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Topic Review
Extraction Methods of Medicinal Plants for Antimicrobial Textiles
Medicinal plants are the product of natural drug discoveries and have gained traction due to their pharmacological activities. Pathogens are everywhere, and they thrive in ideal conditions depending on the nutrients, moisture, temperature, and pH that increase the growth of harmful pathogens on surfaces and textiles.
  • 9.8K
  • 22 Aug 2022
Topic Review
Performance Comparison of SQL and Graph Databases
In developing NoSQL databases, a major motivation is to achieve better efficient query performance compared with relational databases. The graph database is a NoSQL paradigm where navigation is based on links instead of joining tables. Links can be implemented as pointers, and following a pointer is a constant time operation, whereas joining tables is more complicated and slower, even in the presence of foreign keys. Therefore, link-based navigation has been seen as a more efficient query approach than using join operations on tables. Existing studies strongly support this assumption. Query complexity has received less attention. For example, in enterprise information systems, queries are usually complex so data need to be collected from several tables or by traversing paths of graph nodes of different types.
  • 9.8K
  • 15 Jul 2022
Topic Review
Cat Anatomy
The anatomy of the domestic cat is similar to that of other members of the genus Felis.
  • 9.8K
  • 14 Nov 2022
Topic Review
Hat Puzzle
Hat puzzles are logic problems that date back to as early as 1961. Such hat puzzles, frequently contextualized as prisoners and hats puzzles, are induction puzzles (a kind of logic puzzle) that involve reasoning about the actions of other people, drawing in aspects of Game theory sometimes called the hierarchy of beliefs. There are many variations, but the central theme remains the same. A number of players are each wearing a hat, which may be of various specified colours. Players can see the colours of at least some other players' hats, but not that of their own. With highly restricted communication or none, some of the players must guess the colour of their hat. The problem is to find a strategy for the players to determine the colours of their hats based on the hats they see and what the other players do. In some versions, they compete to be the first to guess correctly; in others, they can work out a strategy beforehand to cooperate and maximize the probability of correct guesses. One variation received some new publicity as a result of Todd Ebert's 1998 Ph.D. thesis at the University of California, Santa Barbara. It is a strategy question about a cooperative game, which has connections to algebraic coding theory.
  • 9.8K
  • 24 Oct 2022
Topic Review
Libra
The constellation Libra, known as the Scales or the Balance, is one of the 12 zodiac constellations representing an inanimate object. It is located in the southern sky and is associated with justice and balance. Libra is depicted as scales held by the Greek goddess of justice, Astraea, and is the only zodiac constellation named after an object rather than an animal or character from mythology.
  • 9.8K
  • 15 Mar 2024
Topic Review Video
Ecological Stoichiometry
Ecological stoichiometry considers how nutritional needs of organisms for basic body-building molecules shape their ecology. It asks how nutritional demands of organisms and supply of nutrients in their environments affects organisms growth, their interactions with the biotic and abiotic worlds and nutrient cycling in whole ecosystem.
  • 9.8K
  • 04 Nov 2020
Topic Review
Biopolymers for Medical Applications
Biopolymers are the organic substances present in natural sources. The term biopolymer originates from the Greek words bio and polymer, representing nature and living organisms. Large macromolecules made up of numerous repeating units are known as biopolymers. As per the IUPAC definition, a macromolecule defines a single molecule. The biopolymers are found to be biocompatible and biodegradable, making them useful in different applications, such as edible films, emulsions, packaging materials in the food industry, and as drug transport materials, medical implants like medical implants organs, wound healing, tissue scaffolds, and dressing materials in pharmaceutical industries. 
  • 9.8K
  • 18 Mar 2022
Topic Review
Wind Tower Houses in Dubai
Due to the similar climate conditions and proximity of the United Arab Emirates to other neighboring countries such as Iran and India, who have been familiar with the use of wind towers as cooling devices for a long time, wind towers were readily adopted in traditional buildings in the UAE. The most concentrated number of wind towers can be found in the residential neighborhood of Dubai called Alfahidi Historic Area. The number reaches around 50 wind towers in less than 0.25 km2, with an average of one wind tower per house. This neighborhood was originally designed for merchants who immigrated from Bastak in Iran. Later, wind towers were applied to various different types of buildings, such as shops and stores, as well as other residential neighborhoods of Shindagah and Deira.
  • 9.8K
  • 19 Apr 2022
Topic Review
Angle-Resolved Photoemission Spectroscopy (ARPES)
Angle-resolved photoemission spectroscopy (ARPES) is a vital technique in which spectra are collected from both the energy and momentum of photoemitted electrons and is indispensable for investigating the electronic band structure of solids. 
  • 9.8K
  • 08 Dec 2020
Topic Review
Direct and Indirect Solar Gain Systems
The energy crisis, the risk of interruptions or irregular supplies of conventional energy carriers, and the need to protect the environment stimulate the search for new solutions to improve the heat balance of buildings with the use of solar energy. Based on the criterion of the storage, distribution, and discharge time of stored heat, passive solar gain solutions can be divided into direct and indirect solar gain systems.
  • 9.8K
  • 15 Dec 2022
Topic Review
History of Statistics
The history of statistics in the modern way is that it originates from the term statistics, found in 1749 in Germany. Although there have been changes to the interpretation of the word over time. The development of statistics is intimately connected on the one hand with the development of sovereign states, particularly European states following the peace of Westphalia (1648); and the other hand with the development of probability theory, which put statistics on a firm theoretical basis (see history of probability). In early times, the meaning was restricted to information about states, particularly demographics such as population. This was later extended to include all collections of information of all types, and later still it was extended to include the analysis and interpretation of such data. In modern terms, "statistics" means both sets of collected information, as in national accounts and temperature records, and analytical work which requires statistical inference. Statistical activities are often associated with models expressed using probabilities, hence the connection with probability theory. The large requirements of data processing have made statistics a key application of computing; see history of computing hardware. A number of statistical concepts have an important impact on a wide range of sciences. These include the design of experiments and approaches to statistical inference such as Bayesian inference, each of which can be considered to have their own sequence in the development of the ideas underlying modern statistics.
  • 9.8K
  • 19 Oct 2022
Topic Review
Compact Cassette
The Compact Audio Cassette (CAC) or Musicassette (MC), also commonly called the cassette tape or simply tape or cassette, is an analog magnetic tape recording format for audio recording and playback. It was developed by Philips in Hasselt, Belgium, and released in 1962. Compact cassettes come in two forms, either already containing content as a prerecorded cassette, or as a fully recordable "blank" cassette. Both forms are reversible by the user. The compact cassette technology was originally designed for dictation machines, but improvements in fidelity led the Compact Cassette to supplant the Stereo 8-track cartridge and reel-to-reel tape recording in most non-professional applications. Its uses ranged from portable audio to home recording to data storage for early microcomputers. The first cassette player (although mono) designed for use in car dashboards was introduced in 1968. Between the early 1970s and the early 2000s, the cassette was one of the two most common formats for prerecorded music, first alongside the LP record and later the compact disc (CD). Compact Cassettes contain two miniature spools, between which the magnetically coated, polyester-type plastic film (magnetic tape) is passed and wound. These spools and their attendant parts are held inside a protective plastic shell which is 4 by 2.5 by 0.5 inches (10 cm × 6.3 cm × 1.3 cm) at its largest dimensions. The tape itself was commonly referred to as "eighth-inch" tape, supposedly ​1⁄8 inches wide, but it was slightly larger: 0.15 inches (3.81 mm). Two stereo pairs of tracks (four total) or two monaural audio tracks are available on the tape; one stereo pair or one monophonic track is played or recorded when the tape is moving in one direction and the second (pair) when moving in the other direction. This reversal is achieved either by flipping the cassette, or by the reversal of tape movement ("auto-reverse") when the mechanism detects that the tape has come to an end.
  • 9.8K
  • 18 Oct 2022
Topic Review
Structure and Physiological Activities of Anthocyanins
Anthocyanidin is a kind of water-soluble natural pigment that widely exists in natural plants. Like other natural flavonoids, anthocyanin has a C6-C3-C6 carbon skeleton. Due to the different carbon substituents (-OH, -OCH3) on the B ring, different types of anthocyanins were derived. The six common anthocyanins were Pelargonidin (Pg), Cyanidin (Cy), Delphinidin (Dp), Peonidin (Pn), Petunidin (Pt), and Malvidin (Mv). In addition to giving food a variety of bright colors, anthocyanin also has important biological activities, such as antioxidant, anti-inflammatory, and anti-aging effects, among others. A large number of studies have shown that dietary anthocyanins have a good preventive effect on cardiovascular diseases.
  • 9.8K
  • 01 Aug 2022
Topic Review
Shopping Hours
Customs and regulations for shopping hours for sunday (times that shops are open) vary from countries to cities.
  • 9.8K
  • 01 Dec 2022
Topic Review
Bombardier Dash 8
The Bombardier Dash 8 or Q Series, previously known as the de Havilland Canada Dash 8 or DHC-8, is a series of twin-engined, medium-range, turboprop airliners. Introduced by de Havilland Canada (DHC) in 1984, they are now produced by Bombardier Aerospace. Over 1,000 Dash 8s of all models have been built. The Dash 8 was developed from the de Havilland Canada Dash 7, which featured extreme short take-off and landing (STOL) performance. With the Dash 8, DHC focused on improving cruise performance and lowering operational costs. The engine chosen was the Pratt & Whitney Canada PW100. The aircraft has been delivered in four series. The Series 100 has a maximum capacity of 39, the Series 200 has the same capacity but offers more powerful engines, the Series 300 is a stretched, 50-seat version, and the Series 400 is further stretched to 90 passengers. Models delivered after 1997 have cabin noise suppression and are designated with the prefix "Q". Production of the Series 100 ceased in 2005, followed by the 200 and 300 in 2009, leaving the Q400 as the only series still in production. Bombardier currently markets the aircraft as the Q Series, complementing the company's CRJ Series aircraft.
  • 9.7K
  • 21 Oct 2022
Topic Review
Geography and Cartography in Medieval Islam
Medieval Islamic geography and cartography refer to the study of geography and cartography in the Muslim world during the Islamic Golden Age (variously dated between the 8th century and 16th century). Muslim scholars made advances to the mapmaking traditions of earlier cultures, particularly the Hellenistic geographers Ptolemy and Marinus of Tyre,:193 combined with what explorers and merchants learned in their travels across the Old World (Afro-Eurasia). Islamic geography had three major fields: exploration and navigation, physical geography, and cartography and mathematical geography. Islamic geography reached its apex with Muhammad al-Idrisi in the 12th century.
  • 9.7K
  • 26 Oct 2022
Topic Review
Enzyme Based Biosensors
Enzyme-based biosensors were the earliest biosensors. In 1962, Clark proposed the idea of enzyme electrodes for a glucose sensor. Subsequently, enzyme-based biosensors have been experimenting a massive growth in several applications.
  • 9.7K
  • 29 Oct 2021
Biography
Nikolai Aleksandrovich Kozyrev
Nikolai Alexandrovich Kozyrev (Russian: Никола́й Алекса́ндрович Ко́зырев; 2 September 1908 – 27 February 1983) was a Soviet astronomer/astrophysicist. He was born in St. Petersburg, and by 1928 he had graduated from the Leningrad State University. In 1931 he began working at the Pulkovo Observatory, located to the south of Leningrad. He was considered to be one
  • 9.7K
  • 30 Dec 2022
Topic Review
Secular Humanism
Secular humanism, often simply called humanism, is a philosophy or life stance that embraces human reason, secular ethics, and philosophical naturalism while specifically rejecting religious dogma, supernaturalism, and superstition as the basis of morality and decision making. Secular humanism posits that human beings are capable of being ethical and moral without religion or belief in a deity. It does not, however, assume that humans are either inherently good or evil, nor does it present humans as being superior to nature. Rather, the humanist life stance emphasizes the unique responsibility facing humanity and the ethical consequences of human decisions. Fundamental to the concept of secular humanism is the strongly held viewpoint that ideology—be it religious or political—must be thoroughly examined by each individual and not simply accepted or rejected on faith. Along with this, an essential part of secular humanism is a continually adapting search for truth, primarily through science and philosophy. Many secular humanists derive their moral codes from a philosophy of utilitarianism, ethical naturalism, or evolutionary ethics, and some advocate a science of morality. Humanists International is the world union of more than one hundred humanist, rationalist, irreligious, atheist, Bright, secular, Ethical Culture, and freethought organizations in more than 40 countries. The "Happy Human" is recognized as the official symbol of humanism internationally, used by secular humanist organizations in every part of the world. Those who call themselves humanists are estimated to number between four and five million people worldwide.
  • 9.7K
  • 14 Oct 2022
Topic Review
AI Control Problem
In artificial intelligence (AI) and philosophy, the AI control problem is the issue of how to build AI systems such that they will aid their creators, and avoid inadvertently building systems that will harm their creators. One particular concern is that humanity will have to solve the control problem before a superintelligent AI system is created, as a poorly designed superintelligence might rationally decide to seize control over its environment and refuse to permit its creators to modify it after launch. In addition, some scholars argue that solutions to the control problem, alongside other advances in AI safety engineering, might also find applications in existing non-superintelligent AI. Major approaches to the control problem include alignment, which aims to align AI goal systems with human values, and capability control, which aims to reduce an AI system's capacity to harm humans or gain control. Capability control proposals are generally not considered reliable or sufficient to solve the control problem, but rather as potentially valuable supplements to alignment efforts.
  • 9.7K
  • 22 Nov 2022
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