The Limits of Sea Power

Sea powers have many handicaps that often are forgotten, resulting in a dangerous overestimation of their safety, influence, and staying power in a competitive world. A more clear-eyed assessment of sea power—one less enamored of the grandeur associated with naval might—reveals that often their hopes were unwarranted and ended up having tragic results

Nanostructured poly(benzimidazole) membranes by N-alkylation

Modification of poly(benzimidazole) (PBI) by N-alkylation leads to polymers capable of undergoing microphase separation. Polymers with different amounts of C18 alkyl chains have been prepared. The polymers were analyzed by spectroscopy, thermal analysis, electron microscopy and X-ray scattering. The impact of the amount of alkyl chains on the observed microphase separation was analyzed. Membranes prepared from the polymers do show microphase separation, as evidenced by scattering experiments. While no clear morphology could be derived for the domains in the native state, evidence for the formation of lamellar morphologies upon doping with phosphoric acid is provided. Finally, the proton conductivity of alkyl-modified PBI is compared with that of pure PBI, showing that the introduction of alkyl side chains does not result in significant conductivity changes

Main-chain poly(ionic liquid)-derived nitrogen-doped micro/mesoporous carbons for CO₂ capture and selective aerobic oxidation of alcohols

Sustainable development and the recent fast-growing global demands for energy and functional chemicals urgently call for effective methods for CO2 remediation and efficient metal-free catalysts for selective oxidation of aromatic alcohol. Herein, a unique main-chain poly(ionic liquid) (PIL) is employed as the precursor to prepare nitrogen-doped micro/mesoporous carbons via simultaneous carbonization and activation, which bear high yield, large specific surface area above 1700 m2 g−1 and rich nitrogen dopant. The porous carbon products deliver a high CO2 adsorption capacity up to 6.2 mmol g−1 at 273 K and 1 bar with outstanding reversibility and satisfactory selectivity. Besides, they work excellently as metal-free carbocatalysts for the selective aerobic oxidation of benzyl alcohol to benzaldehyde with high selectivity. It is believed that this work not only provides a facile approach to prepare nitrogen-doped porous carbon, but also advances the related research in the fields of environment and catalysis

SPORT: A new sub-nanosecond time-resolved instrument to study swift heavy ion-beam induced luminescence - Application to luminescence degradation of a fast plastic scintillator

We developed a new sub-nanosecond time-resolved instrument to study the dynamics of UV-visible luminescence under high stopping power heavy ion irradiation. We applied our instrument, called SPORT, on a fast plastic scintillator (BC-400) irradiated with 27-MeV Ar ions having high mean electronic stopping power of 2.6 MeV/\mu m. As a consequence of increasing permanent radiation damages with increasing ion fluence, our investigations reveal a degradation of scintillation intensity together with, thanks to the time-resolved measurement, a decrease in the decay constant of the scintillator. This combination indicates that luminescence degradation processes by both dynamic and static quenching, the latter mechanism being predominant. Under such high density excitation, the scintillation deterioration of BC-400 is significantly enhanced compared to that observed in previous investigations, mainly performed using light ions. The observed non-linear behaviour implies that the dose at which luminescence starts deteriorating is not independent on particles' stopping power, thus illustrating that the radiation hardness of plastic scintillators can be strongly weakened under high excitation density in heavy ion environments.Comment: 5 figures, accepted in Nucl. Instrum. Methods

Instytucjonalne i rynkowe uwarunkowania rozwoju inwestycji etycznych – doświadczenia europejskie i ich implikacje dla Polski

The market of ethical investments is growing rapidly. Ethical investing is no longer a niche phenomenon or a fad, but it becomes a permanent and desirable element of the financial market. The development of ethical investments is not steady. Existing cross-country differences in the level of popularity of ethical investments result from local institutional and market conditions. In Poland these conditions are not very favourable. The development of domestic SRI market is therefore dependent on introducing incentives, similar to those functioning in other countries, that could contribute to the increase of interest in ethical investments among domestic investors.Rynek inwestycji etycznych dynamicznie rośnie. Inwestowanie etyczne nie jest już zjawiskiem niszowym czy przejściową modą, ale staje się trwałym i pożądanym elementem rynku finansowego. Rozwój inwestowania etycznego nie jest jednak równomierny. Istniejące między poszczególnymi krajami różnice w poziomie popularności inwestowania etycznego wynikają z odmiennego układu występujących w nich czynników instytucjonalnych i rynkowych. W Polsce układ tych czynników nie jest zbyt korzystny. Rozwój rodzimego rynku SRI uzależniony jest więc od wprowadzenia zachęt, podobnych do tych funkcjonujących w innych krajach, które mogłyby przyczynić się do wzrostu zainteresowania inwestowaniem etycznym wśród krajowych inwestorów

Energy deposition by heavy ions: Additivity of kinetic and potential energy contributions in hillock formation on CaF2

The formation of nano-hillocks on CaF2 crystal surfaces by individual ion impact has been studied using medium energy (3 and 5 MeV) highly charged ions (Xe19+ to Xe30+) as well as swift (kinetic energies between 12 and 58 MeV) heavy ions. For very slow highly charged ions the appearance of hillocks is known to be linked to a threshold in potential energy while for swift heavy ions a minimum electronic energy loss is necessary. With our results we bridge the gap between these two extreme cases and demonstrate, that with increasing energy deposition via electronic energy loss the potential energy threshold for hillock production can be substantially lowered. Surprisingly, both mechanisms of energy deposition in the target surface seem to contribute in an additive way, as demonstrated when plotting the results in a phase diagram. We show that the inelastic thermal spike model, originally developed to describe such material modifications for swift heavy ions, can be extended to case where kinetic and potential energies are deposited into the surface.Comment: 12 pages, 4 figure

Structural effects in UO2 thin films irradiated with fission-energy Xe ions

Uranium dioxide thin films have been successfully grown on LSAT (Al10La3O51Sr14Ta7) substrates by reactive magnetron sputtering. Irradiation by 92 MeV 129Xe23+ ions to simulate fission damage that occurs within nuclear fuels caused microstructural and crystallographic changes. Initially flat and continuous thin films were produced by magnetron sputtering with a root mean square roughness of 0.35 nm determined by AFM. After irradiation, this roughness increased to 60–70 nm, with the films developing discrete microstructural features: small grains (∼3 μm), along with larger circular (up to 40 μm) and linear formations with non-uniform composition according to the SEM, AFM and EDX results. The irradiation caused significant restructuring of the UO2 films that was manifested in significant film-substrate mixing, observed through EDX analysis. Diffusion of Al from the substrate into the film in unirradiated samples was also observed

Structural effects in UO2 thin films irradiated with U ions

This work presents the results of a detailed structural characterisation of irradiated and unirradiated single crystal thin films of UO2. Thin films of UO2 were produced by reactive magnetron sputtering onto (0 0 1), (1 1 0) and (1 1 1) single crystal yttria-stabilised zirconia (YSZ) substrates. Half of the samples were irradiated with 110 MeV 238U31+ ions to fluences of 5 × 1010, 5 × 1011 and 5 × 1012 ions/cm2 to induce radiation damage, with the remainder kept for reference measurements. It was observed that as-produced UO2 films adopted the crystallographic orientation of their YSZ substrates. The irradiation fluences used in this study however, were not sufficient to cause any permanent change in the crystalline nature of UO2. It has been demonstrated that the effect of epitaxial re-crystallisation of the induced radiation damage can be quantified in terms of kernel average misorientation (KAM) and different crystallographic orientations of UO2 respond differently to ion irradiation