Luxembourg ( (listen) LUK-səm-burg; Luxembourgish: Lëtzebuerg [ˈlətsəbuəɕ] (listen); French: Luxembourg; German: Luxemburg), officially the Grand Duchy of Luxembourg, is a small landlocked country in Western Europe. It borders Belgium to the west and north, Germany to the east, and France to the south. Its capital and most populous city, Luxembourg, is one of the four institutional seats of the European Union (together with Brussels, Frankfurt, and Strasbourg) and the seat of several EU institutions, notably the Court of Justice of the European Union, the highest judicial authority. Luxembourg's culture, people, and languages are highly intertwined with its French and German neighbors; while Luxembourgish is legally the only national language of the Luxembourgish people, French and German are also...

Zen (Chinese: 禪; pinyin: Chán; Japanese: 禅, romanized: zen; Korean: 선, romanized: Seon; Vietnamese: Thiền) is a school of Mahayana Buddhism that originated in China during the Tang dynasty, known as the Chan School (Chánzong 禪宗), and later developed into various sub-schools and branches. From China, Chán spread south to Vietnam and became Vietnamese...

Blow molding (or moulding) is a manufacturing process for forming hollow plastic parts. It is also used for forming glass bottles or other hollow shapes. In general, there are three main types of blow molding: extrusion blow molding, injection blow molding, and injection stretch blow molding. The blow molding process begins with softening plastic by heating a preform or parison. The parison is a tube-like piece of plastic with a hole in one end through which compressed air can enter. The plastic workpiece is then clamped into a mold and air is blown into it. The air pressure inflates the plastic which conforms to the mold. Once the plastic has cooled and hardened the mold opens and the part is ejected. Water channels within the mold assist cooling. History The process principle comes from the idea of glassblowing. Enoch Ferngren and William Kopitke produced a blow molding machine and sold it to Hartford Empire Company in 1938. This was the beginning of the commercial blow molding process. During the 1940s the variety and number of products was still very limited and therefore...

SN 1604, also known as Kepler's Supernova, Kepler's Nova or Kepler's Star, was a Type Ia supernova that occurred in the Milky Way, in the constellation Ophiuchus. Appearing in 1604, it is the most recent supernova in the Milky Way galaxy to have been unquestionably observed by the naked eye, occurring no farther than 6 kiloparsecs (20,000 light-years) from Earth. Before the adoption of the current naming system for supernovae, it was named for Johannes Kepler, the German astronomer who described it in De Stella Nova. Observation Visible to the naked eye, Kepler's Star was brighter at its peak than any other star in the night sky, with an apparent magnitude of −2.5. It was visible during the day for over three weeks. Records of its sighting exist in European, Chinese, Korean, and Arabic sources. It was the second supernova to be observed in a generation (after SN 1572 seen by Tycho Brahe in Cassiopeia). No further supernovae have since been observed with certainty in the Milky Way, though many others outside the galaxy have been seen since S Andromedae in 1885....

Biomechanics is the study of the structure, function and motion of the mechanical aspects of biological systems, at any level from whole organisms to organs, cells and cell organelles, using the methods of mechanics. Biomechanics is a branch of biophysics. In 2022, computational mechanics goes far beyond pure mechanics, and involves other physical actions: chemistry, heat and mass transfer, electric and magnetic stimuli and many others. Etymology The word "biomechanics" (1899) and the related "biomechanical" (1856) come from the Ancient Greek βίος bios "life" and μηχανική, mēchanikē "mechanics", to refer to the study of the mechanical principles of living organisms, particularly their movement and structure. Subfields Biofluid mechanics Biological fluid mechanics, or biofluid mechanics, is the study of both gas and liquid fluid flows in or around biological organisms. An often studied liquid biofluid problem is that of blood flow in the human cardiovascular system. Under certain mathematical...

The alpha helix (α-helix) is a common motif in the secondary structure of proteins and is a right hand-helix conformation in which every backbone N−H group hydrogen bonds to the backbone C=O group of the amino acid located four residues earlier along the protein sequence. The alpha helix is also called a classic Pauling–Corey–Branson α-helix. The name 3.613-helix is also used for this type of helix, denoting the average number of residues per helical turn, with 13 atoms being involved in the ring formed by the hydrogen bond. Among types of local structure in proteins, the α-helix is the most extreme and the most predictable from sequence, as well as the most prevalent. Discovery In the early 1930s, William Astbury showed that there were drastic changes in the X-ray fiber diffraction of moist wool or hair fibers upon significant stretching. The data suggested that the unstretched fibers had a coiled molecular structure with a characteristic repeat of ≈5.1 ångströms (0.51 nanometres). Astbury initially proposed a linked-chain structure for the fibers. He later joined...

A castell (Catalan pronunciation: [kəsˈteʎ]) is a human tower built traditionally at festivals in Catalonia, the Balearic islands and the Valencian Community. At these festivals, several colles castelleres (teams that build towers) attempt to build and dismantle a tower's structure. On 16 November 2010, castells were declared by UNESCO to be amongst the Masterpieces of the Oral and Intangible Heritage of Humanity. Origin Although based on the earlier traditional Muixeranga of Algemesí in Valencia, the tradition of castells within Catalonia originated in the Ball dels Valencians (Valencian Dance) in Valls, near the city of Tarragona, first documented in 1712. Over the course of the 18th century, they spread to other towns and cities in the area, including Vilafranca del Penedès and Tarragona, though it was not until the last 50 years that the practice of building castells began to spread to the rest of Catalonia. Interest in castells began to grow in the 1960s and 1970s. In...

Coconut milk is an opaque, milky-white liquid extracted from the grated pulp of mature coconuts. The opacity and rich taste of coconut milk are due to its high oil content, most of which is saturated fat. Coconut milk is a traditional food ingredient used in Southeast Asia, Oceania, South Asia, and East Africa. It is also used for cooking in the Caribbean, tropical Latin America, and West Africa, where coconuts were introduced during the colonial era. Coconut milk is differentiated into subtypes based on fat content. They can be generalized into coconut cream (or thick coconut milk) with the highest amount of fat; coconut milk (or thin coconut milk) with a maximum of around 20% fat; and coconut skim milk with negligible amounts of fat. This terminology is not always followed in commercial coconut milk sold in western countries.Coconut milk can also be used to produce milk substitutes (differentiated as "coconut milk beverages"). These products are not the same as regular coconut milk products which are meant for...

In astronomy, axial tilt, also known as obliquity, is the angle between an object's rotational axis and its orbital axis, which is the line perpendicular to its orbital plane; equivalently, it is the angle between its equatorial plane and orbital plane. It differs from orbital inclination. At an obliquity of 0 degrees, the two axes point in the same direction; that is, the rotational axis is perpendicular to the orbital plane. The rotational axis of Earth, for example, is the imaginary line that passes through both the North Pole and South Pole, whereas the Earth's orbital axis is the line perpendicular to the imaginary plane through which the Earth moves as it revolves around the Sun; the Earth's obliquity or axial tilt is the angle between these two lines. Earth's obliquity oscillates between 22.1 and 24.5 degrees on a 41,000-year cycle. Based on a continuously updated formula (here Laskar, 1986, though since 2006 the IMCCE and the IAU recommend the P03 model), Earth's mean obliquity (without taking into account the nutation in obliquity) is currently about 23°26′10.7″ (or 23.43629°) and decreasing; according to P03 astronomical...