A ballpoint pen, also known as a biro,[1] or ball pen, is a pen that dispenses ink over a metal ball at its point, i.e. over a “ball point”. The metal commonly used is steel, brass, or tungsten carbide.[2] It was conceived and developed as a cleaner and more reliable alternative to dip pens and fountain pens, and it is now the world’s most-used writing instrument:[3] millions are manufactured and sold daily.[4] As a result, it has influenced art and graphic design and spawned an artwork genre.
Tin is a chemical element with symbol Sn (from Latin: stannum) and atomic number 50. It is a post-transition metal in group 14 of the periodic table. It is obtained chiefly from the mineralcassiterite, which contains tin dioxide, SnO2. Tin shows a chemical similarity to both of its neighbors in group 14, germanium and lead, and has two main oxidation states, +2 and the slightly more stable +4. Tin is the 49th most abundant element and has, with 10 stable isotopes, the largest number of stable isotopes in the periodic table, thanks to its magic number of protons. It has two main allotropes: at room temperature, the stable allotrope is β-tin, a silvery-white, malleable metal, but at low temperatures it transforms into the less dense grey α-tin, which has the diamond cubic structure. Metallic tin is not easily oxidized in air.
A ballpoint pen, also known as a biro,[1] or ball pen, is a pen that dispenses ink over a metal ball at its point, i.e. over a “ball point”. The metal commonly used is steel, brass, or tungsten carbide.[2] It was conceived and developed as a cleaner and more reliable alternative to dip pens and fountain pens, and it is now the world’s most-used writing instrument:[3] millions are manufactured and sold daily.[4] As a result, it has influenced art and graphic design and spawned an artwork genre.
X-Acto is a brand name for a variety of cutting tools and office products owned by Elmer’s Products, Inc. Cutting tools include hobby and utility knives, saws, carving tools and many small-scale precision knives used for crafts and other applications.
SRAM Corporation is a privately owned bicycle component manufacturer based in Chicago, Illinois, United States, founded in 1987.[2] SRAM is an acronym comprising the names of its founders, Scott, Ray, and Sam, (where Ray is the middle name of company head Stan Day).[2] The company is known for producing cycling components, including some internally developed, such as Grip Shift, EAGLE (1×12), DoubleTap, dedicated 1×11 mountain and road drivetrains and SRAM Red eTap.[3][4][5]
SRAM Corporation is a privately owned bicycle component manufacturer based in Chicago, Illinois, United States, founded in 1987.[2] SRAM is an acronym comprising the names of its founders, Scott, Ray, and Sam, (where Ray is the middle name of company head Stan Day).[2] The company is known for producing cycling components, including some internally developed, such as Grip Shift, EAGLE (1×12), DoubleTap, dedicated 1×11 mountain and road drivetrains and SRAM Red eTap.[3][4][5]
SRAM Corporation is a privately owned bicycle component manufacturer based in Chicago, Illinois, United States, founded in 1987.[2] SRAM is an acronym comprising the names of its founders, Scott, Ray, and Sam, (where Ray is the middle name of company head Stan Day).[2] The company is known for producing cycling components, including some internally developed, such as Grip Shift, EAGLE (1×12), DoubleTap, dedicated 1×11 mountain and road drivetrains and SRAM Red eTap.[3][4][5]
SRAM Corporation is a privately owned bicycle component manufacturer based in Chicago, Illinois, United States, founded in 1987.[2] SRAM is an acronym comprising the names of its founders, Scott, Ray, and Sam, (where Ray is the middle name of company head Stan Day).[2] The company is known for producing cycling components, including some internally developed, such as Grip Shift, EAGLE (1×12), DoubleTap, dedicated 1×11 mountain and road drivetrains and SRAM Red eTap.[3][4][5]
SRAM Corporation is a privately owned bicycle component manufacturer based in Chicago, Illinois, United States, founded in 1987.[2] SRAM is an acronym comprising the names of its founders, Scott, Ray, and Sam, (where Ray is the middle name of company head Stan Day).[2] The company is known for producing cycling components, including some internally developed, such as Grip Shift, EAGLE (1×12), DoubleTap, dedicated 1×11 mountain and road drivetrains and SRAM Red eTap.[3][4][5]
Common roller bearings use cylinders of slightly greater length than diameter. Roller bearings typically have higher radial load capacity than ball bearings, but a lower capacity and higher friction under axial loads. If the inner and outer races are misaligned, the bearing capacity often drops quickly compared to either a ball bearing or a spherical roller bearing.
Common roller bearings use cylinders of slightly greater length than diameter. Roller bearings typically have higher radial load capacity than ball bearings, but a lower capacity and higher friction under axial loads. If the inner and outer races are misaligned, the bearing capacity often drops quickly compared to either a ball bearing or a spherical roller bearing.
Common roller bearings use cylinders of slightly greater length than diameter. Roller bearings typically have higher radial load capacity than ball bearings, but a lower capacity and higher friction under axial loads. If the inner and outer races are misaligned, the bearing capacity often drops quickly compared to either a ball bearing or a spherical roller bearing.
The purpose of a ball bearing is to reduce rotational friction and support radial and axialloads. It achieves this by using at least two races to contain the balls and transmit the loads through the balls. In most applications, one race is stationary and the other is attached to the rotating assembly (e.g., a hub or shaft). As one of the bearing races rotates it causes the balls to rotate as well. Because the balls are rolling they have a much lower coefficient of friction than if two flat surfaces were sliding against each other.
A fingerprint in its narrow sense is an impression left by the friction ridges of a human finger.[1]The recovery of fingerprints from a crime scene is an important method of forensic science. Fingerprints are easily deposited on suitable surfaces (such as glass or metal or polished stone) by the natural secretions of sweat from the eccrine glands that are present in epidermal ridges. These are sometimes referred to as “Chanced Impressions”.
A comedo is a clogged hair follicle (pore) in the skin.[2]Keratin (skin debris) combines with oil to block the follicle.[3] A comedo can be open (blackhead) or closed by skin (whitehead), and occur with or without acne.[3] The word comedo comes from the Latincomedere, meaning “to eat up”, and was historically used to describe parasitic worms; in modern medical terminology, it is used to suggest the worm-like appearance of the expressed material.[1]
The chronic inflammatory condition that usually includes both comedones and inflamed papules and pustules (pimples) is called acne.[3][4] Infection causes inflammation and the development of pus.[2] Whether or not a skin condition classifies as acne depends on the amount of comedones and infection.[4] Comedones should not be confused with sebaceous filaments.
Rotary Stage for Manual Micro/Macro 3D Imaging
