Composition, quality control and antimicrobial activity of the essential oil of cumin (Cuminum cyminum L.) seeds from Bulgaria that had been stored for up to 36 years

The essential oil of seeds of cumin (Cuminum cyminum L.) from Bulgaria stored for more than 35 years was analyzed by physicochemical methods, GC, GC‐MS and olfactometry and its antimicrobial activity tested using different strains of microorganisms. More than sixty constituents of this cumin oil could be identified as essential volatiles, responsible for the pleasant fresh, clean, spicy (typical cumin‐like) odour of a high quality product. Cumin aldehyde (36%), β‐pinene (19.3%), p‐cymene (18.4%) and γ‐terpinene (15.3%) were the principal compounds found. Antimicrobial testing showed high activity of the essential C. cyminum oil against the mold Aspergillus niger, the Gram (+) bacteria Bacillus subtilis and Staphylococcus epidermidis as well as the yeast Saccharomyces cerevisiae and Candida albicans.     

Electrostrictive properties of ceramics obtained on the basis of ferroelectrk relaxors

We present the results for search of the best ceramic materials for electrostrictive transducers. We performed the following investigations: (1) investigation of different types of ferroelectric, antiferroelectric and non-polar complex oxides with perovskite (OPS) and tetragonal tungsten bronze (TBS) structures; (2) the investigations of the OPS with different degrees of the cations ordering; (3) the measurements of the electrostrictive coefficient Q, Curie-Weiss constant C_W, coefficient of linear thermal expansion λ, polarization P and dielectric permittivity ^σ_r; (4) the X-ray analysis of the structure. The electrostrictive deformation may be very high and the relative strain can be of the order 10^-3 in such materials.     

Manufacturing hollow parts by extension at the internal surface

A theory of extension at the internal surface of a hollow blank has been developed. All the design formulas required for such extension processes have been derived. The accuracy and reliability of the formulas is confirmed by comparison with experimental data. Extension at the inner surface is shown to be highly effective.     

Influence of a reaction mixture streamline on partial oxidation of methane in an asymmetric microchannel reactor

Partial oxidation of methane (POM) has been tested in an asymmetric microchannel reactor with different inlet configurations. One inlet of the reactor provided successive splitting of an inlet flow into parallel channels, whereas the opposite inlet allowed the inlet flow to enter the parallel channels simultaneously. It was found that concentrations of carbon monoxide and carbon dioxide changed by 20–30% and the conversion of methane changed by 5–20%, depending on the rate and direction of the inlet flow. The hydrogen production rate practically did not depend on the inlet configuration and equaled 15 l/h at the inlet flow rates from 600 to 1400 cm³/min and at the methane conversion of 80%. The data obtained demonstrated that the use of different operating modes of the asymmetric microreactor allows changing the composition of produced syngas.     

Photocatalytic hydrogen evolution from aqueous solutions of organophosphorous compounds

Photocatalytic hydrogen production from water solutions of dimethyl methylphosphonate (DMMP), trimethyl phosphate (TMP), triethyl phosphate (TEP), and radiation protective amine WR 2721, that imitate nerve chemical warfare agents was studied for the first time. Platinized titianium dioxide Degussa P25 was used as catalyst. No significant hydrogen evolution was detected without organic electron donors – sacrificial agents.     

Stamping of Nonuniform Channels. 5. Calculation Methods for Channel Extrusion. 5.1. Formulas

Russian Engineering Research - Formulas are derived for the most important parameters of channel extrusion.     

Stamping of Nonuniform Channels. 4. Deformed State of the Workpiece on Channel Extrusion. 4.2. Deformation under the End of the Punch

Russian Engineering Research - Attention focuses on determining the deformed state of the workpiece in free channel extrusion. The formulas obtained permit calculation of the accumulated strain at...