صلی الله علیک یا امیر المومنین(ع) و یا اباعبد الله الحسین ع

Time-Intensity plots are a standard method for evaluating sensory response over time.  The method records both the length of time and the intensity of response on an x-y axis.. The  attached article demonstrates the use of  Time-Intensity for odor and astringency responses when ingesting copper.

Article Effect of copper speciation at different pH on temporal sens...

Concerning the second question of everlasting smells in the world, this is complex as it will depend on the rated of generation of the odor, the rate of decay of the odors, and the odor threshold concentration at which humans detect the odorant. The generation and decay rates are affected by many chemical and biological factors that will be odorant specific. Human detection of the odorant will be affected by presence of syneristic and antagonisting odorants as well as humidity, prior exposure of subjects, physiological/psychological/environmental factors. I am interested in seeing comments from other researchers on this question. 

There are several odour impact criteria, depending on the national legislation. The time series of the ambient concentrations at a certain site is evaluated by a preselected odour impact criterion which is defined by an odour threshold concentration CT and the exceedance probability pT of this threshold. This odour concentration threshold is related to a one hour mean value.

If an OIC is used for shorter time intervals as one hour, then the peak-to-mean factor F > 1 has to be considered to adapt the odour concentration threshold for this short time interval CT* to a one hour mean value CT. The corresponding odour concentration threshold for a one hour mean value CT is then calculated by CT = CT* / F.

There is a wide variety of OIC used for this purpose, which differ by the odour concentration threshold between 0.12 ou m-3 and 10 ou m-3 and by the tolerated exceedance probability of this threshold between 0.1% and about 35%.

Two typical national OIC for a protection level of rural residential areas are (1) for Ireland with a threshold of 6 ou m-3 and a exceedance probability of 2% and (2) Germany with 0.25 ou m 3 / 20%.

Article Comparability of separation distances between odour sources ...

which components are much more aromatic( or everlasting )?  the components which have aromatic cycles or odorous  aliphatic  materials?

Actually there is no exact criteria to describe lasting time of an odour. I think it relates to odour itself and contact surface of a media. Some sticky smells with low odour thresholds can last very long. Good example of this is smoking odour that may last forever to some sensitive noses.

Don't stay overnight at a smoking room if you hate that smell!

The idea of the odour impact criteria OIC are the evaluation of the environmental odour exposure. This exposure is calculated by the use of the odour  emission rate (in ou/s) and the dilution in the atmosphere. This calculation is done by dispersion modles for every single hour of the year (8760 h) for a certain site. Then the exceedance of  an pre-selected threshold is determined. If the exceedance at this site is higher than the OIC then annoyance can be expected in a certain percentage of the population. 

thanks a lot, I can't understand completely, can you explain more and/or say some example or text

When molecules of odorant interact with olfactory receptors, they generate miniature potentials that travel along the olfactory cilia, then along the body of olfactory neuron, then reach the olfactory axon, and collectively generate action potential. The action potential travel trough the neurons of olfactory bulb, and then to the brain.

When a short pulse odor is applied to olfactory epithelium by a short sniff (or by olfactometer), the part of olfactory epithelium is electrically depolarized, producing a short electrical pulse. This potential rises for a few fractions of a second, reach a maximum of a few mV, and then it decays within a second. It will require a few seconds before the normal olfactory response can be evoked by the next odorant pulse. During this time between pulses, some restorative physiological processes take place to prepare the system to the next odorant pulse. Thus if series of fast odorant pulses is applied, olfactory neurons cannot keep up with the speed of evoking pulses if they applied faster than ~2 seconds.

If the duration of evoking odorant pulses is increased, the electrical response of the olfactory neurons will stay the same to a certain duration of the odorant pulse. Say, you apply pulses of 0.1, 0.25, 1, 5, 10 s, the individual groups of neurons are able to produce responses with the same kinetics (~.3 s rise, ~1 s decay a few mV amplitude). When the duration of the odor impulses become longer than 10 s, like 20, 30 s, or very long, the kinetics is slowed and amplitude of the olfactory response is reduced until practically disappear at the long exposure to odorant. This phenomena is named "olfactory adaptation".  The olfactory adaptation is a physiological process that  can occur at multiple levels in the olfactory system and can involve both receptor level and more central (brain) components. Therefore, it is difficult to find a "super-odorant".  However, molecules that have physical advantages in travelling to receptor sites may be better.

There is a method for comparison of duration and other properties of odorant responses, that is based on the measurement of the electrical response to odorant, so called "Electroolfactogram (EOG). There is a   non-invasive version of EOG  that can be used in human. The  duration of the EOG response is measured in seconds and can be used for a quantitative comparison of odorants.

thanks a lot

can man develop his ability for recognizing a lot of odors simultaneously? such as odor seller 

When a few odorants are mixed, they perceived as a new odor. If more than 5 different odorants are mixed, the mixture  may not have odor at all. The mixture creates so called  "white odor" similarly to the "white light" when we have a mixture of various color lights. Dogs can be trained to recognized the target odor mixed with a strong background odor. For example, explosive hidden in coffee powder. The special olfactory mechanism is involve in this process, called "masking". The special training  in dogs, may result  in masking the background odor and recognition of the target. The mechanism of masking is not very well understood. I believe that olfactory receptors associated with the inhibitory G-proteins are involved. There are some attempts to make masking in the human perception.   See for example https://www.nysearch.org/tech_briefs/OdorMasking_TechBriefupdatedat82913dcd.pdf.