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47-644: The Welsh Terrier was a latecomer to the British show-ring (being primarily a working dog) and was not officially registered as a breed until the 19th century. The Breed has managed to win best in show at Crufts four times, the last being in 1998 with Saredon Forever Young (Mel) owned by Judith Averis. It is on the UK Kennel Club's list of breeds that are in danger of dying out, having as few as 300 or so pups registered annually. The most popular breeds are registered in tens of thousands each year. The Welsh Terrier

94-733: A challenge is perceived, it will not back down. Dogs of this breed can be devoted friends and can function either as city dogs or as country dogs. Welsh Terriers were developed to hunt independently and this required that they be very assertive and stoic dogs. As a consequence, developing obedience in a Welsh Terrier is a long-term proposition and one has to constantly work on and reinforce the training. They rank 101st in Stanley Coren 's The Intelligence of Dogs , being of average working/obedience intelligence. This, however, does not mean that Welsh Terriers fail to learn or understand commands, just that they tend to make their own decisions; thus

141-459: A challenge to keep them entertained. For example, they love chasing toys and love swimming (a good example would be lake activities with their families). Welsh Terriers get along well with children; they love to play and follow a child as it plays, however, and they will often tug at pant legs and can knock young ones off their feet. If they are around young children at an early age, they will easily learn to play more gently. As with all breeds, it

188-716: A coat, wrap, or shawl. The manufacturing of fur clothing involves obtaining animal pelts where the hair is left on the animal's processed skin. In contrast, making leather involves removing the hair from the hide or pelt and using only the skin. Fur is also used to make felt . A common felt is made from beaver fur and is used in bowler hats , top hats , and high-end cowboy hats . Common furbearers used include fox , rabbit , mink , muskrat , leopard , beaver , ermine , otter , sable , jaguar , seal , coyote , chinchilla , raccoon , lemur , and possum . " Fur-Bearing Animals ". New International Encyclopedia . 1905. Thermal insulation Thermal insulation

235-418: A different type of hair. Down hair (also known as underfur , undercoat , underhair or ground hair ) is the bottom – or inner – layer, composed of wavy or curly hairs with no straight portions or sharp points. Down hairs, which are also flat, tend to be the shortest and most numerous in the coat. Thermoregulation is the principal function of the down hair, which insulates

282-553: A foam-like structure. This principle is used industrially in building and piping insulation such as ( glass wool ), cellulose , rock wool , polystyrene foam (styrofoam), urethane foam , vermiculite , perlite , and cork . Trapping air is also the principle in all highly insulating clothing materials such as wool, down feathers and fleece. The air-trapping property is also the insulation principle employed by homeothermic animals to stay warm, for example down feathers , and insulating hair such as natural sheep's wool . In both cases

329-415: A larger bulk flow of gas driven by buoyancy and temperature differences, and it does not work well in small cells where there is little density difference to drive it, and the high surface-to-volume ratios of the small cells retards gas flow in them by means of viscous drag . In order to accomplish small gas cell formation in man-made thermal insulation, glass and polymer materials can be used to trap air in

376-419: A layer of dry air next to the skin. The awn hair can be thought of as a hybrid, bridging the gap between the distinctly different characteristics of down and guard hairs. Awn hairs begin their growth much like guard hairs, but less than halfway to their full length, awn hairs start to grow thin and wavy like down hair. The proximal part of the awn hair assists in thermoregulation (like the down hair), whereas

423-676: A means to increase engine performance. Insulation performance is influenced by many factors, the most prominent of which include: It is important to note that the factors influencing performance may vary over time as material ages or environmental conditions change. Industry standards are often rules of thumb, developed over many years, that offset many conflicting goals: what people will pay for, manufacturing cost, local climate, traditional building practices, and varying standards of comfort. Both heat transfer and layer analysis may be performed in large industrial applications, but in household situations (appliances and building insulation), airtightness

470-422: A period of time, asbestos was also used, however, it caused health problems. Window insulation film can be applied in weatherization applications to reduce incoming thermal radiation in summer and loss in winter. When well insulated, a building is: In industry, energy has to be expended to raise, lower, or maintain the temperature of objects or process fluids. If these are not insulated, this increases

517-559: A region of insulation in which thermal conduction is reduced, creating a thermal break or thermal barrier , or thermal radiation is reflected rather than absorbed by the lower-temperature body. The insulating capability of a material is measured as the inverse of thermal conductivity (k) . Low thermal conductivity is equivalent to high insulating capability ( resistance value ). In thermal engineering , other important properties of insulating materials are product density (ρ) and specific heat capacity (c) . Thermal conductivity k

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564-401: Is added. However, at the same time, the convective resistance is reduced. This implies that adding insulation below a certain critical radius actually increases the heat transfer. For insulated cylinders, the critical radius is given by the equation This equation shows that the critical radius depends only on the heat transfer coefficient and the thermal conductivity of the insulation. If

611-483: Is coloured tan on the head, legs and underbelly with a black or sometimes grizzle saddle. Females are sometimes a simple darker tan all over. The breed is a sturdy and compact dog of about medium size that can grow up to 15.5 in (39 cm) with a weight of 20–22 pounds (9.1–10.0 kg). The tail was usually docked until this was prohibited in the United Kingdom in 2006, being preferred in order to complete

658-439: Is commonly installed in industrial and commercial facilities. Thermal insulation has been found to improve the thermal emittance of passive radiative cooling surfaces by increasing the surface's ability to lower temperatures below ambient under direct solar intensity. Different materials may be used for thermal insulation, including polyethylene aerogels that reduce solar absorption and parasitic heat gain which may improve

705-417: Is driven largely by camouflage. Differences in female and male coat color may indicate nutrition and hormone levels, important in mate selection. Some arboreal mammals, notably primates and marsupials, have shades of violet, green, or blue skin on parts of their bodies, indicating some distinct advantage in their largely arboreal habitat due to convergent evolution . The green coloration of sloths, however,

752-473: Is important to socialize Welsh Terriers as early as possible to a wide range of dogs, people, and experiences. The body of the Welsh Terrier is normal and healthy so that the physique is durable and lasting. Some studies have suggested a genetic predisposition to primary lens luxation which results in secondary glaucoma . Onychodystrophy, a disorder of nail growth causing nails to be weak and brittle,

799-401: Is inversely proportional to the surface area and therefore the radius of the cylinder, while the thermal resistance of a cylindrical shell (the insulation layer) depends on the ratio between outside and inside radius, not on the radius itself. If the outside radius of a cylinder is increased by applying insulation, a fixed amount of conductive resistance (equal to 2×π×k×L(Tin-Tout)/ln(Rout/Rin))

846-439: Is measured in watts -per-meter per kelvin (W·m ·K or W/mK). This is because heat transfer , measured as power , has been found to be (approximately) proportional to From this, it follows that the power of heat loss P {\displaystyle P} is given by P = k A Δ T d {\displaystyle P={\frac {kA\,\Delta T}{d}}} Thermal conductivity depends on

893-455: Is relatively common in the breed. Down hair Fur is a thick growth of hair that covers the skin of almost all mammals . It consists of a combination of oily guard hair on top and thick underfur beneath. The guard hair keeps moisture from reaching the skin; the underfur acts as an insulating blanket that keeps the animal warm. The fur of mammals has many uses: protection, sensory purposes, waterproofing, and camouflaging, with

940-449: Is the reduction of heat transfer (i.e., the transfer of thermal energy between objects of differing temperature) between objects in thermal contact or in range of radiative influence. Thermal insulation can be achieved with specially engineered methods or processes, as well as with suitable object shapes and materials. Heat flow is an inevitable consequence of contact between objects of different temperature . Thermal insulation provides

987-445: Is the result of a symbiotic relationship with algae. Coat color is sometimes sexually dimorphic , as in many primate species . Coat color may influence the ability to retain heat, depending on how much light is reflected. Mammals with darker colored coats can absorb more heat from solar radiation and stay warmer; some smaller mammals, such as voles , have darker fur in the winter. The white, pigmentless fur of arctic mammals, such as

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1034-438: Is usually fixed by the geometry of the object to be insulated. Multi-layer insulation is used where radiative loss dominates, or when the user is restricted in volume and weight of the insulation (e.g. emergency blanket , radiant barrier ) For insulated cylinders, a critical radius blanket must be reached. Before the critical radius is reached, any added insulation increases heat transfer. The convective thermal resistance

1081-496: The Space Shuttle . See also Insulative paint . Internal combustion engines produce a lot of heat during their combustion cycle. This can have a negative effect when it reaches various heat-sensitive components such as sensors, batteries, and starter motors. As a result, thermal insulation is necessary to prevent the heat from the exhaust from reaching these components. High performance cars often use thermal insulation as

1128-674: The Sphynx cat . Similarly, there are some breeds of hairless dogs . Other examples of artificially selected hairless animals include the hairless guinea-pig , nude mouse , and the hairless rat . Fur has long served as a source of clothing for humans, including Neanderthals . Historically, it was worn for its insulating quality, with aesthetics becoming a factor over time. Pelts were worn in or out, depending on their characteristics and desired use. Today fur and trim used in garments may be dyed bright colors or to mimic exotic animal patterns, or shorn close like velvet . The term "a fur" may connote

1175-499: The distal part can shed water (like the guard hair). The awn hair's thin basal portion does not allow the amount of piloerection that the stiffer guard hairs are capable of. Mammals with well-developed down and guard hairs also usually have large numbers of awn hairs, which may even sometimes be the bulk of the visible coat. Guard hair ( overhair ) is the top—or outer—layer of the coat. Guard hairs are longer, generally coarser, and have nearly straight shafts that protrude through

1222-542: The fur industry as a furbearer . The use of fur as clothing or decoration is controversial; animal welfare advocates object to the trapping and killing of wildlife, and the confinement and killing of animals on fur farms . The modern mammalian fur arrangement is known to have occurred as far back as docodonts , haramiyidans and eutriconodonts , with specimens of Castorocauda , Megaconus and Spinolestes preserving compound follicles with both guard hair and underfur. Fur may consist of three layers, each with

1269-522: The muskox has guard hairs measuring 30 cm (12 in) as well as a dense underfur, which forms an airtight coat, allowing them to survive in temperatures of −40 °C (−40 °F). Some desert mammals, such as camels, use dense fur to prevent solar heat from reaching their skin, allowing the animal to stay cool; a camel's fur may reach 70 °C (158 °F) in the summer, but the skin stays at 40 °C (104 °F). Aquatic mammals , conversely, trap air in their fur to conserve heat by keeping

1316-431: The black-and-white pelage of many mammals which are able to defend themselves, such as in the foul-smelling skunk and the powerful and aggressive honey badger . In arctic and subarctic mammals such as the arctic fox ( Vulpes lagopus ), collared lemming ( Dicrostonyx groenlandicus ), stoat ( Mustela erminea ), and snowshoe hare ( Lepus americanus ), seasonal color change between brown in summer and white in winter

1363-420: The coat is not regularly raked. Ungroomed coats can also fade and thin out as the old hair loses colour and texture. The Welsh Terrier closely resembles a compact Airedale Terrier . The Welsh Terrier has a typical terrier temperament. In the right hands, it is a happy, lively, and seldom shy or timid dog, but sometimes can have an attitude. The Welsh Terrier is generally friendly with people and dogs but when

1410-402: The emitter's performance by over 20%. Other aerogels also exhibited strong thermal insulation performance for radiative cooling surfaces, including a silica-alumina nanofibrous aerogel. A refrigerator consists of a heat pump and a thermally insulated compartment. Launch and re-entry place severe mechanical stresses on spacecraft, so the strength of an insulator is critically important;

1457-487: The energy requirements of a process, and therefore the cost and environmental impact. Space heating and cooling systems distribute heat throughout buildings by means of pipes or ductwork. Insulating these pipes using pipe insulation reduces energy into unoccupied rooms and prevents condensation from occurring on cold and chilled pipework. Pipe insulation is also used on water supply pipework to help delay pipe freezing for an acceptable length of time. Mechanical insulation

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1504-583: The failure of insulating tiles on the Space Shuttle Columbia caused the shuttle airframe to overheat and break apart during reentry, killing the astronauts on board. Re-entry through the atmosphere generates very high temperatures due to compression of the air at high speeds. Insulators must meet demanding physical properties beyond their thermal transfer retardant properties. Examples of insulation used on spacecraft include reinforced carbon -carbon composite nose cone and silica fiber tiles of

1551-462: The first year they change colour to standard black and tan grizzle. This breed does not shed (see Moult ). However, the coat requires regular grooming maintenance including brushing and hand stripping. An undocked Welsh Terrier tail is only an inch or so longer than a docked tail and does not make a great deal of difference to the overall appearance. The coat does not moult out but old hairs will eventually be stripped out through play and movement if

1598-418: The gene HR can lead to complete hair loss , though this is not typical in humans. At times, when a hairless domesticated animal is discovered, usually owing to a naturally occurring genetic mutation, humans may intentionally inbreed those hairless individuals and, after multiple generations, artificially create hairless breeds. There are several breeds of hairless cats, perhaps the most commonly known being

1645-436: The image of a square dog, as tall as it is long. The body shape is rectangular, with an elongated, "brick-like" face. This shape is formed by the whiskers and beard. With pedigrees the face can take a more oval shape and be finer boned and more distinct. The hair contains two layers, an undercoat that insulates and abrasive fur on top that protects against dirt, rain, and wind. Welsh Terriers are born mostly all black and during

1692-476: The largest extant terrestrial mammals, the elephant and the rhinoceros , are largely hairless. The hairless bat is mostly hairless but does have short bristly hairs around its neck, on its front toes, and around the throat sac, along with fine hairs on the head and tail membrane. Most hairless animals cannot go in the sun for long periods of time, or stay in the cold for too long. Marsupials are born hairless and grow out fur later in development. Humans are

1739-421: The layer of softer down hair. The distal end of the guard hair is the visible layer of most mammal coats. This layer has the most marked pigmentation and gloss , manifesting as coat markings that are adapted for camouflage or display. Guard hair repels water and blocks sunlight, protecting the undercoat and skin in wet or aquatic habitats, and from the sun's ultraviolet radiation. Guard hairs can also reduce

1786-465: The material and for fluids, its temperature and pressure. For comparison purposes, conductivity under standard conditions (20 °C at 1 atm) is commonly used. For some materials, thermal conductivity may also depend upon the direction of heat transfer. The act of insulation is accomplished by encasing an object in material with low thermal conductivity in high thickness. Decreasing the exposed surface area could also lower heat transfer, but this quantity

1833-468: The need for constant reinforcement. When acting on their own, they are quite creative and quick in decision making. They also have the potential for excessive barking. Like other terrier breeds, the Welsh Terrier enjoys digging. A Welsh Terrier is full of energy and requires regular exercise. A run around the yard during the day is insufficient. They become excited, and if bored, they may explore and potentially cause mischief and damage. Welsh Terriers need

1880-484: The only primate species that have undergone significant hair loss. The hairlessness of humans compared to related species may be due to loss of functionality in the pseudogene KRTHAP1 (which helps produce keratin ) Although the researchers dated the mutation to 240 000 ya, both the Altai Neandertal and Denisovan peoples possessed the loss-of-function mutation, indicating it is much older. Mutations in

1927-646: The polar bear, may reflect more solar radiation directly onto the skin. The term pelage  – first known use in English c.  1828 (French, from Middle French, from poil for 'hair', from Old French peilss , from Latin pilus ) – is sometimes used to refer to an animal's complete coat . The term fur is also used to refer to animal pelts that have been processed into leather with their hair still attached. The words fur or furry are also used, more casually, to refer to hair-like growths or formations, particularly when

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1974-495: The primary insulating material is air, and the polymer used for trapping the air is natural keratin protein. Maintaining acceptable temperatures in buildings (by heating and cooling) uses a large proportion of global energy consumption . Building insulations also commonly use the principle of small trapped air-cells as explained above, e.g. fiberglass (specifically glass wool ), cellulose , rock wool , polystyrene foam, urethane foam , vermiculite , perlite , cork , etc. For

2021-464: The primary usage being thermoregulation. The types of hair include Hair length is negligible in thermoregulation, as some tropical mammals, such as sloths, have the same fur length as some arctic mammals but with less insulation; and, conversely, other tropical mammals with short hair have the same insulating value as arctic mammals. The denseness of fur can increase an animal's insulation value, and arctic mammals especially have dense fur; for example,

2068-497: The radius of the insulated cylinder is smaller than the critical radius for insulation, the addition of any amount of insulation will increase heat transfer. Gases possess poor thermal conduction properties compared to liquids and solids and thus make good insulation material if they can be trapped. In order to further augment the effectiveness of a gas (such as air), it may be disrupted into small cells, which cannot effectively transfer heat by natural convection . Convection involves

2115-717: The severity of cuts or scratches to the skin. Many mammals, such as the domestic dog and cat, have a pilomotor reflex that raises their guard hairs as part of a threat display when agitated. Hair is one of the defining characteristics of mammals; however, several species or breeds have considerably reduced amounts of fur. These are often called "naked" or "hairless". Some mammals naturally have reduced amounts of fur. Some semiaquatic or aquatic mammals such as cetaceans , pinnipeds and hippopotamuses have evolved hairlessness, presumably to reduce resistance through water. The naked mole-rat has evolved hairlessness, perhaps as an adaptation to their subterranean lifestyle. Two of

2162-413: The skin dry. Mammalian coats are colored for a variety of reasons, the major selective pressures including camouflage , sexual selection , communication, and physiological processes such as temperature regulation. Camouflage is a powerful influence in many mammals, as it helps to conceal individuals from predators or prey. Aposematism , warning off possible predators, is the most likely explanation of

2209-410: The subject being referred to exhibits a dense coat of fine, soft "hairs". If layered, rather than grown as a single coat , it may consist of short down hairs, long guard hairs , and in some cases, medium awn hairs . Mammals with reduced amounts of fur are often called "naked", as with the naked mole-rat , or "hairless", as with hairless dogs . An animal with commercially valuable fur is known within

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