Questões de Concursos Inglês

NASA Researchers Studying Advanced Nuclear Rocket Technologies

January 9, 2013

By using an innovative test facility at NASA’s Marshall Space Flight Center in Huntsville, Ala., researchers are able to use non-nuclear materials to simulate nuclear thermal rocket fuels - ones capable of propelling bold new exploration missions to the Red Planet and beyond. The Nuclear Cryogenic Propulsion Stage team is tackling a three-year project to demonstrate the viability of nuclear propulsion system technologies. A nuclear rocket engine uses a nuclear reactor to heat hydrogen to very high temperatures, which expands through a nozzle to generate thrust. Nuclear rocket engines generate higher thrust and are more than twice as efficient as conventional chemical rocket engines.

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.

Nuclear-powered rocket concepts are not new; the United States conducted studies and significant ground testing from 1955 to 1973 to determine the viability of nuclear propulsion systems, but ceased testing when plans for a crewed Mars mission were deferred.

The NTREES facility is designed to test fuel elements and materials in hot flowing hydrogen, reaching pressures up to 1,000 pounds per square inch and temperatures of nearly 5,000 degrees Fahrenheit - conditions that simulate space-based nuclear propulsion systems to provide baseline data critical to the research team.

“This is vital testing, helping us reduce risks and costs associated with advanced propulsion technologies and ensuring excellent performance and results as we progress toward further system development and testing,” said Mike Houts, project manager for nuclear systems at Marshall.

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.

Building on previous, successful research and using the NTREES facility, NASA can safely and thoroughly test simulated nuclear fuel elements of various sizes, providing important test data to support the design of a future Nuclear Cryogenic Propulsion Stage. A nuclear cryogenic upper stage - its liquid- hydrogen propellant chilled to super-cold temperatures for launch - would be designed to be safe during all mission phases and would not be started until the spacecraft had reached a safe orbit and was ready to begin its journey to a distant destination. Prior to startup in a safe orbit, the nuclear system would be cold, with no fission products generated from nuclear operations, and with radiation below significant levels.

“The information we gain using this test facility will permit engineers to design rugged, efficient fuel elements and nuclear propulsion systems,” said NASA researcher Bill Emrich, who manages the NTREES facility at Marshall. “It’s our hope that it will enable us to develop a reliable, cost-effective nuclear rocket engine in the not-too-distant future."

The Nuclear Cryogenic Propulsion Stage project is part of the Advanced Exploration Systems program, which is managed by NASA’s Human Exploration and Operations Mission Directorate and includes participation by the U.S. Department of Energy. The program, which focuses on crew safety and mission operations in deep space, seeks to pioneer new approaches for rapidly developing prototype systems, demonstrating key capabilities and validating operational concepts for future vehicle development and human missions beyond Earth orbit.

Marshall researchers are partnering on the project with NASA’s Glenn Research Center in Cleveland, Ohio; NASA’s Johnson Space Center in Houston; Idaho National Laboratory in Idaho Falls; Los Alamos National Laboratory in Los Alamos, N.M.; and Oak Ridge National Laboratory in Oak Ridge, Tenn.

The Marshall Center leads development of the Space Launch System for NASA. The Science & Technology Office at Marshall strives to apply advanced concepts and capabilities to the research, development and management of a broad spectrum of NASA programs, projects and activities that fall at the very intersection of science and exploration, where every discovery and achievement furthers scientific knowledge and understanding, and supports the agency’s ambitious mission to expand humanity’s reach across the solar system. The NTREES test facility is just one of numerous cutting-edge space propulsion and science research facilities housed in the state-of- the-art Propulsion Research & Development Laboratory at Marshall, contributing to development of the Space Launch System and a variety of other NASA programs and missions.

Available in: http://www.nasa.gov

What are the best energy sources? "Best" depends on many factors - how the energy is being used, where it is being used, what energy sources are available, which sources are most convenient and reliable, which5 are easiest to use, what each costs, and the effects on public safety, health, and the environment. Making smart energy choices means understanding resources and their relative costs and benefits. Some energy sources have advantages for specific10 uses or locations. For example, fuels from petroleum are well suited for transportation because they pack a lot of energy in a small space and are easily transported and stored. Small hydroelectric installations are a good solution for supplying power or mechanical energy close15 to where it is used. Coal is widely used for power generation in many fast-developing countries - including China, India, and many others - because domestic supplies are readily available. Efficiency is an important factor in energy costs.20 How efficiently can the energy be produced, delivered, and used? How much energy value is lost in that process, and how much ends up being transformed into useful work? Industries that produce or use energy continually look for ways to improve efficiency, since this is a key to25 making their products morecompetitive. The ideal energy source - cheap, plentiful, and pollution-free - may prove unattainable in our lifetime, but that is the ultimate goal. The energy industry is continuing to improve its technologies and practices, to30 produce and use energy more efficiently and cleanly. Energy resources are often categorized as renewable or nonrenewable. Renewable energy resources are those that can be replenished quickly - examples are solar power,35 biomass, geothermal, hydroelectric, wind power, and fast-reaction nuclear power. They supply about seven percent of energy needs in the United States; theother 93 percent comes from nonrenewables. The two largest categories of renewable energy now in use in the U.S.40 are biomass - primarily wood wastes that are used by the forest products industry to generate electricity and heat - and hydroelectricity. Nonrenewable energy resources include coal, oil, natural gas, and uranium-235, which is used to fuel45 slow-reaction nuclear power. Projections of how long a nonrenewable energy resource will last depend on many changeable factors. These include the growth rate of consumption, and estimates of how much of the remaining resources can be economically recovered. New exploration50 and production technologies often increase theability of producers to locate and recover resources. World reserves of fossil energy are projected to last for many more decades - and, in the case of coal, for centuries.In: http://www.classroom-energy.org/teachers/energy_tour/pg5.html

 Generation Y
By Sally Kane, About.com Guide

Born in the mid-1980"s and later, Generation Y legal professionals are in their 20s and are just entering the workforce. With numbers estimated as high as 70 million, Generation Y (also -1- as the Millennials) is the fastest growing segment of today"s workforce. As law firms compete for available talent, employers cannot ignore the needs, desires and attitudes of this vast generation. Below are a few common traits that define Generation Y.

Tech-Savvy: Generation Y grew up with technology and rely on it to perform their jobs better. Armed with BlackBerrys, laptops, cellphones and other gadgets, Generation Y is plugged-in 24 hours a day, 7 days a week. This generation prefers to communicate through e-mail and text messaging rather than face-to-face contact and -2- webinars and online technology to traditional lecture-based presentations.

Family-Centric: The fast-track has lost much of its appeal for Generation Y who is willing to trade high pay for fewer billable hours, flexible schedules and a better work/life balance. While older generations may view this attitude as narcissistic or lacking commitment, discipline and drive, Generation Y legal professionals have a different vision of workplace expectations and prioritize family over work.

Achievement-Oriented: Nurtured and pampered -3- parents who did not want to make the mistakes of the previous generation, Generation Y is confident, ambitious and achievement-oriented. They have high expectations of their employers, seek out new challenges and are not afraid to question authority. Generation Y wants meaningful work and a solid learning curve

Team-Oriented: As children, Generation Y participated in team sports, play groups and other group activities. They value teamwork and seek the input and affirmation of others. Part of a no-person-left-behind generation, Generation Y is loyal, committed and wants to be included and involved.

Attention-Craving: Generation Y craves attention in the forms of feedback and guidance. They appreciate being kept in the loop and seek frequent praise and reassurance. Generation Y may benefit greatly from mentors who can help guide and develop their young careers.

Font: http://legalcareers.about.com/od/practicetips/a/Ge...

     It now seems to me that what matters most in the majority
of organizations is to have reasonably intelligent, hard-working
managers who have a sense of pride and loyalty toward their
organization; who can get to the root of a problem and are inclined
toward action; who are decent human beings with a natural empathy
and concern for people; who possess humor, humility, and common
sense; and who are able to couple drive with stick-to-it-iveness* and
patience in the accomplishment of a goal.
     It is the ability to make positive things happen that most
distinguishes the successful manager from the mediocre or
unsuccessful one. It is far better to have dependable managers who
can make the right things happen in a timely fashion than to have
brilliant, sophisticated, highly educated executives who are excellent
at planning and analyzing, but who are not so good at implementing.
The most cherished manager is the one who says “I can do it,” and
then does.
     Many business schools continue to focus almost exclusively
on the development of analytical skills. As a result, these schools are
continuing to graduate large numbers of students who know a great
deal about analyzing strategies, dissecting balance sheets, and using
computers — but who still don’t know how to manage!
     As a practical matter, of course, schools can go only so far
in teaching their students to manage. Only actual work experience
will fully develop the kinds of managerial traits, skills, and virtues
that I have discussed here.

*the ability and determination to continue doing something despite difficulties.
Wegman, Knezevic, Bernstein. A reading skills book, 3.d
ed. Mac Graw-Hill Companies, Inc. (adapted).

Based on the text above, judge the items below.

What are the best energy sources? "Best" depends on many factors - how the energy is being used, where it is being used, what energy sources are available, which sources are most convenient and reliable, which5 are easiest to use, what each costs, and the effects on public safety, health, and the environment. Making smart energy choices means understanding resources and their relative costs and benefits. Some energy sources have advantages for specific10 uses or locations. For example, fuels from petroleum are well suited for transportation because they pack a lot of energy in a small space and are easily transported and stored. Small hydroelectric installations are a good solution for supplying power or mechanical energy close15 to where it is used. Coal is widely used for power generation in many fast-developing countries - including China, India, and many others - because domestic supplies are readily available. Efficiency is an important factor in energy costs.20 How efficiently can the energy be produced, delivered, and used? How much energy value is lost in that process, and how much ends up being transformed into useful work? Industries that produce or use energy continually look for ways to improve efficiency, since this is a key to25 making their products morecompetitive. The ideal energy source - cheap, plentiful, and pollution-free - may prove unattainable in our lifetime, but that is the ultimate goal. The energy industry is continuing to improve its technologies and practices, to30 produce and use energy more efficiently and cleanly. Energy resources are often categorized as renewable or nonrenewable. Renewable energy resources are those that can be replenished quickly - examples are solar power,35 biomass, geothermal, hydroelectric, wind power, and fast-reaction nuclear power. They supply about seven percent of energy needs in the United States; theother 93 percent comes from nonrenewables. The two largest categories of renewable energy now in use in the U.S.40 are biomass - primarily wood wastes that are used by the forest products industry to generate electricity and heat - and hydroelectricity. Nonrenewable energy resources include coal, oil, natural gas, and uranium-235, which is used to fuel45 slow-reaction nuclear power. Projections of how long a nonrenewable energy resource will last depend on many changeable factors. These include the growth rate of consumption, and estimates of how much of the remaining resources can be economically recovered. New exploration50 and production technologies often increase theability of producers to locate and recover resources. World reserves of fossil energy are projected to last for many more decades - and, in the case of coal, for centuries.In: http://www.classroom-energy.org/teachers/energy_tour/pg5.html

UN announces program to help hunger hot spots

A UN agency rolled out a $ 214 million program Tuesday to help 16 needy places hit hard by high prices for food and oil, amid a crisis already making it hard for aid groups to provide enough food for the worlds hungry.

The World Food Program said almost 1 billion poor people around the world are struggling to survive amid the higher prices. The agency is trying to reach those in critical need of assistance in Africa, Asia and the Caribbean.

"Food prices are not abating, and the worlds most vulnerable have exhausted their coping strategies", said Josette Sheeran, the agencys executive director. "Our action plan is targeted and customized to help the most vulnerable meet their urgent needs.
"The plan will provide assistance to groups such as pregnant women, undernourished children and people living in urban areas affected most by the food crisis.

The Rome-based agency also hopes to cut transportation costs and help support farmers in countries where emergency food can be bought locally.

But the agency already faces "obstacles" in procuring food, particularly when trying to buy supplies locally, spokeswoman Brenda Barton said.
"At the markets we have been buying food it has become just too expensive", Barton told The Associated Press by telephone. And she added: "a lot of markets just dont have any food to buy."
Internet: (adapted).

Based on the text above, it can be deduced that

UN announces program to help hunger hot spots

A UN agency rolled out a $ 214 million program Tuesday to help 16 needy places hit hard by high prices for food and oil, amid a crisis already making it hard for aid groups to provide enough food for the worlds hungry.

The World Food Program said almost 1 billion poor people around the world are struggling to survive amid the higher prices. The agency is trying to reach those in critical need of assistance in Africa, Asia and the Caribbean.

"Food prices are not abating, and the worlds most vulnerable have exhausted their coping strategies", said Josette Sheeran, the agencys executive director. "Our action plan is targeted and customized to help the most vulnerable meet their urgent needs.
"The plan will provide assistance to groups such as pregnant women, undernourished children and people living in urban areas affected most by the food crisis.

The Rome-based agency also hopes to cut transportation costs and help support farmers in countries where emergency food can be bought locally.

But the agency already faces "obstacles" in procuring food, particularly when trying to buy supplies locally, spokeswoman Brenda Barton said.
"At the markets we have been buying food it has become just too expensive", Barton told The Associated Press by telephone. And she added: "a lot of markets just dont have any food to buy."
Internet: (adapted).

Based on the text above, it can be deduced that