Measurement of volume

Reduced Equations of State. A simple modification to the cubic van der Waals equation, developed in 1946 (72), uses a term called the ideal or pseudocritical volume, to avoid the uncertainty in the measurement of volume at the critical point. 

Possible inaccurate measurement of volume of gas and weight of liquid. 

The cup is a measure of volume widely used in cookbooks. One cup is equivalent to 225 mL. What is the density of clover honey (in grams per milliliter) if three quarters of a cup has a mass of252 g ... 

V = (1000 0.4) ml (from supplier s catalogue), iq (V) = 0.10 ml (standard deviation of replicate measurements of volume of liquid in flask when filled to the calibration mark). 

In order to work out reacting volumes of gases, we can use Gay-Lussac s law of combining volumes When gases react they do so in volumes which bear a simple ratio to each other and to the volumes of the products if they are gases, all measurements of volume being at the same temperature and pressure . 

Cubic Meter (m3) A measure of volume in the metric system. 

As with the weighing of solids on a prescription balance, there are limitations to liquid measuring devices as well. For example, assume that only one pipet having graduations from one to ten milliliters is available, and it is desired to measure one fluid ounce. In such a case, one ounce can be measured by measuring 10 mL three times. Measurement of volumes less than that of the... 

Quite clearly, any measurement of fluid uptake before equilibrium is reached could be misleading. Equally, if there is also extraction, measurement of volume change and other properties should wait until equilibrium, represented by a final plateau condition, is reached. If oxidation or another chemical reaction is taking place an even longer time-... 

The ICF should be written in a language that can be understood by the average study subject.Simple words should be used wherever possible for example, stop instead of discontinue, avoid instead of abstain and cause instead of induce. Many study subjects will not understand technical words such as placebo and erythema. Measurements of volumes should be described in domestic measurement such as teaspoonfuT rather than in millilitres. For therapeutic trials ICFs should include a description or mention of alternative procedures or courses of treatment. 

Positive displacement vacuum pumps. Measurement of performance characteristics. Part 1 - Measurement of volume rate of flow (pumping speed) 12/93... 

Medium-chain alcohols such as 2-butoxyethanol (BE) exist as microaggregates in water which in many respects resemble micellar systems. Mixed micelles can be formed between such alcohols and surfactants. The thermodynamics of the system BE-sodlum decanoate (Na-Dec)-water was studied through direct measurements of volumes (flow denslmetry), enthalpies and heat capacities (flow microcalorimetry). Data are reported as transfer functions. The observed trends are analyzed with a recently published chemical equilibrium model (J. Solution Chem. 13,1,1984). By adjusting the distribution constant and the thermodynamic property of the solute In the mixed micelle. It Is possible to fit nearly quantitatively the transfer of BE from water to aqueous NaDec. The model Is not as successful for the transfert of NaDec from water to aqueous BE at low BE concentrations Indicating self-association of NaDec Induced by BE. The model can be used to evaluate the thermodynamic properties of both components of the mixed micelle. 

Frequency-Dependent Specific Heat. We mention measurements of volume relaxation through the frequency-dependent specific heat Cn(co) as in fluids near the glass transition [52]. This is feasible when the experimental frequency co is of the order fi0 in small gels. The deviations of the entropy, temperature, and volume are related by SS = CV5T + (dH/dT)v8Vand the relaxation equation reads... 

The procedure outlined above has many possible sources of both random and systematic error. The measurements of volume and of mass will not be perfectly accurate if the equipment has been correctly calibrated and the laboratory technique is good, these errors are random (equally likely to be positive or negative). The masses of the two nuclei are not perfectly known, but these errors can be assumed to be random as well (the error bars are the results of many careful measurements). The silver chloride and water will both have impurities, which will tend to make systematic errors. Some impurities (e.g., chloride ions in the water) would tend to make the measured solubility product smaller than the true value. Some impurities (e.g., sodium chloride in the silver chloride) would tend to make the measured solubility product larger than the true value. Finally, even without impurities, there is one (probably small) systematic error... 

K Measurement of volume change as a function of pressure a. Dilatometer method (Bekkedahl, 1949) (sample immersed in mercury) b. Piston-cylinder method (Warfield, 1980) (cylindrical sample in bore of rigid container under varying pressure) Combined measurement of speed of longitudinal and shear waves (Hartmann, 1980) K = p(ul lush)... 

Used to study the composition and -> Volume of Explosion Gases. It consists of a heavy steel case sealed by a screw cap. The construction withstands the dynamic shock of a detonating explosive sample. The gas developed can be vented by a valve in the screw cap for measurement of volume and for gas analysis. 

Note Any of these prefixes may be combined with any of the symbols permitted within the SI. Thus, kPa and GPa will both be common combinations in measurements of pressure, as will mL and cm for measurements of volume and length, respectively. As a general rule, however, the prefix chosen should be 10 raised to that multiple of 3 that will bring the numerical value of the quantity to a positive value less than 1000. 

Rabbit 4 Whole body 50,100,200 30 min Lung measurements of volume-pressure relationships and inspiratory-expiratory flow rate taken periodically between 30 min and 60 d after exposure. No effects observed at 50 ppm. Alterations in flow rate ratios observed at 100 ppm and 200 ppm, recovered after 14 and 60 d, NOAEL 50 LOAEL 100 Barrow and Smith 1975... 

---