A simple method to prepare high surface area activated carbon from carboxyl methyl cellulose by low temperature physical activation

Activated carbon with high surface area was prepared from sodium salt of carboxyl methyl cellulose by physical activation at 400 °C followed by treatment in boiling water. The carbon was characterized by XRD, SEM, EPR, TG, IR, surface areas and porosity measurements. The carbon showed alkaline reaction in aqueous solution. It showed high surface area and pore volume in comparison to two commercially available carbons.     

Experimental NMR and MS study of benzoylguanidines. Investigation of E/Z isomerism

Molecules containing the guanidinic nuclei possess several pharmacological applications, and knowing the preferred isomers of a potential drug is important to understand the way it operates pharmacologically. Benzoylguanidines were synthesized in satisfactory to good yields and characterized by NMR, Electrospray Ionization Mass Spectrometry (ESI‐MS) and Fourrier Transform InfraRed Spectroscopy techniques (FTIR). E/Z isomerism of the guanidines was studied and confirmed by NMR analysis in solution (¹H‐¹³C Heteronuclear Single Quantum Coherence (HSQC) and Heteronuclear Multiple‐Bond Correlation (HMBC), ¹H‐¹⁵N HMBC, ¹H‐¹H Correlation Spectroscopy (COSY) and Nuclear Overhauser Effect Spectroscopy (NOESY) experiments) at low temperatures. Compounds with p‐Cl and p‐Br aniline moiety exist mainly as Z isomer with a small proportion of E isomer, whereas compounds with p‐NO2 moiety showed a decrease in proportion of isomer Z. The results are important for the application of these molecules as enzymatic inhibitors. Copyright © 2013 John Wiley & Sons, Ltd.     

On idempotents of a class of commutative rings

Abstract

In the present work, a procedure for determining idempotents of a commutative ring having a sequence of ideals with certain properties is presented. As an application of this procedure, idempotent elements of various commutative rings are determined. Several examples are included illustrating the main results.     

Laser stabilization to an atomic transition using an optically generated dispersive line shape

We report a simple and robust technique to generate a dispersive signal which serves as an error signal to electronically stabilize a monomode continuous-wave laser emitting around an atomic resonance. We explore nonlinear effects in the laser beam propagation through a resonant vapor by way of spatial filtering. The performance of this technique is validated by locking semiconductor lasers to the cesium and rubidium D₂ lines and observing long-term reduction of the emission frequency drifts, making the lasers well adapted for many atomic physics applications.     

Determination of elements in kidney,serum and urine of Wistar rats with Acute Renal Insufficiency using NAA

In this investigation ions in serum, urine and kidney of Wistar rats (control group) and Wistar with Acute Renal Insufficiency (ARI) were quantified using instrumental neutron activation analysis. The measurements in serum and urine were performed before, during and after ischemia-induced ARI. The measurements in kidney were performed for the control and ARI groups. Also, a comparative analysis between the concentration ratios before, during and after ARI was performed in urine and serum samples for both groups. The variations results for Cu in serum and I in urine, before and after ischemia-induced ARI, suggest that these elements must be also investigated in renal dysfunction.     

Propargylation of aromatic compounds using Ce(OTf)3 as catalyst

Ce(OTf)₃ was successfully employed as catalyst for the activation of the hydroxyl group in the Friedel–Crafts reaction of aromatic compounds with propargylic alcohols in nitromethane. The products were obtained in good to excellent yields.     

Raman and Infrared Spectroscopic Characterization of the Phosphate Mineral Lithiophilite—LiMnPO4

Abstract

The metal lithium is very important in industry, including lithium batteries. An important source of lithium besides continental brines is granitic pegmatites as in Australia. Lithiophilite is a lithium and manganese phosphate with chemical formula LiMnPO₄ and forms a solid solution with triphylite, its Fe analog, and belongs to the triphylite group that includes karenwebberite, natrophilite, and sicklerite. The mineral lithiophilite was characterized by chemical analysis and spectroscopic techniques. The chemical is: Li_1.01(Mn_0.60, Fe_0.41, Mg_0.01, Ca_0.01)(PO₄)_0.99 and corresponds to an intermediate member of the triphylite-lithiophilite series, with predominance of the lithiophilite member. The mineral lithiophilite is readily characterized by Raman and infrared spectroscopy.