3D printing An ORDbot Quantum 3D printer. 3D printing or additive manufacturing[1] is a process of making a three-dimensional solid object of virtually any shape from a digital model. 3D printing is achieved using an additive process, where successive layers of material are laid down in different shapes.[2] 3D printing is also considered distinct from traditional machining techniques, which mostly rely on the removal of material by methods such as cutting or drilling (subtractive processes). A 3D printer is a limited type of industrial robot that is capable of carrying out an additive process under computer control. The 3D printing technology is used for both prototyping and distributed manufacturing with applications in architecture, construction (AEC), industrial design, automotive, aerospace, military, engineering, dental and medical industries, biotech (human tissue replacement), fashion, footwear, jewelry, eyewear, education, geographic information systems, food, and many other fields.
Aerospace engineering Aerospace engineering is the primary branch of engineering concerned with the research, design, development, construction, testing, science and technology of aircraft and spacecraft.[1] It is divided into two major and overlapping branches: aeronautical engineering and astronautical engineering. Aeronautics deals with aircraft that operate in Earth's atmosphere, and astronautics deals with spacecraft that operate outside the Earth's atmosphere. Aeronautical engineering was the original term for the field. As flight technology advanced to include craft operating in outer space, the broader term "aerospace engineering" has largely replaced it in common usage.[2] Aerospace engineering, particularly the astronautics branch, is often referred to colloquially as "rocket science",[3] such as in popular culture. Overview[edit] History[edit] Elements[edit] Some of the elements of aerospace engineering are:[10][11] A fighter jet engine undergoing testing. Taught courses[edit] In popular culture[edit]
Wind power in Alaska Wind power in Alaska has the potential to provide all of the electricity used in the U.S. state of Alaska. From its installation in July 2009 though October 2012, the Pillar Mountain Wind 4.5 MW wind farm has saved the use of almost 3,000,000 gallons of diesel fuel in Kodiak, Alaska.[1] Potential[edit] Alaska wind resources In early 2010, the National Renewable Energy Laboratory released the first comprehensive update of wind energy potential by state since 1993, showing that Alaska has the potential to install 494,700 MW of wind power, capable of generating 1,620,000 million kWh/year.[2] Alaska used 6,291 million kWh in 2011, so Alaska has the potential to generate all energy used in the state from windpower.[3] Projects[edit] Eva Creek Wind ProjectFire Island Wind Project[4]Pillar Mountain Wind Project See also[edit] Wind power in the United States References[edit] External links[edit] Renewable Energy Projects
Labor unions in the United States Most unions in the United States are aligned with one of two larger umbrella organizations: the AFL-CIO created in 1955, and the Change to Win Federation which split from the AFL-CIO in 2005. Both advocate policies and legislation on behalf of workers in the United States and Canada, and take an active role in politics. The AFL-CIO is especially concerned with global trade issues. In 2013 there were 14.5 million members in the U.S., compared with 17.7 million in 1983. In the 21st century the most prominent unions are among public sector employees such as city employees, government workers, teachers and police. Although much smaller compared to their peak membership in the 1950s, American unions remain a political factor, both through mobilization of their own memberships and through coalitions with like-minded activist organizations around issues such as immigrant rights, trade policy, health care, and living wage campaigns. History[edit] Post-war[edit] Labor unions today[edit]
Physics Various examples of physical phenomena Physics is one of the oldest academic disciplines, perhaps the oldest through its inclusion of astronomy.[8] Over the last two millennia, physics was a part of natural philosophy along with chemistry, certain branches of mathematics, and biology, but during the Scientific Revolution in the 17th century, the natural sciences emerged as unique research programs in their own right.[b] Physics intersects with many interdisciplinary areas of research, such as biophysics and quantum chemistry, and the boundaries of physics are not rigidly defined. Physics also makes significant contributions through advances in new technologies that arise from theoretical breakthroughs. History Ancient astronomy Astronomy is the oldest of the natural sciences. Natural philosophy Classical physics Physics became a separate science when early modern Europeans used experimental and quantitative methods to discover what are now considered to be the laws of physics.[15] Philosophy
Alternative energy Alternative energy is any energy source that is an alternative to fossil fuel. These alternatives are intended to address concerns about such fossil fuels. The nature of what constitutes an alternative energy source has changed considerably over time, as have controversies regarding energy use. Today, because of the variety of energy choices and differing goals of their advocates, defining some energy types as "alternative" is highly controversial.[1] In a general sense, alternative energy as it is currently conceived, is that which is produced or recovered without the undesirable consequences inherent in fossil fuel use, particularly high carbon dioxide emissions, an important factor in global warming. Definitions[edit] History[edit] Coal as an alternative to wood[edit] Historian Norman F. "Europeans had lived in the midst of vast forests throughout the earlier medieval centuries. Petroleum as an alternative to whale oil[edit] Alcohol as an alternative to fossil fuels[edit] Algae fuel[edit]
Distributed generation Distributed generation, also called on-site generation, dispersed generation, embedded generation, decentralized generation, decentralized energy, distributed energy or district energy,[1] generates electricity from many small energy sources. Most countries generate electricity in large centralized facilities, such as fossil fuel (coal, gas powered), nuclear, large solar power plants or hydropower plants. These plants have excellent economies of scale, but usually transmit electricity long distances and can negatively affect the environment. Distributed generation allows collection of energy from many sources and may give lower environmental impacts and improved security of supply. Local wind generator, Spain, 2010 Economies of scale[edit] Historically, central plants have been an integral part of the electric grid, in which large generating facilities are specifically located either close to resources or otherwise located far from populated load centers. Grid parity[edit] Microgrid[edit]
Computational complexity theory Computational complexity theory is a branch of the theory of computation in theoretical computer science and mathematics that focuses on classifying computational problems according to their inherent difficulty, and relating those classes to each other. A computational problem is understood to be a task that is in principle amenable to being solved by a computer, which is equivalent to stating that the problem may be solved by mechanical application of mathematical steps, such as an algorithm. A problem is regarded as inherently difficult if its solution requires significant resources, whatever the algorithm used. The theory formalizes this intuition, by introducing mathematical models of computation to study these problems and quantifying the amount of resources needed to solve them, such as time and storage. Closely related fields in theoretical computer science are analysis of algorithms and computability theory. Computational problems[edit] Problem instances[edit] Turing machine[edit]
Geothermal electricity Geothermal electricity is electricity generated from geothermal energy. Technologies in use include dry steam power plants, flash steam power plants and binary cycle power plants. Geothermal electricity generation is currently used in 24 countries,[1] while geothermal heating is in use in 70 countries.[2] Estimates of the electricity generating potential of geothermal energy vary from 35 to 2,000 GW.[2] Current worldwide installed capacity is 10,715 megawatts (MW), with the largest capacity in the United States (3,086 MW).[3] El Salvador, Kenya, the Philippines, Iceland and Costa Rica generate more than 15% of their electricity from geothermal sources. Geothermal power is considered to be sustainable because the heat extraction is small compared with the Earth's heat content.[4] The emission intensity of existing geothermal electric plants is on average 122 kg of CO 2 per kilowatt-hour (kW·h) of electricity, about one-eighth of a conventional coal-fired plant.[5] Resources[edit]
AutoCAD AutoCAD is a software application for 2D and 3D computer-aided design (CAD) and drafting — available since 1982 as a desktop application and since 2010 as a mobile web- and cloud-based app marketed as AutoCAD 360. As Autodesk's flagship product, by March 1986 AutoCAD had become the most ubiquitous microcomputer design program worldwide, with functions such as "polylines" and "curve fitting".[3] Prior to the introduction of AutoCAD, most other CAD programs ran on mainframe computers or minicomputers, with each CAD operator (user) working at a graphical terminal or workstation.[citation needed] AutoCAD is used across a range of industries, including architects, project managers and engineers, among other professions, with 750 training centers established worldwide as of 1994.[2] History[edit] Design[edit] File formats and versions[edit] The native file format of AutoCAD is .dwg. Compatibility with other software[edit] ESRI ArcMap 10 permits export as AutoCAD drawing files. Languages[edit] View 1
Astrophysics Astrophysics (from Greek astron, ἄστρον "star", and physis, φύσις "nature") is the branch of astronomy that deals with the physics of the universe, especially with "the nature of the heavenly bodies, rather than their positions or motions in space."[1][2] Among the objects studied are galaxies, stars, planets, extrasolar planets, the interstellar medium and the cosmic microwave background.[3][4] Their emissions are examined across all parts of the electromagnetic spectrum, and the properties examined include luminosity, density, temperature, and chemical composition. Because astrophysics is a very broad subject, astrophysicists typically apply many disciplines of physics, including mechanics, electromagnetism, statistical mechanics, thermodynamics, quantum mechanics, relativity, nuclear and particle physics, and atomic and molecular physics. In practice, modern astronomical research often involves a substantial amount of work in the realm(s) of theoretical and/or observational physics.
Manley Hot Springs, Alaska Manley Hot Springs (Too Naaleł Denh in Koyukon) is a census-designated place (CDP) in Yukon-Koyukuk Census Area, Alaska, United States. At the 2010 census the population was 89. Geography[edit] Manley Hot Springs is located at WikiMiniAtlas Manley Hot Springs is located about 8 km (5.0 mi) north of the Tanana River on Hot Springs Slough, at the end of the Elliott Highway, 260 km (160 mi) west of Fairbanks. According to the United States Census Bureau, the CDP has a total area of 54.3 square miles (141 km2), all of it land. Demographics[edit] There were 36 households out of which 19.4% had children under the age of 18 living with them, 47.2% were married couples living together, 5.6% had a female householder with no husband present, and 47.2% were non-families. 38.9% of all households were made up of individuals and 2.8% had someone living alone who was 65 years of age or older. The median income for a household in the CDP was $29,000, and the median income for a family was $59,583.
Amateur radio An example of an amateur radio station with four transceivers, amplifiers, and a computer for logging and for digital modes. On the wall are examples of various awards, certificates, and a reception report card (QSL card) from a foreign amateur station. Amateur radio (also called ham radio) is the use of designated radio frequency spectra for purposes of private recreation, non-commercial exchange of messages, wireless experimentation, self-training, and emergency communication. The amateur radio service (amateur service and amateur satellite service) is established by the International Telecommunication Union (ITU) through the International Telecommunication Regulations. Amateur radio is officially represented and coordinated by the International Amateur Radio Union (IARU), which is organized in three regions and has as its members the national amateur radio societies which exist in most countries. History[edit] An amateur radio station in the United Kingdom. Ham radio[edit]
Agricultural science Agricultural science is a broad multidisciplinary field of biology that encompasses the parts of exact, natural, economic and social sciences that are used in the practice and understanding of agriculture. (Veterinary science, but not animal science, is often excluded from the definition.) Agriculture and agricultural science[edit] The two terms are often confused. However, they cover different concepts: Agriculture is the set of activities that transform the environment for the production of animals and plants for human use. Agricultural sciences include research and development on: Fertilizer[edit] One of the most common yield reducers is because of fertilizer not being applied in slightly higher quantities during transition period, the time it takes the soil to rebuild its aggregates and organic matter. Agricultural science: a local science[edit] With the exception of theoretical agronomy, research in agronomy, more than in any other field, is strongly related to local areas.