Initial vapor pressure

Hasegawa and Sato analyzed motion pictures and radiation measurements at a distance of 15 m from the center of the glass vessel. They then correlated, first, fireball duration and maximum diameter to initial fuel mass and, second, radiation to initial vapor pressure. 

Fig.4.8. Oscilloscope traces of variation of the electric conductivity of a ZnO sensor upon admission of isopropyl alcohol vapor to the vessel (the initial vapor pressure is 0.01 Torr) at the temperature of 390 C (/), 370 C (2), 350 C (5), 320 C (4), and upon admission of H2 at the temperature of 390 C (5).

In all cases, the fraction of heat energy radiated, F, lies between 0.2 and 0.4. For more detailed modeling, a correlation giving based on initial vapor pressure of the fluid at ambient temperature (Roberts, 1982) can be used ... 

Grams monomer/mole initiator Vapor pressure osmometry Light scattering... 

Research clear octane (R + 0) Research leaded octane (R + 3) Motor clear octane (M + 0) Motor leaded octane (M + 3) Distributed clear octane (D + 0) Front end clear octane (FE + 0) Vapor pressures Initial vapor pressure (IVP)... 

Initial vapor pressure the vapor pressure of a liquid of a specified temperature and zero percent evaporated. 

Fig. 6 Calculated contributions to the pressure rise in a manometric temperature measurement experiment. Calculations were made for a typical product with an initial ice temperature of —20°C, corresponding to an initial vapor pressure of 775mTorr. Open circles = effect 1, sublimation open triangles = effect 2, dissipation of temperature gradient open squares = effect 3, heat flow from shelf to product filled circles = sum of all effects. (Adapted from Ref...

The same type of calculation can be carried out for a dissociating species such as HNO. Assuming that the initial vapor pressure is... 

The different cuts obtained are collected their initial and final distillation temperatures are recorded along with their weights and specific gravities. Other physical characteristics are measured for the light fractions octane number, vapor pressure, molecular weight, PONA, weight per cent sulfur, etc., and, for the heavy fractions, the aniline point, specific gravity, viscosity, sulfur content, and asphaltene content, etc. 

Some mention should be made of perhaps the major topic of conversation among surface and colloid chemists during the period 1966-1973. Some initial observations were made by Shereshefsky and co-workers on the vapor pressure of water in small capillaries (anomalously low) [119] but especially by Fedyakin in 1962, followed closely by a series of papers by I>eijaguin and co-workers (see Ref. 120 for a detailed bibliography up to 1970-1971). 

Chloroacetyl chloride [79-04-9] (CICH2COCI) is the corresponding acid chloride of chloroacetic acid (see Acetyl chloride). Physical properties include mol wt 112.94, C2H2CI2O, mp —21.8 C, bp 106°C, vapor pressure 3.3 kPa (25 mm Hg) at 25°C, 12 kPa (90 mm Hg) at 50°C, and density 1.4202 g/mL and refractive index 1.4530, both at 20°C. Chloroacetyl chloride has a sharp, pungent, irritating odor. It is miscible with acetone and bensene and is initially insoluble in water. A slow reaction at the water—chloroactyl chloride interface, however, produces chloroacetic acid. When sufficient acid is formed to solubilize the two phases, a violent reaction forming chloroacetic acid and HCl occurs. 

Health and Safety Factors. Because of their high vapor pressures (methyl vinyl ether is a gas at ambient conditions), the lower vinyl ethers represent a severe fire hazard and must be handled accordingly. Contact with acids can initiate violent polymerization and must be avoided. Although vinyl ethers form peroxides more slowly than saturated ethers, distillation residues must be handled with caution. 

Anionic polymerization of vinyl monomers can be effected with a variety of organometaUic compounds alkyllithium compounds are the most useful class (1,33—35). A variety of simple alkyllithium compounds are available commercially. Most simple alkyllithium compounds are soluble in hydrocarbon solvents such as hexane and cyclohexane and they can be prepared by reaction of the corresponding alkyl chlorides with lithium metal. Methyllithium [917-54-4] and phenyllithium [591-51-5] are available in diethyl ether and cyclohexane—ether solutions, respectively, because they are not soluble in hydrocarbon solvents vinyllithium [917-57-7] and allyllithium [3052-45-7] are also insoluble in hydrocarbon solutions and can only be prepared in ether solutions (38,39). Hydrocarbon-soluble alkyllithium initiators are used directiy to initiate polymerization of styrene and diene monomers quantitatively one unique aspect of hthium-based initiators in hydrocarbon solution is that elastomeric polydienes with high 1,4-microstmcture are obtained (1,24,33—37). Certain alkyllithium compounds can be purified by recrystallization (ethyllithium), sublimation (ethyllithium, /-butyUithium [594-19-4] isopropyllithium [2417-93-8] or distillation (j -butyUithium) (40,41). Unfortunately, / -butyUithium is noncrystaUine and too high boiling to be purified by distiUation (38). Since methyllithium and phenyllithium are crystalline soUds which are insoluble in hydrocarbon solution, they can be precipitated into these solutions and then redissolved in appropriate polar solvents (42,43). OrganometaUic compounds of other alkaU metals are insoluble in hydrocarbon solution and possess negligible vapor pressures as expected for salt-like compounds. 

SJng Je Rod-Fed Electron Beam Source. The disadvantages of multiple sources for alloy deposition can be avoided by using a single wire-fed or rod-fed source (Fig. 3) (3). A molten pool of limited depth is above the soHd rod. If the equiUbrium vapor pressures of the components of an alloy A B are in the ratio of 10 1 and the composition of the molten pool is A qB, under steady-state conditions, the composition of the vapor is the same as that of the soHd being fed into the molten pool. The procedure can be started with a pellet of appropriate composition A qB on top of a rod A B to form the molten pool initially, or with a rod of alloy A B to evaporate the molten pool until it reaches composition A qB. The temperature and volume of... 

Vinyl acetate is a colorless, flammable Hquid having an initially pleasant odor which quickly becomes sharp and irritating. Table 1 Hsts the physical properties of the monomer. Information on properties, safety, and handling of vinyl acetate has been pubUshed (5—9). The vapor pressure, heat of vaporization, vapor heat capacity, Hquid heat capacity, Hquid density, vapor viscosity, Hquid viscosity, surface tension, vapor thermal conductivity, and Hquid thermal conductivity profile over temperature ranges have also been pubHshed (10). Table 2 (11) Hsts the solubiHty information for vinyl acetate. Unlike monomers such as styrene, vinyl acetate has a significant level of solubiHty in water which contributes to unique polymerization behavior. Vinyl acetate forms azeotropic mixtures (Table 3) (12). 

A minimum volatihty is frequently specified to assure adequate vaporization under low temperature conditions. It can be defined either by a vapor pressure measurement or by initial distillation temperature limits. Vaporization promotes engine start-up. Fuel vapor pressure assumes an important role particularly at low temperature. For example, if fuel has cooled to —40°C, as at arctic bases, the amount of vapor produced is well below the lean flammabihty limit. In this case a spark igniter must vaporize enough fuel droplets to initiate combustion. Start-up under the extreme temperature conditions of the arctic is a major constraint in converting the Air Force from volatile JP-4 to kerosene-type JP-8, the military counterpart of commercial Jet Al. 

The reaction involves two electrons per thionyl chloride [7719-09-7] molecule (40). Also, one of the products, SO2, is a Hquid under the internal pressure of the cell, facihtating a more complete use of the reactant. Finally, no cosolvent is required for the solution, because thionyl chloride is a Hquid having only a modest vapor pressure at room temperature. The electrolyte salt most commonly used is lithium aluminum chloride [14024-11-4] LiAlCl. Initially, the sulfur product is also soluble in the electrolyte, but as the composition changes to a higher SO2 concentration and sulfur [7704-34-9] huA.ds up, a saturation point is reached and the sulfur precipitates. 

Although pressure P is to be determined, an estimate is required to permit any X T.E calculations at all. A reasonable initial value is the sum of the pure-species vapor pressures, each weighted by its known hquid-phase mole fraction. 

The chains of hollow carbon may be initially chains consisting of Ni (or carbide) particles covered with graphitic carbon. The chains lying on the hot surface of the cathode are heated, and Ni atoms evaporate through defects of the outer graphitic carbon because the vapor pressure of Ni is much higher than carbon. Thus, the carbon left forms hollow graphitic layers. 

Assume an initial split of components in the inlet that yields the desired vapor pressure. That is, assume a split of each component between the tower overhead (gas) and bottoms (liquid). There are various rules of thumb that can be used to estimate this split in order to give a desired vapor pressure. Once the split is made, both the assumed composition of the liquid and the assumed composition of the gas lue known. 

Consider an apparatus in which A and B are two 1.00-L flasks joined by a stopcock C. The volume of the stopcock is negligible. Initially, A and B are evacuated, the stopcock C is closed, and 1.50 g of diethyl ether, C2HsOC2H5, is introduced into flask A. The vapor pressure of diethyl ether is 57 Torr at —45°C, 185 Torr at 0.°C, 534 Torr at 25°C, and negligible below — 86°C. (a) If the stopcock is left closed and the flask is brought to equilibrium at —45°C, what will be the pressure of diethyl ether in flask A (b) If the temperature is raised to 25°C, what will be the pressure of diethyl ether in the flask (c) If the temperature of the assembly is returned... 

Since we did not measure the conversion during the experiment, we computed the equilibrium vapor pressure at the average solution temperature. We believe that, for safety design, the equilibrium vapor pressure is an adequate estimate of the styrene vapor pressure. For example, even at a 50% conversion, the difference is only 10 at the experimental temperatures. Figures 6, 7 and 8 compared the observed pressures with the computed total pressures. The latter were based on the equilibrium vapor pressure. As expected, there were increasing variations in Tests 1, 2 and 3 respectively because of their higher initial conversions. From these figures we can verify that our pressure and temperature measurements were in phase with respect to time. 

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