scholarly journals Crack mechanisms in concrete – from micro to macro scale

2020 ◽  
Vol 19 (4) ◽  
pp. 053-066
Author(s):  
Marta Słowik ◽  
Piet Stroeven ◽  
Amanda Akram
Keyword(s):  
Crack Initiation ◽  
Experimental Research ◽  
Crack Formation ◽  
Aggregate Size ◽  
Crack Development ◽  
Crack Model ◽  
Significant Progress ◽  
Macro Scale ◽  
Fictitious Crack

The paper discusses a fictitious crack model of concrete in tension proposed by Hillerborg. This model presents a concept that illustrates the mechanism of crack initiation and its propagation in concrete on meso-level. It has proven to be a very useful tool for practical use, for both numerical and experimental research. The model was derived from findings on crack mechanisms on more advanced micro- and macro-scale, as presented in this paper. One of the paramount issues regarding crack analysis is the influence of aggregate size on mechanical and fracture parameters of concrete, and also on micro-crack development and associated macro-crack formation. Although significant progress in recognizing crack mechanisms in concrete has been achieved, there are still some aspects that should be studied in depth, for example the role of aggregate particles on crack development. This problem is analysed in the paper as well.

The Role of Microtexture on Fatigue Lifetime Variability and Crack Initiation Mechanisms (Preprint)

2011 ◽  
Author(s):  
Christopher J. Szczepanski ◽  
S. L. Semiatin ◽  
James M. Larsen
Keyword(s):  
Crack Initiation ◽  
Fatigue Lifetime

scholarly journals The Pivotal Player: Components of NF-κB Pathway as Promising Biomarkers in Colorectal Cancer

2021 ◽  
Vol 22 (14) ◽  
pp. 7429
Author(s):  
Matthew Martin ◽  
Mengyao Sun ◽  
Aishat Motolani ◽  
Tao Lu
Keyword(s):  
Colorectal Cancer ◽  
Biological Response ◽  
Significant Progress ◽  
Therapeutic Approaches ◽  
Successful Development ◽  
Diagnostic Screening ◽  
Proteomic Data ◽  
Large Groups ◽  
Made In

Over the last several decades, colorectal cancer (CRC) has been one of the most prevalent cancers. While significant progress has been made in both diagnostic screening and therapeutic approaches, a large knowledge gap still remains regarding the early identification and treatment of CRC. Specifically, identification of CRC biomarkers that can help with the creation of targeted therapies as well as increasing the ability for clinicians to predict the biological response of a patient to therapeutics, is of particular importance. This review provides an overview of CRC and its progression stages, as well as the basic types of CRC biomarkers. We then lay out the synopsis of signaling pathways related to CRC, and further highlight the pivotal and multifaceted role of nuclear factor (NF) κB signaling in CRC. Particularly, we bring forth knowledge regarding the tumor microenvironment (TME) in CRC, and its complex interaction with cancer cells. We also provide examples of NF-κB signaling-related CRC biomarkers, and ongoing efforts made at targeting NF-κB signaling in CRC treatment. We conclude and anticipate that with more emerging novel regulators of the NF-κB pathway being discovered, together with their in-depth characterization and the integration of large groups of genomic, transcriptomic and proteomic data, the day of successful development of more ideal NF-κB inhibitors is fast approaching.

scholarly journals Experimental research Concomitant protective and therapeutic role of verapamil in chronic mercury induced nephrotoxicity in the adult rat: histological, morphometric and ultrastructural study

2015 ◽  
Vol 1 ◽  
pp. 199-209 ◽  
Author(s):  
Nabila Yousef Abdel Haleem ◽  
Hoda Mahmoud El-Aasar ◽  
Sherif Mohamed Zaki ◽  
Sherif Mohamed Sabry ◽  
Ahmed Wafiq El-Zainy
Keyword(s):  
Experimental Research ◽  
Ultrastructural Study ◽  
Therapeutic Role ◽  
Adult Rat

Role of plasticity on interface crack initiation from a free edge and propagation in a nano-component

2007 ◽  
Vol 145 (4) ◽  
pp. 261-271 ◽  
Author(s):  
Hiroyuki Hirakata ◽  
Yoshimasa Takahashi ◽  
Do Truong ◽  
Takayuki Kitamura
Keyword(s):  
Crack Initiation ◽  
Interface Crack ◽  
Free Edge

The ethics of experimental research employing intrusive technologies in tourism: A collaborative ethnography perspective

2021 ◽  
pp. 146735842199389
Author(s):  
Aaron Tham ◽  
Vikki Schaffer ◽  
Laura Sinay
Keyword(s):  
Eye Tracking ◽  
Experimental Research ◽  
Experimental Setting ◽  
Approval Process ◽  
Dichotomous Outcome ◽  
Scant Attention ◽  
Tourism And Hospitality ◽  
Collaborative Ethnography

This study probes the ethics of intrusive technologies for experimental research in tourism, through the lens of collaborative ethnography. Amidst the increasing uptake of technology to assess participant responses, the role of ethics in an experimental setting has received scant attention in tourism and hospitality. While intrusive technologies such as eye tracking, skin sensors and neuroscience headgear become more ubiquitous, the ethical boundaries of using such equipment are increasingly blurred and inconsistently approved. Seeking convergence of ethics concerning intrusive technologies is complicated when framing political spaces, target audiences and management of data obtained. Rather than view the role of intrusive technologies as a dichotomous outcome of ethical or unethical approaches, this paper argues that ethics needs to be contextually embedded with increased collaboration and co-creation in the application preparation and approval process.

scholarly journals Calcium Signaling in Plant Programmed Cell Death

Cells ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1089
Author(s):  
Huimin Ren ◽  
Xiaohong Zhao ◽  
Wenjie Li ◽  
Jamshaid Hussain ◽  
Guoning Qi ◽  
...  
Keyword(s):  
Cell Death ◽  
Programmed Cell Death ◽  
Abiotic Stresses ◽  
Animal Studies ◽  
Future Research ◽  
Significant Progress ◽  
Biotic And Abiotic Stresses ◽  
Stress Perception ◽  
The Past

Programmed cell death (PCD) is a process intended for the maintenance of cellular homeostasis by eliminating old, damaged, or unwanted cells. In plants, PCD takes place during developmental processes and in response to biotic and abiotic stresses. In contrast to the field of animal studies, PCD is not well understood in plants. Calcium (Ca2+) is a universal cell signaling entity and regulates numerous physiological activities across all the kingdoms of life. The cytosolic increase in Ca2+ is a prerequisite for the induction of PCD in plants. Although over the past years, we have witnessed significant progress in understanding the role of Ca2+ in the regulation of PCD, it is still unclear how the upstream stress perception leads to the Ca2+ elevation and how the signal is further propagated to result in the onset of PCD. In this review article, we discuss recent advancements in the field, and compare the role of Ca2+ signaling in PCD in biotic and abiotic stresses. Moreover, we discuss the upstream and downstream components of Ca2+ signaling and its crosstalk with other signaling pathways in PCD. The review is expected to provide new insights into the role of Ca2+ signaling in PCD and to identify gaps for future research efforts.

Społeczne i kulturowe determinanty funkcjonowania państwa u progu XXI wieku

1970 ◽  
Vol 21 (282) ◽  
pp. 3-18
Author(s):  
Michał Strzelecki
Keyword(s):  
Political Institutions ◽  
Common Good ◽  
The State ◽  
Political Conflicts ◽  
Role Of The State ◽  
Macro Scale ◽  
The Common ◽  
Civic Awareness ◽  
Political Scene

The contemporary state crisis is a derivative of complex economic and social processes. His indicators include not only the visible increase in the intensity of political conflicts (both on a micro and macro scale), the revival and development of separatist tendencies, and the weakening of the role of the state as the basic instrument of organizing collective life. It is also increasing fragmentation of the political scene, the development of particularisms, weakening and progressive dysfunctionality of existing political institutions, increasing economic rivalry and the collapse of the generally accepted axiological system, which is accompanied by increasingly clear questioning of the idea of the common good and progressing pragmatism and egoism. An important element is therefore the disappearance of civic awareness and activity. The intensification of these disturbing tendencies is certainly not supported by the modern education system, whose hallmarks are commercialization and economization, withdrawal of the state and professionalization.

Study of Crack Resistance of Layers Applied by Laser Surface Cladding

2014 ◽  
Vol 682 ◽  
pp. 410-413
Author(s):  
S.N. Namazov ◽  
E.D. Rzayev ◽  
V.F. Jivishov
Keyword(s):  
Chemical Composition ◽  
Crack Initiation ◽  
Crack Resistance ◽  
Crack Formation ◽  
Laser Surface ◽  
Surface Cracks ◽  
Welding Technology

The paper describes the crack initiation in the layers which were applied by laser surface cladding. The paper investigates the influence of the chemical composition of layer materials and welding technology on the tendency of the crack formation. Proposed method can dramatically reduce the formation of surface cracks in the applied layers.

scholarly journals The setup and application of the multi-scale in-situ test system for fatigue damage analysis

2018 ◽  
Vol 165 ◽  
pp. 04005
Author(s):  
Yi Shi ◽  
Xiaoguang Yang ◽  
Guolei Miao ◽  
Duoqi Shi
Keyword(s):  
Growth Rate ◽  
Fatigue Crack ◽  
Crack Growth Rate ◽  
Crack Initiation ◽  
Crack Growth ◽  
Test System ◽  
In Situ Test ◽  
Multi Scale ◽  
Macro Scale

This essays aims at introducing the setup for the multi-scale in-situ test system which is applied for the fatigue crack initiation test. The setup of the experiment system is first introduced, including the image capturing system, optical path system, image acquisition and storage system and the three-axis mobile platform. Then the preparation of micro speckle and the corresponding technique for spatial adjustment are improved to realize the DIC measurement in micro scale. Finally three experiments from macro-meso scale to macro scale: fatigue initiation test, the observation of micro crack and the fatigue crack growth rate in macro scale were conducted to verify the application of the system. The test result can indicate the location of crack initiation, the crack growth rate and the evolution of displacement/strain field, etc.

scholarly journals Restorative Design for Heritage Requalification: Selected Roman Works

2021 ◽  
pp. 227-244
Author(s):  
Luciano Cupelloni
Keyword(s):  
Human Resources ◽  
Public Space ◽  
Experimental Research ◽  
Common Good ◽  
Urban Systems ◽  
Technological Design ◽  
Transformative Power ◽  
The Public ◽  
New Perspective

AbstractThe theme is the urban re-qualification, applied in particular to the architectural heritage and the public space. The goal is the ongoing challenge of outlining a new perspective aimed at “common good” and sustainability. The instrument chosen is the “environmental technological design,” understood as a cultural, scientific, and social position, that is, as a position on the role of architecture. The contribution reiterates the urgency of restoring the transformative power of the design mission to the project, too often reduced to a set of technical compilation procedures. In the best cases, a position that is lost in the complication of procedures, in the extension of time, in the waste of economic and human resources. A crisis of the project as “anticipation” of progressive scenarios, precisely in the most acute, ever more serious phase, of the urgency of the reorganization of urban systems, with a view to environmental, social and economic sustainability. Not a recent urgency, today only brought to light, dramatically, by the reality of the SARS-CoV-2 pandemic. Among the solutions, the design experimental research, well beyond the objective of flexibility, up to the notion of “functional indifference,” understood not as shapeless neutrality, but as the maximum functionality of spatial, architectural and urban quality.

Sign in / Sign up

Export Citation Format

Share Document