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

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."
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 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...

    Recent corporate s, such as EBS International and Société Générale, have brought about renewed scrutiny into corporate governance mechanisms. Given the pervasiveness of Information Technology (IT) in many organizations, the examination of corporate governance mechanisms also includes IT governance mechanisms. IT governance is defined as “a structure of relationships and processes to direct and control the enterprise in order to achieve the enterprise’s goals by adding value while balancing risk versus return over IT and its processes”.
    In light of increased public awareness, professional bodies such as the Information Systems Audit and Control Association (ISACA) have undertaken a number of steps to provide guidance in the implementation of effective IT governance. The approach taken by ISACA appears to be largely based upon two concepts. The first concept relates to increasing the awareness of issues and concepts relating to IT governance in the public domain. The second concept involves the provision of guidelines and the identification of best-practice IT governance mechanisms. Interestingly, the effectiveness of these best-practice mechanisms in improving IT governance is largely based upon conceptual arguments. As such, it becomes important to ascertain if these best-practice mechanisms do impact upon the level of IT governance.
    As IT escalates in terms of importance and pervasiveness in the operations of firms, it is inexorably tied to specific mechanisms that are prescribed for good corporate governance, most notably, a sound system of internal controls. Accordingly, effective IT governance is a critical underpinning for a system of good corporate governance that minimizes agency losses for a firm.

Internet: < http://onlinelibrary.wiley.com > (adapted).

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