New low-level a-c amplifier provides adjustable noise cancellation and automatic temperature compensation

Circuit utilizing a transistorized differential amplifier is developed for biomedical use. This low voltage operating circuit provides adjustable cancellation at the input for unbalanced noise signals, and automatic temperature compensation is accomplished by a single active element across the input-output ends

Method and apparatus for continuously monitoring blood oxygenation, blood pressure, pulse rate and the pressure pulse curve utilizing an ear oximeter as transducer Patent

Ear oximeter for monitoring blood oxygenation and pressure, pulse rate, and pressure pulse curve, using dc and ac amplifier

Temperature compensated solid state differential amplifier Patent

Temperature compensated solid state differential amplifier with application in bioinstrumentation circuit

Ear oximeter-transducer monitors four physiological responses

Device monitors blood oxygen saturation, blood pressure, pulse rate, and pulse-pressure curve during conditions of high stress in simulated space flight

Balanced-bellows spirometer

Compact balanced-bellows dry type spirometer was designed to be insensitive to acceleration fields along any or all coordinate axes. It provides true indication of respiratory action of test subject without need for calibration in acceleration fields

Transfer valve Patent

Three-port transfer valve with one port open continuously suitable for manned space fligh

Respiratory transfer value has fail-safe feature

Quick-acting, remote controlled valve connects either one of two oxygen or air supplies to a breathing tube. The valve, which is fall-safe, incorporates a cammed piston arrangement that is driven by a remote controlled reversible rotary solenoid or reversible electric motor

Electrohydrodynamic charge relaxation and interfacial perpendicular field instability

Electrohydrodynamic charge relaxation and interfacial perpendicular-field instabilit

An electrohydrodynamically induced spatially period cellular Stokes-flow

Spatially periodic, time invariant electric field used to create spatially periodic cellular flow by action of electric shear stress in region of fluid-fluid interfac

Allelopathic Observations in Rice (Oryza sativa L.) to Ducksalad (Heteranthera limosa)

More than 50 weed species infest drill-seeded rice in the U.S. and one of the most prevalent aquatic weeks is ducksalad (Heteranthera limosa). During the summer of 1988, a field experiment was conducted to identify rice accessions from the USDA/ARS rice germplasm collection for allelopathic effects to ducksalad. In this field experiment, 5,000 accessions were evaluated for allelopathic activity. Five to seven seeds of each rice accession were planted in hills about 75cm apart in two replications. Allelopathic activity was recorded as 1) radius of the area affected by allelochemical from the base of the rice plant and 2) percentage of weed control within the affected area. Ducksalad was rated at the panicle initiation stage of rice development. Of the 5,000 accessions that were evaluated, approximately 191 were identified as having evident allelopathic activity. The accessions that demonstrated allelopathic activity originated in 26 countries (Afghanistan, Argentina, Australia, Brazil, Columbia, Dominican Republic, France, India, Iran, Iraq, Israel, Italy, Japan, Malaysia, Mexico, Pakistan, Peru, Philippines, Portugal, Republic of Korea, People Republic of China, Soviet Union, Taiwan, Thailand, Turkey, and United States)