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Project

3D Floor Plan

Floor plans show walls, windows, doors, and other features of a room or building. Architects and engineers use them to study spatial relationships and describe their designs. Typically, floor plans are rendered as two-dimensional drawings.In this…

Project

3D Skull Candy Mold

Whether preparing for Halloween or just a regular day, you can make skull-shaped edibles from this project's 3D candy mold. Like many molds, this one is a hollow container into which you can pour water or hot liquids, such as gelatin, chocolate, or…

Project

3D Spur Gear

A spur gear is a common toothed wheel that works with other wheels in a set to adjust the speed, power, or direction of a complex machine. It's found in many everyday devices, such as electric screwdrivers, washing machines, and mechanical clocks…

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3D Terrain Map

Terrain maps are physical models that give you an at-a-glance overview of landforms. Architects, builders, and engineers often use these types of maps to provide context to proposed building designs. In this project, you'll create a layered…

Project

3x3x3 LED Cube

LEDs (light-emitting diodes) are rectifying semiconductor devices that convert electrical energy into electromagnetic radiation. You can use these devices to create a 3-dimensional light display. LED cubes require some care and good soldering skills…

Project

Arduino Oscilloscope

An oscilloscope is a device that allows you to see an electronic signal so that it appears as a waveform. Traditional oscilloscopes work by amplifying a signal to control the position of a dot on the y-axis (vertical axis) of a cathode-ray tube…

Project

Heart-Rate Monitor

This project uses a sensitive light-detecting resistor to detect small changes in the light beaming through your finger as your blood pumps through tiny arteries in the finger. This device is not the same as the heart-rate monitors typically used in…

Project

Jumbo Foam Glider

This project takes you through the steps to build, launch, and fly a foam glider in sustained and controlled flight. Control in flight is achieved by modifying the wind the glider flies through with a large cardboard sheet (paddle). If this is your…

Project

Levitation Machine

This project allows you to use electromagnetic levitation to suspend a globe of the world above a surface. The "globe" is actually a table tennis ball painted to look like a globe. Keeping it in place requires careful control of electrical current…

Project

Light and Temperature Logger

Environmental research often involves the use of data loggers to record data at regular intervals over a period of time. Most data loggers are based on digital processors, and can be fairly expensive, but you can build your own. This project uses a…

Project

Pulse Generator Circuit

A pulse generator circuit is an important building block for many electronic projects, such as the heart of a digital clock. Its purpose is basically to switch an output on and off for as long as the circuit is activated. Sometimes, these circuits…

Project

Text-Controlled RGB LED

A red, green, and blue (RGB) light-emitting diode (LED) is a useful electronic component that can produce visible light in a variety of colors. This is done by varying the intensity of the light output of the three different color LED elements (red,…

Project

Tumblewing Walkalong Glider

This project takes you through the steps to build, launch,and fly a paper airplane (glider) in sustained and controlled flight. Control in flight is achieved by modifying the wind the glider flies through with a large cardboard sheet or foam board…

Project

Ultralight Foam Glider

This project takes you through the steps to build, launch, and fly an ultralight foam glider in sustained and controlled flight. Controlled flight is achieved by modifying the wind the glider flies through with a large cardboard sheet, or paddle.The…

Project

Wind Lantern

In this project, you will build a small, vertical-axis wind turbine, or VAWT for short. VAWTs are not as efficient as their horizontal-axis cousins, but they are better suited to urban environments where wind can come from different…

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from article Information processing (psychology)

The four major lobes of the cerebral cortex, that is, the frontal, parietal, temporal, and occipital lobes, are responsible for different aspects of information processing. (Copyright © McGraw-Hill Education)

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from article Information processing (psychology)

Horizontal associative memory with a serious associative interference problem (who plays tennis—John, Peter, or both?) and no encoding of where each proposition begins and ends. (Copyright © McGraw-Hill Education)

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from article Information processing (psychology)

Vertical associative memory where concepts are grouped into phrases and propositions by associating each concept to a higher-order node that represents the entire group. (Copyright © McGraw-Hill Education)

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from article Octopoda

An octopod swimming in the ocean. (Credit: Getty Images/iStockphoto)

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from article Octopoda

Hapalochlaena maculosa, the Southern or lesser blue-ringed octopus, has vivid, small blue rings on its body and arms, highlighted with black outlines. Location: Mrs. Watson's Bay, Lizard Island, Great Barrier Reef, Australia. (Credit: Clyde F. E.…

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from article Octopoda

Hapalochlaena fasciata, the blue-lined octopus, has vivid blue lines on its body and rings on its arms, highlighted with black outlines. Location: Long Reef, New South Wales, Australia. (Credit: Clyde F. E. Roper)

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from article Octopoda

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from article Polyplacophora

Chiton on a rock surface. (Photo courtesy of the NOAA Okeanos Explorer Program, National Oceanic and Atmospheric Administration)

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from article Polyplacophora

Polyplacophoran mollusk (chiton): (a) dorsal view; (b) ventral view.

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from article Pituitary gland disorders

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from article Pituitary gland disorders

Infarction (obstruction of the blood supply) of the pituitary gland. This pituitary gland is almost entirely infarcted. Only a thin rim of viable cells remains (arrow). Pituitary infarcts can occur during pregnancy (Sheehan's disease) or as a result…

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from article Clathrate compounds

Schematic drawing of the lattices of (a, c) urea and (b, d) thiourea; c and d show accommodation of unbranched and branched paraffin chains, respectively.

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from article Clathrate compounds

Molecular model of α-dextrin–iodine compound seen in the direction of the c axis, that is, in the direction of the iodine chains, which lie in channels.

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from article Space flight

Earthrise, with the surface of the Moon in the foreground, photographed by astronauts aboard the Apollo 8 mission in late 1968. Apollo 8 was the first crewed mission to the Moon. (Credit: NASA)

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from article Space flight

Soyuz, a third-generation Soviet spacecraft. 1 m = 3.3 ft.

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from article Space flight

Comparison of U.S. spacecraft and launch vehicle configurations through 1972. (Credit: NASA)

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from article Space flight

The Apollo 11 lunar module on the surface of the Moon in July 1969. (Credit: NASA)

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from article Space flight

Skylab in orbit around Earth. (Credit: NASA)

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from article Space flight

The space shuttle Discovery launching in July 2006. (Credit: NASA)

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from article Space flight

Shuttle Atlantis returning home to Kennedy Space Center after its final mission, July 21, 2011. (Credit: NASA)

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from article Space flight

The completed International Space Station in orbit around Earth. (Credit: NASA)

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from article Space flight

Artist's impression of the Space Launch System with the Orion spacecraft on top. (Credit: NASA)

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from article Wire drawing

Wire being drawn through a die.

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from article Wire drawing

Comparison of (a) ideal and (b) redundant deformation.

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from article Wire drawing

Variation of the work terms with die angle according to Eqs. (1), (3), (4), and (6), with ε = 0.3 and η = 0.08.

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from article Wire drawing

Dependence of the efficiency on die angle for several reductions. A friction coefficient of μ = 0.08 was assumed.

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from article Wire drawing

Comparison of the predictions of I.F. from Eq. (12) with experiments on copper.

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from article Wire drawing

Microstructure of a tungsten wire cold-drawn to an 87% reduction of area, viewed along the wire axis.

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from article Metal rolling

Rolling process. (a) Direction of friction forces in the roll gap. (b) Velocity distribution. (c) Normal pressure acting on the strip in the roll gap.

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from article Metal rolling

Basic types of roll arrangement. (a) Two-high. (b) Three-high. (c) Four-high. (d) Cluster. (e) Tandem rolling with three stands. (f) Planetary mill.

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from article Metal rolling

Development of the Mannesmann process for producing seamless tubing (a–c explained in text).

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from article Trace fossils

Domichnial dwelling burrow with pelleted wall, probably created by a burrowing crustacean. Ophiomorpha, Cretaceous, North Dakota. (From W. Häntzschel, in C. Teichert, ed., Treatise on Invertebrate Paleontology, pt. W, revised, University of Kansas…

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from article Trace fossils

Highly branched, fodinichnial mining burrow, possibly produced by a deposit-feeding crustacean or worm. (a) Chondrites, Tertiary, Austria. (b) Chondrites, Tertiary, Spain. (From W. Häntzschel, in C. Teichert, ed., Treatise on Invertebrate…

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from article Trace fossils

Agrichnial farming trace of an unknown organism, composed of a hexagonal, meshlike network of tunnels. Paleodictyon, Tertiary, Poland. (Photograph by W. Häntzschel)

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from article Trace fossils

Agrichnial farming traces of unknown organisms, including a double-spiral tunnel (Spirorhaphe) and a meshlike network of tunnels (Paleodictyon). Tertiary, Austria. (Photograph by W. Häntzschel)

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from article Trace fossils

Loosely meandering, agrichnial farming trace of an unknown organism. Cosmorhaphe, Tertiary, Poland. (From W. Häntzschel, in C. Teichert, ed., Treatise on Invertebrate Paleontology, pt. W, revised, University of Kansas Press, 1975)

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from article Trace fossils

Praedichnial boring drilled in a bivalve shell by a carnivorous gastropod. Oichnus, Recent, Texas. (Photograph by A. A. Ekdale)

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from article Trace fossils

Tightly meandering, pascichnial grazing trail, created by an unknown worm. Helminthoida, Tertiary, Austria. (From W. Häntzschel, in C. Teichert, ed., Treatise on Invertebrate Paleontology, pt. W, revised, University of Kansas Press, 1975)

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from article Trace fossils

Repichnial trail of an arthropod, possibly a trilobite. Cruziana, Cambrian, Alberta. (Photograph by J. P. A. Magwood)

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from article Trace fossils

Unnamed escape structure (fugichnial trace) in sandstone. Cretaceous, Utah. (Photograph by A. A. Ekdale)

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from article Trace fossils

Cubichnial resting trace of an ophiuroid brittle star. Asteriacites, Jurassic, Germany. (Photograph by W. Häntzschel)

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from article Trace fossils

Complex, composite ichnofabric created by numerous successive phases of burrowing in a fine-grained pelagic carbonate deposit, which has been weakly cemented to become chalk. Upper Cretaceous, Denmark. (Photograph by A. A. Ekdale and R. G. Bromley)

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from article Surveillance radar

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from article Phonoreception

Generalized sketch of the vertebrate labyrinth. The three cristae, macula ultriculi, and macula sacculi are always present in vertebrates, and the other endings appear as indicated, with a few exceptions.

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from article Phonoreception

Diagram (from above) of the two labyrinths of an ostariophysan fish and their connections with the swim bladder through the Weberian ossicles.

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from article Phonoreception

Simplified diagram of the frog ear.

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from article Phonoreception

Diagram of the ear of a snake. The nonauditory parts and endings are not shown.

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from article Phonoreception

Auditory sensitivity of a wood turtle (Clemmys insculpta), as shown by the potentials produced in its ear by sounds. The curve shows the sound pressure necessary to produce a potential of 0.3 microvolt.

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from article Phonoreception

Graph showing threshold sensitivity in the bullfinch (mean of four birds). (Credit: J. Schwartzkopff)

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from article Phonoreception

Auditory thresholds in primates. The curves show the sound pressures that are barely audible for humans, chimpanzees, rhesus monkeys, and marmosets.

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from article Phonoreception

Diagram of the ear of a grasshopper.

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from article Phonoreception

Auditory thresholds of the katydid (Conocephalus strictus). Sensitivity is greatest in the 7000–60,000-Hz region. (Credit: E. G. Wever and J. A. Vernon)

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from article Guided missile

GBU-15 with data link system, mounted on F-4 Phantom II fighter. (Hughes Aircraft Co.)

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from article Guided missile

TOW (tube-launched, optically tracked, wire-guided) antitank missile and launch tube. Wings and tails fold to permit tube mounting. (Hughes Aircraft Co.)

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from article Guided missile

Launching of a field-mobile, short-range, all-weather surface-to-air Roland missile. The West German–French Roland has been licensed for production in the United States for use as a U.S. Army air defense weapon. (U.S. Army)

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from article Guided missile

F-15 Eagle fighter aircraft equipped with a mixture of short-range, infrared Sidewinder and medium-range, radar Sparrow air-to-air missiles. (McDonnell-Douglas)

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from article Guided missile

Phoenix long-range air-to-air supersonic missile. (a) Side view (Hughes Aircraft Co.). (b) Launch from F-14 fighter aircraft (U.S. Navy).

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from article Guided missile

Falcon air-to-air missile family, including missiles with infrared and radar guidance, and high-explosive and nuclear warheads. (Hughes Aircraft Co.)

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from article Guided missile

Tomahawk long-range, subsonic cruise missile. (a) Side view. (b) Submerged launch. Missile may also be launched from surface or air. (General Dynamics)

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from article Guided missile

Harpoon antiship cruise missile. (a) Ship-launched. (b) Air launch version on A-6 intruder attack aircraft. (McDonnell-Douglas)

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from article Guided missile

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from article Neandertals

Neandertal cranium excavated from Forbes' Quarry, Gibraltar. Note the pronounced brow ridges, large braincase, and receding forehead. (Credit: Clive Finlayson/Gibraltar Museum)

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from article Neandertals

Gorham's Cave, Gibraltar, is the last known site of Neandertal occupation, being dated possibly to 30,000 years ago. (Credit: Clive Finlayson/Gibraltar Museum)

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from article Neandertals

Reconstructed skull of a Neandertal from the cave at La Chapelle-aux-Saints, France. (Credit: Illustration adapted from an original drawing by M. F. Ashley Montagu)

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from article Atomic bomb

The mushroom cloud over Nagasaki, Japan, after an atomic bomb was dropped by U.S. aircraft on August 9, 1945. (Credit: Everett Historical/Shutterstock)

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from article Atomic bomb

Conceptual diagrams illustrating the main features of (a) implosion type and (b) gun-barrel type of fission weapons. (Credit: A. DeVolpi)

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from article Gain

Gain by an amplifier or other system.

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from article Gain

Bode diagrams. (a) Gain plot. (b) Phase plot.

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from article Robotics

A dexterous humanoid robot (robonaut) built at the NASA Johnson Space Center in Houston, Texas, USA to work alongside humans in space. (Credit: NASA)

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from article Robotics

A model for the selective compliance assembly robot arm (SCARA). It has 3 links. Horizontal links move sideways and the third (vertical) link moves up and down. It shown here with a drill, a chuck, and drill bit. (Credit: Richard Pasala)

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from article Robotics

The right hand of a NASA robot grasping a hook. The robot's hands closely mimics the human hand in order to use tools and handholds designed for astronauts. (Source: NASA)

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from article Robotics

Six-legged walking robot. (Odetics)

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from article Notch signaling

Notch-ligand interactions. Two Notch ligands, Delta and Serrate, are shown on the signal-sending cell (left). These ligands are distinguished by differing numbers of EGF-like repeats (indicated by the light boxes) and an extracellular cysteine-rich…

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from article Optical flat

Optical flat being used to determine flatness of seal ring. Interference bands on the seal ring face show lines of constant depth. (Van Keuren Co.)

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from article Optical flat

Measurement of height of sphere determined by means of gage blocks and optical flat. 1″ = 25.4 mm.

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from article Composite material

NASA technicians inspecting the keel section of a PRSEUS (Pultruded Rod Stitched Efficient Unitized Structure). This is a new way for aircraft sections to be built by sewing together layers and rods of composite material. (Credit: NASA…

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from article Composite material