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Topic Review
May 20: Vasco da Gama Reaches India
Vasco da Gama’s arrival in Calicut, India on May 20, 1498, marked the first time a European reached India by sea, successfully navigating around the Cape of Good Hope and across the Indian Ocean. This event opened a direct maritime trade route between Europe and Asia, breaking the centuries-old overland monopoly held by Middle Eastern and Venetian traders. It initiated an era of European exploration, imperial expansion, and global maritime dominance, especially for Portugal.
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  • 20 May 2025
Topic Review
The Perception of Achievement of Complex Thinking
The development of life competencies has become one of the primary objectives of contemporary universities. Beyond ensuring that students acquire knowledge, educational institutions are committed to developing professional skills that enable their graduates to know how to accomplish certain tasks, especially problem solving. One of these competencies, complex thinking, values people’s ability to reason when faced with challenging situations or problems. Globalization, daily use of technology, interactions in diverse environments, and the ever-increasing pressures of social movements mean that new professionals require a broader capacity for thinking than previous generations, which challenges universities to provide adequate training.
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  • 23 May 2022
Topic Review
Hot Dry Rock Geothermal Energy
Hot dry rock (HDR) is an extremely abundant source of geothermal energy that is difficult to access. A vast store of thermal energy is contained within hot – but essentially dry and impervious crystalline basement rocks found almost everywhere deep beneath Earth's surface. A concept for the extraction of useful amounts of geothermal energy from HDR originated at the Los Alamos National Laboratory in 1970, and Laboratory researchers were awarded a U.S. patent covering it. This technology has been tested extensively with multiple deep wells drilled in several field areas around world including the USA, Japan, Australia, France, and the UK and investment of billions of research funds. It continues to be the focus along with a related technique called EGS for sizable government-led research studies involving costly deep drilling and rock studies. Thermal energy has been recovered in reasonably sustainable tests over periods of years and in some cases electrical power generation was also achieved. However no commercial projects are ongoing or likely due to the high cost and limited capacity of the engineered reservoirs, associated wells, and pumping systems. Commonly tests have opened just one or more fractures such that the reservoir surface heat exchange areas are limited. For this technology to successfully compete with other energy sources, drilling costs would have to drop drastically or new approaches that result in much more extensive, complex, and higher rate flow paths through actual fracture networks would have to be established. The enthusiasim evident here on Wikipedia and in the research community is justified by the vast extent of the energy supply and the low environmental impact of the method however significant breakthroughs will be required to make this a commercial energy resource.
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  • 30 Oct 2022
Topic Review
Dhyāna in Buddhism
In the oldest texts of Buddhism, dhyāna (Sanskrit) or jhāna (Pāḷi) is the training of the mind, commonly translated as meditation, to withdraw the mind from the automatic responses to sense-impressions, and leading to a "state of perfect equanimity and awareness (upekkhā-sati-parisuddhi)." Dhyāna may have been the core practice of pre-sectarian Buddhism, in combination with several related practices which together lead to perfected mindfulness and detachment, and are fully realized with the practice of dhyana. In the later commentarial tradition, which has survived in present-day Theravāda, dhyāna is equated with "concentration," a state of one-pointed absorption in which there is a diminished awareness of the surroundings. In the contemporary Theravāda-based Vipassana movement, this absorbed state of mind is regarded as unnecessary and even non-beneficial for awakening, which has to be reached by mindfulness of the body and vipassanā (insight into impermanence). Since the 1980s, scholars and practitioners have started to question this equation, arguing for a more comprehensive and integrated understanding and approach, based on the oldest descriptions of dhyāna in the suttas. In Chán and Zen, the names of which Buddhist traditions are the Chinese and Japanese pronunciations, respectively, of dhyāna, dhyāna is the central practice, which is ultimately based on Sarvastivāda meditation practices, and has been transmitted since the beginning of the Common Era.
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  • 11 Oct 2022
Topic Review
Agriculture in Ancient Mesopotamia
Agriculture was the main economic activity in ancient Mesopotamia. Operating under harsh constraints, notably the arid climate, the Mesopotamian farmers developed effective strategies that enabled them to support the development of the first states, the first cities, and then the first known empires, under the supervision of the institutions which dominated the economy: the royal and provincial palaces, the temples, and the domains of the elites. They focused above all on the cultivation of cereals (particularly barley) and sheep farming, but also farmed legumes, as well as date palms in the south and grapes in the north. In reality, there were two types of Mesopotamian agriculture, corresponding to the two main ecological domains, which largely overlapped with cultural distinctions. The agriculture of southern or Lower Mesopotamia, the land of Sumer and Akkad, which later became Babylonia received almost no rain and required large scale irrigation works which were supervised by temple estates, but could produce high returns. The agriculture of Northern or Upper Mesopotamia, the land that would eventually become Assyria, had enough rainfall to allow dry agriculture most of the time so that irrigation and large institutional estates were less important, but the returns were also usually lower.
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  • 02 Dec 2022
Topic Review
Modular Construction
A modular construction is an assembly of standardized-dimension building elements such as wall panel, slab, beam or also an assembly of container-type units called “modules” or else “prefabricated prefinished volumetric construction (PPVC)” which are prefabricated in factory and afterwards transported and assembled on-site. The naming of “container house” is given to transportable modules that are completely finished in the factory and ready to be inhabited; for smaller units, eventually with different shapes, the nomenclature of “living pod” or “capsule” is also found in literature. Modular buildings are always prefabricated buildings, but the reverse is not necessarily true. The degree of prefabrication and assembly technique mainly varies depending on the life span of the building (temporary or permanent), the desired space layout and the technical equipment to install (heating, electricity, sewer, plumbing, etc.).
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  • 26 Oct 2020
Topic Review
Vacuum State
In quantum field theory, the quantum vacuum state (also called the quantum vacuum or vacuum state) is the quantum state with the lowest possible energy. Generally, it contains no physical particles. Zero-point field is sometimes used as a synonym for the vacuum state of an individual quantized field. According to present-day understanding of what is called the vacuum state or the quantum vacuum, it is "by no means a simple empty space". According to quantum mechanics, the vacuum state is not truly empty but instead contains fleeting electromagnetic waves and particles that pop into and out of existence. The QED vacuum of quantum electrodynamics (or QED) was the first vacuum of quantum field theory to be developed. QED originated in the 1930s, and in the late 1940s and early 1950s it was reformulated by Feynman, Tomonaga and Schwinger, who jointly received the Nobel prize for this work in 1965. Today the electromagnetic interactions and the weak interactions are unified (at very high energies only) in the theory of the electroweak interaction. The Standard Model is a generalization of the QED work to include all the known elementary particles and their interactions (except gravity). Quantum chromodynamics (or QCD) is the portion of the Standard Model that deals with strong interactions, and QCD vacuum is the vacuum of quantum chromodynamics. It is the object of study in the Large Hadron Collider and the Relativistic Heavy Ion Collider, and is related to the so-called vacuum structure of strong interactions.
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  • 17 Oct 2022
Topic Review
Country Code Top-Level Domain
A country code top-level domain (ccTLD) is an Internet top-level domain generally used or reserved for a country, sovereign state, or dependent territory identified with a country code. All ASCII ccTLD identifiers are two letters long, and all two-letter top-level domains are ccTLDs. In 2018, the Internet Assigned Numbers Authority (IANA) began implementing internationalized country code top-level domains, consisting of language-native characters when displayed in an end-user application. Creation and delegation of ccTLDs is described in RFC 1591, corresponding to ISO 3166-1 alpha-2 country codes. While gTLD have to obey international regulations, ccTLD are subjected to requirements that are determined by each country’s domain name regulation corporation. With over 150 million domain name registrations today, ccTLDs make up 40% of the total domain name industry. Country code extension applications began in 1985. The registered first extensions that year were .us (United States), .uk (United Kingdom), and .il (Israel). There are 312 ccTLDs in active use totally. .cn, .tk, .de and .uk contain the highest number of domains.
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  • 08 Nov 2022
Topic Review
Conifers Phytochemicals
The phytochemical constituents present in conifer extracts are nontoxic at therapeutic levels, with polyphenolic compounds having significant biological activities. Stilbenes, terpenes, alkaloids, lignins and flavanoids, such as quercetin, rutin, resveratrol, and the compounds PYC and enzogenol, are the phytochemical components of conifer extracts reported to have sedative, antidiabetic, anticancer and anesthetic effects. In addition, phytochemicals present in conifer extracts assist in the regulation of glucose and lipid metabolism, insulin secretion, stimulating β cells, the NF-kB signaling pathway, the inhibition of gluconeogenic enzymes, ROS protective action as well as targeting and modulating cytokines which affect neuron cells and reduce oxidative stress.
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  • 01 Jun 2021
Topic Review
Dhunge Dhara
A dhunge dhara (Nepali:ढुङ्गे धारा Listen (help·info)) or hiti (Newari) is a traditional stone drinking fountain found in Nepal. It is an intricately carved stone waterway through which water flows uninterrupted from underground sources. Dhunge dharas are part of a comprehensive drinking water supply system, commissioned by various rulers of Ancient and Medieval Nepal. The system is supported by numerous ponds and canals that form an elaborate network of water bodies, created as a water resource during the dry season and to help alleviate the water pressure caused by the monsoon rains. After the introduction of modern, piped water systems, starting in the late 19th century, this old system has fallen into disrepair and some parts of it are lost forever. Nevertheless, many people of Nepal still rely on the old hitis on a daily basis.
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  • 21 Oct 2022
Topic Review
Black Soldier Fly Larvae Frass
Frass is a compost-like material and has the characteristics of immature compost. In a commercial context, black soldier fly larvae (BSFL) frass often refers to a mixture of primarily BSFL faeces, substrate residues, and shed BSFL exoskeletons. Schmitt and de Vries contended that frass is a mixture of uneaten feed materials, insect derivatives, such as skins and faeces, and a microbial population that carries out fermentation.
  • 7.3K
  • 27 Sep 2022
Topic Review
IPTV
Internet Protocol television (IPTV) is the delivery of television content over Internet Protocol (IP) networks. This is in contrast to delivery through traditional terrestrial, satellite, and cable television formats. Unlike downloaded media, IPTV offers the ability to stream the source media continuously. As a result, a client media player can begin playing the content (such as a TV channel) almost immediately. This is known as streaming media. Although IPTV uses the Internet protocol it is not limited to television streamed from the Internet, (Internet television). IPTV is widely deployed in subscriber-based telecommunications networks with high-speed access channels into end-user premises via set-top boxes or other customer-premises equipment. IPTV is also used for media delivery around corporate and private networks. IPTV in the telecommunications arena is notable for its ongoing standardisation process (e.g., European Telecommunications Standards Institute). IPTV services may be classified into three main groups:  Live television and live media, with or without related interactivity; Time-shifted media: e.g. catch-up TV (replays a TV show that was broadcast hours or days ago), start-over TV (replays the current TV show from its beginning); Video on demand (VOD): browse and view items in a stored media catalogue.
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  • 27 Oct 2022
Topic Review
Metallic Alloy Nanoparticles
Metallic alloy nanoparticles are synthesized by combining two or more different metals. Bimetallic or trimetallic nanoparticles are considered more effective than monometallic nanoparticles because of their synergistic characteristics. In this review, we outline the structure, synthesis method, properties, and biological applications of metallic alloy nanoparticles based on their plasmonic, catalytic, and magnetic characteristics.
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  • 03 Aug 2020
Topic Review
E-Book
An electronic book, also known as an e-book or eBook, is a book publication made available in digital form, consisting of text, images, or both, readable on the flat-panel display of computers or other electronic devices. Although sometimes defined as "an electronic version of a printed book", some e-books exist without a printed equivalent. E-books can be read on dedicated e-reader devices, but also on any computer device that features a controllable viewing screen, including desktop computers, laptops, tablets and smartphones. In the 2000s, there was a trend of print and e-book sales moving to the Internet, where readers buy traditional paper books and e-books on websites using e-commerce systems. With print books, readers are increasingly browsing through images of the covers of books on publisher or bookstore websites and selecting and ordering titles online; the paper books are then delivered to the reader by mail or another delivery service. With e-books, users can browse through titles online, and then when they select and order titles, the e-book can be sent to them online or the user can download the e-book. By the early 2010s, e-books had begun to overtake hardcover by overall publication figures in the U.S. The main reasons for people buying e-books are possibly lower prices, increased comfort (as they can buy from home or on the go with mobile devices) and a larger selection of titles. With e-books, "[e]lectronic bookmarks make referencing easier, and e-book readers may allow the user to annotate pages." "Although fiction and non-fiction books come in e-book formats, technical material is especially suited for e-book delivery because it can be [electronically] searched" for keywords. In addition, for programming books, code examples can be copied. The amount of e-book reading is increasing in the U.S.; by 2014, 28% of adults had read an e-book, compared to 23% in 2013. This is increasing, because by 2014 50% of American adults had an e-reader or a tablet, compared to 30% owning such devices in 2013.
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  • 30 Sep 2022
Topic Review
Common Factors Theory
Common factors theory, a theory guiding some research in clinical psychology and counseling psychology, proposes that different approaches and evidence-based practices in psychotherapy and counseling share common factors that account for much of the effectiveness of a psychological treatment. This is in contrast to the view that the effectiveness of psychotherapy and counseling is best explained by specific or unique factors (notably, particular methods or procedures) that are suited to treatment of particular problems. According to one review, "it is widely recognized that the debate between common and unique factors in psychotherapy represents a false dichotomy, and these factors must be integrated to maximize effectiveness". In other words, "therapists must engage in specific forms of therapy for common factors to have a medium through which to operate". Common factors is one route by which psychotherapy researchers have attempted to integrate psychotherapies.
  • 7.3K
  • 08 Nov 2022
Topic Review
Indian Remote Sensing Programme
India's remote sensing program was developed with the idea of applying space technologies for the benefit of human kind and the development of the country. The program involved the development of three principal capabilities. The first was to design, build and launch satellites to a sun synchronous orbit. The second was to establish and operate ground stations for spacecraft control, data transfer along with data processing and archival. The third was to use the data obtained for various applications on the ground.
  • 7.3K
  • 17 Nov 2022
Topic Review
Ti Nitrides and Ti Silicides
The diffusion of nitrogen into TiSi2 films of low electrical resistivity, deposited on complementary metal oxyde semiconductor (CMOS) and Schottky diodes components increases their performances. TiN acts as a good diffusion barrier, gate material, Schottky barrier contact...Both TiSi2 and TiN are synthesized in Ti films coated on Si wafers and processed in an expanding microwave plasma producing nitrogen species such as NHx...This process promotes the chemical reactions at the surface of the metal. The growth of both compounds give rise to two competing processes which are thermodynamically and kinetically controlled. Ti films, 250 nm thick, processed at 600°C for  30 min, only consist of TiSi2 crystallites and TiN of amorphous structure. TiN crystallizes at 800°C and grows at the expense of TiSi2 according to thermodynamic data. 
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  • 30 Oct 2020
Topic Review
Indane-1,3-Dione: From Synthetic Strategies to Applications
Indane-1,3-dione is a versatile building block used in numerous applications ranging from biosensing, bioactivity, bioimaging to electronics or photopolymerization. Indane-1-3-dione is among one of the most privileged scaffolds in chemistry, as the derivatives of this structure can find applications in various research fields ranging from medicinal chemistry, organic electronics, photopolymerization, to optical sensing and non-linear optical (NLO) applications. 
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  • 29 Sep 2022
Topic Review
Early Germanic Law
Early Germanic law was the form of law followed by the early Germanic peoples. It was an important element of early Germanic culture. Several Latin law codes of the Germanic peoples written in the Early Middle Ages after the Fall of the Western Roman Empire (also known as leges barbarorum "laws of the barbarians") survive, dating to between the 5th and 9th centuries. They are influenced by Roman law, canon law, and earlier tribal customs. Central and West European Germanic law differed from North Germanic law. Germanic law was codified in writing under the influence of Roman law; previously it was held in the memory of designated individuals who acted as judges in confrontations and meted out justice according to customary rote, based on careful memorization of precedent. Among the Franks they were called rachimburgs. "Living libraries, they were law incarnate, unpredictable and terrifying." Power, whose origins were at once said to be magical, divine, and military, was, according to Michel Rouche, exercised jointly by the "throne-worthy" elected king and his free warrior companions. Oral law sufficed as long as the warband was not settled in one place. Germanic law made no provisions for the public welfare, the res publica of Romans. The language of all these continental codes was Latin; the only known codes drawn up in any Germanic language were the Anglo-Saxon laws, beginning with the Laws of Æthelberht (7th century). In the 13th century customary Saxon law was codified in the vernacular as the Sachsenspiegel. All these laws may be described in general as codes of governmental procedure and tariffs of compositions. They all present somewhat similar features with Salic law, the best-known example, but often differ from it in the date of compilation, the amounts of fines, the number and nature of the crimes, the number, rank, duties and titles of the officers, etc. In Germanic Europe in the Early Middle Ages, every man was tried according to the laws of his own ethnicity, whether Roman, Salian or Ripuarian Frank, Frisian, Burgundian, Visigoth, Bavarian etc. A number of separate codes were drawn up specifically to deal with cases between ethnic Romans. These codes differed from the normal ones that covered cases between Germanic peoples, or between Germanic people and Romans. The most notable of these are the Lex Romana Visigothorum or Breviary of Alaric (506), the Lex Romana Curiensis and the Lex Romana Burgundionum.
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  • 02 Dec 2022
Topic Review
List of Largest Stars
Below is a list of the largest stars currently known, ordered by radius. The unit of measurement used is the radius of the Sun (approximately 695,700 km; 432,300 mi). The angular diameters of stars can be measured directly using stellar interferometry. Other methods can use lunar occultations or from eclipsing binaries, which can be used to test indirect methods of finding stellar radii. Only a few useful supergiant stars can be occulted by the Moon, including Antares A (Alpha Scorpii A). Examples of eclipsing binaries are Epsilon Aurigae (Almaaz), VV Cephei, and V766 Centauri (HR 5171). Angular diameter measurements can be inconsistent because the boundary of the very tenuous atmosphere (opacity) differs depending on the wavelength of light in which the star is observed. Uncertainties remain with the membership and order of the list, especially when deriving various parameters used in calculations, such as stellar luminosity and effective temperature. Often stellar radii can only be expressed as an average or be within a large range of values. Values for stellar radii vary significantly in different sources and for different observation methods. All the sizes stated in this list have various inaccuracies and may be disputed. This list is still a work in progress and various parameters are extremely disputed.
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  • 21 Nov 2022
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