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from article Blueberry
Blueberries (Vaccinium sp.). (Photograph courtesy of Scott Bauer, Agricultural Research Service, United States Department of Agriculture)
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from article Blueberry
Mummy berry disease caused by the fungus Monilinia vaccinii-corymbosi. (a) Healthy fruit and (b) diseased fruit (from R. D. Milholland, Sclerotium germination and histopathology of Monilinia vaccinii-corymbosi on highbush blueberry, Phytopathology,…
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from article Non-Newtonian fluid
Steady shear flow of a fluid between a fixed plate and a parallel moving plate, illustrating the concept of viscosity.
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from article Non-Newtonian fluid
Examples of the counterintuitive behavior display by non-newtonian fluids. (a) Weissenberg effect. (b) Die swell. (c) Tubeless siphon.
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from article Non-Newtonian fluid
Typical dependence of the viscosity (ε) on shear rate (γ) for a non-Newtonian fluid. The functional from shown is called the Carreau model.
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from article Botulism
A colony of Clostridium botulinum, the causative agent of botulism, growing on egg yolk agar. (Credit: Larry Stauffer/Centers for Disease Control and Prevention)
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from article Ribonucleic acid (RNA)
Portion of an RNA molecule showing four nucleotides, each representing one of the four bases present in RNA.
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from article Ribonucleic acid (RNA)
Structural representations of a generalized tRNA molecule. (a) Secondary structure model showing base-pairing interactions within the tRNA. The characteristic and/or invariant nucleotides are the same regardless of the type of tRNA; the remainder…
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from article Halimeda
Halimeda kanaloana found in the waters off Hawaii. (Photo courtesy of the Deep Water Macroalgal Meadows 2004 Exploration, Office of Ocean Exploration, National Oceanic and Atmospheric Administration)
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from article Liver
The human liver is located in the right upper quadrant of the abdomen, immediately beneath the diaphragm. Two hepatic lobes are recognized: a larger right lobe and a smaller left lobe. The hepatic artery and portal vein provide the liver with a dual…
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from article Liver
Diagram of the histology of the liver. (Copyright © McGraw-Hill Education)
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from article Liver
Human liver and its major dorsal connections. Rami venae portae: C, centralis; I, intermedius; ID, inferior dexter; Inf, inferior sinister; L, lateralis; Q, quadratus; SS, superior sinister. Venae hepaticae: HCD, dorsocaudalis; HD, dextra; HM,…
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from article Liver
Liver structure. (Credit: E. Oppenheimer/Ciba)
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from article Liver
Disposition of the hepatic (liver-cell) plate and sinusoids around the terminal hepatic venule or central vein, showing centripetal flow of blood from branches of the hepatic artery and portal vein and centrifugal flow of bile to the small bile duct…
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from article Liver
Relationship of the liver (parenchymal) cells to each other and to the sinusoids, with principal components of the hepatic cell as seen in electron micrographs. (Credit: W. Bloom and D. W. Fawcett/Saunders)
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from article Dysprosium
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from article Inclined plane
Weight resting on an inclined plane (a) with principal forces applied, and (b) their resolution into normal force.
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from article Stenurida
Stenurida. (a) Ventral view of an arm and mouth frame plates of Bdellacoma vermiformis, a stenurid with long, slender arms. (b) Stenaster obtusus, a stenurid with short, broad arms. (After W. K. Spencer and C. W. Wright, Asterozoans, in R. C. Moore,…
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from article Anharmonic oscillator
Interaction between atoms. (a) Potential function of the interaction, V, plotted against r, the separation distance of the atomic nuclei. V(r) is plotted on a linear scale in units of negative joules. (b) Force, F(r), that is associated with the…
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from article Anharmonic oscillator
Potential function for the rigid, planar simple pendulum.
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from article Anharmonic oscillator
Anharmonic potential responsible for internal friction damping. Only at low levels (as noted by the ×10 enlargement) does the nonlinear nature of the potential become observable.
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from article Anharmonic oscillator
Comparison of nonlinear and linear oscillator damping. (a) Nonlinear damping due to internal friction. (b) Linear damping due to an external force.
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from article Anharmonic oscillator
Comparison of (1) viscous (linear) damping that derives from an external-to-the-oscillator friction force and (2) hysteretic (nonlinear) damping of the internal friction type. Both oscillators are in free decay with quality factor Q = 10 and angular…
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from article Cambrian
Cambrian, the first period of the Paleozoic Era.
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from article Cambrian
Reconstruction of the Lower Cambrian world. (After W. S. McKerrow, C. R. Scotese, and M. D. Brasier, Early Cambrian continental reconstructions. J. Geol. Soc., 149:599–606, 1992)
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from article Cambrian
North American divisions of the Cambrian System. Asterisks denote levels of major trilobite extinctions.
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from article Cambrian
Representative Cambrian fossils: (a–c) trilobites; (d–f) brachiopods; (g) hyolithid; (h–i) mollusks; (j–l) echinoderms; and (m, n) archaeocyathids.
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from article Hypergeometric functions
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from article Matched-field processing
Plane-wave signal incident on a linear sensor array without any reflections. (a) Signal and sensor-array geometry. (b) Typical plane-wave array-signal-processor output, A(θ), and the matched-field processing output, B(θ), versus signal incident…
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from article Matched-field processing
Plane-wave signal incident on a linear sensor array with one reflection. (a) Signal and sensor-array geometry. (b) Typical plane-wave array-signal-processor output, A(θ), and the matched-field processing output, B(θ), versus signal incident angle, θ.
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from article Matched-field processing
Signals from a remote source incident on a linear sensor array in a waveguide with two reflecting surfaces and four signal paths connecting the source and the array. (a) Signal and sensor-array geometry. (b) Typical plane-wave array-signal-processor…
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from article Structural steel
Structural steel beams being fabricated by automatic beam-welding machine. (Conrac Corp.)
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from article Sarcopterygii
Marbled or speckle-bellied lungfish (Protopterus aethiopicus). This African lungfish, a member of the class Sarcopterygii, can reach up to 2 m (6.6 ft) in length. (Photo by Joel Abroad)
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from article Aquarius
Modern boundaries of the constellation Aquarius, the Water Bearer. The celestial equator is 0° of declination, which corresponds to celestial latitude. Right ascension corresponds to celestial longitude, with each hour of right ascension…
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from article Acoustic microscope
Acoustic lens.
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from article Acoustic microscope
Acoustic images. (a) Bipolar transistor on silicon integrated circuit and (b) myxobacterium, both images taken in superfluid helium at 0.2 K (from J. S. Foster and D. Rugar, Low-temperature acoustic microscopy, IEEE Trans., SU-32, 139–151, 1985).…
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from article Acoustic microscope
Acoustic rays interacting to produce contrast enhancement in imaging at defocus and to generate V(z) curve.
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from article Onion
Pungent red onions (Allium cepa). (Photo by Stephen Ausmus, Agricultural Research Service, U.S. Department of Agriculture)
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from article Onion
Collection of yellow onions (Allium cepa) after harvesting. (Photo by Doug Wilson, Agricultural Research Service, U.S. Department of Agriculture)
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from article Onion
Common onions (Allium cepa) infected by Urocystis cepulae, causing onion smut. (Photo by Howard F. Schwartz, Colorado State University)
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from article Cryptomonadida
Examples of cryptomonads. (a) Chilomonas paramecium. (b) Cryptomonas erosa.
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from article Foot-and-mouth disease
Mouth of a steer with foot-and-mouth disease lesions on the tongue, along the lower gum, and inside the lower lip.
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from article Foot-and-mouth disease
Schematic diagram of the capsid of a foot-and- mouth disease virion. The four structural proteins, VP1–4 (also called 1A, 1B, 1C, and 1D), make up a protein subunit or protomer. Five protomers join to form a pentamer, and a capsid is an assembly of…
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from article Turnbuckle
Turnbuckle with eyes.
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from article Tarragon
Tarragon (Artemisia dracunculus). (Photo by Leo Michels)
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from article Lawrencium
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from article Computer-aided design and manufacturing
Computer-aided design workstation where the designer creates and refines a geometric model of a product. (Center for Computer-Aided Engineering, University of Virginia)
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from article Computer-aided design and manufacturing
Horizontal machining workstation. (a) Workstation with an industrial robot that loads and unloads parts processed on a numerically controlled machining center. (b) Computer simulation display used to verify the robot and part programs which control…
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from article Computer-aided design and manufacturing
Computer-aided design and manufacturing display on a system that allows the part programmer to create a cutter location file and preview the cutter path before machining. (Control Data Corp.)
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from article Computer-aided design and manufacturing
Numerically controlled machine tool in profiling operation using data from the part program. (Control Data Corp.)
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from article Computer-aided design and manufacturing
Rapid prototyping systems. (a) Stereolithography apparatus, which uses a CAD-driven laser beam to draw individual layers of an object by transforming a photosensitive epoxy plastic into a solid material (3D Systems). (b) Fused deposition modeling…
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from article Gravimetric analysis
In gravimetric analysis, a filtration step is required to collect the precipitate. (Credit: Matt Meadows/McGraw-Hill Education)
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from article Particle track etching
Upper images show increasing radiation damage produced by a high-energy uranium nucleus in the cosmic radiation as it penetrates a thick stack of Lexan plastic sheets and slows down. The lengths of the etched cones in these three sheets, taken at…
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from article Particle track etching
Etched conical pits in a sheet of allyl diglycol carbonate (CR-39 plastic) irradiated at normal incidence with 60-MeV alpha particles. (From P. B. Price et al., Do energetic heavy nuclei penetrate deeply into the Earth's atmosphere?, Proc. Nat.…
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from article Particle track etching
Etched fossil particle tracks. (a) Tracks from spontaneous fission of 238U and 244Pu in a zircon crystal from a lunar breccia, seen by scanning electron microscopy (from D. Braddy et al., Crystal chemistry of Pu and U and concordant fission track…
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from article Particle track etching
Reconstructed images of right and left breasts of a patient taken by using a 3600-MeV carbon-ion beam at the Lawrence Berkeley Laboratory Bevalac accelerator. Arrow indicates 1-cm (0.4-in.) carcinoma. (From C. A. Tobias et al., Lawrence Berkeley…
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from article Medical ultrasonic tomography
Ultrasonic B-scan of the abdomen.
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from article Rivet
Standard rivet heads.
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from article Rivet
Two types of blind rivet.
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from article Porcupine
North American porcupine (Erethizon dorsatum). (Photo from National Park Service)
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from article Eclipsing variable stars
Relative sizes and separation of components of R Canis Majoris. Shaded star represents cooler component. It is shown in two positions: at the middle of an eclipse and when separation would be greatest as viewed from Earth. Even at the greatest…
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from article Eclipsing variable stars
Model generally accepted for certain types of eclipsing binary stars, in particular those known as dwarf novae.
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from article Neandertal DNA
The geographical range within which Neandertal remains have been found (dashed line). White dots show the sites of the discoveries used to estimate the almost-complete hypervariable segment I (HVS-I) sequence of the Neandertal mtDNA. The approximate…
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from article Neandertal DNA
The mtDNA hypervariable segment I (HVS-I) diversity found in eight Neandertals. The nucleotide substitutions and insertions relative to the Cambridge Reference Sequence (CRS) are shaded. (Credit: Igor Ovchinnikov and William Goodwin)
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from article Neandertal DNA
Phylogenetic analysis of the Neandertal mtDNA hypervariable segment I (HVS-I) sequence. (a) Neighbor-joining tree of the Neandertal mtDNA sequences and 2500 modern human HVS-I sequences from 43 modern populations. (b) Neighbor-joining tree of the…
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from article Optical modulators
Electrooptic intensity modulator.
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from article Optical modulators
Acoustooptic modulator-deflector. (a) Raman-Nath regime. (b) Bragg regime.
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from article Optical modulators
Waveguide acoustooptic modulator-deflector.
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from article Optical modulators
Titanium-diffused LiNbO3 strip waveguide with coplanar electrodes for electrooptic phase modulation.
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from article Optical modulators
Directional coupler waveguide modulator switch.
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from article Optical modulators
Mach-Zehnder electrooptic waveguide modulator.
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from article Optical modulators
Semiconductor laser modulation. (a) Unmodulated semiconductor laser. (b) Directly modulated laser. (c) Electroabsorption modulator. (d) Integrated externally modulated laser.
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from article Thermionic emission
Richardson-Dushman plot for tungsten, an important thermionic emitter. (After G. Herrmann and S. Wagener, The Oxide-Coated Cathode, vol. 2, Chapman and Hall, 1951)
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from article Thermionic emission
Free electrons are assumed to move in approximately constant potential. (a) Occupation of electron states between the bottom of the conduction band and the Fermi level of a metal is indicated for T = 0 by the shaded area. (b) Fermi distribution…
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from article Thermionic emission
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from article Moving-target indication
Diagram of radar system with moving-target indication.
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from article Hydraulic press
Principle of hydraulic press.
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from article Hydraulic press
Hydraulic jack.
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from article Amplitude-modulation radio
An example of a low-frequency broadcast antenna. This three-tower array is connected to the Beidweiler long-wave transmitter (located in Beidweiler, Luxembourg), which broadcasts at a frequency of 234 kHz. Each tower is 290 m (951 ft) tall. (Photo…
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from article Borrelia
A digitally colorized scanning electron micrograph of a grouping of numerous Borrelia burgdorferi bacteria. The B. burgdorferi pathogen is responsible for causing Lyme disease, which is transmitted to humans by way of a tick bite. Borrelia…
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from article Cognition
The internal structures and processes that constitute the basis for cognition emanate from the brain (shown here in a colorized magnetic resonance image). (Credit: Shutterstock)
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from article Cognition
Cognitive models of information processing take into account information from the environment, sensory and perceptual processes, memory, thinking, and language. (Copyright © McGraw-Hill Education)
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from article Cognition
Light micrograph of Purkinje neurons (light blue) in the cerebellum. Nerve cells of the brain act collectively to process information needed for proper cognitive functioning. (Credit: Steve Gschmeissner/Science Photo Library/Alamy Stock Photo)
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from article Magnetic observatory
Panoramic view of the San Juan, Puerto Rico geomagnetic observatory (foreground buildings) that is operated by the U.S. Geological Survey.
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from article Magnetic observatory
A typical magnetic sensor suite at an INTERMAGNET-standard observatory: (front) fluxgate variometer, (left) proton-precession magnetometer, (right) theodolite with small fluxgate attached to telescope.
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from article Magnetic observatory
Map showing the locations observatories that have been part of the INTERMAGNET consortium 1991–2011.
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from article Redwood
Redwood trees (Sequoia sempervirens). (Photo courtesy of Forest and Kim Starr)
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from article Euglenophyceae
Euglena sp., showing overall morphology and intracellular structures.
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from article Coir
Coir fibers. (Photo courtesy of the Fiber Industry Development Authority, Department of Agriculture, the Philippines)
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from article Oral glands
The three major bilateral pairs of salivary oral glands found in mammals: the parotid, submandibular, and sublingual glands. (Image from A. L. Mescher, Junqueira's Basic Histology, 13th edition, McGraw-Hill, New York, 2013)
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from article Scattering of electromagnetic radiation
Pressure-induced density fluctuations in a fluid.
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from article Scattering of electromagnetic radiation
The role of interference in determining the angular dependence of light scattering from particles that are comparable in size to the wavelength.
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from article Grassland ecosystem
Map of grassland types in central and western North America.
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from article Hypodermis
Transection from the outer part of a Smilax root, illustrating a thick-walled hypodermis (exodermis) beneath the epidermis. One hypodermal cell is not thickened. (After K. Esau, Plant Anatomy, 2d ed., John Wiley and Sons, 1965)
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from article Xiphosurida
Segmentation of Limulus polyphemus. Inconclusive evidence indicates that there are 15 segments (6 in the prosoma, 9 in the opisthosoma). The telson (XV) may be a terminal spine that has become articulated and has incorporated the anus into its base.
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from article Xiphosurida
Phylogeny and representative species of the class Xiphosura, including the order Xiphosurida and its sister group, synziphosurines (a paraphyletic stem group).
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from article Xiphosurida
Paleolimulus signatus, a limuline xiphosurid from the Permian of Kansas, showing appendages and book gills. Length of specimen: 1.25 cm (0.5 in.).
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from article Xiphosurida
Carapaces of adult male Limulina. (a) Limulus polyphemus. (b) Tachypleus tridentatus. (c) Carcinoscorpius rotundicauda.
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from article Xiphosurida
Embryonic and larval development of Limulus polyphemus. (a) Early embryo, side view. (b) Late embryo. (c) Yolk-filled digestive tract of larva. Note the segmentation of yolk in the newly hatched stage and the six lobes of digestive gland. (d) First…
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from article Xiphosurida
Morphology of adult male Limulus polyphemus. (a) Dorsal view. (b) Ventral view, appendages not shown. (c) Cross section through prosoma showing internal anatomy. (d) Posterior view. (e) Lateral view.
