[en] A method of combining laser beams with different wavelengths, by Brewster angle dispersive prism made of SrTiO₃ crystal is presented. Such a prism enables combining of beams with 5 nm difference in the red, it has minimal absorption losses and high damage threshold. (Author)

No abstract available

[en] The vapor cloud produced by a magnetron sputtering gun in the vacuum chamber is not uniform. In order to coat substrates within a desired tolerance of thickness uniformity, a 'flattening' of the vapor flux distribution is required. This is achieved by means of mechanical masks which intercept the vapor cloud, by a carefully designed motion of the substrate through the vapor cloud, or by a combination of both. The present work describes a design method for masks, to be used with planar substrates, and its application in the case of a Varian S-GUN magnetron sputtering gun. By using the mask the coating thickness uniformity on large ring shaped flat substrates, 200 mm wide, has been improved from ±35% to ±9% around the mean value of the thickness. (author)

[en] The principles of operation of a pulsed laser-pumped dye laser and its design considerations are discussed theoretically. A detailed description of the laser and its constituents is presented. T me basic construction of the laser is described and a step by step procedure for its optical alignment is provided. The important performance data of the dye laser are: (a) Efficiency of about 0.15 in Rhodamine 6G and Rhodamine B when pumped with Nd:YAG laser (second harmonic) and Cu vapor laser; (b) Minimal divergence of about twice diffraction limit; (c) Variable bandwidth that can be tailored to specifications by placing etalons with various air gaps within the cavity

[en] Published in summary form only

No abstract available

No abstract available

[en] To study the effect of chemical carcinogens on the amplification of specific genes, we have constructed a model system, utilizing integrated SV40 as an example for an endogenous gene. Recently, we have shown that exposure of SV40 transformed Chinese hamster cells to a variety of carcinogens induced the amplification of the integrated SV40 genome. Functional T-antigen was necessary for the amplification phenomenon. The work presented in this manuscript shows that the functional origin of replication, which consists of the sequences at the origin of replication and an active T-antigen, is required for the amplification. Utilizing cloned SV40 inserts and the adjacent Chinese hamster sequences we were able to show that SV40 and the flanking cellular sequences were amplified. As the distance from the SV40 origin of replication increased, the extent of amplification was decreased. The amplified sequences are associated with both chromosomal and extrachromosomal sequences. Carcinogen-mediated amplification is not restricted to SV40 sequences and endogenous genes such as dehydrofolate reductase (dhfr), the histocompatibility gene (HLA) and c-ras/sup Ha/ gene are amplified. 26 references, 5 figures

No abstract available

[en] A commercial hollow cathode lamp operated in a pulsed mode is used as a source of atomic uranium for spectroscopic measurements based on laser induced fluorescence. This method is especially convenient for stepwise laser spectroscopy of refractory elements