Explicit formulation for the axial collapse of a pipe during drilling

2010 ◽  
Vol 224 (8) ◽  
pp. 1547-1549
Author(s):  
A Almasi
Keyword(s):  
Closed Form ◽  
Plastic Hinge ◽  
Variable Length ◽  
Experimental Results ◽  
Displacement Curve ◽  
Explicit Formulation ◽  
Theoretical Predictions ◽  
Hinge Zone ◽  
Good Agreement

New closed-form expressions are introduced for ax-symmetric progressive axial collapse of pipes that use a plastic folding mechanism based on variable length of an active plastic hinge zone. A procedure for determination of a load—displacement curve of axial pipe collapse is presented. Theoretical predictions give a good agreement with the experimental results owing to the influence of presented new refinements.

A Technique for the Laboratory Determination of Recirculation in Single Needle Dialysis

1993 ◽  
Vol 16 (2) ◽  
pp. 63-70 ◽  
Author(s):  
N.A. Hoenich ◽  
P.T. Smirthwaite ◽  
C. Woffindin ◽  
P. Lancaster ◽  
T.H. Frost ◽  
...  
Keyword(s):  
Experimental Data ◽  
Flow Rate ◽  
Experimental Results ◽  
New Technique ◽  
Treatment Efficiency ◽  
Single Lumen ◽  
Theoretical Predictions ◽  
Lumen Catheter ◽  
A New Technique

Recirculation is an important factor in single needle dialysis and, if high, can compromise treatment efficiency. To provide information regarding recirculation characteristics of access devices used in single needle dialysis, we have developed a new technique to characterise recirculation and have used this to measure the recirculation of a Terumo 15G fistula needle and a VasCath SC2300 single lumen catheter. The experimentally obtained results agreed well with those established clinically (8.5 ± 2.4% and 18.4 ± 3.4%). The experimental results have also demonstrated a dependence on access type, pump speeds and fistula flow rate. A comparison of experimental data with theoretical predictions showed that the latter exceeded those measured with the largest contribution being due to the experimental fistula.

Theoretical Determination of Absorption With an Emphasis on High Temperatures and a Specific Application to Carbon Monoxide

1973 ◽  
Vol 95 (4) ◽  
pp. 535-538 ◽  
Author(s):  
J. C. Lin ◽  
R. Greif
Keyword(s):  
Carbon Monoxide ◽  
High Temperatures ◽  
Rotational Band ◽  
Experimental Results ◽  
Theoretical Determination ◽  
Hot Band ◽  
Good Agreement

The absorption of a vibrational-rotational band has been studied and the contribution from the first hot band has been included. A specific application has been made to carbon monoxide and good agreement with experimental results has been obtained.

Determination of the limits of stable combustion at high supersonic flow velocities in a channel

2010 ◽  
Vol 3 (2) ◽  
pp. 47-60
Author(s):  
Alexey V. Starov
Keyword(s):  
Paper Analysis ◽  
Measurement Methods ◽  
Experimental Results ◽  
Physical Parameters ◽  
Supersonic Speed ◽  
Combustion Limits ◽  
Criterial Description ◽  
Selection Of ◽  
Good Agreement

In this paper, analysis of existing methods application of criterial description of ignition conditions and combustion break-out for summarizing of experimental results is carried out. Experimental results are obtained at investigations of hydrogen combustion in combustor with high supersonic speed of airflow. For these conditions selection of several criterions was substantiated and they have a good agreement with new experimental results. At the same time complexity of determination of experimental physical parameters, which are included in criterions, do not allow confidently to apply them for prediction of steady-state combustion limits. Therefore further accumulation of experimental data and development of measurement methods are necessary for accurate criterions obtaining.

scholarly journals Nanomechanics of few-layer materials: do individual layers slide upon folding?

2020 ◽  
Vol 11 ◽  
pp. 1801-1808
Author(s):  
Ronaldo J C Batista ◽  
Rafael F Dias ◽  
Ana P M Barboza ◽  
Alan B de Oliveira ◽  
Taise M Manhabosco ◽  
...  
Keyword(s):  
2D Materials ◽  
Adhesion Energy ◽  
Flexural Properties ◽  
2D Systems ◽  
Number Of Layers ◽  
Graphene Flakes ◽  
Theoretical Predictions ◽  
Tip Enhanced Raman Spectroscopy ◽  
Good Agreement

Folds naturally appear on nanometrically thin materials, also called “2D materials”, after exfoliation, eventually creating folded edges across the resulting flakes. We investigate the adhesion and flexural properties of single-layered and multilayered 2D materials upon folding in the present work. This is accomplished by measuring and modeling mechanical properties of folded edges, which allows for the experimental determination of the bending stiffness (κ) of multilayered 2D materials as a function of the number of layers (n). In the case of talc, we obtain κ ∝ n 3 for n ≥ 5, indicating no interlayer sliding upon folding, at least in this thickness range. In contrast, tip-enhanced Raman spectroscopy measurements on edges in folded graphene flakes, 14 layers thick, show no significant strain. This indicates that layers in graphene flakes, up to 5 nm thick, can still slip to relieve stress, showing the richness of the effect in 2D systems. The obtained interlayer adhesion energy for graphene (0.25 N/m) and talc (0.62 N/m) is in good agreement with recent experimental results and theoretical predictions. The obtained value for the adhesion energy of graphene on a silicon substrate is also in agreement with previous results.

scholarly journals Determination of freeze-out conditions from lattice QCD calculations

Open Physics ◽  
2012 ◽  
Vol 10 (6) ◽  
Author(s):  
Frithjof Karsch
Keyword(s):  
Lattice Qcd ◽  
Heavy Ion Collisions ◽  
Heavy Ion ◽  
Experimental Results ◽  
Ion Collisions ◽  
Theoretical Predictions ◽  
Freeze Out

AbstractFreeze-out conditions in Heavy Ion Collisions are generally determined by comparing experimental results for ratios of particle yields with theoretical predictions based on applications of the Hadron Resonance Gas model. We discuss here how this model dependent determination of freeze-out parameters may eventually be replaced by theoretical predictions based on equilibrium QCD thermodynamics.

Measurement of the Isothermal Volume Dilation Accompanying the Unilateral Extension of Rubber

1959 ◽  
Vol 32 (2) ◽  
pp. 428-433
Author(s):  
Fred G. Hewitt ◽  
Robert L. Anthony
Keyword(s):  
Molecular Weight ◽  
Young’S Modulus ◽  
Experimental Results ◽  
Molecular Weights ◽  
Rubber Specimen ◽  
A Value ◽  
Fractional Increase ◽  
Internal Agreement ◽  
Good Agreement

Abstract The fractional increase in volume accompanying the isothermal extension of soft gum rubber was measured for four rubber samples at mean extensions of 14, 33, and 51%. The chain molecular weights Mc of the four samples were 5500, 5100, 4400, and 3000, with an estimated uncertainty of about 10% in each value of Mc. The observed fractional increase in volume ranged from 3.2×10−5 to 142×10−5, the latter value being observed for the sample of lowest chain molecular weight and at the extension of 51%. The experimental results for each sample have been represented by theoretical curves based on Gee's expression for the fractional increase in volume as a function of the sample extension. The theoretical curves exhibit good agreement with those of Gee, Stern, and Treloar. The process of fitting the theoretical curves to the experimental points constituted a determination of Young's modulus E for each rubber specimen. As a check on the experimental results, and also on the theory employed, determinations of E were also made by two additional methods, namely, from rough stess-strain curves, and from the relation E=3γρRT/Mc. With one exception, the internal agreement between the three determinations of E for the four different samples was satisfactory. The exception noted can probably be ascribed to the use of too small a value of Mc for the sample of lowest chain molecular weight.

Measurement of sheath characteristics in the presence of convection and ionization

1996 ◽  
Vol 74 (9-10) ◽  
pp. 671-675 ◽  
Author(s):  
R. M. Clements ◽  
J. R. Dawe ◽  
S. A. H. Rizvi ◽  
P. R. Smy
Keyword(s):  
Boundary Layer ◽  
Plasma Electron ◽  
Experimental Results ◽  
Ion Density ◽  
Current Voltage ◽  
Planar Grid ◽  
Theoretical Predictions ◽  
Flame Plasma ◽  
Theoretical Paper ◽  
Good Agreement

A flame plasma whose electron and (or) ion density can be varied over several orders of magnitude is constrained to flow perpendicular to a planar grid Langmuir probe. The probe is biased negative to the plasma, and the current–voltage characteristics and the thickness of the ion sheath formed at the probe are measured. The level of the electron and (or) ion density is set within a range at which the probe current due to thermal ionization throughout the sheath is comparable with the current of ions convected into the sheath. The experimental results are compared with the predictions of a recent theoretical paper that calculates the effect of recombination upon the characteristics of planar, cylindrical, and spherical probes with boundary layer sheaths. The theoretical predictions and experimental results for an idealized planar configuration show good agreement over wide ranges of variation of probe bias and plasma electron and (or) ion density. This verification of the theoretical planar electrode – perpendicular-flow model, which is the basis for all three boundary layer relations, is seen as providing strong backing for these relations, which have application to ionization measurements in various forms of recombinant plasma.

Paper 31: Capsule-Pipeline Flow—A Theoretical Study

1969 ◽  
Vol 184 (7) ◽  
pp. 89-100
Author(s):  
V. K. Garg ◽  
G. F. Round
Keyword(s):  
Theoretical Study ◽  
Theoretical Solution ◽  
Experimental Results ◽  
Free Flow ◽  
Average Flow ◽  
Pipe System ◽  
Liquid Carrier ◽  
Pipeline Flow ◽  
Theoretical Predictions ◽  
Good Agreement

Theoretical predictions of the behaviour of various parameters governing the free flow of a single, very long, denser-than-liquid carrier, cylindrical capsule in a horizontal pipeline are reported in this paper. The study was carried out for average flow velocities of approximately 1–10 ft/s in pipes of diameters 4, 6, 12, and 24 in with diameter ratios varying from 0·9 to 0·99. While two liquid carriers—water and an oil ( μ = 10 cP and sp. gr. = 0·85)—were used, the eccentricity of the capsule-pipe system was fixed at 0·999. The theoretical solution was found to be in good agreement with the experimental results.

The bursting of a charged cylindrical film

1972 ◽  
Vol 328 (1575) ◽  
pp. 529-539 ◽  
Keyword(s):  
Experimental Data ◽  
Finite Length ◽  
Experimental Results ◽  
Exact Calculation ◽  
Conducting Film ◽  
Half Wavelength ◽  
Theoretical Predictions ◽  
Long Cylinder ◽  
Good Agreement

This paper is a sequel to Sir Geoffrey Taylor’s study of the bursting of an electrified cylindrical conducting film. Taylor described experiments in which the voltages, at which the film becomes statically unstable, were observed for various lengths of film. These results were compared with the theoretical predictions for disturbances on an infinitely long cylinder having a wavelength equal to the length of film used. It is shown here that a transition in the mode of bursting from an axisymmetric whole wavelength mode to a lateral half wavelength mode is to be expected and that the experimental data conform with this transition. An exact calculation of the modes for a film of finite length is also given here and the resulting theoretical predictions of instability and bursting voltages are in very good agreement with the experimental results.

Using Superhydrophobic SU-8 Film as the Dielectric for Electrowetting-on-Dielectric

2018 ◽  
Vol 281 ◽  
pp. 604-609
Author(s):  
Yu Hao Piao ◽  
Wei Qiang Wang
Keyword(s):  
Contact Angle ◽  
Dielectric Layer ◽  
Superhydrophobic Surface ◽  
High Performance ◽  
Apparent Contact Angle ◽  
Experimental Results ◽  
Electrowetting On Dielectric ◽  
Dc Voltage ◽  
Theoretical Predictions ◽  
Good Agreement

In this paper, we study the electrowetting effect of superhydrophobic SU-8 film as the dielectric for Electrowetting-on-Dielectric (EWOD). The change of apparent contact angle (APCA) on superhydrophobic surface in electrowetting systems was measured and analyzed using a modified Lippmann-Yong equation. The variation of APCA between droplet and device surface under various DC voltage and AC voltage of different frequencies was fully experimented. The experimental results were in good agreement with the theoretical predictions. This study shows the potential of using superhydrophobic SU-8 film as the dielectric layer in high-performance EWOD devices.

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