The boom units of a mining shovel are structurally complex metal structures of large dimensions. Traditional methods of design calculations for such structures are based on beam-type structural ...models, while the actual configuration is taken into account by introducing complex built-up sections which include sections of pipes, sheets, and ribs. The correspondence of such beam-type structural models has not been systematically studied yet, which leads to crack initiation and destruction of structures on the one hand and to an unreasonably high use of metal on the other. As a result of numerical analysis of the boom units in three-dimensional statement, the actual errors of beam-type structural models in characteristic sections of structures in the most complex design cases of mining shovel loading have been determined and analysed.
This work is devoted to analysis of deformation and destruction of structurally heterogeneous joint assembly. The mathematical formulation of interacting parts of joint assembly is investigated. ...Logical and computational model of joint assembly presents various modes of its destruction and describes impairment conditions because of different damage states.
The work is devoted to the analysis of the computer simulation capabilities of dynamic testing of large-scaled structures when exposed to acoustic noise, sinusoidal and random vibration, linear ...acceleration, mechanical single and multiple shocks. The simulation results obtained with regard to the regulatory requirements for the test methods for the action of external influencing factors reflect the effect of the main conceptual and technical solutions of the structures on their dynamic behaviour. Computer simulation of dynamic tests allows, on the one hand, to exclude unacceptable dynamic effects due to unsuccessful design decisions, on the other hand, can be considered as an important part of the design conformity assessment with technical requirements.
Dynamics of spin dimers in multiple quantum NMR experiment is studied on the 5-qubit superconducting quantum processor of IBM Quantum Experience for the both pure ground and thermodynamic equilibrium ...(mixed) initial states. The work can be considered as a first step towards an application of quantum computers to solving problems of magnetic resonance. This article is dedicated to Prof. Klaus Möbius and Prof. Kev Salikhov on the occasion of their 85th birthdays.
The purpose of this study was to determine whether oligonucleotides the size of siRNA are permeable to gap junctions and whether
a specific siRNA for DNA polymerase β (pol β) can move from one cell ...to another via gap junctions, thus allowing one cell
to inhibit gene expression in another cell directly. To test this hypothesis, fluorescently labelled oligonucleotides (morpholinos)
12, 16 and 24 nucleotides in length were synthesized and introduced into one cell of a pair using a patch pipette. These probes
moved from cell to cell through gap junctions composed of connexin 43 (Cx43). Moreover, the rate of transfer declined with
increasing length of the oligonucleotide. To test whether siRNA for pol β was permeable to gap junctions we used three cell
lines: (1) NRK cells that endogenously express Cx43; (2) Mβ16tsA cells, which express Cx32 and Cx26 but not Cx43; and (3)
connexin-deficient N2A cells. NRK and Mβ16tsA cells were each divided into two groups, one of which was stably transfected
to express a small hairpin RNA (shRNA), which gives rise to siRNA that targets pol β. These two pol β knockdown cell lines
(NRK-kcdc and Mβ16tsA-kcdc) were co-cultured with labelled wild type, NRK-wt or Mβ16tsA-wt cells or N2A cells. The levels
of pol β mRNA and protein were determined by semiquantitative RT-PCR and immunoblotting. Co-culture of Mβ16tsA-kcdc cells
with Mβ16tsA-wt, N2A or NRK-wt cells had no effect on pol β levels in these cells. Similarly, co-culture of NRK-kcdc with
N2A cells had no effect on pol β levels in the N2A cells. In contrast, co-culture of NRK-kcdc with NRK-wt cells resulted in
a significant reduction in pol β in the wt cells. The inability of Mβ16tsA-kcdc cells to transfer siRNA is consistent with
the fact that oligonucleotides of the 12 nucleotide length were not permeable to Cx32/Cx26 channels. This suggested that Cx43
but not Cx32/Cx26 channels allowed the cell-to-cell movement of the siRNA. These results support the novel hypothesis that
non-hybridized and possible hybridized forms of siRNA can move between mammalian cells through connexin-specific gap junctions.
The work deals with the extraction and preconcentration of novocaine using mixed surfactants of nonionic (Triton X-114) and anionic (sodium dodecyl sulfate) types with the photometric registration of ...an analytical signal. The method is based on the condensation reaction of novocaine with
p
-dimethylaminobenzaldehyde (pH 2.5–3.5) and the subsequent micellar extraction of the colored analytical form, the Schiff base. For the effective extraction of this form, the parameters of micellar extraction (concentrations of reagents:
с
NaCl
= 0.5–1 М,
c
Triton X-114
= 2 × 10
–3
–1 × 10
–2
M; conditions: centrifugation time 5 min at 3000 rpm) are optimized. The proposed method makes it possible to determine novocaine in the concentration range 38–4800 ng/mL (RSD ≤ 7%, limit of detection 19 ng/mL), which is several orders of magnitude lower than in the known spectrophotometric versions. The Bouguer–Lambert–Beer law is obeyed in the range 8 × 10
–7
–4 × 10
–5
M. The developed extraction-photometric method was tested in the determination of novocaine in 0.5% ampoule solutions for injection.
New test tools made of nanofibers based on polyamide-6 (PA-6) for the sorption preconcentration of some phenols as their azo derivatives followed by colorimetric determination are obtained. ...Approaches to the derivatization of phenol and chlorine derivatives by azo coupling with 4-nitrophenyldiazonium and oxidative condensation with 4-aminoantipyrine for improving the sorption characteristics of the studied phenols are proposed. The efficiency of the two derivatization methods is compared. The sorption kinetics of phenol and 2-chlorophenol derivatives and the effect of pH on the nature of their sorption are studied. The features of the sorption of phenol derivatives on nonwoven materials and the corresponding sorption isotherms are interpreted. Examples of the quantitative assessment of the concentration of phenols in aqueous media by the mathematical processing of digital images of the colored areas of test tools are presented. It is shown that the proposed methods can be used for the determination of phenol and 2-chlorophenol with the preconcentration of their derivatives on a PA-6 nanofiber in the range 0.2–1.0 μM (≈0.02–0.09 mg/L for phenol, ≈0.03–0.13 mg/L for 2-chlorophenol) with an error of colorimetric determination of no more than 20% (MAC
hshld
phenol is 0.001 mg/L for the amount of volatile phenols in water bodies, provided that water is disinfected with chlorine; in other cases, the MAC is 0.1 mg/L).
We simulate the evolution of three-node spin chain on the quantum processor of IBM Quantum Experience using the diagonalization of
XX
-Hamiltonian and representing the evolution operator in terms of ...CNOT operations and one-qubit rotations. We study the single excitation transfer from the first to the third node and show the significant difference between calculated and theoretical values of state transfer probability. Then, we propose a method reducing this difference by applying the two-parameter transformation including the shift and scale of the calculated probabilities. We demonstrate the universality of this transformation inside of the class of three-node evolutionary systems governed by the
XX
-Hamiltonian.
Four types of reactions (azo coupling, protolytic and oxidative condensation, ion association), accompanied by the formation of hydrophobic colored analytical forms of corresponding organic analytes, ...are proposed on an example of biologically active substances (aromatic amines, α-amino acids, antibiotics of aminoglycoside and β-lactam series, anionic surfactants). It is shown that, in these systems, the hydrophobicity of both the initial reactants, e.g., tetrafluoroborates of diazonium salts, and analytical forms (azo compounds, Schiff bases, Ruemann’s purpura, ion associates with surfactants) can be increased. Possibilities of various methods for the derivatization of organic analytes with the formation of colored analytical forms with increased hydrophobicity for the best fixation on solid matrices and the development of test systems on their basis, which can be used to control the quality of various samples with rather good performance characteristics, are considered.
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