Miracle-dz/UniFAR-FTUs huggingface dataset:
Rational design of organoboron heteroarene derivatives as luminescent and charge transport materials for organic light-emitting diodes

A series of organoboron heteroarene derivatives have been designed for applications in organic light-emitting diodes (OLEDs). Their optical, electronic, and charge transport properties have been explored theoretically by using density functional theory (DFT) and time-dependent DFT (TD-DFT). The frontier molecular orbitals (FMOs) and local density of states analysis have turned out that the vertical electronic transitions of absorption and emission are characterized as intramolecular charge transfer (ICT). The calculated results show that their optical, electronic, and charge transport properties are affected by the different heteroaromatic groups. Our results reveal that the molecules under investigation can serve as luminescent materials for OLEDs. In addition, molecules under investigation are expected to be promising candidates for hole and/or electron transport materials. We have also predicted the mobility of the studied compounds. On the basis of investigated results, we proposed a rational method for the design of luminescent materials as well as charge transport materials simultaneously for OLEDs.
Photosynthesis, ion accumulation, antioxidants activities and yield responses of different cotton genotypes to mixed salt stress

This study analyzes the effects of soil salinity on photosynthetic character, osmoregulation, content of pigment, K+/Na+ ratio, lipoxygenase and antioxidants activities in functional leaves during the flowering and boll-forming stages of two cotton cultivars, namely, CCRI-44 (salt-tolerant) and Sumian12 (salt-sensitive), grown under different soil salinity conditions. In the control plants, non-significant differences were found in gas exchange, saturation irradiance (SI) and carotenoid (Car) content between the two cultivars. However, it showed higher K+/Na+ ratio, antioxidant enzyme activities, soluble sugar and protein contents, and lower chlorophyll (Chl) content and yield in CCRI-44. Salinity stresses remarkably increased soluble sugar and protein contents, lipoxygenase and the antioxidant activities, but decreased K+/Na+ ratio, Chl and Car contents, SI, photosynthetic capacities and yield, the extent being considerably larger in Sumian12 than CCRI-44. Although the soluble sugar, protein contents and the antioxidant activities of Sumian12 elevated more evidently under salt stresses, those variables never reached the levels of CCRI-44. Thus, CCRI-44 could maintain higher seed cotton yield than Sumian12 by sustaining higher osmoregulation and antioxidative abilities, which led to higher photosynthetic capacity. Hence, the salt-tolerant cotton cultivars could harmonize the relationship between CO2 assimilation (source) and the seed cotton yield (sink) under the experimental conditions. Key words: Cotton (Gossypium hirsutum L.), mixed salt stress, salt tolerance, photosynthesis, ion accumulation, antioxidant enzyme activity, seed cotton yield.
Pfg NMR studies of lateral diffusion in oriented lipid bilayers

The pfg-NMR diffusion technique is proposed to have an appreciable potential for future biophysical investigations in the field of membrane biology. Topics like transport of molecules both across and in the plane of the membrane can be successfully studied, as well as the formation of lipid domains and their intrinsic dynamics can be scrutinized. This short review will introduce the fundamental aspects of orientation dependent NMR interactions and the technique of macroscopically oriented bilayers for eliminating the unwanted effects of those interactions. The pfg-NMR technique will be briefly introduced and finally, some recent results illustrating the potential of the method are presented.
New potential model for molecular dynamic simulation of liquid HF. I—Parameter optimization for charge equilibration method

In order to build a complete potential model to perform classical molecular dynamic simulations of liquid HF, a new optimization method is proposed to obtain transferable parameters for charge equilibration method on the basis of ab initio reference data. The optimized parameters (the electronegativity χ and the Slater orbital exponent ζ for H and F atoms) appear to be able to reproduce the variations of the electrostatic potential calculated from an ab initio method in a liquid phase of HF molecules for different thermodynamic conditions. It is concluded that the proposed method is general, precise and efficient to obtain transferable and realistic parameters.
High-molecular-weight poly(p-phenyleneterephthalamide) by CaCl2 promoted direct polycondensation with thionyl chloride in N-methylpyrrolidone

The direct polycondensation of terephthalic acid and p-phenylenediamine hydrochloride (PPD.2HCl) with thionyl chloride was found to be significantly promoted in N-methylpyrrolidone (NMP) by dissolved CaCl2 and tertiary amines. The inherent viscosity of the polymer obtained varied with the amount of CaCl2 and tertiary amines added. The reaction, when effectively promoted by CaCl2, proceeded homogeneously in the early state of polycondensation, and then resulted in a highly swollen gel. CaCl2 had to be present in the PPD.2HCl/tertiary amines/NMP solution as well as in the TPA/SOCl2/NMP mixture for the polycondensation to proceed to high molecular weight. Complexes of CaCl2, PPD.2HCl, and tertiary amines in NMP similar to the well known complex, CaCl2 · nNH3 (n = 2, 4, 8) was proposed to facilitate the polycondensation.
The Role of Adaptive Immunity in Chronic Hypoxia-Induced Pulmonary Hypertension

Inflammation is a prominent pathologic feature in pulmonary arterial hypertension as demonstrated by pulmonary vascular infiltration of inflammatory cells, including T and B lymphocytes. However, the contribution of the adaptive immune system is not well characterized in pulmonary hypertension (PH) caused by chronic hypoxia (CH). Inflammatory cells, through various mechanisms, have the capability to increase pulmonary vascular resistance in various disease states. CD4 T cells have the potential to play a significant role in the disease process initiated by hypoxia. CD4 T cells are largely responsible for orchestrating downstream immune processes and are critical in focusing and amplifying inflammatory responses by other immune effector cells. Actions of CD4 T cells are essential for the full development of adaptive immune
Kinetics of the Pyrolysis of Lignin Using Thermogravimetric and Differential Scanning Calorimetry Methods

The thermal behavior of a hardwood lignin found in Eastern Canada was investigated by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). Kinetic parameters were determined for pyrolysis of lignin from room temperature to 300 at 15 °C·min −1. The maximum rate of thermal destruction of lignin occurred between 246−259 °C. The DSC thermogram of lignin showed an endothermic peak at approximately 113 °C. The kinetic model was applied, and the activation energy for the lignin was calculated. The weight loss data showed first order decomposition with Arrhenius behavior. The activation energy value obtained for lignin was in the range of 8−68 kcal·mol −1. The results showed that the kinetic model fitted the data well in the specific range of temperatures. The present model was also compared with the experimental data available in the literature, and the comparisons of E a values are tabulated.
Field-dependent [M-2H]+. formation in the field desorption mass spectrometric analysis of hydrocarbon samples

High-boiling hydrocarbons often yield abundant [M − 2H] +. ions under the conditions of field desorption mass spectrometry (FDMS). This work evaluated [M − 2H] +. formation from various saturated and aromatic compounds. The most intense [M − 2H] +. signals observed resulted from the analysis of saturated compounds containing long and branched chains. The presence of an aromatic ring in a molecule, however, strongly diminished [M − 2H] +. formation during FDMS. Experiments involving manipulation of the applied potential between the FD anode and cathode reveal the strong field dependence of this phenomenon. At a potential difference of 10 kV, strong [M − 2H] +. formation occurred for samples including squalane, hexatriacontane (C 36 n-alkane) and a Polywax 655 mixture. Analyses of the same samples conducted at a potential difference of 4kV produced only weak (if measurable) [M-2H] +. signals. The magnitude of [M-2H] +. formation also decreased as the sample quantity decreased
Mechano-chemical control of cell behaviour by elastomer templates coated with biomimetic Layer-by-Layer nanofilms

Within the field of biomaterials, the control of cell–surface interactions is generally addressed through surface chemistry modification. In this respect, Layer-by-Layer (LbL) coatings constitute promising versatile tools. Most cells are mechanosensitive, therefore the stiffness of their microenvironment should also be considered as a crucial parameter when designing polymer-based biomaterials. Here, we report on the combination of mechanics and surface chemistry of LbL-treated polydimethylsiloxane substrates of tunable stiffness to control cell behaviour. Biomimetic LbL films consist of poly-L-lysine (PLL) and chondroitin-4-sulfate (CSA). Stiffness, surface chemistry, wettability and topography of bare and LbL-treated polydimethylsiloxane were analysed. We demonstrated that cells adhered and grew up on all the substrates with significant promotive effects of PLL-terminated films and stiffer substrates. Pre-osteoblasts differentiation was enhanced onto PLL-terminated films irrespective of stiffness and onto CSA-terminated films in a mechanical dependent manner. These results open outlooks within the field of bone tissue engineering, as they demonstrate that osteoconductive surfaces can be obtained by combining uncrosslinked biomimetic LbL films and the intrinsic mechanical properties of the substrates, that is, without any commonly used, potentially cytotoxic chemical crosslinking.
Development and evaluation of the aerosol dynamics and gas phase chemistry model ADCHEM

Abstract. The aim of this work was to develop a model suited for detailed studies of aerosol dynamics, gas and particle phase chemistry within urban plumes, from local scale (1 × 1 km 2 ) to regional scale. This article describes and evaluates the trajectory model for Aerosol Dynamics, gas and particle phase CHEMistry and radiative transfer (ADCHEM). The model treats both vertical and horizontal dispersion perpendicular to an air mass trajectory (2-space dimensions). The Lagrangian approach enables a more detailed representation of the aerosol dynamics, gas and particle phase chemistry and a finer spatial and temporal resolution compared to that of available regional 3D-CTMs. These features make it among others well suited for urban plume studies. The aerosol dynamics model includes Brownian coagulation, dry deposition, wet deposition, in-cloud processing, condensation, evaporation, primary particle emissions and homogeneous nucleation. The organic mass partitioning was either modeled with a 2-dimensional volatility basis set (2D-VBS) or with the traditional two-product model approach. In ADCHEM these models consider the diffusion limited and particle size dependent condensation and evaporation of 110 and 40 different organic compounds respectively. The gas phase chemistry model calculates the gas phase concentrations of 61 different species, using 130 different chemical reactions. Daily isoprene and monoterpene emissions from European forests were simulated separately with the vegetation model LPJ-GUESS, and included as input to ADCHEM. ADCHEM was used to simulate the ageing of the urban plumes from the city of Malmo in southern Sweden (280 000 inhabitants). Several sensitivity tests were performed concerning the number of size bins, size structure method, aerosol dynamic processes, vertical and horizontal mixing, coupled or uncoupled condensation and the secondary organic aerosol formation. The simulations show that the full-stationary size structure gives accurate results with little numerical diffusion when more than 50 size bins are used between 1.5 and 2500 nm, while the moving-center method is preferable when only a few size bins are selected. The particle number size distribution in the center of the urban plume from Malmo was mainly affected by dry deposition, coagulation and vertical dilution. The modeled PM2.5 mass was dominated by organic material, nitrate, sulfate and ammonium. If the condensation of HNO 3 and NH 3 was treated as a coupled process (pH independent) the model gave lower nitrate PM2.5 mass than if considering uncoupled condensation. Although the time of ageing from that SOA precursors are emitted until condensable products are formed is substantially different with the 2D-VBS and two product model, the models gave similar total organic mass concentrations.
Dynamics of reversible networks

We present a model for dynamics of entangled networks made up of linear chains with many temporary cross-links. At times shorter than the lifetime of a cross-link such networks behave as elastic rubbers (gels). On longer time scales the successive breaking of only a few cross-links allows the chain to diffuse along its confining tube. The motion of a chain in this hindered reptation model is controlled by the concentration and lifetime of tie points. We calculate the self-diffusion coefficient and discuss the stress relaxation in terms of molecular parameters, including the chain length, the number of cross-linking groups per chain, and the lifetime and probability of formation of cross-links. We find good agreement with recent experiments by Stadler et al. on model thermoplastic elastomers.
Direct determination of ethanol in all types of alcoholic beverages by near-infrared derivative spectrometry

A rapid and accurate method has been developed for the direct determination of ethanol in all types of alcoholic beverages. The method, which does not require any sample treatment (except for simple de-gassing for beer samples or dilution with distilled water for spirits), is based on the use of the first derivative of the near-infrared absorbance spectrum. Measurements, carried out between the 1680 nm peak and the 1703 nm valley, provide a typical calibration graph [dA/dλ= 0.00002+ 0.0127 c(where c is the concentration of ethanol in % v/v)] for a concentration range up to 25% v/v with a regression coefficient of 0.999992 and a limit of detection (for k= 3) of 0.1% v/v. The interference of sugars in the determination of ethanol can be seen by the presence of bands in the derivative spectrum in the range between 1300 and 1800 nm and can be corrected. Results comparable to those found by a reference pycnometric procedure or by gas chromatography were obtained when the proposed method was applied to the determination of ethanol in beer, white and red wines, whisky, gin and rum samples and also in sweet wines and fruit liqueurs.
FROM FOURIER SERIES TOWARDS CRYSTAL STRUCTURES A survey of conventional methods for solving the phase problem

This introduction to the phase-problem in crystallography is addressed to those who are not familiar with the standard techniques used for crystal structure determination. Whereas the basic concepts of Fourier synthesis and the related phase-problem are introduced in the first section, the second part focuses on some methods that have successfully been used to solve structures from electron data, i.e. crystallographic image processing (CIP) of high-resolution electron microscopy images, Patterson vector-maps and conventional direct methods.
Analysis of 5-Hydroxymethyl-2-Furfuraldehyde in Electrolytic Products and Energy Drink Products

Electrolytic products and energy drink products are used as electrolyte to heal diarrehoea, energy serving for athlete and labour people.Both products contain the main component such as sodium ion, potassium ion ,sugar, artificial flavor and colour. 5-Hydroxymethyl-2-furfuraldehyde(HMF) is the one product from browning reaction in food. It was claimed as a toxic substance. The aim of this work was to analyse HMF content in electrolytic products and energy drink products by High Performance Liquid Chromatography. The optimum conditions for analysis HMF were studied and validated method, then applied for analysis HMF content in products. The optimization method showed that HMF could be eluted with isocratic elution by the mixture of water/acetonitrile (90:10, v/v) that controlled flow rate at 1.5 ml/min. and detected at 280 nm by diode array detector (DAD). The limit of detection (LOD) and limit of quantitation (LOQ) were 0.89 µg/L and 2.9 µg/L, respectively. The relative standard deviation(%RSD) ( replicate numbers = 10) was 0.55%. The HMF could be detected in both samples products within the range of 0.03- 6 mg/L.This work proved that the toxic substance such as hydroxymethylfurfuraldehyde present in the electrolytic products and energy drink products, so the consumer should care about the using of electrolytic products.
Radiocarbon Content of PM2.5 Ambient Aerosol in Tampa, FL

Radiocarbon ( 14 C) measurements showed substantial levels of biogenic carbon, 52 to 89%, in PM2.5 samples collected near Tampa, Florida, during May 3–22, 2002. Nighttime biogenic percentages tended to be higher than daytime percentages. The average PM2.5 biogenic carbon concentration was 2.4 μ g m − 3 . The 14 C (and carbon mass concentration) results were highly reproducible, based on duplicate analyses of samples from collocated samplers. The work includes a first-time treatment of the potential for distortion of the 14C results by organic artifact during sampling, and a re-consideration of the impact on present-day 14 C results of the mid-twentieth century “bomb” effect. Neither was found to have a significant impact on the 14 C results. Concurrent organic and elemental carbon measurements were used to provide estimates of secondary organic aerosol (SOA) in the samples. The results of this study closely resemble those found in other summertime studies near Nashville, Tennesse (1999) and near Houston, Texas (2000) with regard to the joint importance and connection of biogenic PM2.5 and SOA in the Southeastern U.S. during summertime.
Mass transfer of SO2 absorption with an instantaneous chemical reaction in a bubble column

Gas absorption accompanied by an instantaneous irreversible chemical reaction in bubble columns has been analyzed theoretically. A mass transfer model based on the Dankwerts surface-renewal model as well as the penetration theory for surface stretch proposed by Angelo et al. was developed, in which the effects of bulk motion and turbulence on mass transfer were taken into account. The analytical expressions for the time-average mass transfer coefficient and the enhancement factor have been obtained. The fast reactive absorption of SO2 from gas mixtures into aqueous NH4HCO3 solution was investigated experimentally in a bubble column reactor to validate the mass transfer model, and the results calculated by the present model agree well with the experimental results.
A simple and efficient method for the solid‐phase extraction of dissolved organic matter (SPE‐DOM) from seawater

A simple protocol is presented for the solid‐phase extraction of dissolved organic matter (SPE‐DOM) from seawater using commercially prepacked cartridges. The method does not require major instrumentation and can be performed in the field. Modified styrene divinyl benzene polymer type sorbents (Varian PPL and ENV) and sorbents of a silica structure bonded with different hydrocarbon chains (Varian C8, C18, C18OH, and C18EWP) were considered. Except for C18OH, which heavily contaminated the samples, none of the sorbents leached significant amounts of dissolved organic carbon (DOC) or nitrogen (DON). Samples from the North Brazil shelf with strong mixing gradients of terrigenous and marine DOM were used to compare the various sorbents. PPL was the most efficient—on average, 62% of DOC was recovered as salt‐free extracts. C18 was found to be most efficient among the silica‐based sorbents, but it showed only two‐thirds of the extraction efficiency of PPL. As indicated by [1H]NMR, C/N, and δ13C analyses, PPL extracted a more representative proportion of DOM than C18. Therefore, PPL was used for comparative studies in the Gulf of Mexico and Antarctica. From brackish marsh and river waters, 65% and 62% of total DOC, respectively, could be extracted. For purely marine DOM in Antarctica and the deep sea, the extraction efficiency was lower (43% on average). The efficiency of the new method to isolate marine DOM is better than or similar to highly laborious methods. A further advantage is the complete desalination of the sample. The isolation of a major DOM fraction, which is salt‐free, offers many possibilities to further characterize DOM by advanced analytical techniques.
Electrical and polarization behaviour of titania nanoparticles doped ferroelectric liquid crystal

The present study focuses on the effect of anatase TiO2 (titania) nanoparticles (NPs) on conductivity and polarization in a ferroelectric liquid crystal (FLC). Different dielectric and electro-optical measurements have been conducted to explore the charge transportation and polarization mechanism in titania NPs doped FLC system. Doping of titania NPs show reduced dc conductivity of doped LC system attributed to the trapping of free charges by titania NPs at its surface. Polarization has been found to increase at low fields indicating reduction of field screening effect in doped FLC system. Optical response of the doped FLC system has been improved due to decreased intervention of ionic charges particularly at small electric fields. The present study will be helpful in minimizing the slow response problems and the grey level shift in liquid crystal devices which arise due to ionic effects. Copyright © 2015 VBRI Press.
X-Ray absorption spectroscopy investigations of the hydrophobic hydration of krypton at high pressure

The development of third-generation synchrotron radiation sources has created considerable opportunities for the investigation of systems under extreme sample conditions of pressure and temperature. This paper presents the application of a recently developed pressure cell and pressurization and circulation system to the investigation of the hydrophobic hydration of noble gases by X-ray absorption spectroscopy. This system operates in the pressure range from 1 bar to 1 kbar, and allows for mixing of gaseous and liquid components and the control of the ultimate gas in liquid concentration. First results demonstrate the remarkable resilience of the first hydration shell of a nonpolar solute (krypton) to the application of pressure in the 150 bar to 700 bar range. These results suggest questioning the conclusions of some recent computer simulations, in particular with regards to the potential impact of such studies on our understanding of pressure induced protein denaturation.