Miracle-dz/UniFAR-FTUs huggingface dataset:
NMR and IR Studies on Hydrogenated Amorphous Si1-xCx Films

NMR and IR studies have been carried out on glow-discharge-deposited a-Si1-xCx:H films. The hydrogen content increases with an increase in x up to 0.4 mainly in gathered form contributing to the broad component of the NMR line. By combining the NMR and IR results, the proportionality between the number of H bonded to C and the intensity of IR absorption due to the C–H stretching mode vibration is ascertained. The proportionality constant is found to be AstrC–H=1.7×1021 cm-2.
Constrained/Directed Crystallization of Nylon-6. I. Nonstoichiometric Inclusion Compounds Formed with Cyclodextrins

Noncovalently bonded crystalline inclusion compounds (ICs) have been formed by threading host cyclic starches, cyclodextrins (CDs), onto guest nylon-6 (N-6) chains. When excess N-6 is employed, nonstoichiometric (n-s)-N-6-CD-ICs, with partially uncovered and “dangling” N-6 chains, result. While the host crystalline CD lattice is stable to ∼300 °C, the uncovered, yet constrained, portions of the N-6 chains emanating from the CD-IC surfaces may crystallize below or be molten above ∼225 °C. We have been studying the constrained crystallization of the unthreaded N-6 chains “dangling” from (n-s)-N-6-CD-ICs, with comparison to bulk N-6 samples, as functions of N-6 molecular weights, lengths of uncovered N-6 chains (N-6:CD stoichiometry), and the CD host used. In the IC channels formed with host α- and γ-CDs containing 6 and 8 glucose units, respectively, single and pairs of side-by-side N-6 chains are threaded and included. In α-CD-ICs, the ∼0.5 nm channels produced by stacked α-CDs are separated by ∼1.4 nm, wh.
Silicate Dissolution in Las Pailas Thermal Field: Implications for Microbial Weathering in Acidic Volcanic Hydrothermal Spring Systems

A longitudinal field microcosm study was conducted in the Las Pailas hot spring system, located on the SW flank of Rincon de la Vieja, Costa Rica, in order to investigate initial microbial attachment and colonization, as well as chemical (abiotic) and biological silicate weathering under hydrothermal conditions. Solution chemistry was pH = 2.42–3.96, T = 43–89.3°C, Si = 4.45–8.19 mmol L−1, Fe = 1.50–6.95 mmol L−1and PO3− 4 = below detection limits-4.9 μmol L−1. Microcosms consisted of washed, sonicated primary silicate samples in polycarbonate vessels. The vessels were enclosed either by mesh to observe water/rock/microbial interactions or by 0.2–0.45 μm filters to observe water/rock interactions. Microcosms were incubated for periods of 6 h, 24 h, or 2 mo, fixed in the field, then analyzed in the laboratory. Scanning electron microscopy (SEM) analysis revealed that microbial attachment to mineral samples occurred in as little as 6 h. Microbial colonization and the development of minor etch pits associated with microorganisms occurred within 24 h. The most significant differences in chemical vs. biological weathering were observed after 2 mo. SEM analysis of these incubated surfaces showed that volumetric losses to mineral samples were more than one order of magnitude greater for samples that had been colonized by microorganisms and thus weathered biologically. With time, preferential colonization of anorthoclase mineral samples with Fe-oxides and apatite inclusions occurred. Subsequent weathering, therefore, may be a metabolic strategy by microorganisms to access mineral-bound PO3− 4, which is otherwise scarce in solution. Results from this study suggest that microorganisms may play a significant role in weathering in some hydrothermal systems.
Understanding Malaysian Consumer Online Purchase Intention: The Roles of Perceived Risk and Pervceived Value

The 11th Malaysian Plan (2016-2020) targets broadband infrastructure to reach 95% of populated areas. This is to fulfil Malaysia’s goal of creating a production-centric digital economy by 2020, one of the strategic thrust of the Digital Malaysia programme to fully capitalise on the internet for revenue generation. The marked increase in connected device ownership in Malaysia will inevitably result in the solid growth of the number of Malaysian consumers making online purchases, thus placing a foundation for a booming online business to consumer market in Malaysia. Using the Theory of Reasoned Action (TRA), this review investigates the determinants of online purchase intention of Malaysian consumers by examining the roles of perceived value and perceived risk.
Systematic Studies on Chain Lengths, Halide Species, and Well Thicknesses for Lead Halide Layered Perovskite Thin Films

Two-dimensional layered perovskite compounds, (CnH2n+1NH3)2(CH3NH3)m−1PbmX3m+1 (n = 2, 3, 4, 6, and 10; X = Cl, Br, and I; m = 1, 2, and 3) were systematically prepared. The influences of the barri.
Methanol Adsorption on TiO2 Film Studied by Sum Frequency Generation Vibrational Spectroscopy

A broadband infrared surface sum frequency generation vibrational spectroscopy (SFG-VS) and an in situ UV excitation setup devoted to studying surface photocatalysis have been constructed. With a home-made compact high vacuum cell, organic contaminants on TiO2 thin film surface prepared by RF magnetron sputtering were in situ removed under 266 nm irradiation in 10 kPa O2 atmosphere. We obtained the methanol spectrum in the CH3 stretching vibration region on TiO2 surface with changing the methanol pressure at room temperature. Features of both molecular and dissociative methanol, methoxy, adsorbed on this surface were resolved. The CH3 symmetric stretching vibration frequency and Fermi resonance of molecular methanol is red-shifted by about 6–8 cm−1 from low to high coverage. Moreover, the recombination of dissociative methanol and H on surfaces in vacuum was also observed. Our results suggest two equilibria exist: between molecular methanol in the gas phase and that on surfaces, and between molecular meth.
Utilization of sewage sludge ashes in the brick and tile industry

Several aspects of using ashes from sewage sludge incineration in the brick and tile industry have been examined. After discussing the item of ash production in Germany, the impact of different wastewater treatment methods is described; for instance, the use of precipitation agents containing iron will considerably influence the ash quality. Depending on their respective chemical composition, different ashes have different effects on the ceramic qualities of the bricks made of clay blended with ashes. These effects will be shown in regard to the major ceramic parameters. Similarly, the quality of the ashes also influences the elution behaviour and the mineral fixation of heavy metals.
Thermal and dielectric investigations of the curie transition in Poly(vinylidene fluoride—trifluoroethylene) copolymers

Abstract The ferroelectric-to-paraelectric phase transition in poly(vinylidene fluoride-trifluoroethylene) copolymers has been investigated by differential scanning calorimetry and dielectric techniques. The transition appears to be very dependent on the crystallization kinetics and thermal history. The anomalies accompanying the transition show that the structural transformations are complex. In particular, the 30 mol % TrFE sample presents the most remarkable effects. The results are discussed in terms of the existence of a possible intermediate crystalline phase. The role of defects and of the anchored amorphous phase have also been considered.
The Formula for the Optical Rotatory Dispersion of Quartz

The optical rotation of quartz has been measured over a large band of wavelengths. We have Gumlich’s original work over the range from λ = 2·140 μ to λ = 0·21935 μ , repeated and extended into the ultra-violet by Soret and Sarasin and Guye. More recently a series of accurate measurements covering the same range was published by Lowry, and then Duclaux and Jeantet gave a series of results for a range in the ultra-violet from λ = 0·30876 μ to λ = 0·1853980 μ . Finally, Lowry and Coode-Adams, having improved the accuracy of their original method, succeeded in obtaining a very accurate set of readings extending from λ = 2·5170 μ in the infra-red to λ = 0·2280 μ in the ultra-violet, reaching thus just up to the region measured by Duclaux and Jeantet. Various attempts have been made to fit these results into a formula. Gumlich found it possible to represent his results by a formula of the type ω = α1/λ2 + α2/λ4 + α3/λ6 + α4/λ8 + α5/λ10, but Kettler had almost equal success with the simpler form ω = (λ2 α)/β.
Plasma treatment of polydimethylsiloxane

Plasma treatment of silicone surfaces is a useful way of increasing wettability to improve adhesion and a first step in producing various organosilicon thin-film composites. Despite numerous earlier studies, there is no consensus on the effect of plasma treatment nor on the mechanism of the subsequent hydrophobic recovery. X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) were used to study the effect of plasma treatments of polydimethylsiloxane elastomer using four different plasma gases: argon, helium, oxygen, and nitrogen. In each case, the surface was oxidized to produce a thin, wettable, brittle silica-like layer. These surfaces progressively recover their hydrophobicity by diffusion of untreated polymer chains through cracks in the treated layer. Angle-resolved XPS detected the untreated, diffused layer and SEM revealed the common occurrence of cracks in the treated layer, although conditions could be found for each gas where the surface becomes completely wettable by wat.
Evolution of microstructure during shear alignment in a polystyrene-polyisoprene lamellar diblock copolymer

The process of flow-induced alignment in a lamellar diblock copolymer melt is investigated using simultaneous measurements of shear stress and birefringence. Flow birefringence, in situ, during oscillatory shear clarifies how the orientation distribution evolves toward either parallel or perpendicular alignment, i.e., layers normal to either the velocity gradient or the vorticity axis, respectively. A nearly symmetric, polystyrene-polyisoprene diblock (ODT ≃ 164 °C) is studied at 120 °C (T/T ODT ≃ 0.90). The critical frequency (ω' c ) associated with a crossover in the relaxation dynamics from being dominated by the macromolecular response to being dominated by the microstructural response is estimated to be ω' c 3-7 rad/s at 120 °C. At high frequencies (relative to ω' c ), shearing induces parallel alignment, while shearing at lower frequencies leads to perpendicular alignment. In all cases, alignment proceeds through a fast process followed by a slow one. The fast process is dominated by depletion of the projection of the orientation distribution along either the perpendicular direction or the transverse direction (layers normal to the flow). The resulting biaxial distribution is transformed into a well-aligned uniaxial one during the slow process. Surprisingly, the projection along the perpendicular direction can disappear faster than the projection along the transverse direction. This occurs during the fast process en route to parallel alignment with sufficiently high frequencies. As the shearing frequency is lowered, the projection along transverse orientation decreases faster than that along the perpendicular direction.
The effects of molecular geometry on the depolarized stimulated gain spectra of simple liquids

Depolarized Rayleigh‐wing spectra of simple liquids, including CS2, chlorinated methanes, benzene and benzene derivatives have been recorded using stimulated gain spectroscopy. To adequately interpret these spectra of simple liquids, a dephasing dynamical contribution in an intermediate time scale is needed in addition to a slower Debye reorientation relaxation and a faster broad inhomogeneous oscillator. The curve‐fit dynamical characteristic parameters of these simple liquids are tabulated for comparison. The microscopic molecular properties, shape anisotropy, and dominating moment of inertia are found to play an important role in determining the rates of interaction‐induced dynamics; smaller shape anisotropy and smaller moment of inertia give rise to faster collision rate in the intermediate frequency regime and faster oscillation in the higher frequency regime, respectively. In the low frequency region, the shear viscosity (a macroscopic property) of the liquid and the general molecular shapes dictate.
Theoretical prediction of tie‐chain concentration and its characterization using postyield response

In the past, relative tie-chain concentration has been semiquantitatively characterized by infrared dichroism on a stretched sample and from brittle fracture strenght. The probability of tie-molecule formation has also been theoretically estimated from chain dimensions and the semicrystalline morphology of the polymers. In this article the probability of tie-chain formation of monodisperse and homogeneous single-site ethylene copolymers has been estimated over a range of densities and molecular weights using the model proposed by Huang and Brown. The relative tie-chain concentration is obtained by multiplying tie-chain probability with the volume fraction crystallinity of polymer. A modified rubber elasticity theory is applied to calculate the concentration of chain links between junction points (crystallites) of the INSITE technology polymers (ITPs) from measured rubber modulus. It is expected that the chain-link concentration should relate to the tie-chain concentration. The calculated rubber modulus, or the chain-links concentration, of the ITPs increases with an increase in density in the 0.865 to 0.910 g/cc range and did not change significantly in the density range of about 0.91 g/cc to 0.954 g/cc. Normalized rubber modulus and relative tie-chain concentration data shows that the relative tie-chain concentration predicated by Huang and Brown model and measured using the modified rubber elasticity theory are quantitatively similar below 0.01 g/cc density. However, above 0.91 g/cc density, the measured rubber modulus is influenced by additional tie-chain formation during deformation due to breakdown of crystallities and, hence, the discrepancy exists between the two methods of estimating relative tie-chain concentration. © 1996 John Wiley & Sons, Inc.
APT a next generation QM-based reactive force field model

Modelling reactivity at the nanoscale is a major computational challenge. Both reactive force field and combined QM–MM methodologies have been and are being developed to study reactivity at this boundary between molecules and the solid state. There have been more than 1500 publications since the mid-1990s, on combined QM–MM methodologies. Limitations in current models include the distortional characteristics of force field potential terms, the smooth transit from one potential surface to another, rather than surface hopping, and the blending of electrostatics between QM and MM portions of a QM–MM model. Functional forms, potential surface coupling terms, and parameterization strategies for the Approximate Pair Theory (APT), a next generation reactive force field model, are described. The APT model has been developed to correct a number of limitations in current reactive force field models as well as providing a foundation for a next generation QM–MM model. Chemical bonding concepts are used to develop fully dissociative bond stretch, bend, torsion, and inversion valence terms. Quantum mechanics also provides functional forms for potential surface coupling terms that permit a general description of reactivity from hydrogen bonding, through non-classical carbocations and cracking, to olefin polymerization, oxidation, and metathesis. Van der Waals, electrostatic, and metallic bonding models also derive from quantum mechanical resonance. Finally, Pauli Principle-based orthogonality provides a way to electrostatically couple the QM and MM portions of a QM–MM model that will support arbitrarily large basis sets.
Dendritic europium complex as a single dopant for white-light electroluminescent devices

Three novel dendritic europium complexes containing grafted carbazole units as their functional peripheries were prepared and characterized. The Forster energy transfer from the peripheries of carbazole units to β-diketonates as well as from the ligands to the central Eu(III) ions in these complexes has been demonstrated. Under the indirect excitation of carbazole units, a characteristic red emission peak at 615 nm due to the Eu(III) ion transition of 5D0 → 7F2 was observed for the complexes in solution or solid films. As a result of the light-harvesting and site isolation of carbazole dendrons, compared with the reference compound Eu(BPPD)3(Phen), PL efficiencies of Eu(MCPD)3(Phen), Eu(BCPD)3(Phen) and Eu(TCPD)3(Phen) in the film state are 3.3, 7.9 and 4.5 fold increased, respectively. Notably, white light emission with the CIE coordinates of (0.333, 0.348) has been achieved with a single dopant of Eu(TCPD)3(Phen) in an EL device of configuration ITO/NPB/CBP : Eu(TCPD)3(Phen)/BCP/Mg : Ag. Its maximum external quantum efficiency is more than 1.1% and maximum brightness reached 229 cd m−2. The origin of the blue and green emission is attributed to the dendron-grafted carbazole units forming an exciplex and an electroplex with CBP (4,4′-N,N′-dicarbazole biphenyl) and ligand β-diketonate, respectively. The results suggest that modifying ligands can not only tune the carrier-transporting properties of complexes, but also provide a useful clue to the use of electroplexes or exciplexes to realize broad or even white electroluminescence.
Reverse thermogelling biodegradable polymer aqueous solutions

A reverse thermogelling polymer aqueous solution is a free-flowing sol at a low temperature and becomes a semisolid gel as the temperature increases. It is expected to be a very promising biomaterial as a minimally invasive injectable system for drug delivery and tissue engineering applications. The principles of materials design are (1) balancing the hydrophobicity and hydrophilicty of a polymer, (2) controlling the topology of a polymer, (3) matching the degradation kinetics of a polymer with a specific biomedical application, and (4) controlling the biocompatibility of the material with a drug as well as a host. This article covers recent progress of reverse theromogelling biodegradable polymers based on aliphatic polyesters, polyphosphazenes, poloxamer derivatives, polysaccharides, polypeptides, poly(propylene phosphate)s, polyorthoesters, polycarbonates, polycyanoacrylates, and poly(N-(2-hydroxyethyl) methacrylamide-lactate)s. The material characteristics, driving forces or mechanism for sol-gel transition, and their biomedical applications are summarized. In addition, the authors' perspectives on future reverse theromogelling materials design are suggested.
Finite element solution of the navier-stokes equations by a velocity-vorticity method

A velocity-vorticity formulation of the Navier-Stokes equations is presented as an alternative to the primitive variables approach. The velocity components and the vorticity are solved for in a fully coupled manner using a Newton method. No artificial viscosity is required in this formulation. The pressure is updated by a method allowing natural imposition of boundary conditions. Incompressible and subsonic results are presented for two-dimensional laminar internal flows up to high Reynolds numbers
Significance of litter layer in enhancing mesofaunal abundance and microbial biomass nitrogen in sweet corn-white clover living mulch systems

Living mulch is a type of sustainable farming system that consists of cover crops planted either before or with a main crop; a living mulch is maintained as a living ground cover throughout the growing season of the main crop. Microbial biomass and abundance of mesofauna (microarthropods and enchytraeids) are important soil biological parameters in relation to soil function, plant productivity, and nutrient cycling; however, the effects of living mulch on these parameters are not fully understood. In this study we examined the effects of living mulch treatment with nitrogen fertilizer (0, 40, 160, or 200 kg ha−1) on the abundance of soil microarthropods (Oribatida, Mesostigmata, Prostigmata, and Collembola) and the effects of living mulch treatment on the dynamics of the soil biota (mesofauna, microarthropods, enchytraeids, and microbial biomass nitrogen) from spring to autumn. Our results showed that living mulch treatment significantly (p < 0.05) increased the grain weight of the main crop in both experiments. Generally, living mulch treatment had a positive effect on the abundance of mesofauna and microbial biomass nitrogen, despite pesticide usage. Nitrogen levels did not affect the number of microarthropods. The litter layer in living mulch significantly (p < 0.05) enhanced microbial biomass nitrogen and the abundance of Oribatida, Prostigmata, and Collembola. We conclude that living mulch enhances mesofaunal abundance and microbial biomass nitrogen and that the production of a litter layer by living mulch is one of the major mechanisms for this enhancement.
Protonation kinetics of acrylate radical anions

The radical anions of acrylamide, methacrylamide and 2-hydroxypropyl acrylate were produced by pulse radiolysis of moderately acidic aqueous solutions well below the pKa of the radical anion. The rate coefficients of protonation were determined by UV kinetic spectroscopy at wavelengths where the protonated and ionic forms have considerably different absorbances. The rate coefficients of protonation were measured as (6.0±0.9)×1010, (6.6±1.0)×1010 and (5.0±1.0)×1010 mol−1 dm3 s−1. Using these rate coefficients and the pKa values of the radical anion, 7.9, 8.0 and 5.5, the rate coefficients of deprotonation were determined as 7.5×102, 6.6×102 and 1.6×105 s−1. The results clearly showed that in acidic solution the protonation occurred with H3O+ and not with H2O. The rate coefficients determined were discussed and compared with relevant data in the literature.
COMPARISON OF SOIL EXTRACTION PROCEDURES FOR ESTIMATING PHOSPHORUS RELEASE POTENTIAL OF AGRICULTURAL SOILS

Excessive phosphorus (P) discharge from agricultural soils to freshwater may contribute to eutrophication processes. The study of the release of P from soil, using laboratory simulations (long-term desorption experiments with different solution:soil ratios) can provide an idea of the amount of P that can be released from soil particles to water (potentially desorbable P). In the studied soils, the P release patterns are clearly related to the dominant P forms and soil properties. In this sense, the fraction of Total P (TP) that is released at 340 days (solution:soil ratio=10,000) is positively correlated (P<0.001) with the Index of Surface Saturation by P (SI), defined as the ratio between the Isotopically Exchangeable P at 1 day (IEP1) and the maximum P sorption capacity calculated using the Langmuir equation (Xm¯). A figure of the amount of potentially desorbable P from an environmental point of view can be provided by extrapolation of the amount of released molybdate reactive P (MRP) to a reference concentration of MRP in the solution which can be assumed to be 0.01 mg L−1. The ratio between this predicted amount (Q0.01) and TP in soil is also closely related to SI, indicating that the amount of P that can be released from soil to water depends on soil properties and especially on the degree of surface saturation by P. Phosphorus extraction methods using chemical extractions and P sinks can provide a quantification of the potential for P to be released from soils to water. Goethite, that is a near-infinite P sink, and mixed resins [cation and anion exchange resins (CAER)] are effective in extracting soil P, and the extracted amounts using these methods are closely related to the estimated amounts of potentially desorbable P. The extraction using goethite at 2 days is also a useful method for estimating the Total P Available for Plants (TPAP). Thus, this extraction method constitutes an alternative method to traditional agronomic soil tests in order to assess agronomic P availability as well as the P content of soils with environmental significance.