Search results for "Life time"
showing 10 items of 14 documents
Accelerated bearing life-Time test rig development for low speed data acquisition
2017
Condition monitoring plays an important role in rotating machinery to ensure reliability of the equipment, and to detect fault conditions at an early stage. Although health monitoring methodologies have been thoroughly developed for rotating machinery, low-speed conditions often pose a challenge due to the low signal-to-noise ratio. To this aim, sophisticated algorithms that reduce noise and highlight the bearing faults are necessary to accurately diagnose machines undergoing this condition. In the development phase, sensor data from a healthy and damaged bearing rotating at low-speed is required to verify the performance of such algorithms. A test rig for performing accelerated life-time t…
Seafood Consumption, Omega-3 Fatty Acids Intake, and Life-Time Prevalence of Depression in the PREDIMED-Plus Trial.
2018
Background: The aim of this analysis was to ascertain the type of relationship between fish and seafood consumption, omega-3 polyunsaturated fatty acids (&omega
Application of the Dang‐Van criterion for life determination under uniaxial random tension–compression with different mean values
2004
In this paper the experimental fatigue lives of specimens made of 10HNAP steel with the lives calculated with the Goodman and Gerber methods of cycle amplitude transformation and the Dang Van criterion for uniaxial loading are compared. Cycles were counted with the rain flow algorithm and damage was accumulated according to the Palmgren-Miner hypothesis. This paper includes comparison of the results for constant amplitude loading with a non-zero mean value and for random loading with zero or non-zero mean values. It has been shown that for 10HNAP steel the algorithm of fatigue life calculations using the Dang Van criterion gives satisfactory results.
A statistic approach of cables ageing in MV lines on thermal and electrical combined stress
2006
The paper introduces a methodology that through a probabilistic characterisation of load for MV network, and implementing a life model for combined electric and thermal stresses, simulates the process of ageing of the insulating materials evaluating the expected life time of the cable. Such evaluation is necessary to the possibility of assuming less restrictive thermal overloading limits on electrical cables, with the consequential increase on reserve that cables could offer. A numerical example is reported to better explain the methodology
Aging and Cell Aging: An Introduction
2013
Since more than 100 years people are constantly growing older and a further significant increase in life time is expected in the decades to come. A person born today has a high statistical chance to reach the age of 100, to become a centenarian. Since aging is the primary risk factor for many human disorders it is mandatory to understand the aging process and how it affects onset and course of disorders of the elderly. Scientifically the medium life span is discriminated from the maximum life span. While the latter is rather constant at approximately 120 years the medium life span is increasing. But not only the whole organism, also each single cell out of the billions making up our body ha…
High-resolution records of past and modern Pb exposure: Laser-ablation ICPMS profiles from tooth enamel
2006
We present compositional and isotopic profiles of past and modern tooth enamel aimed at reconstructing in-vivo Pb exposure at high spatial and time resolution. Focus is on dental enamel because of its sequential mineralization preserving time-series information, and due to its resistance to post-mortem diagenetic alteration. Examples include medieval Pb–Ag miners from SW Germany (Black Forest), the port of ancient Rome (Isola Sacra) for an assessment of the ‘Pb poisoning hypothesis’, and a modern Pb–Zn smelter village in NE NSW. (Sub-)ppb levels of U, LREEs, Y in soil-buried enamel resembling modern enamel are utilized as indicators for the preservation of pristine in-vivo concentrations. T…
Heterogeneity at the glass transition: what do we know?
2002
We critically discuss the information that can be obtained from experiments with respect to the existence, the life time, and the length scale of dynamical heterogeneity in glass-forming liquids. The ability to select a dynamically distinguishable subensemble and observe its return to the full equilibrium ensemble is illustrated by examples from multi-dimensional NMR. We also discuss non-resonant hole burning spectroscopy as an example for which two separate time scales are involved.
Effects of age and life-time physical training on fibre composition of slow and fast skeletal muscle in rats.
1987
The effects of age and endurance training on muscle fibre characteristics were studied in a slow (m. soleus, MS) and in a fast (m. rectus femoris, MRF) skeletal muscle. Wistar rats at ages of 1, 2, 4, 10, and 24 months were used as experimental animals. The trained rats were put to run on a motor-driven treadmill 5 d/wk beginning from the age of 1 month. The body weights of the animals increased continuously throughout their lives. The muscle weights increased up to the age of 10 months, after which they tended to decrease. The trained adult rats had lower body weights as well as lower muscle weights than the untrained adult rats. The amount of the intramuscular lipid decreased with age, es…
Features of level broadening in a ring-stub system
2000
When a one dimensional (1D) ring-stub system is coupled to an electron reservoir, the states acquire a width (or broadening characterized by poles in the complex energy plane) due to finite life time effects. We show that this broadening is limited by anti-resonances due to the stub. The differences in level broadening in presence and absence of anti-resonance is exemplified by comparison to a 1D ring coupled to an infinite reservoir. We also show that the anti-resonances due to the stub has an anchoring effect on the poles when a magnetic flux through the ring is varied. This will have implication on change in distribution of the poles in disordered multichannel situation as magnetic flux …
Annual effective dose and excess life time cancer risk assessment from tobacco plants
2019
Cigarette smoking is one of the pathways that might cause radiation exposure due to the presence of radioactive elements in tobacco leaves used in the manufacture of cigarettes. From the health point of view, the knowledge of radioactivity content of the various radionuclides in tobacco leaves and their derivative products is important to assess the radiological effects associated with tobacco smoking for smokers. In this work, naturally occurring radionuclides 226Ra, 232Th and 40K and man-made 137Cs were measured in tobacco using gamma-ray spectrometry. Results show that the average concentrations of 226Ra, 232Th and 40K vary from 4.30 ± 0.2 to 11.85 ± 0.7 (average 8.17), 1.35 ± 0.1 to 16.…