High Velocity Flow in and Around Long Perforation Tunnels

In oil industries, wells are mostly cased and perforated rather than completing the producing formation as open-hole. This study concentrates on the steady-state flow behaviour of a single-phase fluid in and around perforated completion tunnels (up to 50 inches long) including inertial effects (Non-Darcy flow). It is shown that the pressure drop inside long perforated tunnels under high flow velocity conditions is negligible compared to that around the perforated region within the porous medium. The results also indicate that the impact of perforation parameters varies with increasing fluid velocity but approaches an asymptotic value at very high flow velocity. The perforation length is the most important parameter whereas perforation radius, rock and fluid properties have little impact on the perforation performance.     

Application of a Sawdust/Fe3O4 and Sawdust/Fe3O4/PEI as a Selective Adsorbent for Pb(II) Removal

Based on the advantages of Fe₃O₄ nanoparticles (MNPs), sawdust (SD), and polyethlenimine (PEI) respectively, the SD/MNPs/PEI composites with layered structure were synthesized. The features of the nanocomposites were characterized and experimental conditions were used to evaluate the potential of SD/ MNPs and SD/MNPs/PEI nanocomposites in removing lead ions Pb2+ in a batch system. By cross-linking PEI on the SD/ MNPs, chelating group on the surface of adsorbent is made, which increases the ability of the nanocomposite to attract Pb(II) from aqueous solutions. Results show an increase in the adsorption by about 31% on SD/MNPs, by about 98% in SD/MNPs/PEI.

     

Chemical composition of Silene morganae Freyn volatile oil

The essential oil composition of flowering aerial parts of Iranian Silene morganae Freyn (Caryophyllaceae) was analysed for the first time using gas chromatography and gas chromatography–mass spectrometry. Thirty-one compounds consisting of 90.3% of the volatile oil were detected. The major constituents were benzaldehyde (11.6%), (Z)-3-hexenyl acetate (9.6%), (E)-β-ocimene (8.2%) and linalool (7.4%). Terpenoids (43.5%), particularly monoterpene hydrocarbons (24.2%), had the highest contribution in S. morganae Freyn flowering aerial parts oil.     

Evaluation of poly ε-caprolactone electrospun nanofibers loaded with Hypericum perforatum extract as a wound dressing

Research on Chemical Intermediates - In this study, for the first time, a biocompatible and non-toxic herbal wound dressing was made by encapsulation of Hypericum perforatum alcoholic extract at...     

Dynamic simulation of a heat recovery steam generator dedicated to a brine concentration plant

Journal of Thermal Analysis and Calorimetry - Considering water level and pressure variation in drum of a natural circulation heat recovery steam generator (HRSG) is very crucial to...     

Pre‐concentration of trace amount of bisphenol A in water samples by palm leaf ash and determination with high‐performance liquid chromatography

Palm leaf ash was characterized and used as low‐cost adsorbent for solid‐phase extraction and preconcentration of bisphenol A (BPA) in real water samples. Analysis of BPA was carried out using HPLC involving Eurospher 100–5‐C₁₈ (25 cm × 4.5 mm, particle size 5 μm) column and water–acetonitrile (40:60, v/v) as mobile phase. The adsorption was achieved quantitatively at a pH of 6 with elution by 3 mL acetonitrile. The limits of detection and enrichment factor were 0.02 μg L^?1 and 333, respectively. Under optimum conditions the relative standard deviation (RSD) was 2% (n = 10). Comparison of qualification criteria of presented preconcentration procedure with other research indicated that palm leaf ash adsorbent was better than many of the adsorbents in terms of cost and reusability. Also, the limit of detection, precision and enrichment factor were comparable and even better than the previously reported methods. Finally, the efficiency of method was computed by determination of trace amounts of BPA in sea, river, mineral and tap waters with recoveries of 93.3–105.5% and RSDs of 0.61–3.12%.. Briefly, the developed solid‐phase extraction and Preparative layer chromatography (PLC) methods may be used for bisphenol A monitoring in any environmental water sample. Copyright © 2016 John Wiley & Sons, Ltd.     

Phosphoramidates: Synthesis,spectroscopy, and X‐Ray crystallography

A series of novel phosphoramidates with a general formula P(O)X₁X₂X₃, where X₁ = X₂ = X₃ = 1H‐1,2,4‐triazol ( 1 ); X₁ = X₂ = X₃ = N‐phenylhydrazine ( 2 ); X₁ = Br, X₂ = X₃ = N‐phenylhydrazine ( 3 ), X₁ = Br, X₂ = X₃ = dipropylamine ( 4 ), and X₁ = X₂ = X₃ = 1,4‐dioxa‐8‐azaspiro[4.5]decane ( 5 ) as well as [P(O)(NC₄H₈NH‐CH₃)⁺₃.3Cl^‐] ( 6 ), were synthesized and characterized by ¹H, ¹³C, ³¹P NMR, IR spectroscopy, and elemental analysis. It is interesting that the P atoms of compounds 3 and 4 are the most upfielded atoms (δ(³¹P) = −23.00, −21.65 ppm) among molecules 1–6 . This indicates that the Br atom acts as a strong electron donor to the P atom via a resonance interaction. The ¹H and ¹³C NMR spectra of compound 5 reveal three separate sets of peaks for the aliphatic CH² protons of three four‐membered rings. This can be explained by different spatial orientations (conformations) of the aliphatic rings. The crystal structure of compound 6 was also determined by X‐ray crystallography. There are intermolecular N H ···Cl hydrogen bonds in this structure. © 2012 Wiley Periodicals, Inc. Heteroatom Chem 23:478–485, 2012; View this article online at wileyonlinelibrary.com . DOI 10.1002/hc.21040     

Synthesis and characterization of activated carbon@zerovalent iron–nickel nanoadsorbent for highly efficient removal of Reactive Orange 16 from aqueous sample: experimental design,kinetic, isotherm and thermodynamic studies

Research on Chemical Intermediates - A simple and fast method based on activated carbon@nanozerovalent iron–nickel (AC@nZVI/Ni) nanoadsorbent was developed for highly efficient removal of...