Miracle-dz/UniFAR-FTUs huggingface dataset:
Ion-pair dissociation of highly excited carbon clusters, size and charge effects

Ion-pair dissociation of a highly excited molecule is a relaxation process giving rise to emission of anionic and cationic fragments. We present first measurements of ion-pair dissociation of carbon clusters. We found that ion- pair relaxation is an ubiquitous, although very small, relaxation channel common to all sizes and charges of Cq+n species produced in high velocity C+n-He collisions. Quantitative interpretation of measured branching ratios is conducted on the basis of a statistical approach i.e through listing of all possible final states.
SYNTHESIS AND CHARACTERIZATION OF DIPHENYLTIN(IV) DITHIOCARBAMATE COMPOUNDS (Sintesis dan Pencirian Sebatian Difenilstanum(IV) Ditiokarbamat)

Ten compounds of diphenyltin(IV) with N-dialkyldithiocarbamate were successfully prepared using in situ methods. Elemental analysis data (C, H, N and S) showed an agreement with the general formula of (C6H5)2Sn[S2CNR1R2] (R1 = CH3, C2H5, C7H7; R2 = C2H5, C4H9, C6H11, iC3H7, C7H7). The structures of these compounds have been examined by infrared spectroscopy, ultraviolet, 1 H, 13 C & 119 Sn NMR spectroscopy and X-ray crystallography. The infrared spectra of these compounds showed three important peaks for v(C N), v(C S) and v(C S) bands that appeared in the region of 1474 -1499, 969 - 995 and 324 - 335 cm -1 respectively. Data for 13 C NMR spectroscopy showed an important peak in the region of 198 – 200 ppm that corresponded to the NCS2 group. Single crystal X-ray diffraction studies showed (C6H5)2Sn[S2CN(C2H5)(CH3)]2 (1) is six coordinated and adopted a monoclinic system with space group C2/c, while (C6H5)2SnCl[S2CN(C7H7)(iC3H7)] (2) is five coordinated, crystallized in monoclinic system with space group Pb1/n. Meanwhile, six coordinated (C6H5)2Sn[S2CN(CH3)(iC3H7)]2 (3) adopted a orthorhombic system with a space group Pbcn.
Measurement of ventilation and aerosol particles in buildings

The work described in the paper is concerned with the measurement of the flow of tracer gas and aerosol particles in rooms. Measurements were carried out in single- and two-zone systems using SF6 tracer gas and oil-smoke particles. Initial tests were carried out in a single-zone system using different arrangements of window opening. Results indicated that tracer-gas exchange rates were generally higher than particle exchange rates. This was due to the fact that the ventilation air entering the zone contained a significant concentration of particles but a negligible quantity of tracer gas. The exchange rates of tracer gas and smoke particles through a doorway were also measured in a two-zone system. The doorway coefficients of discharge were calculated using a theory based on the Bernoulli equation. The coefficients of discharge for the opening were in the range 0.4–0.96 for tracer gas measurements and 0.15–0.42 for smoke-particle measurements.
EPR Spectroscopy of Different Sol Concentration Synthesized Nanocrystalline-ZnO Thin Films

Nanocrystalline zinc oxide (nc-ZnO) thin films were grown on p-type silicon substrate through spin coating by sol-gel process using different sol concentrations (10 wt.%, 15 wt.%, and 25 wt.%). These films were characterized by high resolution nondestructive X-ray diffraction (XRD), scanning electron microscopy (SEM) with energy dispersive X-ray analysis (EDS) attachment, and electron paramagnetic resonance (EPR) techniques to understand variations in structural, morphological, and oxygen vacancy with respect to sol concentration. The film surface morphology changes from nanowall to nanorods on increasing sol concentration. EPR spectra revealed the systematic variation from ferromagnetic to paramagnetic nature in these nc-ZnO films. The broad EPR resonance signal arising from the strong dipolar-dipolar interactions among impurity defects present in nc-ZnO film deposited from 10 wt. % sol has been observed and a single strong narrow resonance signal pertaining to oxygen vacancies is obtained in 25 wt. % sol derived nc-ZnO film. The concentrations of impurity defects and oxygen vacancies are evaluated from EPR spectra, necessary for efficient optoelectronic devices development.
A Single Particle Thermal Model for Lithium Ion Batteries

COMSOL Single Particle Model for Lithium-Ion Batteries (Model ID: 14527) is generalized to include an energy balance. This is accomplished by approximating the solution phase polarization as a function of current and temperature. The theoretical approach for this work is similar to Guo et al. (Journal of the Electrochemical Society, 158, (2) A122-A132 (2011)) for modelling lithium ion cells. The COMSOL isothermal model run at 0.1 A provided the baseline for the open circuit potentials (OCPs).
Synthesis of CdSe Nanocrystals through a Reaction of H2Se Gas and Cd2+ Ions in Aqueous Medium and Their Optical and Structural Properties

Colloidal CdSe nanocrystals were synthesized by a reaction of H2Se gas and Cd2+ ions in aqueous medium. The CdSe nanocrystals are characterized by UV‐vis absorption and photoluminescence spectra, AFM as well as XRD. The freshly synthesized CdSe sol shows a very weak photoluminescence (PL) and an unstructured absorption feature. Two methods, refluxing and UV irradiating, were used to activate the PL of as‐synthesized CdSe sol. The mechanism of the PL enhancement is discussed.
Silk fibroin as a water-soluble bio-resist and its thermal properties

Thermal diffusivity of silk fibroin films, α = (1.6 ± 0.24) × 10−7 m2 s−1, was measured by a direct contact method. It was shown to be reduced down to ∼1 × 10−7 m2 s−1 in the crystallized phase, consistent with the multi-domain composition of β-sheet assemblies. Crystalline silk with β-sheets was made by dipping into alcohol and was used as a positive electron beam lithography (EBL) resist. It is shown by direct IR imaging of the 1619 cm−1 amide-I CO spectral signature and 3290 cm−1 amide-A N–H stretching band that an e-beam is responsible for unzipping β-sheets, which subsequently results in exposed areas returning to a water soluble state. This makes it possible to develop a water-based biocompatible silk resist and use it in lithography applications. The general principles of protein crystallization, traceable to spectral changes in IR amide bands of silk, can be used as a guide for the creation of new protein EBL resists and to quantify the electron dose required for solubility. Foam formation and laser treatments of silk can provide new approaches in surface functionalization and fabrication of 3D bio-scaffolds.
Influence of PVDF concentration on the morphology, surface roughness, crystalline structure, and filtration separation properties of semicrystalline phase inversion polymeric membranes

Abstract This study was focused on the fabrication of nanoporous poly(vinylidene fluoride) (PVDF) membranes at different polymer concentration (14, 17, and 20 wt%) via phase inversion method. The morphology and surface roughness of the resulting membranes were investigated by scanning electron microscopy (SEM) and atomic force microscope, respectively. SEM results showed that with the increase of polymer concentration, the pore size of membranes and the overall porosity decrease. Also, the results showed that varying concentration results in significant changes on the surface roughness. Analysis of the crystalline structures of PVDF membranes by X-ray diffraction showed that the membranes, which precipitated in the higher concentration of polymer (20 wt%) had a typical “β” form of the crystalline phase, whereas those membranes that formed at lower concentration (14 wt%) showed crystallites of the “α + β” form of the crystalline phase. Furthermore, the filtration separation experiments of Acid Yellow 23 (A.
Investigation of 15 Polycyclic Aromatic Hydrocarbons in Selected Medicinal Herbs Used as Health Food Additives by Ultra-Performance Liquid Chromatography

A rapid and highly sensitive ultra-performance liquid chromatography–fluorescence detection (UPLC–FLD) method combined with oscillation extraction and solid phase extraction cleanup was developed for the determination of 15 polycyclic aromatic hydrocarbons (PAHs) as the representative pollutants in 8 Chinese medicinal herbs as additive for health food. The PAHs can be baseline separated within 14 min. Calibration curves showed a good linearity for all PAHs (R2 > 0.999), except for naphthalene (Naph, R2 = 0.9957). The quantification limit (LOQ) ranged from 0.07 to 1.65 µg/kg in herb sample. Recoveries were in the range of 80.1–96.3% with RSD of 5.7–10.8%, except for Naph, which is 67.6% with RSD of 6.2% and 68.6% with RSD of 5.8% for spiked level of 10 and 100 µg/kg, respectively. The proposed method was applied for analysis of 8 Chinese medicinal herbs. The levels of total PAHs varied from 28.9 µg/kg in poria to 206.7 µg/kg in pinellia. The highest level was found for Naph in pinellia tuber (140.6 µg/kg) and phenanthrene in panax (80.8 µg/kg). The proposed method has high speediness, sensitivity, and accuracy, and could provide a helpful basic for herb safety monitoring and risk management for PAHs in health food industry.
ANTIOXIDANT AND FREE RADICAL SCAVENGING PROPERTY OF METHANOL EXTRACT OF BLUMEA LANCEOLARIA LEAF IN DIFFERENT IN VITRO MODELS

Summary The defatted methanol extract of Blumea lanceolaria (MEBL) was evaluated for its antioxidant property in various invitro systems. DPPH radical scavenging, nitric oxide radical scavenging, hydroxyl radical scavenging, lipid peroxidation inhibition, reductive ability and estimation of total phenolics were evaluated for this study. The methanol extract of Blumea lanceolaria exhibited significant DPPH radical scavenging property with an IC50 of 45. 79µg/ml whereas the IC50 value of the standard drug L-ascorbic acid was found to be 13. 76µg/ml. The methanol extract also exhibited significant antilipid peroxidative effect in Fe 2+ –ascorbate system. The IC50 value of the extract was found to be 62. 48µg/ml, where as the standard drug exhibited 32. 64µg/ml. The extract significantly scavenged the hydroxyl radicals by Fe 3+ –ascorbate system generated through the Fenton’s reaction and it has also significant reducing ability at IC50 of 31. 78µg/ml. The extract also exhibited significant nitric oxide radical scavenging property at IC50 of 80. 85µg/ml. In the estimation of total phenolics was found that one milligram of the extract contains 59. 03µg equivalent of pyrocatechol. Thus from the present investigation it can be concluded that the defatted methanol extract of Blumea lanceolaria exhibited significant antioxidant property in various invitro system.
Validated new spectrophotometric methods for the estimation of bosentan in bulk and pharmaceutical dosage forms

Three simple, precise and accurate spectrophotometric methods have been developed for the estimation of bosentan in pharmaceutical formulations. Bosentan exhibits maximum absorbance at 272.0 nm (Method A). In Method B (D 1 ) is a first derivative method showing minima at 284.65 nm and Method C is an Area under Curve (AUC) method (260.0-280.0 nm). The drug obeys the Beer-Lambertis law in the concentration range of 0.5-100 µg/ ml in all the three methods. The methods were validated and can be successfully applied to estimate bosentan in pharmaceutical dosage forms.
ADSORPTION OF HEXAVALENT CHROMIUM FROM AQUEOUS SOLUTIONS BY ALOE VERA LEAF

In this research, adsorption of chromium (VI) ions on Aloevera has been studied through using batch adsorption techniques. The main objectives of this study are to 1) investigate the chromium adsorption from aqueous solution by Aloevera, 2) study the influence of contact time, pH, adsorbent dose and initial chromium concentration on adsorption process performance and 3) determine appropriate adsorption isotherm and kinetics parameters of chromium (VI) adsorption on Aloevera. The results of this study showed that adsorption of chromium by Aloevera reached to equilibrium after 180 mts and the change of chromium removal efficiency was observed. Higher chromium adsorption was observed at lower pHs, and maximum chromium removal (60 %) obtained at pH of 2. It is clear that Aloevera has considerable numbers of heterogeneous layer of pores sphere is a good possibility for metal ion to be adsorbed.
Chiral separation of local anaesthetics by a capillary electrophoresis/partial filling technique coupled on‐line to micro‐electrospray mass spectrometry

A novel procedure for analysing chiral compounds is described in which a capillary electrophoresis/partial filling technique was coupled on-line to microelectrospray mass spectrometry. Enantiomers of bupivacaine and ropivacaine were separated using methyl-β-cyclodetrin, a non-volatile buffer additive, as a chiral selector. To avoid introduction of the selector into the ion source, the capillary was coated with polyacrylamide to minimize the electroosmotic flow. Prior to sample injection, the capillary was partially filled with cyclodextrin dissolved in acetate buffer. When 30 kV was applied, the positively charged enantiomers migrated towards the mass spectrometer through the zone containing the neutral selector, which acted as a pseudo-stationary phase. A racemic mixture of bupivacaine and ropivacaine was successfully separated and an impurity of 0.25% of (R)-ropivacaine in (S)-ropivacaine could be detected.
Analysis of the ASTM standards for impulse excitation of vibration and acoustic resonance techniques for rectangular parallelepipeds

Impulse excitation of vibration and acoustic resonance are techniques for determining the elastic constants of solid materials from the lowest resonance frequencies, excited by means of an impulse or by a periodic stimulus. Several geometries can be used for this purpose: parallelepipeds, disks, cylinders, etc. The details of the technique are the subject of many ASTM standards, whose suitability and precision are analyzed in this work in the case of parallelepipeds. The results show that errors of the order of 1% can be expected even if the samples dimensions and resonance frequencies are measured to a much higher precision (better than 0.1%).
Use of Thermogravimetry–Differential Scanning Calorimetry to Characterize Modelable Soil Organic Matter Fractions

We used thermal analysis to compare the proportions of active and more stable components in soil organic matter (SOM) fractions and whole soil under contrasting agricultural land-uses. The fractions (free light, intra-aggregate, and organomineral fractions) were isolated using density fractionation. Exothermic weight loss between 300 and 350°C was attributed to a relatively labile portion comprising carboxyl and aliphatic C, and that between 400 and 450°C to the decomposition of material rich in aromatic components. Under arable cultivation, free light SOM showed much greater weight loss in the first exothermic range than intra-aggregate SOM. In soil receiving very small inputs of organic matter (a long-term bare fallow) the free light and intra-aggregate fractions displayed similar characteristics and resembled the intra-aggregate fraction from the arable soil. The difference between the free light and intra-aggregate fractions was also small for the grassland soil but the fractions resembled the free light fraction from the arable soil. Small total weight loss for whole soil and organomineral fractions demonstrated the value of physical fractionation techniques in establishing the effect of land-use on SOM with greater precision than is possible whole (unfractionated) soil.
Synthesis, Characterization, and In Vitro Bioactivity of Sol-Gel-Derived SiO2–CaO–P2O5–MgO-SrO Bioactive Glass

In this study, the synthesis of SiO2–CaO–P2O5–MgO-SrO bioactive glass was performed by the sol-gel method. Sol-gel-derived bioactive glass material was produced both in powder and in discs form by uniaxial pressing, followed by sintering at 700°C. The obtained material was evaluated by X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM). Cytocompatibility of ionic products of the bioactive glass were assessed using MTT assay and direct contact test. The surface reactivity of the resultant bioactive glass specimens was analyzed by immersion studies in simulated body fluid (SBF) for different time intervals while monitoring the concentration of silicon, calcium, phosphorus, strontium, and magnesium in the SBF medium. The SEM, XRD, and FTIR studies were conducted before and after soaking of the material in SBF. At first, an amorphous calcium phosphate was formed; after 7 days this surface consisted of deposited crystalline apatite. In vitro experiments with human osteosarcoma cell lines (MG-63) indicated that bioactive glass incorporating a limited amount of magnesium and strontium in the composition stimulates bone cell production of alkaline phosphatase. Finally, this material proved to be non-toxic and compatible for the proposed work in segmental defects in the goat model in vivo.
Dynamic Mechanical and Dielectric Properties of Ethylene Vinyl Acetate/Carbon Nanotube Composites

A comparative study of the dielectric and mechanical properties of ethylene vinyl acetate copolymer (EVA) filled with various concentrations of pristine and modified carbon nanotubes is reported. The surface of the carbon nanotubes was modified with 4-(2-(cholesteryloxycarboxy)ethyl) phenyl to improve the interaction of the filler with the block copolymer matrix. The improved interaction and the better dispersion of the modified carbon nanotubes (mMWCNTs) were demonstrated by a detailed study of the EVA molecular mobility through dynamic mechanical analysis and broadband dielectric relaxation spectroscopy. The storage modulus of the nanocomposite with 6 wt. % of mMWCNTs at −50°C was enhanced by 103%, whereas for the nanocomposite with the same amount of unmodified filler, the storage modulus was only enhanced by 76% compared to the pure elastomeric matrix. This difference is more pronounced in the rubbery region in which the storage moduli were increased by 117% and 48% for the composite with the modified and unmodified fillers, respectively. The morphologies of the nanocomposites were studied with scanning and transmission electron microscopies to demonstrate the dispersion of the mMWCNTs within the EVA matrix.
Nanoflowers Grown from Phthalocyanine Seeds: Organic Nanorectifiers

Nanoparticles and nanoflowers of different metal(II) phthalocyanines (MPc; copper, nickel, tin, magnesium, and zinc) as well as metal-free (H2Pc) have been grown, at room temperature, by vapor deposition at high vacuum (∼10-6 Torr). This article describes the role of the effect of substrate condition in molecular organization of phthalocyanine on gold coated quartz substrates. The particle size and morphology of the nanostructures were found to be mainly determined/controlled by the nature of the template (substrate) used. The formation of different nanostructures is discussed. Field emission scanning electron microscopy (FESEM) and scanning tunneling microscopy (STM) observations of the ordered crystalline films indicated that domains are grown from the bottom to the top of the film and are densely packed with little grain boundary. UV−vis absorption spectra of the ordered films were recorded, showing unique dependences on the molecular alignments. The fractal dimension of the assembly of nanostructures .
Synthese von 7-Desaza-2′,3′-didesoxyguanosin durch Desoxygenierung seines 2′-Desoxy-β-D-ribofuranosids

7-Desaza-2′,3′-didesoxyguanosin (4) wurde ausgehend von 7-Desaza-2′-desoxyguanosin (1) durch Barton-Desoxygenierung dargestellt. Der Schutz der 5′-Hydroxygruppe erfolgte durch den 4,4′-Dimethoxytriphenylmethyl-Rest, der der 2-Aminofunktion ent-weder durch die Dimethylaminomethylengruppe oder ebenfalls durch den 4,4′-Dimethoxytriphenylmethyl-Rest. Die Zuordnung der 1H- und 13C-NMR-Signale des 2′,3′-Didesoxy-β-D-glycero-pentofuranosyl-Restes wurde bei 4 mittels 2D-NMR-Spektroskopie vorgenommen. Das Didesoxynucleosid 4 zeichnet sich gegenuber 2′,3′-Didesoxyguanosin durch eine extrem hydrolysestabile N-glycosylische Bindung aus. Synthesis of 7-Deaza-2′,3′-dideoxyguanosine by Deoxygenation of Its 2′-Deoxy-β-D-ribofuranoside 7-Deaza-2′,3′-dideoxyguanosine (4) was prepared by Barton deoxygenation from 7-deaza-2′-deoxyguanosine (1). Protection of the 5′-hydroxy group was accomplished by the 4,4′-dimethoxytriphenylmethyl residue. The 2-amino function was protected either with the same group or the dimethylaminomethylene residue. Assignment of 1H- and 13C-NMR signals of the 2′,3′-dideoxy-β-D-glycero-pentofuranosyl moiety of 4 was made on the basis of 2D-NMR spectra. In contrast to 2′,3′-dideoxyguanosine compound 4 has an extremely stable N-glycosylic bond towards proton-catalyzed hydrolysis.
Size-dependent training effect in exchange coupled NiFe2O4/NiO nanogranular systems

The particle size dependent training effect has been investigated on the exchange coupled NiFe2O4/NiO nanogranular systems, with average particle size (DNFO) of NiFe2O4 ranging from ∼3 nm to ∼55 nm. For all samples, analysis of the field cycles (n) dependence on exchange bias fields (HEB) suggests the existence of two distinct forms of training mechanism during training procedure. One is related to an athermal contribution leading to the abrupt single cycle training, the other is the conventional thermal activation mechanism responsible for the gradual reduction of HEB during the subsequent cycles. With the increase of particle size, the relative change of HEB and enhanced coercivity (△HC) after training display a nonmonotonic size-scaling behavior and reaches the maxima for DNFO ∼ 22 nm. In this system, this largest reduction reveals the weakest dynamic stability of the interfacial exchange coupling energy during field cycle process. Moreover, different decay rate of HEB and ΔHC with field cycles are obs.
Exploitation of the complex chemistry of hindered amine stabilizers in effective plastics stabilization

Hindered amine stabilizers (HAS) remain a prominent class of stabilizers having a fortunate development with continuous interest in shaping the future properties of plastics: increase in polymer durability, application extension, reaching new effects. Commercial tests provided much information. Insufficient mechanistic interpretations of the complex effects of environmental factors (harshness of testing, penetration of radiation and oxygen, superposition of temperature, atmospheric impurities) and those of the microenvironment (morphology of the polymer matrix, physical relations of HAS–polymer, interference between HAS and other additives) are a drawback. Model experiments complement commercial studies and explain some phenomena. A careful transfer of information from model experiments must be done to avoid misinterpretation of mechanisms, particularly of the HAS regenerative cycle. A critical analysis of primary steps of the HAS activity mechanism in the polymer matrix based on HAS‐related primary nitroxides, formation of their stationary concentration and concentration gradients influenced by polymer morphology, spatial competition between autoreactions, and oxidation of polymer‐developed alkyl radicals and their scavenging by nitroxides (the key process of HAS efficiency) is outlined. Cyclic regeneration of nitroxides affected by the structure of the amino moiety in the HAS molecule, influence of acid environment, atmospheric ozone or singlet oxygen, cooperative mixtures of HAS with UV absorbers, combinations with additives increasing the thermal stabilization effect and improving color retention, assessment of the heat stabilization performance of HAS by proper testing, and influence of the molecular weight of HAS are mentioned together with examples of the chemical consumption of HAS in the final phases of their lifetime. lifetime. J. VINYL ADDIT. TECHNOL. , 13:119–132, 2007. © 2007 Society of Plastics Engineers