Cold-press capability

For the vast majority of essential oils, meeting these characterization requirements does not require exotic analytical techniques and the identi cation of the constituents is of a routine nature. However, what would the requirements be for very high-volume essential oils, such as orange oil, cold pressed (567,000 kg), or peppermint oil (1,229,000 kg) In these cases, a practical limit must be applied and can be justi ed based on the concept that the intake of these oils is widespread and far exceeds the 10% assumption of MSDI. Based on current analytical capabilities, 0.10% or 0.05% could be used as a reasonable limit of detection, with the lower level used for an essential oil that is known or suspected to contain constituents of higher toxic potential (e.g., methyl eugenol in basil). 

G. Canneri found that the treatment of a suspension of thallium sesquioxide in water with liquid nitrous anhydride, and subsequent evaporation of the soln., even in the cold under reduced press., yields, not thallic nitrite, but thallous nitrate. The latter is also obtained when soln. of thallic sulphate and barium nitrite are mixed in the cold, and the resulting liquid evaporated at low temp. That thallic nitrite is capable of existence in soln., although it cannot be obtained in the solid condition, is shown by the analyses and properties of the soln. The treatment of an aq. soln. of thallic nitrite with alcohol yields a precipitate of the sequioxide. In ethereal soln., thallic nitrite is far more stable, and the salt separates in the solid state on evaporation of the solvent it could not, however, be analyzed directly. Decomposition of thallic nitrite, with formation of thallous nitrate, takes place solely in accordance with the equation T1 (N02)3->TlN03+N2Os, neither intermediate reduction products nor thallous-thallic complex compounds being formed. 

The apparatus used to study densification by compression is shown in Figure 1 (a). It consists of a steel die and piston 2.5 cm in diameter capable of being heated to various temperatures during pressing. The travel of the piston was measured as a function of applied pressure. Ten-gram samples of minus 10 mesh pine sawdust dried at 110 C were held at temperature for 15 min after initial cold compaction at 200 psi, and the pressure was then increased in 300-psi increments to 10,000 psi. The resulting densities are shown as a function of pressure in Figure 2 for temperatures from 100-225 C, Runs were made also at 250 and 300 C, but wood was heavily pyrolyzed in the process and the results were discarded. 

The manufacture of filter presses has become a speciality with several well-known firms of engineers, who construct them in many varieties, to suit special purposes. They may be obtained capable of dealing with substances which either have, during filtration, to be kept at a raised temperature so as not to crystallise out, or which may have to be kept at a low temperature so as not to melt. These purposes are generally effected by channels being provided in the chambers through which steam, hot or cold water may be passed. 

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