Resonant liquids

Spatial Profile of resonant (anisotropic) absorption by resonant liquid crystalline structure of chromophore... 

Another oscillatory method makes use of a drop acoustically levitated in a liquid. The drop is made to oscillate in shape, and the interfacial tension can be calculated from the resonance frequency [113]. 

Bax A 1982 2-Dimensional Nuclear Magnetic Resonance in Liquids (Delft Delft University Press)... 

Huntress WT 1970 The study of anisotropic rotation of molecules in liquids by NMR quadrupolar relaxation Adv. Magn. Reson. 4 1-37... 

Mdbius K, Lubitz W and Plato M 1989 Liquid-state ENDOR and TRIPLE resonance Advanced EPR in Biology and Biochemistry ed A J Hoff (Amsterdam Elsevier) ch 13, pp 441-99... 

Freed J 1979 Theory of multiple resonance and ESR saturation In liquids and related media Multiple Electron Resonance Spectroscopy ed M M Dorlo and J H Freed (New York Plenum) ch 3, pp 73-142... 

Of spectroscopic teclmiques, nuclear magnetic resonance (NMR) has been most widely used to measure orientational ordering in liquid crystals [M, 57 and ]. Most commonly, changes of line splittings in the spectra of... 

Schmidt C and Spiess H W 1998 Magnetic resonance Handbook of Liquid Crystais Voi 1. Fundamentais ed D Demus, J Goodby, G W Gray, H-W Spiess and V Vill (New York Wiley-VCH)... 

Emsiey J W (ed) 1985 Nuciear Magnetic Resonance of Liquid Crystais (Dordrecht Reidel)... 

It also forms compounds known as carbonyls with many metals. The best known is nickel tetracarbonyl, Ni(CO)4, a volatile liquid, clearly covalent. Here, donation of two electrons by each carbon atom brings the nickel valency shell up to that of krypton (28 -E 4 x 2) the structure may be written Ni( <- 0=0)4. (The actual structure is more accurately represented as a resonance hybrid of Ni( <- 0=0)4 and Ni(=C=0)4 with the valency shell of nickel further expanded.) Nickel tetracarbonyl has a tetrahedral configuration,... 

Liquid helium s use in magnetic resonance imaging (MRI) continues to increase as the medical profession accepts and develops new uses for the equipment. This equipment has eliminated some need for exploratory surgery by accurately diagnosing patients. Another medical application uses MRE to determine (by blood analysis) whether a patient has any form of cancer. 

Polyamides. The next two compounds are the amide counterparts of the esters listed under item (4). Although the values of AH j are less for the amides than for the esters, the values of T j, are considerably higher. This is a consequence of the very much lower values of AS j for the amides. These, in turn, are attributed to the low entropies of the amide in the liquid state owing to the effects of hydrogen bonding and chain stiffness arising from the contribution of the resonance form... 

For twice-distilled material infrared (liquid film) cm." 1745 strong, 1565 strong, 1430 medium strong proton magnetic resonance (chloro-form-d) (number of protons, multiplicity, coupling constant J in Hz) 3.14-3.45 (1, multiplet), 3.76 (3, singlet), 3,86 (3, singlet), 5.6 (1, doublet of doublets, J = 6 and 8). 

The mixture was characterized as follows infrared (liquid film) cm. 1745 strong (shoulder at 1720), 1640 medium strong, 1440 medium strong proton magnetic resonance (chloroform-d) B (multiplicity, number of protons) 3.75 (singlet, 6), 4.12 (singlet, 2), 6.21 and 6.30 (two singlets, 1). 

The product was further characterized as follows infrared (liquid film) cm. 2195 strong, 1370 strong, 1170 strong proton magnetic resonance (chloroform-d) S 3.43 (singlet). 

A versatile Laser-SNMS instrument consists of a versatile microfocus ion gun, a sputtering ion gun, a liquid metal ion gun, a pulsed flood electron gun, a resonant laser system consisting of a pulsed Nd YAG laser pumping two dye lasers, a non-resonant laser system consisting of a high-power excimer or Nd YAG laser, a computer-controlled high-resolution sample manipulator on which samples can be cooled or heated, a video and electron imaging system, a vacuum lock for sample introduction, and a TOF mass spectrometer. 

Element mapping with non-resonant laser- SNM S can be used to investigate the structure of electronic devices and to locate defects and microcontaminants [3.114]. Typical SNMS maps for a GaAs test pattern are shown in Fig. 3.43. In the subscript of each map the maximum number of counts obtained in one pixel is given. The images were acquired by use of a 25-keV Ga" liquid metal ion source with a spot size of approximately 150-200 nm. For the given images only 1.5 % of a monolayer was consumed -"static SNMS". 

When equipment receives impulses at its own natural frequency of vibration, excessive vibration (resonance) occurs, and this can lead to rapid failure. A control valve was fitted with a new spindle with slightly different dimensions. This changed its natural frequency of vibration to that of the impulses of the liquid passing through it (the frequency of rotation of the pump times the number of passages in the impeller). The spindle failed after three months. Even a small change in the size of spindle is a modification [24]. 

The modern electronic industry has played a very important role in the development of instrumentation based on physical-analytical methods As a result, a rapid boom in the fields of infrared, nuclear magnetic resonance (NMR), Raman, and mass spectroscopy and vapor-phase (or gas-liquid) chromatography has been observed. Instruments for these methods have become indispensable tools in the analytical treatment of fluonnated mixtures, complexes, and compounds The detailed applications of the instrumentation are covered later in this chapter. 

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