The ‘tyranny of discounting’ in economic efficiency evaluation of capital investment projects susceptible to ecological and climatic changes

In this article, we consider the question of barriers to increasing investment activity in the Boreal and Arctic regions of Siberia, taking into account the factors of ecological and climatic changes. We investigate the current tendencies of large Russian companies in financing environmental policy measures. This is studied mainly in the dynamic of the ratio of ‘current expenditures to investments’ for environmental protection. It is essential to change the financial preference of remedying environmental damage to one of preventing environmental damage by improving warning technology and conducting research and development. Solving this problem is only possible by dictating a standard discounting procedure based on correcting discount rates, periods of cash flow analysis and regulations of Russian accounting standards regarding expenditures on natural resource development.     

The challenging task of summary evaluation: an overview

Evaluation is crucial in the research and development of automatic summarization applications, in order to determine the appropriateness of a summary based on different criteria, such as the content it contains, and the way it is presented. To perform an adequate evaluation is of great relevance to ensure that automatic summaries can be useful for the context and/or application they are generated for. To this end, researchers must be aware of the evaluation metrics, approaches, and datasets that are available, in order to decide which of them would be the most suitable to use, or to be able to propose new ones, overcoming the possible limitations that existing methods may present. In this article, a critical and historical analysis of evaluation metrics, methods, and datasets for automatic summarization systems is presented, where the strengths and weaknesses of evaluation efforts are discussed and the major challenges to solve are identified. Therefore, a clear up-to-date overview of the evolution and progress of summarization evaluation is provided, giving the reader useful insights into the past, present and latest trends in the automatic evaluation of summaries.     

Polymeric Giant Unilamellar Vesicles with Integrated DNA-Origami Nanopores: An Efficient Platform for Tuning Bioreaction Dynamics Through Controlled Molecular Diffusion

Giant unilamellar vesicles (GUVs) are microcompartments serving to confine reactions, allow signaling pathways, or design synthetic cells. Polymer GUVs are composed of copolymer membranes mimicking cell membranes, and present advantages over lipid-based GUVs, such as higher mechanical stability and chemical versatility. Such microcompartments are essential for understanding reactions/signaling occurring in cells, which are difficult to study by in vivo approaches due to the cell's complexity. However, the lack of control over their production, stability, and membrane diffusion properties is still limiting their use for bio-related applications. Here, polymer GUVs produced by microfluidics and permeabilized with DNA-origami nanopores (DoNs) that present a high level of control over these essential properties are introduced. After systematic optimization of conditions, DoN-GUVs reveal a narrow size distribution, allow for high encapsulation efficiencies, and are stable for weeks, protecting encapsulated biomolecules. The kinetics of diffusion of molecules through the GUV's membrane is tuned by insertion of DoNs with a controlled 3D- structure. DNA polymerase I, encapsulated as model for bioreactions, successfully produced DNA duplex strands with spatiotemporal control. DoN-GUVs loaded with active molecules open new avenues in bioreactions, from the detection of biomolecules, over the tuning of molecular transport rates, to the investigation of cellular processes/signaling.     

Solvent-free derivatization of pristine multi-walled carbon nanotubes with dithiols

We report on direct solvent-free derivatization of pristine multi-walled carbon nanotubes (MWNTs) with aliphatic dithiols (1,4-butanedithiol, 1,6-hexanedithiol and 1,8-octanedithiol), by means of heating at 130–150 °C under reduced pressure. This method requires no additional chemical activation and about 2 h only for completion. Studies by high-resolution transmission electron microscopy and scanning electron microscopy with energy dispersive X-ray spectroscopy showed that dithiol-derivatized MWNTs have a high affinity to ZnCl₂ in solution, which covers the nanotubes with a dense amorphous layer. According to PM3 semi-empirical calculations, employing a closed-cap zigzag (10,0) single-walled carbon nanotube (SWNT) model incorporating a Stone-Wales defect, site-specificity of the addition depends on the mutual position of pentagons. If the nanotube contains pyracylene units or Stone-Wales defect, the addition takes place on their 6,6 or 7,7 bonds, respectively, whereas for isolated pentagons, preferential reaction sites are their C–C bonds. Ideal graphene sheet sidewalls with cylindrical curvature are relatively inert (although one cannot discard the possibility to activate the reaction by heating). Dithiol groups introduced in the way proposed can be used as chemical linkers for anchoring metal complexes and nanoparticles to carbon nanotubes, attaching SWNTs to gold tips for atomic force and scanning tunneling microscopy, and potentially for adsorption and concentration of trace metal ions.     

Dead-beat estimation problems for 2D behaviors

In this paper we address the dead-beat estimation problem for the class of two-dimensional (2D) behaviors which are described by means of a 2D difference equation, and whose trajectories evolutions pertain the “nonnegative half-plane”. For this class of behaviors, the concept of nilpotency is defined and fully characterized. After this preliminary step, the estimation problem is formally addressed. Indeed, the concept of (consistent or not) 2D dead-beat observer (DBO) of the system relevant variables from the system measured variables is introduced, and a set of necessary and sufficient conditions for the existence of such a DBO is given. Finally, a complete parametrization of the family of all consistent DBOs is given, and some partial results, together with an interesting counterexample, regarding the class of (not necessarily consistent) DBOs are presented. To conclude the paper, the general dead-beat estimation theory developed in this paper is adjusted to address and solve several problems, like state estimation, the design of unknown input observers or the design of fault detectors and identifiers (possibly in the presence of disturbances), for 2D systems described by quarter-plane causal 2D state space models.     

Composite electrodes of disordered carbon and graphite for improved battery state estimation with minimal performance penalty

Voltage based state of charge (SOC) estimation is challenging for lithium ion batteries that exhibit little open circuit voltage (OCV) change over a large SOC range. We demonstrate that by using a composite negative electrode composed of disordered carbon and graphite, we were able to introduce additional features to the OCV-SOC relationship that facilitate voltage-based SOC estimation. In contrast to graphite, the potential of disordered carbon is sensitive to the state of charge; this behavior, when manifested in a lithium ion battery, gives rise to additional beneficial features of the cell OCV-SOC relationship in terms of state estimation. We have demonstrated the effectiveness of the approach by comparing model simulations and corresponding experimental data of a cell composed of LiFePO₄ positives and graphite + disordered carbon composite negative electrodes. Last, we find that although the graphite material has a higher coulombic capacity, very little (dynamic) performance loss is manifest with the mixed graphite + disordered carbon composite is employed.     

Nanostructured polyethylene glycol-titanium oxide composites as solvent-free viscous electrolytes for electrochromic devices

Composites of polyethylene glycol (PEG) and titanium oxide compounds have been prepared by sol-gel method using different molar ratio between PEG and titanium isopropoxide. Transmission electron microscope (TEM) images and UV-vis absorption spectra of these composites indicate that titanium oxide particles or clusters were formed inside the composite materials and their maximum sizes were between 1.8 and 7 nm for PEG:Ti molar ratio changing from 24:1 to 4:1. Fourier Transform Infrared spectroscopy analysis of the same PEG-Ti composites suggests the presence of tetragonal titanium oxide compounds and its association with ether oxygen atoms of PEG molecules. As lithium iodide salt was added into PEG-Ti composites, iodide ions were oxidized into iodine and tri-iodides and, at the same time, titanium oxide compounds should be reduced. Color change speeds of tungsten oxide thin films were significantly improved when PEG-Ti-LiI composites were used as electrolytes compared to salt-in-polymer one (PEG-LiI); the bleaching time of tungsten oxide was reduced from 22 to 2.5 s under +1.0 V polarization, and the coloring time under −1.5 V lowered from 16 to 2.2 s. The transfer of negative charges from smaller iodide ions onto longer or crosslinked PEG-Ti macromolecules could be the origin of faster lithium ion transport/insertion speeds in PEG-Ti composite electrolyte based electrochromic devices.     

Solidification of a PEG 1500-epoxy nanocomposite around a horizontal pipe

A PCM-epoxy phase change material composite (polyethylene glycol 1500-epoxy) was developed as heat storage building element for houses with low energy consumption. The PCM component, polyethylene glycol 1500, was integrated in an epoxy matrix, and presents a phase change interval of 34-42 °C and an enthalpy of solidification of 103.411 kJ/kg. Experiments on solidification were conducted using a Plexiglas test cell filled with the PEG 1500-epoxy nanocomposite material (P15-E) for further implementation of this material in buildings. The forwarded solidification model assumes negligible convection in the liquid region and predicts the time for radial formation of two regions: a mushy-zone and a solid, annular one around the pipe during solidification. The heat transfer during solidification can be also characterized by the time evolution of both liquid and solid radial fronts. The model was analytically solved using Megerlin approximation concerning “solidification with mushy zone”, with the third order condition at the external frontier. The experimental values are in agreement with the calculated theoretical curves.     

Pushing the Boundaries of Structural Heterogeneity with the Lipid A of Marine Bacteria Cellulophaga

Marine bacteria, which are often described as chemical gold, are considered an exceptional source of new therapeutics. Considerable research interest has been given to lipopolysaccharides (LPSs), the main components of the Gram-negative outer membrane. LPS and its lipid A portion from marine bacteria are known to exhibit a tricky chemistry that has been often associated with intriguing properties such as behaving as immune adjuvants or anti-sepsis molecules. In this scenario, we report the structural determination of the lipid A from three marine bacteria within the Cellulophaga genus, which showed to produce an extremely heterogenous blend of tetra- to hexa-acylated lipid A species, mostly carrying one phosphate and one D-mannose on the glucosamine disaccharide backbone. The ability of the three LPSs in activating TLR4 signaling revealed a weaker immunopotential by C. baltica NNO 15840^T and C. tyrosinoxydans EM41^T, while C. algicola ACAM 630^T behaved as a more potent TLR4 activator.