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Biography
Burt Rutan
Elbert Leander "Burt" Rutan (born June 17, 1943) is a retired American aerospace engineer and entrepreneur noted for his originality in designing light, strong, unusual-looking, energy-efficient aircraft. He designed the record-breaking Voyager, which in 1986 was the first plane to fly around the world without stopping or refueling, and the sub-orbital spaceplane SpaceShipOne, which won the Ansa
  • 1.5K
  • 22 Nov 2022
Topic Review
GNSS Positioning Calculation
The global navigation satellite system (GNSS) positioning for receiver's position is derived through the calculation steps, or algorithm, given below. In essence, a GNSS receiver measures the transmitting time of GNSS signals emitted from four or more GNSS satellites (giving the pseudorange) and these measurements are used to obtain its position (i.e., spatial coordinates) and reception time.
  • 1.5K
  • 05 Dec 2022
Topic Review
Biofuel
A biofuel is a fuel that is produced through contemporary processes from biomass, rather than a fuel produced by the very slow geological processes involved in the formation of fossil fuels, such as oil. Since biomass technically can be used as a fuel directly (e.g. wood logs), some people use the terms biomass and biofuel interchangeably. More often than not, however, the word biomass simply denotes the biological raw material the fuel is made of, or some form of thermally/chemically altered solid end product, like torrefied pellets or briquettes. The word biofuel is usually reserved for liquid or gaseous fuels, used for transportation. The U.S. Energy Information Administration (EIA) follows this naming practice. If the biomass used in the production of biofuel can regrow quickly, the fuel is generally considered to be a form of renewable energy. Biofuels can be produced from plants (i.e. energy crops), or from agricultural, commercial, domestic, and/or industrial wastes (if the waste has a biological origin). Renewable biofuels generally involve contemporary carbon fixation, such as those that occur in plants or microalgae through the process of photosynthesis. Some argue that biofuel can be carbon-neutral because all biomass crops sequester carbon to a certain extent – basically all crops move CO2 from above-ground circulation to below-ground storage in the roots and the surrounding soil. For instance, McCalmont et al. found below-ground carbon accumulation ranging from 0.42 to 3.8 tonnes per hectare per year for soils below Miscanthus x giganteus energy crops, with a mean accumulation rate of 1.84 tonne (0.74 tonnes per acre per year), or 20% of total harvested carbon per year. However, the simple proposal that biofuel is carbon-neutral almost by definition has been superseded by the more nuanced proposal that for a particular biofuel project to be carbon neutral, the total carbon sequestered by the energy crop's root system must compensate for all the above-ground emissions (related to this particular biofuel project). This includes any emissions caused by direct or indirect land use change. Many first generation biofuel projects are not carbon neutral given these demands. Some have even higher total GHG emissions than some fossil based alternatives. Some are carbon neutral or even negative, though, especially perennial crops. The amount of carbon sequestrated and the amount of GHG (greenhouse gases) emitted will determine if the total GHG life cycle cost of a biofuel project is positive, neutral or negative. A carbon negative life cycle is possible if the total below-ground carbon accumulation more than compensates for the total life-cycle GHG emissions above ground. In other words, to achieve carbon neutrality yields should be high and emissions should be low. High-yielding energy crops are thus prime candidates for carbon neutrality. The graphic on the right displays two CO2 negative Miscanthus x giganteus production pathways, represented in gram CO2-equivalents per megajoule. The yellow diamonds represent mean values. Further, successful sequestration is dependent on planting sites, as the best soils for sequestration are those that are currently low in carbon. The varied results displayed in the graph highlights this fact. For the UK, successful sequestration is expected for arable land over most of England and Wales, with unsuccessful sequestration expected in parts of Scotland, due to already carbon rich soils (existing woodland) plus lower yields. Soils already rich in carbon includes peatland and mature forest. Grassland can also be carbon rich, and Milner et al. argue that the most successful carbon sequestration in the UK takes place below improved grasslands. The bottom graphic displays the estimated yield necessary to compensate for related lifecycle GHG-emissions. The higher the yield, the more likely CO2 negativity becomes. The two most common types of biofuel are bioethanol and biodiesel. Bioethanol is an alcohol made by fermentation, mostly from carbohydrates produced in sugar or starch crops such as corn, sugarcane, or sweet sorghum. Cellulosic biomass, derived from non-food sources, such as trees and grasses, is also being developed as a feedstock for ethanol production. Ethanol can be used as a fuel for vehicles in its pure form (E100), but it is usually used as a gasoline additive to increase octane and improve vehicle emissions. Bioethanol is widely used in the United States and in Brazil. Biodiesel is produced from oils or fats using transesterification and is the most common biofuel in Europe. It can be used as a fuel for vehicles in its pure form (B100), but it is usually used as a diesel additive to reduce levels of particulates, carbon monoxide, and hydrocarbons from diesel-powered vehicles. In 2018, worldwide biofuel production reached 152 billion liters (40 billion gallons US), up 7% from 2017, and biofuels provided 3% of the world's fuels for road transport. The International Energy Agency want biofuels to meet more than a quarter of world demand for transportation fuels by 2050, in order to reduce dependency on petroleum. However, the production and consumption of biofuels are not on track to meet the IEA's sustainable development scenario. From 2020 to 2030 global biofuel output has to increase by 10% each year to reach IEA's goal. Only 3% growth annually is expected. Here are some various social, economic, environmental and technical issues relating to biofuels production and use, which have been debated in the popular media and scientific journals.
  • 1.5K
  • 12 Oct 2022
Biography
Gustav Otto
Gustav Otto (12 January 1883 – 28 February 1926) was a German aircraft and aircraft engine designer and manufacturer. Gustav was born in Cologne to Nikolaus August Otto, the founder of N. A. Otto & Cie. and inventor of the four-stroke internal combustion engine. It is therefore regarded that his interest in engines, specifically aircraft and the manufacture thereof, was something he inherited
  • 1.5K
  • 22 Nov 2022
Topic Review
Grand Power K100
The K100 is a 9×19mm semi-automatic pistol designed and built by Grand Power s.r.o. in Slovenská Ľupča, Slovakia located approximately 11 kilometers east of Banská Bystrica, Slovakia which is the region's major city.
  • 1.5K
  • 03 Nov 2022
Topic Review
Homi
Homi (Korean: 호미), also known as a Korean hand plow, is a short-handled traditional farming tool used by Koreans. It is a farming tool that removes grasses from paddies and fields. It is also used when plowing a rice field, planting seeds, plowing up soil, and digging potatoes in fields. It is a farming tool similar to the hoe. It is an important extension of agriculture from the ancient times because the homi was excavated in the Bronze Age historic site of the Pyeongnam Mangsan Daepyeong-ri and the early Iron Age historic site of Yangpyong, Gyeonggi Province. Homi is distributed nationwide, but they are characterized by locality. In other words, homi is classified into Plowshare-shaped(보습형), Sickle-shaped(낫형), and Triangle-shaped(세모형) depending on the natural conditions of the local area and the characteristics of agricultural management.
  • 1.5K
  • 26 Oct 2022
Topic Review
Orphan Train
The Orphan Train Movement was a supervised welfare program that transported orphaned and homeless children from crowded Eastern cities of the United States to foster homes located largely in rural areas of the Midwest. The orphan trains operated between 1854 and 1929, relocating about 200,000 orphaned, abandoned, or homeless children. Three charitable institutions, Children's billage (founded 1851 by 24 philanthropists), the Children's Aid Society (established 1853 by Charles Loring Brace) and later, the New York Foundling Hospital, endeavored to help these children. The institutions were supported by wealthy donors and operated by professional staff. The two institutions developed a program that placed homeless, orphaned, and abandoned city children, who numbered an estimated 30,000 in New York City alone in the 1850s, in foster homes throughout the country. The children were transported to their new homes on trains that were labeled "orphan trains" or "baby trains". This relocation of children ended in the 1920s with the beginning of organized foster care in America.
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  • 28 Nov 2022
Topic Review
Frugal Engineering
Frugal innovations are all the rage! With their genesis at grassroots levels of society, these products have evolved into Advanced Frugal Innovations (AFIs) possessing good technological sophistication. Many advanced frugal products need cutting edge research other than routine science and technology for their fruition. Frugal engineering is an important tool for tackling the challenges thrown by climate-change and other planetary and manmade crises of our time.  Frugal engineering is significant for all-round sustainable development.  Frugal engineering will increasingly impact all human endeavours, both commercial and public, for widespread sustainable development. Instances include, but not limited to, UN’s Sustainable Development Goals (SDGs), pandemic-related efforts, commercial and academic interests.  Irrespective of your field of interest or current vocation, please drop Professor Balkrishna Rao a line for your interest and/or need for research-solution using principles of frugal engineering.
  • 1.5K
  • 09 Nov 2020
Topic Review
Lazar Armored Vehicle
LAZAR is an 8×8 multi-role military vehicle family produced by the Serbian defence industry company Yugoimport SDPR.
  • 1.5K
  • 16 Nov 2022
Topic Review
Natural Ventilation
Natural ventilation is the process of supplying air to and removing air from an indoor space without using mechanical systems. It refers to the flow of external air to an indoor space as a result of pressure differences arising from natural forces. There are two types of natural ventilation occurring in buildings: wind driven ventilation and buoyancy-driven ventilation. Wind driven ventilation arises from the different pressures created by wind around a building or structure, and openings being formed on the perimeter which then permit flow through the building. Buoyancy-driven ventilation occurs as a result of the directional buoyancy force that results from temperature differences between the interior and exterior. Since the internal heat gains which create temperature differences between the interior and exterior are created by natural processes, including the heat from people, and wind effects are variable, naturally ventilated buildings are sometimes called "breathing buildings".
  • 1.5K
  • 25 Oct 2022
Topic Review
Freight Bicycle
Freight bicycles, carrier cycles, freight tricycles, cargo bikes, box bikes, or cycletrucks are human powered vehicles designed and constructed specifically for transporting loads. Vehicle designs include a cargo area consisting of an open or enclosed box, a flat platform, or a wire basket, usually mounted over one or both wheels, low behind the front wheel, or between parallel wheels at either the front or rear of the vehicle. The frame and drivetrain must be constructed to handle loads larger than those on an ordinary bicycle.
  • 1.5K
  • 03 Jan 2023
Topic Review
Annealing (Metallurgy)
In metallurgy and materials science, annealing is a heat treatment that alters the physical and sometimes chemical properties of a material to increase its ductility and reduce its hardness, making it more workable. It involves heating a material above its recrystallization temperature, maintaining a suitable temperature for an appropriate amount of time and then cooling. In annealing, atoms migrate in the crystal lattice and the number of dislocations decreases, leading to a change in ductility and hardness. As the material cools it recrystallizes. For many alloys, including carbon steel, the crystal grain size and phase composition, which ultimately determine the material properties, are dependent on the heating rate and cooling rate. Hot working or cold working after the annealing process alters the metal structure, so further heat treatments may be used to achieve the properties required. With knowledge of the composition and phase diagram, heat treatment can be used to adjust from harder and more brittle to softer and more ductile. In the case of ferrous metals, such as steel, annealing is performed by heating the material (generally until glowing) for a while and then slowly letting it cool to room temperature in still air. Copper, silver and brass can be either cooled slowly in air, or quickly by quenching in water. In this fashion, the metal is softened and prepared for further work such as shaping, stamping, or forming.
  • 1.5K
  • 09 Oct 2022
Topic Review
Coyote Reconnaissance Vehicle
The Light Armoured Vehicle II (LAV II) Coyote (and the related Bison) are armoured cars (or armoured personnel carriers) built by General Dynamics Land Systems Canada for the Canadian Forces. They are a later generation of the LAV-25 and of the same family as the Australian ASLAV, as all are part of the Light Armoured Vehicle family produced by General Dynamics Land Systems - Canada and based on the MOWAG Piranha 8x8.
  • 1.5K
  • 03 Nov 2022
Topic Review
History of South Asian Domes
Islamic rule over northern and central India brought with it the use of domes constructed with stone, brick and mortar, and iron dowels and cramps. Centering was made from timber and bamboo. The use of iron cramps to join together adjacent stones was known in pre-Islamic India, and was used at the base of domes for hoop reinforcement. The synthesis of styles created by this introduction of new forms to the Hindu tradition of trabeate construction created a distinctive architecture. Domes in pre-Mughal India have a standard squat circular shape with a lotus design and bulbous finial at the top, derived from Hindu architecture. Because the Hindu architectural tradition did not include arches, flat corbels were used to transition from the corners of the room to the dome, rather than squinches. In contrast to Persian and Ottoman domes, the domes of Indian tombs tend to be more bulbous.
  • 1.5K
  • 20 Oct 2022
Topic Review
Proposed Melbourne Rail Extensions
Several proposals have been put forward by various groups to expand the Melbourne rail network—proposals for additional rail lines, extensions to existing lines, as well as electrification to existing lines and new stations on existing lines. Some of these plans were so seriously considered at various times that they appeared in the Melway street directory, and on suburban train destination rolls.
  • 1.5K
  • 31 Oct 2022
Topic Review
Emission Standard
Emission standards are the legal requirements governing air pollutants released into the atmosphere. Emission standards set quantitative limits on the permissible amount of specific air pollutants that may be released from specific sources over specific timeframes. They are generally designed to achieve air quality standards and to protect human life.
  • 1.5K
  • 29 Nov 2022
Topic Review
Dragon C2+
SpaceX COTS Demo Flight 2 (COTS 2), also known as Dragon C2+, was the second test-flight for SpaceX's uncrewed Cargo Dragon spacecraft, launched on the third flight of the company's two-stage Falcon 9 launch vehicle. The flight was performed under a funded agreement from NASA as the second Dragon demonstration mission in the Commercial Orbital Transportation Services (COTS) program. The purpose of the COTS program is to develop and demonstrate commercial sources for cargo re-supply of the International Space Station (ISS). The Dragon C2+ spacecraft was the first American vehicle to visit the ISS since the end of the Space Shuttle program. It was also the first commercial spacecraft to rendezvous and berth with another spacecraft. Initially, the objectives of the C2+ mission were to have been accomplished by two separate missions; Dragon C2 would have carried out a fly-by of the ISS, practiced rendezvous maneuvers and communications with the station, before returning to Earth. A second mission, Dragon C3, would have been the first mission to berth with the station. In July 2011, NASA gave tentative approval to combine the objectives of the two missions. In December 2011, NASA formally approved the merger of the COTS 2 and 3 missions into the Dragon C2+ flight. There were several launch delays, the last one occurring on 19 May 2012, due to a launch abort during the last second before liftoff. Dragon C2+ successfully launched from Cape Canaveral on 22 May 2012. During the mission's first three days all of the COTS 2 objectives were successfully completed. The mission's COTS 3 phase began on 25 May when Dragon rendezvoused again with the ISS and then was successfully captured using the Canadarm2. It was berthed to the station later that day, using the robotic arm. Dragon stayed for almost six days during which the astronauts unloaded cargo, and then reloaded Dragon with Earth-bound cargo. On 31 May, Dragon unberthed from the ISS, its capsule landed in the Pacific Ocean off the California coast and was recovered. All the objectives of the mission were successfully completed, and the Falcon 9-Dragon system became certified to start regular cargo delivery missions to the ISS under the Commercial Resupply Services program.
  • 1.5K
  • 04 Nov 2022
Topic Review
Harmonic Radio Frequency Identification
Harmonic Radio Frequency Identification (RFID) system operates at two different frequencies for uplink and downlink communication unlike conventional RFID systems. Operating at two frequencies provides many operational advantages over RFID system.
  • 1.4K
  • 22 Apr 2021
Topic Review
Electric Gates
An electric gate is an entrance gate which can be opened and closed via an electric powered mechanism.
  • 1.4K
  • 08 Nov 2022
Biography
Ben Horowitz
Benjamin Abraham Horowitz (born June 13, 1966) is an American businessman, investor, blogger, and author. He is a high technology entrepreneur and co-founder and general partner along with Marc Andreessen of the venture capital firm Andreessen Horowitz. He previously co-founded and served as president and chief executive officer of the enterprise software company Opsware, which Hewlett-Packard a
  • 1.4K
  • 21 Nov 2022
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