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Topic Review
Responsive Architecture
Responsive architecture is a type of architecture, an artificial entity, that reacts to data and information collected by a variety of types of sensors. It is also defined as an interactive and collective platform where diverse computing or operating systems are executed, leading to architectural behaviors like changing forms or services.
  • 8.4K
  • 20 May 2021
Topic Review
Extreme Weather Events of 535–536
The extreme weather events of 535–536 were the most severe and protracted short-term episodes of cooling in the Northern Hemisphere in the last 2,000 years. The event is thought to have been caused by an extensive atmospheric dust veil, possibly resulting from a large volcanic eruption conjectured to be either in Asia, the Americas, Europe, or other locations. Its effects were widespread, causing unseasonable weather, crop failures, and famines worldwide.
  • 8.4K
  • 23 Nov 2022
Topic Review
International Trade Theory
International trade theory is a sub-field of economics which analyzes the patterns of international trade, its origins, and its welfare implications. International trade policy has been highly controversial since the 18th century. International trade theory and economics itself have developed as means to evaluate the effects of trade policies.
  • 8.4K
  • 14 Nov 2022
Topic Review
White–Juday Warp-Field Interferometer
The White–Juday warp-field interferometer is an experiment designed to detect a microscopic instance of a warping of spacetime. If such a warp is detected, it is hoped that more research into creating an Alcubierre warp bubble will be inspired. A research team led by Harold "Sonny" White in collaboration with Dr. Richard Juday at the NASA Johnson Space Center and Dakota State University are conducting experiments, but results so far have been inconclusive.
  • 8.4K
  • 24 Nov 2022
Topic Review
Yan Tan Tethera
Yan Tan Tethera is a sheep-counting rhyme/system traditionally used by shepherds in Northern England and earlier in some other parts of Britain. Until the Industrial Revolution, the use of traditional number systems was common among shepherds, especially in the fells of the Lake District. The Yan Tan Tethera system was also used for counting stitches in knitting. The words derive from a Brythonic Celtic language. Though most of these number systems fell out of use by 1910, some are still in use. The word yan or yen for "one" in some northern English dialects generally represents a regular development in Northern English in which the Old English long vowel /ɑː/ was broken into /ie/, /ia/ and so on. This explains the shift to yan and ane from the Old English ān, which is itself derived from the Proto-Germanic *ainaz. Another example of this development is the Northern English word for "home", hame, which has forms such as hyem, yem and yam all deriving from the Old English hām.
  • 8.4K
  • 20 Nov 2022
Topic Review
Cat Café
A cat café is a theme café whose attraction is cats who can be watched and played with. Patrons pay a cover fee, generally hourly, and thus cat cafés can be seen as a form of supervised indoor pet rental. "Cat café" has been officially recognized in the online edition of the Oxford Dictionary of English since August 2015.
  • 8.3K
  • 20 Oct 2022
Topic Review
WikiLeaks
WikiLeaks (/ˈwɪkiliːks/) is an international non-profit organisation that publishes news leaks and classified media provided by anonymous sources. Its website, initiated in 2006 in Iceland by the organisation Sunshine Press, stated in 2015 that it had released online 10 million documents in its first 10 years. Julian Assange, an Australian Internet activist, is generally described as its founder and director. Since September 2018, Kristinn Hrafnsson has served as its editor-in-chief. WikiLeaks has variously described itself as an organization of journalists, political activists, mathematicians, and start-up company technologists, an intermediary between sources and journalists, an advocacy group for sources, and a public intelligence agency. The group has released a number of prominent document caches that exposed serious violations of human rights and civil liberties to the US and international public. Early releases included documentation of equipment expenditures and holdings in the Afghanistan war, a report about a corruption investigation in Kenya, and an operating procedures manual for the U.S. prison at Guantanamo Bay, Cuba. In April 2010, WikiLeaks released the Collateral Murder footage from the 12 July 2007 Baghdad airstrike in which Iraqi Reuters journalists were among several civilians killed. Other releases in 2010 included the Afghan War Diary and the "Iraq War Logs". The latter release allowed the mapping of 109,032 deaths in "significant" attacks by insurgents in Iraq that had been reported to Multi-National Force – Iraq, including about 15,000 that had not been previously published. In 2010, WikiLeaks also released classified diplomatic cables that had been sent to the US State Department. In April 2011, WikiLeaks began publishing 779 secret files relating to prisoners detained in the Guantanamo Bay detention camp. In 2012, WikiLeaks released the "Syria Files," over two million emails sent by Syrian politicians, corporations and government ministries. In 2015, WikiLeaks published Saudi Arabian diplomatic cables, documents detailing spying by the U.S. National Security Agency on successive French presidents, and the intellectual property chapter of the Trans-Pacific Partnership, a controversial international trade agreement which had been negotiated in secret. During the 2016 U.S. presidential election campaign, WikiLeaks released emails and other documents from the Democratic National Committee and from Hillary Clinton's campaign manager, John Podesta, showing that the party's national committee favoured Clinton over her rival Bernie Sanders in the primaries, leading to the resignation of DNC chairwoman Debbie Wasserman Schultz and an apology to Sanders from the DNC. These releases caused significant harm to the Clinton campaign, and have been attributed as a potential contributing factor to her loss in the general election against Donald Trump. The U.S. intelligence community expressed "high confidence" that the leaked emails had been hacked by Russia and supplied to WikiLeaks. WikiLeaks said that the source of the documents was not Russia or any other state. During the campaign, WikiLeaks promoted conspiracy theories about Hillary Clinton and the Democratic Party. In 2016, WikiLeaks released nearly 300,000 emails it described as coming from Turkey's ruling Justice and Development Party, later found to be taken from public mailing archives, and rereleased over 50,000 emails from the Turkish Minister of Energy and Natural Resources. In 2017, WikiLeaks published internal CIA documents describing tools used by the agency to hack devices including mobile phones and routers. In 2019, WikiLeaks published over 30,000 files as part of the Fishrot Files, exposing corruption at Samherji, a multinational fishing company based in Iceland. In October 2021, WikiLeaks' secure chat stopped working and in February 2022 their submission system and email server went offline. The organisation has been criticised for inadequately curating its content and violating the personal privacy of individuals. WikiLeaks has, for instance, revealed Social Security numbers, medical information, credit card numbers and details of suicide attempts.
  • 8.3K
  • 11 Oct 2022
Topic Review
Segmentation
Segmentation in biology is the division of some animal and plant body plans into a series of repetitive segments. This article focuses on the segmentation of animal body plans, specifically using the examples of the taxa Arthropoda, Chordata, and Annelida. These three groups form segments by using a "growth zone" to direct and define the segments. While all three have a generally segmented body plan and use a growth zone, they use different mechanisms for generating this patterning. Even within these groups, different organisms have different mechanisms for segmenting the body. Segmentation of the body plan is important for allowing free movement and development of certain body parts. It also allows for regeneration in specific individuals.
  • 8.3K
  • 29 Sep 2022
Topic Review Peer Reviewed
Natural Disasters: Origins, Impacts, Management
Natural hazards are processes that serve as triggers for natural disasters. Natural hazards can be classified into six categories. Geophysical or geological hazards relate to movement in solid earth. Their examples include earthquakes and volcanic activity. Hydrological hazards relate to the movement of water and include floods, landslides, and wave action. Meteorological hazards are storms, extreme temperatures, and fog. Climatological hazards are increasingly related to climate change and include droughts and wildfires. Biological hazards are caused by exposure to living organisms and/or their toxic substances. The COVID-19 virus is an example of a biological hazard. Extraterrestrial hazards are caused by asteroids, meteoroids, and comets as they pass near earth or strike earth. In addition to local damage, they can change earth inter planetary conditions that can affect the Earth’s magnetosphere, ionosphere, and thermosphere. This entry presents an overview of origins, impacts, and management of natural disasters. It describes processes that have potential to cause natural disasters. It outlines a brief history of impacts of natural hazards on the human built environment and the common techniques adopted for natural disaster preparedness. It also lays out challenges in dealing with disasters caused by natural hazards and points to new directions in warding off the adverse impact of such disasters. 
  • 8.3K
  • 13 Apr 2022
Topic Review
Parental Involvement
Parental involvement is seen as an important strategy for the advancement of the quality of education. The ultimate objective of this is to expand the academic and social capacities of students, especially those of disadvantaged backgrounds determined by ethnic minority origin and low socio-economic status. In this contribution, various forms of both parental and school-initiated involvement will be described. In addition, results of studies into the effectiveness of parental involvement will be presented.
  • 8.3K
  • 15 Nov 2021
Topic Review
Incineration Bottom Ash from Municipal Solid Waste
Incineration bottom ash (IBA) is the main residue from municipal solid waste (MSW) incineration and refers to the incombustible materials that remain in the furnace after combustion. IBA is a very heterogeneous material, comprising irregularly shaped particles and a wide particle size distribution. This material is a complex inorganic mixture generally composed of melt products, minerals, metallic compounds, ceramics, and glass [1]. The classification and the management practices of IBA differ worldwide and, particularly, among the EU Member States. However, different applications have been studied for this material.
  • 8.3K
  • 24 Dec 2021
Topic Review
SoundCloud
SoundCloud is an online audio distribution platform and music sharing website based in Berlin, Germany that enables its users to upload, promote, and share audio.
  • 8.3K
  • 20 Oct 2022
Topic Review
Slope Stability Analysis
Slope stability analysis is performed to assess the safe design of a human-made or natural slopes (e.g. embankments, road cuts, open-pit mining, excavations, landfills etc.) and the equilibrium conditions. Slope stability is the resistance of inclined surface to failure by sliding or collapsing. The main objectives of slope stability analysis are finding endangered areas, investigation of potential failure mechanisms, determination of the slope sensitivity to different triggering mechanisms, designing of optimal slopes with regard to safety, reliability and economics, designing possible remedial measures, e.g. barriers and stabilization. Successful design of the slope requires geological information and site characteristics, e.g. properties of soil/rock mass, slope geometry, groundwater conditions, alternation of materials by faulting, joint or discontinuity systems, movements and tension in joints, earthquake activity etc. The presence of water has a detrimental effect on slope stability. Water pressure acting in the pore spaces, fractures or other discontinuities in the materials that make up the pit slope will reduce the strength of those materials. Choice of correct analysis technique depends on both site conditions and the potential mode of failure, with careful consideration being given to the varying strengths, weaknesses and limitations inherent in each methodology. Before the computer age stability analysis was performed graphically or by using a hand-held calculator. Today engineers have a lot of possibilities to use analysis software, ranges from simple limit equilibrium techniques through to computational limit analysis approaches (e.g. Finite element limit analysis, Discontinuity layout optimization) to complex and sophisticated numerical solutions (finite-/distinct-element codes). The engineer must fully understand limitations of each technique. For example, limit equilibrium is most commonly used and simple solution method, but it can become inadequate if the slope fails by complex mechanisms (e.g. internal deformation and brittle fracture, progressive creep, liquefaction of weaker soil layers, etc.). In these cases more sophisticated numerical modelling techniques should be utilised. Also, even for very simple slopes, the results obtained with typical limit equilibrium methods currently in use (Bishop, Spencer, etc.) may differ considerably. In addition, the use of the risk assessment concept is increasing today. Risk assessment is concerned with both the consequence of slope failure and the probability of failure (both require an understanding of the failure mechanism). Within the last decade (2003) Slope Stability Radar has been developed to remotely scan a rock slope to monitor the spatial deformation of the face. Small movements of a rough wall can be detected with sub-millimeter accuracy by using interferometry techniques.
  • 8.3K
  • 19 Oct 2022
Topic Review
Sophia (Gnosticism)
Sophia (Koinē Greek: Σοφíα "Wisdom", Coptic: ⲧⲥⲟⲫⲓⲁ "the Sophia") is a major theme, along with Knowledge (γνῶσις gnosis, Coptic sooun), among many of the early Christian knowledge-theologies grouped by the heresiologist Irenaeus as gnostikoi (γνωστικοί), ‘knowing’ or ‘men that claimed to have deeper wisdom’. Gnosticism is a 17th-century term expanding the definition of Irenaeus' groups to include other syncretic and mystery religions. In Gnosticism, Sophia is a feminine figure, analogous to the human soul but also simultaneously one of the feminine aspects of God. Gnostics held that she was the syzygy (female twin divine Aeon) of Jesus (i.e. the Bride of Christ), and Holy Spirit of the Trinity. She is occasionally referred to by the Hebrew equivalent of Achamōth (Ἀχαμώθ, Hebrew: חכמה‎ chokhmah) and as Prunikos (Προύνικος). In the Nag Hammadi texts, Sophia is the lowest Aeon, or anthropic expression of the emanation of the light of God. She is considered to have fallen from grace in some way, in so doing creating or helping to create the material world.
  • 8.3K
  • 23 Nov 2022
Topic Review
Perovskite Materials
In the development of hydrogen-based technology, a key challenge is the sustainable production of hydrogen in terms of energy consumption and environmental aspects. However, existing methods mainly rely on fossil fuels due to their cost efficiency, and as such, it is difficult to be completely independent of carbon-based technology. Electrochemical hydrogen production is essential, since it has shown the successful generation of hydrogen gas of high purity. Similarly, the photoelectrochemical (PEC) method is also appealing, as this method exhibits highly active and stable water splitting with the help of solar energy. We discuss the exceptional optical and electrical characteristics of perovskite materials which often dictate PEC performance. We further extend our discussion to the material limit of perovskite under a hydrogen production environment, i.e., that PEC reactions often degrade the contact between the electrode and the electrolyte.
  • 8.3K
  • 30 Jul 2021
Topic Review
Compounds of Fluorine
Fluorine forms a great variety of chemical compounds, within which it always adopts an oxidation state of −1. With other atoms, fluorine forms either polar covalent bonds or ionic bonds. Most frequently, covalent bonds involving fluorine atoms are single bonds, although at least two examples of a higher order bond exist. Fluoride may act as a bridging ligand between two metals in some complex molecules. Molecules containing fluorine may also exhibit hydrogen bonding (a weaker bridging link to certain nonmetals). Fluorine's chemistry includes inorganic compounds formed with hydrogen, metals, nonmetals, and even noble gases; as well as a diverse set of organic compounds. For many elements (but not all) the highest known oxidation state can be achieved in a fluoride. For some elements this is achieved exclusively in a fluoride, for others exclusively in an oxide; and for still others (elements in certain groups) the highest oxidation states of oxides and fluorides are always equal.
  • 8.3K
  • 16 Nov 2022
Topic Review
Cluster Chemistry
In chemistry, a cluster is an ensemble of bound atoms or molecules that is intermediate in size between a molecule and a bulk solid. Clusters exist of diverse stoichiometries and nuclearities. For example, carbon and boron atoms form fullerene and borane clusters, respectively. Transition metals and main group elements form especially robust clusters. Clusters can also consist solely of a certain kind of molecules, such as water clusters. The phrase cluster was coined by F.A. Cotton in the early 1960s to refer to compounds containing metal–metal bonds. In another definition a cluster compound contains a group of two or more metal atoms where direct and substantial metal bonding is present. The prefixed terms "nuclear" and "metallic" are used and imply different meanings. For example, polynuclear refers to a cluster with more than one metal atom, regardless of the elemental identities. Heteronuclear refers to a cluster with at least two different metal elements. The main cluster types are "naked" clusters (without stabilizing ligands) and those with ligands. For transition metal clusters, typical stabilizing ligands include carbon monoxide, halides, isocyanides, alkenes, and hydrides. For main group elements, typical clusters are stabilized by hydride ligands. Transition metal clusters are frequently composed of refractory metal atoms. In general metal centers with extended d-orbitals form stable clusters because of favorable overlap of valence orbitals. Thus, metals with a low oxidation state for the later metals and mid-oxidation states for the early metals tend to form stable clusters. Polynuclear metal carbonyls are generally found in late transition metals with low formal oxidation states. The polyhedral skeletal electron pair theory or Wade's electron counting rules predict trends in the stability and structures of many metal clusters. Jemmis mno rules have provided additional insight into the relative stability of metal clusters.
  • 8.3K
  • 08 Nov 2022
Topic Review
Design Considerations of Fixed and Floating Offshore Structures
Offshore structures exist in a variety of forms, and they are used for a variety of functions in varied sea depths. These structures are tailored for certain environments and sea depths and other design considerations. 
  • 8.3K
  • 29 Jul 2022
Topic Review Peer Reviewed
OAM of Light: Origins and Applications
Orbital Angular Momentum (OAM) of light is generating growing interest within the scientific community. This entry reviews the origins and applications of OAM. It is the counterpart of linear momentum for systems in rotation. The general expression of OAM is discussed, followed by its implications in terms of phase distribution and donut-shaped intensity profiles. Applications described include the generation of optical torque, telecommunications enhancement, and the rotational Doppler effect, emphasizing the role and consequences of angular momentum. In particular, its use to manipulate systems or to detect rotations is described. Finally, further developments and technological barriers are considered.
  • 8.3K
  • 17 Sep 2025
Topic Review
Land Suitability Assessment
Land suitability assessment is a method of land evaluation, which identifies the major limiting factors for planting a particular crop. Land suitability assessment includes qualitative and quantitative evaluation. In the qualitative land suitability evaluations, information about climate, hydrology, topography, vegetation, and soil properties is considered and in quantitative assessment, the results are more detailed and yield is estimated. At present study we prepared land suitability assessment map for rain-fed wheat and barley crops based on FAO "land suitability assessment framework" using parametric method and machine learning algorithms in Kurdistan Province, located in west of Iran. This is a unique study that compared two machine learning-based and traditional-based approaches for mapping current and potential future land suitability classes. Moreover, potential yield of rain-fed wheat and barley crop were computed by FAO model.
  • 8.3K
  • 30 Oct 2020
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