Self-intersection elimination in metamorphosis of two-dimensional curves

H :[0, 1]× ³→ ³, where H(t, r) for t=0 and t=1 are two given planar curves C ₁(r) and C ₂(r). The first t parameter defines the time of fixing the intermediate metamorphosis curve. The locus of H(t, r) coincides with the ruled surface between C ₁(r) and C ₂(r), but each isoparametric curve of H(t, r) is self-intersection free. The second algorithm suits morphing operations of planar curves. First, it constructs the best correspondence of the relative parameterizations of the initial and final curves. Then it eliminates the remaining self-intersections and flips back the domains that self-intersect.     

Electrical properties of thin PbTe films on Si substrates

An attempt was made to reduce the carrier concentration in thin PbTe films on Si substrates by optimizing deposition conditions. A modified hot-wall method was used for reproducible growth ofp-type films with 5 × 10¹⁵ < p(77 K) < 5 × 10¹⁷ cm^-3 andn-type films with 3 × 10¹⁵ < n(77 K) < 5 × 10¹⁶ cm^-3. The IR irradiation was found to have a significant effect on the temperature variation of film resistance. The activation energy of the IR-sensitivity centers was determined to be 0.11 ± 0.005 eV at room temperature and 0.18 ± 0.005 eV between 150 and 180 K.     

Ga Doping of Thin PbTe Films on Si Substrates during Growth

In depositing thin PbTe films onto Si substrates by a modified hot-wall method, Pb_{1 – x} Ga _x melts were used as Ga vapor sources in combination with separate Pb and Te sources. Data on the vaporization behavior of Pb_{1 – x} Ga _x melts were used to devise a new technique for reproducible growth of PbTe/Si and PbTe/SiO₂/Si structures. The lattice parameter of the PbTe films was found to vary nonmonotonically with Ga content, which was interpreted as evidence that the dopant can be incorporated by different mechanisms. Conductivity and Hall effect measurements between 77 and 300 K reveal a nonmonotonic variation of carrier concentration with doping level and suggest that Ga is an amphoteric impurity in narrow-gap IV–VI semiconductors.     

Some Features of Operation of Sectioned Adsorbers

It is theoretically substantiated and experimentally demonstrated that sectioning of a stationary bed of adsorbent with walls parallel to flow of the treated feedstock increases the efficiency of the adsorbent. Mathematical modeling of sectioned adsorbers with a mobile bed of adsorbent demonstrated the possibility of increasing the quality of the sampled narrow fractions and decreasing the power consumption for regeneration of the adsorbent.     

Computational analysis of the effectiveness of the working elements of the safety and control system in a vpbér-600 core by means of engineering and precision programs

Special Office of Machine Design Institute of Fast Reactors, Russian Academy of Sciences. Translated from Atomnaya énergiya, Vol. 79, No. 3, pp. 171–174, September, 1995.