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Topic Review
Tumbling Mills
Tumbling mills have been widely implemented in many industrial sectors for the grinding of bulk materials. They have been used for decades in the production of fines and in the final stages of ore comminution, where optimal levels for the enrichment particles’ sizes are obtained. Even though these ubiquitous machines of relatively simple construction have been subjected to extensive studies, the industry still struggles with a very low energy efficiency of the comminution process. Moreover, obtaining an optimal size for the grinding product particles is crucial for the effectiveness of the following processes and waste production reduction. New, innovative processing methods and machines are being developed to tackle the problem; however, tumbling mills are still most commonly used in all ranges of the industry. Since heavy equipment retrofitting is the most costly approach, process optimization with dedicated models and control systems is the most preferable solution for energy consumption reduction. While the classic technological measurements in mineral processing are well adopted by the industry, nowadays research focuses on new methods of the mill’s internal dynamics analysis and control.
  • 5.7K
  • 19 Jan 2021
Topic Review
Stock Market Prediction
Stock Market Prediction (SMP) is an example of time-series forecasting that promptly examines previous data and estimates future data values. Financial market prediction has been a matter of worry for analysts in different disciplines, including economics, mathematics, material science, and computer science. Driving profits from the trading of stocks is an important factor for the prediction of the stock market.
  • 5.7K
  • 09 Dec 2021
Topic Review
Two-Dimensional Silicon Carbide
Two-dimensional silicon carbide (2D SiC) is a single/few atomic layer of silicon carbide.   2D SiC has a graphene-like honeycomb structure consisting of alternating Si and C atoms. In the monolayer SiC, the C and Si atoms bond through  sp2 hybridization to form the SiC sheet.  As a direct wide bandgap semiconducting material, 2D SiC has the potential to bring revolutionary advances into power electronics, optoelectronic and other SiC-based devices. It can overcome current limitations with silicon, bulk SiC, and gapless graphene. In addition to SiC, which is the most stable form of monolayer silicon carbide, other compositions, i.e. SixCy, are also predicted to be energetically favorable. Depending on the stoichiometry and bonding, monolayer SixCy may behave as a semiconductor, semimetal or topological insulator. With different Si/C ratios, the emerging 2D silicon carbide materials could attain novel electronic, optical, magnetic, mechanical, and chemical properties that go beyond those of graphene, silicene, and already discovered 2D semiconducting materials.
  • 5.7K
  • 08 May 2022
Topic Review
Colorectal Cancer Development
Colorectal cancer (CRC) is a disorder that occurs exclusively in the colon or rectum and is caused by the colon’s aberrant proliferation of glandular epithelial cells.
  • 5.7K
  • 19 Apr 2022
Topic Review
Emirate of Ras Al Khaimah
Ras Al Khaimah (RAK) (Arabic: رَأْس ٱلْخَيْمَة; IPA: [raʔs lˈxajma]), also spelled as Ras al Khaimah or Ras al-Khaimah, is one of the seven emirates that make up the United Arab Emirates (UAE). The city of Ras Al Khaimah, sometimes simply abbreviated to RAK City, is the capital of the emirate and home to most of the emirate's residents. It is linked to the medieval trading port of Julfar.[lower-alpha 1] Its name in English means "top of the tent". The emirate borders Oman's exclave of Musandam, and occupies part of the same peninsula. It covers an area of 2,486 km2 (960 sq mi) and has 64 km (40 mi) of beach coastline. As of 2015, the emirate had a population of about 345,000, of which about 31% were Emirati citizens. RAK city has two main areas - the Old Town and Nakheel - on either side of a creek that is home to mangroves and is framed by the North-Western Hajar Mountains. The emirate also consists of several villages and new gated residential developments, such as Al Hamra Village and Mina Al Arab. The emirate is served by Ras Al Khaimah International Airport. Its geography consists of a northern part (where Ras Al Khaimah City and most towns are situated) and a large southerly inland exclave (near the Dubai exclave of Hatta), and a few small islands in the Persian Gulf. Ras Al Khaimah has the most fertile soil in the country, due to a larger share of rainfall and underground water streams from the Hajar.
  • 5.7K
  • 10 Oct 2022
Topic Review
Temporal Envelope and Fine Structure
Temporal envelope (ENV) and temporal fine structure (TFS) are changes in the amplitude and frequency of sound perceived by humans over time. These temporal changes are responsible for several aspects of auditory perception, including loudness, pitch and timbre perception and spatial hearing. Complex sounds such as speech or music are decomposed by the peripheral auditory system of humans into narrow frequency bands. The resulting narrow-band signals convey information at different time scales ranging from less than one millisecond to hundreds of milliseconds. A dichotomy between slow "temporal envelope" cues and faster "temporal fine structure" cues has been proposed to study several aspects of auditory perception (e.g., loudness, pitch and timbre perception, auditory scene analysis, sound localization) at two distinct time scales in each frequency band. Over the last decades, a wealth of psychophysical, electrophysiological and computational studies based on this envelope/fine-structure dichotomy have examined the role of these temporal cues in sound identification and communication, how these temporal cues are processed by the peripheral and central auditory system, and the effects of aging and cochlear damage on temporal auditory processing. Although the envelope/fine-structure dichotomy has been debated and questions remain as to how temporal fine structure cues are actually encoded in the auditory system, these studies have led to a range of applications in various fields including speech and audio processing, clinical audiology and rehabilitation of sensorineural hearing loss via hearing aids or cochlear implants.
  • 5.7K
  • 12 Oct 2022
Topic Review
Compartmental Models in Epidemiology
Compartmental models are a very general modelling technique. They are often applied to the mathematical modelling of infectious diseases. The population is assigned to compartments with labels – for example, S, I, or R, (Susceptible, Infectious, or Recovered). People may progress between compartments. The order of the labels usually shows the flow patterns between the compartments; for example SEIS means susceptible, exposed, infectious, then susceptible again. The origin of such models is the early 20th century, with important works being that of Ross in 1916, Ross and Hudson in 1917, Kermack and McKendrick in 1927 and Kendall in 1956 The models are most often run with ordinary differential equations (which are deterministic), but can also be used with a stochastic (random) framework, which is more realistic but much more complicated to analyze. Models try to predict things such as how a disease spreads, or the total number infected, or the duration of an epidemic, and to estimate various epidemiological parameters such as the reproductive number. Such models can show how different public health interventions may affect the outcome of the epidemic, e.g., what the most efficient technique is for issuing a limited number of vaccines in a given population.
  • 5.7K
  • 02 Dec 2022
Topic Review
Social Innovation and Vulnerable Communities
This study aims to analyze the actions of the Invisible Cities Project (ICP) as an example of social innovation and as a way of giving visibility to vulnerable communities. Initially, a theoretical framework was established to understand the possibilities of the visibility of isolated and poor communities located within the urban setting. This framework was established based on the literature that addresses the role of social innovation in cities. Then, participant observations were made in a community to analyze the initiatives that are part of the ICP. Finally, semi-structured interviews were conducted; these interviews reported the lived experiences of participants involved in the project through the narratives of the community members. Drawing from the specialized literature, it was found that this project carries out various aspects of social innovation, such as social visibility, empowerment, the articulation of different actors in society, social inclusion, and the improvement of the urban public space. The project also addresses a variety of Sustainable Development Goals (SDGs), such as eradicating poverty, promoting health and well-being, reducing inequalities, and fostering more sustainable cities and communities.
  • 5.7K
  • 29 Sep 2025
Topic Review
Arms Industry
The arms industry, also known as the defense industry or the arms trade, is a global industry responsible for the manufacturing and sales of weapons and military technology. It consists of a commercial industry involved in the research and development, engineering, production, and servicing of military material, equipment, and facilities. Arms-producing companies, also referred to as arms dealers, defence contractors, or as the military industry, produce arms for the armed forces of states and civilians. Departments of government also operate in the arms industry, buying and selling weapons, munitions and other military items. An arsenal is a place where arms and ammunition are made, maintained and repaired, stored, or issued, in any combination, whether privately or publicly owned. Products include guns, artillery, ammunition, missiles, military aircraft, military vehicles, ships, electronic systems, night vision devices, holographic weapon sights, laser rangefinders, laser sights, hand grenades, landmines and more. The arms industry also provides other logistical and operational support. Stockholm International Peace Research Institute (SIPRI) estimated that 2012 military expenditures were roughly $1.8 trillion. This represents a relative decline from 1990 when military expenditures made up 4% of world GDP. Part of the money goes to the procurement of military hardware and services from the military industry. The combined arms sales of the top 100 largest arms-producing companies amounted to an estimated $395 billion in 2012 according to SIPRI. In 2004 over $30 billion were spent in the international arms trade (a figure that excludes domestic sales of arms). According to SIPRI, the volume of international transfers of major weapons in 2010–14 was 16 per cent higher than in 2005–2009. The five biggest exporters in 2010–2014 were the United States, Russia, China, Germany and France, and the five biggest importers were India, Saudi Arabia, China, the United Arab Emirates and Pakistan. Many industrialized countries have a domestic arms-industry to supply their own military forces. Some countries also have a substantial legal or illegal domestic trade in weapons for use by its citizens, primarily for self-defence, hunting or sporting purposes. Illegal trade in small arms occurs in many countries and regions affected by political instability. The Small Arms Survey estimates that 875 million small arms circulate worldwide, produced by more than 1,000 companies from nearly 100 countries. Contracts to supply a given country's military are awarded by governments, making arms contracts of substantial political importance. The link between politics and the arms trade can result in the development of what U.S. President Dwight D. Eisenhower described as a military-industrial complex, where the armed forces, commerce, and politics become closely linked, similarly to the European multilateral defence procurement. Various corporations, some publicly held, others private, bid for these contracts, which are often worth many billions of dollars. Sometimes, as with the contract for the international Joint Strike Fighter, a competitive tendering process takes place, with the decision made on the merits of the designs submitted by the companies involved. Other times, no bidding or competition takes place.
  • 5.7K
  • 10 Dec 2025
Topic Review
Convergent Evolution
Convergent evolution is the independent evolution of similar features in species of different periods or epochs in time. Convergent evolution creates analogous structures that have similar form or function but were not present in the last common ancestor of those groups. The cladistic term for the same phenomenon is homoplasy. The recurrent evolution of flight is a classic example, as flying insects, birds, pterosaurs, and bats have independently evolved the useful capacity of flight. Functionally similar features that have arisen through convergent evolution are analogous, whereas homologous structures or traits have a common origin but can have dissimilar functions. Bird, bat, and pterosaur wings are analogous structures, but their forelimbs are homologous, sharing an ancestral state despite serving different functions. The opposite of convergence is divergent evolution, where related species evolve different traits. Convergent evolution is similar to parallel evolution, which occurs when two independent species evolve in the same direction and thus independently acquire similar characteristics; for instance, gliding frogs have evolved in parallel from multiple types of tree frog. Many instances of convergent evolution are known in plants, including the repeated development of C4 photosynthesis, seed dispersal by fleshy fruits adapted to be eaten by animals, and carnivory.
  • 5.7K
  • 24 Oct 2022
Topic Review
Potential Flow Around a Circular Cylinder
In mathematics, potential flow around a circular cylinder is a classical solution for the flow of an inviscid, incompressible fluid around a cylinder that is transverse to the flow. Far from the cylinder, the flow is unidirectional and uniform. The flow has no vorticity and thus the velocity field is irrotational and can be modeled as a potential flow. Unlike a real fluid, this solution indicates a net zero drag on the body, a result known as d'Alembert's paradox.
  • 5.7K
  • 31 Oct 2022
Topic Review
Steroid-Induced Iatrogenic Adrenal Insufficiency
This entry focuses on steroid-induced adrenal insufficiency (SIAI) in children and discusses the latest findings by surveying recent studies. SIAI is a condition involving adrenocorticotropic hormone (ACTH) and cortisol suppression due to high doses or prolonged administration of glucocorticoids. While its chronic symptoms, such as fatigue and loss of appetite, are nonspecific, exposure to physical stressors, such as infection and surgery, increases the risk of adrenal crisis development accompanied by hypoglycemia, hypotension, or shock. The low-dose ACTH stimulation test is generally used for diagnosis, and the early morning serum cortisol level has also been shown to be useful in screening for the condition. 
  • 5.7K
  • 20 Jan 2021
Topic Review Peer Reviewed
Entropy
The concept of entropy constitutes, together with energy, a cornerstone of contemporary physics and related areas. It was originally introduced by Clausius in 1865 along abstract lines focusing on thermodynamical irreversibility of macroscopic physical processes. In the next decade, Boltzmann made the genius connection—further developed by Gibbs—of the entropy with the microscopic world, which led to the formulation of a new and impressively successful physical theory, thereafter named statistical mechanics. The extension to quantum mechanical systems was formalized by von Neumann in 1927, and the connections with the theory of communications and, more widely, with the theory of information were respectively introduced by Shannon in 1948 and Jaynes in 1957. Since then, over fifty new entropic functionals emerged in the scientific and technological literature. The most popular among them are the additive Renyi one introduced in 1961, and the nonadditive one introduced in 1988 as a basis for the generalization of the Boltzmann–Gibbs and related equilibrium and nonequilibrium theories, focusing on natural, artificial and social complex systems. Along such lines, theoretical, experimental, observational and computational efforts, and their connections to nonlinear dynamical systems and the theory of probabilities, are currently under progress. Illustrative applications, in physics and elsewhere, of these recent developments are briefly described in the present synopsis.
  • 5.7K
  • 07 May 2022
Topic Review
List of Intel Core 2 Microprocessors
The Core 2 brand refers to Intel's x86 and x86-64 microprocessors with the Core microarchitecture made for the consumer and business markets (except servers) above Pentium. The Core 2 solo branch covered single-core CPUs for notebook computers, Core 2 Duo – dual-core CPUs for desktop and notebook computers, Core 2 Quad – quad-core CPUs for desktop and notebook computers, and Core 2 Extreme – dual-core and quad-core CPUs for desktop and notebook computers.
  • 5.7K
  • 18 Oct 2022
Topic Review
Deep Learning Based Speech Synthesis
Speech synthesis, also known as text-to-speech (TTS), has attracted increasingly more attention. Recent advances on speech synthesis are overwhelmingly contributed by deep learning or even end-to-end techniques which have been utilized to enhance a wide range of application scenarios such as intelligent speech interaction, chatbot or conversational artificial intelligence (AI). For speech synthesis, deep learning based techniques can leverage a large scale of <text, speech> pairs to learn effective feature representations to bridge the gap between text and speech, thus better characterizing the properties of events.
  • 5.7K
  • 08 Apr 2021
Topic Review
Bongo Drum
Bongos (Spanish: bongó) are an Afro-Cuban percussion instrument consisting of a pair of small open bottomed hand drums of different sizes. They are struck with both hands, most commonly in an eight-stroke pattern called martillo (hammer). They are mainly employed in the rhythm section of son cubano and salsa ensembles, often alongside other drums such as the larger congas and the stick-struck timbales. Bongo drummers (bongoseros) emerged as the only drummers of son cubano ensembles in eastern Cuba toward the end of the 19th century. The instrument remained important as son groups evolved into larger conjuntos and orchestras in Havana in the 1940s, at which point they began to share the stage with congas. Bongos later reached the United States, where they are commonly played in salsa, Afro-Cuban jazz, Latin rock and other genres. Bongo drums are about 20 centimetres (8 in) high and have diameters of approximately 20 centimetres (8 in) and 25 centimetres (10 in) (the smaller drum is called macho, male, and the larger drum, hembra, female). They are the smallest drums in Latin percussion, some models being only 15 centimetres (6 in) in diameter. The shells of the drums and the bridge (the small block that joins them) are usually made of wood, although fiberglass is also common. The heads are typically made of calfskin and attached to the shells via steel hardware that enables their tuning. Originally, metal tacks were used, so tuning had to be done by heating the skins.
  • 5.7K
  • 02 Nov 2022
Topic Review
Unintended Consequences
In the social sciences, unintended consequences (sometimes unanticipated consequences or unforeseen consequences) are outcomes of a purposeful action that are not intended or foreseen. The term was popularised in the twentieth century by American sociologist Robert K. Merton and expanded by economist Thomas Sowell and psychologist Stuart Vyse. Unintended consequences can be grouped into three types: Unexpected benefit: A positive unexpected benefit (also referred to as luck, serendipity or a windfall). Unexpected drawback: An unexpected detriment occurring in addition to the desired effect of the policy (e.g., while irrigation schemes provide people with water for agriculture, they can increase waterborne diseases that have devastating health effects, such as schistosomiasis). Perverse result: A perverse effect contrary to what was originally intended (when an intended solution makes a problem worse).
  • 5.7K
  • 14 Oct 2022
Topic Review
LD-Steelmaking
Basic Oxygen Furnace (BOF) steelmaking is, worldwide, the most frequently applied process. According to the world steel organization statistical report, 2021, it saw a total production share of 73.2%, or 1371.2 million tons per year of the world steel production in 2020. The rest is produced in Electric Arc Furnace (EAF)-based steel mills (26.3%), and only a very few open-hearth and induction furnace-based steel mills. The BOF technology remains the leading technology applied based on its undoubted advantages in productivity and liquid steel composition control. The BOF technology started as the LD process 70 years ago, with the first heat applied in November 1952 in a steel mill in Linz, Austria. The name LD was formed from the first letters of the two sites with the first industrial scale plants, Linz and Donawitz, both in Austria. The history and development of the process have been honored in multiple anniversary publications over the last few decades. Nevertheless, the focus of the steel industry worldwide is significantly changing following a social and political trend and the requirement for fossil-free energy generation and industrial production to be in accordance with the world climate targets committed to in relation to the decades leading up to 2050.
  • 5.7K
  • 09 Jun 2022
Topic Review
Unbibium
Unbibium /uːnˈbɪbiəm/, also known as eka-thorium or simply element 122, is the currently hypothetical chemical element in the periodic table with the placeholder symbol of Ubb and atomic number 122. Unbibium and Ubb are the temporary systematic IUPAC name and symbol respectively, until a permanent name is decided upon. In the periodic table of the elements, it is expected to follow unbiunium as the second element of the superactinides, or the g-block and the fourth element of the 8th period. It has attracted recent attention, for similarly to unbiunium, it is expected to fall within the range of the island of stability. Despite many attempts, unbibium has not yet been synthesized, and therefore no natural isotopes have been found to exist. It is currently predicted that it has a g-orbital, the second element of which to have such besides unbiunium, which also has yet to be synthesized. It will most likely require nuclear fission to be produced artificially. In 2008, it was claimed to have been discovered in natural thorium samples but that claim has now been dismissed by recent repetitions of the experiment using more accurate techniques.
  • 5.7K
  • 29 Nov 2022
Topic Review
Poly(N-isopropylacrylamide)-Based Hydrogels
Poly(N-isopropylacrylamide) (PNIPAM) is a widely utilized negative thermosensitive polymer (as it has increased solubility with lowering of temperature, causing volume phase transition by forming hydrogen bonds) that has currently sparkled a lot of scientific inquisitiveness. Smart hydrogels based on PNIPAM demonstrate distinct thermoresponsive features close to a lower critical solution temperature (LCST) that enhance their capability in various biomedical applications such as drug delivery, tissue engineering, and wound dressings.
  • 5.7K
  • 29 Jul 2022
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