Mechanical Behavior during Self-Oscillating of NIPAAm-Co-(Ru(bpy)3 Gel

2007 ◽  
Vol 353-358 ◽  
pp. 2235-2238 ◽  
Author(s):  
Reiko Aoki ◽  
Manabu Enoki ◽  
Ryo Yoshida
Keyword(s):  
Mechanical Behavior ◽  
Stress Amplitude ◽  
Ccd Camera ◽  
Swelling Behavior ◽  
Mechanical Parameters ◽  
Swelling Ratio ◽  
Thermosensitive Polymer ◽  
Polymer Swelling ◽  
Bz Reaction ◽  
Oscillating Period

Self-oscillating gel is designed by copolymerizing the catalyst for the Belousov-Zhabotinsky (BZ) reaction with thermosensitive polymer. The cylindrical-shaped specimens of NIPAAm-co-(Ru(bpy)3 gel were prepared by copolymerizing (Ru(bpy)3) monomer as catalyst with NIPAAm as thermosensitive polymer. Swelling behavior during self-oscillating of gel by BZ reaction was observed using CCD camera and the force due to this reaction was evaluated using semiconductor gauge. Self-oscillating swelling-deswelling behavior in samples with different swelling ratio was evaluated by this apparatus, and mechanical parameters such as Young’s modulus, stress amplitude and oscillating period were quantitatively estimated.

Strain rate effects on the mechanical behavior of single-lap glass/carbon nanofiber/epoxy composite bolted joints

2020 ◽  
Vol 54 (30) ◽  
pp. 4807-4819 ◽  
Author(s):  
AR Shamaei-Kashani ◽  
MM Shokrieh
Keyword(s):  
Strain Rate ◽  
Mechanical Behavior ◽  
Epoxy Composite ◽  
Bolted Joints ◽  
Dynamic Strain ◽  
Experimental Program ◽  
Strain Rates ◽  
Mechanical Parameters ◽  
Damage Initiation ◽  
Bearing Strength

In the present research, effects of applying strain rate on the mechanical behavior of single-lap glass/CNF/epoxy composite bolted joints including, damage initiation bearing stress, 2% offset bearing strength, ultimate bearing strength, bearing chord stiffness, ultimate bearing strain, and energy absorption were studied. To this end, a comprehensive experimental program was conducted. The protruding head bolt was used, the clearance was considered to be near fit and a finger-tight bolt condition was applied to all joints. The dimensions of joints were chosen to promote the bearing failure mode based on the ASTM standard. Four types of single-lap bolted joints (SLJs) with lay-ups of [–45/0/45/90]s and [90/–452/45]s with and without CNFs were tested at strain rates in the range of 0.0048 s−1 to 0.89 s−1. Unlike the available experimental results, the results obtained by the present experiments showed that the strain rate has a significant effect on all the above-mentioned mechanical parameters of SLJs. Also, it was shown that employing CNFs improved the mechanical parameters of SLJs under quasi-static and dynamic strain rates.

Study on the Effect of [Al13]7+ over the Free Swelling Ratio of Expansive Soil

2017 ◽  
Vol 748 ◽  
pp. 341-345 ◽  
Author(s):  
Liang Liu ◽  
Hai Lin Yao ◽  
Zheng Lu ◽  
Zhong Wen Yin ◽  
Xing Wen Luo ◽  
...  
Keyword(s):  
Expansive Soil ◽  
Swelling Behavior ◽  
Molar Ratio ◽  
Cross Linking ◽  
Swelling Ratio ◽  
Free Swelling ◽  
The Cross ◽  
Alkali Neutralization

The hydroxy-aluminum solution is prepared by alkali neutralization titration and the subsequent cross-linking tests are designed by mixing the hydroxy-aluminum solution and expansive soil, followed by the discussion on the influence of the molar ratio of OH- to Al3+ and ratio of total aluminum to expansive soil on the swelling behavior of the cross-linked soil. The free swelling ratio of the cross-linked soil decreased significantly, indicating that the main aluminum species that changes the expansion properties of the cross-linked soil is [Al13]7+.

scholarly journals The effect of saturation on the physical and mechanical behavior of some rock samples

2021 ◽  
Vol 2 (3) ◽  
pp. 23-31
Author(s):  
Mohammad Taghi Hamzaban
Keyword(s):  
Tensile Strength ◽  
Mechanical Behavior ◽  
Physical And Mechanical Properties ◽  
Intact Rock ◽  
P Wave ◽  
Mechanical Parameters ◽  
Brazilian Tensile Strength ◽  
Rock Samples ◽  
Rock Types ◽  
Major Factors

Different major factors control the strength of solid rocks. Moisture content is one of the most important factors, which can change the physical and mechanical behavior of intact rock as well as rock mass. Several early studies have shown that rock is weaker if tested wet rather than dry. In this paper, the density, P-wave velocity, uniaxial compressive strength, Brazilian tensile strength, and modulus of elasticity of seven different intact rock samples were measured under both dry and saturated conditions. The porosity of the samples was reported as well. Based on the obtained results, some correlations were proposed for estimating the saturated physical and mechanical properties from dry ones. The proposed correlations include different rock types and are more general than the previously reported ones. Comparing the obtained results showed that the mechanical and physical properties of weaker samples are more sensitive to the saturation process. Moreover, among the different mechanical parameters, Brazilian tensile strength exhibited more sensitivity to saturation. Comparing the results with the calculated porosities revealed that porosity is one of the key factors in the effect of saturation on physical and mechanical parameters. It seems that in the more porous rock samples, greater changes in the different measured parameters occur after saturation.

scholarly journals The Implication of Petrographic Characteristics on the Mechanical Behavior of Middle Eocene Limestone, 15th May City, Egypt

2020 ◽  
Vol 12 (22) ◽  
pp. 9710
Author(s):  
Abdelaziz El Shinawi ◽  
Peter Mésároš ◽  
Martina Zeleňáková
Keyword(s):  
Mechanical Properties ◽  
Mechanical Behavior ◽  
Carbonate Rocks ◽  
Direct Relationship ◽  
Middle Eocene ◽  
Urban Expansion ◽  
Engineering Properties ◽  
Mechanical Parameters ◽  
Thin Sections ◽  
Limestone Bedrock

The construction purposes of carbonate rocks are considered a major aspect of using these bedrocks based on their mechanical behavior. Accordingly, the physical and mechanical characterization of Middle Eocene Limestone bedrock in the new urban area at the 15th May City, Egypt was studied to assess the suitability of the carbonate rocks for construction. This study has been carried out to investigate the effect of petrographic characteristics on mechanical properties. To achieve this objective, the intact 30 rock core samples from 15 boreholes were selected at different depths. Based on study of the selected samples in thin sections, the limestone in the area was classified as lime-mudstone, wackestone, and grainstone. Additionally, the uniaxial compressive strength (UCS) and Schmidt Rebound Hammer (Rn) were determined to detect the mechanical properties of the limestone bedrock. The measured parameters (UCS and Rn) demonstrated a high direct relationship with mudstone and a poor direct relationship with dolomite and high negative correlation with wackestone and grainstone. Therefore, the Middle Eocene Limestone bedrock is more durable and has medium-strength, which made it suitable for constructions. Regression analysis was performed to find out some linear relationship between mechanical properties (UCS) with petrographic characteristics. The study reveals significant positive correlation between UCS and Rn with mudstone in accordance higher values of regression coefficient (R2 = 0.91 and R2 = 0.036), and an inverse relationship of Rn with dolomite % (R2 = 0.89 and R2 = 0.02), respectively. Consequently, the strong confidence on the mechanical parameters opens the way for engineers to predict the mechanical parameters that are required for engineering properties of limestone for the urban expansion.

scholarly journals Elastin haploinsufficiency in mice has divergent effects on arterial remodeling with aging depending on sex

2020 ◽  
Vol 319 (6) ◽  
pp. H1398-H1408
Author(s):  
Jie Z. Hawes ◽  
Austin J. Cocciolone ◽  
Amy H. Cui ◽  
Diana B. Griffin ◽  
Marius Catalin Staiculescu ◽  
...  
Keyword(s):  
Mechanical Behavior ◽  
Arterial Wall ◽  
Circumferential Stress ◽  
Arterial Remodeling ◽  
Mechanical Parameters ◽  
Structural Stiffness ◽  
Set Point ◽  
Material Stiffness ◽  
Future Work ◽  
Comprehensive Study

A comprehensive study on arterial mechanical behavior as a function of elastin content, aging, and sex in mice. Elastin haploin-sufficient arteries start at a different homeostatic set point for mechanical parameters such as circumferential stress, stretch, and material stiffness. Structural stiffness of the arterial wall greatly increases with aging, as expected, but there are interactions between sex and aging for most of the mechanical parameters that are important to consider in future work.

Preparation and Properties of Glutaraldehyde Cross-Linked Silk Sericin Films

2017 ◽  
Vol 748 ◽  
pp. 148-152 ◽  
Author(s):  
Fang Yu Zhan ◽  
Kun Yan Wang ◽  
Miao Miao Niu
Keyword(s):  
Thermal Decomposition ◽  
Chemical Structure ◽  
Decomposition Temperature ◽  
Swelling Behavior ◽  
Cross Linking ◽  
Swelling Ratio ◽  
Thermal Decomposition Temperature ◽  
Silk Sericin ◽  
Peak Intensity ◽  
The Cross

Glutaraldehyde cross-linked silk sericin films were successfully prepared. FTIR was applied to characterize the chemical structure of films. Compared to pure silk sericin, cross-linked silk sericin film with 3% glutaraldehyde was found a new peak at 1620 cm-1 and the peak intensity of cross-linked film decreased markedly, which indicating cross-linking reaction has been occurred. Thermal and swelling behavior of cross-linked films was investigated. The cross-linking reaction increased the thermal decomposition temperature. The swelling ratio of glutaraldehyde cross-linked silk sericin films went up with increasing glutaralehyde loading to 3wt%.

Effects of Microstructure and Shock Prestrain on the Dynamic Mechanical Behavior of Ti-6Al-4V Alloy

2020 ◽  
Vol 837 ◽  
pp. 51-57
Author(s):  
Shi Meng Zhou ◽  
Zhi Wei Wang ◽  
Yu Ren
Keyword(s):  
Mechanical Behavior ◽  
Stress Amplitude ◽  
Lamellar Microstructure ◽  
Uniaxial Stress ◽  
Strengthening Effect ◽  
Enhancement Ratio ◽  
Mechanical Behaviors ◽  
Dynamic Mechanical ◽  
Impact Stress ◽  
Dynamic Mechanical Behavior

Ti–6Al–4V alloy (Ti64) with different microstructures was first preshocked at ~6–13 GPa and then compression reloaded at 4×103s-1 to investigate the effect of microstructure and shock prestrain on the dynamic mechanical behavior of this alloy. The strengthening effect caused by shock prestrain is weaker than that introduced by the uniaxial stress compression during dynamic reloading process regardless of microstructure type and impact stress amplitude. However, the shock-induced enhancement ratio is higher in Ti64 having bimodal microstructures or the lamellar microstructure with wide α-platelets. These mechanical behaviors exhibited by postshock materials are closely related to the shock-induced microstructure evolution. Dislocations more tend to nucleate and interact in large-sized α phases such as equiaxed primary α and wide α-platelets. The generation of high-density micro-defects during the propagation of shock waves results in the improvement of strength but degradation of ductility of Ti64 during dynamic reloading process.

Effects of Synthesis-Solvent on Characteristics of Poly(N-Isopropylacrylamide) Hydrogels Synthesized by Frontal Polymerization

2011 ◽  
Vol 295-297 ◽  
pp. 1193-1197 ◽  
Author(s):  
Qiao Feng ◽  
Ling Zhi Du ◽  
Qing Zhi Yan ◽  
Chang Chun Ge
Keyword(s):  
Mixed Solvent ◽  
Mixed Solvents ◽  
Frontal Polymerization ◽  
Swelling Behavior ◽  
Polymerization Process ◽  
Swelling Ratio ◽  
The One ◽  
Short Time ◽  
Responsive Hydrogels

The synthesis of thermo-responsive hydrogels poly(N-isopropylacrylamide )(PNIPAm) by frontal polymerization (FP) was carried out in four mixed solvents, i.e. dimethylsulfoxide (DMSO) mixing with water, ethanol, tetrahydrofuran (THF) and acetone, respectively. The influences of mixed solvent on frontal parameters, pore morphologies, swelling behavior of PNIPAm hydrogels were investigated. The pore of PNIPAm hydrogel synthesized in THF/DMSO was observed a big honeycomb cells, others were channel-like cells. Furthermore, the sample obtained in THF/DMSO had higher swelling ratio as compared to others, and the one synthesized in Water/DMSO showed the lowest. Above results indicated that fine-tuned poly(N-isopropylacrylamide) hydrogels can be prepared in short time and with easy protocol by adjusting mixed solvents in frontal polymerization process.

scholarly journals Hydrophilic films based on starch and carboxymethyl starch

2019 ◽  
Vol 21 (2) ◽  
pp. 26-30 ◽  
Author(s):  
Katarzyna Wilpiszewska
Keyword(s):  
Tensile Strength ◽  
Physicochemical Properties ◽  
Young’S Modulus ◽  
Moisture Absorption ◽  
Crosslinking Density ◽  
Mechanical Parameters ◽  
Swelling Ratio ◽  
Solubility In Water ◽  
Agricultural Industry ◽  
Carboxymethyl Starch

Abstract The hydrophilic films based on starch and carboxymethyl starch (CMS) were obtained using cast method. The effect of CMS content on the physicochemical properties of prepared films were evaluated. With increasing content of starch derivative the moisture absorption, solubility in water as well as swelling ratio increased. The highest values of mechanical parameters (tensile strength and Young’s modulus) were determined for the starch/CMS film containing the lowest CMS amount, i.e. 10 wt.% (1.1 MPa, 15 MPa, respectively). For the same system the lowest moisture absorption, solubility in water as well as swelling ratio were reported. Thus, it could be concluded that for this system the highest crosslinking density has been achieved, what was confirmed by DMTA results. Such a film could potentially find application in food or agricultural industry.

scholarly journals BUILDINGS’ DAMAGE AT HOREMI VILLAGE, ARKADIA, GREECE: EVALUATION OF THE GEOTECHNICAL CONDITIONS AT SHALLOW DEPTHS

2017 ◽  
Vol 43 (3) ◽  
pp. 1202
Author(s):  
Kynigalaki M. Kynigalaki M. ◽  
D. Kanaris ◽  
N. Nikolaou ◽  
V. Kontogianni
Keyword(s):  
Laboratory Testing ◽  
Swelling Behavior ◽  
High Plasticity ◽  
Mechanical Parameters ◽  
Sample Collection ◽  
Geotechnical Investigation ◽  
The Village ◽  
Geological Formations ◽  
Very High

Horemi village is located in Central Peloponnesus, at the western margins of Megalopoli basin. For several years failure phenomena on the village buildings have been reported, causing problems related both to the safety of the inhabitants, as well as to the development of the area. For the above reasons a geotechnical investigation program was carried out, to study the origin of the failures and lead to certain conclusions for the mitigation of the phenomena. In situ exploratory works, with reference to the investigation of litho-stratigraphy, ground foundation conditions, as well as laboratory testing, provided the necessary data for further research testing of the soil physical and mechanical parameters. Building failure recording, trial pits description, sample collection and laboratory testing, pointed out that failure phenomena are due to geotechnical rather than geological effects. The detection of a clayey horizon, presenting high to very high plasticity and swelling behavior, related to the significant montmorillonite proportion in the surface or shallow geological formations, showed good correlation to building damages. The aforementioned observations are considered to clarify the case presented in this paper.

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