نتایج جستجو برای: effective lifetime
تعداد نتایج: 734003 فیلتر نتایج به سال:
BACKGROUND Occupational doses from fluoroscopy-guided interventional procedures are the highest ones registered among medical staff using x-rays. The aim of the present study was to evaluate the order of magnitude of cancer risk caused by professional radiation exposure in modern invasive cardiology practice. METHODS From the dosimetric Tuscany Health Physics data bank of 2006, we selected do...
abstract: the lifetime of a cutting tool is an important and determinant parameter for evaluating its performance. the amount of tool abrasion affects seriously dimensions and surface quality of the working piece so that one of the main factors to determine the lifetime of a tool is the level of its wearing. for this purpose, an abrasion standard is defined for each particular tool above which ...
In this research, the lifetime of green organic light emitting diodes (OLEDs) is studied using four passivation layers. To encapsulate the OLEDs, MgF2, YF3, composed of alternating MgF2/ZnS and YF3/ZnS layers were grown by thermal vacuum deposition. Measurements show that the device lifetime is significantly improved by using YF3 and ZnS as passivation layers. However, diodes encapsulated by Mg...
A copper catalyst based on a delafossite precursor (CuAlO(2)) displays high activity and extraordinary lifetime in the gas-phase oxidation of HCl to Cl(2), representing a cost-effective alternative to RuO(2)-based catalysts for chlorine recycling.
Positron annihilation lifetime spectroscopy method with valuation of non-destructive investigation of material, provides information about electron density, defect concentration, type of defects and atoms around the defects. The stability of the system was tested with a source. The time resolution of the whole system has been derived about 365 ps at FWHM. Then n- and p-type silicon samples we...
In this paper, a new five-parameter lifetime and reliability distribution named “the exponentiated Uniform-Pareto distribution (EU-PD),” has been suggested that it has a bathtub-shaped and inverse bathtub-shape for modeling lifetime data. This distribution has applications in economics, actuarial modelling, reliability modeling, lifetime and biological sciences. Firstly, the mathematical and st...
In this paper a new four-parameter lifetime distribution named “the exponentiated Lomax – Rayleigh (E-LR) distribution” has been suggested that it has an increasing hazard rate for modeling lifetime data. The Lomax distribution has applications in economics, actuarial modelling, reliability modeling, lifetime and queuing problems and biological sciences. In this paper Firstly, the mathematical ...
BACKGROUND Atrial fibrillation (AF) is the most common cardiac dysrhythmia and a source of considerable morbidity and mortality, but lifetime risk for AF has not been estimated. METHODS AND RESULTS We included all participants in the Framingham Heart Study who were free of AF at index ages of 40 years and older. We estimated lifetime risks for AF (including atrial flutter) to age 95 years, wi...
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