Research trace

Pietra, R., Fortaner, S., and Sabbioni, E. (1993). Use of Chelex 100 resin in preconcentration and radiochemical separation neutron activation analysis applied to environmental toxicology and biomedical research. /. Trace Microprobe Tech. 11, 235-250. 

Starbird s research traces the origin and extent of the heresy of the Holy Grail, whose medieval adherents believed that Jesus was married and that his wife and child emigrated... 

Angier, Natalie. Researchers Trace the Primary Cause of Cystic Fibrosis to the Stone Age. New York Times (June 1, 1994) A13. 

The presence of indole or an indole derivative in a food is not always desirable. Some white wines develop an off-flavor described as ...floor polish like... within a few months of storage [33]. The chemical responsible for this unpleasant flavor was identified as 2-aminoacetophenone 16 in 1993 [34]. Reported in a series of papers over the next 10 years, researchers traced the ultimate source of this agent to indole-3-acetic acid 15 that was present in the grapes before harvesting Indole-3-acetic acid itself is derived from another indole L-tryptophan. The proposed mechanism for this transformation is shown in Scheme 14 [35]. 

Carbon-14 Reactor Biological and chemical research tracing and carbon dating... 

A variety of experimental techniques have been employed to research the material of this chapter, many of which we shall not even mention. For example, pressure as well as temperature has been used as an experimental variable to study volume effects. Dielectric constants, indices of refraction, and nuclear magnetic resonsance (NMR) spectra are used, as well as mechanical relaxations, to monitor the onset of the glassy state. X-ray, electron, and neutron diffraction are used to elucidate structure along with electron microscopy. It would take us too far afield to trace all these different techniques and the results obtained from each, so we restrict ourselves to discussing only a few types of experimental data. Our failure to mention all sources of data does not imply that these other techniques have not been employed to good advantage in the study of the topics contained herein. 

Littie research is available regarding the amounts of vitamins and minerals needed by young mminants. However, it is common to supply calcium, phosphoms, trace-mineralized salt, and vitamins A, D, and E (4). In the absence of a functional mmen, B-vitamins and vitamin K should be... 

D. A. Tillman and C. Leone, "Control of Trace Metals in Flyash at the Tacoma, Washington Multifiiels Incinerator," Proceedings of the Mmerican Flame Research Committee Fall International Symposium, San Francisco, 1990. 

The octane number requirement (ONR) of a car is the octane number which causes barely audible, ie, trace knock when driven by a trained rater. The Coordinating Research Council (CRC), a research organi2ation funded joindy by the American Petroleum Institute (API) and the American Automobile Manufacturers Association (AAMA), has defined test procedures for measuring ONR. Each car is driven under a set of light and heavy accelerations until the most sensitive driving mode is determined. Then a series of fuels is mn in the car until trace knock is determined. Each year, CRC members measure ONR of more than 100 cars and pubHsh the results. 

Suitable catalysts include the hydroxides of sodium (119), potassium (76,120), calcium (121—125), and barium (126—130). Many of these catalysts are susceptible to alkali dissolution by both acetone and DAA and yield a cmde product that contains acetone, DAA, and traces of catalyst. To stabilize DAA the solution is first neutralized with phosphoric acid (131) or dibasic acid (132). Recycled acetone can then be stripped overhead under vacuum conditions, and DAA further purified by vacuum topping and tailing. Commercial catalysts generally have a life of about one year and can be reactivated by washing with hot water and acetone (133). It is reported (134) that the addition of 0.2—2 wt % methanol, ethanol, or 2-propanol to a calcium hydroxide catalyst helps prevent catalyst aging. Research has reported the use of more mechanically stable anion-exchange resins as catalysts (135—137). The addition of trace methanol to the acetone feed is beneficial for the reaction over anion-exchange resins (138). 

Microscopists in every technical field use the microscope to characterize, compare, and identify a wide variety of substances, eg, protozoa, bacteria, vimses, and plant and animal tissue, as well as minerals, building materials, ceramics, metals, abrasives, pigments, foods, dmgs, explosives, fibers, hairs, and even single atoms. In addition, microscopists help to solve production and process problems, control quaUty, and handle trouble-shooting problems and customer complaints. Microscopists also do basic research in instmmentation, new techniques, specimen preparation, and appHcations of microscopy. The areas of appHcation include forensic trace evidence, contamination analysis, art conservation and authentication, and asbestos control, among others. 

The neutrons in a research reactor can be used for many types of scientific studies, including basic physics, radiological effects, fundamental biology, analysis of trace elements, material damage, and treatment of disease. Neutrons can also be dedicated to the production of nuclear weapons materials such as plutonium-239 from uranium-238 and tritium, H, from lithium-6. Alternatively, neutrons can be used to produce radioisotopes for medical diagnosis and treatment, for gamma irradiation sources, or for heat energy sources in space. 

J. P. Hu and co-workers. Structure Activity Relationship oJFlavonoids with Superoxide S cavenging Activity, Biological Trace Element Research, Vol. 47, The Humana Press Inc., Clifton, N.J., pp. 327—331, 1995. 

Catalyst testing and evaluation have been revolutionized by computers, automated test reactors, and analytical methods. With modem equipment, researchers can systematically prepare and screen many catalysts in a short time and efftciendy deterrnine, not only the initial catalytic activity and selectivity, but also the stabiUty and the appearance of trace products that may indicate some new catalytic properties worthy of further development. 

Such trace impurities can actually determine the activity or selectivity of a catalyst. However, this serious problem ia catalyst reproducibiUty can also offer leads toward discovery of new catalytic species, and a promising area of catalyst research iavolves ferreting out which active trace impurities are determining the performance of estabhshed catalysts. 

MAFF/SOAFD Pesticide Usage Survey Group, Arable Farm Crops in Great Britain 1994, 1995. Water Research Council, Atmospheric Sources of PoUntion. Inputs of Trace Organics to Surface Waters, R D Report No. 20, Water Research Council, 1995. 

NAA is well suited for Si semiconductor impurities analysis. The sensitivity and the bulk mode of analysis make this an important tool for controlling trace impurities during crystal growth or fer monitoring cleanliness of various processing operations for device manufacturing. It is expected that research reactors will ser e as the central analytical facilities for NAA in the industry. Since reactors are already set up to handle radioactive materials and waste, this makes an attractive choice over installing individual facilities in industries. 

TRACES (1968) Technology in Retrospect and Critical Events in Science (TRACES). Illinois Institute of Technology, Research Institute published for the National Science Foundation (no editor or author named). 

The condition is usually non-specific and seldom traced to a single cause. This has been termed sick building syndrome. Despite much research, little has been proven but the building features associated with the condition are ... 

For these reasons many research groups prefer to dry the chromatograms in a vacuum desiccator with protection from light. Depending on the mobile phase employed phosphorus pentoxide, potassium hydroxide pellets or sulfuric acid can be placed on the base of the desiccator, to absorb traces of water, acid or base present in the mobile phase. 

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