Absorption Coefficient Measurements of Strongly Scattering Media Using Time-Resolved Transmittance of a Short Pulse in Near-Infrared (NIR) Wavelength Range

Absorption coefficient measurements of strongly scattering and weakly absorbing media have been performed using time resolved transmittance of a 100 fs pulse through a 30 mm slab containing latex spheres suspended in water and absorbing ink solutions. The scattering and absorption coefficients were selected so that the optical properties of the media were similar to those of biological tissues. Measured curves of time-resolved transmittance of the pulse through the media were used to estimate the optical properties of the media. The experiment was made at two different wavelengths, 784 nm and 810 nm. Estimated absorption coefficients were in good agreement with those measured in a nonscattering case by a spectrophotometer.Presented at the 7th International Workshop on Multiple Scattering Lidar/Light Experiments (MUSCLE7), July 21-23 1994, Chiba, Japan.     

Chemical composition of a CO2 extract of rose fruit

The chemical composition and physicochemical characteristics of a CO₂ extract of rose fruit have been studied. It was established that the main component of the extract consisted of lipids, and the class and fatty-acid compositions of these are given.Almaty Pharmaceutical Factory Company Limited, 480008, Republic of Kazakhstan, Almaty, ul. Shevchenko, 162-E, fax 42 96 75. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 880–882, November–December, 1997.     

Automorphic functions and the Bass-Milnor-Serre homomorphism,II

One investigates the residue of the Eisenstein series considered in the first part of the paper.Translated from Zapiski Nauchnykh Seminarov Leningradskogo Otdeleniya Matematicheskogo Instituta im. V. A. Steklova AN SSSR, Vol. 129, pp. 127–163, 1983.     

Spectral characteristics of sign-alternating self-oscillatory endoplasm mobility in a myxomycete plasmodium

The results of a short time Fourier transform of the time dependences of the self-oscillatory endoplasm velocity in an isolated strand of the Physarum polycephalum plasmodium recorded using a sign-sensitive laser Doppler microscope are described. Unlike the mode recording an absolute velocity, a sign-sensitive mode makes it possible to detect the pairs of equidistant harmonic components in the time dependence spectra of endoplasm movement. The resulting frequency and amplitude values are used to construct a model adequately describing the alternating endoplasm mobility.     

Stability of Poiseuille flow in the presence of a longitudinal magnetic field

The stability of the plane flow of an electrically conducting fluid with respect to small perturbations was studied at large Reynolds numbers in the presence of a longitudinal magnetic field. The dependence of the critical Reynolds number on the electrical conductivity is investigated. At large Reynolds numbers, a new branch of instability and a sudden change in the critical Reynolds numbers is found. __________ Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 49, No. 3, pp. 45–53, May–June, 2008.     

Numerical Simulation of Photon Migration in Homogeneous and Inhomogeneous Cylindrical Phantoms

Optics and Spectroscopy - Features of the propagation of low-coherent pulse radiation in phantoms of soft biological tissues (blood-perfused tissues of brain, breast, etc.) are described. Results...     

On Twisted Kloosterman Sums

For the Kloosterman sums twisted by characters over a finite field, addition formulas of convolution type are derived. As a corollary, orthogonality relations connecting the Kloosterman and Salie vectors are obtained. Bibliography: 4 titles.__________Translated from Zapiski Nauchnykh Seminarov POMI, Vol. 302, 2003, pp. 96–106.     

The group G2(ℂ) in connection with the theory of metaplectic forms

Some preliminary information which makes the consideration of metaplectic forms on G₂() possible is recounted.Translated from Zapiski Nauchnykh Seminarov Leningradskogo Otdeleniya Matematicheskogo Instituta im. V. A. Steklova AN SSSR, Vol. 162, pp. 169–185, 1987.     

Summation formulas for general Kloosterman sums

N. V. Kuznetsov's summation formula is generalized to the case of a discrete subgroup GSL₂() and a system of multiplicators , satisfying certain not too restrictive conditions. In the arithmetic cases, when G is a congruence-subgroup in SL₂(), these conditions are satisfied. N. V. Kuznetsov's formula has been proved for the case G=SL₂()., =1.Translated from Zapiski Nauchnykh Seminarov Leningradskogo Otdeleniya Matematicheskogo Instituta im. V. A. Steklova AN SSSR, Vol. 82, pp. 103–135, 1979.     

Positive rudimentarity of the graphs of Ackermann and Grzegorczyk

The representability is proved of the graphs of the W. Ackermann functions xy^. g_n(x, y) and the A. Grzegorczyk functions f_n in the class of positive rudimentary predicates of J. H. Bennett, found in the initial class of A. Grzegorczyk. This essentially improves a result of S. V. Pakhomov on the representability of the graphs of f_n in. A generalization of the method of proof allows one to prove the positive rudimentarity of the graph of the W. Ackermann function nxy · g_n(x, y).Translated from Zapiski Nauchnykh Seminarov Leningradskogo Otdeleniya Matematicheskogo Instituta im. V. A. Steklova AN SSSR, Vol. 88, pp. 186–191, 1979.