Classical Route Research Articles

Comparative analysis of two maritime routes in part of North America in the context of global warming, melting ice caps and opening of new passages for navigation

The subject of this paper is to analyze comparative two maritime routes planned different for a ship that carry cargo from the United Kingdom to the Norton Sound, (63o 48’N / 161o21’W). The route are analyzed separately as a result of the evolution of the thermal regime, the ice in the last ten years in the area of North America and the impact of ice caps, from the perspective of total distance and opportunity of navigation. Take into consideration all three possible routes on this date, only the north-west route was included in this comparative analysis. The results presents a difference of 6070 Nm between the classic route (using Panama Channel) and the route through north-west passage, in safety condition.

Thermoplastic forming of additively manufactured Zr-based bulk metallic glass: A processing route for surface finishing of complex structures

Additive manufacturing of bulk metallic glasses (BMGs) through laser powder bed fusion (LPBF) has drawn growing interest in the last years, especially concerning industry-relevant alloys based on iron or zirconium. The process-inherent high cooling rates and localized melting pools allow to overcome geometrical restrictions given for the production of BMGs by classical casting routes. Yet, the achievable surface qualities are still limited, making an adequate post-processing necessary. In this work, we report on applying thermoplastic forming on LPBF-formed parts for the first time to decrease surface roughness and imprint finely structured surface patterns without the need for complex abrasive machining. This BMG-specific post-processing approach allows to functionalize surface areas on highly complex LPBF-formed specimens, which could be of interest especially for medical or jewelry applications.

Novel approach for processing complex carbonate-rich copper-cobalt mixed ores via reverse flotation

The vast majority of current global production of cobalt from primary sources originates from extraction of Cu-Co sediment-hosed deposits in the Democratic Republic of Congo. With the progressive depletion of oxidic supergene mineralisation, many operations are progressively starting to extract sulphide ore at depth. Ore in the transition zone between oxides and sulphides usually hosts both oxide and sulphide mineralisation which is extremely difficult to process by conventional flotation. These mixed ores are complex to process by flotation alone because carbonate minerals, such as dolomite and magnesite, may represent a significant proportion of the gangue. Hence, mixed ores are usually processed through flotation of sulphides followed by oxide flotation using controlled potential sulphidisation (CPS) and further processing via acid leaching. The main challenges associated with carbonate-rich mixed ores are the low recovery of cobalt, mostly due to cobalt present in oxide minerals, the floatability of the carbonate gangue minerals, which can make up to 50% of the concentrate, and technical difficulties with regards to industrial application of CPS. This study investigates alternative options to the classic two-step CPS flotation route, including direct reverse flotation of the carbonate gangue at neutral or acid pH, as well as a two-step combined sulphide-reverse flotation route. The latter, including a sulphide flotation stage at neutral pH, followed by an acidic reverse flotation stage at pH 4.5–5, increased the overall copper and cobalt recoveries. The best performance is achieved with reverse flotation, using Na-Oleate and a mixture of phosphoric and sulphuric acid (ratio of 4:1). Overall Cu-Co recoveries of 93.5% and 85.1% respectively were achieved. It is postulated that phosphoric acid acts as a depressant of the Cu-Co oxide minerals through surface passivation while enabling selective flotation of magnesite and dolomite. Further investigation into the effect of phosphoric acid on flotation of these minerals is required. Overall, the results suggest that, following flotation of sulphides, an acidic reverse flotation stage increases the global Cu-Co recovery while producing a concentrate which is suitable for further processing by flotation or acid leaching. Hence, the suggested combined approach could be a viable alternative to aforementioned CPS stage in Cu-Co oxide-sulphide mixed ores flotation plants, especially in operations where the mixed ore contains significant proportions of carbonate gangue minerals.

Osteoporosis in Rheumatoid Arthritis: Dangerous Liaisons.

Osteoporosis has been classically considered a comorbidity of rheumatoid arthritis (RA). However, recent advances in the pathogenesis of osteoporosis in RA have shown a close interplay between cells of the immune system and those involved in bone remodeling, introducing new actors into the classic route in which osteoclast activation is related to the RANK/RANKL/OPG pathway. In fact, the inflammatory state in early stages of RA, mediated by interleukin (IL)-1, IL-6, IL-8 and tumor necrosis factor (TNF)-α has the ability to activate and differentiate osteoclasts not only through their relationship with RANKL, but also through the Wnt/DKK1/sclerostin pathway, leading to bone loss. The role of synovial fibroblasts and activated T lymphocytes in the expression of the RANKL system and its connection to bone destruction is also depicted. In addition, autoantibodies such as rheumatoid factor and anti-citrullinated protein antibodies are other pathogenic mechanisms for the development of bone erosions and systemic osteoporosis in RA, even before the onset of arthritis. The aim of this review is to unravel the relationship between different factors involved in the development of osteoporosis in RA patients, both the classic factors and the most novel, based on the relationship of autoantibodies with bone remodeling. Furthermore, we propose that bone mineral density measured by different techniques may be helpful as a biomarker of severity in early arthritis patients.

Wpływ interleukiny 6 na sen i chorobę Alzheimera

Interleukina (IL)-6 charakteryzuje się szerokim, plejotropowym działaniem nie tylko na komórki układu odpornościowego, ale na szereg innych komórek, w tym komórki ośrodkowego układu nerwowego. Cytokina ta oddziałuje na komórki poprzez 2 rodzaje receptorów: mIL-6R?, transbłonowy receptor (droga klasyczna), oraz jego rozpuszczalną formę sIL-6R? (transsygnalizacja). Wywoływana przez IL-6 transsygnalizacja jest odpowiedzialna za neurodegenerację, podczas gdy klasyczna sygnalizacja pełni rolę regeneracyjną i protekcyjną w tkance nerwowej. Komórki mikrogleju przejawiają działanie prozapalne prawie wyłącznie w wyniku transsygnalizacji. IL-6 zwiększa popęd snu zgodnie z rytmem dobowym i sprawuje kontrolę nad wzorcem snu. Bardzo poważne zaburzenia snu dotykają większości osób chorych na chorobę Alzheimera (AD) sprzyjając odkładaniu ? amyloidu (A?). Badania in vitro wskazują na szkodliwą rolę transsygnalizacji IL-6-sIL-6R w AD opartą o zwiększanie A? i hiperfosforylację białka tau, a badania in vivo przeciwnie, wskazują, że IL-6 umożliwia komórkom mikrogleju degradację fibrylarnego A?.

Biocatalytic Reduction Reactions from a Chemist's Perspective.

Reductions play a key role in organic synthesis, producing chiral products with new functionalities. Enzymes can catalyse such reactions with exquisite stereo‐, regio‐ and chemoselectivity, leading the way to alternative shorter classical synthetic routes towards not only high‐added‐value compounds but also bulk chemicals. In this review we describe the synthetic state‐of‐the‐art and potential of enzymes that catalyse reductions, ranging from carbonyl, enone and aromatic reductions to reductive aminations.

Hybridization of additive manufacturing processes to build ceramic/metal parts: Example of HTCC

Stereolithography is an additive manufacturing process, which makes it possible to fabricate useful complex 3D ceramic parts with a high dimensional resolution, a good surface roughness and properties close to those obtained by classical routes. Previous work concerning LTCC components, demonstrates that it is possible, by coupling the stereolithography with robocasting additive processes, to obtain multi-material components (e.g. ceramic / metal components). On the base of this previous work, the manufacturing of HTCC components using this innovative hybrid additive manufacturing process is described. Various complex and innovative geometries of HTCC alumina/tungsten components, in order to improve the characteristics of current circuits, are built and the mechanical and electrical properties characterized. Finally, hyper-frequency parameters of simulated HTCC complex micro strip resonators were compared to measured values on components manufactured by additive manufacturing.

A Novel Bioactive Glass Containing Therapeutic Ions with Enhanced Biocompatibility.

A novel bioactive glass containing therapeutic ions with enhanced biocompatibility was designed and produced by the classical melt-quenching route. Starting from a very promising composition (Bio_MS), which combined bioactivity and high crystallization temperature, the ratio between some oxides was tailored to obtain a new and more reactive (in terms of dissolution rate) bioactive glass, called BGMSN (composition in mol%: 6.1 Na2O, 31.3 CaO, 5 MgO, 10 SrO, 2.6 P2O5, 45 SiO2). The aim of this work was to produce a bioactive glass with a good biological performance, preserving, at the same time, the high crystallization temperature achieved for Bio_MS; this is strategic in order to avoid undesired crystalline phases during thermal treatments, which can undermine the bioactivity and even the stability of final products. A complete characterization of the novel bioactive glass was performed in terms of thermal, mechanical and biological properties and in vitro bioactivity. The thermal behavior of the bioactive glass was studied by heating microscopy, differential thermal analysis (DTA) and optical dilatometry; BGMSN showed a very high crystallization temperature and a high sinterability parameter, thus being suitable for applications where thermal treatments are required, such as sintered samples, coatings and scaffolds. Mechanical properties were investigated by the micro-indentation technique. The in vitro biological properties were evaluated by means of both direct and indirect cell tests, i.e., neutral red (NR) uptake and MTT assay, using murine long bone osteocyte Y4 (MLO-Y4) cells: the cellular viability of BGMSN was higher compared to cellular viability of 45S5, both in direct and indirect tests. Finally, the in vitro bioactivity test by soaking samples in simulated body fluid (SBF) showed high dissolution rate, with a good rate of formation of hydroxyapatite.

Current developments and challenges of green technologies for the valorization of liquid, solid, and gaseous wastes from sugarcane ethanol production

The sugarcane industry is one of the largest in the world and processes huge volumes of biomass, especially for ethanol and sugar production. These processes also generate several environmentally harmful solid, liquid, and gaseous wastes. Part of these wastes is reused, but with low-added value technologies, while a large unused fraction continues to impact the environment. In this review, the classic waste reuse routes are outlined, and promising green and circular technologies that can positively impact this sector are discussed. To remain competitive and reduce its environmental impact, the sugarcane industry must embrace technologies for bagasse fractionation and pyrolysis, microalgae cultivation for both CO2 recovery and vinasse treatment, CO2 chemical fixation, energy generation through the anaerobic digestion of vinasse, and genetically improved fermentation yeast strains. Considering the technological maturity, the anaerobic digestion of vinasse emerges as an important solution in the short term. However, the greatest environmental opportunity is to use the pure CO2 from fermentation. The other opportunities still require continued research to reach technological maturity. Intensifying the processes, the exploration of driving-change technologies, and the integration of wastes through biorefinery processes can lead to a more sustainable sugarcane processing industry.

CsPbBrxI3-x thin films with multiple ammonium ligands for low turn-on pure-red perovskite light-emitting diodes

All-inorganic α-CsPbBrxI3-x perovskites featuring nano-sized crystallites show great potential for pure-red light-emitting diode (LED) applications. Currently, the CsPbBrxI3–x LEDs based on nano-sized α-CsPbBrxI3-x crystallites have been fabricated mainly via the classical colloidal route including a tedious procedure of nanocrystal synthesis, purification, ligand or anion exchange, film casting, etc. With the usually adopted conventional LED device structure, only high turn-on voltages (> 2.7) have been achieved for CsPbBrxI3-x LEDs. Moreover, this mix-halide system may suffer from severe spectra-shift under bias. In this report, CsPbBrxI3-x thin films featuring nano-sized crystallites are prepared by incorporating multiple ammonium ligands in a one-step spin-coating route. The multiple ammonium ligands constrain the growth of CsPbBrxI3-x nanograins. Such CsPbBrxI3-x thin films benefit from quantum confinement. The corresponding CsPbBrxI3-x LEDs, adopting a conventional LED structure of indium-doped tin oxide (ITO)/poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS)/CsPbBrxI3-x/[6, 6]-phenyl C61 butyric acid methyl ester (PCBM)/bathocuproine (BCP)/Al, emit pure-red color at Commission Internationale de l’eclairage (CIE) coordinates of (0.709, 0.290), (0.711, 0.289), etc., which represent the highest color-purity for reported pure-red perovskite LEDs and meet the Rec. 2020 requirement at CIE (0.708, 0.292) very well. The CsPbBrxI3-x LED shows a low turn-on voltage of 1.6 V, maximum external quantum efficiency of 8.94%, high luminance of 2,859 cdm−2, and good color stability under bias.

Increase of electric performances in Bi2Sr2-xRbxCo2O8+δ laser grown ceramics induced by annealing

Bi2Sr2-xRbxCo2O8+δ materials with 0 ≤ x ≤ 0.125 were fabricated via the classical solid-state route, and textured using the laser floating zone method. As-grown materials were composed of different secondary phases due to the incongruent melting of this compound. These secondary phases were drastically reduced through an annealing procedure, consisting in heating at 800 °C for 12 h. XRD has not detected any secondary phase on the annealed samples, due to the overlapping of thermoelectric and main secondary phase diffraction peaks. SEM observations have confirmed this microstructural evolution, and shown that Rb-substitution further decreases the secondary phases content and enhances grain orientation. These microstructural features, together with the possible increment of charge carrier concentration due to Rb-doping, decreased electrical resistivity, while Seebeck coefficient has only been slightly reduced. Consequently, the Rb doped samples reached higher power factor (PF) values than the pure ones. The biggest PF values at room temperature (0.11 mW/K2m) are higher than the reported for single crystals (0.07 mW/K2m), while at 650 °C (0.20 mW/K2m), they are also higher than the obtained in textured samples and measured along the conducting plane (0.14 mW/K2m).

Water-Zeolite Interfaces for Controlling Reaction Routes in Fischer- Tropsch Synthesis of Alternative Fuels

Background: The Fischer-Tropsch Synthesis (FTS) remains an important process for motor fuel production from CO and H2. The composition of the FTS products (hydrocarbon mixtures) depends on the properties of a catalyst and on the process conditions. Summary: The introduction of zeolites into catalytic systems can alter the molecular weight distribution paving the way to tailor-made fuels, as was revealed by recent research results produced in the laboratories worldwide. The AlO4 and SiO4 tetrahedrons, which constitute the zeolites, are able to transfer electrons and ions in a way, which makes water-zeolite interfaces capable of initiating active carbonium ions. It was shown in a number of works that the water-zeolite interface plays a key role in diverting the FTS from the classical route. Conclusion: This review gives a critical analysis of literature data on the role of water-zeolite interfaces on FTS cobalt catalysts and on the interactions of hydrophobic and hydrophilic zeolites with water.

Highly crystalline MAPbI3 perovskite grain formation by irreversible poor-solvent diffusion aggregation, for efficient solar cell fabrication

Energy efficient synthesis providing high quality crystalline thin films are highly desired in many applications. Here we devise a non-toxic solvent approach for production of highly crystalline MAPbI 3 perovskite by exploiting diffusion aggregation processes. Isopropanol solution based methylammonium lead triiodide (MAPbI 3 ) is used in this context, where the crystal growth initiation starts in an unstable suspension far from equilibrium and the subsequent crystallization is driven by the solubility parameters. The crystal formation is monitored by scanning transmission electron microscope (STEM), observing small crystallization centers growing as time evolves to large grains with high crystal purity. Energy dispersive X-ray spectroscopy (EDS) in STEM mode revealed a Pb rich core-shell structure in newly formed grains. Nano-beam Electron Diffraction (NBED) scan defined PbI 2 crystallites in the Pb rich shell with a single crystal MAPbI 3 core in newly formed grains. After a week stirring, the same aggregated suspension exhibited grains with only single crystal MAPbI 3 structure. The NBED analysis shows a kinetically slow transition from a core shell structure to a single crystal grain. This research presents an impactful insight on the factors that may cause sub-stoichiometric grain boundary effects which can influence the solar cell performance. In addition, the structure, morphology and optical properties of the perovskite grains have been presented. A powder of highly crystalline particles was subsequently prepared by evaporation of the solvent in a low-vacuum oven. Thin film MAPbI 3 solar cells were fabricated by dissolving the powder and applying it in a classical fabrication route. The MAPbI 3 solar cells gave a champion efficiency of 20% (19.9%) and an average efficiency at approximately 17% with low hysteresis effects. Here a strategy to manufacture the material structure without toxic solvents is highlighted. The single-crystal growth devised here opens both for shelf storage of materials as well as a more flexible manufacturing of devices. The process can likely be extended to other fields, where the intermediate porous framework and large surface area would be beneficial for battery or super capacitor materials. • A non-toxic solvent approach for production of high quality MAPbI 3 perovskite grains. • Nano-beam electron diffraction scan on PbI 2 crystallites and single crystal MAPbI 3 grains. • The porous framework of grains and large surface area would be beneficial for energy storage. • Low hysteresis effects and high efficiency for the perovskite solar cells.

Production of 2-keto-L-gulonic acid by metabolically engineered Escherichia coli

The 2-keto-L-gulonic acid (2-KLG) is the direct precursor for industrial vitamin C production. The main biosynthetic method for 2-KLG production is the classical two-step fermentation route. However, disadvantages of this method are emerging, including high consumption of energy, difficulties in strain screening, complex operation, and poor stability. In this study, five recombinant Escherichia coli strains overexpressing different sorbose/sorbosone dehydrogenases were constructed and used for 2-KLG production. By optimizing catalytic conditions and further expressing pyrroloquinoline quinone in the recombinant strain, the titer of 2-KLG reached 72.4 g/L, with a conversion ratio from L-sorbose of 71.2% in a 5-L bioreactor. To achieve direct biosynthesis of 2-KLG from D-sorbitol, a co-culture system consisting of Gluconobacter oxydans and recombinant E. coli was designed. With this co-culture system, 16.8 g/L of 2-KLG was harvested, with a conversion ratio from D-sorbitol of 33.6%. The approaches developed here provide alternative routes for the efficient biosynthesis of 2-KLG.

A rationally identified marine GH1 β‐glucosidase has distinguishing functional features for simultaneous saccharification and fermentation

AbstractThe classical route for second‐generation ethanol from lignocellulosic biomass is hampered by high process costs, fostering the development of alternative strategies such as simultaneous saccharification and fermentation (SSF). However, the lack of compatible enzyme cocktails poses a challenge. In this study, the enzyme EmBgl from the marine bacterium Exiguobacterium marinum was rationally identified based on structural and phylogenetic analyses, known desirable properties of close orthologs, and the ecological niche of its organism source. EmBgl is a multifunctional and glucose‐tolerant enzyme that efficiently hydrolyzes cello‐oligosaccharides due to a positive‐subsite region that can accommodate long cello‐oligosaccharides without imposing steric impediments. The efficacy of EmBgl in an SSF process was demonstrated using pretreated sugarcane bagasse as feedstock, yielding 28 g L−1 of ethanol in 30 h. The distinguishing functional properties of EmBgl and its successful utilization in an SSF process highlight its potential in biotechnological applications in which lignocellulose deconstruction is desirable under milder temperatures © 2020 Society of Chemical Industry and John Wiley & Sons, Ltd.

Drastic modification of low temperature thermoelectric properties of Na-doped Bi2Sr2Co2Oy ceramics prepared via laser floating zone technique

In this study, Bi2Sr2−xNaxCo2Oy (x = 0.0, 0.05, 0.075, 0.10, and 0.15) ceramic powders have been fabricated via the classical ceramic route, followed by a texturing process through the laser floating zone technique. XRD patterns show the thermoelectric phase as the major one. In addition, Na-substitution reduces the amount of secondary phases, when compared to the pure sample. SEM observations point out that grain orientation is significantly improved when Na-content is increased. Na-substitution reduces electrical resistivity from 35 (in pure samples) to 19.6 mΩ cm (in Na = 0.05 ones) at around room temperature, while Seebeck coefficient is, approximately, twice measured in Na-free. On the other hand, thermal conductivity is slightly lower in undoped samples (0.83 W/K m), when compared to the Na-substituted ones (1.10–1.40 W/K m) at room temperature, due to their lower electrical conductivity. Finally, ZT values are higher when the Na-content is increased, reaching 0.022 at around 400 K.

Ionothermal Synthesis of Imide-Linked Covalent Organic Frameworks.

Covalent organic frameworks (COFs) are an extensively studied class of porous materials, which distinguish themselves from other porous polymers in their crystallinity and high degree of modularity, enabling a wide range of applications. COFs are most commonly synthesized solvothermally, which is often a time‐consuming process and restricted to well‐soluble precursor molecules. Synthesis of polyimide‐linked COFs (PI‐COFs) is further complicated by the poor reversibility of the ring‐closing reaction under solvothermal conditions. Herein, we report the ionothermal synthesis of crystalline and porous PI‐COFs in zinc chloride and eutectic salt mixtures. This synthesis does not require soluble precursors and the reaction time is significantly reduced as compared to standard solvothermal synthesis methods. In addition to applying the synthesis to previously reported imide COFs, a new perylene‐based COF was also synthesized, which could not be obtained by the classical solvothermal route. In situ high‐temperature XRPD analysis hints to the formation of precursor–salt adducts as crystalline intermediates, which then react with each other to form the COF.

Ionothermal Synthesis of Imide‐Linked Covalent Organic Frameworks

AbstractCovalent organic frameworks (COFs) are an extensively studied class of porous materials, which distinguish themselves from other porous polymers in their crystallinity and high degree of modularity, enabling a wide range of applications. COFs are most commonly synthesized solvothermally, which is often a time‐consuming process and restricted to well‐soluble precursor molecules. Synthesis of polyimide‐linked COFs (PI‐COFs) is further complicated by the poor reversibility of the ring‐closing reaction under solvothermal conditions. Herein, we report the ionothermal synthesis of crystalline and porous PI‐COFs in zinc chloride and eutectic salt mixtures. This synthesis does not require soluble precursors and the reaction time is significantly reduced as compared to standard solvothermal synthesis methods. In addition to applying the synthesis to previously reported imide COFs, a new perylene‐based COF was also synthesized, which could not be obtained by the classical solvothermal route. In situ high‐temperature XRPD analysis hints to the formation of precursor–salt adducts as crystalline intermediates, which then react with each other to form the COF.

Commentary: Dogs and the classic route of Guinea Worm transmission: an evaluation of copepod ingestion.

Commentary: Dogs and the classic route of Guinea Worm transmission: an evaluation of copepod ingestion.

Theoretical Foundations of Memristor Cellular Nonlinear Networks: A DRM2-Based Method to Design Memcomputers With Dynamic Memristors

In the memristive version of a standard space-invariant Cellular Nonlinear Network, each cell accommodates one first-order non-volatile memristor in parallel with a capacitor. In case, the resistance switching memory may only undergo almost-instantaneous switching transitions between two possible resistive states, acting at any time, as either the on or the off resistor, the processing elements effectively operate as first-order dynamical systems, and the classical Dynamic Route Map technique may be applied to investigate their operating principles. On the contrary, in case the memristors experience smooth conductance changes, as the bioinspired array implements memcomputing paradigms, each cell truly behaves as a second-order dynamical system. The recent extension of the Dynamic Route Map analysis tool to systems with two degrees of freedom constitutes a powerful technique to investigate the nonlinear dynamics of memristive cellular networks in these scenarios. This paper exploits this system-theoretic technique, called Second-Order Dynamic Route Map, to introduce a novel systematic procedure to design memristive arrays, in which a given memcomputing task is executed by ensuring that, depending upon the network inputs and initial conditions, the analogue dynamic routes of the states of the processing elements, namely capacitor voltages and memristor states, asymptotically converge toward pre-defined stable equilibria.