737) Yvonne Brill

Yvonne Brill, (Yvonne Madelaine Claeys), Canadian-born American rocket scientist (born Dec. 30, 1924, St. Vital, Man.—died March 27, 2013, Princeton, N.J.), pioneered the electrothermal hydrazine thruster—a more fuel-efficient rocket thruster designed to keep communications satellites from slipping out of orbit. Brill was not admitted to the men-only engineering department at the University of Manitoba, but she graduated (1945) at the top of her class with degrees in chemistry and mathematics. (She later received a master’s degree [1951] in chemistry from the University of Southern California.) Despite her lack of an engineering degree, she was recruited (1945) by Douglas Aircraft (which became the basis for the RAND Corporation) in Santa Monica, Calif., to help create the first designs for an American satellite. Throughout that period she was believed to be the only woman in the U.S. conducting research in the field of rocket science. Brill put her career on hold in the late 1950s to stay home with her children, but she returned (1966) to work full-time for RCA’s rocket subsidiary, where she developed the thruster that rapidly became the industry standard. She also was involved in developing the Nova rockets that were used in American Moon missions; Tiros, the first weather satellite; the Atmosphere Explorer, the first upper-atmosphere satellite; and the Mars Observer satellite (1992). While working (1981–83) for NASA, she contributed to the development of a rocket engine for the space shuttle. Brill received numerous awards for her groundbreaking work, and in 2010 she was inducted into the National Inventors Hall of Fame.

Yvonne Madelaine Brill (née Claeys; December 30, 1924 – March 27, 2013) was a Canadian-American rocket and jet propulsion engineer. She is responsible for inventing the fuel-efficient rocket thruster that keeps satellites in orbit today. During her career she was involved in a broad range of national space programs in the United States, including NASA and the International Maritime Satellite Organization.

Early life

Brill was born in Winnipeg, Manitoba, Canada. Her parents were immigrants from Belgium, making her and her two siblings first-generation Canadians. While she was in high school, one of her teachers told her that a woman wouldn't get anywhere in science. Her father wanted her to stay at home and open a little shop in town[4]. She definitely did not listen to them. She attended the University of Manitoba, but was barred from studying engineering because of her gender, so she studied chemistry and mathematics. She graduated at the top of her class in 1945 with a bachelor's degree in chemistry and mathematics. She went on to study at the University of Southern California, where she took night classes and graduated in 1951 with a master's degree in chemistry.

Career

Brill's work in satellite propulsion systems resulted in a number of significant developments. She developed the concept for a new rocket engine, the hydrazine resistojet, and proposed the use of a single propellant because of the value and simplicity that it would provide. Her invention resulted in not only higher engine performance, but also increased the reliability of the propulsion system. The reduction in propellant weight requirements enabled either increased payload capability or extended mission life.

Brill was believed to be the only woman in the United States researching rocket science in the 1940s. In 1945 she was recruited by Douglas Aircraft despite her lack of a degree in engineering to help develop the first American satellites. She put her career on hold in the 1950s to stay at home and raise her children. Then in 1966 she returned to the field, where she rejoined the Radio Corporation of America (RCA).

Brill invented the hydrazine resistojet propulsion system in 1967, for which she holds U.S. Patent No. 3,807,657. Her invention became a standard in the industry and has translated into millions of dollars of increased revenue for commercial communications satellite owners.

Brill contributed to the propulsion systems of TIROS, the first weather satellite; Nova, a series of rocket designs that were used in American Moon missions; Explorer 32, the first upper-atmosphere satellite; and the Mars Observer, which in 1992 almost entered a Mars orbit before losing communication with Earth.

Awards and honors

Brill was awarded the AIAA Wyld Propulsion Award (2002) and the American Association of Engineering Societies John Fritz Medal (2009). In 1980, Harper's Bazaar and the DeBeers Corporation gave her their Diamond Superwoman award for returning to a successful career after starting a family. In 2001 she was awarded the NASA Distinguished Public Service Medal.[10] In 2010 President Barack Obama presented her with the National Medal of Technology and Innovation. In 2010 she was also inducted into the National Inventors Hall of Fame.

She was elected to the National Academy of Engineering in 1987. She was named fellow of The Society of Women Engineers (SWE) in 1985 and received its highest honor, the Achievement Award, the following year.

The Yvonne C. Brill Lectureship of the American Institute of Aeronautics and Astronautics (AIAA) is named in her honor and presented annually.

As her life dwindled down, she spent the last twenty years promoting women in science and engineering and nominated them for awards and prizes she thought they deserved.

Death

A longtime resident of the Skillman section of Montgomery Township, New Jersey, United States, Brill died of complications of breast cancer in Princeton, New Jersey.

An obituary of Brill published in the March 30, 2013 issue of the New York Times originally began: "She made a mean beef stroganoff, followed her husband from job to job and took eight years off from work to raise three children". The obituary was heavily criticized for leading with and overemphasizing Brill's gender and family life, rather than her scientific and career accomplishments and was cited as an example of an article that failed the Finkbeiner test. The Times later dropped the reference to her cooking and changed the lead of the article.

Hi,

#7800. 35% of a number is two times 75% of another number. What is the ratio of the first and second numbers respectively?

636) Metamorphic Rocks

Metamorphic rocks start as one type of rock an - with pressure, heat, and time - gradually change into a new type of rock.

The term “metamorphosis” is most often used in reference to the process of a caterpillar changing into a butterfly. However, the word “metamorphosis” is a broad term that indicates a change from one thing to another. Even rocks, a seemingly constant substance, can change into a new type of rock. Rocks that undergo a change to form a new rock are referred to as metamorphic rocks.

In the rock cycle, there are three different types of rocks: sedimentary, igneous, and metamorphic. Sedimentary and igneous rocks began as something other than rock. Sedimentary rocks were originally sediments, which were compacted under high pressure. Igneous rocks formed when liquid magma or lav - magma that has emerged onto the surface of the Earth - cooled and hardened. A metamorphic rock, on the other hand, began as a rock - either a sedimentary, igneous, or even a different sort of metamorphic rock. Then, due to various conditions within the Earth, the existing rock was changed into a new kind of metamorphic rock.

The conditions required to form a metamorphic rock are very specific. The existing rock must be exposed to high heat, high pressure, or to a hot, mineral-rich fluid. Usually, all three of these circumstances are met. These conditions are most often found either deep in Earth’s crust or at plate boundaries where tectonic plates collide. In order to create metamorphic rock, it is vital that the existing rock remain solid and not melt. If there is too much heat or pressure, the rock will melt and become magma. This will result in the formation of an igneous rock, not a metamorphic rock.

Consider how granite changes form. Granite is an igneous rock that forms when magma cools relatively slowly underground. It is usually composed primarily of the minerals quartz, feldspar, and mica. When granite is subjected to intense heat and pressure, it changes into a metamorphic rock called gneiss.
Slate is another common metamorphic rock that forms from shale. Limestone, a sedimentary rock, will change into the metamorphic rock marble if the right conditions are met.

Although metamorphic rocks typically form deep in the planet’s crust, they are often exposed on the surface of the Earth. This happens due to geologic uplift and the erosion of the rock and soil above them. At the surface, metamorphic rocks will be exposed to weathering processes and may break down into sediment. These sediments could then be compressed to form sedimentary rocks, which would start the entire cycle anew.

Hi sybil8464,

Welcome to the forum!

Original value = 304,000.
Reduced value = 232,000.
Difference = 72,000 decrease.
Percentage decrease = -23.68% approximately, roughly -23.7%.

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#3639. What does the noun equerry mean?

#3640. What does the noun equestrian mean?

635) Igneous Rocks

Igneous rocks are one of three main types of rocks (along with sedimentary and metamorphic), and they include both intrusive and extrusive rocks.

Igneous rocks form when magma (molten rock) cools and crystallizes, either at volcanoes on the surface of the Earth or while the melted rock is still inside the crust. All magma develops underground, in the lower crust or upper mantle, because of the intense heat there.

Igneous rocks can have many different compositions, depending on the magma they cool from. They can also look different based on their cooling conditions. For example, two rocks from identical magma can become either rhyolite or granite, depending on whether they cool quickly or slowly.

The two main categories of igneous rocks are extrusive and intrusive. Extrusive rocks are formed on the surface of the Earth from lava, which is magma that has emerged from underground. Intrusive rocks are formed from magma that cools and solidifies within the crust of the planet.

When lava comes out of a volcano and solidifies into extrusive igneous rock, also called volcanic, the rock cools very quickly. Crystals inside solid volcanic rocks are small because they do not have much time to form until the rock cools all the way, which stops the crystal growth. These fine-grained rocks are known as aphaniti - from a Greek word meaning “invisible.” They are given this name because the crystals that form within them are so small that they can be seen only with a microscope. If lava cools almost instantly, the rocks that form are glassy with no individual crystals, like obsidian. There are many other kinds of extrusive igneous rocks. For example, Pele’s hair is long, extremely thin strands of volcanic glass, while pahoehoe is smooth lava that forms shiny, rounded piles.

Intrusive rocks, also called plutonic rocks, cool slowly without ever reaching the surface. They have large crystals that are usually visible without a microscope. This surface is known as a phaneritic texture. Perhaps the best-known phaneritic rock is granite. One extreme type of phaneritic rock is called pegmatite, found often in the U.S. state of Maine. Pegmatite can have a huge variety of crystal shapes and sizes, including some larger than a human hand.

Hi,

#1502. What are 'Paschen bodies'?

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Excellent!

M # 601. A solid sphere of radius 7 centimeters is melted and recast into a cone of same radius of the sphere. Calculate the height of the cone.

634) Sedimentary Rocks

Sedimentary rocks are one of three main types of rocks, along with igneous and metamorphic. They are formed on or near the Earth’s surface from the compression of ocean sediments or other processes.

Sedimentary rocks are formed on or near the Earth’s surface, in contrast to metamorphic and igneous rocks, which are formed deep within the Earth. The most important geological processes that lead to the creation of sedimentary rocks are erosion, weathering, dissolution, precipitation, and lithification.

Erosion and weathering include the effects of wind and rain, which slowly break down large rocks into smaller ones. Erosion and weathering transform boulders and even mountains into sediments, such as sand or mud. Dissolution is a form of weathering—chemical weathering. With this process, water that is slightly acidic slowly wears away stone. These three processes create the raw materials for new, sedimentary rocks.

Precipitation and lithification are processes that build new rocks or minerals. Precipitation is the formation of rocks and minerals from chemicals that precipitate from water. For example, as a lake dries up over many thousands of years, it leaves behind mineral deposits; this is what happened in California’s Death Valley. Finally, lithification is the process by which clay, sand, and other sediments on the bottom of the ocean or other bodies of water are slowly compacted into rocks from the weight of overlying sediments.

Sedimentary rocks can be organized into two categories. The first is detrital rock, which comes from the erosion and accumulation of rock fragments, sediment, or other materials—categorized in total as detritus, or debris. The other is chemical rock, produced from the dissolution and precipitation of minerals.

Detritus can be either organic or inorganic. Organic detrital rocks form when parts of plants and animals decay in the ground, leaving behind biological material that is compressed and becomes rock. Coal is a sedimentary rock formed over millions of years from compressed plants. Inorganic detrital rocks, on the other hand, are formed from broken up pieces of other rocks, not from living things. These rocks are often called clastic sedimentary rocks. One of the best-known clastic sedimentary rocks is sandstone. Sandstone is formed from layers of sandy sediment that is compacted and lithified.

Chemical sedimentary rocks can be found in many places, from the ocean to deserts to caves. For instance, most limestone forms at the bottom of the ocean from the precipitation of calcium carbonate and the remains of marine animals with shells. If limestone is found on land, it can be assumed that the area used to be under water. Cave formations are also sedimentary rocks, but they are produced very differently. Stalagmites and stalactites form when water passes through bedrock and picks up calcium and carbonate ions. When the chemical-rich water makes its way into a cave, the water evaporates and leaves behind calcium carbonate on the ceiling, forming a stalactite, or on the floor of the cave, creating a stalagmite.

Hi,

#4809. If 10% of a number is 70, then what is 25% of that number?

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Neat work!

CG # 118. Show that A(6,4), B(5,-2), and C(7,-2) are the vertices of an isosceles triangle.