Pooler et al., Photochem. & Photobiol., vol. 30, pp. 581-584, 1979. Piechoski et al., J. Phys. Chem., vol. 88, pp. 934-950, 1984. Nakashima et al., Chem. Pharm. Bull, vol. 29, No. 6, pp. 1755-1758, 1981. Gasha et al., vol. 92, No. 4, pp. 490-497, Yakugaku Zasshi, 1972. Jesthi et al., J. Inst. Chemists (India), vol. 50, Nov. 78. Andreasch, Monatscheft fur Chemie, 1908, 29, 399. Ganitkevich and Turkewitsch, J. Gen. Chen. U.S.S.R. 1959, 29, 2061. Tambor, Ber, 1900, 33, 864. Weinschenk, Ber., 1901, 34, 1685. Dox and Plaisance, J. Amer. Chem. Soc. 1916, 38,2165. Werner, J. Am. Chem. Soc., 1920, 42, 2309. Phillips, J. Org. Chem, 1947, 12, 333. Brooker, Keyes and Heseltine, J. Anner. Chem. Soc. 1951, 73,5350. Schneider and Pothman, 1941, 74B, 4761. Wizinger and Wenning, Helv. Chem. Acta 1940, 23, 274. Blazsek-Bodo, Vernes and Szurkos, Pharmacia (Bucha rest), 1974, 22, 345. Primary Examiner-Douglas W. Robinson Assistant Examiner-Mike Meller Attorney, Agent, or Firm-Larson and Taylor

The chirp response of a thickness-drive tunable transducer for wide range time-bandwidth and sweep rates chirp signals is demonstrated experimentally and computationally. The computational evaluation uses recursive digital-filter model based on the z-transform method. The model is limited to simple lossless structure with no front and backing layers. The model and experimental results show that there is no limit on the maximum sweep rate of the chirp signal but practically the limit is determined by the limitation of the circuit that generates the control voltage that simulates a variable electric load.

The effects of a flat sea surface on the secondary wave field for a nonsaturation limited parametric source with a piston-type transmit transducer have been assessed both theoretically and experimentally. When the virtual array of the parametric source interacts with the sea surface, the amplitude of the secondary signal is reduced. In addition to the normal interference between the direct and surface reflection paths, there is also one extra mechanism which causes the reduction of the secondary signal level. This is the destructive summation of the secondary field generated before and after intersection with the water surface. A numerical model and the Westervelt model are used to predict the secondary field which is a function of grazing angle. Experiments in an in-door laboratory tank have been carried out to measure the primary and secondary fields of a parametric array under these circumstances. It is shown that the surface reflection affects the beam pattern of the secondary field and the induced reduction in the signal level depends on the characteristics of the parametric source and the geometry of the problem. The level of reduction caused by the effects of the surface interaction approaches a constant at large grazing angles.

Tuning or varying the resonance frequency of a transducer by adding an additional layer of ceramic, called the control ceramic, is a method for designing a wide bandwidth transducer. By loading the control ceramic with an inductive electrical load the resonance frequency of the whole structure is variable or tunable over a wide range of frequency. Two designs of tunable transducer are discussed in this paper; a two-plate thickness-driven structure with a fundamental frequency of 240 kHz and a sandwich structure with a fundamental frequency of 30 kHz. Tunable ranges of 1.5 and 1.8 oct are obtained, respectively. It is established that the limit of the tunable range for the two-plate transducer is between the fundamental harmonic and the second overtone of the whole structure, which are defined with the control ceramic short circuited. For the sandwich transducer the tunable range is between the fundamental harmonic and the first overtone of the whole structure, which are defined when the control ceramic short circuited. An analysis based on the Mason transmission-line model shows that the fundamental limit of the tunable range is determined by the fundamental resonance frequency and the dynamic coupling coefficient of the drive ceramic and is affected by the presence of any bonds and shims between the ceramics. To obtain a continuously tunable frequency range the position of the drive ceramic must be between the radiating front-end of the structure and the control ceramic.

The chirp response of a thickness-resonant, single-plate transducer is evaluated using a recursive digital-filter method. The theoretical model using the z-form method is most suitable for lossless and simple transducer structures, such as with back and front resistive loads, and with no front layer. The results of the analysis are compared with experimental measurements and are also compared with theoretical results obtained with a simple lumped-element, tuned-circuit model of the plate.

The paper addresses some reflection and scattering phenomena for a model telemetry channel with a periodically fluctuating surface. Limitations on the extent of surface fluctuations are derived from the reflection and scattering area, Rayleigh parameter and shadow function. These results are related to the observed pulsed response of the surface. Finally the effect of the scattering process on communication coherence is briefly discussed.< >

X-ray crystal structure analysis of the title compound shows that it has the Z-configuration at the exocyclic double bond. Steric hindrance within the molecule is responsible for a considerable deviation from planarity in some regions of the molecule. The relationship of this compound to the structural pattern shown by other thiazolidin-4-one derivatives is briefly discussed.

The spatial correlation in the backscattered field for waves incident normally on a random boundary is derived using Kirchhoff–Helmholtz scattering theory in which the effects of both boundary heights and slopes are included. The acoustically rough case is considered and it is shown that the scattering process may be interpreted in terms of a deep, random phase screen; the influence of the boundary slopes is interpreted as diffraction at the screen. For a directive source, it is shown that the spatial correlation distance of the field is determined by the correlation of the source shading for a wide variety of boundary conditions; limited experimental data supports this result. For an omnidirectional source, the spatial correlation coefficient is 2J1(kg)/kg.

A linear relationship exists between the microcalorimetrically observed biological response to challenge of a sensitive organism by a series of drugs and the number of methylene groups present in the alkyl chains of these same drugs. A Collander type relationship is shown to exist for microcalorimetric response data obtained for interaction of alkyi m-hydroxybenzoates with Escherichia coli and Staphylococcus aureus.

Enthalpies of transfer for ortho- and para-alkoxyphenols from aqueous isotonic solution to non-growing Escherichia coli are reported. The values are compared, for ortho-alkoxyphenols, to ΔtrsH for transfer from water to octan-1-ol. The values for both ortho- and para-homologues show breaks in ΔtrsH(isotonic aqueous solution to cells) values as a function of carbon number in the side chain = 4. The differences in ΔtrsH values for ortho-, meta-(published previously) and para-alkoxyphenols are compared.

Microcalorimetric assay of the antibacterial activity of 14 phenols shows that the activities can be expressed as two additive factors due to the aromatic portion and to the number of methylene groups.

AbstractDie ungesättigten Verbindungen (I) werden bei Belichtung in Gegenwart von (II) in die gesättigten Derivate (III) umgewandelt.

Chemischer InformationsdienstVolume 11, Issue 8 Natural Products ChemInform Abstract: DEOXYGENATION OF A Δ3-CEPHEM S-OXIDE USING ARENESELENOLS M. J. PERKINS, M. J. PERKINSSearch for more papers by this authorB. V. SMITH, B. V. SMITHSearch for more papers by this authorB. TEREM, B. TEREMSearch for more papers by this authorE. S. TURNER, E. S. TURNERSearch for more papers by this author M. J. PERKINS, M. J. PERKINSSearch for more papers by this authorB. V. SMITH, B. V. SMITHSearch for more papers by this authorB. TEREM, B. TEREMSearch for more papers by this authorE. S. TURNER, E. S. TURNERSearch for more papers by this author First published: February 26, 1980 https://doi.org/10.1002/chin.198008379Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume11, Issue8February 26, 1980 RelatedInformation

AbstractDie Kinetik des basenkatalysierten H‐D‐Austausches in α‐Stellung zur Carbonylgruppe (DzO‐NaOH in Pyridin; 35.5°C) wird für die Phenylketone (I)‐(VII) vergleichend untersucht.

Chemischer InformationsdienstVolume 7, Issue 7 Isocyclic Compounds ChemInform Abstract: REARRANGEMENTS ACCOMPANYING THE ALUMINUM TRICHLORIDE-CATALYZED CYCLIZATION OF (1-PHENYLCYCLOPROPYL)ACETYL CHLORIDE M. J. PERKINS, M. J. PERKINSSearch for more papers by this authorN. B. PEYNIRCIOGLU, N. B. PEYNIRCIOGLUSearch for more papers by this authorB. V. SMITH, B. V. SMITHSearch for more papers by this author M. J. PERKINS, M. J. PERKINSSearch for more papers by this authorN. B. PEYNIRCIOGLU, N. B. PEYNIRCIOGLUSearch for more papers by this authorB. V. SMITH, B. V. SMITHSearch for more papers by this author First published: February 17, 1976 https://doi.org/10.1002/chin.197607189Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume7, Issue7February 17, 1976 RelatedInformation

AbstractDie Belichtung des Ketons (I) liefert zunächst das cis‐Isomere (II).