Miracle-dz/UniFAR-FTUs huggingface dataset:
Microwave assisted extraction of essential oils from enzymatically pretreated lavender (Lavandula angustifolia Miller)

In this study, microwave assisted a hydrodistillation process (MWHD) of essential oils from lavender (Lavandula angustifolia Miller) was investigated. In order to examine any potential differences in essential oil extraction, the lavender flowers underwent enzymatic pretreatment.A 23 factorial design of experiments, combined with statistical methods of data analysis were used to optimize enzymatic pretreatment and to evaluate the influence of major variables (enzyme concentration, temperature and pH) on the performance of the microwave assisted extraction.Under optimal conditions, an extraction yield of 24 mg oil g−1 substrate was achieved (an increase by approximately 25% in comparison with the classic extraction conditions of conventional hydrodistillation). The main compounds of the essential oils obtained were analyzed and identified by gas chromatography coupled to mass spectrometry (GC-MS). Analyzing the data obtained indicated that the content of main compounds (linalool and linalyl acetate − 73%) was greater than that obtained by conventional extraction (67%).
Synthesis, Physicochemical Properties, and Toxicity Data of New Hydrophobic Ionic Liquids Containing Dimethylpyridinium and Trimethylpyridinium Cations†

Hydrophobic ionic liquids containing 1-butyl-2,3-dimethylpyridinium [B2M3MPYR], 1-butyl-3,5-dimethylpyridinium [B3M5MPYR], 1-butyl-2-methyl-5-ethylpyridinium [B2M5EPYR], 1-butyl-2,3,5-trimethylpyridinium [B2M3M5MPYR], 1-octyl-2,3-dimethylpyridinium [O2M3MPYR], 1-octyl-3,5-dimethylpyridinium [O3M5MPYR], 1-octyl-2-methyl-5-ethylpyridinium [O2M5EPYR], or 1-octyl-2,3,5-trimethylpyridinium [O2M3M5MPYR] as the cation and bis(trifluoromethanesulfonyl)imide [NTf2], trifluoromethanesulfonate [TfO], dicyanamide [N(CN)2], thiocyanate [SCN] or iodide as the anion have been synthesized, and their physicochemial properties have been studied. Thermal properties, solubilities in water and water contents, UV−vis spectra, densities, refractive indices, electrochemical windows, and toxicities on Vibrio fischeri have been measured. These ionic liquids, most of which are liquid at room temperature, exhibit high refractive indices and increased hydrophobicity. Despite high toxicity values toward V. fischeri, ionic liquids containing a dialkylpyridinium or trialkylpyridinium cation with an octyl chain represent good alternatives to extracting solvents.
Geometrical structure and vibrational frequencies of several electronic states of Si2C

The ground state of the Si2C molecule is found to be a closed‐shell C2v symmetry structure with unusually short Si–C bonds. In these theoretical studies a double zeta plus polarization (DZ+P) basis set was used initially. At the self‐consistent‐field (SCF) level of theory the DZ+P C2v symmetry structure collapses to the linear 1Σ+g state. Extension of the basis set to include a second set of d functions (DZ+2P) on each atom, however, shows the SCF linear state to be a transition state and the C2v structure to be the minimum. Optimization of the linear and C2v symmetry states using configuration interaction (CI) wave functions in conjunction with the DZ+2P basis gives a final prediction that the C2v structure lies 2.1 kcal/mol below linear Si–C–Si.
Research on the Influencing Factors of Purchasing Intention of Brand Agricultural Products from the Perspective of Perceived Value

According to the theory of customer perceived value and brand agricultural characteristics, this paper puts forward that customer perceived value of the brand agricultural products has a functional value, economic value, emotional value, social value and image value of five dimension. Through empirical analysis, it is proved that the existence of five dimensions of perceived value and the five dimensions have significant positive effects on the purchase intention of brand agricultural products, among them, the effect of social value is the largest. And product involvement has a moderating effect on perceived value and purchase intention. Finally, based on the above steps, this paper puts forward the ranking of consumers’ attention to the perceived value dimension, and accordingly provides more accurate marketing countermeasures for enterprises.
Curie temperature of GaMnN and GaMnAs from LDA-SIC electronic structure calculations

We present the electronic structures, magnetic exchange interactions and Curie temperature (TC) of GaMnN and GaMnAs calculated by self-interaction-corrected local-density approximation (LDA-SIC). In GaMnAs, the LDA-SIC results of TC do not differ so much from the LDA results. Both the LDA and LDA-SIC values are in a good agreement with the experimental data. In GaMnN, on the other hand, the ferromagnetic exchange interactions are enhanced due to the suppression of antiferromagnetic super-exchange interaction, resulting in TC higher than the LDA results. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
Non-invasive SFG spectroscopy: a tool to reveal the conformational change of grafted chains due to bacterial adhesion

In many fields such as biomedical or food industry, surface colonization by micro-organisms leads to biofilms formation that are tridimentional biostructures highly resistant to the action of antimicrobials, by mechanisms still unclear. In order to deepen our understanding of the initial interaction of bacteria cells with a solid surface, we analyze by in situ vibrational Sum Frequency Generation (SFG) spectroscopy the effect of the adhesion of hydrophilic Lactoccocus lactis bacteria and its hydrophobic mutants in distilled water on a self-assembled monolayer (SAM) of octadecanethiol (ODT) on a gold film. When a homogeneous bacterial monolayer is deposited on this ordered surface, SFG spectrum of the ODT SAM shows significant intensity changes from that in air or in water. Its modelling as a function of conformation allows to distinguish optical effects due to the water solution surrounding bacteria from conformational changes of the ODT SAM due to the presence of the bacteria cells. Futhermore, bacterial adhesion induces different measurable effects on the ODT SAM conformation, depending on the hydrophobic / hydrophilic character of the bacterial surface. Such a result deserves to be taken into account for the design of new materials with improved properties or to control biofilm formation.
Enhanced second harmonic generation by nanorough surfaces: nanoscale depolarization, dephasing, correlations, and giant fluctuations

On the basis of spectral-expansion Green’s function theory, we theoretically describe the topography, polarization, and spatial-coherence properties of the second-harmonic (SH) local fields at rough metal surfaces. The spatial distributions of the fundamental-frequency and SH local fields are very different, with highly-enhanced hot spots of the SH. The spatial correlation functions of the amplitude, phase, and direction of the SH polarization all show spatial decay on the nanoscale in the wide range of the metal fill factors. This implies that SH radiation collected from even nanometer-scale areas is strongly depolarized and dephased, i.e., has the nature of hyper- Rayleigh scattering, in agreement with recent experiments. The present theory is applicable to nanometer-scale nonlinear-optical illumination, probing, and modification.
Ultrasonic spectrometry for particle size analysis in dense submicron suspensions

Ultrasonic spectrometry was applied to the particle size analysis of disperse systems. The investigations were made for acoustic conditions called the long-wavelength regime (LWR). In the LWR the acoustic behaviour is governed by dissipative effects rather than by scattering. Two principal theoretical approaches to ultrasonic spectrometry — scattering theory and coupled phase models — are introduced. A model based on a newly developed coupled phase model and the scattering theory (ECAH theory) is implemented in the ultrasonic spectrometer Acousto Phor. Experiments were carried out for several suspensions with a high density contrast. It could be demonstrated that the model successfully describes acoustic attenuation and that the inversion algorithm finds particle size distributions comparable to those given by other measurement techniques. With regard to the particle size, a lower and an upper limit for the applicability were determined, which include three decades. As a further result, the model was validated at concentrations up to 10 vol.%. The model is considered to be open to development to cover even higher concentrations.
Monomer Exchange and Concentration Fluctuations of Micelles. Broad-Band Ultrasonic Spectrometry of the System Triethylene Glycol Monohexyl Ether/Water

At four temperatures between 17.5 and 40 °C and several surfactant concentrations, the ultrasonic absorption spectra in the frequency range from 100 kHz to 2 GHz, the sound velocities, and the shear viscosities have been measured for aqueous solutions of triethylene glycol monohexyl ether. At solute concentrations smaller than or close to the critical micelle concentration (cmc), the broad-band spectra reveal one relaxation region reflecting the formation/decay kinetics of oligomeric species. The spectra of the more concentrated solutions show two different relaxations, one subject to a small the other to a broad distribution of relaxation times. The former relaxation is due to the monomer exchange between micelles and the suspending liquid. The parameters of this process largely follow the predictions of the Teubner−Kahlweit theory, which is based on the Aniansson−Wall model of micelle kinetics. Close to the cmc, however, the principal relaxation rate shows a different behavior, which is assumed to also .
Kinetics of stochastic degradation∕evaporation processes in nanoparticle aggregates and polymerlike systems with multiple bonds

Using the graph representation of stochastic degradation∕evaporation processes, general solutions of kinetic rate equations are found and analyzed, describing degradation of complex systems with multiple bonds, such as particle aggregates, fractals, self-arranged systems, double-stranded polymers and polymer networks, biological molecules, etc. The analysis is conducted on the example of thermal fragmentation of aerosol nanoparticles, caused by stochastic evaporation of bonding volatile molecules. A simple analytical approach for the determination of numbers of particles at different degradation stages, undertaking different evolutionary paths, is developed and applied for the analysis of several specific types of aerosol particle aggregates. Significant probabilistic delays are shown to occur during degradation∕fragmentation of intermediate modes, resulting in accumulation of particles in these modes. Conditions for such accumulation are determined and discussed. The obtained results are immediately appl.
Bioremediation of Olive-Mill Wastewaters By Composting

Olive-mill wastewaters (O.M.W.) containing about 7% solids were composted with wheat straw in a forced aeration static pile. Two percent urea was added to ensure a C/N ratio of about 35. To avoid overdosing with water, a fraction of the O.M. W. equal to the weight of the straw was added initially. When composting had reached the thermophilic phase, additional doses of O.M. W. were added every 3 days as water evaporated. The ratio of O.M. W. solids:straw approached 1:1 and the thermophilic phase was extended to 35 days. Temperature, oxygen consumption, pH, C/N, total organic carbon, total extractable carbon, humic and fulvic acids and lignin degradation were followed during the process. The humification was assayed following the degree of humification, the humification rate and the humification index which respectively reached the values of 78%, 37.8% and 0.28 after 2 months. Humic acids were characterized by their elemental composition and molecular weight. A lignin degradation of about 70% was assayed at the end of the thermophilic phase. No phytotoxicity was recorded on the end product, the chemical and physical properties of which suggest its possible use as fertilizer. © 1995 ISWA
Sorption characteristics of peat of Brunei Darussalam V: removal of Congo red dye from aqueous solution by peat

AbstractPeat collected from Panaga, Brunei Darussalam, shows strong affinity towards the adsorption of Congo red (CR) dye from aqueous solution. The adsorption capacity of Bruneian peat under optimized conditions of shaking time, settling time, and medium pH is determined to be 10.1 mg g−1 at equilibrium. Adsorption of CR on Bruneian peat follows monolayer adsorption with small contribution to multilayer formation qualifying the validity of the Redlich–Peterson model, which is further supported by error function determination. In addition, changes in peat structure and surface were studied using scanning electron microscopic and X-ray fluorescence techniques. Kinetics studies were in agreement with the pseudo-second-order model and the adsorption reaction proceeds according to intra-particle diffusion.
Electric field-assisted self-organization of polymer:fullerene hybrids on the photovoltaic performance

In this article, we would like to demonstrate an electric field annealing method to assist the self-organization of a poly(3-hexylthiophene) (P3HT):[6,6]-phenyl-C61-butyric acid methyl ester (PCBM) hybrid without any thermal post-treatment. By applying a DC electric field perpendicular to the substrate during the solvent-drying process, the formation of fibrous P3HT crystalline domains and phase-separated domains of bulk heterojunctions can be achieved, resulting in a power conversion efficiency (PCE) of over 4%. The grazing incidence X-ray diffraction (GIXRD) measurement suggests that the electric field-assisted annealing will facilitate the crystallization of P3HT in both lamellar stacking and vertical stacking, as a result of improved carrier transport and photovoltaic performance. The method of electric field-assisted annealing can easily be integrated into large-area and low-temperature processes, providing a new route to fabricate low-cost and flexible polymer solar cells.
Nanomorphology and Charge Generation in Bulk Heterojunctions Based on Low‐Bandgap Dithiophene Polymers with Different Bridging Atoms

Carbon bridged (C‐PCPDTBT) and silicon‐bridged (Si‐PCPDTBT) dithiophene donor–acceptor copolymers belong to a promising class of low bandgap materials. Their higher field‐effect mobility, as high as 10−2 cm2 V−1 s−1 in pristine films, and their more balanced charge transport in blends with fullerenes make silicon‐bridged materials better candidates for use in photovoltaic devices. Striking morphological changes are observed in polymer:fullerene bulk heterojunctions upon the substitution of the bridging atom. XRD investigation indicates increased π–π stacking in Si‐PCPDTBT compared to the carbon‐bridged analogue. The fluorescence of this polymer and that of its counterpart C‐PCPDTBT indicates that the higher photogeneration achieved in Si‐PCPDTBT:fullerene films (with either [C60]PCBM or [C70]PCBM) can be correlated to the inactivation of a charge‐transfer complex and to a favorable length of the donor–acceptor phase separation. TEM studies of Si‐PCPDTBT:fullerene blended films suggest the formation of an interpenetrating network whose phase distribution is comparable to the one achieved in C‐PCPDTBT:fullerene using 1,8‐octanedithiol as an additive. In order to achieve a balanced hole and electron transport, Si‐PCPDTBT requires a lower fullerene content (between 50 to 60 wt%) than C‐PCPDTBT (more than 70 wt%). The Si‐PCPDTBT:[C70]PCBM OBHJ solar cells deliver power conversion efficiencies of over 5%.
Caracterización clínica, microbiológica y epidemiológica de la enfermedad invasiva por Streptococcus pneumoniae en población pediátrica en Bogotá posterior a la implementación de la vacunación en forma masiva

El Streptococcus pneumoniae es un microorganismo responsable de infecciones graves en la edad pediatrica, produciendo un espectro de enfermedades que van desde infecciones de buen pronostico y manejo sencillo como otitis media aguda y sinusitis hasta infecciones invasivas como bacteremia, meningitis y neumonia asi como complicaciones derivadas de estas. El presente trabajo busca realizar una caracterizacion clinica y epidemiologica de los pacientes que cursaron con enfermedad invasiva por S. pneumoniae en el Hospital de la Misericordia durante los anos 2008 a 2015. Se realizo una busqueda de los pacientes a quienes se aislo en areas normalmente esteriles el germen, y posteriormente se realizo una revision de la historia clinica correspondiente. Se realiza posteriormente una caracterizacion clinica, microbiologica y epidemiologica de la enfermedad invasiva por S. pneumoniae. Se realiza una correlacion del estado vacunal de dichos pacientes con el serotipo causante, y el perfil de resistencia antibiotica de los serotipos aislados. Se hallo que algunos serotipos circulantes no se encuentran dentro del perfil de la vacuna disponible actualmente, concluyendo la importancia de la vigilancia del neumococo y las cepas circulantes en nuestro medio para toma de medidas epidemiologicas para el control de mismo.
Preparation and characterisation of carbon-modified TiO 2 composite

Carbon-modified TiO2 composite was synthesised via the template method and multi-step calcinations by using a tinfoil package. The carbon-coated TiO2 (C–TiO2) composite was characterised via X-ray diffraction, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy and N2 sorption and thermogravimetry. TiO2 was wrapped up in a carbon layer with a thickness of less than 1 nm. The specific surface area and pore volume of C–TiO2 were 95.6 m2g−1 and 0.247 cm3g−1, respectively. The C–TiO2 composite exhibited mesopore structures, showed preferable adsorption capacity for methyl orange and had a higher photocatalytic activity than its unmodified counterpart.
Adsorption of Cu2+ on Epichlorohydrin-Modified Magnetic Fe3O4 Microspheres Prepared by One-Step Solvothermal Synthesis

Monodisperse epichlorohydrin (ECH)-modified magnetic Fe3O4 microspheres (Fe3O4–ECH-n, where n indicates the initial ECH-to-Fe molar ratio) were prepared by a one-step solvothermal method using mono-ethylene glycol. ECH was grafted onto the surface of Fe3O4 microspheres by in situ dehydrochlorination and hydrolysis. The ECH-derived organic groups (e.g. 1, 2-dihydroxypropyl) provide surface functional sites for the adsorption of Cu2+ on Fe3O4–ECH-n. The Fe3O4–ECH-0.8 microspheres were found to have the highest Cu2+ adsorption capacity (17.5 mg/g), and were magnetically recoverable and reusable for Cu2+ adsorption for at least seven times without significant loss in their adsorption capacity. The addition of 2.5 wt% of NaCl significantly enhanced its Cu2+ adsorption (from 17.5 to 28.5 mg/g). The apparent activation energy of the adsorption process was 14.7 kJ mol−1. The adsorption process was endothermic (ΔH° = 11.8 kJ mol−1) and resulted in an increase in the entropy (ΔS° = 56.7 J mol−1 K−1). The negative value of ΔG° ensures that the adsorption occurs spontaneously.
Structural studies of schultenite in the temperature range 125–324 K by pulsed single crystal neutron diffraction — hydrogen ordering and structural distortions

Abstract The structure of the mineral schultenite, PbHAsO4, has been studied using pulsed neutron single crystal diffraction. The low-temperature, low-symmetry structure is found to exhibit substantial ordering of the hydrogen atom onto one of two possible sites, which are equally occupied in the high-temperature phase above 313 K. The occupancies found at low temperature agree well with the normal behaviour for such a hydrogen ordering phase transition in this type of material. In addition the heavy atom lattice distortion has been characterised as a function of temperature and found to follow broadly the pattern of hydrogen ordering. Higher-temperature measurements at and above the phase transition confirm the high symmetry nature of the structure in this region, with no significant distortions from this within the resolution of the present data.
Enhanced selectivity and capacity of adsorption of CO2 and CH4 in zeolite-like metal-organic frameworks with different extra-framework cations: a molecular simulation study

In this study, grand canonical Monte Carlo simulation was carried out to systematically study the effects of extra-framework cations on the capacity of storage and separation of carbon dioxide (CO2) and methane (CH4) in cation-exchanged rho-zeolite-like metal-organic framework (rho-ZMOF). Monovalent (Na+, NH4 + and Li+), divalent (Mg2+ and Sr2+) and trivalent (Al3+) cations with different ion radii were adopted as the representative extra-framework cations. The simulations of the single-component adsorption of CO2 molecules indicate that the varieties in extra-framework cations do not bring evident differences in the dispersion interaction contributions to the isosteric adsorption heats of CO2 but rather the electrostatic interaction contributions. Higher the valence a cation has, stronger the electrostatic interaction with CO2 is and, therefore, a higher storage capacity, though the corresponding accommodation number of the extra-framework cations is smaller. For the cations having the same valence, the storage capacity decreases with the increase in the accessible surface area and total free volume of the host structure. The single-component adsorption isotherms of CO2 and CH4 can be described by a dual-site Langmuir–Freundlich equation. Under typical operating conditions (298 K and 1 atm) in a pressure swing adsorption (PSA) process, the simulation results of the adsorption of CO2 and CH4 mixture demonstrate that the Al-exchanged rho-ZMOF exhibits an unprecedented high selectivity of CO2 over CH4 up to 112, compared with other metal-organic frameworks and nanoporous materials reported to date. Our results suggest that the variation of extra-framework cations is an efficient way to improve the adsorption capacity of the rho-ZMOF for the storage and separation of CO2 and CH4 mixtures using the PSA process at ambient temperature and pressure.
Chemical differentiation of Da-Cheng-Qi decoction and its three analogous decoctions using UFLC-IT-TOF/MS-based chemomic and chemometric approach

A rapid, sensitive and efficient ultrafast liquid chromatography (UFLC)-ion trap time-of-flight mass spectrometry (IT-TOF/MS) coupled with multivariate statistical analysis method has been developed and validated for evaluating chemical differentiation of Da-Cheng-Qi Decoction (DCQD) and its three analogous decoctions. DCQD, Xiao-Cheng-Qi Decoction (XCQD), Hou-Pu-San-Wu Decoction (HPSWD) and Hou-Pu-Da-Huang Decoction (HPDHD), four similar prescriptions of traditional Chinese medicines (TCMs) widely used in the treatment of gastrointestinal diseases, were decocted according to literature and then subjected to UFLC-MS analysis. The data matrix integrating of retention time (tR), mass-to-charge ratio (m/z) pairs, ion intensities and sample codes were processed with principal components analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA). The results indicate significant differences existing among these four decoctions and twenty-six chemical markers were screened out, of which five were from the root and bark of Radix et Rhizoma Rhei, eight from the bark of Magnolia officinalis Rehd and the rest from Fructus Aurantii Immaturus after identification by retention time and MS data. The underlying relationship between the difference in quantity of chemical markers and the difference in pharmacological effect of four similar decoctions is discussed. The LC/MS method combined with chemomic and chemometric approach provided a global research direction of chemical differentiation of DCQD and its three analogous decoctions and laid a foundation for the subsequent comparative pharmacological study of the four decoctions in vivo.