Plants warning signals

Much railway equipment is based on fail-safe principles dedicated to the concept that gravity is a force that will always be there. As a result, semaphores, signal switches, and the lights to which they are connected are weighted devices. In the event of a power or system failure, a heavy arm is allowed to drop and activate the fail-safe warning signal. In the processing plants, if instrument air is lost control valves go to the more safe position— either fail open or fail closed. 

The correct identification of situations and the correct selection of the appropriate package become more important in this automatic mode. Thus incorrect identification of a warning signal in a plant control room can result in initiation of an incorrect shut-down procedure, which because it has been frequently practiced may proceed unchecked despite the fact that it is making the situation worse rather than better. 

The development of plant operator support systems to provide an ad hoc evaluation of the plant status and search for the optimal responses to the warning signals ... 

It also appears that emissions of molecules like (E) -3-hexenal from damaged plants prime other nearby plants to activate their defense mechanisms, such as the formation of protease inhibitors and release of molecules that attract pest predators. So they may act like warning signals, letting other plants know that danger is near. 

Warning system signals for system shutdown, plant evacuation, and emergency services response. 

For human hazard the statements required hy EPA include the signal word, child hEtzard warning, statements of practical treatment, and any general precautionary statements which are applicable. For environmental hazard, the EPA requires statements on toxicity to nontarget fish, wildlife, birds, aquatic invertebrates, beneficial insects, and plants. Statements required for physical and chemical hazards focus primarily on flammability, but may include hazards related to explosion, oxidation, chemical reactions, or other characteristics of the product. 

Many insects metabolize terpenes they have received with their plant food to growth hormones and pheromones. Pheromones are luring and signal compounds (sociohormones) that insects and other organisms excrete in order to communicate with others like them, e.g. to warn (alarm pheromones), to mark food resources and their location (trace pheromones), as well of assembly places (aggregation pheromones) and to attract sexual partners for copulation (sexual pheromones). Harmless to the environment, pheromones may replace conventional insecticides to trap harmful and damaging insects such as bark beetles. 

An alarm is provided to warn the plant operators of a leak in the PHE. It is based on a sensor which sends a signal if the water stream becomes acidic. 

Typically means an anditory alarm (e.g., siren) or visual indication (e.g., flashing lights) to warn of a hazard aspect occurring over a wide area (e.g., toxic gas release in a chemical plant tsnnami approach, etc.) and the need for immediate actions to prevent injury or damage (e.g., evacuation, shelter-in-place, etc.). The effectiveness of the signal is dependent on its capability to be observed, the population s awareness of the signal characteristics, and the actions to be taken upon its activation. 

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