Stress and Strain State Analysis of Defective Pipeline Portion

The paper presents computer simulation results of the pipeline having defects in a welded joint. Autodesk Inventor software is used for simulation of the stress and strain state of the pipeline. Places of the possible failure and stress concentrators are predicted on the defective portion of the pipeline

Stress-strain analysis of pipelines laid in permafrost

Increasing reliability of pipelines becomes a real challenge at all stages: design, construction and operation of pipeline systems. It is very important to determine the behaviour of the constructed pipeline under the operational and environmental loads using the design model in accordance with that one adopted in the rules and regulations. This article presents the simulation of pipeline in permafrost. The evaluation of the stress-strain state is given herein and the areas of the stress concentration are detected with the account for different loads occurred during the pipeline operation. Information obtained from the assessment of the stress-strain state of the pipeline allows determining sections in pre-emergency state (even before damages) and take all the necessary measures for eliminating them, thus increasing the pipeline system reliability. It is shown that the most critical pipeline cross-section is observed at the point of transition from one environment to another. The maximum strains decrease the level of the pipeline reliability. The finite element model is presented to determine the pipeline sections in pre-emergency state

Contribution of some immunological and metabolic factors to formation of piglets’ post-vaccination immunity

The role and responsibility of natural resistance factors, protein and lipid metabolism in the formation of piglets post-vaccination immunity against circovirus is researched. Blood was taken for tests before and on the 15th, 40th and 70th day after the vaccination. The sampled blood was analyzed to determine immunological and biochemical parameters. It was revealed that before vaccination, 31.46% of the studied samples have a positive reaction in ELISA; their number increases to 67.80–71.16% on the 40th and 70th days after vaccination.In the blood of piglets, especially on the 40th and 70th day after the vaccination, the total count of leukocytes, monocytes and lymphocytes increases by 1.21; 2.28 times and 1.48 times, but neutrophils reduced by 1.74 times along with the phagocytic properties activation. The anabolic directivity of protein metabolism is defined by the synthesis of globulin proteins. At the same time albumin-synthesizing activity in a liver decreased and “cytolysis reaction” of hepatocytes was detected. In the lipid profile of piglets’ blood, the content of LDL‑cholesterol increased by 1.44 times, while that of triglycerides decreased by 2.64 times. X‑ray spectral analysis revealed the correlation between the formation of post-vaccination immunity and two factors: the factor of the principal component (PC) 1, which is predominantly associated with indicators of natural resistance, and PC2, which is associated with metabolism indicators. The research results show that in order to increase the efficiency of formation of post-vaccination immunity in piglets, it is necessary to combine vaccination with hepatoprotective drugs

Pathological features of the lungs and liver of piglets under conditions of constant vaccination of livestock against circovirus infection

The pathogenicity of PCV 2 in the body of vaccinated piglets was studied based on the results of pathomorphological changes in the lungs and liver of animals. The work was carried out on commercial piglets vaccinated with the vaccine Ingelvak CircoFLEX (Germany) against circovirus. The work used clinical, zootechnical, enzyme immunoassay and pathomorphological research methods. It has been established that under the conditions of ongoing vaccination of piglets against PCV2, 30.3% of piglets still do not have virus-neutralizing antibodies. The main reason for the culling of animals are circovirus diseases that have respiratory clinical signs, as well as signs of multisystem wasting syndrome, determining the safety of the livestock at the level of 68.05%, the average live weight of 1 head at the moment of its transfer for fattening is 40.44±0.78 kg, and the average daily gain in live weight is 346.00±9.18 g. At autopsy, sick piglets reveal an increase in the lungs and liver, and the signs of inflammation in them, as a result of circulatory disorders, damage to the lymphoid tissue, the development of dystrophic and necrotic changes. The results of the research suggest that in order to increase the efficiency of the formation of post-vaccination immunity, specific medical preparations can be used to stimulate the immune response of the body, as well as to enhance the resistance of the lymphoid tissue of the lungs and liver in animals.The pathogenicity of PCV 2 in the body of vaccinated piglets was studied based on the results of pathomorphological changes in the lungs and liver of animals. The work was carried out on commercial piglets vaccinated with the vaccine Ingelvak CircoFLEX (Germany) against circovirus. The work used clinical, zootechnical, enzyme immunoassay and pathomorphological research methods. It has been established that under the conditions of ongoing vaccination of piglets against PCV2, 30.3% of piglets still do not have virus-neutralizing antibodies. The main reason for the culling of animals are circovirus diseases that have respiratory clinical signs, as well as signs of multisystem wasting syndrome, determining the safety of the livestock at the level of 68.05%, the average live weight of 1 head at the moment of its transfer for fattening is 40.44±0.78 kg, and the average daily gain in live weight is 346.00±9.18 g. At autopsy, sick piglets reveal an increase in the lungs and liver, and the signs of inflammation in them, as a result of circulatory disorders, damage to the lymphoid tissue, the development of dystrophic and necrotic changes. The results of the research suggest that in order to increase the efficiency of the formation of post-vaccination immunity, specific medical preparations can be used to stimulate the immune response of the body, as well as to enhance the resistance of the lymphoid tissue of the lungs and liver in animals

Phonon Localization in One-Dimensional Quasiperiodic Chains

Quasiperiodic long range order is intermediate between spatial periodicity and disorder, and the excitations in 1D quasiperiodic systems are believed to be transitional between extended and localized. These ideas are tested with a numerical analysis of two incommensurate 1D elastic chains: Frenkel-Kontorova (FK) and Lennard-Jones (LJ). The ground state configurations and the eigenfrequencies and eigenfunctions for harmonic excitations are determined. Aubry's "transition by breaking the analyticity" is observed in the ground state of each model, but the behavior of the excitations is qualitatively different. Phonon localization is observed for some modes in the LJ chain on both sides of the transition. The localization phenomenon apparently is decoupled from the distribution of eigenfrequencies since the spectrum changes from continuous to Cantor-set-like when the interaction parameters are varied to cross the analyticity--breaking transition. The eigenfunctions of the FK chain satisfy the "quasi-Bloch" theorem below the transition, but not above it, while only a subset of the eigenfunctions of the LJ chain satisfy the theorem.Comment: This is a revised version to appear in Physical Review B; includes additional and necessary clarifications and comments. 7 pages; requires revtex.sty v3.0, epsf.sty; includes 6 EPS figures. Postscript version also available at http://lifshitz.physics.wisc.edu/www/koltenbah/koltenbah_homepage.htm

Piezoelectric-Layered Structures Based on Synthetic Diamond

Results of theoretical, modeling, and experimental investigation of microwave acoustic properties of piezoelectric layered structure “Me1/AlN/Me2/(100) diamond” have been presented within a wide frequency band 0.5–10 GHz. The highest among known material quality parameter Q × f ~ 1014 Hz for the IIa type synthetic diamond at operational frequency ~10 GHz has been found. Conditions of UHF excitation and propagation of the bulk, surface, and Lamb plate acoustic waves have been established and studied experimentally. Frequency dependencies of the impedance and quality factor have been studied to obtain a number of piezoelectric layered structure parameters as electromechanical coupling coefficient, equivalent circuit parameters, etc. Results of 2D finite element modeling of a given piezoelectric layered structure have been compared with the experimental ones obtained for the real high-overtone bulk acoustic resonator. An origin of high-overtone bulk acoustic resonator’s spurious resonant peaks has been studied. Results on UHF acoustic attenuation of IIa-type synthetic single crystalline diamond have been presented and discussed in terms of Akhiezer and Landau–Rumer mechanisms of phonon–phonon interaction. Identification and classification of Lamb waves belonging to several branches as well as dispersive curves of phase velocities have been executed. Necessity of introducing a more correct Lamb-mode classification has been recognized

Correlations in Transmission of Light through a Disordered Amplifying Medium

The angular and frequency correlation functions of the transmission coefficient for light propagation through a strongly scattering amplifying medium are considered. It is found that just as in the case of an elastic scattering medium the correlation function consists of three terms. However, the structure of the terms is rather different. Angular correlation has a power-law decay and exhibits oscillations. There is no "memory effect" as in the case of an elastic medium. Interaction between diffusion modes is strongly enhanced near the lasing threshold. Frequency correlation scale decreases close to the lasing threshold. We also consider time correlations of the transmission in the case of nonstationary inhomogeneities. We find short- and long-range time correlations. The scale of the short-range correlation decreases, while the long-range correlation scale becomes infinite near the threshold.Comment: 16 pages, 7 postscript figure