Deformation properties of complex viscose yarns before and after relaxation in water

1987 ◽  
Vol 18 (6) ◽  
pp. 468-470
Author(s):  
A. B. Pakshver ◽  
I. P. Baksheev ◽  
M. V. Fedorova ◽  
G. G. Finger
Keyword(s):  
Complex Viscose ◽  
Deformation Properties ◽  
Before And After

scholarly journals Investigation of the fluids influence on change of sandstones collectors mechanical properties during saturation and degassing

2019 ◽  
Vol 109 ◽  
pp. 00103
Author(s):  
Serhii Tynyna ◽  
Vasyl Babenko
Keyword(s):  
Mechanical Properties ◽  
Stress State ◽  
Mechanical Characteristics ◽  
Partial Discharge ◽  
Laboratory Studies ◽  
Deformation Properties ◽  
Before And After ◽  
Surface Active ◽  
Sandstone Formation ◽  
State Of The Environment

The article discusses the effect of fluids on the properties of rocks. It is known that surface active environments, including gas, can significantly change the mechanical characteristics of solids. To establish the dependence of the effect of methane on the strength characteristics of rocks, the results of full-scale and laboratory studies are considered. The experiments were carried out on samples of outburst sandstone formation m3, taken at a depth of 915 m. Analysis of research results allowed to establish the effect of changes in gas saturation of rocks on their mechanical properties before and after degassing and partial discharge of experimental areas after they have been worked by lavas along m3 formation. It has been established that the reason for the increase in drillability and strength of sandstones was their degassing, and not a change in the stress state of the environment. This led to a change in the deformation properties of rocks in gas-saturated and degassed states.

Al-21Ti-23Cr High-Temperature Protective Coating on TiAl Intermetallic Compounds by RF Magnetron Sputtering

1996 ◽  
Vol 460 ◽  
Author(s):  
J. Y. Park ◽  
H. N. Lee ◽  
S. W. Park ◽  
M. H. Oh ◽  
D. M. Wee
Keyword(s):  
High Temperature ◽  
Magnetron Sputtering ◽  
Tensile Test ◽  
Protective Coating ◽  
Cyclic Oxidation ◽  
Oxidation Behavior ◽  
Tensile Deformation ◽  
Rf Magnetron Sputtering ◽  
Deformation Properties ◽  
Before And After

ABSTRACTTi-48A1 specimens were coated with Al-21Ti-23Cr film at 200 W, 0.8 Pa and 573 K by RF magnetron sputtering. The oxidation behavior of the coated specimens was investigated through isothermal and cyclic oxidation tests, and the tensile deformation properties of the coated specimens were also investigated before and after oxidation. The isothermal and cyclic oxidation curves showed that the Al-21Ti-23Cr film was very effective in decreasing the oxidation rate of Ti-48A1. This excellent oxidation resistance is attributable to the formation of a protective Al2O3 layer on the surface of the Al-21Ti-23Cr film. It was found from the results of the tensile test that the protective Al2O3 layer on the surface of the Al-21Ti-23Cr film enabled the Ti-48A1 to maintain its tensile properties in an oxidizing environment.

scholarly journals Experimental Study on Grouting Effect and Mechanical Properties of the Rockfill Materials Grouted with SCM

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Cheng-Jin Deng ◽  
Fa-Ning Dang ◽  
Xing-Zhou Chen ◽  
Zhe Miao ◽  
Li-Li Chen
Keyword(s):  
Mechanical Properties ◽  
Shear Test ◽  
Gansu Province ◽  
Triaxial Shear Test ◽  
Rockfill Dam ◽  
Rockfill Materials ◽  
Deformation Properties ◽  
Before And After ◽  
The Face ◽  
Grouting Reinforcement

Insufficient compactness of rockfill materials may potentially cause excessive deformation of a concrete face rockfill dam (CFRD), thus resulting in cracking of the face slab and leakage of the dam body, thereby requiring reinforcement treatment. To date, there are no effective measures in strengthening rockfill materials. In this study, self-compacting mortar (SCM) was applied to the Shibaozhai CFRD in Gansu Province, China, to test the effectiveness of grouting reinforcement. Simultaneously, an indoor triaxial shear test was conducted to investigate the changes in the mechanical properties of rockfill materials before and after the grouting reinforcement. The on-site test results showed that the rockfill reached the desired porosity after grouting and grouting reinforcement enhanced the cementation degree of rockfill materials while maintaining uninterrupted drainage capacity, which met the requirements of rockfill grouting for the face rockfill dam. The results of the triaxial shear test indicated that the cohesive force of the rockfill materials rose by 3.95 times and the modulus increased by 7.24 times after grouting reinforcement，significantly enhancing the mechanical and deformation properties of the rockfill. An increase in the content of coarse particles was shown to enhance the stability of cementitious structures, which leads to a better skeleton effect and thereby raises the effectiveness of the grouting reinforcement. The rockfill materials also exhibited strain-softening characteristics following the grouting reinforcement. The research showed that grouting reinforcement technology is suitable for managing the deformation of high CFRDs or reinforcing ill rockfill dams.

Mechanical properties of a 20 vol % SiC whisker-reinforced, yttria-stabilized, tetragonal zirconia composite at elevated temperatures

1995 ◽  
Vol 10 (1) ◽  
pp. 113-118 ◽  
Author(s):  
S.E. Dougherty ◽  
T.G. Nieh ◽  
J. Wadsworth ◽  
Y. Akimune
Keyword(s):  
Grain Size ◽  
High Temperature ◽  
Elevated Temperatures ◽  
Tetragonal Zirconia ◽  
Tensile Tests ◽  
Engineering Properties ◽  
High Temperature Deformation ◽  
Temperature Deformation ◽  
Deformation Properties ◽  
Before And After

The high-temperature deformation behavior of a SiC whisker-reinforced, yttria-stabilized, tetragonal zirconia polycrystalline composite containing 20 vol % SiC whiskers (SiC/Y-TZP) has been investigated. Tensile tests were performed in vacuum at temperatures from 1450 °C to 1650 °C and at strain rates from 10−3 to 10−5 s−1. The material exhibits useful high-temperature engineering properties (e.g., ∼100 MPa and 16% elongation at T = 1550 °C and at a strain rate of ∼10−4 s−1). The stress exponent was determined to be n ≍ 2. Scanning electron microscopy was used to characterize the grain size and morphology of the composites, both before and after deformation. The grain size in the composite was initially fine, but coarsened at the test temperatures; both dynamic and static grain growth were observed. The morphology of ceramic reinforcements appears to affect strongly the plastic deformation properties of Y-TZP. A comparison is made between the properties of monolithic Y-TZP, 20 wt. % Al2O3 particulate-reinforced Y-TZP (Al2O3/Y-TZP), and SiC/Y-TZP composites.

scholarly journals Forecast of seismic resistance of structures by the results of numerical simulation of deformation properties of soil bases

2021 ◽  
Vol 303 ◽  
pp. 01015
Author(s):  
Mikhail Sokolov ◽  
Sergey Prostov ◽  
Andrey Pokatilov
Keyword(s):  
Numerical Simulation ◽  
Seismic Intensity ◽  
Seismic Resistance ◽  
Mathematical Methods ◽  
New Approach ◽  
Geological Surveys ◽  
Deformation Properties ◽  
Before And After ◽  
Real Objects ◽  
Properties Of Soil

The object of the research is the forecast of seismic resistance when strengthening the soil foundations of structures. The purpose of the work is to numerically estimate the total increment of seismic intensity during artificial transformation and strengthening of foundation soils based on the results of geomechanical modeling. The study is based on classical mathematical methods for modeling soil foundations in a flat nonlinear setting. A new approach to determining the total increment of seismic intensity is presented, based on determining the ratio of the values of subsidence of the foundations of buildings and structures before and after soil strengthening. The paper presents the results of predicting changes in seismic resistance for real objects, obtained from the data of engineering and geological surveys and numerical computer models. It was found that due to the transformation of soil foundations, seismic resistance can decrease by more than 0.5 points. This technique can be used both to adjust the scoring for individual objects and to clarify the boundaries of seismic zones on OCP maps.

scholarly journals Numerical simulation of subgrade soil deformation properties for prediction of earthquake resistance of structures

2021 ◽  
Vol 23 (3) ◽  
pp. 167-178
Author(s):  
M. V. Sokolov ◽  
S. M. Prostov ◽  
O. V. Gerasimov
Keyword(s):  
Numerical Simulation ◽  
Practical Implication ◽  
Seismic Intensity ◽  
Earthquake Resistance ◽  
Mathematical Methods ◽  
Subgrade Soils ◽  
Subgrade Soil ◽  
Deformation Properties ◽  
Before And After ◽  
Real Objects

Purpose: The aim of this paper is to predict the earthquake resistance in strengthening the subgrade soils of structures. Numerical simulation of the total increment of seismic intensity during the artificial transformation and strengthening of subgrade soils based on geomechanical modeling.Research methods: Classical mathematical methods for modeling subgrade soils in a plane nonlinear problem.Originality: A new approach is developed to determine the total increment of seismic intensity using the ratio between the subsidence values of building foundations and structures before and after soil strengthening. The paper presents the prediction results of changes in seismic resistance of real objects, based on engineering and geologi cal surveys and numerical computer models. It is shown that due to the transformation of subgrade soils, the earthquake resistance can be reduced by more than 0.5 points.Practical implication: This technique can be used to adjust the score for individual objects and map the boundaries of seismic zones.

Deformation Replication

1970 ◽  
Vol 28 ◽  
pp. 280-281
Author(s):  
J. Temple Black
Keyword(s):  
Cutting Speed ◽  
Machining Process ◽  
Depth Of Cut ◽  
Rake Face ◽  
Orthogonal Machining ◽  
Aluminum Chips ◽  
Before And After ◽  
Materials Used ◽  
Glass Knife ◽  
Very High

Tool materials used in ultramicrotomy are glass, developed by Latta and Hartmann (1) and diamond, introduced by Fernandez-Moran (2). While diamonds produce more good sections per knife edge than glass, they are expensive; require careful mounting and handling; and are time consuming to clean before and after usage, purchase from vendors (3-6 months waiting time), and regrind. Glass offers an easily accessible, inexpensive material ($0.04 per knife) with very high compressive strength (3) that can be employed in microtomy of metals (4) as well as biological materials. When the orthogonal machining process is being studied, glass offers additional advantages. Sections of metal or plastic can be dried down on the rake face, coated with Au-Pd, and examined directly in the SEM with no additional handling (5). Figure 1 shows aluminum chips microtomed with a 75° glass knife at a cutting speed of 1 mm/sec with a depth of cut of 1000 Å lying on the rake face of the knife.

The Clinical, Roentgenological and Morphological Effects of an Acute Exposure of Phosgene on the Lungs of Dogs

1971 ◽  
Vol 29 ◽  
pp. 236-237
Author(s):  
R. F. Bils ◽  
W. F. Diller ◽  
F. Huth
Keyword(s):  
Latent Period ◽  
Chemical Industry ◽  
Toxic Substance ◽  
Lung Edema ◽  
X Rays ◽  
Beagle Dogs ◽  
Male And Female ◽  
Morphological Alterations ◽  
Before And After ◽  
Electron Microscopes

Phosgene still plays an important role as a toxic substance in the chemical industry. Thiess (1968) recently reported observations on numerous cases of phosgene poisoning. A serious difficulty in the clinical handling of phosgene poisoning cases is a relatively long latent period, up to 12 hours, with no obvious signs of severity. At about 12 hours heavy lung edema appears suddenly, however changes can be seen in routine X-rays taken after only a few hours' exposure (Diller et al., 1969). This study was undertaken to correlate these early changes seen by the roengenologist with morphological alterations in the lungs seen in the'light and electron microscopes.Forty-two adult male and female Beagle dogs were selected for these exposure experiments. Treated animals were exposed to 94.5-107-5 ppm phosgene for 10 min. in a 15 m3 chamber. Roentgenograms were made of the thorax of each animal before and after exposure, up to 24 hrs.

Ultrastructure of Melanin Formation in Curvularia sp., Alternaria sp., and Drechslera Sorokiniana

1977 ◽  
Vol 35 ◽  
pp. 398-399
Author(s):  
M. H. Wheeler ◽  
W. J. Tolmsoff ◽  
A. A. Bell
Keyword(s):  
Potassium Phosphate ◽  
Thielaviopsis Basicola ◽  
Wild Type ◽  
Potassium Phosphate Buffer ◽  
Transmission Microscopy ◽  
Electron Transmission ◽  
Melanin Formation ◽  
Before And After ◽  
Alternaria Sp ◽  
Electron Transmission Microscopy

(+)-Scytalone [3,4-dihydro-3,6,8-trihydroxy-l-(2Hj-naphthalenone] and 1,8-di- hydroxynaphthalene (DHN) have been proposed as intermediates of melanin synthesis in the fungi Verticillium dahliae (1, 2, 3, 4) and Thielaviopsis basicola (4, 5). Scytalone is enzymatically dehydrated by V. dahliae to 1,3,8-trihydroxynaphthalene which is then reduced to (-)-vermelone [(-)-3,4- dihydro-3,8-dihydroxy-1(2H)-naphthalenone]. Vermelone is subsequently dehydrated to DHN which is enzymatically polymerized to melanin.Melanin formation in Curvularia sp., Alternaria sp., and Drechslera soro- kiniana was examined by light and electron-transmission microscopy. Wild-type isolates of each fungus were compared with albino mutants before and after treatment with 1 mM scytalone or 0.1 mM DHN in 50 mM potassium phosphate buffer, pH 7.0. Both chemicals were converted to dark pigments in the walls of hyphae and conidia of the albino mutants. The darkened cells were similar in appearance to corresponding cells of the wild types under the light microscope.

Evaluation of Freezing Methods by Low Temperature X-Ray Diffraction

1977 ◽  
Vol 35 ◽  
pp. 330-333
Author(s):  
T. Gulik-Krzywicki ◽  
M.J. Costello
Keyword(s):  
Biological Materials ◽  
Molecular Organization ◽  
X Ray Diffraction ◽  
Glass Capillary ◽  
X Ray ◽  
Rate Dependent ◽  
Before And After ◽  
Freeze Etching ◽  
Diffraction Patterns ◽  
Set Up

Freeze-etching electron microscopy is currently one of the best methods for studying molecular organization of biological materials. Its application, however, is still limited by our imprecise knowledge about the perturbations of the original organization which may occur during quenching and fracturing of the samples and during the replication of fractured surfaces. Although it is well known that the preservation of the molecular organization of biological materials is critically dependent on the rate of freezing of the samples, little information is presently available concerning the nature and the extent of freezing-rate dependent perturbations of the original organizations. In order to obtain this information, we have developed a method based on the comparison of x-ray diffraction patterns of samples before and after freezing, prior to fracturing and replication.Our experimental set-up is shown in Fig. 1. The sample to be quenched is placed on its holder which is then mounted on a small metal holder (O) fixed on a glass capillary (p), whose position is controlled by a micromanipulator.

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