A comparison of the finite difference and finite element methods for heat transfer calculations

The finite difference method and finite element method for heat transfer calculations are compared by describing their bases and their application to some common heat transfer problems. In general it is noted that neither method is clearly superior, and in many instances, the choice is quite arbitrary and depends more upon the codes available and upon the personal preference of the analyst than upon any well defined advantages of one method. Classes of problems for which one method or the other is better suited are defined

A test matrix sequencer for research test facility automation

The hardware and software configuration of a Test Matrix Sequencer, a general purpose test matrix profiler that was developed for research test facility automation at the NASA Lewis Research Center, is described. The system provides set points to controllers and contact closures to data systems during the course of a test. The Test Matrix Sequencer consists of a microprocessor controlled system which is operated from a personal computer. The software program, which is the main element of the overall system is interactive and menu driven with pop-up windows and help screens. Analog and digital input/output channels can be controlled from a personal computer using the software program. The Test Matrix Sequencer provides more efficient use of aeronautics test facilities by automating repetitive tasks that were once done manually

Why the composite index of leading indicators doesn't lead

Economic indicators

The Role of Genome Mapping in Diagnosing Bipolar Disorder

Genome mappings as a mechanism for diagnosis in bipolar disorder

Growth and variation in sea urchins of York, Maine

From a three square meter plot of intertidal shore on a rocky point of York, Maine, sea urchins (Strongylocentrotus droebachiensis) were collected on June 28 and 29, 1957 for study of their size-frequency distribution. Test height, test weight, number of wedges in the spines, number of pore-pairs in the ambulacral arcs, number of ocular plates insert, and number of coronal plates have been related to test diameter...

The Use of Finite Element Methodology in Designing Ultrasonic Tests and the Detection of Weak Bond Planes

The ideal ultrasonic test should define unambiguously the size and location of defects, require a minimum of signal processing (i.e., operator intuition and decision) and use a minimum number of transducers. To do this it is necessary to choose the appropriate transducers and transducer locations; unfortunately this may require a time consuming series of iterative pre-test s using samples with manufactured defects which are presumed to behave similarly to real defects. The question arises as to whether numerical simulations may not provide a faster and more efficient way to design these tests. Accordingly a series of numerical tests were designed to: a) demonstrate the validity of numerical simulation; b) define the range of problems which can be treated numerically; c) describe the protocol for determining the optimal transducer position; d) determine the type of signal processing which would provide the maximum information

Interactive computation of radiation view factors

The development of a pair of computer programs to calculate the radiation exchange view factors is described. The surface generation program is based upon current graphics capabilities and includes special provisions which are unique to the radiation problem. The calculational program uses a combination of contour and double area integration to permit consideration of radiation with obstruction surfaces. Examples of the surface generation and the calculation are given

Interview with David Emery by Mike Hastings

Biographical NoteDavid Farnham Emery was born on September 1, 1948, in Rockland, Maine. His father was a bookkeeper, accountant, and golfer (he also played baseball for the University of Pennsylvania), and his mother was a nurse. Both parents served in the military during World War II, his father as a staff sergeant and his mother as an officer. He grew up in a Republican family and attended Worcester Polytechnic Institute in Worcester, Massachusetts from 1967-1970. He was elected to the Maine legislature immediately after graduation, during the Vietnam War. In 1974, he was elected as a U.S. congressman during the Nixon administration and served from 1975-1982. In 1982, he was the Maine Republican candidate for the U.S. Senate and lost to Democrat George Mitchell in the election. He served as deputy director of the United States Arms Control and Disarmament Agency from 1983-1988. At the time of this interview he was involved in political polling and management consulting, as well as renewable energy resource strategies in Maine. SummaryInterview includes discussion of: election to Maine state legislature; early involvement in politics; Dick Berry; Sawin Millet; the 1974 House election and the recount; Emery’s win; Mitchell’s 1974 loss to Jim Longley; meeting Mitchell in the 1974 campaign; 1974 Maine congressional race recount and Peter Kyros, Sr.; the staff in the Congressional Office; Charlie Smith; Stan McGeehan, Emery’s campaign manager; Emery’s 1981 decision to run for Senate; political consulting/polling; Emery’s view of current politics in Maine; the 2nd and 1st Districts in Maine; and the 1982 U.S. Senate race

Respective influences of pair breaking and phase fluctuations in disordered high Tc superconductors

Electron irradiation has been used to introduce point defects in a controlled way in the CuO2 planes of underdoped and optimally doped YBCO. This technique allows us to perform very accurate measurements of Tc and of the residual resistivity in a wide range of defect contents xd down to Tc=0. The Tc decrease does not follow the variation expected from pair breaking theories. The evolutions of Tc and of the transition width with xd emphasize the importance of phase fluctuations, at least for the highly damaged regime. These results open new questions about the evolution of the defect induced Tc depression over the phase diagram of the cupratesComment: 5 pages, 4 figure

Experimental study of acoustic displays of flight parameters in a simulated aerospace vehicle

Evaluating acoustic displays of target location in target detection and of flight parameters in simulated aerospace vehicle