The term "183 mm artillery" generally refers to artillery pieces, particularly howitzers, that have a caliber of 183 millimeters. Artillery pieces of this caliber are typically used for long-range bombardment and are capable of firing various types of munitions, including high-explosive shells, guided munitions, and others, depending on their design and capabilities.

400 mm artillery refers to heavy artillery pieces that have a caliber of 400 millimeters (mm), which is approximately 15.75 inches. This type of artillery is typically used for long-range bombardment and can deliver a significant explosive payload over great distances. The use of 400 mm artillery is primarily associated with large siege guns, coastal defense weapons, or heavy artillery systems designed to provide support against fortified positions or to engage enemy forces at long ranges.

203 mm artillery typically refers to howitzers that fire shells with a diameter of 203 millimeters (8 inches). This caliber of artillery is known for its significant firepower and is used for long-range bombardment, support for ground troops, and to destroy fortified positions. Historically, 203 mm artillery has been utilized by various countries, particularly during the 20th century.

Endovenous laser treatment (EVLT) is a minimally invasive procedure used to treat varicose veins and venous insufficiency. It employs laser energy to close off or seal the affected veins, thereby redirecting blood flow to healthier veins. ### How the Procedure Works: 1. **Consultation and Diagnosis**: Before the procedure, a healthcare provider will usually perform a physical examination and possibly an ultrasound to assess the veins and determine the extent of the condition.

Endre Mester was a Hungarian-born scientist notable for his pioneering work in laser research and medicine. He is best known for his contributions to the development of laser therapy in the field of ophthalmology. Mester is credited with discovering that low-level laser light could stimulate healing in tissues and promote hair growth, leading to investigations into the therapeutic effects of lasers in various medical applications. Mester's research laid the groundwork for the use of laser therapy in different fields, including dermatology and wound healing.

Er:YAG laser stands for Erbium-doped Yttrium Aluminum Garnet laser. It is a type of solid-state laser that uses erbium ions (Er³⁺) as the active laser medium, with yttrium aluminum garnet (YAG) as the host crystal. The Er:YAG laser operates at a wavelength of approximately 2940 nanometers, which falls within the infrared spectrum.

The term "254 mm artillery" typically refers to large-caliber artillery systems that use 254 mm shells. While 254 mm isn't a standard caliber in modern artillery, this dimension can be associated with specific historical artillery pieces. One notable example is the **254 mm howitzer**, which was used by some military forces during the 20th century.

The term "350 mm artillery" typically refers to large-caliber artillery pieces designed to fire projectiles with a diameter of 350 millimeters (mm). Such artillery systems can include howitzers, mortars, or coastal defense guns. These types of artillery are typically used for heavy bombardment in military operations and can cause significant destruction due to the large size of the shells they fire.

The term "82 mm artillery" typically refers to a specific caliber of artillery, commonly associated with mortars. The 82 mm mortar is designed to launch explosive projectiles at high angles for indirect fire support, making it effective for engaging targets that are not in the direct line of sight. One of the most notable examples of 82 mm artillery is the 82mm mortar used by various countries, particularly by the Soviet Union and its successors.

The term "83 mm artillery" typically refers to artillery pieces or munitions that have a caliber of 83 millimeters. This caliber is relatively uncommon compared to the more standard calibers such as 105 mm, 155 mm, or 120 mm. One notable example of 83 mm artillery is the Soviet/Russian 2A28 "Grom" smoothbore gun, which is mounted on the BMP-1 infantry fighting vehicle.

305 mm artillery typically refers to artillery pieces that have a bore diameter of 305 millimeters (approximately 12 inches). This caliber has been used in various types of artillery systems, including howitzers, cannons, and coastal defense guns, throughout military history. The 305 mm caliber was notably employed during the early to mid-20th century, particularly in World War I and World War II.

The term "320 mm artillery" typically refers to heavy artillery pieces that have a caliber of 320 millimeters. This caliber is relatively uncommon and is not typically found in standard field artillery. One of the most notable pieces of artillery that fits this classification is the **320 mm gun** developed for specific military purposes.

"Space guns" can refer to a few different concepts depending on the context in which the term is used: 1. **Theoretical Space Weapons**: This refers to concepts of weapons designed for use in space, including orbital bombardment systems, laser weapons, and railguns. These types of weapons are often discussed in military and strategic contexts, considering their potential applications in conflicts related to space.

A square is a unit of area that is commonly used in real estate and property measurement. It represents a square measurement of one unit of length by one unit of length. The most commonly used square measurement is the square foot (sq ft), which is the area of a square with sides that are each one foot long. Similarly, there are square meters, square yards, and other units of measurement.

The term "413 mm artillery" generally refers to artillery pieces or gun systems with a caliber of 413 millimeters. One notable example is the **Schwerer Gustav**, a German super-heavy railway gun used during World War II. The Schwerer Gustav was one of the heaviest artillery pieces ever constructed, designed to be able to fire massive shells capable of penetrating fortified targets, such as the heavily defended French Maginot Line.

The term "420 mm artillery" typically refers to large-caliber artillery pieces that fire projectiles with a diameter of 420 millimeters (approximately 16.5 inches). This caliber is notably associated with heavy artillery systems that are designed for long-range bombardment and can cause significant destruction. One of the most well-known examples of a 420 mm artillery piece is the German "Dora" and "Großdeutschland" railway guns used during World War II.

The term "520 mm artillery" typically refers to large-caliber artillery pieces that have a bore diameter of 520 millimeters. This caliber is notably larger than standard artillery used in most conventional military applications. An example of a 520 mm artillery piece is the Soviet "K欲" (also known as "Katushka" or "K-3," which is a railway gun).

The term "600 mm artillery" typically refers to a type of heavy artillery with a caliber of 600 millimeters (mm). One of the most notable examples of this caliber is the **German "Dora" railway gun** used during World War II. The Dora was a massive piece of artillery designed for long-range bombardment, capable of firing heavy shells over great distances.

75 mm artillery refers to a type of artillery weapon that uses a 75 mm caliber projectile. This caliber has been used in various artillery pieces, including howitzers, field guns, and anti-tank guns, throughout military history. The term "75 mm" indicates the diameter of the shell fired from the cannon. Historically, 75 mm artillery has been significant in multiple conflicts, especially during World War I and World War II.

76 mm artillery generally refers to a caliber of artillery that uses projectiles with a diameter of 76 millimeters. This size has been utilized in various types of artillery pieces, including field guns and naval guns, and was particularly prominent during the 20th century. One of the most famous 76 mm artillery systems is the 76 mm OTO Melara gun, which is widely used in naval applications and has been mounted on a variety of ships.