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Topic Review
The Diachronic Heritage Management and Development of At-Turaif
The At-Turaif District in ad-Dir’iyah (often known and referred to as ‘Historic Diriyah’) has always been the heart and symbol of Saudi Arabian cultural heritage due to its historic values and significance that date back to earlier Saudi states. Historic Diriyah is a World Heritage Site (WHS), and it can still project a successful massive makeover development if a sustainable development approach is used, and visual integrity and site authenticity are preserved. The site of Historic Diriyah and its surroundings were critical in promoting the site as a national identity, an international destination, and presenting a new development agenda for the entire kingdom of Saudi Arabia. It has a significant impact on policymakers who are interested in how heritage sites can be integrated into a larger vision.
  • 6.6K
  • 13 Sep 2022
Topic Review
History of Pregnancy Test
The home pregnancy test is the most frequently performed laboratory test for self-diagnosis (home diagnostic test). It is also the first laboratory test that has been adapted for self-use at home.
  • 6.6K
  • 11 Sep 2023
Topic Review
Biodiesel Production from Animal Fats Versus Vegetable Oils
Biodiesel, a mixture of fatty acids alkyl esters shows properties, which make it a feasible substitute for fossil diesel. Biodiesel can be produced using different processes and different raw materials. The most common, first generation, biodiesel is produced by methanolysis of vegetable oils using basic or acid homogeneous catalysts. The use of vegetable oils for biodiesel production raises serious questions about biodiesel sustainability. Used cooking oils and animal fats can replace the vegetable oils in biodiesel production thus allowing to produce a more sustainable biofuel. 
  • 6.6K
  • 19 Jan 2024
Topic Review
Tomato Fruit and its Colors
Fruit colour represents a genetic trait with ecological and nutritional value. Plants mainly use colour to attract animals and favour seed dispersion. Thus, in many species, fruit colour coevolved with frugivories and their preferences. Environmental factors, however, represented other adaptive forces and further diversification was driven by domestication. All these factors cooperated in the evolution of tomato fruit, one of the most important in human nutrition. Tomato phylogenetic history showed two main steps in colour evolution: the change from green-chlorophyll to red-carotenoid pericarp, and the loss of the anthocyanic pigmentation. These events likely occurred with the onset of domestication. Then spontaneous mutations repeatedly occurred in carotenoid and phenylpropanoid pathways, leading to colour variants which often were propagated. Introgression breeding further enriched the panel of pigmentation patterns.
  • 6.6K
  • 30 Sep 2021
Topic Review
Serendipity
Serendipity is defined as an ability to notice, evaluate, and take advantage of unexpected information for survival purposes (both natural and social). The concept has been discussed for centuries. Still, it has only caught the attention of academia quite recently due to its strategic advantage in all aspects of life, such as daily life activities, science and technology, business and entrepreneurship, politics and economics, education administration, career choice and development, etc.
  • 6.6K
  • 01 Sep 2022
Topic Review
Yao's Millionaires' Problem
Yao's Millionaires' problem is a secure multi-party computation problem which was introduced in 1982 by computer scientist and computational theorist Andrew Yao. The problem discusses two millionaires, Alice and Bob, who are interested in knowing which of them is richer without revealing their actual wealth. This problem is analogous to a more general problem where there are two numbers [math]\displaystyle{ a }[/math] and [math]\displaystyle{ b }[/math] and the goal is to determine whether the inequality [math]\displaystyle{ a \geq b }[/math] is true or false without revealing the actual values of [math]\displaystyle{ a }[/math] and [math]\displaystyle{ b }[/math]. The Millionaires' Problem is an important problem in cryptography, the solution of which is used in e-commerce and data mining. Commercial applications sometimes have to compare numbers which are confidential and whose security is important. Many solutions have been introduced for the problem, among which the first solution, presented by Yao himself, was exponential in time and space.
  • 6.6K
  • 15 Nov 2022
Topic Review
Soil Erosion Hazards
Soil erosion is a severe threat to food production systems globally. Food production in farming systems decreases with increasing soil erosion hazards. Hazard is a situation or potential condition to harm or threat to life, health or damage to property or environment, social and economic disruption. The mass movement of soil is an indicator of a soil erosion hazard. This includes gully erosion, riverbank erosion, rock-falls, debris-falls and landslides that can create damage to the environment and livelihoods.
  • 6.6K
  • 22 Dec 2020
Topic Review
Wave Energy Converter
The overview of the types of wave energy converters (WECs) are classified through operational principle, absorbing wave direction, location, and power take-off.
  • 6.6K
  • 20 Oct 2020
Topic Review
Inedia
Inedia (Latin for "fasting") or breatharianism /brɛθˈɛəriənɪzəm/ is the belief that it is possible for a person to live without consuming food. Breatharians claim that food, and in some cases water, are not necessary for survival, and that humans can be sustained solely by prana, the vital life force in Hinduism. According to Ayurveda, sunlight is one of the main sources of prana, and some practitioners believe that it is possible for a person to survive on sunlight alone. The terms breatharianism or inedia may also refer to this philosophy when it is practiced as a lifestyle in place of the usual diet. Breatharianism is considered a deadly pseudoscience by scientists and medical professionals, and several adherents of these practices have died from starvation and dehydration. Though it is common knowledge that biological entities require sustenance to survive, breatharianism continues.
  • 6.5K
  • 25 Oct 2022
Topic Review
Nanolubricants
Nanolubricants are the name given to the dispersion of nanoparticles in a base oil, and has attracted researchers due to its potential application. In addition to being used in the tribology field, nanoparticles are also used for medical, space, and composites purposes. The addition of nanoparticles in base oils is promising because it enhances specific tribological characteristics including wear-resistance and friction, and the most important reason is that the majority of them are environmentally friendly. 
  • 6.5K
  • 17 Nov 2020
Topic Review
Cardiff
Cardiff (/ˈkɑːrdɪf/ (listen); Welsh: Caerdydd [kairˈdiːð, kɑːɨrˈdɨːð] (listen)) is the capital of Wales, and its largest city. The eleventh-largest city in the United Kingdom , it is Wales's chief commercial centre, the base for most national cultural institutions and Welsh media, and the seat of the National Assembly for Wales. The unitary authority area's 2017 population was estimated to be 362,756. Cardiff is a significant tourist centre and the most popular visitor destination in Wales with 21.3 million visitors in 2017. In 2011, Cardiff was ranked sixth in the world in National Geographic's alternative tourist destinations. Cardiff is the county town of the historic county of Glamorgan (and later South Glamorgan). Cardiff is part of the Eurocities network of the largest European cities. A small town until the early 19th century, its prominence as a major port for the transport of coal following the arrival of industry in the region contributed to its rise as a major city. The Cardiff Built-up Area covers a slightly larger area outside the county boundary and includes the towns of Dinas Powys and Penarth. In 1905, Cardiff was made a city and proclaimed the capital of Wales in 1955. Since the 1980s, Cardiff has seen significant development. A new waterfront area at Cardiff Bay contains the Senedd building, home to the Welsh Assembly and the Wales Millennium Centre arts complex. Current developments include the continuation of the redevelopment of the Cardiff Bay and city centre areas with projects such as the Cardiff International Sports Village, a BBC drama village, and a new business district in the city centre. Sporting venues in the city include the Principality Stadium—the national stadium and the home of the Wales national rugby union team—Sophia Gardens (the home of Glamorgan County Cricket Club), Cardiff City Stadium (the home of Cardiff City football team and the Wales football team), Cardiff International Sports Stadium (the home of Cardiff Amateur Athletic Club), Cardiff Arms Park (the home of Cardiff Blues and Cardiff RFC rugby union teams) and Ice Arena Wales (the home of Cardiff Devils ice hockey team). The city hosted the 1958 British Empire and Commonwealth Games. The city was awarded the title of European City of Sport twice, due to its role in hosting major international sporting events: first in 2009 and again in 2014. The Principality Stadium hosted 11 football matches as part of the 2012 Summer Olympics, including the games' opening event and the men's bronze medal match.
  • 6.5K
  • 18 Oct 2022
Topic Review
Early Flood Warning System
The early-warning model for flash floods is based on a hydrological and geomorphological concept connected to the river basin, with the principle that flash floods will only occur where there is a high potential risk and when rainfall exceeds the threshold. In the model used to build flash-floods risk maps, the parameters of the basin are analyzed and evaluated and the weight is determined using Thomas Saaty’s analytic hierarchy process (AHP). The flash-floods early-warning software is built using open source programming tools. With the spatial module and online processing, a predicted precipitation of one to six days in advance for iMETOS (AgriMedia—Vietnam) automatic meteorological stations is interpolated and then processed with the potential risk maps (iMETOS is a weather-environment monitoring system comprising a wide range of equipment and an online platform and can be used in various fields such as agriculture, tourism and services). The results determine the locations of flash floods at several risk levels corresponding to the predicted rainfall values at the meteorological stations. The system was constructed and applied to flash floods disaster early warning for Thuan Chau in Son La province when the rainfall exceeded the 150 mm/d threshold. The system initially supported positive decision-making to prevent and minimize damage caused by flash floods.
  • 6.5K
  • 27 Jan 2022
Topic Review
Structure of Oxide Perovskite
Materials crystalizing in the perovskite crystal structure are common crystals that are currently employed for multiples applications, including transistors, solar cells, light-emitting devices, memories, catalysts, and superconductors.One of the biggest players within the perovskite structures is the family of oxide perovskites. This is a prominent family with the general formula of ABO3, where A commonly designates an alkaline or rare earth metal cation, occupying the 12-fold coordinated cuboctahedral cages of the oxygen sub-lattice, and B stands for a transition-metal cation (e.g., Fe, Ni, Mn, Co, Cu, or Ti) coordinated with six oxygen atoms in an octahedral coordination. In fact, in the perovskite structure, distortions frequently occur due to the deviation from ideal values of ionic size ratios between the different A, B, and O sites of the crystal. In addition, A or B cations may have distinctive sizes and valences that could result into oxygen non-stoichiometry, involving both oxygen excess and/or oxygen deficiency.
  • 6.5K
  • 24 Sep 2021
Topic Review
CamPro Engine
The CamPro engine is the first automotive engine developed together with Lotus by the Malaysian automobile manufacturer, Proton. The name CamPro is short for Cam Profiling. This engine powers the Proton Gen-2, Proton Satria Neo, Proton Waja Campro, Proton Persona, Proton Saga, Proton Exora, Proton Preve, Proton Suprima S and Proton Iriz. The CamPro engine was created to show Proton's ability to make its own engines that produce good power output and meet newer emission standards. The engine prototype was first unveiled on 6 October 2000 at the Lotus factory in UK before it debuted in the 2004 Proton Gen•2. All CamPro engines incorporate drive-by-wire technology (specifically electronic throttle control) for better response, eliminating the need for friction-generating mechanical linkages and cables.
  • 6.5K
  • 28 Oct 2022
Topic Review
Current Applications of Membrane Bioreactors
A membrane bioreactor (MBR) can be described as a chamber designed for a biochemical transformation combined with a membrane separation process. The membrane can be used for different purposes inside the bioreactor, such as the addition of a reactant or the selective removal of one of the reaction products. Moreover, membranes can be utilized to retain the biocatalyst or act as the support for the biocatalyst or for the separation of enzymes by size exclusion.
  • 6.5K
  • 21 Oct 2020
Topic Review
Early Chinese Cartography
Early Chinese cartography began in the 5th century BC during the Warring States period when cartographers started to make maps of the Earth's surface. Its scope extended beyond China's borders with the expansion of the Chinese Empire under the Han dynasty. It entered its golden age with the invention of the compass in the 11th century during the Song dynasty, and reached its peak in the 15th century when the Ming dynasty admiral Zheng He went on a series of voyages to the South China Sea, Indian Ocean, and beyond.
  • 6.5K
  • 10 Oct 2022
Topic Review
Pan-Tompkins Algorithm
The Pan-Tompkins algorithm is commonly used to detect QRS complexes in electrocardiographic signals (ECG). The QRS complex represents the ventricular depolarization and the main spike visible in an ECG signal (see figure). This feature makes it particularly suitable for measuring heart rate, the first way to assess the heart health state. In the first derivation of Einthoven of a physiological heart, the QRS complex is composed by a downward deflection (Q wave), an high upward deflection (R wave) and a final downward deflection (S wave). The Pan-Tompkins algorithm applies a series of filters to highlight the frequency content of this rapid heart depolarization and removes the background noise. Then, it squares the signal to amplify the QRS contribute. Finally, it applies adaptive thresholds to detect the peaks of the filtered signal. The algorithm was proposed by Jiapu Pan and Willis J. Tompkins in 1985, in the journal IEEE Transactions on Biomedical Engineering . The performance of the method was tested on an annotated arrhythmia database (MIT/BIH) and evaluated also in presence of noise. Pan and Tompkins reported that the 99.3 percent of QRS complexes was correctly detected.
  • 6.5K
  • 24 Oct 2022
Topic Review
Worldview
A worldview refers to an individual's comprehensive framework of beliefs, values, assumptions, and perceptions that shape their understanding of reality, identity, and purpose in life. It encompasses one's philosophical, religious, cultural, and ideological perspectives, influencing their interpretation of the world, moral judgments, and decision-making processes.
  • 6.5K
  • 02 Feb 2024
Topic Review
Composite Structures
Common types of engineering materials include metals, polymers, ceramics, and composites. Among these, composite materials are often a better alternative for traditional materials, such as metals, ceramics, and polymers due to their light weight, corrosion resistance, high strength and stiffness, ability to withstand high temperatures, and simple manufacturing process. Composite structures are used in a range of different industries from aerospace, marine, aviation, transport, and sports/leisure to civil engineering. For example, advanced composite materials have been used in different structures regarding the above industries, such as rotor blades, aircraft main body, and wing skins.
  • 6.5K
  • 28 Mar 2022
Topic Review
Energy Resources in Algeria
Algeria is a wealthy country with natural resources, namely, nuclear, renewable, and non-renewable sources. The non-renewable energy sources are considered the lion’s share for energy production (98%). Algeria’s efforts to ensure and strengthen its energy security will take an important step in the coming decades by commissioning new energy infrastructure based on intensive use of water, coal, nuclear, non-renewable, and renewable sources.
  • 6.5K
  • 06 Jul 2022
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