Miracle-dz/UniFAR-FTUs huggingface dataset:
Análisis de los extremos pluviométricos en las Islas Canarias y su relación con el índice NAO

espanolEn este trabajo se han estudiado las tendencias de los eventos extremos de precipitacion en invierno, primavera y otono para el periodo 1970-2010, en las Islas Canarias. Aplicando el estadistico de Mann-Kendall se ha analizado la existencia de tendencias en los indices de extremos. Las tendencias encontradas para los indices pxcdd y pxcwd en la zona occidental junto con las encontradas en los indices de intensidad (px3d, px5d y pint), teniendo en cuenta que las precipitaciones medias muestran, en general, un descenso en la mayor parte de las islas, permiten concluir que existe una tendencia hacia una concentracion de la precipitacion en menos dias, dando lugar a la existencia de episodios mas intensos. Asimismo, el comportamiento de los indices analizados (excepto para pxcdd) es muy similar para el invierno y el otono, siendo diferente al de la primavera. Por otro lado, se ha abordado la posible influencia de la Oscilacion del Atlantico Norte (NAO, North Atlantic Oscillation) en los episodios en los que se registran precipitaciones intensas en las Islas Canarias. Los resultados muestran que en la mitad occidental, la relacion entre estos dias lluviosos y la NAO negativa es evidente, mientras que para en la mitad oriental, hay una mayor frecuencia de eventos de la NAO positiva en los dias con precipitaciones intensas. En cuanto a la relacion existente entre los dias lluviosos que superan el percentil 95 y la NAO extrema positiva (NAO≥1) y extrema negativa (NAO≤-1), se pueden observar pocas diferencias entre la mitad occidental y oriental, aunque la mayor parte de ellos se da para valores neutros del indice NAO. EnglishThis work studies the trends of extreme precipitation events in winter, spring and autumn for the period 1970-2010 in the Canary Islands. The existence of trends in extremes indices has been analysed applying the Mann-kendall statistic. Taking into account that mean precipitation generally shows a decrease in most of the islands, the study of trends found in the pxcdd and pxcwd indices in the west of the region, along with those found in the intensity indices (px3d, px5d and pint), shows a tendency towards a concentration of precipitation events in less days, resulting in the existence of more severe episodes. Furthermore, the behaviour of the analyzed indices (except for pxcdd) is very similar during winter and autumn but it differs in spring. On the other hand, we have addressed the possible influence of the North Atlantic Oscillation (NAO) in heavy rainfall episodes recorded in the Canary Islands. Results show that in the western half of the region, the relationship between days with heavy precipitation and negative NAO is clear, while for the eastern, there is a higher frequency of these events with positive NAO. For the relationship between rainy days exceeding the 95th percentile and extreme positive NAO (NAO ≥ +1) and extreme negative NAO (NAO ≤ -1), we can see few differences between eastern and western half of the Islands. However, most of these very rainy days are present for neutral NAO situations.
Apixaban and RosuvasŁŁtatin Pharmacokinetics in Nonalcoholic Fatty Liver Disease

There is little known about the impact of nonalcoholic fatty liver disease (NAFLD) on drug metabolism and transport. We examined the pharmacokinetics of oral apixaban (2.5 mg) and rosuvastatin (5 mg) when administered simultaneously in subjects with magnetic resonance imaging–confirmed NAFLD (N = 22) and healthy control subjects (N = 12). The area under the concentration-time curve to the last sampling time (AUC0–12) values for apixaban were not different between control and NAFLD subjects (671 and 545 ng/ml 3 hour, respectively; P = 0.15). Similarly, the AUC0–12 values for rosuvastatin did not differ between the control and NAFLD groups (25.4 and 20.1 ng/ml 3 hour, respectively; P = 0.28). Furthermore, hepatic fibrosis in NAFLD subjects was not associated with differences in apixaban or rosuvastatin pharmacokinetics. Decreased systemic exposures for both apixaban and rosuvastatin were associated with increased body weight (P < 0.001 and P < 0.05, respectively). In multivariable linear regression analyses, only participant weight but not NAFLD, age, or SLCO1B1/ABCG2/CYP3A5 genotypes, was associated with apixaban and rosuvastatin AUC0–12 (P < 0.001 and P = 0.06, respectively). NAFLD does not appear to affect the pharmacokinetics of apixaban or rosuvastatin.
Enhanced corrosion protection coatings prepared from soluble electronically conductive polypyrrole‐clay nanocomposite materials

A series of electronically conductive nanocomposite materials that consisted of soluble polypyrrole (PPY) and layered montmorillonite (MMT) clay platelets were prepared by effectively dispersing the inorganic nanolayers of MMT clay in organic PPY matrix via an in situ oxidative polymerization with dodecylbenzene sulfonic acid (DBSA) as dopant. Organic pyrrole monomers were first intercalated into the interlayer regions of organophilic clay hosts and followed by a one-step oxidative polymerization. The as-synthesized electronically conductive polypyrrole–clay nanocomposite (PCN) materials were then characterized by Fourier transformation infrared (FTIR) spectroscopy, wide-angle powder X-ray diffraction (XRD), and transmission electron microscopy (TEM). PCNs in the form of coatings with low clay loading (e.g., 1.0 wt %) on cold-rolled steel (CRS) were found to exhibit much better in corrosion protection over those of pristine PPY based on a series of electrochemical measurements including corrosion potential, polarization resistance, and corrosion current in 5 wt % aqueous NaCl electrolyte. Effects of the material composition on the thermal stability, optical properties, and electrical conductivity of pristine PPY along with PCN materials, in the form of fine powder, powder-pressed pellet, and solution, were also studied by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), UV-visible absorption spectra, and four-point probe technique, respectively. The viscosity of PPY existed in PCN materials and pristine PPY were determined by viscometric analysis with m-cresol as solvent. The heterogeneous nucleating effect of MMT clay platelets in PPY matrix was studied by wide-angle powder XRD. The corresponding morphological images of the nucleating behavior of clay platelets in PPY matrix were investigated by scanning electron microscopy (SEM). © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 3264–3272, 2003
ON THE ROLE OF CARBON DIOXIDE IN THE COMBUSTION OF ALUMINUM DROPLETS

ABSTRACT In this paper, the influence of carbon dioxide on the combustion of aluminum droplets is investigated. Millimeter-sized droplets were heated and ignited by a laser in an aerodynamic levitation system in several CO2 containing atmospheres (H2O/CO2, H2O/CO2/N2) with a large range of compositions (wet – xH2O < 3%, 80/20, 50/50, 12.5/87.5, 50/25/25, 20/40/40). The combustion processes were observed with a high-speed CCD camera, and the droplet radiation was recorded by two optical pyrometers. The ignition occurs with the oxide coating breakdown, which liquefies to form an initial cap moving on the droplet surface. Aluminum vaporizes and burns with the oxidizers as a detached diffusion flame. The droplet regression rate, i.e., the burning rate, strongly depends on the oxidizing atmosphere, from β = 0.58 mm2/s in wet 50% CO2/50% N2 to β = 2.45 mm2/s in 80% H2O/20% CO2. It is shown that CO2 is the worst oxidizer with a smaller “oxidizer efficiency” compared to H2O and O2 . The burning droplet temperature in wet CO2 and in the H2O/CO2 mixtures is around T ≈ 2600 K, and is smaller in H2O/CO2/N2 (T ≈ 2450 K). The non-correlation between the burning rates and the droplet temperatures confirms that the combustion processes are limited by molecular diffusion, and highlights the influence of H2 in the gas-phase transport. An estimation of the exponent n of the “d n law” shows that n decreases with the increase of CO2 from n = 1.7 to n = 0.6. The stagnant burning rates are evaluated as being 7 to 9 times smaller than the measured ones with convective effects. Furthermore, during the droplet regression, the oxide cap dimensions also regress, and it is generally completely removed. Oxide cap regression rates are estimated and are slower than their respective burning rates. Nevertheless, there is a good correlation between the oxide cap regression rate and the droplet temperature that shows that the oxide cap regression results from the chemical decomposition of Al2O3 by the liquid Al droplet producing gaseous AlxOy. For CO2 concentration higher than 40%, a solid phase suddenly appears on the liquid Al surface which entirely covers the droplet leading to the end of the gas-phase combustion. This phenomenon is the consequence of the massive dissolution of carbon in the droplet during burning. Analyses of the unburnt residues showed amounts of dissolved carbon up to 20–23% molar, which is near the saturation concentration limit. Thus, the solid coating corresponds to the ejection of carbon from the droplet because of its continuing regression and is expected to be also present for smaller particles. Therefore, carbon dioxide plays a double role. First, it participates in the gas-phase combustion, but it is the worse oxidizer with smaller burning rates. Second, CO2 causes the carbon dissolution in the Al droplet and finally stops the gas-phase burning. A further implication could be that carbon dioxide may promote the appearance of a combustion regime with surface reactions only.
Carbon nanotube‐hybridized supramolecular hydrogel based on PEO‐b‐PPO‐b‐PEO/α‐cyclodextrin as a potential biomaterial

In virtue of the potential biomedical application of carbon nanotube (CNT), the CNT was hybridized into a supramolecular hydrogel based on the selective inclusion of α-cyclodextrin (α-CD) onto poly(ethylene oxide) (PEO) segments of a triblock copolymer, i.e., PEO-block-poly(propylene oxide)-block-PEO. Different from the previous report, the content of α-CD, in contrast to that of ethylene oxide unit, was decreased to decrease the network density in hydrogel and hence improve the diffusion of encapsulated substances. As a result, the modulus of the hydrogels climbed slightly after introducing CNT. Furthermore, as the essential properties for wound dressing, the antimicrobial activity, the skin-adhesion, and water-retention of such supramolecular hybrid hydrogels were also verified. On the other hand, the supramolecular hybrid hydrogels inherited the shear-thinning property and are suitable as an injectable biomaterial. The cell viability assay confirmed the equivalent cytotoxicity of the supramolecular hybrid hydrogels to that of the native hydrogels without CNT. Consequently, such CNT-hybridized supramolecular hydrogel shows a great potential in the biomedical application. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
CHEMICAL COMPOSITION OF ESSENTIAL OIL OF MENTHA LONGIFOLIA L. SUBSP. LONGIFOLIA GROWING WILD

The essential oil of Mentha longifolia L. , is very important to some culinary usage and antimicrobial activity. The essential oil of Mentha longifolia subsp. longifolia growing in the Bahçesaray area (Van Province, Turkey) was studied. This study designed for determine of essential oil constituent Mentha longifolia subsp. longifolia that collected from wild area. Mint leaves sample essential oils obtained by hydro distillation and essential oil components were determined using GC-MS. The main component of wild grown Mentha longifolia subsp. longifolia was Menthone (19.31%). Second one and others were Pulegone (12.42%), Piperitone (11.05%), Dihydrocarvon (8.32%), Limonene (6.1%), 3-Terpinolenone (5.66%), 1,8-Cineole (4.37%), Germacrene D (3.38%) and Caryopyllene (3.19%), respectively.
[Cr(phen)(ox)2]−: a versatile bis-oxalato building block for the design of heteropolymetallic systems. Crystal structures and magnetic properties of AsPh4[Cr(phen)(ox)2]·H2O, [NaCr(phen)(ox)2(H2O)]·2H2O and {[Cr(phen)(ox)2]2[Mn2(bpy)2(H2O)2(ox)]}·6H2O

The new complexes of formula AsPh4[Cr(phen)(ox)2]·H2O (1), [NaCr(phen)(ox)2(H2O)]·2H2O (2) and {[Cr(phen)(ox)2]2[Mn2(bpy)2(H2O)2(ox)]}·6H2O (3) (AsPh4=tetraphenylarsonium cation; phen=1,10-phenanthroline; ox=oxalate dianion; bpy=2,2′-bipyridine) have been prepared and characterized by single-crystal X-ray diffraction. The structure of 1 consists of discrete [Cr(phen)(ox)2]− anions, tetraphenylarsonium cations and uncoordinated water molecules. The chromium environment in 1 is distorted octahedral with Cr–O bond distances between 1.959(3) and 1.947(3) A and Cr–N bonds of 2.083(4) and 2.072(4) A. The angles subtended at the chromium atom by the two oxalates are 83.6(2) and 83.3(1)° whereas the N–Cr–N angle is 79.9(2)°. The [Cr(phen)(ox)2]− unit of 1 is also present in 2 and 3 but it accomplishes different coordination functions, acting as a bridging (2) or terminal (3) ligand. 2 has a layered structure made up of oxalato-bridged bimetallic CrIII–NaI helical chains that are interconnected through centrosymmetric Na2O2 units. The two oxalates of [Cr(phen)(ox)2]− in 2 are bis-chelating within the bimetallic chain but one of them is in addition monodentate towards a sodium atom of a neighbouring chain, yielding a sheetlike structure. The sodium atom in 2 has a distorted octahedral geometry with five Na–O(ox) bonds ranging from 2.453(5) to 2.319(4) A and the sixth position being occupied by an aqua ligand with Na–O(w)=2.384(6) A. The intralayer chromium–sodium and sodium–sodium separations through bridging oxalate in 2 are 5.560(4) and 3.643(8) A, respectively. The structure of 3 consists of neutral tetranuclear Cr2IIIMn2II units in which two terminal [Cr(phen)(ox)2]− entities act as monodentate ligands towards a central oxalato-bridged manganese(II) dimer. Each manganese atom is six-coordinated as MnN2O4: two nitrogen atoms of a chelating bpy, one aqua ligand and three oxalate oxygens build a distorted octahedron around the manganese atom. The Mn–O(ox) and Mn–N(bpy) bond lengths vary in the ranges 2.219(12)–2.160(13) and 2.33(2)–2.14(2) A, respectively. The intramolecular chromium–manganese separation [5.507(5) and 5.502(5) A for Cr(2)···Mn(2) and Cr(1)···Mn(1)] is somewhat shorter that the manganese–manganese one [5.703(2) A]. The magnetic properties of 1–3 have been investigated in the temperature range 1.9–300 K. Very weak antiferromagnetic interactions between the chromium centers are observed in 1 and 2 in agreement with their crystal structures. In the case of 3, significant intramolecular antiferromagnetic interactions between the adjacent chromium(III) and manganese(II) ions ( j=−1.1 cm−1, through the chelating/monodentate oxalato) and between the two manganese(II) ions (J=−2.2 cm−1, through the bis-chelating oxalato) occur, the Hamiltonian being defined as Ĥ=−JŜMn1· ŜMn2−j[ŜCr1·ŜMn1+ŜCr2·ŜMn2].
A comprehensive thermodynamic theory of the Soret effect in a multicomponent gas, liquid, or solid

A comprehensive theory for the Soret effect (also called thermal diffusion) is presented which incorporates both the thermodynamic contribution from selective attraction/repulsion and the kinetic contribution from selective collision interaction between the components. The new theory is an extension of a theory presented earlier in which the thermodynamic contribution only was modeled. The single assumption of the theory is that the Soret effect in the steady state is the macroscopic state accomplished by a maximum number of microstates with respect to the ideal gas state. As a result, the Soret effect in a multicomponent mixture can be calculated by using input from an equation-of-state of the mixture and kinetic gas theory without the use of matching parameters. The theory is not limited to systems with a small temperature difference and/or a small concentration difference. The methodology of the new theory can be used to model other cross-effects in irreversible thermodynamics. A test of the theory aga.
Adhesion and tribological properties of hydrophobin proteins in aqueous lubrication on stainless steel surfaces

Macroscale tribological properties of hydrophobin layers bound on stainless steel surfaces were investigated in an aqueous environment. Emphasis was on boundary lubrication because water easily fails in hydrodynamic lubrication due to its low viscosity. We studied the affinities of two different proteins, HFBI and FpHYD5, on stainless steel and their ability to bind water at the surface by combining quartz crystal microbalance (QCM-D) and ellipsometry. Both proteins contained an adhesive hydrophobic domain, but FpHYD5 also had a very strongly hydrating carbohydrate structure attached to it. The lubrication properties of the proteins were studied with two different methods, pin-on-disc (POD) (stainless steel vs. stainless steel) and circular translation pin-on-disc (CTPOD) (UHMWPE vs. stainless steel). It was observed that both hydrophobins could adhere to the stainless steel surface and form highly hydrated layers. Both proteins reduced friction and wear of the sliding contact between two stainless steel surfaces. With UHMWPE against stainless steel, the hydrophobins prevented the polyethylene transfer to the counterface. The lowest coefficient of friction (COF) 0.13 was observed when FpHYD5 hydrophobins were employed in pure water. On the other hand, the lowest wear was observed when FpHYD5 proteins were added in a 50 mM sodium acetate buffer. Increasing the water content and loosening the hydrophobin film structure on the stainless steel surface led to a reduction in friction and wear.
Determination of Centrifugal Distortion Coefficients of Asymmetric‐Top Molecules

The rotational Hamiltonian of an asymmetric‐top molecule in a given vibrational state, obtained by the usual vibrational perturbation treatment, contains more parameters than can be determined from the observed energy levels. This Hamiltonian is therefore transformed by means of a unitary transformation to a reduced Hamiltonian which is suitable for fitting to observed energies. The unitary transformation can be chosen so that the reduced Hamiltonian has the following properties: (i) It is totally symmetric in the point group D2, regardless of the symmetry of the molecule; (ii) It contains only (n+1) independent terms of total degree n in the components of the total angular momentum, for each even value of n; (iii) Its matrix elements in a symmetric‐top basis satisfy the selection rule ΔK=0, ±2. This paper is concerned mainly with the possibility of carrying out this reduction in general. However, the reduced Hamiltonian described above contains one less quartic coefficient than has been used previously, .
Hydrolytic Stabilities of Halogenated Disinfection Byproducts: Review and Rate Constant Quantitative Structure–Property Relationship Analysis

Abstract As toxicity studies of disinfection byproducts (DBPs) progress, enhanced knowledge of the stability of DBPs can help determine the likelihood of DBP occurrence in water and thus enable accurate exposure assessments. To elucidate the roles of functional group, halogen number, and halogen type on the hydrolytic stability of halogenated DBPs, this study reviewed the hydrolysis rate constants (kH) of six groups of DBPs, including haloacetic acids, trihalomethanes, haloacetaldehydes, haloketones, haloacetonitriles, and cyanogen halides. Quantitative structure–property relationship models were developed and validated via previously tested compounds, and by extrapolation, these models were projected to nontested chemicals of emerging health concern, especially iodinated DBPs. In general, the kH values follow the order haloketone > haloacetonitrile > haloacetaldehyde >haloacetic acid > trihalomethane for chlorinated and brominated species, increase with increasing number of halogen atoms within one DBP g.
Effect of Stabilized Rice Bran Fractions on the Formation of Rice Flour Pasting Properties

ABSTRACT Rice flour composition played a key role in determining the changes in pasting properties of rice flour. The influence of incorporating defatted rice bran (DFRB), rice bran fiber (RBF), rice bran protein (RBP), and stabilized rice bran (SRB) fractions on the mechanism of rice flour pasting viscosities was investigated. Pasting properties of long- and medium-grain rice flour substituted with 5, 10, 15, 20, and 100% bran fractions resulted in a significant decrease (P < 0.05) in rice flour pasting property values. Flour substituted with RBP had the lowest pasting property measurements compared with other fractions, and the greater the percentage substituted, the lower the pasting property values. DFRB and RBF were least affected properties when used as a replacement. Results were attributed to the contribution of rice starch in the mechanism of rice paste formation, in which decreasing starch in a rice flour sample, as a result of substituting with fractions of SRB, may have resulted in faster swel.
Mechanism of Adsorption of Water Vapor by Muscovite: A Model Based on Adsorption Calorimetry

Adsorption isotherms and differential heats of adsorption of water vapor by muscovite were measured at 303 K. The heats of adsorption are stepwise and each step corresponds to the stoichiometric formation of adsorption complexes of H2O molecules with K+ ions, (H2O)n/K+, (n = 1–6), which are located on the basal and lateral (edge) faces. At saturation, the ditrigonal cavities of the basal faces are fully occupied by hexameric clusters. It is suggested that half of the K+ ions on the basal faces come from neighboring layers by migration under the influence of the adsorbed H2O at the initial stage of adsorption. Similar migration of K+ to the edges was also hypothesized, suggesting that only every second site can be occupied by a cluster. At the final stage of adsorption, H2O molecules are believed to form H-bonded bridges between the hexameric water/cation clusters on the basal faces, whereas on the edge faces no such effect is believed to occur. The mean molar integral adsorption entropy of water is ∼−7 J/mol K less than the molar entropy of the bulk liquid. The mobility of H2O on muscovite is slightly less than in bulk water. Migration of K+ cations under the influence of adsorbed H2O both on the basal and lateral faces of muscovite is reversible.
Chemical Structures Present in Biofuel Obtained from Lignin

Technical lignins from various sources can be converted into bio-oil with a low O/C ratio by pyrolysis in the presence of formic acid and an alcohol. By application of different analytical techniques, such as Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR), electrospray ionization mass spectrometry (ESI-MS), and size-exclusion chromatography (SEC), it has been shown that a complete degradation of the lignin takes place irrespective of the origin. The resulting bio-oil has a low-molecular-mass distribution with a preponderance of aliphatic hydrocarbon structures. A substantial number of phenolic compounds are, however, also present, and some of these also contain carboxyl groups. The results clearly show that formic acid is a powerful supplier of atomic hydrogen. By further optimization of the pyrolysis reaction, it should be possible to further reduce the content of aromatic structures.