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Topic Review
Sami Drum
A Sami drum is a shamanic ceremonial drum in the culture of the Sami people of Northern Europe. Sami ceremonial drums have two types: a bowl drum in which the drumhead is strapped over a burl, and a frame drum in which the drumhead stretches over a thin ring of bentwood. Both variations are oval-shaped. The drumhead is fashioned from reindeer hide. In Sami shamanism, the noaidi – the Sami shaman – used the drum to get into a trance, or to obtain information from the future or about other places. The drum was held in one hand, and operated with the other hand. While the noaidi was in trance, his free spirit left his body to visit the spiritual world or other places. When used for divination purposes, the drum was used together with a drum hammer and an vuorbi (index or pointer) made of brass or horn. Answers could be interpreted from where the vuorbi stopped on the membrane, and at which symbols. The patterns on the drum membrane reflect the world view of the owner and his family, both in religious and worldly matters, such as reindeer herding, hunting, householding and relations to their neighbours and to the non-Sami community. Many drums were taken out of their use and Sami ownership during the 18th century. A large number of drums were confiscated by Sami missionaries and other officials as a part of an intensified Christian mission towards the Sami. Other drums were bought by collectors. Between 70 and 80 drums are preserved; the largest collection of drums is at the Nordic Museum, Stockholm.
  • 5.9K
  • 27 Oct 2022
Topic Review
Fiscal Year
A fiscal year (or financial year, or sometimes budget year) is used in government accounting, which varies between countries, and for budget purposes. It is also used for financial reporting by businesses and other organizations. Laws in many jurisdictions require company financial reports to be prepared and published on an annual basis, but generally do not require the reporting period to align with the calendar year (1 January to 31 December). Taxation laws generally require accounting records to be maintained and taxes calculated on an annual basis, which usually corresponds to the fiscal year used for government purposes. The calculation of tax on an annual basis is especially relevant for direct taxation, such as income tax. Many annual government fees—such as Council rates, license fees, etc.—are also levied on a fiscal year basis, while others are charged on an anniversary basis. Some companies—such as Cisco Systems—end their fiscal year on the same day of the week each year, i.e. the day that is closest to a particular date (for example, the Friday closest to 31 December). Under such a system, some fiscal years will have 52 weeks and others 53 weeks. The calendar year is used as the fiscal year by about 65% of publicly traded companies in the United States and for a majority of large corporations in the UK. It's the case in many countries around the world with a few exceptions, for example, Australia, New Zealand, and Japan. Many universities have a fiscal year which ends during the summer to align the fiscal year with the academic year (and, in some cases involving public universities, with the state government's fiscal year), and because the university is normally less busy during the summer months. In the northern hemisphere this is July to the next June. In the southern hemisphere this is calendar year, January to December. Some media/communication-based organizations use a broadcast calendar as the basis for their fiscal year. The fiscal year is usually denoted by the calendar year in which it ends, so United States federal government spending incurred on 14 November 2022 would belong to fiscal year 2023, operating on a fiscal calendar of October–September.
  • 5.9K
  • 11 Oct 2022
Topic Review
Online Auction
An online auction is an auction which is held over the internet. Online auctions come in many different formats, but most popularly they are ascending English auctions, descending Dutch auctions, first-price sealed-bid, Vickrey auctions, or sometimes even a combination of multiple auctions, taking elements of one and forging them with another. The scope and reach of these auctions have been propelled by the Internet to a level beyond what the initial purveyors had anticipated. This is mainly because online auctions break down and remove the physical limitations of traditional auctions such as geography, presence, time, space, and a small target audience. This influx in reachability has also made it easier to commit unlawful actions within an auction. In 2002, online auctions were projected to account for 30% of all online e-commerce due to the rapid expansion of the popularity of the form of electronic commerce. Online auctions include business to business (B2B), business to consumer (B2C), and consumer to consumer (C2C) auctions. The largest online auction site is eBay, which was the first to support person-to-person transactions. Other popular examples of online auction sites include WebStore, OnlineAuction and Overstock.
  • 5.9K
  • 06 Dec 2022
Topic Review
Landsat 8 and Landsat 9
With the launch of Landsat 9 in September 2021, an optimal opportunity for in-flight cross-calibration occurred when Landsat 9 flew underneath Landsat 8 while being moved into its final orbit. Since the two instruments host nearly identical imaging systems, the underfly event offered ideal cross-calibration conditions. Using the underfly imagery collected by the instruments to estimate cross-calibration parameters for Landsat 9 for a calibration update scheduled at the end of the on-orbit initial verification (OIV) period was studied. Three types of uncertainty were considered: geometric, spectral, and angular (bidirectional reflectance distribution function—BRDF). Differences caused by geometric uncertainty were found to be negligible for this application. 
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  • 01 Jun 2022
Topic Review
Surface Passivation
Passivation, in physical chemistry and engineering, refers to coating a material so it becomes "passive", that is, less readily affected or corroded by the environment. Passivation involves creation of an outer layer of shield material that is applied as a microcoating, created by chemical reaction with the base material, or allowed to build by spontaneous oxidation in the air. As a technique, passivation is the use of a light coat of a protective material, such as metal oxide, to create a shield against corrosion. Passivation of silicon is used during fabrication of microelectronic devices. In electrochemical treatment of water, passivation reduces the effectiveness of the treatment by increasing the circuit resistance, and active measures are typically used to overcome this effect, the most common being polarity reversal, which results in limited rejection of the fouling layer.[clarification needed] When exposed to air, many metals naturally form a hard, relatively inert surface layer, usually an oxide (termed the "native oxide layer") or a nitride, that serves as a passivation layer. In the case of silver, the dark tarnish is a passivation layer of silver sulfide formed from reaction with environmental hydrogen sulfide. (In contrast, metals such as iron oxidize readily to form a rough porous coating of rust that adheres loosely and sloughs off readily, allowing further oxidation.) The passivation layer of oxide markedly slows further oxidation and corrosion in room-temperature air for aluminium, beryllium, chromium, zinc, titanium, and silicon (a metalloid). The inert surface layer formed by reaction with air has a thickness of about 1.5 nm for silicon, 1–10 nm for beryllium, and 1 nm initially for titanium, growing to 25 nm after several years. Similarly, for aluminium, it grows to about 5 nm after several years. Surface passivation refers to a common semiconductor device fabrication process critical to modern electronics. It is the process by which a semiconductor surface such as silicon is rendered inert, and does not change semiconductor properties when it interacts with air or other materials. This is typically achieved by thermal oxidation, in which the material is heated and exposed to oxygen. In a silicon semiconductor, this process allows electricity to reliably penetrate to the conducting silicon below the surface, and to overcome the surface states that prevent electricity from reaching the semiconducting layer. Surface passivation by thermal oxidation is one of the key features of silicon technology, and is dominant in microelectronics. The surface passivation process was developed by Mohamed M. Atalla at Bell Labs in the late 1950s. It is commonly used to manufacture MOSFETs (metal-oxide-semiconductor field-effect transistors) and silicon integrated circuit chips (with the planar process), and is critical to the semiconductor industry. Surface passivation is also critical to solar cell and carbon quantum dot technologies.
  • 5.9K
  • 22 Nov 2022
Topic Review
Weave Structure and Fabric Properties
Fabric structures are created by interlacing yarns or intermeshing loops to create two-dimensional (2D) flexible materials. The most prevalent structure is woven fabrics, which are made up of two sets of perpendicular yarns that are crossed and interwoven to form a coherent and stable structure.
  • 5.9K
  • 16 Sep 2022
Topic Review
Railway Nationalization
Railway nationalization is the act of taking rail transport assets into public ownership. Several countries have at different times nationalized part or all of their railway system. More recently, the international trend has been towards privatization. In some areas, notably Great Britain, resultant problems with track maintenance have led back to a more mixed solution, with a nationalised infrastructure operator but privately run train operating companies. National characteristics influenced the structures under which countries' rail networks developed. Some national railways were always under direct State management, some were State-planned but privately operated (as in France, others were wholly private enterprises lightly regulated (as in Great Britain, Ireland and Spain). Nationalization was therefore a bolder step to take in some countries than in others. While ideology has played a role, so too has the need for systematic reconstruction of vital infrastructure devastated by war, often following a period of State control over private companies initiated during the conflict.
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  • 01 Dec 2022
Topic Review
Old Azeri Language
Old Azeri (Persian: آذری‌ باستان‎), also referred to as Azeri or Azari (Persian: آذری‎ Āḏarī [ɑːzæri]), is the extinct Iranian language that was once spoken in Azerbaijan (historic Azerbaijan, also known as Iranian Azerbaijan) before the Turkification of the Azeris. Some linguists believe the southern Tati varieties of Iranian Azerbaijan around Takestan such as the Harzandi and Karingani dialects to be remnants of Azeri. In addition, Old Azeri is known to have strong affinities with Talysh. Azeri was the dominant language in Azerbaijan before it was replaced by Azerbaijani, which is a Turkic language.
  • 5.9K
  • 30 Nov 2022
Topic Review
Lifestyle (Sociology)
Lifestyle is the interests, opinions, behaviours, and behavioural orientations of an individual, group, or culture. The term was introduced by Austrian psychologist Alfred Adler in his 1929 book, The Case of Miss R., with the meaning of "a person's basic character as established early in childhood". The broader sense of lifestyle as a "way or style of living" has been documented since 1961. Lifestyle is a combination of determining intangible or tangible factors. Tangible factors relate specifically to demographic variables, i.e. an individual's demographic profile, whereas intangible factors concern the psychological aspects of an individual such as personal values, preferences, and outlooks. A rural environment has different lifestyles compared to an urban metropolis. Location is important even within an urban scope. The nature of the neighborhood in which a person resides affects the set of lifestyles available to that person due to differences between various neighborhoods' degrees of affluence and proximity to natural and cultural environments. For example, in areas near the sea, a surf culture or lifestyle can often be present.
  • 5.9K
  • 13 Oct 2022
Topic Review
Euler–Mascheroni Constant
The Euler–Mascheroni constant (also called Euler's constant) is a mathematical constant recurring in analysis and number theory, usually denoted by the lowercase Greek letter gamma (γ). It is defined as the limiting difference between the harmonic series and the natural logarithm, denoted here by [math]\displaystyle{ \log: }[/math] Here, [math]\displaystyle{ \lfloor x\rfloor }[/math] represents the floor function. The numerical value of the Euler–Mascheroni constant, to 50 decimal places, is: 0.57721566490153286060651209008240243104215933593992... 
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  • 02 Dec 2022
Biography
Joshua David Stone
Joshua David Stone (7 December 1953 – 13 August 2005) was an American author and teacher in the Ascended Master Teachings (sometimes called the Ascension Movement), a group of religions based on Theosophy. He was an influential Spiritual teacher in the Ascension Movement. Stone had a Ph.D. in Transpersonal Psychology and was a Licensed Marriage, Family and Child Counselor in California USA.
  • 5.9K
  • 26 Dec 2022
Topic Review
ATtiny Microcontroller Comparison Chart
ATtiny (also known as TinyAVR) are a subfamily of the popular 8-bit AVR microcontrollers, which typically has fewer features, fewer I/O pins, and less memory than other AVR series chips. The first members of this family were released in 1999 by Atmel (later acquired by Microchip Technology in 2016).
  • 5.9K
  • 03 Nov 2022
Topic Review
Football Goalkeeper Injuries
Knowledge and research about football goalkeeper (GK) injuries are scarce, which prevents the development of evidence-based injury prevention programs. Fortunately, progress is evident in injury prevention strategies in outfield football players. However, a GK fulfills a unique role, and an injured GK can substantially impact a team. Thus, there is a need to clarify and summarize current knowledge concerning football goalkeeper pain and injuries.
  • 5.9K
  • 31 May 2021
Topic Review Peer Reviewed
Frederick II of Hohenstaufen (1208–1250)
Frederick II of Hohenstaufen, King of Sicily (1208–1250). Frederick II of Hohenstaufen was the second king of the Swabian dynasty to sit on the throne of Sicily. He was crowned in 1198, but, in consideration of his young age, he only ruled independently from 1208 to 1250 (the year of his death). He not only held the title of King of Sicily but also was the King of Germany (or of the Romans), the King of Jerusalem, and, above all, Emperor of the Holy Roman Empire. His most relevant and innovative iconographic representations were in Southern Italy. For this reason, we focus on the images in this geographical context. In particular, we have nine official (that is, those commissioned directly by him or his entourage) representations of him: the bull (in three main versions), the seal (in three main versions), five coins (four denari and one augustale), the statue of the Capua Gate, and the lost image of the imperial palace in Naples.
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  • 13 Apr 2022
Topic Review
History of Purgatory
The idea of purgatory has roots that date back into antiquity. A sort of proto-purgatory called the "celestial Hades" appears in the writings of Plato and Heraclides Ponticus and in many other pagan writers. This concept is distinguished from the Hades of the underworld described in the works of Homer and Hesiod. In contrast, the celestial Hades was understood as an intermediary place where souls spent an undetermined time after death before either moving on to a higher level of existence or being reincarnated back on earth. Its exact location varied from author to author. Heraclides of Pontus thought it was in the Milky Way; the Academicians, the Stoics, Cicero, Virgil, Plutarch, the Hermetical writings situated it between the Moon and the Earth or around the Moon; while Numenius and the Latin Neoplatonists thought it was located between the sphere of the fixed stars and the Earth. Perhaps under the influence of Hellenistic thought, we find another intermediate state entering Jewish religious thought in the last centuries B.C.E. In Maccabees we find the practice of prayer for the dead with a view to their after life purification a practice accepted by some Christians. The same practice appears in other traditions, such as the medieval Chinese Buddhist practice of making offerings on behalf of the dead, who are said to suffer numerous trials. Among other reasons, Catholic belief in purgatory is based on the practice of prayer for the dead. Descriptions and doctrine regarding purgatory developed over the centuries. Those who believe in purgatory interpret extra-biblical passages such as 2 Maccabees 12:41-46 (not accepted as Scripture by Protestants but recognized by Orthodox and Catholics), and biblical passages such as 2 Timothy 1:18, Matthew 12:32, Luke 16:19-16:26, Luke 23:43, 1 Corinthians 3:11-3:15 and Hebrews 12:29 as support for prayer for the dead, an active interim state for the dead prior to the resurrection, and purifying flames after death. The first Christians looked forward to the imminent return of Christ and did not develop detailed beliefs about the interim state. Gradually, Christians, especially in the West, took an interest in circumstances of the interim state between one's death and the future resurrection. Christians both East and West prayed for the dead in this interim state, although theologians in the East refrained from defining it. Augustine of Hippo distinguished between the purifying fire that saves and eternal consuming fire for the unrepentant. Gregory the Great established a connection between earthly penance and purification after death. All Soul's Day, established in the 10th century, turned popular attention to the condition of departed souls. The idea of Purgatory as a physical place (like heaven and hell) was "born" in the late 11th century. Medieval theologians concluded that the purgatorial punishments consisted of material fire. The Western formulation of purgatory proved to be a sticking point in the Great Schism between East and West. The Catholic Church believes that the living can help those whose purification from their sins is not yet completed not only by praying for them but also by gaining indulgences for them as an act of intercession. The later Middle Ages saw the growth of considerable abuses, such as the unrestricted sale of indulgences by professional "pardoners" sent to collect contributions to projects such as the rebuilding of St. Peter's Basilica in Rome. These abuses were one of the factors that led to the Protestant Reformation. Most Protestants rejected the idea of purgatory, as never clearly mentioned in Luther's canon of the Bible, which excludes the Deuterocanonical books. Modern Catholic theologians have softened the punitive aspects of purgatory and stress instead the willingness of the dead to undergo purification as preparation for the happiness of heaven The English Anglican scholar John Henry Newman argued, in a book that he wrote before becoming Catholic, that the essence of the doctrine on purgatory is locatable in ancient tradition, and that the core consistency of such beliefs are evidence that Christianity was "originally given to us from heaven".
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  • 14 Nov 2022
Topic Review
Metabolic N-Dealkylation and N-Oxidation
Metabolic reactions that occur at alkylamino moieties may provide insight into the roles of these moieties when they are parts of drug molecules that act at different receptors. N-dealkylation of N,N-dialkylamino moieties has been associated with retaining, attenuation or loss of pharmacologic activities of metabolites compared to their parent drugs. Further, N-dealkylation has resulted in clinically used drugs, activation of prodrugs, change of receptor selectivity, and providing potential for developing fully-fledged drugs.
  • 5.9K
  • 13 Apr 2021
Topic Review
RealSense Depth Sensors
RealSense technology comprises a microprocessor for image processing, a module for creating depth images, an IR emitter, a segment for tracking movements, and depth sensors.
  • 5.9K
  • 09 Mar 2022
Topic Review
Chloramine
Chloramines are derivatives of ammonia by substitution of one, two or three hydrogen atoms with chlorine atoms: monochloramine (chloroamine, NH2Cl), dichloramine (NHCl2), and nitrogen trichloride (NCl3). The term chloramine also refers to a family of organic compounds with the formulas R2NCl and RNCl2 (where R is an organic group). Monochloramine (chloramine) is an inorganic compound with the formula NH2Cl. It is an unstable colorless liquid at its melting point of −66 °C (−87 °F), but it is usually handled as a dilute aqueous solution, in which form it is sometimes used as a disinfectant. Chloramine is too unstable to have its boiling point measured. It is listed as a tumorigen and mutagen. The wholesale cost in the developing world is about 13.80 to 18.41 U.S. dollars per 500 grams.
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  • 16 Nov 2022
Topic Review
Immunoformulation for COVID-19
The number of patients infected with the SARS-CoV-2 is still growing worldwide, with no current vaccine or medicinal treatment up to this date. Here we describe the cases of four COVID-19 patients that used a combination of therapeutic/nutraceutical agents for improvement of their symptoms. The ingredients were: immune transfer factor (oligo- and polypeptides fractions from porcine spleen, ultrafiltered at <10 kDa; Imuno TF®), anti-inflammatory natural blend (Uncaria tomentosa, Endopleura uchi and Haematoccocus pluvialis; Miodesin®), zinc, selenium, ascorbic acid, cholecalciferol, ferulic acid, spirulina, N-acetylcysteine, glucosamine sulfate potassium hydrochloride, trans-resveratrol, and maltodextrin-stabilized orthosilicic acid (SiliciuMax®). The four showed improvement in general symptoms after using the combination proposed here. The cases presented here are just a first hint towards its benefit (decreases time necessary for the recovery of the patients), this would be a good starting point to the further investigation of this possible add-on therapy in controlled clinical studies. Limited sample size and study design are limitations for definitive conclusions on the add-on therapy.
  • 5.9K
  • 05 Nov 2020
Topic Review
Tobacco Products
Tobacco is the agricultural product of the leaves of plants in the genus Nicotiana. All species of Nicotiana contain the addictive drug nicotine—a stimulant and sedative contained in all parts of the plants except the seeds—which occurs in varying amounts depending on the species and variety cultivated. See types of tobacco and curing of tobacco for more information. The vast majority of commercially available tobacco is derived from the species Nicotiana tabacum, although it is also produced from Nicotiana alata, and to a lesser extent Nicotiana clevelandii, Nicotiana longiflora, and Nicotiana rustica, among others. N. rustica in particular contains much more nicotine than N. tabacum and other species of Nicotiana, and forms the basis of a number of unique tobacco products, including several preparations used in Latin American shamanic ceremonies. Once tobacco has been grown, harvested, cured, and processed, it is used to produce a number of different products. These are most often consumable; however, tobacco and the nicotine derived from it are also used to create pesticides. Tobacco products can generally be divided into two types: smoked tobacco (see tobacco smoking) and smokeless tobacco. An expert in tobacco and tobacco products — especially pipes, pipe tobacco, and cigars—including their procurement and sale, is called a tobacconist. The health effects of tobacco consumption are discussed in health effects of tobacco.
  • 5.9K
  • 19 Oct 2022
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