Nuclear power will continue to provide energy for the foreseeable future, but it can pose significant challenges in terms of the disposal of waste and potential release of untreated radioactive ...substances. Iodine is a volatile product from uranium fission and is particularly problematic due to its solubility. Different isotopes of iodine present different issues for people and the environment.
I has an extremely long half-life of 1.57 × 10
years and poses a long-term environmental risk due to bioaccumulation. In contrast,
I has a shorter half-life of 8.02 days and poses a significant risk to human health. There is, therefore, an urgent need to develop secure, efficient and economic stores to capture and sequester ionic and neutral iodine residues. Metal-organic framework (MOF) materials are a new generation of solid sorbents that have wide potential applicability for gas adsorption and substrate binding, and recently there is emerging research on their use for the selective adsorptive removal of iodine. Herein, we review the state-of-the-art performance of MOFs for iodine adsorption and their host-guest chemistry. Various aspects are discussed, including establishing structure-property relationships between the functionality of the MOF host and iodine binding. The techniques and methodologies used for the characterisation of iodine adsorption and of iodine-loaded MOFs are also discussed together with strategies for designing new MOFs that show improved performance for iodine adsorption.
High resolution atomic force microscopy (AFM) is used to resolve the evolution of crystallites of a metal organic framework (HKUST-1) grown on Au(111) using a liquid-phase layer-by-layer methodology. ...The nucleation and faceting of individual crystallites is followed by repeatedly imaging the same submicron region after each cycle of growth and we find that the growing surface is terminated by {111} facets leading to the formation of pyramidal nanostructures for 100 oriented crystallites, and triangular 111 islands with typical lateral dimensions of tens of nanometres. AFM images reveal that crystallites can grow by 5–10 layers in each cycle. The growth rate depends on crystallographic orientation and the morphology of the gold substrate, and we demonstrate that under these conditions the growth is nanocrystalline with a morphology determined by the minimum energy surface.
High-pressure single-crystal X-ray structural analyses of isostructural MFM-133(M) (M = Zr, Hf) of flu topology and incorporating the tetracarboxylate ligand TCHB4– H4TCHB = ...3,3′,5,5′-tetrakis(4-carboxyphenyl)-2,2′,4,4′,6,6′-hexamethyl-1,1′-biphenyl and {M6(μ3-OH)8(OH)8(COO)8} clusters confirm negative linear compressibility (NLC) behavior along the c axis. This occurs via a three-dimensional wine-rack NLC mechanism leading to distortion of the octahedral cage toward a more elongated polyhedron under static compression. Despite the isomorphous nature of these two structures, MFM-133(Hf) shows a higher degree of NLC than the Zr(IV) analogue. Thus, for the first time, we demonstrate here that the NLC property can be effectively tuned in a framework material by simply varying the inorganic component of the frameworks without changing the network topology and structure.
This article uses random and fixed effects regressions with 743,788 observations from panels of East and West Germany, the UK, Australia, South Korea, Russia, Switzerland and the United States. It ...shows how the life satisfaction of men and especially fathers in these countries increases steeply with paid working hours. In contrast, the life satisfaction of childless women is less related to long working hours, while the life satisfaction of mothers hardly depends on working hours at all. In addition, women and especially mothers are more satisfied with life when their male partners work longer, while the life satisfaction of men hardly depend on their female partners’ work hours. These differences between men and women are starker where gender attitudes are more traditional. They cannot be explained through differences in income, occupations, partner characteristics, period or cohort effects. These results contradict role expansionist theory, which suggests that men and women profit similarly from moderate work hours; they support role conflict theory, which claims that men are most satisfied with longer and women with shorter work hours.
We apply event history analysis to analyze career and publication data of virtually all political scientists in German university departments, showing that each published refereed journal article ...increases a political scientist's chance for tenure by 9 percent, while other publications affect the odds for tenure only marginally and in some cases even negatively. Each received award and third party funding increases the odds for tenure by respectively 41 and 26 percent, while international experience, social capital and children hardly have a strong influence. Surprisingly, having degrees from a German university of excellence strongly decreases the odds for tenure. Women with similar credentials have at least 20 percent higher odds to get tenure than men. Our data therefore suggests that the lower factual hiring rates of women are better explained by a leaky pipeline, e.g. women leaving academia, rather than because women are not hired even when they are as productive as men. The article contributes to a better understanding of the role of meritocratic and non-meritocratic factors in achieving highly competitive job positions.
A robust binary hydrogen-bonded supramolecular organic framework (SOF-7) has been synthesized by solvothermal reaction of 1,4-bis-(4-(3,5-dicyano-2,6-dipyridyl)dihydropyridyl)benzene (1) and ...5,5′-bis-(azanediyl)-oxalyl-diisophthalic acid (2). Single crystal X-ray diffraction analysis shows that SOF-7 comprises 2 and 1,4-bis-(4-(3,5-dicyano-2,6-dipyridyl)pyridyl)benzene (3); the latter formed in situ from the oxidative dehydrogenation of 1. SOF-7 shows a three-dimensional four-fold interpenetrated structure with complementary O–H···N hydrogen bonds to form channels that are decorated with cyano and amide groups. SOF-7 exhibits excellent thermal stability and solvent and moisture durability as well as permanent porosity. The activated desolvated material SOF-7a shows high CO2 adsorption capacity and selectivity compared with other porous organic materials assembled solely through hydrogen bonding.
Efficient electro-reduction of CO2 over metal–organic framework (MOF) materials is hindered by the poor contact between thermally synthesized MOF particles and the electrode surface, which leads to ...low Faradaic efficiency for a given product and poor electrochemical stability of the catalyst. We report a MOF-based electrode prepared via electro-synthesis of MFM-300(In) on an indium foil, and its activity for the electrochemical reduction of CO2 is assessed. The resultant MFM-300(In)-e/In electrode shows a 1 order of magnitude improvement in conductivity compared with that for MFM-300(In)/carbon-paper electrodes. MFM-300(In)-e/In exhibits a current density of 46.1 mA cm–2 at an applied potential of −2.15 V vs Ag/Ag+ for the electro-reduction of CO2 in organic electrolyte, achieving an exceptional Faradaic efficiency of 99.1% for the formation of formic acid. The facile preparation of the MFM-300(In)-e/In electrode, coupled with its excellent electrochemical stability, provides a new pathway to develop efficient electro-catalysts for CO2 reduction.
This article shows for the first time that people are less satisfied when inequality in their country is higher than before, but not when inequality in their country is higher than in another ...country. It distinguishes this between- and within-country effect of inequality on life satisfaction by using hybrid regressions with the World Values Survey, the British Household Panel Study, the Australian panel study of Household Income and Labour Dynamics, the Korean Labor and Income Panel, the Russian Longitudinal Monitoring study, the Swiss Household Panel and the German Socio-Economic Panel. That life satisfaction is unaffected by long-run levels of inequality, but by changes of inequality over time, suggests that life satisfaction researchers should focus on changes of inequality over time to understand its influence on life satisfaction.
Reaction of β-amino-β-(pyrid-4-yl)acrylonitrile with the aromatic dicarboxaldehydes 9,10-bis(4-formylphenyl)anthracene and terephthalaldehyde affords the dihydropyridyl products ...9,10-bis(4-((3,5-dicyano-2,6-dipyridyl)dihydropyridyl)phenyl)anthracene (L1) and 1,4-bis(4-(3,5-dicyano-2,6-dipyridyl)dihydropyridyl)benzene (L2), respectively. In the solid state L1·2.5DMF·3MeOH (SOF-1) crystallizes in the monoclinic space group P21/c and forms a 3D stable supramolecular organic framework via strong N−H···Npy hydrogen bonds and π−π interactions. The material incorporates pyridyl-decorated channels and shows permanent porosity in the solid state. The pore volumes of the desolvated framework SOF-1a calculated from the N2 isotherm at 125 K and the CO2 isotherm at 195 K are 0.227 and 0.244 cm3 g−1, respectively. The N2 absorption capacity of SOF-1a at 77 K is very low, with an uptake of 0.63 mmol g−1 at 1 bar, although saturation N2 adsorption at 125 K is 6.55 mmol g−1 (or 143 cm3 g−1). At ambient temperature, SOF-1a shows significant CO2 adsorption with approximately 3 mol of CO2 absorbed per mole of host at 16 bar and 298 K, corresponding to 69 cm3 g−1 at STP. SOF-1a also adsorbs significant amounts of C2H2, with an uptake of 124 cm3 (STP) g−1 (5.52 mmol g−1) at 1 bar at 195 K. Methane uptake at 195 K and 1 bar is 69 cm3 (STP) g−1. Overall, gas adsorption measurements on desolvated framework SOF-1a reveal not only high capacity uptakes for C2H2 and CO2, compared to other crystalline molecular organic solids, but also an adsorption selectivity in the order C2H2 > CO2 > CH4 > N2. Overall, C2H2(270 K)/CH4(273 K) selectivity is 33.7 based on Henry’s Law constant, while the C2H2(270 K)/CO2(273 K) ratio of uptake at 1 bar is 2.05. The less bulky analogue L2 crystallizes in the triclinic space group P1̅ as two different solvates L2·2DMF·5C6H6 (S2A) and L2·2DMF·4MeOH (S2B) as pale yellow tablets and blocks, respectively. Each L2 molecule in S2A participates in two N−H···O hydrogen bonds between dihydropyridyl rings and solvent DMF molecules. Packing of these layers generates 1D nanochannels along the crystallographic a and b axes which host DMF and benzene molecules. In S2B, each L2 ligand participates in hydrogen bonding via an N−H···O interaction between the N−H of the dihydropyridyl ring and the O of a MeOH and also via an N···H−O interaction between the N center of a pyridine ring and the H−O of a second MeOH molecule. The presence of the L2−HOMe hydrogen bonds prevents ligand−ligand hydrogen bonding. As a result, S2B crystallizes as one-dimensional chains rather than as an extended 3D network. Thermal removal of solvents from S2A results in conversion to denser phase S2C which shows no effective permanent porosity.
This study uses hybrid effects regressions with the German Socio-Economic Panel to compare differences in happiness between Germans during times of high and low income inequality. It shows that ...Germans interviewed during times of persistently low inequality were no more satisfied with their lives than Germans during times of persistently high inequality. However, the article also uses within effects to show that the same individual is less satisfied with life in those years where inequality is higher than during a typical year. This non-negative between-person influence of inequality on life satisfaction, coupled with the negative within-person effect of inequality on life satisfaction, indicates that short-term increases in inequality decrease life satisfaction, but long-run levels of inequality do not. Part of the negative effect of inequality on life satisfaction exists because increased media attention to inequality seems to decrease life satisfaction. This indicates that perceptions of above-average inequality are damaging to life satisfaction, but long-run levels of inequality are not. The results from this study therefore indicate that the existing literature may find ambiguous effects of inequality on life satisfaction because people get used to long-run inequality, so that short-run increases in inequality, rather than long-run levels of inequality, make people unsatisfied with life. This may explain why populations of countries with persistently high inequality are as satisfied with life as populations of more equal countries, even though the same individual is less satisfied with life in those years where inequality is above-average.
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