Separator yield

Cadmium occurs primarily as sulfide minerals ia ziac, lead—ziac, and copper—lead—ziac ores. Beneftciation of these minerals, usually by flotation (qv) or heavy-media separation, yields concentrates which are then processed for the recovery of the contained metal values. Cadmium follows the ziac with which it is so closely associated (see Zinc and zinc alloys see also Copper Lead). 

Consequently, inappropriate (P-6) and appropriate (P-6/S-200) separations yield significantly different results for the degree of polymerization distribution and average values of degree of polymerization (Fig. 16.27). In a first and qualitative evaluation, dp distribution achieved from P-6/S-200 differs significantly in symmetry from the dp distribution of P-6. In particular, differences in separation performance become obvious for high dp components. In a... 

The amyl alcohol and sodium nitrite are mixed in a flask (500 C.C.), and whilst the mixture is cooled in ice-water, the cone, sulphuric with constant shaking. Towards the end of the process a more vigorous reaction sets in, when care must be taken to add the sulphuric acid more slowly. When the whole of the acid has been added, the top layer of amyl nitrite is decanted into a separating-funnel. A little water is then added to the residue and, after shaking, a further quantity of amyl nitrite separates and is decanted as before. The whole of the amyl nitrite is then separated from water, dehydrated over calcium chloride and distilled. The liquid boiling at 95—100° is collected separately. Yield, 30—35 grams. 

After standing for several hours a small amount of precipitate (about 2 to 3 mg) was formed and was then separated from the solution. This solution was diluted with an additional 2 ml of acetone and again allowed to stand for several hours. During this time about 4 to 5 mg of noncrystalline precipitate formed. This solid was separated from the solution and an additional 2 ml of acetone was added to the solution. On standing, vitamin began to crystallize in the form of red needles. After standing for 24 hours, the crystalline material was separated, yield 12 mg. By further dilution of the mother liquor with acetone additional crystalline precipitate formed (from U.S. Patent 2,738,302). 

A mixture of phenacyl 2-aminobenzoate (3.0 g, 12 mmol), POCl3 (9 mL, large excess) and benzene (50 mL) was heated under reflux for 2 h. The mixture was cooled and decanted from a gummy residue, which was repeatedly triturated with hexane. The resulting solid was dissolved in aq EtOH (70 mL) and the solution was neutralized to pH 7 by adding 5% aq NaOH, whereupon the product separated yield 1.65 g (59 %) mp 273-275 C (EtOH). 

An ice-cold solution of diazepinone 5a (1.76 g, 8.8 mmol) in 10% aq K.OH (10 mL, 18 mmol) was treated dropwisc with a solution of dimethyl sulfate (1.4 mL, 11.2 mmol) in MeOH (2mL), whereupon a red solid was precipitated. H20 (10mL) was added and the solid was filtered off, washed with 10% aq MeOH and suspended in MeOH (10 mL). 2M HC1 (15 mL) was added slowly, whereupon the solid dissolved and presently orange crystals of l,5-dimethyl-4-phenyl-l//-1,2-diazepin-6(7//)-one (12) appeared. H20 (10mL) was added and the product was collected yield 0.74g (39%) mp 71-72 C. The filtrate was made alkaline by slowly adding 40% K.OH, whereupon the betaine 13 separated yield 0.76 g (41 %) red plates mp 90-91 C (Et20). 

The benzodiazepine 4-oxide 5 (15 g, 50 mmol) in warm dioxane (200 mL) was cooled to 20 C and hydrogenated at atmospheric pressure in the presence of Raney nickel (20 g). The theoretical volume of hydrogen had been absorbed after 2 h. The precipitated product was dissolved by heating tile mixture and the catalyst was removed by filtration. The product separated yield 14.1 g (99.5%) yellowish plates mp 240-241 C (acetone). 

A suspension of the acetoxy derivative 24b (3.4 g, 10.4 mmol) in EtOH (50 mL) was treated with 4M NaOH (6 mL, 24 mmol). A clear solution resulted, and then a precipitate which dissolved upon the addition of H20 (80 mL). The solution was acidified with HOAc, whereupon the product separated yield 2.4 g (81 %) colorless crystals mp 203-204 0 (EtOH). 

A suspension of the oxime 27 (475 g, 1.70 mol) arid 5% Ru/ C ( 9g) in fvleOH (8 L) was warmed to 50 C and stirred in a closed, evacuated autoclave. Hydrogen was admitted and the pressure inside the autoclave was maintained at 40 psi while the temperature was increased to 68-74 C. The mixture was stirred for 19-24h, cooled and filtered through Filter Aid and the solid was washed with MeOH (2x4 L). The combined filtrate and washings were concentrated to 4 L under reduced pressure, MeCN (4 L) was added and the mixture was again concentrated to 4L and the cycle was repeated twice more. The MeCN solution was cooled to 10 C and benzenesulfonic acid (260 g, 1.64 mol) in MeCN (1.6L) was added, whereupon the benzenesulfonate of the amine 28 separated yield 579 g (80%). The free amine had mp 110-112 C. 

The performance of any type of molecular separator is characterized in terms of its separation factor (enrichment) M and separator yield (efficiency) Y (8). The separator yield is defined as the ratio of the amount of sample entering the mass spectr( eter to that entering the separator, usually expressed as a percentage, it represents the ability of device to allow... 

Measurements of the streak separations yield the repeat distances of the guest molecules along the canal. These measurements have been made5), and the results generally correspond with the known length of the guest molecule in extended conformation. See also Section 6. 

If the ligands are not allowed to be chiral, they can be characterized by a single scalar parameter A. The starting function y> in Eq. (1) is chosen to be a homogeneous polynomial in the A. Since each of the monomial terms in y> separately yields either zero or a function with the desired property, we can consider y> to be a monomial without loss of generality. We choose the monomial to be of the lowest order which will not be annihilated by the operations of Eq. (1). 

The ligands of Table 4 were investigated in the carboxytelomerization reaction using the solvents IPA and IPA/PF-hexane (Table 6). The hgand (P(et - Rf8)3). which showed the best separability, yielded the worst performance (entry 30). We also tested the reaction in the best solvent system of Table 5, the system IPA/PF-hexane. However, as shown in entry 31, the stability of Pd was improved but was still insufficient. The solvent system works quite well, but the main problem remains the activity of the ligand. 

A common technique for separating the water and the oil in a microemulsion is a temperature-induced phase separation, yielding an excess water phase (increasing the temperature) or an excess oil phase (decreasing the temperature). It is the simplest way to separate the oil and the water. Nevertheless this method is quite time consuming and often not complete. In case of enzymatic reaction, a change in temperature can lead to a loss of enzyme stabiUty. 

A liquid/solid separation yields a residue and a solution. The solution is cooled to produce crystalline PbCl2 which is later electrolyzed to lead metal and chlorine in a fused salt cell. The residue consists of elemental sulphur, pyrite and gangue. 

At low enough temperatures vibrational fine structure of aromatic chromophores may be well resolved, especially if they are embedded in a suitable matrix such as argon or N2, which is deposited on a transparent surface at 15 K. This matrix isolation spectroscopy77166 may reveal differences in spectra of conformers or, as in Fig. 23-16, of tautomers. In the latter example the IR spectra of the well-known amino-oxo and amino-hydroxy tautomers of cytosine can both be seen in the matrix isolation IR spectrum. Figure 23-16 is an IR spectrum, but at low temperatures electronic absorption spectra may display sharp vibrational structure. For example, aromatic hydrocarbons dissolved in n-heptane or n-octane and frozen often have absorption spectra, and therefore fluorescence excitation spectra, which often consist of very narrow lines. A laser can be tuned to excite only one line in the absorption spectrum. For example, in the spectrum of the carcinogen ll-methylbenz(a)anthrene in frozen octane three major transitions arise because there are three different environments for the molecule. Excitation of these lines separately yields distinctly different emission spectra.77 Likewise, in complex mixtures of different hydrocarbons emission can be excited from each one at will and can be used for estimation of amounts. Other related methods of energy-... 

Sodium hydroxide is unsatisfactory for this saponification because an organic sodium salt separates, yielding a semi-solid mass. 

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