Analytical method for evaluating the quality of acoustic fields radiated by a multielement therapeutic array with electronic focus steering

The paper presents an analytical method for calculating and analyzing the quality of 3-D acoustic fields of multielement phased arrays used in noninvasive ultrasound surgical devices. An analytical solution for the far field of each of its elements is used when calculating the array field. This method significantly accelerates calculations while preserving the high accuracy of results as compared to conventional direct numerical integration. Radiation from typical phased arrays is calculated using this approach, and the quality of their dynamic focusing is analyzed. Undesired diffraction effects caused by electronic focus steering are considered: an amplitude decrease in the main maximum and the appearance of grating lobes. The quality of dynamic focusing of the acoustic fields of two practically interesting arrays with a quasi-random element distribution (256 and 1024 elements, respectively), as well as of the regular array consisting of 256 elements is compared. In addition as well, a study is made of how the dimensions of the array elements and their spatial distributions affect the dimensions of the areas in which dynamic focusing is possible without occurrence of strong grating lobes and significant decrease in pressure amplitude at the main focus.

     

A study of the globulin of cottonseeds. XXIV. Isolation and characterization of a glycopeptide of the 7S globulin

From a pronase hydrolysate of the 7S globulin of cottonseeds, using a column containing Sephadex G-25 and paper chromatography, a glycopeptide has been isolated which contains in its molecule residues of aspartic acid, glucosamine, and mannose in a ratio of 1:2:5. It has been shown by an analysis of the products of the methylation of the glycopeptide that the carbohydrate chain has a branched structure.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 215–217, March–April, 1981.     

Inclusive deuteron production in <Superscript>16</Superscript>O<Emphasis Type="Italic">p</Emphasis> collisions at a momentum of 3.25 GeV/<Emphasis Type="Italic">c</Emphasis> per nucleon

Experimental data on inclusive deuteron production in ¹⁶Op collisions at high energies were obtained for the first time under conditions of 4π geometry. An irregularity in the momentum spectrum of deuterons in the rest frame of oxygen nuclei is found in the range 0.40 ≤ p ≤ 0.55 GeV/c, and the reasons for its appearance are discussed. The mean multiplicities of secondary fragments are correlated with the presence of deuterons in an event, these correlations being positive for fragments of charge in the range z _f ≤ 4 and negative for fragments of charge in the range 5 ≤ z _f ≤ 7. This is likely to be due to baryon-charge conservation.     

1H NMR study on the solvent effect on imine-enamine tautomerism of the condensation product of gossypol with 4-aminoantipyrine

According to the ¹H NMR data, the condensation product of gossypol with 4-aminoantipyrine in chloroform-d exists in the imine form, while in DMSO-d ₆, as the enamine tautomer. The condensation product of 2-hydroxynaphthalene-1-carbaldehyde with 4-aminoantipyrine has the imine tautomer structure in both solvents.