Density measurement buoyancy

Either directly or indirectly, the concept of density plays an important role in a myriad of scientific operations construction of equipment, preparation of solutions, determination of volumes, accurate weighings, measuring buoyancy of objects, studying properties of gases, and so on. Density is defined as the mass per unit volume, or... 

Thus gas adsorption provides essentially important information on the nanopores from the sub-nanometer level, which is often inherent to a specific molecule. Also the density measurement is necessary for the exact porosity evaluation. The accurate particle and true densities give close porosity. Even He molecules are adsorbed in small nanopores at room temperature and thereby the He replacement method is not fit for determination of the particle density. Authors developed the high pressure He buoyancy method until 10... 

Density measurements. Polymer densities were measured using the neutral buoyancy method using a pyconometer (75). The neutral buoyancy medium was a mixture of tetrachloromethane and hexane. 

NPL (National Physical Laboratory, UK) (2002), Buoyancy Correction and Air Density Measurement [available at http // www.npl.co.uk/mass/guidance/balancetypes.html]. 

In order to eliminate the complications of mass transfer and changing droplet size in the coalescence experiments, the solutions were allowed to equilibrate for at least one month at 25.0 C 0.5°C. Interfacial tension was determined on the spinning drop apparatus in the course of the coalescence experiments. Viscosities were determined using Canon-Fenske viscometers. Density measurements were made on an analytical balance by measuring the buoyancy of a solid plummet immersed in the fluid. 

Although more labor-intensive and less efficient, information on the densification kinetics and densification can also be obtained from density measurements on different individual samples as a function of time for otherwise identical sintering conditions. Bulk density measurements on <92% dense sintered samples containing open porosity can be determined from the measured mass and dimensions of the compact, while Archimedes method works well for closed pore, >92% dense bodies. The density of closed pore samples can also be determined by pycnome-try (e.g., helium pycnometry),, 37 mercury porosimetry, and by the sink-float method (i.e., whereby the buoyancy of the sample is assessed and compared in different density liquids). Density can also be estimated from micrographs using quantitative stereology. 

The quantity Z =Z(p, T,ypy ) is the compressibility factor of the gas mixture which today in fairly wide ranges of pressure and temperature is known for many industrial gas mixtures [4.19], [4.20], The masses of the sorptive gas components in adsorption equilibrium (m[,i = l,2) can be calculated from gas density measurements by the buoyancy of a sinker coupled to the magnetic suspension balance, i. e. the equation... 

MSB...magnetic suspension balance, Si...sinkerforgas density measurements by buoyancy effect. 

For binary coadsorption equilibria with non-isomeric gas components (Ml 7 M2) gravimetric-chromatographic measurements are not needed. Instead densimetric-volumetric measurements are recommended [6]. The measurement procedure can be grasped from the experimental scheme sketched in Figure 5 below. Basically, a gas expansion experiment is combined with a density measurement of the equilibrium sorptive gas mixture by the buoyancy of a sinker coupled to a magnetic suspension balance. 

Elastic Modulus. The elastic modulus was determined by combining the results of acoustic-wave velocity and density (aqueous buoyancy) measurements. 

Bridgman flexible bellows with slide wire 369 Brillouin scattering 719-726 broken aspects, textures 439 bubble domains, ultrasonic fields 557 building blocks, synthesis 98 bulk fluids, molecular modelling 77 bulk SHG, optical properties 577 bulk systems, large-scale simulation 83 buoyancy method, density measurements 332 Burgers vectors, defects 425,447... 

Density measurements are closely akin to liquid level measurements because both are often required simultaneously to establish the mass contents of a tank, and the same physical principle may often be used for either measurement. Thus, the methods of density determination include the techniques of direct weighing, buoyancy, differential pressure, capacitance, optical, acoustic, ultrasonic, momentum, rotating paddle, transverse momentum, nuclear radiation attenuation, and nuclear magnetic resonance. Each of the principles involved will be discussed along with its relative merits and shortcomings. 

To ensure that S eas is determined accurately, we calibrate the equipment or instrument used to obtain the signal. Balances are calibrated using standard weights. When necessary, we can also correct for the buoyancy of air. Volumetric glassware can be calibrated by measuring the mass of water contained or delivered and using the density of water to calculate the true volume. Most instruments have calibration standards suggested by the manufacturer. 

For normally buried tanks, tanks with measures against buoyancy and tanks with a secondary containment, no difficulties are to be expected for protection current densities below 200 fJ.A m. On the other hand, the protective action can... 

With this relationship for all samples was calculated from ninh This M is used for evaluating the reaction data. The ultracen rifuge (u.c measurements were carried out in a Spinco model E analytical ultracentrifuge, with 0.4% solutions in 90% formic acid containing 2.3 M KCl. By means of the sedimenta- ion diffusion equilibrium method of Scholte (13) we determine M, M and M. The buoyancy factor (1- vd = -0.086) necessary for tSe calculation of these molecular weights from ultracentrifugation data was measured by means of a PEER DMA/50 digital density meter. 

In well-developed fires, the convective heat fraction is typically measured at more than about 65% of the total heat release rate (Heskestad, 2002). This heat is carried away by the plume above the flames. Prediction of plume velocity and temperatures above the flames serve as the basis for convective heat transfer calculations where overhead equipment exists. Widely used fire plume theory assumes a point source origin, and uniformity throughout the plume relative to air density, air entrainment, velocity profile, and buoyancy. 

The velocity u0 and the laminar path length x0 can be related to measurable physical quantities by using dimensional analysis. Indeed, the circulatory motion is induced by the buoyancy force gAp, where Ap is the difference between the density near the wall (assumed to be equal to that of the liquid) and the density of the bubble bed... 

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