Experimental investigation on heat transfer behavior of the novel ternary eutectic PCM embedded with MWCNT for thermal energy storage systems

Journal of Thermal Analysis and Calorimetry - In this paper, the variation of thermophysical properties such as the thermal conductivity, thermal energy storage capacity, viscosity, and phase...     

Generation of 0.2-TW 5.5-fs optical pulses at 1 kHz using a differentially pumped hollow-fiber chirped-mirror compressor

Optical pulses with 1.1-mJ energy and 5.5-fs duration have been generated at 1-kHz repetition rate from a chirped pulse amplification Ti:Sapphire laser incorporating a differentially pumped hollow-fiber chirped-mirror compressor. The effects of self-focusing and multi-photon ionization during the beam propagation were minimized by differentially pumping the hollow fiber filled with neon. The spectral broadening at the hollow-fiber compressor was optimized by adjusting gas pressure, laser intensity, and laser chirp, covering from 540 nm to 950 nm. PACS 42.65.Jx; 42.65.Re     

Synthesis and antimycobacterial activity of some beta-carboline alkaloids

In view of the attributed medicinal properties of beta-carboline alkaloids, some new O-acyl derivatives of beta-carboline alkaloid--harmol, were prepared and tested for possible antimycobacterial activity against Mycobacterium tuberculosis H37Rv.     

Spectrophotometric determination ofo- andp-phenylenediamines

Summary Cupric chloride-triphenylphosphine complex gives red color witho-phenylenediamine having maximum absorption at 505–520 nm and 0.5g/ml as visual limit of identification. The reaction is specific foro-phenylenediamine and obeys Beer's law (1 to 10g/ml). This reaction provides the basis of a new method for the Spectrophotometric determination ofo-phenylenediamine ing quantities.Ruthenium trichloride-triphenylphosphine complex gives blue color withp-phenylenediamine having maximum absorption at 580 nm and 2g/ml as visual limit of identification. On the basis of this color reaction a Spectrophotometric method for the determination ofp-phenylenediamine in hair dyes is described. The recovery of the dye from commercial preparations is better than 97%. Other organic compounds do not interfere.

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Zusammenfassung Kupfer(II)chlorid-triphenylphosphin reagiert mito-Phenylendiamin unter Rotfärbung mit maximaler Absorption bei 505 bis 520 nm und 0,5g/ml als Erfassungsgrenze. Die Reaktion ist für o-Phenylendiamin spezifisch und folgt dem Beerschen Gesetz zwischen 1 und 10g/ml. Sie dient als Grundlage für eine neue Methode der spektrophotometrischen Bestimmung von Mikrogrammengen o-Phenylendiamin.Rutheniumtrichlorid-triphenylphosphin reagiert mit p-Phenylendiamin unter Blaufärbung mit maximaler Absorption bei 580 nm und 2g/ml als Erfassungsgrenze. Auf dieser Grundlage läßt sich p-Phenylendiamin in Haarfärbemitteln bestimmen. In handelsüblichen Präparaten werden mehr als 97% des enthaltenen Farbstoffes gefunden. Andere Verbindungen stören nicht.

     

The thermal dissociation of some metal cupferrate chelates

The thermal dissociation of the cupferron complexes with Cu(II), Ni, Co(II), Zn, Cd, Mn(II), Hg(II), Mg, Ca, Ba, Sr, Al, Fe(III). Ce(III), La, and Nd was studied by differential thermal analysis (DTA) and by pyrolysis into a mass spectrometer. The DTA curves consisted mainly of endothermic peaks although some contained exothermic peaks as well. The mass spectrometer showed that cupferron decomposes slightly above room temperature, giving off N₂, NO, N₂O, NH₃ and H₂O. A mechanism for the thermal dissociation of the coppcr(II) cupferrate is proposed.     

Semiquantitative determination of thiourea,thiocyanate, and sulfide by circular thin layer chromatography

Summary A method for semiquantitative determination of thiourea, thiocyanate, and sulfide is described. It involves making circular spots or rings on chromatoplates using the circular thin layer Chromatographic apparatus. The method is based on sensitivity and specificity of spot reactions and comparison of the color intensity of a circular spot with that of sensitivity standards. The accuracy of the method is ± 5% and the procedure is rapid, simple and economical.

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Zusammenfassung Ein Verfahren zur halbquantitativen Bestimmung von Thioharnstoff, Thiocyanat und Sulfid wurde beschrieben. Es beruht auf der chromatographischen Herstellung kreisförmiger Flecken oder Ringe auf Dünnschichtplatten. Mit empfindlichen und spezifischen Tüpfelreaktionen wurden die Flecken gefärbt und die Farbintensität mit Standardproben verglichen. Die Genauigkeit beträgt ± 5%.

     

A sensitive and rapid liquid chromatography tandem mass spectrometry method for quantitative determination of 7-ethyl-10-hydroxycamptothecin (SN-38) in human plasma containing liposome-based SN-38 (LE-SN38)

7-Ethyl-10-hydroxycamptothecin (SN-38) is an active metabolite of Irinotecan (CPT-11), an anticancer pro-drug. To support clinical pharmacokinetic studies for liposome based formulation of SN-38 (LE-SN38) in cancer patients, a rapid, simple and sensitive liquid chromatography tandem mass spectrometry (LC-MS/MS) method has been developed and validated for the quantification of total SN-38 in human plasma. Sample preparation was carried out by one-step protein precipitation using cold acetonitrile with 0.5% acetic acid (v/v). Camptothecin was used as an internal standard (IS). Chromatographic separation of SN-38 and IS was achieved using a Synergi Hydro-RP column (C(18), 50 x 2 mm, 4 micro m), with a gradient elution of acetonitrile and 0.1% acetic acid. After ionization in electrospray source (positive ions), the acquisition was performed in the multiple reactions monitoring mode. Quantitation was accomplished using the precursor-->product ion combinations of m/z 393.1-->349.2 for SN-38 and 349.1-->305.1 for IS. The quantification limit of 0.05 ng/mL was achieved by using much lower volume (0.2 mL) of plasma and in the presence of LE-SN38. The method was validated over the concentration range of 0.05-400 ng/mL. Accuracy was within +/-12% of nominal at all concentration levels. Inter-day and intra-day precisions expressed as percentage coefficient of variation (%CVs) for quality control (QC) samples were less than 14 and 5%, respectively.     

Solvent‐assisted anionic ring opening polymerization of glycidol: Toward medium and high molecular weight hyperbranched polyglycerols

Hyperbranched polyglycerols (HPGs) are globular structures with a large number of functionalizable hydroxyl groups and have excellent in vitro and in vivo biocompatibility profiles comparable to polyethylene glycol. This work introduces a facile method for the synthesis of medium molecular weights (M_ws) (50–300 kDa) HPGs, which has been difficult to synthesize with low polydispersity, with the assistance of solvents by ring opening polymerization. The influence of different solvents (1,4‐dioxane, tetrahydropyran (THP), ethylene glycol diethyl ether (EGDE) and decane), solvent to glycidol ratio, concentration of glycidol and the time of polymerization on M_w and polydispersity of HPGs has been studied. The M_w and polydispersity of HPGs are significantly affected by the nature of the polymerization phase (homogeneous or heterogeneous) and chemical structure of the solvent. The differences in the solvation of the potassium cations and change in the nucleophilicity of the alkoxide anion in various solvents may be responsible for the changes in M_w and PDI of the HPG. The M_w of the HPG decreases in the order 1,4‐dioxane > THP > EGDE >decane. The microstructure, solution and thermal properties of the HPG do not depend on the nature of solvent. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 2614–2621