Fatigue Phenomena Research Articles

The Relationship Between Highly Sensitive People and Compassion Fatigue and Intervention Methods

In a state of compassion fatigue, peoples work performance and social status are easily affected, and in severe cases, they may even cause some influence and harm to others. Therefore, it is important to study the factors that tend to affect empathy fatigue, the people who are prone to empathy fatigue and how to alleviate empathy fatigue, so as to reduce the occurrence of empathy fatigue. In this paper, the relationship between hypersensitive people and empathy fatigue and how to intervene and alleviate this fatigue phenomenon is studied through theoretical analysis and questionnaire survey. The analysis of the data from the questionnaire revealed that the more oversensitive people are, the more likely they are to develop the phenomenon of empathy fatigue, as well as the explanation that self-care and self-compassion can effectively intervene and alleviate empathy fatigue. This study has some limitations, which are explained at the end of this paper.

Achieving ultrahigh fretting fatigue endurance in TB8 titanium alloy with hierarchical structure via triggering nanocomposite and phase transformation

Extraordinary fretting fatigue endurance is critical for engineering structures prone to contact with expected long service lifetimes. Here, we propose a strategy to achieve ultrahigh fretting fatigue endurance in titanium alloy. A special hierarchical structure, i.e. gradient amorphous-nanocrystalline grain/coarse grain, was designed in a TB8 titanium alloy via surface severe plastic deformation, which forms an nanocomposite structure comprising of amorphous-nanocrystalline and nano-lamellae and β to α phase transformation upon repeated fretting wear. The nanocomposite surface and phase transformation suppress cracks initiation and propagation, resulting in the high fretting fatigue life that was 30.2-times higher than that of the original TB8 titanium alloy via triggering an exceptional fretting fatigue phenomenon where damage-crack initiate towards the interior of non-fretting contact zone. This study provides a new insight into improving the fretting fatigue endurance of titanium alloys.

Chronic fatigue syndrome – challenge in diagnosis and management: a literature review

Introduction. Chronic fatigue syndrome is a disease that includes a number of various symptoms, among which the most characteristic symptom is fatigue. Diagnostic criteria are not unambiguous and vary depending on the scientific society by which they were developed. The aim of this review is to discuss the phenomenon of chronic fatigue, including its diagnostic criteria, epidemiology, pathophysiology, symptoms, and pharmacological and non-pharmacological strategies. Material and methods. 45 articles published were reviewed and placed in the PubMed and Google Scholar databases. Results. Chronic fatigue syndrome is defined as a group of symptoms whose dominant symptom is fatigue that persists after rest for at least 6 months. The Oxford or CDC criteria are most commonly used to make the diagnosis. Statistics on prevalence are inconclusive. There are several theories of origin - infectious, immunological, neuroendocrine, bioenergetic, neurological, autonomic and genetic. Other symptoms of chronic fatigue syndrome include sleep and memory disorders or muscle and joint pain. Current treatment focuses on symptomatic treatment, including education, diet, and physical activity, as well as pharmacotherapy for pain, sleep, and cognition. Discussion. Diagnosis and treatment of chronic fatigue syndrome undoubtedly is a medical challenge, due to non-specific symptoms, multifactorial pathogenesis and difficult to estimate prevalence of this disease. Future scientific development should focus especially on exploring the pathomechanism of CFS, which would enable the implementation of causal treatment.

Research on the segmentation method of a highway landscape corridor zone

Highway landscaping is an important part of highway construction, which plays a role in highway engineering to ensure traffic safety, alleviate visual fatigue, manifest culture, and many other roles. In the actual highway landscape design, the concept of highway landscape planning and design remains unclear, the content is complex, and the design lags behind the main construction of the problem. Different landscape themes should be set for different sections of the road to enable the motorway landscape to play its role, and the reasonable division of the highway landscape paragraph nodes and the determination of different landscape themes are the keys to the problem. This study collects natural and humanistic materials along the highway, arranges and classifies them through the cluster analysis method, and then divides the highway landscape into paragraphs through the fusion of cluster analysis and node control method. Then, the landscape resources in the paragraphs are integrated and refined to define the theme of the paragraphs, the landscape of the paragraphs based on the theme of the paragraphs is generated to bring out the regional cultural connotation, and a highway paragraph landscape theme division process is constructed. Finally, based on the survey of the landscape status quo of the Zhunxing Highway, the landscape theme division method is applied to verify its scientificity. The research results show that the highway paragraph landscape division method based on the cluster analysis method can effectively reflect the landscape characteristics of different road sections, enrich the road landscape design content, reflect the regional cultural characteristics, reduce the phenomenon of driver fatigue due to the landscape content of a single driving, and protect the traffic safety of the highway. This method can effectively guide the highway landscape paragraph planning and node design, has simple operation, and has strong practicality.

Prediction of Remaining Life of Turbo Pump Inducer for Spacecraft Using Cumulative Damage Model

In the near future, to operate reusable spacecraft safely and efficiently, it is necessary to have failure prediction technology for reusable rocket engines. Among the components that constitute a rocket engine, the failure of the turbo pump inducer has a significant impact on missions. Therefore, we have been researching to monitor the remaining life of the inducer. This method estimates the fluctuating stress field excited in the inducer section based on the time-series signals from pressure sensors installed upstream. It predicts the remaining life using a Rain flow model to account for high- cycle fatigue (HCF) phenomena. To validate the effectiveness of the proposed method, we attempted to acquire experimental data, particularly for the challenging pressure-stress transfer section where concrete specifications are difficult to define. Through experiments using an elemental model, we demonstrated that a certain degree of remaining life can be predicted based on measurement from the upstream sensor. This indicates that the proposed method is a promising option for solving the remaining life prediction problem of reusable spacecraft.

Effect of physical activity on long COVID fatigue: an unsolved enigma.

Covid-19 disease is well documented and often the most common symptoms include myalgia and muscle fatigue. Approximately 10% of those infected complain of persistent fatigue even many months after the end of the acute phase of the disease. This gives rise to a condition different from the previous one and commonly known as 'post-acute COVID-19 syndrome' or simply Long-COVID. Although the origin of muscle fatigue is multifactorial, the state of prolonged fatigue observed in the Long-COVID syndrome suggests the existence of a possible state of atrophy or rather acute sarcopenia. Under these conditions, the use of physical activity programs can effectively counteract the state of atrophy underlying the fatigue phenomena observed. If this is also the situation during the Long-COVID, the muscular symptom should be positively influenced by the administration of programmed physical activity cycles. In fact, in patients with Long-COVID, the few published papers seem to indicate that patients who are physically active and who make an effort to engage in physical activity even during the illness have decreased duration and intensity of the illness. However, analysis of the studies in the literature also suggests that a small percentage of people with Long-COVID do not appear to benefit from the application of physical activity programs, so further studies on homogeneous samples are needed to provide a firm answer to the question: can planned physical activity help patients during the pathological course of Long-COVID?

Ratcheting–Fatigue Damage Assessment of Additively Manufactured SS304L and AlSi10Mg Samples under Asymmetric Stress Cycles

The present study aims to investigate the interaction of ratcheting and fatigue phenomena for additively manufactured (AM) samples of SS304L and AlSi10Mg undergoing uniaxial asymmetric stress cycles. Overall damage was accumulated through fatigue and ratcheting on AM samples prepared from three-dimensional-printed plates along vertical and horizontal directions. Fatigue damage was evaluated based on the strain energy density fatigue approach and ratcheting damage was calculated through use of an isotropic–kinematic hardening framework. The isotropic description through the Lee–Zavrel (L–Z) model formed the initial and concentric expansion of yield surfaces while the Ahmadzadeh–Varvani (A–V) kinematic hardening rule translated yield surfaces into the deviatoric stress space. Ratcheting of AM samples was simulated using finite element analysis through use of triangular and quadrilateral elements. Ratcheting values of the AM samples were simulated on the basis of Chaboche’s materials model. The predicted and simulated ratcheting damage curves placed above the experimental fatigue–ratcheting experimental data while predicted fatigue damage curves collapsed below the measured values. The overall damage was formulated to partition damage weights due to fatigue and ratcheting phenomena.

Achieving ultrahigh fatigue resistance in AlSi10Mg alloy by additive manufacturing.

Since the first discovery of the fatigue phenomenon in the late 1830s, efforts to fight against fatigue failure have continued. Here we report a fatigue resistance phenomenon in nano-TiB2-decorated AlSi10Mg enabled by additive manufacturing. This fatigue resistance mechanism benefits from the three-dimensional dual-phase cellular nanostructure, which acts as a strong volumetric nanocage to prevent localized damage accumulation, thus inhibiting fatigue crack initiation. The intrinsic fatigue strength limit of nano-TiB2-decorated AlSi10Mg was proven to be close to its tensile strength through the in situ fatigue tests of a defect-free microsample. To demonstrate the practical applicability of this mechanism, printed bulk nano-TiB2-decorated AlSi10Mg achieved fatigue resistance more than double those of other additive manufacturing Al alloys and surpassed those of high-strength wrought Al alloys. This strategy of additive-manufacturing-assisted nanostructure engineering can be extended to the development of other dual-phase fatigue-resistant metals.

Meso to macro connections to capture fatigue damage in cemented materials

Fatigue-induced damage is a common issue in cemented materials, involving the progressive formation and complicated propagation of fatigue cracks. These cracks typically localise on weak or fracture planes, leading to inhomogeneous deformation within the material. Thus, accurately predicting the fatigue phenomenon becomes challenging due to the material’s inhomogeneity and the complex evolution of cracks, from initiation to propagation and eventual failure. To address this challenge, this paper presents a constitutive model that accounts for strain discontinuity across fracture planes by employing kinematic enrichment. This enhancement facilitates interaction between the material responses of cracks and the outer bulk, thereby contributing to the overall macro behaviour of the materials. Moreover, the proposed model incorporates a new cohesive-frictional fatigue model that couples damage mechanics and bounding surface plasticity to describe the fatigue behaviour of fracture planes/cracks. Since the proposed model features a characteristic length scale, it exhibits size-dependent behaviour and helps overcome the issue of mesh dependence. The model's validity is demonstrated through its ability to capture nonlinear fatigue damage under constant/variable cyclic loading and to simulate the propagation of fatigue fracture process zones. Furthermore, the model effectively captures the significant influence of stress amplitudes on the fatigue lives of materials, making it an essential tool for predicting and mitigating fatigue-induced damage in cemented materials.

A brief note on entire fracture surface topography parameters for 18Ni300 maraging steel produced by LB-PBF after LCF

The concept of entire fracture surface investigation is helpful in explaining fatigue phenomena. In this paper, this method has been applied for 18Ni300 maraging steel using a 3D measurement system. Before post-mortem analysis, the specimens produced by laser beam powder bed fusion (LB-PBF) were tested under low-cycle fatigue (LCF) for eight strain amplitudes in the interval 0.3% to 1.0%. The attention was placed on the relationship between the fatigue features, represented by the strain level and the fatigue life as well as the fracture surface topography evaluated in the form of areal, volume and fractal dimension parameters. It was found that fatigue life predictions calculated using the core material volume Vmc, obtained with the entire fracture surface method were within a scatter band with factors of ±1.5. The present results can be useful for the analysis of damaged structural elements exposed to LCF, especially for materials produced by additive manufacturing (AM). The outcomes of this brief note are important for the development of other fractographic methods and validation of fatigue life evaluation procedures.

Citizenship fatigue and employee commitment: moderating role of psychological ownership among artisans of family-owned construction firms

The study investigates an association between citizenship fatigue, psychological ownership, and employee commitment among artisans of family construction firms. A purposive and convenience sampling techniques were used to select 121 family-owned construction companies and 295 respondents, respectively, in Ghana. Data was collected using either self-reported or interviewer-administered questionnaires and analyzed using a partial least squares structural equation model. Citizenship fatigue negatively influences employees’ commitment. Additionally, employee commitment was positively predicted by psychological ownership. Finally, psychological ownership moderates the link between citizenship fatigue and employee commitment. The effects of moderation of psychological ownership on employee commitment were found to be higher for lower citizenship fatigue and lower in the face of higher citizenship fatigue. This study represents a pioneering investigation into the role of psychological ownership as a boundary condition in the relationship between citizenship fatigue and employee commitment among artisans employed by family-owned construction firms. The findings suggest employees act as stewards when they possess a sense of ownership feeling towards the firm. Consequently, management of family construction firms must work to enhance employees’ ownership feelings to mitigate the effect of the phenomenon of citizenship fatigue on their levels of commitment in the work environment.

Влияние усовершенствованных технологий создания и использования бобово-злаковых травостоев на урожайность и плодородие дерново-подзолистой почвы луговых сенокосов

To solve the problems posed in the Doctrine to ensure the food security of the population of Russia (2020), it is important to increase the productivity and quality of voluminous fodder on meadow hayfields. In the Federal Scientific Center "VIK named after V.R. Williams", improved technologies have been developed for the creation and use of legume-grass stands (with the participation of four legume species) using presowing inoculation of seeds with complementary strains of nodule bacteria, as well as an agricultural technique — changing the predecessor during overplanting (in order to eliminate the phenomenon of soil fatigue). Articles published in recent years (2008, 2020, 2021, 2023) show the high efficiency of the creation and use of these hayfields. Promising technologies make it possible to obtain 5.8–6.2 thousand feed units/ha with high quality hay with a content of metabolic energy of 9.13–9.65 MJ per 1 kg of dry matter and availability of digestible protein per feed unit — 118–164 g. The payback of capital investments is 1–1.5 years, and the cost of 1 feed unit is 26–30% lower than the prevailing prices for 1 kg of fodder oats. For the first time in the article, materials are presented on the impact of the developed technologies on the change in the fertility of soddy-podzolic soils of the Non-Chernozem zone.

Усталостная прочность ленточных пил

One of the major disadvantages of band saws is their low durability. Breakages during the operation are mostly caused by fractures in notches between the blades of the band as a result of the fatigue phenomenon. The strength of the band saw blades is ensured if the assurance coefficient value is greater than the theoretically determined one. The value of the assurance coefficient of 2 is recommended. A schematic limit-amplitude diagram was used to calculate the durability of band saws. A formula for the estimation of the assurance coefficient was derived. It was used for the calculation of the assurance coefficients of the band saw blades manufactured in accordance with GOST 6532–77, which are applicable in dividing band saw machines. The resulting value of the assurance coefficient was 1.44. The value is extremely low for the band saws because it is much lower than required. Band saw blades should be sharpened regularly to ensure a long and reliable service life. It should be made not only to ensure the required sharpness of the blades but also to remove the defective layers in notches caused by fatigue phenomena. In the article, there are more recommendations for improving the durability of the blades of the band saws. The durability of a new type of band saw with curved aerostatic guides and hard alloy blades was evaluated. Its assurance coefficient was 2.4. Therefore, the machine can be operated reliably for a long time without regular treatment of the notches. Consequently, band saws have low durability due to their increased breakdown rate and low wear resistance. Hence, the costs of their purchase and treatment rise. Therefore, the results presented in the article are practically applicable. For citation: Prokofiev G.F., Kovalenko O.L. Fatigue Strength of Band Saws. Lesnoy Zhurnal = Russian Forestry Journal, 2023, no. 4, pp. 136–145. (In Russ.). https://doi.org/10.37482/0536-1036-2023-4-136-145

Fatigue life estimation of aircraft structural component using FE approach and validation through analytical and experimental methods

Aircraft structural design requirements encompass safe-life and damage-tolerant design, analysis, and verification through testing to arrive at the overall service life. The fatigue phenomenon is most critical and local; hence fatigue studies are necessary to conduct first at the coupon level before attempting at the component or full-scale level. The present work demonstrates the development of fatigue life estimation procedures such as high cycle fatigue (HCF) life and fatigue crack growth (FCG) life on specimens as per ASTM standards.The HCF life is predicted for the Aluminum (Al) 2024-T3 ASTM E466 specimen subjected to constant amplitude loading with a stress ratio (R) of 0.1 based on Basquin's method. The computational 2D finite element (FE) model is developed to predict HCF life using a safe-life approach through Nastran Embedded Fatigue (NEF). The effect of fatigue strength modifying factors affecting fatigue life is also explored. Similarly, the FCG life is predicted for the Al 2024-T3 ASTM E647 specimen subjected to constant amplitude loading with a stress ratio of 0.1 using Walker's equation. The computational 3D FE models with a single edge crack in each are developed to predict FCG life using FRANC3D. The FE-based HCF and FCG life prediction procedures demonstrated in this work are verified by comparing FE results with analytical and experimental ones. Therefore, these FE-based methodologies for HCF and FCG life prediction can be adopted at the feature and structural component levels. The developed computational methods reduce the experimental effort, cost, and time involved in the overall fatigue design of the aircraft structures.

A unified approach for fatigue detail categorization applied to rack structures

Rack structures made of thin-walled cold-formed mild steel profiles integrate automated storage-and-retrieval (S&R) systems operating on a 24/7 basis to satisfy the current demands of warehouse logistics. The cyclic storage of palletized goods combined with dynamic actions from S&R systems results in fatigue phenomena responsible for interruptions. However, cold-formed steel is missing from current European standards for fatigue design. Answering to the industry’s needs, the FASTCOLD project financed by the RFCS of the EU investigated the problem, generating important fatigue data. Additionally, several fatigue details are categorized via a unified approach based on a large data set regarding full- and small-scale fatigue tests.

Study on the Impact of Gamified Teaching Using Mobile Technology on College Students’ Learning Engagement

Mobile technology has become an indispensable resource in people’s lives, and educational software applications are closely related to day-to-day life. These applications provide an effective basis for implementing interactive teaching and allow teachers and students to quickly exchange information through mobile devices. Compared with teachers, students are tolerant and open about mobile technology. To meet the learning needs of students, adopting different teaching methods to improve learners’ learning outcomes is the focus of mobile learning. Therefore, gamified teaching supported by various information technologies such as computers, multimedia, and mobile technology has received widespread attention. In this study, 124 undergraduate students majoring in Civil Engineering from Harbin University of Science and Technology, Heilongjiang Province, were randomly assigned to one experimental group (with gamified teaching design, 62 students) and one control group (without gamified teaching design, 62 students). The paired sample T test was used to compare the pre- and post-test scores of the learners, while the independent sample T test was used to analyze the learning engagement (behavioral, cognitive, and emotional engagement) of college students under gamified teaching using mobile technology. Results show no significant difference in pre-test scores between the experimental and control groups (P = 0.374 > 0.05), meeting the prerequisite for the comparative experiment. Gamified teaching using mobile technology found significantly improved test scores (P = 0.003 < 0.05), where independent sample T test results showed a significant difference in learning engagement (behavioral, cognitive, and emotional). After using gamified teaching using mobile technology, the experimental group of students showed a significant increase in learning engagement, which is consistent with the results of most of the literature. The results of this study have important reference value for school administrators to propose new teaching strategies and for teachers to integrate information technology to assist the teaching process, to propose solutions for building interactive teaching environments, and to alleviate the fatigue phenomenon that often occurs in the application of multimedia technology in current information technology teaching in universities.

Влияние факторов риска и защиты на профессиональную жизнеспособность специалистов помогающих профессий

<p style="text-align: justify;">The article presents an overview of researches on the impact of risk and protection factors on the professional resilience of specialists in the helping professions which were published over the last five years. In the analysis of the international literature, several main trends in the study of the phenomenon of professional resilience of specialists in the helping professions (SHP) are presented. In particular, the consequences of the pandemic are considered as risk factor for the SHP resilience. It is noted that most of the research papers on professional resilience are devoted to SHP in the field of social work and medicine (nurses, doctors), less - to psychologists and psychotherapists. A number of the papers concern the peculiarities of the formation of professional resilience among students studying these specialties. The protection factors and some components of professional resilience, in particular, "spirituality", are presented in more details. Among risk factors, the phenomenon of compassion fatigue is analyzed, as specific for SHP. Among the protection factors the phenomenon of warmth and competence is parsed. The article briefly describes several tests designed to measure professional resilience, as well as programs aimed at improving the SHP resilience.</p>

Indicators of community disaster fatigue: A case study in the New South Wales Blue Mountains

A succession of disasters affecting eastern Australia left communities, regions, and states with physical, mental, and resource exhaustion during 2019–2022. Fire, pandemic, and flood occurred in successive waves, hampering recovery efforts. We propose the phenomenon of community disaster fatigue to explain the failure of a community to recover, effectively function, and move forward following a series of disasters. To investigate indicators of community disaster fatigue, we undertook a case study in the Blue Mountains of New South Wales (NSW) and interviewed community leaders. The interviews were thematically analysed and then categorised through the application of the three overarching domains previously used to define community disaster fatigue: (A) defeatism, deterioration, and a lack of planning, (B) weakening health and wellbeing, and (C) corrosion of economic entrepreneurialism and decline in social capital. The results explain how disaster fatigue manifests in a diverse group of community leaders and the issues arising for their careers, volunteer workers, and communities. A major finding is that community disaster fatigue appears to be associated, on a collective level, with elements reflecting the breakdown of community resilience. Thus, as a contribution to practice, a theory of community disaster fatigue can also be useful in developing a strategy for building community resilience. Furthermore, the lack of surge funding, disengagement as a means of self-protection, and closure of local businesses, put the viability of the community at risk. Recent events indicate that closely occurring disasters should be factored into emergency planning, which is a realistic approach given the current trend of recurrent disasters in Australia.

Patient Profiling: Determining the Effects of Patient Factors on Vocal Fatigue

The phenomenon of vocal fatigue and the types of patients that are at greatest risk for vocal fatigue are not fully understood. The goal was to investigate patient profiles such as voice disorder type, demographics (age and gender), singing identity, interoceptive awareness, and psychosocial impacts on the severity of vocal fatigue. Prospective cohort study. Ninety-five subjects with voice disorders were asked to completePart 1 of the Vocal Fatigue Index (VFI-Part1), the Voice Handicap Index-10 (VHI-10), and the Multidimensional Assessment of Interoceptive Awareness, version 2 (MAIA-2). The effects of voice disorder type (structural, neurological, functional), psychosocial impact, age, gender, self-reported singing identity, and interoceptive awareness on self-perceived vocal fatigue (VFI-Part1) were determined using multivariate linear regression. Vocal fatigue had a significant psychosocial impact on patients with voice disorders, as measured by the VHI-10 (P<0.001). However, there were no significant effects of vocal fatigue across any of the three voice disorder types (P's>0.05). Age (P=0.220), gender (P=0.430), and self-identified singing experience (P=0.360) also did not have significant effects on vocal fatigue. Additionally, there were no significant relationships between interoceptive awareness MAIA-2 sum scores (P=0.056) or any of the MAIA-2 sub-scores (P's>0.05) and vocal fatigue severity (VFI-Part1). Vocal fatigue has a significant psychosocial impact on patients with voice disorders. However, patient profiles, including voice disorder type, patient age, gender, singing identity, and level of interoceptive awareness do not appear to play a major role in vocal fatigue symptom reporting. These findings suggest caution should be exercised when attributing patient profiles to vocal fatigue presentation and severity. Studying pathophysiological mechanisms underlying vocal fatigue may help better distinguish unconscious bias in patient profiling from the etiology and severity of vocal fatigue.

Influence of thermal stresses on the phenomenon of thermal fatigue of rolling cylinders

Hot rolling cylinders are the most important machine parts in plastic deformation equipment. They are taken out of operation due to breakage caused by the predominant action of thermal stresses which cause accidental breakdowns of rolling mills. In view of these aspects, the question arose is to knowing the nature of these stresses, as well as their evaluation. This paper will experimentally determine the mechanical and thermal stresses that arise in the process of plastic deformation of hot rolling cylinders. The purpose of this paper is to evaluate the thermal stresses and compare them with the mechanical ones, as well as to highlight their influence on the thermal fatigue phenomenon. The study shows that the stresses in rolling cylinders are cyclical and occur at each rotation of the cylinders. The thermal stresses are mainly the result of the action of symmetric and asymmetric temperature fields. The overall action of thermal stresses presents an aspect of destruction of the surface layer that characterizes the effect of thermal fatigue phenomenon. The separation of the temperature fields that produce thermal stresses in symmetric and asymmetric and their experimental confirmation represents the originality of the research presented in this paper.