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Topic Review
Gabor Filters
The use of Gabor filters in image processing has been well-established, and these filters are recognized for their exceptional feature extraction capabilities. These filters are usually applied through convolution.
  • 1.8K
  • 19 Dec 2023
Topic Review
Biodegradable Iron and Porous Iron
Biodegradable metals have been extensively studied due to their potential use as temporary biomedical devices, on non-load bearing applications. These types of implants are requested to function for the healing period, and should degrade after the tissue heals. A balance between mechanical properties requested at the initial stage of implantation and the degradation rate is required. The use of temporary biodegradable implants avoids a second surgery for the removal of the device, which brings high benefits to the patients and avoids high societal costs. Among the biodegradable metals, iron as a biodegradable metal has increased attention over the last few years, especially with the incorporation of additive manufacturing processes to obtain tailored geometries of porous structures, which give rise to higher corrosion rates. Withal by mimic natural bone hierarchical porosity, the mechanical properties of obtained structures tend to equalize that of human bone.
  • 1.8K
  • 24 Jun 2022
Topic Review
Postcrossing
Postcrossing is an online project that allows its members to send and receive postcards from all over the world. The project's tag line is "send a postcard and receive a postcard back from a random person somewhere in the world!” Its members, also known as postcrossers, send postcards to other members and receive postcards back from other random postcrossers. Where the postcards come from is always a surprise. Postcrossing is the union of the words "postcard" and "crossing" and its origin "is loosely based on the Bookcrossing site". However, the "crossing" or exchange of postcards works in a different way. A member sends a postcard to another postcrosser and receives a postcard back from a random postcrosser. Exchanges between the same two members only occur once; although direct swaps between members happen, they are not part of the official happenings on the site. The project is completely free and anyone with an address can create an account. The postcards and postage fees to mail them are the responsibility of each user. By February 2018 Postcrossing had more than 719,000 members in 212 countries who had registered and exchanged over 45 million postcards that traveled over 229 billion kilometers. The highest concentration of Postcrossing members reside (in order) in Russia, Taiwan, China, the United States, Germany, the Netherlands, Poland, Belarus, Ukraine, Finland and the Czech Republic, each with over 20,000 members. Globally, most postcrossers reside in North America, Europe and East Asia. Of particular note, Postcrossing is popular in eastern European and former-Soviet states. As of January 2012, more than a quarter of the combined total of postcards were sent from Finland, Russia, Estonia, Latvia, Lithuania, Belarus and Ukraine.
  • 1.8K
  • 04 Nov 2022
Topic Review
GPS Block IIIA
GPS Block IIIA consists of the first ten (known as "tranche") of GPS III satellites, which will be used to keep the Navstar Global Positioning System operational. Lockheed Martin designed, developed and manufactured the GPS III Non-Flight Satellite Testbed (GNST) and all ten Block IIIA satellites. The first satellite in the series was projected to launch in 2014, but significant delays have pushed the scheduled launch to December 2018. The tenth and final GPS Block IIIA launch is projected in Q2 2023.
  • 1.8K
  • 10 Nov 2022
Topic Review
Quad Flat No-leads Package
Flat no-leads packages such as quad-flat no-leads (QFN) and dual-flat no-leads (DFN) physically and electrically connect integrated circuits to printed circuit boards. Flat no-leads, also known as micro leadframe (MLF) and SON (small-outline no leads), is a surface-mount technology, one of several package technologies that connect ICs to the surfaces of PCBs without through-holes. Flat no-lead is a near chip scale plastic encapsulated package made with a planar copper lead frame substrate. Perimeter lands on the package bottom provide electrical connections to the PCB. Flat no-lead packages include an exposed thermal pad to improve heat transfer out of the IC (into the PCB). Heat transfer can be further facilitated by metal vias in the thermal pad. The QFN package is similar to the quad-flat package (QFP), and a ball grid array (BGA).
  • 1.8K
  • 11 Nov 2022
Topic Review
Vehicle Tracking System
A vehicle tracking system combines the use of automatic vehicle location in individual vehicles with software that collects these fleet data for a comprehensive picture of vehicle locations. Modern vehicle tracking systems commonly use GPS or GLONASS technology for locating the vehicle, but other types of automatic vehicle location technology can also be used. Vehicle information can be viewed on electronic maps via the Internet or specialized software. Urban public transit authorities are an increasingly common user of vehicle tracking systems, particularly in large cities.
  • 1.8K
  • 04 Nov 2022
Topic Review
Surface Acoustic Wave
A surface acoustic wave (SAW) is an acoustic wave traveling along the surface of a material exhibiting elasticity, with an amplitude that typically decays exponentially with depth into the material. Materials with relatively high magnitude of Young's modulus (e.g., buildings) can be destructed once exposed to strong SAWs (as in earthquakes), whereas, those with relatively low Young's modulus (e.g., bubbles,and biological cells) can start to oscillate when driven by weak SAWs.
  • 1.8K
  • 03 Nov 2022
Topic Review
Robo-Taxi
A Robo-Taxi, also known as a Robo-Cab, a self-driving taxi or a driverless taxi is an autonomous car (SAE Level 4 or 5) operated for an e-hailing (on-demand mobility) service. The fact of eliminating the need for a human chauffeur, which represents a significant part of the operating costs of that type of services, could make it a very affordable solution for the customers and accelerate the spreading of Transportation-as-a-Service (TaaS) solutions as opposed to individual car ownership. However, it raises the issue of job destruction. Several studies highlighted that robo-taxis operated in an Autonomous Mobility on Demand (AMoD) service could be one of the most rapidly adopted applications of autonomous cars at scale and a major mobility solution in the near future, especially in urban areas, providing the majority of vehicle miles in the United States within a decade of their first introduction. Moreover, they could have a very positive impact on road safety, traffic congestion and parking. Concerning pollution and consumption of energy and other resources, robo-taxis could lead to significant improvement since these services will most probably use electric cars and for most of the rides, less vehicle size and range is necessary compared to usual, individually owned vehicles. The expectable reduction of the number of vehicles means less embodied energy but energy consumption for redistribution of empty vehicles must be taken into account.
  • 1.8K
  • 17 Oct 2022
Topic Review
Characteristics of Battery Energy Storage Systems
With increasing concerns about climate change, there is a transition from high-carbon-emitting fuels to green energy resources in various applications including household, commercial, transportation, and electric grid applications. Even though renewable energy resources are receiving traction for being carbon-neutral, their availability is intermittent. To address this issue to achieve extensive application, the integration of energy storage systems in conjunction with these resources is becoming a recommended practice. Additionally, in the transportation sector, the increased demand for electric vehicles (EVs) requires the development of energy storage systems that can deliver energy for rigorous driving cycles, with lithium-ion-based batteries emerging as the superior choice for energy storage due to their high power and energy densities, length of their life cycle, low self-discharge rates, and reasonable cost. As a result, battery energy storage systems (BESSs) are becoming a primary energy storage system. 
  • 1.8K
  • 15 Mar 2024
Topic Review
Bronze and Brass Ornamental Work
The use of bronze dates from remote antiquity. This important metal is an alloy composed of copper and tin, in proportion which vary slightly, but may be normally considered as nine parts of copper to one of tin. Other ingredients which are occasionally found are more or less accidental. The result is a metal of a rich golden brown colour, capable of being worked by casting — a process little applicable to its component parts, but peculiarly successful with bronze, the density and hardness of the metal allowing it to take any impression of a mould, however delicate. It is thus possible to create ornamental work of various kinds. The process of casting is known as cire perdue, and is the most primitive and most commonly employed through the centuries, having been described by the monk Theophilus, and also by Benvenuto Cellini. Briefly, it is as follows: a core, roughly representing the size and form of the object to be produced, is made of pounded brick, plaster or other similar substance and thoroughly dried. Upon this the artist overlays his wax, which he models to the degree required in his finished work. Passing from the core through the wax and projecting beyond are metal rods. The modelling being completed, called lost-wax casting, the outer covering which will form the mould has to be applied; this is a liquid formed of clay and plaster sufficiently thin to find its way into every detail of the wax model. Further coatings of liquid are applied, so that there is, when dry, a solid outer coating and a solid inner core held together by the metal rods, with the work of art modelled in wax between. Heat is applied and the wax melts and runs out, and the molten metal is poured in and occupies every detail which the wax had filled. When cool, the outer casing is carefully broken away, the core raked out as far as possible, the projecting rods are removed and the object modelled in wax appears in bronze. If further finish is required, it is obtained by tooling.
  • 1.8K
  • 28 Nov 2022
Topic Review
Eagle Computer
Eagle Computer of Los Gatos, California, was an early microcomputer manufacturing company. Spun off from Audio-Visual Laboratories (AVL), it first sold a line of popular CP/M computers which were highly praised in the computer magazines of the day. After the IBM PC was launched, Eagle produced the Eagle 1600 series, which ran MS-DOS but were not true clones. When it became evident that the buying public wanted actual clones of the IBM PC, even if a non-clone had better features, Eagle responded with a line of clones, including a portable. The Eagle PCs were always rated highly in computer magazines.
  • 1.8K
  • 01 Dec 2022
Topic Review
Electromagnetic Coil
An electromagnetic coil is an electrical conductor such as a wire in the shape of a coil (spiral or helix). Electromagnetic coils are used in electrical engineering, in applications where electric currents interact with magnetic fields, in devices such as electric motors, generators, inductors, electromagnets, transformers, and sensor coils. Either an electric current is passed through the wire of the coil to generate a magnetic field, or conversely, an external time-varying magnetic field through the interior of the coil generates an EMF (voltage) in the conductor. A current through any conductor creates a circular magnetic field around the conductor due to Ampere's law. The advantage of using the coil shape is that it increases the strength of the magnetic field produced by a given current. The magnetic fields generated by the separate turns of wire all pass through the center of the coil and add (superpose) to produce a strong field there. The more turns of wire, the stronger the field produced. Conversely, a changing external magnetic flux induces a voltage in a conductor such as a wire, due to Faraday's law of induction. The induced voltage can be increased by winding the wire into a coil because the field lines intersect the circuit multiple times. The direction of the magnetic field produced by a coil can be determined by the right hand grip rule. If the fingers of the right hand are wrapped around the magnetic core of a coil in the direction of conventional current through the wire, the thumb will point in the direction the magnetic field lines pass through the coil. The end of a magnetic core from which the field lines emerge is defined to be the North pole. There are many different types of coils used in electric and electronic equipment.
  • 1.8K
  • 01 Dec 2022
Biography
Gene Haas
Eugene "Gene" Francis Haas (born November 12, 1952) is founder, president, and sole stockholder of Haas Automation, a CNC machine tool manufacturer. He also has a presence in motorsports, having founded NASCAR team Haas CNC Racing (now known as Stewart-Haas Racing) and the Formula One team, Haas F1 Team. Haas graduated from California State University Northridge in 1975 with a Bachelor of Sci
  • 1.8K
  • 29 Nov 2022
Topic Review
Biological Quality of Soils
As is it known, soil is the basis of all activity in which man is involved. At the same time, it is the key factor for the development of the life and biodiversity of the planet's flora and fauna. Hence, as result of global warming and climate change, ecological research has recently increased its importance on the bases that extensive forest areas, act as carbon sinks mitigating greenhouse gas emissions. But no less important for investigation should be to inquire under this plant cover. Because there is a totally unimaginable and diverse world that remains in constant interactions to keep alive and from the green covering habitat to the diverse forms from small mammals to man. Man in its early days learned to manage the soil with the aim of producing food. Afterwards the exponential growth of the population was produced, and a high demand for food, caused the expansion of livestock borders, caused the devastation of large areas of forests, and generated a great impact to the soil and ecosystem. As a result, the change in land use and the application of chemicals impoverished and impairs the soil and the life that inhabits it. This is why this work highlights the importance of the biological component of soil to the context of the Amazon of Ecuador. For this reason, is important to consider different organisms as Essential Indicators of Soil Quality, mainly for the tropical soil field. In order to reach this objective, we compiled information presenting it in tables. They facilitate the interpretation of the importance of species of organisms and parameters from a biological point of view. At the same time, they can be used as a theoretical basis for the development of projects and research aimed to the management of biological soil composites.
  • 1.8K
  • 30 Oct 2020
Topic Review
Fruit and Vegetable Wastes
Food waste (FW) is already acknowledged as a major global issue that threatens the long-term viability of the food supply chain.
  • 1.8K
  • 26 Oct 2021
Biography
Roopam Sharma
Roopam Sharma, FRSA (born 24 May 1995) is an Indian scientist. He is best known for his work on Manovue, a technology which enables the visually impaired to read printed text. His research interests include Wearable Computing, Mobile Application Development, Human Centered Design, Computer Vision, AI and Cognitive Science. Roopam was recently awarded the Gifted Citizen Prize 2016[1] and has been
  • 1.8K
  • 25 Nov 2022
Topic Review
Mathematics Models in Reverse Osmosis Evaluation Processes
An effective alternative for water purification is reverse osmosis (RO). Laboratory-scale RO modeling is widely applied worldwide, and allows the evaluation of the behavior of the system to find the most convenient operating variables to be applied in future industrial scale-ups. Statistical models provide a wide range of information that allows a statistical prediction of the operation of the plant, and allows people to obtain efficiency indices in its development; these are useful in the planning, operation and monitoring process in RO plants. The mathematical models describe the physical behavior of the membrane and allow the identification of optimal operating conditions, taking into account economic aspects, guaranteeing a greater implementation of RO technology in developing countries which have problems with water contaminated with toxic heavy metals. A comparative method is proposed to establish the advantages and selection criteria to apply the different models in IO.
  • 1.8K
  • 28 Oct 2022
Topic Review
Shooting Star (Spacecraft)
The Shooting Star is an expendable American cargo spacecraft (transport vehicle) developed by Sierra Nevada Corporation as part of the Dream Chaser Launch System. It attaches to the back of Dream Chaser® spaceplane serving as a Service Module and holding up to 4,536 kg (10,000 lb) of supplies, cargo and experiments for the International Space Station. It is launched by ULA's Vulcan rocket and is designed to transport supplies to the International Space Station (ISS) and return items to Earth. Shooting Star can support three unpressurized payloads weighing up to 500 kg (1,100 lb) each or one payload weighing as much as 1,500 kg (3,300 lb). Once the module is at the station, the Canadarm2 robotic arm would unload the externally attached payload and install it on the station's exterior. The Shooting Star module is versatile, supplying power and ECLSS for the Dream Chaser system. It can be customized for special mission needs, such as autonomous docking to ISS instead of berthing. Upon re-entry into Earth’s atmosphere, it also performs disposal of cargo from the International Space Station.
  • 1.8K
  • 27 Oct 2022
Topic Review
Electroless Nickel Plating
Electroless nickel (EN) plating is an auto-catalytic reaction that deposits an even layer of nickel-phosphorus or nickel-boron alloy on the surface of a solid material, or substrate, like metal or plastic. The process involves dipping the substrate in a bath of plating solution, where a reducing agent, like hydrated sodium hypophosphite (NaPO2H2 · H2O), reacts with the material's ions to deposit the nickel alloy. The metallurgical properties of the alloy depend on the percentage of phosphorus, which can range from 2–5% (low phosphorus) to 11–14% (high phosphorus). Unlike electroplating, it is not necessary to pass an electric current through the plating solution to form a deposit. Electroless plating prevents corrosion and wear, and can be used to manufacture composite coatings by suspending powder in the bath.[1] EN plating creates an even layer regardless of the geometry of the surface – in contrast to electroplating which suffers from flux-density issues as an electric field will vary due to the surface profile and result in uneven depositions. Depending on the catalyst, EN plating can be applied to non-conductive surfaces.
  • 1.8K
  • 23 Nov 2022
Topic Review
Vehicular Ad-hoc Network
Vehicular ad-hoc networks (VANETs) are created by applying the principles of mobile ad hoc networks (MANETs) – the spontaneous creation of a wireless network of mobile devices – to the domain of vehicles. VANETs were first mentioned and introduced in 2001 under "car-to-car ad-hoc mobile communication and networking" applications, where networks can be formed and information can be relayed among cars. It was shown that vehicle-to-vehicle and vehicle-to-roadside communications architectures will co-exist in VANETs to provide road safety, navigation, and other roadside services. VANETs are a key part of the intelligent transportation systems (ITS) framework. Sometimes, VANETs are referred as Intelligent Transportation Networks While, in the early 2000s, VANETs were seen as a mere one-to-one application of MANET principles, they have since then developed into a field of research in their own right. By 2015,(p3) the term VANET became mostly synonymous with the more generic term inter-vehicle communication (IVC), although the focus remains on the aspect of spontaneous networking, much less on the use of infrastructure like Road Side Units (RSUs) or cellular networks.
  • 1.8K
  • 11 Oct 2022
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