The Chemical Drying Process in Alkyd Emulsion Paint Films

This paper deals with the oxidative drying of films (dry thickness 100 mm) made of an alkyd emulsion based on a high viscosity resin. Half of the soybean fatty acids in this resin were partly conjugated. The oxidation process is studied by monitoring the disappearance of the double bonds both the conjugated and the non-conjugated cis bonds. This was achieved by using by spatially resolved Confocal Raman Microscopy. The principle and some technical limitations of Confocal Raman microscopy are briefly discussed. The effect of various driers is reported. The results show a number of interesting features. Apart from the expected rapid disappearance of double bonds near the surface, the double bonds also disappear fairly rapidly and uniformly in a slab of 60 mm at the substrate side of the film, depending on conditions. It is only slightly visible with manganese drier, pronounced with cobalt drier and very pronounced with a cobalt zirconium combination drier. Additionally, with only cobalt the conversion is also uniform in a surface slab of a thickness of 10-15 mm. The experimental data were complemented by computer simulations of the combined reaction / oxygen diffusion process. A model is presented to explain the disappearance of double bonds in the absence of new supply of oxygen. Unless a cis-cis set of double bonds, a conjugated set of double bonds can become saturated without the consumption of radical activity. On the basis of the used theoretical model, time and length scales of the diffusion reaction mechanism are discussed

Oxidative degradation of benzoic acid using Fe0- and sulfidized Fe0-activated persulfate: A comparative study

Implications of sulfidized Fe-0(nFe/FeS) for the abatement of pollutants of various categories are widely established. In this study, degradation of one of the major organic pollutants, benzoic acid (BA), has been performed using persulfate activated with nFe/FeS. Complete degradation of BA and its transformed product, hydroxybenzoic acid, was observed within 6 min. When the degradation was performed at alkaline pH, the degradation decreased to 8% in the case of Fe-0, but nFe/FeS still showed 100% degradation after 60 min. Iron dissolution and persulfate decomposition in the presence of scavengers showed that both sulfate and hydroxyl radicals were involved in the Fe-0-persulfate system and that the hydroxyl radicals were the major species in the nFe/FeS-persulfate system. The major degradation pathway of benzoic acid was hydroxylation followed by complete mineralization, as supported by the practical removal of total organic carbons (more than 75% within 15 min). The observed results are promising in using perstlfate activated by nFe/FeS for the remediation of various micro-pollutants from a multitude of water sources. (C) 2017 Elsevier B.V. All rights reserved.1195sciescopu

Negative emissions at negative cost-an opportunity for a scalable niche

In the face of the rapidly dwindling carbon budgets, negative emission technologies are widely suggested as required to stabilize the Earth’s climate. However, finding cost-effective, socially acceptable, and politically achievable means to enable such technologies remains a challenge. We propose solutions based on negative emission technologies to facilitate wealth creation for the stakeholders while helping to mitigate climate change. This paper comes up with suggestions and guidelines on significantly increasing carbon sequestration in coffee farms. A coffee and jackfruit agroforestry-based case study is presented along with an array of technical interventions, having a special focus on bioenergy and biochar, potentially leading to “negative emissions at negative cost.” The strategies for integrating food production with soil and water management, fuel production, adoption of renewable energy systems and timber management are outlined. The emphasis is on combining biological and engineering sciences to devise a practically viable niche that is easy to adopt, adapt and scale up for the communities and regions to achieve net negative emissions. The concerns expressed in the recent literature on the implementation of emission reduction and negative emission technologies are briefly presented. The novel opportunities to alleviate these concerns arising from our proposed interventions are then pointed out. Our analysis indicates that 1 ha coffee jackfruit-based agroforestry can additionally sequester around 10 tonnes of CO2-eq and lead to an income enhancement of up to 3,000–4,000 Euros in comparison to unshaded coffee. Finally, the global outlook for an easily adoptable nature-based approach is presented, suggesting an opportunity to implement revenue-generating negative emission technologies on a gigatonne scale. We anticipate that our approach presented in the paper results in increased attention to the development of practically viable science and technology-based interventions in order to support the speeding up of climate change mitigation efforts

Toward superlensing with metal-dielectric composites and multilayers

We report on the fabrication of two types of adjustable, near-field superlens designs: metal-dielectric composites and metal-dielectric multilayer films. We fabricated a variety of films with different materials, thicknesses and compositions. These samples were characterized physically and optically to determine their film composition, quality, and optical responses. Our results on metal-dielectric composites indicate that although the real part of the effective permittivity generally follows effective medium theory predictions, the imaginary part does not and substantially higher losses are observed. Going forward, it appears that multilayer metal-dielectric designs are more suitable for sub-diffraction imaging applications because they could provide both tunability and low loss

Sum1, a Component of the Fission Yeast eIF3 Translation Initiation Complex, Is Rapidly Relocalized During Environmental Stress and Interacts with Components of the 26S Proteasome

Eukaryotic translation initiation factor 3 (eIF3) is a multisubunit complex that plays a central role in translation initiation. We show that fission yeast Sum1, which is structurally related to known eIF3 subunits in other species, is essential for translation initiation, whereas its overexpression results in reduced global translation. Sum1 is associated with the 40S ribosome and interacts stably with Int6, an eIF3 component, in vivo, suggesting that Sum1 is a component of the eIF3 complex. Sum1 is cytoplasmic under normal growth conditions. Surprisingly, Sum1 is rapidly relocalized to cytoplasmic foci after osmotic and thermal stress. Int6 and p116, another putative eIF3 subunit, behave similarly, suggesting that eIF3 is a dynamic complex. These cytoplasmic foci, which additionally comprise eIF4E and RNA components, may function as translation centers during environmental stress. After heat shock, Sum1 additionally colocalizes stably with the 26S proteasome at the nuclear periphery. The relationship between Sum1 and the 26S proteasome was further investigated, and we find cytoplasmic Sum1 localization to be dependent on the 26S proteasome. Furthermore, Sum1 interacts with the Mts2 and Mts4 components of the 26S proteasome. These data indicate a functional link between components of the structurally related eIF3 translation initiation and 26S proteasome complexes