Miracle-dz/UniFAR-FTUs huggingface dataset:
Global optimization-based method for deriving intermolecular potential parameters for crystals

A new global optimization-based method for deriving parameters of atom-atom potentials for crystals has been developed. The method consists of two parts (force minimization and a novel Monte Carlo method, Vector Monte Carlo [VMC]) to minimize a vector target function consisting of three components. The first component depends on the rank of the minimized experimental structure among all structures found by a global search; the second one is a function that allows minimization of deviations between experimental and minimized experimental structures; and the third one is a penalty function that provides the best fit to the available heats of sublimation. The method enables the limitations of any chosen form of the potential to be evaluated and finds the best possible set of parameters for a given form. The method has been applied to sets of saturated hydrocarbon and ether molecules. For hydrocarbons, the resulting set of potential parameters describes observed crystal structures with high accuracy. Significant improvement was achieved in the case of ethers for which the experimental structures of the selected molecules (except dioxane) were stable upon local energy minimization and were found as global minima of the refined potential. Our results for dioxane are in agreement with those of Mooij et al. (J. Phys. Chem. A 1999, 103, 9883) and show that potential energy calculations with simple "6-exp-1" energy functions are not adequate for predicting the crystal structure of dioxane.
Nanohybrid membranes with hydroxide ion transport highways constructed from imidazolium-functionalized graphene oxide

Graphene oxide (GO) and functionalized GO have been widely employed to design and fabricate polymer–inorganic nanohybrid materials for electrochemical applications. In this study, a series of imidazolium-functionalized graphene oxide (ImGO) nanosheets bearing different types of ligands (namely butyl, decyl, carbethoxy, and benzyl groups) on quaternary ammonium (QA) groups are prepared via distillation–precipitation polymerization and quaternarization, and then embedded into chitosan (CS) to fabricate nanohybrid membranes. The addition of ImGO significantly enhanced the thermal, mechanical, and anti-swelling stabilities of membranes due to the strong electrostatic attractions at CS/ImGO interface. More importantly, hydroxide ion transport highways were constructed at CS/ImGO interface via interfacial interactions. Meanwhile, the influence of the ligands on QA groups on the physicochemical properties, OH− conductivity, and conduction mechanism is systematically elucidated. Due to the optimal hydrophilicity and ion exchange capacity, ImGO with carbethoxy group as the ligand confers the highest OH− conductivity on nanohybrid membrane (up to 1.02 × 10−2 S cm−1 at 90 °C and 100% RH, about four times of that of CS control membrane). Correspondingly, a fuel cell with such a membrane shows an OCV of 0.71 V and a maximum power density of 75.8 mW cm−2 at a current density of 298.8 mA cm−2.
Detection of propofol concentrations in blood by Raman spectroscopy

In this paper we present a proof-of-concept of a Raman spectroscopy-based approach for measuring the content of propofol, a common anesthesia drug, in whole human blood, and plasma, which is intended for use during clinical procedures. This method utilizes the Raman spectroscopy as a chemically–sensitive method for qualitative detection of the presence of a drug and a quantitative determination of its concentration. A number of samples from different patients with added various concentrations of propofol IV solution were measured. This is most equivalent to a real in-vivo situation. Subsequent analysis of a set of spectra was carried out to extract qualitative and quantitative information. We conclude, that the changes in the spectra of blood with propofol, overlap with the most prominent lines of the propofol solution, especially at spectral regions: 1450 cm-1, 1250- 1260 cm-1, 1050 cm-1, 875-910 cm-1, 640 cm-1. Later, we have introduced a quantitative analysis program based on correlation matrix closest fit, and a LOO cross-validation. We have achieved 36.67% and 60% model precision when considering full spectra, or specified bands, respectively. These results prove the possibility of using Raman spectroscopy for quantitative detection of propofol concentrations in whole human blood.
Anisotropic Etching of Crystalline Silicon in Alkaline Solutions I . Orientation Dependence and Behavior of Passivation Layers

The anisotropic etching behavior of single-crystal silicon and the behavior of SiO2 and Si3N4 in an ethylenediaminebased solution as well as in aqueous KOH, NaOH, and LiOH were studied. The crystal planes bounding the etch front and their etch rates were determined as a function of temperature, crystal orientation, and etchant composition. A correlation was found between the etch rates and their activation energies, with slowly etching crystal surfaces exhibiting higher activation energies and vice versa. For highly concentrated KOH solutions, a decrease of the etch rate with the fourth power of the water concentration was observed. Based on these results, an electrochemical model is proposed, describing the anisotropic etching behavior of silicon in all alkaline solutions. In an oxidation step, four hydroxide ions react with one surface silicon atom, leading to the injection of four electrons into the conduction band. These electrons stay localized near the crystal surface due to the presence of a space charge layer. The reaction is accompanied by the breaking of the backbonds, which requires the thermal excitation of the respective surface state electrons into the conduction band. This step is considered to be rate limiting. In a reduction step, the injected electrons react with water molecules to form new hydroxide ions and hydrogen. It is assumed that these hydroxide ions generated at the silicon surface are consumed in the oxidation reaction rather than those from the bulk electrolyte, since the latter are kept away from the crystal by the repellent force of the negative surface charge. According to this model, monosilicic acid Si(OH)4 is formed as the primary dissolution product in all anisotropic silicon etchants. The anisotropic behavior is due to small differences of the energy levels of the backbond surface states as a function of the crystal orientation.
Diffraction and Spectroscopic Studies of the Cobaltic Acid System HCoC2–DCoO2

Cobaltic acid, HCoO2, and deuterated cobaltic acid, DCoO2, have been prepared and studied by x‐ray and neutron‐diffraction techniques, and by infrared spectroscopy and cold‐neutron scattering. The materials crystallize in apparent space group D3d5–R<3¯m of the trigonal system with three molecules in a hexagonal cell of dimensions: HCoO2, a = 2.851(1), c = 13.150(5) A; DCoO2, a = 2.854(1), c = 13.354(5) A. The O–O distance, as determined by neutron‐powder studies, of HCoCO2 is 2.50(2) A. On this basis and the fact that there are three O–H–O bonds along the c direction, the O–D–O distance is 2.57(2) A. Hence, the isotope effect here is as large as in the system HCrO2–DCrO2. Infrared studies at room temperature and at − 195°C over the region 70–4000 cm−1 may be interpreted in terms of an effectively symmetric O–H–O bond and an effectively asymmetric O–D–O bond. Although the neutron inelastic scattering measurements are not inconsistent with this interpretation, there is a band centered at 264 cm−1 in the neutron spectrum for HCoC2, which is not observed in the infrared spectrum. Model calculations, based on a two‐dimensional potential function in which the asymmetric stretching frequency is coupled to the symmetric stretching frequency, were unsuccessful owing to the magnitude of the coupling term required to account for the very large isotope effect.
Nerve and muscle excitation

Important quantities used in this book electrical recordings from neurons and single muscle fibres the membrane analogue ionic properties of resting and active membranes metabolic pumps and membrane potentials voltage clamping the Hodgkin-Huxley model and other theories of excitation further studies of the sodium and potassium currents calcium conductances and action potentials repetitive firing synaptic transmission single-channel currents in excitable membranes theories of single-channel behaviour structural basis of channel function new directions solutions to end-of-chapter problems.
Sub-microhartree accuracy potential energy surface for H3 + including adiabatic and relativistic effects. II. Rovibrational analysis for H3 + and D3 +

The 69 potential energy points of H3+ computed by Cencek et al. [J. Chem. Phys., 108, 2831 (1998), preceding paper] have been fitted to an analytical potential energy surface (PES). Rovibrational frequencies have been derived for the symmetric H3+ and D3+ isotopomers. A comparison with experiment shows residual discrepancies of a few tenths of cm−1 which can be ascribed mainly to nonadiabatic effects.
Spiked Sediment Toxicity Testing of Hydrophobic Organic Chemicals: Bioavailability, Technical Considerations, and Applications

Many evaluations estimating safe levels of hydrophobic organic chemicals in sediments do not account for confounding factors such as physical habitat quality or covariance among chemicals. Controlled experiments demonstrating cause and effect can be conducted with spiked sediment toxicity tests, but application of this methodology has been limited in part by concerns about chemical bioavailability and challenges in achieving target concentrations. Relevant literature was reviewed to assess the utility of standardizing sediment equilibration times; hydrophobicity, complex sediment characteristics, and temperature were identified as potentially equally important factors. Disequilibrium appears likely following limited equilibration time but should yield conservative toxicity test results relative to aged field sediments. Nominal and measured concentrations in over 20 published studies were compared to assess spiked chemical recovery (i.e., measured concentration/nominal concentration). Recovery varied substantially among studies and was not readily predictable based on spiking or extraction method, chemical properties, or measured sediment characteristics, although unmeasured differences between sediments appeared to be important. Factors affecting specific studies included chemical adsorption to glassware, biodegradation, and volatilization. Pre- and post-toxicity test analyses are recommended to confirm exposure concentrations. Studies with 2,3,7,8-tetrachloro-dibenzo-p-dioxin (2,3,7,8-TCDD) and hexachlorobenzene (HCB) exemplify the utility of verifying results of field studies using spiked sediment tests. Sediments spiked with these chemicals at concentrations greatly exceeding those in associated field studies caused no adverse effects in test organisms, demonstrating that other chemicals co-occurring in test sediment samples caused toxicity initially attributed to 2,3,7,8-TCDD and HCB in the field studies. Another key application of spiked sediment tests has been the investigation of TOC as the primary factor affecting bioavailability of hydrophobic organic chemicals. A review of LC50s for nine chemicals reported in 12 studies shows that comparable LC50s derived in different sediments generally agree within a factor of five when concentrations are normalized to a constant TOC. Additionally, use of spiked sediment toxicity testing to investigate toxicological interactions among chemicals provides a promising approach to improving the ability to predict sediment toxicity in the field.
Structure, electronic properties and vibrational spectra of (MgF2)n clusters through a combination of genetic algorithm and DFT-based approach

In this article, we look at the option of using a stochastic optimisation technique, namely genetic algorithm (GA) in association with density functional theory (DFT) to find out the global minimum structures of (MgF2)n clusters with the range of n being between 2 and 10. To confirm whether the structures are indeed the acceptable ones, we go on to evaluate several properties like IR spectroscopic modes, vertical excitation energy, cluster formation energy, vertical ionisation potential and the HOMO–LUMO gap. We stress on the fact that an initial estimation of structure using GA, on two empirical potentials (with and without inclusion of polarisation), leads to a very quick convergence to structures which are quite close to the structures obtained from quantum chemical calculations done from the outset, such as using a DFT calculation. The general structural trend of these systems to form three-dimensional networks is also clear from our study. The lowest energy isomers of these clusters show preference for four-membered Mg2F2 and six-membered Mg3F3 rings. In the IR spectra of (MgF2)n clusters, a blueshift of the Mg–F symmetric stretch and a redshift of asymmetric Mg–F stretching as n increases are obtained.
Extractability of the Phospholipid Envelope of Magnetoliposomes by Organic Solvents

Abstract Magnetoliposomes, consisting of nanometer-sized superparamagnetic magnetite cores surrounded by a phospholipid bilayer, were subjected to extraction using various organic solvent systems. When chloroform orn-hexane were used, there was little change in the phospholipid/Fe3O4ratio. In contrast, upon including short-chain alcohols to these extraction systems, the outer shell of the bilayer, comprising approximately two-thirds of the original phospholipid content, was entirely removed. The resistance to extraction of the inner leaflet is due to very strong forces, thought to be chemisorptive in nature. Preliminary experiments demonstrating the apolar character of the surface of the remaining monolayer are also presented.
Gold nanoparticles supported on Ce–Zr oxides for the oxidative esterification of aldehydes to esters

Au nanoparticles supported on Ce–Zr oxides were prepared and characterized in order to study the role of the support in the oxidative esterification of aldehydes in the presence of molecular oxygen. Ce–Zr solid solutions were synthesized by using (NH4)2Ce(NO3)6 as a precursor, while the mixed oxides were obtained by using a Ce(NO3)3 precursor. The solid solutions exhibited a smaller crystallite size, higher BET surface area, larger amount of H2 consumption, and higher acidity and basicity than the mixed oxides at the same Ce/Zr molar ratio due to the incorporation of Zr4+ into the ceria lattice. The effect of the support was investigated because all the samples presented similar Au particle sizes, as confirmed by the HAADF-STEM study. Supports with higher reducibility showed better performance by activating methanol to methoxy and facilitating the β-H elimination of hemiacetal. We also found that the formation of hemiacetal was enhanced by the acidic sites and basic sites of Au catalysts supported on solid solutions possessing similar reducibility. A plausible reaction mechanism for the oxidative esterification of aldehydes on Ce–Zr solid solution-supported Au nanoparticles was proposed. The screened catalyst was also applicable to the oxidative esterification of different benzylic aldehydes, producing high yields. This catalyst could be reused after a simple separation eight times, keeping a high selectivity of above 99%.
Cumulative energy demand for small molecule and polymer photovoltaics

Organic photovoltaics (OPVs) are expected to be a low cost, environmentally friendly energy solution with advantageous properties such as flexibility and light weight that enable their use in new applications. Considerable progress in power conversion efficiencies has brought OPV technology closer to commercialization. However, little consideration has been given to potential environmental impact associated with their production. Although environmental life cycle studies of OPV exist, their scope is narrow or too reliant on outdated technologies. Some of the most significant recent improvements are the result of new semiconductors materials, which have not yet been assessed from a life cycle perspective. Therefore, this study calculates life cycle embodied energy for 15 new materials encompassing a variety of donor, acceptor, and interface compounds showing the most promise in organic electronics. With the use of new inventory data, life cycle energy impact associated with production of both single junction and multi‐junction architectures has been calculated including bulk heterojunction polymer, planar small molecule, and planar‐mixed small molecule devices. The cumulative energy demand (CED) required to fabricate small molecule and polymer photovoltaics were found to be similar from 2.9 to 5.7 MJ/Wp. This CED is on average of 50% less than for conventional inorganic photovoltaics, motivating the continued development of both technologies. The use of fullerenes was shown to have a dramatic impact on polymer solar cells, comprising 18–30% of the CED, despite only being present in small quantities. Increases in device efficiency are shown to marginally reduce CED for both small molecule and polymer designs. Copyright © 2012 John Wiley & Sons, Ltd.
Diagnostic and modeling of N2-H2 discharges for iron nitriding

The production of N and H atoms has been studied in DC and HF N 2 -H 2 flowing discharges and post-discharges in connection with nitriding of iron substrates. Experimentally, the N and H atoms have been detected by emission spectroscopy and Laser Induced Fluorescence (LIF). A strong increase of the Mayn gas atom density (N or H) was found when a small amount of a second gas (H 2 or N 2 ) was added. This increase in N or H atom densities is interpreted by a model describing the kinetics in the reactive gas volume and on the surface of the reactor walls (pyrex tube). In particular, it is shown that the destruction probabilities of N and H atoms on the tube wall are reduced by a factor of about 2 as a few % of H 2 or N 2 is introduced into N 2 or H 2 . Correlations are established between the density of N and H atoms and the thickness and quality of iron nitride layers growing on iron substrates located within a reactor and placed in the post-discharge of a N 2 −H 2 HF flowing discharge. Under the conditions of maximum N and H atom density, thick ϵ−Fe 2 N 1− x layers without iron oxide superficial sublayer have been found on the iron surface.
Arborescent Graft Copolymers: Highly Branched Macromolecules with a Core-Shell Morphology

Macromolecules incorporating a highly branched polystyrene core and a poly(ethylene oxide) shell were synthesized. A comb-branched (generation G = 0) polystyrene was prepared by initiating the polymerization of styrene with sec-butyllithium, capping with 1,1-diphenylethylene, and titrating the living anions with a solution of chloromethylated linear polystyrene. A twice-grafted (G = 1) core with protected hydroxyl end groups was obtained using (6-lithiohexyl)acetaldehyde acetal to initiate the polymerization of styrene, followed by capping and grafting on the chloromethylated comb polymer. The acetal functionalities were hydrolyzed, and the core was titrated in solution with potassium naphthalide, before adding ethylene oxide. To maintain a narrow apparent molecular weight distribution, it was necessary to eliminate residual chloromethyl sites by a metal−halogen exchange reaction, prior to shell growth. Core-shell polymers based on a G = 1 core with Mw = 7 × 105 g·mol-1 containing 19% and 66% poly(ethyle.
Analysis of impact of EGR valve construction on the exhaust gas flow parameters in the engine

COMBUSTION ENGINES, No. 3/2013 (154) 1. Modeling of gas flow through the EGR valve In this article analysis of the flow of gases through the exhaust gas recirculation valve (EGR) was made. The valve was the component of the exhaust gas recirculation diesel engine Z1505, its structure is shown schematically in Fig. 1. Role of the exhaust gas recirculation valve is to control flow quantity of gas supplied to the engine intake manifold. Because the costs involved in testing of valves in a laboratory environment are high and measurements are time-consuming therefore, to simulate a physical phenomena and processes in the valve numerical computational techniques are often used. The use of advanced computational programs allows the modeling and analysis of gas flows including the distribution of the velocity and pressure vectors. One of such programs is FLUENT. Calculations performed with FLUENT package are based on the finite volume method [1, 2]. Simulation studies examined the usefulness of design a new type of EGR valve (Fig. 1) to control the amount of recirculated exhaust gas. For simulation research a faithful representation of the actual geometry of element is very important [4]. For this purpose GAMBIT program was used Agata LENC-BROL Jarosław MAMALA
Estimating the Composition of Tomato Juice Products by near Infrared Spectroscopy

The use of near infrared (NIR) reflectance spectroscopy for the rapid and accurate measurement of moisture, sugar, acid, protein and salt was explored in a diverse group of tomato juice products. Partial and overall calibrations were performed on four different tomato juice products. Partial calibrations for each product included samples of the specific product, whereas overall calibration used samples of all the products. Samples were analysed employing traditional chemical methods and scanned using an Instalab 600-Dickey-John NIR apparatus to obtain NIR spectra. Calibrations were achieved with the use of multilinear regression between chemical and spectral data from each calibration data set. A separate set of samples was used to validate the calibrations. Linear regression was applied to compare the results obtained by NIR spectroscopy for all constituents of the validation set with those obtained by the reference methods. In addition, the root mean square error of prediction (RMSEP), the bias and the correlation coefficients (r and r′) were calculated. All of the statistical parameters were better with overall than with partial calibrations. Prediction ability of overall calibration was very good for all the constituents. r and r′ values were higher than 0.9488 and 0.9453, respectively, RMSEP values were smaller than 0.1067, whereas bias varied from −0.020 to 0.016. The partial calibrations are considerable less variable with the correlation coefficients r and r′ ranged from 0.8890 to 0.9477 and from 0.7202 to 0.8518, respectively, RMSEP varied from 0.0647 to 0.4942 and bias from −0.365 to 0.071. NIR measurement as performed by the Dickey-John Analyser was proved a rapid and accurate method for analysis of tomato juice samples and may be used as a replacement for conventional expensive and time-consuming wet chemistry methods.
Fabrication of White Organic Light-Emitting Diodes Using Two Complementary Color Methods

White organic light-emitting diodes (WOLEDs) were fabricated using two complementary color methods with two emissive layer structure such as NPB (500 Å)/DPVBi (65 Å)/MADN:DCM2-0.5% (170 Å)/Bphen (300 Å)/Liq (20 Å)/Al (1000 Å). A deep blue and orange emissions were obtained from DPVBi layer and MADN host doped with a red fluorescent DCM2 dopant each. White emission was achieved through controlling hole-electron recombination by optimization of emissive layers thicknesses and DCM2 concentrations. Optimized WOLED device shows emission efficiency of 5.04 cd/A, current density of 2.64 mA/cm2 and luminance of 938 cd/m2 at 6 V with CIEx,y color coordinate of (0.338, 0.330). These results indicate that DPVBi layer effects on hole blocking and the exciton generation due to difference of energy level in highest occupied molecular orbital. The CIEx,y coordinates of device was slightly changed change from (0.338, 0.330) at 6 V to (0.341, 0.333) at 12 V, which is almost independent on driving voltages.