Subject:
All Disciplines Arts & Humanities Biology & Life Sciences Business & Economics Chemistry & Materials Science Computer Science & Mathematics Engineering Environmental & Earth Sciences Medicine & Pharmacology Physical Sciences Public Health & Healthcare Social Sciences
Sort:
Hottest Latest Alphabetical (A-Z) Alphabetical (Z-A)
Type:
All Topic Review Biography
Biography
Jack R. Janney
Jack Raymond Janney (June 17, 1924 – October 9, 2006), born in Alamosa, Colorado, was a U.S. structural engineer and an innovator in the understanding of structural behavior and a recognized leader in the investigation of structural collapses. Janney’s love of mathematics and science spurred his decision to become an engineer, and in 1942, he enrolled in the College of Engineering at the Uni
  • 456
  • 06 Dec 2022
Topic Review
List of Intel Celeron Microprocessors
The Celeron is a family of microprocessors from Intel targeted at the low-end consumer market. CPUs in the Celeron brand have used designs from sixth- to eighth-generation CPU microarchitectures.
  • 1.5K
  • 06 Dec 2022
Topic Review
Exposure Effects Related to Nanomaterial Life Cycles
Nanoparticle-based biosensors are produced and utilized at different scales ranging from laboratory to industrial domains. While incorporating nanomaterials is beneficial to developing high-performance biosensors, at the stages of scale-up and disposal, it may lead to the unmanaged release of toxic nanomaterials. When considering the potential environmental impact and health safety of the scaled-up production of nano biosensors, it is necessary to examine the manufacturing, utilization, and end-of-life disposal of the nanomaterials used. 
  • 432
  • 06 Dec 2022
Topic Review
Surface Water and Floods Detection with Multispectral Satellites
The use of multispectral satellite imagery for water monitoring is a fast and cost-effective method that can benefit from the growing availability of medium–high-resolution and free remote sensing data. Since the 1970s, multispectral satellite imagery has been exploited by adopting different techniques and spectral indices. The high number of available sensors and their differences in spectral and spatial characteristics led to a proliferation of outcomes that depicts a nice picture of the potential and limitations of each. 
  • 1.1K
  • 06 Dec 2022
Topic Review
Tin Halide Perovskite-Based Solar Cells
The excellent optoelectronic properties of tin halide perovskites (Sn-PVKs) have made them a promising candidate for replacing toxic Pb counterparts. Concurrently, their enormous potential in photon harvesting and thermoelectricity applications has attracted increasing attention. The optoelectronic properties of Sn-PVKs are governed by the flexible nature of SnI6 octahedra, and they exhibit extremely low thermal conductivity. Due to these two contradictory properties, they are equally explored in solar cell as well as thermoelectric devices.
  • 365
  • 06 Dec 2022
Topic Review
Messerschmitt Me 321
The Messerschmitt Me 321 Gigant was a large German cargo glider developed and used during World War II. Intended to support large scale invasions, the Me 321 saw very limited use due to the low availability of suitable tug aircraft, high vulnerability whilst in flight and the difficult ground handling, both at base and at destination landing sites. The Me 321 was developed, in stages, into the six-engined Messerschmitt Me 323 Gigant, which removed some of the problems with ground handling, but vulnerability to ground fire and aerial attack remained a constant problem during operations of all variants.
  • 1.1K
  • 06 Dec 2022
Biography
Barnes Wallis
Sir Barnes Neville Wallis CBE FRS RDI FRAeS[1] (26 September 1887 – 30 October 1979), was an English scientist, engineer and inventor. He is best known for inventing the bouncing bomb used by the Royal Air Force in Operation Chastise (the "Dambusters" raid) to attack the dams of the Ruhr Valley during World War II. The raid was the subject of the 1955 film The Dam Busters, in which Wallis wa
  • 772
  • 06 Dec 2022
Topic Review
Power-Flow Study
In power engineering, the power-flow study, or load-flow study, is a numerical analysis of the flow of electric power in an interconnected system. A power-flow study usually uses simplified notations such as a one-line diagram and per-unit system, and focuses on various aspects of AC power parameters, such as voltages, voltage angles, real power and reactive power. It analyzes the power systems in normal steady-state operation. Power-flow or load-flow studies are important for planning future expansion of power systems as well as in determining the best operation of existing systems. The principal information obtained from the power-flow study is the magnitude and phase angle of the voltage at each bus, and the real and reactive power flowing in each line. Commercial power systems are usually too complex to allow for hand solution of the power flow. Special purpose network analyzers were built between 1929 and the early 1960s to provide laboratory-scale physical models of power systems. Large-scale digital computers replaced the analog methods with numerical solutions. In addition to a power-flow study, computer programs perform related calculations such as short-circuit fault analysis, stability studies (transient and steady-state), unit commitment and economic dispatch. In particular, some programs use linear programming to find the optimal power flow, the conditions which give the lowest cost per kilowatt hour delivered. A load flow study is especially valuable for a system with multiple load centers, such as a refinery complex. The power flow study is an analysis of the system’s capability to adequately supply the connected load. The total system losses, as well as individual line losses, also are tabulated. Transformer tap positions are selected to ensure the correct voltage at critical locations such as motor control centers. Performing a load flow study on an existing system provides insight and recommendations as to the system operation and optimization of control settings to obtain maximum capacity while minimizing the operating costs. The results of such an analysis are in terms of active power, reactive power, magnitude and phase angle. Furthermore, power-flow computations are crucial for optimal operations of groups of generating units. The Open Energy Modelling Initiative promotes open source load-flow models and other types of energy system models.
  • 382
  • 06 Dec 2022
Topic Review
Cylinder (Engine)
A cylinder is the central working part of a reciprocating engine or pump, the space in which a piston travels. Multiple cylinders are commonly arranged side by side in a bank, or engine block, which is typically cast from aluminum or cast iron before receiving precision machine work. Cylinders may be sleeved (lined with a harder metal) or sleeveless (with a wear-resistant coating such as Nikasil). A sleeveless engine may also be referred to as a "parent-bore engine". A cylinder's displacement, or swept volume, can be calculated by multiplying its cross-sectional area (the square of half the bore by pi) by the distance the piston travels within the cylinder (the stroke). The engine displacement can be calculated by multiplying the swept volume of one cylinder by the number of cylinders. Presented symbolically, A piston is seated inside each cylinder by several metal piston rings fitted around its outside surface in machined grooves; typically two for compressional sealing and one to seal the oil. The rings make near contact with the cylinder walls (sleeved or sleeveless), riding on a thin layer of lubricating oil; essential to keep the engine from seizing and necessitating a cylinder wall's durable surface. During the earliest stage of an engine's life, its initial breaking-in or running-in period, small irregularities in the metals are encouraged to gradually form congruent grooves by avoiding extreme operating conditions. Later in its life, after mechanical wear has increased the spacing between the piston and the cylinder (with a consequent decrease in power output) the cylinders may be machined to a slightly larger diameter to receive new sleeves (where applicable) and piston rings, a process sometimes known as reboring.
  • 1.1K
  • 06 Dec 2022
Topic Review
Katana (Rocket Engine)
Masten Space Systems was an aerospace manufacturer startup company in Mojave, California (formerly in Santa Clara, California) that is developing a line of vertical takeoff, vertical landing (VTVL) rockets, initially for uncrewed research sub-orbital spaceflights and eventually intended to support robotic orbital spaceflight launches. In 2020, NASA awarded Masten a contract for a lunar lander mission; NASA is to pay Masten US$75.9 million for Masten to build and launch a lander called XL-1 to take NASA and other customer payloads to the south pole of the Moon. Masten Mission One will be Masten's first space flight; it is scheduled for launch in November 2023. The company filed for Chapter 11 bankruptcy on 28 July 2022. The company would later be purchased by Astrobotic Technology on 11 September 2022.
  • 368
  • 06 Dec 2022
  • Page
  • of
  • 678
Featured Entry Collections
>>

Featured Books

>>
Encyclopedia of Social Sciences
Encyclopedia of COVID-19
Encyclopedia of Fungi
Encyclopedia of Digital Society, Industry 5.0 and Smart City
ScholarVision Creations
Feedback