Miracle-dz/UniFAR-FTUs huggingface dataset:
Influence of the dye molecular structure on the TiO2 conduction band in dye-sensitized solar cells: disentangling charge transfer and electrostatic effects†

We report a thorough theoretical and computational investigation of the effect of dye adsorption on the TiO2 conduction band energy in dye-sensitized solar cells that is aimed at assessing the origin of the shifts induced by surface adsorbed species in the position of the TiO2 conduction band. We thus investigate a series of working dye sensitizers and prototypical surface adsorbers and apply an innovative approach to disentangle electrostatic and charge-transfer effects occurring at the crucial dye–TiO2 interface. We clearly demonstrate that an extensive charge rearrangement accompanies the dye–TiO2 interaction, which amounts to transfer of up to 0.3–0.4 electrons from the dyes bound in a dissociative mode to the semiconductor. Molecular monodentate adsorption leads to a much smaller CT. We also find that the amount of CT is modulated by the dye donor groups, with the coumarin dyes showing a stronger CT. A subtle modulation of the semiconductor conduction band edge energy is found by varying the nature of the dye, in line with the experimental data from the literature obtained by capacitance and open circuit voltage measurements. We then decompose the total conduction band shift into contributions directly related to the sensitizer properties, considering the effect of the electric field generated by the dye on the semiconductor conduction band. This effect, which amounts to ca. 40% of the total shift, shows a linear correlation with the TiO2 conduction band shifts. A direct correlation between the dye dipole and the observed conduction band shift is retrieved only for dyes of similar structure and dimensions. We finally found a near-exact proportionality between the amount of charge transfer and the residual contribution to the conduction band shift, which may be as large as 60% of the total shift. The present findings constitute the basis for obtaining a deeper understanding of the crucial interactions taking place at the dye–semiconductor interface, and establish new design rules for dyes with improved DSC functionality.
Chronic retene exposure causes sustained induction of CYP1A activity and protein in rainbow trout (Oncorhynchus mykiss)

The removal of persistent chlorinated organic compounds from pulp mill effluents has not eliminated mixed function oxygenase (MFO) induction by these effluents. Therefore, continuous MFO induction downstream of pulp mills may be due to exposure to more labile compounds, such as retene (an alkyl‐substituted phenanthrene), which typically cause transient induction after a single brief exposure. Because fish are exposed continuously to pulp mill effluents, we have tested, and rejected, the null hypothesis that continuous exposure of fish to retene does not cause sustained MFO induction. Rainbow trout exposed continuously to retene, a component of some pulp mill effluents and sediments downstream of pulp mills, showed concentration‐dependent increases in hepatic ethoxyresorufin‐O‐deethylase (EROD) activity. The increase in EROD activity was sustained over 32 d of continuous exposure, but it diminished to background levels within 4 d after transfer to clean water. The enzymatic response was confirmed by measuring changes in the content of immunodetectable cytochrome P4501A (CYP1A) protein. These data support a role for labile, nonhalogenated compounds in chronic effects of pulp mill effluents on fish.
Sulphide self-heating: moisture content and sulphur formation

Spontaneous or self-heating of sulphides can occur under certain conditions of moisture, temperature and oxygen concentration. This can lead to emission of toxic gases such as SO2 and if uncontrolled, to ignition. Research has established that self-heating divides into three stages: A (below 100 oC), B (above 100 oC) and C (above 350 oC). The understanding is that conditions in stage A promote oxidation of sulphides to elemental sulphur which in stage B oxidizes to SO2. A standard test based on air injections is used to measure stage A and stage B self-heating. In this thesis, a mitigation method using hygroscopic reagents to control moisture has been tested on a pyrrhotite-rich material. Water retention capacity was determined to select reagents for application in the standard self-heating test. Tests showed that the water retention capacity correlated with mitigation of self-heating. Two reagents that showed the best mitigating effect were silica gel and poly (acrylic acid sodium salt). It is hypothesized that temperature and relative humidity have an effect on elemental sulphur production in stage A. To test, pyrrhotite (Fe1-xS) samples were exposed (weathered) at temperatures of 40 oC and 60 oC and relative humidities of 100%, 70% and 30% for 31 days. The weathering apparatus and sulphur analysis method are described. At the end of weathering (31 days), samples were subjected to stage B self-heating test. Self-heating rate and total number of air injections until heating ceased were determined. Both measurements showed that sulphur formed at 40 oC in stage A gave higher heating response than sulphur formed at 60 oC. This observation raises two possibilities that are discussed: there are different types of sulphur formed at the two temperatures; and there is a factor other than just sulphur content that controls stage B self-heating. %%%%L'autochauffage spontane des sulfures peut se produire sous certaines conditions d'humidite et d'oxygene. Cela peut entrainer l'emission de gaz toxiques tel que le SO2. Si l'autochauffage n'est pas controle, la combustion peut se produire spontanement. La recherche a etabli que l'autochauffage se divise en trois etapes, soit : l'etape A (en dessous de 100 oC), l'etape B (plus de 100 oC) et l'etape C (plus de 350 oC). Nous comprenons que l'oxydation des sulfures en soufre elementaire survient lors de l'etape A. Le soufre elementaire s'oxyde pour produire le SO2 dans l'etape B. L'autochauffage lors des etapes A et B est mesure en utilisant un test standard qui injecte l'air dans les echantillons.Dans ce memoire, la methode testee pour l'attenuation des sulfures autochauffantes consistait a controler l'humidite en utilisant des produits hygroscopiques sur des echantillons riches en pyrrhotite. Le facteur de selection des produits hygroscopiques utilises lors des tests d'autochauffage etait leur capacite de retention d'eau. Les tests ont montre qu'il y a une correlation entre la retention d'eau et l'attenuation d'autochauffage. Le gel de silice et le polymere…
Observation of a low-symmetry phase in Na0.5Bi0.5TiO3 crystals by optical birefringence microscopy

Single crystals of sodium bismuth titanate (Na0.5Bi0.5TiO3, NBT) (pure and Mn-doped) have been investigated by means of optical birefringence microscopy. For both crystals, it was found that, above ∼573 K, the optical axis is perfectly aligned with one of the pseudocubic 〈001〉PC directions, while the domain walls appearing in the images are parallel to the pseudocubic 〈011〉PC directions. These observations are consistent with a tetragonal symmetry. Below ∼573 K, the observed optical orientation of both crystals shows a broad angular distribution, with no clearly visible crystallographically oriented domain walls. These results are consistent with monoclinic symmetry. Most importantly, the direct observation of the temperature-driven rotation of the optical axis within the monoclinic plane is reported for the first time in a perovskite oxide material, in the present case for Mn-doped NBT. This has consequences for the understanding of phase transitions in technologically relevant compounds, such as PbZr1−xTixO3, which are considered to have monoclinic structure in some parts of the phase diagram.
Structure and Stability of Water Clusters (H2O)n, n ) 8-20: An Ab Initio Investigation

Extensive ab initio calculations have been performed using the 6-31G(d,p) and 6-311++G(2d,2p) basis sets for several possible structures of water clusters (H2O)n, n = 8−20. It is found that the most stable geometries arise from a fusion of tetrameric or pentameric rings. As a result, (H2O)n, n = 8, 12, 16, and 20, are found to be cuboids, while (H2O)10 and (H2O)15 are fused pentameric structures. For the other water clusters (n = 9, 11, 13, 14, and 17−19) under investigation, the most stable geometries can be thought of as arising from either the cuboid or the fused pentamers or a combination thereof. The stability of some of the clusters, namely, n = 8−16, has also been studied using density functional theory. An attempt has been made to estimate the basis set superposition error and zero-point energy correction for such clusters at the Hartree−Fock (HF) level using the 6-311++G(2d,2p) basis set. To ensure that a minimum on the potential-energy surface has been located, frequency calculations have been c.
Novel Cubic Magnetite Nanoparticle Synthesis Using Room Temperature Ionic Liquid

Room Temperature Ionic liquids are relatively more useful in the synthesis of inorganic nanostructured materials because of their unique properties. To synthesize the iron oxide nanoparticle in simple precipitation method, a novel ionic liquid was used as the greener medium and stabilizing agent namely “1-n-butyl-3-methylimidazolium trifluoromethane sulfonate [BMIM][TfO]”. The crystallinity, chemical structure, morphology and magnetic properties of the synthesized magnetite nanoparticles have been characterized by using X-ray diffraction (XRD), Fourier Transform Infrared (FT-IR), Scanning electron microscopy (SEM), Atomic force microscopy(AFM), Transmission electron microscopy (TEM) and Vibrating sample magnetometer (VSM) studies. The XRD study is divulge that the synthesized magnetite nanoparticles have inverse spinel face centered cubic structure. The FT-IR vibration peaks show the formation of Fe3O4 nanoparticles, where the vibration peak for Fe-O is deliberately presence at 584 cm-1. The average particle size of the synthesized nanoparticles is found to be 35 nm. Homogeneously dispersed cubic shape with superstructure is found through SEM, AFM and TEM examination studies. The synthesized iron oxide nanoparticles have a high saturation magnetization value of 25 emu/g, which is very much useful for biomedical applications.
Uptake of HNO3 on water-ice and coadsorption of HNO3 and HCl in the temperature range 210–235 K

[1] The uptake of HNO3 on water-ice films was investigated in a coated wall flow reactor under tropospheric temperature conditions. Experiments were performed in the “ice” region of the HNO3–H2O phase diagram. With HNO3 partial pressures in the range of (0.3–2.0) × 10−6 Torr, continuous uptake was observed below 215 K; whereas above 215 K, the uptake was time dependent. Using the geometric surface area of the ice film, the surface coverage at 218 K was 3.0 × 1014 molecules/cm2, decreasing to 1.5 × 1014 molecules/cm2 at 233 K; the timescales for saturation were 700 and 800 s at 218 and 233 K, respectively. The surface coverage was found to change by a factor of 2 over a 10-fold change in HNO3 partial pressure. By assuming that the surface coverage can be represented by a Langmuir isotherm for dissociative adsorption, the enthalpy of adsorption of HNO3 onto ice was found to be −(54.0 ± 2.6) kJ/mol. At a constant HNO3 partial pressure, the maximum uptake coefficients, γ, were measured as a function of temperature, decreasing from 0.03 at 215 K down to 0.006 at 235 K. The uptake coefficients at 218 K were not significantly affected by changes in HNO3 partial pressure. The uptake of HCl at 218 K on ice surfaces previously dosed with HNO3 was found to be reversible, and the coadsorption of HNO3 with HCl indicates that HCl is displaced from surface sites by HNO3 molecules. Uptake of HNO3 on HCl-dosed surfaces showed that HNO3 molecules displace ∼1013 molecules/cm3 of HCl. The efficiency of cirrus clouds in scavenging HNO3 is discussed, as well as the implications for chlorine activation reactions under tropospheric temperature conditions.
Recent advances in the synthesis of well-defined glycopolymers

Glycopolymers are receiving increasing interest due to their application in areas, such as glycomics, medicine, biotechnology, sensors, and separation science. Consequently, new methods for their synthesis are constantly being developed, with an increasing emphasis on the preparation of well-defined polymers and on the production of complex macromolecular architectures such as stars. This review covers recent developments in the synthesis of glycopolymers, with a particular emphasis on (i) the use of controlled radical polymerization to prepare well-defined glycopolymers from unprotected monomers and (ii) postpolymerization modification strategies using reactive polymer precursors (including "click" reactions). Recent work on the production of glycosylated polypeptides, which are under investigation as mimics of naturally occurring glycoproteins, is also included. The authors offer some suggestions as to future developments and remaining challenges in this topical area of polymer chemistry. (C) 2007 Wiley Periodicals, Inc.
Effect of Zn and Fe Foliar Application on Yield, Yield Components and some Physiological Traits of Cumin (Cuminum cyminum) in Dry Farming

Water and nutrition deficiency are serious abiotic stress factors that limit plant production in arid and semi arid regions. In order to study the effects of zinc and iron foliar application on yield, yield components and some physiological traits of cumin (Cuminum cyminum) in dry farming, an experiment was carried out at Agricultural Research Center of Kerman, Iran during 2011-2012. Field experiment was conducted in split plot design based on randomized completely block (RCB) at three replications. Main plots included dry farming and normal irrigation and sub plots were the treatments of zinc (Zn), iron (Fe), zinc+iron (Zn+Fe) foliar application and without foliar application (water). Our results showed that Zn+Fe foliar application had significantly effects on yield and yield components such as number of umbels per plant, number of umbellets per umbel and 1000 seed weight. Zn+Fe foliar application had significant effect (a>0.05) on most physiological traits in dry farming such as relative water content (RWC), malondialdehyde content (MDA), Hydrogen peroxide (H2O2) accumulation, proline and protein content. The activity of superoxide dismutase (SOD), catalase (CAT) and peroxidase (GPX) increased in treated plants with Zn+Fe foliar application in dry farming. Means comparisons effect showed that zinc and iron foliar application are effective on cumin resistance in dry farming.
Self-Improvement of Teachers of Physical Education at Various Stages of Professional Development

The article deals with the issue of professional development and peculiarities of self-improvement of teachers of physical education. Teachers of physical education from higher educational establishments took part in the experiment. A number of methods were used: analysis, comparison, systematization, survey, discussion, teachers interviewing, questionnaire, pedagogical experiment, methods of mathematical statistics, and graphic display of results. Also, results of practical experience allowed to elaborate the structure of self-improvement of teacher of physical education, which includes the following components: theoretical and methodological knowledge, pedagogical communication, physical self-improvement, computer literacy and personal view on self-improvement of teachers of physical education in the process of professional activity, which we define as an individual process of improvement of professionally-significant components of activity oriented on “Professional I-ideal”. “Professional I-ideal” is construed by us as a concept of professional qualities and features that a teacher must possess being oriented on professional requirements.
Influence of surface texture on the defect‐induced breakdown behavior of multicrystalline silicon solar cells

The defect‐induced diode breakdown behavior in multicrystalline silicon solar cells, which is located at recombination active crystal defects, is influenced by the surface texturization because the wet chemical treatment selectively etches grain boundaries and dislocations, resulting in etch pits. On textured surfaces, the defect‐induced breakdown voltage is decreased, and the slope of the local reverse I–V characteristics in breakdown is steeper. We find that the local defect‐induced breakdown voltage correlates with the depth of the etch pits. It is suggested that the enhanced electric field in the space charge region at the tip could be superimposed by an electric field around metallic precipitates because of the internal Schottky contact formation with the surrounding silicon. The combined electric field could be responsible for the dependence of the defect‐induced breakdown behavior on the surface texture. Copyright © 2012 John Wiley & Sons, Ltd.
A new evaluation of carbon stocks in British forest soils

Carbon (C) stocks in forest soils were evaluated in the first comprehensive survey of Great Britain, the BioSoil soil survey, using a total of 167 plots (72 in England, 26 in Wales and 69 in Scotland). The average C stock down to 80 cm depth for seven main soil types ranged between 108 and 448 t C/ha with maximum values from 511 to 927 t C/ha. Carbon stock varied with soil depth and type, forest type, and stand age. Stocks within the upper mineral soil (0–20 cm) represented between 29 and 69% of the total 0–80 cm C stock, while those in the top 40 cm comprised 59–100% of the total. Carbon stocks decreased in the order deep peats > peaty gleys > groundwater gleys > surface‐water gleys > podzols and ironpans > brown earths > rankers and rendzinas. Litter and fermentation horizons on average contributed an additional 7.3 and 8.8 t C/ha, respectively, to the overall soil C stock. Measured soil C stocks (0–80 cm) were upscaled by area of main soil and forest types to provide national estimates. Total forest soil stocks for England, Wales and Scotland were upscaled to 163, 46 and 337 Mt C, respectively, with an additional 17, 4 and 21 Mt C within surface organic layers (litter and fermentation horizons). Carbon stocks were larger under conifers compared with broadleaves. Peaty gleys contributed most to the total C stock in Scotland, while brown earths and podzolic soils made the largest contribution in Wales, and brown earths and surface‐water gley soils in England. Estimated total carbon stocks in forest soils in Great Britain, including organic layers, are 589 Mt C in the top 80 cm and 664 Mt C in the top 1 m of soil. The BioSoil soil survey provides the most comprehensive estimate of forest soil C stocks in Great Britain to date and provides a good baseline for assessing future change even though variability in forest soil C stocks is high. However, a relatively small number of additional plots to fill existing gaps in spatial coverage and to increase representation of rendzinas and highly organic soils would significantly reduce the level of uncertainty.
Dye‐sensitized TiO2 solar cells based on nanocomposite photoanode containing plasma‐modified multi‐walled carbon nanotubes

A series of anatase TiO2‐based nanocomposite incorporated with plasma‐modified multi‐walled carbon nanotubes (MWNTs) was prepared by physical blending and shows its capability for efficient electron transport when used as photoanode in dye‐sensitized solar cells (DSSCs). These MWNTs characterized with good dispersal performance were obtained by functionalization technique via in situ plasma treatment and subsequent grafting with maleic anhydride (MA) onto the external walls reported previously. Compared with the conventional DSSCs, the TiO2 film with 1D carbon nanotubes possesses more outstanding ability to transport electrons injected from the excited dye within the device under illumination. As a result, at an optimum addition of 0.3 wt% MWNTs‐MA in TiO2 matrix, the photocurrent–voltage (J–V) characteristics showed a significant increase in the short‐circuit photocurrent (Jsc) of 50%, leading to an increase in overall solar conversion efficiency by a factor of 1.5. Electrochemical impedance spectroscopy analyses reveal that the MWNTs‐MA/TiO2 incur smaller resistances at the photoanode in assembled DSSCs when compared with those in the anatase titania DSSCs. These features suggest that the conducting properties of the MWNTs‐MA within the anodes are crucial for achieving a higher transport rate for photo‐induced electrons in TiO2 layer by exhibiting lower resistance in the porous network and hence retard charge recombination that could result in poor conversion efficiency. Copyright © 2012 John Wiley & Sons, Ltd.
Chalcopyrite dissolution rate law from pH 1 to 3

Chalcopyrite dissolution kinetics in the pH range of 1 to 3 were studied by means of long-term flow-through experiments to obtain a dissolution rate law which can be coupled with reactive transport models to forecast Acid Rock Drainage. In the range of conditions under study, the rate of chalcopyrite dissolution is only slightly dependent on hydrogen ion activity, increasing with decreasing pH. The steady-state dissolution rates obtained in the present study were combined with earlier results presented by Acero et al. (2007a) to obtain the following expression for chalcopyrite dissolution rate law: where Rchalcopyrite is the chalcopyrite dissolution rate (mol m-2 s-1), aH+ is the activity of hydrogen ion in solution, R is the gas constant (kJ mol-1 K-1) and T is the temperature (K). This expression can applied through a wide range of environmental conditions similar to the ones found in systems affected by acid drainage. In agreement with earlier chalcopyrite kinetic studies, iron was released to solution preferentially over copper and sulfur, compared with the stoichiometry of the pristine mineral. Consistently, XPS examination of the samples showed that reacted surfaces were enriched in sulfur and copper (relative to iron) compared with the initial, pristine chalcopyrite surface. However, this surface layer does not exert any passivating effect on chalcolpyrite dissolution and the kinetics of the overall process in the long term seems to be surface-controlled.
Characterization of the Uptake and Intracellular Trafficking of G4 Polyamidoamine Dendrimers

Polyamidoamine (PAMAM) dendrimers are highly branched spherical polymers that have emerged as potent synthetic drug and gene carriers; however, much remains to be learned about the mechanism of dendrimer-mediated cellular uptake. In this study, the endocytic pathway and intracellular trafficking of generation 4 (G4) PAMAM dendrimers were evaluated via fluorescein isothiocyanate (FITC) conjugation. We found that the G4-FITC dendrimers were internalized by energy-dependent and non-specific endocytic pathways. Interesting, G4-FITC dendrimers can not only buffer the endosomal/lysosomal pH but also co-localize with lysosomal markers over a period of 3 to 12 h, after which the signal decreased in the lysosomes and began to co-localize with the mitochondrial marker. This study contributes to the understanding of the molecular behaviour of G4 PAMAM dendrimers in a cellular environment and will facilitate the development of more effective PAMAM-mediated drug and gene delivery systems.
Computing laminar boundary layers with the von Mises equation

There is much current interest in numerical methods of solution of the laminar boundary-layer equations. Methods used to date may generally be classified as (i) explicit finite-difference methods (e.g. Refs. 1, 2, 3); (ii) implicit finite-difference methods (e.g. Refs. 4, 5, 6, 7); (iii) difference-differential methods (e.g. Ref. 8). A method based on converting the boundary-layer problem into an integral equation and solving the latter by iteration has been developed by one of the present authors.