scholarly journals A novel experimental method to characterise the shear strength of concrete based on pre-stressed samples. A comparison with existing techniques

2018 ◽  
Vol 183 ◽  
pp. 02049
Author(s):  
Pascal Forquin ◽  
Reem Abdul-Rahman ◽  
Dominique Saletti
Keyword(s):  
Experimental Method ◽  
Shear Fracture ◽  
Plain Concrete ◽  
Concrete Specimen ◽  
Compression Tests ◽  
Second Stage ◽  
Wide Range ◽  
Metallic Ring ◽  
Do So ◽  
Metallic Cell

Mode II shear fracture process can be observed in plain-concrete structures exposed to intensive loadings such as shock, blasting or projectile-impact. It is the reason why the quasi-static and dynamic shear fracturing properties of concrete need to be investigated. In previous works performed by Forquin and coauthors a passive confining cell was applied to PTS (Punch-Through-Shear) specimens in a similar way than in quasi-oedometric compression tests where metallic ring are used as passive confinement. However the change of confining level during the sample loading constitutes a main drawback of this technique. In the present work a novel testing method is proposed based on a pre-stressing of the sample. To do so, the concrete specimen is inserted into pre-stressed metallic cell. During the unloading stage confining stresses are transferred to the ligament of the sample. In a second stage, a differential displacement applied to the central part of the sample toward the side parts produces a shearing of the ligament. The experiments performed in static and dynamic conditions (SHPB testing) allow the shear response of concrete to be determined over a wide range of strain-rates. In the present communication, the testing technique and obtained results are compared to the obtained data with the previous experimental method.

A New Elastoplastic Kinematic Hardening and Softening Model for Concrete

2003 ◽  
Vol 6 (2) ◽  
pp. 111-120
Author(s):  
Xila Liu ◽  
B. Wen ◽  
J. F. Xu
Keyword(s):  
Kinematic Hardening ◽  
Plain Concrete ◽  
Flow Rule ◽  
Good Prediction ◽  
Compression Tests ◽  
Proportional Loading ◽  
Loading Surface ◽  
Wide Range ◽  
Associated Flow Rule ◽  
Hardening And Softening

On the basis of experimental results already reported by others, a new kinematic-hardening and softening model is proposed for plain concrete. The contribution of the paper is that the loading surface here was calibrated at six control points derived from four traditional types of material test. By abandoning the conventional non-associated flow rule, the new proposed model can justify the validity and applicability of the associated flow rule and gives a good prediction on the behaviour of concrete not only in the proportional loading of tension, shear, and compression tests, but also in cyclic loading cases. The model can also predict the softening behaviour of concrete without transferring the loading surface from stress-space to strain-space. Since the associated flow rule can be successfully used, the derived stiffness matrices are symmetrical, thus easing the computation requirement and saving much computer time and cost. Good agreement with a wide range of experimental data has generally been observed.

scholarly journals Towards Reduced CNNs for De-Noising Phase Images Corrupted with Speckle Noise

Photonics ◽  
2021 ◽  
Vol 8 (7) ◽  
pp. 255
Author(s):  
Marie Tahon ◽  
Silvio Montresor ◽  
Pascal Picart
Keyword(s):  
Phase Error ◽  
Speckle Noise ◽  
Experimental Conditions ◽  
Benchmark Data ◽  
Wide Range ◽  
Phase Images ◽  
Different Depths ◽  
Phase Data ◽  
Do So

Digital holography is a very efficient technique for 3D imaging and the characterization of changes at the surfaces of objects. However, during the process of holographic interferometry, the reconstructed phase images suffer from speckle noise. In this paper, de-noising is addressed with phase images corrupted with speckle noise. To do so, DnCNN residual networks with different depths were built and trained with various holographic noisy phase data. The possibility of using a network pre-trained on natural images with Gaussian noise is also investigated. All models are evaluated in terms of phase error with HOLODEEP benchmark data and with three unseen images corresponding to different experimental conditions. The best results are obtained using a network with only four convolutional blocks and trained with a wide range of noisy phase patterns.

Socio-Semantic Processes in Social Actors Representation: A Case Study of “Ya-Sin”

2017 ◽  
Vol 15 (2) ◽  
pp. 145-169
Author(s):  
Roghayeh Farsi
Keyword(s):  
Case Study Approach ◽  
Academic Field ◽  
Social Actors ◽  
Study Approach ◽  
Wide Range ◽  
New Perspective ◽  
Linear Nature ◽  
Do So ◽  
Semantic Processes

AbstractThe academic field of Qurʾānic Studies employs a wide range of approaches, each one of which helps to open up a new perspective on the Qurʾānic text. The Holy Book was revealed to guide people; it is thus of relevance to all aspects of people’s lives. This article focuses on the way social actors are represented in one Meccansūra, entitled “Ya-Sin”, and employs a case-study approach to do so. The analysis carried out includes the socio-semantic processes that thesūrauses in order to represent social actors either by behavior (action) or meaning (reflection), and it also analyzes the actors as they are represented in processes such as activation and passivation. The methodology adopted is eclectic and analytic. It is a hybrid of Swales’ move analysis, El-Awa’s identification of shift-markers, and Halliday’s and Van Leeuwen’s theories of social actor representation. This study shows how such an analysis can contribute to understanding the apparently fragmented and non-linear nature of “Ya-Sin”.

A Short Fatigue Crack Growth Law for 1Cr18Ni9Ti Weld Metal

2006 ◽  
Vol 324-325 ◽  
pp. 571-578 ◽  
Author(s):  
Yong Xiang Zhao ◽  
Bing Yang ◽  
Wei Hua Zhang
Keyword(s):  
High Speed ◽  
Compression Tests ◽  
Temporal And Spatial Distribution ◽  
Primary Stage ◽  
Second Stage ◽  
Final Failure ◽  
Brewing Process ◽  
Ae Signal ◽  
Failure Location ◽  
Low Amplitude

A series of uniaxial-compression tests were conducted on some representative brittle rock specimens, such as granite, marble and dolerite. A multi-channel, high-speed AE signal acquiring and analyzing system was employed to acquire and record the characteristics of AE events and demonstrate the temporal and spatial distribution of these events during the rupture-brewing process. The test result showed that in the primary stage, many low amplitude AE events were developed rapidly and distributed randomly throughout the entire specimens. In the second stage, the number of AE increased much slower than that in the first stage, while the amplitude of most AE events became greater. Contrarily to the primary stage, AE events clustered in the middle area of the specimen and distributed vertically conformed to the orientation of compression. The most distinct characteristic of this stage was a vacant gap formed approximately in the central part of the specimen. In the last stage, the number of AE events increased sharply and their magnitude increased accordingly. The final failure location coincidently inhabited the aforementioned gap. The main conclusion is that most macrocracks are developed from the surrounding microcracks existed earlier and their positions occupy the earlier formed gaps, and the AE activity usually becomes quite acute before the main rupture occurs.

Evaluation of Belleville Springs and Damping Through Static Cyclic Loading “Hysteresis” for pVARD Optimization: Part-I

2021 ◽  
Author(s):  
Abdelsalam Abugharara ◽  
Stephen Butt
Keyword(s):  
Data Analysis ◽  
Cyclic Loading ◽  
Dynamic Compression ◽  
Range Data ◽  
Compression Tests ◽  
Rotary Drilling ◽  
Static Compression ◽  
Drilling Performance ◽  
Wide Range ◽  
Compression Hysteresis

Abstract One unconventional application that researchers have been investigating for enhancing drilling performance, has been implemented through improving and stabilizing the most effective downhole drilling parameters including (i) increasing downhole dynamic weight on bit (DDWOB), (ii) stabilizing revolution per minutes (rpm), (iii) minimizing destructive downhole vibrations, among many others. As one portion of a three-part-research that consists of a comprehensive data analysis and evaluation of a static compression hysteresis, dynamic compression hysteresis, and corresponding drilling tests, this research investigates through static cyclic loading “Hysteresis” of individual and combined springs and damping the functionality of the passive Vibration Assisted Rotary Drilling (pVARD) tool that could be utilized towards enhancing the drilling performance. Tests are conducted on the two main pVARD tool sections that include (i) Belleville springs, which represent the elasticity portion and (ii) the damping section, which represents the viscous portion. Firstly, tests were conducted through static cyclic loading “Hysteresis” of (i) a mono elastic, (ii) a mono viscus, and (iii) dual elastic-viscus cyclic loading scenarios for the purpose of further examining pVARD functionality. For performing static compression tests, a calibrated geomechanics loading frame was utilized, and various spring stacking of different durometer damping were tested to seek a wide-range data and to provide a multi-angle analysis. Results involved analyzing loading and displacement relationships of individual and combined springs and damping are presented with detailed report of data analysis, discussion, and conclusions.

Experimental-Numerical Characterization of Ordinary Concrete at the Meso-Scale

2021 ◽  
Author(s):  
GIANLUCA MAZZUCCO ◽  
Beatrice Pomaro ◽  
Giovanna Xotta ◽  
Enrico Garbin ◽  
Valentina Salomoni ◽  
...  
Keyword(s):  
Yield Criterion ◽  
Plain Concrete ◽  
Point Of View ◽  
Good Prediction ◽  
Deformation Capacity ◽  
Compression Tests ◽  
Fe Method ◽  
Stress States ◽  
Meso Scale

Modeling the post-peak behaviour of brittle materials like concrete is still a challenge from the point of view of computational mechanics, due to the strong nonlinearities arising in the material behaviour during softening and the complexity of the yield criterion that may describe their deformation capacity in generic triaxial stress states. A numerical model for plain concrete in compression is formulated within the framework of the coupled elasto-plastic-damage theory. The aim is to simulate via the Finite Element (FE) method the stress-strain behaviour of concrete at the meso-scale, where local confinement effects generally characterize the cement paste under the action of the surrounding aggregates. The mechanical characterization of the components are accomplished through a specific experimental campaign. With the subsequent validation study, it is shown that a few calibration parameters give a good prediction of load strength and deformation capacity coming from real uniaxial compression tests.

scholarly journals Everything You Always Wanted to Know about β3-AR * (* But Were Afraid to Ask)

Cells ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 357 ◽  
Author(s):  
Giorgia Schena ◽  
Michael J. Caplan
Keyword(s):  
Adrenergic Receptor ◽  
Species Differences ◽  
Current Clinical Practice ◽  
Substantial Body ◽  
Cellular Models ◽  
Wide Range ◽  
The Subject ◽  
And Function ◽  
Novel Therapeutic ◽  
Do So

The beta-3 adrenergic receptor (β3-AR) is by far the least studied isotype of the beta-adrenergic sub-family. Despite its study being long hampered by the lack of suitable animal and cellular models and inter-species differences, a substantial body of literature on the subject has built up in the last three decades and the physiology of β3-AR is unraveling quickly. As will become evident in this work, β3-AR is emerging as an appealing target for novel pharmacological approaches in several clinical areas involving metabolic, cardiovascular, urinary, and ocular disease. In this review, we will discuss the most recent advances regarding β3-AR signaling and function and summarize how these findings translate, or may do so, into current clinical practice highlighting β3-AR’s great potential as a novel therapeutic target in a wide range of human conditions.

scholarly journals Perception of investing in crypto in India using UTAUT model

2021 ◽  
Vol 9 (10) ◽  
pp. 1396-1400
Author(s):  
Vidhi Shah
Keyword(s):  
Indian Population ◽  
Social Benefits ◽  
Short Term ◽  
Perceived Safety ◽  
Utaut Model ◽  
Performance Expectancy ◽  
Wide Range ◽  
Effort Expectancy ◽  
Do So

Abstract: This research was conducted to gather data and understand the perception what the Indian population holds when it comes to investing in cryptocurrency. To do so, a survey was designed using the UTAUT model and was circulated by the means of google forms. A wide range of parameters were considered to avail the maximum possible accuracy for the data collected. Parameters like, the ease of investing crypto, short term and long term benefits, monetary benefits, social benefits were considered. All of these parameters were supposed to be answered on a scale of 5. After collecting all the data, the results were analyzed and evaluated using which the hypothesis made were proved. Keywords: Cryptocurrency, UTAUT, performance expectancy, effort expectancy, perceived monetary benefits, perceived safety, social influence, adoption intension.

scholarly journals Online Life Writing

2020 ◽  
Vol 1 (1) ◽  
pp. 147-150
Author(s):  
Silvia Schultermandl
Keyword(s):  
Life Style ◽  
Asylum Seekers ◽  
Life Writing ◽  
The Political ◽  
Online Media ◽  
The Past ◽  
Everyday Lives ◽  
Wide Range ◽  
Literary Market ◽  
Do So

In lieu of an abstract, here is the first paragraph of this contribution to this forum: The advent of Facebook in 2004, Twitter in 2006, Tumblr in 2007, Instagram and Pinterest in 2010, and Snapchat and Google+ in 2011 facilitated the emergence of “everyday” autobiographies out of keeping with memoir practices of the past.[1] These “quick media” enable constant, instantaneous, and seemingly organic expressions of everyday lives.[2] To read quick media as “autobiographical acts” allows us to analyze how people mobilize online media as representations of their lives and the lives of others.[3] They do so through a wide range of topics including YouTube testimonials posted by asylum seekers (Whitlock 2015) and the life-style oriented content on Pinterest.[4] To be sure, the political content of these different quick media life writing varies greatly. Nevertheless, in line with the feminist credo that the personal is political, these expressions of selfhood are indicative of specific societal and political contexts and thus contribute to the memoir boom long noticed on the literary market.[5]

scholarly journals ANALYSIS OF ENDOCRINE RESPONSE TO PERCEIVED DIFFERENCE IN CROSS-CULTURAL INTERACTIONS

2017 ◽  
Vol 1 (2) ◽  
Author(s):  
Carole Woolford-Hunt ◽  
Marlene Murray ◽  
Tevni Guerra ◽  
Kristina Beenken-Johnson
Keyword(s):  
Cross Cultural ◽  
Human Relations ◽  
Endocrine Response ◽  
The Social ◽  
Wide Range ◽  
Education Psychology ◽  
The Impact ◽  
Practical Implications ◽  
Do So ◽  
Cultural Interactions

We live in a world where awareness of ethnic and cultural diversity is an ever increasing reality. Business and education turn to the social sciences to inform them about how to manage and optimize cross-cultural interactions. Although much research has been done on the impact of cross-cultural interactions on a wide range of variables, one less researched area is the endocrine response to cross-cultural interactions. In this study we set out to investigate the endocrine response to cross cultural interactions and the impact of these interactions on perceived differences. To do so we measured the pre and post levels of the stress hormone cortisol of individuals communicating in dyads for 15 minutes. Results showed a significant impact of ethnic interaction on perceived differences and cortisol levels. Practical implications of these findings could have application in the areas of education, psychology, business and human relations in general. Implications for further research are discussed.

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