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Patterns of cellular phone use among young people in 12 countries: Implications for RF exposure
Langer, Chelsea E.,de Llobet, Patricia,Dalmau, Albert,Wiart, Joe,Goedhart, Geertje,Hours, Martine,Benke, Geza P.,Bouka, Evdoxia,Bruchim, Revital,Choi, Kyung-Hwa,Eng, Amanda,Ha, Mina,Karalexi, Maria,Ki Elsevier 2017 Environment international Vol.107 No.-
<P><B>Abstract</B></P> <P>Characterizing exposure to radiofrequency (RF) fields from wireless telecommunications technologies during childhood and adolescence is a research priority in investigating the health effects of RF. The Mobi-Expo study aimed to describe characteristics and determinants of cellular phone use in 534 young people (10–24years) in 12 countries. The study used a specifically designed software application installed on smartphones to collect data on the use of wireless telecommunications devices within this age group. The role of gender, age, maternal education, calendar period, and country was evaluated through multivariate models mutually adjusting for all variables. Call number and duration were higher among females compared to males (geometric mean (GM) ratio 1.17 and 1.42, respectively), among 20–24year olds compared to 10–14year olds (GM ratio 2.09 and 4.40, respectively), and among lowest compared to highest social classes (GM ratio 1.52 and 1.58, respectively). The number of SMS was higher in females (GM ratio 1.46) and the middle age group (15–19year olds: GM ratio 2.21 compared to 10–14year olds) and decreased over time. Data use was highest in the oldest age group, whereas Wi-Fi use was highest in the middle age group. Both data and Wi-Fi use increased over time. Large differences in the number and duration of calls, SMS, and data/Wi-Fi use were seen by country, with country and age accounting for up to 50% of the variance. Hands-free and laterality of use did not show significant differences by sex, age, education, study period, or country. Although limited by a convenience sample, these results provide valuable insights to the design, analysis, and interpretation of future epidemiological studies concerning the health effects of exposure resulting from cellular phone use in young people. In addition, the information provided by this research may be used to design strategies to minimize RF exposure.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Number and duration of calls varied by sex, age range, and socioeconomic status </LI> <LI> Laterality and hands-free use were less influenced by user characteristics </LI> <LI> Country of origin explained most of the variance in number and duration of calls, as well as SMS and data/Wi-Fi </LI> </UL> </P>
정일경,성연수,송태권,M. H. Kim,A. Llobet 한국물리학회 2015 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.67 No.9
We performed neutron powder diffraction measurements on (Bi0.5Na0.5+x)TiO3 and (Bi0.5+y Na0.5)TiO3 to study the structural evolution induced by the non-stoichiometry. Despite the nonstoichiometry, the local structure (r 3.5 °A) from the pair distribution function analysis is barely affected by a sodium deficit of up to −5 mol%. With increasing pair distance, however, the atomic pair correlations weaken due to the disorder caused by the sodium deficiency. Although the sodium and the bismuth share the same crystallographic site, their non-stoichiometries have rather opposite effects as revealed from distinctive distortions of the Bragg peaks. In addition, a Rietveld refinement demonstrates that the octahedral tilting is continually suppressed for sodium deficits up to −5 mol%. This is contrary to the effect of the bismuth deficiency, which induces little variation in the octahedral tilting.
Jeong, I.-K.,Lee, Seunghun,Llobet, A. American Institute of Physics 2012 Journal of Applied Physics Vol.112 No.7
<P>Neutron total scattering measurements were performed at 300 K and 15 K to study local structural disorder in deuterium plasma treated and as-prepared Zn0.9Co0.1O nanocrystalline powder. We found that static disorder becomes a determining factor for atomic pair correlations on the length scale larger than r similar to 9 angstrom. On the source of the static disorder, we propose a partial occupancy of Zn/Co further away from its crystallographic site along the c-axis. Between the deuterium plasma treated and as-prepared Zn0.9Co0.1O samples, we observed no local structural difference, which suggests that no additional disorder is induced by the deuterium plasma treatment. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4758183]</P>
Hong, Dachao,Mandal, Sukanta,Yamada, Yusuke,Lee, Yong-Min,Nam, Wonwoo,Llobet, Antoni,Fukuzumi, Shunichi American Chemical Society 2013 Inorganic chemistry Vol.52 No.16
<P>Thermal water oxidation by cerium(IV) ammonium nitrate (CAN) was catalyzed by nonheme iron complexes, such as Fe(BQEN)(OTf)<SUB>2</SUB> (<B>1</B>) and Fe(BQCN)(OTf)<SUB>2</SUB> (<B>2</B>) (BQEN = <I>N</I>,<I>N</I>′-dimethyl-<I>N</I>,<I>N</I>′-bis(8-quinolyl)ethane-1,2-diamine, BQCN = <I>N</I>,<I>N</I>′-dimethyl-<I>N</I>,<I>N</I>′-bis(8-quinolyl)cyclohexanediamine, OTf = CF<SUB>3</SUB>SO<SUB>3</SUB><SUP>–</SUP>) in a nonbuffered aqueous solution; turnover numbers of 80 ± 10 and 20 ± 5 were obtained in the O<SUB>2</SUB> evolution reaction by <B>1</B> and <B>2</B>, respectively. The ligand dissociation of the iron complexes was observed under acidic conditions, and the dissociated ligands were oxidized by CAN to yield CO<SUB>2</SUB>. We also observed that <B>1</B> was converted to an iron(IV)-oxo complex during the water oxidation in competition with the ligand oxidation. In addition, oxygen exchange between the iron(IV)-oxo complex and H<SUB>2</SUB><SUP>18</SUP>O was found to occur at a much faster rate than the oxygen evolution. These results indicate that the iron complexes act as the true homogeneous catalyst for water oxidation by CAN at low pHs. In contrast, light-driven water oxidation using [Ru(bpy)<SUB>3</SUB>]<SUP>2+</SUP> (bpy = 2,2′-bipyridine) as a photosensitizer and S<SUB>2</SUB>O<SUB>8</SUB><SUP>2–</SUP> as a sacrificial electron acceptor was catalyzed by iron hydroxide nanoparticles derived from the iron complexes under basic conditions as the result of the ligand dissociation. In a buffer solution (initial pH 9.0) formation of the iron hydroxide nanoparticles with a size of around 100 nm at the end of the reaction was monitored by dynamic light scattering (DLS) in situ and characterized by X-ray photoelectron spectra (XPS) and transmission electron microscope (TEM) measurements. We thus conclude that the water oxidation by CAN was catalyzed by short-lived homogeneous iron complexes under acidic conditions, whereas iron hydroxide nanoparticles derived from iron complexes act as a heterogeneous catalyst in the light-driven water oxidation reaction under basic conditions.</P><P>Water oxidation by Ce<SUP>IV</SUP> was catalyzed by nonheme iron complexes under acidic conditions. The ligand of the iron complexes dissociated and oxidized to yield CO<SUB>2</SUB>, resulting in limited reactivity. In contrast to the homogeneous catalysis under acidic conditions, light-driven water oxidation was catalyzed by iron hydroxide nanoparticles derived from the iron complexes as the result of the ligand dissociation under basic conditions.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/inocaj/2013/inocaj.2013.52.issue-16/ic401180r/production/images/medium/ic-2013-01180r_0014.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/ic401180r'>ACS Electronic Supporting Info</A></P>
Fukuzumi, Shunichi,Mandal, Sukanta,Mase, Kentaro,Ohkubo, Kei,Park, Hyejin,Benet-Buchholz, Jordi,Nam, Wonwoo,Llobet, Antoni American Chemical Society 2012 JOURNAL OF THE AMERICAN CHEMICAL SOCIETY - Vol.134 No.24
<P>Four-electron reduction of O<SUB>2</SUB> by octamethylferrocene (Me<SUB>8</SUB>Fc) occurs efficiently with a dinuclear cobalt-μ-1,2-peroxo complex, <B>1</B>, in the presence of trifluoroacetic acid in acetonitrile. Kinetic investigations of the overall catalytic reaction and each step in the catalytic cycle showed that proton-coupled electron transfer from Me<SUB>8</SUB>Fc to <B>1</B> is the rate-determining step in the catalytic cycle.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jacsat/2012/jacsat.2012.134.issue-24/ja303674n/production/images/medium/ja-2012-03674n_0011.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/ja303674n'>ACS Electronic Supporting Info</A></P>