scholarly journals Bio-Influenced Self-Healing Mechanism in Concrete and Its Testing: A Review

2020 ◽  
Vol 10 (15) ◽  
pp. 5161 ◽  
Author(s):  
Albert A. Griño ◽  
Ma. Klarissa M. Daly ◽  
Jason Maximino C. Ongpeng
Keyword(s):  
Service Life ◽  
Latent Dirichlet Allocation ◽  
Future Research ◽  
Self Healing ◽  
Concrete Material ◽  
Existing Problems ◽  
Load Combination ◽  
Micro Cracks ◽  
To Come ◽  
Concrete Matrix

The micro-cracks in concrete structures are inevitable due to deterioration throughout their service life through various load combination factors. For that reason, there is a need to repair and maintain the concrete in order to prevent the cracks from propagating, which can decrease the service life of the structure. Using bacteria is one of the possible solutions to repair and heal the cracks. Recent research has shown that, in order to achieve the extended service life of a concrete material, a bio-influenced material, such as bacteria, can be used in order to induce the autonomous self-healing of cracks in concrete. Many researchers are still exploring the potential of bacteria for improving the durability and strength of concrete. However, an inclusive literature review revealed that a self-healing mechanism using bacteria can still be improved. There is an imperative need to conduct a comprehensive review about the recent development of and studies into the self-healing mechanism of concrete, in particular with the behavior of bacteria and its effect on the macro, micro and nanostructure of the concrete matrix. This review article can reveal the potential research gap, predict the emerging research topics and define all existing problems or challenges about the bio-influenced self-healing mechanism in concrete. The latest articles are summarized and analyzed using the Latent Dirichlet Allocation (LDA) in Matlab software in order to come up with a possible area of development and future research into bio-concrete. Microencapsulated technology and acoustic emission could be the emerging methods for evaluating the performance of the bacteria and detecting real time cracks inside the concrete matrix in the future. However, there are still existing problems and challenges regarding the adoption of bacteria in the field of construction industry.

scholarly journals Effect of Water Proofing Materials on Self-Healing Concrete

2020 ◽  
Vol 3 (1) ◽  
pp. 35
Author(s):  
Tayfun Uygunoğlu ◽  
İlker Bekir Topçu
Keyword(s):  
Service Life ◽  
External Factors ◽  
Powder Materials ◽  
Self Healing ◽  
Micro Cracks ◽  
Water Proofing ◽  
Long Term Performance ◽  
Term Performance ◽  
Water Repellents

Improving the strength of the concrete structures and increasing the service life is an important issue. The service times of the concrete remained; external factors such as water penetrating into these micro-cracks and shorten the life of the concrete. In order to solve this problem, the idea of self-healing concrete with bacteria or other materials has been put forward and studies have shown that using CaO based materials that repair cracks in this direction by precipitating calcite. It is obvious that long term performance of concrete will increase with to prevent water pass to concrete interior. Instead of forming a barrier on the positive or negative side of concrete, water proofing admixture turn the concrete itself into a water barrier. Internal concrete waterproofing systems can be water repellents or crystalline admixtures. In this study, water proofing admixture was added to concrete mixture as water proofing material and its effect on self-healing in terms of filling the pores was investigated. Beam samples including the CaO based water proofing powder materials were produced in size of 285x75x25 mm. The samples were cracked in the flexural machine. After some days, the cracks were investigated by microscope. Crak control was continued till 28 days. At the end of study, the cracks smaller than 0.3 mm were self-healed. However, the bigger cracks than 0.3 mm cannot be self-healed by water proofing material. Consequently, self-healing of concrete with CaO based water proofing powder material is very promising for the environmentally friendly and sustainable structures of the future.

scholarly journals Influence of Loading Peak and Loading Rate on Twin Fibers Pullout Test of Concrete Matrix

2021 ◽  
Vol 237 ◽  
pp. 03009
Author(s):  
Yafang Zhang ◽  
Feihua Luo ◽  
Juan Lu ◽  
Juan He ◽  
Yuhai Zhuang
Keyword(s):  
Crack Propagation ◽  
Loading Rate ◽  
Pullout Test ◽  
Concrete Material ◽  
Damage Area ◽  
Whole Process ◽  
Pull Out ◽  
Crack Penetration ◽  
Micro Cracks ◽  
Concrete Matrix

Numerical analysis software based on linear finnite element method and statistical damage theory concrete material has been adopted in this study. Dynamic numerical model of twin fibers pullout test of concrete matrix have been created by considering the meso-heterogeneity of concrete material. The whole process from micro-cracks initiation, propagation to crack penetration has been simulated. The influence of stress wave loading peak and loading rate on twin fibers pull-out test of concrete matrix under dynamic load has, therefore, been scrutinized. Results show that loading rate has effect on failure mode and crack propagation along interface of the twin fibers pull-out specimens. With increasing loading rates, the rate of interface crack propagation and damage area increase either.

Android Malware Detection Techniques: A Literature Review

2020 ◽  
Vol 14 ◽  
Author(s):  
Meghna Dhalaria ◽  
Ekta Gandotra
Keyword(s):  
Machine Learning ◽  
Deep Learning ◽  
Malware Detection ◽  
Future Research ◽  
Android Malware ◽  
Detection Techniques ◽  
Android Malware Detection ◽  
Future Research Directions ◽  
To Come ◽  
Tools And Techniques

Purpose: This paper provides the basics of Android malware, its evolution and tools and techniques for malware analysis. Its main aim is to present a review of the literature on Android malware detection using machine learning and deep learning and identify the research gaps. It provides the insights obtained through literature and future research directions which could help researchers to come up with robust and accurate techniques for classification of Android malware. Design/Methodology/Approach: This paper provides a review of the basics of Android malware, its evolution timeline and detection techniques. It includes the tools and techniques for analyzing the Android malware statically and dynamically for extracting features and finally classifying these using machine learning and deep learning algorithms. Findings: The number of Android users is expanding very fast due to the popularity of Android devices. As a result, there are more risks to Android users due to the exponential growth of Android malware. On-going research aims to overcome the constraints of earlier approaches for malware detection. As the evolving malware are complex and sophisticated, earlier approaches like signature based and machine learning based are not able to identify these timely and accurately. The findings from the review shows various limitations of earlier techniques i.e. requires more detection time, high false positive and false negative rate, low accuracy in detecting sophisticated malware and less flexible. Originality/value: This paper provides a systematic and comprehensive review on the tools and techniques being employed for analysis, classification and identification of Android malicious applications. It includes the timeline of Android malware evolution, tools and techniques for analyzing these statically and dynamically for the purpose of extracting features and finally using these features for their detection and classification using machine learning and deep learning algorithms. On the basis of the detailed literature review, various research gaps are listed. The paper also provides future research directions and insights which could help researchers to come up with innovative and robust techniques for detecting and classifying the Android malware.

The Importance of the Posterolateral Area of the Diaphragm Muscle for Palpation and for the Treatment of Manual Osteopathic Medicine

2021 ◽  
pp. 1-9
Author(s):  
Bruno Bordoni ◽  
Stevan Walkowski ◽  
Allan Escher ◽  
Bruno Ducoux
Keyword(s):  
Functional Anatomy ◽  
Diaphragm Muscle ◽  
Physiological Data ◽  
Future Research ◽  
Physical Aspect ◽  
Osteopathic Medicine ◽  
Self Healing ◽  
Hands On ◽  
Critical Issues ◽  
Solid Foundation

The eupneic act in healthy subjects involves a coordinated combination of functional anatomy and neurological activation. Neurologically, a central pattern generator, the components of which are distributed between the brainstem and the spinal cord, are hypothesized to drive the process and are modeled mathematically. A functionally anatomical approach is easier to understand although just as complex. Osteopathic manipulative treatment (OMT) is part of osteopathic medicine, which has many manual techniques to approach the human body, trying to improve the patient’s homeostatic response. The principle on which OMT is based is the stimulation of self-healing processes, researching the intrinsic physiological mechanisms of the person, taking into consideration not only the physical aspect, but also the emotional one and the context in which the patient lives. This article reviews how the diaphragm muscle moves, with a brief discussion on anatomy and the respiratory neural network. The goal is to highlight the critical issues of OMT on the correct positioning of the hands on the posterolateral area of the diaphragm around the diaphragm, trying to respect the existing scientific anatomical-physiological data, and laying a solid foundation for improving the data obtainable from future research. The correctness of the position of the operator’s hands in this area allows a more effective palpatory perception and, consequently, a probably more incisive result on the respiratory function.

Self-Healing and Repairing Concrete Cracks Based on Bio-Mineralization

2014 ◽  
Vol 629-630 ◽  
pp. 494-503 ◽  
Author(s):  
Chun Xiang Qian ◽  
Mian Luo ◽  
Li Fu Ren ◽  
Rui Xing Wang ◽  
Rui Yang Li ◽  
...  
Keyword(s):  
Concrete Surface ◽  
Cellular Respiration ◽  
Self Healing ◽  
Capillary Suction ◽  
Water Permeation ◽  
Carbonate Ions ◽  
Micro Cracks ◽  
Small Cracks ◽  
The Common ◽  
The One

In this paper, three bio-mineralization mechanisms were proposed to repair cement-based materials cracks. The common feature is that the three are all induced by bacterial. A type of bacterial which can decompose urea and release carbonate ions could be applied to repair micro cracks on concrete surface when combining calcium ions. But what need to be noted is that the way of repairing cracks is passive. Some alkaliphilic bacterial spores could be added to concrete when casted and two different types of bacterial were used to realize the function of self-healing. The sources of carbonate ions made them different, the one release carbonate dioxide through its own cellular respiration, the other could transfer carbon dioxide in air to bicarbonate. Coefficient of capillary suction, apparent water permeation coefficient and area repairing rate were applied to characterize the repairing effectiveness. The tests results were that all three bio-mineralization mechanisms showed excellent repair effect to small cracks formed at early ages. When the bacteria were immobilized by ceramsite, the self-healing effect could be improved for the cracks formed at late ages.

scholarly journals The Current Situation and Prospect Of Study Quality Evaluation Research in China in The Last 10 Years

2020 ◽  
Vol 2 (1) ◽  
pp. 101-112
Author(s):  
Wu Aixia ◽  
Zhou Ying ◽  
Tommy Tanu Wijaya
Keyword(s):  
Quality Evaluation ◽  
Evaluation Research ◽  
Teaching Quality ◽  
Current Situation ◽  
Annual Number ◽  
Future Research ◽  
Existing Problems ◽  
Content Analysis Method ◽  
Future Research Directions

With the deepening of China's educational reform, the evaluation of teaching quality has become an important aspect of teaching reform.And the evaluation of students'learning quality is an important part of teaching evaluation. Research on it will help to improve the teaching quality of our country and promote the overall improvement of students' morality, intelligence, physical fitness and beauty.Therefore, this study takes 108 literatures related to the study of learning quality evaluation in China as the research object, uses content analysis method, carries out statistical analysis on the annual number of literatures, Journal distribution, author status, paper influence, research content, etc., analyzes the current situation and existing problems of the study of learning quality evaluation in China, and puts forward the need for further deepening.On the basis of these questions, possible future research directions are proposed.

Screening of Different Encapsulated Polymer-Based Healing Agents for Chloride Exposed Self-Healing Concrete Using Chloride Migration Tests

2018 ◽  
Vol 761 ◽  
pp. 152-158 ◽  
Author(s):  
Philip van den Heede ◽  
Bjorn van Belleghem ◽  
Maria Adelaide Araújo ◽  
João Feiteira ◽  
Nele de Belie
Keyword(s):  
Service Life ◽  
High Viscosity ◽  
Cementitious Materials ◽  
Self Healing ◽  
Polymer Precursor ◽  
Marine Environments ◽  
Steel Reinforced Concrete ◽  
Low Viscosity ◽  
Chloride Migration ◽  
The One

The service life of steel reinforced concrete in aggressive marine environments could be increased substantially by embedding a self-healing mechanism that ensures autonomous healing of cracks upon their occurrence. Previous proof-of-concept experiments have shown that the incorporation of encapsulated polymer-based healing agents (HAs) counts as a very appropriate way to achieve this goal. Over the years, several polymer-precursor-capsule systems have been developed in that perspective at our laboratory. Cementitious materials containing either commercial or in-house developed encapsulated HAs have been subjected to preliminary feasibility tests (water absorption, permeability tests, etc.). However, these experiments did not yet allow for a fast and straightforward assessment of the self-healing efficiency (SHE) in relation to the expected durability and service life performance of the material. This approach would have many advantages when having to select the most suitable polymer-precursor-capsule system for a particular concrete application. In this paper, a modified chloride migration test based on the one prescribed in NT Build 492 has been proposed to support the development of self-healing concrete for marine environments. Four polymer-based HAs have been screened that way, i.e. an in-house developed high-viscosity polyurethane (PU) precursor, a commercial low-viscosity PU precursor, the same commercial PU precursor with addition of accelerator and benzoyl peroxide (BPO), and an in-house developed 2-component acrylate-endcapped precursor + cross-linker. For now, a highly repeatable SHE value of 100% could only be obtained for the second option.

Culture and Websites Interaction

2014 ◽  
pp. 1461-1495
Author(s):  
Ramazan Nacar ◽  
Sebnem Burnaz ◽  
Nimet Uray
Keyword(s):  
Information Technologies ◽  
Communication Channels ◽  
High Potential ◽  
Future Research ◽  
Cultural Issues ◽  
Methodological Issues ◽  
Business World ◽  
Culturally Adapted ◽  
To Come ◽  
Research Recommendations

With the increasing globalization of the business world, websites have become ever more important tools in international business. After the invention of websites, researchers have begun to analyze the websites as they have for traditional communication channels. Websites, as the communication medium of global firms, are not culturally neutral mediums. Website components should be analyzed very carefully in terms of their interaction with cultural issues to come up with culturally adapted websites. In this chapter, 114 studies on culture and websites are critically reviewed, and selected papers among them from a variety of areas such as marketing, communications, management, information technologies, and others, are analyzed in detail to consolidate the existing knowledge and approaches. This chapter aims to analyze how scholarly research on the interaction of culture and websites has developed. The studies are categorized according to the framework developed and selected. Forty of them are discussed in detail under some subcategories. A number of conceptual and methodological issues that deserve more attention are discussed to fulfill the high potential of websites. A state-of-the-art review of several innovative advances in culture and websites is provided to stimulate new streams for future research, and future research recommendations are proposed at the end of the chapter.

Striving for Inclusion in E-Learning and E-Health

2021 ◽  
pp. 44-72
Author(s):  
Sandra Sanchez-Gordon
Keyword(s):  
Life Cycle ◽  
Literature Review ◽  
Online Courses ◽  
Research Process ◽  
Future Research ◽  
Online Platforms ◽  
E Learning ◽  
Learning Platforms ◽  
To Come ◽  
Definition Of

The purpose of this chapter is to present a seven-year journey to understand the barriers that people face when interacting with e-learning and e-health online platforms and to come up with software engineering solutions to make these platforms more inclusive. This chapter per the author presents a set of contributions intended to serve as steppingstones to future research efforts. These contributions include a literature review about accessibility of e-learning platforms; the accessibility audit of e-learning and e-health platforms; the identification of accessibility requirements; the design of architectures, process, and models to improve accessibility; and the definition of a life cycle for the management of accessible online courses. In this context, this chapter relate the evolution of the research process followed and summarize the results obtained so far.

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