Journal of Applied Chemistry http://www.hindawi.com The latest articles from Hindawi Publishing Corporation © 2014 , Hindawi Publishing Corporation . All rights reserved. Ultrasonic Investigations of Molecular Interaction in Binary Mixtures of Cyclohexanone with Isomers of Butanol Thu, 18 Dec 2014 07:30:28 +0000 http://www.hindawi.com/journals/jac/2014/741795/ Ultrasonic speed, , and density, , have been measured in binary liquid mixtures of cyclohexanone with the isomers of butanol (-butanol, sec-butanol, and tert-butanol) at 308.15 K over the entire range of composition. Molar volume (), adiabatic compressibility (), intermolecular free length (), acoustic impedance (), and their excess/deviation along with have been calculated from the experimental data. These values have been fitted to Redlich-Kister type polynomial equation. Positive values of , , and negative values of , have been observed for all the liquid mixtures indicating the existence of weak interactions between components. Rupture of H-bond or reduction in H-bond strength of isomers of butanol or breaking of the structure of one or both of the components in a solution causes the existence of dispersions in the present investigated binary mixtures. The data obtained from , , and excess partial molar volumes , , reflects the inferences drawn from . Furthermore, FTIR spectra support the conclusions drawn from excess/deviation properties. The measured values of ultrasonic speed for all the investigated mixtures have been compared with the theoretically estimated values using empirical relations such as, Nomoto, Van Dael and Vangeels, Impedance and Rao specific sound speed. Sk. Md Nayeem, M. Kondaiah, K. Sreekanth, and D. Krishna Rao Copyright © 2014 Sk. Md Nayeem et al. All rights reserved. Kinetics and Thermodynamic Studies of Depolymerization of Nylon Waste by Hydrolysis Reaction Mon, 08 Dec 2014 10:42:46 +0000 http://www.hindawi.com/journals/jac/2014/286709/ Depolymerization reaction of nylon waste was carried out by hydrolysis reaction. Yield of depolymerization products was up to 72.20% for a two-hour reaction time. The products obtained were characterized by melting point and FTIR spectra. The values obtained for dibenzoyl derivative of hexamethylenediamine (DBHMD) agreed with those of the pure substance. Chemical kinetics of this reaction shows that it is a first-order reaction with respect to hexamethylenediamine (HMD) concentration with velocity constant  min−1. The energy of activation and Arrhenius constant obtained by Arrhenius plot were 87.22 KJg−1 and 0.129, respectively. The other thermodynamic parameters such as enthalpy of activation () and entropy of activation () and free energy of activation were 5975.85 J and −270.86 J·K−1·mol−1 and 101.59 KJ·mol−1, respectively. D. B. Patil and S. V. Madhamshettiwar Copyright © 2014 D. B. Patil and S. V. Madhamshettiwar. All rights reserved. Characterization of Native and Modified Starches by Potentiometric Titration Wed, 03 Dec 2014 00:10:02 +0000 http://www.hindawi.com/journals/jac/2014/162480/ The use of potentiometric titration for the analysis and characterization of native and modified starches is highlighted. The polyelectrolytic behavior of oxidized starches (thermal and thermal-chemical oxidation), a graft copolymer of itaconic acid (IA) onto starch, and starch esters (mono- and diester itaconate) was compared with the behavior of native starch, the homopolymer, and the acid employed as a graft monomer and substituent. Starch esters showed higher percentages of acidity, followed by graft copolymer of itaconic acid and finally oxidized starches. Analytical techniques and synthesis of modified starches were also described. Diana Soto, Jose Urdaneta, and Kelly Pernia Copyright © 2014 Diana Soto et al. All rights reserved. Methods for Detection of Aflatoxins in Agricultural Food Crops Thu, 13 Nov 2014 06:18:27 +0000 http://www.hindawi.com/journals/jac/2014/706291/ Aflatoxins are toxic carcinogenic secondary metabolites produced predominantly by two fungal species: Aspergillus flavus and Aspergillus parasiticus. These fungal species are contaminants of foodstuff as well as feeds and are responsible for aflatoxin contamination of these agro products. The toxicity and potency of aflatoxins make them the primary health hazard as well as responsible for losses associated with contaminations of processed foods and feeds. Determination of aflatoxins concentration in food stuff and feeds is thus very important. However, due to their low concentration in foods and feedstuff, analytical methods for detection and quantification of aflatoxins have to be specific, sensitive, and simple to carry out. Several methods including thin-layer chromatography (TLC), high-performance liquid chromatography (HPLC), mass spectroscopy, enzyme-linked immune-sorbent assay (ELISA), and electrochemical immunosensor, among others, have been described for detecting and quantifying aflatoxins in foods. Each of these methods has advantages and limitations in aflatoxins analysis. This review critically examines each of the methods used for detection of aflatoxins in foodstuff, highlighting the advantages and limitations of each method. Finally, a way forward for overcoming such obstacles is suggested. Alex P. Wacoo, Deborah Wendiro, Peter C. Vuzi, and Joseph F. Hawumba Copyright © 2014 Alex P. Wacoo et al. All rights reserved. Studies on Mechanical, Thermal, and Morphological Properties of Glass Fibre Reinforced Polyoxymethylene Nanocomposite Thu, 06 Nov 2014 11:02:03 +0000 http://www.hindawi.com/journals/jac/2014/782618/ Polyoxymethylene is a material which has excellent mechanical properties similar to Nylon-6 filled with 30% GF. 75% POM and 25% glass fibre (POMGF) were blended with nanoclay to increase the tensile and flexural properties. Samples were extruded in twin screw extruder to blend POMGF and (1%, 3%, and 5%) Cloisite 25A nanoclay and specimens were prepared by injection moulding process. The tensile properties, flexural properties, impact strength, and hardness were investigated for the nanocomposites. The fibre pull-outs, fibre matrix adhesion, and cracks in composites were investigated by using scanning electron microscopy. 1% POMGF nanocomposite has low water absorption property. Addition of nanoclay improves the mechanical properties and thermal properties marginally. Improper blending of glass fibre and nanoclay gives low tensile strength and impact strength. SEM image shows the mixing of glass fibre and nanoclay among which 1% POMGF nanocomposite shows better properties compared to others. The thermal stability decreased marginally only with the addition of nanoclay. K. Mohan Babu and M. Mettilda Copyright © 2014 K. Mohan Babu and M. Mettilda. All rights reserved. Visual Detection and Determination of Melamine Using Synthetic Dyes Thu, 25 Sep 2014 10:51:43 +0000 http://www.hindawi.com/journals/jac/2014/457254/ We have used spectroscopic technique for the detection of melamine. The effect of melamine on the colour as well as the pH of bromophenol, methyl red and alizarin red dye solutions was examined at different mole ratios. It is found that we observe color transition and the absorption maxima for bromophenol were at 598 nm, while for methyl red, and alizarin red-S dye they are at 520 nm and 423 nm, respectively. We observe an increase in the absorption intensities at 598 nm with increase in the concentration of melamine in bromophenol blue dye. The absorption intensities at 520 nm decreases and new peak at 420 nm emerges in methyl red dye-melamine mixture. While the absorption intensities at 420 nm decreases and 520 nm peak emerges in alizarin red S dye-melamine at higher mole ratios. The results indicate that we can choose the appropriate dye of suitable range to detect the concentration of melamine from 3 to 206 mg dm−3. The results demonstrate possible use of the simple method for the qualitative and quantitative detection of melamine in adulterated food samples. Ramesh Thimmasandra Narayan and Kirana Devarahosahally Veeranna Copyright © 2014 Ramesh Thimmasandra Narayan and Kirana Devarahosahally Veeranna. All rights reserved. Industrial Waste-Derived Nanoparticles and Microspheres Can Be Potent Antimicrobial and Functional Ingredients Wed, 17 Sep 2014 12:31:45 +0000 http://www.hindawi.com/journals/jac/2014/171427/ Rapeseed oilcake or press-cake is generated as bulk waste during oil extraction from oilseeds. Owing to its high protein content, further processing of oilcakes into vegetable protein generates large quantities of fibrous residue (“oil-and-protein” spent meal) as by-product, which currently has very limited practical utility. Here, we report hydrothermal carbonization of this industrial waste to convert it into carbon nanoparticles, bestowed with multitude of functionalities. We demonstrate that these nanoparticles can be assembled into micrometer-sized spheres when precipitated from water by acetone. These microspheres, with their added feature of hemocompatibility, can be potentially utilized as an encapsulation vehicle for the protection of thermolabile compounds (such as protein); however, the secondary and tertiary features of the protein were marginally perturbed by the encapsulation process. The synthesized carbon nanoparticle was found to be an effective biocidal agent, exhibiting bacterial cellular damage and complex formation with the bacterial plasmid (evident from ethidium bromide exclusion assay), which are critical for cell survival. The results show the ability to convert industrial biowaste into useful nanomaterials for use in food industries and also suggest new scalable and simple approaches to improve environmental sustainability in industrial processes. Manashi Das Purkayastha, Ajay Kumar Manhar, Manabendra Mandal, and Charu Lata Mahanta Copyright © 2014 Manashi Das Purkayastha et al. All rights reserved. Averrhoa carambola: A Renewable Source of Oxalic Acid for the Facile and Green Synthesis of Divalent Metal (Fe, Co, Ni, Zn, and Cu) Oxalates and Oxide Nanoparticles Wed, 17 Sep 2014 12:12:48 +0000 http://www.hindawi.com/journals/jac/2014/767695/ A green, simple, and environmentally benign synthetic approach has been utilised to obtain some bivalent metal oxalates from Averrhoa carambola juice extract, without any purification or special treatment of the juice. The main acid components (oxalic acid and ascorbic acid) of the juice were identified by HPLC technique. The effect of temperature on the purity of the product has been investigated. The as-synthesized metal oxalates were thermally decomposed at low temperatures to their respective metal oxide nanoparticles. The metal oxalates and their respective thermal decomposition products were characterized by Fourier Transform Infrared spectroscopy, X-ray diffraction analysis, and thermogravimetry. Nguimezong Nguefack Marius Borel, Josepha Foba-Tendo, Divine Mbom Yufanyi, Ekane Peter Etape, Jude Namanga Eko, and Lambi John Ngolui Copyright © 2014 Nguimezong Nguefack Marius Borel et al. All rights reserved. Bioavailability Studies of Metals in Surface Water of River Challawa, Nigeria Mon, 15 Sep 2014 13:11:06 +0000 http://www.hindawi.com/journals/jac/2014/648453/ Due to industrialization of Kano City, more industries located within Challawa industrial estate have discharged waste informed of effluents into River Challawa, which is the main source of irrigation water for agricultural land. Hence, this study is aim at assessing the bioavailable fractions of the metals zinc (Zn), lead (Pb), copper (Cu), chromium (Cr) and cadmium (Cd) in surface water of river Challawa, Kano, Nigeria, across seasons. It was found that the concentrations of most metals increased significantly during the dry seasons. Concentrations of Cu and Zn are within the standard limits of EPA and WHO for these metals in drinking water while Pb, Cr, and Cd have their concentrations higher than EPA and WHO standard limits. Analysis of relationship between metals indicated significant positive correlation () between Cr and Zn, in all seasons with exception of warm and dry season. This might explain the consistent variation of these metals in the sites in a particular season. Also, significant negative correlation was observed between Cd and Cu (hot and dry season). The chemical fractionation trends were found to be dominated by particulate fractions of metals studied except Zn (cool and dry season) and Cd. The highest percentages of all metals analysed were found in the particulate fraction with exception of Cd. This could reflect less availability of this metal to the immediate environment. However, availability of metals such as Cd, Cr, and Pb in the dissolved and mobile fractions reflects the greater tendency to become available to the aquatic system and through the food chain to man. A. Uzairu, O. J. Okunola, R. J. Wakawa, and S. G. Adewusi Copyright © 2014 A. Uzairu et al. All rights reserved. Validation of a Serum Analysis Method to Analyze Antihistamines by Capillary Electrophoresis Mon, 25 Aug 2014 00:00:00 +0000 http://www.hindawi.com/journals/jac/2014/842519/ The validation of an electrophoresis-based analytical method to quantify 17 antihistamines in pharmaceutical formulations and serum is described. Then, whether the methodology provides true values with low uncertainty and is able to detect the concentration range level of analyte usually found in the matrix was evaluated. The analytical method was validated following the recommendations of an official guide to provide more reliability to the results. The ICH Harmonized Tripartite Guideline was selected because it was especially developed for analysis of drugs. The guide and the following required validation parameters, selectivity, calibration range, linearity, limit of detection, limit of quantification, inter- and intraday accuracy and precision, and robustness, were described. The method was inexpensive, fast, simple, environmentally friendly, and useful for routine analysis. The methodology was successfully validated and applied to commercial pharmaceutical formulations and spiked blank serum samples. J. Peris-Vicente, S. Carda-Broch, and J. Esteve-Romero Copyright © 2014 J. Peris-Vicente et al. All rights reserved. Processing and Properties of Carbon Nanotube PVC Composites Sun, 17 Aug 2014 08:03:55 +0000 http://www.hindawi.com/journals/jac/2014/307274/ Commercially available multiwalled carbon nanotubes (MWCNT) were incorporated in coating masses based on PVC by means of three roll mill. The best results could be obtained using the 5 µm gap. Thin PVC sheets were formed via knife coating having an electrical conductivity up to 1,500 S/m that are applicable as electric heating elements. For the use in the antistatic range, CNT contents ≤0.5% are sufficient. Rheological measurements indicate the quality of particle processing. AFM investigations are suitable to investigate the alignment of the nanoparticles in the bulk polymer. Using this method, the decrease of agglomerates as well as the splitting of CNT bundles within further mass processing could be visualized. Kristin Trommer, Carina Petzold, and Bernd Morgenstern Copyright © 2014 Kristin Trommer et al. All rights reserved. Electron Donor-Acceptor Interaction of 8-Hydroxyquinoline with Citric Acid in Different Solvents: Spectroscopic Studies Sun, 17 Aug 2014 06:27:03 +0000 http://www.hindawi.com/journals/jac/2014/484361/ Charge transfer complex formation between 8-hydroxyquinoline as the electron donor and citric acid as the electron acceptor has been studied spectrophotometrically in ethanol and methanol solvents at room temperature. Absorption band due to charge transfer complex formation was observed near 320 and 325 nm in ethanol and methanol, respectively. The stoichiometric ratio of the complex has been found 3 : 1 by using Job’s and conductometric titration methods. Benesi-Hildebrand equation has been applied to estimate the formation constant and molecular extinction coefficient. It was found that the value of formation constant was larger in ethanol than in methanol. The physical parameters, ionization potential, and standard free energy change of the formed complex were determined and evaluated in the ethanol and methanol solvents. Demelash Jado, Khalid Siraj, and Nathan Meka Copyright © 2014 Demelash Jado et al. All rights reserved. A Study of the Uptake of Heavy Metals by Plants near Metal-Scrap Dumpsite in Zaria, Nigeria Tue, 12 Aug 2014 09:45:56 +0000 http://www.hindawi.com/journals/jac/2014/394650/ The research work investigates the metal uptake of the plants Lycopersicon esculentum (tomato), Rumex acetosa (sorrel), and Solanum melongena (garden egg) collected from experimental sites and a control area in Zaria, Nigeria. The concentrations of Cd, Cu, Fe, Pb, Mn, and Zn in different parts of each of the plant species grown on the experimental and control soils were determined using atomic absorption spectrophotometry. The experimental levels of the metals were higher than those at the control site and the limits recommended by Food and Agricultural Organisation/World Health Organisation (FAO/WHO). Solanum melongena showed bioaccumulation factor (BF) and transfer factor (TF) greater than 1 for Cd, Pb, and Mn; Rumex acetosa showed BF and TF greater than 1 for Mn and Zn, and TF was greater than 1 for Cu and Fe; Lycopersicon esculentum had only the TF for Fe, Pb, Mn, and Zn greater than 1. This results implies that Solanum melongena and Rumex acetosa plants can be effectively used for phytoremediation of Cd, Pb, Mn, and Zn from the dumpsite. Pearson’s correlation coefficient values were greater than 0.75 for all the metals studied which indicated that the high metal level in the experimental soil was a result of the metal-scrap. Zakka Israila Yashim, Omoniyi Kehinde Israel, and Musa Hannatu Copyright © 2014 Zakka Israila Yashim et al. All rights reserved. Investigation of Regenerated Cellulose/Poly(acrylic acid) Composite Films for Potential Wound Healing Applications: A Preliminary Study Tue, 06 May 2014 06:25:03 +0000 http://www.hindawi.com/journals/jac/2014/325627/ Regenerated cellulose/poly(acrylic acid) composite films have been synthesized for wound dressing applications. The water absorbency of these films was studied as a function of amount of cross-linker N,N′-methylenebisacrylamide and cellulose contents in the feed mixture. The samples, having different compositions, showed tensile strength and percent elongation in the range of to  N/m2 and 110 to 265, respectively. The water vapor transmission rate (WVTR) for various films was found to be in the range of 2.03 to 7.18 mg/cm2/h. These films were loaded with antibacterial drug miconazole nitrate and their release was studied in the physiological pH at 37°C. The release data was found to fit well the diffusion controlled Higuchi model. Finally the films demonstrated fair antibacterial and antifungal action, thus establishing their strong candidature as wound dressing materials. Manjula Bajpai, S. K. Bajpai, and Dinesh Gautam Copyright © 2014 Manjula Bajpai et al. All rights reserved. Benign Methodology and Efficient Catalysis for the One-Pot Multicomponent Synthesis of Dihydropyrimidinones and Thiones: A New Key for Old Lock Wed, 09 Apr 2014 12:17:53 +0000 http://www.hindawi.com/journals/jac/2014/835758/ In the present communication, under the influence of microwaves, cuprous chloride has been demonstrated to be safe, mild, efficient, and inexpensive catalyst for the Biginelli discovered multicomponent reaction (MCR) between aromatic aldehydes, urea/substituted urea, and ethyl acetoacetate to produce structurally diverse dihydropyrimidin-2(1H)-ones (DHPMs) and thiones in an ecofriendly solvent-free protocol. The practical and simple protocol led to excellent yields of the dihydropyrimidin-2(1H)-one derivatives under mild reaction conditions and within short span of reaction times with easy reaction workup by maintaining excellent atom economy. Parvez Ali, Naziyanaz Pathan, and Taibi Ben Hadda Copyright © 2014 Parvez Ali et al. All rights reserved. Synthesis of Triphenyltin (IV) and Dibutyltin (IV) Complexes of 1-Aryl-2,5-dithiohydrazodicarbonamides and Their Characterization Wed, 05 Mar 2014 15:55:38 +0000 http://www.hindawi.com/journals/jac/2014/529764/ Organotin complexes of the types Ph3SnL and Bu2SnL [where Ph = phenyl and Bu = butyl; HL = 1-phenyl-2,5-dithiohydrazodicarbonamide (HPhthc), 1-benzyl-2,5-dithiohydrazodicarbonamide (Hbzthc), 1-(4-ethoxyphenyl)-2,5-dithiohydrazodicarbonamide (HEtOPhthc)] have been prepared. Molar conductance studies demonstrate the nonionic behavior of the complexes. The 1H and 13C nuclear magnetic resonance and FAB mass spectra of the complexes are consistent with the proposed stoichiometry. Infrared spectra suggest an anionic bidentate coordinating behavior of the ligands. Rashmi B. Rastogi, Karuna Singh, and Vinay Jaiswal Copyright © 2014 Rashmi B. Rastogi et al. All rights reserved. Chalcogenide Thin Film Substrate for Protein Biochip Application Wed, 05 Mar 2014 11:40:23 +0000 http://www.hindawi.com/journals/jac/2014/152734/ Diagnostic of pathogen in the human biological liquids by biochip technology is an intensively developed methodic now. The main and the most important part of biochip is the adsorbing layer. Adsorption properties of chalcogenide films to protein (rat monoclonal antibodies) were tested. The films were prepared by conventional thermal deposition technique and by pulsed laser deposition technique. Two methods were used for forming in the films the two-dimensional map of adsorbing places for probe testing. One is using photoresist properties of chalcogenide films; another is using photo-induced oxidation of chalcogenide films. It was shown Good selectivity of the developed structures to protein markers was shown. A. S. Tveryanovich, A. S. Vasileva, A. V. Belykh, E. N. Borisov, and Yu. S. Tveryanovich Copyright © 2014 A. S. Tveryanovich et al. All rights reserved. Measurement and Correlation for Solubility of Some Pyrimidine Derivatives in Different Solvents Mon, 03 Mar 2014 12:17:20 +0000 http://www.hindawi.com/journals/jac/2014/450294/ Some new pyrimidine derivatives have been synthesized and their characterization was done by IR, NMR, and mass spectral data. The solubility of these synthesized compounds has been studied in methanol, N,N dimethylformamide (DMF), and carbon tetrachloride (CCl4) by gravimetrical method from 298.15 to 328.15 K under atmospheric pressure and the solubility data were correlated against temperature. The solubility is found to increase with temperature and order of solubility is DMF > methanol > CCl4. The experimental solubility data is correlated with the modified Apelblat equation. Some thermodynamic parameters such as dissolution enthalpy, Gibbs energy of dissolution, and entropy of mixing have also been calculated. Kapil Bhesaniya and Shipra Baluja Copyright © 2014 Kapil Bhesaniya and Shipra Baluja. All rights reserved. Polyaniline/Palm Oil Blend for Anticorrosion of Mild Steel in Saline Environment Mon, 17 Feb 2014 13:54:19 +0000 http://www.hindawi.com/journals/jac/2014/973653/ The corrosion protective performance of polyaniline/palm oil (PAni-PO) blend coated on mild steel in 3% NaCl aqueous solutions has been evaluated by electrochemical methods, namely, open circuit potential (ocp), potentiodynamic polarization, and EIS spectroscopy. The surface of mild steel was covered by a dark green protective layer due to the physical interaction between the coating and steel. The permanent shifts of ocp and potentiodynamic polarization towards higher positive value of oxidation potential by about 800 mV and by a decrease in corrosion current density by sixfold in magnitude and an increase of 10 orders of magnitude in charge transfer resistance are due to protective coating. Mohd Rashid, Suhail Sabir, Afidah A. Rahim, and Umesh Waware Copyright © 2014 Mohd Rashid et al. All rights reserved. Synthesis and Spectral Characterization of Novel Spiroindan-1,3-Dione: A Diels Alder Adduct Mon, 30 Dec 2013 08:09:14 +0000 http://www.hindawi.com/journals/jac/2013/415639/ DMSO/Ac2O reagent converts 1,3-indandione (1) to an unusual dimer 1H,1′H-2,2′-biindene-1,1′,3,3′(2H,2′H) tetrone and a dimeric condensation product along with an ylide (1a) at room temperature. This reagent also brings about oxidation of secondary alcohols to corresponding ketones, methyl thiomethylation, and N-hydroxymethylation in phthalimide and converts 4-hydroxycoumarins and dicoumarol to different oxidative and degradation products under varying conditions. However, when 1,3-indandione was refluxed with DMSO/Ac2O reagent at 150°C, it afforded a novel compound, 2-spiroindan 1,3-dione (2), a Diels Alder Adduct, analogous to (3) obtained upon treatment of 1,3-indandione with formaldehyde in presence of primary amines. N. D. Zargar and K. Z. Khan Copyright © 2013 N. D. Zargar and K. Z. Khan. All rights reserved. Contribution of Ion-Exchange and Non-Ion-Exchange Reactions to Sorption of Ammonium Ions by Natural and Activated Aluminosilicate Sorbent Wed, 25 Dec 2013 16:11:50 +0000 http://www.hindawi.com/journals/jac/2013/789410/ The effect of acid and alkaline activation of complex natural aluminosilicate sorbent on its chemical composition, surface properties, and adsorption capacity towards ammonium ions was studied. An increase in specific surface area of the sorbent by 1.3 times after acid treatment and by 1.5 times after alkaline activation was shown. The change of ion-exchange complex of sorbent as a result of activation was observed. Sorption isotherms of ammonium ions on natural and activated samples were obtained and were satisfactorily described by the Langmuir equation. The evaluation and comparison of desorbed cations of alkali and alkaline earth metals were carried out. It was confirmed that ion-exchange processes primarily contributed to sorption of ammonium ions by natural and acid-activated silica-alumina, in contrast to alkali-activated one, for which absorption of nonexchangeable ammonium ions increased adsorption capacity of ammonium ions by 1.5 times. Larisa Belchinskaya, Lyudmila Novikova, Vladimir Khokhlov, and Jen Ly Tkhi Copyright © 2013 Larisa Belchinskaya et al. All rights reserved. Structural Transitions in Sheared Electrically Stabilized Colloidal Crystals Tue, 24 Dec 2013 17:49:18 +0000 http://www.hindawi.com/journals/jac/2013/909841/ A Landau theory is presented for the structural transition of electrically stabilized colloidal crystals under shear. The model suggests that a structural transition from an ordered layered colloidal crystal into a disordered structure occurs at a critical shear stress. The shear induced structural transition is related to a change of the rheological properties caused by the variation of the microstructure which can be verified by scattering experiments. The theory is used to establish the shape of the flow curves. A good qualitative agreement with experimental results can be achieved, while a scaling relation similar to the elastic scaling is established. Joachim Kaldasch, Bernhard Senge, and Jozua Laven Copyright © 2013 Joachim Kaldasch et al. All rights reserved. Analgesic, Anti-Inflammatory, and Antiplatelet Profile of Hydrazones Containing Synthetic Molecules Tue, 17 Dec 2013 10:24:31 +0000 http://www.hindawi.com/journals/jac/2013/247203/ Hydrazones are present in many of the bioactive compounds with wide interest because of their diverse pharmacological applications. Hydrazones possess wide variety of biological activities such as anticonvulsant, antidepressant, analgesic, anti-inflammatory, antiplatelet, antimicrobial, anticancer, antihypertensive, anthelmintic, antidiabetic, antiparasitic, and other anticipated activities. This created an interest for researchers towards synthesized variety of hydrazone derivatives for different biological activities. Therefore many researchers have synthesized hydrazone derivatives as target structures for their biological activities. This is paper focuses on the analgesic, anti-inflammatory, and antiplatelet activities of hydrazones. Mohammad Asif and Asif Husain Copyright © 2013 Mohammad Asif and Asif Husain. All rights reserved. Green Extraction: Enhanced Extraction Yield of Asiatic Acid from Centella asiatica (L.) Nanopowders Sat, 14 Dec 2013 10:58:07 +0000 http://www.hindawi.com/journals/jac/2013/460168/ Nanopowders of Centella asiatica (L.) were produced using planetary ball mill in order to investigate the differences of water extraction yield of asiatic acid as compared to micropowders of Centella asiatica. Effect of extraction time (20–60 min) on extraction yield of asiatic acid from Centella asiatica was examined. Results showed that water extraction of asiatic acid using Centella asiatica nanopowders exhibits was almost 50% higher extraction yield with 7.09 mg/g as compared to the micropowders of Centella asiatica. It was concluded that nanopowders contributed in enhancing water extraction yield of asiatic acid as compared to micropowders. Thereby utilizing nanopowders in water extraction could improve the extraction of asiatic acid via clean, eco-friendly, and less expensive process. M. Z. Borhan, R. Ahmad, M. Rusop, and S. Abdullah Copyright © 2013 M. Z. Borhan et al. All rights reserved. Development of Stability Indicating LC Method for the Estimation of Tolperisone in Bulk and Pharmaceutical Dosage Form Tue, 10 Dec 2013 11:26:57 +0000 http://www.hindawi.com/journals/jac/2013/352984/ A rapid, specific, and sensitive reverse phase high performance liquid chromatographic method has been developed and validated for analysis of tolperisone in both bulk and pharmaceutical dosage form. The HPLC method was performed with a reversed phase C18 SunFire column (250 mm × 4.6 mm i.d., 5 mm particle size), detection at 261 nm and a mixture of methanol, water and pH 7.5 adjusted by use of 1% solution of triethylamine (60 : 40) as mobile phase. The flow rate was 1.0 mL min−1 and effluents were monitored at 261 nm. The retention time of tolperisone was 4.8 min. Tolperisone was subjected to acid and alkali hydrolysis, chemical oxidation, wet hydrolysis, dry heat degradation, and sunlight degradation. The degraded product peaks were well resolved from the pure drug peak with significant difference in their retention time values. Stressed samples were assayed using developed LC method. The proposed method was validated with respect to linearity, accuracy, precision, and robustness. The method was successfully applied to the estimation of tolperisone in tablet dosage forms. U. K. Chhalotiya, K. K. Bhatt, D. A. Shah, S. L. Baldania, and S. B. Patel Copyright © 2013 U. K. Chhalotiya et al. All rights reserved. Modification of Poly(ether ether ketone) Polymer for Fuel Cell Application Tue, 03 Dec 2013 09:52:15 +0000 http://www.hindawi.com/journals/jac/2013/386903/ Polyelectrolyte membrane (PEM) is an important part of PEM fuel cell. Nafion is a commercially known membrane which gives the satisfactory result in PEM fuel cell operating at low temperature. Present research paper includes functionalization of Poly(ether ether ketone) (PEEK) polymer with phosphonic acid group. The functionalization was done with the help of nickel-based catalyst. Further, the polymer was characterized by the FTIR, EDAX, DSC, TGA, and 1H NMR, and it was found that PEEK polymer was functionalized with phosphonic acid group with good thermal stability in comparison to virgin PEEK. Finally, the thin films of functionalized polymer were prepared by solution casting method, and proton conductivity of film samples was measured by impedance spectra whose value was found satisfactory with good thermal stability in comparison to commercially available Nafion membrane. Devesh Shukla, Yuvraj Singh Negi, and Vijai Kumar Copyright © 2013 Devesh Shukla et al. All rights reserved. Naturally Occurring Xanthones: Chemistry and Biology Thu, 14 Nov 2013 13:13:42 +0000 http://www.hindawi.com/journals/jac/2013/621459/ Xanthones are one of the biggest classes of compounds in natural product chemistry. A number of xanthones have been isolated from natural sources of higher plants, fungi, ferns, and lichens. They have gradually risen to great importance because of their medicinal properties. This review focuses on the types, isolation, characterization, biological applications, and biosynthesis of naturally occurring xanthones isolated so far. Different physicochemical and instrumental methods such as liquid-solid and liquid-liquid extraction, TLC, flash chromatography, column chromatography, IR, 1H NMR and 13C NMR spectroscopy, GLC, HPLC, GC, and LCMS have been widely used for isolation and structural elucidation of xanthones. Hepatoprotective, anticarcinogenic, antileprosy, antimalarial, antioxidant, anticholinergic, mutagenicity, radioprotective, immunomodulatory, antibone resorption, antiparasitic, neuraminidase inhibitory, anticomplement, antibacterial, antifungal, algicidal, anti-HIV, cardioprotective, antitumoral, antidiabetes, antihyperlipidemic, antiatherogenic, anti-inflammatory, antiulcer, antidiabetic, hypolipidemic, analgesic, antiasthmatic, antihistaminic, antiamoebic, diuretic, antidiarrheal, larvicidal, and ovicidal activities have been reported for natural occurring xanthones. To a certain extent, this review provides necessary foundation for further research and development of new medicines. J. S. Negi, V. K. Bisht, P. Singh, M. S. M. Rawat, and G. P. Joshi Copyright © 2013 J. S. Negi et al. All rights reserved. Quantification of Benazepril Hydrochloride and Hydrochlorothiazide in Tablet Dosage Form by Simultaneous Equation Spectrophotometric Method Mon, 16 Sep 2013 14:08:03 +0000 http://www.hindawi.com/journals/jac/2013/316137/ Simple, accurate, precise, reproducible, requiring no prior separation, and economical procedures for simultaneous estimation of benazepril hydrochloride (BEN) and Hydrochlorothiazide (HCT) in tablet dosage form have been developed. Simultaneous equation method employs for estimation of both drugs in methanol at 240 nm and 270 nm as two analytical wavelengths. BEN and HCT at their respective (240 nm and 270 nm) show linearity in a concentration range of 2–12 μg/mL and 4–14 μg/mL. Recovery studies for BEN are 100.0–100.6% and 99.8–100.0% for HCT in the case of simultaneous equation method confirming the accuracy of the proposed method. The proposed method is recommended for routine analysis since it is rapid, simple, accurate and also sensitive and specific. Varsha Parmar, Usmangani Chhalotiya, Dimal Shah, Kashyap Bhatt, and Sunil Baldania Copyright © 2013 Varsha Parmar et al. All rights reserved. Synthesis, Antimicrobial, and Anti-HIV1 Activity of Quinazoline-4(3H)-one Derivatives Thu, 12 Sep 2013 10:04:46 +0000 http://www.hindawi.com/journals/jac/2013/387191/ The present investigation aims to synthesize 11 compounds of quinazoline-1 derivatives and to test their antimicrobial and anti-HIV1 activities. A quick-witted method was developed for the synthesis of novel substituted quinazolinone derivatives by summarizing diverse diamines with benzoxazine reactions, and it demonstrated the benefits of typical reactions, handy operation, and outstanding product yields. These compounds were confirmed by elemental analysis, I R, 1H NMR, 13C NMR, and mass spectra. Then antimicrobial and anti-HIV1 activities of the compounds were tested in-vitro. It was found that compounds 7–11 possessed a wide range of anti microbial and anti-HIV1 activity. K. Vijayakumar, A. Jafar Ahamed, and G. Thiruneelakandan Copyright © 2013 K. Vijayakumar et al. All rights reserved. Study of Transport Properties of Tris (hydroxymethyl)aminomethane Hydrochloride in 20% (v/v) Acetone-Water System at Tue, 20 Aug 2013 14:10:46 +0000 http://www.hindawi.com/journals/jac/2013/820153/ Viscometric properties of Tris-(hydroxymethyl)amino methane hydrochloride are measured in 20% (v/v) acetone-water system 303.15°K. The related parameters are the experimental values of viscosity () allow to determine relative viscosity (), viscosity -coefficient of the Jones-Dole equation, free energies of activation of viscous flow and per mole solvent, and solute, respectively. The excess molar volume, excess viscosity, excess Gibb’s free energy, and interaction parameter of Grunberg and Nissan have also been calculated. These studies are of great help in characterizing the structure and properties of solutions. The addition of an organic solvent to water brings about a sharp change in the solvation of ions. Ajita Dixit Copyright © 2013 Ajita Dixit. All rights reserved.