bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis, characterization and application of [CTA+]MCM-41 in the catalytic conversion of soybean oil to fatty acid methyl esters
Authors: Kothe Vinícius , Alves Helton José , Silveira Marcos Henrique Luciano , Pereira Luiz
Published: May 2018

The transesterification of vegetable oil and/or animal fats in homogeneous alkaline medium is still the most widely used method for the production of biodiesel. However, this process requires raw materials with low acidity and moisture content to prevent undesirable side reactions such as saponification, which leads to emulsification and promotes losses in the reaction yield. Many solid compounds can be used in catalytic processes to reduce these limitations. Heterogeneous catalysts allow easy separation of the reaction media and have the possibility of reuse in several cycles. In this work, [CTA+]MCM-41 molecular sieves were synthesized and characterized by several methods (XRD, SEM, TGA and BET) to be applied in the methanolysis of soybean oil. The resulting materials were characterized as mesoporous solids of type IV with similar textural properties and thermal stability. The catalytic activity of [CTA+]MCM-41 in soybean oil methanolysis was analyzed by gel permeation chromatography (GPC) and the best solid catalyst was applied in a factorial design that was validated by Analysis of Variance (ANOVA). The oil:methanol molar ratio and the catalyst concentration were the variables with the highest statistical effects, with the latter showing a quadratic profile in relation to the response function. The best conversion was achieved at 343 K, 30 min and 3.75 wt % catalyst, which corresponded to a product with 99.2% in fatty acid methyl esters. Calcination caused a total loss in catalytic activity due to the removal of CTA+ cations from the mesoporous solids. Hence, such activity was associated with the formation of (SiO-)(CTA+) ion pairs at the surface of the solid catalyst
Experimental and Theoretical Investigations of Complex Formation of Substituted Phenylazo-Derivatives of Methylphloroglucinol
Authors: Kovalchukova Olga , A.T. Amangdam , S.B. Strashnova , P.V. Strashnov , E.P. Romashkina , O.V. Volyansky
Published: May 2018

Using spectrophotometric titration technique, the processes of complex formation of some phenylazo-derivatives of methylphloroglucinol (MPG) containing hydroxo-, nitro- and nitroso-substituents were studied. The spectral criteria of neutral and ionized forms of the organic ligands in their different tautomeric forms were determined.It was detected that the complex formation is accompanied by formation of one or two chelate cycles which involve azo- or nitroso-fragments and neighboring OH-groups of the organic ligands. Different types of coordination lead to different changes in the electronic absorption spectra.The DFT-B3LYP modeling of a Ni(II) complex of α-hydroxyphenylazo MPG established the most probable coordination mode of the organic ligand: tridentate chelating dianion, distorted square coordination of Ni-cations including one water molecule.  The theoretical results are in a good accordance with the experimental data.
Determination of the Candidiasis Marker in the Urine of Autistic Children
Authors: Czaplińska Joanna Kałużna , Grys Wioletta , Rozetti-Szymańska Anna , Rynkowski Jacek
Published: May 2018

Introduction: Determination of the D/L-arabinitol ratio in urine appears to be a useful diagnostic test to indicate overgrowth of Candida yeast. The aim of this study was to find out whether levels of D/L-arabinitol ratio in the urine of children with  autism are heightened.Material and methods: D/L-arabinitol ratio in urine was determined by capillary gas chromatography with electron  capture detection (GC-ECD). Urine samples were collected from 83 autistic children  (2.5–16 years old) and from 50 healthy children (1.5-16 years old).Results: (16.87%) of autistic children under study had an elevated D/L ratio in urine (>4.25). For 8 of them, the stated norm  was  exceeded less than twice (D/L: 4.39-6.98); for 4 of them the levels of  D/L-arabinitol were higher than cutoff limit 2-3 times (D/L: 8.57-11.6); for 1 child the norm was  exceeded over 5-times (D/L: 21.76); 1 child had a highly rebounding value (D/L: 89.13).       Conclusion: Some of the autistic children show  a raised D/L- arabinitol ratio in urine. Such percentage, in comparison to that reported in literature  for other hospitalized patients, is lower than in the case of hematological, cardiac diseases and cancer, but higher than in the case of children from intensive care unit and persons after long term antibiotic therapies.
Synthesis of Some New Tetracyclic Pyrimidine Derivatives Using Exocyclic α,β-Unsaturated Ketone and Evaluation of Their Antitumor Activities
Authors: El-Mahdy Kamelia
Published: May 2018

Thiazolopyrimidine 2 was obtained from the reaction of dihydropyrimidinone with chloroacetic acid and benzaldehyde. Thiazolopyrimidine 2 containing an α,β-unsaturated ketonic function [-CH=CH-CO-] has been used as a component of Michael addition with an equimolar amount of dinucleophiles to give a series of novel tetracyclic pyrimidine derivatives. Treatment of thiazolopyrimidine 2 with uracil, aminotriazole, cyanoacetic acid hydrazide, o-phenylenediamine or diaminopyridine afforded the corresponding pyridopyrimidine, triazolopyrimidine, pyrazolone, benzodiazepine and triazepine derivative, respectively. The detailed synthesis, spectroscopic data, and antitumor activity for synthesized compounds were reported.
Extraction and Characterization of New Cellulose Fiber from the Agrowaste of Lagenaria Siceraria (Bottle Guard) Plant
Authors: Saravanan N. , Sampath P.S. , Sukantha T.A.
Published: May 2018

This article explores the extraction and characterization of natural fiber from the agro-waste of Lagenaria siceraria (LS)plant stem (commonly known as „bottle guard‟) for the first time. The extracted fiber from the waste stems has highcellulose content (79.91 %) with good tensile strength (257–717 MPa) and thermal stability (withstand up to 339.1°C). Theimmense percentage of crystalline index (92.4%) with the crystalline size (7.2 nm) as well as low density (1.216 g/cm3) ofthe LS fiber renders their possibilit
SYSTEMATIC REVIEW OF SAR REDUCTION TECHNIQUES FOR MINIMIZING MOBILE PHONE RADIATION
Authors: Rajan S.Palanivel , Vivek C.
Published: May 2018

In this mobile digital world cellular handsets and tablet pc’s have become the common used devices .These devices use the Electromagnetic Frequency (EMF) Spectrum which is wide spread in our atmosphere. Electromagnetic fields of all frequencies represent one of the most common and fastest growing environmental influences, about which anxiety and speculation are spreading. All populations are now exposed to varying degrees of EMF, and the levels will continue to increase as technology advances. The World Health Organization (WHO) established the International EMF Project in 1996 to assess the scientific evidence of possible health effects of EMF in the frequency range from 0 to 300 GHz and possibly reducing the effects caused by them. Our project aims in limiting the hazardous EM radiation emitted from the mobile phones. This can be achieved by using the PIFA antenna in the Transfer electromagnetic (TEM) cell experimental setup
COMPARATIVE AND PERFORMANCE ANALYSIS OF INDUCTION MOTOR WITH ANN CONTROLLER
Authors: S Durairaj , Robinson Y. , Muthuramalingam M.
Published: May 2018

A novel design of an adaptive artificial neural network technique (ANN) for controlling of the essential parameters, like as speed,  torque, flux, voltage, current, and power etc of the induction motor is presented in this paper. Induction motors are characterized by way of incredibly non-linear, complicated and time-various dynamics and inaccessibility of its states and outputs for measurements. Thus it can be considered as a challenging engineering difficulty in the industrial sector. A few of them, such as PI, fuzzy strategies, Fuzzy logic based controllers are regarded as capability candidates for such application for operating induction motor. Hence of which, the outcome of the controller is also random and high-rated results are probably not obtained. Resolution of the proper rule base application upon the drawback can be achieved by the use of an ANN controller, which becomes a built-in system of method for the manipulate purposes and yields results, which is the focus of this paper. Within the designed ANN scheme, neural community tactics are used to prefer an appropriate rule base, which is utilizing the back propagation algorithm. The simulation outcome provided on this paper is exhibit the effectiveness of the developed approach, which has acquired faster response time or settling times. Additionally, the procedure developed has got a huge number of benefits within the industrial sector will also be converted into a real time application making use of some interfacing cards.
Groundwater Quality Studies Using Geographic Information System in Dharmapuri District, Tamil Nadu, India
Authors: Rajendran V. , Venkatasubramani R. , Suresh M.
Published: May 2018

This scientific report deals with the quality of groundwater for drinking purpose in the hard-rock aquifer of Dharmapuri district, Tamil Nadu South India. 135 Groundwater samples were collected based on the equal grid method and groundwater quality was assessed. Geographically the aerial extent of the study area is plain portion 3313.15 Sq.Km and Hill and forest 1346.25 Sq.Km. groundwater samples was analyzed in various physicochemical parameters and major ion chemistry like pH, EC, TDS, Ca2+, Mg2+, Na+, K+, HCO3-, Cl-, SO42-, NO3- and  F-. Based on the analytical results, to prepared spatial distribution maps with help of WHO standard. ArcGIS was employed. Attributes were linked and spatial interpolation tool was used. IDW technique was followed for raster and vector mapping. Finally integration analysis was carried out to locate the worst quality zone. Based on the analysis, most of the samples are suitable for drinking. The final integrated map (Drinking quality) reveals that for suitable for drinking and domestic purpose. “Not permissible” water quality zone cover about area 2467.09 sq. km respectively. While “Maximum allowable” water quality zone cover an area of 836.87 sq. km. The “Most desirable” water quality zone an area 9.19 sq.km for drinking and domestic purposes.
Corrosion Inhibition of Mild-Steel in (1M) HCl using Spands Reagent
Authors: Hussain Ala' a. A.
Published: May 2018

The effect of Spands Reagent on the dissolution of Mild-steel in  1M HCl  solution was studied using weight loss and galvanostatic polarization techniques. The inhibition efficiency of inhibitor increases with concentration to attain (75.26%) at concentration  1×10-2 M ,and standing time for 180 min at 25°C. Temperature effect on the corrosion behavior was studied at temperature range from 25-45°C, the results showed that inhibition efficiency decreased with increasing temperature to attain (64.53%) at concentration 1×10-2  M at 45°C and with standing time equal to 180 min. The effect of temperature on the rate of corrosion in the absence and presence of   Spands Reagent was also studied. The Kinetic Parameters were calculated and discussed. The polarization curves revealed that the studied inhibitor represent a mixed–type inhibitors. Adsorption of inhibitor was isotherm physisorption type.
Investigation of using bleaching earth and activated carbon mixturein sunfloweroilrefining
Authors: Gudret Guliyev Nihad , Hikmet Jamal Ibrahimov , Arif Alekperov Jamil , Fariz Ali Amirov , Meherrem Ibrahimova Zenfira
Published: May 2018

Adsorption is one commonly used technique for treatment of sunflower oil. In this study, activated carbon and bleaching earth as a bleaching agent mixed with certain proportions and1% of the mixture added to sunflower oil in the bleaching process. The combination of bleaching earth and activated carbon produced higher adsorption capacity than the single bleaching earth. This article focuses more particularly on heavy metals and polycyclic aromatic hydrocarbons (PAHs) removal. It was detected that, the mixture is an excellent adsorbent in the adsorption of PAHs and metals from sunflower oil with the highest adsorption capacity. The results showed that, the adsorption of metals and PAHs depend strongly on activated carbon and decreased with increasing activated carbonin mixture and the maximum adsorption was reached after using B5 (95 % bleaching earth and 5 % activated carbon combination).
Computational study of the chemical reactivity properties of bis (trimethyl tetrathiafulvalenyl) thiophene
Authors: Amel Bendjeddou , Abbaz Tahar , Gouasmia Abdelkrim , Villemin Didier
Published: May 2018

The chemical reactivity of four bis (trimethyltetrathiafulvalenyl) thiophene is determined by its potential (electronic) energy (hyper) surface. All the quantum chemical calculations have been carried out using DFT level of theory, B3LYP functional and 6-31G(d,p) as basis set. Molecular electrostatic potential (MEP) and HOMO-LUMO energy levels have been performed. The local reactivity descriptor such as Fukui function is also performed to determine the reactive sites within the title molecules. The chemometric methods PCA and HCA were employed to find the subset of variables that could correctly classify the compounds according to their reactivity.
Oxidative cyclisation and methylene insertion in 1,3-indandione derivatives .The mechanistic studies
Authors: Zargar N .D .
Published: May 2018

Dimethyl sulphoxide activated by acetic-anhydride introduces methylthiomethyl group into phenols,oxidises certain medicinally useful secondary alcohols to their corresponding ketones and brings about oxidative rearrangements in different substrates.It converts 4-hydroxy coumarins and dicoumarols,under varying conditions,to a variety of products of both pharmaceutical and mechanistic interest.

When1,3-indandione (1) was interacted with this versatile reagent at water bath temperature,it  afforded an ylide (2) and an oxidative cyclisation product (3).However,its interaction with Ar â€“CH = (CN)R,leads to the formation of a mechanistically interesting compound,indeno[1,2-b]-4H pyran(4).  

DMSO alone has been used as a reagent and yields a number of products of mechanistic interest with different substrates.When 1,3-indandione (1) was refluxed with DMSO alone at elevated temperature,it results the formation of poly(methylene-bis) 1,3-indandione(5) involving methylene group insertion between different 1,3-indandione moieties.Methylene insertion has also been observed when 1,3-indandione (1) was condensed with formaldehyde in presence of alkali carbonates or primary amines to yield (6)and(7) respectively.
Electrochemical and Spectrastudies of Some Sulfa Drug Azodyes and Their Metal Complexes in Aqueous Solution
Authors: Mabrouk E.M. , Omary Kh.A.Al , Omary A.S.Al- , El-Mossalamy E.H.
Published: May 2018

The electrochemical behavior of some azo compounds derived from sulfa drugs derivatives in B.R. buffer solutions of different pH containing 20 (v/v) ethanol was investigated at the mercury  electrode using different techniques (DC,DPP,CV and Coulometry) to investigate the effect of medium on the electro reduction process and suggestion the electrode reaction mechanism. The obtained results denoted that these compounds were reduced undergo a single irreversible 4- electron polarographic wave in acid and neutral solutions which represent the cleavage of the N=N center to the amine stage, whereas in alkaline solution, two wave are obtained the second is 2-electron irreversible wave corresponding to the reduction ofCHO group to CH2OH. The DPP and CV data showed a single peak in solutions of pH< 8, whereas three peaks are in alkaline solutions. The dissociation constants of the investigated compounds were determined by using spectrophotometric and potentiometric methods. Also the metal â€“ ligand formation constants were determined potentiometrically and found in the order CuËƒ CoËƒ Ni ËƒZn.
Comparison Of Fe(II) And Fe(III)-Hydralazine Complexes, A Potentiometric And Spectrophotometric Studa
Authors: Imad Saima , Iqbal Muhammad , Nisar Shazia , Ghaffar Shazia
Published: May 2018

Iron in oxidation states (+2 and +3) is very essential element for human body, and its concentration significantly altered in cardio vascular disease. So the aim of the present work is to study the interaction of Fe(II) and Fe(III) with very commonly used antihypertensive drug hydralazine through potentiometric and spectrophotometric methods. The objectives of the work is to study the stoichiometry, behavior of the complexes in aqueous solution, effect of pH and behavior of this drugs towards both oxidation states of Iron. Both methods show that hydralazine forms a stable complex with both oxidation states of the metal, but the nature of complex changes with change in pH, ligand concentration and with time span. Both methods confirms 1:2 stoichiometry for Fe(II)-Hydralazine while 1:3 for Fe(III)-Hydralazine. Stabilities of both complexes were also calculated. For Fe(II)-Hydralazine complex values of log Î²1 and log Î²2 were found to be 4.99 and  7.58 respectively. For Fe(III)-Hydralazine complex log Î²1, log Î²2 and log Î²3 values were found to be 2.74, 7.39 and 11.32 respectively. At high ligand concentration hydralazine also show reducing properties. The study suggests a strong interaction of hydralazine with iron; however the nature of interaction is different with both oxidation states of iron.
Sorption of Ni(II) and Cr(III) ions by the Chironomus yoshimatsui larvae from wastewater
Authors: Ryoo Keon Sang
Published: May 2018

In this study, Chironomus yoshimatsui larvae were applied to remove Ni(II) and Cr(III) ions from wastewater. The sorption studies were carried out using laboratory-reared C. y. larvae. It was found that C. y. larvae are very susceptible to Cr(III) as compared to Ni(II). The survival capacity of C. y. larvae was sharply reduced when exposed to even low Cr(III) concentration. Sorption isotherm and kinetics of C. y. larvae for Ni(II) were determined by means of controlled experiments in a batch system. It was observed that sorpyion efficiency of Ni(II) was largely concentration dependent and more effective at lower concentration. At each equilibrium, Ni(II) was removed up to roughly 44âˆ¼80 %. Sorption data were better fitted to the Langmuir isotherm model because of its correlation coefficient R2 value greater than that of the Freundlich isotherm model. The sorption kinetics by C. y. larvae for Ni(II) was well described a pseudo-first-order rate expression. C. y. larvae have enormous potential for application in wastewater treatment technologies because they are widespread and abundant all around the world and can be easily kept in culture.
Physicochemical Parameters Of Effluents From A Lubricating Oil Company And Metal Analysis Of The Sediment Of The Receiving Stream In Osogbo Osun State, Nigeria
Authors: Adeniji Ayodeji Oluwole , Olabanji Iyabo Oluremi , Oluyemi Ayodele Emmanuel
Published: May 2018

Effluent and its receiving sediment samples were collected on seasonal basis, comprising of three months (August to October, 2014) in the wet season and three months (December 2014 to February 2015) in the dry season. Five sampling points around the lubricating oil company were marked for the study. Physicochemical parameters of the effluent samples such as pH, temperature, conductivity, total dissolve solids were determined in situ. Dissolved oxygen and biochemical oxygen demand were determined by WinklerÂ´s method. Digestion of the sediments was carried out by acid dissolution. The heavy metals (Mn, Ni, Co, Cd and Pb) level was determined using Flame Atomic Absorption Spectrophotometer. The results revealed that the physicochemical parameters ranged between (27.40 to 29.860C) for temperature, pH (6.89 to 7.88), electrical conductivity (92.27 to 292.84Âµs/cm), total dissolve solids, dissolved oxygen (2.58 to 7.01mg/L), biochemical oxygen demand (5.00 to 14.00mg/L) for the sampling periods. The overall total metal was in similar order: Mn > Ni > Co > Cd > Pb for both seasons. Most of the results were within the recommended limit required except for the levels of biochemical oxygen demand which exceeded the recommended value of 10mg/L in dry season by WHO, (2006). Statistically, no significant difference at p â‰¤ 0.05 between the parameters obtained in both seasons. The study concluded that the effluents discharged from the lubricating oil company in osogbo was polluted based on the results of biochemical oxygen demand and the Cd concentrations in the sediment samples.
Preparation, Surface active properties, and Anticorrosion Application of some novel surfactants based on cottonseed oil and diethanolamine on carbon steel in CO2 environments
Authors: Abd El-Lateef Hany , Ismayilova I. T. , Abbasova V. M. , Efremenkob E. N. , Aliyevaa L. I. , Mamedxanovaa S. A.
Published: May 2018

Novel surfactants were synthesized based on cottonseed oil and diethanolamine and the structures of these compounds were confirmed by FTIR spectroscopy. The surface and thermodynamic properties of these compounds have been investigated. The corrosion behavior of the synthesized surfactant corrosion inhibitors was evaluated by using potentiodynamic (Tafel) polarization curves, linear polarization resistance corrosion rate techniques. The experimental results showed that these inhibitors revealed a very good corrosion inhibition even at low concentrations. The protection efficiency increased with increasing inhibitor concentration, getting maximum values ranged between 87.37 and 97.91 % at 100 ppm after 20 hour of exposure. The adsorption process was found to obey the Langmuir adsorption isotherm.
The present status and prospect of research on the de-ironing and bleaching technology of kaolin
Authors: Li Hua , Jiao Xing-li , Zhou Jin-liang
Published: May 2018

The increase of degree of whiteness is an important method for Kaolin growth in value. In this paper, the occurrence of iron in kaolin was briefly described, and the methods of the de-ironing and bleaching technology of kaolin were introduced. The characteristics and the existing problems of all kinds of method were analyzed. Some new green environmental protection technology of the de-ironing and bleaching kaolin were introduced.
Computing Atom-Bond Connectivity (ABC4) index for Circumcoronene Series of Benzenoid
Authors: Farahani Mohammad Reza
Published: May 2018

Let G=(V; E) be a simple connected graph. The sets of vertices and edges of G are denoted by V=V(G) and E=E (G), respectively. In such a simple molecular graph, vertices represent atoms and edges represent bonds. The Atom-Bond Connectivity (ABC) index is a topological index was defined as  where dv denotes degree of vertex v. In 2010, a new version of Atom-Bond Connectivity (ABC4) index was defined by M. Ghorbani et. al as  where and NG(u)={vV(G)|uvE(G)}. The goal of this paper is to compute the ABC4 index for Circumcoronene Series of Benzenoid
CONSERVATIVE FLUIDS AND LUBRICANTS BASED ON TURBINE OIL, NITRO, AMIDO AND PARAFFIN WAX
Authors: Abdullaev E. Sh. , Abbasov V. M. , Aghazadeh E. J. , Gasanov E. K. , Aliyev L. I.
Published: May 2018

To create conservation fluids and lubricants based on the oil acids and polyethylene polyamine (PEPA) synthesized amidoamines, and based on α-olefins (C12, C14 and C16-C18) and the nitric acids-nitro compounds. Using of amido, nitro and solid n-paraffins in the turbine oil T-30 (Standard 32-74) formulated lubricants and conservation fluid which are tested under different conditions. It is shown that in comparison with the preservative fluid, the preservative lubrication more effective.
Hydrophilic interactions; their Origin, their Magnitude and their Relevance to Protein Folding
Authors: Naim Arieh Ben
Published: May 2018

A simple model is constructed in which the phenomenon of hydrophilic ( ) interactions may be studied exactly. This model reveals the origin of the strong interaction, as well as providing an approximate method of estimating its order of magnitude. The results are in agreement with previous theoretical calculations, as well as with experimental data, and simulated calculations. The source of the non-additivity of the interactions among three and four groups is examined. A few comments on the relevance of the interactions to the process of protein folding are discussed.
Synthesis,Characterization and Evaluation of the Anticancer and Antimicrobial Activities of Some Novel Benzazole and Benzazine Derivatives
Authors: Shehab Wesam Saber , Eleiwa Naglaa Z.H. , Mouneir Samar.M.
Published: May 2018

The present study was designed to synthesize  and develop new useful lead compounds (some novel benzazole and benzazine derivatives ) of simple structure , exhibiting optimal in vitro anticancer  and antimicrobial potency. Phenylenediamine derivative 1 was condensed  with  dithiocarboxylic acid derivatives 2 and produced   benzimidazole derivative 4. The benzotriazepines 8 and 10  were formed by the reaction of 1 with dicarbonyl derivatives followed by intermolecular coupling reaction. The synthesis of benzotriazine12, benzotriazole 14,17, benzimidazole16 and benzothiadiazine 19 from compound 1 was also described. The Synthesized Compounds were characterized by Spectral Studies like IR, H1 – NMR and Analysis Spectra .The title compounds were screened for their possible In vitro anticancer and antimicrobial activities. Among the synthesized compounds, some have shown promisingly remarkable activities against  different  cancer cell lines (MCF-7 human breast cancer cells, HepG2 human hepatocarcinoma cells and PC3 human prostate cancer cells)and moderate  to high antibacterial and antifungal activities. The obtained results showed that the most active compounds could be useful as a template for future design, modification and investigation to produce more active analogs.
New Cyanoacetamide Derivatives as Corrosion Inhibitors for Carbon Steel in Acidic Media
Authors: Fouda Abdel Aziz , El-desoky A. M. , Muhtar M. M.
Published: May 2018

The corrosion behavior of carbon steel  in 1 M HCl solution in the absence and presence of 4-(2-Cyano-7- hydroxy-4-methylene-hepta-2,5-dienoylamino)-benzoic acid (a), 4-[2-Cyano-3-(4-methoxy -phenyl)-acryloylamino]-benzoicacid.(b), 4-(2-Cyano-3-phenyl acryloylamino)-benzoic acid (c) ,4-[3-(4-Chloro-phenyl)-2-cyano-acryloylamino]-benzoic acid(d), was investigated using weight loss , potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and electrochemical frequency modulation (EFM) techniques. The inhibitive action of the investigated compounds was discussed in terms of blocking the electrode surface by adsorption of the molecules through the active centers contained in their structures. The adsorption of these derivatives on carbon steel surface is consistent with Freundlich adsorption isotherm. The effect of temperature on the rate of corrosion in the absence and presence of these compounds were also studied. Physical adsorption mechanism is proposed from the calculated thermodynamic parameters for all investigated compounds.
Method development and validation of simultaneous determination of seventeen metals in water by ICP/MS
Authors: Alrimawi Foud , Kanan Khalid , Qutob Mutaz
Published: May 2018

A simple, precise, accurate, and sensitive method is developed and validated for simultaneous determination of seventeen metals (Li, Sr, Ba, Tl, Pb, Bi, Al, K, Cr, Mn, Co, Ni, Cu, Zn, Mo, Ag, and Cd) in water by ICP-MS. The optimum conditions of the ICP-MS are as follows: nebulizer gas (argon) flow rate: 0.9 L/min, auxiliary gas (argon) flow 0.3 L/min, plasma (argon) gas flow: 15 L/min, reaction gas flow (helium) 4mL/min. This method is validated according to the requirements for new methods, which include linearity and range, accuracy, precision, selectivity, limit of detection (LOD), and limit of quntitation (LOQ). The current method demonstrates good linearity over the range of 1-1000 ppb with r2 greater than 0.999 for the seventeen metals. The recovery of the metals from water samples ranges from 97.5 to 101.7%. The method is selective where minimal interferences between the metals is observed (CeO/Ce = 1%, and Ce+2/Ce+1 = 1%), and with good resolution (0.8 amu at 10% height). The method is also precise where the RSD of the responses (cps) of replicates of the metals at three concentration levels is less than 1%. Low LOD and LOQ of metals using this method enable the detection and quantitation of these metals at low concentrations. Real water samples from West Bank in Palestine (groundwater) were analyzed for their trace metals content using this method.
Development and Validation of Enantiomeric Purity of Montelukast by SFC Method on Amylose Based Stationary Phase
Authors: Maddala Vijaya Lakshmi , Ch Kameswararao , Polisetty Srinivasulu , Koduri Sai Venkata Srinivas , Ray P.C.
Published: May 2018

A new Supercritical fluid liquid chromatographic (SFC) method has been developed in normal-phase conditions for the determination of enantiomeric purity of Montelukast sodium (S,E)-2-(1-((1-3-(2-(7-chloroquinolin-2-yl)vinyl)phenyl)-3-(2-(2-hydroxypropan-2-yl)phenyl)propylthio)ethyl) cyclopropyl) acetic acid (R-isomer) (Anti asthmatic drug) in bulk drugs and in dosage forms. The sample was screened on the analytical SFC to determine the best column for the separation. The screening conditions are Column: Chiralpak AS-H (250 mm x 4.6 mm, 5 μm) column using a mobile phase system containing Supercritical fluid (Co2) and 2-Propanol in the ratio (85:15% v/v). The mobile-phase compositions and the differences in separation capability of the method is noted. The resolution between two enantiomers is found to be greater than 1.5. The SFC method for the separation of enantiomers of Montelukast is proved Accurate, Precise, Linear and robust. Relative standard deviation of retention times and peak areas were better than 0.2% and 0.4%, respectively, for precision.
Synthesis of Dynamic 2-Ethoxycarbonyl-4H-3, 1-Benzoxazin-4-one and its Behavior Towards Nitrogen Nucleophiles
Authors: El-Hashash M. A. , El-Badry Yaser Abdel-Moemen
Published: May 2018

The behavior of  2-ethoxycarbonyl-4H-3,1-benzoxazin-4-one and its behavior towards nitrogen nucleophiles namely, hydrazine hydrate, formamide, benzylamine, ethylamine, piperidine, ethanol amine, o-phenylenediamine, and glucosamine hydrochloride has been investigated. Also the reaction of 3-[aminoquinazolin-4(3H)-one-2-yl]formic acid hydrazide with aromatic aldehydes and phenylisothiocyanate has been discussed. The structure of the prepared compounds are elucidated using physical and spectral data like, FT-IR, 1HNMR, and mass spectroscopy.
A Nuclear Spin Selective Control over the DNA Repair Key Enzyme Might Renovate the Cancer–Fight Paradigm. DNA Polymerase Beta to Engage with a Magnetic Isotope Effect
Authors: Shatalov Oleg A. , Grigoryev Maxim E. , Bukhvostov Alexander A. , Kuznetsov Dmitry A.
Published: May 2018

DNA Polymerase Beta (EC 2.7.7.7) is found to be operated by magnetic isotope effect (MIE) of Calcium once the Mg2+ ions replaced with the stable 43Ca2+ isotopes inside the enzyme catalytic sites. The isotope mentioned is the only paramagnetic species of the Calcium isotopic set with a 0.135 natural abundance value and the negative 7/2 nuclear spin providing a nuclear magnetic moment equal to 1.317 Bohr magnetons. As compared to the Mg/40Ca substitution, a 2.25-fold enzyme inhibition has been shown to provethe43Ca-MIE dependent mode of the catalysis turning down.An ion-radical mechanism based on the singlet – triplet conversion of the enzyme generated intermediates (ion-radical pairs) is found to be engaged once the paramagnetic metal isotope involved into the catalysis studied.The MIE promotes a primary reaction in DNA synthesis constituting in electron transfer between the ion – radical forming partners, [Ca(H2O)n2+] and [Ca2+(dNTP)]. Once the metal isotope substitution takes place inside just one of two DNA Polymerase Beta catalytic sites, a consequent43Ca – promoted inhibition leads to a residual synthesis of shorted DNA fragments that counts 25 – 35 nucleotides in length contrasting with the 180n – 210n DNA produced by either intact or40Ca – loaded polymerase. Being occurred simultaneously with a marked MIE – promoted enzyme inhibition, this fact itself makes possible to consider these short (“size-invalid”) DNA segments hardly efficient in the DNA base – excision repair. The latter is a survival factor in leukemic cells where the DNApolβ was found overexpressed. That supports a standpoint considering theDNApolβ a legitimate target for antitumor agents since its inhibition deprives the malignant cell from a DNA base – excision repair in neoplasma. A possible trend making role of these data in the current developments on a novel concept - establishing chemical background for cancer therapies is in a focus.
Molecular Simulation of Hyperbranched Polyester
Authors: Yanmei Liu , Haihua Li , Yulei Tai , Guoku Chao , Yajuan Zhao
Published: May 2018

A new types of hyperbranched polyester was synthesized by the 2,2-bis(hydroxymethyl) propionic acid as an AB2-type monomer and glycerol as the core moiety. Molecular weights were confirmed by Gel Permeation Chromatography. Acid values were titrated by KOH. The hydroxy value was obtained by titration. Furthermore, we calculate logarithmic value of acid value, hydroxy value, and molecular weight, respectively, and the simulation model curves were obtained. Based on the simulation model curves, we establish the empirical equation of the relationship of molecular weight, acid value and hydroxy value.
Interaction of Dioxovanadium (V) ion with L-alanine at Different Ionic Strengths
Authors: Fekri Mohammad Hossein , Gharib F. , Darvishpour M.
Published: May 2018

The formation constants of species formed in the system H+ + alanine and VO2+ +alanine have been determined in aqueous solution for 1.0<pH<7.0 and at different ionic strengths ranging from 0.1 to 1.0 mol dm-3 NaClO4, using a combination of potentiometric and spectrophotometric techniques.The compositions of the formd complexes and their stability constants were determined by curve fitting method and it was shown that dioxivanadium(V) forms two mononuclear 1:1 and 1:2 species with alanineof type VO2L and VO2L2-.The porotonation constant of the amino group of alanine has been determined using potentiometric techniques and calculated using a computer program wich employ a least-squares method. The dependence of the porotonation of alanine and the stability constants of the species on ionic strength are described by a deby-huckel type equation.
A Study of the Photocatalytic Degradation of Acetaldehyde
Authors: Ameta Suresh C. , Gomber Chetna
Published: May 2018

Photocatalytic degradation of acetaldehyde over cadmium sulfide, a semiconductor was investigated. The effect of various parameters, such as pH, concentration of acetaldehyde, amount of semiconductor, effect of light intensity were observed. A tentative mechanism has been proposed for the photocatalytic degradation of acetaldehyde using cadmium sulphide semiconductor.
Extraction-Spectrophotometric Studies on the Ion-Pairing Between Some 2,3,5-Substituted Monotetrazolium Cations and Anions Deriving from 4-(2-Thiazolylazo)resorcinol or 4-(2-Pyridylazo)resorcinol
Authors: Gavazov Kiril Blazhev , Toncheva Galya K.
Published: May 2018

The ion-pairing between some 2,3,5-substituted monotetrazolium cations (T+) and anions deriving from 4-(2-pyridylazo)resorcinol (PAR) or 4-(2-thiazolylazo)resorcinol (TAR) was studied by water-chloroform extraction and spectrophotometry. The following tetrazolium salts (TS) were used as a source of T+: i) 2,3,5-triphenyl-2H-tetrazolium chloride (TTC); ii) 3-(4,5-dimethyl-2-thiazol)-2,5-diphenyl-2H-tetrazolium bromide (MTT); iii) 3-(2-naphtyl)-2,5-diphenyl-2H-tetrazolium chloride (Tetrazolium violet, TV); and iv) 2-(4-iodophenyl)-3-(4-nitrophenyl)-5-phenyl-2H-tetrazolium chloride (INT). The spectral characteristics of the extracted species were established at different pH and TS concentration. The composition and stability of the ion-pairs were determined at pH 9, where the extraction of neutral PAR (H2PAR) and TAR (H2TAR) species was negligible. The results showed that the ion-pairs can be expressed with the following formulae (T+)(HTAR–) (where T+ = TT+, MTT+, TV+ or INT+), (T+)(HPAR–) (where T+ = TT+, MTT+ or TV+) and [(INT+)(HPAR–)]2. Relationships involving the molecular masses of the ion-pairs (MIP) or T+ (MT+) and the values of the constants of association (b) or conditional molar absorptivities (e’) were examined, namely Log b = f(Log MIP) and e’ = f(Log MT+). Some practical aspects concerning the investigation of metal complexes with TS-PAR/TS-TAR were discussed.
4-(3,4-Dichlorophenyl)-6-(Furan-2-yl)Pyrimidine-2-Thiol as Building Block in Heterocyclic Synthesis
Authors: EL-Hashash M. A. , El-badry Yaser Abdel-moemen , Morsy J. M.
Published: May 2018

Pyrimidine-2-thiol (1) has been synthesized via one-pot, three component synthesis. Its behavior towards nitrogen nucleophiles like hydrazine hydrate, ethylamine, piperidine, and 2-aminobenzoic acid has been studied. A speculation to explain the activities of the thioamide-iminothiol equilibrium based on their thermodynamic and kinetic control under the experimental conditions were investigated. The hydrazinopyrimidine 2 and aminocarbamoyl derivative 8 were used as key starting materials for synthesis of some interesting nitrogen bridgehead compounds 10-13, hydrazones 14-16, and some mixed and non-mixed heterocyclic systems 17-19 respectively.
Chemical characterization of volatile oils of different parts of Satureja Bachtarica Bunge
Authors: Meshkatalsadat Mohammad Hadi , Rabiei Khadijeh , Shabaninejad Yaghub
Published: May 2018

In this study, essential oils from different organs of Satureja bachtiarica Bunge were obtained by hydro-distillation. Quality and quantity of chemical composition of essential oils were determined by capillary gas chromatography and using gas-chromatography and mass spectrometric detection. The numbers of compounds were identified in the essential oils of leaves; stem and aerial parts were 45, 39 and 35, respectively. Also, carvacrol was the main component found in essential oils from leaves (39.3%), stem (39.4%) and aerial parts (67.88%) of S. bachtiarica in flowering stage. In addition, results showed that there were some different in compositions of the essential oils of different parts of S. bachtiarica and there are some minor components in each oil that are not present in the others parts. In addition chemical analysis of essential oils obtained from leaves and stem of S. bachtiarica were rich in oxygenated monoterepens (55.64% and 67.53%) while oxygenated monoterepen (77.22%) were the main class of compounds in the essential oils from aerial parts of S. bachtiarica. Results of this study showed that the essential oils from different organs of S. bachtiarica have a potential to be used as a new carvacrol source in drug and food industries.
Corrosion Monitoring of Sabic Iron in Hydrochloric Acid Solutions using some Azo Compounds – Molecular Dynamics, Chemical and Electrochemical Studies
Authors: Shokry H. , Shah R. , Mabrouk E. M.
Published: May 2018

The corrosion inhibition behaviour of Sabic iron in the absence and in presence of some azo compounds derived from 2, 3-and 2, 7-dihydroxynaphthalene was investigated using weight loss, thermometry and galvanostatic polarizations techniques. It was found that, the inhibition efficiency of these compounds depends on their concentration and chemical structure. The inhibitive action of these azo compounds was discussed in terms of blocking the electrode surface by adsorption of the azo dye molecules through the active centres in their structure. The adsorption process follows Temkin isotherm. The effect of temperature on the rate of corrosion was considered and some activated thermodynamic functions were computed and discussed. Quantum chemical calculations and molecular simulations were further applied to reveal the adsorption structure and explain the experimental results.
Impedance Spectroscopy, Electrical Relaxation and Ac Conductivity Studies of an Organic-Inorganic Hybrid Compound: C12H14N2CuCl4
Authors: Wamani W. , Elwej R. , Mhiri T. , Belhouchet Mohamed
Published: May 2018

The AC conductivity of the compound, C12H14N2CuCl4, in the temperature and frequency range from 373 to 423 K and 209 Hz – 5 MHz, respectively, is reported. The differential scanning calorimetry and thermogravimetric analysis indicate the presence of a phase transition at 400 K. The Z’ and Z’’ vs. frequency plots are found to be well fit by using the equivalent circuit model. The circuits consist of a parallel combination of bulk resistance Rp and constant phase element. Besides, the analysis of the experimental data based on the jump relaxation model shows that the translation motion of the charge carrier and reorientation hopping between the equivalent sites of the metal chloride anion and the cation groups are responsible for the observed AC conductivity in the temperature regions I (373–400 K) and II (400–423 K). The frequency dependence of the conductivity which follows the Arrhenius equation is interpreted in terms of Jonscher's law: σ (ω) = σdc +A ω S.
Electrocatalytic Oxidation of Nitric Oxide at Carbon Paste Electrode Modified with Chromium (III) Oxide
Authors: Berisha Liridon S. , Kalcher Kurt , Maloku Arsim , Andoni Eduard , Arbneshi Tahir
Published: May 2018

Chromium (III) oxide was used as a bulk mediator in carbon paste electrodes to improve the better performance of the carbon electrodes for the detection of nitric oxide in comparison with unmodified electrodes. The reaction mechanism of the electrocatalytic oxidation of NO at the modified electrode was studied using cyclic voltammetry and differential pulse voltammetry. The chemical sensor could be operated under physiological conditions (pH 7.5, 0.1 M phosphate buffer), with an operating potential of 750 mV (vs. Ag/AgCl), in hydrodynamic amperometry. The amperometric response of the sensor showed good linearity up to 200 mmol/L with a detection limit (3σ) of 0.69 mmol/L. The effect of the interferent nitrite was not fatal and could be eliminated by the use of the standard addition method. The new chemical sensor seems also promising to detect NO in car exhaust fumes.
Convenient one-step Synthesis of Substituted Pyrano[2,3-c]isoquinoline (2-amino-4H-chromenes) via three Component Reaction between Alkyl isocyanides and Dialkyl Acetylenedicarboxylate in the presence of 3-Hydroxyisoquinoline
Authors: Mohtat Bita , Salmani Shahla , Aminian Amineh , Djahaniani Hoorieh
Published: May 2018

The reactive intermediate generated by the addition of alkyl isocyanides to dialkyl acetylenedicarboxylate are trapped by 3-hydroxyisoquinoline to produce highly functionalized 4H-chromenes in 83-92% yields.
Preparative Purification of Delphinidin 3-0-sambubioside from Roselle (Hibiscus sabdariffa L.) Petals by fast Centrifugation Partition Chromatography
Authors: Kouakou Hilaire Tanoh , Kouakou Laurent Kouakou , Decendit Alain , Badoc Alain , Da-Costa Gregory , Merillon Jean-Michel , Teguo Pierre Waffo
Published: May 2018

Delphinidin 3-0-sambubioside, a Hibiscus anthocyanin, was isolated from MeOH/TFA dried flower of H. sabdariffa. Its purification on preparative scale was obtained by centrifugal partition chromatography (CPC) using the ternary biphasic solvent systems composed of ethyl acetate/1-butanol/water, acidified by 0.1% of TFA. Stationary phase was ethyl acetate/1-butanol/water (5:5:90; v/v). We tested 4 mobile phases and found that the system acetate/1-butanol/water (40:46:14; v/v) was the best to separate anthocyanin mentioned above. This support-free liquid-liquid chromatographic procedure made it possible to isolate delphinidin 3-0-sambubioside from flower of H. sabdariffa. The antiamyloidogenic activity of the isolated stilbenes was evaluated versus b-amyloid fibrils. delphinidin 3-0-sambubioside was found to be active with 67% inhibition at 10 mM.
Inhibitive Effect of Urea and Urea Derivatives on the Corrosion of Silver in Acetic Acid Solutions
Authors: Wanees S. Abd El , Shehata A.M.A , Barakat M. , Hathoot A.
Published: May 2018

The corrosion of silver in acetic acid was studied using potentiodynamic polarization technique in absence and presence of different concentrations of urea, thiourea and N-allylthiourea. The inhibition efficiency was found to depend on both the inhibitor type and concentration. The inhibitive action of these compounds is based on the formation of salt complex and/or the adsorption of the protonated species on the metal surface according to Temkin's isotherm. The thermodynamic parameters Kads and ΔG°ads for the adsorption process are calculated and discussed.
Magnetic Solid Phase Extraction of Au(III) using Fe3O4 Nanoparticles Prior to its Flame Atomic Absorption Spectrometric Determination
Authors: Khoshhesab Zahra Monsef
Published: May 2018

A simple solid phase extraction procedure has been proposed for determination of Au(III) based on separation and preconcentration using magnetite nanoparticles (MNPs) prior to its determination by flame atomic absorption spectrometry. The influences of experimental parameters including sample pH, sorbent mass, contact time, volume and type of eluent, and interference of some ions with extraction of Au(III) ions were investigated using batch procedure. The maximum adsorption capacity of the sorbent for Au(III) was found to be 45.0 mg g-1. The sorption of Au(III) ions was quantitative in the pH range of 4.0â€“5.0 and quantitative desorption was achieved using 10 mL of thiourea (0.5 mol L-1)/hydrochloric acid (1 mol L-1) solution. In the initial solution, the calibration curve was linear in the range of 8.8 - 666.0 Î¼g L-1 with R2 = 0.9994 (n = 8), the detection limit (3Sb, n = 8) was 6.2 Î¼g L-1, relative standard deviation (R.S.D) of 20 Î¼g mL-1 of Au(III) was 3.9% (n = 8), and the preconcentration factor was 30. The proposed method has been applied to the determination of Au(III) in water and wastewater samples with good recoveries in the range of 95% â€“103%.
Anti-cancer, Anti-inflammatory, Cytotoxic and Biochemical Activities of a Novel Phosphonotripeptide Synthesized from Formyl Pyrazolofuran using TUBU as Condensing Agent
Authors: H. Ouf Nabil , A.Hamed Mohamed , El Sayed Ibrahim , Sakran Mohamed Ibrahim
Published: May 2018

A novel and mild protocol for the synthesis of phosphonotripeptide 16 were achieved from novel formylpyrazolofuran 3, benzyl carbamate 5, triphenyl phosphite 6 by Birum-Oleksyszyn reaction using copper (II) trifliate as Lewis acid catalyst in dry dichloromethane at room temperature which synthesis of novel N-benzyloxy-α-aminophosphonate 7 . A mechanism for this condensation reaction is proposed. Cleavage of the N-benzyloxy carbonyl group under acid hydrolysis afford the free α-aminophosphonate 9 in quantitative yield. This in turn, by reaction with N-phthaloylglycine 12 via TUBU to phthalimido group 13.Cleavage of phthalimido group under hydrazinedihydrochloride afford free peptide 14 .the result phosphonotripeptide 16 obtained by the reaction of free peptide with bioactive cyclic moiety-COCl 15. The structures of all new compounds were established by IR,1HNMR and mass spectral data. Also anti-cancer, anti-inflammatory  and biochemical activities of all these compounds were reported.
Synthesis of Spirooxoindole Derivatives
Authors: Ismail Mahmoud Fawzy , Mahmoud Mahmoud Refaee
Published: May 2018

This review summarizes the methods for preparing spirocyclic oxoindole derivatives in the past years until 2012 which are divided into several groups according to ring size of the fused spiroindoles.