Search Results

Search Results

Refine this search

7,198 results

Project

1-Wire Weather Station

The weather station in this project is quite basic, measuring only temperature, pressure, and humidity, but it may be easily expanded to measure other weather components, such as wind speed and rainfall. The design is based on using a series of…

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 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

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…

Image

from article Pine nut

Result thumbnail
Pine nuts in their hard shell (Mexican piñon pine, Pinus cembroides). (Photo by Steve Hurst, U.S. Department of Agriculture–Natural Resources Conservation Service PLANTS Database)

Image

from article Pine nut

Result thumbnail
Cone containing pine nuts (stone pine, Pinus pinea). (Photo by Vito Buono, Bari, Italy)

Image

from article Biofilm

Result thumbnail
Biofilms are highly structured communities of microorganisms that are surface-associated or attached to one another, and are enclosed within a self-produced protective extracellular matrix. Biofilm formation and actions involve a number of stages:…

Image

from article Ctenothrissiformes

Result thumbnail
A Cretaceous ctenothrissiform fossil, Ctenothrissa sp. (order Ctenothrissiformes), on a limestone matrix found in Lebanon. Size: 90 mm (3.5 in.). (Photo courtesy of The Virtual Fossil Museum)

Image

from article Pyroclastic rocks

Result thumbnail
Distribution downwind of the pyroclastic fall deposit from the climactic eruption of Mount St. Helens, Washington, on May 18, 1980. The contours (isopachs) are drawn through points of measured equal thickness (in centimeters) of this ash layer.…

Image

from article Pyroclastic rocks

Result thumbnail
Aerial view in March 1998 of the fan-shaped pyroclastic delta formed by repeated entries of pyroclastic flows and surges into the Caribbean Sea during the Soufrière Hills Volcano eruption in 1996–1997. (Photograph by R.P. Hoblitt, USGS)

Image

from article Pyroclastic rocks

Result thumbnail
Observed or postulated mechanisms for the generation of pyroclastic flow and surge deposits (from W. E. Scott, 1989). (a, b) Mechanisms that commonly produce block-and-ash flow deposits. (b, c) Mechanisms that trigger laterally directed blasts.…

Image

from article Pyroclastic rocks

Result thumbnail
Some variations in pyroclastic rock formations. (a) Layers of pyroclastic fall deposits from the eruption plume of the June 15, 1991, explosive eruption of Mount Pinatubo (Luzon, Philippines). This exposure, located about 9 km (5.5 mi) southeast of…

Image

from article Food science

Result thumbnail
Food scientist examining a tomato. (Credit: Adam Gault/Age Fotostock)

Image

from article Animal testing

Result thumbnail
Mice are the most commonly used vertebrate species in animal testing and research. (Credit: Dolores Bonaparte)

Image

from article Animal testing

Result thumbnail
The use of animals in biomedical research remains essential, but the handling of these sentient beings must be done humanely to minimize and prevent animal harm. (Credit: U.S. Department of Agriculture)

Image

from article Common cold

Result thumbnail
Adenovirus structure. An adenovirus binds to the host cell via its fiber through the knob at the end of the fiber "spikes" on the capsid (protein coat) surface. (Credit: M. K. Cowan and H. Smith; copyright © McGraw Hill)

Image

from article Common cold

Result thumbnail
Human respiratory system. Common cold viruses enter through the nose, mouth, or eyes, infecting epithelial cells of the oropharynx. (Credit: M. K. Cowan and H. Smith; copyright © McGraw Hill)

Image

from article Common cold

Result thumbnail
Life cycle of a double-stranded DNA virus, such as an adenovirus. The virus attaches to specific receptors, after which it is taken up by the cell. Following entry into the cell, the viral capsid (protein coat) is digested, releasing DNA, which…

Image

from article Common cold

Result thumbnail
Electron micrograph (tinted green) of human coronavirus 229E particles. Coronaviruses are named for the corona, or halo, surrounding the capsid (protein coat). The crown-like corona results from the presence of viral spikes protruding from the viral…

Image

from article Earth's interior

Result thumbnail
Speculative models of the interiors of the terrestrial planets. All are rocky, divided into a crust (not shown here), mantle, and metallic core. (After R. T. Merrill and M. W. McElhinny, The Earth's Magnetic Field, Academic Press, 1983)

Image

from article Earth's interior

Result thumbnail
Preliminary Reference Earth Model (PREM) for P- and S-wave velocities, vp and vs, and density ρ. In the part of the upper mantle where the model is anisotropic, velocities are given in both the vertical and horizontal direction. The broken lines…

Image

from article Earth's interior

Result thumbnail
Variations of gravity and pressure inside the Earth. 1 m = 3.3 ft. 1 megabar = 100 GPa. (After P. Melchior, The Physics of the Earth's Core, Pergamon Press, 1986)

Image

from article Earth's interior

Result thumbnail
Density versus depth for several mantle constituents along the 1400°C (2552°F) adiabat. Data points show the density variation of PREM. All three constituents shown here contain magnesium-rich silicates. (After D. L. Anderson, Where on Earth is the…

Image

from article Earth's interior

Result thumbnail
P-wave velocity anomalies above the core–mantle boundary in terms of spherical harmonics up to degree and order 6, obtained by inverting P-wave travel time data. Positive perturbations indicate faster-than-average material. Contour interval = 25…

Image

from article Earth's interior

Result thumbnail
Speculative, schematic model of the core–mantle boundary layer. A heterogeneous chemical boundary layer is embedded in a thermal boundary layer. Large-scale mantle circulation transports chemical heterogeneity to the base of the mantle as well as…

Image

from article Earth's interior

Result thumbnail
Schematic temperature profile of the mantle. Subsequent estimates of core temperature are higher than suggested in the figure; the temperature jump across the thermal boundary layer at the base of the mantle will then be correspondingly higher. °F =…

Image

from article Earth's interior

Result thumbnail
Schematic temperature profile of the core. The melting-point curve for the core is substantially below the melting point of pure iron. All temperatures may have to be raised to correspond with further estimates of the melting point of iron. °F = (K…

Image

from article Earth's interior

Result thumbnail
Contour plots of the radial component of the magnetic field at the core–mantle boundary (a) for the year 1715 and (b) for 1980. The contour interval is 100 microteslas; solid-line contours represent flux into the core, and broken-line contours…

Image

from article Anthrax

Result thumbnail
A color-enhanced scanning electron micrograph showing splenic tissue from a monkey with inhalation anthrax. Rod-shaped bacilli of Bacillus anthracis (yellow) and an erythrocyte (red) are shown. (Credit: Arthur Friedlander/National Institute of…

Image

from article Anthrax

Result thumbnail
Micrograph (stained with hematoxylin and eosin) showing submucosal hemorrhage in the small intestine of a person fatally affected by gastrointestinal anthrax. (Credit: Marshal Fox/Centers for Disease Control and Prevention)

Image

from article Tumor virus

Result thumbnail
Under certain conditions, human papillomaviruses are capable of causing cancer in humans. (Credit: Laboratory of Tumor Virus Biology, National Cancer Institute)

Image

from article Ecosystem

Result thumbnail
Levels of organization in ecosystems, which involve both biotic (living) components and abiotic (nonliving, physical) components. (Copyright © McGraw-Hill Education)

Image

from article Ecosystem

Result thumbnail
General model of energy flow through ecosystems. (Copyright © McGraw-Hill Education)

Image

from article Ecosystem

Result thumbnail
Food chains are limited by energy transfer. In this illustration, energy is transferred from the Sun to a plant (producer) to a primary consumer and to a secondary consumer. Energy is used by the producer and consumer organisms and is lost to the…

Image

from article Ecosystem

Result thumbnail
General model of the nitrogen cycle in ecosystems. (Copyright © McGraw-Hill Education)

Image

from article Ecosystem

Result thumbnail
General model of the carbon cycle in ecosystems: (A) carbon dioxide (CO2) from the air; (B) carbon from decomposition; (C) carbon from fossil fuels; (D) natural events (for example, forest fires and volcanoes) release CO2 into the air. (Copyright ©…

Image

from article Salicylate

Result thumbnail
Chemical structures of (a) salicylate, the conjugate base of (b) salicylic acid, and the nonsteroidal anti-inflammatory drug (NSAID) (c) acetylsalicylic acid (aspirin).

Image

from article Meningococcus

Result thumbnail
A photomicrograph reveals the presence of the bacterium Neisseria meningitidis, which can be pathogenic, leading to meningococcal meningitis. (Credit: James Volk/Centers for Disease Control and Prevention)

Image

from article Poplar

Result thumbnail
Quaking aspen (Populus tremuloides). (Photo courtesy of North Dakota State Soil Conservation Committee, USDA–NRCS PLANTS Database)

Image

from article Poplar

Result thumbnail
Common poplar species. (a) Quaking aspen (P. tremuloides); leaf scar with an axial bud, leaf, and twig. (b) Bigtooth aspen (P. grandidentata); leaf, terminal bud, and twig. (c) Cottonwood poplar (P. deltoides); leaf, leaf scar, terminal bud, and…

Image

from article Hydrological consequences of global warming

Result thumbnail
The hydrologic cycle is characterized by evaporation and transpiration from the surfaces; transport of water vapor in the atmosphere by the wind, clouds, and precipitation; and water storage in snow, glaciers, groundwater, and oceans. Units: 1000…

Image

from article Hydrological consequences of global warming

Result thumbnail
Spatial patterns of climate model projections of (a) precipitation, (b) soil moisture, (c) runoff, and (d) evaporation for 2090–2099 under the mid-range A1B emission scenario from the Intergovernmental Panel for Climate Change 2007. (Climate Change…

Image

from article Biodiversity

Result thumbnail
Global biodiversity hotspots. There are more than 30 biodiversity hotspots located around the world. These areas have experienced severe habitat losses (at least 70%) as the result of human activities, hampering the work of conservationists in their…

Image

from article Biodiversity

Result thumbnail
A regional analysis of 25 oceanic regions shows that 92% of all known biodiversity falls into a dozen groups, of which crustaceans (for example, crabs, shrimps, and lobsters), mollusks (for example, snails, bivalves, squids, and octopus), and fish…

Image

from article Biodiversity

Result thumbnail
Ecosystem function (a) as a positive, linear function of biodiversity and (b) as a nonlinear, satiating function of biodiversity. (Copyright © McGraw Hill)

Image

from article Micrometeorology

Result thumbnail
Soundings of temperature versus height for (a) day time and (b) nighttime obtained by radiosonde measurements during the Wangara experiment near Hay, New South Wales, Australia, in 1967. Soundings are shown for 9 A.M. through 9 P.M. on day 33 of the…

Image

from article Micrometeorology

Result thumbnail
The 3 P.M. sounding from Fig. 1a showing the layers of the daytime convective boundary layer.

Image

from article Urodela

Result thumbnail
A typical member of the order Urodela: the longtail salamander (Eurycea longicauda). (Credit: Ryan Hagerty/U.S. Fish and Wildlife Service)

Image

from article Urodela

Result thumbnail
Southern dwarf siren (Pseudobranchus axanthus), which has undergone limb degeneration and retains only tiny forelimbs. (Credit: U.S. Geological Survey)

Learn more about AccessScience

a female college student looking at the screen of her silver-cased laptop computer
Watch the YouTube video

flyer thumbnail

Download the flyerGet Adobe Acrobat Reader pdf icon