[en] A rapid method to generate tritium gas for small scale labeling is described. Tritium labelled sodium borohydride is used with cobalt (II) chloride to generate isotopic hydrogen gas. The reaction was carried out in a closed vessel and three different compounds were concurrently labelled. This simple and inexpensive method can be applied to a broad range of molecules and does not require any special set up. (author)

[en] The time structure of synchrotron radiation from a single bunch of high-energy electrons circulating in a storage ring is readily exploited for studies of fast kinetic and radiative processes involving shortlived electronically-excited species in bulk matter. The sample is excited repetitively by very short bursts of monochromatized synchrotron radiation once each orbital period, as the radiation pattern associated with the radially accelerating electron bunch sweeps past an entrance aperture. Time resolved mesurements of the rise and fall of features in the afterglow fluorescence spectrum are analyzed to yield rates for the formation and decay of the radiating species. 14 refs

[en] During the past decades, astronomers have directed their attention toward the study of the solar system bodies, like comets, and they have made many discoveries. These studies have provided profound insights into the formation and earliest story of the solar system. A complementary role in the study of comets has been played by laboratory research on cometary models. In this paper, we discuss some aspects of laboratory experiments proposed in the literature, specially those associated with the chemical reactions that may occur in the comets. These comments are made the light of chemical composition, energy source, relevant chemical reactions and compounds detected in several laboratory simulations of cometary material. (author). Abstract only

[en] This book is divided into two parts. In the first part we introduce the foundations of special relativity, such as, the inertial frame of reference, the definition of simultaneity, and Einstein's two basic hypotheses. We give the main relativistic effects, e.g. the relativity of simultaneity,velocity addition, length-contraction, the apparent shape of a moving body, time-dilation,Doppler effect, and the Thomas precession, In particular, the simultaneity problem and slow transport of clocks are investigated in detail by means of the test theories of special relativity.In the second part, variant types of experiments performed up to now are analyzed and compared to the predictions of special relativity. This shows that the experiments are a test of the two-way speed of light, but not of the one-way speed of light

[en] Design of a laboratory experiment, to supprt further development of an already initiated theoretical model of wind-aided flame spread through a fuel matrix of large porosity, is presented. The design goals include delineation of a well-defined fuel matrix, careful control of the combustion environment (air flow and radiation), capacity for varying parameters (including fuel element type, matrix geometries, and introduction of upslope), and provision for attaining steady-state rate of spread (if one exists). If the model, given initial credibility by the laboratory experiment, is corroborated by field-scale data, then the model may be used with more confidence for predicting the movement in time of a fire front (with current position specified), through a partially combustible debris field of known topographical and aerothermochemical properties, under given meteorological conditions

[en] A laboratory test of the inverse square law of gravity has been conducted. The almost null field inside a long precisely machined tube was probed by a test mass suspended from a torsion balance. In terms of a distance-dependent gravitational constant G(r), the experiment is sensitive to variations in G(r) over the distance range of approximately 2 to 5 cm. If G(r) = G₀ [1 + epsilon In r(cm)], epsilon is found to be (1 +- 7) x 10^-5, in support of the inverse square law

[en] The experimental status of B/sup O/B-bar/sup O/ mixing is reviewed. The ARGUS experiment has recently reported evidence for substantial mixing in the B/sub d//sup O/B-bar/sub d//sup O/ system. UA1 has also reported evidence for mixing, but this cannot be un-ambiguously interpreted to yield a measurement of the amount of mixing in the B/sub s//sup O/B-bar/sub s//sup O/ system. The CLEO, Mk. II, and JADE experiments have all reported upper limits, and the MAC experiment a lower limit, which are compatible with the ARGUS and UA1 results

[en] Two melting tests with metal-added corium of about 10 kg in mass were performed in the TROI experiment. Corium of two compositions (UO₂/ZrO₂ 86/14 and 82/18 at a weight percent) was used for the tests. Metal components added to the corium were zirconium metal and stainless steel. For the first test, a mixture of 76.13 % of 86: 14 corium, 12.27 % of zirconium and 11.6 % of stainless steel was melted in a cold crucible and then cooled down. For the second test, a mixture of 76.31 % of 82: 18 corium, 12.55 % of zirconium and 11.13 % of stainless steel was used. In each test, a layer inversion was observed due to an extracted metal layer on the bottom of the solidified melt. The metal layer was mainly composed of iron (Fe) and uranium metal (U). The uranium component in the charged UO₂ was reduced to uranium metal by 13 % and 18 % for each test, similar to the MASCA test (18 %). (authors)

[en] The kinematics are discussed for the demonstration of two balls dropped simultaneously one on top of another

[en] It is pointed out that the direction in which a Crooke's radiometer rotates can be controlled by changing the temperature of its surroundings