bluuebunny/crossref_metadata_2025 huggingface dataset:
Differential Effects of Literacy Instruction Time and Homogeneous Ability Grouping in Kindergarten Classrooms
Authors: Hong Guanglei , Corter Carl , Hong Yihua , Pelletier Janette
Published: December 2011

This study challenges the belief that homogeneous ability grouping benefits high-ability students in cognitive and social-emotional development at the expense of their low-ability peers. From a developmental point of view, the authors hypothesize that homogeneous grouping may improve the learning behaviors and may benefit the literacy learning of kindergartners at all ability levels through adaptive instruction under adequate instructional time. The benefits are expected to be more evident for medium- and low-ability children than for high-ability children. However, when instructional time is limited, low-ability children may suffer from high-intensity grouping, defined as grouping taking up a large proportion of instructional time. The authors also examine whether low-ability kindergartners develop lower self-esteem as a result of homogeneous grouping. Analyzing Early Childhood Longitudinal Study kindergarten cohort data, the authors find no overall advantage of homogeneous grouping for high-ability students. For medium-ability students’ literacy growth, homogeneous grouping appears to be optimal when teachers spend more than 1 hour per day on literacy instruction; high-intensity grouping shows additional advantage for improving these students’ general learning behaviors. For low-ability kindergartners, homogeneous grouping with ample instruction time seems to improve their general learning behaviors, whereas low-intensity grouping with ample instruction time seems to reduce internalizing problem behaviors. Yet for low-ability students’ literacy growth, a detrimental effect of high-intensity grouping is found when instructional time is limited. These findings contradict results from past research and have important implications for educational theories and practice.
Estimating a Meaningful Point of Change
Authors: Klotsche Jens , Gloster Andrew T.
Published: December 2011

Longitudinal studies are increasingly common in psychological research. Characterized by repeated measurements, longitudinal designs aim to observe phenomena that change over time. One important question involves identification of the exact point in time when the observed phenomena begin to meaningfully change above and beyond baseline fluctuations. The authors introduce a nonparametric modeling framework to estimate the change-point of interest using derivatives of the underlying regression function for an outcome variable across time. The estimator of Huh and Carriere (HC) consistently performed acceptably when using a plug-in bandwidth in a Monte Carlo simulation study. It was shown that the estimator performed well with a minimum number of 15 design points. This procedure was applied to longitudinal data collected on performance anxiety. Results suggest that the HC estimator combined with plug-in bandwidth selection provides an efficient strategy for investigating a possible change-point at which an observed outcome variable starts changing across time.
Synthesis of Novel Triazole Derivatives of Methyl 3-Oxocholanate Using Microwave Irradiation
Authors: Yang Jie , Cheng YuYu , Shi ZhiChuan , Zhao ZhiGang
Published: December 2011

An efficient rapid method for the synthesis of new triazole derivatives derived from methyl 3-oxocholanate under microwave irradiation has been developed. These new compounds were characterised by 1H NMR, IR, ESI-MS spectra and elemental analyses. Some of these triazoles were tested for antibacterial activity against Staphylococcus aureus, Candida albicans and Escherichia coli.
Synthesis of Tetrahydrobenzo[b]Pyran Derivatives Catalysed by Aliquat®336 in Water Under Microwave Irradiation
Authors: Patra Amarendra , Mahapatra Tanusri
Published: December 2011

A series of 4 H-5,6,7,8-tetrahydrobenzo[ b]pyran derivatives has been synthesised in excellent yield in a single pot using trioctylmethylammonium chloride (Aliquat®336) as phase-transfer catalyst in water under microwave irradiation. This method provides a clean access to the desired products. The structures of the products were confirmed by IR, 1H NMR, 13C NMR in all cases and HRMS in several cases, and supported by single crystal X-ray diffraction analysis of 2-amino-4-(3-benzyloxy-4-methoxyphenyl)-3-cyano-7,7-dimethyl-5-oxo-4 H-5,6,7,8-tetrahydrobenzo[ b]pyran and 2-amino-3-cyano-4-(3-iodo-4-hydroxy-5-methoxyphenyl)-7,7-dimethyl-5-oxo-4 H-5,6,7,8-tetrahydrobenzo[ b] pyran.
One-Pot Synthesis of 4,6-Diarylpyrimidin-2(1H)-Ones via Multicomponent Reaction Promoted by Chlorotrimethylsilane
Authors: Wang Lizhong , Bian Xiaoqin , Liu Hui , Sun Qian , Wang Cunde
Published: December 2011

4,6-Diarylpyrimidin-2(1 H)-ones were effectively synthesised by utilising chlorotrimethylsilane (TMSCI) as an efficient promoter in the cyclisation condensation of arylketones, substituted benzaldehydes and urea by a one-pot, three-component reaction under air in DMF/CH3CN. The clean, mild reaction conditions, operational simplicity and high yields were attractive features of the reaction which enables a facile preparative procedure for building the pyrimidine ring.
A Novel Sesquiterpenoid Glucoside from Hedyosmum Orientale
Authors: Rao Gui-Wei , Zhan Zha-Jun , Li Cheng-Ping , Shan Wei-Guang
Published: December 2011

One novel sesquiterpenoid guaiane glucoside, hedyosmum F, and three known sesquiterpenoids, hedyosmum D–E and 7, 10-epoxy-hedyosminolide were isolated from the aerial of Hedyosmum orientale. The structure of hedyosmum F was established on the basis of spectroscopic data, including IR, HR-ESI-MS, 1D and 2D NMR spectroscopy.
Synthesis of (Z)-2-(4-(Arylimino)-3,4-Dihydroquinazolin-2(1H)-Ylidene)-1H-Indene-1,3(2H)Dione Using 2-Amino-N′-Aryl-Benzimidamides as a Starting Material
Authors: Abdel-Latif Fathy F. , El-Shaieb Kamal M. , El-Deen Ahmed G.
Published: December 2011

The reaction between 2-amino- N′-arylbenzimidamide derivatives (3a–g) and 2-dicyanomethyleneindan-1,3-dione (4, CNIND) is described. The product that was obtained in moderate to good yields via CT-complexation is identified as ( Z)-2-[4-(arylimino)-3,4-dihydroquinazolin-2(1 H)-ylidene]-1 H-indene-1,3(2 H)-dione (5a–g).
Iron-Catalysed Mizoroki–Heck Reaction using 2,2′-Diamino-6,6′-Dimethylbiphenyl as the Ligand
Authors: Wang Xiu-Ren , Chen Fan
Published: December 2011

FeCl3·6H2O-catalysed Mizoroki–Heck reactions of aryl iodides with methyl acrylate have been achieved by using 2,2′-diamino-6,6′-dimethylbiphenyl as the ligand and NaHCO3 as the base in DMF and H2O. It was found that an appropriate amount of H2O is essential for high yields in these reactions.
A Green and Efficient Synthesis of 1-Chloromethyl -2,3,4,5-Tetramethoxy-6-Methylbenzene
Authors: Wang Jin , Yang Jian , Yang Bo , Hu Xiao , Sun Jia-Qiang , Yang Tao
Published: December 2011

The title compound, a key intermediate for preparing coenzyme Q analogues, was prepared in excellent yield by a reaction sequence starting from the commercially available 3,4,5-trimethoxybenzadehyde via Wolff–Kishner reduction, selective bromination, methoxylation and Blanc chloromethylation reaction.
Synthesis of 1,3,4-Thiadiazole Chrysanthemamide Derivatives Promoted by Phenyldichlorophosphate Catalysis
Authors: Yu Peng , Wang Rong Wan Peng , Zhang Jiang-Qiang , He Qiu
Published: December 2011

A series of novel pro-pesticides with the activity of both 1,3,4-thiadiazole and chrysanthemic acid were synthesised using phenyldichlorophosphate catalysis. These 1,3,4-thiadiazole chrysanthemamides were identified by IR, 1H NMR and elemental analyses.
A New Abietane Diterpenoid from Clerodendrum Kaichianum Hsu
Authors: Xu Mingfeng , Shen Lianqing , Wang Kuiwu , Du Qizhen
Published: December 2011

A new abietane diterpenoid has been isolated from Clerodendrum kaichianum Hsu and characterised as 11-methoxyl-12,14-dihydroxy-13-(2-hydroxypropyl)-3,5,8,11,13-abietapentaen-7-one. Its structure was established by spectroscopic analysis, including 2D NMR.
Alternative Synthesis of 5-Chloromethyl-2,3-Dimethoxy-6-Methyl-1,4-Benzoquinone: A Key Intermediate for Preparing Coenzyme Q Analogues
Authors: Wang Jin , Yang Jian , Yang Bo , Sun Jia-Qiang , Yang Tao
Published: December 2011

The title compound, a key intermediate for preparing Coenzyme Qn family, was prepared in high yield by a reaction sequence starting from the commercially available 3, 4, 5-trimethoxy-benzadehyde via Wolff–Kishner reduction, Vilsmeier–Haack reaction, Blanc chloromethylation reaction, Dakin reaction and oxidation.
The Asymmetric Transfer Hydrogenation of Benzoylpyridine: Preparation and Crystal Structure of Chiral Heterocyclic Schiff Base Ligands
Authors: Zhang Yu-Mei , Zhang Hong-Li , Liu Peng
Published: December 2011

Two optically active heterocyclic imine ligands 3 (3a and 3b) have been synthesised for the iridium catalysed asymmetric transfer hydrogenation of 4-benzoylpyridine. 3b was characterised by single crystal X-ray diffraction analysis. The two ligands (3a and 3b) were applied to Ir-catalysed asymmetric transfer hydrogenation of 4-benzoylpyridine using 2-propanol as a source of hydrogen. The results showed that the corresponding chiral alcohol could be obtained with moderate yield and enantioselectivity at an optimum temperature.
An Efficient Iodine-Catalysed Knoevenagel Condensation Reaction in the Presence of Acetic Anhydride
Authors: Li Zhong-Xian , Liu Xiao-Pei , Qiu Zhen , Xu Dan , Yu Xue-Jun
Published: December 2011

A mild, simple and efficient iodine catalysed system has been developed for the Knoevenagel condensation of 1,3-dicarbonyl compounds with various aromatic aldehydes in the presence of acetic anhydride. The reaction gave good to excellent yields for a broad range of substrates.
A simple and convenient approach to the synthesis of aminofuropyrimidindiones
Authors: Shaabani Ahamd , Teimouri Mohammad Bagher , Afgheh Mohammad , Eskandari Mehrdad
Published: December 2011

The one-pot three-component reactions of 1,3-dimethylbarbituric acid, aromatic aldehydes and alkyl or aryl isocyanides proceed smoothly at room temperature to give the corresponding 5-aryl-6-alkyl or arylamino-1,3-dimethylfuro[2,3- d]pyrimidine-2,4(1 H,3 H)-dione derivatives in good to excellent yields within 30 minutes in DMF. This three-component reaction represents a facile and efficient route to the described biologically interesting molecules.
Synthesis and biological evaluation of novel n-[3-(4-phenylpip-erazin-1-yl)-propyl]-carboxamide derivatives
Authors: Weng Zhiyong , Gao Yanping , Zhang Jiankang , Dong Xiaowu , Liu Tao
Published: December 2011

A series of novel N-[3-(4-phenylpiperazin-1-yl)-propyl]-carboxamide derivatives were synthesised and studied for the potential treatment of HIV. These compounds were obtained through the efficient synthetic route that involved microwave assisted synthesis. These new compounds have been characterised by IR, 1H NMR, MS and elemental analysis. The cell–cell fusion inhibitory activities of the compounds have also been evaluated.
Three-component reaction between 4-hydroxycoumarin, ammonium thiocyanate and acid chlorides in the presence of N-methylimidazole under solvent-free conditions
Authors: Hassanabadi Alireza , Mosslemin Mohammad H. , Tadayonfar Seyd Ehsan
Published: December 2011

A novel method for oxazine ring formation is established using the reaction of ammonium thiocyanate and acid chlorides with 4-hydroxy coumarin in the presence of N-methylimidazole to afford oxazine derivatives in excellent yields.
Viscous dissipation and Joule heating effects on steady MHD combined heat and mass transfer flow through a porous medium in a rotating system
Authors: Alam Mahmud Md , Hossain M. Delower , Hossain M Arif
Published: January 2012

Viscous dissipation and Joule heating effects on steady MHD combined heat and mass transfer flow through a porous medium along a semi-infinite vertical porous plate in a rotating system has been studied numerically. The boundary layer equations have been transformed into dimensionless coupled nonlinear ordinary differential equations by appropriate transformations. The similarity solutions of the transformed dimensionless equations for the flow field and heat and mass transfer characteristics are obtained by shooting iteration technique. Numerical results are presented in the form of primary and secondary velocities, temperature and concentration distributions within the boundary layer for different parameters entering into the analysis. Finally, the effects of the pertinent parameters on the Skin-friction coefficients, Nusselt number and Sherwood number are also examined.Keywords: MHD; Joule heating; porous medium; rotating system simulation. doi: http://dx.doi.org/10.3329/jname.v8i2.5055 Journal of Naval Architecture and Marine Engineering 8(2011) 105-120
Improving the quality of hexahedral mesh generated by automatic mesh generators
Authors: Islam Md. Shahidul
Published: January 2012

Automatic hexahedral mesh generation is a very deserving solution for better performance of finite element analysis of complex large structures. At present plastering, whisker weaving and whisker weaving based plastering algorithm are available to perform such tasks. As these hexahedral mesh generation processes are fully automatic, it is possible to form some elements, which don’t have high enough qualities for finite element analysis. For this reason, a reliable post-processing method is presented in this paper which can modify the shapes of the already generated hexahedrons. Four different structural models are tested and the results show that the proposed method can effectively modify the quality of the inverted hexahedrons and eliminate the invalid ones.Keywords: Doublet; triplet; quadruplet; Whisker weaving based plastering algorithm; hexahedral meshDOI: http://dx.doi.org/10.3329/jname.v8i2.5646Journal of Naval Architecture and Marine Engineering 8(2011) 121-128
Melting heat transfer in a nanofluid flow past a permeable continuous moving surface
Authors: Gorla Rama S.R. , Chamkha Ali J. , Aloraier Abdulkareem
Published: January 2012

A boundary layer analysis is presented for the warm, laminar nanoliquid flow to a melting surface moving parallel to a uniform free stream. The resulting system of non-linear ordinary differential equations is solved numerically using Runge-Kutta method with shooting techniques. Numerical results are obtained for the velocity, temperature and concentration distributions, as well as the friction factor, local Nusselt number and local Sherwood number for several values of the parameters, namely the velocity ratio parameter, melting parameter and nanofluid parameters. The obtained results are presented graphically  and in tabular form and the physical aspects of the problem are discussed.Keywords: Suction/injection; moving surface; nanofluid; boundary layer; shooting technique. doi: http://dx.doi.org/10.3329/jname.v8i2.6830 Journal of Naval Architecture and Marine Engineering 8(2011) 83-92
A flexible system for initial ship design parameters estimation using a system of neural networks
Authors: Senousy Hamada , Abou-Elmakarem Mahmoud
Published: January 2012

To initialize ship design process, it is very important to be able to develop an initial estimate of ship parameters to satisfy designer required specifications. For new emerging designs, this estimate has to be made based on a limited available set of examples. Moreover, a practical estimate prediction strategy should be flexible enough having no distinction between input (specified constraints) and outputs (parameters required to be estimated), since these vary from one design case to another.  Conventional regression-based techniques, which are usually employed to provide the required estimates, suffer from low accuracy in case of a small number of available examples. In addition to that, they fail to capture the interrelation between different design parameters. To overcome these limitations and others, the present paper proposes a new approach based on a system of artificial neural-networks (ANNs). The new approach not only overcomes regression limitations but is also capable of providing a reliable estimate of initial design offset table based on different ANN outputs.  The paper uses a case study for demonstrating the merits of the proposed approach.Keywords: Ship design; regression; ship series; Artificial Neural Networks (ANNs); Multilayer Perceptrons (MLPs); Normalized Gaussian Modified Lagrangian (NGML) doi: http://dx.doi.org/10.3329/jname.v8i2.6945 Journal of Naval Architecture and Marine Engineering 8(2011) 71-82
Application of non-linear k-e turbulence model in flow simulation over underwater axisymmetric hull at higher angle of attack
Authors: Sakthivel R , Vengadesan S , Bhattacharyya S K
Published: January 2012

This paper addresses the Computational Fluid Dynamics Approach (CFD) to simulate the flow over underwater axisymmetric bodies at higher angle of attacks.  Three Dimensional (3D) flow simulation is carried out over MAYA Autonomous Underwater Vehicle (AUV) at a Reynolds number (Re) of 2.09×106. These 3D flows are complex due to cross flow interaction with hull which produces nonlinearity in the flow. Cross flow interaction between pressure side and suction side is studied in the presence of angle of attack. For the present study standard k-ε model, non-linear k-ε model models of turbulence are used for solving the Reynolds Averaged Navier-Stokes Equation (RANS). The non-linear k-ε turbulence model is validated against DARPA Suboff axisymmetric hull and its applicability for flow simulation over underwater axisymmetric hull is examined. The non-linear k-ε model performs well in 3D complex turbulent flows with flow separation and flow reattachment.  The effect of angle of attack over flow structure, force coefficients and wall related flow variables are discussed in detail. Keywords: Computational Fluid Dynamics (CFD); Autonomous Underwater Vehicle (AUV); Reynolds averaged Navier-Stokes Equation (RANS); non-linear k-ε turbulence modeldoi: http://dx.doi.org/10.3329/jname.v8i2.6984   Journal of Naval Architecture and Marine Engineering 8(2011) 149-163
Effective simple methods for numerical modelling of marine engines in ship propulsion control systems design
Authors: Altosole M. , Figari Massimo
Published: January 2012

In the last year, the Department of Naval Architecture and Marine Engineering of Genoa University (now Department of Naval Architecture, Marine Technology and Electrical Engineering) collaborated to the design of the propulsion automation of two different naval vessels; within these projects the authors developed different ship propulsion simulators used to design and test the propulsion control schemes. In these time-domain simulators, each propulsion component is represented by a specific mathematical model, mainly based on algebraic and differential equations. One of the key aspects of the propulsion simulation is the engine dynamics. This problem in principle can be dealt with models based on thermodynamic principles, which are able to represent in detail the behaviour of many variables of interest (engine power and speed, air and gas pressures, temperatures, stresses, etc.). However, thermodynamic models are often characterized by a long computation-time and moreover their development usually requires the knowledge of specific engine information not always available. It is generally preferable to adopt simpler simulation models, for the development of which, very few kinds of information are necessary. In fact, for the rapid prototyping of control schemes, it is generally more important to model the whole plant (in a relatively coarse way) rather than the detailed model of some components. This paper deals with simple mathematical methods, able to represent the engine power or torque only, but they can be suitably applied to many types of marine engines in a straightforward way. The proposed simulation approaches derived from the authors’ experience, gained during their activity in the marine simulation field, and they are particularly suitable for a fast prototyping of the marine propulsion control systems. The validation process of these particular models, regarding a Diesel engine, a marine gas turbine and an electric motor, is illustrated based on the sea trials data and engine manufacturers’ data. Keywords: Dynamic simulation; marine engines performance; gas turbine; propulsion control. doi: http://dx.doi.org/10.3329/jname.v8i2.7366   Journal of Naval Architecture and Marine Engineering 8(2011) 129-147
Influence of centered conducting obstacle on MHD combined convection in a wavy chamber
Authors: Nasrin Rehena
Published: January 2012

The development of centered heat conducting obstacle effect on combined magnetoconvective flow in a lid driven chamber has been numerically studied. The enclosure considered has rectangular horizontal lower surfaces and vertical side surfaces. The lower and upper surfaces are insulated. The left wall is mechanically lid driven having uniform temperature Ti and velocity v0 while other vertical side is wavy and maintains higher temperature Th than the lid. The governing two-dimensional flow equations have been solved by using Galerkin weighted residual finite element technique. The investigations are conducted for different values of Richardson number (Ri) and physical parameter i.e. diameter (D) of square solid body. Various characteristics such as streamlines, isotherms and heat transfer rate in terms of the mean Nusselt number (Nu), the average temperature (?av) of the fluid and temperature of obstacle center (?c) are presented. The results indicate that the mentioned parameters strongly affect the flow phenomenon and temperature field inside the chamber. Conducting largest obstacle is preferable for effective heat transfer mechanism in presence of magnetic field.Keywords: Combined convection, MHD, wavy chamber, heat conducting obstacle, finite element simulation.doi: http://dx.doi.org/10.3329/jname.v8i2.7392 Journal of Naval Architecture and Marine Engineering 8(2011) 93-104
Synthesis, Antitumor and Antimicrobial Activities of Some Novel 1-(Substituted)-3-Methyl-1H-Pyrazol-5(4H)-One
Authors: Antre R. V. , Cendilkumar A. , R. Nagarajan R. , Goli D. , Oswal R. J.
Published: January 2012

Several 1-(substituted)-3-methyl-1H-pyrazol-5(4H)-one as RA1-RA9 were synthesized and compounds were screened for antitumor activity against Ehrlich ascites carcinoma (EAC) cells and antimicrobial activity. Elemental analysis, mass spectral data, 1H-NMR, and IR confirmed the structure of the newly synthesized compounds. Some of the tested compounds showed good antitumor and antimicrobial activity. Compounds RA1, RA4, and RA9 exhibit highest antitumor activity against EAC cells in comparison with 5-flurouracil as standard drug.Keywords: Ehrlich ascites carcinoma; Pyrazolone; Antitumor; N-substitution; Antimicrobial.© 2012 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved.doi: http://dx.doi.org/10.3329/jsr.v4i1.7027 J. Sci. Res. 4 (1), 183-192 (2012)
On Some R1-Properties in Fuzzy Topological Spaces
Authors: Ali D. M. , Azam F. A.
Published: January 2012

In this paper, we introduce six R1-axioms for fuzzy topological spaces (in short, fts). We study their interrelations, goodness and initialities. Besides we recall nine R0-axioms for fts. A complete answer is given with regard to all possible (R1=>R0)-type implications for fts.Keywords: Fuzzy topological space; Fuzzy R1-axiom; Fuzzy R0-axiom.© 2012 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved.doi:10.3329/jsr.v4i1.7044               J. Sci. Res. 4 (1), 21-32  (2012)
Essential Mechanical Properties of Structural Steels for Steel Reinforced Buildings in the Earthquake Sensitive Areas
Authors: Islam M. A.
Published: January 2012

During earthquake, the ground along with its various natural and manmade structures experiences shaking of various intensities and frequencies depending on the nature of the earthquake. The loading activities caused by earthquakes on various structures are very much cyclic type, which is popularly known as fatigue loading. On the other hand, for modern high-rise buildings a large volume of steel bar is used to reinforce the concrete because of the pioneer role of steel bars embedded inside the concrete for safety of the buildings. In this study various mechanical properties of reinforcing steel bars that are essential to counter balance the earthquake effects have been identified first. At the same time these essential mechanical properties have been defined and studied for most commonly used reinforcing steel bars. For doing this, both the conventional and advanced structural steels were selected. The mechanical properties and fatigue behaviours of these steels have been presented and discussed in this paper.  Keywords: Earthquake; High-rise buildings; Reinforcing steel bars; Conventional structural steel; Advanced structural steel.© 2012 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved.doi: http://dx.doi.org/10.3329/jsr.v4i1.7069 J. Sci. Res. 4 (1), 51-63 (2012)
Antioxidant Activity of the Ethanol Extract of Manilkara zapota Leaf
Authors: Islam M. E. , Parvin M. S. , Islam M. R. , Islam M. S. , Hasan S. M. R.
Published: January 2012

The present study evaluated the antioxidant activity of cold ethanolic extract of Manilkara zapota (Sapotaceae) leaves. In vitro antioxidant activity was determined using 1, 1-diphenyl-2-picrylhydrazyl radical, reducing power capacity, total phenol and flavonoid content. The extract demonstrated significant dose dependent antioxidant activity in vitro methods. In DPPH radical scavenging assay IC50 values of Manilkara zapota leaves (MZL) and ascorbic acid (standard) were found to be 68.27 and 16.17 μg/ml, respectively. In vivo, the extract was evaluated by carbon tetrachloride (CCl4) induced liver damage rats in hepatoprotective model. CCl4 produced significant alteration of serum marker enzymes, total bilirubin, total protein and liver weight. Restoration of these values towards normal, which is comparable to control group, indicated hepatoprotective activity, which reflects the antioxidant potential of the extract. Results presented here indicate that MZL possess strong antioxidant activity and they can therefore be used as a good natural source of antioxidant.Keywords: MZL; DPPH; Scavenging activity; Serum marker enzymes.© 2012 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved.doi: http://dx.doi.org/10.3329/jsr.v4i1.7148J. Sci. Res. 4 (1), 193-202 (2012)
Theoretical Studies on the Structural, Electronic and Optical Properties of the New π-conjugated Copolymers Based on Carbazole and Thiophene
Authors: El Maliki Z. , Bouachrine M. , Hamidi M. , Bejjit L. , Haddad M.
Published: January 2012

This work reports a theoretical investigation of π-conjugated oligomers constituted by n units (n = 1-4) based on carbazole and ethylenedioxythiophene. The molecular geometry, torsional potential, electronic and optical properties of the oligomers [Cbz-(Edot)n-Cbz] (n = 1-4) are investigated using DFT (B3LYP/3-21G*) calculations. The discussion is focused on the influence of chain length on the properties of these copolymers. The analyses of torsional angles for [Cbz-(Edot)4-Cbz] reveal that the structure has a anti-planar conformation. The electronic properties of the molecules, HOMO, LUMO and Eg (HOMO-LUMO), are studied using B3LYP functional. The results have been compared with those of thiophene and ethylenedioxythiophene. The lowest excitation energies (Eex) and the maximal absorption wavelength (λabs) are studied using the TD/DFT, ZINDO and CIS methods. The electronic transitions of the absorption spectrum derived by TD/DFT method give useful structural and electronic information for designing novel conducting organic polymer materials. The bridging effect by C=C(CN)2 on the optoelectronic properties of the (carbazole-thiophene-carbazole) comonomer is investigated. Keywords: Conducting polymer; Carbazole-(Ethylenedioxythiophene)n-Carbazole comonomers; DFT Optoelectronic properties; absorption coefficient; Bridging effect. © 2012 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved. doi: http://dx.doi.org/10.3329/jsr.v4i1.7450J. Sci. Res. 4 (1), 119-133 (2012)
Water Requirements of Qat (Catha edulis) Cultivation in the Central Highlands of Yemen
Authors: Atroosh K. B. , Al-Moayad M. A.
Published: January 2012

Water requirements of qat (Catha edulis) under irrigated and rainfed production systems in the central highlands in Yemen were studied during 2003 and 2004 at 6 sites. The crop evapotranspiration of qat was calculated by balancing method, where the sources of evapotranspiration were irrigation water and rainfall. The amounts of crop evapotranspiation of qat during winter months were less than other months of the year under both irrigated and rainfed conditions. The maximum daily evapotranspiration was 2.5 mm during summer season. The annual crop evapotranspiration for the irrigated qat in the Yemeni central highlands was 602.8 to 786.7 mm and 412.8 to 506.2 mm for the rainfed qat. The average annual crop evapotranspiration of qat for both production systems (irrigated and rainfed) was about 553.6 mm/year.Keywords: Crop water requirement; Evapotranspiration; Qat; Central highlands; Yemen.© 2012 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved.doi: http://dx.doi.org/10.3329/jsr.v4i1.7544J. Sci. Res. 4 (1), 77-82 (2012)
Analysis of Chemical Components Involved in Germination Process of Rice Variety Jhapra
Authors: Islam M. , Ye X.
Published: January 2012

Notice of withdrawal/removalThe article Analysis of Chemical Components Involved in Germination Process of Rice Variety Jhapra which appeared in J. Sci. Res. 4 (1), 251-262 (2012) has now been removed from journals website for violation of journals established policy.Journal of Scientific Research17 March 2012 doi: http://dx.doi.org/10.3329/jsr.v4i1.7598J. Sci. Res. 4 (1), 251-262 (2012)
In vitro Interaction of Metronidazole and Mebendazole with Copper (II) and Chromium (III) in Aqueous Media
Authors: Azam A. T. M. Z. , Siraji F. , Amran M. S. , Islam J. N. , Amjad F. M. , Hossain M. A.
Published: January 2012

The interaction of metronidazole, an antiprotozoal agent and mebendazole, an important anthelmentic agent with Cu (II) and Cr(III) ions have been studied in aqueous systems at a fixed temperature of 37±0.5°C  and at different pH values. It has been found that metronidazole and mebendazole form stable 1:1 complexes with Cu(II), but a less stable complex with Cr(III) ion.  The studies were performed by electroanalytical and spectrophotometric methods. Spectral studies helped to detect initial complexation between the species. Conductometric titration indicated the nature of interaction and the stoichiometries of complexation. The conductometric study also indicated the formation of complexes of various molar ratios viz 1:2, 4:1, 3:1, 1:2, 1:3 and 1:4. etc. along with 1:1 complexes at various pH conditions. Similar types of complexation were observed by Job’s plots at various pH values. The Ardon’s spectroscopic method confirmed the 1:1 complexation and the values of stability constant were calculated using Ardon’s plot. Complexation at molar ratios 1:3 and 1:4 can not be ruled out. Keywords:  Metronidazole; Mebendazole; Cu(II); Cr(III); Ardon’s plot; Complexation. © 2012 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved. doi: http://dx.doi.org/10.3329/jsr.v4i1.7599J. Sci. Res. 4 (1), 173-181 (2012)
Antimicrobial activity of Cressa cretica L., a Halophytic Plant
Authors: Sunita P. , Jha S. , Pattanayak S. P. , Mishra S. K.
Published: January 2012

In the present investigation different fractions (hexane, ethylacetate and methanol) of the whole methanolic extract of Cressa cretica L.(Convolulaceae), a widely grown halophytic plant were studied against wide ranges of bacteria (both positive and negative strain) and five fungi  Candida albicans, Candida tropicalis – dimorphic fungi, Aspergillus fumigatus, Aspergillus niger – systemic fungi and fusarium oxysporum by agar disc diffusion method. Among the three fractions the ethylacetate fraction of C.cretica showed the highest activity, but among the pathogens highest activity was revealed against Escherichia coli, Klebsiella pneumoniae  (zone of inhibition diameter in mm was found to be 26 and 31, respectively). The ethylacetate fraction was sensitive to both gram +ve and gram –ve bacterias. C.cretica showed higher inhibitory activity against the Aspergillus fumigates, Aspergillus niger (zone of inhibition diameter in mm was found to be 26 and 22, respectively) than the Candida albicans and Candida tropicalis and least was found for Fusarium oxysporum. As ethylacetate fraction revealed better activity than other fractions, further study of morphological and biochemical alterations were carried out only with ethylacetate fraction and the results revealed some morphological and biochemical alterations, which indicates that ethylacetate fraction of C. cretica possess potential broad spectrum antimicrobial activity.Keywords: Cressa cretica; Antifungal; Gram positive bacteria; Gram negative bacteria; Biochemical alterations.© 2012 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved.doi: http://dx.doi.org/10.3329/jsr.v4i1.7719J. Sci. Res. 4 (1), 203-212 (2012)
Effects of SEA0400 on Ouabain-induced Arrhythmias in Guinea Pigs
Authors: Amran M. S. , Homma N. , Hashimoto K.
Published: January 2012

The sodium-calcium exchange (NCX) is one of the major regulators of intracellular Ca2+ concentration in cardiac myocytes. The effects of NCX blockers as antiarrhythmic agents are still controversial. We investigated antiarrhythmic effects of SEA0400 (SEA), a novel NCX inhibitor, on ouabain-induced arrhythmias in guinea pigs. In the whole animal arrhythmia model, we observed effects of SEA on the ouabain-induced arrhythmia using ECG recordings. In the isolated myocyte, we observed action potential configurations and oscillations due to calcium overload using the current clamp method. In the whole animal model, SEA at a dose range of 1-10 mg/kg (intravenous, bolus) suppressed ouabain-induced arrhythmias dose-dependently. In isolated ventricular myocytes, SEA (0.1-3 µM) suppressed ouabain-induced oscillatory activity observed between action potentials. SEA (0.1-3 µM) also suppressed ouabain-induced NCX current (INCX) that is also called transient inward current (ITI). Our results indicate that NCX is involved in arrhythmia and oscillatory activity induced by ouabain. The inhibition of these arrhythmias and oscillatory activity by SEA might result from the inhibition of NCX.Keywords: Na+-Ca2+ exchange (NCX); SEA0400; NCX inhibitors; current clamp; ECG.© 2012 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved.doi: http://dx.doi.org/10.3329/jsr.v4i1.7722J. Sci. Res. 4 (1), 213-225 (2012)
Enzymatic Saccharification of Sugar Cane Bagasse by the Crude Enzyme from Indigenous Fungi
Authors: Mahamud M. R. , Gomes D. J.
Published: January 2012

Sugar cane bagasse is a cheap lignocelluloses which has high carbohydrate content and, if properly pre-treated, could be converted to fermentable sugar. In this study various fungal isolates isolated from lignocellulosic waste were assayed for their CMCase, FPase and xylanase activity. Four potent plant cell wall-degrading fungi were identified as Trichoderma sp., Aspergillus niger, Cladosporium sp. and Curvularia sp. Among these isolates Trichoderma sp. produced the highest enzymatic activity in the culture filtrates containing steamed NaOH treated-bagasse. The yield of endo-β-glucanase i.e., carboxymethylcellulase (CMCase), FPase and xylanase were 0.977, 0.110 and 9.280 U/ml. The highest degree of saccharification (DoS) was also achieved by Trichoderma sp. which was 45.71%. Trichoderma sp. is a potential source of extracellular hydrolases, which can be used for enzymatic saccharification of bagasse to produce fermentable sugar for ethanol production.Keywords: Bagasse; CMCase; FPase; Xylanase; Lignocellulose; Degree of saccharification; Graeco-Latin square design.© 2012 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved.doi: http://dx.doi.org/10.3329/jsr.v4i1.7745J. Sci. Res. 4 (1), 227-238 (2012)
Seasonal Variations of Arsenic in the Ganges and Brahmaputra River, Bangladesh
Authors: Islam S. M. N. , Rahman S. H. , Chowdhury D. A. , Rahman M. M. , Tareq S. M.
Published: January 2012

Dissolved arsenic concentrations in the Ganges, Brahmaputra Rivers and confluence of these two rivers show important seasonal variations and maximum arsenic concentrations are observed during the monsoon season (July–October). These seasonal variations of dissolved arsenic concentrations were closely related to intense river-water discharge during the monsoon season with high arsenic-rich suspended particulate matter (SPM) loads. These arsenic-rich SPM mainly are primarily originated from erosion of agricultural land in upstream region irrigated with arsenic contaminated shallow groundwater and to some extent weathering of bed rocks. Considerable amount of iron and manganese enriched SPM adsorbs arsenic and increased water temperature in the summer accelerates microbially-mediated reduction of arsenic (V) to more soluble arsenic (III). Additionally, dissolution of solid arsenic-bearing mineral phases also attributes to high arsenic concentrations in water and causes seasonal variations. It is realized that the SPM of these two major rivers primarily controls the arsenic inputs into the Ganges-Brahmaputra-Meghna delta system. The cycling of arsenic in this delta is related to the monsoon seasonal dynamics, land use patterns and biogeochemical processes.Keywords: Arsenic; Ganges; Brahmaputra; Seasonal variation; Bangladesh.© 2012 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved.doi: http://dx.doi.org/10.3329/jsr.v4i1.7820J. Sci. Res. 4 (1), 65-75 (2012)
Synthesis of Biheterocycles Containing Indole Nucleus and Their Antibacterial Activity
Authors: Jain S. , Reddy B. N. , Rao K. S.
Published: January 2012

Indole-3-carboxaldehydes (1a-d) undergo condensation with ethyl cyanoacetate and malononitrile to give the acrylonitrile 2a-d and 3a-d which on reaction with hydrazine hydrate yield 3,5-diamino-5-hydroxy-4-(3-indolylmethylene)pyrazoles (4a-d) and 3-amino-5-hydroxy -4-(3-indolylmethylene)pyrazoles (5a-d), respectively. The new compounds were also screened for their antibacterial activity.Keywords:  Indole-3-carboxaldehydes ; Active methylene compounds; Base; Hydrazine hydrate;  Pyrazoles.© 2012 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved.doi: http://dx.doi.org/10.3329/jsr.v4i1.7821 J. Sci. Res. 4 (1), 273-278 (2012)
Synthesis and Characterization of Methoxy-bridged Bis(silylene)tungsten Complexes
Authors: Begum R. , Islam S. M. S.
Published: January 2012

Synthesis of two methoxy bridged bis(silylene) complexes (CpMe4)W(CO)2 {(Et2Si)••OMe••(SiMe2)}(3) and (CpMe)W(CO)2 {(Et2Si)••OMe••(SiMe2)}(4) have been synthesized. Both the compounds contain chiral tungsten center and formed via oxidative addition of an Si-H bond to a coordinatively unsaturated metal center. The complexes were characterized by 1H, 13C, 29Si NMR, IR and elemental analysis. A plausible mechanism of formation is also suggested.Keywords:  Coordinatively unsaturated; Chiral tungsten; Oxidative addition.© 2012 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved.doi: http://dx.doi.org/10.3329/jsr.v4i1.7890J. Sci. Res. 4 (1), 109-118 (2012)
The Quality Cost Reduction in Hollow Glass Manufacturing by Taguchi Method
Authors: Adil A. , Moutawakil A.
Published: January 2012

This paper presents the results of an experimental investigation carried out to optimize the weight of a glass manufacturing bottle of a product called CC35 by Taguchi method of parameter design. The experiments have been designed using an L16 orthogonal array with thirteen factors and two levels each. So the effects of each control factor level on the performance characteristic are analyzed using signal-to-noise ratios, mean response data and analysis of variance (ANOVA). Hence, an experimental setting is established; and to measure the performance of the Taguchi method on the manufacturing process before and after the experiment, three tools are used. The Xbar and range charts measure the stability of the process, the capability index estimates the process ability to deliver a good product in regard to the target value and customer specifications. The quality loss function (QLF) was used to determine the reduction in quality cost due to the elimination of deviation of the quality characteristic (weight) from the target value. Experiment shows that the Taguchi method applied on the glass bottle’s manufacturing process (CC35) ensures best stability and capability of the manufacturing process and reduces the weight which results in the quality cost down to 92%. Keywords: Hollow glass manufacturing; Taguchi; Quality loss function (QLF); Design of experiments; Optimization; Capability; ANOVA; Signal-to-noise ratio. © 2012 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved. doi: http://dx.doi.org/10.3329/jsr.v4i1.7900J. Sci. Res. 4 (1), 155-172 (2012)
Generalized Derivations Acting as Homomorphisms and Anti-Homomorphisms of Gamma Rings
Authors: Dey K. K. , Paul A. C.
Published: January 2012

Let M be a prime G-ring and let I be a nonzero ideal of M. Suppose that D: M ® M is a nonzero generalized derivation with associated derivation d : M ® M. Then we prove the following: (i) If D acts as a homomorphism on I, then either d = 0 on M or M is commutative.(ii) If M satisfies the assumption (*) (see below), and if D acts as an anti-homomorphism on I, then either d = 0 on M or M is commutative.Keywords: Prime G-rings; Generalized derivations; Torsion free G-rings; Homomorphisms; Anti-homomorphisms.© 2012 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved.doi: http://dx.doi.org/10.3329/jsr.v4i1.7911J. Sci. Res. 4 (1), 33-37 (2012)
Diffusion Interactions of Some Biologically Important Transition Metal Complexes on Micellar Properties of Sodium Dodecyl Sulphate
Authors: Hossain M. A. , Rahman M. A. , Subhan M. A.
Published: January 2012

The specific conductance of aqueous solutions of sodium dodecyl sulphate (SDS) was measured from 20 to 35 ºC with an interval of 5 °C in the absence and presence of metal complexes such as [Cr(acac)2(H2O)2]Cl, K3[Fe(C2O4)3] and (NH4)4[Co(C6H5O7)2] at concentrations ranging from 2.0 × 10-4 to 8.0 x 10-4 M. The specific conductance rapidly increased at the pre-micellar region with increasing of temperature and concentration of SDS, but after critical micelle concentration (CMC) the rate of increase was slower. As the concentrations of metal complexes [Cr(acac)2(H2O)2]Cl, K3[Fe(C2O4)3] and (NH4)4[Co(C6H5O7)2] increased, the CMC of SDS decreased exponentially, which was sharp with increasing temperature. The CMC decreases due to the formation of pre-micellar aggregates of the positive counter ions of the complexes with dodecyl sulphate ions (DS-) and hydrophobic interaction between ligands of complexes and hydrophobic tail of SDS. The pre-micellar aggregate formation was essentially influenced by the counter ions binding abilities to the anionic micelle. The effect of metal complexes on lowering the CMC of SDS was found to follow the order [Cr(acac)2(H2O)2]Cl < K3[Fe(C2O4)3] < (NH4)4[Co(C6H5O7)2]. Thermodynamics of metal complexes with SDS and parameters of micellization ΔG°mic, ΔH°mic and TΔS°mic  were calculated.Keywords:  Surfactants; Sodium dodecyl sulphate; Critical micelle concentration; Pre-micellar aggregate; Hydrophobic interaction.© 2011 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved.doi: http://dx.doi.org/10.3329/jsr.v4i1.7989J. Sci. Res. 4 (1), 135-141 (2012)
Extraction Equilibrium of Ni(II) in the Ni2+-SO42--Ac-(Na+, H+) - Cyanex 272 (H2A2)-kerosene-3%(v/v) Octan-1-ol System
Authors: Biswas R. K. , Karmakar A. K. , Rahman M. S.
Published: January 2012

The title system has been studied elaborately. 3% (v/v) octan-1-ol is added as de-emulsifier. Equilibration time is < 2 min. Distribution ratio (D) at constant pH(eq) and [H2A2] is independent of [Ni(II)](aq). The pH dependency is always found to be 2; whilst the extractant dependence is found to vary from 1 (at lower concentration region, lcr) to 3 (at high concentration region, hcr). Moreover, the distribution ratio is found to be inversely proportional to (1+6.92 [SO42-]) and [Ac-]. Based on these results, the extraction equilibrium reactions have been proposed at various parametric conditions. The extraction process is endothermic (?H = 54.66 kJ/mol). The Kex values at 303 K are evaluated to be 10-11.086 and 10-11.56 at lcr and hcr of extractant, respectively. The maximum loading capacity is 21.28 g Ni(II) per 100 g extractant indicating the formation of NiAcA at maximum loading. The stripping ability of various inorganic acids towards loaded nickel, as well as, the possibilities of separation of Ni(II) from its binary mixtures with other ions of 3d-block elements have also been investigated.Keywords:  Extraction equilibrium; Ni(II) extraction; Cyanex 272; Sulphate-acetato medium; Kerosene-octanol.© 2012 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved.doi: http://dx.doi.org/10.3329/jsr.v4i1.8007J. Sci. Res. 4 (1), 83-97 (2012)
Joule Heating Effect on MHD Combined Convection in a Wavy Chamber Having Conducting Square Cylinder
Authors: Nasrin R.
Published: January 2012

The current simulation is focused on MHD combined convection flow and heat transfer characteristics in a square lid driven chamber. At the centre of this chamber a heat conducting solid square cylinder is located. Galerkin weighted residual finite element method is used to solve the governing equations of mass, momentum and energy. The left vertical wall of the chamber is mechanically lid driven and having temperature Tcold and velocity V0.  But the right wall is sinusoidal wavy pattern and contains more temperature (Thot) than the left lid. The top and bottom surfaces are adiabatic. The behavior of the fluid for the values of Joule heating parameter J (0, 1, 4, 7) and Richardson number Ri (0.1, 1, 10) is described in details. The variations of the average Nusselt number (Nu), the mean temperature of the fluid ( ) and the temperature at cylinder centre ( ) for various Ri and J are also presented. Maximum rate of heat transfer is occurred for the lowest J at each Ri.Keywords:  MHD; Wavy chamber; Conducting cylinder; Combined convection; Finite element formulation.© 2012 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved.doi: http://dx.doi.org/10.3329/jsr.v4i1.8014J. Sci. Res. 4 (1), 39-49 (2012)
Psychopharmacological Studies of Hydro Alcoholic Extract of Whole Plant of Marsilea quadrifolia
Authors: Reddy K. S. , Reddy C. S. , Ganapaty S.
Published: January 2012

The hydro alcoholic extract of the entire plant Marsilea quadrifolia (HEMQ) was evaluated for different psychopharmacological actions such as behaviour, exploratory behaviour, muscle relaxant activity and phenobarbitone induced sleeping time. The extract was found to cause reduction in spontaneous activity, decrease in exploratory behavioural pattern by swimming and pole climbing test., reduction in the muscle relaxant by traction test. In addition, the extract signi?cantly potentiated the phenobarbitone-induced sleeping time.  Preliminary tests indicate that the hydro alcoholic extract of Marsilea quadrifolia in doses of 200-400 mg/kg has signi?cant psychopharmacological activity.Keywords: Marsilea quadrifolia; Hydro alcoholic extract; Muscle relaxant; Exploratory behaviour.© 2012 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved.doi: http://dx.doi.org/10.3329/jsr.v4i1.8159J. Sci. Res. 4 (1), 279-285 (2012)