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Topic Review
Radio Frequency Energy Harvesting System and Technologies
Radio frequency energy harvesting (RF-EH) is a potential technology via the generation of electromagnetic waves. This advanced technology offers the supply of wireless power that is applicable for battery-free devices, which makes it a prospective alternative energy source for future applications.
  • 1.8K
  • 05 Aug 2022
Topic Review
Beam-Squinting Effect in Broadband Mobile Communication
Due to the fact that the quality of the received signal is adversely affected by the beam squint phenomenon, which is especially pertinent to the millimeter wave (mmwave) bands, many studies have been utilised by other researchers to provide light on some of the challenges that come with analysing this type of occurrence. Squint causes several issues, the most important of which are its detrimental effects on gain, line of sight, angle of arrival, progressive phase, usable bandwidth, and fading effect. As a result of these obstacles, the advantages of adopting a high-frequency band such as mmwave in modern wireless communication systems are severely limited.
  • 1.8K
  • 06 Feb 2023
Topic Review
Components and Production of Asphalt Mixture
The environmental concerns of global warming and energy consumption are among the most severe issues and challenges facing human beings worldwide. Due to the relatively higher predicted temperatures (150–180 °C), the latest research on pavement energy consumption and carbon dioxide (CO2) emission assessment mentioned contributing to higher environmental burdens such as air pollution and global warming. However, warm-mix asphalt (WMA) was introduced by pavement researchers and the road construction industry instead of hot-mix asphalt (HMA) to reduce these environmental problems.
  • 1.8K
  • 22 Dec 2022
Topic Review
Oil Spill Modeling
Several oil spill simulation models exist in the literature, which are used worldwide to simulate the evolution of an oil slick created from marine traffic, petroleum production, or other sources. These models may range from simple parametric calculations to advanced, new-generation, operational, three-dimensional numerical models, coupled to meteorological, hydrodynamic, and wave models, forecasting in high-resolution and with high precision the transport and fate of oil. This study presents a review of the transport and oil weathering processes and their parameterization and critically examines eighteen state-of-the-art oil spill models in terms of their capacity (a) to simulate these processes, (b) to consider oil released from surface or submerged sources, (c) to assimilate real-time field data for model initiation and forcing, and (d) to assess uncertainty in the produced predictions. Based on our review, the most common oil weathering processes involved are spreading, advection, diffusion, evaporation, emulsification, and dispersion. The majority of existing oil spill models do not consider significant physical processes, such as oil dissolution, photo-oxidation, biodegradation, and vertical mixing. Moreover, timely response to oil spills is lacking in the new generation of oil spill models. Further improvements in oil spill modeling should emphasize more comprehensive parametrization of oil dissolution, biodegradation, entrainment, and prediction of oil particles size distribution following wave action and well blow outs.
  • 1.8K
  • 02 Mar 2021
Topic Review
KH-11 Kennen
The KH-11 KENNEN (later renamed CRYSTAL, then Evolved Enhanced CRYSTAL System, and codenamed 1010 and Key Hole) is a type of reconnaissance satellite first launched by the American National Reconnaissance Office in December 1976. Manufactured by Lockheed in Sunnyvale, California, the KH-11 was the first American spy satellite to use electro-optical digital imaging, and so offer real-time optical observations. Later KH-11 satellites have been referred to by outside observers as KH-11B or KH-12, and by the names "Advanced KENNEN", "Improved Crystal" and "Ikon". Official budget documents refer to the latest generation of electro-optical satellites as Evolved Enhanced CRYSTAL System. The Key Hole series was officially discontinued in favor of a random numbering scheme after repeated public references to KH-7 Gambit, KH-8 Gambit-3, KH-9 Hexagon, and KH-11 satellites. The capabilities of the KH-11 are highly classified, as are images they produce. The satellites are believed to have been the source of some imagery of the Soviet Union and China made public in 1997; images of Sudan and Afghanistan made public in 1998 related to the response to the 1998 U.S. embassy bombings; and a 2019 photo, revealed by President Donald Trump, of a failed Iranian rocket launch.
  • 1.8K
  • 09 Oct 2022
Topic Review
Pavement Surface Types and Distress Assessment Indicators
Pavement or road surfaces can be categorized into four general classes, i.e., asphalt, concrete, gravel, and brick and block. Pavement condition is assessed by measuring several pavement characteristics such as roughness, surface skid resistance, pavement strength, deflection, and visual surface distresses.
  • 1.8K
  • 29 Nov 2022
Topic Review
Mobile Phone Overuse
Mobile phone overuse (smartphone addiction, mobile-phone addiction, problem mobile phone use, or mobile phone dependency) is a dependence syndrome seen among mobile phone users. Some mobile phone users exhibit problematic behaviors related to substance use disorders. These behaviors can include preoccupation with mobile communication, excessive money or time spent on mobile phones, use of mobile phones in socially or physically inappropriate situations such as driving an automobile. Increased use can also lead to increased time on mobile communication, adverse effects on relationships, and anxiety if separated from a mobile phone or sufficient signal.
  • 1.8K
  • 14 Nov 2022
Topic Review
The Interband Cascade Laser
The interband cascade laser (ICL) has recently become the go-to coherent optical source for applications in the mid-wave infrared spectral band (especially 3–6 μm) that require high efficiency, low drive power, and small system footprint. The ICL combines a relatively long upper-level lifetime, characteristic of semiconductor interband transitions, with the voltage-efficient cascading scheme originally introduced for the quantum cascade laser (which employs intersubband transitions to produce light). Following the first room-temperature (RT) continuous wave (cw) operation in 2008, ICLs have operated in cw mode up to 118 ºC, produced > 500 mW of cw power at RT, displayed wallplug efficiencies up to 18% for RT cw operation, and operated in cw mode at RT to wavelengths as long as 6 µm. The low ICL drive power, which is 1-2 orders of magnitude less than is required for a quantum cascade laser (QCL), is especially important in applications such as portable battery- or solar-powered laser spectroscopy systems that require a small footprint. Distributed-feedback (DFB) ICLs emitting in a single spectral mode have generated up to 55 mW of cw power at RT, and have operated at wavelengths as long as 6.6 µm. Newer device classes include ICL frequency combs, interband cascade vertical-cavity surface-emitting lasers, interband cascade LEDs, interband cascade detectors, and ICLs incorporated into photonic integrated circuits.
  • 1.8K
  • 22 Sep 2020
Topic Review
Sustainable Innovation Ecosystems
Innovation ecosystem is a intertwined network of multi-layer relationships through which relevant knowledge and creativity flow through a framework of sustained value co-creation. The term gained popularity among academics, policymakers, managers and entrepreneurs in the last decades. These complex relations between players aim to enable technology development and innovation with an open mindset and promoting the responsible and inclusive exploitation of resources.
  • 1.8K
  • 27 Oct 2020
Topic Review
Springfield Armory XDM
The Springfield Armory XDM (X-Treme Duty, the M is for the match grade barrel and match grade trigger) are a series of semi-automatic pistols that are polymer-framed and striker-fired. They closely resemble their predecessor, the HS2000 pistol (most widely known in the United States as Springfield Armory XD). Manufactured in the city of Karlovac, Croatia by HS Produkt (formerly I.M. Metal), the Springfield Armory XDM is the marketing name for the firearm, which is licensed and sold in the United States by Springfield Armory, Inc..
  • 1.8K
  • 25 Oct 2022
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