Miracle-dz/UniFAR-FTUs huggingface dataset:
Recognition of α-amino acid derivatives by N,N′-dibenzylated S,S-(+)-tetrandrine

Complexation of free and N-acetylated α-amino acid anions (Gly, Ala, Phe) and some structurally related guests by a dicationic cyclophane-type N,N′-dibenzylated chiral derivative of a bisisoquinoline macrocyclic alkaloid S,S-(+)-tetrandrine (DBT) has been studied by 1H-NMR titrations in D2O. In contrast to other macrocyclic hosts like cyclodextrins and calixarenes, DBT shows highest affinity and large enantioselectivity (K(S)/K(R) ≥ 10) toward smaller N-acetylalanine and binds larger phenylalanine derivatives more weakly and non-selectively. With 1,2,3,4-tetrahydroisoquinoline-3-carboxylate, a rigid analog of phenylalanine, binding again becomes enantioselective with K(S)/K(R) = 3.8. The binding specificity of DBT is rationalized on the basis of molecular mechanics calculations.
Electric properties of formaldehyde, thioformaldehyde, urea, formamide, and thioformamide—Post‐HF and DFT study

Dipole moments μ, static electric polarizabilities α, and hyperpolarizabilities β of formaldehyde, thioformaldehyde, urea, formamide, and thioformamide have been evaluated in the DFT and post-HF approximations. Within the DFT, the family of HCTH and hybrid functionals (B3LYP, B97–1) have been adopted. The qualitative and quantitative performance of both functional types have been examined by confrontation with the CCSD(T) method. The DFT model appears to be adequate for dipole moments and polarizabilities, while the hyperpolarizabilities are exaggerated, especially βyyy (too negative) and βzzz (too positive) components. The replacement of oxygen by sulfur reduces the DFT hyperpolarizability, which contradicts an increase predicted with the post-HF approach. HCTH dipole moments in majority of cases are in better agreement with the CCSD(T) estimates than are the hybrid functionals. On the other hand, the hybrid functionals perform slightly better for polarizability and hyperpolarizability evaluations. The effects of basis set size with aug-cc-pVXZ (X = D, T, Q) on the electric properties have also been studied. The sensitivity of the electric properties to the basis set effects increases from the dipole moment to the hyperpolarizability. The axial αzz and βzzz components display smaller sensitivity to the basis set extension. The carbonyl/thiocarbonyl containing molecules are characterized by negative/positive sign of hyperpolarizability vector projection into the dipole moment direction. © 2007 Wiley Periodicals, Inc. Int J Quantum Chem, 2007
Evaluation of Hindered Phenols for Minimization of Foam Discoloration Using the Microwave Scorch Test

Antioxidants are added to polyether polyols to protect the integrity of the polyol during processing and storage and to prevent discoloration or scorch of the flexible foam during production. In the latter, the antioxidant retards degradation of the foam during the exotherm which results from the chemical reaction of diisocyanate with water and polyol. It is not uncommon for low density foams to reach temperatures in excess of 160 °C on the foam production line and to maintain these elevated temperatures for several hours before cooling. The scorch can range from a slight yellow discoloration at the center of the bun to the extreme of combustion if the antioxidant system is not adequate for the formulation. The reactions leading to scorch have been suggested to consist of oxidation of remaining amine groups to highly colored quinoid type chromophores in the milder form to thermal and hydrolytic degradation of allophonate, urethane and biuret groups and oxidation of the polyether segments in the more severe instances [1,2]. A large number of factors as listed in Table 1 may promote scorch in flexible foams with the more important being the use of higher water containing formulations used to reduce density while attempting to maintain load bearing properties [3,4]. As the trend toward lower density foams continues, polyol manufacturers have attempted to keep ahead by advances in the understanding of scorch and its inhibition by antioxidants. Generally, this has resulted in the use of higher concentrations of antiox-
Self-consistent electron and heavy-particle kinetics in a low-pressure - glow discharge

A homogeneous kinetic model of a low-pressure - positive column is developed. The model is based on the self-consistent solutions to the electron Boltzmann equation coupled to the rate balance equations for the vibrationally excited molecules (X ) and (X ), the electronically excited states of , and NO(), and species. Further, this set is still solved together with the continuity equations for the electrons and the main positive ions (, , , , ) in order to determine the maintenance reduced electric field. This formulation allows us to determine the concentrations of the various neutral and ionic species, the electron density and the vibrational temperatures, and , as a function of the gas pressure, discharge current, gas temperature, tube radius and fractional composition. The calculated results are shown to be in satisfactory agreement with published experimental data. The complex interplay kinetics is analysed in detail and the effects of the poor knowledge of some collisional and surface data on the results are discussed.
Lipase-catalysed esterification of some α-D-glucopyranosides in dry media under focused microwave irradiation

Immobilized Candida antarctica lipase (Novozym 435)-catalysed esterifications of methyl α-D-glucopyranoside 1,α-D-glucose 2 and α,α-trehalose 3 with dodecanoic acid in dry media under focused microwave irradiation and classical heating conditions are described, under the same conditions of time and temperature. The advantages of performing the reactions in the microwave reactor are evident in all cases either in terms of yields and (or) purities of products.
Synthesis and characterization of DNA‐functionalized calcium phosphate nanoparticles

Calcium phosphate nanoparticles were prepared by precipitation from aqueous solution. A stable colloid was formed by coating with DNA. The properties of the colloidal dispersion can be adjusted by variation of the inorganic nanoparticles. In particular, the partial substitution of calcium by magnesium or aluminum led to stable dispersions of nanoparticles. By a multi‐step precipitation process, it is also possible to include DNA into the particles in order to protect it from intracellular biochemical degradation. The dispersions were analyzed by dynamic light scattering, zeta potential measurements, analytical ultracentrifugation, and transmission electron microscopy.
Production and study of a Ti/Ti02/Noble metal anode

Plusieurs metaux de notre vie courante sont obtenus industriellement au moyen de procedes electrolytiques. Un des procedes les plus communs est l’electro-obtention de cuivre, dans lequel le metal est depose a la cathode tandis que l'oxygene se degage a l'anode. Generalement, en usine, plusieurs anodes et cathodes, ayant une surface de 1 m2 et separees par plus ou moins 10 cm sont alternees dans une cellule contenant une solution d'acide sulfurique riche en sulfate de cuivre. En fonction des conditions d'utilisation, les cathodes sont remplacees, apres un certain temps, par des nouvelles de facon a recuperer le cuivre depose. De ce fait, les anodes doivent etre capables de resister sans se corroder, se deformer ou perdre leurs proprietes electrocatalytiques pendant de longues periodes. Au debut, des alliages en Pb (pb-Ag, Pb-Ca-Sn,.) ont ete utilises comme anodes. Malheureusement, malgre leur faible prix, ces anodes presentent des surtensions elevees et une faible resistance a la corrosion et au fluage. Par consequent, une alternative aux anodes traditionnelles en 1 developpee. Ce nouveau type d'anode, connu sous le nom d’anode dimensionnellement stable (DSA) est fabriquee a partir d'une tole en Ti recouverte par un melange d'oxydes de metaux nobles catalysant la reaction de degagement d'oxygene. Differentes techniques peuvent etre utilisees pour preparer la couche d'oxyde. La technique la plus souvent employee consiste a decomposer thermiquement une solution de chlorures contenant un ou plusieurs nobles. Malheureusement, ce type d'anode est cher et a tendance a perdre son activite electrocatalytique avec le temps.Dans le but de produire une DSA a faible prix, pouvant resister de longues periodes sans se passiver, un nouveau type de DSA a ete developpe dans le present travail. Cette anode est produite par electrodepot d'un metal noble dans les pores d'un substrat microporeux en Ti/TiO2.Ce travail a permis de demontrer qu'une DSA avec une concentration en metal noble peut etre obtenue par la voie proposee. Il a ete montre que les proprietes electriques et electrochimiques de ces DSAs sont directement liees aux caracteristiques morphologiques et structurales du en Ti/TiO2. Lorsque la couche barriere existant au fond des pores est suffisamment fine et que le film presente des defauts, la resistance me l'interface Ti/metal noble est faible. Ceci abouti a des DSAs possedant d'excellentes proprietes electrocatalytiques. Les DSAs optimales sont capables de resister a des conditions similaires a celles employees en industrie avec des surtensions de ~ 0.4 V, ce qui represente un gain de 50% par rapport aux surtensions normalement atteintes par les anodes traditionnelles en Pb.
An Experimental Study on Stripe Pattern Formation of Ag−Sb Electrodeposits

Transient changes in surface morphologies of Ag-Sb thin films electrodeposited from an aqueous electrolyte have been studied. Measurements of the potential and current density applied during electrodeposition reveal that stripe patterns that comprise bright and dark regions are formed within a small range of the potential and current density that exhibits no oscillatory behavior. In addition, the experimental results on the transient current density are found to be in good agreement with the solutions of unsteady diffusion equations, whose results give the ratios of the kinetic constants to the diffusion coefficient that may be related to a necessary condition for the Turing instability in reaction-diffusion systems. Fourier analysis of the time-series stripe images shows that stripe spacings change with the area ratio of the bright regions to the dark regions fixed. This indicates that the stripe patterns formed at the different deposition times emerge on different length-scales.
Biogas production from the anaerobic digestion of Laminaria digitata in a 10 L pilot-plant with digestate re-use as fertiliser

Seaweed has received considerable interest as a potential feedstock for producing biofuels. The anaerobic digestion (AD) of seaweed is a feasible technology where biogas is produced as a source of renewable energy. The effluent (digestate) is considered a by-product that can be used as bio-fertiliser. This investigation examined the co-digestion of Laminaria digitata with bovine slurry in a batch two-phase AD process. Two 10 L pilot-plants running in parallel were fed with the mixture and incubated at 35°C for 109 days. Two biofuel crops, ryegrass and sunflower, were grown with different concentrations of digestate and the effect on seed germination and plant growth was evaluated. Three hundred and seventy-five millilitre and 217 ml g/VS of biogas and methane, respectively, were produced from the AD. Digestate addition enhanced plant growth.
Synthesis and Characterization of Hexagonal and Truncated Hexagonal Shaped MoO3 Nanoplates

Hexagonal and truncated hexagonal shaped MoO3 nanoplates (MoO3 HNP) were synthesized through a simple vapor-deposition method in Ar atmosphere under ambient pressure without the assistant of any catalysts. The structure and morphology of MoO3 HNP were investigated by XRD, EDX, SEM, TEM, and HRTEM. The results reveal that the HNP are α-MoO3 and have a large area surface. The Raman spectrum shows a significant size effect on the vibrational property of MoO3 HNP. The photoluminescence (PL) spectrum was carried out, and two peaks at 351 and 410 nm were observed in the spectrum. In addition, a possible growth mechanism proposed as VS is discussed in detail.
Surface-Constrained Foaming of Polymer Thin Films with Supercritical Carbon Dioxide

Microcellular polymer foams afford a wide variety of attributes relative to their dense analogues, and efforts remain underway to establish viable routes to generate foams with substantially reduced pore cell size and increased pore cell density. Barrier constraints are applied in the present work to achieve diffusion-controlled isothermal foaming of thin polymer films in the presence of supercritical carbon dioxide (scCO2). Poly(methyl methacrylate) (PMMA) films measuring ca. 95−100 μm in thickness are physically constrained between two impenetrable plates so that scCO2 exit diffusion is restricted to the film edges. Results obtained here demonstrate that the pore size can be systematically reduced to less than 100 nm in such systems by applying high saturation scCO2 pressures, relatively low foaming temperatures (near the glass transition temperature of the scCO2-plasticized polymer), and a rapid pressure quench. Classical nucleation theory (CNT) modified to account for the compressible nature of scCO2 .
Strengthening Treatment of Aged Hanji with Solvent Soluble Polymers

In this study, 13 water soluble polymers(6 natural polymer, 7 synthetic polymer) were treated on Hanji. Mechanical properties, morphology and oxidation index with thermal aging were measured on the aged Hanji, dewaxed Hanji and polymer treated Hanji. 3 natural polymer(such as CMC, EC, MC) and 3 synthetic polymers(such as PVA 1500, 2000, PEG 1500) treated Hanji had higher strength than other polymer treated Hanji. The oxidation index of 3% methyl cellulose solution treated Hanji did a little increase with thermal aging. Finally, methyl cellulose was found to be the most efficient method for strengthening the dewaxed Hanji. The best aging safety and thermal stability were obtained at the methyl cellulose 3% water solution.
DME DIRECT SYNTHESIS FROM SYNGAS IN A LARGE-SCALE THREE-PHASE SLURRY BUBBLE COLUMN REACTOR: TRANSIENT MODELING

In this research, a new transient mathematical model based upon tanks-in-series configuration was developed to simulate the direct synthesis of dimethyl ether (DME) from syngas in a commercial-scale slurry bubble column reactor. A comparison between the simulation results and experimental data showed that the applied model might acceptably describe the behavior of the slurry reactor. Furthermore, simulation results in the heterogeneous bubble flow regime indicated that the proposed model with 10 tanks-in-series provided the optimum condition. Utilizing this transient model and considering catalyst deactivation, the effect of operating conditions on DME productivity and CO conversion were investigated. In addition, the dynamic behavior of the reactor was studied after implementing a step change in the reactor's coolant fluid temperature.
Effects of dendrimer generation on site isolation of core moieties : Electrochemical and fluorescence quenching studies with metalloporphyrin core dendrimers

The ability of a dendritic shell to afford site isolation to a porphyrin core was evaluated using electron-transfer experiments with a series of porphyrin-core dendrimers. Cyclic voltammograms show that surrounding a porphyrin site with even a small generation (G ∼ 2) dendrimer can significantly lower the rate of interfacial electron transfer, ostensibly by decreasing the proximity of the porphyrin core to the electrode surface. This inhibition of electron transfer is more pronounced when larger generation dendrimers are employed. While a significant measure of site isolation is achieved with respect to an electrode surface, no hindrance to penetration of a small molecule is afforded by the dendritic shell surrounding the porphyrin core, an encouraging result if dendrimers are to be designed as macromolecular hosts with a functioning catalyst at the core. Stern−Volmer analysis was used to investigate the accessibility of a small molecule, benzylviologen, to the porphyrin core. For generations 1−3, the den.
PREDICTION OF HPLC RETENTION FACTOR OF POTENTIAL ANTITUBERCULOTICS BY QSRR

Derivatives of 3-phenyl-2H-1,3-benzoxazine-2,4(3H)-dione (PBOD) have become important mainly as perspective antituberculotic drugs. Quantitative structure-retention relationship (QSRR) is used for predicting the HPLC retention factor of this group of compounds and optimal chromatographic conditions appropriate for this purpose are selected. Among many molecular properties utilizable as the QSRR descriptors, mainly, in silico variables are advantageous as they closely characterize the HPLC retention of the PBOD molecule. Additionally, they are available without a need of the compound synthesis, which is important in the first stage of development of the potential drug. Artificial neural networks (ANN) were successfully used as the basic modeling QSRR tools because their regression outputs allow a direct prediction of retention factors for different combinations of the stationary and mobile phases. To prevent overfitting in ANN calculations, a distinctive elimination step, reducing about 50% of initial variables, was necessary to assure a desirable QSRR performance. Thoroughly tuned ANN models enabled a very accurate prediction of the PBOD retention factors when using C18 stationary phase and acetonitrile/water or methanol/water mobile phase.
Bilinear Driving Force Approximation in the Modeling of a Simulated Moving Bed Using Bidisperse Adsorbents

The linear driving force (LDF) approximation has been extensively used to represent the intraparticle diffusion in adsorptive processes regardless of its real nature. This work introduces a bilinear driving force (bi-LDF) approximation to account for intraparticle diffusion and to obtain concentration profiles in the macropores and microparticles of the adsorbent. The bi-LDF approximation is applied to the simulation of glucose/fructose breakthrough curves in a fixed bed and to their separation in a simulated moving bed (SMB). Equivalence with the simple LDF model is well-established for both fixed-bed operation and the SMB mode. The flow rate constraints that define a region of separation (both product purities higher than 99.5%) for a SMB configuration are shown to be greatly affected by relatively small deviations in the macro- and microparticle time constants, which illustrate the relevance of the proposed approximation.
Molecular Simulation of the Interface between Two Immiscible Electrolyte Solutions

In this paper we analyze the properties of an interface between two immiscible electrolyte solutions. The study is conducted using high concentrations of an ionic salt in the aqueous phase (1 and 3 mol·dm-3 MgCl2). The profile of the electric potential drop across the interface is calculated, and it is concluded that the surface potential is originated by the orientational anisotropy of the solvents near the interface. The ionic density profile shows a monotonic decrease as the ions approach the interface. The resultant ionic net charge density was found to be null across all the simulation box, within statistical uncertainty, confirming that the potential drop is only caused by the orientation of the solvent molecules. The orientational structure of the solvents is not disturbed by the presence of the ions. The radial distribution functions for the hydration shell of the ions show that the hydration shell remains almost unaffected at the interfacial region. The hydration number is reduced with the increa.
Development of a fully automated inorganic nitrogen analyzer for continuous, unattended monitoring of water quality

A fully automated spectrophotometric analyzer for continuous, unattended determination of inorganic nitrogen (nitrite, nitrate, and ammonia) was developed. The analysis involves online UV photo-induced conversion of nitrate to nitrite and chemical oxidation of ammonia to nitrite. In both cases, nitrite was then subsequently determined by spectrophotometry using the sulfanilamide and N-1-naphthyl-ethylenediamine color reagents. Experimental conditions investigated to optimize the determination of nitrate and ammonia are presented. The linear ranges of the methods for nitrate and ammonia are 0.01–14 ppm and 0.01–5 ppm, respectively. The proposed method is simple, low cost, and sensitive. The analyzer was operated automatically and unattended for a period of 30 days. © 2000 John Wiley & Sons, Inc. Lab Robotics and Automation 12:312–316, 2000
Developing a simple screening method for the identification of historic biocide residues on herbarium material in museum collections

The National Museum of Wales (NMW), houses ca 250 000 higher plant specimens, with material dating back to the 17th century. Herbaria have been a major source of botanical research and reference for centuries and the collections have increased over time from donations and through collecting. Owing to its organic content, botanical material is susceptible to insect and fungal attack. Even aged, dried material is a source of sugar and protein. Institutions and collectors have prevented such attacks through the application of pesticides. Treatments containing compounds of arsenic, lead and mercury were commonplace, and have remained stable over time. Consequently, present-day handling of these collections presents a potential health risk to staff and visitors through inhalation and skin absorption, particularly since the quantity and nature of the pesticide applied is unknown. Occasionally the residues are visible, but research has shown that herbarium sheets, which appear untouched and have been previously treated, contain high concentrations of toxic metals. The use of a UV hand-held lamp has helped to identify sheets that have been treated, even though treatment is not visible to the naked eye. The UV causes areas to fluoresce on the herbarium mount sheet. These areas were analysed by particle induced x-ray emission (PIXE), and have been found to correlate with pesticide applications containing mercury and arsenic. This research has shown the feasibility of using a hand-held UV lamp as a screening method for identifying contaminated samples within museum collections and provided a means to prioritise which collections require immediate re-mounting.
Magnetic response of (Cr,Al,Si)N nanocrystallites on the microstructure of Cr—Al—Si—N nanocomposites

Abstract A combination of microstructure analysis and ab initio calculations helped us to describe the interplay between the microstructure of Cr—Al—Si—N thin film nanocomposites and the ordering of the magnetic moments in the chromium-rich phase of (Cr,Al)N. The microstructure of the Cr—Al—Si—N nanocomposites was modified through the degree of ionisation of the deposited species in three physical vapour deposition processes – cathodic arc evaporation, unbalanced magnetron sputtering and high power impulse magnetron sputtering. According to the results of the ab initio calculations, the magnetic ordering was concluded from the expansion of the elementary cell and from the change of the crystal anisotropy of the elastic constants of (Cr,Al)N; these microstructure features were obtained from X-ray diffraction experiments. The microstructure of the Cr—Al—Si—N nanocomposites was furthermore characterised using the combination of X-ray diffraction and transmission electron microscopy with high resolution in order to obtain information about the phase composition of the thin films, distribution of individual elements and the crystallite size.