Index to 1981 NASA Tech Briefs, volume 6, numbers 1-4

Short announcements of new technology derived from the R&D activities of NASA are presented. These briefs emphasize information considered likely to be transferrable across industrial, regional, or disciplinary lines and are issued to encourage commercial application. This index for 1981 Tech Briefs contains abstracts and four indexes: subject, personal author, originating center, and Tech Brief Number. The following areas are covered: electronic components and circuits, electronic systems, physical sciences, materials, life sciences, mechanics, machinery, fabrication technology, and mathematics and information sciences

Development Of Electrochemical Biosensor Systems For Chlorpyrifos Pesticide Detection

Environmental monitoring systems are of great interest and highly significant in our life since every day we are exposed to many and various dangerous and fatal contaminants. Organophosphate pesticides such as Chlorpyrifos are widely used in agriculture to eliminate plant destroying pests. However, these pesticides may affect the environmental equilibrium unless continuous monitoring on their presence in water, soil, and agricultural products is carried out to protect human health and other living organisms. One of the approaches that can be adopted is to develop an on-line monitoring system. The widely used electronic and computer technology can simplify the development process of acquiring and monitoring system. In addition, the invention of biosensors to detect biologically-based materials such as Chlorpyrifos pesticide in the agricultural sector, glucose level in blood, heavy elements in the drinking water etc., have attracted interest

National Aeronautics and Space Administration (NASA)/American Society for Engineering Education (ASEE) Summer Faculty Fellowship Program 1988, volume 1

The 1988 Johnson Space Center (JSC) National Aeronautics and Space Administration (NASA)/American Society for Engineering Education (ASEE) Summer Faculty Fellowship Program was conducted by the University of Houston and JSC. The 10-week program was operated under the auspices of the ASEE. The program at JSC, as well as the programs at other NASA Centers, was funded by the Office of University Affairs, NASA Headquarters, Washington, D.C. The objectives of the program, which began in 1965 at JSC and in 1964 nationally, are (1) to further the professional knowledge of qualified engineering and science faculty members; (2) to stimulate an exchange of ideas between participants and NASA; (3) to enrich and refresh the research and teaching activities of participants' institutions; and (4) to contribute to the research objectives of the NASA Centers

CheapStat: An Open-Source, “Do-It-Yourself” Potentiostat for Analytical and Educational Applications

Although potentiostats are the foundation of modern electrochemical research, they have seen relatively little application in resource poor settings, such as undergraduate laboratory courses and the developing world. One reason for the low penetration of potentiostats is their cost, as even the least expensive commercially available laboratory potentiostats sell for more than one thousand dollars. An inexpensive electrochemical workstation could thus prove useful in educational labs, and increase access to electrochemistry-based analytical techniques for food, drug and environmental monitoring. With these motivations in mind, we describe here the CheapStat, an inexpensive (<$80), open-source (software and hardware), hand-held potentiostat that can be constructed by anyone who is proficient at assembling circuits. This device supports a number of potential waveforms necessary to perform cyclic, square wave, linear sweep and anodic stripping voltammetry. As we demonstrate, it is suitable for a wide range of applications ranging from food- and drug-quality testing to environmental monitoring, rapid DNA detection, and educational exercises. The device's schematics, parts lists, circuit board layout files, sample experiments, and detailed assembly instructions are available in the supporting information and are released under an open hardware license

Aerospace medicine and biology: A continuing bibliography with indexes (supplement 341)

This bibliography lists 133 reports, articles and other documents introduced into the NASA Scientific and Technical Information System during September 1990. Subject coverage includes: aerospace medicine and psychology, life support systems and controlled environments, safety equipment, exobiology and extraterrestrial life, and flight crew behavior and performance

Index to 1985 NASA Tech Briefs, volume 10, numbers 1-4

Short announcements of new technology derived from the R&D activities of NASA are presented. These briefs emphasize information considered likely to be transferrable across industrial, regional, or disciplinary lines and are issued to encourage commercial application. This index for 1985 Tech Briefs contains abstracts and four indexes: subject, personal author, originating center, and Tech Brief Number. The following areas are covered: electronic components and circuits, electronic systems, physical sciences, materials, life sciences, mechanics, machinery, fabrication technology, and mathematics and information sciences

Cathodic Protection Modeling of Nodes in Offshore Structures

A three-dimensional computer model for analyzing the potential distribution on the metal surface and in the water surrounding nodes in offshore platforms was developed. The model is based on the Laplace equation as the governing equation and uses the finite difference method to solve the equation numerically. The model is the first of its kind and is unique because it is designed for microcomputers. The model can model dozens of different node geometries. Most of these geometries have been tested for convergence problems and they are error free. The model is promising because it can expand to incorporate more node geometries.Chemical Engineerin

Instrumental development of novel detection methods for liquid chromatography and capillary electrophoresis

The versatility and exceptional efficiencies afforded by modern liquid chromatography (LC) have made it indispensable for separations and quantitative analysis in virtually every discipline within the physical and biological sciences. Despite rapid advances in column technology, the development and applications of LC have been slowed by the absence of truly universal and highly sensitive detectors. On the other hand, the recent explosive growth of capillary electrophoresis (CE) applications has created challenges in developing highly efficient detectors. This dissertation presents the development and improvements of instrumental techniques for detection in LC and CE. The first chapter reviews the current status of the various detection methods for LC and CE;Section I presents the first universal detector based on magneto-optical rotation (MOR) for high performance liquid chromatography (HPLC). The experimental results confirm the linear dependance of the MOR signal on the analyte concentration. The feasibility of this method is demonstrated in the detection of polynuclear aromatic hydrocarbons, where the limit of detection is in the sub-microgram range;For the first time, a novel axial-beam on-column absorption detector for open tubular capillary liquid chromatography is described in Section II. The axial coupling of source light with the capillary columns and the use of optical waveguide capillary columns made it possible to utilize the full length of the sample bands inside the capillary columns as the path length for absorbance measurements. For a typical 10 [mu]m i.d. capillary column, the axial-beam detection provides an increase of up to 1000 times in path length and a 192-fold associated improvement on the limit of detection;The project described in the third section is the optimization of detectability in the laser-based polarimetric detector for HPLC. A mathematical simulation is performed in order to optimize the detectability of the detector. The designing parameters of the detector are systematically chosen for optimum performance. The experimental verification of the optimized parameters provides the performance approaching the shot-noise limit;Finally, Section IV demonstrated the feasibility of axial-beam absorption detection for capillary electrophoresis using a conventional light source. The cross-beam and axial-beam detection schemes can be easily switched. The high stability of light intensity, variable wavelength and UV ability make this detector attractive. The improved limit of detection in the axial-beam arrangement should make CE with absorption detection feasible to a wider range of applications