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The Consumer Perception of Odour
Published in G. Thilagavathi, R. Rathinamoorthy, Odour in Textiles, 2022
Ingun Grimstad Klepp, Kirsi Laitala, R. Rathinamoorthy
The sense of smell or olfaction, the ability to perceive odours, is one of the most complex human senses as it depends on unique interactions between the olfactory system and diverse chemical substances. The olfactory system works as a defense mechanism for the human body against malodours and irritants. Much of its function and functionality is still unexplored (Reinarz 2014). The sense of smell is affected by chemical compounds in gaseous form. The olfactory epithelium, located at the top of the nasal cavity on both sides of the nasal septum, is a mucous membrane with olfactory cells, a type of nerve cell that is associated with the olfactory region of the brain. Similar to taste, the sense of smell is a chemical sense. The olfactory cells are stimulated only by volatile substances, i.e., by substances that evaporate and release molecules into the air. The odorants bind to odour receptors on the olfactory cells. This will trigger a biochemical reaction chain that leads to a nerve impulse, which in turn is sent to the brain (Winther 2018).
Human and Biomimetic Sensors
Published in Patrick F. Dunn, Fundamentals of Sensors for Engineering and Science, 2019
An odor is sensed by first having its molecules dissolve and move in the nasal mucus layer, eventually reaching and binding to an odorant receptor protein on olfactory cilia (see Figure 3.5). This chemical binding activates the protein, which leads to the opening of ionic channels. This subsequently yields a graded receptor potential within the olfactory cell that develops into an action potential in the olfactory nerve. The signal transmission end of the neuron terminates in the olfactory bulb. The spatial organization and connections of neurons in the olfactory pathway produce a two-dimensional mapping in the olfactory bulb of each odorant. The additional dimensionality and connectivity helps to explain why 1 000 different odorant receptors can detect millions of different odors.
Mesoscopic Systems
Published in James J Y Hsu, Nanocomputing, 2017
The spatial patterns of the odor-sensing mechanism in the fruit fly may shed some light. The well-studied brain of fruit fly indicates that there are 57 genes that encode the repertoire of Drosophila odorant receptors. Each of them encodes a putative seven trans-membrane domain protein of 380 amino acids. Upon sensing the odors, the olfactory receptors pass on the messages to the neurons that are connected to the sensory centers in the brain. Studies show that being able to discriminate odors is highly conserved in the fly. Five hundred million years of evolution separates insects from mammals perhaps reflecting an efficient solution to the complex problem of olfactory sensory perception. Animals are masters at sensing chemical messages, whereas we humans are rather insensitive. Mimicking the insect’s sensory will be of great importance to nanotechnology. Likewise, mimicking the human brain power will be particularly interesting for molecular computer. The brain could be said as the last “Pandora’s box” in science.
Design and implementation of an electronic nose system for real-time detection of marijuana
Published in Instrumentation Science & Technology, 2021
Lucas Sampaio Leite, Valeria Visani, Paulo César Florentino Marques, Maria Aparecida Barreto Lopes Seabra, Natália Cybelle Lima Oliveira, Priscila Gubert, Victor Wanderley Costa de Medeiros, Jones Oliveira de Albuquerque, José Luiz de Lima Filho
E-nose systems simulate the mammalian olfactory response, where odor specificity, stemming from a unique response pattern, is generated from several hundred olfactory receptors.[25] In an e-nose, volatile compounds are introduced through the sampling mechanism and transferred to a chamber containing a matrix of sensors.[26] Under the influence of an odor stimulus, the sensor array generates a characteristic fingerprint corresponding to the smell of each sample. The sum of these fingerprints provides a recognition pattern for qualitative analysis using appropriate multivariate analysis tools based on these standards.[2,27] The most used algorithms include principal component analysis (PCA), linear discriminant analysis (LDA), discriminant function analysis (DFA), soft independent modeling of class analogies (SIMCA), and artificial neural networks (NAA).[28] These chemometric tools have been successfully applied in the development of methodologies aimed at solving forensic science problems, including gunpowder residues,[29] semen in tissues,[30] and counterfeit documents by identifying the inks.[31]
Multisensory stress reduction: a neuro-architecture study of paediatric waiting rooms
Published in Building Research & Information, 2020
Juan Luis Higuera-Trujillo, Carmen Llinares Millán, Antoni Montañana i Aviñó, Juan-Carlos Rojas
In the olfactory modality, these stimuli have been found to have a positive effect on psychological and behavioural processes (Herz, 2009). A variety of scents have been studied, notably lavender and orange. However, although aromatherapy implementation in healthcare facilities has a long history and significant benefits (Cannard, 1996), this modality has been addressed by few studies. Lavender is one of the most frequently studied fragrances (Fenko & Loock, 2014). It has been observed to have benefits in reducing stress in neonatal (Kawakami et al., 1997), needle insertion (Kim et al., 2011), postpartum (Kianpour, Mansouri, Mehrabi, & Asghari, 2016), and palliative care contexts (Berger, Tavares, & Berger, 2013). In the staff sector, this scent also contributes to reducing stress (Sung & Eun, 2007) and improving performance (Birnbach, King, Vlaev, Rosen, & Harvey, 2013).The scent of orange, although it has been less widely studied, has been shown to reduce stress in healthcare facilities. Contexts where this effect has been observed include women waiting in the dentist’s office (Lehrner, Eckersberger, Walla, Pötsch, & Deecke, 2000) and pregnant women in childbirth units (Rashidi-Fakari, Tabatabaeichehr, & Mortazavi, 2015).
Effects of drying methods on quality attributes of peach (Prunus persica) leather
Published in Drying Technology, 2019
S. M. Roknul Azam, Min Zhang, Chung Lim Law, Arun S. Mujumdar
Biological olfactory sensory functions are digitally expressed by e-nose and used to determine odors and flavors. PCA and linear discrimination analysis of PL dried by the four drying techniques are shown in Figure 5(a) and (b). The total PCA value is 97.9 PCA1 and PCA2 is 94.2 and 3.7% respectively, however the liner differentiation index is −27.3% which indicate e-nose could sense almost all the flavor information of the PL samples but could not differentiate their differences among the samples. Studies on the volatile composition of peach identified of more than one hundred volatile compounds. The most abundant components are C6 compounds, linalool, benzaldehyde, esters, terpenoids, C13 norisoprenoids, ketones, and lactones.[33,34] It can be seen from Figure 5(b) that other than MWD sample, the other three drying techniques maintain much closer distance among them, which indicates their odor profile is much closer to each other than MWD. Figure 5(c) shows the radar plots representing the sensors response produced by the 14 sensors. Radar plots of the four drying techniques are given. S1 and S5 exhibit the higher values than the rest of the sensors of e-nose. This indicates that these two sensors are the major odor output obtained from PL. S1 is the sensor for aromatic compounds (phenol, phenolic ether, aromatic aldehyde), S5 is for odor generated by oxidative degradation of carotenoids and Maillard reaction. This is consistent with PCA and LDA outcome. Liu et al.[34] regarding the making of snack food from asparagus stalks. From e-nose analysis it is found that IRD dried PL retains most characteristics flavor of peach than that of other drying techniques.