Solid formation

Gas-liquid contactors may be operated either by way of gas bubble dispersion into liquid or droplet dispersion in gas phase, while thin film reactors, i.e. packed columns and trickle beds are not suitable for solid formation due... 

It is apparent from DTA studies [1021] of the decompositions of Group IA formates in inert or oxidizing atmospheres that reaction is either preceded by or accompanied by melting. Anion breakdown leading to carbonate production may involve formation of the oxalate, through dimerization [1022] of the postulated intermediate, C02, especially during reaction of the Na and K salts in an inert atmosphere and under isothermal conditions. Oxalate production is negligible in reactions of the Li and Cs formates. Reference to oxalate formation is included here since this possibility has seldom been considered [1014] in discussions of the mechanisms of decompositions of solid formates. 

Proton transfer occurs as well as solid formation.) (c) How many kilograms of lime are required to remove all the phosphoms from a 1.00 X 10 L holding tank filled with contaminated water that is... 

Gallstone (cholelithiasis) A solid formation in the gallbladder or bile duct composed of cholesterol and bile salts. 

Although a few amperometric pH sensors are reported [32], most pH electrodes are potentiometric sensors. Among various potentiometric pH sensors, conventional glass pH electrodes are widely used and the pH value measured using a glass electrode is often considered as a gold standard in the development and calibration of other novel pH sensors in vivo and in vitro [33], Other pH electrodes, such as metal/metal oxide and ISFETs have received more and more attention in recent years due to their robustness, fast response, all-solid format and capability for miniaturization. Potentiometric microelectrodes for pH measurements will be the focus of this chapter. 

Shiying L., Michiaki H., Yoshizo S. and Hiroyuki H., Continuous Experiment Regarding Hydrogen Production by Coal/CaO Reaction with Steam (II)—Solid Formation, Fuel, 85, 1143-1150,2006. 

H. A. Taylor f made a similar experiment with phosphorus trichloride vapour and chlorine, which in glass vessels combine almost instantaneously to give the solid pentachloride. In this instance the combination still took place with immeasurable rapidity in a vessel of paraffin wax. This combination, unlike that of ethylene and bromine, appears to be a homogeneous reaction, since when the trichloride and chlorine are mixed there is a delay of a few seconds due to supersaturation, and then the solid is formed as a cloud which settles slowly to the bottom of the vessel. Some solid formation also takes place on the walls. 

The formation of small particles is favoured when solids formation is maintained via primary nucleation throughout the batch crystallization. A widely used relationship between the nucleation rate and supersaturation is usually given as ... 

Through the choice of the appropriate combination of solvent and operating conditions for a particular compound, PGSS can eliminate some of the disadvantages of traditional methods of particle-size redistribution in material processing. Solids formation by PGSS therefore shows potential for the production of crystalline and amorphous powders with a narrow and controllable size-distribution, thin films, and mixtures of amorphous materials. 

When acidic (pH 3 to 4) mixed solution containing 0.08 M CdCl2 and 1 M NH4SCN (or KSCN) is heated, the solution remains clear because no chemical solid formation takes place. When ITO glass or polycrystalline Ni substrates are cathodized at -0.7 V (vs. SCE) in this solution, although very slowly compared to CBD or ETCD, transparent yellow thin films grow. Film thickness increased... 

The induction time or lag time is the period between cooling (i.e., supercooling as in 3.1.1.1) to the left of Point R in Figure 3.4a, until the time of solid formation. 

Although solvent samples have been observed for approximately one year without any solids formation, work was completed to define a new solvent composition that was thermodynamically stable with respect to solids formation and to expand the operating temperature with respect to third-phase formation.109 Chemical and physical data as a function of solvent component concentrations were collected. The data included BC6 solubility cesium distribution ratio under extraction, scrub, and strip conditions flowsheet robustness temperature range of third-phase formation dispersion numbers for the solvent against waste simulant, scrub and strip acids, and sodium hydroxide wash solutions solvent density viscosity and surface and interfacial tension. These data were mapped against a set of predefined performance criteria. The composition of 0.007 M BC6, 0.75 M l-(2,2,3,3-tetrafluoropropoxy)-3-(4-.sw-butylphenoxy)-2-propanol, and 0.003 M TOA in the diluent Isopar L provided the best match between the measured properties and the performance criteria. 

A variety of processing approaches has been tested to control solids formation, typically by modifying the composition of the feed mixture or the recycle. The addition of hydrogenated middle distillates increases conversion and suppresses solids formation (Carlson et al., 1958 Langer et ah, 1962), and the success of this approach is normally attributed to the donation of hydrogen from the solvent to the bitumen. 

Crystalline-Solid Formation versus Glass Formation... 

How does glass formation differ from crystalline-solid formation ... 

Crystalline solid formation is a slow process that can occur at room temperature.. It can occur through chemical change (see Activity 4.1). It can occur when a supersaturated solution is disturbed. It can also occur when a saturated solution slowly evaporates. 

Students will state observed differences between crystalline-solid formation and glass formation. 

Demonstration 4.1 The Difference Between Crystalline-Solid Formation and Glass Formation... 

By and large, ejectors and motionless mixers have similar mass transfer performance at a given gas-to-liquid flow ratio and energy input. However, ejectors have a number of benefits and drawbacks compared to a motionless mixer. On the positive side, the ejector suction means that a pressurized gas supply is not required. The unrestricted mixing tube means that solid formation due to reaction is not problematic. Against this, the operation is sensitive to changes in the gas-liquid flow ratio and diameter/length ratio. Gas-to-liquid flow ratios are also more limited in ejectors. 

In soils, the solid phases typically are mixtures of chemical compounds. The generic term used to describe the processes by which these mixtures form is coprecipitation, the simultaneous precipitation of a compound in conjunction with other compounds by any mechanism at any rate. Three broad categories of coprecipitation phenomena have been identified in soils mixed solid formation, adsorption, and inclusion. 

Despite the importance, fundamental understanding of precipitation processes remains fragmentary, and the control of product properties is limited, which is due to restricted experimental access to the key steps of solid formation and to the multitude of influencing parameters. Precipitation basically involves four steps, including the following ... 

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