Three-Dimensional Measurement of Ice Crystals in Frozen Materials by Near-Infrared Imaging Spectroscopy

A novel technique was developed to recognize ice crystals in biological materials and to analyze their three-dimensional morphology using a Cryogenic Micro-Slicer Spectral Imaging System with a micro-slicer unit and a near-infrared spectral imaging unit. Consecutive cross-sections of a frozen sample were exposed by the multi-slicing operations with a minimum thickness of 1 µm, and their images were taken by the imaging unit. Spectroscopic analysis using a near-infrared spectrum meter showed an absorption peak at 1460 nm for pure water. Based on the observations of the absorption band of ice crystals in the wavelength range of 1450–1570 nm and its peak at 1495 nm, a commodity-type bandpass filter with a central wavelength of 1500 nm was adopted to identify ice crystals in near-infrared images. The absorption peak of water exhibited a tendency to move toward longer wavelengths with decreasing sample temperature from 25 °C to ?15 °C. The filtered images of ice crystals in frozen samples were darker than the other components at the peak wavelength of ice crystals. The three-dimensional reconstructed morphology of ice crystals revealed that they were formed along the direction of heat transfer while freezing. The proposed method provides a novel tool to investigate the effects of freezing conditions on the size, morphology and distribution of ice crystals.     

Pilot-Scale Operation of a Concrete Sludge Recycling Plant and Simultaneous Production of Calcium Carbonate

A pilot-scale plant to treat concrete sludge and produce calcium carbonate (CaCO₃) and an environmental purification agent (phosphorus adsorbent derived from concrete sludge, PAdeCS®) was designed, constructed, and operated. Concrete sludge from a concrete pile and pole production plant, boiler gas containing CO₂, and groundwater were used in the plant. The process involved calcium extraction from concrete sludge into water, followed by reaction of the calcium with CO₂ to produce crystalline CaCO₃. The pilot-scale plant was operated for 1 week, and the mass flows, conversion of CO₂ to CaCO₃, and net CO₂ emissions of the process were estimated. High-purity CaCO₃ (>97%) suitable for industrial use was obtained. Based on the power consumption of the process and the amount of CO₂ sequestered into CaCO₃, a net reduction in CO₂ emissions can be achieved using this process. The produced PAdeCS can be used as an inexpensive substitute for calcium series environmental purification agents.     

Enhancing oil repellency of electron beam-grafted polyethylene terephthalate fabric with 2-(perfluorohexyl) ethyl acrylate monomer via pre-irradiation

Electron beam (EB)-induced graft polymerization is advantageous for the surface modification of fabrics. We investigated the effect of monomer concentration and the addition of alkyl groups on the oil repellency of polyethylene terephthalate (PET) fabrics treated with monomers containing fluoroalkyl groups through EB-induced graft polymerization via pre-irradiation. We use 2-(perfluorohexyl) ethyl acrylate (FEA) and stearyl acrylate (SA(C18)) with long alkyl chains as vinyl monomers to induce reaction with radicals generated from EB irradiation. The weight gain and surface morphology of the PET fabrics change with the FEA monomer concentration. The uniformity of the EB-grafted PET fabric surface is determined at low monomer solution concentrations. Results of X-ray photoelectron spectroscopy analysis show that adding 0.1 mol/L of FEA monomer to the EB-grafted PET fabric yields the highest dodecane contact angle of 93.4° and a surface fluorine concentration of 39.8%. The addition of SA(C18) monomer to the FEA monomer decreases the dodecane contact angle by 77.5° and yields a surface fluorine concentration of 19.1%. EB graft polymerization via pre-irradiation results in a uniformly treated surface, and stable oil repellency is achieved when using solely the FEA monomer at a lower monomer concentration than that used in a similar irradiation method reportedly previously.     

Microporous carbons prepared from cationic surfactant-resorcinol/formaldehyde composites

Microporous carbons have been synthesized by the carbonization of cationic surfactant-resorcinol/formaldehyde (RF) composites, which were themselves formed by electrostatic organic-organic interaction. The porous structure produced by the decomposition of the surfactant plays an important role for the gasification of the RF polymer at higher temperatures. The pore size of the carbon prepared from tetrapropylammonium bromide (TPAB)-RF, cetyltrimethylammonium bromide (C₁₆TAB)-RF and decyltrimethylammonium bromide (C₁₀TAB)-RF mixtures can be estimated as 0.53 nm from the Horvath-Kawazoe method using N₂ adsorption isotherms. Their pore size distributions were very narrow, showing that the microporous carbons derived from surfactant-RF mixture may have promise as adsorbents and membrane materials.     

Site‐Selective Iron(III) Chloride‐Catalyzed Arylation of 4‐Aryl‐4‐methoxy‐2,5‐cyclohexadienones for the Synthesis of Polyarylated Phenols

The iron(III) chloride‐catalyzed Friedel–Crafts arylation of 4‐aryl‐4‐methoxy‐2,5‐cyclohexadienones, which were easily prepared by the phenyliodine(III) diacetate (PIDA)‐mediated oxidation of 4‐arylphenols in methanol, proceeded site‐selectively to form meta‐terphenyl (2,4‐diarylphenol) derivatives in good yields. The subsequent PIDA‐mediated oxidation and iron(III) chloride‐catalyzed Friedel–Crafts arylation of the resulting products gave the corresponding 2,4,6‐triarylphenol derivatives. The present method provides useful highly substituted polyarylated compounds.

     

Immunomodulatory Properties and Osteogenic Activity of Polyetheretherketone Coated with Titanate Nanonetwork Structures

Polyetheretherketone (PEEK) is a potential substitute for conventional metallic biomedical implants owing to its superior mechanical and chemical properties, as well as biocompatibility. However, its inherent bio-inertness and poor osseointegration limit its use in clinical applications. Herein, thin titanium films were deposited on the PEEK substrate by plasma sputtering, and porous nanonetwork structures were incorporated on the PEEK surface by alkali treatment (PEEK-TNS). Changes in the physical and chemical characteristics of the PEEK surface were analyzed to establish the interactions with cell behaviors. The osteoimmunomodulatory properties were evaluated using macrophage cells and osteoblast lineage cells. The functionalized nanostructured surface of PEEK-TNS effectively promoted initial cell adhesion and proliferation, suppressed inflammatory responses, and induced macrophages to anti-inflammatory M2 polarization. Compared with PEEK, PEEK-TNS provided a more beneficial osteoimmune environment, including increased levels of osteogenic, angiogenic, and fibrogenic gene expression, and balanced osteoclast activities. Furthermore, the crosstalk between macrophages and osteoblast cells showed that PEEK-TNS could provide favorable osteoimmunodulatory environment for bone regeneration. PEEK-TNS exhibited high osteogenic activity, as indicated by alkaline phosphatase activity, osteogenic factor production, and the osteogenesis/osteoclastogenesis-related gene expression of osteoblasts. The study establishes that the fabrication of titanate nanonetwork structures on PEEK surfaces could extract an adequate immune response and favorable osteogenesis for functional bone regeneration. Furthermore, it indicates the potential of PEEK-TNS in implant applications.     

Mechano-catalytic overall water splitting on some mixed oxides

Simple transition metal oxides such as NiO, Co₃O₄, Fe₃O₄ and Cu₂O were found to catalytically decompose water into H₂ and O₂ by mechanical energy. The reaction is regarded as “mechano-catalytic” overall water splitting” and is a quite novel catalytic reaction. In this paper, some general aspects on the mechano-catalytic overall water splitting are reviewed on simple oxides. In addition, recent results on the mechano-catalytic activity of a groups of mixed oxides, wolramite-type oxides with a formula of ABO₄ (A=Fe, Co, Ni and Cu, etc., B=W, Mo), are shown. AWO₄ (A=Fe, Co, Ni and Cu) decomposed water into H₂ and O₂ under the supply of mechanical energy, indicating that mechano-catalytic overall water splitting proceeded on wolframite-type compounds containing 3d-transition metals. AMoO₄ (A=Fe, Co, Ni) also decomposed water into H₂ and O₂ under supply of mechanical energy. The reaction properties on wolframite-type oxides are discussed.     

Chemical response of Picea glehnii seed-epiphytic Penicillium species to Pythium vexans under in vitro competitive conditions for mycelial growth

The potential protection of Picea glehnii seedlings from damping-off by seed-epiphytic Penicillium species was investigated. We studied the chemical response of seed-epiphytic Penicillium species (Pen. cyaneum, Pen. damascenum, and Pen. implicatum) to Pythium vexans, a damping-off fungus, in vitro. Penicillium species were cultured singly or cocultured with Pyt. vexans for 14 or 18 d, and mycelial growth, pH of culture filtrate, antifungal activity of the culture filtrate against Pyt. vexans, and the amount of antifungal compound produced by each Penicillium species, were examined. The filtrate of both the single culture of Penicillium and the coculture of Penicillium and Pyt. vexans showed antifungal activity against Pyt. vexans. In a coculture with Pyt. vexans, Pen. cyaneum produced an antifungal compound (patulin) as in the single culture. Pen. damascenum cocultured with Pyt. vexans produced an antifungal compound (citrinin), as it did in the single culture and in larger amounts on day 10. Pen. implicatum produced two antifungal compounds, frequentin and palitantin, and the ratio of frequentin (with higher antifungal activity than palitantin) to palitantin was higher in the coculture with Pyt. vexans than in the single culture. Our results indicate that these Penicillium species have the ability to produce antifungal compounds and to keep antifungal activity under competitive condition with Pyt. vexans. The chemical response of these Penicillium species to Pyt. vexans may contribute to protect P. glehnii seedlings from damage by Pyt. vexans.     

Application of Ni-free high nitrogen stainless steel for bipolar plates of proton exchange membrane fuel cells

Ni-free 23Cr-1N stainless steel was examined as bipolar plates for proton exchange membrane fuel cells. Corrosion resistance of the 23Cr-1N stainless steel was better relative to 22Cr stainless steel in the simulated cathodic environments. As confirmed by X-ray photoelectron spectroscopy, the polarized 22Cr and 23Cr-1N stainless steels at pH 2.3 presented predominantly chromium oxide in the outer passive layers. At pH 4.3, the passive layer of the polarized 22Cr stainless steel changed to iron oxides dominant. Interestingly, on the other hand, the polarized 23Cr-1N stainless steel preserved chromium oxide rich outer passive layer, which provides good corrosion resistance. As a result, although the initial cell voltage was slightly lower (∼40 mV), the 23Cr-1N stainless steel bipolar plates employing cell showed better cell voltage stability up to 1000 h, compared with the 22Cr stainless steel employing cell. The operation voltage became further higher through a surface modification of the 23Cr-1N stainless steel with TiN nanoparticles. It seems that the corrosion resistive Ni-free 23Cr-1N is possible to apply for bipolar plates of proton exchange membrane fuel cells.