Miracle-dz/UniFAR-FTUs huggingface dataset:
Charge Density Dependent Nongeminate Recombination in Organic Bulk Heterojunction Solar Cells

Apparent recombination orders exceeding the value of two expected for bimolecular recombination have been reported for organic solar cells in various publications. Two prominent explanations are bimolecular losses with a carrier concentration dependent prefactor due to a trapping limited mobility and protection of trapped charge carriers from recombination by a donor–acceptor phase separation until re‐emission from these deep states. In order to clarify which mechanism is dominant temperature‐ and illumination‐dependent charge extraction measurements are performed under open circuit and short circuit conditions at poly(3‐hexylthiophene‐2,5‐diyl):[6,6]‐phenyl‐C61 butyric acid methyl ester (P3HT:PC61BM) and PTB7:PC71BM (poly[[4,8‐bis[(2‐ethylhexyl)oxy]benzo[1,2‐b:4,5‐b′]dithiophene‐2,6‐diyl][3‐fluoro‐2‐[(2‐ethylhexyl)carbonyl]thieno[3,4‐b]thiophenediyl]]) solar cells in combination with current–voltage characteristics. It is shown that the charge carrier density n dependence of the mobility μ and the recombination prefactor are different for P3HT:PC61BM at temperatures below 300 K and PTB7:PC71BM at room temperature. Therefore, in addition to μ(n), a detrapping limited recombination in systems with at least partial donor–acceptor phase separation is required to explain the high recombination orders.
CO2 methanation over heterogeneous catalysts: recent progress and future prospects

Catalytic approaches for CO2 fixation can play an important role, because CO2 can be artificially converted into reusable chemicals. Among the catalytic reactions of CO2, hydrogenation of CO2, the so-called methanation reaction, is a suitable technique for the fixation of CO2. This technique can be used to convert exhausted CO2 into methane (CH4), which can be recycled for use as a fuel or a chemical as well as by contributing to the reduction of CO2 emissions. Heterogeneous catalysts have been used to hydrogenate CO2 to methane. Heterogeneous catalysts are preferable to homogenous catalysts in terms of stability, separation, handling, and reuse, which reflects in lower costs for large-scale production. Significant progress has been made in this direction, the exploitation of novel heterogeneous catalysts. In this review, we discussed recent developments in this area, with emphases on catalytic reactivity and its physicochemical properties and reaction mechanism. Apart from materials aspects and catalytic performance, we also discuss fundamental strategies for the rational design of materials for effective transformation of CO2 to methane with the help of H2 and power sources.
Evaluation of colour fastness and thermal migration in softened polylactic acid fabrics dyed with disperse dyes of differing hydrophobicity

This paper addresses the relative effects of softeners having different properties and their method of application (exhaust vs pad) on the colour fastness of poly(lactic acid) fabrics dyed with a range of disperse dyes with different levels of hydrophobicity. A comparison was made with a correspondingly finished polyethylene terephthalate fabric. Possible relationships between the levels of hydrophilicity/hydrophobicity of the dye, and softener, and the colour fastness were explored. Finally, the amount of dye thermally migrated into the finish on the softened poly(lactic acid) and polyethylene terephthalate fabrics was examined in comparison with their colour fastness. Softened poly(lactic acid) fabrics dyed with CI Disperse Red 167.1 exhibited more thermal migration, and hence lower colour fastness, than the corresponding polyethylene terephthalate fabrics. Conversely, softened poly(lactic acid) fabrics dyed with Dianix Deep Red SF exhibited less thermal migration, and hence better colour fastness, than the corresponding polyethylene terephthalate fabrics. Overall, no clear relationship was found between the hydrophobic nature of the disperse dye and the hydrophobic character of the softener on the colour fastness.
Removal of Direct Yellow 12 from Water Samples by Cloud Point Extraction Using Triton X-100 as Nonionic Surfactant

A surfactant mediated cloud point extraction (CPE) procedure has been developed to remove color from wastewater containing direct yellow 12 (Chrysophenine G), using triton x-100 (TX-100) as nonionic surfactant. The effects of the concentration of the surfactant, pH, temperature and salt concentration on the different concentration of dye have been studied and optimum conditions were obtained for the removal of direct yellow 12 (DY 12). The concentration of DY 12 in the dilute phase was measured using UV-Vis spectrophotometer. It was found that the separation of phases was complete and the recovery of DY 12 was very effective in the presence of NaCl as an electrolyte. The results showed that up to 600 mg L−1 of DY 12 can quantitatively be removed (>96%) by Cloud point extraction procedure in a single extraction using optimum conditions.
Temperature dependence of isotope fractionation in N2O photolysis

Stratospheric ultraviolet (UV) photolysis is the dominant sink reaction and main origin of isotopic enrichment for atmospheric nitrous oxide (N2O). To a large extent, the flux of isotopically heavy N2O from the stratosphere is responsible for the enrichment of tropospheric N2O relative to its sources at the Earth's surface. In order to simulate the stratospheric enrichments quantitatively in atmospheric models and to examine the global N2O cycle using isotope measurements, knowledge of the fractionation constants is required. However, to date, all experimental studies of isotopic enrichment in N2O photolysis have been performed at room temperature only. Here we report the first temperature-dependent (193 < T/K < 295) measurements of 18O and position-dependent 15N fractionation constants obtained by broadband photolysis at wavelengths of relevance to the stratospheric “UV window”. For a given extent of reaction, we find higher enrichments at lower temperatures, qualitatively in agreement with theoretical predictions. The relative changes are in the order 14N15NO > N218O > 15N14NO, similar to the absolute values. If temperature was the only parameter of influence, not only the fractionation constants themselves, but also the ratio of fractionation constants at the central to terminal nitrogen sites, η = 15e2/15e1, should decrease along the vertical stratospheric temperature gradient. These temperature effects do not help to explain the lower η values observed in the lower stratosphere, but they are nevertheless essential ingredients for models of atmospheric isotope chemistry. We also investigate a hitherto unexplained artefact in laboratory measurements of N2O photolysis: At high degrees of conversion, N2O loss by the reaction with O(1D) becomes important, presumably due to the photochemical production and subsequent photolysis of NO2 in the reaction cell. The effect gains importance with increasing concentration and in the present study, it caused decreases in the measured fractionation constants requiring correction for initial N2O mixing ratios of 4 mmol mol−1.
Built‐in elastic strain and localization effects on GaAs luminescence of MOVPE‐grown GaAs–AlGaAs core–shell nanowires

cm/s) surface carrier recombination ve-locity of GaAs and the nanowire large surface-to-volume ratios, effective and long-term stable passivation of GaAs surface states is however, necessary. A common approach is to overgrow a wider bandgap AlGaAs shell around GaAs nanowires. GaAs–AlGaAs core–shell nanowires thus show strong enhancement of luminescence intensity, improved minority carrier diffusion lenghts, and recombi-nation lifetimes with respect to bare GaAs nanowires [3, 4]. Also, the small lattice mismatch between the two materials may induce elastic strain fields and piezo-electric effects along the nanowire [111] axial direction; recently, Hocevar et al. [4] demonstrated the occurrence of systematic red-shifts in the core luminescence of molecular beam epitaxy (MBE) grown GaAs–Al
Effect of Gamma Irradiation on the Overall Quality of a Commercial Plain-type Yogurt Products

To develop a yogurt for sensitive consumer such as infants, children or immuno-compromised patients using gamma irradiation, the effects of gamma irradiation on the microbiological, chemical, and sensory quality in a commercial plain yogurt were investigated. No viable coliform bacteria were detected in the sample and approximately a 6 decimal reduction was achieved in the number of total aerobic bacteria by irradiation at 5 kGy. The initial population of lactic acid bacteria observed in the commercial plain yogurt was 8.95 log CFU/g. Gamma irradiation significantly reduced the initial microbial level to 6.47 and 2.85 log CFU/g after irradiation at 1 and 3 kGy, respectively (p
Fundamental Study of nanostructured electro-catalysts with reduced noble metal content for PEM based water electrolysis

Identification and development of non-noble metal based electro-catalysts or electro-catalysts with significant reduction of expensive noble metal contents (E.g. IrO2, Pt) with comparable electrochemical performance as the standard noble metal/metal oxide for proton exchange membrane (PEM) based water electrolysis would constitute a major breakthrough in the generation of hydrogen by water electrolysis. Accomplishing such a system would not only result reduction of the overall capital costs of PEM based water electrolyzers, but also help attain the targeted hydrogen production cost [< $ 3.0 / gallon gasoline equivalent (gge)] comparable to conventional liquid fuels. In line with these goals, it was demonstrated that fluorine doped IrO2 thin films and nanostructured high surface area powders display remarkably higher electrochemical activity, and comparable durability as pure IrO2 electro-catalyst for the oxygen evolution reaction (OER) in PEM based water electrolysis. Furthermore, corrosion resistant SnO2 and NbO2 support has been doped with F and coupled with IrO2 or RuO2 for use as an OER electro-catalyst. A solid solution of SnO2:F or NbO2:F with only 20 - 30 mol. % IrO2 or RuO2 yielding a rutile structure in the form of thin films and bulk nanoparticles displays similar electrochemical activity and stability as pure IrO2/RuO2. This would lead to more than 70 mol. % reduction in the noble metal oxide content. Novel nanostructured ternary (Ir,Sn,Nb)O2 thin films of different compositions have also been studied. It has been shown that (Ir0.40Sn0.30Nb0.30)O2 shows similar electrochemical activity and enhanced chemical robustness as compared to pure IrO2. F doping of the ternary (Ir,Sn,Nb)O2 catalyst helps in further decreasing the noble metal oxide content of the catalyst. As a result, these reduced noble metal oxide catalyst systems would potentially be preferred as OER electro-catalysts for PEM electrolysis. The excellent performance of the catalysts coupled with its robustness would make them great candidates for contributing to significant reduction in the overall capital costs of PEM based water electrolyzers. This thesis provides a detailed fundamental study of the synthesis, materials, characterization, theoretical studies and detailed electrochemical response and potential mechanisms of these novel electro-catalysts for OER processes.
A quantum chemistry study of benzene dimer

We have performed a detailed quantum chemistry study of the gas‐phase benzene dimer. Large atomic orbital basis sets with multiple polarization functions were used. The effects of basis set size, electron correlation, and basis set superposition error were investigated for the low‐energy planar sandwich (D6h and C6v), parallel displaced (C2h), and T‐shaped (C2v) dimer structures. Our studies indicate that the C2h‐symmetry parallel displaced geometry is the lowest‐energy structure for the benzene dimer. The T‐shaped structure was found to be a low‐energy saddle point for interconversion between parallel displaced structures, while the planar sandwich structure was found to be a saddle point on a higher‐energy interconversion path between parallel displaced structures. Detailed analysis of the low‐energy (T‐shaped saddle point) path revealed the presence of a shallow minimum corresponding to a tilt angle between phenyl ring planes of about 45°. Much of the behavior of the benzene dimer observed through mole.
Hydrological Properties of Soils in Reclaimed and Unreclaimed Sites after Brown-Coal Mining

Bulk density, porosity, water holding capacity, water field capacity, wilting point, clay content, hydraulic conductivity, and soil moisture were studied in unreclaimed sites (5, 15, and 25 years old) and reclaimed sites (20-30 years old) on a post-mining spoil heap near Sokolov, Czech Republic. The unreclaimed sites had been spontaneously colonized by shrubs, and the reclaimed sites had been planted with pine, spruce, oak, alder, or meadow (the meadows were created by the spreading of topsoil and grass seed). Soil bulk density decreased with site age and was similar in unreclaimed and reclaimed sites except in the meadow sites, where bulk density was highest. Field capacity (in terms of volumetric soil water content) increased with site age and was similar in unreclaimed and reclaimed sites except for the meadow sites, which had the lowest field capacity. The wilting point (in terms of volumetric soil water content) decreased with age in unreclaimed sites, was higher in reclaimed sites than in unreclaimed sites, and was higher for the meadows than for other sites. Hydraulic conductivity was generally low but was highest in young sites. Soil moisture content had no clear seasonal pattern in young, unreclaimed sites (which had little vegetation), but decreased in summer in all vegetated sites. Soil moisture was highest in the reclaimed alder sites and was lowest in the reclaimed pine and meadow sites. Relative to unreclaimed sites, reclaimed sites had a higher ability to hold water but a higher wilting point, such that water availability for plants was similar in both kinds of sites. The water deficit was highest in the reclaimed oak sites followed by the meadow sites. The latter finding indicates that the spreading of topsoil during reclamation does not result in improved soil moisture conditions 20 years later.
The Thermodynamics of Sorption of Three Direct-Dye Mixtures on Cellulose

The equilibrium absorption of binary mixtures of Direct Red 2, Direct Blue 8, and Direct Yellow 12 by cellulose film has been studied, and a correlation between single and mixture dyeing is presented. In each case, the competition of the dyes for available surface area suppressed the sorption. In some cases, evidence was obtained of interaction of the dyes in solution. When this occurred, it was difficult to define quantitatively the com petition of the dyes for available surface area. All of the results correlated with the degree of interaction in solution, as measured by transmission studies made at 90°C. The data are interpreted in terms of a Langmuir equation which has been modified to take into consideration the compe tition of two dyes for available surface area.
Phosphate sorption of some Nigerian soils and its effect on cation exchange capacity

Abstract Langmulr phosphate sorption isotherms for several representative Nigerian soils derived from different parent materials were studied. Two straight‐line portions of the isotherm were obtained for each soil studied after 24‐hour equilibration. The number of straight‐line portions or “breaks”; of the isotherm for a soil was found to depend not only on the P concentration range but on the time of equilibration as well. Phosphate sorption capacity of the soil studied follows the order: Alfisols from basalts > Ultisols from sandstone > Alfisols from basement complex rocks (gneisses) ~ Alfisols from coastal sediments ~ Alfisols from eolian drift. The sandy forest soils derived from basement complex rocks and from coastal sediments in south‐western Nigeria require relatively low amounts of phosphate for maximum crop yield as determined by the Langmuir isotherm. Phosphate sorption resulted in significant increases in cation exchange capacity of the soils studied. The percentage CEC increase ranged from 17.
MAXIMUM HARDNESS INDEX OF QUANTUM ACID-BASE BONDING

A unified picture of the hard-and-soft-acids-and-bases and maximum hardness principles was approached through introducing the maximum hardness index Y. It provides particular chemical hardness ranges where the chemical bonding behaves like hard-hard, soft-soft, and hard-soft or soft-hard acid-base interaction characters and furnishes the key to analytical classification of acids and bases in an intrinsic structural manner. The reliability of the present recipe and index was tested by the chemical hardness ordering predictability and chemical bond nature characterization on a particular series of molecular Lewis acids and bases within various computational and experimental atomic chemical hardness scales. Although a consistent chemical hardness principles and related- indices picture was furnished in all cases, considerable differences were noted with respect to the old-fashioned Pearson classification.
Rates of Nitrogen Mineralization of Meat and Bone Meals in Mediterranean Soils

Animal by-products such as meat and bone meals are now certified as free from bovine spongiform encephalopathy (BSE), and their use as organic fertilizers is considered safe again. Given that knowing the rates at which their nutrients are released is key to efficient use, nitrogen (N) mineralization in Mediterranean soils fertilized with meat and bone meals (MBMs) has been studied by means of 12 incubation experiments using three soils of different textures and organic-matter contents and five MBMs of varied origin and characteristics. After the application of the organic products, the amounts of mineral N released after 2, 4, 8, 12, 16, 20, and 35 weeks of aerobic incubation at 25 °C were measured and the data were adjusted to first-order reaction kinetics. In all cases, the results were consistent with the assumption of N mineralization being a first-order reaction with k constants ranging from 0.177 week−1 to 1.603 week−1. Mineralization was fast, with most of the N release taking place during the first 5–10 weeks of the incubations. Despite the different origin and characteristics of the MBMs compared in the experiment, soil type was the most influential factor in the mineralization process. The N mineralization rates were greater in the loam soil, suggesting a relevant role of enzymes immobilized in inorganic colloids such as clay.
Malliavin calculus for marked binomial processes: portfolio optimisation in the trinomial model and compound Poisson approximation

In this paper we develop a stochastic analysis for marked binomial processes, that can be viewed as the discrete analogues of marked Poisson processes. The starting point is the statement of a chaotic expansion for square-integrable (marked binomial) functionals, prior to the elaboration of a Markov-Malliavin structure within this framework. We take advantage of the new formalism to deal with two main applications. First, we revisit the Chen-Stein method for the (compound) Poisson approximation which we perform in the paradigm of the built Markov-Malliavin structure, before studying in the second one the problem of portfolio optimisation in the trinomial model.
Symmetric Continuous Subgraph Matching with Bidirectional Dynamic Programming

In many real datasets such as social media streams and cyber data sources, graphs change over time through a graph update stream of edge insertions and deletions. Detecting critical patterns in such dynamic graphs plays an important role in various application domains such as fraud detection, cyber security, and recommendation systems for social networks. Given a dynamic data graph and a query graph, the continuous subgraph matching problem is to find all positive matches for each edge insertion and all negative matches for each edge deletion. The state-of-the-art algorithm TurboFlux uses a spanning tree of a query graph for filtering. However, using the spanning tree may have a low pruning power because it does not take into account all edges of the query graph. In this paper, we present a symmetric and much faster algorithm SymBi which maintains an auxiliary data structure based on a directed acyclic graph instead of a spanning tree, which maintains the intermediate results of bidirectional dynamic programming between the query graph and the dynamic graph. Extensive experiments with real and synthetic datasets show that SymBi outperforms the state-of-the-art algorithm by up to three orders of magnitude in terms of the elapsed time.
Skye: A Differentiable Equation of State

Stellar evolution and numerical hydrodynamics simulations depend critically on access to fast, accurate, thermodynamically consistent equations of state. We present Skye, a new equation of state for fully ionized matter. Skye includes the effects of positrons, relativity, electron degeneracy, Coulomb interactions, nonlinear mixing effects, and quantum corrections. Skye determines the point of Coulomb crystallization in a self-consistent manner, accounting for mixing and composition effects automatically. A defining feature of this equation of state is that it uses analytic free energy terms and provides thermodynamic quantities using automatic differentiation machinery. Because of this, Skye is easily extended to include new effects by simply writing new terms in the free energy. We also introduce a novel thermodynamic extrapolation scheme for extending analytic fits to the free energy beyond the range of the fitting data while preserving desirable properties like positive entropy and sound speed. We demonstrate Skye in action in the MESA stellar evolution software instrument by computing white dwarf cooling curves.
Unitarization Through Approximate Basis

We introduce the problem of unitarization. Unitarization is the problem of taking $k$ input quantum circuits that produce orthogonal states from the all $0$ state, and create an output circuit implementing a unitary with its first $k$ columns as those states. That is, the output circuit takes the $k$th computational basis state to the state prepared by the $k$th input circuit. We allow the output circuit to use ancilla qubits initialized to $0$. But ancilla qubits must always be returned to $0$ for any input. The input circuits may use ancilla qubits, but we are only guaranteed the they return ancilla qubits to $0$ on the all $0$ input. The unitarization problem seems hard if the output states are neither orthogonal to or in the span of the computational basis states that need to map to them. In this work, we approximately solve this problem in the case where input circuits are given as black box oracles by probably finding an approximate basis for our states. This method may be more interesting than the application. This technique is a sort of quantum analogue of Gram-Schmidt orthogonalization for quantum states. Specifically, we find an approximate basis in polynomial time for the following parameters. Take any natural $n$, $k = O\left(\frac{\ln(n)}{\ln(\ln(n))}\right)$, and $\epsilon = 2^{-O(\sqrt{\ln(n)})}$. Take any $k$ input quantum states, $(|\psi_i \rangle)_{i\in [k]}$, on polynomial in $n$ qubits prepared by quantum oracles, $(V_i)_{i \in [k]}$ (that we can control call and control invert). Then there is a quantum circuit with polynomial size in $n$ with access to the oracles $(V_i)_{i \in [k]}$ that with at least $1 - \epsilon$ probability, computes at most $k$ circuits with size polynomial in $n$ and oracle access to $(V_i)_{i \in [k]}$ that $\epsilon$ approximately computes an $\epsilon$ approximate orthonormal basis for $(|\psi_i \rangle)_{i\in [k]}$.