Life science research in space brings health on Earth

Leading scientists and physicians review groundbreaking research that is leading the way to better health care for astronauts and new treatments for medical problems on Earth. This research includes the development and testing of a new Ventricular Assist Device for patients with heart failure awaiting heart transplantation; advancements in telemedicine that bring medical care to remote areas on Earth and aid in the diagnosis and treatment of illness during space flight; advanced technologies, such as a miniature mass spectrometer, cardiac ultrasound equipment, bone imaging, non-invasive High-Intensity Focused Ultrasound, non-invasive techniques for blood and tissue chemistry measurements; and advances in the treatment of spinal cord injuries.     

The American Institute of Aeronautics and Astronautics pre-college outreach program

Many United States, school children perceive science, technology, engineering, and mathematics (STEM) as difficult, boring and often irrelevant subjects. The possible reasons for this problem are endlessly debated. However, the economic, social, and overall national importance of producing graduates who are technically literate and enthusiastic in their support of a rational scientific world is essential to our nation. This apparent STEM crisis should motivate the many scientific and engineering societies to develop STEM outreach programs aimed at students, parents, teachers and schools (grades K-12).     

用分级淬火油来控制工件变形

用分级淬火油来控制工件变形好富顿国际公司Ｒ．Ｊ．ＢＲＥＮＮＡＮ分级淬火油这个名词是１９４２年首先提出来的。它是指将钢件由奥氏体状态放到温度比Ｍｓ略高一点的介质中进行淬火。钢件放在其中的时间恰好使各部分温度平衡，随后放在空气中冷却，从而减少表面和芯部转...     

Ultrawideband microwave-radar conceptual design

This paper outlines the special considerations that characterize the design of an UWB radar for the detection of low-altitude missiles over the sea. It discusses the factors which enter into the choice of frequency, and the selection of the transmitter, antenna, and receiver. Reviewed are signal processing issues concerning detection of UWB signals in noise and clutter, nondoppler MTI based on the pulse-to-pulse change in range due to target motion, measurement of target height based on multipath time delay, and target recognition. As the investigation progressed, the authors became disappointed with the available UWB technology, but encouraged about the potential advantages of UWB for this application. The chief limitation of UWB radar that must be overcome before applications are viable is its poor electromagnetic compatibility (EMC)     

Probability Densities and Characteristic Functions for Fluctuating Targets

Probability density functions and characteristic functions for the projected area of a tumbling target object are derived together with the densities and characteristic functions for the corresponding signal-plus-noise voltage output of an infrared sensor. Several cases are considered in which the signal pulse arrival time is either known or unknown, a matched filter or a suboptimum filter is used; the signal pulse shape is either Gaussian or is unspecified; and the target orientation angles are either uniformly or nonuniformly distributed.     

Atmospheric science on the Galileo mission

Observations from the ground and four fly-by spacecraft have provided initial reconnaissance of Jupiter's atmosphere. The Pioneer and Voyager data have raised new questions and underlined old ones about the basic state of the atmosphere and the processes determining the atmosphere's behavior. This paper discusses the main atmospheric science objectives which will be addressed by the Galileo (Orbiter and Probe) mission, organizing the discussion according to the required measurements of chemical composition, thermal structure, clouds, radiation budget, dynamics, upper atmosphere, and satellite atmospheres. Progress on the key questions will contribute not only to our knowledge of Jupiter's atmosphere but to a general understanding of atmospheric processes which will be valuable for helping us to understand the atmosphere and climate of the Earth.Realization of the atmospheric science objectives of the Galileo mission depends upon: (a) coordinated measurements from the entry probe and the orbiter; (b) global observations; and (c) observations over the range of time-scales needed to characterize the basic dynamical processes.The Atmospheres Working Group also includes: M. D. Allison, M. J. S. Belton, R. W. Boese, R. W. Carlson, C. R. Chapman, T. Encrenaz, V. R. Eshleman, P. J. Gierasch, C. W. Hord, H. T. Howard, L. J. Lanzerotti, H. B. Niemann, G. S. Orton, T. Owen, C. B. Pilcher, J. B. Pollack, B. Ragent, W. B. Rossow, A. Seiff, A. I. Stewart, P. H. Stone, F. W. Taylor, G. L. Tyler, U. von Zahn, and R. A. West.     

The clouds of Venus

The current state of knowledge of the Venusian clouds is reviewed. The visible clouds of Venus are shown to be quite similar to low level terrestrial hazes of strong anthropogenic influence. Possible nucleation and particle growth mechanisms are presented. The Pioneer Venus experiments that emphasize cloud measurements are described and their expected findings are discussed in detail. The results of these experiments should define the cloud particle composition, microphysics, thermal and radiative heat budget, rough dynamical features and horizontal and vertical variations in these and other parameters. This information should be sufficient to initialize cloud models which can be used to explain the cloud formation, decay, and particle life cycle.