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Topic Review
Electric Arc Furnace Slag
EAF slag is a non-metallic by-product that consists mainly of silicates and oxides formed during the process of refining the molten steel. Raw EAF slag often appears as grey or black colored lumps, depending on its ferrous oxide content. This type of slag generally has a rough surface texture, with a surface pore diameter of 0.01–10 μm.
  • 11.6K
  • 26 Oct 2020
Topic Review
Technological Dualism
Technological dualism was proposed by Benjamin Higgins. He was the Ritchie Professor of Economics at the University of Melbourne in the late 1940s. His theory explains the causes of unemployment in the underdeveloped economies. Developing countries of today are often characterized by dualistic economies. One is the modern (or formal) sector while the other is the traditional (informal) sector. Their relation has been explained by Higgins in his theory explained below.
  • 11.6K
  • 23 Nov 2022
Topic Review
Emerging Technologies
According to G. Veletsianos, from a general point of view, an emerging technology is “a new tool with promising potential”. However, an emerging technology is generally defined according to the field in which it is analyzed. B.R. Martin describes an emerging technology as a technology the use of which will benefit many sectors of the economy and/or society. Other important characteristics of emerging technology, according to D. Rotolo, D. Hicks and B. R. Martin, include radical novelty, relatively fast growth, coherence, and prominent impact. Which refers to the crucial following contexts: aspect of future time, anticipation, uncertainty and Industry 4.0. the following definition of an emerging technology has been created by the author – „Emerging technology in Industry 4.0 is a technology the development of which, from today’s point of view, is uncertain and not obvious, but through complex anticipatory research, it is possible to identify its potential radical impact in selected areas, e.g., social, technological, economic, scientific.”
  • 11.6K
  • 10 Dec 2021
Topic Review
Six-factor Model of Psychological Well-being
The Six-factor Model of Psychological Well-being is a theory developed by Carol Ryff which determines six factors which contribute to an individual's psychological well-being, contentment, and happiness. Psychological well-being consists of positive relationships with others, personal mastery, autonomy, a feeling of purpose and meaning in life, and personal growth and development. Psychological well-being is attained by achieving a state of balance affected by both challenging and rewarding life events.
  • 11.6K
  • 20 Oct 2022
Topic Review
Orgasm
Orgasm (from Greek ὀργασμός, orgasmos; "excitement, swelling") or sexual climax is the sudden discharge of accumulated sexual excitement during the sexual response cycle, resulting in rhythmic, involuntary muscular contractions in the pelvic region characterized by sexual pleasure. Experienced by males and females, orgasms are controlled by the involuntary or autonomic nervous system. They are usually associated with involuntary actions, including muscular spasms in multiple areas of the body, a general euphoric sensation and, frequently, body movements and vocalizations. The period after orgasm (known as the refractory period) is typically a relaxing experience, attributed to the release of the neurohormones oxytocin and prolactin as well as endorphins (or "endogenous morphine"). Human orgasms usually result from physical sexual stimulation of the penis in males (typically accompanying ejaculation) and of the clitoris in females. Sexual stimulation can be by self-practice (masturbation) or with a sex partner (penetrative sex, non-penetrative sex, or other sexual activity). The health effects surrounding the human orgasm are diverse. There are many physiological responses during sexual activity, including a relaxed state created by prolactin, as well as changes in the central nervous system such as a temporary decrease in the metabolic activity of large parts of the cerebral cortex while there is no change or increased metabolic activity in the limbic (i.e., "bordering") areas of the brain. There is also a wide range of sexual dysfunctions, such as anorgasmia. These effects affect cultural views of orgasm, such as the beliefs that orgasm and the frequency or consistency of it are either important or irrelevant for satisfaction in a sexual relationship, and theories about the biological and evolutionary functions of orgasm.
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  • 30 Nov 2022
Topic Review
Power Electronic Converters in Electric Vehicle Applications
In the electric vehicle (EV) powertrain, all the electric input sources are connected to a HV–DC bus by an individual DC–DC converter, and the output three-phase electric motor (EM), i.e., the main load of the EV, is powered from this HV–DC bus through a three-phase inverter which drives the EM. Here, the voltage level of this HV–DC bus of the EV is around 400–750 V. Moreover, moving the EV via an EM from electric batteries, a DC–DC voltage is required because the batteries’ output voltage is much lower than the required voltage of EM. A traction inverter is needed to drive the EM by converting the DC batteries into variable-frequency AC. However, a disagreement could be made for stepping up the output AC voltage level of the inverter by utilizing a high-voltage transformer instead of a DC–DC converter. This is due to its having several essential advantages, such as reliability, cost-effectiveness, compact size, and lightweight DC–DC converters appear to be excellent candidates for EVs and HEVs powertrains.
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  • 10 Jan 2023
Topic Review
High Dynamic Range (Display and Formats)
High Dynamic Range (HDR) is a video and image technology that improves the way light is represented. It overcomes the limits of the standard format that is named Standard Dynamic Range (SDR). HDR offers the possibility to represent substantially brighter highlights, darker shadows, more details in both sides and more colorful colors than what was previously possible. HDR do not increase display's capabilities, rather it allows to make better use of displays that have high brightness, contrast and colors capabilities. Not all HDR displays have the same capabilities and HDR contents will thus look different depending the display used. HDR emerged first for videos in 2014. HDR10, HDR10+, Dolby Vision and HLG are common HDR formats. Some still pictures formats do also support HDR.
  • 11.6K
  • 01 Nov 2022
Topic Review
News International Phone Hacking Scandal
The News International phone hacking scandal was a controversy involving the now-defunct News of the World and other British newspapers owned by Rupert Murdoch. Employees of the newspaper were accused of engaging in phone hacking, police bribery, and exercising improper influence in the pursuit of stories. Whilst investigations conducted from 2005 to 2007 appeared to show that the paper's phone hacking activities were limited to celebrities, politicians, and members of the British royal family, in July 2011 it was revealed that the phones of murdered schoolgirl Milly Dowler, relatives of deceased British soldiers, and victims of the 7 July 2005 London bombings had also been hacked. The resulting public outcry against News Corporation and its owner Rupert Murdoch led to several high-profile resignations, including that of Murdoch as News Corporation director, Murdoch's son James as executive chairman, Dow Jones chief executive Les Hinton, News International legal manager Tom Crone, and chief executive Rebekah Brooks. The commissioner of London's Metropolitan Police Service (MPS), Sir Paul Stephenson, also resigned. Advertiser boycotts led to the closure of the News of the World on 10 July 2011, after 168 years of publication. Public pressure forced News Corporation to cancel its proposed takeover of the British satellite broadcaster BSkyB. The prime minister David Cameron announced on 6 July 2011 that a public inquiry, known as the Leveson Inquiry, would look into phone hacking and police bribery by the News of the World, consider the wider culture and ethics of the British newspaper industry and that the Press Complaints Commission would be replaced "entirely". A number of arrests and convictions followed, most notably of the former News of the World managing editor Andy Coulson. Murdoch and his son, James, were summoned to give evidence at the Leveson Inquiry. Over the course of his testimony, Rupert Murdoch admitted that a cover-up had taken place within the News of the World to hide the scope of the phone hacking. On 1 May 2012, a parliamentary select committee report concluded that Murdoch "exhibited wilful blindness to what was going on in his companies and publications" and stated that he was "not a fit person to exercise the stewardship of a major international company". On 3 July 2013, Channel 4 News broadcast a secret tape in which Murdoch dismissively claims that investigators were "totally incompetent" and acted over "next to nothing" and excuses his papers' actions as "part of the culture of Fleet Street".
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  • 11 Oct 2022
Topic Review
Anaphase Bridges
Anaphase bridges are DNA threads stretching between the two DNA masses as cells attempt to segregate them during anaphase. Anaphase bridges arise from unresolved DNA intertwines between sister chromatids. Sister chromatid intertwines (SCIs) naturally arise during DNA replication and represent a non-proteinaceous source of cohesion between sister chromatids. SCIs and are mainly resolved in S phase, although some do persist and must be fully removed during mitosis to allow faithful chromosome segregation and avoid the arising of DNA lesions and genome instability, a hallmark of cancer development. As complete resolution of SCIs only occurs during chromosome segregation, it is not clear whether intertwines that persist in mitosis are simply an unwanted leftover or whether they have a functional role.
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  • 04 Sep 2020
Topic Review
Application of Standardized Regression Coefficient in Meta-Analysis
The β coefficient is the estimate resulting from an analysis carried out on variables that have been standardized so that their standard deviations (and variances) are equal to one. Therefore, the standardized coefficient refers to how many standard deviations the response or outcome variable will change per a standard deviation increase in the explanatory or predictor variable. Thus, the standardized coefficient β can be regarded as an attempt to make regression coefficients more comparable, and can be used as an effect-size estimate when the exposure levels in original studies are measured in different units of measurement.
  • 11.5K
  • 14 Sep 2022
Topic Review
Circassian Beauties
Circassian beauty or Adyghe beauty (Adyghe: Адыгэ пшъашъэ, romanized: Adıgə pş̂aş̂ə) is a stereotype and a belief used to refer to an idealized image of the women of the Circassian people of the Northwestern Caucasus. A fairly extensive literary history suggests that Circassian women were thought to be unusually beautiful, spirited, and elegant, and as such were desirable as concubines. This reputation dates back to the Late Middle Ages, when the Circassian coast was frequented by traders from Genoa, and the founder of the Medici dynasty, Cosimo de' Medici, had an illegitimate son from a Circassian slave. During the Ottoman Empire and Persian Safavid and Qajar dynasties, Circassian women living as slaves in the Sultan's Imperial Harem and Shah's harems started to build their reputation as extremely beautiful and genteel, which then became a common trope in Western Orientalism. As a result of this reputation, in Europe and America Circassians were often characterised as ideals of feminine beauty in poetry and art. Cosmetic products were advertised, from the 18th century on, using the word "Circassian" in the title, or claiming that the product was based on substances used by the women of Circassia. In consequence, most wives of several Ottoman Sultans were ethnic Circassians converted to Islam, e.g. Valide Sultans (Empress mothers), including Perestü Valide Sultan, Şevkefza Valide Sultan, Tirimüjgan Valide Sultan, Nükhetseza Başhanımefendi, other important Hatuns (Ladies) and Sultans like Şemsiruhsar Hatun and Saçbağlı Sultan, Haseki sultans (chief consorts) such as Hümaşah Haseki Sultan, Hatice Muazzez Haseki Sultan, and Ayşe Haseki Sultan besides numerous Başkadınefendis (most senior consorts), including Bedrifelek I, Bidar II, Kamures I, and Servetseza I as well as Kadınefendis (senior consorts) such as Bezmara VI, Düzdidil III, Hayranıdil II, Meyliservet IV, Mihrengiz II, Neşerek III, Nurefsun II, Reftaridil II, Şayan III, amongst many others, or İkbals (honoured lady consorts), most notable of them being Cevherriz II, Ceylanyar II, Dilfirib I, Nalanıdil III, and Nergis IV in addition to Gözdes (favourite lady consorts), including Dürdane I, Hüsnicenan III, Safderun IV, amongst others. The "golden age" of the Circassian beauty may be considered to be between the 1770s, when the Russian Empire seized the Crimean Khanate and cut off their slave trade, which increased the demand for Circassian women in Near Eastern harems; and the 1860s, when the Russians massacred thousands of Circassians and conquered Circassia. In the 1860s the showman P. T. Barnum exhibited women who he claimed were Circassian beauties. They wore a distinctive curly, big hair style, which had no precedent in earlier portrayals of Circassians, but which was soon copied by other female performers in the United States, who became known as "moss-haired girls". This hair style was a sort of exhibit's trademark and was achieved by washing the hair of women in beer, drying it and then teasing it. It is not clear why Barnum chose this hairstyle. It may have been a reference to the Circassian fur hat, rather than the hair. There were also several classical Turkish music pieces and poems that praise the beauty of the Circassian ethnic group like "Lepiska Saçlı Çerkes" (Straight, flaxen-haired Circassian; "lepiska" refers to long blonde hair which is straight, as if flatironed). As a foreign group, they were always praised in Turkey for what they labeled as distinct and pure European features.
  • 11.5K
  • 24 Nov 2022
Topic Review
Mechanisms of anticoagulant drugs
Anticoagulant drugs have been used to prevent and treat thrombosis. However, they are associated with risk of hemorrhage. Therefore, prior to their clinical use, it is important to assess the risk of bleeding and thrombosis. In case of older anticoagulant drugs like heparin and warfarin, dose adjustment is required owing to narrow therapeutic ranges. The established monitoring methods for heparin and warfarin are activated partial thromboplastin time (APTT)/anti-Xa assay and prothrombin time – international normalized ratio (PT-INR), respectively. Since 2008, new generation anticoagulant drugs, called direct oral anticoagulants (DOACs), have been widely prescribed to prevent and treat several thromboembolic diseases. Although the use of DOACs without routine monitoring and frequent dose adjustment has been shown to be safe and effective, there may be clinical circumstances in specific patients when measurement of the anticoagulant effects of DOACs is required. Recently, anticoagulation therapy has received attention when treating patients with coronavirus disease 2019 (COVID-19).
  • 11.5K
  • 23 Feb 2023
Topic Review
Plasmons
Researchers briefly review applications of surface-plasmon polariton modes, related to the design and fabrication of electro–optical circuits.
  • 11.5K
  • 14 Jan 2025
Topic Review
German Student Movement
The German student movement (also called 68er-Bewegung, movement of 1968, or soixante-huitards) was a protest movement that took place during the late 1960s in West Germany. It was largely a reaction against the perceived authoritarianism and hypocrisy of the West German government and other Western governments, and the poor living conditions of students. A wave of protests—some violent—swept West Germany, fueled by violent over-reaction by the police and encouraged by contemporary protest movements across the world. Following more than a century of conservatism among German students, the German student movement also marked a significant major shift to the left and radicalization of student activism.
  • 11.5K
  • 03 Nov 2022
Topic Review
Library Catalog
A library catalog or library catalogue is a register of all bibliographic items found in a library or group of libraries, such as a network of libraries at several locations. A bibliographic item can be any information entity (e.g., books, computer files, graphics, realia, cartographic materials, etc.) that is considered library material (e.g., a single novel in an anthology), or a group of library materials (e.g., a trilogy), or linked from the catalog (e.g., a webpage) as far as it is relevant to the catalog and to the users (patrons) of the library. The card catalog was a familiar sight to library users for generations, but it has been effectively replaced by the online public access catalog (OPAC). Some still refer to the online catalog as a "card catalog". Some libraries with OPAC access still have card catalogs on site, but these are now strictly a secondary resource and are seldom updated. Many libraries that retain their physical card catalog will post a sign advising the last year that the card catalog was updated. Some libraries have eliminated their card catalog in favour of the OPAC for the purpose of saving space for other use, such as additional shelving. The largest library catalog in the world is the WorldCat.org union catalog managed by the non-profit library cooperative OCLC, based in Dublin, Ohio. In January 2016, WorldCat.org had over 360,000,000 catalog records and over 2 billion library holdings.
  • 11.5K
  • 21 Oct 2022
Topic Review
Atmospheric Reentry
Atmospheric reentry is the process by which vehicles that are outside the atmosphere of a planet can enter that atmosphere and reach the planetary surface intact. Vehicles that undergo this process include spacecraft from orbit, as well as suborbital ICBM reentry vehicles. Typically this process requires special methods to protect against aerodynamic heating. Various advanced technologies have been developed to enable atmospheric reentry and flight at extreme velocities.
  • 11.5K
  • 01 Dec 2022
Topic Review
Direct Amidations of Carboxylic Acids with Amines
The prevalence of amides in biological systems and chemical fields such as polymers, materials and natural products drives continuous research on novel procedures to obtain these ubiquitous functional groups. Efforts to this purpose are mainly focused around the discovery of direct and catalytic methods that are more atom economic, safe and practical for diversified applications (e.g., organic, medicinal and peptide chemistries, material and polymer purposes, etc.), in accordance with green chemistry principles. 
  • 11.5K
  • 22 Feb 2023
Topic Review
Negawatt Power
Negawatt power is a theoretical unit of power representing an amount of electrical power (measured in watts) saved. The energy saved is a direct result of energy conservation or increased energy efficiency. The term was coined by the chief scientist of the Rocky Mountain Institute and environmentalist Amory Lovins in 1985, within the article, "Saving Gigabucks with Negawatts," where he argued that utility customers don’t want kilowatt-hours of electricity; they want energy services such as hot showers, cold beer, lit rooms, and spinning shafts, which can come more cheaply if electricity is used more efficiently. Lovins felt an international behavioral change was necessary in order to decrease countries' dependence on excessive amounts of energy. The concept of a negawatt could influence a behavioral change in consumers by encouraging them to think about the energy that they spend. A negawatt market can be thought of as a secondary market, in which electricity is allocated from one consumer to another consumer within the energy market. In this market, negawatts could be treated as a commodity. Commodities have the ability to be traded across time and space, which would allow negawatts to be incorporated in the international trading system. Roughly 10% of all U.S. electrical generating capacity is in place to meet the last 1% of demand and there is where the immediate efficiency opportunity exists. On March 15, 2011, the Federal Energy Regulatory Commission (FERC), the agency that regulates the U.S. electrical grid, approved a rule establishing the approach to compensation for demand response resources intended to benefit customers and help improve the operation and competitiveness of organized wholesale energy markets. This means that negawatts produced by reducing electrical use can demand the same market prices as real megawatts of generated electricity. The incentives for a negawatt market include receiving money, reduction of national energy dependency, and the local electricity deregulation within certain nations or states. As for the cost incentive, those who produce negawatts or simply conserve energy can earn money by selling the saved energy. The negawatt market could help nations or states obtain a deregulated electricity system by creating another market to purchase electricity from. The negawatt market also has two main drawbacks. Currently, there is no way to precisely measure the amount of energy saved in negawatts, and electricity providers may not want customers to use less energy due to the loss of profit.
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  • 22 Nov 2022
Topic Review
Gemini Surfactants
Gemini surfactants are dimeric structures, composed of two hydrophobic chains and two hydrophilic heads, linked by a spacer at or near the head groups. They present lower CMC, better efficiency to form micelles, and solubilization capacity comparedto their conventional (monomeric) counterparts. They can also reduce the surface tension of water and the oil–water interfacial tension from 10 to 100 times. This behaviour depends mainly on the nature of their components (heads, hydrophobic chains and spacer); thus, their synthesis is focused mainly on varying the type and length of these components.
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  • 21 Feb 2022
Topic Review
Soil Bioremediation
Petroleum hydrocarbons, heavy metals and agricultural pesticides have mutagenic, carcinogenic, immunotoxic and teratogenic effects and cause drastic changes in soil physicochemical and microbiological characteristics, thereby representing a serious danger to health and environment. Therefore, soil pollution urgently requires the application of a series of physicochemical and biological techniques and treatments to minimize the extent of damage. Among them, bioremediation has been shown to be an alternative that can offer an economically viable way to restore polluted areas.
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  • 27 Oct 2020
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