ii New Patents fi

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II II I -NHNHC(CH&-CNHNH-

wherein n is 2, 4, 6, 8 or 10;

Lipid-soluble impermeant spectroscopic probes for the study of intact biological membranes are disclosed.

4538910

DUAL BEAM FOURIER SPECTROMETER

Walter Doyle assigned to Laser Precision Cor- poration

A dual beam Fourier-type spectrometer is dis- closed in which the collimated output beam of a Michelson type interf=ometer is divided (post- interferometer) by a reflector which (a) ref’lccts the bulk of said beam to the sample and there- after a first detector, but (b) transmits part of said beam (preferably through apertures in the reflector) directly to a second detector. The rela- tively small portion of said beam which is trans- mitted to the second detector preferably passes thruugh a substantial number of very small aper- tures in the reflector which are spaced in such a way as to maximize the spatial identity of the beams reaching the first and second detectors.

4540281

DOUBLEBEAM SPECTROPHOTOMETER

@amu Akiyama, Kyoto, Japan assigned to Shimadzu Corporation

A double-beam s~tr~photometer which uses an integrating sphere for measurement of the total reflected light from a sample or only the dif- fuse reflection component thereof. The sphere is provided with a first pair of windows in which a sample and a reference are detachably and ex- changeably set and a second pair of windows through one of which one of a sample and a reference light beam enters the integrating sphere so as to impinge perpendicularly on said sample or reference set in one of said first pair of windows, while through the other of said second pair of windows the other of said sample and reference light beams enters said integrating sphere to impinge aslant on said reference or sample set in the other of said first pair of win- dows. The positions of said sample and reference are exchanged in accordance measurement to be made.

4540282

&th the type of

APPARATUS FOR UPTICAL;LY ANALYZING A SAMPLE

Isaac J Landa, Ronal Shideler assigned to Landa Isaac

An electro-optical system for rapid, accurate spectral analysis of the reflectivity or trans-

New Patents 111

missivity of samples. A concave, holographic diffraction grating is oscillated at high speed to provide a rapid scanning of monochromatic light through a spectrum of wavelengths. The grating drive system is an electrically driven mechanical oscillator which utilizes the back EMF of the oscillator motor to maintain oscilla- tion at the desired amplitude and frequency. A passive optical shutter mounted to the grating al- ternately blocks the light entering and exiting the monochrometer as the grating is oscillated. The resultant dark period is utilized by the system to provide a reference offset value and to control cooling of the detectors. A unique phase-locked loop circuit is employed to provide sample com- mands at precisely determined intervals to cor- rectly correlate the spectral data with the output of the monochrometer. Source and exit optics are employed to optimally shape the light pas- sing through the system. A unique detection head is provided to allow measurement of light transmission or reflectance with only slight modification of the system. An optical fiber is used to divert light from the beam at or near the sample. This light is electronically detected and the electronic detection signal is used to adjust the gain of the sample signal so as to compensate for atmospheric bands, temporal variations, and system response. This provides a true double (dual) beam operation.

4543529

METHOD OF TUNING AN NMR APPARATUS

Gary Mee, M Robert Willcott assigned to NMR Imaging Inc

A method of tuning an NMR spectrometer is disclosed that includes the step of locating a specimen in a stationary magnetic field, gene- rating a 90 degrees alternating magnetic field ex-

citation pulse at the Larmor frequency of the selected nuclei of the specimen followed by one or more 180 degrees alternating magnetic field refocusing pulses of preselected duration at fixed time intervals having the same phase relation- ships using a free-running oscillator that is turned off between pulses, measuring the primary echo train of a selected nuclear magnetic resonance signal, changing the strength of the stationary magnetic field to change the Larmor frequency of the selected nuclei, repeating the pulsing step and the measuring step until the maximum primary echo is obtained, and while holding the stationary field at that strength, measuring the desired nuclear magnetic resonance characteristic using the spin-echo method and the free-running oscillator to supply the pulses.

4544270

APPARATUS FOR THE SPECTROGRAPHIC ANALYSIS

OF WORKPIECES FORMED FROM IRON AND STEEL ALLOYS

Wilhelm Berstermann, Uhich Grisar, Egon Koerfer, Georgsmarienh Federal Republic Of Germana assigned to Klockner-Werke Ak- tiengesellschaft

The determination, through spectrographic analysis, of the C content of iron and steel alloy workpieces via the C 193 1.02 line is made using spectrometers having a test head that can be at- tached to the workpiece. The region of the dis- charge near the surface of the workpiece is isolated in an argon atmosphere from the light path of the discharge to be imaged onto the grating, so that the two unwanted iron lines, the Fe 193 1.4 and the Fe 1930.8 lines, do not occur in the grating spectrum.