Dodecane, from dodecanal

Fig. III-9. Representative plots of surface tension versus composition, (a) Isooctane-n-dodecane at 30°C 1 linear, 2 ideal, with a = 48.6. Isooctane-benzene at 30°C 3 ideal, with a = 35.4, 4 ideal-like with empirical a of 112, 5 unsymmetrical, with ai = 136 and U2 = 45. Isooctane-

An improved solvent extraction process, PUREX, utilizes an organic mixture of tributyl phosphate solvent dissolved in a hydrocarbon diluent, typically dodecane. This was used at Savannah River, Georgia, ca 1955 and Hanford, Washington, ca 1956. Waste volumes were reduced by using recoverable nitric acid as the salting agent. A hybrid REDOX/PUREX process was developed in Idaho Falls, Idaho, ca 1956 to reprocess high bum-up, fuUy enriched (97% u) uranium fuel from naval reactors. Other separations processes have been developed. The desirable features are compared in Table 1. 

Water-borne polyurethane coatings are formulated by incorporating ionic groups into the polymer backbone. These ionomers are dispersed in water through neutrali2ation. The experimental 1,12-dodecane diisocyanate (C12DI Du Pont) is especially well suited for the formation of water-borne polyurethanes because of its hydrophobicity (39). Cationomers are formed from IPDI, /V-methyIdiethan olamine, and poly(tetramethylene adipate diol)... 

Example 5 Calculation of the SR Method Use the SR method with the PR equation of state for K values and enthalpy departures. The oil was taken as n-dodecane. To compute stage temperatures and interstage vapor and hquid flow rates and compositions for ahsorher-column specifications shown in Fig. 13-52. Note that a secondary ahsorher oil is used in addition to the main ahsorher oil and that heat is withdrawn from the seventh theoretical stage. 

Dodecane-l,10-dioic acid (decane-1,10-dicarboxylic acid) [693-23-2] M 230.3, m 129°, b 245°/10mm, pK ,t -4.8. Crystd from water, 75% or 95% EtOH (sol 10%), or glacial acetic acid. 

Several components of the organic phase contribute greatly to the character of the final product. The pore size of the gel is chiefly determined by the amount and type of the nonsolvent used. Dodecane, dodecanol, isoamyl alcohol, and odorless paint thinner have all been used successfully as nonsolvents for the polymerization of a GPC/SEC gel. Surfactants are also very important because they balance the surface tension and interfacial tension of the monomer droplets. They allow the initiator molecules to diffuse in and out of the droplets. For this reason a small amount of surfactant is crucial. Normally the amount of surfactant in the formula should be from 0.1 to 1.0 weight percent of the monomers, as large amounts tend to emulsify and produce particles less than 1 yam in size. 

Because all the variables that influence the properties of the final product are known, one can use a statistical design (known as a one-half factorial) to optimize the properties of the GPC/SEC gels. Factorial experiments are described in detail by Hafner (10). For example, four variables at two levels can be examined in eight observations. From these observations the significance of each variable as related to the performance of the gel can be determined. An example of a one-half factorial experiment applied to the production of GPC/SEC gel is set up in Table 5.2. The four variables are the type of DVB, amount of dodecane, type of methocel, and rate of stirring. 

Figure 15.9 Use of heart-cutting for the identification of target compounds in 90% evaporated gasoline. Peak identification is as follows 1, 1,2,4,5-teti amethylbenzene 2, 1,2,3,5-teti amethylbenzene 3, 4-methylindane 4, 2-methylnaphthalene 5, 5-methylindane 6, 1-methylnaphthalene 7, dodecane 8, naphthalene 9,1,3-dimethylnaphthalene. Adapted from Chromatography, 39, A. Jayatilaka and C.F. Poole, Identification of petroleum distillates from fire debris using multidimensional gas chromatography , pp. 200-209, 1994, with permission from Vieweg Publishing.

To identify the specific aldehyde that is actually involved in the light-emitting reaction of living luminous bacteria, Shimomura et al. (1974a) extracted and purified the aldehyde from 40 g each of the bacterial cells of P. phosphoreum, Achromobacter (Vibrio or Photobacterium) fischeri, and an aldehydeless mutant of A. fischeri. The aldehyde fractions were purified, and then oxidized with Tollens reagent (silver oxide dissolved in ammonia) to convert the CHO group into the COOH group. Then the acids obtained were analyzed by mass spectrometry. The results indicated that P. phosphoreum had contained a mixture of aldehydes dodecanal (5%), tetradecanal (63%) and hexadecanal (30%), as shown in Table 2.2. Thus, tetradecanal was clearly predominant in... 

P. phosphoreum. In the case of A. fischeri, the total amount of aldehydes was only 15% of that from P. phosphoreum, which consisted of dodecanal (36%), tetradecanal (32%) and hexadecanal (20%). The contents of aldehydes having the carbon atoms of 10, 11, 13, 15, 17 and 18 were negligibly small in both bacterial species. 

Fig. 2.2 Assay of luciferase by the injection of FMNH2. The assay was initiated by the injection of 1 ml of 50 JtM FMNH2 solution into 1 ml of air equilibrated buffer, pH 7.0, containing 0.1% BSA, luciferase, and 20 gl of 0.01% sonicated suspension of dodecanal. From Baldwin et al., 1986, with permission from Elsevier.

In common with all the higher AB polyamides, PA-12 can be made from either die amino acid or the lactam.12 In practice, PA-12 is made from the cheaper 12-laurolactam (12-dodecane lactam or laboratory-scale synthesis it is advisable to start with the amino acid or a combination of amino acid and lactam. 

FIG. 33 X-Ray Diffraction Patterns of Ammonium Dodecane 1-Sulfonate. 2-D (a) and 3-D plots (b) of oriented samples. Both pictures show the presence of a nonordered smectic phase, since the diffuse, weak, wide-angle diffraction indicates only an average distance between the molecules and the sharp, intense small angle reflections a very well defined layer distance. The reflections are perpendicular to each other, so the structure should correspond to an orthogonal smectic A type. The pictures were obtained using an x-1000 area detector from Siemens. 

The phase diagram for the dodecane 1-sulfonic acid/water system was drawn from data obtained by visual inspection, microscopic observations through a... 

The HLB numbers decrease with increasing chain length, e.g., from 13.25 for sodium decane 1-sulfonate to 9.45 for the C18 homolog [72]. Typical HLB numbers for positional isomers range from 12.3 for sodium dodecane 1-sulfonate to 13.2 for the more hydrophilic 6 isomer [73]. The HLB numbers of alkanesulfonates are less influenced by the isomeric position of the functional group and by substituents than the cM values [68]. HLB numbers can be correlated with partition coefficients for the distribution of a surfactant between the aqueous and oily phases, which emphasizes that the partition coefficient is dependent on the carbon number [68]. 

Copper clusters containing two to four atoms have been formed (94) in argon and methane, whereas large, colloidal-copper particles resulted in dodecane matrices (94). The authors suggested that the "birth of the band structure of copper is clearly visible on passing from the dimer to the tetramer, with CU4 already possessing many of the features of the bulk metal (94). 

The use of the fire fly light-emitting system. Light generation depends on the oxidation of a substance known as luciferin. This is a fatty aldehyde such as dodecanal. An enzyme called luciferase, extracted from fire flies, catalyses the oxidation. The reaction also requires ATP. Thus, light emission measures ATP. 

Figure 2.7 Activity test of an uncoated fused silica capillary after deactivation with poly(phenyliaethylhydrosiloxane), (A), and before deactivation, (B). Precolunn 15 x 0.20 m I.D. coated with SE-54. Test columns 10 a x 0.20 I.D. The column tandem was programmed from 40 to I80 c at a C/min after a 1 min isothermal hold with a hydrogen carrier gas velocity of 50 cm/s. The test mixture contained 10 n-decane, Cg-NH = l-aminooctane, PY 3,5-dimethylpyrimidine, C 2 n-dodecane, - 1-amlnodecane, DMA ...

In the commercial version of the PAMPA assay, a sandwich (Fig. 7.9) is formed from a specially-designed 96-well microtiter plate [pION] and a 96-well microfilter plate [several sources], such that each composite well is divided into two chambers donor at the bottom and acceptor at the top, separated by a 125-pm-thick microfilter disk (0.45 pm pores, 70% porosity, 0.3 cm2 cross-sectional area), coated with a 10% wt/vol dodecane solution of egg lecithin (a mixed lipid containing mainly PC, PE, a slight amount of PI, and cholesterol), under conditions that multilamellar bilayers are expected to form inside the filter channels when the system contacts an aqueous buffer solution [543]. 

Figure 7.17 shows the asymmetry ratios of a series of compounds (acids, bases, and neutrals) determined at iso-pH 7.4, under the influence of sink conditions created not by pH, but by anionic surfactant added to the acceptor wells (discuss later in the chapter). The membrane barrier was constructed from 20% soy lecithin in dodecane. All molecules show an upward dependence on lipophilicity, as estimated by octanol-water apparent partition coefficients, log KdaA). The bases are extensively cationic at pH 7.4, as well as being lipophilic, and so display the highest responses to the sink condition. They are driven to interact with the surfactant by both hydrophobic and electrostatic forces. The anionic acids are largely indifferent... 

The increase of negative charge from 0.6% to 1.1% wt/vol in dodecane (modeling the expected increase between BBM and BBB lipid compositions see Table 7.1) shows further increases to the permeabilities of the dramatically affected molecules, especially amiloride, which becomes effectively more permeable than piroxicam. 

Figure 7.36 shows the log Pe-pH plots for three nonionizable molecules carba-mazepine, caffeine, and antipyrine. As is expected, there is no pH dependence shown neither the molecules, nor the 2% DOPC/dodecane membrane show charge-state changes in the pH interval from pH 3 to 9. 

TABLE 7.15 Intrinsic Permeabilities and Unstirred Water Layer Permeabilities Determined from Iso-pH Dependence of Effective Permeabilities 2% DOPC in Dodecane... 

Figure 7.40 Permeability-pH profiles for ketoprofen under iso-pH conditions for two different PAMPA models unfilled circles = 2% DOPC/dodecane, filled circles = 20% soy lecithin/dodecane. [Reprinted from Avdeef, A., in van de Waterbeemd, H. Lennemas, H. Artursson, P. (Eds.). Drug Bioavailability. Estimation of Solubility, Permeability, Absorption and Bioavailability. Wiley-VCH Weinheim, 2003 (in press), with permission from Wiley-VCH Verlag GmbH.]...

TABLE 7.18 Interpolated Apparent and Membrane Permeabilities Determined from Double-Sink Conditions 20% Soy Lecithin in Dodecane... 

It is difficult to prove that quaternary ammonium compounds can cross lipid bilayers using cell uptake experiments, since several mechanisms may be operative, and separating contributions from each may be very difficult [1]. It may be an advantage to use PAMPA to investigate transport properties of permanently ionized molecules. Of all the molecules whose permeabilities were measured under iso-pH conditions in 2% DOPC/dodecane, verapamil, propranolol, and especially quinine seem to partially violate the pH partition hypothesis, as shown in Figs. 7.47a-c. In Fig. 7.47c, the solid line with slope of +1 indicates the expected effective permeability if the pH partition hypothesis were strictly adhered to. As can be seen at pH 4... 

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