Indium tin oxide (ITO) has extensively used as an electrode in diverse application areas of electrochemistry, displays, photovoltaics, and catalysts. Herein, terpyridine-modified ITO and thioterpyridinefunctionalized Au-modified ITO electrodes were prepared and evaluated for electrochemical redox behaviors and conversion rates of Ce(III)/Ce(IV) ions, and recycling recovery rates on the newly developed electrode by cyclic voltammetry and amperometry. Scanning electron microscopy, X-ray photoelectron spectroscopy, Ultraviolet photoelectron spectroscopy, X-ray diffraction crystallography, and fluorescence spectroscopy were employed for the physiochemical properties of the demonstrated electrodes before and after electrochemistry. The interfacial energy level was examined by ultraviolet photoelectron spectroscopy for ITO-Au and ITO-Au-STpy. Density functional theory calculations were performed to examine complexation between the functionalized ligand and Ce(III)/Ce(IV) ions by obtaining molecular orbital energy levels and thermodynamics. Thermal CO oxidation catalytic activity was tested for Ceelectrodeposited ITO electrode. In addition, electrochemical CO2 reduction performance was evaluated for Au-modified ITO electrode with and without thioterpyridine-functionalization. (C) 2021 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.

The photophysical properties of 2-hydroxy-4-(5-methoxythiophen-2-yl)benzoic acid (HmoTBAH) and methyl 2hydroxy-4-(5-methoxythiophen-2-yl)benzoate (MHmoTB) were investigated in methylenechloride (MC), methanol (MeOH) and dimethyl sulfoxide (DMSO). Ultraviolet (UV) excitation of the thiophene-modified salicylate derivatives produced strong luminescence spanning over the 380-500 nm region, and the spectral features were not affected by the solvent. However, the luminescence quantum yield (Q) of HmoTBAH was higher than that of MHmoTB in a given solvent. The effects of pH on the luminescence properties of the two derivatives were also examined in a DMSO/water mixed solvent (90 vol%), and it was found that the base-treated HmoTBAH produced complex emission and excitation spectra. Furthermore, to interpret the observed photophysical properties, quantum-mechanical calculations of the structural geometry and the electronic transitions were performed using the density functional theory (DFT) and the time-dependent DFT (TDDFT), respectively.

In one of our previous publications, we developed the first mathematical model for acoustic emission from an internal point source in a transversely isotropic cylinder. The point source, as an internal defect, is the most fundamental source generating AE in homogeneous media; it is represented by a spatiotemporal concentrated force and generates three scalar potentials for compressional, and horizontally and vertically polarized shear waves. The mathematical formulas for the displacements were derived by introducing the concentrated force-incorporated potentials into the Navier–Lamé equation. Since the publication of that paper, we detected some errors. In this paper, we correct the errors and extend the analytical modeling to a cylindrical shell structure. For acoustic emission in general circular cylindrical structures, we derived solutions by applying the boundary conditions at inner and outer surfaces of the structures. Under these conditions, we solve the radial, tangential, and axial displacement fields. Analytical simulations of the acoustic emission were carried out at several point source locations for circular cylindrical geometries. We show that the maximum amplitude of the axial displacement is dependent on the point source position and 2π-aperiodicity of the cylindrical geometry. Our mathematical formulas are very useful for characterizing AE features generated from an internal defect source in cylindrical geometries.

Thio-terpyridyl derivatized Au electrodes (Au-STpy) were first employed to understand electrochemical redox behaviors of Ce3+/Ce4+ and Eu2+/Eu3+ ions by cyclic voltammetry (CV). For Ce3+/Ce4+ ions in H2SO4 electrolyte, real-time amperometry and fluorescence spectroscopy revealed that the reduction process was more facile than the oxidation process, and the functionalized Au showed enhanced redox rates. CV and amperometry of Eu2+/Eu3+ ions were performed in KCl electrolyte. X-ray photoelectron spectroscopy (XPS) and fluorescence data confirmed Eu3+ state for electrodeposited Eu complexes. Density functional theory was employed for optimized geometry, electronic energy levels and thermodynamics of the complexation of thio-terpyridyl-functionalized Au with Ce3+/Ce4+ and Eu2+/Eu3+ ions. The role of functionalization was also shown in electrochemical CO2 reduction with major products of CO and H2. Ultraviolet photoelectron spectroscopy revealed the newly aligned energy level at the interface of Au and STpy. The present unique results provide deeper information on functionalized Au for electrochemical applications to the treatment/recycling of lanthanide elements, in addition to catalysts, displays, and metal-organic complexes.

In this paper, the displacement fields responsible for acoustic emission (AE), excited from a point source in a transversely isotropic cylinder, are derived by solving the Navier-Lamé (NL) equation. The point source as an internal defect is represented by a spatiotemporal concentrated force. The introduction of three potentials correlated with the point source to displacement field vector decouples the coupled NL equation in cylindrical coordinates. Under these conditions, we solve the radial, tangential, and axial displacement fields. Analytical simulations of AE were carried out at several point source locations. Our results demonstrate that analytical modeling is a powerful tool for characterizing AE features generated from an internal defect source.

Understanding the electrochemical behaviors of lanthanide (Ln) ions is essential for the treatment, separation, and recovery of radioactive materials and Ln-containing industry waste. Herein, the electrochemical behavior of Eu(III)/Eu(II) ions and their recovery were studied over terpyridine-functionalized indium tin oxide (ITO) electrodes. Two different functionalization processes were performed via Au-S bonding on Au nanoparticleloaded ITO and amide bonding on an amino alkoxysilane-functionalized ITO. Cyclic voltammetry was performed for the electrodes, with and without surface functionalization, in electrolytes containing NaClO4 and H2SO4. Electrodeposition by amperometry was performed to recover Eu ions as EuSO4 on the developed electrodes at a reduction potential of similar to 1.0 V (vs. Ag/AgCl), which is an irreversible reduction potential in NaClO4 electrolyte. The electrodes were fully characterized by scanning electron microscopy, X-ray diffraction crystallography, energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, photoluminescence spectroscopy, and fluorescence lifetime measurements. Density functional theory calculations at the B3LYP/GENECP level of theory were employed for geometry optimization and the electronic energy state calculation for the complexation of Eu(III) and Eu(II) ions with the functionalized groups. The results obtained herein provide valuable information on the development of electrodes for the treatment of Ln and other related elements.

The Eu element was recovered as EuSO4 over new terpyridine-functionalized ITO by an electrochemical method and luminescent Eu2O2SO4 was obtained by post-thermal annealing.

Understanding the electrochemical behaviors of Ce(III)/Ce(IV) ions is essential for better treatment, separation, and recycling of lanthanide (Ln) and actinide (An) elements. Herein, electrochemical redox behavior and interconversion of Ce(III)/Ce(IV) ions and their recoveries were demonstrated over newly developed thio-terpyridine-functionalized Au-modified carbon paper electrodes in acidic and neutral electrolytes. Cyclic voltammetry and amperometry were performed for the electrodes with and without thio-terpyridine functionalization. Ce oxide nanostructure recovery was successfully conducted by amperometry, and the electrodeposited nanostructured Ce materials were fully characterized by scanning electron microscopy, high-resolution transmission electron microscopy, X-ray diffraction crystallography, and X-ray photoelectron spectroscopy. Geometry optimization and the electronic energy state calculations were conducted by density functional theory at the B3LYP/GENECP level for the complexes of Ce(III) and Ce(IV) ions with the thio-terpyridine in an aqueous state. The present unique results provide valuable information on understanding redox behaviors of Ln and An ions for their recycling and treatment processes.

Detoxification of hexavalent chromium (Cr(VI)) in the environment and development of corresponding new materials and detoxification protocols have actively been studied and applied. Herein, 2,2':6',2 ''-terpyridine-4'-thiol (STpy) was functionalized on Au nanoparticle (NP)-loaded carbon paper (CP) and indium-fin-oxide (ITO) electrodes (CP-AuNP and ITO-AuNP, respectively), and the photoelectrochemical (PEC) and photocatalytic detoxification of Cr(VI) using the resulting electrodes was investigated by cyclic voltammetry. Density functional theory at the B3LYP/6-31G level was used for geometry optimization, and the electronic energy state calculation was conducted at the TD-SCF/DFT/B3LYP level. For bare CP, ITO, and STpy-modified AuNP electrodes, the reduction potentials of Cr(VI) were around +0.3, -0.2 V, and +0.5 V (vs. Ag/AgCl), respectively. The PEC and photocatalytic Cr(VI) reduction performance of CP-AuNP was significantly improved upon STpy functionalization. Thus, these newly developed functionalized systems can provide very useful information for further improving the detoxification performances for various hazardous metals.

Decontamination of organophosphorus chemical warfare nerve agents (CWNAs) is gaining importance for human security. Herein, we have employed a dry-photodecontamination method for CWNA model molecules of dimethyl methylphosphonate, dimethyl phosphite, diethyl methylphosphonate, and diethyl phosphite contaminated on aluminum (Al) and oxidized Al foils. For understanding their photo-degradation pathways, the photo decomposition secondary chemical products generated as a result of UVC-decontamination were fully examined for the contaminated Al and oxidized Al target areas in a closed reactor system by gas chromatography and mass spectrometry. Solid residues were also fully examined by X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy. Density functional theory at the B3LYP/6-31 G level was used for geometric optimization, and the electronic energy state calculation was conducted on the level of TD-SCF/B3LYP/6-31 G. The new results further deepen the photo-decomposition mechanism of CWNAs, the development of dry UV light photo-decontamination methods, and the treatment of secondary by-products.

Methyl 2-hydroxy-4-(5-methoxythiophen-2-yl)benzoate (MHmoTB) and methyl 2-hydroxy-4-(5-cyanothiophen-2-yl)benzoate (MHncTB) have been synthesized and their photophysical properties are investigated in various solvents. Introducing methoxy and cyano groups to 5 position of the thiophenyl moiety results in very unique characters in the luminescence properties depending on the substituted group. Compared with the unsubstituted MHTB, the methoxy group as electron donator enhances the quantum yield of the deep blue luminescence more than 9 times in methylene chloride, while do not present an apparent solvatochromic effect on the luminescence spectral feature. In contrast, the cyano group as electron withdrawer enhances the quantum yield slightly. However, the UV excitation (<360 nm) of MHncTB produces not only deep blue emission but also orange emission in dimethylformamide and dimethyl sulfoxide. The new low-energy emission is attributed to an excited state proton transfer from the solute to the solvent. Quantum mechanical calculations on the structural geometries and the electronic structures have been conducted to reveal ESPT of MHncTB by using the time-dependent density functional theory.

Three different S, N and Se-modified methyl salicylate derivatives, methyl 2-hydroxy-4-(pyridin-2-yl)benzoate (MHPB), methyl 2-hydroxy-4-(thiophen-2-yl)benzoate (MHTB) and methyl 2-hydroxy-4-(selenophen-2-yl) benzoate (MHSB) have been synthesized and their photophysical properties are examined in dichloromethane. The three derivatives produce absorption spectra with different shapes spanning over 260-370 nm region. The UV excitation of the derivatives produces characteristic emission features, associated with the Franck-Condon (FC) excited-state configuration at high-energy side and excited state intramolecular proton transfer configuration at low-energy side. For MHPB, two emission bands peaking at around 380 and 450 nm are observed with relatively strong intensities. However, for MHTB the intensity of the blue emission is significantly reduced and for MHSB the emission is significantly quenched. Quantum mechanical calculations on the structural geometry and the electronic transition are performed to reveal the effect of the substituent moieties on the photophysical properties.

This experiment was conducted to investigate effects of brown rice as alternatives on immune responses and gut microbiota of weaned pigs. A total of 72 weaned pigs (7.06 ± 0.57 kg BW; 28 d old) were randomly allotted to 2 dietary treatments (6 pigs/pen; 6 replicates/treatment) in a randomized complete block design (block = BW). Dietary treatments were a nursery diet based on corn-soybean meal (CON) and the other diets formulated by replacing corn with brown rice (BR). The diets did not include animal plasma, fish meal, zinc oxide, or antibiotics to avoid their antibacterial or physiological effects. Pigs were fed respective dietary treatments for 6 weeks. Blood was collected from randomly selected 1 pig in each pen on d 0, 3, 7, or 14 after weaning. Measurements were tumor necrosis factor-α (TNF-α), transforming growth factor-β (TGF-β), and C-reactive protein (CRP), cortisol and immunoglobulin G, M, and A by the enzyme-linked immunosorbent assay. Three weaned pigs per dietary treatment were randomly selected to collect feces on the last day of the experiment to verify their gut microbiota by metagenomic analysis with pyrosequencing. Data were analyzed using the PROC GLM procedure of SAS. Weaned pigs fed BR tended to decrease cortisol on d 0 (25.72 vs. 10.23 pg/ml; P = 0.08) compare with those fed CON. However, there were no differences on serum TNF-α, TGF-β, CRP, Ig G, A, and M between dietary treatments. Pigs fed BR increased (P < 0.05) phylum Firmicutes and genus Lactobacillus and Streptococcus in gut microbiota compared with those fed CON. However, pigs fed BR decreased (P < 0.05) phylum Bacteroidetes and genus Barnesiella and Prevotella in gut microbiota compared with those fed CON. In conclusion, substitution of corn with brown rice may modulated gut microbiome of weaned pigs without changes in immune responses.

This study was conducted to characterize the effects of dietary multigrain carbohydrase on colostrum and milk miRNA of lactating sows. A total of 12 sows (218.37 ± 5.5 kg BW; 2.0 parity) were housed in individual pens for 28 d after farrowing to weaning and randomly assigned to 2 dietary treatments (3 sows/treatment): 1) a typical lactation diet based on corn-soybean meal (CON) and 2) CON added with 0.01% of multigrain carbohydrase (MCS). The MCS contained xylanase, glucanase, and cellulase. Three sows per dietary treatment were randomly selected to collect colostrum within 24 h after farrowing and mature milk at weaning for measuring immune-related miRNA, including let-7a, miR-182, miR-191, miR-21, miR-27b-3p, and miR-30a-5p, by quantitative RT-PCR. The MCS group showed higher expression of all miRNA, especially miR-191 (P < 0.05), in colostrum than the CON group. On the other hand, expression levels of immune-related miRNA in mature milk were similar between the MCS and the CON, only miR-182 were highly expressed in the mature milk of the MCS (P < 0.05). In conclusion, addition of dietary multigrain carbohydrase in the lactation diets altered the expression of immune-related miRNA in colostrum and mature milk.

The experiment was conducted to investigate effects of brown rice as alternatives on growth performance, nutrient digestibility, and gut microbiota of growing-finishing pigs. A total of 50 growing pigs (23.80 ± 2.96 kg BW) were randomly allotted to 2 dietary treatments (5 pigs/pen; 5 replicates/treatment) in a randomized complete block design (block = BW). Dietary treatments were a grower-finisher diet based on corn-soybean meal (CON) and the other diets formulated by replacing corn with 100 % of brown rice (BR). Pigs were fed respective dietary treatments for 12 weeks during growing and finishing periods, respectively. For the last week of experiment period, pigs were fed respective dietary treatments containing 0.2 % chromic oxide as an indigestible marker. Fecal samples were collected from randomly selected 1 pig in each pen daily for the last 3 d after the 4 d adjustment period. Measurements were growth performance, nutrient digestibility by an index method and gut microbiota by metagenomic analysis with pyrosequencing. Data were analyzed using the PROC GLM procedure of SAS. The pyrosequencing data was analyzed using CLcommunity program. There were no differences on growth performance and nutrient digestibility during overall experimental period between dietary treatments. No differences were detected on gut microbiota of growing pigs between dietary treatments. Finishing pigs fed BR increased (P < 0.05) phylum Bacteroidetes and genus Barnesiella in gut microbiota compared with those fed CON. However, decreased (P < 0.05) phylum Firmicutes and genus Lactobacillus and Streptococcus in gut microbiota were observed in finishing pigs fed BR compared with those fed CON. In conclusion, substitution of corn with brown rice in growing-finishing diets may modulate gut microbiota of pigs without no negative effects on growth performance.

This experiment was conducted to investigate immune responses of weaned pigs from lactating sows fed palm kernel expellers. Total 12 lactating sows (200 ± 12 kg BW; 2.5 parity) were randomly assigned to two dietary treatments in a completely randomized design. The treatments were a diet based on corn-soybean meal (CON) and CON replaced by 20% of palm kernel expellers (PKE). Sows were fed the dietary treatments from d 30 before farrowing to weaning. Weaned pigs were allotted to pens by treatments of lactating sows (6 replicates/treatments of lactating sows) and fed a typical nursery diet for 6 wk. Measurements were serum tumor necrosis factor (TNF)-α, transforming growth factor (TGF)-β1, C-reactive protein (CRP) and cortisol by the enzyme-linked immunosorbent assay. Blood were collected from randomly selected 2 weaning pigs per replicate on weaning day, d 3, 7, and 14 after weaning. Data were analyzed using the PROC GLM procedure of SAS. The statistical model for every measurement included dietary effect. Weaned pigs from lactating sows fed PKE tended to have higher TNF-α (304.16 vs. 272.22 pg/ml; P = 0.077) on d 3 compared with those from lactating sows fed CON. There were no differences on serum CRP and cortisol between weaned pigs from sows fed CON and PKE. Consequently, diets replaced by 20% of PKE for lactating sows affected immune responses of their weaned pigs compared with those from lactating sows fed CON.

A blue fluorophore of Schiff base zinc complex is prepared by a hydrolysis-free solution-based synthetic method. Under ultraviolet (UV) excitation, the complex produces blue emission with a quantum yield ( Q) of 42.6% in methylene chloride and 24.0% in standalone powder form. Quantum mechanical calculations show that the blue emission is generated by the change in the chemical state of the ligand associated with the complexation with Zn cations. Thin films of Zn complexes incorporated in polymethylmethacrylate (PMMA) and cellulose acetate butyrate (CAB) polymers are also prepared by dispersing the complexes into the polymer matrices. These hybrid polymer films exhibit several notable features, particularly enhanced luminescence efficiency (with maximum Q of 85.8% for PMMA and 30.0% for CAB) and scalability for fabrication over a large area while retaining the original properties of the host polymers. Light-emitting diodes are also fabricated using the CAB hybrid thin films, and they show a Q of 43.2% with excellent photostability. The complex and its hybrid films demonstrate their great potential for such applications as UV-to-blue conversion devices in photoelectronics, solar-cell concentrators, solid-state lighting and display, and greenhouse agriculture.

The study evaluated the effects of dietary multigrain carbohydrase in lactation diets on immune response and gut microbiota of lactating sows and their litters. A total of 12 sows (218.37 ± 5.5 kg BW; 2.0 parity) were randomly assigned to 2 dietary treatments: a diet based on corn-soybean meal (CON) and CON supplemented with 0.01% multigrain carbohydrase. Sows were fed the dietary treatments for 28 days (lactation) after farrowing. Blood samples were collected from sows on d 0, 3, and 7 after farrowing and randomly selected 2 nursing piglets in each sow on d 3, 7, and 14 after birth. Measurements were serum tumor necrosis factor-α (TNF-α), transforming growth factor-β (TGF-β), C-reactive protein (CRP), cortisol and immunoglobulin G, M, and A by the enzyme-linked immunosorbent assay. Three sows per dietary treatment and two nursery pigs were randomly selected to collect feces on d 7 and 28 after farrowing to verify their microbiota changes by pyrosequencing analysis. Data were analyzed using the PROC GLM procedure of SAS. There were no differences in immune response of lactating sows between CON and MCS. However, TNF-α of nursery pigs from sows fed MCS was increased on d 3 of lactation (244.14 vs. 282.11 pg/ml; P < 0.05) compared with those from sows fed CON. Nursing pigs from MCS-sows had lower CRP on d 7 of lactation (128.65 vs. 92.63 ng/ml; P < 0.05) than those from CON-sows. No differences were detected on TGF-β, cortisol and immunoglobulin G, M, and A of nursery pigs between dietary treatments. During lactation period, MCS increased (P < 0.05) genus Lactobacillus in gut microbiota of sows and their litters compared with CON. In conclusion, addition of dietary multigrain carbohydrase in the lactation diet influenced immune responses and gut microbiota of lactating sows and their litters.

To gain better optical and optoelectrical properties, doping trivalent lanthanide cations into host materials is a very attractive approach in nanoscience. Here, we use a transparent conducting oxide, zinc oxide, as the host material to directly embed trivalent terbium cations without the need for any postgrowth treatment, and we investigate the photophysical effect of the dopant. Trivalent Tb cations embedded in ZnO nanowalls produce hypersensitive green emission (at 545 nm, corresponding to the 5D4 → 7F5 transition) and convert the emission color of ZnO from yellow into white. Evidently, the photoluminescence emission intensity of Tb(III) is further increased by close to 10-fold due to the plasmonic effect introduced by noble metal (Ag and Pt) nanoparticles. The characteristic Tb(III) emission is found to be tunable from white to red and is examined for its potential chemosensing application for rhodamine B involving a plausible cascade energy transfer mechanism from ZnO to rhodamine B via Tb(III) cations.

The single crystal structure, luminescence and magnetic susceptibility of Cs[Ln(DBM)4] and Ln(DBM)3(phen) (Ln=Eu and Gd, DBM=dimenzoylmethanto and phen=1,10-phenanthroine) were characterized in detail. A pentanuclear Eu(III) cluster with the formula, Eu5(DBM)10(OH)5, was obtained from Cs[Eu(DBM)4] in ethanol, while from Cs[Gd(DBM)4] in acetonitrile, a one-dimensional polymeric Gd(III) assembly with the formula, {Cs[Gd(DBM)4]}n, was achieved via a heterobimetallic backbone, composed of alternating Cs and Gd atoms bridged by DBM. Exciting the Eu(III) complexes with near-UV light produced sensitized red emission by energy transfer from the triplet excited state of DBM to the Eu(III) ion. Replacing DBM by phen increased the quantum yield from Q=8.3% for Cs[Eu(DBM)4] to Q=16.6% for Eu(DBM)3(phen). This was attributed to a reduction in the site-symmetry of Eu(III) from D4h to C2v. The magnetic susceptibilities of the synthesized Ln(III) complexes in the crystalline or powder states were measured using a SQUID magnetometer. The Eu(III) complexes illustrated magnetic anisotropy at low temperatures and temperature-dependent susceptibilities. The coercive field inducing the magnetic anisotropy of Eu5(DBM)10(OH)5 was more than 40-fold stronger than those of Cs[Eu(DBM)4] and Eu(DBM)3(phen). In particular, the calculation based on the Van Vleck׳s treatment confirmed that the thermal mixing between the excited and ground states played a key role in the temperature-dependent susceptibilities of Eu(III). The magnetic susceptibility of the Gd(III) ion in Gd(DBM)3(phen) was identical to that of the free Gd(III) ion, wheras that of the Gd(III) ion in Cs[Eu(DBM)4] was higher. The phen ligand with the π-conjugate rigid planar structure decreased the magnetic susceptibilities of the Eu(III) and Gd(III) ions.