Microwave spectroscopy of furfural in vibrationally excited states

The results of microwave spectrum investigation of the excited vibrational states of furfural in the frequency range between 49 and 149 GHz are reported. In total 15 excited vibrational states (9 for trans-furfural and 6 for cis-furfural) were assigned and analyzed. Six of the 15 investigated states were assigned for the first time. Accurate values of rigid rotor and quartic centrifugal distortion constants of asymmetric top Hamiltonian have been determined for 13 excited states. Also for some states several sextic and octic level constants were needed in order to fit the data within experimental accuracy. The v_t = 3 and v_s = 1, v_a = 1 states of trans-furfural were found to be strongly perturbed and only rotational transitions with low K_a values can be reliably identified in this study.     

A New Fluorescent Squaraine Probe for the Measurement of Membrane Polarity

The present study was undertaken to evaluate the sensitivity of newly synthesized squaraine dye 1 to the changes in lipid bilayer physical properties and compared it with the well-known dye 2. Partitioning of the dye 1 into lipid bilayer was found to be followed by significant increase of its fluorescence intensity and red-shift of emission maximum, while intensity of the dye 2 fluorescence increased only slightly on going from aqueous to lipidic environment. This suggests that dye 1 is more sensitive to the changes in membrane properties as compared to dye 2. Partition coefficients of the dye 1 have been determined for the model membranes composed of zwitterionic phospholipid phosphatidylcholine (PC) and its mixtures with positively charged detergent cetyltrimethylammonium bromide (CTAB), anionic phospholipid cardiolipin (CL), and sterol (Chol). The spectral responses of the dye 1 in different liposome media proved to correlate with the increase of bilayer polarity induced by Chol and CL or its decrease caused by CTAB. It was concluded that dye 1 can be used as fluorescent probe for examining membrane-related processes.     

Millimeter-Wave Spectrum of CF(2)Cl(2), Taking into Account the Hyperfine Structure

A new investigation of the CF(2)(35)Cl(2) ground state rotational spectrum in the 50-100 GHz frequency range gave an opportunity to improve the accuracy of rotational and quartic distortion parameters by an order of magnitude and to determine values of six sextic centrifugal distortion parameters. A special technique was used to process line profiles of unresolved or partially resolved hyperfine structures of rotational transitions. It allowed us to improve significantly values for the diagonal parameters of quadrupole coupling chi(aa), (chi(bb)-chi(cc)) and to determine the off-diagonal parameter chi(ab). Copyright 2000 Academic Press.     

Submillimeter rotational spectrum of the formamide molecule: Ground and first excited vibrational states

The results of a study of the submillimeter rotational spectrum of formamide in states v_T=0 and 1 at frequencies of 290–500 GHz are presented. More than 300 transition frequencies are identified. Watson Hamiltonian constants are obtained for both states.Radio-Astronomy Institute, Academy of Sciences of Ukraine. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 37, No. 2, pp. 259–264, February, 1994.     

The second torsional state of acetic acid

We have fitted to within experimental accuracy a data set for acetic acid CH₃COOH consisting of 2103 v_t=0, 1111 v_t=1 and 634 v_t=2 microwave lines, using the so-called “rho axis method” and a model extended to include perturbation terms through eighth order. The previously published 2109 v_t=0 and 409 v_t=1 microwave lines have been extended by new measurements from Kharkov. The final fit requires only 62 parameters to achieve a unitless weighted standard deviation for the whole fit of 0.85 for a total of 3848 lines and includes transitions with J27 (15) and |K_a|13 (8) for the v_t=2 A (E)-species, respectively. This result represents a significant improvement over our previous fit which was dominated by v_t=0 transitions. A calculation of the linestrengths of torsion–rotation transitions is also provided.     

Non-minimal and non-universal supersymmetry

I motivate and discuss non-minimal and non-universal models of supersymmetry and supergravity consistent with string unification at 10¹⁰ GeV.