Liquid-crystal variable retarders for aerospace polarimetry applications

We present the optical effects of different tests that simulate the aerospace environment on the liquid-crystal variable retarders (LCVRs) used in the Imaging Magnetograph eXperiment postfocal instrument of the SUNRISE payload within the NASA Long Duration Balloon program. Analysis of the influence of vacuum, temperature, vibration, and gamma and ultraviolet radiation is performed by measuring the effects of these tests on the optical retardance, the response time, the wavefront distortion, and the transmittance, including some in situ measurements. Outgassing measurements of the different parts of the LCVRs are also shown. From the results obtained it can be concluded that these optical devices are suitable and seem to be excellent candidates for aerospace platforms.     

1,2-Mannobioside mimic: synthesis, DC-SIGN interaction by NMR and docking, and antiviral activity

The design and preparation of carbohydrate ligands for DC-SIGN is a topic of high interest because of the role played by this C-type lectin in immunity and infection processes. The low chemical stability of carbohydrates against enzymatic hydrolysis by glycosylases has stimulated the search for new alternatives more stable in vivo. Herein, we present a good alternative for a DC-SIGN ligand based on a mannobioside mimic with a higher enzymatic stability than the corresponding disaccharide. NMR and docking studies have been performed to study the interaction of this mimic with DC-SIGN in solution demonstrating that this pseudomannobioside is a good ligand for this lectin. In vitro studies using an infection model with Ebola pseudotyped virus demonstrates that this compound presents an antiviral activity even better than the corresponding disaccharide and could be an interesting ligand to prepare multivalent systems with higher affinities for DC-SIGN with potential biomedical applications.     

Decomposition analysis of CO2 emission in long-term climate stabilization scenarios

To achieve the stabilization of greenhouse gas (GHG) concentrations in the atmosphere, the international community will need to intensify its long-term efforts. Many EU countries have released national long-term scenarios toward 2050, and their ambitious targets for CO₂ emission reduction are aiming at a decrease of more than 50% of today's emission. In April 2004, Japan began a research project on its long-term climate policy. This paper discusses the long-term scenarios in other countries and the medium-term scenarios in Japan to support the development of a Japan's long-term climate stabilization scenario. In this study, CO₂ emission is decomposed with an extended Kaya identity (indexes: CO₂ capture and storage, carbon intensity, energy efficiency, energy intensity, economic activity) and a Reduction Balance Table is developed.     

Who formulates renewable-energy policy? A Swedish example

A broad participation by stakeholders and an extensive reliance on expert advice are often seen as preconditions for a legitimate and successfully implemented renewable energy policy. However, we have lacked systematic data for testing this argument. This article’s contribution is to examine the actors who take part in the making of Swedish energy policy with the help of data on the composition of various committees of inquiry over the last twenty years (1988–2009). Swedish renewable energy policy is often characterised with words like “pioneering” and “forerunner”, suggesting that the policy-making process in this area engages many different experts and stakeholders. Our data give only some support to this argument. Results point to a noteworthy predominance of politicians, civil servants, and representatives of state agencies within the policy-process. Producers of uranium and fossils based energy have been engaged more often than producers of renewable energy. Experts have played a prominent role, but this is mostly due to the participation of expert bureaucrats rather than of scientists. The study suggests that a better understanding of the making of energy policy, both in Sweden and elsewhere, requires greater attention to the networks and role of various state employees.     

Understanding the influence of the alkaline cation K+ or Na+ in the regeneration efficiency of a biogas upgrading unit

This paper reveals a regeneration method for a carbonate compound after carbon dioxide (CO₂) absorption in a biogas upgrading unit run with caustic mixtures, obtaining precipitated calcium carbonate (PCC) as valuable by‐product. This process arises as an alternative to physical regeneration, which is highly energy intensive. This work provides novel insights on the regeneration efficiency of carbonates to hydroxides while also studying the influence of K⁺ or Na⁺ in the caustic CO₂‐trapping solution. The compared parameters were the reaction time, temperature, and molar ratio. Moreover, psychochemical characterization of solids was obtained by means of Fourier‐transform infrared spectroscopy (FTIR), Raman spectroscopy, X‐ray powder diffraction (XRD), and scanning electron microscopy (SEM) images. The results indicate that regeneration efficiencies are slightly lower when potassium is used instead of sodium, but quite acceptable for both of them. The chemical characterization experiments showed the predominance of calcium carbonate. Overall, the results obtained in this study proved that this process is feasible to upgrade biogas through PCC precipitation, which appears to be a promising economically viable process to synergize carbon capture and storage (CCS) and carbon capture and utilization (CCU).