Investigation and analysis of kinetic regularities of wear of internal surfaces of equipment under conditions of intense corrosion using different working media

2021 ◽  
pp. 62-75
Author(s):  
V.N. Gadalov ◽  
O.M. Gubanov ◽  
D.S. Alymov ◽  
V. M. Roshchupkin
Keyword(s):  
Theoretical Data ◽  
Uniform Corrosion ◽  
Term Operation ◽  
Internal Surfaces ◽  
Analysis Experiment ◽  
Wear And Tear ◽  
Equipment Failures ◽  
Steel Equipment ◽  
Working Media ◽  
Experimental Values

The reasons for failures of technological equipment made of structural steels during long-term operation in various environments and fields of application are considered. Investigations of the intensity of wear of equipment failures through the rate of damaging processes are presented. Modeling the processes of wear and tear of steel equipment, its failures was carried out using regression and correlation analyzes. The results of diagnostics are presented in accordance with the theoretical principles of statistical analysis, experiment in the form of polynomial kinetic wear models. The results of comparison of experimental and theoretical data on the wear rate for various types of equipment are also presented. The results of the normal distribution of the experimental values of the degree of wear for various types of equipment are shown, which is confirmed by the general uniform corrosion.

scholarly journals Assessment of the technical condition of lift guides using a magnetic field

2021 ◽  
Vol 2130 (1) ◽  
pp. 012003
Author(s):  
P Lonkwic ◽  
T Krakowski ◽  
H Ruta
Keyword(s):  
Early Stage ◽  
Technical Condition ◽  
Operating Conditions ◽  
Measuring Head ◽  
Cross Sectional ◽  
Correct Operation ◽  
Emergency Braking ◽  
Wear And Tear ◽  
Equipment Failures ◽  
Novel Concept

Abstract The systems that monitor individual components of machines and devices are under constant development. The ability to detect damages at an early stage allows failures to be prevented, so any uncontrolled downtime can be predicted in a controlled manner. Continuous monitoring of technical condition is an activity that also helps to reduce the losses due to equipment failures. However, not all areas can be monitored continuously. Such areas include lift guides where wear and tear can occur naturally, i.e. through abrasion of the material layer due to interaction with moving guide shoes or after emergency braking. Emergency braking causes local damages to the guide through plastic deformation of its surface resulting from indentation of the knurled roller of the brake. Such places are cleaned mechanically, which results in local reduction of the cross-sectional area. In such a case, it is difficult to continuously assess the technical condition of guides due to the prevailing operating conditions. Therefore, a concept of a head enabling assessment of the technical condition of guides at every stage of their operation has been developed. This article presents the novel concept of a magnetic head used for assessing the technical condition of lift guide rails that are the running track of lifting equipment. The initial tests were performed on the original test setup. The concept of the developed measuring head was verified for correct operation on specially prepared flat bars with holes. The results obtained in the form of laboratory tests proved that the proposed measuring head concept can be applied to the measurements under real conditions.

Experimental and Theoretical Studies of 2- (naphthalen-1-yl (piperidin-1-yl) methyl)phenol Compound

2020 ◽  
Vol 42 (6) ◽  
pp. 818-818
Author(s):  
Yeliz Ula Yeliz Ula
Keyword(s):  
Molecular Orbital ◽  
Theoretical Data ◽  
Biologically Active ◽  
Oscillator Strengths ◽  
Excitation Energies ◽  
Petasis Reaction ◽  
Vis Spectroscopy ◽  
Phenol Compound ◽  
Lowest Unoccupied Molecular Orbital ◽  
Experimental Values

The 2- (naphthalen-1-yl (piperidin-1-yl) methyl) phenol compound is an alkylaminophenol compound and has been experimentally synthesized by the Petasis reaction. In this study Structural analysis was carried out by FT-IR, NMR, UV-Vis spectroscopy. The high antioxidant value of the compound showed that it could be a potential biologically active drug. Theoretical data support all experimental analysis of the new compound. Comparisons were made by double method. For this purpose, DFT (B3LYP) and HF methods have been used with 6-311G ++ (d, p) set. Also, the compoundand#39;s electronic and structural properties (bond lengths, bond angles and dihedral angles), the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) energies, electrostatic potential (MEP), vibrational frequencies, Mulliken atomic charges, excitation energies, and oscillator strengths were calculated. As a result; the theoretical and experimental values were found to be compatible.

Electron-density-based calculations of intermolecular energy: case of urea

1999 ◽  
Vol 55 (5) ◽  
pp. 821-827 ◽  
Author(s):  
Kyrill Yu. Suponitsky ◽  
Vladimir G. Tsirelson ◽  
Dirk Feil
Keyword(s):  
Interaction Energy ◽  
Electron Density ◽  
Theoretical Data ◽  
Multipole Moments ◽  
Intermolecular Interaction Energy ◽  
Hartree Fock ◽  
Intermolecular Energy ◽  
Crystalline Urea ◽  
To Come ◽  
Experimental Values

The intermolecular interaction energy in crystalline urea has been calculated both from diffraction data and from the Hartree–Fock crystalline electron-density distribution, using a modified atom–atom approximation scheme. The electrostatic part of this energy has been calculated from the atomic multipole moments, obtained by adjustment of the multipole model to experimental X-ray and to theoretical Hartree–Fock structure amplitudes. To obtain the induction energy, multipole moments were calculated from structure amplitudes for the crystalline electron density and from those that refer to the electron density of a superposition of isolated molecules. This worked well for the calculation of the interaction energy from Hartree–Fock data (6% difference from the sublimation-energy value), but not for the interaction energy from experimental data, where the moments of the superposition have to come from Hartree–Fock calculations: the two sets of multipole moments are far too different. The uncertainty of the phases of the structure amplitudes, combined with systematic errors in the theoretical data and noise in the experimental values, may account for the discrepancies. The nature of the different contributions to intermolecular interactions for urea is examined.

Photon-Induced L-Shell X-Ray Production Cross Sections for Lanthanides at 59.54 keV

2017 ◽  
Vol 890 ◽  
pp. 223-226 ◽  
Author(s):  
Rıdvan Durak ◽  
Ferdi Akman ◽  
Abdulhalik Karabulut
Keyword(s):  
High Resolution ◽  
Cross Sections ◽  
Production Cross ◽  
Theoretical Data ◽  
Experimental Results ◽  
X Rays ◽  
X Ray ◽  
Reflection Geometry ◽  
Experimental Values ◽  
Annular Source

The Ll, Lα and Lβ X-ray production cross sections for Pr, Nd, Sm, Eu, Gd and Tb elements were determined using a reflection geometry. The excitation was performed with a 241Am radioactive annular source and the L X-rays emitted from targets were counted with a high-resolution Si (Li) detector. The experimental values were compared with other available experimental results and theoretical data. An agreement is observed between the measured and other experimental results or theoretical data.

On the Laminar Flow Characteristics of Conical Bearings. Part II—Experimental Verification

1986 ◽  
Vol 108 (1) ◽  
pp. 59-64 ◽  
Author(s):  
W. Kalita ◽  
N. Yegani ◽  
Cz. M. Rodkiewicz ◽  
J. S. Kennedy
Keyword(s):  
Laminar Flow ◽  
Close Agreement ◽  
Load Capacity ◽  
Flow Characteristics ◽  
Theoretical Data ◽  
Pressure Distributions ◽  
Experimental Values ◽  
Main Effects ◽  
Narrow Gaps ◽  
Experimental Pressure

The laminar flow characteristics of the externally pressurized central recess conical bearings with narrow gaps, predicted theoretically in Part I of this paper, have been verified experimentally. Two main effects on the performance of conical bearings have been investigated, namely: the effect of nonconstant film thickness along the gap of the bearing and the effect of rotation. It was found that experimental pressure distributions and load capacity of the constant and divergent gap bearings were in close agreement with the theoretical data for the low rotational velocities however, with the increased rotation, the experimental values were higher than theoretically predicted. The experimental values of pressure, load capacity, and the torque of convergent gap bearings were found higher than theoretical.

Process Smoothing of the Inner Surface of Cylinders after Honing and its Role in Eliminating Wear in the Activation of the Heat Engine

2013 ◽  
Vol 837 ◽  
pp. 43-48 ◽  
Author(s):  
Daniel Chirita
Keyword(s):  
Metal Cutting ◽  
Heat Engine ◽  
Theoretical Data ◽  
Internal Diameter ◽  
Cylinder Surface ◽  
Initial Surface ◽  
Surface Smoothing ◽  
Machining Processes ◽  
Internal Surfaces ◽  
Inner Surface

It is known that one of the basic requirements of the market economy is product competitiveness; competitiveness ensures their operating performance and the costs of obtaining them and therefore manufacturing costs. Process smoothing of the cylindrical internal surfaces must ensure a very high diameters precision and a low surface roughness. Cylindrical inner surface smoothing can be achieved through the following processes: indoor spinning roller, honing, lapping, etc. Fine machining processes without material removing, ensures based on the initial surface quality, initial quality metal cutting, work regime that is processed, hardness increasing by (20…60)%, roughness Ra=(1.6…0.4)μm, and fine processing procedures with material removal, ensures a high quality of machined surfaces, resulting in roughness Ra=(0.4…0.02)μm. Deformed layer size reducing at the previous processing, and reducing of micro depths serving as lubricant deposits, contributes to increasing wear resistance of cylinder surface. Cylinder inner surface smoothing by honing machines is performed on honing machines with a specially designed tool called hon. In the honing process, abrasive grain trajectories are forming on the cylinder a network of fine spiral lines. If carried out on a flat surface, these helical lines become straight and intersecting an angle 2α. Processing accuracy depends on the accuracy of the previous bore. In this paper, the focus is on several methods of heat engine cylinder forming the passage of the piston and rings share repair and their effect giving the engine operating parameters specified by eliminating the running operation. With the help of experimental and theoretical data and the methodology of approach to the subject, several aspects have been clarified regarding the depth of the asperities on the honed surface compared to a process-smoothed surface. The influence of all factors on the processing results has not been thoroughly explained. The following research methods shall be discussed in the future: improving the method of adjusting the pressure of the centrifugal rollers with the help of an automatically controlled device and the creation of an auxiliary device to adjust the bars to which the rollers are connected according to the internal diameter of the processed cylinders.

scholarly journals THEORETICAL STUDYING EXCITED STATES SPECTRUM OF THE YTTERBIUM WITHIN THE OPTIMIZED RELATIVISTIC MANY-BODY PERTURBATION THEORY

2021 ◽  
pp. 118-125
Author(s):  
V. Ternovsky ◽  
A. Svinarenko ◽  
Yu. Dubrovskaya
Keyword(s):  
Perturbation Theory ◽  
Excited States ◽  
Theoretical Data ◽  
Zeroth Approximation ◽  
Relativistic Energy ◽  
Many Body ◽  
Hartree Fock ◽  
Ytterbium Atom ◽  
Many Body Perturbation Theory ◽  
Experimental Values

Theoretical studying spectrum of the excited states for the ytterbium atom is carried out within the relativistic many-body perturbation theory with ab initio zeroth approximation and generalized relativistic energy approach.  The zeroth approximation of the relativistic perturbation theory is provided by the optimized Dirac-Kohn-Sham ones. Optimization has been fulfilled by means of introduction of the parameter to the Kohn-Sham exchange potentials and further minimization of the gauge-non-invariant contributions into radiation width of atomic levels with using relativistic orbital set, generated by the corresponding zeroth approximation Hamiltonian. The obtained theoretical data on energies E and widths W of the ytterbium excited states are compared with alternative theoretical results (the Dirac-Fock, relativistic Hartree-Fock, perturbation  theories) and available experimental data. Analysis shows that the theoretical and experimental values ​​of energies are in good agreement with each other, however, the values ​​of widths differ significantly. In our opinion, this fact is explained by insufficiently accurate estimates of the radial integrals, the use of unoptimized bases, and some other approximations of the calculation.

scholarly journals Experimental transition probabilities for 4p – 4d spectral lines in V II

2019 ◽  
Vol 622 ◽  
pp. A154 ◽  
Author(s):  
H. Nilsson ◽  
J. Andersson ◽  
L. Engström ◽  
H. Lundberg ◽  
H. Hartman
Keyword(s):  
Transition Probabilities ◽  
Branching Fractions ◽  
Theoretical Data ◽  
Spectral Lines ◽  
Time Resolved ◽  
Excitation Scheme ◽  
Photon Excitation ◽  
Experimental Transition ◽  
Experimental Values ◽  
Absolute Transition

Aims. We aim to measure lifetimes of levels belonging to the 3d3(4F)4d subconfiguration in V II, and derive absolute transition probabilities by combining the lifetimes with experimental branching fractions.Methods. The lifetimes were measured using time-resolved laser-induced fluorescence in a two-photon excitation scheme. The branching fractions were measured in intensity calibrated spectra from a hollow cathode discharge lamp, recorded with a Fourier transform spectrometer.Results. We report lifetimes for 13 levels at an energy around 73 000 cm−1. Absolute transition probabilities of 78 lines are derived by combining the lifetimes and branching fractions. The experimental values are compared with theoretical data from the literature.

Open Questions in Nanosegregation

2017 ◽  
Vol 891 ◽  
pp. 3-10
Author(s):  
Pavel Lejček
Keyword(s):  
Grain Boundary ◽  
Grain Boundaries ◽  
Boundary Segregation ◽  
Theoretical Data ◽  
Grain Boundary Segregation ◽  
The Past ◽  
Open Questions ◽  
Experimental Values ◽  
Boundary Core

Despite nanosegregation of solutes at grain boundaries has been intensively studied in the past decades and numerous theoretical data as well as experimental values on characteristic energies and/or enthalpies and entropies exist some questions remain still unanswered. In this paper some of these questions – Which energetic quantities obtained in different ways, experimentally and theoretically, can be mutually compared? What is the segregation site of a solute in the grain boundary core? – are discussed in more detail. It will be shown that the entropy of grain boundary segregation plays an important and indisputable role in responding some issues and that understanding of its role will help us to elucidate fundamentals of the grain boundary segregation.

scholarly journals Accounting for the resistivity contribution of grain boundaries in metals: critical analysis of reported experimental and theoretical data for Ni and Cu

2021 ◽  
Vol 136 (4) ◽  
Author(s):  
I. Bakonyi
Keyword(s):  
Grain Size ◽  
Reflection Coefficient ◽  
Grain Boundary ◽  
Grain Boundaries ◽  
Theoretical Data ◽  
Phenomenological Approach ◽  
Microscopy Imaging ◽  
Reliable Parameter ◽  
Good Relation ◽  
Experimental Values

AbstractIn the present paper, reported literature data on the grain-size dependence of resistivity of Ni and Cu are critically evaluated by two conceptually different methods. One is the phenomenological approach of Andrews (Phys. Lett. 19: 558, 1965) according to which in a polycrystalline metal there is a resistivity contribution inversely proportional to the average grain diameter, the proportionality constant defined as the Andrews parameter A. The other method is the customary Mayadas–Shatzkes (MS) model (Phys Rev B 1: 1382, 1970) yielding a grain-boundary reflection coefficient R. During the analysis, special care was taken to rely only on data for which the surface scattering resistivity contribution was definitely negligibly small and the grain size was determined by direct microscopy imaging. By sorting out with this analysis the most reliable grain-size-dependent resistivity data for polycrystalline Ni and Cu metals with random grain boundaries, we have then derived the current best room-temperature values of the Andrews parameter A, the specific grain-boundary resistivity and the reflection coefficient R. We have also found a fairly good relation between the parameters A and R and compared the experimental values with their theoretical estimates reported in the literature. Then, the conceptual differences between the two approaches are discussed and the deficiencies of the MS model, especially in connection with the validity of Matthiessen’s rule, are highlighted. A major conclusion is that by the Andrews method one can derive a model-independent reliable parameter characterizing the grain-boundary contribution to the resistivity of metals.

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