Miracle-dz/UniFAR-FTUs huggingface dataset:
Reaction of the Pentacyanocobaltate(II) Ion with Molecular Oxygen

By spectrophotometric scanning of reacting solutions, we have studied the processes which can occur when Oz is admitted to aqueous solutions containing the Ion [CoII(CN)5]3- in the concentration range 0.0002-0.4M, at 0°. A scheme is given to explain the formation of and inter-relations between [(CN)5CoIII-O-O-CoIII(CN)5]6-; [(CN)5CoIII-O-O-CoIV(CN)5]5-; [(CN)5CoIIIOH2]2- ; [CoIII(CN)6]3-, and a complex believed to be [(CN)5CoIII-O-OH]3-, which absorbs at 272 mp Preparative methods are described for obtaining several of the oxidation products in the crystaline state. Hydrolysis of [(CN)5CoIII-O-O-CoIII(CN)5]6- to [(CN)5CoIIIOH2]2- takes place via the 272 mμ complex, which is fairly stable in alkaline solution and is resistant to oxidation. The same 272 mμ complex can be formed more directly by oxygenation of the hydrido complex [(CN)5CoIIIH]3-, which is present in aged or hydrogenated solutions of pentacyanocobaltate(II). All of the pentacyano oxidation products can be reduced by sodium borohydride to [(CN)5CoIIIH]3-, which is further reduced by excess borohydride to an insoluble green compound and finally to metallic cobalt. We have briefly examined the reactions of ammonia and CN- with [(CN)5CoIIIOH2]2-, and the reaction of [(CN)5CoIII-O-O-CoIV(CN)5]5- with reducing agents, including [CoII(CN)5]3-.
Single-molecule spontaneous emission close to absorbing nanostructures

The spontaneous emission of a single molecule is substantially modified close to a metallic nanostructure. We study the spectral behavior of the radiative and nonradiative decay rates and of the local-field factor in the vicinity of a plasmon resonance. We show that the highest fluorescence enhancement is obtained for an emission wavelength redshifted from the plasmon resonance, and that quenching always dominates at plasmon resonance. These results may have experimental implications in spectroscopy and monitoring of elementary light sources.
Unique Temperature Dependence of Acetic Acid Formation in CO2 Hydrogenation on Ag-promoted Rh/SiO2 Catalyst

The rate of acetic acid formation in CO2 hydrogenation on Ag-Rh/SiO2 catalyst took two maxima at 463 K and 553 K. At 463 K, the rate was much faster than that of C2-oxygenates formation in CO hydrogenation. It was suggested that, at lower temperature, acetic acid is formed through the direct incorporation of adsorbed CO2.
Long‐Range (Retarded) Intermolecular Forces

The Casimir and Polder retarded dipole—dipole energy of interaction between two ground‐state (non‐degenerate) atoms is expressed in terms of sine and cosine integrals. This result should be accurate for all interatomic separations R. In the range of moderately large separations (discussed in the preceding paper), where the charge distributions do not overlap and where R is small compared to λ/0=(αΔe)−1, the Casimir and Polder results can be expanded in the form Eint=R−6C6+α2R−4W4+α3R−3A+α4R−2B+···. This expansion is only accurate for R/λ/0<0.6. Here α is the fine‐structure constant. The R−6C6 term is the usual London dispersion energy. The α2R−4W4 term was obtained in the preceding paper by taking the expectation value of the Breit—Pauli Hamiltonian using the wavefunction for the two‐atom system corrected for the classical electrostatic dipole—dipole interactions. Thus, at least in the dipole—dipole approximation, the Breit—Pauli Hamiltonian gives the energy of interaction accurate through O(α2). For larg.
Metal contamination and potential toxicity of sediment from lock gate port in South Korea

ABSTRACT Choi, K.Y. , Kim, S.H. , Hong, G.H. , Kim, C.J., 2013. Assessment of the metal contamination and potential toxicity of sediment from artificially closed system port in South Korea. A study was performed to determine the total and potentially bioavailable heavy metal concentrations in sediments from the Port of Incheon, and the differences in contamination for each pier were identified. Metal enrichment factors (EF) suggested that contamination with Cu, Zn, Cd, Pb, and Hg was occurring at the port. Ni, Cu and Zn concentrations exceeded the effect range low level at most sampling sites according to U.S. NOAA sediment quality guidelines (SQGs). The potential toxicity of metals was determined by 1M HCl extractions. Large portions of Cu, Zn, Cd, and Pb were present as potentially bioavailable fractions (1M HCl extractable fractions) and they were introduced from anthropogenic activities. Principal component analysis (PCA) was performed in order to assess the sources of contamination of the sediment and the influence of anthropogenic activities on sediment quality. Two PCA factors were obtained for identifying the sampling sites affected by anthropogenic activities. Patterns of sediment contamination at each pier were classified, and the results showed that Cu–Zn–Cd–Pb–Hg and Ni were the main components.
An analysis of ozone variation in the Greater Athens Area using Granger Causality

Abstract Air pollution in urban areas is a topic of interest for many researchers as it impacts negatively the human health, the environment and the quality of life. As part of the effort in exploring ways for efficient and timely assessment of the urban air pollution patterns and their association with the local meteorology and photochemistry, an advanced statistical approach is proposed for the analysis of the spatiotemporal ozone (O 3 ) variations and interdependencies to other pollutants. The focus of the work is placed on the investigation and determination of the causality between the local and regional factors causing the observed ozone variability, by applying a holistic methodology on multiple–year meteorological data and air pollution monitoring data, referenced in Athens (Greece). The methodology includes the Positive Matrix Factorization (PMF), for data scaling and reduction, a k –means clustering algorithm, for determining groups of data with common properties, and importantly, the Granger Causality test, for obtaining the causal links between the ozone and nitrogen oxides as well as the local meteorological conditions. The methodology revealed six dominant combined patterns of weather and air pollution. The application of the Granger Causality allowed the determination of relationships across the pollution patterns of dispersed geographic locations and the interdependence of those with the local meteorological conditions and photochemistry effects.
In‐Situ Coating of SBA‐15 with MgO: Direct Synthesis of Mesoporous Solid Bases from Strong Acidic Systems

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Controlled positions and kinetic analysis of spontaneous tin whisker growth

This study achieved controlling the positions of spontaneous growth of tin whiskers. We surmounted the unpredictable growing nature of such whiskers and performed accurately quantitative analyses of the growth kinetics and yielded precise measurement of the growth rate. Furthermore, using synchrotron radiation x-ray, this study determined the stress variations in conjunction with whisker growth that fitted appropriately to the model. Accordingly, the results could address the debate held for decades and prove that forming a surface oxide layer is one of the required and necessary conditions for controlling the positions of spontaneous growth of tin whiskers.
Interactions between asphaltenes and naphthenic acids

Asphaltenes separated from two different North Sea oils were studied upon addition of two kinds of naphthenic acids by employing PFG-SE NMR (pulsed field gradient-spin echo nuclear magnetic resonance) and NIR (near-infrared) spectroscopy. The results indicated that there were interactions between asphaltenes and naphthenic acids. It also appeared as if the tendency of the acids to interact with asphaltenes depended on the asphaltene type. Furthermore, a concentration series of one of the asphaltenes was prepared, and a dramatic decrease in diffusion coefficients upon increased concentration was observed. This suggests that the asphaltenes studied were prone to self-associate in toluene-d8.
Removal of Fluoride from Aqueous Solution Using Aluminum-Impregnated Chitosan Biopolymer

Abstract Aluminum impregnated chitosan (AIC) was prepared and applied as an adsorbent for the removal of fluoride from aqueous solutions. The process involved two stages: (i) isolation of chitosan from chitin, (ii) impregnation of aluminum in isolated chitosan at fixed pH. SEM and EDS techniques were used to characterize the composition of adsorbent AIC. Dynamic adsorption experiments on AIC were carried out at various pH, contact times, adsorption dosages, and initial fluoride concentration to determine optimum adsorption properties. The experimental data were analyzed using two adsorption models, Langmuir and Freundlich, with the later system providing the best fit. Thermodynamic parameters showed the adsorption process as spontaneous and endothermic. The adsorption process follows first-order kinetics for which a mechanism has been proposed. Reusability of the AIC was tested up to four consecutive cycles. The desorption experiment showed 92% elution of adsorbed fluoride at a pH of 12. Finally, the performance of the adsorbent material was studied on field water samples collected from a fluorosis endemic-region.
Zinc fertilization of lentil for grain yield and grain zinc concentration in ten Saskatchewan soils

ABSTRACT Fertilization of grain legumes with zinc (Zn) can affect both marketable yield and Zn content of the grain, which is important in addressing human nutritional deficiencies in certain regions of the world. A pot experiment was conducted to determine the response of three different market classes of lentil to Zn fertilization using ten surface soils from Saskatchewan (Canada). The distribution of Zn among labile and stable fractions chemically separated from the soil was also determined in the ten prairie soils and related to the lentil responses observed. The three market classes of lentils (large and small green, small red) were grown without Zn (control), and with 2.5 and 5 kg Zn ha−1 added as zinc sulfate to each soil prior to planting. Zinc fertilizer application significantly influenced grain yield and was soil dependent. A significant increase in grain yield over the control was observed from application of Zn on some low organic matter, high pH Brown Chernozem soils whereas a decrease in grain yield over control was observed in other soils such as a Black Chernozem of high organic matter content and low (<7) pH. Lack of positive yield response to addition of Zn were related to measured high diethylene triamine pentaacetic acid (DTPA) extractable and plant root simulator (PRS) resin membrane probe Zn, and large amounts of native Zn in exchangeable and iron/manganese (Fe/Mn) oxide bound fractions. Application of Zn fertilizer generally increased the grain concentration of Zn. For example, an increase of ∼20% in Zn concentration over control was observed when 5 kg Zn ha−1 was added to a loamy textured low organic matter Brown Chernozem soil. Overall, small green lentil was more consistent in producing a positive response to Zn fertilizer application on soils with low plant available Zn compared to large green lentil and small red lentil.
The Impact of Silver Nanoparticles on Bacterial Aerobic Nitrate Reduction Process

Due to the effective antimicrobial properties of silver nanoparticles (Ag NPs), these particles are receiving an extensive interest for applying in wide range of consumer products and water purification systems. Entering the Ag-based material in wastewater system can influence the biological cycle such as nitrogen. Denitrification as a part of nitrogen cycle is an effective biological process in wastewater systems which can be affected by Ag NPs. The objective of this research was to study the impact of Ag NPs on aerobic nitrate reduction. We showed that Rhizobium sp and Azotobacter sp isolates were able to reduce nitrate aerobically. Adding 0.2 ppm of Ag NPs in culture medium of Azotobacter PHB+ enhanced the of the nitrate reduction activity about 20% and Ag NPs at this concentration has no significant effect on the nitrate reduction activity of periplasmic extracts of the selected isolates in aerobic conditions. Thus, entering certain ation of Ag NPs in environments has no significant impact on microbial aerobic denitrification as an important part of nitrogen cycle.
Continuous Model of the Positive Column in Glow Oxygen Discharge at Several Hundreds of Pascals

The aim o f the article is to introduce a simple model of positive column of the oxygen glow discharge. Our fluid model is based on continuity equation and electric field is calculated from Gauss's law. It is tested the ability of the model to cover properties and behaviour of the electronegative oxygen discharge at the pressure several hundreds of pascals. The model qualitatively estimates properties of the discharge as negative ion concentration and in addition to that, radial profiles of charged and metastable particles are determined.
Biocatalytic Synthesis and Characterization of Copolymers Based on Poly(Ethylene Glycol) and Unsaturated Methyl Esters

Biocatalytic organic synthesis has proved to be a significant breakthrough in the area of polymer synthesis. Environmentally benign methodology and the use of mild reaction conditions are a hallmark of this approach. We have studied the biocatalytic synthesis of unsaturated polyesters under solvent‐less conditions by the condensation copolymerization of dimethyl fumarate and dimethyl maleate with polyethylene glycol (PEG) catalyzed by Novozyme‐435 (immobilized Candida antarctica lipase B). The structures of the resulting polymers, poly(ethylene glycol)‐co‐dimethyl fumarate and poly(ethylene glycol)‐co‐dimethyl maleate were studied from their 1H and 13C‐NMR spectra. The molecular weights of polymers were determined by size exclusion chromatography.
Nut water analysis as a diagnostic tool in coconut nutrition studies

Abstract Coconut water (liquid endosperm) is used as a diagnostic tool in studies on coconut nutrition. Ease of sampling, minimum sampling error, a limited preparative phase in both sampling and chemical analysis, and economy in use of chemicals are positive features. Modern instrumentation, especially flame emission and absorption, makes possible the direct estimation of cations on diluted samples of nut water, an added advantage. Phosphorus, S and Cl are estimated by colorimetry, turbidimetry/HPLC and coulometry, respectively. A comparison of nut water analysis to leaf analysis showed that nut water analysis is sensitive to Na and K, not to Ca or Mg. Nut water analysis is equally sensitive to P, S and Cl content. Nitrogen remains elusive, and workers must use the standard Kjeldahl procedure, which concentrates the nut water and involves acid digestion and distillation. Work carried out so far on micro nutrients has been inadequate.
Ameliorative Effects of All-Trans Retinoic Acid on Behavioural Symptoms of Mononeuropathic Pain in Wistar Rats

Although, retinoids are mainly involved in regulation of cell development, cell differentiation, proliferation, emberogenesis, vision, reproduction, maintenance of immune function. Growing evidences indicates that all-trans retinoic acid (ATRA) has shown to suppress the inflammatory and oxido-nitrosative stress. Herein, we investigated the effect of ATRA in rat chronic constriction sciatic nerve injury (CCI)-induced neuropathic pain (NP). Unilateral peripheral mononeuropathy was induced by sciatic nerve ligation. Thermal and mechanical hyperalgesia and cold allodynia were assessed. The extent of oxido-nitrosative stress was assessed by estimating the levels of thiobarbituric acid reactive substances (TBARS), catalase and superoxide dismutase (SOD) activity and nitrite levels in both sciatic nerve and dorsolumbar spinal cord homogenate. CCI-induced marked allodynia and hyperalgesia in ipsilateral paws, which was associated with significantly elevated oxido-nitrosative stress in spinal cord and sciatic nerve. Repeated administration of ATRA (2.5 and 5 mg/kg, p.o.) significantly reverse the established thermal and mechanical hyperalgesia and cold allodynia. These observed ameliorative effects on neuropathic pain symptoms are correlated with the extent of reduction of oxido-nitrosative stress. Thus, it may be concluded that repeated administration of ATRA ameliorates the behavioral symptoms of CCI-induced NP, possibly through an activation of anti-inflammatory and anti-oxidant mechanisms.
Antifungal activity of volatile metabolites emitted by mycelial cultures of saprophytic fungi

The antifungal activity of molecular identified Chilean saprobiontic fungi, Trichoderma viride, Schizophyllum commune and Trametes versicolor, on the fungal plant pathogens Botrytis cinerea and Fusarium oxysporum, and the saprotrophic mould Mucor miehei was investigated using two types of inhibition bioassay: (1) bi-compartmented Petri dishes and (2) two Erlenmeyer flasks connected by their upper parts. The chemical composition of volatile organic compounds (VOCs) released by saprobiontic fungi was also investigated using headspace solid-phase microextraction (SPME) and gas chromatography/mass spectrometry (GC-MS) analysis. Of the saprobiontic fungi evaluated, one isolate of S. commune showed the highest inhibitory activity against B. cinerea and M. miehei, 86.0±5.4 and 99.5±0.5% respectively. The volatile profiles of fungal isolates were shown to contain a different class of compounds. The major components in the headspace of mycelial cultures were 6-pentyl-α -pyrone (T. viride), ethanol and β -bisabolol (S. commune), and a sesquiterpene alcohol (Tr. versicolor). This is the first study reported on the release of VOCs by Chilean native fungi and their antifungal activity wrt. plant pathogenic fungi.
Multiscale measurements of residual strains in a stabilized zirconia layer

Residual stresses in a polycrystalline material have been determined experimentally at different length scales using three different techniques, with the aim of obtaining quantitative values. The polycrystalline material used is the electrolyte of solid oxide fuel cells, made of yttria-stabilized zirconia and submitted to a high biaxial compression stress state. Macroscopic measurements were performed using traditional X-ray diffraction with the sin2ψ method. Residual stresses within the grains were determined by the X-ray microdiffraction technique using synchrotron radiation. The variation in the strain within each grain was analysed by high-resolution electron backscatter diffraction. The results are self-consistent and give further information on the relation between strain/stress values and grain orientation, and on intragranular strain variations. These results are very important for the validation of mechanical microscopic constitutive equations.
Photovoltaic cells made from conjugated polymers infiltrated into mesoporous titania

We have made photovoltaic cells by infiltrating the conjugated polymer regioregular poly(3-hexylthiophene) into films of mesoporous titania, which are self-assembled using a structure directing block copolymer. The mesoporous titania films were chosen because they have pores with a diameter slightly less than 10 nm, which is the exciton diffusion length in many conjugated polymers, and because they provide continuous pathways for electrons to travel to an electrode after electron transfer has occurred. The photovoltaic cells have an external quantum efficiency of 10% and a 1.5% power conversion efficiency under monochromatic 514 nm light. Experiments that vary the amount of polymer in the titania films suggest that the performance of the cells is limited by poor hole transport in the polymer.
Influence of thermodynamic state on nanojet break-up

Using non-equilibrium molecular dynamics, argon nanojet injection was simulated under vacuum conditions. A series of simulations with different shapes of solid platinum injectors was conducted. Observed droplet sizes and jet break-up characteristics resemble the Rayleigh break-up theory. However, the different injector shapes did not cause a significant change in the nanojet break-up behaviour. The liquid temperature inside the injector was found to be a controlling factor in determining the subsequent break-up characteristics. A higher liquid temperature is preferred for the faster nanojet break-up with the shorter break-up length.
Drying Kinetics of Hygroscopic Porous Materials Under Isothermal Conditions and the Use of a First‐Order Reaction Kinetic Model for Predicting Drying

Abstract Drying curves have been obtained from bread samples using an isothermal drying apparatus designed and developed in our laboratory. Previous work showed that Fick's diffusion equation was shown only to predict drying time and not drying rate. The results showed that proper measurement of effective moisture diffusivity under isothermal conditions did not solve the problem of accurately predicting moisture transfer. A first‐order irreversible kinetic model was developed to predict moisture loss during isothermal drying by modeling evaporation during drying. The drying curves obtained from the isothermal drying experiments were analyzed to determine the first‐order rate constant. The first‐order rate constant at temperatures between 40 and 70°C ranged from 0.04 s−1 to 0.19 s−1, and the activation energy determined by Arrhenius analysis was 48.7 kJ/mol. The rate equation was shown to impressively predict drying of bread samples throughout the entire moisture range, from 0.9 to 0.002 g/g dry solid.
Nanoparticle Free Synthesis of Fluorescent Gold Nanoclusters at Physiological Temperature

Few-atom gold nanoclusters exhibit strong size-dependent fluorescence emission. For many applications, these clusters are preferable to quantum dots or organic fluorophores as fluorescent labels. However, the published synthetic procedures to create these nanoclusters involve toxic chemicals, are of low synthetic yield, and concurrently produce large nanoparticles. Here, we report two methods for high-yield synthesis of gold nanoclusters, utilizing physiological temperature and green chemistry. Blue, green, and red emissive nanoclusters with pH stability in a range of 6−8 were produced.
Organometal halide perovskite thin films and solar cells by vapor deposition

Organometal halide perovskites (OHPs) are currently under the spotlight as promising materials for new generation low-cost, high-efficiency solar cell technology. Within a few years of intensive research, the solar energy-to-electricity power conversion efficiency (PCE) based on OHP materials has rapidly increased to a level that is on par with that of even the best crystalline silicon solar cells. However, there is plenty of room for further improvements. In particular, the development of protocols to make such a technology applicable to industry is of paramount importance. Vapor based methods show particular potential in fabricating uniform semitransparent perovskite films across large areas. In this article, we review the recent progress of OHP thin-film fabrication based on vapor based deposition techniques. We discuss the instrumentation and specific features of each vapor-based method as well as its corresponding device performance. In the outlook, we outline the vapor deposition related topics that warrant further investigation.