric chlorobutanes, / Chem. Eng. Data, 44(4) 887-891. 2003. 

Solutions were prepared in an inert atmosphere box. Volumetric measurements based upon density were used. Stock solutions appeared stable for several months in the box. Hypodermic syringes and small volumetric flasks were used to measure and store the solutions. 

C. Large-scale oxidation protocol. The large-scale oxidations reactions were carried out in a 300mL Parr autoclave equipped with an injection port, a thermocouple port, a septa sealed addition port and port connected to the volumetric measurement and gas supply module. The module consists of a forward pressure regulator and a calibrated ballast reservoir. The pressure in the reactor and in the ballast reservoir is monitored constantly and the pressure drop in the ballast reservoir is constantly converted into moles of oxygen uptake recorded vs. the time. 

The desire is always to load a specific weight of expl. This objective can be achieved to a sufficient degree of accuracy for many purposes by volumetric control, as in commercial blasting caps and squibs. The two most common volumetric measuring devices are scoops and charging plates. Scoops (Fig 1)... 

The results obtained by Loebenstein and Deitz agreed with vacuum volumetric measurements on a large variety of samples with a wide range of surface areas. They were also able to establish that the quantities of nitrogen adsorbed were independent of the presence of helium. 

With krypton, the ability to use larger samples of low-area powders facilitates measuring low surface areas because larger signals are generated in the absence of thermal diffusion. Also, as is true for nitrogen, krypton measurements do not require void volume, or ideality corrections, nor is thermal transpiration a factor as in the volumetric measurements. 

Volumetric measurements require that adsorbed volumes be corrected for ideality. The continuous flow method does not require this correction because the detector senses the gas concentration change at ambient temperature and pressure. Gravimetric apparatus measure the adsorbed weight directly and needs no correction for deviations from ideality. 

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