Type Of Deformation Research Articles

Largest Lyapunov exponent as a tool for detecting relative changes in the particle positions.

Dynamics of the driven Frenkel-Kontorova model with asymmetric deformable substrate potential is examined by analyzing response function, the largest Lyapunov exponent, and Poincaré sectionsfor two neighboring particles. The obtained results show that the largest Lyapunov exponent, besides being used for investigating integral quantities, can be used for detecting microchanges in chain configuration of both damped Frenkel-Kontorova model with inertial term and its strictly overdamped limit. Slight changes in relative positions of the particles are registered through jumps of the largest Lyapunov exponent in the pinning regime. The occurrence of such jumps is highly dependent on type of commensurate structure and deformation of substrate potential. The obtained results also show that the minimal force required to initiate collective motion of the chain is not dependent on the number of Lyapunov exponent jumps in the pinning regime. These jumps are also registered in the sliding regime, where they are a consequence of a more complex structure of largest Lyapunov exponent on the step.

Families and unfoldings of singular holomorphic Lie Algebroids

In this paper, we investigate families of singular holomorphic Lie algebroids on complex analytic spaces. We introduce and study a special type of deformation called unfoldings of Lie algebroids, which generalizes the theory of singular holomorphic foliations developed by T. Suwa. We show that a one to one correspondence between transversal unfoldings and holomorphic flat connections on a natural Lie algebroid on the bases exists.

Lactobacillus rhamnosus reduces CD8+T cell mediated inflammation in patients with rheumatoid arthritis

BackgroundThe T cells, components of adaptive immunity participate in immune pathology of the autoimmune inflammatory disorder called rheumatoid arthritis (RA). The presence of TLRs on the surface of the CD8+ T cells and their ability to recognize bacterial moieties adds to the inflammatory burden in case of RA. It has been reported that the gut microbiome is necessary for the crucial shift in the balance between proinflammatory and anti-inflammatory cytokines. The altered gut microbiome and the presence of TLRs emphasizes on the microbiome driven inflammatory responses in case of RA. MethodsEighty-nine RA patients participated in this study. Clinical variations like disease duration, number of actively inflamed joints, number and type of bone deformities, CRP, RF, Anti-CCP, ESR, DAS 28 score were recorded for each patient. Co-culture of CD8+T cells and bacteria has been performed with proper culture condition. TLRs and inflammatory mediators’ expression level were checked by both qPCR and flow cytometry analysis. ResultsWe observed in the suppression of pro-inflammatory molecules like Granzyme B and IFNƳ and expression of TLR2 in CD8 + T cells upon treatment with Lactobacillus rhamnosus (L. rhamnosus). Moreover, L. rhamnosus activated CD8+T cells such that they could induce FOXP3 expression in CD4+T cells thereby skewing T cell population towards a regulatory phenotype. On the contrary, TLR4 engagement on CD8+T cell by Escherichia coli (E.coli) increased in inflammatory responses following ERK activation. ConclusionsThus, we conclude that L. rhamnosus can effectively suppress CD8+T cell mediated inflammation by a simultaneous decrease of Th1 cells that may potentiate better treatment modalities for RA.

Analisis Pengaruh Panas dan Beban terhadap Kerusakan Traveling Grate pada Boiler Di PLTU Tembilahan 2x7 MW

Rack grate is a component composed of rack clip and rack bone arrangement that serves as a dropping cross-section media of coal and as a media of coal burned in the boiler. As part of the main component, the rack grate can be regarded as one of the components that ensure the success of combustion in the boiler. Failure to this component will certainly interfere with the implementation of boiler operations. In addition to require the boiler to be shut down while repaired, in addition to requiring the boiler to be extinguished during repairs, the inoperability of the boiler makes the steam production process at the PLTU impossible and ultimately the electricity generation process cannot be carried out as usual. Damage to the rack grate component has a type of plastic deformation with variable loads and fluctuating heat, which means that the thermal stress in the system has reached the yield stress point. To find out the root cause of this component damage quickly and accurately, an analysis of the results of the implementation of engineering software in this case Ansys Workbench, and a comparison of actual operating data, and data design is the best choice. Lastly, by evaluating the optimum values of temperature, equivalent stress and strain, total deformation, input process parameters value can be controlled to the desired values, resulting in less stress concentration occurs, so that the damage to the workpiece can be reduced or even eliminated.

Ear Molding for Congenital Auricular Deformities: Efficacy and Factors Affecting Outcomes.

Objective: This study's aim was to assess the effectiveness of ear molding for congenital auricular deformities, analyze the factors affecting prognosis, and provide more clinical data supporting nonsurgical correction for this condition. Methods: A prospective study of a consecutive series of infants treated with ear molding from January 2021 to December 2022 in the department of otolaryngology, Second Affiliated Hospital of Harbin Medical University, was conducted. Demographic and clinical information were collected, and photographs of the ear were taken before and after treatment. Treatment efficacy and the relevant influencing factors were evaluated. Results: Thirty-five patients, including 59 with congenital ear anomalies, underwent noninvasive ear molding. The deformity type, treatment initiation age, and number of treatment cycles affected treatment efficacy. Earlier treatment initiation was associated with a shorter treatment period. Treatments were started earlier if decision-makers were more anxious. Conclusion: The earlier the neonatal auricle deformity is treated, the shorter the treatment time and the more ideal the clinical effect will be. Early noninvasive treatment for microtia is valuable. Early detection and parental awareness and education can help children receive treatment earlier and improve the success rate.

Incidence of cardiac anomalies in congenital vertebral deformity: systematic review and meta-analysis of 2910 patients.

This study aimed to analyze the overall incidence of cardiac abnormalities in patients with congenital scoliosis and the possible influencing factors. PubMed, Embase, and Cochrane Library were searched for relevant studies. The quality of the studies was assessed independently by two authors using the methodological index for nonrandomized studies (MINORS) criteria. The following data were extracted from the included studies: bibliometric data, number of patients, number of patients with cardiac anomalies, gender, types of deformity, diagnostic method, type of cardiac anomaly, location, and other associated anomalies. The Review Manager 5.4 software was used to group and analyze all the extracted data. This meta-analysis included nine studies and identified that 487 of 2,910 patients with congenital vertebral deformity had cardiac anomalies diagnosed by ultrasound (21.05%, 95% CI of 16.85-25.25%). The mitral valve prolapse was the most frequent cardiac anomaly (48.45%) followed by an unspecified valvular anomaly (39.81) and an atrial septal defect (29.98). A diagnosis of cardiac anomalies was highest in Europe (28.93%), followed by USA (27.21%) and China (15.33%). Females and formation defects were factors significantly associated with increased incidence of cardiac anomalies: 57.37%, 95% CI of 50.48-64.27% and 40.76%, 95% CI of 28.63-52.89%, respectively. Finally, 27.11% presented associated intramedullary anomalies. This meta-analysis revealed that the overall incidence of cardiac abnormalities detected in patients with congenital vertebral deformity was 22.56%. The incidence rate of cardiac anomalies was higher in females and those with formation defects. The study offers guidance for ultrasound practitioners to accurately identify and diagnose the most common cardiac anomalies.

Three-Dimensional Ultrasound Elastography Detects Age-Related Increase in Anterior Peripapillary Sclera and Optic Nerve Head Compression During IOP Elevation.

High-frequency ultrasound elastography offers a tool to resolve the complex and heterogeneous deformation through the full thickness of the optic nerve head (ONH) and peripapillary sclera (PPS). Using this tool, we quantified the three-dimensional deformation of the ONH and PPS in human donor eyes and evaluated age-associated changes. The ONH and PPS in 15 human donor globes were imaged with a 50-MHz ultrasound probe while increasing intraocular pressure (IOP) from 15 to 30 mmHg. Tissue displacements were obtained using correlation-based ultrasound speckle tracking. Three-dimensional spherical strains (radial, circumferential, meridional, and respective shear strains) were calculated for the ONH and PPS volumes segmented from three-dimensional ultrasound images. Age-related trends of different strains in each region of interest were explored. The dominant form of IOP-induced deformation in the ONH and PPS was radial compression. High-magnitude localized out-of-plane shear strains were also observed in both regions. Most strains were concentrated in the anterior one-half of the ONH and PPS. The magnitude of radial and volumetric strains increased with age in the anterior ONH and anterior PPS, indicating greater radial compression and volume loss during IOP elevation in older age. The age-associated increase of radial compression, the predominant form of IOP-induced deformation in anterior ONH and PPS, may underlie age-associated glaucoma risk. High-frequency ultrasound elastography offers a useful tool to quantify all types of deformation comprehensively in all regions of ONH and PPS, which may improve our understanding of the biomechanical factors contributing to glaucoma risk.

Mechanical properties of 2D metal–organic and covalent–organic frameworks with non trivial topological band dispersion

Using density functional theory (DFT), we investigate mechanical properties of a few 2D metal–organic frameworks (MOFs) and covalent–organic frameworks (COFs) having Dirac and flat bands. These porous materials have become a subject of great captivation because of their physical stability, distinctive structural characteristics and large surface to volume ratio. The inherent porosity of these frameworks gives rise to many fascinating and occasionally surprising phenomena, which makes them potential candidates for technological applications. For reliable usage of MOFs/COFs in functional nanodevice and practical application, it is quite imperative to investigate their mechanical properties. Thus, herein a particular attention is paid to study elastic deformation of few 2D MOFs and COFs having non trivial topological band dispersion in the regime with linear dependency of stress upon strain. Specially, we consider different types of deformation and find all the components of elastic tensor from the stress–strain and energy–strain curves. These findings may provide useful information to fabricate the MOFs/COFs based devices by lowering the number of experiments.

Accuracy of the hexapod external fixator in treating tibial angular deformities with or without limb length discrepancy: a retrospective study.

Hexapod external fixator systems allow simultaneous deformity correction in multiple planes as well as limb lengthening. The aim of this study is to evaluate the accuracy of a hexapod frame (smart correction frame) in different types of tibial deformities requiring correction with or without lengthening. A total of 54 tibial angular deformities and limb length discrepancies operated with a hexapod frame between January 2015 and January 2021 were classified into four groups: "Group A (n = 13): only lengthening," "Group B (n = 14): lengthening and uniplanar correction," "Group C (n = 16): only uniplanar correction," and "Group D (n = 11): biplanar correction." The accuracy of angular deformity correction/lengthening was calculated by dividing the actual correction/lengthening achieved after frame removal by the preoperative planned lengthening/correction. The lengthening accuracy in Group A and Group B was 96.3 ± 7.1% and 95.7 ± 5.9%, respectively (P = 0.685). The angular deformity correction accuracy was 85.1 ± 9.9% for Group B, 85.2 ± 13.9% for Group C, and 80.2 ± 18.4% for Group D (P = 0.852). A revision program was performed in six cases (1 in Group B, 1 in Group C, and 4 in Group D) for full correction of the deformities. The accuracy of tibial lengthening is high with the hexapod frame and is minimally affected by simultaneous deformity correction; however, the accuracy of angular correction slightly reduces as the deformity becomes more complex. Surgeons should be aware that reprogramming may be required after complex deformity correction.

Foot deformity and quality of life among independently ambulating children with spina bifida in South Korea

BackgroundChildren with spina bifida (SB) may have congenital or acquired foot deformities due to neurological defects in the spinal cord. As the musculoskeletal system keeps growing, foot deformities can develop or become aggravated. Thus, healthcare providers should provide constant monitoring and proper orthopedic management. Since foot deformities can affect not only the gait but also the daily life of children with SB, it is necessary to investigate the impact of foot deformities on everyday life. The purpose of this study was to examine the relationship between foot deformity and health-related quality of life (HRQoL) among independently ambulating children with SB.MethodsThis cross-sectional study examined the associations between foot deformity and HRQoL using two patient-reported outcome measures (Oxford Ankle Foot Questionnaire, Pediatric Outcomes Data Collection Instrument) in 93 children with SB aged 7–18 years between January 2020 and July 2021.ResultsChildren with foot deformity (n = 54) reported lower scores in all subscales (physical, school and play, emotional, and footwear) of the Oxford Ankle Foot Questionnaire for children than those without foot deformity (n = 39; p < 0.001). Additionally, in terms of the Pediatric Outcomes Data Collection Instrument, children with foot deformity also reported poorer scores in four subscales (transfer and basic mobility, sports and physical functioning, comfort and pain, happiness with physical functioning; p < 0.001) than those without foot deformity, whereas upper extremity functioning was not significantly affected. Children with foot deformities, particularly those with bilateral foot deformities, equinus deformities, or mixed deformities, which are different types of right and left foot deformities, have a lower perceived HRQoL (p < 0.05).ConclusionsAmong independently ambulating children with SB, those with foot deformities showed lower HRQoL. Moreover, children with foot deformities tend to have other clinical problems, including bladder and bowel dysfunction. Therefore, orthopedic management should consider the multifaceted factors that affect children’s daily life and HRQoL.

3‐1: Distinguished Paper: High‐Resolution Active‐Matrix Micro‐LED Stretchable Displays

We have developed 12‐inch 100 PPI active‐matrix micro‐LED stretchable displays that can be stretched up to 20%. Our work has involved the development of key technologies such as stretchable interconnect, stretchable film, micro‐LED, and the integration process for these components. The stretchable displays exhibited various types of deformations, suggesting the potential for new applications in information display.

Static tensile mechanical properties and engineering application of constant resistance and large deformation anchor cable

Deep engineering is faced with mechanical phenomena, such as substantial soft rock deformation and in situ stresses, that results in frequent disasters because the energy of the surrounding rock cannot be released normally after excavation. Traditional support materials have low elongation and safety reserves, cannot adapt to large deformations of the surrounding rock, and cannot apply high preload, making it difficult to absorb energy. This study introduces a new type of constant resistance and large deformation (CRLD) cable through static tensile experiments, and compared the results of which with those of ordinary high-strength (HS) cables. Our results showed that the CRLD cable had an obvious constant resistance stage, with a constant resistance value of approximately 415 kN and an elongation rate as high as 25%, which is 3.9 times that of the HS cable. Furthermore, the energy absorption of the CRLD cable was 3.5 times that of the HS cable. Before the first steel strand broke, the temperature of the entire cable was approximately 33 °C, and the energy was absorbed evenly without obvious energy concentration. After breaking, the standard deviation of the segmental elongation of the steel strand was 4.16 mm, with a small degree of dispersion. The deformation of each section of the steel strand was uniform lengthwise and the necking rate of the fracture was 8.5%, indicating that there was no obvious necking. On this basis, a comprehensive mechanical performance evaluation index of the cable, that is, the static toughness UT, was proposed, reflecting the strength, elongation, and energy absorption density of the cable. Compared with the HS cable and another widely used He cable with excellent energy absorption characteristics, the UT of the CRLD cable was 117% higher than that of the HS cable and 38.1% higher than that of the He cable. This study also proposes a support and design principle for the CRLD cable and applies a CRLD cable to a roadway with a buried depth of 1050 m. Our results show that, owing to the high-strength reserve of the CRLD cable, the applicable preload can reach more than 85% of the breaking load of the cable, which is 2.3 times that of the HS cable. After this new support was adopted, the maximum deformation of the surrounding rock of the roadway was 180 mm, which is 36% of that of the traditional support. The deformation of the roadway was controlled and the surrounding rock was stable.

Reconstructive surgeries in the case of the knee joint osteoarthritis

Objective. To clarify the indications and volume of reconstructive surgeries under conditions of knee joint arthritis and to improve the methods of surgical correction of peri-articular deformations using an external rod fixator. Methods. During the last 10 years (2012‒2022), reconstructive surgeries were performed in 45 patients (49 joints). Indications for surgery were based on the study of pain and its localization, peri-articular deformation of the limb, ultrasound (USD) and X-ray examinations. Results. Indications for certain reconstructive surgical interventions on the knee joint are substantiated. The role of pathological changes of the meniscus in the development of knee joint arthritis has been determined. The positive clinical effect of paracapsular resection of the front part of the meniscus with hyperplastic growths of synovial tissue is shown. Deformation of the extremety (43 patients — with varus deformity, 2 — with valgus deformity) limited the function of the limb and caused pain. Surgical treatment in such cases were aimed at eliminating the deformation of the proximal part of the tibia. The types of osteotomies, the features of the author's rod external fixation device application, and the postoperative management of patients are presented. Due to external fixator, it is possible to perform, if necessary, angular correction of the limb axis during the period when the patient begins to walk with partial weight bearing, and the functional load of the limb makes it possible to achieve fusion of fragments within 3.5–4 months. A long-term positive clinical effect was obtained in 42 (93 %) patients. Conclusions. Indications for pathogenetic treatment should be based, first of all, on the identification of the source (or pathogenesis) of the pain syndrome, then on the analysis of the type and magnitude of peri-articular deformation of the limb, signs of functional insufficiency of the limb associated with it. In the third place, the X-ray signs should be analyzed. Elimination of angular peri-articular deformation of the limb has a positive effect on the course of knee arthritis, reduces pain, increases physical activity, and slows down the progression of cartilage destruction.

Clinical Presentation of Connective Tissue Disease Patients with and without Interstitial Lung Disease: A Retrospective Study

Background: Connective tissue diseases (CTDs) are responsible for about 20% of interstitial lung disease (ILD) cases, but their diagnosis in a pulmonary unit (PU) is not always straightforward due to a heterogeneous clinical picture. Objectives: The aim of this study was to evaluate the clinical presentation of rheumatoid arthritis (RA) and CTD-ILD cases diagnosed in PU, compared to RA and CTD patients diagnosed in a rheumatologic unit (RU). Methods: Patients with RA, systemic sclerosis (SSc), primary Sjӧgren’s syndrome (pSS), and idiopathic inflammatory myopathy were retrospectively enrolled from an RU and a PU designated to manage ILD during a period from January 2017 to October 2022. The classification of CTD-PU was carried out in a multidisciplinary setting, including the same rheumatologists that diagnosed CTD in the RU. Results: ILD-CTD-PU patients were prevalently male and older. Progression from undifferentiated CTD to a specific condition was more common in ILD-CTD-PU, and those patients generally obtained a lower score on specific classification criteria. RA-PU patients resembled polymyalgia rheumatica in 47.6% of cases, also showing a greater proportion of typical joint deformities (p = 0.02). SSc-PU patients showed a usual interstitial pneumonia pattern in 76% of cases and, compared with SSc-RU, were more commonly seronegative (p = 0.03) and generally lacked fingertip lesions (p = 0.02). The majority of the diagnoses of pSS-PU were in patients with previously diagnosed ILD, in which seropositivity and sicca syndrome developed during follow-up. Conclusions: CTD-ILD patients diagnosed in the PU show severe lung involvement and a nuanced autoimmune clinical picture.

Qualitative and quantitative assessment of diatom deformities and protoplasmic condition under metal and metalloid stress.

Metals and metalloids are toxic, persistent, and non-biodegradable and can be biomagnified (e.g., Hg), and therefore pose a serious threat to the algal flora of aquatic ecosystems. This laboratory study tested the effects of metals (Zn, Fe, and Hg) and a metalloid (As) on the cell wall morphology and protoplasmic content of living cells of six widespread diatom genera over 28days. Diatoms exposed to Zn and Fe had a higher frequency of deformed diatom frustules (> 1%) compared to the As, Hg, and control treatments (< 1%). Deformities in the valve outline and striae were found in all treatments, including the control, whereas deformed raphes and more than one type of deformity were more prevalent under Zn and Hg stress. The order of toxicity is as follows: Zn > Fe > Hg≈As. Deformities were more frequent in Achnanthes and Diploneis (adnate forms) than in the motile genera of Nitzschia and Navicula. The correlation between the % healthy diatoms and % deformities in all six genera showed a negative relationship with the integrity of protoplasmic content (i.e., greater alteration in protoplasmic content was associated with greater frustule deformation). We conclude that diatom deformities can be a good indicator of metal and metalloid stress in waterbodies and are very useful in the rapid biomonitoring of aquatic ecosystems.

Особливості розроблення піроболтів з низькими ударними та віброімпульсними характеристиками

One of the systems in the integrated launch vehicle responsible for prelaunch processing and launch is a ground thermal conditioning system, which supplies the low-pressure air into the launch vehicle’s “dry” compartments. Thermal conditioning system is mated with the launch vehicle, using the mating interfaces, proper functioning of which enhances reliability of the ground support equipment, the launch vehicle and the entire space launch system. The article describes key requirements to the interfaces of the thermal conditioning system and the drawbacks of the existing designs. The article proposes a new design concept of the interface that connects the pipeline of the ground thermal conditioning system to the orifice of the launch vehicle using the corrugated rubber hose composed of three basic parts, attached with the help of a metal lock/release assembly. The proposed solution provides reliable leaktightness, ease of operation, providing multiple connections to the launch vehicle, including at various angles, and automatic disconnection by rocket motion or manual removal in case of launch abort. Using rubber as a high-elasticity structural material to manufacture the hoses, enabled minimization of efforts required to disconnect the interface from the launch vehicle. In its high-elasticity state, rubber can absorb and dissipate mechanical energy within a wide range of temperatures, which prevents transmission of engine vibrations to the ground thermal conditioning system. The article presents key properties of rubber used as a structural material and its peculiarities to be considered during design of similar products. Unlike metal showing two types of deformation (elastic and plastic), rubber can exhibit three types of deformation (elastic, superelastic and plastic). In the process of interface design, we took into account two types of deformations (elastic and superelastic ones). Experimental studies of the interface showed its full compliance with technical specification. Key words: orifice of the launch vehicle, corrugated rubber hose, lock/release assembly, superelastic deformation, leaktightness.

Automated Sagittal Skeletal Classification of Children Based on Deep Learning.

Malocclusions are a type of cranio-maxillofacial growth and developmental deformity that occur with high incidence in children. Therefore, a simple and rapid diagnosis of malocclusions would be of great benefit to our future generation. However, the application of deep learning algorithms to the automatic detection of malocclusions in children has not been reported. Therefore, the aim of this study was to develop a deep learning-based method for automatic classification of the sagittal skeletal pattern in children and to validate its performance. This would be the first step in establishing a decision support system for early orthodontic treatment. In this study, four different state-of-the-art (SOTA) models were trained and compared by using 1613 lateral cephalograms, and the best performance model, Densenet-121, was selected was further subsequent validation. Lateral cephalograms and profile photographs were used as the input for the Densenet-121 model, respectively. The models were optimized using transfer learning and data augmentation techniques, and label distribution learning was introduced during model training to address the inevitable label ambiguity between adjacent classes. Five-fold cross-validation was conducted for a comprehensive evaluation of our method. The sensitivity, specificity, and accuracy of the CNN model based on lateral cephalometric radiographs were 83.99, 92.44, and 90.33%, respectively. The accuracy of the model with profile photographs was 83.39%. The accuracy of both CNN models was improved to 91.28 and 83.98%, respectively, while the overfitting decreased after addition of label distribution learning. Previous studies have been based on adult lateral cephalograms. Therefore, our study is novel in using deep learning network architecture with lateral cephalograms and profile photographs obtained from children in order to obtain a high-precision automatic classification of the sagittal skeletal pattern in children.

Quantifying the effect of non-seasonal non-tidal loadings on background noise properties of GPS vertical displacements in mainland China

Global positioning system (GPS) vertical displacements measuring the elastic response of Earth’s crust to tectonic motion have been used to produce vertical velocity estimates. These accurate estimates require minimal contamination by non-tectonic deformations, mainly including atmospheric-oceanic-hydrologic mass loadings. However, the variability of background noise properties in GPS time-series caused by the removal of these loading deformations remains unclear. In this study, we investigate how the non-seasonal parts of two types of combined non-tidal loading deformations (i.e., atmospheric plus non-tidal oceanic loadings (AO) or AO plus hydrological loadings (AOH)) affect the background noise properties. The study region is focused on the mainland China, and the data are 258 GPS vertical land motion time-series from the Crustal Movement Observation Network of China (CMONOC). Before and after the loading correction, we found that the more satisfactory background noise model is white plus power-law noise. The AO correction achieves significant improvement in white noise estimates and drastically reduces power-law noise content. Meanwhile, the estimated spectral index shows the worse stationarity of background noise properties but can be alleviated by additional hydrological loading correction. Besides, the exploited GPS imaging method reveals the spatial heterogeneity of the background noise amplitude, spectral index, and velocity uncertainty.

GNSS-based long-term deformation at Mount Etna volcano (Italy)

We estimated a long-term velocity field for Mount Etna volcano by taking into account a dense GNSS dataset collected during the 2004.42 - 2018.95 period. To properly isolate the volcanic deformation from the background tectonic one, we defined a new local reference frame (termed MERF23) by using 32 stations mainly located in north-western and south-eastern Sicily. The computed long-term velocity field well highlights contrasting patterns between the north-western flank and the eastern one. The north-western flank was characterized by a general radial pattern with small deformations, mainly related to inflation and deflation episodes occurred during the investigated period. The eastern flank was characterized by a vigorous seaward motion, with rates ranging from ∼60 mm/yr on the Pernicana fault (northern boundary) to ∼29 mm/yr along the Aci Trezza fault (southern boundary), clearly evidencing as flank instability remains by far the predominant type of deformation at Mount Etna. A small contraction along the peripheral base of the volcano, coupled with a small uplift has been also detected; both patterns lend credit to the concurrent action of different processes as local and regional tectonics as well as long-term magmatic doming.

The key role of grain boundary state in deformation-induced softening effect in Al processed by high pressure torsion

The influence of type and amount of additional severe plastic deformation (SPD) on the magnitude of the deformation-induced softening (DIS) effect in ultrafine-grained (UFG) aluminum processed by high-pressure torsion (HPT) has been studied for the first time. Drastic DIS effect (the increase of plasticity from ∼1% to ∼23%), while maintaining high strength (ultimate tensile strength ∼ 180 MPa) is observed after a small additional deformation by HPT to 0.25 turns in UFG aluminum annealed at 150 °C for 1 h. An increase of additional HPT deformation to 0.75 turns does not lead to an increase of the DIS effect. The change of the type of additional deformation from HPT to cold rolling does not lead to any DIS effect, but slight hardening occurs and plasticity remains at low level (1–3%). The analysis of the evolution of the microstructure in correlation with mechanical behavior after annealing and subsequent deformations of both types indicates the key role of the state of the grain boundaries for the DIS effect in pure aluminum processed by HPT.