METHOD OF PAINT COAT DURABILITY ASSESSMENT EXPOSED TO MINERAL MASS

Tribologia ◽  
2018 ◽  
Vol 278 (2) ◽  
pp. 123-131
Author(s):  
Piotr SZCZYGLAK
Keyword(s):  
Original Method ◽  
Mechanical Forces ◽  
Rotating Drum ◽  
Testing Method ◽  
Wear And Tear ◽  
Durability Assessment ◽  
Testing Stand ◽  
Mechanical Factors ◽  
The Impact ◽  
Mineral Mass

This study analyses issues concerning defects of passive paint coats. Four reasons of their occurrence have been identified: constructional, technological, operational, and caused by wear and tear. Standardized methods of paint coat assessment are discussed based on the impact of mechanical factors (PN-EN ISO 2409:2013-06, ASTM D3359-17, PN-EN ISO 1522:2008, PN-EN ISO 4624:2016-05, PN-EN ISO 1518-1:2011, PN-EN ISO 16276-2:2008, PN-EN ISO 6272:2011, PN-EN ISO 6860:2006, PN-EN ISO 2815:2004, PN-EN ISO 1519:2000). The original method of paint coat durability evaluation is presented with the consideration of synergetic impact of mechanical forces. This method permits carrying out testing in conditions close to those during normal service. The testing stand equipped with a rotating drum filled with mineral mass has been described as well as the optical method of assessing paint coat quality using original software developed by authors. Tests for three coating systems were carried out in order to present the possibilities of the developed method. In summary, the conclusions relating to the presented testing method are presented.

scholarly journals Porosity Evaluation of Concrete Containing Supplementary Cementitious Materials for Durability Assessment through Volume of Permeable Voids and Water Immersion Conditions

Buildings ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 378
Author(s):  
Manish Kewalramani ◽  
Ahmad Khartabil
Keyword(s):  
Water Absorption ◽  
Water Immersion ◽  
Cementitious Materials ◽  
Chloride Penetration ◽  
Supplementary Cementitious Materials ◽  
Partial Replacement ◽  
Testing Method ◽  
Durability Assessment ◽  
Astm C1202 ◽  
The Impact

Concrete containing supplementary cementitious materials (SCMs) as partial replacement of ordinary Portland cement is regarded as green and durable concrete, with several advantages such as improved strength gain mechanism, resistance to degradation and extended service life of structure. Water absorption or porosity of concrete is directly related to the durability of concrete. In this present study, five concrete mixes involving three different SCMs are investigated for water absorption and rapid chloride penetration rating. A comparison between porosity values obtained using four standard testing methods, i.e., BS 1881-122, RILEM CPC 11.1, RILEM CPC 11.3, and ASTM C642 are presented for three different concrete mixes containing varied compositions and proportions of two SCMs. The testing method by RILEM CPC 11.3 includes distinctive sample preparation and is regarded as a stringent method to represent the degree of concrete porosity. Two additional concrete mixes with three SCMs are further investigated for their water absorption and immersion following the testing method by RILEM CPC 11.3. The impact of SCMs on concrete porosity is discussed. A linear correlation between porosity and rapid chloride penetration (RCP) ratings obtained as per ASTM C1202-19 on specimens of all investigated concrete mixes is proposed as a rapid approach to assess chloride penetration of concrete specimens containing SCMs.

scholarly journals Mechanosensation and Mechanotransduction by Lymphatic Endothelial Cells Act as Important Regulators of Lymphatic Development and Function

2021 ◽  
Vol 22 (8) ◽  
pp. 3955
Author(s):  
László Bálint ◽  
Zoltán Jakus
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Cell Fate ◽  
Molecular Mechanisms ◽  
Critical Role ◽  
Mechanical Forces ◽  
Lymphatic Endothelial Cells ◽  
Lymphatic Development ◽  
And Function ◽  
The Impact

Our understanding of the function and development of the lymphatic system is expanding rapidly due to the identification of specific molecular markers and the availability of novel genetic approaches. In connection, it has been demonstrated that mechanical forces contribute to the endothelial cell fate commitment and play a critical role in influencing lymphatic endothelial cell shape and alignment by promoting sprouting, development, maturation of the lymphatic network, and coordinating lymphatic valve morphogenesis and the stabilization of lymphatic valves. However, the mechanosignaling and mechanotransduction pathways involved in these processes are poorly understood. Here, we provide an overview of the impact of mechanical forces on lymphatics and summarize the current understanding of the molecular mechanisms involved in the mechanosensation and mechanotransduction by lymphatic endothelial cells. We also discuss how these mechanosensitive pathways affect endothelial cell fate and regulate lymphatic development and function. A better understanding of these mechanisms may provide a deeper insight into the pathophysiology of various diseases associated with impaired lymphatic function, such as lymphedema and may eventually lead to the discovery of novel therapeutic targets for these conditions.

scholarly journals The Impact of Mechanical Forces in Heart Morphogenesis

2012 ◽  
Vol 5 (1) ◽  
pp. 132-142 ◽  
Author(s):  
Javier T. Granados-Riveron ◽  
J. David Brook
Keyword(s):  
Mechanical Forces ◽  
Heart Morphogenesis ◽  
The Impact

scholarly journals Keloidal pathophysiology: Current notions

2021 ◽  
Vol 7 ◽  
pp. 205951312098032
Author(s):  
Chenyu Huang ◽  
Rei Ogawa
Keyword(s):  
Web Of Science ◽  
English Literature ◽  
The Body ◽  
Mechanical Forces ◽  
Healthy Skin ◽  
Level Of Evidence ◽  
Extracellular Matrix Components ◽  
Keloid Formation ◽  
Mechanical Factors ◽  
Pathological Scar

Introduction: Keloids are pathological scars that are notorious for their chronic and relentless invasion into adjacent healthy skin, with commonly seen post-therapeutic recurrence after monotherapies. Methods: An English literature review on keloid pathophysiology was performed by searching the PubMed, Embase and Web of Science databases, to find out the up-to-date relevant articles. The level of evidence was evaluated based on the included studies with the highest level of evidence first. Results: Keloid morphology, signs, symptoms and the histopathological changes that occur in the local cells and extracellular matrix components are described. The theories on the pathophysiology of keloidogenesis that have been proposed to date are also covered; these include endocrinological, nutritional, vascular, and autoimmunological factors. In addition, we describe the local mechanical forces (and the mechanosignalling pathways by which these forces shape keloid cell activities) that promote keloid formation and determine the direction of invasion of keloids and the body sites that are prone to them. Conclusion: A better understanding of this pathological entity, particularly its mechanobiology, will aid the development of new diagnostic and therapeutic strategies for use in the clinic to prevent, reduce or even reverse the growth of this pathological scar. Lay Summary Keloids are skin scars that are famous for their chronic invasion into healthy skin, with commonly seen recurrence after surgeries. Cells such as lymphocytes, macrophages, mast cells and endothelial cells are involved in keloid growth. Particularly, endocrinological, nutritional, vascular, autoimmunological and mechanical factors actively take part in keloid progression.

scholarly journals The Impact of Changing to an Algorithm-Based Clostridioides difficile Test on the Decision to Treat Clostridioides difficile

2020 ◽  
Vol 41 (S1) ◽  
pp. s407-s407
Author(s):  
Lana Dbeibo ◽  
Joy Williams ◽  
Josh Sadowski ◽  
William Fadel ◽  
Vera Winn ◽  
...  
Keyword(s):  
Critical Care ◽  
Toxic Megacolon ◽  
Adverse Outcomes ◽  
Clinical Criteria ◽  
Testing Method ◽  
Clostridioides Difficile ◽  
Critical Care Admission ◽  
The Impact ◽  
Test Result ◽  
Pcr Test

Background: Polymerase chain reaction (PCR) testing for the diagnosis of Clostridioides difficile infection (CDI) detects the presence of the organism; a positive result therefore cannot differentiate between colonization and the pathogenic presence of the bacterium. This may result in overdiagnosis, overtreatment, and risking disruption of microbial flora, which may perpetuate the CDI cycle. Algorithm-based testing offers an advantage over PCR testing as it detects toxin, which allows differentiation between colonization and infection. Although previous studies have demonstrated the clinical utility of this testing algorithm in differentiating infection from colonization, it is unknown whether the test changes CDI treatment decisions. Our facility switched from PCR to an algorithm-based testing method for CDI in June 2018. Objective: In this study, we evaluated whether clinicians’ decisions to treat patients are impacted by a test result that implies colonization (GDH+/Tox−/PCR+ test), and we examined the impact of this decision on patient outcomes. Methods: This is a retrospective cohort study of inpatients with a positive C. diff test between June 2017 and June 2019. The primary outcome was the proportion of patients treated for CDI. We compared this outcome in 3 groups of patients: those with a positive PCR test (June 2017–June 2018), those who had a GDH+/Tox−/PCR+ or a GDH+/Tox+ test result (June 2018–June 2019). Secondary outcomes included toxic megacolon, critical care admission, and mortality in patients with GDH+/Tox−/PCR+ who were treated versus those who were untreated. Results: Of patients with a positive PCR test, 86% were treated with CDI-specific antibiotics, whereas 70.4% with GDH+/Tox+ and 29.25% with GDH+/Tox−/PCR+ result were treated (P < .0001). Mortality was not different between patients with GDH+/Tox−/PCR+ who were treated versus those who were untreated (2.7% vs 3.4%; P = .12), neither was critical care admission within 2 or 7 days of test result (2% vs 1.4%; P = .15) and (4.1% vs 5.4%, P = .39), respectively. There were no cases of toxic megacolon during the study period. Conclusions: The change to an algorithm-based C. difficile testing method had a significant impact on the clinicians’ decisions to treat patients with a positive test, as most patients with a GDH+/Tox−/PCR+ result did not receive treatment. These patients did not suffer more adverse outcomes compared to those who were treated, which has implications for testing practices. It remains to be explored whether clinicians are using clinical criteria to decide whether or not to treat patients with a positive algorithm-based test, as opposed to the more reflexive treatment of patients with a positive PCR test.Funding: NoneDisclosures: None

An Investigation of the Vibration Testing Method for Small Diameter Endmills

2014 ◽  
Vol 625 ◽  
pp. 134-139
Author(s):  
Takenori Ono
Keyword(s):  
Small Diameter ◽  
Milling Process ◽  
Modal Parameters ◽  
Vibration Testing ◽  
Function Generator ◽  
Testing Method ◽  
Milling Tool ◽  
Compliance Curve ◽  
Vibration Tests ◽  
The Impact

This paper introduced about the in-process vibration testing method for small diameter endmill. By this method, the natural frequency and modal parameters such as mass, damping, and stiffness of the milling tool can be determined in the milling process. An oscillation of the vibrator is controlled by the function generator to apply the impact force at the appropriate cutting period. The measurement setup can determine the compliance curve by the measurement signals of the exiting force and tool deformation. To evaluate the feasibility of the new method, vibration tests were performed on a square endmill which has the diameter of 4 mm in the milling on brass material. Results of vibration tests show that modal parameters of the specific vibration mode can be determined by the new developed method.

scholarly journals A Decision-Making Model on the Impact of Vehicle Use on Urban Safety

2021 ◽  
Vol 13 (6) ◽  
pp. 3585
Author(s):  
Dariusz Masłowski ◽  
Małgorzata Dendera-Gruszka ◽  
Ewa Kulińska
Keyword(s):  
Decision Making ◽  
Internal Combustion Engines ◽  
Urban Traffic ◽  
Brake Pads ◽  
Wear And Tear ◽  
Urban Safety ◽  
Negative Impacts ◽  
Urban Conditions ◽  
Decision Making Model ◽  
The Impact

In the current era of urban development, people are already using electric vehicles more and more often for transport purposes, which reduces negative impacts on the environment. However, there are still vehicles in towns and cities that run on ordinary internal combustion engines. Performing optimization measures on the operation of these vehicles improves their performance, which can result in positive sustainable development effects. This article presents measures to reduce the wear and tear of urban vehicles and outlines a decision model to determine which of the vehicle parts described suffer the most frequent wear and tear under urban conditions. The article presents a list of structural elements that are most affected by urban traffic, as well as corrective actions to improve such specialized vehicles. Based on the decision analysis, Rule 1 was eliminated as having the least significant impact on vehicle wear and tear, and the least significant impact on urban safety. On the other hand, the most worn-out elements were found to be gearboxes, clutches, bus levelling electronics, and brake pads and discs. The decision-making model made it possible to identify the factors which have the greatest impact on reducing safety in urban spaces.

scholarly journals Male and Female Partner-Caregivers’ Burden: Does It Get Worse Over Time?

2018 ◽  
Vol 59 (6) ◽  
pp. 1103-1111 ◽  
Author(s):  
Joukje C Swinkels ◽  
Marjolein I Broese van Groenou ◽  
Alice de Boer ◽  
Theo G van Tilburg
Keyword(s):  
Caregiver Burden ◽  
Process Model ◽  
Female Partner ◽  
General View ◽  
Data Set ◽  
Change Over Time ◽  
Men And Women ◽  
Wear And Tear ◽  
The Impact ◽  
Over Time

Abstract Background and Objectives The general view is that partner-caregiver burden increases over time but findings are inconsistent. Moreover, the pathways underlying caregiver burden may differ between men and women. This study examines to what degree and why partner-caregiver burden changes over time. It adopts Pearlin’s Caregiver Stress Process Model, as it is expected that higher primary and secondary stressors will increase burden and larger amounts of resources will lower burden. Yet, the impact of stressors and resources may change over time. The wear-and-tear model predicts an increase of burden due to a stronger impact of stressors and lower impact of resources over time. Alternatively, the adaptation model predicts a decrease of burden due to a lower impact of stressors and higher impact of resources over time. Research Design and Methods We used 2 observations with a 1-year interval of 279 male and 443 female partner-caregivers, derived from the Netherlands Older Persons and Informal Caregivers Survey Minimum Data Set. We applied multilevel regression analysis, stratified by gender. Results Adjusted for all predictors, caregiver burden increased over time for both men and women. For female caregivers, the impact of poor spousal health on burden increased and the impact of fulfillment decreased over time. Among male caregivers, the impact of predictors did not change over time. Discussion and Implications The increase of burden over time supports the wear-and-tear model, in particular for women. This study highlights the need for gender-specific interventions that are focused on enabling older partners to be better prepared for long-term partner-care.

Forced Response Sensitivity of a Mistuned Rotor From an Embedded Compressor Stage

2015 ◽  
Author(s):  
Fanny M. Besem ◽  
Robert E. Kielb ◽  
Nicole L. Key
Keyword(s):  
Experimental Data ◽  
Forced Response ◽  
Symmetric System ◽  
Response Analysis ◽  
Cfd Simulations ◽  
Forcing Function ◽  
Wear And Tear ◽  
The Individual ◽  
The Impact ◽  
Interblade Phase Angle

The frequency mistuning that occurs due to manufacturing variations and wear and tear of the blades can have a significant effect on the flutter and forced response behavior of a blade row. Similarly, asymmetries in the aerodynamic or excitation forces can tremendously affect the blade responses. When conducting CFD simulations, all blades are assumed to be tuned (i.e. to have the same natural frequency) and the aerodynamic forces are assumed to be the same on each blade except for a shift in interblade phase angle. The blades are thus predicted to vibrate at the same amplitude. However, when the system is mistuned or when asymmetries are present, some blades can vibrate with a much higher amplitude than the tuned, symmetric system. In this research, we first conduct a deterministic forced response analysis of a mistuned rotor and compare the results to experimental data from a compressor rig. It is shown that tuned CFD results cannot be compared directly with experimental data because of the impact of frequency mistuning on forced response predictions. Moreover, the individual impact of frequency, aerodynamic, and forcing function perturbations on the predictions is assessed, leading to the conclusion that a mistuned system has to be studied probabilistically. Finally, all perturbations are combined and Monte-Carlo simulations are conducted to obtain the range of blade response amplitudes that a designer could expect.

scholarly journals A Short Note about the Impact Action of a Water Jet Stabilized by a Coaxial Air Stream in the Air and Underwater

Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 5015
Author(s):  
Josef Poláček ◽  
Irena Marie Hlaváčová ◽  
Martin Tyč
Keyword(s):  
Near Field ◽  
Pure Water ◽  
Air Flow ◽  
Relevant Literature ◽  
Short Note ◽  
Original Method ◽  
Water Jet ◽  
Impact Action ◽  
Dual Action ◽  
The Impact

A new original method, applying a coaxial protective airflow, was tested aiming to improve the pure water jet efficiency in surface layer removal or medium hard materials cutting or blasting. The dual action of the air flow is expected: the air co-flowing the water jet with approximately the same velocity should prevent the central jet from breaking up into tiny droplets in the near field, and simultaneously, it should support jet decomposition into big parts with enough destructive potential in the far-field. A brief survey of the relevant literature dealing with the water jet instability is presented, introducing four recognized breakup regimes. An original cutting head designed to generate a waterjet surrounded by protective coaxial air flow is introduced. The submitted device is supposed to operate within the first wind-induced regime. Two types of experiments, consisting of blasting limestone bricks placed either in the air or underwater, were realized. The depths of kerfs produced with different water pressures and air overpressures were evaluated. While no substantial positive effect was recognized in the air performance, the submerged blasting of the same material under similar conditions appeared to be promising.

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