GE 4.8 cu. ft. Smart Satin Nickel Front Load Washer with OdorBlock UltraFresh Vent System with Sanitize and Allergen

4 (four) is a number, numeral and digit. It is the natural number following 3 and preceding 5.

4 is the smallest square number > 1, the smallest semiprime and composite number, and the 3rd highly composite number.

The number 4 is considered unlucky in many East Asian cultures.

An allergen is an otherwise harmless substance that triggers an allergic reaction in sensitive individuals by stimulating an immune response.

In technical terms, an allergen is an antigen that is capable of stimulating a type-I hypersensitivity reaction in atopic individuals through immunoglobulin E (IgE) responses. Most humans mount significant Immunoglobulin E responses only as a defense against parasitic infections. However, some individuals may respond to many common environmental antigens. This hereditary predisposition is called atopy. In atopic individuals, non-parasitic antigens stimulate inappropriate IgE production, leading to type I hypersensitivity.

Sensitivities vary widely from one person (or from one animal) to another. A very broad range of substances can be allergens to sensitive individuals.

Nickel is a chemical element; it has symbol Ni and atomic number 28. It is a silvery-white lustrous metal with a slight golden tinge. Nickel is a hard and ductile transition metal. Pure nickel is chemically reactive, but large pieces are slow to react with air under standard conditions because a passivation layer of nickel oxide forms on the surface that prevents further corrosion. Even so, pure native nickel is found in Earth's crust only in tiny amounts, usually in ultramafic rocks, and in the interiors of larger nickel–iron meteorites that were not exposed to oxygen when outside Earth's atmosphere.

Meteoric nickel is found in combination with iron, a reflection of the origin of those elements as major end products of supernova nucleosynthesis. An iron–nickel mixture is thought to compose Earth's outer and inner cores.

Use of nickel (as natural meteoric nickel–iron alloy) has been traced as far back as 3500 BCE. Nickel was first isolated and classified as an element in 1751 by Axel Fredrik Cronstedt, who initially mistook the ore for a copper mineral, in the cobalt mines of Los, Hälsingland, Sweden. The element's name comes from a mischievous sprite of German miner mythology, Nickel (similar to Old Nick). Nickel minerals can be green, like copper ores, and were known as kupfernickel – Nickel's copper – because they produced no copper.

Although most nickel in the earth's crust exists as oxides, economically more important nickel ores are sulfides, especially pentlandite. Major production sites include the Sudbury region, Canada (which is thought to be of meteoric origin), New Caledonia in the Pacific, Western Australia, and Norilsk, Russia.

Nickel is one of four elements (the others are iron, cobalt, and gadolinium) that are ferromagnetic at about room temperature. Alnico permanent magnets based partly on nickel are of intermediate strength between iron-based permanent magnets and rare-earth magnets. The metal is used chiefly in alloys and corrosion-resistant plating.

About 68% of world production is used in stainless steel. A further 10% is used for nickel-based and copper-based alloys, 9% for plating, 7% for alloy steels, 3% in foundries, and 4% in other applications such as in rechargeable batteries, including those in electric vehicles (EVs). Nickel is widely used in coins, though nickel-plated objects sometimes provoke nickel allergy. As a compound, nickel has a number of niche chemical manufacturing uses, such as a catalyst for hydrogenation, cathodes for rechargeable batteries, pigments and metal surface treatments. Nickel is an essential nutrient for some microorganisms and plants that have enzymes with nickel as an active site.

A satin weave is a type of fabric weave that produces a characteristically glossy, smooth or lustrous material, typically with a glossy top surface and a dull back; it is not durable, as it tends to snag. It is one of three fundamental types of textile weaves alongside plain weave and twill weave.

The satin weave is characterised by four or more fill or weft yarns floating over a warp yarn, and four warp yarns floating over a single weft yarn. Floats are missed interfacings, for example where the warp yarn lies on top of the weft in a warp-faced satin. These floats explain the high lustre and even sheen, as unlike in other weaves, light is not scattered as much when hitting the fibres, resulting in a stronger reflection. Satin is usually a warp-faced weaving technique in which warp yarns are "floated" over weft yarns, although there are also weft-faced satins. If a fabric is formed with a satin weave using filament fibres such as silk, polyester or nylon, the corresponding fabric is termed a 'satin', although some definitions insist that a satin fabric is only made from silk. If the yarns used are short-staple yarns such as cotton, the fabric formed is considered a sateen.

Many variations can be made of the basic satin weave, including a granite weave and a check weave.

Satin is commonly used in clothing, for items such as lingerie, nightgowns, blouses, and evening gowns, but is also used for boxer shorts, shirts and neckties. It is also used in the production of pointe shoes for ballet. Other uses include interior furnishing fabrics, upholstery, and bed sheets.

Smart may refer to a high level of intelligence or "street smarts".

"Smart" or SMART may also refer to the following.

A system is a group of interacting or interrelated elements that act according to a set of rules to form a unified whole. A system, surrounded and influenced by its environment, is described by its boundaries, structure and purpose and is expressed in its functioning. Systems are the subjects of study of systems theory and other systems sciences.

Systems have several common properties and characteristics, including structure, function(s), behavior and interconnectivity.

Washer most commonly refers to:

• Washer (hardware), a thin usually disc-shaped plate with a hole in the middle typically used with a bolt or nut
• Washing machine, for cleaning clothes

Washer may also refer to:

• Dishwasher, a machine for cleaning dishware, cookware and cutlery
• Dishwasher (occupation), a person who cleans dishware, cookware and cutlery
• Washer, a person with obsessive-compulsive disorder who washes her/his hands compulsively
• Washer method, a mathematical formula for finding volume
• Washer pitching, an outdoor game involving tossing discs at a target

With or WITH may refer to:

• With, a preposition in English
• Carl Johannes With (1877–1923), Danish doctor and arachnologist
• With (character), a character in D. N. Angel
• With (novel), a novel by Donald Harrington
• With (album), a 2014 album by TVXQ
• With (EP), a 2021 EP by Nam Woo-hyun