Validation of CFD‐CSD coupling interface methodology using commercial codes

Coupling interface between computational fluid dynamics (CFD) and computational structural dynamics (CSD) is required to provide exchange of information for the simulation of fluid–structure interaction (FSI) phenomena. Accuracy and consistency of information exchanged through coupling interface between the independent CFD and CSD solvers plays a central role in the simulation and prediction of FSI phenomenon, like flutter. In this paper validation of an implemented coupling interface methodology is presented for subsonic, transonic and near supersonic mach regime. The test case chosen for this purpose is the flutter of AGARD445.6 standard I‐wing weakened model configuration for subsonic to near transonic flow regime. Gambit^® and Fluent^® are used for CFD grid generation and solution of fluid dynamic equations, respectively. CSD modeling and simulation are provided by numerical time integration of modal dynamic equations derived through the finite element modeling in ANSYS^® environment. Copyright © 2009 John Wiley & Sons, Ltd.     

Optimization and validation of a fast ultrahigh‐pressure liquid chromatographic method for simultaneous determination of selected sulphonamides in water samples using a fully porous sub‐2 μm column at elevated temperature

High temperature in HPLC is considered a valuable tool helping to overcome the increase in the column backpressure when using small packing particles such as sub‐2 μm, as it allows reduction in the mobile‐phase viscosity. In this study, a fast analytical method based on HPLC‐UV was developed using a sub‐2 μm column at elevated temperature for the simultaneous determination of nine sulphonamides. Owing to the lower viscosity of the mobile phase, the separation could be achieved in 3 min at 60°C for all analytes. The effect of temperature, the organic modifier percentage and the flow rate on the retention time was studied. The method developed was used for the determination of selected sulphonamides in surface and wastewater samples. Sample preparation was carried out by solid‐phase extraction on Oasis HLB cartridges. The method developed was validated based on the linearity, precision, accuracy, detection and quantification limits. The recovery ranged from 70.6 to 96 % with standard deviations not higher than 4.7%, except for sulphanilamide. Limits of detection ranged from 1 to 10 μg/L after optimization of all analytical steps. This method has the highest performance in terms of analytical speed compared with other published HPLC‐UV methods for the determination of sulphonamides in water.     

Quality by Design for Development,Optimization and Characterization of Brucine Ethosomal Gel for Skin Cancer Delivery

Natural products have been extensively used for treating a wide variety of disorders. In recent times, Brucine (BRU) as one of the natural medications extracted from seeds of nux vomica, was investigated for its anticancer activity. As far as we know, this is the first study on BRU anticancer activity against skin cancer. Thus, the rational of this work was implemented to develop, optimize and characterize the anticancer activity of BRU loaded ethosomal gel. Basically, thin film hydration method was used to formulate BRU ethosomal preparations, by means of Central composite design (CCD), which were operated to construct (3²) factorial design. Two independent variables were designated (phospholipid percentage and ethanol percentage) with three responses (vesicular size, encapsulation efficiency and flux). Based on the desirability function, one formula was selected and incorporated into HPMC gel base to develop BRU loaded ethosomal gel. The fabricated gel was assessed for all physical characterization. In-vitro release investigation, ex-vivo permeation and MTT calorimetric assay were performed. BRU loaded ethosomal gel exhibited acceptable values for the characterization parameters which stand proper for topical application. In-vitro release investigation was efficiently prolonged for 6 h. The flux from BRU loaded ethosome was enhanced screening optimum SSTF value. Finally, in-vitro cytotoxicity study proved that BRU loaded ethosomal gel significantly improved the anticancer activity of the drug against A375 human melanoma cell lines. Substantially, the investigation proposed a strong motivation for further study of the lately developed BRU loaded ethosomal gel as a prospective therapeutic strategy for melanoma treatment.     

Advancements in synthesis of pharmacologically active imidazolidin-4-ones and stereochemistry of their Reactions with some Reagents

1-Aryl, 1,3-diaryl- and 5-(2-oxo-2-arylethyl)-2-thioxo-imidazolidin-4-ones 2 were prepared as before, nevertheless, equivalent amounts of potassium hydroxide were added to the reaction conditions. This change, dramatically, reduced the reaction time and highly increased the yield of some derivatives. Treatment of 2 with sulfuric acid converted them into their analogous (E)/(E,Z)-5-(2-oxo-2-arylethylidene) derivatives 3 . Reactions of 2 and/or 3 with chromium trioxide affected their conversion into the corresponding 2,4-diones 4 and 5 , respectively. Treatment of 2 and/or 3 with ethyl bromoacetate affected conversion of the former into their respective 2,4-diones 4 , whereas it gave the respective 2-alkylthio derivatives of the latter. Reactions of 2b with aromatic aldehydes gave mixtures of spiro-1H- and 2H-pyrrole diastereomers. Structures of the new products were evidenced by infrared, EI-MS, ¹H- and ¹³C-NMR spectroscopic measurements. Many of the selected compounds showed good antimicrobial activity.     

Flow‐Through Potentiometric Sensors for Alizarin Red S Dye and Their Application for Aluminum Determination

Novel selective and sensitive poly (vinyl chloride) membrane sensors are developed for measuring alizarin red S (AR) based on the use of aliquate 336, Mg^IIphthalocyanine (MgPc), Cu^IIphthalocyanine (CuPc) and Fe^II phthalocyanine (FePc) plasticized poly (vinyl chloride) membrane. The sensors display Nernestian response with slopes of ‐50.6 ± 0.6 , ‐37.4 ± 0.5 , ‐37.7 ± 0.8 and ‐35.0 ± 0.7 mV decade^?1 over the range of 5.2 × 10^?6 to 1 × 10^?2 mol L^?1 for all of them and detection limits of 5.9 × 10^?7, 1.9 × 10‐^?6 2.3 × 10^?6 and 1.9 × 10^?6 mol L^?1 for aliquate, MgPc, CuPc and FePc membrane based sensor, respectively. The sensors exhibit long life span, long term potential stability, high reproducibility, fast response and good discrimination ability towards alizarinate ion in comparison with many other anions. A tubular detector based on aliquate, MgPc, CuPc and FePc was further developed and coupled to a flow‐injection system for alizarin (AR) determination. Under optimized conditions, the linearity range is 1.0 × 10^?5‐ 1.0 × 10^?1 mol L^?1, with a slope of ‐52.1 ± 0.8, 20.9 ± 0.7, 23.6 ± 0.4 and 25 ± 1.1 mV decade^?1 and a reproducibility of ± 0.8 mV (n = 6) for aliquate, MgPc, CuPc and FePc membrane based sensors, respectively. The sensor based on aliquate is further utilized for a potentiodynamic quantification of aluminum in sludge samples and deodorants. The buffered solution of alizarin was allowed to react in a flow system with aluminum. The calibration curve of Al was found to be linear over a concentration range of 0.1 to 1.8 and 1.0 ‐ 40 μg mL^?1 with a slope = 16.9 (r² = 0.993) and 1.76 (r² = 0.994) mV (μg/mL)^?1 and a detection limit of 0.08 and 0.5 μg mL^?1 for 10^?4 and 10^?3 mol L^?1 AR^? as a carrier, respectively. The method was successfully used for determining aluminum in sludge samples and deodorants. The data agree fairly well the nominal values and with results obtain by continuous flow hydride generation inductively coupled plasma (ICP) method.     

Second representable modules over commutative rings*

Let R be a commutative ring. We investigate R-modules which can be written as finite sums of second R-submodules (we call them second representable). The class of second representable modules lies between the class of finitely generated semisimple modules and the class of representable modules; moreover, we give examples to show that these inclusions are strict even for Abelian groups. We provide sufficient conditions for an R-module M to be have a (minimal) second presentation, in particular within the class of lifting modules. Moreover, we investigate the class of (main) second attached prime ideals related to a module with such a presentation.     

Synthesis and Antitumor Activity of New Polysubstituted Thiophenes and 1,3,4‐Thiadiazoles Incorporating 2,6‐Pyridine Moieties

The versatile multifunctional unreported pyridine‐2,6‐bis(2‐cyano‐N‐phenyl‐3‐oxopropanethioamide) ( 3 ) was prepared starting from pyridine‐2,6‐bis‐(3‐oxopropanenitrile) ( 1 ). Several new series of polysubstituted thiophenes and 1,3,4‐thiadiazoles incorporating 2,6‐pyridine moiety were efficiently synthesized. The newly synthesized compounds were evaluated for their in vitro anticancer activity against human cancer cell lines: hepatocellular liver carcinoma (HEPG2) and Caucasian breast adenocarcinoma (MCF‐7). Some of the newly synthesized compounds exhibited better activity than doxorubicin as a reference drug.     

Synthesis,antimicrobial and anticancer activities of some new N-methylsulphonyl and N-benzenesulphonyl-3-indolyl heterocycles: 1st Cancer Update

A series of 1-(N-methyl 2a–c and N-benzenesulphonyl-1H-indol-3-yl)-3-aryl-prop-2-ene-1-ones 3a–c were prepared and allowed to react with urea, thiourea or guanidine and gave the pyrimidine derivatives 4a–c to 9a–c. Base catalyzed reaction of 2a–c or 3a–c with ethyl acetoacetate gave cyclohexanone derivatives 10a–c and 11a–c, respectively. Reaction of the latter compounds with hydrazine hydrate afforded indazole derivatives 12a–c and 13a–c, respectively. On the other hand, condensation of 2c or 3c with some hydrazine derivatives namely, hydrazine hydrate, acetyl hydrazine, phenyl hydrazine and benzyl hydrazine hydrochloride gave pyrazole derivatives 14a,b-17a,b, respectively. Moreover, reaction of 2c or 3c with hydroxyl amine hydrochloride gave isoxazole derivatives 18a,b. The newly synthesized compounds were tested for their antimicrobial activity and showed that, compounds 14a, 14b, 15a and 15b were found to be the most active ones of all the tested compounds toward Salmonella typhimurium (ATCC 14,028) compared to the reference drug chloramphenicol. Eighteen new compounds namely, pyrimidin-2(1H)-ones 4a–c and 5a–c, pyrimidin-2(1H)-thiones 6a–c and 7a–c and pyrimidin-2-amines 8a–c and 9a–c were tested for their in vitro cytotoxicity against human liver carcinoma (HEPG2), human breast cancer (MCF7) and human colon cancer (HCT-116) cell lines and showed that, compounds 4c, 5c, 6c, 8c and 9c were found to be the highly active compounds compared to the reference drug doxorubicin.     

Electrical Properties of Polymethylmethacrylate Polymer Dispersed Liquid Crystals*

The effect on the electrical properties of polymethylmethacrylate polymer containing liquid crystal as dispersed molecules is investigated in the temperature range 30-100°C and the frequency ange from 100 Hz to 10 kHz. It is found that increasing the liquid crystal content enhances the ac-impedance, decreases the ac-loss conductivity and decreases the value of the dielectric constant. The decrease in the ac-impedance with increasing frequency is associated with a dramatic increase in the ac-loss conductivity at frequencies higher than 1 kHz. The decrease in the ac-conductivity with increasing the dispersed liquid crystal phase is attributed to the reduction of the mobility of the charge carriers. Thus, the dielectric property of the system improves.     

A novel method for the synthesis of 4(3H)-quinazolinones

Condensation of anthranilamide with aryl, alkyl or heteroaryl aldehydes in refluxing ethanol and the presence of CuCl₂ afforded the corresponding 2-substituted quinazolinones in excellent yields.