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Topic Review
Ophthalmoscopy
Ophthalmoscopy, also called funduscopy, is a test that allows a health professional to see inside the fundus of the eye and other structures using an ophthalmoscope (or funduscope). It is done as part of an eye examination and may be done as part of a routine physical examination. It is crucial in determining the health of the retina, optic disc, and vitreous humor. The pupil is a hole through which the eye's interior will be viewed. Opening the pupil wider (dilating it) is a simple and effective way to better see the structures behind it. Therefore, dilation of the pupil (mydriasis) is often accomplished with medicated eye drops before funduscopy. However, although dilated fundus examination is ideal, undilated examination is more convenient and is also helpful (albeit not as comprehensive), and it is the most common type in primary care. An alternative or complement to ophthalmoscopy is to perform a fundus photography, where the image can be analysed later by a professional.
  • 901
  • 19 Oct 2022
Topic Review
Proton Exchange Membrane Fuel Cells
Proton exchange membrane fuel cells (PEMFCs) operate by converting the chemical energy in a fuel into electrical energy. The most crucial parameters in the operation process are the temperature, pressure, relative humidity, and air stoichiometry ratio. The classical structure of a PEMFC consists of a proton exchange membrane, anode electrode, cathode electrode, catalyst layers (CLs), microporous layer (MPLs), gas diffusion layers (GDLs), two bipolar plates (BPs), and gas flow channels (GFCs). The mechanical behavior and the conductivity of the protons are highly dependent on the structure of the MEAs.
  • 901
  • 20 Feb 2023
Topic Review
Evolution of Access Network Sharing
Network sharing is part of a fundamental principle of statistical multiplexing of link capacity. Regardless of whether the nodes are setting up connections that reserve capacity in the Plain Old Telephone Service (POTS), or sending packets in a connection-less packet-switched network, the overall link capacity is only a fraction of the total interconnection capacity required if all nodes attempted communicating at once. Network sharing also applies to the progressive aggregation of link capacity where the ratio of multiplexing increases in moving from the access towards the core. From the mid-90s’, the concept of sharing was extended to also cover the multi-tenant use of the network, where third party network operators compete with the incumbent national operator, so that the same common infrastructure is shared across multiple competing entities. The degree to which infrastructure is shared is limited, on the one hand by physical and logical boundaries that separate resources, and on the other hand by economic complexities such as settlements, agreements and regulations that complicate the sharing process.
  • 900
  • 27 Oct 2020
Topic Review
Very-High-Temperature Reactor
The very-high-temperature reactor (VHTR), or high-temperature gas-cooled reactor (HTGR), is a Generation IV reactor concept that uses a graphite-moderated nuclear reactor with a once-through uranium fuel cycle. The VHTR is a type of high-temperature reactor (HTR) that can conceptually have an outlet temperature of 1000 °C. The reactor core can be either a "prismatic block" (reminiscent of a conventional reactor core) or a "pebble-bed" core. The high temperatures enable applications such as process heat or hydrogen production via the thermochemical sulfur–iodine cycle.
  • 900
  • 16 Nov 2022
Topic Review
Perovskite Solar Cells with g-C3N4
Perovskite solar cells (PSCs) have attracted great research interest in the scientific community due to their extraordinary optoelectronic properties and the fact that their power conversion efficiency (PCE) has increased rapidly in recent years, surpassing other 3rd generation photovoltaic (PV) technologies. Graphitic carbon nitride (g-C3N4) presents exceptional optical and electronic properties and its use was recently expanded in the field of PSCs. The addition of g-C3N4 in the perovskite absorber and/or the electron transport layer (ETL) resulted in PCEs exceeding 22%, mainly due to defects passivation, improved conductivity and crystallinity as well as low charge carriers’ recombination rate within the device. Significant performance increase, including stability enhancement, was also achieved when g-C3N4 was applied at the PSC interfaces and the observed improvement was attributed to its wetting (hydrophobic/hydrophilic) nature and the fine tuning of the corresponding interface energetics. 
  • 900
  • 26 Apr 2021
Topic Review
Electrochemical Lithium Recovery System
Various lithium recovery technologies have been developed as securing lithium resources has become increasingly important. Among these technologies, the electrochemical lithium recovery (ELR) system is a rapid and eco-friendly extraction method that has been studied recently. In this study, an ELR system using a spinel-type LiMn2O4 (LMO) is briefly reviewed. As LMO electrodes have high Li+ selectivity and stability compared to other lithium battery cathodes, they have been widely used as positive electrodes for the ELR system. 
  • 900
  • 15 Dec 2020
Topic Review
DAISY Digital Talking Book
DAISY (Digital Accessible Information SYstem) is a technical standard for digital audiobooks, periodicals and computerized text. DAISY is designed to be a complete audio substitute for print material and is specifically designed for use by people with "print disabilities", including blindness, impaired vision, and dyslexia. Based on the MP3 and XML formats, the DAISY format has advanced features in addition to those of a traditional audio book. Users can search, place bookmarks, precisely navigate line by line, and regulate the speaking speed without distortion. DAISY also provides aurally accessible tables, references and additional information. As a result, DAISY allows visually impaired listeners to navigate something as complex as an encyclopedia or textbook, otherwise impossible using conventional audio recordings. DAISY multimedia can be a book, magazine, newspaper, journal, computerized text or a synchronized presentation of text and audio. It provides up to six embedded "navigation levels" for content, including embedded objects such as images, graphics, and MathML. In the DAISY standard, navigation is enabled within a sequential and hierarchical structure consisting of (marked-up) text synchronized with audio. DAISY 2 was based on XHTML and SMIL. DAISY 3 is a newer technology, also based on XML, and is standardized as ANSI/NISO Z39.86-2005. The DAISY Consortium was founded in 1996 and consists of international organizations committed to developing equitable access to information for people who have a print disability. The consortium was selected by the National Information Standards Organization (NISO) as the official maintenance agency for the DAISY/NISO Standard.
  • 899
  • 09 Nov 2022
Topic Review
Digital and Smart Cities
Mobility is notoriously a key aspect of our modern economy and humans' way of life. In an edge situation such as the current coronavirus pandemic, transportation is one of the first affected mechanisms of a city. In our paper, we highlight the potential of operations research and computational intelligence tools for cities' services. The contributions involves aspects of optimization, internet-of-thing and internet-of-value (brought with concepts of Blockchain). When we sum up all these tools, it becomes possible to envision the potential that emerging software and systems can bring to society, associated with the wave of innovation surroundings the smart cities.
  • 899
  • 21 Jan 2021
Topic Review
Sustainable Water and Energy Supply
This entry aims to reveal the economic, technical, and environmental impacts of different system configurations (centralized or decentralized, components, and technologies) on transition plans to achieve a higher share of renewable energy and desalination supplies for regions facing water scarcity. The main contribution of this research is the comparative evaluation of on-grid decentralized or distributed renewable-powered desalination systems for sustainable water and energy supply planning. Applying a novel nexus approach, an interactive multi-period planning model is developed to highlight synergies and to identify conflicts of planning both energy and water sectors at the same time as endogenous subsystems of one overall system. For studying these synergies in this study, the pace of technology deployment and the path of decline in overall costs are assumed to be a function of experience and knowledge as two-factor learning curves. Using data from 81 projects, the levelized cost and capacity factor of utility-scale photovoltaic and wind supplies in the Middle East were calculated. The results indicate that a scenario with a decentralized water sector and renewable-powered multiple-effect distillation technology has the best overall performance among the proposed scenarios. The authors consider that the current study provides novel insights: (1) Designing and planning both the water and energy sectors at the same time, (2) detailed representation of short-term operational aspects in long-run planning of the water and energy sectors to capture the inherent variability of renewable energy resources, (3) modeling the water sector with centralized and decentralized on-grid renewable-powered desalination systems, (4) proposing a new methodology to study the synergies and conflicts of designing the water and energy sectors as an integrated system/separated system, and (5) estimating the two-factor learning curves for wind, photovoltaic, reverse osmosis desalination, and multi-effect distillation desalination industries in the Middle East.
  • 899
  • 27 Oct 2020
Topic Review
Air Displacement Pipette
Piston-driven air displacement pipettes are a type of micropipette, which are tools to handle volumes of liquid in the microliter scale. They are more commonly used in biology and biochemistry, and less commonly in chemistry; the equipment is susceptible to damage from many organic solvents.
  • 899
  • 25 Oct 2022
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