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Shoe Tree (device)
A shoe tree is a device approximating the shape of a foot that is placed inside a shoe to preserve its shape, stop it from developing creases, and thereby extend the life of the shoe. Perhaps more important than maintaining the shape, shoe trees also play a crucial part in wicking away moisture caused by sweat - a major cause of lining rot and leather degradation. This is especially important when shoes are worn without socks. Higher quality shoe trees are made from softwood, usually cedar, which helps control odor and absorb moisture. Types Among wooden shoe trees, there are generally three categories, which correspond to price and quality. Spring shoe trees The cheapest are a wooden shoe tree without a full heel. Although they help with odour, and will help preserve the original shape at the front of the shoe, the narrow knob on the heel puts excess pressure on one section of the heel and prolonged use may deform the shoe. Notwithstanding, this style of shoe tree is popu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cedar Wood
Cedar is part of the English common name of many trees and other plants, particularly those of the genus ''Cedrus''. Some botanical authorities consider the Old-World ''Cedrus'' the only "true cedars". Many other species worldwide with similarly aromatic wood, including several species of genera '' Calocedrus'', '' Thuja'', and '' Chamaecyparis'' in the Pacific Northwest of North America, are referred to as "false cedars". Plants called "cedar" include: Family Pinaceae *''Cedrus'', common English name cedar, a genus of coniferous trees in the plant family Pinaceae **''Cedrus libani'', the Lebanon cedar, native to Lebanon, western Syria and south-central Turkey **'' Cedrus atlantica'', the Atlas cedar, native to the Atlas Mountains of Morocco and Algeria **'' Cedrus deodara'', the Deodar cedar, native to the western Himalayas **'' Cedrus brevifolia'', the Cyprus cedar, found in the island of Cyprus' Cedar Valley in the Troodos Mountains *'' Pinus sibirica'', the Siberian pine, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Odor
An odor (American English) or odour ( Commonwealth English; see spelling differences) is a smell or a scent caused by one or more volatilized chemical compounds generally found in low concentrations that humans and many animals can perceive via their olfactory system. While ''smell'' can refer to pleasant and unpleasant odors, the terms ''scent'', ''aroma'', and ''fragrance'' are usually reserved for pleasant-smelling odors and are frequently used in the food and cosmetic industry to describe floral scents or to refer to perfumes. Odor physiology Sense of smell The perception of odors, or sense of smell, is mediated by the olfactory nerve. The olfactory receptor (OR) cells are neurons present in the olfactory epithelium, which is a small patch of tissue at the back of the nasal cavity. There are millions of olfactory receptor neurons that act as sensory signaling cells. Each neuron has cilia in direct contact with the air. Odorous molecules bind to receptor pro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Moisture
Moisture is the presence of a liquid, especially water, often in trace amounts. Moisture is defined as water in the adsorbed or absorbed phase. Small amounts of water may be found, for example, in the air (humidity), in foods, and in some commercial products. Moisture also refers to the amount of water vapor present in the air. The soil also includes moisture. Moisture control in products Control of moisture in products can be a vital part of the process of the product. There is a substantial amount of moisture in what seems to be dry matter. Ranging in products from cornflake cereals to laundry detergent, washing powders, moisture can play an important role in the final quality of the product. There are two main aspects of concern in moisture control in products: allowing too much moisture or too little of it. For example, adding some water to cornflake cereal, which is sold by weight, reduces costs and prevents it from tasting too dry, but adding too much water can affect th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Last
A last is a mechanical form shaped like a human foot. It is used by shoemakers and cordwainers in the manufacture and repair of shoes. Lasts come in many styles and sizes, depending on the exact job they are designed for. Common variations include simple one-size lasts used for repairing soles and heels, custom-purpose mechanized lasts used in modern mass production, and custom-made lasts used in the making of bespoke footwear. Lasts are made of firm materialshardwoods, cast iron, and high-density plasticsto withstand contact with wetted leather and the strong forces involved in reshaping it. Since the early 19th century, lasts typically come in pairs to match the separate shapes of the right and left feet. The development of an automated lasting machine by the Surinamese-American Jan Ernst Matzeliger in the 1880s was a major development in shoe production, immediately improving quality, halving prices, and eliminating the previous putting-out systems surrounding shoema ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spring (device)
A spring is a device consisting of an Elasticity (physics), elastic but largely rigid material (typically metal) bent or molded into a form (especially a coil) that can return into shape after being compressed or extended. Springs can Energy storage, store energy when compressed. In everyday use, the term most often refers to coil springs, but there are many different spring designs. Modern springs are typically manufactured from spring steel. An example of a non-metallic spring is the Bow (weapon), bow, made traditionally of flexible Taxus baccata, yew wood, which when Bow draw, drawn stores energy to propel an arrow. When a conventional spring, without stiffness variability features, is compressed or stretched from its resting position, it exerts an opposing force approximately proportional to its change in length (this approximation breaks down for larger deflections). The ''rate'' or ''spring constant'' of a spring is the change in the force it exerts, divided by the cha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bistability
In a dynamical system, bistability means the system has two Stability theory, stable equilibrium states. A bistable structure can be resting in either of two states. An example of a mechanical device which is bistable is a light switch. The switch lever is designed to rest in the "on" or "off" position, but not between the two. Bistable behavior can occur in mechanical linkages, electronic circuits, nonlinear optical systems, chemical reactions, and physiological and biological systems. In a conservative force field, bistability stems from the fact that the potential energy has two local minimum, local minima, which are the stable equilibrium points. These rest states need not have equal potential energy. By mathematical arguments, a local maximum, an unstable equilibrium point, must lie between the two minima. At rest, a particle will be in one of the minimum equilibrium positions, because that corresponds to the state of lowest energy. The maximum can be visualized as a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
