[en] The authors emphasize the importance of all imaging techniques in the planning of treatments with high voltage radiotherapy particularly for lung, breast and colon cancer. It must be pointed out that treatment planning and computed dosimetry must generally be achieved with the help of CT scans performed in treatment position for proper irradiation of the target volume as well as to avoid useless radiation damage of normal tissues. (Author)

[en] Our program is an investigation of the hadronization process through measurement of rare particle production in high energy nuclear interactions. Such collisions of heavy nuclei provide an environment similar in energy density to the conditions in the Big Bang. We are currently involved in two major experiments to study this environment, E896 at the AGS and STAR at RHIC. We have completed our physics running of E896, a search for the H dibaryon and measurement of hyperon production in AuAu collisions, and are in the process of analyzing the data. We have produced the electronics and software for the STAR trigger and will begin to use these tools to search for anti-nuclei and strange hadrons when RHIC turns on later this year

[en] We present a compositional analysis of the phase separation, nano-structure and electrical performance of blended hole-accepting and electron-accepting polyfluorene derivatives, in films and in photovoltaic devices. We use varying molecular weights to vary the thin film morphology, without altering the blend composition. We show that photoluminescence quenching is insensitive to variations in the blend morphology but the photovoltaic quantum yield is strongly dependent on morphology. This indicates that charge transport, and not charge generation, is the factor that limits device performance. We develop a model for the charge transport within a meso-scale phase separated film and estimate the distance which charges can travel within the minor component of each phase

[en] At present, the National Institute of Standards and Technology (NIST) Center for Neutron Research (NCNR) is the only neutron facility in the United States that is fully competitive with the best in the world across the full spectrum of thermal and cold neutron capabilities. In the present paper, a few examples of recent work at the NCNR in the area of condensed-matter and materials science will be presented. Additional details and references to journal articles can be found in recent NIST publications

[en] The major advantage of digital subtraction angiography (DSA) is that the digitized image can be computerized and processed in an efficient way. Hence, DSA offers the potential for dynamic analysis of blood circulation. The authors attempted to develop a two-dimensional mathematical model of contrast-medium transport and diffusion phenomena in the blood circulation. The equations take into account several parameters such as blood velocity, radial and axial diffusion coefficients, and vessel shapes. The model parameters are identified by using data extracted from the temporal sequence. Experiments were carried out on large renal and femoral arteriographs. Preliminary results point to a good agreement between experimental observations and the theoretical simulations

[en] By the formulation of a relativistic kinetic theory, a system in which the particles have variable rest mass is studied. Macroscopic quantities and their evolution equations are directly linked to the action responsible for the variation of the rest mass of the particles. The dissipative character of this 'force' gives a slight modification to the Liouville theorem and the Boltzmann equation. A detailed study of reversible processes shows that the macroscopic quantities keep the same form for the usual perfect fluid (no bulk viscosity appears) though they are not conserved and can give rise to shearing and vortices. This pattern could serve as a model for the study of certain dissipative processes where mass is lost. (author)

No abstract available

No abstract available

[en] The economic and scientific importance of neutron diffraction residual stress analysis has led to an increasing number of suitable instruments worldwide. Recently, a dedicated state-of-the-art diffractometer has been installed at the National Institute of Standards and Technology reactor. It has been used for a variety of measurements on basic and engineering stress problems. Among the most prominent examples that have been investigated are residual stresses in rails, weldments, and plasma-sprayed coatings

[en] The incorporated radioactivity arising from the Chernobyl reactor accident has been measured by whole body counter on 4 persons coming from Eastern European countries, among them one from Kiev, and on a person living near Chernobyl, in August 86. According to the results computer, the highest ¹³¹I intake (in Kiev) corresponds to 92,5 kBq (2,5μCi); incorporation in a foetus was demonstrated and the whole body activity expressed in counts/m² body surface was not proportional to the distance between the place of residence and Chernobyl. Use of 'iodine pills', change in alimentary habits and the fact of leaving the contaminated zone sooner, diminished altogether the absorbed radioactivity. 10 refs