: A personal colorimetric dosimeter for nitrogen dioxide has been developed. Detector strips are prepared by dipping Eastman Chromagram Sheet, Type K301R2, in a solution of diphenylamine and oxalic acid in methanol. When dry, the strips can be used to estimate the concentration-time product to which an individual has been exposed. The strips are sensitive to heat and light. Nitrogen dioxide develops a green color while other oxidizers develop a blue color. The strips are not affected by moisture and should have a shelf life greater than one year. Color standards for concentration-time products of 50, 100, and 300 ppm-minutes and a blue standard to indicate an expired strip are described. A plastic holder for the sensitive detector strips is shown.
Abstract : Previous telemetry designs were improved to produce a system specific to the physiological evaluation of the thermal adequacy of space suits. A small seven-channel pulse duration multiplexed telemetry system which transmits an electrocardiogram, rectal temperature with an accuracy better than + or - 0.05C, and five skin temperatures with an accuracy better than + or - 0.2C was constructed. The entire unit is enclosed in a 13 by 10 by 5 cm box worn under the space suit. Components that have become available since construction could reduce this size to one-fifth without sacrificing performance. Three mercury batteries (12 v) power the equipment for 40 hours and provide reliable reception at distances of 90 m. The system is activated by connecting the sensor harness, and the output is checked and calibrated by a 3-position switch. The unit has been tested during exercise studies in space suits and during metabolic experiments on men exercising in cold environments. It provided reliable transmission of accurate temperature and heart rate data for both laboratory and field studies. It has simplified experimental procedures by eliminating all complications of hard wire leads penetrating pressure shells in space suits and by completely freeing the subject in field studies. (Author)
Abstract : When the head is tilted to the side, the eyes rotate slightly in the opposite, compensatory, direction. This ocular counterrolling has been related to, and may provide a useful index of, otolith function. This report describes a technique for inducing and precisely recording ocular counterrolling. In normal subjects the eyes rotate as much as plus or minus 6 degrees depending on the amount, direction, and speed of head rotation around its X (fore and aft) axis. Counterrolling is maximum under static or low rotation-rate conditions. Labyrinthine-defective subjects exhibit little or no compensatory counterrolling. (Author)
: The effects of single experimental exposures of plants, fish and microorganisms to members of a group of inorganic fluoride oxidizing agents have been summarized. The information obtained has enabled estimation of the damage to be expected as a result of single accidental exposures in the field. These agents--nitrogen trifluoride (NF3), tetrafluorohydrazine (N2F4), oxygen difluoride (OF2), chlorine trifluoride (ClF3), bromine pentafluoride (BrF5), and chlorine pentafluoride (ClF5)--vary in chemical behavior and biological effects. NF3 is relatively innocuous; OF2 must be avoided absolutely by animals and plants, and both are quite stable chemically. The interhalogens react readily in contact with environmental constituents, and while destructive at the site of initial contact, they are self limiting in effect. N2F4 also reacts easily, but should cause only moderate damage. Plant injury in all cases would probably be limited to the currently growing crop, with little possibility of carry-over effects in soil.
Abstract : The report describes three experimental evaluations of a procedure for aiding men in combining probabilistic (inconclusive) information. The procedure is called 'Semi PIP' (Probabilistic Information Processing). In the semi PIP procedures, a computer relieves man of part of the task of combining probabilistic evidence. The experiments involved a simulated military threat-diagnosis task in which probabilistic data are used as a basis for deciding among alternative hypothesized threats. The Semi PIP was compared with an unaided procedure called POP (Posterior Probability), and both procedures compared with a mathematically ideal combination of evidence (Bayes' theorem). It was found from the three experiments that: (1) overall, the difference between Semi PIP and POP performance was very slight; (2) POP was best when a small total amount of evidence accumulated very rapidly; and, (3) Semi PIP was slightly, though consistently, superior when the total amount of evidence to be evaluated was large, when the total diagnostic impact in a set of evidence was large, or when both these conditions prevailed. Specific implications of the results for diagnostic system design and for research on basic human inference processes are summarized. A glossary of key terms from Bayesian decision theory is included in the report. (Author)
: An assessment was made of the bactericidal efficacy of 17 biologically active elastomeric materials against 7 genera of microorganisms under static and varying dynamic conditions. A test cell and a laboratory model of a vacuum distillation water reclamation system used in the study are described. Compounds showing the greatest overall effectiveness in buffered distilled water solutions and in urine are delineated. Taste thresholds and data on rat feeding experiments using one of the biocidal agents are included. A neoprene elastomer with either hexabutyl distannoxane or hexabutyl distannthiane seemed the most promising.
The activities of the Toxic Hazards Research Unit (THRU) for the period of September 1967 through May 1968 are reviewed in this report. The experimental research program was partially curtailed during the first half of this period while major modifications to the Thomas Domes of the Altitude Facility were being completed. The dome modifications, primarily for improved fire safety protection, were required to be complete before experimentation in oxygen enriched environments could be resumed. Additional facilities for toxicity screening of space cabin materials were placed in service and the evaluation of materials has been continued with little evidence of toxicity exhibited by their gas-off products. One cabin material, carboxy nitroso rubber (CNR), did exhibit toxic manifestations and its acute toxic effects were investigated in depth. The CNR pyrolysis products formed at 300 C were found to be highly toxic and any human exposure to these products should be guarded against. Acute toxicity experiments on monomethylhydrazine and nitrogen trifluoride, including MMH emergency tolerance limits studies were conducted in the Ambient Facilities of the THRU. Investigations on the use of sham exposed dome controls and techniques for determining organ to body weight ratios are reported. TRI-SERVICE TOXICOLOGY iii CONSORTIUM LIBRARY WRIGHT-PATTERSON AFB, OH
: A simulated aerospace study was conducted to assess the biochemical effects of space flight by determining the volume of urine output of each crewman. The Apollo urine transport system (UTS), using a radioisotope, tritium, dilution technique, was tested by four human male subjects. The Apollo UTS met minimum requirements for 14 days even when a single unit was used by four individuals. The best individual performance by a subject gave a ratio of 101.4 plus or minus 4.6%. The overall value for volume measurement from the four subjects was 100.6 plus or minus 4.6%. Any void volume may be calculated by this radioisotope method with the UTS system plus or minus 10% of its volume at the 95% confidence level. One experimental error was the incomplete mixing of the radiosotope. The practicability of this procedure in actual space missions still has to be determined. (Author)
