Identification of the effective bundle length in a multifilament yarn from the size effect response

2011 ◽  
Vol 45 (25) ◽  
pp. 2659-2667 ◽  
Author(s):  
Rostislav Chudoba ◽  
Miroslav Vořechovský ◽  
Rostislav Rypl
Keyword(s):  
Size Effect ◽  
Stress Transfer ◽  
Tensile Tests ◽  
Specimen Length ◽  
Transfer Length ◽  
Effect Curve ◽  
Mean Size ◽  
The Mean ◽  
Multifilament Yarn

The article proposes a method for characterizing the in situ interaction between filaments in a multifilament yarn. The stress transfer between neighboring filaments causes the reactivation of a broken filament at some distance from the break. The utilized statistical bundle models predict a change in the slope of the mean size effect curve once the specimen length becomes longer than the stress transfer length. This fact can be exploited in order to determine the stress transfer length indirectly using the yarn tensile test with appropriately chosen test lengths. The identification procedure is demonstrated using two test series of tensile tests with AR-glass and carbon yarns.

Effect of Water on the Size Distribution of Free-Volume Holes in Nafion Membrane

2012 ◽  
Vol 733 ◽  
pp. 49-52 ◽  
Author(s):  
Jakub Čížek ◽  
Zuzana Barnovská ◽  
Michal Šourek ◽  
Ivan Procházka
Keyword(s):  
Size Distribution ◽  
Free Volume ◽  
Water Uptake ◽  
Positron Lifetime ◽  
Ionic Clusters ◽  
Mean Size ◽  
Positron Lifetime Spectroscopy ◽  
The Mean ◽  
Kinetics Of

Positron lifetime spectroscopy was employed for investigation of the size distribution of free volume holes in Nafion N-1110 membrane. Size distribution of free volume holes was determined in the as-received and dried membrane and in the membrane immersed in water at various temperatures. It was found that absorbed water causes reduction of the mean size of free volume holes and increase of their dispersion and concentration. This indicates that free volumes are split by swollen ionic clusters absorbing water. The kinetics of water uptake and the amount of absorbed solvent was determined by in-situ measurement of the weight increase.

Micromechanical Tensile Testing

1996 ◽  
Vol 436 ◽  
Author(s):  
S. Greek ◽  
F. Ericson ◽  
S. Johansson ◽  
J.-Å. Schweitz
Keyword(s):  
Fracture Strength ◽  
Tensile Testing ◽  
Weibull Modulus ◽  
Tensile Tests ◽  
Cross Sectional ◽  
Weibull Statistics ◽  
Electrodeposited Nickel ◽  
The Mean ◽  
Scanning Electron

AbstractA method is described where tensile tests can be performed in situ on micromachined structures. The testing equipment consists of a testing unit mounted on a micromanipulator in a Scanning Electron Microscope (SEM). The fracture loads of micromachined beam structures made from thick and thin film polysilicon as well as from electrodeposited nickel and nickeliron alloy were measured, and the fracture strengths then calculated via measurements of the test structures’ initial cross-sectional areas. The statistical scatter of the polysilicon fracture strength values were evaluated by Weibull statistics. The mean fracture strength and the Weibull modulus, a measure of the scatter, were obtained

scholarly journals S31 Size Effect in the Plasticity of Multiscale Nanofilamentary Cu/Nb Composite Wires During In-Situ Tensile Tests Under Neutron Beam

2008 ◽  
Vol 23 (2) ◽  
pp. 185-185
Author(s):  
V. Vidal ◽  
L. Thilly ◽  
P. O. Renault ◽  
U. Stuhr ◽  
S. Van Petegem ◽  
...  
Keyword(s):  
Size Effect ◽  
Neutron Beam ◽  
Tensile Tests ◽  
Composite Wires

Size Effect in the Plasticity of Multiscale Nanofilamentary Cu/Nb Composite Wires During in-situ Tensile Tests Under Neutron Beam

2006 ◽  
Vol 977 ◽  
Author(s):  
Vanessa Vidal ◽  
Ludovic Thilly ◽  
Steven Van Petegem ◽  
Uwe Stuhr ◽  
Florence Lecouturier ◽  
...  
Keyword(s):  
Size Effect ◽  
Neutron Beam ◽  
Load Transfer ◽  
High Strength ◽  
Tensile Tests ◽  
Copper Matrix ◽  
Lattice Strains ◽  
Matrix Embedding ◽  
Pulsed Magnets

AbstractCopper-based high strength nanofilamentary wires reinforced by bcc nanofilaments (Nb or Ta) are prepared by severe plastic deformation for the winding of high pulsed magnets. In-situ tensile tests under neutron beam were performed on a Cu/Nb nanocomposite composed of a multiscale Cu matrix embedding 554 Nb filaments with a diameter of 267 nm and spacing of 45 nm. The evolution of elastic strains for individual lattice plane in each phase and peak profiles in the copper matrix versus applied stress evidenced the co-deformation behavior with different elastic-plastic regimes and load sharing: the Cu matrix exhibits size effect in the finest channels while the Nb nanowhiskers remain elastic up to the macroscopic failure, with a strong load transfer from the copper matrix onto zones that are still in the elastic regime. Taking into account results from residual lattice strains also determined by neutron diffraction, the yield stress in the finest Cu channels is in agreement with calculations based on a single dislocation regime.

scholarly journals Simultaneous visualization of pulmonary nodules and intersegmental planes on fluorescent images in pulmonary segmentectomy

2020 ◽  
Vol 58 (Supplement_1) ◽  
pp. i77-i84
Author(s):  
Yeasul Kim ◽  
Jiyun Rho ◽  
Yu Hua Quan ◽  
Byeong Hyeon Choi ◽  
Kook Nam Han ◽  
...  
Keyword(s):  
Indocyanine Green ◽  
Resection Margin ◽  
Pulmonary Nodules ◽  
Resection Margins ◽  
Adenocarcinoma In Situ ◽  
Segmental Artery ◽  
Mean Size ◽  
Intersegmental Plane ◽  
The Mean

Abstract OBJECTIVES The technique of simultaneously visualizing pulmonary nodules and the intersegmental plane using fluorescent images was developed to measure the distance between them intraoperatively. METHODS Patients who underwent pulmonary segmentectomy were consecutively included in this study between March 2016 and July 2019. Computed tomography or electromagnetic bronchoscopy-guided localization with indocyanine green–lipiodol emulsion was performed on the day of surgery. In the middle of the surgery, after dividing the segmental artery, vein and bronchus to a targeted segment, 0.3–0.5 mg/kg of indocyanine green was injected intravenously. RESULTS In total, 31 patients (17 men and 14 women with a mean age of 63.2 ± 9.8 years) were included in this study. The mean size and depth of the nodules were 1.2 ± 0.5 (range 0.3–2.5) cm and 16.4 ± 9.9 (range 1.0–42.0) mm, respectively. Pulmonary nodules and intersegmental plane of all the patients were visualized using a fluorescent thoracoscope. The resection margins were more than the size of the tumour or were 2 (mean 2.4 ± 1.2) cm in size in all patients except one. The resection margin of this patient looked sufficient on the intraoperative view. However, adenocarcinoma in situ at the resection margin was identified based on the pathological report. The mean duration of the operation was 168.7 ± 53.3 min, and the chest tube was removed on an average of 4.7 ± 1.8 days after surgery in all patients. CONCLUSIONS The dual visualization technique using indocyanine green could facilitate an easier measurement of the distance between pulmonary nodules and the intersegmental plane during pulmonary segmentectomy.

scholarly journals Analysis of the plastic deformation behavior for two austenitic NiCr-steels with different stacking fault energies

2018 ◽  
Vol 1 (1) ◽  
pp. 137-141
Author(s):  
Göran Engberg ◽  
Mikael Grehk ◽  
Karin Yvell
Keyword(s):  
Plastic Deformation ◽  
Dislocation Density ◽  
Tensile Tests ◽  
Stacking Fault ◽  
Size Distributions ◽  
Stress Strain ◽  
Free Distance ◽  
The Mean ◽  
Stacking Fault Energies

Two austenitic stainless steels, with low and medium stacking fault energies (SFE), 20 mJ/m2 and 30 mJ/m2 respectively, have been studied by conventional tensile tests and in situ tensile tests in a FEG-SEM equipped for EBSD. High angle boundaries (HAB) and low angle boundaries (LAB) with misorientations >= 10o and >= 2o respectively have been determined, and size distributions for the LABs have been derived by linear intercepts. It was found that the size distributions could be described by bimodal lognormal functions. For the steel with highest SFE plastic deformation took place by dislocation slip only while the steel with low SFE deformed by slip and twinning. Using a model for slip based on the evolution of the dislocation density with the generation of dislocations inversely proportional to the mean free distance of slip and recovery of dislocations proportional to the dislocation density the stress strain-curves were analyzed and the results compared with the measured quantities. The mean free distance of slip as evaluated from the stress-strain curve for the steel with the highest SFE correlates very well with the mean size of the LABs intercept. The rate of recovery also gave an expected stress dependence. The stress needed to start deformation twinning was based on the assumption that Shockley partials become completely separated in the slip plane. The thus calculated values for the twinning stress showed an excellent agreement with the observed start of twinning as given by EBSD evaluation of twin boundaries (TB). For the alloy with low SFE both surface grains (in situ test) and bulk grains (from interrupted conventional tests) were studied. The stress needed for slip and twinning of surface grains was, as expected, in the order of 0.5-0.6 times the applied stress.

scholarly journals In-Situ Tensile Tests of Snow-Pack Layers

1990 ◽  
Vol 36 (122) ◽  
pp. 102-106 ◽  
Author(s):  
J.B. Jamieson ◽  
C.D. Johnston
Keyword(s):  
Coefficient Of Variation ◽  
Rocky Mountains ◽  
Tensile Tests ◽  
Western Canada ◽  
Snow Pack ◽  
Micro Structure ◽  
Strength Data ◽  
The Mean ◽  
Critical Strains

AbstractDuring the winter of 1987–88, an average of seven tensile tests was made for each of 66 snow layers in the Rocky Mountains of western Canada. The precision of the mean strength for seven tests, expressed in terms of the coefficient of variation, was 15% with 90% confidence. Snow with a faceted micro-structure was approximately half as strong as partly settled or rounded snow of the same density. Notch sensitivity in the strength data and critical strains of 1% or less indicate that the test fractures were essentially brittle.

scholarly journals In-Situ Tensile Tests of Snow-Pack Layers

1990 ◽  
Vol 36 (122) ◽  
pp. 102-106 ◽  
Author(s):  
J.B. Jamieson ◽  
C.D. Johnston
Keyword(s):  
Coefficient Of Variation ◽  
Rocky Mountains ◽  
Tensile Tests ◽  
Western Canada ◽  
Snow Pack ◽  
Micro Structure ◽  
Strength Data ◽  
The Mean ◽  
Critical Strains

AbstractDuring the winter of 1987–88, an average of seven tensile tests was made for each of 66 snow layers in the Rocky Mountains of western Canada. The precision of the mean strength for seven tests, expressed in terms of the coefficient of variation, was 15% with 90% confidence. Snow with a faceted micro-structure was approximately half as strong as partly settled or rounded snow of the same density. Notch sensitivity in the strength data and critical strains of 1% or less indicate that the test fractures were essentially brittle.

Novel Formulation Development and Evaluation of Nanoparticles Based in Situ Gelling System for The Ophthalmic Delivery of Ciprofloxacin Hydrochloride

2015 ◽  
Vol 5 (4) ◽  
Author(s):  
Kranti Singh ◽  
Surajpal Verma ◽  
Shyam Prasad ◽  
Indu Bala
Keyword(s):  
Particle Size ◽  
Zeta Potential ◽  
Drug Loading ◽  
In Vitro Release ◽  
Formulation Development ◽  
Ciprofloxacin Hydrochloride ◽  
Potential Value ◽  
The Mean ◽  
In Situ Gelling

Ciprofloxacin hydrochloride loaded Eudragit RS100 nanoparticles were prepared by using w/o/w emulsification (multiple emulsification) solvent evaporation followed by drying of nanoparticles at 50°C. The nanoparticles were further incorporated into the pH-triggered in situ gel forming system which was prepared using Carbopol 940 in combination with HPMC as viscosifying agent. The developed nanoparticles was evaluated for particle size, zeta potential value and loading efficiency; nanoparticle incorporated in situ gelling system was evaluated for pH, clarity, gelling strength, rheological studies, in-vitro release studies and ex-vivo precorneal permeation studies. The nanopaticle showed the mean particle size varying between 263.5nm - 325.9 nm with the mean zeta potential value of -5.91 mV to -8.13 mV and drug loading capacity varied individually between 72.50% to 98.70% w/w. The formulation was clear with no suspended particles, showed good gelling properties. The gelling was quick and remained for longer time period. The developed formulation was therapeutically efficacious, stable and non-irritant. It provided the sustained release of drug over a period of 8-10 hours.

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