|
Air Bubble
A bubble is a globule of one substance in another, usually gas in a liquid. Due to the Marangoni effect, bubbles may remain intact when they reach the surface of the immersive substance. Common examples Bubbles are seen in many places in everyday life, for example: * As spontaneous nucleation of supersaturated carbon dioxide in soft drinks * As water vapor in boiling water * As air mixed into agitated water, such as below a waterfall * As sea foam * As a soap bubble * As given off in chemical reactions, e.g., baking soda + vinegar * As a gas trapped in glass during its manufacture * As the indicator in a spirit level Physics and chemistry Bubbles form and coalesce into globular shapes because those shapes are at a lower energy state. For the physics and chemistry behind it, see nucleation. Appearance Bubbles are visible because they have a different refractive index (RI) than the surrounding substance. For example, the RI of air is approximately 1.0003 and the RI of water ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isla De Corbera, Santander, España, 2019-08-15, DD 68
Isla or ISLA may refer to: Organizations * International Securities Lending Association, a trade association * International School of Los Angeles * International Bilingual School, later named International School of Los Angeles People * Isla (given name) * Víctor Isla, Peruvian politician and a Congressman representing Loreto for the 2006–2011 term * Mauricio Isla, Chilean football player * Isla Fisher, actress and author Music * ''Isla'' (Portico Quartet album), a 2009 album by Portico Quartet Places *Isla, Queensland, a locality in the Shire of Banana, Australia * Mt. Izla, location of ancient Christian monasteries, on the border between Turkey and Syria * Isla (Cantabria), a village in the Spanish region of Cantabria * River Isla, Perthshire, a tributary of the River Tay in Perthshire, Scotland; flows through Glen Isla and Strathmore * River Isla, Moray a tributary of the River Deveron in North-East Scotland; flows through Keith in Banffshire * Senglea, Isla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Internal Reflection
Total internal reflection (TIR) is the optical phenomenon in which waves arriving at the interface (boundary) from one medium to another (e.g., from water to air) are not refracted into the second ("external") medium, but completely reflected back into the first ("internal") medium. It occurs when the second medium has a higher wave speed (i.e., lower refractive index) than the first, and the waves are incident at a sufficiently oblique angle on the interface. For example, the water-to-air surface in a typical fish tank, when viewed obliquely from below, reflects the underwater scene like a mirror with no loss of brightness (Fig.1). TIR occurs not only with electromagnetic waves such as light and microwaves, but also with other types of waves, including sound and water waves. If the waves are capable of forming a narrow beam (Fig.2), the reflection tends to be described in terms of " rays" rather than waves; in a medium whose properties are independent of direction, such as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Torpedo
A modern torpedo is an underwater ranged weapon launched above or below the water surface, self-propelled towards a target, and with an explosive warhead designed to detonate either on contact with or in proximity to the target. Historically, such a device was called an automotive, automobile, locomotive, or fish torpedo; colloquially a ''fish''. The term ''torpedo'' originally applied to a variety of devices, most of which would today be called mines. From about 1900, ''torpedo'' has been used strictly to designate a self-propelled underwater explosive device. While the 19th-century battleship had evolved primarily with a view to engagements between armored warships with large-caliber guns, the invention and refinement of torpedoes from the 1860s onwards allowed small torpedo boats and other lighter surface vessels, submarines/ submersibles, even improvised fishing boats or frogmen, and later light aircraft, to destroy large ships without the need of large guns, though ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bazooka
Bazooka () is the common name for a man-portable recoilless anti-tank rocket launcher weapon, widely deployed by the United States Army, especially during World War II. Also referred to as the "stovepipe", the innovative bazooka was among the first generation of rocket-propelled anti-tank weapons used in infantry combat. Featuring a solid-propellant rocket for propulsion, it allowed for high-explosive anti-tank (HEAT) warheads to be delivered against armored vehicles, machine gun nests, and fortified bunkers at ranges beyond that of a standard thrown grenade or mine. The universally applied nickname arose from the M1 variant's vague resemblance to the musical instrument called a " bazooka" invented and popularized by 1930s American comedian Bob Burns. During World War II, the German armed forces captured several bazookas in early North African and Eastern Front encounters and soon reverse engineered their own version, increasing the warhead diameter to 8.8 cm (amon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ultrasound
Ultrasound is sound waves with frequencies higher than the upper audible limit of human hearing. Ultrasound is not different from "normal" (audible) sound in its physical properties, except that humans cannot hear it. This limit varies from person to person and is approximately 20 kilohertz (20,000 hertz) in healthy young adults. Ultrasound devices operate with frequencies from 20 kHz up to several gigahertz. Ultrasound is used in many different fields. Ultrasonic devices are used to detect objects and measure distances. Ultrasound imaging or sonography is often used in medicine. In the nondestructive testing of products and structures, ultrasound is used to detect invisible flaws. Industrially, ultrasound is used for cleaning, mixing, and accelerating chemical processes. Animals such as bats and porpoises use ultrasound for locating prey and obstacles. History Acoustics, the science of sound, starts as far back as Pythagoras in the 6th century BC, who ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cavitation
Cavitation is a phenomenon in which the static pressure of a liquid reduces to below the liquid's vapour pressure, leading to the formation of small vapor-filled cavities in the liquid. When subjected to higher pressure, these cavities, called "bubbles" or "voids", collapse and can generate shock waves that may damage machinery. These shock waves are strong when they are very close to the imploded bubble, but rapidly weaken as they propagate away from the implosion. Cavitation is a significant cause of wear in some engineering contexts. Collapsing voids that implode near to a metal surface cause cyclic stress through repeated implosion. This results in surface fatigue of the metal causing a type of wear also called "cavitation". The most common examples of this kind of wear are to pump impellers, and bends where a sudden change in the direction of liquid occurs. Cavitation is usually divided into two classes of behavior: inertial (or transient) cavitation and non-inertial ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Andrea Prosperetti
Andrea Prosperetti is the Distinguished Professor of Mechanical Engineering at the University of Houston, the Berkhoff Professor of Applied Physics at the University of Twente in the Netherlands and an elected member of the National Academy of Engineering in 2012"for contributions to the fundamentals and applications of multiphase flows". He is known for his work in the field of multiphase flows including bubble dynamics and cavitation. He was the editor-in-chief of the International Journal of Multiphase Flow and serves on the editorial board of the Annual Review of Fluid Mechanics. He completed his doctoral work in 1974 at the California Institute of Technology under the supervision of Milton Plesset (of the Rayleigh–Plesset equation and Møller–Plesset perturbation theory) and holds a B.S. in Physics from Universitá di Milano, Italy (1968). Prosperetti was awarded the Fluid Dynamics Prize (the highest award in Fluid Mechanics) by the American Physical Society in 200 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microfluidics
Microfluidics refers to the behavior, precise control, and manipulation of fluids that are geometrically constrained to a small scale (typically sub-millimeter) at which surface forces dominate volumetric forces. It is a multidisciplinary field that involves engineering, physics, chemistry, biochemistry, nanotechnology, and biotechnology. It has practical applications in the design of systems that process low volumes of fluids to achieve multiplexing, automation, and high-throughput screening. Microfluidics emerged in the beginning of the 1980s and is used in the development of inkjet printheads, DNA chips, lab-on-a-chip technology, micro-propulsion, and micro-thermal technologies. Typically, micro means one of the following features: * Small volumes (μL, nL, pL, fL) * Small size * Low energy consumption * Microdomain effects Typically microfluidic systems transport, mix, separate, or otherwise process fluids. Various applications rely on passive fluid control using capillary ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inkjet Printer
Inkjet printing is a type of computer printing that recreates a digital image by propelling droplets of ink onto paper and plastic substrates. Inkjet printers were the most commonly used type of printer in 2008, and range from small inexpensive consumer models to expensive professional machines. By 2019, laser printers outsold inkjet printers by nearly a 2:1 ratio, 9.6% vs 5.1% of all computer peripherals. The concept of inkjet printing originated in the 20th century, and the technology was first extensively developed in the early 1950s. While working at Canon in Japan, Ichiro Endo suggested the idea for a "Bubble jet" printer, while around the same time Jon Vaught at HP was developing a similar idea. In the late 1970s, inkjet printers that could reproduce digital images generated by computers were developed, mainly by Epson, Hewlett-Packard (HP) and Canon. In the worldwide consumer market, four manufacturers account for the majority of inkjet printer sales: Canon, HP, Eps ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Contrast-enhanced Ultrasound
Contrast-enhanced ultrasound (CEUS) is the application of ultrasound contrast medium to traditional medical sonography. Ultrasound contrast agents rely on the different ways in which sound waves are reflected from interfaces between substances. This may be the surface of a small air bubble or a more complex structure. Commercially available contrast media are gas-filled microbubbles that are administered intravenously to the systemic circulation. Microbubbles have a high degree of echogenicity (the ability of an object to reflect ultrasound waves). There is a great difference in echogenicity between the gas in the microbubbles and the soft tissue surroundings of the body. Thus, ultrasonic imaging using microbubble contrast agents enhances the ultrasound backscatter, (reflection) of the ultrasound waves, to produce a sonogram with increased contrast due to the high echogenicity difference. Contrast-enhanced ultrasound can be used to image blood perfusion in organs, measure bl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ultrasound
Ultrasound is sound waves with frequencies higher than the upper audible limit of human hearing. Ultrasound is not different from "normal" (audible) sound in its physical properties, except that humans cannot hear it. This limit varies from person to person and is approximately 20 kilohertz (20,000 hertz) in healthy young adults. Ultrasound devices operate with frequencies from 20 kHz up to several gigahertz. Ultrasound is used in many different fields. Ultrasonic devices are used to detect objects and measure distances. Ultrasound imaging or sonography is often used in medicine. In the nondestructive testing of products and structures, ultrasound is used to detect invisible flaws. Industrially, ultrasound is used for cleaning, mixing, and accelerating chemical processes. Animals such as bats and porpoises use ultrasound for locating prey and obstacles. History Acoustics, the science of sound, starts as far back as Pythagoras in the 6th century BC, who ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bubblegram
A bubblegram (also known as laser crystal, 3D crystal engraving or vitrography) is a solid block of glass or transparent plastic that has been exposed to laser beams to generate three-dimensional Three-dimensional space (also: 3D space, 3-space or, rarely, tri-dimensional space) is a geometric setting in which three values (called '' parameters'') are required to determine the position of an element (i.e., point). This is the inform ... designs inside. The image is composed of many small points of fracture or other visible deformations and appears to float inside the block. Description Each point is created by a laser beam focused to high intensity at that location by a computer-controlled opto-mechanical system. A complex or highly detailed image occupying a 5 cm (2 inch) cubic volume typically requires the creation of tens of thousands of such points. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
