Cyclic Strain Research Articles

A Tetrahydropyran‐Based Weakly Solvating Electrolyte for Low‐Temperature and High‐Voltage Lithium Metal Batteries

AbstractEther‐based electrolytes show great potential in low‐temperature lithium metal batteries (LMBs) for their low viscosity and decent reduction stability. However, conventional ethers with multidentate chelate sites suffer from low oxidation stability and high desolvation energy barrier due to the strong coordination between oxygen and Li+. Herein, cyclic tetrahydropyran (THP) with a unidentate site is designed as a solvent, and fluoroethylene carbonate (FEC) and lithium nitrate (LiNO3) serve as additives for low‐temperature LMBs. The cyclic strain and unidentate chelate effect endow THP with a weak affinity to Li+ ions, which accelerates Li+ desolvation process and induces the anion‐derived electrode/electrolyte interface at low temperature. The formed inorganic‐rich interface further improves the oxidation stability and expedites the interfacial ion transportation. As a result, the assembled Li‐LiNi0.8Mn0.1Co0.1O2 (NMC811) cell stably cycles with 87% capacity retention after 100 cycles at −40 °C and 4.5 V. The 2.7 Ah Li‐NMC811 pouch cell with an energy density of 403 Wh kg−1 delivers 53% of the room‐temperature capacity at −50 °C. This work reveals that regulating the chelate site of solvents can well optimize the electrolytes to realize low‐temperature LMBs.

The Influence of Nordic Walking Training on the Serum Levels of Sirtuins, FOXO3a, and Vitamin D Metabolites in Patients with Multiple Myeloma

Background: Multiple myeloma, a malignancy of plasma cells, often involves the disruption of vitamin D metabolism. Vitamin D, acting through its receptor (VDR), affects transcription factors like FOXO and sirtuins, which regulate cellular processes. The impact of physical activity on these markers in multiple myeloma patients is unclear. Therefore, the objective of this study was to evaluate the effects of a 6-week training program on these parameters. Material and methods: The study was completed by 30 patients, including 16 in the Nordic walking training group (TG) and 14 in the control group (non-exercising, CG). All participants underwent a thorough medical interview before starting the project. Venous blood samples were collected from all participants four times—at baseline, after 3 weeks, after 6 weeks, and after 9 weeks (follow-up). The serum concentrations of sirtuin 1, sirtuin 3, Foxo3a, vitamin D receptor (VDR), 25(OH)D3, and 1,25(OH)2D were determined. Body composition, physical fitness, and physical activity level were assessed at baseline and after 6 weeks. Results: No statistically significant changes were observed in the serum levels of sirtuins, the FOXO3a protein, and 1,25(OH)2D. A statistically significant difference was observed in the levels of VDR for both time and group factors, but this was not confirmed in the post hoc test. Vitamin 25(OH)D3 level increased significantly in the study group with time. Conclusions: The applied 6-week Nordic walking training cycle positively affected the level of vitamin 25(OH)D3 but did not influence the rest of the biochemical parameters studied. The obtained results also indicate that the applied intervention is safe for patients and does not interfere with body composition.

Modeling and Simulation of Fatigue Crack Initiation Process Based on Field Theory of Multiscale Plasticity (FTMP): Part II: Modeling Vacancy Formation and Coupling with Diffusion Analysis

Cyclic straining simulations using incompatibility-incorporated crystal plasticity-FEM, which exhibit PSB ladder structure evolutions as detailed in Part I, are coupled with diffusion analyses of produced vacancies. A new vacancy source model is introduced based on the Field Theory of Multiscale Plasticity (FTMP), interpreting the relationship between the incompatibility rate and the flux of dislocation density as edge dipole annihilation processes. Both direct and indirect coupling diffusion analyses, with and without cyclic straining, demonstrate that varying incompatibility rates tend to further promote vacancy diffusion, leading to surface grooving, enhanced extension rates, and eventual transition to cracks. The findings reveal that (i) the evolved PSB ladder structure serves as a site for vacancy formation, (ii) it provides a diffusion path toward the specimen surface, and (iii) it significantly enhances groove extension rates. These factors effectively facilitate the transition from a “groove” to a “crack”, evidenced by the abrupt acceleration of the extension rate, mirroring systematic experimental observations. These achievements validate the FTMP’s capability to simulate complex phenomena and significantly deepen our understanding of slip band–fatigue crack transition mechanisms.

Cyclic and monotonic undrained response of unsaturated filtered copper tailings

This article studies the undrained behavior of filtered copper tailings in unsaturated conditions under monotonic and cyclic loading at controlled matric suction. Two dry densities with the same water content were used. The material behavior was studied in terms of the increase of saturation, the evolution of suction, and volumetric strain during the transition from unsaturated to saturated conditions. The results show that, during the shearing, suction decreases and the degree of saturation increases, regardless of the type of load applied (cyclic or monotonic). This effect is related to the volume reduction of the air phase during the transition to a fully saturated condition. In terms of undrained shear strength, the evolution of the material is studied in terms of the phase transformation line (PTL), comparing its location in saturated and unsaturated cases. Regarding the cyclic strength ratio (CSR), the unsaturated condition shows a higher value than the saturated case by about 26% and 58% for the high and low densities, respectively. However, when the volumetric strain is higher than 3% or the double amplitude axial strain exceeds 2%, a cyclic strain localization takes place, leading to an extension failure over the sample.

Determinants of physical recreation among Generation Z people

The aim of the study was to characterize the determinants of physical recreation undertaken by people from Generation Z. The research was conducted in 2024. The research sample consisted of 109 respondents. The study used a survey technique. The link to the questionnaire was posted on Facebook. The most frequently indicated source of inspiration for undertaking physical activity for the respondents were social media, as well as friends. The most frequently mentioned motives for practicing physical recreation included improving physical fitness, maintaining fitness and improving figure. The most frequently undertaken forms were walking, cycling and strength training. The respondents most often exercised in their own home, apartment or dormitory. The factor hindering more frequent physical activity was mainly lack of strength and fatigue, as well as insufficient free time.

Evaluation of leg symmetry in muscle oxygen saturation during submaximal to maximal cycling exercise.

It is unclear whether physiological responses, such as muscle oxygen saturation (SmO2), can be considered symmetrical during cycling. This knowledge has important practical implications for both training and performance assessment. The aim of this study was to determine whether oxygenation profiles in the three active muscles of both legs were symmetrical during cycling at different intensities. Twenty-six trained cyclists and triathletes completed a graded exercise test (GXT) and an 8-min functional threshold power estimation test (8MTT) on a cycle ergometer over two nonconsecutive days. SmO2 was bilaterally assessed using NIRS technology in the vastus lateralis, gastrocnemius medialis, and tibialis anterior. Symmetry was compared between legs in both tests, and reliability and agreement between the measurements were quantified. The main results were that SmO2 in the three muscles assessed did not differ between legs during the GXT and 8MTT (p>0.05). Reliability of the measures was poor to good in the vastus lateralis (ICC=0.83-0.37), moderate to excellent in the tibialis anterior (ICC=0.92-0.73), and poor to good for the gastrocnemius medialis (ICC=0.80-0.24). Overall, the group variability in SmO2 showed a narrower distribution at lower intensities, with data dispersion increasing at higher intensities. In conclusion, the SmO2 was similar and showed symmetrical responses in both the preferred and nonpreferred limb in different muscles assessed during cycling at different intensities within a range of 10%-20%. Although individual physiological differences that might be relevant in some clinical/performance settings should not be disregarded, these findings indicate that measuring a single lower limb provides an accurate approximation of the responses in both lower limbs.

The effect of quercetin and citrulline on cycling time trial performance.

There is growing interest in the use of nutrition and dietary supplements to optimize training and time-trial (TT) performance in cyclists. Separately, quercetin (QCT) and citrulline (CIT) have been used as ergogenic aids to improve oxygen (VO2) kinetics, perceived effort, and cycling TT performance. However, whether the combination of QCT and CIT can provide additive benefits and further enhance cycling performance production is currently unknown. We examined 28-days of QCT + CIT supplementation on TT performance and several performance measures (i.e. mean power, VO2, respiratory exchange ratio (RER), and rate of perceived exertion (RPE)). Forty-eight highly trained cyclists were assigned to one of four supplementation groups: (1) QCT + CIT (QCT: 500 mg, CIT: 3000 g), (2) QCT (500 mg), (3) CIT (3000 mg), or (4) placebo (3500 mg of a zero-calorie flavored crystal light package). Supplements were consumed two times per day for 28 consecutive days. Participants performed a 20-km cycling time-trial race, pre- and post-supplementation to determine the impact of the combined effects of QCT + CIT. There were no potential benefits of QCT +CIT supplementation on TT performance and several performance measures. However, there was an improvement in VO2 from pre-to-post-supplementation in QCT (p = 0.05) and CIT (p = 0.04) groups, but not in the QCT+CIT and PL groups. QCT + CIT does not seem beneficial for 20-km TT performance; further exploration with a focus on an increase in cycling duration or QCT+CIT combined with additional polyphenols may amplify any perceived bioactive or metabolic effects on cycling performance. The efficacy of QCT + CIT supplementation to improve cycling performance remains ambiguous.

Unveiling deformation microstructure during cyclic straining of 316 L stainless steel at 873 K

Cyclic plastic deformation behaviour of 316L steel with an average grain size ∼ 30 μm was investigated at high temperature (873K) under completely reversed straining at ±0.5% strain amplitude with a constant total strain rate of 3 × 10−3S−1. Maximum true tensile stress initially increased due to cyclic hardening until 100 cycles, then stress saturation occurred and finally failed at 1250 cycles. Deformation microstructure varied significantly with imposed fatigue cycles. Occurrence of planar glide and isolated dislocation walls were observed in the initial hardening stage, while dislocation walls accompanied by connected equiaxed dislocation cells were predominant in the saturation stage. The deformation microstructure at failure stage mainly composed of elongated dislocation cells and diffusive dislocation walls. Dislocation densities estimated by X-ray diffraction were ∼ 1013m-2.

Effects of Heart Rate Fluctuation on Aerobic Training Outcomes in Patients With Stable Coronary Artery Disease: A Prospective Study.

This study aimed to evaluate the effects of different heart rate fluctuation ranges during aerobic training on outcomes in patients with stable coronary artery disease (CAD). Ninety-seven patients diagnosed with stable CAD were enrolled between March 2017 and December 2019. Participants were randomly assigned to three groups: the control (CON) group, the medium-intensity heart rate small range (MIS) group, and the medium-intensity heart rate large range (MIL) group. The CON group received standard care and patient education, while the MIS and MIL groups underwent personalized rehabilitation training with specific heart rate fluctuation targeted ranges, in addition to standard care. Cardiopulmonary function and exercise performances were assessed using resting heart rate (RHR), maximum heart rate (HRmax), heart rate recovery (HRR), and a 6-min walk test (6MWT) at the baseline and after 16 weeks of training. The MIS group demonstrated a significant reduction in RHR compared to the CON and MIL groups. While both exercise rehabilitation groups exhibited improvement in HRR, only the MIS group achieved a statistically significant improvement compared to the CON group. Post-training HRmax and 6MWT performance increased in both MIS and MIL groups, with only the MIL group presenting statistical significance compared to the CON group. Exercise rehabilitation with different training regimens can enhance cardiac function in patients with CAD. Different heart rate modulation strategies yielded distinct effects on cardiopulmonary function. Maintenance of a narrower heart rate fluctuation during exercise was observed to significantly enhance the effectiveness of rehabilitation, which could lead to new treatment protocols or optimization of existing strategies for patients with cardiovascular conditions. The combination of 6MWT and power bicycle training may offer an effective method for improving cardiac function in community-based rehabilitation settings.

A Comparison Study of High-Temperature Low-Cycle Fatigue Behaviour and Deformation Mechanisms Between Incoloy 800H and Its Weldments

The high-temperature low-cycle fatigue (LCF) behaviour of Incoloy 800H and its weldments with Haynes 230 and Inconel 82 filler metals, which were fabricated with the gas tungsten arc welding (GTAW) technique, was investigated and compared at 760 °C. The results revealed that the Incoloy 800H weldments showed lower fatigue lifetimes compared to the base metal. However, the weldments with the Haynes 230 filler metal demonstrated an improved fatigue life at the low strain amplitude compared to both Incoloy 800H and the weldment with the Inconel 82 filler metal. The Incoloy 800H base metal showed pronounced initial cyclic hardening with hardening factors increasing with strain amplitudes. In contrast, the weldments with Haynes 230 and Inconel 82 filler metals displayed short initial cyclic hardening and saturation stages, followed by long continuous cyclic softening. The fractography and microstructure after LCF the tests were characterized with scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Transgranular fracture with multiple crack initiations was the predominant failure mode on the fracture surfaces of both Incoloy 800 base metal and the weldments. TEM examination revealed that planar dislocation slips at the low strain amplitude evolved to wavy slips, eventually forming a cell structure at high strain amplitudes in the Incoloy 800H material as the strain amplitudes increased. However, the weld metal exhibited a planar slip mode deformation mechanism regardless of cyclic strain amplitude in the weldment specimens. The differing cyclic hardening and softening behaviours between Incoloy 800H and its weldments are attributed to the higher strength of the weldment specimens compared to the base metal. In the Incoloy 800H base material specimens, the reverse strains during LCF created wavy dislocation structures, which could not fully recover due to the non-reversible nature of the microstructure. As a result, cells or subgrains formed within the microstructure once created. In contrast, the higher strength of the weld metal in the weldment specimens significantly suppressed the formation of wavy dislocation structures, and deformation primarily manifested as planar arrays of dislocations.

The content of the professional and practical training of teachers-philologists in Ukraine

The aim of the article is to analyze the content of language professional and practical training of future teachers-philologists using the curriculum for specialty 014 “Secondary Education. English Language and Literature” at Zhytomyr Polytechnic State University as a case study. The authors review the 2021/2022 academic year curriculum for this specialty. The article states that the teacher philologist training consists of three cycles: general, professional and practical training. In turn, the first two cycles are divided into two parts: educational disciplines of the normative and variable part. The article calculates the percentage ratio of study time allocated to the study of academic disciplines of the normative and variable part of the professional training cycle of specialty 014 “Secondary Education. English Language and Literature” in the 2021/2022 academic year. It is concluded that the language professional and practical training of teachers-philologists in Ukraine is balanced due to the successful distribution of study time for the study of basic philological and methodical disciplines. Optional educational disciplines in the variable part significantly enrich the curriculum and thereby contributing to positive dynamics in students’ knowledge.

ВИБІРКОВІ ОСВІТНІ КОМПОНЕНТИ В ПРОФЕСІЙНІЙ ПІДГОТОВЦІ МАЙБУТНІХ УЧИТЕЛІВ УКРАЇНСЬКОЇ МОВИ І ЛІТЕРАТУРИ В МАГІСТРАТУРІ

The author of this article characterizes the role of selective educational components in the professional training of future teachers of the Ukrainian language and literature in the master’s degree. It was found that one of the ways of forming the individual educational trajectory of a student is the mastering of selective educational components aimed at improving general and professional competencies defined in the educational and professional program. The procedures for the development and selection of the specified educational components are outlined in university regulations, in particular, it is stated that they should cover 25% of the total volume of ECTS credits planned by the relevant educational and professional program. Analysis of educational activities for the implementation of the educational and professional program 014.01 Secondary education. Ukrainian language and literature in the master’s program of the T. H. Shevchenko National University «Chernihiv Colehium» made it possible to characterize selective components from cycles of general and professional training. It was established that those seeking higher education should master three academic disciplines of the cycle of general training and five academic disciplines of the cycle of professional training, which are evenly distributed within three semesters. The author of the article characterizes those educational disciplines that are particularly popular among future teachers of the Ukrainian language and literature, in particular: “Pedagogical rhetoric”, “Basics of academic integrity”, “Artistic systems in Ukrainian literature of the 20th-21st centuries”, “Literature of the Siver region in historical-typological context”, “Technologies of studying theoretical and literary concepts in high school”, “Ukrainian language in scientific and pedagogical communication”. It has been established that educational disciplines that have a practical direction and may be needed during professional activities are particularly popular among future teachers. It is noted that teachers of university in the process of developing selective educational components try to take into account branch and regional aspects. Key words: professional training, educational component, educational and professional program, educational discipline, future teachers of the Ukrainian language and literature, master’s degree.

Skeletal muscle hypertrophy and enhanced mitochondrial bioenergetics following electrical stimulation exercises in spinal cord injury: a randomized clinical trial.

We examined the combined effects of neuromuscular electrical stimulation-resistance training (NMES-RT) and functional electrical stimulation-lower extremity cycling (FES-LEC) compared to passive movement training (PMT) and FES-LEC on mitochondrial electron transport chain (ETC) complexes and citrate synthase (CS) in adults with SCI. Thirty-two participants with chronic SCI were randomized to 24weeks of NMES-RT + FES [n = 16 (14 males and 2 females) with an age range of 20-54years old] or PMT + FES [n = 16 (12 males and 4 females) with an age range of 21-61years old]. The NMES-RT + FES group underwent 12weeks of surface NMES-RT using ankle weights followed by an additional 12weeks of FES-LEC. The PMT + FES performed 12weeks of passive leg extension movements followed by an additional 12weeks of FES-LEC. Using repeated measures design, muscle biopsies of the vastus lateralis were performed at baseline (BL), post-intervention 1 (P1) and post-intervention 2 (P2). Spectrophotometer was used to measure ETC complexes (I-III) and CS using aliquots of the homogenized muscle tissue. Magnetic resonance imaging was used to measure skeletal muscle CSAs. A time effect was noted on CS (P = 0.001) with an interaction between both groups (P = 0.01). 46% of the participants per group had zero activities of CI without any changes following both interventions. A time effect was noted in CII (P = 0.023) following both interventions. Finally, NMES-RT + FES increased CIII at P1 compared to BL (P = 0.023) without additional changes in P2 or following PMT + FES intervention. Skeletal muscle hypertrophy may potentially enhance mitochondrial bioenergetics after SCI. NMES-RT is likely to enhance the activities of complex III in sedentary persons with SCI. Clinical trials # NCT02660073.

Silver-decorated laser-induced graphene for a linear, sensitive, and almost hysteresis-free piezoresistive strain sensor

A new approach has recently emerged in graphene synthesis by direct laser writing (LIG), which is highly economical and scalable, unlike previous methods. Here, the sputtering method has been used to coat silver onto the laser-induced graphene-based sensor. The results demonstrate that the chosen approach substantially impacts the expected outcomes. The initial resistance values were consistent across the different sensor samples. The average resistance was slightly lower in the silver-coated samples compared to the uncoated samples, demonstrating the effectiveness of the Ag coating in enhancing the electrical conductivity of the LIG material. However, the difference in resistance was not statistically significant. The electromechanical behavior of the Ag-coated LIG strain sensor was tested under cyclic tensile strain. The gauge factor increased from 12.9-14.7 for the uncoated LIG sensor to 17.2-26.7 for the Ag-coated sensor, with the difference growing at higher strains. At 5%, 30%, and 70% strain, the gauge factor increased by 30%, 80%, and 82%, respectively. Sensors measuring 1-70% strain were developed, enabling use in various applications. Blood pulse measurements showed the silver-coated sample produced more uniform and reliable results than the uncoated sample. The number of beats matched a commercial pulse oximeter. This sensitivity, linearity, and reliability demonstrate the potential for commercializing these sensors.

Quantitative benefits of geocells in controlling liquefaction in sands

Geocells have become an integral part of many geosystems like road and railway embankments, retaining walls and foundations, attributed to their multiple merits in terms of stability and strength, but their contributions towards liquefaction mitigation are unknown. The present study aims to understand the role of geocell reinforcement on the liquefaction and post-liquefaction shear response of saturated sands through monotonic and cyclic triaxial tests. Low-strength geocells of required physical and mechanical properties were fabricated through ultrasonic welding of 3D printed polypropylene (PP) sheets. The liquefaction benefits of including a single geocell in sand were quantified in terms of the reduction in pore water pressure, retardation in stiffness degradation and delay in the retardation of effective stress. In general, the inclusion of geocells delayed liquefaction, with higher beneficial effects at lower initial confining pressure, higher cyclic strain amplitude and higher cyclic loading frequency. The maximum benefit measured in terms of percentage rise in the number of cycles needed to liquefy was calculated to be about 230 %. Geocell reinforcement also helped in the quick regain of post-liquefaction shear strength and stiffness.

Influence of the Loading Frequency on Very High Cycle Fatigue Behavior of Structural Steels

ABSTRACTIn ultrasonic fatigue tests, the VHCF properties can be determined in a reasonable time. Nevertheless, the high frequency can affect the fatigue behavior for some materials. This study investigated the fatigue capability of 34CrNiMo6 and 42CrMo4 steels, both of which find widespread applications in several mechanical components. These steels were carried out for conventional and ultrasonic fatigue tests under fully reversed testing conditions. A microplasticity strain amplitude was calculated, indicating an order of magnitude decreases around 10–100, when compared with the experimental results from low‐frequency tests. Cyclic strain rates were estimated for each steel and correlated with the number of cycles to failure. A conversion constant was obtained by fitting a curve to convert the high frequency results into theoretical results at low frequency. The experimental and predicted results were evaluated. The results proved the relevance of the strain rate in frequency effect. The converted results showed strong agreement with the experimental results in low‐frequency tests for the steels being studied.

Neural and Cardio-Respiratory Responses During Maximal Self-Paced and Controlled-Intensity Protocols at Similar Perceived Exertion Levels: A Pilot Study

Self-paced exercise protocols have gained attention for their potential to optimize performance and manage fatigue by allowing individuals to regulate their efforts based on perceived exertion. This pilot study aimed to investigate the neural and physiological responses during a self-paced V˙O2max (SPV) and incremental exercise tests (IET). Six trained male cyclists (mean age 39.2 ± 13.3 years; V˙O2max 54.3 ± 8.2 mL·kg−1·min−1) performed both tests while recording their brain activity using electroencephalography (EEG). The IET protocol involved increasing the power every 3 min relative to body weight, while the SPV allowed participants to self-regulate the intensity using ratings of perceived exertion (RPE). Gas exchange, EEG, heart rate (HR), stroke volume (SV), and power output were continuously monitored. Statistical analyses included a two-way repeated measures ANOVA and Wilcoxon signed-rank tests to assess differences in alpha and beta power spectral densities (PSDs) and the EEG/V˙O2 ratio. Our results showed that during the SPV test, the beta PSD initially increased but stabilized at around 80% of the test duration, suggesting effective management of effort without further neural strain. In contrast, the IET showed a continuous increase in beta activity, indicating greater neural demand and potentially leading to an earlier onset of fatigue. Additionally, participants maintained similar cardiorespiratory parameters (V˙O2, HR, SV, respiratory frequency, etc.) across both protocols, reinforcing the reliability of the RPE scale in guiding exercise intensity. These findings suggest that SPV better optimizes neural efficiency and delays fatigue compared to fixed protocols and that individuals can accurately control exercise intensity based on perceived exertion. Despite the small sample size, the results provide valuable insights into the potential benefits of self-paced exercise for improving adherence to exercise programs and optimizing performance across different populations.

Accuracy of Wrist-Worn Heart Rate Monitors: A Comprehensive Review of Smartwatches in Exercise Monitoring

Wrist-worn heart rate monitors have become integral in personal health monitoring, particularly during exercise and daily activities. This review evaluates the precision of various commercially available smartwatches in assessing heart rate, focusing on their accuracy across different physical activities, such as walking, running, cycling, and elliptical training. A systematic analysis of 29 peer-reviewed studies, encompassing over 900 participants, was conducted to compare devices like the Apple Watch, Fitbit, Garmin, and others. The results demonstrate significant variation in accuracy depending on the device, type of activity, and individual factors such as body mass index and skin tone. The Apple Watch consistently outperformed other devices, showing the lowest mean absolute percentage error (MAPE), particularly during moderate-intensity activities. In contrast, devices such as the Fitbit Blaze exhibited greater error rates, especially during high-intensity exercises or activities involving significant arm movement. Although wrist-worn heart rate monitors provide users with convenient real-time data, limitations such as motion artifacts, device placement, and external factors may affect their reliability.

Non-linear elasticity, earthquake triggering and seasonal hydrological forcing along the Irpinia fault, Southern Italy

Pump-probe experiments investigate the strain sensitivity of crustal elastic properties, showing nonlinear variations during the strain cycle. In the laboratory, pre-seismic reductions in seismic velocity indicate that asperity contacts within the fault zone begin to fail before the macroscopic frictional sliding. The recognition of such effects in natural seismic-cycles has been challenging. Here we exploit seasonal hydrological strains, performing a natural analogue to a quasi-static laboratory pump-probe experiment to investigate the nonlinear strain sensitivity of crustal rocks and its role in seismic failure along the tectonically-active Irpinia Fault System (Southern Italy). By comparing 14-years-long series of spring discharge, strain, seismic velocity variations and earthquakes rate, we find that seismicity peaks during maximum hydrological forcing and minimum seismic velocity. Seasonal strains of ~10−6 are required for both earthquake triggering and significant nonlinearity effects arising from modulus reduction. We suggest that, for faults in a critical state, cyclical softening may lead to failure and seasonal seismicity.

Natural Semantic Networks: The Concept of Mistreatment and Good Treatment in Students of Health Careers.

Natural semantic networks (NSNs) provide an approach to understanding concepts in terms of their density and strength. The objective of this study was to conceptualize mistreatment and good treatment among health science students in Chile, according to gender and training cycle. Methods: A mixed-methods study with a relational scope was conducted, involving 994 health science students. The present study is exploratory and combines both qualitative and quantitative analysis. We utilized the NSN technique, applying a questionnaire via SurveyMonkey after obtaining informed consent. Results: A total of 4386 defining words for mistreatment were identified, with the most relevant being 'aggression', 'abuse', and 'violence'. In the case of good treatment, a total of 4146 defining words were obtained, with 'respect', 'empathy', and 'kindness' standing out. For good treatment, a statistically significant relationship was observed between the defining words and the variables of gender (χ2 = 41.158; p < 0.05) and training cycle (χ2 = 28.698; p < 0.05). For mistreatment, a statistically significant relationship was found only with training cycle (χ2 = 35.858; p < 0.05). Conclusions: Exploring the meanings associated with mistreatment and good treatment has a theoretical implication in the way in which two highly polysemic aspects of the educational environment can be understood.