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Topic Review
Markov Chain Applications to Education
The theory of Markov chains is a smart combination of Linear Algebra and Probability theory offering ideal conditions for modelling situations depending on random variables. Markov chains have found important applications to many sectors of the human activity. In this work a finite Markov chain is introduced representing mathematically the teaching process which is based on the ideas of constructivism for learning. Interesting conclusions are derived and a measure is obtained for the teaching effectiveness. An example on teaching the derivative to fresher university students is also presented illustrating our results.
  • 4.2K
  • 03 Dec 2020
Topic Review
Polyphenol Analysis
The analysis of polyphenols can be approached from two main perspectives: by liquid chromatography, which provides the polyphenolic profile, but also allows the quantification of target individual polyphenols, or by spectrophotometric or electrochemical assays, which provide an estimation of the total polyphenol content or the antioxidant capacity.
  • 4.2K
  • 11 Feb 2022
Topic Review
Non-Sieving Mechanism
Non-sieving mechanism is a particle removal process in which particles smaller than the membrane pores are captured by adsorption at the pore surface. The non-sieving mechanism plays an important role for charged solute. There are three accepted non-sieving mechanisms: Donnan exclusion, dielectric exclusion, and hydration mechanism.
  • 4.2K
  • 18 Feb 2022
Topic Review
Youth Empowerment for Sustainable Development
Youth, generally defined as young people aged between 15 and 24, are a key population. Their empowerment as members of our societies is vital for the societal ecosocial transition from a human-centered to an ecosocial focus, in pursuit of Sustainable Development (SD) and the United Nations “The 2030 Agenda for Sustainable Development” with its 17 Sustainable Development Goals (SDGs). In relation to sustainability, ecosocial transition is a holistic perspective with ecological, economic, and social dimensions of development focusing on the interlinkage between social and ecological sustainability.
  • 4.2K
  • 21 Apr 2022
Topic Review
The Alveolar Epithelium at Homeostasis
The alveolar epithelium serves as a barrier between the body and the external environment. To maintain efficient gas exchange, the alveolar epithelium has evolved to withstand and rapidly respond to an assortment of inhaled, injury-inducing stimuli. Alveolar damage can lead to loss of alveolar fluid barrier function and exuberant, non-resolving inflammation that manifests clinically as acute respiratory distress syndrome (ARDS).
  • 4.2K
  • 21 Sep 2022
Topic Review
Digital Twins in Automotive Industry
A digital twin is a nonphysical model that has been designed in order to accurately reflect an artificial or physical system, where sensors are placed to acquire a variety of data regarding different aspects concerning the performance of the system.
  • 4.2K
  • 13 Jul 2022
Topic Review
Homogeneous and Heterogeneous Copper Catalyst
The applications of Copper-based nanoparticles have received great attention due to the earth-abundant, low toxicity and inexpensive. Due to these characteristics, copper nanoparticles have generated a great deal of interest especially in the field of catalysis. Traditional Ullmann-type couplings suffer from limited substrate scopes and harsh reaction conditions. The introduction of a new copper-based catalyst over the past two decades has totally changed this situation as it enables the reaction promoted in mild condition. The reaction scope has also been greatly expanded, rendering this copper-based cross-coupling attractive for both academia and industry. Transition metal-catalyzed chemical transformation of organic electrophiles and organometallic reagents belong to the most important cross-coupling reaction in organic synthesis. The biaryl ether division is not only popular in natural products and synthetic pharmaceuticals but also widely found in many pesticides, polymers, and ligands. Copper catalyst has received great attention owing to the low toxicity and low cost. The introduction of homogeneous copper catalysts with the presence of bidentate ligands and also heterogeneous copper catalyst over the past two decades has totally changed this situation as these ligands enable the reaction promoted in mild condition. The reaction scope has also been greatly expanded, rendering this copper-based cross-coupling attractive for both academia and industry. This review had been summarized recently advance homogeneous and heterogeneous copper catalyst in Ullmann reaction and its application and natural product and pharmaceutical industry.
  • 4.2K
  • 09 Oct 2020
Topic Review
The Relationship between Empathy and Attachment
Empathy is an important channel for health improvement and social adaptation of individuals, laying a foundation for moral development and positive outcomes. A high level of empathy can promote prosocial behavior and the well-being of people while upgrading interpersonal relationships. In contrast, a low level of empathy is closely related with the externalization of aggressive behavior and social adjustment.
  • 4.2K
  • 17 Feb 2022
Topic Review
Recession of 1937–38
The recession of 1937–1938 was an economic downturn that occurred during the Great Depression in the United States. By the spring of 1937, production, profits, and wages had regained their early 1929 levels. Unemployment remained high, but it was slightly lower than the 25% rate seen in 1933. The American economy took a sharp downturn in mid-1937, lasting for 13 months through most of 1938. Industrial production declined almost 30 percent, and production of durable goods fell even faster. Unemployment jumped from 14.3% in May 1937 to 19.0% in June 1938. Manufacturing output fell by 37% from the 1937 peak and was back to 1934 levels. Producers reduced their expenditures on durable goods, and inventories declined, but personal income was only 15% lower than it had been at the peak in 1937. In most sectors, hourly earnings continued to rise throughout the recession, partly compensating for the reduction in the number of hours worked. As unemployment rose, consumer expenditures declined, leading to further cutbacks in production.
  • 4.2K
  • 25 Oct 2022
Topic Review
Operation Bertram
Operation Bertram was a Second World War deception operation practised by the Allied forces in Egypt led by Bernard Montgomery, in the months before the Second Battle of El Alamein in 1942. Bertram was devised by Dudley Clarke to deceive Erwin Rommel about the timing and location of the Allied attack. The operation consisted of physical deceptions using dummies and camouflage, designed and made by the British Middle East Command Camouflage Directorate led by Geoffrey Barkas. These were accompanied by electromagnetic deceptions codenamed Operation Canwell, using false radio traffic. All of these were planned to make the Axis believe that the attack would take place to the south, far from the coast road and railway, about two days later than the real attack. Bertram consisted of the creation of the appearance of army units where none existed and in concealing armour, artillery and matériel. Dummy tanks and guns were made mainly of local materials including calico and palm-frond hurdles. Real tanks were disguised as trucks, using light "Sunshield" canopies. Field guns and their limbers were also disguised as trucks, their real wheels visible, under a simple box-shaped "Cannibal" canopy to give the shape of a truck. Petrol cans were stacked along the sides of existing revetted trenches, hidden in the shadows. Food was stacked in piles of boxes and draped with camouflage nets to resemble trucks. Trucks were parked openly in the tank assembly area for some weeks. Real tanks were similarly parked openly, far behind the front. Two nights before the attack, the tanks replaced the trucks, being covered with "Sunshields" before dawn. The tanks were replaced that same night with dummies in their original positions, so the armour remained seemingly two or more days' journey behind the front line. To reinforce the impression that the attack was not ready, a dummy water pipeline was constructed, at an apparent rate of 5 mi (8.0 km) per day. Some days' worth remained to be built at the time of the attack; dummy tanks, guns and supplies were constructed to the south. After the battle, the captured German panzerarmee general Wilhelm Ritter von Thoma told Montgomery that he had believed the Allies had at least one more armoured division than they did and that the attack would be in the south. Rommel's stand-in, general Georg Stumme, thought the attack would not begin for several weeks. Bertram had succeeded; when announcing the victory at El Alamein in the House of Commons, Winston Churchill praised the camouflage operation.
  • 4.2K
  • 02 Nov 2022
Topic Review
Haze in Beer
Beer is one of the oldest and also most widely consumed alcoholic beverages. It is a kind of colloid solution with complex composition and weak stability. The haze formation in beer is a serious quality problem, as it primarily affects the shelf life and flavor of beer. Hazes are caused by suspended insoluble particles of colloidal or larger size that can be perceived visually or by instruments.
  • 4.2K
  • 06 Jan 2022
Topic Review
Artificial Intelligence Applications and Self-Learning 6G Networks
Artificial Intelligence (AI), federated and distributed learning, big data analytics, blockchain, and edge-cloud computing has urged the design of the upcoming 6G network generation, due to their stringent requirements in terms of the quality of services (QoS), availability, and dependability to satisfy a Service-Level-Agreement (SLA) for the end users. Industries and academia have started to design 6G networks and propose the use of AI in its protocols and operations. 
  • 4.2K
  • 02 Sep 2022
Topic Review
Machine Learning Applications in Failure Predictions
Machine Learning (ML) is a subclass of artificial intelligence (AI) that can be defined as a semi-automated system in which computers create an algorithm by learning from observed data. Machine learning algorithms create a model based on training data and use it to make predictions or judgments without having to be explicitly programmed to do so. In recent years, decision makers and the scientific community have paid close attention to the use of machine learning in risk and reliability assessment. Currently, quite a good amount of work is being carried out in mine equipment failure and reliability assessments and predictive maintenance analysis. A machine learning approach can be used for predicting failures and also to identify important parameters that predict failures.
  • 4.2K
  • 09 Sep 2022
Topic Review
Biofuels for Internal Combustion Engine
Biofuel, a cost-effective, safe, and environmentally benign fuel produced from renewable sources, has been accepted as a sustainable replacement and a panacea for the damaging effects of the exploration for and consumption of fossil-based fuels.
  • 4.2K
  • 28 Sep 2021
Topic Review
List of Minerals (Complete)
Mineralogy is an active science in which minerals are discovered or recognised on a regular basis. Use of old mineral names is also discontinued, for example when a name is no longer considered valid. Therefore, a list of recognised mineral species is never complete. Minerals are distinguished by various chemical and physical properties. Differences in chemical composition and crystal structure distinguish the various species. Within a mineral species there may be variation in physical properties or minor amounts of impurities that are recognized by mineralogists or wider society as a mineral variety. The International Mineralogical Association (IMA) is the international group that recognises new minerals and new mineral names. However, minerals discovered before 1959 did not go through the official naming procedure. Some minerals published previously have been either confirmed or discredited since that date. This list contains a mixture of mineral names that have been approved since 1959 and those mineral names believed to still refer to valid mineral species (these are called "grandfathered" species). Presently, each year about 90-110 new mineral species (the sum of all mutations c. 120/year) are officially approved by the Commission on New Minerals, Nomenclature and Classification (CNMNC) of the International Mineralogical Association. The IMA/CNMNC administrates c. 6,500 names, and (As of January 2018), the Handbook of Mineralogy lists 4,507 species. (As of March 2018), the IMA Database of Mineral Properties/ Rruff Project lists 5,312 valid species (IMA/CNMNC) of a total of 5,525 minerals. There are 1,289 Pre-IMA minerals. (As of April 2011), the Webmineral.com website lists 2,722 published and approved (IMA/CNMNC) minerals, 81 discredited minerals (IMA/CNMNC status; Michael Fleischer discredited around thousand species in his lifetime), 2,691 synonyms and 123 "not approved" names. (As of November 2018), the IMA - CNMNC Master List of Minerals lists 5,413 valid minerals, including c. 1,166 pre-IMA minerals (grandfathered), c. 272 approved minerals but without a published description yet and c. 99 questionable minerals. Due to the length of this list, it is divided into alphabetical groups. The minerals are sorted by name.
  • 4.2K
  • 02 Nov 2022
Topic Review
Metal matrix composites (MMCs)
Metal matrix composites (MMCs) present extraordinary characteristics, including high wear resistance, excellent operational properties at elevated temperature, and better chemical inertness as compared to traditional alloys. These properties make them prospective candidates in the fields of aerospace, automotive, heavy goods vehicles, electrical, and biomedical industries. MMCs are challenging to process via traditional manufacturing techniques, requiring high cost and energy. The laser-melting deposition (LMD) has recently been used to manufacture MMCs via rapid prototyping, thus, solving these drawbacks. Besides the benefits mentioned above, the issues such as lower ultimate tensile strength, yield strength, weak bonding between matrix and reinforcements, and cracking are still prevalent in parts produced by LMD. In this article, a detailed analysis is made on the MMCs manufactured via LMD. An illustration is presented on the LMD working principle, its classification, and dependent and independent process parameters. Moreover, a brief comparison between the wire and powder-based LMDs has been summarized. Ex- and in-situ MMCs and their preparation techniques are discussed. Besides this, various matrices available for MMCs manufacturing, properties of MMCs after printing, possible complications and future research directions are reviewed and summarized.
  • 4.2K
  • 01 Jul 2026
Topic Review
Frying
Frying is one of the oldest unit operations to produce food products with a crisp texture, an aromatic flavour and a golden-brown colour. Deep-fried foods such as French fries, potato/veggie crisps are popular among consumers. Detailed insights into the frying process in terms of heat, mass (water and oil) and momentum transfers are outlined in this entry.
  • 4.2K
  • 28 Jul 2020
Topic Review
Food Waste Used for the Cultivation of Mushroom
Pleurotus ostreatus (P. ostreatus) is considered a high-quality food, rich in proteins and bioactive compounds important for maintaining human health. Lately, a commonly used substrate for oyster mushroom cultivation—wheat straw, is more often replaced by alternative cellulose substrates originated from the agricultural and food industry. Utilization of wastes for mushroom cultivation has its added value: sustainable food waste management, production of high-quality food from low quality waste, as well as solving environmental, economic and global issues.
  • 4.2K
  • 15 Nov 2022
Topic Review
Precambrian
The Precambrian (or Pre-Cambrian, sometimes abbreviated pЄ, or Cryptozoic) is the earliest part of Earth's history, set before the current Phanerozoic Eon. The Precambrian is so named because it preceded the Cambrian, the first period of the Phanerozoic eon, which is named after Cambria, the Latinised name for Wales, where rocks from this age were first studied. The Precambrian accounts for 88% of the Earth's geologic time. The Precambrian (colored green in the timeline figure) is an informal unit of geologic time, subdivided into three eons (Hadean, Archean, Proterozoic) of the geologic time scale. It spans from the formation of Earth about 4.6 billion years ago (Ga) to the beginning of the Cambrian Period, about 541 million years ago (Ma), when hard-shelled creatures first appeared in abundance.
  • 4.2K
  • 15 Nov 2022
Topic Review
Renewable Energy Technologies in Households
Energy sources used in households could be divided into the following two main groups: fossil fuels, which include natural gas, oil and coal, and renewable energy technologies, which include both conventional biomass and modern sources such as solar, wind and geothermal energy. Solar photovoltaic (PV) and solar thermal, micro wind, heat pumps and small-scale biomass heating technologies can be distinguished as the main renewable energy technologies in households.
  • 4.2K
  • 27 Oct 2020
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