scholarly journals Determination of Boussinesq and Coriolis coefficients for pipelines operating with discharge connection along the path

2021 ◽  
pp. 11-17
Author(s):  
Andriy Kravchuk ◽  
Gennadii Kochetov ◽  
Oleksandr Kravchuk
Keyword(s):  
Cross Sections ◽  
Structural Characteristics ◽  
Fluid Motion ◽  
Experimental Studies ◽  
Liquid Jets ◽  
Uniform Motion ◽  
Momentum Coefficient ◽  
Fluid Velocities ◽  
Design Characteristics ◽  
Solid Walls

Peculiarities of the diagrams of averaged fluid velocities in the cross-sections of pressure collecting perforated pipelines were determined on the basis of the experimental studies conducted by the authors. The most characteristic typical diagrams of averaged velocities in the pipelines cross-sections with their different design characteristics were given. A comparative analysis of the obtained diagrams with the diagrams of velocities that occur during uniform motion in pressure pipelines with solid walls was carried out. It is shown that the main difference between them occurs in the flow zones, which are located near the pipeline walls. It was explained by the connected liquid jets effect on the main flow. The degree of diagrams deformation was estimated by the value of the momentum coefficient α0 (Boussinesq coefficient) and the coefficient of kinetic energy α (Coriolis coefficient). It was determined that in the general case these coefficients will be variable in magnitude along the length of the studied pipes. Nevertheless, these coefficients are recommended to be constant in magnitude in engineering calculations. The limits of the structural characteristics of collecting perforated pipes for which this non-uniformity of the diagrams must be taken into account, and for which it can be neglected were determined on the basis of the analysis of the equation of fluid motion with a variable flow rate.

3-D reconstruction and analysis of mammalian mitotic spindle structure

1992 ◽  
Vol 50 (1) ◽  
pp. 578-579
Author(s):  
Kent McDonald ◽  
David Mastronarde ◽  
Rubai Ding ◽  
Eileen O'Toole ◽  
J. Richard McIntosh
Keyword(s):  
Cross Sections ◽  
Mitotic Spindle ◽  
Experimental Studies ◽  
Video Camera ◽  
Three Dimensions ◽  
Mitotic Spindles ◽  
Black And White ◽  
Reconstruction Methods ◽  
Spindle Structure ◽  
Tissue Culture Line

Mammalian spindles are generally large and may contain over a thousand microtubules (MTs). For this reason they are difficult to reconstruct in three dimensions and many researchers have chosen to study the smaller and simpler spindles of lower eukaryotes. Nevertheless, the mammalian spindle is used for many experimental studies and it would be useful to know its detailed structure.We have been using serial cross sections and computer reconstruction methods to analyze MT distributions in mitotic spindles of PtK cells, a mammalian tissue culture line. Images from EM negatives are digtized on a light box by a Dage MTI video camera containing a black and white Saticon tube. The signal is digitized by a Parallax 1280 graphics device in a MicroVax III computer. Microtubules are digitized at a magnification such that each is 10-12 pixels in diameter.

Experimental Studies Of Multilayer Glass Structures On Compression, Compression With Bending And Simple Bending

2019 ◽  
pp. 22-30
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Applied Load ◽  
Experimental Studies ◽  
Strength Properties ◽  
Research Topic ◽  
Normative Values ◽  
Laminated Glass ◽  
The Cross ◽  
Experimental Values

The work of multilayer glass structures for central and eccentric compression and bending are considered. The substantiation of the chosen research topic is made. The description and features of laminated glass for the structures investigated, their characteristics are presented. The analysis of the results obtained when testing for compression, compression with bending, simple bending of models of columns, beams, samples of laminated glass was made. Overview of the types and nature of destruction of the models are presented, diagrams of material operation are constructed, average values of the resistance of the cross-sections of samples are obtained, the table of destructive loads is generated. The need for development of a set of rules and guidelines for the design of glass structures, including laminated glass, for bearing elements, as well as standards for testing, rules for assessing the strength, stiffness, crack resistance and methods for determining the strength of control samples is emphasized. It is established that the strength properties of glass depend on the type of applied load and vary widely, and significantly lower than the corresponding normative values of the strength of heat-strengthened glass. The effect of the connecting polymeric material and manufacturing technology of laminated glass on the strength of the structure is also shown. The experimental values of the elastic modulus are different in different directions of the cross section and in the direction perpendicular to the glass layers are two times less than along the glass layers.

scholarly journals Photoionization Cross-Sections of Carbon-Like N+ Near the K-Edge (390–440 eV)

Atoms ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 27
Author(s):  
Jean-Paul Mosnier ◽  
Eugene T. Kennedy ◽  
Jean-Marc Bizau ◽  
Denis Cubaynes ◽  
Ségolène Guilbaud ◽  
...  
Keyword(s):  
High Resolution ◽  
Cross Section ◽  
Cross Sections ◽  
Experimental Studies ◽  
Photoionization Cross Section ◽  
Theoretical Work ◽  
Rydberg Series ◽  
R Matrix ◽  
Resonance Strengths ◽  
Nitrogen Ion

High-resolution K-shell photoionization cross-sections for the C-like atomic nitrogen ion (N+) are reported in the 398 eV (31.15 Å) to 450 eV (27.55 Å) energy (wavelength) range. The results were obtained from absolute ion-yield measurements using the SOLEIL synchrotron radiation facility for spectral bandpasses of 65 meV or 250 meV. In the photon energy region 398–403 eV, 1s⟶2p autoionizing resonance states dominated the cross section spectrum. Analyses of the experimental profiles yielded resonance strengths and Auger widths. In the 415–440 eV photon region 1s⟶(1s2s22p2 4P)np and 1s⟶(1s2s22p2 2P)np resonances forming well-developed Rydberg series up n=7 and n=8 , respectively, were identified in both the single and double ionization spectra. Theoretical photoionization cross-section calculations, performed using the R-matrix plus pseudo-states (RMPS) method and the multiconfiguration Dirac-Fock (MCDF) approach were bench marked against these high-resolution experimental results. Comparison of the state-of-the-art theoretical work with the experimental studies allowed the identification of new resonance features. Resonance strengths, energies and Auger widths (where available) are compared quantitatively with the theoretical values. Contributions from excited metastable states of the N+ ions were carefully considered throughout.

Application of Thermo-Frictional and Chemical-Thermal Methods Treatments for Surface Strengthening of Materials

2021 ◽  
Vol 1038 ◽  
pp. 93-99
Author(s):  
Alexander Levterov ◽  
Julia Nechitailo ◽  
Tatyana Plugina ◽  
Oleg Volkov
Keyword(s):  
Cross Sections ◽  
Experimental Studies ◽  
Metallographic Analysis ◽  
Thermal Treatments ◽  
Strengthening Effect ◽  
Thermal Methods ◽  
Surface Strengthening ◽  
Before And After ◽  
The Cross

In the article, the issues of using the methods of thermo-frictional and chemical-thermal treatments for surface strengthening of steel tools were disclosed. 65G steel and U8A steel were considered. A flat graver and a cylindrical root roller were considered to be tools in need of hardening. The nature of the jewellery work using such a tool has been described. Hardening techniques, experimental studies and macro photographs of the samples were presented in this article. A detailed metallographic analysis and measurement of the microhardness of the cross-sections of the prototypes after their strengthening using various methods was carried out. The metallographic nature of the reinforcement with the formation of surface "white layers" was shown. Comparison of the properties of the samples before and after strengthening was carried out. Conclusions about the strengthening effect of the thermo-frictional and chemical-thermal methods of strengthening were made.

Designing for Trust: Understanding the Role of Agent Gender and Location on User Perceptions of Trust in Home Automation

2019 ◽  
Vol 141 (6) ◽  
Author(s):  
Nicole Damen ◽  
Christine Toh
Keyword(s):  
Experimental Studies ◽  
Mediating Effect ◽  
Future Research ◽  
Home Automation ◽  
Human Relationships ◽  
User Perceptions ◽  
User Behaviors ◽  
Design Characteristics ◽  
Carry Over

Although trust can have a positively mediating effect on information technology adoption and usage, the concept has not been extensively investigated in the home automation field. Therefore, this work is aimed at exploring the role of agent location and the gender of the agent's voice on users' perception of trust toward automation through two experimental studies (N = 8 and N = 20) and a web-based smart lock simulation. Explicit trust behavior was captured using directly observable behaviors and decisions, while implicit trust behavior was captured using detailed click-level user behaviors with the smart lock simulation as a proxy for reaction time. The results show that users displayed more explicit trusting behavior toward the system when it displayed design characteristics that were stereotype congruent (female-home and male-office) compared to stereotype incongruent systems (male-home and female-office). These results show that users carry over the social expectations and roles encountered in human-to-human relationships to interactions with simulated automated agents. These findings empirically demonstrate the influence of design characteristics on the formation of trust relationships between users and automated devices and provide a foundation for future research geared at critically examining our evolving relationship with technology.

scholarly journals Investigations on Torsion of the Two-Chords Single Laced Members

2017 ◽  
Vol 25 (2) ◽  
pp. 147-160
Author(s):  
Paweł Lorkowski ◽  
Bronisław Gosowski
Keyword(s):  
Cross Sections ◽  
Experimental Studies ◽  
The Finite Element Method ◽  
Second Moment ◽  
Steel Columns ◽  
Numerical Studies ◽  
Traction Network ◽  
Railway Traction ◽  
Parametric Analyses ◽  
The Relationship

Abstract The paper presents experimental and numerical studies to determine the equivalent second moment of area of the uniform torsion of the two-chord steel single laced members. The members are used as poles of railway traction network gates, and steel columns of framed buildings as well. The stiffness of uniform torsion of this kind of columns allows to the determine the critical loads of the spatial stability. The experimental studies have been realized on a single - span members with rotation arrested at their ends, loaded by a torque applied at the mid-span. The relationship between angle of rotation of the considered cross-section and the torque has been determined. Appropriate numerical model was created in the ABAQUS program, based on the finite element method. A very good compatibility has been observed between experimental and numerical studies. The equivalent second moment of area of the uniform torsion for analysed members has been determined by comparing the experimental and analytical results to those obtained from differential equation of non-uniform torsion, based on Vlasov’s theory. Additionally, the parametric analyses of similar members subjected to the uniform torsion, for the richer range of cross-sections have been carried out by the means of SOFiSTiK program. The purpose of the latter was determining parametrical formulas for calculation of the second moment of area of uniform torsion.

scholarly journals Improving the validation of turbulent jet breakup models

2019 ◽  
Author(s):  
Ben Trettel
Keyword(s):  
Fire Suppression ◽  
Experimental Studies ◽  
Droplet Size Distribution ◽  
Turbulent Jet ◽  
Liquid Jets ◽  
Experimental Database ◽  
Quality Guidelines ◽  
Water Jet Cutting ◽  
Jet Breakup ◽  
Quantities Of Interest

Understanding the physics of the breakup of turbulent liquid jets is important for a variety of applications including engine sprays, fire suppression systems, and water jet cutting. Models of turbulent jet breakup allow predictions of quantities of interest like the droplet size distribution and breakup length of the jet. These models are compared against experimental data in a process called validation. If the model predictions are within the experimental uncertainty, then the model is "validated" and believed to be accurate, and possibly can explain the physics. Uncertainty quantification is necessary for model validation. While unfortunately relatively few experimental studies quantify uncertainty, that is not the most pressing validation issue in turbulent jet breakup. I detail 3 additional problems that can make the apparent validation of a model actually an illusion, regardless of how well the model appears to match the data. These problems include: 1. important variables being omitted or guessed in experiments and models, 2. confounding between independent variables, that is, two variables changing simultaneously, making determining cause and effect impossible, and 3. testing only combinations of submodels and not each submodel in isolation. To avoid these problems and others, I developed validation guidelines that are detailed in this work. Following these guidelines, I compiled a large experimental database. Only 28 out of 47 experimental studies considered met my data quality guidelines. Only 18 studies had quantified uncertainty, and only 3 studies had substantial variation in the turbulence intensity.

scholarly journals Investigation of Coolant Local Hydrodynamics in the Mixed Core of the VVER Reactor

2020 ◽  
Vol 63 (2) ◽  
pp. 151-162
Author(s):  
S. M. Dmitriev ◽  
A. V. Gerasimov ◽  
A. A. Dobrov ◽  
D. V. Doronkov ◽  
A. N. Pronin ◽  
...  
Keyword(s):  
Cross Sections ◽  
Experimental Studies ◽  
Reactor Core ◽  
Cross Flow ◽  
Coolant Flow ◽  
Vver Reactor ◽  
Computational Hydrodynamics ◽  
Cross Section Area ◽  
Fuel Assemblies ◽  
Flow Pressure

The article presents the results of experimental studies of the local hydrodynamics of the coolant flow in the mixed core of the VVER reactor, consisting of the TVSA-T and TVSA-T mod.2 fuel assemblies. Modeling of the flow of the coolant flow in the fuel rod bundle was carried out on an aerodynamic test stand. The research was carried out on a model of a fragment of a mixed core of a VVER reactor consisting of one TVSA-T segment and two segments of the TVSA-T.mod2. The flow pressure fields were measured with a five-channel pneumometric probe. The flow pressure field was converted to the direction and value of the coolant velocity vector according to the dependencies obtained during calibration. To obtain a detailed data of the flow, a characteristic cross-section area of the model was selected, including the space cross flow between fuel assemblies and four rows of fuel rods of each of the TVSA fuel assemblies. In the framework of this study the analysis of the spatial distribution of the projections of the velocity of the coolant flow was fulfilled that has made it possible to pinpoint regularities that are intrinsic to the coolant flowing around spacing, mixing and combined spacing grates of the TVSA. Also, the values of the transverse flow of the coolant caused by the flow along hydraulically nonidentical grates were determined and their localization in the longitudinal and cross sections of the experimental model was revealed. Besides, the effect of accumulation of hydrodynamic flow disturbances in the longitudinal and cross sections of the model caused by the staggered arrangement of hydraulically non-identical grates was determined. The results of the study of the coolant cross flow between fuel assemblies interaction, i.e. between the adjacent TVSA-T and TVSA-T mod.2 fuel assemblies were adopted for practical use in the JSC of “Afrikantov OKB Mechanical Engineering” for assessing the heat engineering reliability of VVER reactor cores; also, they were included in the database for verification of computational hydrodynamics programs (CFD codes) and for detailed cell-based calculation of the reactor core.

scholarly journals Sizing and shape optimization material use in 10 bar trusses

2021 ◽  
Vol 343 ◽  
pp. 04004
Author(s):  
Nenad Petrović ◽  
Nenad Kostić ◽  
Vesna Marjanović ◽  
Ileana Ioana Cofaru ◽  
Nenad Marjanović
Keyword(s):  
Genetic Algorithm ◽  
Shape Optimization ◽  
Cross Sections ◽  
Optimization Model ◽  
Structural Characteristics ◽  
Optimization Method ◽  
Truss Optimization ◽  
Algorithm Optimization ◽  
Sizing Optimization ◽  
Bill Of Materials

Truss optimization has the goal of achieving savings in costs and material while maintaining structural characteristics. In this research a 10 bar truss was structurally optimized in Rhino 6 using genetic algorithm optimization method. Results from previous research where sizing optimization was limited to using only three different cross-sections were compared to a sizing and shape optimization model which uses only those three cross-sections. Significant savings in mass have been found when using this approach. An analysis was conducted of the necessary bill of materials for these solutions. This research indicates practical effects which optimization can achieve in truss design.

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