The controlling factor of the CO2 permeance of an ion gel membrane containing a task-specific ionic liquid (tetraphosphonium prolinate) as the CO2 carrier was investigated. Tough double-network (DN) ...ion gel membranes with different thicknesses were fabricated, and their CO2 permeances were evaluated. The results showed that the CO2 permeance of the DN ion gel membrane was not inversely proportional to the membrane thickness, indicating that the CO2 permeance of the membrane was not controlled by diffusion. A theoretical analysis of the relationship between CO2 permeance and the thickness of the membrane revealed that the CO2 stripping rate at the permeate side greatly affected the CO2 permeance of the DN ion gel membrane. Therefore, increasing the decomposition reaction rate of the CO2–carrier complex would be the most important issue for achieving a high CO2 permeance of ion gel membranes containing a task-specific ionic liquid.
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IJS, KILJ, NUK, PNG, UL, UM
Forward osmosis (FO) has attracted research attention as the energy-effective water separation process. For a FO process, it is important to prevent leakage of a solute of the DS. As a low-leakage ...solute, a branched thermo-responsive oligomer, pentaerythritol-oligo(ethylene oxide)m-b-(butylene oxide)n oligomers (PEBs), had been reported. In this study, the relationship between the chemical structure and the permeability of the PEBs through a FO membrane had been investigated in detail. For the detailed investigation, the mole fraction of each component having different absolute molecular weights in the PEBs was determined by the MALDI/TOF-MS, then the permeabilities of the components through the FO membrane were independently quantified. As the result, for the PEBs with low absolute molecular weight, the permeability of the PEBs was strongly affected by the molecular weight of the PEBs. On the other hand, for the PEBs with high absolute molecular weight, it was confirmed that the permeability of the PEBs was affected by the hydrophobicity of the PEBs. Conclusively, it was indicated that not only the molecular weight but also the affinity between the PEBs and the FO membrane is important for the reverse solute flux.
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•Branched oligomer draw solutes with several molecular weights (Mw) were synthesized.•Permeability of the oligomers through a forward osmosis (FO) membrane was measured.•The components permeated through the FO membrane were quantified by mass spectra.•Permeability of oligomers with small absolute Mw was affected by the diffusivity.•Affinity between the oligomer and the FO membrane was important for permeability.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Organic solvent reverse osmosis (OSRO) is currently considered as an energy-efficient membrane technology for separation of organic liquid mixtures. The conventional hydrophilic polyamide thin film ...(TFC) membrane was previously reported to be chemically stable and capable of separation of organic liquids with varying polarity. In order to augment the performance and applicability of the TFC membrane for a wider array of organic liquids, we report the preparation of a hydrophobic fluorine-incorporated TFC membrane for OSRO. 5-Trifluoro-1,3-phenylenediamine (TFMPD) and trimesoyl chloride (TMC) were used as the respective fluorine-containing hydrophobic diamine monomer in aqueous phase and acid chloride in organic phase. The hydrophobic membrane was able to allow the permeation of nonpolar solvents, such as aliphatic and aromatic hydrocarbons, which could not permeate through the conventional hydrophilic polyamide membranes using m -phenylenediamine (MPD) as a diamine monomer. In addition, the OSRO test showed high performance in toluene mixed solvent systems with selective permeation of toluene and 93.9% rejection of 1,3,5-triisopropylbenzene (TIPB). The successful preparation of a hydrophobic fluorine-incorporated polyamide TFC membrane suitable for OSRO for separation of nonpolar organic liquid mixtures has proven to be simple, cost-efficient, and highly-scalable.
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•Thin TiO2-ZrO2-DTBC composite membranes were fabricated.•Pore sizes and surface properties were controlled by changing the firing conditions.•Surface free energy was calculated to ...consider the membrane-solvent interactions.•Membrane-solvent interactions, viscosity, and solvent size affected the solvent permeance.
TiO2-ZrO2-(3,5-di-tert-butylcatechol, DTBC) composite membranes were fabricated via the sol–gel method under four different firing conditions: 300 °C (N2), 300 °C (Air), 350 °C (Air), and 500 °C (Air). The chemical structure of the DTBC originated organic material in the composite was controlled by setting the firing temperature. The average pore sizes of the membranes were 1.0–1.1 nm when fired at 300 °C, 1.4 nm at 350 °C, and 2.1 nm at 500 °C. The molecular weight cut-off of the membranes (in daltons) in water ranged from 480 to 535 when fired at 300 °C, 890 at 350 °C, and 1,680 at 500 °C, whose corresponding molecular diameter was in good agreement with the average pore size measured via nanopermporometery. Permeation tests of the organic solvents showed that the membrane-solvent interaction affected the permeation mechanism in addition to the solvent viscosity and the occupied area of the solvent molecules. The surface free energy difference between the membrane and the solvent expressed the interaction between the membrane and the solvent molecule. The proposed solvent permeation model was examined and showed better agreement with the experimental results compared with the model based on the solubility parameters of a solvent. The organic solvent permeation mechanism of the ceramic NF membrane was greatly affected by the membrane-solvent intermolecular interaction.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
A micro-double-network (μ-DN) ion gel membrane was fabricated using nonvolatile network precursors comprising a presynthesized cross-linkable polymer as the organic part, silica nanoparticles as the ...inorganic part, and 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (C4mimTf2N). The mechanical properties of the ion gel were effectively improved through optimizing the molecular weight of the cross-linkable polymer and the organic/inorganic network composition. The μ-DN ion gel membranes exhibited the CO2 permeability of approximately 920 Barrer under atmospheric pressure, which is much higher than those of the classic double-network ion gel membranes fabricated using volatile network precursors (556 Barrer) and the supported ionic liquid membranes (617 Barrer). The membrane also has good pressure resistance and long-term stability. The μ-DN ion gel membrane formed by nonvolatile network precursors shows good mechanical properties and high CO2 separation performance, which make it a good candidate base material for developing high-permeance thin ion gel membranes.
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IJS, KILJ, NUK, PNG, UL, UM
The light absorption properties of particulate and dissolved materials strongly influence the propagation of visible light in oceanic waters and therefore the accuracy of ocean color algorithms. ...While the general absorption properties of these materials have been reported for Arctic waters, their seasonal variability remains unknown. We investigated the light absorption coefficients of phytoplankton aϕ(λ), nonalgal particles aNAP(λ), and colored dissolved organic matter aCDOM(λ) in both coastal and oceanic waters of the western Arctic Ocean from spring to autumn. Values for the chlorophyll a–specific absorption coefficient of phytoplankton a*ϕ(440) declined significantly from the ice melt period in the early spring to the summer. Using high‐performance liquid chromatography, we show that the decrease in a*ϕ(440) was due to a strong package effect that overwhelmed the influence of the pigment composition. A decrease in the aNAP(λ) values from spring and summer to autumn likely originated from a decrease in the concentration of phytoplanktonic detritus. The aCDOM(λ) near the surface decreased by 34% from spring to summer as a result of photobleaching by solar radiation. The colored dissolved organic matter (CDOM) absorption values then increased significantly during autumn, resulting from the cumulative injection of Alaskan Coastal Waters into the Arctic as well as CDOM generated in situ. Our results suggest that all of the absorption components are tightly linked to biogeochemical processes, and thus the seasonal variability in aϕ(λ), aNAP(λ), and aCDOM(λ) should be taken into account in bio‐optical models.
We report on a process for estimating the retraction force of a pseudopodium of a radiolarian specimen using a video recording of its behavior. Specifically, we focused on the retraction of the axial ...projection, which is the longest and the thickest pseudopodium, using the video recording of the movement of the specimen towards the container bottom to which its axial projection tip had adhered. Our approach consisted of three steps: shape approximation using seventh-order polynomials, estimation of the movement speed, and numerical simulation of the fluid flow around an object with the same shape as the specimen. The retraction force was estimated to be approximately 2.22 × 10−10 N.
Radiolaria is a valuable age index fossil through the Phanerozoic. This article describes the characteristics of the non-taxonomic names of closed nassellarian radiolarians, that is, di-segmented ...closed nassellarian (DiCN), tri-segmented closed nassellarian (TrCN), tetra-segmented closed nassellarian (TeCN), and multi-segmented closed nassellarian (MuCN), based on the number of segments. This article points out a potential as a practical age index for DiCN and TrCN. The TrCN occurrence indicates a Jurassic–Cretaceous age. In particular, the waterdrop-shaped TrCN-dominant occurrence suggests a Middle–Late Jurassic age; the spherical TrCN-dominant occurrence suggests a Cretaceous age. DiCN occurrence indicates a Jurassic–Cretaceous age, and abundant in the Middle Jurassic–Cretaceous.
Abundant Triassic radiolarian fossils were obtained from varicolored bedded cherts exposed in the Buruocang section near Jinlu village, Zedong, southern Tibet. The radiolarian‐bearing rocks represent ...fragmented remnants of the Neotethys oceanic sediments belonging to the mélange complex of the east part of the Yarlung‐Tsangpo Suture Zone. Two new middle Late Anisian radiolarian assemblages recognized from this section named Oertlispongus inaequispinosus and Triassocampe deweveri, respectively, are compared with those known from Europe, Far East Russia, Japan, and Turkey. These Anisian radiolarian fossils are the first reported in southern Tibet and the oldest radiolarian record within the Yarlung‐Tsangpo Suture Zone. They improve time constraints for the evolution of Neotethys in southern Tibet.
豊富な三畳紀放散虫化石が，チベット南部Zedong Jinlu村近郊のBuruocangセクションに露出する多色層状チャートから得られた. 含放散虫岩は，ヤールン‐ツァンポー縫合帯東部のメランジュコンプレックスに属するネオテチス海堆積物の一部を代表する. 本セクションから新たに得られたアニシアン新世中期の2つの群集，すなわち Oertlispongus inaequispinosus 群集とTriassocampe deweveri群集は，ヨーロッパ，極東ロシア，日本，トルコから知られている群集に比較される. これらのアニシアン放散虫化石の報告はチベット南部からは初めてであり，ヤールン‐ツァンポー縫合帯における最古の放散虫記録である. これらの産出記録は，ネオテチスの進化について，より確かな年代的制約を与えるものである.
Two new middle Late Anisian radiolarian assemblages recognized from this section named Oertlispongus inaequispinosus and Triassocampe deweveri, respectively, are compared with those known from Europe, Far East Russia, Japan, and Turkey. These Anisian radiolarian fossils are the first reported in southern Tibet and the oldest radiolarian record within the Yarlung‐Tsangpo Suture Zone. They improve time constraints for the evolution of Neotethys in southern Tibet.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Arctic Ocean microbial eukaryote phytoplankton form subsurface chlorophyll maximum (SCM), where much of the annual summer production occurs. This SCM is particularly persistent in the Western Arctic ...Ocean, which is strongly salinity stratified. The recent loss of multiyear sea ice and increased particulate-rich river discharge in the Arctic Ocean results in a greater volume of fresher water that may displace nutrient-rich saltier waters to deeper depths and decrease light penetration in areas affected by river discharge. Here, we surveyed microbial eukaryotic assemblages in the surface waters, and within and below the SCM. In most samples, we detected the pronounced SCM that usually occurs at the interface of the upper mixed layer and Pacific Summer Water (PSW). Poorly developed SCM was seen under two conditions, one above PSW and associated with a downwelling eddy, and the second in a region influenced by the Mackenzie River plume. Four phylogenetically distinct communities were identified: surface, pronounced SCM, weak SCM and a deeper community just below the SCM. Distance-decay relationships and phylogenetic structure suggested distinct ecological processes operating within these communities. In the pronounced SCM, picophytoplanktons were prevalent and community assembly was attributed to water mass history. In contrast, environmental filtering impacted the composition of the weak SCM communities, where heterotrophic Picozoa were more numerous. These results imply that displacement of Pacific waters to greater depth and increased terrigenous input may act as a control on SCM development and result in lower net summer primary production with a more heterotroph dominated eukaryotic microbial community.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, SBMB, SBNM, UL, UM, UPUK
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