Miracle-dz/UniFAR-FTUs huggingface dataset:
Multi-phase microstructures drive exciton dissociation in neat semicrystalline polymeric semiconductors

The optoelectronic properties of macromolecular semiconductors depend fundamentally on their solid-state microstructure and phase morphology. Hence, it is of central importance to manipulate—from the outset—the molecular arrangement and packing of this special class of polymers from the nano- to the micrometer scale when they are integrated in thin film devices such as photovoltaic cells, transistors or light-emitting diodes, for example. One effective strategy for this purpose is to vary their molecular weight. The reason for this is that materials of different weight-average molecular weight (Mw) lead to different microstructures. Polymers of low Mw form unconnected, extended-chain crystals because of their non-entangled nature. As a result, a polycrystalline, one-phase morphology is obtained. In contrast, high-Mw materials, in which average chain lengths are longer than the length between entanglements, form two-phase morphologies comprised of crystalline moieties embedded in largely un-ordered (amorphous) regions. Here, we discuss how changes in these structural features affect exciton dissociation processes. We utilise neat regioregular poly(3-hexylthiophene) (P3HT) of varying Mw as a model system and apply time-resolved photoluminescence (PL) spectroscopy to probe the electronic landscape in a range of P3HT thin-film architectures. We find that at 10 K, PL originating from recombination of long-lived charge pairs decays over microsecond timescales. Tellingly, both the amplitude and decay-rate distribution depend strongly on Mw. In films with dominant one-phase, chain-extended microstructures, the delayed PL is suppressed as a result of a diminished yield of photoinduced charges. Its decay is significantly slower than in two-phase microstructures. We therefore conclude that excitons in disordered regions between crystalline and amorphous phases dissociate extrinsically with yield and spatial distribution that depend intimately upon microstructure, in agreement with previous work [Paquin et al., Phys. Rev. Lett. , 2011, 106, 197401]. We note, however, that independent of Mw, the delayed-PL lineshape due to charge recombination is representative of that in low-Mw microstructures. We thus hypothesize that charge recombination at these low temperatures—and likely also charge generation—occur in torsionally disordered chains forming more strongly coupled photophysical aggregates than those in the steady-state ensemble, producing a delayed PL lineshape reminiscent of that in paraffinic morphologies at steady state.
Comparison of antioxidant properties of infusions from different parts of Arnica montana and Arnica chamissonis var. foliosa Less.

Arnica chamissonis (aC) was a good source of total phenolics, phenolic acids and flavonoids. irrespective of raw material the highest reducing powers were observed in aC infusions, whereas the highest chelating power (about 100%) was stated in the rhizomes of aC. Free radicals were the most effectively scavenged by extracts of aC flower heads and herb (about 60% – sasa and 90% – aBts, respectively). Lipid peroxidation was strongly inhibited by flower heads infusion of both Arnica genera and herb infusions of Arnica montana (aM) – about 100%. Positive correlations between aBts+. and o2 radical scavenging properties, reducing power and total phenolics content (r=0.97, r=0.79, r=0.83, and r=0.50, respectively), flavonoids content (r=0.92, r=0.77, r=0.66, and r=0.51, respectively) and phenolic acids content (r=0.86, r=0.94 and r=0. 75, respectively) were found. in addition, inhibition of lipid peroxidation was correlated with total phenolics and flavonoids contents (r=0.50, r=0.51, respectively).
Additive Effects on Si3n4 Oxidation/Volatilization in Water Vapor

Two commercially available additive-containing silicon nitride materials were exposed in four environments which ranged in severity from dry oxygen at 1 atm pressure, and low gas velocity, to an actual turbine engine. Oxidation and volatilization kinetics were monitored at temperatures ranging from 1066° to 1400°C. The main purpose of this paper is to examine the surface oxide morphology resulting from the exposures. It was found that the material surface was enriched in rare-earth silicate phases in combustion environments when compared with the oxides formed on materials exposed in dry oxygen. However, the in situ formation of rare-earth disilicate phases offered little additional protection from the volatilization of silica observed in combustion environments. It was concluded that externally applied environmental barrier coatings are needed to protect additive-containing silicon nitride materials from volatilization reactions in combustion environments.
Retrieval of aerosol optical thickness for desert conditions using MERIS observations during the SAMUM campaign

Approximately 30% of the land surface is arid, having desert or semi-desert conditions. Aerosol originating from these regions plays a significant role in climate and atmospheric chemistry of the atmosphere. Retrieving aerosol properties from space-borne platforms above desert conditions, where the surface reflectance is usually very bright, is a challenging task. The proportion of the surface to top of atmosphere (TOA) reflectance can reach values over 90%, especially for wavelength above 500 nm. For these reasons detailed knowledge of aerosol and surface optical properties from these regions is required to separate atmosphere from intrinsically bright surfaces. An approach to retrieve aerosol properties over arid and semi-arid regions based on the Bremen Aerosol Retrieval (BAER) has been developed and validated within the Dust Aerosol Retrievals from Space-Born Instruments (DREAMS) Project, which is part of the Saharan Mineral Dust Experiment (SAMUM, 2006). Combining measurements of the backscattered radiation from the Medium Resolution Imaging Spectrometer (MERIS) instrument aboard Environmental Satellite (ENVISAT) and ground-based measurements in Morocco in radiation closure experiments yields the aerosol optical properties of mineral dust at selected locations.
Thin section studies of Calluna heathland soils subject to prescribed burning

Soil microstructures and biological activity were studied in thin sections of Culluna heathland soils subject to periodic burning. Freely drained Brown Podzolic soils from a species-rich heath at Dinnet Muir, Aberdeenshire, Scotland were compared with shallow Humo-ferric Podzols with a thick humus layer (5–10 cm) supporting a species-poor heath at Balmenach, Aberdeenshire. Structures with greater porosity occurred in all Dinnet soils and the most recently burned Balmenach soil. Burning led to an increase in soil porosity which gradually disappeared after a period of 2–3 years. Soils of the recently burned site had more enchytraeid worms than those burned ten years previously. Most of the Dinnet soil samples were dominated by extremely fine granular structure which could have been produced by flocculation of well decomposed organic matter or by enchytraeid worms. In recently burned sites the increase in soil macro- and microbial activities may lead to the formation of composite structures. Regular burning every 10–15 years has been the land management practice in Scottish heathlands to ensure the production of fresh browse of nutritious heather shoots for herbivores. The near-ground microclimate and regeneration mechanisms of heathland plants are well adjusted to the periodic disturbance by fire. We found that the gradual decrease in surface soil porosity over time can be restored by prescribed burning. Soil structure and the distribution and continuity of pores in the soil profile directly affect soil water movement and retention. These factors have important ecological implications for post-fire vegetation recovery.
Dispersivity Determination Through a Modeling Approach From a Tracer Test Based on Total Br Concentration in Soil Samples

Abstract Determination of reliable solute transport parameters is an essential aspect for the characterization of the mechanisms and processes involved in solute transport (e.g., pesticides, fertilizers, contaminants) through the unsaturated zone. A rapid inexpensive method to estimate the dispersivity parameter at the field scale is presented herein. It is based on the quantification by the X-ray fluorescence solid-state technique of total bromine in soil, along with an inverse numerical modeling approach. The results show that this methodology is a good alternative to the classic Br− determination in soil water by ion chromatography. A good agreement between the observed and simulated total soil Br is reported. The results highlight the potential applicability of both combined techniques to infer readily solute transport parameters under field conditions.
Charged hard spheres in dipolar hard sphere solvents. A model for electrolyte solutions

The linearized and quadratic hypernetted‐chain approximations are solved numerically for mixtures of charged hard spheres in dipolar hard sphere solvents. The pair correlation functions, concentration dependent dielectric constant, and thermodynamic properties are examined for several solvents and a range of ion concentrations. The ion–ion pair correlation functions contain many interesting structural features which are not present in the so‐called primitive model. Solvent separated ion pairs are found to be a very important species in certain solutions.
Selectivity and Charge Transfer in Photoreactions of α,α,α‐Trifluorotoluene with Olefins

In photoreactions of α,α,α-trifluorotoluene with olefins, the mode of reaction strongly depends on the charge transfer between the starting materials. Substitution of an F-atom is preferred if the electron transfer becomes exergonic, i.e. if ΔG 0, the olefins undergo cycloaddition onto the arene ring. In the transition area of ΔG ≈ 0 eV, both the electron transfer and the reaction mode can be controlled by varying the solvent polarity. For instance, 1 and 9 mainly form cycloaddition products in dioxane (ΔG = + 0.11 eV), whereas in solvents with e > 3 (ΔG < 0), substitution is the only observed photoreaction. Moreover, in systems of endergonic electron-transfer processes, the degree and the direction of charge transfer influence both the regio- and the stereochemistry of the cycloaddition.
Membrane elastic heterogeneity studied at nanometrical scale on living cells

The aim of this thesis was to explore the cell mechanical properties using the Atomic Force Microscope (AFM). The cell membrane contains lipids microdomains, called rafts, enriched in cholesterol and sphingolipids. The rafts are believed to play an important role in signal processing by acting as a "signaling platform". Indeed, membrane proteins involved in signal transduction concentrates into these rafts and are coupled with signaling pathways inside the cell. The mechanical properties of these rafts were characterized by targeting one of its component, the glycosylphosphatidylinositol-anchored protein (GPI-AP). During this work, we found these domains to be stiffer than the surrounding membrane. Several control experiments were performed to consolidate this finding. The extraction of cholesterol, one of the major component of raft, was shown to dramatically reduce the stiffness of the raft to reach the surrounding membrane value. The stiffness specificity of rafts may be related to the lower diffusion rate of proteins and can be, therefore, an important property for its role as a signaling platform. During this thesis, we also introduced a new AFM imaging mode, which we called "stiffness tomography". With this imaging mode, we were able to distinguish stiff materials inclusion located into the sample. Different control experiments were done to validate this imaging mode. A virtual experiment was performed with the help of the finite element modeling. This permitted us to validate our methodology, but also pointed us its limitations. The stiffness tomography was also used on living cells and showed significant differences between native and cytoskeleton depolimerized cells. Since no postprocessing tool was available at the beginning of this work, the software development was a very significant part of the project. Its development resulted in a toolbox (a collection of function), that is available for future software development. A non negligible part of the development consisted in the toolbox documentation that is reported in the appendix C. This software permitted to process force volume AFM les and to characterize the elastic properties of the cell membrane with a high precision and reliability.
Docking of An Asphaltene Molecular Model on A Fe2O3 Surface, An Ab Initio Simulated Annealing

Abstract The docking of an asphaltene molecular model over the (1000) hematite surface is analyzed through the use of ab initio molecular dynamics simulation techniques where the Density Functional Theory (DFT) forces were obtained using the Harris functional approach. The (1000) hematite surface is modeled by a supercell slab lattice of 225 atoms with a = b lengths of 25.17 Å; on the c -direction an empty gap space and Fe-O-Fe-Fe-O atomic sequence was built. This structure was thermally stabilized at 400K. The asphaltene-hematite surface interaction was simulated with an annealing process at 400K during 555 fs, and then a geometry optimization process was carried out on the final annealed configuration in order to stabilize the asphaltene-surface system. We find an attractive interaction between the asphaltene and the Fe2O3 which is located mainly at the asphaltene aromatic region. Finally, we have obtained cohesion energy of −417 kcal/mol, indicative of quimisorption energy on the basis of a Harris functional treatment.
Electronic structure and electric field gradient calculations of Al2SiO5 polymorphs

Abstract The electronic structure of the three polymorphs of Al2SiO5, andalusite, sillimanite, and kyanite, is studied by linearized-augmented-plane-wave (LAPW) calculations using the WIEN code. Total energy calculations verify, in agreement with recent pseudopotential calculations, that andalusite is the most stable phase, followed by sillimanite and kyanite.We determine the electronic charge density distribution and find strong polarizations on all oxygen ions. We identify different polarizations due to Al or Si neighbors which depend on their respective distances to the oxygen atom. The chemical bonding is not purely ionic in nature but has important covalent contributions. Electric field gradients (EFGs) at all sites are calculated and agree well (within 10%) with available experimental data on Al. We identify the origin of the EFGs and demonstrate its relation to the nearest-neighbor coordination and the resulting anisotropy of the electronic charge distribution.
Electrodeposition from Ionic Liquids

PREFACE BASIC CONSIDERATIONS OF DEPOSITION IN IONIC LIQUIDS SYNTHESIS OF IONIC LIQUIDS AlCl3 Based First Generation Ionic Liquids Air and Water Stable Ionic Liquids Deep Eutectic Solvents PHYSICOCHEMICAL PROPERTIES OF IONIC LIQUIDS ELECTRODEPOSITION OF METALS Metal Deposition in AlCl3 Based Ionic Liquids Metal Deposition in Air and Water Stable Ionic Liquids Metal Deposition in Deep Eutectic Solvents Troublesome Aspects ELECTRODEPOSITION OF ALLOYS ELECTRODEPOSITION OF SEMICONDUCTORS ELECTRODEPOSITION OF CONDUCTING POLYMERS ELECTRODEPOSITION OF NANOCRYSTALLINE METALS AND ALLOYS ELECTRODEPOSITION ON THE NANOSCALE PLASMA ELECTROCHEMISTRY TECHNICAL ASPECTS Counter Electrode Reactions / Metal Dissolution Reference Electrodes Upscaling Recycling Impurities SURFACE PRETREATMENT / ELECTROPOLISHING PLATING PROTOCOLS FUTURE DIRECTIONS
General methods for geometry and wave function optimization

A combination of variable-metric second-order update schemes and the DIIS method for both geometry and Hartree-Fock wave function optimization is described. A recursive procedure for updating large Hessians is presented. The performances of geometry optimizations with respect to the choice of the coordinate system (symmetry-adapted, internal, and Cartesian coordinates), the initial nuclear Hessian, and the optimization procedure have been investigated by a series of benchmark molecules. Formulas for the generation of initial nuclear Hessians are given
Heterogeneous Ice Nucleation Rate Coefficient of Water Droplets Coated by a Nonadecanol Monolayer

The heterogeneous ice nucleation rate coefficient (jhet) of water droplets coated with a monolayer of 1-nonadecanol was determined from multiple freezing/melting cycles. Freezing was monitored optically with a microscope for droplet radii between 31 and 48 μm and with a differential scanning calorimeter for radii between 320 and 1100 μm. The combination of these two techniques allows the surface area of the 1-nonadecanol nucleating agent to be varied by more than a factor of 1000, showing that jhet increases only by ∼5 orders of magnitude over a temperature range of 18 K. This is roughly 5 times less than the change in the ice nucleation rate coefficient for homogeneous ice freezing at around 238 K or for heterogeneous ice freezing in the presence of a solid ice nucleus, such as Al2O3. This temperature dependence of jhet can be reconciled with the framework of classical nucleation theory, when assuming a reduced compatibility of the alcohol monolayer with the ice embryo as the temperature decreases. We at.
Computational Study of Hydrogen-Bonded Complexes Between the Most Stable Tautomers of Glycine and Uracil

A total of 23 hydrogen bonded complexes between the lowest energy tautomers of uracil and glycine have been characterized at the density functional level of theory with a hybrid B3LYP exchange-correlation functional and 6-31++G** basis sets. The most stable complexes are formed when the carboxylic group of glycine is bound through two hydrogen bonds with a NH proton donor and an O proton acceptor of uracil, and stabilization energies for these cyclic structures span a range of 12.3−15.6 kcal/mol. Interplay between the topological match among proton donor and acceptor sites involved in cyclic structures and their preference to form single hydrogen bonds, measured by the values of proton affinity and deprotonation enthalpy, has been discussed. Upon formation of a uracil−glycine complex, the elongations of proton donor bonds and vibrational red shifts for proton donor stretching modes can reach 0.05 A and 650 cm-1, respectively. These perturbations of proton donor bonds correlate with the magnitude of two-bo.
Robust Measures and the Estimator Limit

A new concept, the Estimator Limit, is proposed as a mean of overcoming discrepanices among the “robust'’measures used in deducing “best values'’from incoherent analytical data on proposed rock reference samples. Un nouveau concept, l'“estimateur limite'’est propose pour surmonter les inconsistances entre les mesures “robustes'’utilisees pour etablir les “meilleures valeurs’a partir de donnees analytiques incoherentes (obtenues) sur des geostandards proposes.
Chemical characterization of the lipid fractions of pumpkin seeds

Purpose – This paper aims to characterize the pumpkin (Cucurbita sp) seed oil from the varieties Nova Caravela, Mini Paulista, Menina Brasileira (Cucurbita moschata) and Moranga de Mesa (Cucurbita maxima) as to their physicochemical properties, vitamins and fatty acid and triacylglycerols profiles. Design/methodology/approach – The oils were extracted from oilseeds by the Bligh and Dyer (1959) method, and chemical characterization was performed by using standard methods for oils and fats. The vitamin A and E content, fatty acid profile and triacylglycerols profile also were determined. Findings – About the chemical properties, the oils showed values within the range for edible vegetable oils. The oil from variety Nova Caravela stood out for presenting better quality, as it showed lower values of free fatty acids, acidity and peroxides. However, it was found that the Moranga de Mesa oil was the most unsaturated, due to the high refractive and iodine index, and was also reported to have lower oxidative stab.
ANTIOXIDANT AND ANTIMICROBIAL ACTIVITY OF GRANGEA MADERASPATANA (L.) POIR. EXTRACT

The extract of aerial parts of Grangea maderaspatana (L.) Poir. , obtained by steam distillation was analyzed by gas chromatography and gas chromatography coupled with mass spectroscopy. Twenty one constituents were identified, constituting 91.5 % of the oil. It was characterized by the dominant presence of sesquiterpenoids (sesquiterpenoid hydrocarbons 36.1 % and oxygenated sesquiterpenoids 28.4 %). Most abundant compounds are γ-gurjunene (26.5%), terpinyl acetate (20.8%) and hinesol (11.7%). The in vitro antioxidant potential of the oil was evaluated using, DPPH radical scavenging, metal chelating and reducing power assays. The oil showed antioxidant potential with significant reducing power (ASE/mL 2.01 ± 0.00), chelating activity (IC50 1.80 ± 0.15) and DPPH radical scavenging activity (IC50 2.90 ± 0.96). Antimicrobial activity of the oil was tested against one gram positive, four gram negative bacteria and two fungi using agar well diffusion method. The ZOI values of the oil were in the range of 2.67 ± 0.58 to 11.00 ± 0.00 mm and MIC of the oil was ranged from 5 to 30 µL/ mL for tested microorganisms. The activity was more pronounced against Candida albicans (ZOI = 11.00 ± 0.00 mm, MIC = 5 µL/mL) followed by Streptomyces candidus (ZOI = 9.33 ± 0.58 mm, MIC = 5 µL/mL), while the oil was least effective against Aeromonas hydrophila and Klebsiella pneumoniae.
Stereochemical investigation of 2,3,4,6-tetra-O-acetyl-1-S-benzhydroximoyl-α-d-glucopyranose

C 21 H 25 NO 10 S cristallise dans C2 avec a=16.247, b=11.182, c=13.420A, β=91.62°, Z=4; affinement jusqu'a R=0.052. Determination de la stereochimie autour de la liaison C=N. La partie glucose a la conformation attendue 4 C 1 . Le groupement hydroxyl sur l'atome N est syn par rapport au cycle du sucre. Analyse du comportement conformationnel et compararison avec les structures connues de thiosucres.
Enhanced Mobility of Poly(3-hexylthiophene) Transistors by Spin-Coating from High-Boiling-Point Solvents

Chloroform is a general solvent for poly(3-hexylthiophene) (P3HT) active layers in field-effect transistors. However, its low boiling point and rapid evaporation limit the time for crystallization during the spin-coating process, and field-effect mobilities achieved for P3HT films spin-coated from chloroform are typically on the order of 0.01 cm2/(V s). Here we investigate a range of solvents with higher boiling points. We find that 1,2,4-trichlorobenzene with good solubility and a high boiling point significantly improves the field-effect mobilities up to 0.12 cm2/(V s) with on:off ratios of 106. By controlling the microstructure through the choice of solvent while keeping the molecular weight fixed, we observe a clear correlation between the field-effect mobility and the degree of microcrystalline order as measured by X-ray diffraction, as well as the strength of polaronic relaxation of charge carriers in the accumulation layer as measured by optical spectroscopy of field-induced charge.
Effects of Ethylene Oxide Fumigation and Gamma Irradiation on the Quality of Ground Red and Black Peppers

Ethylene oxide (E.O) fumigation and gamma irradiation were applied to comparative researches on the sterilizing effect and physicochemical quality of sound red and black peppers. The microorganisms contaminated in the sample, including total bacteria, aerobic spores, acid tolerant bacteria, fungi, osmophilic molds and coliforms were sterilized with irradiation doses of 7 10 kGy, while E.O fumigation in a commonly used condition proved insufficient for the destruction of them. Both treatments affected more or less chemical components of the sample, such as pungent principle, pigment, essential oils and volatile flavors, but the gamma irradiation at the doses for radurization and radicidation was shown to be safer than E.O fumigation.