Scent masking

Authentic skunk spray has become valuable for use in scent-masking products. Show how you would synthesize the two major components of skunk spray (3-methylbutane- 1-thiol and but-2-ene- 1-thiol) from any of the readily available butenes or from buta-1,3-diene. 

The first set of experiments with hamsters suggested that scent masking had occurred. After hamsters investigated (on 5 separate trials) a scent over-mark in which the top scent of one individual covered the bottom scent of another individual, they investigated the top scent of the mark less than a novel scent, indicating memory for the top scent, but they investigated the bottom scent the same amount as a novel scent, suggesting that they did not remember the bottom scent (Johnston et al., 1994). That is, these results supported the hypothesis that the top scent masks information in the bottom scent. 

An alternative explanation of these results could be that the relative area covered by the two scents is the important cue if the top scent masks the bottom scent, the top scent would appear to cover a greater area. This interpretation is ruled out by other experiments... 

Liquid household bleach is generally a 5% solution of sodium hypochlorite (NaOCl). Ammonia cleansers—including general household cleansers, wax removers, glass and window cleaners, and oven cleaners — are aqueous solutions of 5-10% ammonia, NH3. Mixing bleach with cleansers containing ammonia leads to the formation of a family of potentially toxic compounds known as chloramines. These toxic gases have acrid fumes that can bum mucous membranes. Scented bleaches can mask one s natural ability to detect these harmful fumes. 

Prey fish may mask their own odors. Some marine fish avoid predation by covering their body odors. Some parrot fish (Scaridae) sleep in a mucus cocoon. It is believed that this covers up its scent and protects it from predation. Table 12.1 summarizes some chemical predator-prey relationships in marine fish. 

Beyond facial creams, facial masks are usually concentrated partide suspensions, and are used to treat and refresh facial skin. The particles are usually either kaoli-nite, Fuller s earth, or illite ( green clay ) or other days. The particles are intended to act as exfoliants and also to adsorb oils from the skin. Other additives span a wide range of materials, including essential oils, vitamins, fruits and vegetables, scents, and pharmaceutical (cosmeceutical) additives, such as salicylic acid when added to treat mild acne. Body clays are like facial masks except that a higher concentration of clay is used in the suspension. 

Sometimes undesirable odors arise during or after a product s use The wet laundry odor in washing machines or the hot hair scent generated by hair driers are typical examples. In personal deodorants and air fresheners, diaper products and toilet cleaners, masking external odors is a primary reason for the products very existence. 

GiV Scents Fresh Linen Notes. [Givaudan-Roure] Scents for bath-nxxn, bedroom, kitchen, and dining linens mid for t ard also for masking offensive odors. 

Today, we are revolted at the thought of disposing of waste in this fashion, but cleanliness didn t really become a virtue until modem times. When Queen Victoria ascended to the throne in 1837, Buckingham Palace had no baths at all. Perfumes were very popular, since they masked objectionable smells. Madame de Pompadotu spent vast amounts on perfumes, and Madame du Barry hid scented pads on her person when she seduced Louis XV. But some were not put off by a ripe body aroma — among them Samuel Johnson, the creator of the first English dictionary. When an outspoken lady friend told him that he... 

The addition of certain pleasant-smelling fragrances are sometimes also used to masks odours. There are commercial scents available specifically for PE, PP, and thermoplastic elastomers, although they may not last for the lifetime of the product. 

One of the cues used by the visual system for perception of depth or relative distance of two objects from the observer is occlusion. That is, if one object occludes a second object, it is perceived as being in front of that second object. Many vaginal marks of hamsters are deposited as linear streaks or lines, and we hypothesized that hamsters might be able to use olfactory occlusion to determine which scent was on top. That is, in an over-mark the top scent is a continuous streak if it masks the bottom mark in the region of overlap, the underlying scent mark will appear to be discontinuous (interrupted). If hamsters can keep track of the spatial layout of the two scents they could potentially use this continuous versus interrupted information as a means to determine which individual s scent is on top, and thus preferentially remember the top scent. 

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