bluuebunny/crossref_metadata_2025 huggingface dataset:
Robust Frequency Control of Wind-Diesel Hybrid Power System Using Superconducting Magnetic Energy Storage
Authors: Ngamroo Issarachai
Published: April 2009

In an isolated wind-diesel hybrid power system, the variable power consumptions as well as the intermittent wind power may cause a large fluctuation of system frequency. If the system frequency can not be controlled and kept in the acceptable range, the system may lose stability. To reduce system frequency fluctuation, a superconducting magnetic energy storage (SMES) which is able to supply and absorb active power quickly, can be applied. In addition, variation of system parameters, unpredictable power demands and fluctuating wind power etc., cause various uncertainties in the system. A SMES controller which is designed without considering such uncertainties may lose control effect. To enhance the robustness of SMES controller, this paper focuses on a new robust control design of SMES for frequency control in a wind-diesel system. The coprime factorization is used to represent the unstructured uncertainties in a system modeling. The structure of a SMES controller is the practical first-order lead-lag compensator. To tune the controller parameters, the optimization problem is formulated based on loop shaping technique. The genetic algorithm is applied to solve the problem and achieve the control parameters. Simulation results confirm the high robustness of the proposed SMES controller with small power capacity against various disturbances and system uncertainties in comparison with SMES in the previous research.
Dynamic Process and Accident Simulations as Tools to Prevent Industrial Accidents
Authors: Brambilla Sara , Manca Davide
Published: May 2009

The dynamic simulation of chemical processes is an indispensable and central tool for process design, analysis, and operation. Compared to a steady state simulation, the dynamic process simulation has some outstanding advantages, such as the assessment of control system reliability before its implementation on the real plant, the planning and testing of start-up and shutdown procedures, the training of operators, the possibility to investigate the causes of previous accidents, and to determine the consequences of possible accidents. In particular, as far as the accidents are concerned, it is not of minor importance that they are an economic liability to the company and the community (Fewtrell and Hirst, 1998). Fewtrell and Hirst highlighted also that high-cost accidents have some common features. The coupled dynamic simulation of process and accidents allows identifying the aforementioned deficiencies while moving towards a more safe and productive management of chemical processes. This manuscript analyzes the possible plant/accident interactions and suggests the simultaneous dynamic integration of process simulators and accident simulators. In fact, to simulate a realistic accident dynamics, both the dynamics of the plant and of the accidental event should be run simultaneously since they are biuniquely interrelated and they influence one another. The manuscript investigates the feedbacks and interactions between the process and the accident by means of a specific case study.
Continuous Preferences and Discontinuous Choices: How Altruists Respond to Incentives
Authors: Seabright Paul B
Published: April 2009

This paper models two discontinuities that have been claimed to constitute important exceptions to the standard economic theory of human motivation. The first is a discontinuity in the distribution across population types of the willingness to accept payment in return for certain services such as giving blood, because such services given free are more worthwhile than when performed for payment. The second is that people who give services free may refuse to sell them for some positive price (this is known as crowding out). The paper models both phenomena when individuals act to signal their type in a two-period game with assortative matching. The former is the unique equilibrium of a signaling game in which individuals announce the prices at which they will perform a civic action. The latter may be observed as one of two equilibria of a screening game in which individuals have only a binary participation decision available to signal their type.
Sexual Dysfunction in Women With Type 1 Diabetes
Authors: Enzlin Paul , Rosen Raymond , Wiegel Markus , Brown Jeanette , Wessells Hunter , Gatcomb Patricia , Rutledge Brandy , Chan Ka-Ling , Cleary Patricia A. ,   the DCCT/EDIC Research Group
Published: April 2009

OBJECTIVE

This study aimed to investigate the prevalence and risk factors associated with sexual dysfunction in a well-characterized cohort of women with type 1 diabetes.

RESEARCH DESIGN AND METHODS

The study was conducted in women enrolled in the long-term Epidemiology of Diabetes Interventions and Complications (EDIC) study, a North American study of men and women with type 1 diabetes. At year 10 of the EDIC study, 652 female participants were invited to complete a validated self-report measure of sexual function, standardized history and physical examinations, laboratory testing, and mood assessment.

RESULTS

Of the sexually active women with type 1 diabetes in the EDIC study, 35% met criteria for female sexual dysfunction (FSD). Women with FSD reported loss of libido (57%); problems with orgasm (51%), lubrication (47%), and arousal (38%); and pain (21%). Univariate analyses revealed a positive association between FSD and age (P = 0.0041), marital status (P = 0.0016), menopausal status (P = 0.0019), microvasculopathy (P = 0.0092), and depression (P = 0.0022). However, in a multivariate analysis, only depression (P = 0.004) and marital status (P = 0.003) were significant predictors of FSD.

CONCLUSIONS

FSD is common in women with type 1 diabetes and affects all aspects of sexual function and satisfaction. Depression is the major predictor of sexual dysfunction in women with type 1 diabetes. These findings suggest that women with type 1 diabetes should be routinely queried about the presence of sexual dysfunction and possible co-association with depression.
Diabetic Subjects Diagnosed Through the Diabetes Prevention Trial–Type 1 (DPT-1) Are Often Asymptomatic With Normal A1C at Diabetes Onset
Authors: Triolo Taylor M. , Chase H. Peter , Barker Jennifer M. ,   the DPT-1 Study Group
Published: April 2009

OBJECTIVE

Upon diagnosis of type 1 diabetes, patients are usually symptomatic, and many have ketoacidosis. Screening for islet autoantibodies (IAs) has been shown to decrease A1C level and rate of hospitalization at diabetes onset. Metabolic tests and the presence of symptoms were described at diabetes onset during the Diabetes Prevention Trial–Type 1 (DPT-1).

RESEARCH DESIGN AND METHODS

The DPT-1 screened relatives of patients with type 1 diabetes for islet cell autoantiobodies (ICAs). Those with positive ICAs had intravenous and oral glucose tolerance tests (IVGTTs and OGTTs) and were randomized into one of two prevention trials. Throughout the DPT-1 parenteral and oral insulin study, 246 people were diagnosed with type 1 diabetes.

RESULTS

Of the 246 subjects diagnosed with diabetes, 218 had data regarding the presence of symptoms, and 138 (63.3%) reported no symptoms suggestive of diabetes. Eight subjects (3.67%) presented with ketosis. Subjects presented with a mean ± SD A1C of 6.41 ± 1.15%. At diagnosis, 90 subjects (50.8%) had A1C in the normal range (<6.2%). OGTT data at the time of diagnosis indicate that 35.4% had a glucose result of <100 mg/dl at 0 min.

CONCLUSIONS

The majority of subjects diagnosed with type 1 diabetes through the DPT-1 were asymptomatic at onset and had normal fasting glucose and A1C levels. This suggests that intermittent screening (IA followed by OGTT) may allow diagnosis of diabetes before severe metabolic decompensation. Screening with A1C will miss identifying many of the subjects with newly diagnosed type 1 diabetes in this cohort.
Asymmetry of muscle strength in elite athletes
Authors: Drid Patrik , Drapsin Miodrag , Trivic Tatjana , Lukač Damir , Obadov Slavko , Milosevic Zoran
Published: April 2009

Asymmetry of muscle strength in elite athletes

Study aim: To determine muscle strength variables in elite judoists and wrestlers since thigh muscle strength and bilaterally balanced flexor-to-extensor ratio minimise injury risk and are desirable for achieving sport successes.

Material and methods: Judoists, wrestlers and untrained subjects, 10 each, were subjected to isokinetic strength measurements of relative peak torques of knee flexor and extensor muscles on "Easy-Tech" dynamometer in concentric-concentric mode.

Results: Mean relative peak muscle torques for knee flexors ranged from 1.14 ±0.27 (untrained) to 1.57 ±0.40 (judoists) N·m/kg and for knee extensors from 2.77 ± 0.34 (untrained) to 3.60 ± 0.64 (wrestlers) N·m/kg. The flexor-to-extensor ratios ranged from 39.3 ± 6.0 to 47.8 ± 10.8% and did not differ significantly between groups. Absolute right/left asymmetry for knee flexors ranged from 14.6 ± 10.4 to 17.4 ± 11.8% and was significantly (p<0.01) higher than for knee extensors (7.2 ± 6.8 to 8.6 ± 7.7%). All asymmetry indices were significant (p<0.01), no significant between group differences being detected.

Conclusions: Implementing new training elements and modalities may improve the performance and prevent lateral asymmetry thus decreasing the risk of injuries.
Perception of doping-related risks by junior and senior athletes
Authors: Mroczkowska Helena
Published: April 2009

Perception of doping-related risks by junior and senior athletes

Study aim: To assess the degree of acceptance of risk by experienced and inexperienced athletes. Material and methods: Two male teams participated in the study: juniors (football; n = 9) aged 16 - 18 years and seniors (volleyball; n = 13) aged 20 - 32 years. The subjects were requested to assess the doping-related risk of losing every of 6 values: health, medals, ranking position, physical attractiveness, psycho-emotional balance, bonuses and respect of personages, in three modes: importance of losing given value (scale 1 - 6), general likelihood of a doping-related loss of given value (scale 0 - 100) and the doping-related risk of losing given value the subject would be ready to take (scale 0 - 100).

Results: Seniors and juniors rated the importance of individual values and the doping-related general likelihood of losing them alike. As compared with senior athletes, the junior ones significantly underrated the risk of losing health and respect and overrated that of possible bonus.

Conclusions: The emotional, cognitive and social maturation of young athletes throughout a decade have an impact on perceiving doping-related risks and the associated decisions.
Analysis of Heat Transfer in PVC Profiles during the Extrusion Calibration/Cooling Step
Authors: Mousseau P. , Delaunay D. , Lefèvre N.
Published: April 2009

The external vacuum calibration of extruded thermoplastic materials is a complex process, which may hinder the production and even the quality of the parts. Process control requires a thorough knowledge and a deep analysis of the heat transfer phenomena between both the part and the calibrator during the cooling phase. This paper initially presents a detailed description of the experimental setting used to qualify and quantify the heat transfer modes. The experimental specimen is a 100-mm wide PVC strip, which represents one of the three sides of the U-profile. The development of physical models to predict plastic part thermal history during the forming process is a major industrial concern because it can reduce tooling development times and costs significantly. In the extrusion processing field, the external vacuum calibration stage often hinders productivity. The present study has been conducted to examine strip cooling phase so as to propose some thermal models for both global and detailed analyses of heat transfer modes. First, a transparent wall calibrator is used to view the behaviour of the extrudate inside the calibrator for a better understanding of the thermal phenomena at work. A second calibrator equipped with temperature sensors makes it possible to assess, using an inverse calculation method, the heat flux transferred from the extruded material to the calibrator as well as the temperature pattern throughout the tool.
Study on the Bleeding Mechanism of Slip Agents in a Polypropylene Film using Molecular Dynamics
Authors: Wakabayashi M. , Kohno T. , Tanaka Y. , Kanai T.
Published: April 2009

The bleeding (internal transport) process of additives in a polypropylene film under atmospheric pressure was investigated. The experimental results were explained more precisely by a new model assuming the two-step transport between the amorphous and crystalline regions. The diffusion coefficient of a higher fatty acid such as behenic acid (docosanoic acid) in isotactic polypropylene film and that of higher fatty acid amides such as erucamaide (13-cis-docosenamide) in ethylene copolymerized polypropylene film were determined at 40 and 50°C respectively. The difference between the diffusion coefficients of three slip agents in a polypropylene film at 50°C was explained using a molecular dynamics simulation in which self-association of the slip agent molecules by hydrogen bonding was considered.
The Resarch for Asphalt Modified with Phosphorus Trichloride/SBS
Authors: Zhang F. , Yu J.-Y.
Published: April 2009

The high-temperature storage stability of styrene-butadiene-styrene triblock copolymer (SBS) modified asphalt can be improved to some extent with the addition of phosphorus trichloride. The dynamic mechanical and physical properties of SBS-modified asphalts before and after adding phosphorus trichloride were studied respectively. The addition of phosphorus trichloride to asphalt improved the high-temperature performance of asphalt and reduced its temperature susceptibility to a great extent with unfavourable effect on low-temperature ductility. The addition of SBS to phosphorus trichloride modified asphalt increased the low-temperature ductility, viscosity of asphalt and improved its high-temperature performance further. Different SBS structures influenced the rheological and physical properties of asphalt before and after adding phosphorous trichloride.
Predicting the Yield Stress of Polymer Glasses Directly from Processing Conditions: Application to Miscible Systems
Authors: Engels T. A. P. , Schrauwen B. A. G. , van Breemen L. C. A. , Govaert L. E.
Published: April 2009

A previously developed model which predicts the yield stress of a polymer glass directly from processing conditions is applied to a system of miscible polymers. The selected system consists of a blend of polycarbonate with polyester and three blend compositions of increasing weight percentages polyester are investigated with respect to their aging kinetics. Based on these kinetics, the yield stress as it results form the thermal history experienced during processing is predicted and found to be in good agreement with experimental results. The parameters governing the evolution of the yield stress are shown to follow the rule of mixtures, enabling the prediction of the yield stress of any blend composition.
A Design to Study Flow Induced Crystallization in a Multipass Rheometer
Authors: Housmans J.-W. , Balzano L. , Santoro D. , Peters G. W. M. , Meijer H. E. H.
Published: April 2009

The design and performance of a flow geometry for the multipass rheometer (MPR) is described, creating an experimental setup to study in-situ and ex-situ structure and morphology development with a proper control over the processing conditions and shear history. The slit used is equipped with diamond windows, to combine flow with different experimental techniques, such as optical microscopy (OM), birefringence and X-ray scattering. In this paper we present preliminary results, obtained on isotactic polypropylene, that demonstrate the possibilities of this device for more extended future research. The focus is on the in-situ birefringence measurements of crystallization and the relation with the final morphology.
Diamagnetic Susceptibility of a Confined Donor in a Quantum Dot with Different Confinements
Authors: Peter A. J. , Ebenezar J.
Published: April 2009

The binding energies of shallow hydrogenic impurity in a GaAs/GaAlAs quantum dot with spherical confinement, harmonic oscillator-like and rectangular well-like potentials are calculated as a function of dot radius using a variational procedure within the effective mass approximation. The calculations of the binding energy of the donor impurity as a function of the system geometry have been investigated. A comparison of the eigenstates of a hydrogenic impurity in all the confinements of dots is discussed in detail. Â We have computed and compared the susceptibility for a hydrogenic donor in a spherical confinement, harmonic oscillator-like and rectangular well-like potentials for a finite QD and observe a strong influence of the shape of confining potential and geometry of the dot on the susceptibility.Â Keywords: Quantum dot; Quantum well wire; Quantum well; Diamagnetic susceptibility; Donor impurity.Â Â© 2009 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved.Â DOI: 10.3329/jsr.v1i2.1184Â Â Â
Elastic Behaviour of Diborides Under High Pressure
Authors: Gupta Seema , Goyal S. C.
Published: April 2009

The present study deals with the elastic behaviour of diborides (BeB2, MgB2 and NbB2) under high pressure with the help of equation of state (EOS) using the elastic data reported by Islam et al. It is concluded that EOS, which are based either on quantum statistical model orÂ  pseduopotential model, only are capable of explaining high pressure behaviour of the solids under study. Â Moreover the value of first order pressure derivative of bulk modulus at infinite pressure (Kinfinity) is greater than 5/3 and thus the diborides under study do not behave as Thomas-Fermi electron gas under high compression.Â Keywords: Equation of state; High Pressure; Diborides.Â Â© 2009 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved.Â DOI: 10.3329/jsr.v1i2.1189Â
14.8 MeV Neutron Activation Cross Section Measurements for Ge Isotopes
Authors: Haque M. M. , Islam M. T. , Hafiz M. A. , Miah R. U. , Uddin M. S.
Published: April 2009

The cross sections of Ge isotopes were measured with the activation method at 14.8 MeV neutron energy. The quasi-monoenergetic neutron beams were produced via the 3H(d,n)4He reaction at the 150 kV J-25 neutron generator of INST, AERE. The characteristics γ-lines of the product nuclei were measured with a closed end coaxial 17.5 cm2 high purity germanium (HPGe) detector gamma ray spectroscopy. The cross sections were determined with reference to the known 27Al(n,α)24Na reaction. Cross section data are presented for 72Ge(n,p)72Ga, 74Ge(n,α)71mZn and 76Ge(n,2n)75m+gGe reactions. The cross section values obtained for the above reactions were 24.78±1.75 mb, 1.69±0.11 mb and 860±50 mb, respectively. The results obtained were compared with the values reported in literature as well as theoretical calculation performed by the statistical code SINCROS-II. The experimental data were found fairly in good agreement with the calculated and literature data.  Keywords: Activation cross section; Neutron induced reaction; Gamma-ray spectroscopy; 14.8 MeV. © 2009 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved. DOI: 10.3329/jsr.v1i2.1532
Antiulcer Activity of Morinda Citrifolia Linn Fruit Extract
Authors: Srikanth J. , Muralidharan P.
Published: April 2009

The study was designed to investigate the antiulcer activity of ethyl acetate extract of the fruits of Morinda citrifolia Linn (Rubiaceae) using different models of gastric and duodenal ulceration in rats. Gastric ulcers were induced by oral administration of ethanol, aspirin and by pyloric ligation and duodenal ulcers were induced by oral administration of cysteamine HCl. The extract was administered at a dose of 200 and 400 mg/kg orally 30 min prior to ulcer induction. Ranitidine (50 mg/kg) was used as a reference standard.  The antiulcer activity was accessed by determining and comparing the ulcer index in the test group with that of the standard drug treated group. Gastric volume, total acid and free acid were estimated in the pylorus-ligated rats. M.citrifolia (400mg/kg) showed maximum inhibition of gastric acid, free acid and total acid to 53.54%, 52.55% and 30.30%, respectively. The ulcer index in the M.citrifolia treated animals was found to be significantly less in all the models compared to standard drug treated cases. The antiulcer activity of M.citrifolia was, however, less than that of ranitidine. The results suggest that M.citrifolia possesses significant antiulcer property which could be due to cytoprotective action of the drug or strengthening of gastric and duodenal mucosa with the enhancement of mucosal defence. Keywords: Morinda citrifolia; Antiulcer.© 2009 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved.DOI: 10.3329/jsr.v1i2.1625
Some Estimators for the Pareto Distribution
Authors: Prakash Gyan
Published: April 2009

We derive some shrinkage test-estimators and the Bayes estimators for the shape parameter of a Pareto distribution under the general entropy loss (GEL) function. The properties have been studied in terms of relative efficiency. The choices of shrinkage factor are also suggested. Â Keywords: General entropy loss; Shrinkage factor; Shrinkage test-estimator; Bayes estimator; Relative efficiency.Â Â© 2009 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved.Â DOI: 10.3329/jsr.v1i2.1642Â Â
Cytotoxic Studies on Two Meliaceae plants: Chukrasia Tabularis and Aglaia Roxburghiana
Authors: Islam M. K. , Eti I. Z. , Chowdhury J. A.
Published: April 2009

The paper details a biological investigation on chukrasia tabularis and aglaia roxburghiana, species of meliaceae. The methanol crude extract of chukrasia tabularis and aglaia roxburghiana have been screened for antitumor potentials using brine shrimp lethality bioassay with ten different concentrations. An established cytotoxic agent vincristine sulphate has been used to compare the results. From the graphs the concentration of methanolic crude extract yields the value of LC50 (50% mortality) as 1.58mg/ml and 2.21mg/ml for chukrasia tabularis and aglaia roxburghiana, respectively. In the same way the concentration at which 90% mortality (LC90) occurs for the methanol extract are obtained from the graphs and the values have been found to be 141.41mg/ml and 70.70mg/ml for chukrasia tabularis and aglaia roxburghiana, respectively. Keywords: Chukrasia tabularis; Aglaia roxburghiana; Meliacea; Cytotoxicity. © 2009 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved. DOI: 10.3329/jsr.v1i2.1645
Response of Some Medicinal Plants to Vesicular Arbuscular Mycorrhizal Inoculations
Authors: Karthikeyan B. , Joe M. M. , Cheruth A. J.
Published: April 2009

An investigation has been made about the response of vesicular arbuscular mycorrhizal fungi of G. fasciculatum on some medicinal plants. Medicinal plants species selected for the study are Ocimum sanctum, Catharanthus roseus, Coleus forskholii and Cymbopogon flexuosus. The percentage of VAM association is 85 and the intensity of formation of vesicles and arbuscules  are 70% and 30%, respectively in VAM inoculated C. roseus plants. The total dry matter production (shoot and root dry wt), protein and total chlorophyll contents are seen to increase in VAM inoculated plants. The percentage of increase is more in C. roseus, followed by Cymbopogon flexosus when compared to control plants. Keywords: Ocimum sanctum, Coleus forskholii, Cymbopogon flexosus, Catharanthus roseus, VAM fungi.© 2009 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved.DOI: 10.3329/jsr.v1i2.1675
Arsenic Release from Contaminated Soil of Bangladesh in Natural Field Conditions
Authors: Azam M. S. , Shafiquzzaman M. , Mishima Iori , Nakajima Jun
Published: April 2009

Leaching experiment was conducted to understand the mechanism of arsenic release from soil in the natural field conditions. Two types of column were run, one with de-ionized water (DW) and another with synthetic Bangladesh groundwater (GW) as influent which simulated rainfall and groundwater conditions, respectively. As the primary mechanism for the arsenic release from soil it was identified that the redox potential (Eh) was major importance. In highly reducing conditions both arsenic and iron release was high. Released mass of arsenic was higher in DW column than GW column. The difference was caused by the presence of calcium and magnesium ion in the synthetic groundwater. Comparing to the acid-alkali sequential extraction it was found that calcium and magnesium prohibited the release of arsenic bound with iron. The effect of calcium and magnesium was clarified in the batch experiment performed in the study.Keyword: Paddy field; Groundwater; Arsenic; Redox potential; pH. © 2009 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved.Â DOI: 10.3329/jsr.v1i2.1708
Synthesis and Electrochemical Characterizations of 7-Ferrocenycarbonyloxy-1-heptanethiol on Gold Substrates
Authors: Rahman M. M. , Jeon I. C. , Oh K. J.
Published: April 2009

The 7-ferrocenycarbonyloxy-1-heptanethiol (FcCO2C7SH) is synthesized using ferrocene carboxylic acid, 1,6-fibromohexane, and NaS, which is confirmed and separated by FT-IR, 1H NMR, and column chromatography. The basic redox (interfacial) properties are also studied of the self-assembled monolayers (SAMs) formed with this synthesized compound on polycrystalline gold electrode by Electrochemical Quartz Crystal Microbalance (EQCM). The FcCO2C7SH on gold acts as a barrier for the electron transfer between the gold electrode and HClO4 in solutions and as a mediator for the reduction of Fe3+ in solution. The frequency change (interfacial mass change) on the gold electrode surface is observed during the redox of ferrocenyl groups.Keywords: 7-Ferrocenycarbonyloxy-1-heptanethiol; Self-Assembled Monolayers; EQCM; Peak current; Modified gold electrode.© 2009 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved.DOI: 10.3329/jsr.v1i2.1746
Constituents of Peel and Leaf Essential Oils of Citrus Medica L
Authors: Bhuiyan M. N. I. , Begum J. , Sardar P. K. , Rahman M. S.
Published: April 2009

The chemical constituents of leaf and peel essential oil of Citrus medica L. were analysed by gas chromatography mass spectroscopy (GC-MS). Nineteen components accounting for 99.9% of the oil were identified in leaf oil. The major constituents are erucylamide (28.43%), limonene (18.36%) and citral (12.95%). The peel oil contains forty three components accounting for 99.8% of the total oil and the major components are isolimonene (39.37%), citral (23.12%) and limonene (21.78%). Keywords: Citrus medica; Essential oils; GC-MS; Erucylamide; Isolimonene. © 2009 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved.DOI: 10.3329/jsr.v1i2.1760
Elastic Properties of α- and β-phases of Li3N
Authors: Hossain M. A. , Islam A.K.M. A , Islam F. N.
Published: April 2009

Investigations of elastic properties of Li3N in both α- and β-phases have been made by first-principles methods (HF-LCAO, DFT as implemented in CRYSTAL98 and in CASTEP). The theoretical equation of state of the α-phase (D46h structure) produced by our total-energy calculations is compared with the experimental EOS. Five independent elastic constants are calculated for the first time for both the phases. These are compared with the available four elastic constants of α-Li3N estimated from the slopes of the acoustic branches in the long wavelength region of the measured phonon dispersion curves. The aggregate elastic moduli (B, G, E), the Poisson’s ratio (ν) and the Debye temperature ΘD as a function of pressure are also calculated and the results discussed.Keywords: Li3N; α- and β-phases; Elastic properties; Debye temperature.©?2009 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved.DOI: 10.3329/jsr.v1i2.1763
Effect of Leaf Positions on Total Phenolics, Flavonoids and Proanthocyanidins Content and Antioxidant Activities in Lantana Camara (L)
Authors: Bhakta Deepita , Ganjewala Deepak
Published: April 2009

Changes in the level of phenolics, flavonoids and proanthocyanidins with leaf positions were studied in L. camara twigs. Leaves at different positions (from apex to base) in a twig represented gradient increase in the leaf age, apical being the youngest leaves. The study showed that the fresh weight, dry weight and area of the leaves increased rapidly from I until IV position in a twig. Levels of phenolics remained unchanged from I to V leaf position, while a sharp increase in the levels of proanthocyanidins and flavonoids was observed during I to III leaf position which decreased markedly thereafter. At any leaf position in a twig, the level of proanthocynidin was higher than both phenolics and flavonoids, while the proportion of flavonoids was much higher than the phenolics. In fact, phenolics were present in very small amounts. In addition, antioxidant potential of leaves extracts was measured in terms of reducing and scavenging activity. The study revealed that extracts prepared from leaves present from I to III position exhibited significantly higher antioxidant activities than the leaves present from IV to V position. The study thus revealed that leaf positions (age) influence the level of secondary metabolites and thereby their antioxidant properties. Keywords: Antioxidant; Flavonoids; Lantana camara; Phenolics; Proanthocynidins.© 2009 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved.DOI: 10.3329/jsr.v1i2.1873
Reciprocal Symmetry and its Relation to Einstein's Postulate, Lorentz Transformation and Discreteness
Authors: Ahmad Mushfiq
Published: April 2009

Objectivity demands that kinematics should be independent of the quantities (velocities or their reciprocals) we define. This demand is translated as Reciprocal Symmetry (RS), which we have defined. We have shown that RS gives an upper bound velocity, the mathematical analogue of Einstein's postulate, and Lorentz transformation. RS also requires discreteness. RS promises to bridge the gap between relativity and quantum mechanics. Keywords: Galilean velocity; Lorentz-algebraic velocity; Reciprocal symmetry; Reciprocal velocity; Reciprocal symmetric distance; Discrete time; Discreteness. © 2009 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved.DOI: 10.3329/jsr.v1i2.1875
Ferroelectric Phase Transition in Cu-doped BaTiO3 Crystals
Authors: Ouedraogo A. , Palm K. , Chanussot G.
Published: April 2009

The paper examines the ferroelectric-paraelectric phase transition in Cu:BaTiO3 single crystals. Using thermo-currents and dielectric measurements, we found for pure samples the phase transition temperature to be close to Curie temperature (Tc=120°C) with an anisotropy of the dielectric constantε.The lowering of temperature Tm, corresponding to the maximum of pyroelectric signal, with the increase of concentration of impurities is confirmed by measurements of ε. Moreover, the e(T) curves show progressive broadening as well as higher peak with the increase of  impurity concentration, and the transition becomes more and more diffuse. The same effect occurs when the samples are subjected to a laser irradiation (λ=5145Çº). During annealing, crystals lose copper and Tm is thereafter observed to increase again. BaTiO3 is a displacive ferroelectric (having high permittivity k-values) which undergoes a first order phase transition. Ions substitutions have an effect on the lattice dynamics attributed to charge transfer to Ti and a lowering of elastic forces in BaTiO3. Kewwords: Ferroelectric transition; BaTiO3 single crystals; Thermo-currents; Dielectric constant.  © 2009 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved. DOI: 10.3329/jsr.v1i2.1876
MHD Flow of a Dusty Viscous Conducting Liquid Between Two Parallel Plates
Authors: Sreeharireddy P. , Nagarajan A. S. , Sivaiah M.
Published: April 2009

In this paper, the flow of a viscous conducting liquid with uniform distribution of dust particles in a channel is considered under the influence of a uniform transverse magnetic field with pressure gradient varying linearly with time. The velocities of fluid and dust are found to decrease with the increase of the magnetic parameter. Further that the velocity of the fluid particles is observed to be more than that of dust particles.Keywords: Viscous conducting liquid; Uniform transverse magnetic field; Fluidization; Incompressible fluid; Stokeâs resistance coefficient.Â Â© 2009 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved.Â DOI: 10.3329/jsr.v1i2.2280
Transient Stability Enhancement of Wind Generator by PWM Voltage Source Converter and Chopper Controlled SMES Unit
Authors: Sheikh M. R. I. , Nasiruzzaman A. B. M.
Published: April 2009

In order to investigate the impacts of the integration of wind farms into utility networks, transient stability should be analyzed before connecting wind turbine generator system (WTGS) to the power system. This paper proposes a robust controller for Superconducting Magnetic Energy Storage (SMES) unit to enhance the transient stability of a grid connected fixed speed wind generator system. In the proposed controller, both SMES active and reactive powers are controlled to decrease the fluctuations of output power and terminal voltage of the wind generator during transient condition. The power conversion system (PCS) of SMES unit used in this paper is composed of a sinusoidal Pulse Width Modulated Voltage Source Converter (PWM-VSC) and a two-quadrant DC-DC chopper using Insulated Gate turn-off Bipolar Transistors (IGBT). Stability during symmetrical and unsymmetrical faults in the network system is analyzed.Â Â  The effects of the faults on the generator dynamics are also discussed clearly. Simulation results demonstrate that the proposed SMES controller is very effective for stabilizing wind generator as well as the entire power system. Keywords: Â Fixed speed wind generator system; Transient analysis; System faults; PWM-VSC; DC-DC chopper and SMES unit.Â© 2009 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved.Â DOI: 10.3329/jsr.v1i2.2281
Preparation of Polyimide-Clay Nanocomposites and Their Performance
Authors: Alam S. M. M.
Published: April 2009

A series of polyimide (PI)-organically modified clay nanocomposites were made to enhance tensile modulus, thermal stability of PI. PI was made from 3, 3', 4, 4'-biphenyl tetracarboxylic dianhydride (BPDA), p-phenylediamine (PDA).  Montmorillonite (MMT), one type of layered clay, was treated by dodecylamine salt.  XRD indicated that organically modified montmorillonite (OMMT) layers were exfoliated and dispersed into PI-film.  Tensile measurements indicated that small amount of OMMT (up to 3%) increased tensile modulus nicely.  The glass transition temperatures (Tg) of the nano-composites are higher than those of pristine PI.  Thermal gravimetric analysis (TGA) showed that nanocomposites have higher decomposition temperatures in comparison with the original PI.  Keywords: Polyimide; Organically modified clay; Nanocomposites; Dodecylamine. © 2009 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved.DOI: 10.3329/jsr.v1i2.2297
Antibacterial Activity of Different Organic Extracts of Achyranthes Aspera and Cassia Alata
Authors: Alam M. T. , Karim M. M. , Khan Shakila N.
Published: April 2009

Extracts in organic solvents (namely methanol, ethanol, ethyl acetate and chloroform) of two medicinal plants - Achyranthes aspera and Cassia alata were evaluated for their antibacterial activities against Escherichia coli, Bacillus subtilis, Vibrio cholerae, Salmonella typhi and Staphylococcus aureus. These were carried out by taking the organic extracts of both the leaf and stem parts of the plants at a concentration of 5 mg/ml and their activities were recorded by estimating zones of inhibition as produced by disc-diffusion method on Mueller-Hinton agar media. While neither the leaf nor stem parts of A. aspera in any organic extractions showed antibacterial activity, the methanolic extracts of both the leaf and stem parts of C. alata exhibited antibacterial activity, but only to B. subtilis and S. typhi, and the corresponding MIC values of the leaf extracts were estimated as 1.25 and 1.5 mg/ml respectively. However, the ethanolic extracts of both the stem and leaf parts were found equally effective only to S. aureus (MIC= 1.25 mg/ml). The corresponding MBC values are reported. Keywords: Achyranthes aspera; Cassia alata; Antibacterial.© 2009 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved.DOI: 10.3329/jsr.v1i2.2298
Synthesis and Antimicrobial Activities of Some New Thieno and Furopyrimidine Derivatives
Authors: Hossain M. I. , Bhuiyan M. M. H.
Published: April 2009

Fused pyrimidines, 8,9-dimethyl[1,2,4]triazolo[4,3-c]thieno[3,2-e]pyrimidine 5, 3,8,9-trimethyl[1,2,4]triazolo[4,3-c]thieno[3,2-e]pyrimidine 6, 4-benzylidinehydrazono-5,6  dimethylthieno[2,3-d]pyrimidine 7, 4-[4/-hydroxybenzylidine]hydrazono-5,6-dimethylthi-eno[2,3-d]pyrimidine 8, 4-[4/-tolylidin]hydrazono-5,6-dimethylthieno[2,3-d]pyrimidine 9, 4-[4/-nitrobenzylidine]hydrazono-5-ethyl-6-methylthieno[2,3-d]pyrimidine 10 and 4-[4/-chlorobenzylidine]hydrazono-5-ethyl-6-methylthieno[2,3-d]pyrimidine 11 are prepared in good yield by an initial treatment of 2-amino-4,5-dimethylthiophene-3-carbonitrile 1 with formic acid, affording 5,6-dimethylthieno[2,3-d]pyrimidin-4(3H)-one 2, which is chlorinated with thionyl chloride and then hydrazinated with hydrazine hydrate. Finally hydrazino compound 4 is reacted with formic acid, acetic anhydrate, benzaldehyde, p-hydroxybenzaldehyde, p-toluayldehyde, p-nitrobenzaldehyde and p-chlorobenzaldehyde to give thienotriazolopyrimidines 5-6 and thienopyrimidines 7-11 respectively. All the compounds have been screened for their antimicrobial activity. Keywords: Fused pyrimidines; Hydrazino compound; Thienotriazolopyrmidines; Thienopyrimidines; Antimicrobial activity.© 2009 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved.DOI: 10.3329/jsr.v1i2.2299
Simultaneous Quantification of Sinensetin and Tetramethoxyflavone in Misai Kucing Capsules using TLC-UV Densitometric Technique
Authors: Hossain M. A. , Salehuddin S. M.
Published: April 2009

Thin-layer chromatographic (TLC)-UV densitometric method is developed for simultaneous quantification of sinensetin and 5-hydroxy--6,7,3', 4'-tetramethoxyflavone (TMF) in Misai kucing capsules (Orthosiphon stamineus). Sinensetin and TMF are isolated from the leaves of local Orthosiphon stamineus. TheÂ  TLC-UV desitometric quantification is performed by external standard method on silica gel plates using chloroform-ethyl acetate (60:40) as developing solvent and UV detection at 365 nm.The TLC densitometer, although yields slightly higher values than the other analytical methods, is preferred due to its simplicity, easy and low cost. Keywords: Orthosiphon stamineus; Lamiaceae; Local medicinal plant; HPTLC; Quantification; Densitometer. © 2009 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved.DOI: 10.3329/jsr.v1i2.2300
EDITORIAL
Authors: Islam A.K.M.A.
Published: April 2009

It is our pleasure to see the second issue of the Journal of Scientific Research coming out in time. From the trend in the submission of manuscript it seems that the journal is acting as a catalyst for the advancement of science both within and outside the Asian region. Increased submissions from the world research community will eventually fulfill our mission and aim for the journal with its interdisciplinary nature to stand for the international scientific publishing standards.Â  I hope that the journal will soon be recognised by the much wider research community as their forum for the dissemination of knowledge.We continue to recognize that the success of a journal depends on the quality of authors, reviewers and the editorial board. All the people involved in bringing out the issue of the journal should deserve thanks for their indispensable participation. Special mention should be made of the reviewers who voluntarily contributed their valuable time to complete reviews within a reasonable time. I should also acknowledge the International Network for the availability of Scientific Publications (INASP) for helping us publish via BanglaJOL. A K M A Islam Editor-in-Chief email: jsr_editor@ru.ac.bd website: www.banglajol.info/index.php/JSR© 2009 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved.DOI: 10.3329/jsr.v1i2.2390
Announcement
Authors: Board Editorial
Published: April 2009

AnnouncementsÂ Â Â Â Â Publication charge: Currently there is no publication charge from the authors (applicable to issues 1, 2 and 3 of volume 1). Authors get copies of published articles free of charge from the journal web site www.banglajol.info/index.php/JSR, but they have to register for that. Â A modest publication charge of accepted articles (does not include Reprints) to defray the partial cost of journal printing is applicable for accepted articles of volume 2 and onwards â authors will get notification for that at appropriate time after acceptance of their articles. The rate varies from US$ 5 to $10 (or Tk 300) per page of accepted paper depending on authorâs geographical locations. The publication charge will apply to papers that are accepted for publication in volume 2 and onwards. Method of payment at present is via bank draft. Information for electronic transfer will be announced later on.Â Â Draft payable to:Â  Editor-in-Chief, Journal of Scientific Research, Rajshahi University.Â Some useful information for Authors:Â 1.Â  MS Preparation: Consult âAuthor Guidelines and Example Articleâ (vol. 1, issue 1) for preparing articles in MS Word only. May also see any published paper in JSR for style and figure, table sizes etc.Â 2.Â  Submission: Two methods of submission:Â a. Web submission: This is the preferred method of submission â authors are encouraged to use this method.Â  Website: Â Â Â www.banglajol.info/index.php/JSRÂ  Â Complete 5 step processes. For multi-authored manuscript, submit information of all the co-authors during initial submission.Â b. E-mail submission: For multi-authored manuscript, supply e-mails of all the co-authors.Â It is recommended that the authors should make PDF file of their manuscripts to test that everything (Fig., Table, Equations etc.) is reproduced correctly.Â 3.Â  Publication schedule:Â Â  Frequency 3 issues per year as follows:Â Issue 1: Â 1 JanuaryIssue 2:Â  1 MayIssue 3:Â  1 September Â 4.Â  Steps in the process of MS handling:Â a. Â Acknowledgement of submission. Â Auto generated reply with MS ID for web submission. MS ID is allocated and acknowledged by e-mail by the editor for e-mail submission.Â b. Â Peer-review process: Usually takes 2 to 3 months.Â c. Editorial decision: Author is informed as soon as a decision is made upon receipt of reviews.Â Â Â© 2009 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved.DOI: 10.3329/jsr.v1i2.2391Â Â
Application of an Image Tracking Algorithm in Fire Ant Motion Experiment
Authors: Gui Lichuan , Seiner John
Published: April 2009

An image tracking algorithm, which was originally used with the particle image velocimetry (PIV) to determine velocities of buoyant solid particles in water, is modified and applied in the presented work to detect motion of fire ant on a planar surface. A group of fire ant workers are put to the bottom of a tub and excited with vibration of selected frequency and intensity. The moving fire ants are captured with an image system that successively acquires image frames of high digital resolution. The background noise in the imaging recordings is extracted by averaging hundreds of frames and removed from each frame. The individual fire ant images are identified with a recursive digital filter, and then they are tracked between frames according to the size, brightness, shape, and orientation angle of the ant image. The speed of an individual ant is determined with the displacement of its images and the time interval between frames. The trail of the individual fire ant is determined with the image tracking results, and a statistical analysis is conducted for all the fire ants in the group. The purpose of the experiment is to investigate the response of fire ants to the substrate vibration. Test results indicate that the fire ants move faster after being excited, but the number of active ones are not increased even after a strong excitation.
Localization of D-β-Aspartyl Residue-Containing Proteins in Various Tissues
Authors: Motoie Ryota , Fujii Noriko , Tsunoda Shigeru , Nagata Kenji , Shimo-oka Tadashi , Kinouchi Tadatoshi , Fujii Norihiko , Saito Takeshi , Ono Koji
Published: April 2009

Prior to the emergence of life, it is believed that only L-amino acids were selected for formation of protein and that D-amino acids were eliminated on the primitive Earth. Whilst homochirality is essential for life, the occurrence of proteins containing D-β-aspartyl (Asp) residues in various tissues from elderly subjects has been reported recently. Here, we demonstrate the presence of a D-β-Asp-containing protein in the cardiac muscle of heart, blood vessels of the lung, chief cells of the stomach, longitudinal and circular muscle of the stomach, small intestine and large intestine. Since the D-β-Asp residue occurs through a succinimide intermediate, this isomer may potentially be generated in proteins more easily than initially thought. Formation of the D-β-Asp residue in proteins may be related to stress.
Chemopreventive Effects of Sarcophine-diol on Ultraviolet B-induced Skin Tumor Development in SKH-1 Hairless Mice
Authors: Zhang Xiaoying , Bommareddy Ajay , Chen Wei , Hildreth Michael B. , Kaushik Radhey S. , Zeman David , Khalifa Sherief , Fahmy Hesham , Dwivedi Chandradhar
Published: April 2009

Sarcophine-diol (SD), one of the structural modifications of sarcophine, has shown chemopreventive effects on 12-dimethylbenz(a)anthracene-initiated and 12-O- tetradecanoylphorbol-13-acetate-promoted skin tumor development in female CD-1 mice. The objective of this study was to determine the chemopreventive effects of SD on UVB-induced skin tumor development in hairless SKH-1 mice, a model more relevant to human skin cancer, and to determine the possible mechanisms of action. Carcinogenesis was initiated and promoted by UVB radiation. Female hairless SKH-1 mice were divided into two groups having 27 mice in each group: control and SD treatment. The control group was topically treated with 100 μL acetone and SD treatment group was topically treated with SD (30 μg/100 μL in acetone) 1 hour before each UVB radiation for 32 weeks. Tumor counts were recorded on a weekly basis for 30 weeks. Effects of SD on the expression of caspases were investigated to elucidate the possible mechanism of action. The proteins from epidermal homogenates of experimental mice were used for SDS-PAGE and Western blotting using specific antibodies against caspase-3, caspase-8 and caspase-9 respectively. TUNEL assay was used for determining DNA fragmented apoptotic cells in situ. Results showed that at the end of experiment, tumor multiplicity in control and SD treatment groups was 25.8 and 16.5 tumors per mouse respectively. Furthermore, Topical treatment of SD induced DNA fragmented apoptotic cells by upgrading the expressions of cleaved caspase-3 and caspase-8. This study clearly suggested that SD could be an effective chemopreventive agent for UVB-induced skin cancer by inducing caspase dependent apoptosis.