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Biomedical subjects

C K Patel

Publications and source records attributed to C K Patel.

64 records · Page 4Linked to original sources
PubMed1981

Visible absorption spectrum of liquid ethylene.

The visible absorption spectrum of liquid ethylene at approximately 108 K from 5500 A to 7200 A was measured by using a pulsed tunable dye laser, immersed-transducer, gated-detection opto-acoustic spectroscopy technique. The absorption features show the strongest band with an absorption coefficient of approximately 2 x 10(-2) cm(-1) and the weakest band with an absorption coefficient of approximately 1 x 10(-4) cm(-1). Proposed assignments of the observed absorption peaks involve combinations of overtones of local and normal modes of vibration of ethylene.

Journal Article↗
PubMed1980

CO2 laser in vitreoretinal surgery.

Radiation from a CO2 laser has the dual effect of phototransection and photocoagulation. Incisions have been made in scleral-chorioretinal tissue, lens tissue, and the vitreous body (with and without membrane formation). Results indicate that the CO2 laser may be useful in intravitreal surgery. Its simultaneous cutting and coagulating properties may make the experimental transvitreal chorioretinal biopsy reported by Griffin et al [12] and the full-thickness ocular wall resection for small melanosarcomas of the choroid reported by Peyman and Sanders [13] clinical possibilities in the not too distant future. Finally, the effects of CO2 laser radiation on the normal human lens suggests the possibility of the dissolution of cataracts by laser irradiation.

Animals↗
PubMed1979

CO2 laser in vitreoretinal surgery: 1. Quantitative investigation of the effects of CO2 laser radiation on ocular tissue.

Scleral, lens, and vitreoretinal tissue was incised using CO2 laser radiation in a controlled and predictable fashion without producing untoward effects on neighboring ocular tissue. The penetration depth of infrared radiation into normal human vitreous was measured and was found to be exceedingly small. A quantitative correlation was observed between the CO2 laser power and the depth of penetration in scleral-chorio-retinal wall incisions and in lens tissue from human eyebank eyes. The results of this investigation suggest that the CO2 laser may be useful in intravitreal surgery, full-thickness scleral-chorio-retinal wall resections, transvitreal chorioretinal biopsy, and even dissolution of cataracts.

Animals↗
PubMed1972

Air pollution: sensitive detection of ten pollutant gases by carbon monoxide and carbon dioxide lasers.

Detection sensitivities of a few parts per billion for ten gaseous pollutants have been evaluated by measuring the strength of the absorption of infrared radiation from carbon monoxide and carbon dioxide lasers. Ethylene concentrations as small as 5 parts per billion have been detected in air. The measured absorption strengths indicate that in mixtures of pollutants, such as nitrogen dioxide and water vapor, the sensitivity is reduced by overlapping absorption bands. However, calculations indicate that it should be possible to detect nitrogen dioxide concentrations of 0.01 part per million in the presence of water vapor concentrations of 105 parts per million.

Air Pollution↗
PubMed1971

Nitric oxide air pollution: detection by optoacoustic spectroscopy.

Nitric oxide is detected by a new technique in which tunable infrared radiation from a spin-flip Raman laser is used to measure the absorption spectrumn of a gas sample by optoacoustic spectroscopy. This technique is sensitive enough to detect a concentration of 0.01 part per million of nitric oxide pollution in air samples.

Air↗