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Abstract  

The thermally induced structural transformation of a hydrogen-bonded crystal formed from an amphoteric molecule of 6-[2-methoxy-4-(pyridylazo)phenoxy]hexanoic acid MeO was studied using differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction measurement (XRD). Crystal form of the hydrogen-bonded crystal was measured by single crystal four circle diffractometer (Mo-Kα radiation). As a result, the crystal of MeO was stabilized by many C–H⋅⋅⋅O hydrogen bonds, and the C–H⋅⋅⋅O hydrogen bonds were broken by thermal energy reversibly. After transformation the supramolecular architecture was composed of supramolecular polymer including free-rotation pentamethylene main chains.

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Thermal and structural properties of surfactant–picrate compounds

Effect of the alkyl chain number on the same ammonium head group

Journal of Thermal Analysis and Calorimetry
Authors: Tea Mihelj, Zoran Štefanić, and Vlasta Tomašić

of hydrophobic and hydrophilic layers is visible ( Fig. 2 ). The picrate groups are stacked one on top of the other utilizing π…π stacking interactions with closest distance between C atoms of 3.29 Å. Each of the picrate groups forms C–H…O hydrogen

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, the following ones can be found: O–H…N, O–H…O, and C–H…O. They are created between sulphate ion, water and hmta molecules and they are engaged in creating different graph sets [ 34 , 35 ]. Taking into consideration unitary graph set level, the only D

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Abstract  

The present study determined the organic and inorganic composition of human enamel and dentin. The instrumental neutron activation analysis, inductively-coupled plasma spectrometer, thermogravimetric and differential thermal analysis and X-ray diffraction analysis applied were and performed in the Nuclear Technology Development Centre (CDTN) and Elemental Analysis in the Department of Chemistry of the Federal University of Pernambuco, Brazil. The coronal dentin and enamel were separated from dentin mechanically (1) and by wear (2). The analyses were effective and led to the identification of the main elements present in enamel and dentin: Ca, Na, Cl, Zn, P, Mg, N, C, H, O. There was no contamination of samples of enamel or dentin in either separation technique; however, with separation technique 1, lower percentages of mainly Ca (7.25%) and O (15.16%) components were detected in dentin compared with technique 2.

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Abstract  

Fast neutron activation analysis has been applied to the direct determination of oxygen in coal conversion liquids. The detection system consists of two solid 7.6 cm×7.6 cm NaI(T1) detectors connected to a summing amplifier and mounted at 180° with respect to a uniaxially rotated sample container. Differences have been observed in the gamma-ray self-absorption for the low average atomic number organic matrix in coal liquids as compared to the higher average atomic number standards such as USGS Standard Rock BCR-1 and NBS Standard Reference Mateiral 136b, K2Cr2O7, which have commonly been used for oxygen determinations in silicate rocks. In order to minimize problems associated with self-absorption and variable irradiation and counting geometries, a set of organic liquids was selected and evaluated for use as oxygen standards in the analysis of coal-derived liquids. The standard liquids were selected using criteria of high boiling point, well-defined stoichiometry, high purity, non-hygroscopic nature and simple C−H−O elemental composition. The final set of liquid standards is shown to yield an experimental oxygen—stoichiometric oxygen correlation coefficient of 0.9995 with an intercept at the origin, for liquids with oxygen contents from 3.55 to 49.94%. Dilutions of standards from the set with n-hexane permit extension of the range to lower oxygen contents.

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. Agents Chemother. 13 ( 1978 ) 657 – 664 . [5] C.H. O’Callaghan , R.B. Sykes , A. Griffiths , J.E. Thornton . Antimicrob. Agents Chemother. 9

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. C. Loibl C. H. O. Soo Hyun F. L. O. R. Diekmann M. T. Batte

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(OH 2 ) 2 ](NO 3 ) 4 complex. Four nitrate ions, present in lattice have been omitted for clarity Fig. 2 Figure showing C–H ··· O and O–H ··· O intermolecular interactions

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.87 Other monoaromatics 1.95 Other polyfunctional C, H, O 2.20 Other polyfunctional organics 2

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ICD-11 Gaming Disorder: Needed and just in time or dangerous and much too early?

Commentary on: Scholars’ open debate paper on the World Health Organization ICD-11 Gaming Disorder proposal (Aarseth et al.)

Journal of Behavioral Addictions
Author: Wim van den Brink

. M. , Rehbein , F. , Ko , C. H. , & O’Brien , C. P. ( 2015 ). Internet Gaming Disorder in the DSM-5 . Current Psychiatry Reports, 17, 72 . doi: 10.1007/s11920-015-0610-0 10.1007/s11920

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