Deformations and structure of metal during cold butt-seam welding of copper blanks

Calculations by the finite element method are carried out for the deformation mode of copper blanks as they are being joined by cold welding. It is found that the degree of deformation in a shut is distributed nonuniformly and reaches 3-5. A metallographic analysis revealed the appearance of a zone of abrupt grain-size refinement in the region of a weld seam. A study of the distribution of microhardness showed an increase in this parameter up to 1000 MPa in the arrangement region of the weld seam with respect to 790 MPa in the parent metal. The experimental data confirmed the computed characteristics. © 2012 Allerton Press, Inc

Comprehensive Immunological Study of Persons Vaccinated with Live Plague Vaccine Living on the Territory of the Pre-Caspian Sand Foci of the Plague in the Republic of Kalmykia

Relevance. In 2005 International Health Regulations, the plague, is on the list of dangerous infectious diseases that can cause emergency situations of interstate importance. Even single cases of human plague are considered as the basis for carrying out preventive measures. The paper presents the results of immunological monitoring conducted on the territory of the Republic of Kalmykia in order to assess the immunological efficacy and safety of the plague live vaccine The paper presents the results of immunological monitoring in the territory of the Kalmyk Republic over the individuals vaccinated against plague due to epidemiological reasons. Materials and methods. Studies of immunological efficacy of live plague vaccine were conducted alongside stepwise assessment of cellular and humoral components of innate and adaptive immunity in persons revaccinated against plague, using a complex of advanced informative tests. Results and conclusions. It is established that before the second revaccination all the surveyed persons retained expressed immune response by the mixed or cellular type, characterized by high level of spontaneous and induced production of Th1-associated cytokines. Activation of Th1 immune reaction was registered one month after the scheduled revaccination; immune response change-over from Th1 to Th2 type – after 6 months of observation, and retention of adaptive immunity by mixed type at the moderate level – in a year. Specific humoral immunity developed in 85% of the surveyed persons, but throughout the whole investigation the dynamics of antibody titers to plague microbe F1 individualized and did not coincide with cellular immunity indicators. Performed complex study has confirmed the relative safety of the live plague vaccine