Browsing by Subject "ABSOLUTE"

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  • Lahelma, Eero; Pietilainen, Olli; Pentala-Nikulainen, Oona; Helakorpi, Satu; Rahkonen, Ossi (2019)
    Health inequalities exist across countries and populations, but little is known about their long-term trends and even less about factors shaping the trends. We examined the magnitude of absolute and relative educational inequalities in self-rated health over 36 years among Finnish adults, considering individual covariates and macro-economic fluctuations. Our data were derived from representative annual cross-sectional surveys in 1979-2014 conducted among adult men and women. Participants aged 25-64 were included and nine periods used (n = 8870-14235). Our health outcome was less-than-good self-rated health (SRH) and our socioeconomic indicator was completed years of education as a continuous variable. Educational inequalities in self-rated health were analysed using the relative index of inequality (RII) and the slope index of inequality (SII). Nine time-variant sociodemographic and health-related covariates were included in the analyses. Linear trends suggested stable or slightly curvilinear overall trends in both absolute and relative health equalities over 36 years. Among men, absolute and relative inequalities narrowed immediately after economic recession in Finland in 1993-1994. Among women, inequalities narrowed during financial crisis in 2008-2009. Adjusting for most covariates reduced the magnitude of inequalities throughout the nine periods, but affected little the temporal patterning of health inequalities. Educational inequalities in self-rated health remained during 36 years in Finland. While among men and women health inequalities narrowed during and after recessions, they widened soon back to the pre-recession level. The perseverance of the trends calls for novel and powerful measures to tackle health inequalities.
  • Donsberg, Timo; Manoocheri, Farshid; Sildoja, Meelis; Juntunen, Mikko; Savin, Hele; Tuovinen, Esa; Ronkainen, Hannu; Prunnila, Mika; Merimaa, Mikko; Tang, Chi Kwong; Gran, Jarle; Mueller, Ingmar; Werner, Lutz; Rougie, Bernard; Pons, Alicia; Smid, Marek; Gal, Peter; Lolli, Lapo; Brida, Giorgio; Rastello, Maria Luisa; Ikonen, Erkki (2017)
    The predictable quantum efficient detector (PQED) consists of two custom-made induced junction photodiodes that are mounted in a wedged trap configuration for the reduction of reflectance losses. Until now, all manufactured PQED photodiodes have been based on a structure where a SiO2 layer is thermally grown on top of p-type silicon substrate. In this paper, we present the design, manufacturing, modelling and characterization of a new type of PQED, where the photodiodes have an Al2O3 layer on top of n-type silicon substrate. Atomic layer deposition is used to deposit the layer to the desired thickness. Two sets of photodiodes with varying oxide thicknesses and substrate doping concentrations were fabricated. In order to predict recombination losses of charge carriers, a 3D model of the photodiode was built into Cogenda Genius semiconductor simulation software. It is important to note that a novel experimental method was developed to obtain values for the 3D model parameters. This makes the prediction of the PQED responsivity a completely autonomous process. Detectors were characterized for temperature dependence of dark current, spatial uniformity of responsivity, reflectance, linearity and absolute responsivity at the wavelengths of 488 nm and 532 nm. For both sets of photodiodes, the modelled and measured responsivities were generally in agreement within the measurement and modelling uncertainties of around 100 parts per million (ppm). There is, however, an indication that the modelled internal quantum deficiency may be underestimated by a similar amount. Moreover, the responsivities of the detectors were spatially uniform within 30 ppm peak-to-peak variation. The results obtained in this research indicate that the n-type induced junction photodiode is a very promising alternative to the existing p-type detectors, and thus give additional credibility to the concept of modelled quantum detector serving as a primary standard. Furthermore, the manufacturing of PQEDs is no longer dependent on the availability of a certain type of very lightly doped p-type silicon wafers.