Miracle-dz/UniFAR-FTUs huggingface dataset:
Sulfonated poly(arylene ether sulfone) composite membranes having poly(2,5-benzimidazole)-grafted graphene oxide for fuel cell applications

Sulfonated poly(arylene ether sulfone) (SPAES) composite membranes were prepared using thermally-treated graphene oxide (GO) and poly(2,5-benzimidazole)-grafted graphene oxide (ABPBI-GO) as fillers for proton exchange membrane fuel cell (PEMFC) applications. Pristine graphene oxide was obtained from graphite by chemical oxidation, and 3,4-diaminobenzoic acid was then reacted with pristine graphene oxide to obtain ABPBI-GO. When GO and ABPBI-GO were incorporated into the SPAES matrix, the dimensional stability and mechanical strength of the membrane were improved. In particular, the SPAES/ABPBI-GO composite membranes exhibited improved dimensional stability, larger Young's modulus, and larger elongation at break than the SPAES/GO composite membranes due to the acid–base interaction between the sulfonic acid group of the SPAES matrix and the basic imidazole unit of ABPBI-GO. In addition, the SPAES/ABPBI-GO composite membranes possessed higher proton conductivity than pristine SPAES and SPAES/GO composite membranes because the acid–base interaction can generate additional proton conduction pathways in the membrane structures.
Layered α‐Co(OH)2 Nanocones as Electrode Materials for Pseudocapacitors: Understanding the Effect of Interlayer Space on Electrochemical Activity

The effect of space accessible to electrolyte ions on the electrochemical activity is studied for a system of transition‐metal hydroxide‐based pseudocapacitors. Layered α‐Co(OH)2 with various intercalated anions is used as a model material. Three types of layered α‐Co(OH)2 with intercalated anions of dodecyl sulfate, benzoate, or nitrate, are prepared by a simple reflux and an anion‐exchange process. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) observations and X‐ray diffraction (XRD) data show the formation of layered α‐Co(OH)2 nanocones with interlayer spacing between adjacent Co(OH)2 single sheets of 1.6, 0.7, and 0.09 nm, corresponding to the anions as listed above. Electrochemical characterization reveals that interlayer space has a great effect on the electrochemical activity of α‐Co(OH)2 nanocones as an electrode material. For the interlayer spacing of 1.6 nm, in the case of dodecyl sulfate‐intercalated α‐Co(OH)2, the Faradaic reaction takes place more adequately than for benzoate‐ and nitrate‐intercalated α‐Co(OH)2. As a result, a higher specific capacitance and better cycling stability is obtained for the dodecyl sulfate‐intercalated α‐Co(OH)2. The electrochemical activity obviously reduces when the interlayer space decreases to 0.7 nm. Our results suggest the importance of rational designing the interlayer space of layered transition metal hydroxides for high‐performance pseudocapacitors.
Fabrication of super-hydrophobic surfaces on aluminum alloy substrates by RF-sputtered polytetrafluoroethylene coatings

In this work, we present a method of fabricating super-hydrophobic surface on aluminum alloy substrate. The etching of aluminum surfaces has been performed using Beck's dislocation etchant for different time to create micrometer-sized irregular steps. An optimised etching time of 50 s is found to be essential before polytetrafluoroethylene (PTFE) coating, to obtain a highest water contact angle of 165±2° with a lowest contact angle hysteresis as low as 5±2°. The presence of patterned microstructure as revealed by scanning electron microscopy (SEM) together with the low surface energy ultrathin RF-sputtered PTFE films renders the aluminum alloy surfaces highly super-hydrophobic.
Characterization of poly(D,L-lactic acid) synthesized by direct melt polymerization and its application in Chinese traditional medicine compound prescription microspheres

From D,L-lactic acid and with 0.5 wt % stannous chloride (SnCl2) as a catalyst under an absolute pressure of 70 Pa and at 165–170°C, poly(D,L-lactic acid) (PDLLA) with an intrinsic viscosity of 0.2302 dL/g was synthesized after 10 h of melt polycondensation. This directly produced PDLLA was systematically characterized with gel permeation chromatography, Fourier transform infrared, 1H-NMR, differential scanning calorimetry, and X-ray diffraction. The weight-average molecular weight of PDLLA was 17,800 Da, and the weight-average molecular weight/number-average molecular weight ratio was 1.25. It was partly crystalline, and its crystallinity was 20.8%. When first applied to the Chinese traditional medicine compound prescription Osteitis no. 1 PDLLA microsphere (G-PDLLA-MS), the optimal conditions for the extraction of the effective components in three raw herbs (Herba epimedii, Fructus psorakae, and Angelicae) and for the preparation of G-PDLLA-MS were determined with orthogonal testing. After the extractant was obtained by ethanol reflux, G-PDLLA-MS was prepared with a gelatin concentration of 8%, an inner water phase/oil phase volume ratio of 1.5:1, a stirring rate of dispersion of 1000 rpm, and a PDLLA concentration of 20%. Differential scanning calorimetry and scanning electron microscopy proved that G-PDLLA-MS had a good spherical shape. The practical average particle size of G-PDLLA-MS was 8.59 μm, and the particle sum between 2 and 12 μm was greater than 92%; this meets the requirement for an arthritis cure. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 195–200, 2005
Role of Competitive Cation Exchange on Chromatographic Displacement of Cesium in the Vadose Zone beneath the Hanford S/SX Tank Farm

Migration of radionuclides under the SX‐tank farm at the Hanford nuclear waste complex involves interaction of variably water saturated sediments with concentrated NaOH–NaNO3–NaNO2 solutions that have leaked from the tanks. Constant Kd models for describing radionuclide retardation are not valid under these conditions because of strong competition for sorption sites by abundant Na+ ions, and because of dramatically changing solution compositions with time as the highly concentrated tank fluid becomes diluted as it mixes with infiltrating rainwater. A mechanistic multicomponent sorption model is required that can account for effects of competition and spatially and temporally variable solution compositions. To investigate the influence of the high ionic strength tank fluids on Cs+ migration, numerical calculations are performed using the multiphase‐multicomponent reactive transport code FLOTRAN. The computer model describes reactive transport in nonisothermal, variably saturated porous media including both liquid and gas phases. Pitzer activity coefficient corrections are used to describe the high ionic strength solutions. The calculations take into account multicomponent cation exchange based on measured selectivity coefficients specific to the Hanford sediments. Solution composition data obtained from Well 299‐W23‐19, documenting a moderately concentrated leak from the SX‐115 tank, are used to calibrate the model. In addition to exchange of cations Na+, K+, Ca2+, and Cs+, aqueous complexing and a kinetic description of precipitation and dissolution of calcite are also included in the calculations. The fitted infiltration rate of 0.08 m yr−1, and fitted cation exchange capacity of 0.05 mol kg−1 are consistent with measured values for the Hanford sediments. A sensitivity analysis is performed for Na+ concentrations ranging from 5 to 20 m to investigate the mobility of Cs+ interacting with a highly concentrated background electrolyte solution believed to have been released from the SX‐108/SX‐109 tanks. The calculations indicate that during the initial period of the tank leak when Cs+ is associated with high Na+ concentrations, there is little retardation of the Cs+ plume. However, as time increases the Na+ and Cs+ profiles become chromatographically separated due to differences in their selectivity coefficients and dilution of the tank leak plume with infiltrating rainwater. Eventually the two species become separated spatially, and Cs+ becomes highly retarded and remains essentially fixed in the sediments by cation exchange. For the 20 m Na+ simulated tank leak, the sorbed Cs+ profile is in close agreement with data obtained from the slant borehole and consistent with the estimated tank supernatant concentration. The simulations suggest that natural attenuation processes should result in strong fixation of Cs+ in the vadose zone in spite of the release of high Na+ concentrations during a tank leak event.
A dynamic cell model for the formation of epithelial tissues

Abstract A dynamic model is proposed for monolayered epithelial tissue, in which the monolayer is assumed to consist of prismatic cells, so that the system is described as a two-dimensional polygonal pattern. Its dynamic behaviour is determined by equations of motion for vertices in the polygonal pattern and elementary change in the system (change in the connection of vertex pairs). The vertices are driven by the sum of interfacial tension on cell boundaries and the resistance force against the deformation of cells. It is shown by computer simulations that our model possesses the characteristics of epithelial tissue, that is it has a mechanism which makes the edge number and size of a cell uniform and the shape symmetric. This mechanism finally gives rise to a regular polygonal pattern similar to a honeycomb pattern, even though initial patterns have large variations. Local equilibrium dynamics under which the size of each cell is flexibly adapted to its local environment are compared with non-local equilibrium dynamics. The local equilibrium dynamics produce more natural cellular patterns.
Evaluation of a CGC-FID Method for Qualitative and Quantitative Analysis of Azole Antifungal Drugs

Summary This paper presents a new method for identification and quantitative analysis of six azole antifungal drugs — bifonazole, clotrimazole, econazole, fluconazole, ketoconazole, and miconazole — by capillary gas chromatography (CGC) combined with flame ionization detection (FID). The chromatographic separation conditions were established and the method was validated for precision (RSD = 1.49–3.55%), recovery (98.6–101.2%), and linearity within the range under investigation (∼1.0–33.3 ng). The results obtained show the newly developed procedure is suitable for qualitative and quantitative pharmaceutical analysis of the six azoles.
Assessment of random and systematic errors in microwave and submillimetre dielectric measurements

By considering the variation between runs comprising a given experiment, between the average results of independent experiments and between the extrapolated results of different experimental methods, some assessment of the systematic and random errors to be expected in high-frequency dielectric measurements is obtained. The liquid investigated is chlorobenzene as this has good chemical properties, possesses a rigid molecule and has been extensively investigated over a wide frequency range by other workers. Our results show that the random errors are frequency dependent but have average values of ±1.5% for α and ±0.1% for n but that the systematic errors may reach as much as ± 3% for α and ± 0.6% for n in the difficult regions. By combining data over a wide frequency range one may arrive at continuous curves whose estimated errors are ±1% for α and ±0.2% for n.
Nontoxic electrodes of solid amalgams

This is a review of electrodes based on nontoxic solid amalgams (MeSAE) (prepared by amalgamation of soft metal powders) in connection with some other kinds of voltammetric electrodes is given. Information is summarized on various types of MeSAEs (esp. AgSAE, CuSAE, AuSAE), pretreatment of their surfaces, their hydrogen overvoltage in aqueous solutions, conditions for their testing, electroanalytical parameters and use, in compared with the hanging mercury drop electrode (HMDE). Although the solid amalgam electrodes do not reach the quality of the HMDE, in many cases they represent its possible alternative. The broad range of voltammetric applications of the MeSAEs, especially of the AgSAEs, their good mechanical stability, simple handling, and new aspects of their use in electrochemical techniques are documented by numerous examples.
How does elevated carbon dioxide (CO2) affect plant–herbivore interactions? A field experiment and meta‐analysis of CO2‐mediated changes on plant chemistry and herbivore performance

First, we report the results of the longest‐known field study (9 years) to examine the effects of elevated carbon dioxide (CO2) on leaf miner densities in a scrub‐oak community at Kennedy Space Center, Florida. Here, the densities of all leaf miner species (6) on all host species (3) were lower in every year in elevated CO2 than they were in ambient CO2. Second, meta‐analyses were used to review the effects of elevated CO2 on both plants (n=59 studies) and herbivores (n=75 studies). The log of the response ratio was chosen as the metric to calculate effect sizes. Results showed that elevated CO2 significantly decreased herbivore abundance (−21.6%), increased relative consumption rates (+16.5%), development time (+3.87%) and total consumption (+9.2%), and significantly decreased relative growth rate (−8.3%), conversion efficiency (−19.9%) and pupal weight (−5.03%). No significant differences were observed among herbivore guilds. Host plants growing under enriched CO2 environments exhibited significantly larger biomass (+38.4%), increased C/N ratio (+26.57%), and decreased nitrogen concentration (−16.4%), as well as increased concentrations of tannins (+29.9%) and other phenolics. Effects of changes on plant primary and secondary chemistry due to elevated CO2 and consequences for herbivore growth and development are discussed.
The determination of the molecular weight distribution of amylose by gel permeation chromatography

The universal calibration for gel permeation chromatography (GPC) has been applied to amylose and dextrans. The molecular weight distribution of amylose has been measured starting from known data on dextrans. The agreement found between the molecular weight averages resulting from GPC and those obtained by other methods justifies the procedure followed. The GPC measurements were performed with dimethylsulfoxide as the elution solvent and deactivated silica gel (Porasil) as the column-filling material.
Life‐cycle assessment of photovoltaic modules: Comparison of mc‐Si, InGaP and InGaP/mc‐Si solar modules

A higher conversion efficiency of photovoltaic modules does not automatically imply a lower environmental impact, when the life‐cycle of modules is taken into account. An environmental comparison is carried out between the production and use phase, except maintenance, of an indium–gallium–phosphide (InGaP) on multicrystalline silicon (mc‐Si) tandem module, a thin‐film InGaP cell module and a mc‐Si module. The evaluation of the InGaP systems was made for a very limited industrial production scale. Assuming a fourfold reuse of the GaAs substrates in the production of the thin‐film InGaP (half) modules, the environmental impacts of the tandem module and of the thin‐film InGaP module are estimated to be respectively 50 and 80% higher than the environmental impact of the mc‐Si module. The energy payback times of the tandem module, the thin‐film InGaP module and the mc‐Si module are estimated to be respectively 5.3, 6.3 and 3.5 years. There are several ways to improve the life‐cycle environmental performance of thin‐film InGaP cells, including improved materials efficiency in production and reuse of the GaAs wafer and higher energy efficiency of the metalorganic chemical vapour deposition process. Copyright © 2003 John Wiley & Sons, Ltd.
3D-printing of highly uniform CaSiO3 ceramic scaffolds: preparation, characterization and in vivo osteogenesis

Calcium silicate (CaSiO3, CS) ceramics have received significant attention for application in bone regeneration due to their excellent in vitro apatite-mineralization ability; however, how to prepare porous CS scaffolds with a controllable pore structure for bone tissue engineering still remains a challenge. Conventional methods could not efficiently control the pore structure and mechanical strength of CS scaffolds, resulting in unstable in vivo osteogenesis. The aim of this study is to set out to solve these problems by applying a modified 3D-printing method to prepare highly uniform CS scaffolds with controllable pore structure and improved mechanical strength. The in vivo osteogenesis of the prepared 3D-printed CS scaffolds was further investigated by implanting them in the femur defects of rats. The results show that the CS scaffolds prepared by the modified 3D-printing method have uniform scaffold morphology. The pore size and pore structure of CS scaffolds can be efficiently adjusted. The compressive strength of 3D-printed CS scaffolds is around 120 times that of conventional polyurethane templated CS scaffolds. 3D-Printed CS scaffolds possess excellent apatite-mineralization ability in simulated body fluids. Micro-CT analysis has shown that 3D-printed CS scaffolds play an important role in assisting the regeneration of bone defects in vivo. The healing level of bone defects implanted by 3D-printed CS scaffolds is obviously higher than that of 3D-printed β-tricalcium phosphate (β-TCP) scaffolds at both 4 and 8 weeks. Hematoxylin and eosin (H&E) staining shows that 3D-printed CS scaffolds induce higher quality of the newly formed bone than 3D-printed β-TCP scaffolds. Immunohistochemical analyses have further shown that stronger expression of human type I collagen (COL1) and alkaline phosphate (ALP) in the bone matrix occurs in the 3D-printed CS scaffolds than in the 3D-printed β-TCP scaffolds. Considering these important advantages, such as controllable structure architecture, significant improvement in mechanical strength, excellent in vivo osteogenesis and since there is no need for second-time sintering, it is indicated that the prepared 3D-printed CS scaffolds are a promising material for application in bone regeneration.
The T-shaped anisotropic molecule model: a unique perspective of the glass transition and gelation in low valence, directional, network forming liquids

Glass and gel formers exhibit unusual mechanical characteristics and amorphous phases which are highly dependent on their thermal history. We introduce a lattice model with T-shaped molecules that exhibits glassy and gel-like states without introducing artificial frustration. This system has a large number of degenerate energy minima separated by small barriers leading to a broad, kinetically-explored landscape. It particularly replicates valence-limited materials, which can form self-assembled materials with highly controlled physical properties. Despite its remarkable simplicity, this model reveals some of the fundamental kinetic and thermodynamic properties of the glass transition and of gel formation. A dearth of low temperature experimental and simulation measurements has inhibited investigation in this field. We overcome this difficulty by using a modified Metropolis Monte Carlo method to quickly provide equilibrium samples. Then kinetic Monte Carlo techniques are used to explore the properties of the equilibrium system, providing a touchstone for the non-equilibrium glassy states. Fully-dense simulation samples reveal a fragile-to-strong crossover (FSC) near the mean-field (MF) spinodal. At the FSC, the relaxation time returns to Arrhenius behavior with cooling. There is an inflection point in the configurational entropy. This behavior resolves the Kauzmann Paradox which is a result of extrapolation from above the inflection point. In contrast, we find that the configurational entropy remains finite as the temperature goes to zero. We also observe different kinetics as the system is quenched below the FSC, resulting in non-equilibrium, amorphous states with high potential energy persisting for long periods of time. Simulation samples remain at non-equilibrium conditions for observation times exceeding those permitting complete equilibration slightly above the FSC. This suggests the FSC would often be identified as the glass transition without indication that there is true arrest or a diverging length scale. Indeed, our simulations show these samples do equilibrate if sufficient time is allowed. To elucidate the complex, interdependent relation time and length scales at the FSC will require careful consideration of the spatial-dynamic heterogeneity. Dynamic mean-field simulations at high density and in the solvated regime reveal a rich range of morphological features. They are consistent with simulated and experimental results in colloidal systems. Stability limits of decreasing length scales beneath the phase separation bimodal coincide into a single curve, which terminates at the fully-dense MF spinodal, suggesting that gelation and vitrification are the same phenomena. Our work indicates that gelation is, therefore, a result of phase separation arrested by a glass transition.
Homogeneous and heterogeneous catalysts for multicomponent reactions

Organic synthesis performed through multicomponent reactions is an attractive area of research in organic chemistry. Multicomponent reactions involve more than two starting reagents that couple in an exclusive ordered mode under the same reaction conditions to form a single product which contains the essential parts of the starting materials. Multicomponent reactions are powerful tools in modern drug discovery processes, because they are an important source of molecular diversity, allowing rapid, automated and high throughput generation of organic compounds. This review aims to illustrate progress in a large variety of catalyzed multicomponent reactions performed with acid, base and metal heterogeneous and homogeneous catalysts. Within each type of multicomponent approach, relevant products that can be obtained and their interest for industrial applications are presented.
HMT-Induced and NaOH Assisted Hydrothermal Synthesis of ZnO Single Crystal Nanorods

This experiment involves the growth of ZnO nanorods with NaOH by the HMT-assisted hydrothermal method and discusses the efficiency of NaOH is helpful to the growth of ZnO nanorods. The analyses of the synthesized ZnO nanorods by XRD, SEM, EDS and TEM reveal a single crystal structure with good crystallinity where the nanorod growth is along the [001] direction. In addition, it is discovered experimentally that the aspect ratio of the product is increased with the addition of NaOH, which verifies that the basic environment is beneficial to the growth of ZnO nanorods.
Advanced Anticorrosive Coatings Prepared from the Mimicked Xanthosoma Sagittifolium-leaf-like Electroactive Epoxy with Synergistic Effects of Superhydrophobicity and Redox Catalytic Capability

Novel anticorrosion coating materials were prepared by replicating fresh plant leaves; these materials had a synergistic effect of superhydrophobicity and redox catalytic capability. Superhydrophobic electroactive epoxy (SEE) coating applied for corrosion protection was prepared and coated on the surface of cold-rolled steel (CRS) using a nanocasting technique from the surface structure of fresh Xanthosoma sagittifolium leaves. First, the transparent PDMS template was replicated from the surface structure of fresh Xanthosoma sagittifolium. Subsequently, the SEE coating was fabricated on the CRS electrode using a nanocasting technique with a transparent PDMS template and an electroactive-epoxy polymer solution as the ink. The CRS electrode coated with SEE was found to have a water contact angle (CA) of 153°, which was significantly higher than the smooth electroactive epoxy (EE) coated on the CRS by spin coating (CA = 81°). The SEE coating material not only shows superior water repellent properties but als.