Harwood AP CHEM Project

NTREES

As the only super carrier powered by eight nuclear reactors, Enterprise will be the first nuclear powered aircraft carrier to undergo an inactivation.

Nuclear power is particularly suitable for vessels which need to be at sea for long periods without refuelling, or for powerful submarine propulsion. Some 140 ships are powered by more than 180 small nuclear reactors and more than 12,000 reactor years of marine operation has been accumulated. Most are submarines, but they range from icebreakers to aircraft carriers.

USS Enterprise, powered by eight reactor units in 1960

ithout a single radiological incident, over a period of more than 50 years.

A nuclear rocket engine uses a nuclear reactor to heat hydrogen to very high temperatures, which expands through a nozzle to generate thrust.

The team recently used Marshall's Nuclear Thermal Rocket Element Environmental Simulator, or NTREES, to perform realistic, non-nuclear testing of various materials for nuclear thermal rocket fuel elements. In an actual reactor, the fuel elements would contain uranium, but no radioactive materials are used during the NTREES tests. Among the fuel options are a graphite composite and a "cermet" composite - a blend of ceramics and metals. Both materials were investigated in previous NASA and U.S. Department of Energy research efforts.

A first-generation nuclear cryogenic propulsion system could propel human explorers to Mars more efficiently than conventional spacecraft, reducing crews' exposure to harmful space radiation and other effects of long-term space missions. It could also transport heavy cargo and science payloads. Further development and use of a first-generation nuclear system could also provide the foundation for developing extremely advanced propulsion technologies and systems in the future - ones that could take human crews even farther into the solar system.

About 5 bombs per second are dropped out the back and detonated to propel the craft along. A huge shock plate with shock absorbers make up the base of the craft.

This project ended with the nuclear test ban treaty in the 60’s.

Well, rather than bring your fuel along, why not get it as you go. This Bussard Interstellar Ramjet concept, from the 1960’s

roject Orion was the first serious attempt to design a nuclear pulse rocket. The design effort was carried out at General Atomics in the late 1950s and early 1960s. The idea of Orion was to react small directional nuclear explosives against a large steel pusher plate attached to the spacecraft with shock absorbers. Efficient directional explosives maximized the momentum transfer, leading to specific impulses in the range of 6,000 seconds, or about 12 times that of the Space Shuttle Main Engine. With refinements, a theoretical maximum of 100,000 seconds (1 MN·s/kg) might be possible. Thrusts were in the millions of tons, allowing spacecraft larger than eight million tons to be built with 1958 materials.

The reference design was to be constructed of steel using submarine-style construction, with a crew of more than 200 and a vehicle takeoff weight of several thousand tons. This low-tech single-stage reference design would reach Mars and back in four weeks from the Earth’s surface (compared to ≈50 weeks for NASA’s current chemically powered reference mission). The same craft could visit Saturn’s moons in a seven-month mission (compared to chemically powered missions of about nine years).

A number of engineering problems were found, and solved, over the course of the project. Many of these related to crew shielding and pusher-plate lifetime. The system appeared to be entirely workable, and was under serious development in the United States, when the project was shut down in 1965. The primary reason given was that the Partial Test Ban Treaty made it illegal to detonate nuclear explosions in space (before the treaty, the United States and the Soviet Union had already detonated at least nine nuclear bombs, including thermonuclear bombs, in space; i.e., at altitudes over 100 km).

Most current bactericidal antimicrobials, which are the focus of this review, inhibit DNA synthesis, RNA synthesis, cell wall synthesis, or protein synthesis

Quinolones are derivatives of nalidixic acid, which was discovered as a byproduct of chloroquine (quinine) synthesis

Nalidixic acid and other first generation quinolones (i.e., oxolinic acid) are rarely used today owing to their toxicity17. Second (i.e., ciprofloxacin), third (i.e., levofloxacin) and fourth (i.e., gemifloxacin) generation quinolone antibiotics (Table 1) can be classified based on their chemical structure along with qualitative differences in how these drugs kill bacteria

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Bioglass® is a clear bioactive material made of calcium, phosphorous, silicon, and sodium salts. It is a type of artificially made glass classified as a bioceramic. It chemically reacts with body fluids to form a bond at the surfaces of tissues and bones. The elements that make up Bioglass® are needed to repair and grow tissues and bones.

There is no risk of disease or rejection since Bioglass® is made completely of elements found in the human body.

In 1987, a group of experts defined the word biomaterial as “a non-viable material used in a medical device, intended to interact with biological systems” (Europeon Society of Biomaterials Conference, 1987). This definition reflected the state of the field at the time, which was focused on developing materials and coatings to prevent the rejection of implantable medical device