Human observer

Some wave phenomena, familiar to many people from the human senses, include the easy undulation of water waves from a dropped stone or the sharp shock of the sonic boom from high-speed aircraft. The great power and energy of shock events is apparent to the human observer as he stands on the rim of the Meteor Crater of Arizona. Human senses provide little insight into the transition from these directly sensed phenomena to the high-pressure, shock-compression effects in solids. This transition must come from development of the science of shock compression, based on the usual methods of scientific experimentation, theoretical modeling, and numerical simulation. 

Objects close to us are easily perceived, but as we attempt to detect objects farther and farther away from us, the contrast between the object and the background decreases. The lowest limit of contrast for human observers is called the threshold contrast and is important because this value influences the maximum distance at which we can see various objects. 

Complement to human observation, instrumental methods areas with frequent plume blight, discoloration... 

How can human observers, optical measurements along a line of sight, and point measurements by nephelometry provide conflicting information about visual air quality in the same location ... 

Perceived Visual Air Quality (PVAQ) an index that relates directly to how human observers perceive changes in visual air quality. 

With the best observing conditions, it is possible for the trained observer to compete with photoelectric colorimeters for detection of small color differences in samples which can be observed simultaneously. However, the human observer cannot ordinarily make accurate color comparisons over a period of time if memory of sample color is involved. This factor and others, such as variability among observers and color blindness, make it important to control or eliminate the subjective factor in color grading. In this respect, objective methods, which make use of instruments such as spectrophotometers or carefully calibrated colorimeters with conditions of observation carefully standardized, provide the most reliable means of obtaining precise color measurements. 

Sanz P, Rodriguez-Vicente MC, Diaz D, et al. 1991. Red blood cell and total blood acetylcholinesterase and plasma pseudocholinesterase in humans Observed variances. Clin Toxicol 29 81-90. 

Choice of criteria for defining a "safe level of toxin In the environment based on animal and human observations ... 

The A(A), y(A), and z(A) terms were derived by the CIE from data obtained in visual experiments where observers matched colors obtained by the mixing of the blue, green, and red primary colors. The average result for human observers were defined as the CIE 1931 2° standard observer, and the wavelength dependencies of these color-matching functions are illustrated in Fig. 6. 

The most utilized and reliable process control in the petrofeum and related industries is human observation and surveillance. Local pressure and level gages along with control room instrumentation are provided so that human observation and actions can occur to maintain the proper process conditions. First stage process alarms are provided to alert operators to conditions that they may not have already noticed. Typically when secondary alarm stages are reached, computer control systems employed to automatically implement remedial actions to the process. 

COz is a nonflammable gas, therefore it does not present a tire or explosion hazard. The gas is generally considered toxic but will displace oxygen in the air, since it is 1.5 times heavier that air it wall settle and air supplies will be pushed out of the area. The CO2 gas is considered an asphyxiation hazard to personnel for this reason. Since the gas is odorless and colorless it cannot be easily detected by human observation in normal environments. Fire protection CO2 gas is normally stored under high pressure as a liquid and expands 350 times its liquid volume upon release. 

Basic Process Control System (BPCS) - Pneumatic, electronic, hydraulic or programmable instruments and mechanisms that monitor and/or operate a facility or system to achieve a desired function, i.e., flow control, temperature measurement, etc., which are supervised by human observation. 

It was found that tetramethylphosphorodiamidic fluoride (bisdimethylaminofluorophosphine oxide) was very toxic and had a l.d. 50 of the order of 1-0 mg./kg. for subcutaneous injection into mice the concentration for rabbits was higher at 3 0 mg./kg. (intravenously). The Cambridge figure for toxicity by inhalation agreed with that found by American workers, the L.c. 50 for mice being 0 095 mg./l. for a 10 min. exposure. We also carried out experiments with four human observers exposed to a concentration of one part in a million for 5 min. No effects of any kind were noted in particular, myotic action was absent. In this report, therefore, the highly toxic compound... 

LIND VALL, T., (1974). Monitoring air pollutants in the field with human observers. Arm. N.Y. Acad. Sci. 237. 

There are three main sources of evidence for pro-tumorigenic activity of bile acids in the lower gastro-intestinal tract (activity in rodent CRC models, human observational data and mechanistic studies using CRC cells in vitro), which together create a strong case for a role for colorectal mucosal bile acid exposure during human colorectal carcinogenesis. 

Several strands of indirect evidence from human observational studies help put the in vivo rodent data into the context of human colorectal carcinogenesis. 

Berglund, B. (1974). Quantitative and qualitative analysis of industrial odors with human observers. Anna/s of the New York Academy ofSciences 237,35-51. 

It is true that the power spectra are not always easy to obtain and that sometimes other types of information are available. Marmolin et al. (1978) have optimized a restoring filter of this form for optical images, where human observers were called upon to judge the visual quality of the restorations. 

Dose-response model. There is incomplete agreement on the most suitable form of dose-response function for low-LET radiation, and there is no present expectation that human observations will prove decisive. Rather, it appears that appropriate models will require a more adequate understanding of radiation carcinogenesis itself. 

Given this simple concept of thermal sameness or equilibrium, we can express the results of universal human observations in the following Inductive Law 3, also known as the zeroth law of thermodynamics ... 

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