Analysis of Fatigue Process of Rubber Vulcanizates

1978 ◽  
Vol 51 (2) ◽  
pp. 201-214 ◽  
Author(s):  
H. Hirakawa ◽  
F. Urano ◽  
M. Kida
Keyword(s):  
Energy Loss ◽  
Energy Input ◽  
Network Chain ◽  
Fatigue Process ◽  
Filled Rubber ◽  
Linear Relationships ◽  
Wide Range ◽  
Hysteresis Energy Loss ◽  
Number Of Cycles ◽  
The Relationship

Abstract The relationship between energy-input and hysteresis energy-loss during repeated deformation was analyzed, with gum and filled-rubber vuloanizates. It was recognized that the hysteresis energy-loss decreases more quickly with repeated deformation than the energy-input does. After a number of cycles both the energy-input and the energy-loss approach constant values. When these values are plotted against strain, curves similar in shape are obtained, regardless of the type of rubber. This is because the network chain is well relaxed. A group of the linear relationships between log W and log H was found with respect to N and λ. Examining the parameters, g1, g2, f1 and f2 as functions of N and λ, simple expressions, (4) and (5), were obtained for both the first deformation and after many cycles. At the latter state the hysteresis ratio tends to be constant in the wide range of λ. Finally, the relation between W and H at fatigue break is expressed with the same form of equation proposed by Grosch for the tensile break at the first extension.

scholarly journals Evolution of inspiratory and expiratory muscle pressures during endurance exercise

2000 ◽  
Vol 88 (1) ◽  
pp. 234-245 ◽  
Author(s):  
Bharath S. Krishnan ◽  
Trevor Zintel ◽  
Colm McParland ◽  
Charles G. Gallagher
Keyword(s):  
Respiratory Muscle ◽  
Minute Ventilation ◽  
Normal Subjects ◽  
Progressive Increase ◽  
Cycle Ergometer ◽  
Linear Increase ◽  
Inspiratory Muscles ◽  
Linear Relationships ◽  
Wide Range ◽  
The Relationship

We investigated the relationship between minute ventilation (V˙e) and net respiratory muscle pressure (Pmus) throughout the breathing cycle [Total Pmus = mean Pmus, i (inspiratory) + mean Pmus, e(expiratory)] in six normal subjects performing constant-work heavy exercise (CWHE, at ∼80% maximum) to exhaustion on a cycle ergometer. Pmus was calculated as the sum of chest wall pressure (elastic + resistive) and pleural pressure, and all mean Pmus variables were averaged over the total breath duration. Pmus, i was also expressed as a fraction of volume-matched, flow-corrected dynamic capacity of the inspiratory muscles ([Formula: see text]).V˙e increased significantly from 3 min to the end of CWHE and was the result of a significantly linear increase in Total Pmus (Δ = 43 ± 9% from 3 min to end exercise, P < 0.005) in all subjects ( r = 0.81–0.99). Although mean Pmus, i during inspiratory flow increased significantly (Δ = 35 ± 10%), postinspiratory Pmus, i fell (Δ = −54 ± 10%) and postexpiratory expiratory activity was negligible or absent throughout CWHE. There was a greater increase in mean Pmus, e (Δ = 168 ± 48%), which served to increaseV˙e throughout CWHE. In five of six subjects, there were significant linear relationships betweenV˙eand mean Pmus, i( r = 0.50–0.97) and mean Pmus, e( r = 0.82–0.93) during CWHE. The subjects generated a wide range of Pmus, i/[Formula: see text]values (25–80%), and mean Pmus, i/[Formula: see text]increased significantly (Δ = 42 ± 16%) and in a linear fashion ( r = 0.69–0.99) withV˙ethroughout CWHE. The progressive increase inV˙e during CWHE is due to 1) a linear increase in Total Pmus, 2) a linear increase in inspiratory muscle load, and 3) a progressive fall in postinspiratory inspiratory activity. We conclude that the relationship between respiratory muscle pressure andV˙e during exercise is linear and not curvilinear.

The Problem of Identifying and Modeling the Relationship between Monetary Factor and Inflation in the Russian Economy

2008 ◽  
pp. 61-76
Author(s):  
A. Porshakov ◽  
A. Ponomarenko
Keyword(s):  
Money Supply ◽  
Money Demand ◽  
Russian Economy ◽  
Long Run ◽  
Complex Approach ◽  
Wide Range ◽  
Long Time ◽  
The Relationship ◽  
Supply Side Factors

The role of monetary factor in generating inflationary processes in Russia has stimulated various debates in social and scientific circles for a relatively long time. The authors show that identification of the specificity of relationship between money and inflation requires a complex approach based on statistical modeling and involving a wide range of indicators relevant for the price changes in the economy. As a result a model of inflation for Russia implying the decomposition of inflation dynamics into demand-side and supply-side factors is suggested. The main conclusion drawn is that during the recent years the volume of inflationary pressures in the Russian economy has been determined by the deviation of money supply from money demand, rather than by money supply alone. At the same time, monetary factor has a long-run spread over time impact on inflation.

scholarly journals Lack of an association between gallstone disease and bilirubin levels with risk of colorectal cancer: a Mendelian randomisation analysis

2021 ◽  
Author(s):  
Richard Culliford ◽  
Alex J. Cornish ◽  
Philip J. Law ◽  
Susan M. Farrington ◽  
Kimmo Palin ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Large Scale ◽  
Causal Effect ◽  
Gallstone Disease ◽  
Epidemiological Studies ◽  
Mendelian Randomisation ◽  
Linear Relationships ◽  
Potential Risk Factors ◽  
The Relationship ◽  
Circulating Levels

Abstract Background Epidemiological studies of the relationship between gallstone disease and circulating levels of bilirubin with risk of developing colorectal cancer (CRC) have been inconsistent. To address possible confounding and reverse causation, we examine the relationship between these potential risk factors and CRC using Mendelian randomisation (MR). Methods We used two-sample MR to examine the relationship between genetic liability to gallstone disease and circulating levels of bilirubin with CRC in 26,397 patients and 41,481 controls. We calculated the odds ratio per genetically predicted SD unit increase in log bilirubin levels (ORSD) for CRC and tested for a non-zero causal effect of gallstones on CRC. Sensitivity analysis was applied to identify violations of estimator assumptions. Results No association between either gallstone disease (P value = 0.60) or circulating levels of bilirubin (ORSD = 1.00, 95% confidence interval (CI) = 0.96–1.03, P value = 0.90) with CRC was shown. Conclusions Despite the large scale of this study, we found no evidence for a causal relationship between either circulating levels of bilirubin or gallstone disease with risk of developing CRC. While the magnitude of effect suggested by some observational studies can confidently be excluded, we cannot exclude the possibility of smaller effect sizes and non-linear relationships.

scholarly journals Investigation of Deformation Inhomogeneity and Low-Cycle Fatigue of a Polycrystalline Material

2021 ◽  
Vol 11 (6) ◽  
pp. 2673
Author(s):  
Mu-Hang Zhang ◽  
Xiao-Hong Shen ◽  
Lei He ◽  
Ke-Shi Zhang
Keyword(s):  
Cyclic Loading ◽  
Low Cycle Fatigue ◽  
Strain Tensor ◽  
Equivalent Strain ◽  
Differential Entropy ◽  
Strain Components ◽  
Deformation Inhomogeneity ◽  
Standard Deviations ◽  
Number Of Cycles ◽  
The Relationship

Considering the relationship between inhomogeneous plastic deformation and fatigue damage, deformation inhomogeneity evolution and fatigue failure of superalloy GH4169 under temperature 500 °C and macro tension compression cyclic loading are studied, by using crystal plasticity calculation associated with polycrystalline representative Voronoi volume element (RVE). Different statistical standard deviation and differential entropy of meso strain are used to measure the inhomogeneity of deformation, and the relationship between the inhomogeneity and strain cycle is explored by cyclic numerical simulation. It is found from the research that the standard deviations of each component of the strain tensor at the cyclic peak increase monotonically with the cyclic loading, and they are similar to each other. The differential entropy of each component of the strain tensor also increases with the number of cycles, and the law is similar. On this basis, the critical values determined by statistical standard deviations of the strain components and the equivalent strain, and that by differential entropy of strain components, are, respectively, used as fatigue criteria, then predict the fatigue–life curves of the material. The predictions are verified with reference to the measured results, and their deviations are proved to be in a reasonable range.

scholarly journals Polymorphic Iterable Sequential Effect Systems

2021 ◽  
Vol 43 (1) ◽  
pp. 1-79
Author(s):  
Colin S. Gordon
Keyword(s):  
Algebraic Structure ◽  
Position Effect ◽  
Type Systems ◽  
Sequential Effect ◽  
Prior Work ◽  
Sequential Effects ◽  
Wide Range ◽  
The Relationship ◽  
Categorical Semantics

Effect systems are lightweight extensions to type systems that can verify a wide range of important properties with modest developer burden. But our general understanding of effect systems is limited primarily to systems where the order of effects is irrelevant. Understanding such systems in terms of a semilattice of effects grounds understanding of the essential issues and provides guidance when designing new effect systems. By contrast, sequential effect systems—where the order of effects is important—lack an established algebraic structure on effects. We present an abstract polymorphic effect system parameterized by an effect quantale—an algebraic structure with well-defined properties that can model the effects of a range of existing sequential effect systems. We define effect quantales, derive useful properties, and show how they cleanly model a variety of known sequential effect systems. We show that for most effect quantales, there is an induced notion of iterating a sequential effect; that for systems we consider the derived iteration agrees with the manually designed iteration operators in prior work; and that this induced notion of iteration is as precise as possible when defined. We also position effect quantales with respect to work on categorical semantics for sequential effect systems, clarifying the distinctions between these systems and our own in the course of giving a thorough survey of these frameworks. Our derived iteration construct should generalize to these semantic structures, addressing limitations of that work. Finally, we consider the relationship between sequential effects and Kleene Algebras, where the latter may be used as instances of the former.

Age-Dependency of Total Tau in the Cerebrospinal Fluid Is Corrected by Amyloid-β 1–40: A Correlational Study in Healthy Adults

2021 ◽  
pp. 1-8
Author(s):  
Paul Theo Zebhauser ◽  
Achim Berthele ◽  
Marie-Sophie Franz ◽  
Oliver Goldhardt ◽  
Janine Diehl-Schmid ◽  
...  
Keyword(s):  
Cerebrospinal Fluid ◽  
Amyloid Β ◽  
Healthy Adults ◽  
Tau Proteins ◽  
Clinical Settings ◽  
Inclusion Criteria ◽  
Total Tau ◽  
Potential Marker ◽  
Wide Range ◽  
The Relationship

Background: Tau proteins are established biomarkers of neuroaxonal damage in a wide range of neurodegenerative conditions. Although measurement of total-Tau in the cerebrospinal fluid is widely used in research and clinical settings, the relationship between age and total-Tau in the cerebrospinal fluid is yet to be fully understood. While past studies reported a correlation between age and total-Tau in the cerebrospinal fluid of healthy adults, in clinical practice the same cut-off value is used independently of patient’s age. Objective: To further explore the relationship between age and total-Tau and to disentangle neurodegenerative from drainage-dependent effects. Methods: We analyzed cerebrospinal fluid samples of 76 carefully selected cognitively healthy adults and included amyloid-β 1–40 as a potential marker of drainage from the brain’s interstitial system. Results: We found a significant correlation of total-Tau and age, which was no longer present when correcting total-Tau for amyloid-β 1–40 concentrations. These findings were replicated under varied inclusion criteria. Conclusion: Results call into question the association of age and total-Tau in the cerebrospinal fluid. Furthermore, they suggest diagnostic utility of amyloid-β 1–40 as a possible proxy for drainage-mechanisms into the cerebrospinal fluid when interpreting biomarker concentrations for neurodegenerative diseases.

scholarly journals Modelling the elastic mechanical properties of bioactive glass-derived scaffolds

2020 ◽  
Vol 6 (1) ◽  
pp. 50-56
Author(s):  
Francesco Baino ◽  
Elisa Fiume
Keyword(s):  
Elastic Properties ◽  
Poisson’S Ratio ◽  
Mechanical Performance ◽  
Solid Material ◽  
Poisson's Ratio ◽  
Predictive Capability ◽  
Shear Moduli ◽  
Wide Range ◽  
Constitutive Parameters ◽  
The Relationship

AbstractPorosity is known to play a pivotal role in dictating the functional properties of biomedical scaffolds, with special reference to mechanical performance. While compressive strength is relatively easy to be experimentally assessed even for brittle ceramic and glass foams, elastic properties are much more difficult to be reliably estimated. Therefore, describing and, hence, predicting the relationship between porosity and elastic properties based only on the constitutive parameters of the solid material is still a challenge. In this work, we quantitatively compare the predictive capability of a set of different models in describing, over a wide range of porosity, the elastic modulus (7 models), shear modulus (3 models) and Poisson’s ratio (7 models) of bioactive silicate glass-derived scaffolds produced by foam replication. For these types of biomedical materials, the porosity dependence of elastic and shear moduli follows a second-order power-law approximation, whereas the relationship between porosity and Poisson’s ratio is well fitted by a linear equation.

A Progressive View on Religion and Modern Art

2015 ◽  
Vol 19 (5) ◽  
pp. 488-530
Author(s):  
Cynthia Fowler
Keyword(s):  
Cultural Identity ◽  
Modern Art ◽  
Religious Art ◽  
Wide Range ◽  
Museum Professionals ◽  
The Relationship

This article examines the Religious Art of Today exhibition, originally held in 1944 at Boston’s Institute of Modern Art and then reformulated for the Dayton Art Institute in Ohio. The exhibition was eclectic in that it included a wide range of artists and a diversity of faiths, and engaged the debate held among museum professionals about the relationship between religion and modern art. The article focuses closely on Catholic, Jewish, and Navajo art included in the exhibition. The IMA’s commitment to the figurative tradition afforded artists the opportunity to explore their identities—as Jews, as Catholics, as Navajos—using recognizable religious subjects. That the works in the exhibition were selected as representative of modern art resulted in a convergence of discourses related to modern art with those of religious/cultural identity.

scholarly journals New Insights into Molecular Mechanism behind Anti-Cancer Activities of Lycopene

Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 3888
Author(s):  
Boon-Peng Puah ◽  
Juriyati Jalil ◽  
Ali Attiq ◽  
Yusof Kamisah
Keyword(s):  
Immune Cells ◽  
Scientific Evidence ◽  
Special Role ◽  
Real Potential ◽  
Wide Range ◽  
Anti Cancer ◽  
The Family ◽  
The Relationship ◽  
Cancer Activity ◽  
Reduced Risk

Lycopene is a well-known compound found commonly in tomatoes which brings wide range of health benefits against cardiovascular diseases and cancers. From an anti-cancer perspective, lycopene is often associated with reduced risk of prostate cancer and people often look for it as a dietary supplement which may help to prevent cancer. Previous scientific evidence exhibited that the anti-cancer activity of lycopene relies on its ability to suppress oncogene expressions and induce proapoptotic pathways. To further explore the real potential of lycopene in cancer prevention, this review discusses the new insights and perspectives on the anti-cancer activities of lycopene which could help to drive new direction for research. The relationship between inflammation and cancer is being highlighted, whereby lycopene suppresses cancer via resolution of inflammation are also discussed herein. The immune system was found to be a part of the anti-cancer system of lycopene as it modulates immune cells to suppress tumor growth and progression. Lycopene, which is under the family of carotenoids, was found to play special role in suppressing lung cancer.

scholarly journals Differential Influence of Age on the Relationship between Genetic Mismatch and A(H1N1)pdm09 Vaccine Effectiveness

Viruses ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 619
Author(s):  
Lirong Cao ◽  
Shi Zhao ◽  
Jingzhi Lou ◽  
Hong Zheng ◽  
Renee W. Y. Chan ◽  
...  
Keyword(s):  
Age Groups ◽  
The Elderly ◽  
Vaccine Effectiveness ◽  
Amino Acid Mutation ◽  
Epidemic Season ◽  
Vaccine Component ◽  
Linear Relationships ◽  
The Difference ◽  
Middle Aged Adults ◽  
The Relationship

Assessment of influenza vaccine effectiveness (VE) and identification of relevant influencing factors are the current priorities for optimizing vaccines to reduce the impacts of influenza. To date, how the difference between epidemic strains and vaccine strains at genetic scale affects age-specific vaccine performance remains ambiguous. This study investigated the association between genetic mismatch on hemagglutinin and neuraminidase genes and A(H1N1)pdm09 VE in different age groups with a novel computational approach. We found significant linear relationships between VE and genetic mismatch in children, young adults, and middle-aged adults. In the children’s group, each 3-key amino acid mutation was associated with an average of 10% decrease in vaccine effectiveness in a given epidemic season, and genetic mismatch exerted no influence on VE for the elderly group. We demonstrated that present vaccines were most effective for children, while protection for the elderly was reduced and indifferent to vaccine component updates. Modeling such relationships is practical to inform timely evaluation of VE in different groups of populations during mass vaccination and may inform age-specific vaccination regimens.

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