Smell sensors

When one looks at studies on how the dog s nose moves the dust particles [1] to the smell sensors with his nose hairs and mucus, then one realizes that the water in the mucus dissolves the TNT off the dust and offers it to the olfactory sensors. Fjellanger also quoted literature of how a dog s nose uses side muscles to pulse air at a frequency of 3 to 5 puffs per second at the slits on the side of his nostrils when sniffing. The dog then sucks the stirred up dust with a long... 

Sometimes people enter a room and notice at once that the air inside is stuffy , while most people inside the room have been getting tired, but were unaware of the poor air quality. This is because our biological air quality sensor, the nose, gets used to slow changes of surrounding smells. 

COz sensors are suitable for living rooms, offices and bedrooms, whereas for bathrooms (main parameter humidity) and kitchens (main parameter smell ) other non-specific sensors may be used. Therefore combinations of different sensors like humidity sensors, smelF-sensors (unspecific VOC-sensors) and presence sensors could be the best solution. A simple movement detector with an additional manual override (ventilation on/off for a predetermined time) could be a low-cost alternative. 

NPs play a very important role in determining the interactions between individuals (of the same or of different species) that cohabit an area. The interactions between plants and animals provide examples of the way in which NPs play a role in interspecies interactions. In many animals, the key senses of taste and smell have evolved to be acute sensors of a very few NPs but most NPs are quite possibly never sensed by any organism. However, given that NPs evolved billions of years ago, and terrestrial animals and plants only about 400 million years ago, there is a very large hole in om imderstanding of the selection forces in microbes that drove the evolution of NPs for the majority of evolutionary time. 

However, in Nanotechnology Research Directions (a report pubfished by the US government in 1999), it was pointed out that current nanoscale technologies are still highly inferior to those seen in natural systems. The efficiency of the energy conversion that occurs in mitochondrial and photosynthetic systems far exceeds those obtained in artificial systems. A dog can smell and a bat can hear far more sensitively than most artificial sensors. The information pro-... 

The AQS MK IV MF (multi-function) as the latest product of the AQS portfolio, which has a LIN interface and software that can adapt, or self-leam, over a number of duty cycles. It includes a subroutine called cily-delecl , which adopts the software routine best optimized for the special requirements of inner cities. It is also particularly sensitive to tunnel entry/exit The software takes care that the air inlet door only opens after the tunnel exit. AQS MK IV MF even offers a skunk detection function, which is embedded in the software and uses a second sensor element especially to detect that special smell. 

Furlong D N, Gedded N J, Paschinger E, Okahata Y, Ebato H, Ebara Y and Tanaka K 1993 Surface chemical sensors for bitter/sweets, smells and antibodies in aqueous solution Chem. Australia October 552-5... 

Characterisation Of Explosives By The Response Of Gas Sensor Array To Modulated Intensity Of The Smell... 

First, the time constant described by Equation (2) is analysed and the phenomenological rates of the surface chemical interaction between a target gas and the surface are evaluated. A set of the reaction rates specific to a target gas and the sensor surfaces is supposed as the smell features. 

Second, the coefficients of the multiexponential decay are included into a database of the sensor outputs. Original graphical representation of the database is composed for visual inspection and identification of the smell. 

If omitting the fundamental aspects from the comparison of the rates in Table 1, it can be concluded that unique collection of the rate parameters can be associated with individual sensor in a certain atmosphere. In general, such a collection can be accepted as an additional database of the smell features extracted from the transient part of the sensor response. 

The time constant based characterisation of a smell includes an approximation of the response kinetics by multiexponential decay similar to the description (6). A collection of several pairs of the parameters r, a, is usually obtained for each of the sensors in the array from this approximation. The characteristic parameters, namely the time constants r, and the weigh coefficients a, are used for the composition of a graphical representation of the sensor outputs that might be visually inspected. The graphical representation is build up by an original method. 

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