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Topic Review
Power Estimation for Electric Vehicles’s Lithium-Ion Batteries
State of power (SOP), as one of the key states of lithium-ion batteries, is defined as the peak power capability that a battery could deliver or receive over a prediction window while keeping the battery within the safe operating area. By this definition, most existing methods for online SOP estimation employ an equivalent-circuit model (ECM) to simulate battery dynamic behaviour in a prediction window and assume batteries operating at three operation modes, namely the constant current (CC), constant voltage (CV), and constant current constant voltage (CCCV) modes. Accordingly, three online SOP estimation methods have been developed with different basic principles, and many efforts have been made in the past decades for the improved performance of online SOP estimation from three aspects: (1) model structure; (2) online parameter identification technique; and (3) SOP estimation algorithm. 
  • 1.9K
  • 05 Jan 2022
Topic Review
UAVs in the U.S. Military
As of January 2014, the U.S. military operates a large number of unmanned aerial systems (UAVs or Unmanned Air Vehicles): 7,362 RQ-11 Ravens; 990 AeroVironment Wasp IIIs; 1,137 AeroVironment RQ-20 Pumas; and 306 RQ-16 T-Hawk small UAS systems and 246 Predators and MQ-1C Grey Eagles; 126 MQ-9 Reapers; 491 RQ-7 Shadows; and 33 RQ-4 Global Hawk large systems. The military role of unmanned aircraft systems is growing at unprecedented rates. In 2005, tactical- and theater-level unmanned aircraft alone had flown over 100,000 flight hours in support of Operation Enduring Freedom and Operation Iraqi Freedom, in which they are organized under Task Force Liberty in Afghanistan and Task Force ODIN in Iraq. Rapid advances in technology are enabling more and more capability to be placed on smaller airframes, which is spurring a large increase in the number of Small Unmanned Aircraft Systems (SUAS) being deployed on the battlefield. The use of SUAS in combat is so new that no formal DoD wide reporting procedures have been established to track SUAS flight hours. As the capabilities grow for all types of UAS, nations continue to subsidize their research and development, leading to further advances and enabling them to perform a multitude of missions. UAS no longer only perform intelligence, surveillance, and reconnaissance missions, although this still remains their predominant type. Their roles have expanded to areas including electronic attack, drone strikes, suppression or destruction of enemy air defense, network node or communications relay, combat search and rescue, and derivations of these themes. These UAS range in cost from a few thousand dollars to tens of millions of dollars, with aircraft ranging from less than one pound to over 40,000 pounds.
  • 1.9K
  • 14 Oct 2022
Topic Review
High-Speed Motorized Spindles of CNC Machine Tools
High-speed motorized spindles tend to develop in the direction of high precision, high speed, low energy consumption, high efficiency, and high reliability. 
  • 1.9K
  • 28 Mar 2022
Topic Review
Metal Matrix Composite
Composites are generally categorized into three main categories based on the matrix substance. They are called metal matrix composite (MMC), polymer matrix composite (PMC), and ceramic matrix composite (CMC), respectively. MMC gives more elevated ductile properties than CMCs and better environmental stability than PMCs. Additionally, MMCs offer good thermal conductivity (from 220 to 580 W·m−1·K−1), wear resistance (0.01025), wear rate (g·m−1), erosion, and shear strength.
  • 1.9K
  • 06 Sep 2021
Topic Review
Gel Blasters
Gel blasters, also known as gel guns, gel shooters, gel markers, hydro markers, hydro blasters, water bead blasters or gelsoft, are toy guns similar in design to airsoft guns, but the projectiles they shoot are 6–8 mm (0.24–0.31 in) superabsorbent polymer water beads (most commonly sodium polyacrylate, colloquially called water beads, hydrogel balls, gel balls, water bullets or simply gels), which are often sold commercially as moisture retainers for gardening and pot/vase floriculture. Gel blasters are often played in CQB-style shooting skirmishes similar to paintball by squads or local clubs of enthusiasts often referred to as "gelballers", but follow an airsoft-like honor-based gameplay umpiring system. MilSim games involving players wearing camouflage and dump pouches are very popular, while "SpeedGel" players are more casual with team jerseys and often wear paintball masks. In addition to safety gear such as eye protections, the sport is heavily regulated on the field and players must adhere to safety rules.
  • 1.9K
  • 20 Nov 2022
Topic Review
Containment Building
A containment building, in its most common usage, is a reinforced steel, concrete or lead structure enclosing a nuclear reactor. It is designed, in any emergency, to contain the escape of radioactive steam or gas to a maximum pressure in the range of 275 to 550 kPa (40 to 80 psi) . The containment is the fourth and final barrier to radioactive release (part of a nuclear reactor's defence in depth strategy), the first being the fuel ceramic itself, the second being the metal fuel cladding tubes, the third being the reactor vessel and coolant system. Each nuclear plant in the US is designed to withstand certain conditions which are spelled out as "Design Basis Accidents" in the Final Safety Analysis Report (FSAR). The FSAR is available for public viewing, usually at a public library near the nuclear plant. The containment building itself is typically an airtight steel structure enclosing the reactor normally sealed off from the outside atmosphere. The steel is either free-standing or attached to the concrete missile shield. In the United States , the design and thickness of the containment and the missile shield are governed by federal regulations (10 CFR 50.55a), and must be strong enough to withstand the impact of a fully loaded passenger airliner without rupture. While the containment plays a critical role in the most severe nuclear reactor accidents, it is only designed to contain or condense steam in the short term (for large break accidents) and long term heat removal still must be provided by other systems. In the Three Mile Island accident the containment pressure boundary was maintained, but due to insufficient cooling, some time after the accident, radioactive gas was intentionally let from containment by operators to prevent over pressurization. This, combined with further failures, caused the release of up to 13 million curies of radioactive gas to atmosphere during the accident. While the Fukushima Daiichi plant had operated safely since 1971, an earthquake and tsunami well beyond the design basis resulted in failure of AC power, backup generators and batteries which defeated all safety systems. These systems were necessary to keep the fuel cool after the reactor had been shut down. This resulted in partial or complete meltdown of fuel rods, damage to fuel storage pools and buildings, release of radioactive debris to surrounding area, air and sea, and resorting to the expedient use of fire engines and concrete pumps to deliver cooling water to spent fuel pools and containment. During the incident, pressure within the containments of reactors 1-3 rose to exceed design limits, which despite attempts to reduce pressure by venting radioactive gases, resulted in breach of containment. Hydrogen leaking from the containment mixed with air into an explosive mixture which resulted in explosions in Unit 1, 3 and 4, complicating attempts to stabilize the reactors.
  • 1.9K
  • 08 Nov 2022
Topic Review
Strategic Mining Options Optimization
 It is important that the strategic mine plan makes optimum use of available resources and provides continuous quality ore to drive sustainable mining and profitability. This requires the development of a well-integrated strategy of mining options for surface and/or underground mining and their interactions. Understanding the current tools and methodologies used in the mining industry for surface and underground mining options and transitions planning are essential to dealing with complex and deep-seated deposits that are amenable to both surface and underground mining. 
  • 1.9K
  • 29 Jul 2021
Topic Review
Removal of Inorganic Nitrogen from Wastewater
Water contamination due to various nitrogenous pollutants generated from wastewater treatment plants is a crucial and ubiquitous environmental problem nowadays. Nitrogen contaminated water has manifold detrimental effects on human health as well as aquatic life. Consequently, various biological and bioelectrochemical treatment processes are employed to transform the undesirable forms of nitrogen in wastewater to safer ones for subsequent discharge.
  • 1.9K
  • 27 May 2022
Topic Review
Gyrotrons
Gyrotrons are among the most powerful sources of coherent radiation that operate in CW and long pulse regimes in the sub-THz and the THz frequency ranges of the electromagnetic spectrum, i.e. between 0.3 THz and 3.0 THz (corresponding to wavelengths from 1.0 to 0.1 mm). This region, which spans between the frequency bands occupied by various electronic and photonic devices, respectively, is habitually called a THz power gap. The underlying mechanism of the operation of the gyrotron involves a formation of bunches of electrons gyrating in a helical electron beam and their synchronous interaction with a fast (i.e. having a superluminal phase velocity) electromagnetic wave, producing a bremsstrahlung radiation. In contrast to the slow-wave tubes, which utilize tiny structures with dimensions comparable to the wavelength of the radiation, the gyrotrons have a simpler resonant system (cavity resonator) with dimensions that are much greater than the wavelength. This allows much more powerful electron beams to be used and thus higher output powers to be achieved. Although in comparison with the classical microwave tubes the gyrotrons are characterized by greater volume and weight due to the presence of bulky parts (such as superconducting magnets and massive collectors where the energy of the spent electron beam is dissipated) they are much more compact and can easily be embedded in a sophisticated laboratory equipment (e.g. spectrometers, technological systems, etc.) than other devices such as free-electron lasers (FEL) and radiation sources based on electron accelerators. Nowadays, the gyrotrons are used as powerful sources of coherent radiation in the wide fields of high-power sub-THz and THz science and technologies [1][2][3].
  • 1.8K
  • 29 Oct 2020
Topic Review
Human Emotion Recognition
Automated emotion recognition (AEE) is important issue in the various field of activities, which uses human emotional reaction as a signal for marketing, technical equipment or human-robot interaction. Paper analyzes vast layer of scientific research and technical papers for sensor use analysis, where various methods implemented or researched. Paper cover few classes of sensors, using contactless methods, contact and skin-penetrating electrodes with for human emotion detection and measurement of their intensity. Result of performed analysis in this paper presented applicable methods for each type of emotions or their intensity and proposed their classification. Provided classification of emotion sensors revealed area of application and expected outcome from each method as well as noticed limitation of them. This paper should be interested for researchers, needed to use of human emotion evaluation and analysis, when there is a need to choose proper method for their purposes or find alternative decision.
  • 1.8K
  • 27 Jan 2021
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