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Topic Review
Head-Up Display (Video Gaming)
In video gaming, the HUD (heads-up display) or status bar is the method by which information is visually relayed to the player as part of a game's user interface. It takes its name from the head-up displays used in modern aircraft. The HUD is frequently used to simultaneously display several pieces of information including the main character's health, items, and an indication of game progression (such as score or level).
  • 8.2K
  • 31 Oct 2022
Topic Review
Fleischmann–Pons Experiment
The Fleischmann–Pons experiment was an investigation conducted in the 1980s by Martin Fleischmann of the University of Southampton and Stanley Pons of the University of Utah into whether electrolysis of heavy water on the surface of a palladium (Pd) electrode produces physical effects that defy chemical explanation. Of particular interest was evidence of "excess" (i.e. non-chemical) heat extracted from the deuterium fraction of common surface water which, if true, could have delivered the largest economic shock to the global energy industry since the Pennsylvania oil rush. On March 23, 1989, Fleischmann (then one of the world's leading electrochemists) and Pons reported their work via a press release from the University of Utah (who asserted ownership of the technology) claiming that the table-top apparatus had produced anomalous heat (understood as "excess" heat) of a magnitude they asserted would defy explanation except in terms of nuclear processes, which later came to be referred to as "cold fusion". In addition to the results from calorimetry, they further reported measuring small amounts of nuclear reaction byproducts, including neutrons and tritium. The reported results received wide media attention, and raised hopes of a cheap and abundant source of energy. Many scientists tried to replicate the experiment with the few details available. Hopes faded due to the large number of negative replications, the withdrawal of many reported positive replications, the discovery of flaws and sources of experimental error in the original experiment, and finally the discovery that Fleischmann and Pons had not actually detected nuclear reaction byproducts. By late 1989, most scientists considered cold fusion claims dead.
  • 8.2K
  • 26 Oct 2022
Topic Review
Laser Absorption Spectroscopy
Laser absorption spectroscopy (LAS) is an absorption spectroscopic method that employs a laser as the light source and measures the chemical concentration based on detection of a variation of laser beam intensity after transmission along the optical path. 
  • 8.2K
  • 10 Sep 2020
Topic Review
eCommerce and Small and Medium Enterprises
The rise of smaller businesses has been an essential trend since the 1990s, when they became engines for economic development. Now, Small and Medium Enterprises (SMEs) across the world are increasingly relying on eCommerce channels to create and capture value. The growth in eCommerce operations is being fueled by several global and technological developments. eCommerce allows SMEs to benefit from globalization by expanding their ability to access customers around the world and across customer demographics and categories. This emergence of a new range of markets has made strategic flexibility essential for SMEs, as such expansion requires a consistent rethinking and adapting to continually changing dynamics in a global environment.
  • 8.2K
  • 07 May 2022
Topic Review
Seaport
Seaports are well known as the medium that has evolved into the central link between sea and land for complex marine activities. The growth in maritime logistics particularly necessitates a large volume of energy supply in order to maintain the operation of sea trade, resulting in an imbalance between generation and demand sides. Future projections for three major concerns show an increase in load demand, cost of operation, and environmental issues. The involvement of a variety of heavy loads such as all-electric ships, cranes, cold ironing, and buildings infrastructure renders it a complicated arrangement task in several aspects, which necessitates further research and leaves space for improvement.
  • 8.2K
  • 06 Dec 2021
Topic Review
Principles of SERS
SERS (Surface-enhanced Raman spectroscopy) is based on the amplification of the Raman response of an analyte interacting with the surface plasmon of metals such as Au, Ag, or Cu; in some cases, the response results enough to achieve the single–molecule detection
  • 8.2K
  • 21 Apr 2021
Topic Review
Free Society
The term free society is used frequently by American libertarian theorists to denote a society in which their ideal political, legal and economic aims are in effect. In a theoretical free society, all individuals act voluntarily, having the freedom to obtain the power and resources to fulfill their own potential. Adlai Stevenson defined free societies as a society in which individuals find it "safe to be unpopular". Others, such as Chandran Kukathas, described a free society as dependent upon the "principle of freedom of association". Cindy Cohn has argued that the freedom to have a "private conversation" is "central to a free society". These interpretations can also be elaborated in terms of freedom of speech – if people have a right to express their views without fear of arrest, imprisonment, or physical harm. In a free society, individuals would organize in voluntary associations, including free market and communal societies. Individuals would gain more prosperity due to the lack of restrictions on trade and wealth creation.
  • 8.2K
  • 11 Oct 2022
Topic Review
Fundamental Properties of Hempcrete
A bio-fiber composite made up of hemp hurd or shiv and mineral binder, hempcrete is a form of lime-based construction material. The binder that is made by combining water with these ingredients is expected to completely coat all of the hemp shiv particles after sufficient mixing. A chemical reaction between the lime binder and water hardens the binder, cementing the hurd pieces together. The term “bonded cellulose insulation” could be broadly used to describe this mixture. Hempcrete is what is left after the binder has dried and been allowed to build up strength with time. 
  • 8.2K
  • 21 Feb 2024
Topic Review
Laïcité
Laïcité ([la.i.si.te]), literally "secularity", is a French concept of secularism. It discourages religious involvement in government affairs, especially religious influence in the determination of state policies; it also forbids government involvement in religious affairs, and especially prohibits government influence in the determination of religion. Laïcité does not preclude a right to the free exercise of religion. Dictionaries ordinarily translate laïcité as "secularity" or "secularism" (the latter being the political system), although it is sometimes rendered in English as laicity or laicism by its opponents. While the term was first used with this meaning in 1871 in the dispute over the removal of religious teachers and instruction from elementary schools, the word laïcisme dates to 1842. In its strict and official acceptance, it is the principle of separation of church (or religion) and state. Etymologically, laïcité is a noun formed by adding the suffix -ité (English -ity, Latin -itās) to the Latin adjective lāicus, a loanword from the Greek λᾱϊκός (lāïkós "of the people", "layman"), the adjective from λᾱός (lāós "people"). French secularism has a long history. For the last century, the French government policy has been based on the 1905 French law on the Separation of the Churches and the State.
  • 8.2K
  • 04 Nov 2022
Topic Review
Polyelectrolyte
Polyelectrolytes are polymers of oppositely charged ions and their properties differ profoundly than their repeating units. Over recent years, much advancement has been made in the synthesis, characterization, and application of polyelectrolytes and polyelectrolyte complexes (PECs). It has many applications as flocculation agents, dispersant agents, and as super-plasticizers. In this article, the synthesis, types, characteristics, and application of PECs mainly for drug delivery and dynamics study are reviewed.
  • 8.2K
  • 27 Oct 2020
Topic Review
Problems Associated with Plant Micropropagation
The production of micropropagated plants in plant-tissue-culture laboratories and nurseries is the most important method for propagation of many economic plants. Micropropagation based on tissue-culture technology involves large-scale propagation, as it allows multiplication of a huge number of true-to-type propagules in a very short time and in a very limited space, as well as all year round, regardless of the climate.
  • 8.2K
  • 04 Aug 2022
Topic Review
Pollen Germination in Gymnosperms
Gymnosperms are amazing representatives of the flora. On the one hand, they are ancient plants with primitive characteristics of anatomical structure; on the other hand, they are perfectly adapted to their habitat and are the dominant species in many ecosystems due to their impressive size and longevity, with their reproductive system being of particular interest. It has progressive features, because in this group the reduced male gametophyte—pollen grain—first appeared, as well as the ability to form seeds. In addition, this group still represents a wide variety of reproductive patterns, strategies, and relationships. For example, the degree of gametophyte reduction varies, there are both zooidogamy and siphonogamy, and the reproductive process can both be relatively fast and last over several years.
  • 8.2K
  • 20 Jul 2021
Topic Review
Wine Tourism
Nowadays, wine has become an important beverage that is increasingly being consumed more frequently all over the world, and its production and marketing has received increasing attention from consumers, specialists, and producers. As a result, the growing importance of wine tourism for many destinations and the role of this type of tourism in supporting local economies is now beginning to be understood. It has also been highlighted that wine tourism can play a significant role in the development of tourism by contributing to the economic and social support of local regions and communities. Wine is one of the ingredients of people's journeys, and journeys dedicated to wine-producing areas have led to the tourism product known as wine tourism.
  • 8.2K
  • 18 Apr 2022
Topic Review
Peroxisomal β-Oxidation
It is not paradoxical that what has been overlooked tends to be of great importance. Peroxisomes, the widely distributed organelles in the body, play irreplaceable roles in cellular metabolism, especially in fatty acid oxidation (FAO) and the generation and elimination of reactive oxygen species (ROS).
  • 8.1K
  • 15 Jul 2022
Topic Review
Urban Open Space
In land-use planning, urban open space is open-space areas reserved for parks, "green spaces", and other open areas. The landscape of urban open spaces can range from playing fields to highly maintained environments to relatively natural landscapes. Generally considered open to the public, urban open spaces are sometimes privately owned, such as higher education campuses, neighborhood/community parks/gardens, and institutional or corporate grounds. Areas outside city boundaries, such as state and national parks as well as open space in the countryside, are not considered urban open space. Streets, piazzas, plazas and urban squares are not always defined as urban open space in land use planning.
  • 8.1K
  • 14 Oct 2022
Topic Review
Bloch Wave
A Bloch wave (also called Bloch state or Bloch function or Bloch wavefunction), named after Swiss physicist Felix Bloch, is a kind of wave function which can be written as a plane wave modulated by a periodic function. By definition, if a wave is a Bloch wave, its wavefunction can be written in the form: where [math]\displaystyle{ \mathbf{r} }[/math] is position, [math]\displaystyle{ \psi }[/math] is the Bloch wave, [math]\displaystyle{ u }[/math] is a periodic function with the same periodicity as the crystal, the wave vector [math]\displaystyle{ \mathbf{k} }[/math] is the crystal momentum vector, [math]\displaystyle{ \mathrm{e} }[/math] is Euler's number, and [math]\displaystyle{ \mathrm{i} }[/math] is the imaginary unit. Bloch waves are important in solid-state physics, where they are often used to describe an electron in a crystal. This application is motivated by Bloch's theorem, which states that the energy eigenstates for an electron in a crystal can be written as Bloch waves (more precisely, it states that the electron wave functions in a crystal have a basis consisting entirely of Bloch wave energy eigenstates). This fact underlies the concept of electronic band structures. These Bloch wave energy eigenstates are written with subscripts as [math]\displaystyle{ \psi_{n\mathbf{k}} }[/math], where [math]\displaystyle{ n }[/math] is a discrete index, called the band index, which is present because there are many different Bloch waves with the same [math]\displaystyle{ \mathbf{k} }[/math] (each has a different periodic component [math]\displaystyle{ u }[/math]). Within a band (i.e., for fixed [math]\displaystyle{ n }[/math]), [math]\displaystyle{ \psi_{n\mathbf{k}} }[/math] varies continuously with [math]\displaystyle{ \mathbf{k} }[/math], as does its energy. Also, for any reciprocal lattice vector [math]\displaystyle{ \mathbf{K} }[/math], [math]\displaystyle{ \psi_{n\mathbf{k}}=\psi_{n(\mathbf{k+K})} }[/math]. Therefore, all distinct Bloch waves occur for values of [math]\displaystyle{ \mathbf{k} }[/math] which fall within the first Brillouin zone of the reciprocal lattice.
  • 8.1K
  • 30 Nov 2022
Topic Review
Various Attachments for Implant Overdentures
This study presents an overview of the biomechanical and biomolecular aspects of various attachments for implant overdenture. We focused on the following topics: attachment systems, retention of various attachments, stress distribution with different attachments, the design and fabrication of attachments, digital techniques in overdenture attachments, and the effects of attachments in peri-implant health. We found that plastic resin is commonly used for ball and bar attachments, whereas nylon resin is commonly used in locator attachments. The locator system offers a valuable attachment option for implant-retained overdenture. Attachment retention reduces while lateral force increases with implant inclination in overdenture. The higher the retention of an overdenture attachment, the higher the transferred stresses. Additionally, clip loading produces more stress in implants and precision elements than bar-retained dentures. As such, we conclude that the ball and locator systems the best overdenture systems due to their superior tissue response, survival rate, and patient satisfaction.
  • 8.1K
  • 03 Nov 2021
Topic Review
Biochemistry of Hydrogen Peroxide
Hydrogen Peroxide (H2O2) is the nonionized 2-electron reduction product of unstable molecular oxygen (O2), which plays a central role in maintaining the redox cycle of living cells.
  • 8.1K
  • 10 Jan 2022
Topic Review
Transparency for Architecture
Rowe and Slutzky proposed two types of transparency in architecture in the essay, “Transparency: Literal and Phenomenal”. They divided transparency into literal, meaning the material conditions of glass, and phenomenal, as derived from Cubist paintings. “literal transparency” describes the material quality of being see-through, and phenomenal transparency describes the perceptual attributes that allow the mind to discern the underlying governing concepts or spatial concepts. Through their idea of “phenomenal transparency”, they primarily investigated the relationship of visual perceptions using the human eye with superimposed two-dimensional visions of architectural space and the world.
  • 8.1K
  • 27 Aug 2021
Topic Review
Mercedes-Benz W108
The Mercedes-Benz W108 and W109 are luxury cars produced by Mercedes-Benz from 1965 through to 1972 and 1973 in North America only. The line was an update of the predecessor W111 and W112 fintail sedans. The cars were successful in West Germany and in export markets including North America and Southeast Asia. During the seven-year run, a total of 383,361 units were manufactured.
  • 8.1K
  • 19 Oct 2022
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