Search results for "fatigue"
showing 10 items of 651 documents
Data for: PERCEIVED PHYSICAL EXERTION IS A GOOD INDICATOR OF NEUROMUSCULAR FATIGUE OF THE CORE MUSCLES
2019
EMG RMS, EMG median frequency, RPE and angle pelvis values. THIS DATASET IS ARCHIVED AT DANS/EASY, BUT NOT ACCESSIBLE HERE. TO VIEW A LIST OF FILES AND ACCESS THE FILES IN THIS DATASET CLICK ON THE DOI-LINK ABOVE
Probabilistic models for the fatigue resistance of welded steel joints subjected to constant amplitude loading
2022
Abstract S-N curves found in various rules and regulations are the basic tool for the practicing engineer when carrying out life predictions for welded details in dynamically loaded structures. The present work is investigating the expected fatigue life and associated scatter for welded steel joints subjected to Constant Amplitude (CA) loading. The objective is to obtain more reliable life predictions based on advancements in the probabilistic model fitted to collected life data. A Random Fatigue Limit Model (RFLM) is proposed to obtain fatigue resistance curves at given probability levels of survival. As a distinction to more conventional statistical methods, the model is treating both the…
Magnesium Role in Health and Longevity
2018
Reduced Magnesium (Mg) intake is a frequent cause of Mg deficit with age. A decreased intestinal Mg absorption and an increased Mg loss may also contribute, as well as the use of medicaments. Furthermore, Mg requirements may be higher with aging. Alterations of Mg metabolism with age, cellular Mg transport systems and problems with measurement methods are discussed. Mg contained in water is more bio-available than Mg in food and it is a possible alternative to Mg supplementation in the correction of Mg deficiencies. Mild to moderate Mg deficits are generally asymptomatic and clinical signs are usually absent or non-specific. Hyperemotionality, tremor, asthenia, sleep disorders, and amnesic …
Optimal die Design for Cold Extrusion Processes
1999
The design of cold extrusion processes requires the optimisation of several process variables in order to obtain a defect free product. The fulfilment of different objectives, such as the minimisation of forming loads or the homogeneity of the deformations, is highly requested. Nevertheless, several other relevant aspects of extrusion processes have to be taken into account and require a suitable optimisation of the process parameters and in particular of the die shape. In this paper, tool life has been assumed as the most relevant goal and an effective die design procedure as been setup. It is well known that fatigue cracking of the dies is the principal cause of dies failure in cold extru…
A hardware skin-segmentation IP for vision based smart ADAS through an FPGA prototyping
2017
International audience; In this paper we presents a platform based design approach for fast HW/SW embedded smart Advanced Driver Assistant System (ADAS) design and prototyping. Then, we share our experience in designing and prototyping a HW/SW vision based smart embedded system as an ADAS that helps to increase the safety of car's drivers. We present a physical prototype of the vision ADAS based on a Zynq FPGA. The system detects the fatigue state of the driver by monitoring the eyes closure and generates a real-time alert. A new HW/SW codesign skin segmentation step to locate the eyes/face is proposed. Our presented new approach migrates the skin segmentation step from processing system (S…
Molecular hydrogen (H 2 ) as a potential treatment for acute and chronic fatigue
2020
Many diseases as well as acute conditions can lead to fatigue, which can be either temporary or chronic in nature. Acute fatigue develops frequently after physical exercise or after alcohol hangover, whereas microbial infections such as influenza or COVID-19 and chronic diseases like Parkinson's disease or multiple sclerosis are often associated with chronic fatigue. Oxidative stress and a resulting disturbance of mitochondrial function are likely to be common denominators for many forms of fatigue, and antioxidant treatments have been shown to be effective in alleviating the symptoms of fatigue. In this study, we review the role of reactive oxygen and nitrogen species in fatigue and the an…
CONSIDERAZIONI TEORICHE E PRATICHE SUL METODO DEL MASSIMO RETTANGOLO CIRCOSCRITTO PER LA VALUTAZIONE DELL’AMPIEZZA DELLA TENSIONE TANGENZIALE NEI CRI…
2012
The multiaxial fatigue criteria based on the approach of the critical plane require the determination of the amplitude of the alternating shear stress τ aacting on different planes passing through the point of the material analyzed. In the case of non-proportional stresses the shear stress vector varies both in modulus and direction and its tip describes a curvedefined loading path. In these cases τ ais identified and evaluated by means of special procedures the most recent, and apparently more effective, of which is that of the Maximum Circumscribed Rectangle (MCR) to the loading path itself. In particular τ ais equal to the length of the diagonal of the MCR. In this paper, the MCR method …
Improvements in the algorithms for the determination of the shear stress components in critical plane class fatigue criteria
2010
This paper presents two improvements in the procedure for the evaluation of the amplitude and mean values of the shear stress in critical plane class fatigue criteria, when the method of the Minimum Circumscribed Circle (MCC) to the path of the tip of the vector is used. In particular, the paper shows how it is possible to reduce the number of material planes passing through the point of interest in which the MCC has to be determined and the number of points of each curve that has to be considered for the determination of the MCC, noticeably reducing the computational time.
Three different approaches to cognitive fatigue in patients with a mild form of multiple sclerosis : objective cognitive, subjective cognitive and ne…
2017
Tämän tutkimuksen tarkoitus oli arvioida kognitiivista uupumusta lievää multippeli skleroosin (MS) muotoa sairastavilla potilailla kolmea eri lähestymistapaa käyttäen: objektiivista kognitiivista, subjektiivista kognitiivista ja neurofysiologista. Objektiivista kognitiivista uupumusta arvioitiin tarkkaavuuden ylläpitoa, reaktionopeutta ja työmuistia mittaavilla tehtävillä. Subjektiivista kognitiivista uupumusta sekä elämänlaatua arvioitiin itsearvioilla. Neurofysiologiset mittaukset käsittivät aivojen sähköiin herätevasteisiin perustuvia observaatioita. Mittareina olivat kontingentti negatiivinen variaatio (CNV) ja P3. Tutkimukseen osallistui 20 MS-tautia sairastavaa ja 20 verrallistettua t…
Mental Fatigue Effects on the Produced Perception of Effort and Its Impact on Subsequent Physical Performances.
2022
The purpose of this study was to investigate the relationship between mental fatigue induced by a demanding cognitive task and impaired physical performance in endurance due to a higher perception of effort. A total of 12 healthy adults and volunteers, who had previously practiced endurance activities for 4 to 8 h per week, performed a one-hour cognitive task involving either the process of response inhibition (Stroop task) or not (visualization of a documentary as control task), then 20 min of pedaling on a cycle ergometer at a constant perception of effort while cardio-respiratory and neuromuscular functions were measured. The Stroop task induces subjective feelings of mental fatigue (vig…