The Effect of the Calcium Leaching on the Microstructure and Rupture Strength of CA Mortar

2014 ◽  
Vol 1049-1050 ◽  
pp. 325-334
Author(s):  
Yong Wang ◽  
De Hua Deng ◽  
Qiang Yuan ◽  
Jian Wei Peng ◽  
Lei Fang
Keyword(s):  
Mechanical Properties ◽  
Cross Section ◽  
Rupture Strength ◽  
Construction Site ◽  
Calcium Leaching ◽  
Experiment Method ◽  
Porosity Ratio ◽  
Loss Of Mass ◽  
The Relationship ◽  
Ca Mortar

This paper deals with the effect of calcium leaching on the microstructure and rupture strength of cement asphalt (CA) mortar. It is conducted by an accelerated experiment method with species obtained from construction site. Results show that the leaching process mainly contains a total leaching of CaOH2 (CH) and some other cement hydrations. The leaching is proved by the “portlandite dissolution front” on the cross-section of species using a reagent of phenolphthalein. As time goes, the species are continually leached, and then the loss of mass and porosity ratio are obviously increased. Fick’s law can describe the relationship between leaching depth and time very well. The loss of mass and increasing of porosity ratio respond to the shrinking of mechanical properties of CA mortar.

Study on the Relationship between Microscopic Structure and Mechanical Properties of HTPB Propellant

2010 ◽  
Vol 152-153 ◽  
pp. 1151-1155 ◽  
Author(s):  
Xu Chang Li ◽  
Jian Jiao ◽  
Jun Yan Yao ◽  
Liang Wang
Keyword(s):  
Mechanical Properties ◽  
Mechanical Property ◽  
Cross Section ◽  
Structural Integrity ◽  
Solid Particles ◽  
Microscopic Structure ◽  
Structure State ◽  
Htpb Propellant ◽  
The Relationship ◽  
Bond Effect

By means of a tensile instrument and SEM, the mechanical property parameters of HTPB propellant test samples with different formulas were tested, and their microscopic fracture cross section patterns were observed. Take advantage of these testing results, the relationship between microscopic structure and mechanical properties of HTPB propellant was studied. The results show that the mechanical properties of a propellant are closely related to its microscpic structure state. The structural integrity of propellant is mainly influenced by the bond effect of the interface between binder and solid particles, solid particle’s shape, size and its distribution, the content of binder matrix, etc. These factors have important effects on the mechanical properties of propellant.

Experimental and Theoretical Study of Air-Entraining Concrete under Biaxial Compression after Freezing-Thawing Cycle

2011 ◽  
Vol 243-249 ◽  
pp. 214-217
Author(s):  
Jia Wei Yao ◽  
Yu Pu Song ◽  
Ling Xia Gao
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Failure Criterion ◽  
Theoretical Study ◽  
Peak Stress ◽  
Biaxial Compression ◽  
Thawing Cycle ◽  
Experiment Method ◽  
Strength And Deformation ◽  
The Relationship

Mechanical properties experiments of air-entraining concrete after suffered to 0, 100, 200, 300 and 400 freezing-thawing cycles were performed. The experiment method, contents and result of strength and deformation of air-entraining after freezing-thawing cycle under biaxial compression were also introduced. The relationship between the strain corresponding to peak stress and cycle of freezing-thawing as well as the relationship between compressive strength and cycle of freezing-thawing were analyzed. The failure criterion of air-entraining concrete under biaxial compression was established.

Microthermocouples of a Glass-Insulated Bifilar Microwire Based on Bi2Te3

2010 ◽  
Vol 1267 ◽  
Author(s):  
Dragosh F Meglei ◽  
Tito E Huber ◽  
Maria P Dyntu ◽  
Albina Alexandr Nikolaeva
Keyword(s):  
Mechanical Properties ◽  
Cross Section ◽  
Thermoelectric Material ◽  
Rupture Strength ◽  
Microscopic Analysis ◽  
The Other ◽  
Structural Defects ◽  
Signal Value ◽  
P Type ◽  
Type Conduction

AbstractThe paper presents the results of studies related to the technology for obtaining glass-insulated bifilar microwires (BMWs) of a thermoelectric material based on Bi2Te3 with one wire exhibiting the n-type and the other p-type conduction as well as the study of their mechanical properties by the strain method and the microscopic analysis of the morphology of structural defects with a view to preparing microthermocouples on their basis.Preliminary studies showed that BMWs are more flexible than single microwires of the same material. The rupture strength of BMWs per unit cross section of a sample (together with the glass) ranges within 18-6 kg/mm2 with respect to diameters of 90-120 μm.Microthermocouples with a signal value on the order of 2-12 mV in a temperature range of 23-50°C have been developed. The preparation of thermoelectric microthermocouples of BMWs significantly reduces the number of process operations in the course of their production and considerably increases their resistance to impacts and vibrations. Microthermocouples based on glass-insulated BMWs have smaller sizes and weight; they can be used for measuring temperatures in chemically aggressive media.

scholarly journals Study on the Relationship between Fracture Morphology and Splitting Strength of Granite Based on Fabric Distribution

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
GuangSheng Du ◽  
ShiJiang Chen ◽  
Xiaoyi Chen ◽  
Yunfeng Gao ◽  
Hailong Wu
Keyword(s):  
Mechanical Properties ◽  
Correlation Function ◽  
Linear Relationship ◽  
Spatial Correlation ◽  
Failure Mode ◽  
Cross Section ◽  
Water Pressure ◽  
Discrete Element ◽  
Spatial Correlation Function ◽  
The Relationship

Because of the requirement of the mechanical properties of the damaged surrounding granite rock and the existence of the fracture water in hydraulic fracturing engineering, the strength of granite is related to the fabric, and the roughness of the section is also related to the liquid flow rate, a method of roughly determining the strength of the specimen by observing the failure mode of rock is needed. Considering that the physical and mechanical properties of granite are obviously affected by the fabric, the discrete element numerical simulation method was used to reconstruct the granite fabric based on the spatial correlation function to simulate the splitting experiment to investigate the failure mode of the specimen. The relationship between strength, the fractal value of cross-section, and the fabric was analyzed, which was verified through experiment. The results show that (1) the Voronoi GBM model with spatial correlation function of the discrete element can effectively simulate the controllable granite fabric and carry out micromechanical analysis. (2) The strength of the granite specimen and the fractal value of the cross-section have an obvious linear relationship with the fabric; besides, there is also a certain linear relationship between the strength of the specimen and the fractal value, which is influenced by granite fabric. (3) The predicted strength of the specimen according to the fractal value of the section is in good agreement with the actual strength with the error rate of 30%. In a word, this method can predict the strength of the specimen through the failure section and analyze the hydraulic fracture section and water pressure.

Mechanical properties of the living dog aorta

1962 ◽  
Vol 202 (4) ◽  
pp. 619-621 ◽  
Author(s):  
Robert L. Evans ◽  
Eugene F. Bernstein ◽  
Evelyn Johnson ◽  
Carl Reller
Keyword(s):  
Mechanical Properties ◽  
Cross Section ◽  
Cross Sections ◽  
Hooke’S Law ◽  
Before And After ◽  
Hooke's Law ◽  
Pressure Changes ◽  
Relationship Of ◽  
The Relationship ◽  
Propagation Velocities

The variation of living dog aortic cross sections with volemic pressure changes is given for states before and after thoracotomy. The relationship of vessel cross section to pressure is approximately linear, does not follow Hooke's law, and is roughly the same for both dynamic and relatively static changes. The implied and directly measured propagation velocities are comparable to each other.

Sunlight exposure: the effects on the performance of paragliding fabric

2018 ◽  
Vol 69 (05) ◽  
pp. 381-389
Author(s):  
MENGÜÇ GAMZE SÜPÜREN ◽  
TEMEL EMRAH ◽  
BOZDOĞAN FARUK
Keyword(s):  
Mechanical Properties ◽  
Aging Process ◽  
Air Permeability ◽  
Sunlight Exposure ◽  
Test Results ◽  
Coating Materials ◽  
Strength Tests ◽  
Before And After ◽  
The Relationship ◽  
Dark Blue

This study was designed to explore the relationship between sunlight exposure and the mechanical properties of paragliding fabrics which have different colors, densities, yarn counts, and coating materials. This study exposed 5 different colors of paragliding fabrics (red, turquoise, dark blue, orange, and white) to intense sunlight for 150 hours during the summer from 9:00 a.m. to 3:00 p.m. for 5 days a week for 5 weeks. Before and after the UV radiation aging process, the air permeability, tensile strength, tear strength, and bursting strength tests were performed. Test results were also evaluated using statistical methods. According to the results, the fading of the turquoise fabric was found to be the highest among the studied fabrics. It was determined that there is a significant decrease in the mechanical properties of the fabrics after sunlight exposure. After aging, the fabrics become considerably weaker in the case of mechanical properties due to the degradation in both the dyestuff and macromolecular structure of the fiber

scholarly journals Exploring the relationship between spiritual well-being and death anxiety in patients with gynecological cancer: a cross-section study

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Yue Feng ◽  
Xingcan Liu ◽  
Tangwei Lin ◽  
Biru Luo ◽  
Qianqian Mou ◽  
...  
Keyword(s):  
Cancer Patients ◽  
Cross Section ◽  
Death Anxiety ◽  
Religious Beliefs ◽  
Gynecological Cancer ◽  
Well Being ◽  
Life Questionnaire ◽  
Section Study ◽  
Spiritual Well Being ◽  
The Relationship

Abstract Background In recent years, spiritual well-being has gradually gained the attention of health care providers in China, especially those in oncology departments, who have recognized the importance of improving spiritual well-being in cancer patients. Since most of the current research on spiritual well-being has been carried out in areas with religious beliefs, this study was conducted in the context of no development of formal religion. The purpose of this study was to explore the relationship between death anxiety and spiritual well-being and the related factors of spiritual well-being among gynecological cancer patients. Methods This cross-section study was conducted among 586 gynecological cancer patients. The European Organization for Research and Treatment for Cancer Quality of Life Questionnaire-spiritual well-being32 (EORTC QLQ-SWB32) and Templer's Death Anxiety Scale (T-DAS) were used to measure spiritual well-being and death anxiety. The Multiple Linear Regression Model was used to determine the relationship between spiritual well-being and death anxiety. Results For all participants, the highest QLQ-SWB32 centesimal score was 75.13 on the Relationship with Other scale, and the lowest was 60.33 on the Relationship with Someone or Something Greater Scale. The mean Death Anxiety score was 5.31 (SD 3.18). We found that Relationship with Someone or Something Greater was the only scale not associated with death anxiety. Overall, patients with lower death anxiety have a higher level of spiritual well-being. Besides, a high Relationship with Other score was associated with living with a partner (B = 2.471, P < 0.001) and married (B = -6.475, P = 0.001). Patients with higher Global-SWB were retired (B = 0.387, P = 0.019). Conclusions Our study found that the spiritual well-being of patients with gynecological cancer in China was no worse than in other countries with religious beliefs and patients with lower death anxiety have a higher level of spiritual well-being. Clinical staff should pay attention to the spiritual health of cancer patients, and spiritual care should be regarded as an essential element in cancer care.

scholarly journals Water lubrication of graphene oxide-based materials

Friction ◽  
2021 ◽  
Author(s):  
Shaoqing Xue ◽  
Hanglin Li ◽  
Yumei Guo ◽  
Baohua Zhang ◽  
Jiusheng Li ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Graphene Oxide ◽  
Lubrication Theory ◽  
Lubricant Additives ◽  
Water Lubrication ◽  
Broad Application ◽  
Water Dispersibility ◽  
Metal Processing ◽  
The Relationship ◽  
Ph Concentration

AbstractWater is as an economic, eco-friendly, and efficient lubricant that has gained widespread attention for manufacturing. Using graphene oxide (GO)-based materials can improve the lubricant efficacy of water lubrication due to their outstanding mechanical properties, water dispersibility, and broad application scenarios. In this review, we offer a brief introduction about the background of water lubrication and GO. Subsequently, the synthesis, structure, and lubrication theory of GO are analyzed. Particular attention is focused on the relationship between pH, concentration, and lubrication efficacy when discussing the tribology behaviors of pristine GO. By compounding or reacting GO with various modifiers, amounts of GO-composites are synthesized and applied as lubricant additives or into frictional pairs for different usage scenarios. These various strategies of GO-composite generate interesting effects on the tribology behaviors. Several application cases of GO-based materials are described in water lubrication, including metal processing and bio-lubrication. The advantages and drawbacks of GO-composites are then discussed. The development of GO-based materials for water lubrication is described including some challenges.

scholarly journals Mechanical Properties of Spruce Wood Extracted from GLT Beams Loaded by Fire

2021 ◽  
Vol 13 (10) ◽  
pp. 5494
Author(s):  
Lucie Kucíková ◽  
Michal Šejnoha ◽  
Tomáš Janda ◽  
Jan Sýkora ◽  
Pavel Padevět ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Cross Section ◽  
Negative Impact ◽  
Tensile Tests ◽  
Thermal Recovery ◽  
Bending Test ◽  
Small Scale ◽  
Spruce Wood ◽  
The Impact

Heating wood to high temperature changes either temporarily or permanently its physical properties. This issue is addressed in the present contribution by examining the effect of high temperature on residual mechanical properties of spruce wood, grounding on the results of full-scale fire tests performed on GLT beams. Given these tests, a computational model was developed to provide through-thickness temperature profiles allowing for the estimation of a charring depth on the one hand and on the other hand assigning a particular temperature to each specimen used subsequently in small-scale tensile tests. The measured Young’s moduli and tensile strengths were accompanied by the results from three-point bending test carried out on two groups of beams exposed to fire of a variable duration and differing in the width of the cross-section, b=100 mm (Group 1) and b=160 mm (Group 2). As expected, increasing the fire duration and reducing the initial beam cross-section reduces the residual bending strength. A negative impact of high temperature on residual strength has also been observed from simple tensile tests, although limited to a very narrow layer adjacent to the charring front not even exceeding a typically adopted value of the zero-strength layer d0=7 mm. On the contrary, the impact on stiffness is relatively mild supporting the thermal recovery property of wood.

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