Your browser does not fully support modern features. Please upgrade for a smoother experience.
Subject:
All Disciplines Arts & Humanities Biology & Life Sciences Business & Economics Chemistry & Materials Science Computer Science & Mathematics Engineering Environmental & Earth Sciences Medicine & Pharmacology Physical Sciences Public Health & Healthcare Social Sciences
Sort by:
Most Viewed Latest Alphabetical (A-Z) Alphabetical (Z-A)
Filter:
All Topic Review Biography Peer Reviewed Entry Video Entry
Topic Review
Resilience Optimization of Post-Quantum Cryptography Key Encapsulation Algorithms
The developments in quantum computing have shed light on the shortcomings of the conventional public cryptosystem. Even while Shor’s algorithm cannot yet be implemented on quantum computers, it indicates that asymmetric key encryption will not be practicable or secure in the near future. The National Institute of Standards and Technology (NIST) has started looking for a post-quantum encryption algorithm that is resistant to the development of future quantum computers as a response to this security concern. 
  • 2.9K
  • 21 Aug 2023
Topic Review
Alkali-Activated Materials
Alkali-activated materials (AAM) have been introduced as an eco-friendly alternative to conventional binders with fewer environmental impacts. AAM reduce the need for Ordinary Portland Cement (OPC) by substituting it with supplementary cementitious materials (SCM), and therefore, reducing the amount of subsequent carbon emissions. Alkali activation is a complex chemical process between the precursors (alumino-silicate materials) and their dissolution in the activators. The activator and the precursor are two essential components of AAMs. The first step towards the new generation binder is understanding the precursors, alkali activators, alkali activation solution, and alkali activation mechanism.
  • 2.9K
  • 12 May 2023
Topic Review
Multiphase Flows
Multiphase flows appear in many industrial and environmental applications (dredging, oil industry, mining industry, cement industry, among others), quite often as two-phase flows, either solid/liquid, liquid/liquid or gas/liquid flows. When we speak about multiphase flows we are referring both to flow in channels or pipes or in other process units. In our studies we have been more directed to multiphase flows in pipes. Being able to model and accurately predict the behaviour of such flows and to monitor, as well, the flows themselves, is of high importance to guarantee a stable flow and to optimize energy consumption, by designing adequately the conveying system, without the need to overdimensioning conveying equipment to avoid, for instance, pipe blockage.
  • 2.9K
  • 28 Jan 2021
Topic Review
AP-1 Transcription Factors in Myeloma
Multiple myeloma (MM) is an incurable hematologic malignancy characterized by the clonal expansion of malignant plasma cells within the bone marrow. Activator Protein-1 (AP-1) transcription factors (TFs), comprised of the JUN, FOS, ATF and MAF multigene families, are implicated in a plethora of physiologic processes and tumorigenesis including plasma cell differentiation and MM pathogenesis. Depending on the genetic background, the tumor stage, and cues of the tumor microenvironment, specific dimeric AP-1 complexes are formed. For example, AP-1 complexes containing Fra-1, Fra-2 and B-ATF play central roles in the transcriptional control of B cell development and plasma cell differentiation, while dysregulation of AP-1 family members c-Maf, c-Jun, and JunB is associated with MM cell proliferation, survival, drug resistance, bone marrow angiogenesis, and bone disease. The present review article summarizes our up-to-date knowledge on the role of AP-1 family members in plasma cell differentiation and MM pathophysiology. Moreover, it discusses novel, rationally derived approaches to therapeutically target AP-1 TFs, including protein-protein and protein-DNA binding inhibitors, epigenetic modifiers and natural products.
  • 2.9K
  • 25 May 2021
Topic Review
Fiber-Reinforced Geopolymer Composite
Fiber-reinforced geopolymer composite (FRGC) is emerging as one of the alternative materials for cement in the construction industry. FRGC is considered an eco-friendly material due to its role in the global reduction in emission of CO2 to the environment. Simultaneously, the composite provides good mechanical strength of flexural modulus, loss modulus, post-impact strength, and durability for a definite period at room and elevated temperatures. A positive aspect of the geopolymer matrix used for this composite is that could provide a finite period of durability at elevated temperatures without releasing toxic gases to the surroundings. Fibers enhanced the brittle behavior of the geopolymer matrix into ductile one with improved mechanical strength and residual impact strength.
  • 2.9K
  • 09 Jul 2021
Topic Review
Arctic Fox
The Arctic Fox (Vulpes lagopus) is a captivating species uniquely adapted to the harsh Arctic tundra and coastal habitats of the Northern Hemisphere. Renowned for its pristine white fur in winter and gray-brown coat in summer, the Arctic Fox is a master of camouflage in its icy environment. Endowed with specialized behaviors and physical adaptations, such as a thick fur coat, compact body size, and keen hunting skills, the Arctic Fox thrives in one of the most extreme and challenging environments on Earth.
  • 2.9K
  • 08 Mar 2024
Topic Review
Acrylate Polymers in Dentistry
Concerning the composition and method of polymerization initiation, polymers for the production of denture bases are divided into four types: heat-, cold-, light-, and microwave-polymerized. Computer-Aided Design and Manufacturing (CAD/CAM) acrylate dentures are made from factory blocks of dental acrylates and show optimal mechanical and physical properties, undoubtedly better monomer polymerization and thus biocompatibility, and stability of the shape and colour of the base and dentures. Regardless of the number of advantages that these polymers have to offer, they also exhibit certain disadvantages. Technological development enables the enhancement of all acrylate properties to respond better to the demands of the profession. Special attention should be paid to improving the biological characteristics of acrylate polymers, due to reported adverse reactions of patients and dental staff to potentially toxic substances released during their preparation and use. 
  • 2.9K
  • 03 Nov 2022
Topic Review
Climate Variability
Climate variability is the term to describe variations in the mean state and other characteristics of climate (such as chances or possibility of extreme weather, etc.) "on all spatial and temporal scales beyond that of individual weather events." Some of the variability does not appear to be caused systematically and occurs at random times. Such variability is called random variability or noise. On the other hand, periodic variability occurs relatively regularly and in distinct modes of variability or climate patterns. Over the years, the definitions of climate variability and the related term climate change have shifted. While the term climate change now implies change that is both long-term and of human causation, in the 1960s the word climate change was used for what we now describe as climate variability, that is, climatic inconsistencies and anomalies.
  • 2.9K
  • 11 Nov 2022
Biography
Roger Shepard
Roger Newland Shepard (born January 30, 1929) is an American cognitive scientist and author of the "universal law of generalization" (1987). He is considered a father of research on spatial relations. He studied mental rotation, and was an inventor of non-metric multidimensional scaling, a method for representing certain kinds of statistical data in a graphical form that can be apprehended by hu
  • 2.9K
  • 30 Nov 2022
Topic Review
Indoor Positioning Technologies for Mobile Robots
With the in-depth development of Industry 4.0 worldwide, mobile robots have become a research hotspot. Indoor localization has become a key component in many fields and the basis for all actions of mobile robots. Herein, 12 mainstream indoor positioning methods and related positioning technologies for mobile robots are introduced and compared in detail.
  • 2.9K
  • 31 Mar 2023
Topic Review
Federated Learning and Blockchain
The Internet of Things (IoT) compromises multiple devices connected via a network to perform numerous activities. The large amounts of raw user data handled by IoT operations have driven researchers and developers to provide guards against any malicious threats. Blockchain is a technology that can give connected nodes means of security, transparency, and distribution. IoT devices could guarantee data centralization and availability with shared ledger technology. Federated learning (FL) is a new type of decentralized machine learning (DML) where clients collaborate to train a model and share it privately with an aggregator node.
  • 2.9K
  • 30 Aug 2023
Topic Review
Advances in Finger Prosthetic Mechanisms
Approximately 70% of the upper extremity amputations refers to partial hand loss with the involvement of one or more fingers. Historically, this type of limb amputation has been addressed adopting simple opposition designs that use the movement of the residual digit for grasping against a fixed device. Nevertheless, in the last few years, technological advances, and the introduction of modern computer-aided tools for the synthesis and functional design of mechanisms have led to the development of smaller, more robust systems that are constantly improving body-powered and electrically-powered prototypes.
  • 2.9K
  • 26 Oct 2020
Topic Review
Q'uq'umatz
Q'uq'umatz (Mayan: [qʔuː qʔuːˈmats]) (alternatively Qucumatz, Gukumatz, Gucumatz, Gugumatz, Kucumatz etc.) was a deity of the Postclassic K'iche' Maya. Q'uq'umatz was the Feathered Serpent divinity of the Popol Vuh who created humanity together with the god Tepeu. Q'uq'umatz is considered to be the rough equivalent of the Aztec god Quetzalcoatl, and also of Kukulkan of the Yucatec Maya tradition. It is likely that the feathered serpent deity was borrowed from one of these two peoples and blended with other deities to provide the god Q'uq'umatz that the K'iche' worshipped. Q'uq'umatz may have had his origin in the Valley of Mexico; some scholars have equated the deity with the Aztec deity Ehecatl-Quetzalcoatl, who was also a creator god. Q'uq'umatz may originally have been the same god as Tohil, the K'iche' sun god who also had attributes of the feathered serpent, but they later diverged and each deity came to have a separate priesthood. Q'uq'umatz was one of the gods who created the world in the Popul Vuh, the K'iche' creation epic. Q'uq'umatz, god of wind and rain, was closely associated with Tepeu, god of lightning and fire. Both of these deities were considered to be the mythical ancestors of the K'iche' nobility by direct male line. Q'uq'umatz carried the sun across the sky and down into the underworld and acted as a mediator between the various powers in the Maya cosmos. The deity was particularly associated with water, clouds, the wind and the sky. Kotuja', the K'iche' king who founded the city of Q'umarkaj, bore the name of the deity as a title and was likely to have been a former priest of the god. The priests of Q'uq'umatz at Q'umarkaj, the K'iche' capital, were drawn from the dominant Kaweq dynasty and acted as stewards in the city.
  • 2.9K
  • 21 Nov 2022
Topic Review
FTIR for Vehicle Exhaust Emissions
In a Fourier Transform InfraRed (FTIR) spectrometer, some of the infrared (IR) radiation is absorbed by the sample, and some of it is passed through (transmitted). The resulting molecular absorption and transmission response can be used to identify the components of the sample and their concentration.
  • 2.9K
  • 20 Aug 2021
Topic Review
Lactic Acid Bacteria
The antibacterial effect of lactic acid bacteria is attributed to its ability to produce antimicrobial compounds, including bacteriocins, with strong competitive action against many microorganisms. The use of bacteriocins, both separately and in combination with edible coatings, is considered a very promising approach for microbiological quality, and safety for postharvest storage of raw and minimally processed fruits and vegetables.
  • 2.9K
  • 26 Oct 2020
Topic Review
Plasticity
In physics and materials science, plasticity, also known as plastic deformation, is the ability of a solid material to undergo permanent deformation, a non-reversible change of shape in response to applied forces. For example, a solid piece of metal being bent or pounded into a new shape displays plasticity as permanent changes occur within the material itself. In engineering, the transition from elastic behavior to plastic behavior is known as yielding. Plastic deformation is observed in most materials, particularly metals, soils, rocks, concrete, and foams. However, the physical mechanisms that cause plastic deformation can vary widely. At a crystalline scale, plasticity in metals is usually a consequence of dislocations. Such defects are relatively rare in most crystalline materials, but are numerous in some and part of their crystal structure; in such cases, plastic crystallinity can result. In brittle materials such as rock, concrete and bone, plasticity is caused predominantly by slip at microcracks. In cellular materials such as liquid foams or biological tissues, plasticity is mainly a consequence of bubble or cell rearrangements, notably T1 processes. For many ductile metals, tensile loading applied to a sample will cause it to behave in an elastic manner. Each increment of load is accompanied by a proportional increment in extension. When the load is removed, the piece returns to its original size. However, once the load exceeds a threshold – the yield strength – the extension increases more rapidly than in the elastic region; now when the load is removed, some degree of extension will remain. Elastic deformation, however, is an approximation and its quality depends on the time frame considered and loading speed. If, as indicated in the graph opposite, the deformation includes elastic deformation, it is also often referred to as "elasto-plastic deformation" or "elastic-plastic deformation". Perfect plasticity is a property of materials to undergo irreversible deformation without any increase in stresses or loads. Plastic materials that have been hardened by prior deformation, such as cold forming, may need increasingly higher stresses to deform further. Generally, plastic deformation is also dependent on the deformation speed, i.e. higher stresses usually have to be applied to increase the rate of deformation. Such materials are said to deform visco-plastically.
  • 2.9K
  • 10 Nov 2022
Topic Review
Production Disruption
Two kinds of incentive strategies, cost-sharing and penalty, are examined in dealing with production disruption, with consideration of production process reliability as an endogenous factor for a two-echelon supply chain.
  • 2.9K
  • 21 Feb 2023
Topic Review
Picture Bride
The term picture bride refers to the practice in the early 20th century of immigrant workers (chiefly Japan ese, Okinawan, and Korean) in Hawaii and the West Coast of the United States and Canada selecting brides from their native countries via a matchmaker, who paired bride and groom using only photographs and family recommendations of the possible candidates. This is an abbreviated form of the traditional matchmaking process and is similar in a number of ways to the concept of the mail-order bride.
  • 2.9K
  • 01 Dec 2022
Topic Review
Trypanosomatid Pathogens
Unicellular eukaryotes of the Trypanosomatidae family include human and animal pathogens that belong to the Trypanosoma and Leishmania genera. Diagnosis of the diseases they caused requires the sampling of body fluids (blood, lymph, peritoneal fluid, cerebrospinal fluid, etc.) or organ biopsies (bone marrow, spleen, etc.), which are mostly obtained through invasive methods. Body fluids or appendages can be alternatives to these invasive biopsies but their appropriateness remains poorly studied. To further address this question, we perform a systematic review on clues evidencing the presence of parasites, genetic material, antibodies, and antigens in body secretions, appendages, or the organs or proximal tissues that produce these materials.
  • 2.9K
  • 29 Oct 2020
Topic Review
Poly(methyl methacrylate) (PMMA)
Poly (methyl methacrylate) (PMMA) is a thermoplastic synthetic polymer, which displays superior characteristics such as transparency, good tensile strength, and processability. 
  • 2.9K
  • 29 Jun 2021
  • Page
  • of
  • 2795
Featured Entry Collections
>>

Featured Reprints

>>
Encyclopedia of Digital Society, Industry 5.0 and Smart City
Encyclopedia of Engineering
Encyclopedia of Social Sciences
Encyclopedia of Medieval Royal Iconography
Academic Video Service
Feedback

Quick Survey

Encyclopedia MDPI is conducting a targeted survey to identify the specific barriers hindering efficient research. We invite you to spend 3 minutes defining the priorities for our next generation of structured knowledge tools.
Take Survey