Analysis on the Individual Stiffness of the Aerostatic Guide Way and Error Sources of its Vibration

2012 ◽  
Vol 472-475 ◽  
pp. 862-868 ◽  
Author(s):  
Jie Jun Lin ◽  
Dong Sheng Li ◽  
Wen Zhang
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Precision Engineering ◽  
Error Sources ◽  
Low Load ◽  
Horizontal Type ◽  
The Individual ◽  
Film Stiffness ◽  
Air Film ◽  
Shaped Cross Section

At present, the aerostatic guide way is more and more important in the ulta-precision engineering areas, and it is analyzed in this paper. The individual stiffness of the guide, the air film stiffness and the micro-error aroused by the random air vibration of four different bearings, whose cross sections are square, triangular, trapezoid and ∏-shaped, are got one by one. A series of analysis and deductions could draw a conclusion that the aerostatic guide way with ∏-shaped cross section is recommended for obtaining the high machining and measuring accuracy, especially for the horizontal-type use and under low load. In addition, the research in this paper is valuable for the engineers.

scholarly journals Investigation of Welds and Heat Affected Zones in Weld Surfacing Steel Plates Taking into Account the Bead Sequence

Materials ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 5666
Author(s):  
Miloš Mičian ◽  
Jerzy Winczek ◽  
Marek Gucwa ◽  
Radoslav Koňár ◽  
Miloslav Málek ◽  
...  
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Arc Welding ◽  
Gas Metal Arc Welding ◽  
Steel Plates ◽  
Structural Components ◽  
Maximum Hardness ◽  
Qualitative And Quantitative ◽  
Metal Arc Welding ◽  
The Individual

In this paper, the experimental investigation results of the bead sequence input on geometry, structure, and hardness of surfaced layers after multi-pass weld surfacing are analyzed. Three S355 steel plates surfaced by GMAW (Gas Metal Arc Welding) were tested with three different combinations of six beads. The geometric, structural, and hardness analysis was carried out in the cross-section of the plates in the middle of the welded layers. The dimensions of padded layers, fusion and heat-affected zone, as well as the individual padded weld were evaluated. On the basis of metallographic samples, qualitative and quantitative structure analysis was performed. Hardness measurements in surfacing welds and heat-affected zones in the tested cross-sections of the surfacing layers were carried out. A comparative analysis of structure and hardness, taking into account the thermal implications of the bead sequence, allowed for the formulation of conclusions. Comparative studies have shown differences in properties between heat-affected zones (HAZ) for individual surfacing sequences. These differences were mainly in the dimensions of the surfacing layers, the share of structural components, as well as the uniformity of hardness distributions. Finally, the most favorable sequence in terms of structure and hardness distribution, maximum hardness, and range of hardness has been indicated.

NONLINEAR ANALYSIS OF A BARBELL-SHAPED CROSS SECTION WALL USING FIBER SLICE

2014 ◽  
Vol 1 (1) ◽  
Author(s):  
Dae-Han Jun ◽  
Pyeong-Doo Kang
Keyword(s):  
Reinforced Concrete ◽  
Analytical Model ◽  
Cross Section ◽  
Cross Sections ◽  
Axial Load ◽  
Nonlinear Response ◽  
Shear Walls ◽  
Lateral Loads ◽  
Fiber Element ◽  
Shaped Cross Section

Reinforced concrete shear walls are effective for resisting lateral loads imposed by wind or earthquakes. This study investigates the effectiveness of a wall fiber element in predicting the flexural nonlinear response of reinforced concrete shear walls. Model results are compared with experimental results for reinforced concrete shear walls with barbell-shaped cross sections without axial load. The analytical model is calibrated and the test measurements are processed to allow for a direct comparison of the predicted and measured flexural responses. Response results are compared at top displacements on the walls. Results obtained in the analytical model for barbell-shaped cross section wall compared favorably with experimentally responses for flexural capacity, stiffness, and deformability.

scholarly journals Statistical model calculations of the 7Li +11 Β reaction

2019 ◽  
Vol 10 ◽  
pp. 165
Author(s):  
C. Tsabaris ◽  
C. T. Papadopoulos ◽  
R. Vlastou ◽  
A. A. Pakou ◽  
P. A. Assimakopoulos ◽  
...  
Keyword(s):  
Experimental Data ◽  
Statistical Model ◽  
Energy Range ◽  
Cross Section ◽  
Compound Nucleus ◽  
Cross Sections ◽  
Coulomb Barrier ◽  
Reaction Channel ◽  
Model Calculations ◽  
The Individual

The 7Li + 11 Β reaction has been studied in the energy range from a little below to about three times the Coulomb barrier by measuring the cross section of the 7- ray transitions in the residual nuclei produced. Statistical compound nucleus calculations have been performed in order to interpret the experimental data as well as to extract cross sections of the individual exit channels. The statistical compound nucleus theory can reproduce rather well the absolute j - ray and the various reaction channel excitation functions.

A Procedure to Include Slip Damping in a VIV Analysis of an Umbilical

2016 ◽  
Author(s):  
Elizabeth Passano ◽  
Shahriar Abtahi ◽  
Torfinn Ottesen
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Deep Water ◽  
Operating Conditions ◽  
Response Analysis ◽  
Material Damping ◽  
Structural Damping ◽  
Cross Sectional ◽  
The Cross ◽  
The Individual

Ocean currents may cause vortex induced vibrations (VIV) of deep-water umbilicals. The VIV response may give significant contributions to the total fatigue damage. Good estimations of the VIV response and damage are therefore important for the design of deep-water umbilicals. As VIV response is very sensitive to the structural damping, good response and fatigue estimates will be dependent on good estimates of the damping and that they are included in the VIV response analysis in a consistent way. A complex cross section such as an umbilical or a flexible riser will have two sources of structural damping; damping due to the strain variation in the individual materials that make up the cross sections, and damping due to the different layers slipping against one another. The first may be denoted material damping and is present at all response levels, and will be particularly important at low response levels. The second may be denoted slip damping and will contribute when the curvature exceeds the initial slip curvature. Ideally, accurate data for both the material and the slip damping are available. Unfortunately, this is not always the case and the damping parameters must then be estimated. The material damping may be estimated from the material properties of the various layers in the cross section, taking operating conditions such as temperature into account. The slip damping may be estimated from detailed cross-sectional analyses. As the slip damping is dependent on the curvature, iterations are needed to ensure that the applied damping and the calculated response are consistent with each other. A procedure to include these iterations within a VIV response calculation is proposed. A case study is presented demonstrating the use of the proposed procedure for a deep-water umbilical in a lazy wave configuration. For the case studied, the maximum curvatures caused by VIV are significantly reduced.

scholarly journals The Cross Sections of Glaciated Valleys

1947 ◽  
Vol 1 (1) ◽  
pp. 37-38 ◽  
Author(s):  
W. V. Lewis
Keyword(s):  
Climatic Change ◽  
Cross Section ◽  
Cross Sections ◽  
River Valley ◽  
Freezing And Thawing ◽  
Melt Water ◽  
The Cross ◽  
Shaped Cross Section

The typical U-shaped cross-section of glaciated valleys is well known but little understood. If a climatic change results in a glacier occupying a deep river valley, and some erosion is assumed to occur wherever the ice makes contact with the bedrock, then a partial change from the “V” to “U” section is to be expected. A more potent agency in such a change is probably the sapping of the valley sides by the alternate freezing and thawing of melt-water flowing down to, and under, the glacier. This has been briefly suggested by de Martonne and worked out somewhat more fully in the case of cirques1

scholarly journals The Role of Bedload Transport in the Development of a Proglacial River Alluvial Fan (Case Study: Scott River, Southwest Svalbard)

Hydrology ◽  
2021 ◽  
Vol 8 (4) ◽  
pp. 173
Author(s):  
Waldemar Kociuba
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
River Mouth ◽  
Active Role ◽  
Bedload Transport ◽  
Alluvial Fan ◽  
Surface Erosion ◽  
The Individual ◽  
Active Channel

This study, which was conducted between 2010 and 2013, presents the results of direct, continuous measurements of the bedload transport rate at the mouth section of the Scott River catchment (NW part of Wedel-Jarlsberg Land, Svalbard). In four consecutive melt seasons, the bedload flux was analyzed at two cross-sections located in the lower reaches of the gravel-bed proglacial river. The transported bedload was measured using two sets of River Bedload Traps (RBTs). Over the course of 130 simultaneous measurement days, a total of 930 bedload samples were collected. During this period, the river discharged about 1.32 t of bedload through cross-section I (XS I), located at the foot of the alluvial fan, and 0.99 t through cross-section II (XS II), located at the river mouth running into the fjord. A comparison of the bedload flux showed a distinctive disproportion between cross-sections. Specifically, the average daily bedload flux QB was 130 kg day−1 (XS I) and 81 kg day−1 (XS II) at the individual cross-profiles. The lower bedload fluxes that were recorded at specified periods in XS II, which closed the catchment at the river mouth from the alluvial cone, indicated an active role of aggradation processes. Approximately 40% of all transported bedload was stored at the alluvial fan, mostly in the active channel zone. However, comparative Geomorphic Change Detection (GCD) analyses of the alluvial fan, which were performed over the period between August 2010 and August 2013, indicated a general lowering of the surface (erosion). It can be assumed that the melt season’s average flows in the active channel zone led to a greater deposition of bedload particles than what was discharged with high intensity during floods (especially the bankfull stage, effectively reshaping the whole surface of the alluvial fan). This study documents that the intensity of bedload flux was determined by the frequency of floods. Notably, the highest daily rates recorded in successive seasons accounted for 12–30% of the total bedload flux. Lastly, the multi-seasonal analysis showed a high spatio-temporal variability of the bedload transport rates, which resulted in changes not only in the channel but also on the entire surface of the alluvial fan morphology during floods.

The Cross Sections of Glaciated Valleys

1947 ◽  
Vol 1 (01) ◽  
pp. 37-38 ◽  
Author(s):  
W. V. Lewis
Keyword(s):  
Climatic Change ◽  
Cross Section ◽  
Cross Sections ◽  
River Valley ◽  
Freezing And Thawing ◽  
Melt Water ◽  
The Cross ◽  
Shaped Cross Section

The typical U-shaped cross-section of glaciated valleys is well known but little understood. If a climatic change results in a glacier occupying a deep river valley, and some erosion is assumed to occur wherever the ice makes contact with the bedrock, then a partial change from the “V” to “U” section is to be expected. A more potent agency in such a change is probably the sapping of the valley sides by the alternate freezing and thawing of melt-water flowing down to, and under, the glacier. This has been briefly suggested by de Martonne and worked out somewhat more fully in the case of cirques 1

The Neutrino Reaction in 3H

1998 ◽  
Vol 07 (02) ◽  
pp. 275-285
Author(s):  
S. L. Mintz ◽  
G. M. Gerstner ◽  
M. A. Barnett ◽  
M. Pourkaviani
Keyword(s):  
Differential Cross Section ◽  
Cross Section ◽  
Cross Sections ◽  
Differential Cross ◽  
Form Factors ◽  
Individual Form ◽  
Neutrino Reaction ◽  
The Cross ◽  
The Individual ◽  
Sharp Minima

We calculate the cross sections for the reactions, νe+3 H → e-+3 He , and νμ+3 H → μ-+3 He from threshold to 1 GeV. We obtain typical contributions of the individual form factors as well as the interference terms to the cross sections. We find that the cross sections for these processes are extremely large for a number of reasons, making them worthy of consideration for possible experiments. We also obtain a typical differential cross section and note the presence of sharp minima for high neutrino energies.

scholarly journals Expert modelling of a geological cross-section from boreholes: sources of uncertainty and their quantification

2014 ◽  
Vol 6 (2) ◽  
pp. 1687-1721
Author(s):  
R. M. Lark ◽  
S. Thorpe ◽  
H. Kessler ◽  
S. J. Mathers
Keyword(s):  
Statistical Model ◽  
Cross Section ◽  
Cross Sections ◽  
Planning Process ◽  
Route Planning ◽  
Systematic Bias ◽  
Sources Of Uncertainty ◽  
Geological Cross Section ◽  
London Clay ◽  
The Individual

Abstract. We conducted a designed experiment to quantify sources of uncertainty in the expert interpretation of a geological cross-section. A group of 28 geologists participated in the experiment. Each interpreted borehole records which included three Palaeogene bedrock units, including the target unit for the experiment: the London Clay. The set of boreholes was divided into batches from which validation boreholes had been withheld; as a result we obtained 129 point comparisons between the interpreted elevation of the base of the London Clay and its observed elevation in a borehole not used for that particular interpretation. Analysis of the results showed good general agreement between the observed and interpreted elevations, with no evidence of systematic bias. Between-site variation of the interpretation error was spatially correlated, and the variance appeared to be stationary. The between-geologist component of variance was smaller overall, and depended on distance to the nearest borehole. There was also evidence that the between-geologist variance depends on the degree of experience of the individual. We used the statistical model of interpretation error to compute confidence intervals for any one interpretation of the base of the London Clay on the cross-section, and to provide uncertainty measures for decision support in a hypothetical route-planning process. The statistical model could also be used to quantify error-propagation in a full 3-D geological model produced from interpreted cross sections.

Mass and Mass Loss Measurements on DNA and fd Phage

1972 ◽  
Vol 30 ◽  
pp. 186-187
Author(s):  
Joseph Wall
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Scanning Transmission Electron Microscope ◽  
Scattering Data ◽  
Mass Measurements ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Atomic Scattering ◽  
The Individual ◽  
Scattering Cross Sections

Mass measurements can be done with the scanning transmission electron microscope in a manner similar to the densitometry of conventional microscope plates. Since the measurements are made directly on the microscope output signal, however, there are none of the non-linearities associated with film. The two signals (proportional to normalized elastically and inelastically scattered currents) are recorded directly on digital tape for analysis.Mass can be determined from the scattering data using atomic scattering cross-sections and assuming the cross-section of an object is the sum of the individual atomic cross-sections. Since the elastic and inelastic cross-sections have different dependence on atomic number, it also is possible to estimate the average Z of the object being measured. These calculations are performed using a Nova 800 computer system which is interfaced directly to the microscope.

Sign in / Sign up

Export Citation Format

Share Document