Search results for "STRESS"
showing 10 items of 6278 documents
Influence of the passive film properties and residual stresses on the micro-electrochemical behavior of duplex stainless steels
2010
In the present paper, the chemical composition of passive films formed on both phases of two types of duplex stainless steels (UNS S31803 and UNS S32304) is determined at the micro-scale using Auger electron spectroscopy (AES). Samples were either mechanically polished (down to diamond pastes) or electrochemically etched in acidic solutions. The micro-electrochemical behavior of samples was then determined in sodium chloride media by means of the electrochemical micro-cell technique (capillary diameters of 30 μm). The results obtained were analyzed considering the passive film chemical composition. Quantitative relationships between electrochemical parameters and the distribution of chromiu…
Localized hydrogen cracking in the austenitic phase of a duplex stainless steel
1996
The aim of this study is to investigate the role of hydrogen on the mechanical behavior of an austenitic phase, in the particular situation of duplex stainless steels. In these duplex alloys, in presence of hydrogen, the ferritic phase is embrittled by hydrogen and the resistance to cracking is mainly related to the behavior of the austenitic phase. Thus, a discussion of the role of hydrogen at the crack tip of a duplex alloy (as function of the microstructure) has been proposed by T. Perng and C.J. Altester after experiments conducted in gaseous environment. A similar experimental approach has been followed in this study; slow strain rate tests (SSRT) have been performed on duplex stainles…
Influence of friction on the local mechanical and electrochemical behaviour of duplex stainless steels.
2006
International audience; The electrochemical behaviour of ferritic and austenitic phases in duplex stainless steel (UNS S32304) and the modifications induced by straining during sliding were studied by potentiodynamic polarisation curves determined at the microscale in a 1MNaCl (pH 3) solution, using an electrochemical microcell. The mechanical properties and stress state of each phase were determined by microhardness and X-ray microdiffraction measurements, before and after straining. The results show that sliding generates elastic straining of the ferrite and plastic deformation of the austenite. The electrochemical behaviour of these phases is dramatically altered, inducing a reduction of…
Study of the mechanical effects on passivity breakdown by local probe techniques
2006
This paper aims at demonstrating that a relationship exists between surface stress and pitting corrosion. The surface stress field generated by polishing was first calculated using a thermo-mechanical model and a finite element code. Pitting corrosion tests performed at the microscale along the austenite/ferrite interface using the electrochemical microcell technique were then analyzed considering the microstructure and the residual surface stress field. Mechano-chemical criteria are proposed leading to an enhancement of pitting corrosion of duplex steels.
Saikne starp stresu un izdegšanu autiskā spektra traucējumu bērnu vecākiem
2020
Ievads. Autiskā spektra traucējumi (AST) biežāk raksturojas ar agrīnu sākumu. Galvenie raksturlielumi ir traucējumi sociālajā komunikācijā un sociālajā mijiedarbībā, ko papildina ierobežota un atkārtojoša izturēšanās. Attiecīgi šāda milzīga uzmanība, ko bērns pieprasa, varētu sekmēt vecāku izdegšanas pazīmes. Darba mērķis. Ir identificēt izdegšanas faktorus, kas ietekmē autisma spektra bērnu vecāku ikdienas dzīvi. Metodes un materiāli. Šķērsgriezuma pētījumā tika iesaistīti 76 bērnu ar autiska spektra traucējumu vecāki, kuri pilnīgi anonīmi aizpildīja aptaujas. Pielietotās aptaujas bija demogrāfiskā aptauja, Široma-Melameda izdegšanas mēra aptauja, un Stresa skala, kura tika izveidota no Pe…
Neuropsychological Profile, Emotional/Behavioral Problems, and Parental Stress in Children with Neurodevelopmental Disorders
2021
Background: The aim of our study was to trace a specific neuropsychological profile, to investigate emotional-behavioral problems and parental stress in children with Autism Spectrum Disorder Level 1/High functioning (ASD-HF), Specific Learning Disorders (SLD) and Attention Deficit/Hyperactivity Disorder (ADHD) disorders and to highlight similarities and differences among the three groups. Methods: We retrospectively collected the data from a total of 62 subjects with ASD-HF (n = 19) ADHD (n = 21), SLD (n = 22) and 20 typical development. All the participants underwent neuropsychological standardized test for the evaluation of cognitive profile (Wechsler Intelligence Scale for Children Four…
Hsp70 and Its Molecular Role in Nervous System Diseases
2011
Heat shock proteins (HSPs) are induced in response to many injuries including stroke, neurodegenerative disease, epilepsy, and trauma. The overexpression of one HSP in particular, Hsp70, serves a protective role in several different models of nervous system injury, but has also been linked to a deleterious role in some diseases. Hsp70 functions as a chaperone and protects neurons from protein aggregation and toxicity (Parkinson disease, Alzheimer disease, polyglutamine diseases, and amyotrophic lateral sclerosis), protects cells from apoptosis (Parkinson disease), is a stress marker (temporal lobe epilepsy), protects cells from inflammation (cerebral ischemic injury), has an adjuvant role i…
The self-reported stress and stressors in tram and long-haul truck drivers
2022
Work stress may compromise professional drivers’ health and driving capacity. Differences between driver groups in terms of on-duty stress are understudied. Therefore, we examined self-reported stress (Stockholm University Stress Scale) of shift-working tram and long-haul truck drivers (n = 75) across 2–3 weeks. Furthermore, stressors were self-reported retrospectively and categorised as related to the job, driving conditions, personal, or other causes. Stress levels were generally low, but moderate to high stress (≥6) was more frequently reported among the tram drivers. Stressors related to the job (54%) and driving conditions (19% of all shifts) were frequently reported among the tram and…
Effects of anxiety during mental arithmetic stress on heart rate variability in healthy subjects
2011
Aim: Anxiety may cause an increased risk of myocardial infarction by reductions in heart rate variability (HRV). However, no data exists on the effect of anxiety on a standard mental test of HRV. The aim of this study was to evaluate the association between anxiety elicited by mental stress and HRV. Methods: Effect of anxiety in the actual state (A-State) and in everyday life (A-Trait) has been assessed in 13 healthy subjects and its association to low (LF) and high-frequency (HF) of HRV during mental arithmetic stress has been tested through correlation analysis. Results: A significant increase from baseline through arithmetic stress was observed in the LF component (LF(nu) from 56.87 ± 4.…
p62: Friend or Foe? Evidences for OncoJanus and NeuroJanus Roles
2020
p62 is a versatile protein involved in the delicate balance between cell death and survival, which is fundamental for cell fate decision in the context of both cancer and neurodegenerative diseases. As an autophagy adaptor, p62 recognizes polyubiquitin chains and interacts with LC3, thereby targeting the selected cargo to the autophagosome with consequent autophagic degradation. Beside this function, p62 behaves as an interactive hub in multiple signalling including those mediated by Nrf2, NF-κB, caspase-8, and mTORC1. The protein is thus crucial for the control of oxidative stress, inflammation and cell survival, apoptosis, and metabolic reprogramming, respectively. As a multifunctional pr…